Purines, such as adenine and guanine, perform several important functions in the cell. They are found in nucleic acids; are structural components of some coenzymes, including NADH and coenzyme A; and have a crucial role in the modulation of energy metabolism and signal transduction. Moreover, purines have been shown to play an important role in the physiology of platelets, muscles, and neurotransmission. All cells require a balanced number of purines for growth, proliferation, and survival. Under physiological conditions, enzymes involved in purines metabolism maintain a balanced ratio between their synthesis and degradation in the cell. In humans, the final product of purine catabolism is uric acid, while most other mammals possess the enzyme uricase that converts uric acid to allantoin, which can be easily eliminated with urine. During the last decades, hyperuricemia has been associated with a number of human extra-articular diseases  and their clinical severity. In this review, we go through the methods of investigation of purine metabolism dysfunctions, looking at the functionality of xanthine oxidoreductase and the formation of catabolites in urine and saliva. Finally, we discuss how these molecules can be used as markers of oxidative stress. Uric acid (UA) is the final product of both the exogenous pool of purines and their endogenous metabolism. The exogenous pool varies significantly with diet, to which animal protein significantly contributes. Endogenous UA production, instead, mainly comes from the liver, intestine, and other tissues, such as muscle, kidney, and vascular endothelium .5H4N4O3 -trione) and s molecular weight of 168 Daltons, and it is the final metabolic product of purine metabolism in humans.UA is a heterocyclic organic compound with the formula CMany different enzymes are involved in the conversion of the nucleobases adenine and guanine to UA. Adenosine monophosphate (AMP) can be converted to inosine by two different mechanisms: (i) AMP deamination, followed by de-phosphorylation; or (ii) dephosphorylation, followed by deamination. Guanine monophosphate (GMP) is converted to guanosine by a nucleotidase. The nucleosides inosine and guanosine are further converted to the purine bases hypoxanthine and guanine, respectively, by purine nucleoside phosphorylase (PNP). Hypoxanthine is then oxidized to form xanthine by xanthine oxidase (XO), and guanine is deaminated to form xanthine by guanine deaminase. Xanthine is oxidized again by XO to form UA, being the end degradation product of purine nucleotides  Figure .The pathway of urate homeostasis is resumed in The deposition of microcrystals of monosodium urate monohydrate or UA in several parts of the body leads to the development of gastroenteritis and gout . Gout, iUA concentration can be measured in serum, plasma, urine, and exhaled breath condensate. The laboratory methods used to determine the serum UA concentration are deeply described in the next section.Several epidemiological studies have shown that a correlation exists between elevated levels of serum UA (SUA), hypertension, and chronic kidney disease (CKD) ,7. A lonIn light of the current evidence, the multifactorial mechanism linking hyperuricemia to cardiovascular and renal diseases involves both SUA level and XO activity , with thUA is the product of purine metabolism in humans and has antioxidant properties that can be both protective and pro-oxidant, depending on its chemical microenvironment . HyperurToday, hyperuricemia is a common finding in individuals with metabolic syndrome , being aIn humans, uricase inactivation causes the occurrence of much higher urate levels (≈240–360 μM) than other mammals . It has been proposed that higher serum levels of urates may be a selective advantage in hominid evolution because of its antioxidant effects .At the same time, however, there are situations that can cause hypouricemia, such as hereditary xanthinuria, which is caused by a deficiency in the enzyme xanthine dehydrogenase/oxidase and finally, resulting in reduced UA production . This auDrugs that lower urate levels by inhibiting XO  can also cause hypouricemia . A numbeHistorically, UA has always been considered an inert waste product that, when highly concentrated, crystallizes, forming kidney stones and causing gouty arthritis . RecentlUA is presumed to act as a potent antioxidant in the extracellular environment, having also pro-oxidant properties inside the cell, where it stimulates nicotinamide adenine dinucleotide phosphate (NADPH) oxidase . Most reConsistent with the abovementioned studies, hypouricemia has been associated with inflammatory and degenerative diseases, such as acute organ transplantation disease, Huntington’s disease, Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis, attributing these associations to a reduced antioxidative capacity ,37.About two-thirds of all UA in humans is excreted in urine and one-third in the gastrointestinal tract . Urate tThe ABCG2 transport protein is encoded by the ABCG2 gene (chr4: 88090264-88231417c) and is a member of the ATP-binding cassette (ABC) transporter superfamily, in which substrate transfer is coupled to ATP hydrolysis. In addition to its role in urate transport, the ABCG2 protein has also been characterized as a xenobiotic transporter and a resistance factor to chemotherapeutics .In humans, variants of the protein with reduced transport capacity are associated with increased renal excretion of urate. The ABCG2 messenger RNA is expressed in different tissues, such as in the intestine, brain, and placenta. Brain-level expression is suggestive of the demonstrated association between uricemia levels and susceptibility to certain neurodegenerative diseases ,47, whilThus, the identification of genetic variants could help in the prevention and intervention of some diseases. To date, a number of genome-wide association studies (GWASs) have been conducted to discover loci related to hyperuricemia and gout, mostly related to UA transporter proteins such as the widely studied URAT1 and GLUT9, and some of them have been used as targets for drug development. Attention should also be paid to the interconnection between hyperuricemia/gout and other diseases, such as metabolic syndrome and cardiovascular disease, as well as the role of genetic factors in these diseases. Elucidation of these genetic aspects will contribute to improved clinical outcomes and precision medicine .The inadequate activation of XO can increase reactive oxygen species, resulting in oxidative-stress-induced injury in different tissues because, in mammals, xanthine oxidoreductase (XOR) can be reversibly converted into two different forms, XDH and XO. XDH reduces NAD+ to NADH, whereas XO produces hydrogen peroxide and superoxide . XOR is Thus, it has been shown that plasma XOR activity is independently associated not only with hyperuricemia but also with obesity, hepatic dysfunction, smoking, dyslipidemia, and insulin resistance in the general population, suggesting that plasma XOR activity could be a new metabolic biomarker . Plasma One of the critical problems with measurements in purine metabolism is that the time before plasma separation can affect the concentrations of xanthine and hypoxanthine via leakage from erythrocytes. A previous study using blood samples incubated with ethylenediamine tetraacetic acid dipotassium (EDTA-2K) showed that waiting 3 h before plasma separation did not cause a significant increase in hypoxanthine or xanthine levels. Notably, it has been reported that a commercially available tube  for blood sampling allows for accurate hypoxanthine and xanthine measurements regardless of the time elapsed since plasma separation ,58.In the study by Furuhashi M. et al., hypoxanthine concentration—though not xanthine concentration—was independently associated with body mass index and smoking habit, using plasma samples collected in EDTA-2K-coated tubes and centrifuged within 3 h and after adjustment for age, sex, and use of anti-hyperuricemic drugs in the general population . The indGiven the large epidemiological and clinical relevance of UA levels, developing quick and accurate UA detection methods would be important. SUA dosage has a relatively large pre-analytical variability due to biorhythm  , freezinThese scientific research results could prove to be a breakthrough in the field of test strips or test kits because of its rapid response, high sensitivity, and simplicity of operation .The quantitative analysis of relevant metabolites in biofluids such as urine is often a tedious procedure, as it usually requires extraction, purification, or preconcentration. For example, solid-phase extraction is often required for the analysis of methylxanthines in urine. Moreover, prior to urate determination in urine, urine alkalinization is required because urate crystallizes at a pH below 5.5 .In the work of Rodriguez at al., a rapid and highly sensitive “dilute and shoot” method combining ultra-high-performance liquid chromatography and high-resolution mass spectrometry (UHPLC/HRMS) was validated for the urinary determination of twelve analytes: uric acid, hypoxanthine, xanthine, 1-methyluric acid, 1,3-dimethyluric acid, 1-methylxanthine, 3-methylxanthine, 7-methylxanthine, theophylline, theobromine, paraxanthine, and caffeine . These aRecently, a new quantitative assay was developed to simultaneously measure purine metabolites and creatinine in biobanked urine by liquid chromatography–tandem mass spectrometry (LC-MS/MS). The newly developed LC-MS/MS method allows for a reliable quantitative assessment of xanthine, hypoxanthine, allantoin, UA, and creatinine, with intra-day and inter-day coefficients of small variation for all the analytes, not exceeding 1% and 10%, respectively The proposed pre-analytical processing makes the method suitable for both fresh and biobanked urine stored frozen at −80 °C for at least 5.5 years .Saliva is a very promising diagnostic matrix because its noninvasive sampling is characterized by cost-effectiveness, reduced complexity of analysis, and lower risk of patient infection, which are all clear advantages.The UA level in the saliva of patients with oral diseases is considered a biomarker of antioxidant defense against oxidative stress, so that monitoring salivary UA levels is important for both diagnostic purposes and treatment programs . Some reThe paper by Bukharinova MA et al. describes the development of a carbon veil electrode (CVE) for the determination of UA in saliva . The resThe evaluation of salivary UA levels can contribute to the noninvasive diagnosis of a number of serious diseases. Increased salivary UA concentration is associated with cancer, infection by human immunodeficiency virus (HIV), gout, and hypertension. In contrast, low UA levels are associated with Alzheimer disease, the progression of multiple sclerosis, and mild cognitive impairment .Additionally, Liu XY et al. recently described an HPLC-MS/MS method as a fast, sensitive, and accurate tool to simultaneously determine UA and creatinine in human saliva . Other tStudies of pathological mechanisms and characterization of XOR inhibitors, such as allopurinol, febuxostat, and topiroxostat, require accurate and sensitive measurements of XOR activity. However, established assays have some disadvantages, such as susceptibility to endogenous substances such as UA, xanthine, or hypoxanthine.15N2]-xanthine was used as a substrate, and the production of [15N2]-UA was determined. The production of [15N2]-UA by XOR depended on the amounts of [15N2]-xanthine and enzyme and the reaction time. Since high concentrations of endogenous xanthine and hypoxanthine affect the activities of XOR, a multicomponent analysis by LC/HRMS was employed to improve the accuracy of the XOR activity assay. Subsequently, the quantification of [15N2]-UA was validated and showed good linearity, accuracy, and precision [15N2]-xanthin and LC/MS, and it was found to be 38.1 ± 0.7, 158 ± 5, and 928 ± 25 pmol/min/mg protein in plasma, kidney, and liver, respectively . XOR activities were measured in the same samples by using LC/ultraviolet and LC/fluorescence (FL) methods. The level of oxidation of [15N2]-xanthine by XOR was found to be equal to that of xanthine oxidation and about 7.9–8.9 times higher than that of pterin oxidation. A good correlation was found between the activities of XOR examined by LC/MS assay with [15N2]-xanthine and those examined by LC/FL assay with pterin. Then this result suggested that, although both the LC/MS assay with [15N2]-xanthine and the LC/FL assay with pterin are useful, the former provides information on XOR activities that more directly reflects the physiological condition than the latter.Murase T. et al. developed a new XOR activity assay by using a combination of high-performance liquid chromatography (LC) and high-resolution mass spectrometry (HRMS) for tissues, such as liver, kidney, and plasma . The starecision . The XOR13C2,15N2]-UA produced by XOR was determined by LC/TQMS, after synthesizing -xanthine as the substrate, -UA as the analytical standard, and -UA as the internal standard -UA that was obtained by LC/TQMS in the selected reaction monitoring mode was evaluated, and the results indicated good linearity  in the range of 20 to 4000 nM. As a model reaction of less active samples, the XOR activity of serially diluted mouse plasma was measured. The XOR activity of 1024-fold diluted mouse plasma was 4.49 ± 0.44 pmol/100 μL/h (mean ± standard deviation); that is a value comparable to that expected for the XOR activity of healthy human plasma.In the study by Murase T. et al., the amount of [standard . The calAccording to this cumulative evidence, this combined method can be used to obtain high-sensitivity measurements needed for the analysis of XOR activity on different organs or human plasma. In particular, in the study of Kurajoh M et al., plasma XOR activity was found to be positively associated with the SUA level independently of other known confounding factors affecting this level, including sex differences, estimated glomerular filtration rate (eGFR), adiponectin level, visceral fat area (VFA), and homeostatic model assessment of insulin resistance (HOMA-IR) .Uric acid, allantoin, and oxidative stress: Experimental and clinical evidence currently shows that UA is a potential marker of oxidative stress. In particular, UA could have a potential therapeutic role as an antioxidant, being able to react with biologically relevant oxidants, such as the hydroxyl radical and hypochlorous acid (HOCl), and lead to the production of allantoin, which has been proposed to be a marker of oxidative stress itself ,85.In the study of Kanďár R. et al., using HPLC on plasma of erythrocytes from individuals with chronic renal failure before hemodialysis and in healthy blood donors, significantly higher levels of allantoin were found in both plasma and erythrocytes from patients with chronic renal failure, indicating that allantoin can be used as a good marker of oxidative stress ,87. SimiPurines perform important functions in the cell, including the formation of the monomeric precursors of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Purines are structural components of some coenzymes and modulate energy metabolism and signal transduction . In addiDuring the last decades, hyperuricemia has been associated with a number of human diseases, beyond gout. In fact, even though SUA has an antioxidant action in the extracellular environment, asymptomatic hyperuricemia has been associated with the development of atherosclerosis-related cardiovascular diseases, cardiac arrhythmias, heart failure, metabolic syndrome and type 2 diabetes, cognitive decline, and chronic kidney disease . In cardThe increased amount of UA measured in serum, saliva, and urine can be considered a negative prognostic factor for the development of acute renal failure, as well. However, despite the large number of studies on this topic, an important open question regards the identification of a disease-specific UA cutoff value.Recent studies have shown that allantoin quantification could also be a reliable marker of oxidative stress since, like XO, it has a key role in the transformation of xanthine into UA. However, further research in humans is needed before predictive models using allantoin as a biomarker of dysfunctional purine metabolism can be developed and used in clinical practice. In fact, there are yet little data which would clearly determine which biological material and which analytical method of analyzing allantoin concentration may provide the most reliable results , even coTherefore, given the huge epidemiological  relevance of uric acid in determining human diseases, new more specific biomarkers of purine metabolism should be discovered in order to more correctly identify those subjects exposed to an increased disease risk.


Light microscopy was used to assess cervicovaginal cytopathology and vaginal microbiota. Results: In the 56 included women , mean age was 35.9 (SD ± 7.2) years. PVL was higher in PBMCs  than in vaginal fluid  (p < 0.0001). PVL in PBMCs was observed to correlate directly with PVL in vaginal fluid . PVL was detected in the vaginal fluid of 24 of 43 (55.8%) asymptomatic women compared to 12 of 13 (92.3%) HAM/TSP patients, p = 0.02. Cytopathologic analyses revealed no differences between women with detectable or undetectable PVL. Conclusion: HTLV-1 proviral load is detectable in vaginal fluid and correlates directly with proviral load in peripheral blood. This finding suggests that sexual transmission of HTLV-1 from females to males may occur, as well as vertical transmission, particularly in the context of vaginal delivery.Background: The prevalence of human T-lymphotropic virus type-1 (HTLV-1) infection is higher in women, and sexual intercourse has been described as an important route of male-to-female transmission. The present study aimed to quantify HTLV-1 proviral load (PVL) in vaginal fluid, and to investigate correlations with PVL in peripheral blood mononuclear cells (PBMCs). In addition, cytopathological alterations and vaginal microbiota were evaluated. Methods: HTLV-1-infected women were consecutively recruited at a multidisciplinary center for HTLV patients in Salvador, Brazil. All women underwent gynecological examinations to obtain cervicovaginal fluid and venipuncture for blood collection. PVL, as measured by real-time quantitative polymerase chain reaction (RT–qPCR), was expressed as the number of copies of HTLV-1/10 Human T-lymphotropic virus type 1, also known as human T-leukemia virus (HTLV-1), was the first human retrovirus to be isolated and associated with disease before HIV .In the city of Salvador, Brazil, a region where HTLV-1 infection is endemic, a population-based study showed a higher prevalence of HTLV-1 infection in women that increases with age. In 2002, approximately 10% of women over 50 years of age were found to be infected with HTLV-1 . In addiThe presence of HTLV-1 has been detected in semen and cervicovaginal secretions from infected individuals ,6. AlthoWe have previously shown higher levels of Th1, Th2, and Th17 inflammatory cytokines in the vaginal fluid from HTLV-1-infected women compared to that of uninfected women . In thisThis was a cross-sectional observational study conducted at the Integrative Multidisciplinary HTLV Center (CHTLV) of the Bahiana School of Medicine and Public Health (EBMSP) in Salvador, Bahia, Brazil . Women iThe present study protocol was approved by the Institutional Research Board of EBMSP (CAAE 33098414.4.0000.5544). All procedures were planned and carried out in accordance with the ethical principles established by the Declaration of Helsinki . All incClinical and demographic data were collected using a standardized form. Whole blood samples were collected in EDTA tubes and peripheral blood mononuclear cells (PBMCs) were separated by a density gradient centrifugation and cryopreserved until use. A complete gynecologic examination and the collection of cervicovaginal specimens were performed by a single trained gynecologist . In each1 copies. The value of HTLV-1 proviral load was reported as the [(HTLV-1 average copy number)/] × 2 × 106 and expressed as the number of HTLV-1 copies per 106 cells in both blood and vaginal fluid samples, as previously described [HTLV-1 PVL was measured in cervicovaginal cells and PBMCs using the same protocol. Briefly, DNA was extracted using the Spin Column DNA Extraction System . The amount of cells in the vaginal fluid was not evaluated, but the extracted DNA was quantified in a UV-Vis Spectrophotometer (Nanodrop) and all samples were diluted to 30 ng/µL. HTLV-1 proviral load was quantified using a real-time TaqMan polymerase chain reaction (PCR) method, as described previously . Brieflyescribed ,19. Resuescribed .p-values < 0.05 were considered statistically significant. All analyses were performed using GraphPad software version 9.5 and SPSS software version 17.0 for Windows.Quantitative sociodemographic variables without normal distributions, such as family income, educational level, age of partner, number of partners and parity, are presented as medians with 25th and 75th percentiles. Age, a quantitative variable with normal distribution, is presented as mean with standard deviation. The qualitative variables skin color and marital status are expressed as simple frequencies/proportions. PVL comparisons in vaginal fluid and PBMCs were evaluated with the nonparametric Wilcoxon signed rank test, whereas comparisons between asymptomatic and HAM/TSP groups were performed with the Mann–Whitney test. Data were expressed as median values and 25th and 75th percentiles. The frequency of women with detectable PVL in vaginal fluid and PBMCs in the asymptomatic and HAM/TSP groups was evaluated using Fisher’s exact test. Spearman’s rank correlation coefficient was used to analyze the relationship between proviral load in vaginal fluid compared to PBMCs. Differences in cervicovaginal cytopathology and vaginal microbiota profiles were assessed using the Chi-squared test. Fifty-six women were studied, 43 of whom were asymptomatic and 13 diagnosed with HAM/TSP. Almost half of the patients (46.4%) self-reported black skin color. The mean patient age was 35.9 (±7.2) years. Most participants reported being married or in a stable relationship (73.2%) with a median partner age of 42 (33.5–47.5) years. The median number of lifetime sexual partners was four (3–13.5) .6 cells (IQR: 0–2490), compared to PBMCs: median 23,264 copies/106  (p < 0.0001) (p = 0.006)  women compared to 54 women in PBMCs (96.5%). In two women, PVL was undetectable in both the vaginal fluid and PBMCs. PVL levels were statistically lower in vaginal fluid: median 451.9 copies/10 0.0001) A. A posi= 0.006) B.p = 0.03) between asymptomatic women (103.1 copies/106 cells (IQR: 0–2000)) and carriers of HAM/TSP (869 copies/106 cells (IQR: 447.9–3760)), ) were similar (p = 0.48) to those in patients with HAM/TSP ),  and HAM/TSP patients , ), C. PVL le6,420)), D. PVL wa, 100%), E. Two as, 100%), .Lactobacillus spp. (p = 0.004) and a lower frequency of Coccus/Bacillus (p = 0.001). The frequency of Gardnerella vaginalis/Mobiluncus spp. and Candida spp. were similar between the groups . Women with undetectable PVL presented a higher frequency of e groups .The results of the present study demonstrate a direct correlation between HTLV-1 PVL in vaginal fluid and PVL in PBMCs. Interestingly, a 50-fold difference in PVL levels were found in vaginal fluid compared to peripheral blood. Of note, PVL in vaginal fluid was undetectable in one-third of the women evaluated, almost all (n = 19/20) of whom were asymptomatic. To our knowledge, this was the first study that aimed to quantify and correlate HTLV-1 PVL in vaginal fluid and PBMCs.The detection of HTLV-1 DNA in cervicovaginal secretion samples was previously reported in 68% of sex workers infected with the virus in Peru, which was further associated with cervicitis . In addiThe role of PVL as a predictor for the development of HTLV-1-associated diseases has been suggested, as patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and adult T-cell lymphoma/leukemia (ATLL) present higher PVL in PBMCs than asymptomatic carriers ,23. PatiThe present study, it was not possible to determine the factors for correlation of HTLV-1 PVL between vaginal fluid and PBMCs. This interference between the systemic immune response and the immune response activated in the vaginal environment could explain the higher viral concentrations of HTLV-1 in different mucous membranes. However, this still requires in-depth studies, including those on CD4+ and CD8+ T cell counts.Lactobacillus spp. were found in women with undetectable PVL in vaginal fluid, which is likely not clinically relevant considering that high levels are a common finding in the microbiota [Regarding vaginal microbiota, significantly higher levels of crobiota . In addicrobiota ,37. Zuntcrobiota . HoweverThe presence of HTLV-1 in the vaginal fluid of infected women may have implications on the route of viral transmission. Sexual transmission of HTLV-1 can occur both from male-to-female as well as vice versa ,8. OveraOur results support the notion that PVL in peripheral blood may correlate with PVL in vaginal fluid, which is a relevant factor not only for the sexual route of female-to-male HTLV-1 transmission, but could also have repercussions on vertical transmission, particularly in the context of vaginal delivery.


The main mode of mother-to-child transmission of the human T-cell leukemia virus (HTLV)-1 is through breastfeeding. Although the most reliable nutritional regimen to prevent HTLV-1 transmission is exclusive formula feeding, a recent meta-analysis revealed that short-term breastfeeding within 90 days does not increase the risk of infection. The protocol of the Japanese Health, Labor, and Welfare Science Research Group primarily recommended exclusive formula feeding for mothers who are positive for HTLV-1. However, there has been no quantitative research on the difficulties experienced by HTLV-1-positive mothers in carrying out these nutritional regimens, including the psychological burden. Therefore, this review was performed to clarify the burdens and difficulties encountered by mothers who are positive for HTLV-1; to this end, we analyzed the data registrants on the HTLV-1 career registration website “Carri-net” website. The data strongly suggest that it is not sufficient to simply recommend exclusive formula feeding or short-term breastfeeding as a means of preventing mother-to-child transmission; it is important for health care providers to understand that these nutritional regimens represent a major burden for pregnant women who are positive for HTLV-1 and to provide close support to ensure these women’s health. Human T-cell leukemia virus (HTLV)-1 is a human retrovirus responsible for a number of associated diseases, including adult T-cell leukemia lymphoma (ATL), HTLV-1-associated myelopathy (HAM), and HTLV-1-associated uveitis (HAU) ,3. ATL iHTLV-1 infection occurs through three main routes, i.e., breastfeeding from an infected mother, sexual intercourse, and blood transfusion . HTLV-1 https://htlv1carrier.org, accessed on 11 September 2023) which we built and have operated since 2015. These data are expected to be important for building a support system for mothers diagnosed as carriers of HTLV-1.This survey on the thoughts and feelings of HTLV-1-infected mothers in Japan was performed based on data from the HTLV-1 carrier registration website Carri-net . Registrants answer questions about how their infection was discovered, subsequent actions, and so forth on registration, to allow the collection of information on the actual status of HTLV-1-infected patients in Japan by tabulating the various background factors. Starting in 2017, a secondary survey was conducted on the website for registrants who had experienced pregnancy and/or childbirth .A third survey regarding whether mothers who were HTLV-1 carriers would prefer short-term breastfeeding within 90 days if it would not increase the risk of infection in the child was begun in December 2022. The questionnaire for registrants who had experienced pregnancy and/or childbirth included information outlining that research shows no increase in the infection rate of infants by short-term breastfeeding for 90 days or less compared to exclusive formula feeding, and it also asked whether they would prefer short-term breastfeeding within 90 days if it has no impact on the infection rate in infants.Collected data were fixed in February 2022 for the second survey and February 2023 for the third survey.This study was approved by the institutional review board of the University of Tokyo  and performed in accordance with the tenets of the Declaration of Helsinki.In total, 768 individuals with HTLV-1 infection registered on Carri-net, and 256 individuals who had experienced pregnancy and/or childbirth responded to the second survey. The percentage of those diagnosed during antenatal checkups was 67.7%, while 20.1% were diagnosed as infected with HTLV-1 at a checkup on blood donation before pregnancy. The date of last birth was before March 2011 in 46.1% of registrants, between April 2011 and March 2017 in 27.3%, and after April 2017 in 25.8%. The third survey, which began in 2022, had 78 respondents. The percentages of those diagnosed during antenatal checkups and at blood donation were 61.0% and 28.6%, respectively. The proportion of those diagnosed during antenatal checkups was almost the same in each survey.The majority of health care providers who provided explanations regarding mother-to-child HTLV-1 transmission and prevention methods were obstetricians and gynecologists (66.5%) followed by pediatricians (4.3%) . Only 2.The proportions of HTLV-1-infected mothers who chose each nutritional regimen are shown in The mothers who were HTLV-1 carriers were asked whether the regimen they had chosen was difficult. Overall, 37% of the respondents indicated that it was difficult to follow the chosen nutritional regimen regardless of the actual regimen used. Those who indicated that it was difficult were then asked to specify the reason why they felt this way. As shown in Next, the respondents were asked whether they had received sufficient support from their health care providers regarding the prevention of mother-to-child HTLV-1 transmission during the course of pregnancy, delivery, and child rearing. About two-thirds of the respondents (67%) responded that they had received insufficient support. As shown in In the third survey begun 5 years after commencement of the second survey, 42.9% of respondents indicated that they would prefer short-term breastfeeding within 90 days if it would not increase the risk of infection of their infants compared to exclusive formula feeding, while 48.1% responded that they would prefer exclusive formula feeding due to a fear of even low infection risk .The main modes of HTLV-1 transmission are vertical mother-to-child transmission and horizontal transmission through sexual intercourse . Since tp = 0.88). Those results suggest that short-term breastfeeding did not increase the risk for HTLV-1 infection compared to exclusive formula feeding.Miyazawa et al. conducted a prospective cohort study and meta-analysis to determine the efficacy of short-term breastfeeding to prevent mother-to-child transmission of HTLV-1 beginning in 2012, before the change in nutritional regimen recommendations . They enAnother important result of their study was that a considerable proportion of carrier mothers who chose short-term breastfeeding could not stop breastfeeding within 3 months, i.e., 33.5% of HTLV-1-positive mothers continued breastfeeding at 3 months after delivery, and 8% continued for 6 months. The longitudinal change in percentage of babies fed breast milk whose mothers chose short-term breastfeeding was estimated by second-order polynomial analysis, and the results indicated that the rate of breastfeeding in this group was 18.2% at 4 months after delivery. Therefore, it was difficult for mothers who chose short-term breastfeeding to terminate this feeding regimen. There are many possible reasons for this difficulty, including when the baby does not take milk after switching to a bottle and mothers continue to breastfeed out of guilt, and mothers lack access to adequate breast care. In some cases, the desire to allow the baby to feed from their own breast had become so strong that they felt they could not stop. Therefore, a variety of support is needed for mothers to achieve successful short-term breastfeeding.Based on these results, the nutritional recommendations were changed again in 2022. This manual for prevention of mother-to-child transmission of HTLV-1 by the Health, Labor, and Welfare Science Research Group in Japan specifies that the selection of nutritional regimen by HTLV-1-infected mothers should be accompanied by sufficient explanation of the advantages and disadvantages of each nutritional regimen from the perspective of pregnancy, childbirth, and childcare, in addition to the prevention of mother-to-child transmission and shared decision-making support  so that As shown by Miyazawa et al. , it is dHTLV-1-infected mothers have various burdens regardless of the selected nutritional regimen. In this study, 37% of the responders indicated that it was difficult to follow the selected nutritional regimen. As shown in Next, we asked HTLV-1-positive registrants who had experienced pregnancy and/or childbirth whether they would prefer short-term breastfeeding within 90 days if it would not increase the infection risk in their infants compared to exclusive formula feeding after providing an explanation that research data support this view before the recommendation of nutrition protocol was revised. As shown in On the other hand, 51.9% of the mothers who responded that the support of health care providers was insufficient indicated that they had insufficient information about who to consult about their concerns, including those about HTLV-1-associated diseases . A diagnRecently, the number of HTLV-1 infectants through horizontal transmission in Japan was evaluated by Satake et al. . They asThe most reliable nutritional regimen to prevent mother-to-child HTLV-1 transmission is exclusive formula feeding, but short-term breastfeeding within 90 days does not increase the risk of infection among babies of HTLV-1-infected mothers. Although short-term breastfeeding can provide partial benefits of breast milk, it should be noted that it is not always easy to terminate breastfeeding within 90 days, and a suitable support system is essential. On the other hand, exclusive formula feeding represents a critical choice for HTLV-1-carrier mothers and places a psychological burden on these women. It is necessary to provide not only technical but also psychological support for these mothers. It should be noted that HTLV-1-carrier mothers carry a variety of burdens.


Dear Editor,Placenta accreta describes pathological adherence or invasion of the placenta to the myometrium. It may be a consequence of any procedure affecting the integrity of the uterine lining.In certain cases, the implementation of alternatives to standard or agreed interventions is necessary to preserve the potential for future fertility, but this may carry risk of morbidity and adverse events either from the procedure itself or due to deviation from the agreed management published in the guidelines. Such procedures should be individualized to each case according to history, clinical judgment and the patient's desire for future fertility.Biyik et alIn my opinion, subjecting the patient to hemorrhagic morbidity, with added risks of blood transfusion, to pursue future fertility in a patient requesting permanent contraception—which is already performed during the same operation—is not justified.


Numerous evolutionary mechanisms have been proposed for the origins, spread and maintenance of low fertility. Such scholarship has focused on explaining the adoption of fertility-reducing behaviour, especially the use of contraceptive methods. However, this work has yet to engage fully with the dynamics of contraceptive behaviour at the individual level. Here we highlight the importance of considering not just adoption but also discontinuation for understanding contraceptive dynamics and their impact on fertility. We start by introducing contemporary evolutionary approaches to understanding fertility regulation behaviours, discussing the potential for integrating behavioural ecology and cultural evolution frameworks. Second, we draw on family planning studies to highlight the importance of contraceptive discontinuation owing to side-effects for understanding fertility rates and suggest evolutionary hypotheses for explaining patterns of variation in discontinuation rates. Third, we sketch a framework for considering how individual flexibility in contraceptive behaviour might impact the evolution of contraceptive strategies and the demographic transition. We argue that integrating public health and evolutionary approaches to reproductive behaviour might advance both fields by providing (a) a predictive framework for comparing the effectiveness of various public health strategies and (b) a more realistic picture of behaviour by considering contraceptive dynamics at the individual level more explicitly when modelling the cultural evolution of low fertility. Social media summary: Worldwide, millions of women stop using contraceptives. Why? Novel hypotheses from evolutionary public health1.cultural evolution we mean the process of change over time rather than any specific theoretical framework aiming at explaining the evolutionary process . Given that contraceptive use is linked to reduced infant and maternal mortality, as well as improved socioeconomic opportunities  demand theory To understand why a low-fertility variant emerges and spreads, evolutionary scholars have used principles from primarily two frameworks: behavioural ecology Most evolutionary accounts of contraceptive dynamics have focused on identifying the forces underpinning the adoption, or first use, of modern contraception. Studies have been conducted in various settings, from high-fertility to transitioning to low-fertility populations, and predictions from both BE and CE are helpful in advancing knowledge of contraceptive dynamics. From a BE perspective, it is not clear that the initial adoption of modern contraception is driven by the life-history trade-off between fertility and child survival There has been little attempt to harness evolutionary perspectives for understanding patterns of diversity and changes in the prevalence of contraceptive discontinuation within and among populations  studies of contraceptive use test hypotheses relevant to explaining the Darwinian puzzle of fertility decline rather than take contraceptive technologies as an object of study in its own right, and indeed theoretical work has researched the importance of biased social transmission for explaining the maintenance of low fertility in industrial populations ? Women report multiple reasons for discontinuation whilst in need including method-related dissatisfaction due to concerns about side-effects  and efficacy , fears or rumours that hormonal contraceptives cause cancer and/or infertility, partner's desired fertility, issues of cost and availability, as well as community-level contraceptive prevalence and attitudes  evolved physiological mechanisms adjusting reproductive function to one's socioecological circumstances and causing variation in susceptibility to side-effects, (b) evolved cognitive dispositions adjusting reproductive behaviour, including discontinuation owing to side-effects, to context-specific fitness costs and benefits and (c) evolved cognitive dispositions underpinning social learning. Further, these forces might act independently or interact, e.g. the experience of side-effects, such as heavy bleeding or lack of bleeding, may fuel rumours about infertility. Below we outline how an evolutionary approach can shed new light on the dynamics of discontinuation due to side-effects .(a)With regards to contraceptive discontinuation, the question of why some women experience more side-effects than others has, to date, attracted little attention from either clinical trials The experience of physiological side-effects can in turn elicit social side-effects, i.e. additional consequences that have a negative impact on social relations. The nature and severity of these effects depend on the local cultural context. For instance, variation in libido and mood changes have various implications depending on the cultural expectations of a woman's intimate relationships. In Kenya, women report that injectables make users ‘cold’, leading to a lack of sexual arousal and raising suspicions of infidelity from husbands From a behavioural ecology perspective, much of contraceptive discontinuation whilst in need can be seen as the outcome of the impact of side-effects on perceived fertility trade-offs. First, individuals face a life-history trade-off between current reproductive effort and future survival and reproduction. Thus, DSE can be understood as a form of investment in future survival and reproduction at the expense of current effort in offspring and own capital. Within this framework, DSE is expected to be more likely for women suffering the highest cost of side-effects for future survival and reproduction, for instance women at the beginning of their reproductive career: women who have never had a baby will be more likely to discontinue while older women will be more likely to tolerate side-effects. Conversely, if side-effects are perceived to threaten one's immediate chances of survival, which is more likely to be the case for women suffering the strongest side-effects, then the cost of continuing contraceptive use will outweigh the benefits of delaying or spacing fertility. In a study we conducted in Ethiopia, the experience and fear of physiological side-effects of the injectable contraceptive in the form of irregular and heavy bleeding led women to worry about significant threats to their health (the words used for heavy bleeding were synonymous with those used for ‘loss of life’) and their fertility (resulting from a delay to return to fertility after use or amenorrhea and/or a change in bleeding patterns while using). Thus, women experience various trade-offs depending on their circumstances and life-histories, and those need to be considered for predicting the risk to DSE.Second, individuals face a life-history trade-off between fertility and survival of existing offspring Public health does not often make the distinction between women who experience side-effects and those who fear them. Rather, fear of side-effects is often referred to as misinformation, misconceptions or rumours, with an underlying assumption that many fears are not founded in real experience  might favour the spread and maintenance of discontinuation. This may be the case among women living in sub-Saharan Africa where the ideal family size is high, and where fertility decline appears to have stalled  review existing models of the relationship between the cultural evolution of contraceptive behaviour and demography, (b) sketch a new framework for modelling the evolution of contraceptive behaviour to consider change within an individual's lifetime and (c) discuss the implications of considering contraceptive dynamics and its impact on fertility for family planning policy. We argue that understanding how contraceptive uptake, discontinuation and switching between methods interact to shape fertility dynamics is necessary to provide a better understanding of how contraceptive behaviour influences fertility .Figure (a)In the field of cultural evolution, previous studies of the interaction between demography and cultural evolution have aimed at understanding how changes in population size alter the evolution of cumulative culture and the maintenance of cultural complexity Henrich, . Only a In the public health literature, only a few statistical models have formalised the evolving relationship between individual contraceptive behaviour and population level outcomes . Some focused on the impact of method mix on switching and contraceptive prevalence reproductive decision-making to human contraceptive decision-making. When should one change contraceptive behaviour? Behavioural ecology and cultural evolution models potentially make different and complementary predictions for observed patterns. Following Mace Once evolutionary processes have been studied and mechanisms better understood, ecological processes at the timescale of a generation should be considered if one is to consider the impact of contraceptive behaviour on population demography. To that end, epidemiological-like compartment models, such as SIS (susceptible-infected-susceptible) models Modelling contraceptive dynamics as an evolutionary and ecological process provides a starting point to formally investigate the outcomes of various family planning strategies. This approach could be used to compare the efficacy of different strategies to promote the demographic transition such as encouraging switching (e.g. increasing the number of methods available) and improving contraceptive technology (e.g. to reduce side-effects) compared with investing in recruiting new adopters (e.g. acquiring new clients). The current public health default strategy is to increase modern contraceptive prevalence (mCPR) by focusing on counselling. For instance, the UNFPA cites the lack of knowledge and incorrect perceptions about the health risk of contraceptive methods as the main causes for discontinuation UNFPA, . In turnOne strategy often cited to reduce unmet need includes increasing switching between methods through augmenting method mix. FP2020 cites commitment to improving access to long-acting reversible methods (LARMs) FP2020, . Yet thiAn alternative strategy would be to improve current methods. It has been suggested that reducing side-effects may be achieved by changing either the dose of contraceptives or women's physiology. Vitzthum and Ringheim  note thaWhile many countries and family planning programmes focus on increasing mCPR, shifting the focus to tackling unmet need might prove both more efficacious and more ethical. Indeed, women who do not express a desire to limit family size or prefer to space births may be making ‘rational’ choices, from an evolutionary or biocultural perspective, given their local circumstances and the impact of the technology on their immediate health, resources and/or social circumstances. Future public health efforts should aim at providing women who need contraceptives with the right method for their goal  and their sociocultural and biological contexts (Cates & Maggwa, 5.Understanding patterns of contraceptive discontinuation has implications for predicting fertility dynamics and the demographic transition. Evolutionary scholars have yet to consider this issue when modelling the spread of low-fertility ideals, and public health models, aimed at estimating progress towards reducing unmet need for contraception (Kantorová et al., Considering behavioural discontinuation can also more widely inform evolutionary debates over the spread of low fertility. For instance, it has been proposed that institutions associated with monogamous marriage suppress intra-sexual competition and reduce total fertility, which lead them to be favoured by group selection because they promote success in inter-group competition (Henrich et al., Following others who have argued that cultural evolution need not imply group selection (Amir et al.,


The GA and TENDO displayed excellent reliability and acceptable variability during the JS and HHP while the PUSH showed instances of poor–moderate reliability and unacceptable variability at various loads. While the TENDO and PUSH showed instances of various bias, the TENDO device demonstrated greater validity when compared to the GA. Trivial–small differences were shown between the GA and TENDO during the JS and HHP exercises while trivial–moderate differences existed between GA and PUSH during the JS. However, despite trivial–small effects between the GA and PUSH devices at 20 and 40% 1RM during the HHP, practically meaningful differences existed at 60, 80, and 100%, indicating that the PUSH velocity outputs were not accurate. The TENDO appears to be more reliable and valid than the PUSH when measuring MBV and PBV during the JS and HHP.This study examined the reliability, potential bias, and practical differences between the GymAware Powertool (GA), Tendo Power Analyzer (TENDO), and Push Band 2.0 (PUSH) during the jump shrug (JS) and hang high pull (HHP) performed across a spectrum of loads. Fifteen resistance-trained men performed JS and HHP repetitions with 20, 40, 60, 80, and 100% of their 1RM hang power clean, and mean (MBV) and peak barbell velocity (PBV) were determined by each velocity measurement device. Least-products regression and Bland–Altman plots were used to examine instances of proportional, fixed, and systematic bias between the TENDO and PUSH compared to the GA. Hedge’s  Researchers have concluded that weightlifting movements and their derivatives may provide greater strength, power, and speed adaptations compared to other methods of training , especiaWhile some ballistic exercises may be prescribed using percentages of the 1RM of biomechanically similar movement  ,22, a coA method of training that has gained popularity within the last decade has been termed velocity-based training. This method of load prescription uses technology to measure the velocity of a movement  during each exercise repetition to determine whether or not an individual is meeting the desired training goal within a session or phase of training ,35. WhilFifteen resistance-trained men with previous hang power clean (HPC) experience participated in this study  HPC = 1.3 ± 0.2 kg/kg, and relative 1RM back squat = 2.03 ± 0.3 kg/kg). Prior to the study, the participants had been consistently training at least three times per week for the last year. This study was conducted according to the guidelines of the Declaration of Helsinki and was approved by the Carroll University institutional review board . Each participant read and signed an informed consent form prior to their participation.A repeated measures, cross-sectional design was used to examine the reliability, relationships, and differences between three different barbell velocity measurement devices during the JS and HHP performed across a spectrum of loads. Each participant attended three testing sessions over two weeks that included a 1RM HPC, a JS testing session, and HHP testing session. The JS and HHP were performed using percentages of the participant’s 1RM HPC.Each participant performed a 1RM HPC during their first testing session using previously discussed procedures ,28,29. BEach participant returned to the laboratory on two separate occasions to perform sets of either the JS or HHP exercise. The first session took place one week following the 1RM HPC session and the subsequent session followed 48 h later. The order of the JS and HHP testing sessions was randomized for each participant in an effort to prevent an order effect. Upon arriving for the testing session, each participant performed the same general and dynamic warm-up described above before performing a self-selected warm-up with an empty 20 kg barbell. The participant then performed an exercise-specific warm-up that included a set of three repetitions of the testing exercise  with 30 and 50% of their 1RM HPC ,28,29,30Mean (MBV) and peak barbell velocity (PBV) during each JS and HHP repetition were measured concurrently using a GymAware Powertool ((GA) Kinetic Performance Technology, Braddon, Australia), Tendo Power Analyzer ((TENDO) Tendo Sports Machines, London, UK), and Push Band 2.0 ((PUSH) Push Inc., Toronto, ON, Canada). To prevent disruption to the participant’s grip and displacement measurement, the Push Band 2.0 (PUSH) was placed on the inside of the collar while the GA and TENDO tethers were attached on the sleeve of the barbell . The GA 2) were used to examine the association of the TENDO and PUSH devices against the GA. In addition, fixed and proportional bias compared to the GA device was determined using previously described methods with ordinary least-products regression [The Shapiro–Wilks test was used to examine the normality of data distribution of each variable. Two-way mixed intraclass correlation coefficients and typical error expressed as coefficients of variation were used to examine the relative and absolute reliability of each device, respectively. The intraclass correlation coefficients were interpreted as poor, moderate, good, and excellent if magnitudes were <0.50, 0.50–0.74, 0.75–0.90, and >0.90, respectively . In addigression ,50,51. Ugression . All staAll MBV and PBV data were normally distributed. The GA and TENDO devices displayed excellent reliability and acceptable variability for all MBV and PBV data . In cont2 values ranged from 0.88 to 0.98 and 0.87 to 0.98 for MBV and PBV, respectively. While the PUSH device did not show any proportional or fixed bias during the JS, R2 values were considerably lower compared to the TENDO with values ranging from 0.47 to 0.86 and 0.58 to 0.89 for MBV and PBV, respectively.The least-products regression statistics for the JS are displayed in JS systematic bias comparisons for the TENDO and PUSH with the GA are displayed in 2 values ranged from 0.93 to 0.96 and 0.79 to 0.94 for MBV and PBV, respectively. Proportional and fixed bias was displayed by the PUSH device for MBV at 20, 40, and 60% 1RM during the HHP. In addition, fixed bias was shown for PBV during 100% 1RM. The R2 values for the PUSH device ranged from 0.77 to 0.96 and 0.62 to 0.92 for MBV and PBV, respectively.The least-products regression statistics for the HHP are displayed in Systematic bias analyses for the HHP are displayed in The effect size magnitudes between the TENDO and PUSH devices and the GA are displayed in Trivial–small and trivial–moderate effects existed between the PUSH and GA for MBV and PBV during the JS, respectively. In addition, trivial–moderate and small–moderate effects existed between the PUSH and GA for MBV and PBV during the HHP, respectively. It should be noted, however, that the MBV and PBV measured by the PUSH compared to the GA at 60, 80, and 100% 1RM were practically meaningful as indicated by confidence intervals that did not include zero. None of the other differences between the PUSH and GA were practically meaningful.The current study examined the reliability, validity, and bias of the TENDO and PUSH devices compared to the GA during the JS and HHP performed with a spectrum of loads. The primary findings of the current study are as follows. First, excellent test–retest reliability with acceptable variability for MBV and PBV was present for the GA and TENDO during both the JS and HHP exercises while the PUSH reliability ranged from poor to excellent with acceptable or larger variability depending on the exercise and/or load being examined. Second, both the TENDO and PUSH devices showed some instances of proportional, fixed, and systematic bias; however, the validity of the TENDO appeared to be greater than the PUSH device. Finally, while there were no practically meaningful differences between the TENDO and GA for MBV and PBV measured during the JS or HHP, practically meaningful differences existed between the PUSH and GA during the HHP exercise, but not for the JS.Previous researchers indicated that the TENDO provided reliable and valid measurements of average concentric velocity during the back squat exercise but displayed significantly different peak concentric velocities compared to the criterion 3D motion capture system . Excelle2 values for MBV and PBV tended to be much higher across loads compared to the PUSH device, especially at the heaviest load examined . It should be noted that the TENDO showed small systematic bias by overestimating MBV at 20, 40, and 100% 1RM and PBV at 40, 80, and 100% 1RM during the JS. However, the PUSH device showed a lack of consistency where systematic bias was shown by both overestimating MBV at 60 and 80% 1RM and PBV at 40 and 60% 1RM and underestimated MBV at 100% 1RM and PBV at 20% 1RM. It is not entirely surprising that both the TENDO and PUSH devices demonstrated some instances of systematic bias due to the ability of the GA to account for horizontal displacement during resistance training exercises [Both the TENDO and PUSH devices showed some instances of either proportional, fixed, or systematic bias when compared to the GA during both the JS and HHP. The only instance of proportional bias during the JS was shown by the TENDO when measuring MBV at 20% 1RM. Despite this occurrence, the TENDO Rxercises . While txercises ,56. Thusxercises  indicate2 values. Interestingly, the TENDO tended to overestimate MBV and PBV while the PUSH underestimated both variables compared to the GA during the HHP. Again, these instances of systematic bias may be due to each device’s characteristics in how they calculate MBV and PBV. The HHP is a unique weightlifting derivative that requires an individual to elevate the barbell to their chest height [The TENDO and PUSH devices showed several instances of bias during the HHP exercise. Specifically, proportional and fixed bias were present with the TENDO for MBV at 100% 1RM and PBV at 20%. In contrast, proportional and fixed bias for MBV were present with the PUSH device at 20, 40, and 60% 1RM while fixed bias was also shown for PBV at 100% 1RM. Like the JS, greater variance for both MBV and PBV was accounted for with the TENDO versus the PUSH as demonstrated by the Rt height , often sA unique aspect of the current study was the calculation of effect size magnitudes when comparing the MBV and PBV produced by the GA and the TENDO and PUSH. In general, small–moderate and trivial–small differences were shown for MBV and PBV when comparing the GA and TENDO during both the JS and HHP exercises. While trivial–small and trivial–moderate effects existed when comparing MBV and PBV, respectively, between the GA and PUSH during the JS, these trends were not followed during the HHP. Trivial–small effects for MBV and PBV existed when comparing the GA and PUSH devices at 20 and 40% 1RM during the HHP; however, these magnitudes became much larger at loads of 60% 1RM and higher, indicating that the velocity outputs of the PUSH device were meaningfully different and not accurate. This is an important finding given the use of different velocity measurement devices within strength and conditioning settings. Using the GA device as a criterion measurement for comparison may be viewed as a potential limitation of the current study. It should be noted, however, that authors of a recent systematic review concluded that the GA shows the greatest accuracy of available devices when it has been directly compared to the gold standard of 3D high-speed motion capture . AnotherThe results of the current study indicate that the TENDO appears to be more reliable and valid than the PUSH when measuring MBV and PBV during the JS and HHP. Although the TENDO tends to overestimate velocity metrics, this can be accounted for if the device is consistently used. It should also be noted that velocity measurement devices should not be used interchangeably when measuring MBV and PBV during these exercises. However, strength and conditioning practitioners should also be aware of its limitation to account for horizontal displacement. Thus, it is recommended that the necessary time is dedicated to ensuring proficient exercise technique. Our results also indicate that the PUSH device may underestimate MBV and PBV compared to the GA during the HHP, and in some instances provide inaccurate velocity metrics at higher loads. Although researchers have suggested implementing the HHP with lighter loads  ,20,28,29


Protein ubiquitylation acts as a complex cell signaling mechanism since the formation of different mono- and polyubiquitin chains determines the substrate’s fate in the cell. E3 ligases define the specificity of this reaction by catalyzing the attachment of ubiquitin to the substrate protein. Thus, they represent an important regulatory component of this process. Large HERC ubiquitin ligases belong to the HECT E3 protein family and comprise HERC1 and HERC2 proteins. The physiological relevance of the Large HERCs is illustrated by their involvement in different pathologies, with a notable implication in cancer and neurological diseases. Understanding how cell signaling is altered in these different pathologies is important for uncovering novel therapeutic targets. To this end, this review summarizes the recent advances in how the Large HERCs regulate the MAPK signaling pathways. In addition, we emphasize the potential therapeutic strategies that could be followed to ameliorate the alterations in MAPK signaling caused by Large HERC deficiencies, focusing on the use of specific inhibitors and proteolysis-targeting chimeras. Ubiquitylation is a post-translational modification that consists of the attachment of ubiquitin to a substrate protein. Ubiquitin can be linked as a single moiety or in the form of polymeric chains of different topology. Over the years, it has been discovered that proteins can also be modified by ubiquitin-like molecules such as SUMO or NEDD8. In addition, further modifications of ubiquitin with acetylation and phosphorylation have also been identified. Similar to a code, different ubiquitin modifications lead to different outcomes in the cells . TypicalUbiquitin E3 ligases are the enzymes that catalyze the transfer of ubiquitin to a protein substrate. Therefore, they determine the precise substrate specificity of ubiquitylation, and play essential roles in the cell signaling networks mediated by ubiquitin ,5. AccorRING E3s are the most abundant class. Up to 600 different types have been described in humans. They are characterized by the presence of a RING or U-box domain. Although U-box-containing E3 ligases have sometimes been classified as an independent class of E3s, sequence-profile analysis has shown that the U-box is actually a derived version of the RING finger, their mechanism of action being very similar . These dConversely, the HECT E3s catalyze ubiquitin transfer to the substrate protein by a two-step reaction. In brief, they present a HECT domain in their C-terminal region. This domain holds a bilobed structure that enables the transmission of the ubiquitin molecule to the target protein. Specifically, the first lobe (the one closest to the amino terminus) binds the E2 enzyme from which the ubiquitin is transferred to a catalytic cysteine located in the second lobe, forming a thioester bond. Next, the conjugation of ubiquitin to the target protein is catalyzed. In humans, 28 different types of HECT E3s have been identified .RBR E3s represent the third class of E3 ligases. They are characterized by a mixed mechanism of ubiquitin transfer. They bind the E2 enzyme to a RING1 domain and transfer the ubiquitin to a second domain called RING2, which contains a catalytic cysteine. Then, the ubiquitin is transferred to the substrate protein. Despite being a small family, RBR E3s regulate different cellular process in human cells .Centering now on HECT ubiquitin ligases, sequence and structural comparison analysis has shown a complex division of the HECT family into 16 different subfamilies: NEDD4-like proteins, Small HERCs, Large HERCs and 13 different subfamilies formerly called “other HECTs” . In thisUbiquitin modifications regulate different cellular processes through proteolytic mechanisms, including targeting the substrate for proteasomal and autophagic degradation, but also through non-proteolytic mechanisms, for instance regulating protein interactions, subcellular localization and enzymatic activities. It is therefore not surprising that ubiquitylation is implicated in the regulation of several intracellular signaling pathways . Some ofThe physiological relevance of the Large HERCs is illustrated by their involvement in different diseases as shown in HERC1 gene are mostly associated with an autosomal recessive neurodevelopmental disorder called MDFPMR syndrome. This acronym comes from the phenotypic description of this disease, characterized by Macrocephaly, Dysmorphic Facies and PsychoMotor Retardation (OMIM #617011) [HERC1 as a risk factor in the autism spectrum disorder, Parkinson’s disease, schizophrenia and febrile seizures [HERC1 was identified as a differentially expressed gene in the major depressive disorder associated with COVID-19 [Germ-line mutations in the #617011) ,21,22,23seizures ,26,27,28seizures . RecentlCOVID-19 . Other nCOVID-19 , diabeteCOVID-19 , cardiovCOVID-19  and osteCOVID-19  . It was first identified in an Old Amish community holding a loss-of-function mutation in the HERC2 gene . Later, other loss-of-function mutations have also been described. All cases show global developmental delay with Angelman syndrome-like features such as intellectual disability, autism spectrum disorders and movement disorders [On the other hand, germ-line mutations in isorders ,42,43,44isorders . In addiisorders . Other bisorders ,47,48,49isorders , asthma isorders , hyperteisorders ,58, seveisorders ,61 and sOMIM #6156. It wasisorders ,53,54,55The involvement of both Large HERC family members in cancer has been extensively studied and it was previously reviewed in  Figure .Putting efforts into basic research to better understand how cell signaling is altered in these different pathologies is important to uncover novel therapeutic targets. To this end, in this review we will summarize the recent advances in how the HECT E3s and, more specifically, Large HERCs, can regulate the MAPK signaling pathways, emphasizing the potential implications in disease.MAPK signaling pathways are intracellular signal transduction cascades that in response to various extracellular signals elicit an appropriate intracellular response affecting different cellular processes such as cell growth, cell proliferation, differentiation, migration, stress responses, survival and apoptosis. MAPK cascades can be activated by several factors such as hormones, growth factors, inflammatory cytokines and different types of stress . Each MAIn recent years, it has become clear that the MAPK catalytic modules consisting of kinases that mediate the activation of downstream effectors are exposed to several layers of regulation. These regulatory mechanisms are not restricted to protein phosphorylation; instead, they involve other post-translational modifications such as ubiquitylation. Ubiquitylation catalyzed by E3 ligases influences MAPK pathways in terms of the duration and type of the signaling cascade through its role in affecting the assembly of protein kinase complexes, subcellular localization and the degradation of MAPK components or their downstream substrates . For thiIn Some of them regulate a single MAPK pathway. For instance, NEDD4, UBE3A and HUWE1 regulate the ERK signaling pathway. NEDD4 regulates ubiquitylation of the G-protein coupled receptor (GPCR) mGlu7. Going into detail, after agonist stimulation mGlu7 is ubiquitylated by NEDD4, which induces its endocytosis and eventually leads to its degradation by both the lysosomal and proteasomal pathways. This mechanism is required for the mGlu7-induced ERK1/2 activation . Moving Other HECT E3 ubiquitin ligases have been implicated in the p38 signaling pathway. This is the case of HERC2 and UBR5. In both cases, their deficiency is related to increased levels of p38 activity, suggesting that they have an inhibitory role in this pathway. While the mechanism behind p38 regulation by UBR5 is not well established yet, HERC2 regulates p38 activity through controlling C-RAF ubiquitylation and its subsequent proteasomal degradation ,86. LastThere are also some HECT E3s whose involvement in more than one MAPK signaling pathway is currently described. For example, HERC1 regulates both ERK1/2 and p38 signaling pathways by modulating C-RAF protein levels through ubiquitylation ,66,67. AOther HECT E3s have been shown to regulate three distinct MAPK pathways, including the ERK1/2, p38 and JNK cascades. In this regard, the ubiquitin ligase ITCH has been extensively studied for its multiple roles in the regulation of MAPKs, acting at different levels and affecting them in different ways in terms of activation or inhibition depending on the target and the context. Specifically, ITCH is recruited by GRAMD4 to promote ubiquitylation and protein degradation of the MAP3K TAK1, thus controlling activation of the conventional MAPKs ERK1/2, p38 and JNK . In addiAs shown in the table  and indiThe precise molecular mechanisms of how the Large HERCs regulate MAPK signaling pathways through C-RAF are discussed in the following section. Small and Large HERC subfamilies of the HECT ubiquitin ligases were initially classified together and defined by the presence of an HECT domain and RCC1-like domains . HoweverKnowledge about the involvement of the Large HERCs in the regulation of MAPK signaling is fairly recent and has evolved in the past years. In 2018 the involvement of HERC1 in the regulation of these signaling pathways was identified for the first time. More recently, a role for HERC2 was also described. Interestingly, both HERC1 and HERC2 appear to regulate MAPKs through the same protein target, the serine and threonine kinase C-RAF ,68. C-RABoth members of the Large HERC family interact with the C-terminal region of C-RAF, with residues 301 to 648 reported to be the most relevant. This region contains the kinase domain. HERC1 interacts through its N-terminal region, and the residues described as the most relevant are those from position 1 to 412. This region contains a small first portion of the RLD1 domain . In contGoing into detail on the molecular mechanisms, HERC1 interacts with the MAP3K C-RAF and controls its protein stability by regulating its polyubiquitylation and subsequent proteasome-dependent degradation. Thus, HERC1 modulates the activation of the RAF-MEK-ERK1/2 pathway and controls cell proliferation . AccordiSOD1, SOD2, GPX1 and its own transcription through the NFE2L2 gene (HERC2 gene holds putative antioxidant response elements (AREs) in which NRF2 is coupled to promote its transcription [The first evidence of the involvement of the other Large HERC family member, HERC2, in the regulation of MAPK signaling came from proteomic analysis where HERC2 was reported to be associated with E6AP, NEURL4 and the atypical MAPK ERK3 ,94. More2L2 gene b. This ccription . This suIt is interesting to note that although both HERC1 and HERC2 regulate MAPK signaling through modulating C-RAF protein levels, they diverge in the pathways that are finally modulated. I.e., while HERC1 regulates both ERK and p38 cascades, HERC2 regulation of C-RAF affects specifically the p38 pathway. Although the specific molecular mechanism by which these differences occur has not yet been described, there are some considerations important take into account. In first place, HERC1 and HERC2 proteins do not interact, suggesting that each of them forms a different protein complex with C-RAF. Secondly, while HERC1 interacts with the kinase domain of C-RAF through its N-terminal region, HERC2 does it through its C-terminal region, mainly involving its HECT domain a. Hence,Whether the alterations in these MAPK signaling pathways are associated with clinical outcomes in the neurodevelopmental disorders caused by mutations in HERC1 or HERC2 still requires further research. Even so, dysfunctions of the MAPK signaling pathways have already been implicated in several neurodevelopmental disorders, for instance autism spectrum disorder ,97, whicGiven that both HERC1 and HERC2 deficiency causes alterations in MAPK signaling due to increased levels of C-RAF, the most evident therapeutic strategy would be to inhibit C-RAF in order to block the triggered downstream overactivation. Indeed, the RAF inhibitors LY3009120 and sorafenib have shown success in counteracting ERK and p38 overactivation after HERC1 deficiency ,67. In tIn the last few years, an innovative technology called proteolysis-targeting chimera (PROTAC) has gained interest in the field of drug discovery . PROTACsTaking this into account, could we use PROTACs to target MAPK alterations due to Large HERC deficiencies? So far, this approach has not been described nor studied in depth, but it might be a promising line of research. Since C-RAF is a common ubiquitylation target of the Large HERCs, and its accumulation is responsible for altered MAPK signaling in the case of HERC1 or HERC2 deficiency, one possibility could be to target C-RAF. In this aspect, several PROTACs against B-RAF, the most commonly mutated RAF isoform in cancer, have been successfully developed and provided promising results ,109,110.Large HERCs are involved in several diseases, with a notable implication in neurological diseases and cancer.HERC1 regulates ERK and p38 signaling pathways through controlling C-RAF protein levels.HERC2 regulates C-RAF protein levels, affecting the p38 signaling pathway.Downregulation of HERC1 or HERC2 causes accumulation of C-RAF protein levels which alters MAPK signaling.The use of RAF inhibitors such as sorafenib, or the development of specific PROTACs against C-RAF, may represent a promising therapeutic option to counteract alterations in MAPK signaling caused by HERC1 or HERC2 deficiency.


Glaucoma is a progressive disease and the leading cause of irreversible blindness. The limited therapeutics available are only able to manage the common risk factor of glaucoma, elevated intraocular pressure (IOP), indicating a great need for understanding the cellular mechanisms behind optic nerve head (ONH) damage during disease progression. Here we review the known inflammatory and fibrotic changes occurring in the ONH. In addition, we describe a novel mechanism of toll-like receptor 4 (TLR4) and transforming growth factor beta-2 (TGFβ2) signaling crosstalk in the cells of the ONH that contribute to glaucomatous damage. Understanding molecular signaling within and between the cells of the ONH can help identify new drug targets and therapeutics. Glaucoma is currently a leading cause of irreversible blindness, estimated to effect 75 million individuals worldwide, which figure is proposed to increase to over 100 million by the year 2040 ,4,5. In Glaucoma is defined by the loss of retinal ganglion cells (RGCs), the thinning of the retinal nerve fiber layer, and the cupping and remodeling of the ONH resulting in a gradual loss of vision ,14. MultThere are three major supporting cell types in the LC region: Iba1 positive microglial cells, glial fibrillary acidic protein (GFAP) positive ONH astrocytes, and α-smooth muscle actin (αSMA) positive LC cells. Microglia, the resident macrophages of the immune system, are regularly spaced along the walls of the blood vessels, within the glial columns, and in the LC region in the ONH to optimize their ability to survey their microenvironment ,20,21. TIn homeostatic environments, microglia efficiently clear dead cells and cellular debris . This “rAstrocytes are the most common glial cell in the mammalian ONH , providiThe main function of the LC cells is to secret ECM proteins such as collagens, elastin, and fibronectin, to maintain the structural laminar beams that physically support the exiting RGC axons . LC cellAll three supporting cell types in the ONH have been implicated in perpetuating glaucomatous damage . HoweverThe drastic changes to the ECM and increased fibrosis in the glaucomatous ONH and LC region have been extensively reviewed ,49,70,71One predominant hypothesis indicates TGFβ2-induced ECM synthesis as a major player in instigating and exacerbating the increased ECM buildup and dysregulation in glaucoma . The molTGFβ2 is the predominant isoform in the eye, and is found in in the trabecular meshwork (TM), aqueous humor, vitreous humor, neural retina, retinal pigment epithelium, and the ONH . In the Notably, a physiological level of inflammation is beneficial and necessary to fight infection, maintain tissue homeostasis, and recruit immune cells to clear sites of tissue damage . HoweverThe role of innate immune activation and induced pathophysiology during glaucoma disease progression has been extensively reviewed ,85,87, wTlr4 gene polymorphisms are associated with primary open angle glaucoma in multiple patient populations [The TLR family consists of 10 members (TLR1-10) in humans and 12 members  in mice . The rolulations ,103,104,ulations ,105. TLRulations .DAMPs serve as key signals for tissue injury or damage. DAMPs are generated in situ in response to injury, oxidative stress, cell damage, or ECM remodeling . Heat shBiglycan is a proteoglycan that primarily supports tissue when exposed to compressional forces , such asTenascin-C is a large glycoprotein expressed in neural and non-neural tissues , and is Finally, FN is a component of the ECM in the ONH, helping to form the intricate mesh-like layer of the LC region along with other ECM proteins . FN is cHere, we have described the role of ECM DAMPs in both immune system activation and glaucoma pathophysiology. Increased levels of DAMPs, induced by increased TGFβ2 levels, activate TLR4 and exacerbate these signaling pathways in the ONH. This leads us to a fibro-inflammatory hypothesis of TGFβ2 and TLR4 signaling crosstalk between the key ONH supporting cell types leading to glaucomatous damage.Autocrine and paracrine signaling within and between astrocytes, microglia, and LC cells was first proposed over 20 years ago ,131. CroAs we have referenced above, early microglial activation precedes RGC damage and death ,32, incrONH astrocytes produce the DAMP tenascin-C ,68,137, In addition, autocrine and paracrine signaling by neurotrophins (NTs) has been implicated in glaucoma disease progression, especially through the loss of such nutrient and growth factor transport through the damaged LC region of the ONH ,141,142.Hypothesized signaling crosstalk between microglia, astrocytes, and LC cells in the glaucomatous ONH are represented by the dashed lines in In the previous sections, we have outlined the hypothesized immune system and NT autocrine and paracrine signaling within and between microglia, astrocytes, and LC cells in the glaucomatous ONH. Both the immune system and NT signaling have direct interactions with TGFβ2 signaling, a predominant contributor to increased ECM deposition in the glaucomatous ONH ,83,151. Bambi mRNA after TLR4 activation [Bambi in mice induces ocular hypertension and increases ECM production in the TM [The mechanism of TGFβ2 and TLR4 signaling crosstalk has previously been studied in other tissues and disease states through the TGFβ pseudoreceptor BMP and activin membrane-bound inhibitor (BAMBI). It is known that TLR4 activation downregulates BAMBI protein expression in a MyD88-dependent manner via NFκB signaling ,152,153.tivation . When prtivation . We prevn the TM . In addin the TM , and we n the TM ,155. ThuExtensive research has indicated the critical role of both TLR4-immune signaling and TGFβ-induced fibrosis in the glaucomatous ONH in furthering RGC loss. Here, we propose a novel mechanism of TLR4-TGFβ2 signaling crosstalk within and between the supporting cells of the ONH. Elucidating the molecular mechanisms behind this crosstalk in the ONH can hopefully produce more therapeutic targets in treating glaucoma.


Liu Q, Li HT and Ren MY performed the experiments. Liu Q, Li ZQ and Chen YZ analyzed the data. Ren MY, Chen YZ and Zheng ZZ contributed analysis tools. Li ZQ, Meng YQ and Feng HM provided critical inputs on design, analysis and interpretation of the study. All the authors had access to the data. All authors read and approved the final manuscript as submitted.


HTLV-1-associated uveitis (HAU) is an inflammatory reaction of the choroid, retina, optic nerve and vitreous that can lead to vision impairment. The worldwide prevalence of HAU varies widely.To determine the prevalence of HAU in patients from Salvador, Bahia-Brazil, and describe uveitis type and associated symptoms.Cross-sectional analytical study to determine the prevalence of uveitis in HTLV-1-infected patients recruited in Bahia, Brazil, a region considered endemic for HTLV-1. Patients were enrolled at a local reference center for HTLV (infected) and at an outpatient ophthalmology clinic (noninfected group). All patients were examined by the same ophthalmologist following a single protocol. Prevalence ratios (PR) were calculated.+ and HTLV-1− patients was 7.14% and 0.73%, respectively . Bilateral intermediate uveitis, associated with symptoms including visual disturbances and floaters, was most commonly identified in the HTLV-1-infected patients, whereas unilateral anterior uveitis, in association with symptoms such as blurring and ocular pain, was more common in the uninfected group.A total of 168 consecutively examined HTLV-1-infected patients and 410 noninfected patients (randomly selected) were included. Females predominated (82.1%) in the HTLV-1-infected group (versus 64.4% in the uninfected group) (p < 0.001). The mean age of infected and uninfected patients was 53.2 and 62.8 years, respectively (p < 0.001). The prevalence of uveitis in HTLV-1The prevalence of uveitis in patients with HTLV-1 was markedly higher than in uninfected subjects. HAU patients were mostly asymptomatic and exhibited bilateral presentation, with uveitis more frequently localized in the intermediate chamber. Human lymphotropic virus type 1 or human T leukemia virus (HTLV-1) was the first human retrovirus to be isolated and associated with disease . In BrazHTLV-1 is the causative agent of diseases such as adult T-cell leukemia lymphoma, HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), infective dermatitis, and HTLV-associated uveitis (HAU) –9.Uveitis is an inflammation of the choroid, retina, optic nerve and vitreous that can lead to visual impairment or blindness –12. In a18,19,22.In Japan, studies have estimated the prevalence of HTLV-1 in patients with idiopathic uveitis , 16. HowThe present study endeavored to determine the prevalence of HAU in the city of Salvador, the capital of the state of Bahia, an endemic area for HTLV-1 in Brazil, as well as to describe the types of uveitis and associated symptoms identified in both HTLV-1-infected patients and uninfected subjects.The present cross-sectional, controlled study aimed to determine the prevalence of uveitis in HTLV-1-infected patients. The study was conducted between March 2019 to June 2021 at the HTLV Integrative and Multidisciplinary Center of the Bahia School of Medicine and Public Health (CHTLV/EBMSP)  in SalvaPatients infected with HTLV-1  were consecutively enrolled at CHTLV. HTLV-1 patients diagnosed with acute (IgM-positive) toxoplasmosis, toxocariasis, rubella or cytomegalovirus infection, or those with a previous diagnosis of syphilis, HIV, hepatitis B or C, tuberculosis, Crohn’s disease, ulcerative colitis, ankylosing spondylitis, Bechet’s disease, sympathetic ophthalmia, Harada’s disease or sarcoidosis were excluded. The control group of individuals not infected with HTLV-1 consisted of patients randomly selected (using the randomize.org program) by assigning an alphanumeric sequence to medical records.The present study protocol was approved by the EBMSP Institutional Research Board; all participating patients provided signed informed consent or waived consent, as appropriate.To calculate the sample size, we assumed a uveitis prevalence of ~ 6% in HTLV-1-infected patients  comparedAnti-HTLV-1 antibodies were detected by ELISA and confirmed by Western blot assay. Patients infected with HTLV-1 were evaluated for the presence of myelopathy, and HAM/TSP was diagnosed using criteria established by WHO .All ophthalmologic examinations were performed by an ophthalmologist (DPO) specialized in the diagnosis of uveitis. Ophthalmologic signs and symptoms were assessed through the comprehensive examination of both eyes: Measurement of visual acuity using Snellen charts, applanation tonometry, refractometry, biomicroscopy of the anterior and posterior eye chambers, retinal mapping, and tear film evaluation using tear film breakup time (BUT), Rose Bengal Staining 0.1%, and Schirmer I test. The diagnosis of keratoconjunctivitis sicca (KCS) was based on the presence of symptoms, along with positivity on at least two of the three latter tests, as described elsewhere .The diagnosis of uveitis was based on a detailed ophthalmologic examination of the anterior, intermediate and posterior portions of the eye to detect the presence of an inflammatory reaction. Anatomic classifications were based on the International Uveitis Study Group, which designates uveitis into anterior, intermediate, posterior and panuveitis classifications .Anterior and posterior biomicroscopy (performed via slit lamp) was employed to evaluate the presence or absence of anterior chamber reaction, flare, and keratic precipitates as indicators of anterior uveitis, as well as to analyze the cellularity of the anterior vitreous . AnterioIndirect binocular ophthalmoscopy was performed using an indirect binocular ophthalmoscope and a 20-diopter loupe after pupil dilation to assess the presence of intermediate and posterior uveitis. The presence of vitreous cellularity, snowballs, snowbanks, vasculitis, papillitis, retinitis, retinochoroiditis, exudates, and cystoid macular edema were noted. Vitreous cellularity was classified as 0 to 5 crosses, with 0 representing no opacities, 0.5 + representing trace cells, 1 + representing minimal opacities with clearly visible posterior pole, 2 + representing moderate opacities with mild posterior pole opacities, 3 + representing moderate opacities with severe posterior pole opacities, 4 + representing severe opacities with difficulty in posterior pole visibility, and 5 + representing severe opacities with no posterior pole visibility.Results were reported as proportions for categorical variables and as means ± standard deviation (SD) for continuous variables. Shapiro-Wilk test was used to test for normality. Statistical tests included the Student t test or Mann-Whitney non-parametric test for mean comparison of independent variables and the Pearson chi-square test or Fisher’s exact test for comparisons between proportions of ocular disease and sociodemographic data between HTLV-1-infected and uninfected patients. Differences were considered statistically significant when p < 0.05. We used Stata for Mac®, version 13.0.Results were expressed as proportions for categorical variables and as means ± standard deviation (SD) for continuous variables. The Shapiro-Wilk test was used to test normality. To compare the means of age between the HTLV-1 and Control groups, the nonparametric Mann-Whitney test was used after no normality was established. Pearson’s chi-square test or Fisher’s exact test was used when indicated for comparisons between proportions of ocular disease and sociodemographic data between HTLV-1-infected and uninfected patients. Differences were considered statistically significant when p < 0.05. All data were analyzed using STATA v13.0.The population studied consisted of 168 individuals infected with HTLV-1 and 410 uninfected patients who served as controls. The proportion of women in the HTLV-1-infected group (82.1%) was higher than in the uninfected group (64.4%), p < 0.001. The mean age of infected and uninfected patients was 53.2 ± 12.5 and 62.8 ± 14.5 years, respectively (p < 0.001).The prevalence of uveitis was significantly higher in HTLV-1 infected patients than in uninfected subjects ,  of HTLV-1-infected patients, whereas no individuals with bilateral uveitis were identified in the uninfected control group. Intermediate uveitis was the most common form identified in the HTLV-1-infected group , followed by anterior uveitis  and pan uveitis . In contrast, no cases of intermediate uveitis were observed in the uninfected controls. However, anterior uveitis was seen in 2 of 3 patients (66.6%) and pan uveitis in 1 of 3 (33.3%)  of HTLV-1-infected patients reported visual disturbances and floaters, whereas the other six patients (50%) were asymptomatic. In the uninfected group, all three patients reported symptoms of blurring and ocular pain.Table Regarding the three cases of uveitis identified in the HTLV-1-uninfected group, anterior chamber changes were identified in all subjects (100%), including endothelial keratic precipitates and shallow anterior chamber; in one subject (33.3%) with active uveitis, moderate vitreous cells were observed.The present study identified a prevalence of uveitis almost 10-fold higher in HTLV-1-infected subjects than in uninfected subjects. In addition, the characteristics of uveitis differed between HTLV-1-infected and uninfected individuals. HAU was mostly bilateral, more often localized in the intermediate chamber of the eye, and patients were asymptomatic. In contrast, uveitis in uninfected individuals was unilateral, involved the anterior chamber of the eye, and was associated with pain and visual blurring. HTLV-1 infection was the only cause associated with uveitis in the infected group, as one patient with bilateral panuveitis and Crohn’s disease and another with bilateral intermediate uveitis and HIV infection were excluded. In the HTLV-1-uninfected control group, herpes simplex and tuberculosis were found to be associated with uveitis Table . Other BThe prevalence of HAU in other endemic areas varies by geographic region. In Martinique, HAU was found in 14.5% of infected individuals , whereasIn addition, the route of HTLV-1 transmission may also influence the occurrence of HAU. For example, the sexual transmission of HTLV-1 has been associated with HAU development –29 in adSimilar to other reports, the presentation of HAU was mostly bilateral in our patients  and locaThe pathogenesis of HAU may be explained by HTLV-1-infected T cells disrupting the blood-ocular barrier, thereby leading to intraocular inflammation , 31. TheHigh HTLV-1 proviral load could represent a factor responsible for exacerbating the inflammatory response in HTLV-1-infected individuals, as this constitutes a biomarker for the development of inflammatory diseases, such as HAM/TSP , 37, 38,In conclusion, our results indicate a higher prevalence of uveitis was in HTLV-1-infected subjects than in uninfected controls. HAU patients are usually asymptomatic or oligosymptomatic. Visual disturbances may go unnoticed and can potentially lead to permanent visual damage. The findings herein serve to confirm the importance of regular ophthalmologic examinations in HTL-1-infected patients in order to achieve early diagnosis and properly treat uveitis.


TpBpy COF could efficiently oxidase the colorless substrate 3,3′,5,5′-tetramethylbenzydine (TMB) into blue oxidized TMB (oxTMB) under visible light irradiation. Based on the color fade of the TpBpy COF + TMB system by UA, a colorimetric procedure was developed for UA determination with a detection limit of 1.7 μmol L−1. Moreover, a smartphone-based sensing platform was also constructed for instrument-free and on-site detection of UA with a sensitive detection limit of 3.1 μmol L−1. The developed sensing system was adopted for UA determination in human urine and serum samples with satisfactory recoveries (96.6–107.8%), suggesting the potential practical application of the TpBpy COF-based sensor for UA detection in biological samples.Monitoring of uric acid (UA) levels in biological samples is of great significance for human health, while the development of a simple and effective method for the precise determination of UA content is still challenging. In the present study, a two-dimensional (2D) imine-linked crystalline pyridine-based covalent organic framework (TpBpy COF) was synthesized using 2,4,6-triformylphloroglucinol (Tp) and -5,5′-diamine (Bpy) as precursors via Schiff-base condensation reactions and was characterized with scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDS), Powder X-ray diffraction (PXRD), Fourier transform infrared (FT-IR) spectroscopy, and Brunauer–Emmett–Teller (BET) assays. The as-synthesized TpBpy COF exhibited excellent visible light-induced oxidase-like activity, ascribed to the generation of superoxide radicals (O The redox reaction between UA and oxidized TMB  were acquired from Chengjie Chemical Co., Ltd. .2,4,6-triformylphloroglucinol (Tp) and -5,5′-diamine (Bpy) were purchased from Alpha Chemical Co., Ltd. . 3,3,5,5-tetram -5,5′-diamine ethylbenzydine (TMB), o-Phenylenediamine (OPD), and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) were provided by Aladdin Industrial Inc. . Uric acid (UA), HAc, and NaAc were obtained from Sinopharm Chemical Reagent . Ionic liquids  were dissolved in 2.0 mL H2O, and, then, the mixture was stirred at room temperature for 2 h. Thereafter, the produced red solid was collected through centrifugation and was washed three times with acetone and ethanol, respectively. Finally, the product was dried under a vacuum at 60 °C for 12 h.TpBpy COF was synthesized according to a reported procedure with some modifications . Briefly2 adsorption-desorption isotherm was obtained by an Autosorb-IQ-MP-C automatic gas adsorption analyzer at 77 K . Scanning electron microscopy (SEM) images were collected on a SU8010 field-emission electron microscope at a voltage of 5.0 kV . Fourier transform infrared (FT-IR) spectra were recorded using a Nicolet-6700 FT-IR spectrophotometer . Ultraviolet-visible (UV-vis) absorption spectra were obtained on a U-3900 UV-Vis spectrophotometer . Visible light was generated by a white-light LED lamp .Powder X-ray diffraction (PXRD) was collected on a Maxima XRD-7000 diffractometer . N−1) were mixed with 850 μL HAc-NaAc buffer . After irradiation with white-light LED lamp for 15 min, the absorbance at 652 nm was recorded.The steady-state kinetic studies were carried out by changing the concentration of TMB under fixed TpBpy COF levels. In brief, 100 μL TMB of different concentrations and 50 μL COF solution (0.1 mg mL−1) and 250 μL TMB solution (1.0 mmol L−1) were mixed with 600 μL HAc-NaAc buffer , then 100 μL UA solution  was added into the mixture subsequently, and the final volume of the detection system was 1 mL. After that, the resultant mixture was irradiated under a white-light LED lamp  for 15 min to stimulate the catalytic reaction. The absorbance of this system at 652 nm was recorded. The absorbance difference A0 − A (A0 and A represent the absorbance at 652 nm in the absence/presence of UA) was adopted to fabricate the calibration curve.Typically, 50 μL COF solution (0.1 mg mL−1), 250 μL TMB solution (1.0 mmol L−1), 100 μL UA solution , 600 μL HAc-NaAc buffer  were added and irradiated under a white-light LED lamp  for 15 min. Thereafter, removing 100 μL of the resultant mixture into a cover of centrifugal pipe. Digital images were collected in a self-made box (19.5 cm × 18.5 cm × 16.5 cm) by a Mi 10 smartphone under a white-light LED lamp  through the “Color Grab” app and processed into R, G and B parameters. The distance between the smartphone’s camera and the tested sample was 20 cm. The usage of LED lamp as the visible light source was due to its stable and intensive light irradiation.In an EP tube, 50 μL COF solution (0.1 mg mL−1 PBS buffer (pH 7.4).Human blood samples were provided by the Hospital of Northeastern with the volunteers’ consent. The blood samples were dealt with refrigerating centrifugating  for 20 min, and then the collected supernatant was diluted 5-fold with 0.1 mol L−1 PBS buffer (pH 7.4), and then directed to colorimetric detection.Urine sample was donated by the author. The urine samples are 10-fold, diluted with 0.1 mol L3C-symmetric Tp and 2C-symmetric Bpy at room temperature, by using ionic liquids [BmimN(CN)2] as a catalyst. The obtained TpBpy COF was an aggregate of nanorods and presented an irregular geometric shape , (110), and (002) planes  was TMB content, mK resembles the Michaelis–Menten constant, V was the initial velocity of the reaction, and maVx was the maximal velocity of TMB oxidation.To understand the kinetic mechanism of the oxidase-like activity of TpBpy COF, apparent steady-state kinetic parameters of the catalytic oxidation reaction are determined by changing the concentrations of TMB under fixed TpBpy COF levels. A series of initial reaction rates are calculated and applied to the double reciprocal of the Michaelis–Menten equation :V = VmaxmK) and the maximum initial velocity (maxV) of TpBpy COF were deduced to be 94.8 μmol L−1 and 4.31 × 10−6 M min−1, respectively. Generally, Km has been identified as an indicator of enzyme affinity with substrates. Compared with other oxidase-like catalysts  presented a good linear relationship with UA in the concentration range of 5–80 μmol L−1 (R2 = 0.98) (−1.  = 0.98) B, and th+, K+, Mg2+, Ca2+, lysine (Lys), glycine (Gly), tryptophan (Try), glucose (Glu), urea, albumin (Alb), and immunoglobulin (IgG). As illustrated in To evaluate the selectivity of the TpBpy COF-based system for UA sensing, the response of the sensing system was investigated in the presence of potentially interfering substances that coexisted in biological samples, including Na−1 (R2 = 0.99), giving access to the UA detection by a portable smartphone independent of lab equipment, and the detection limit was 3.1 μmol L−1.Due to the fact that the presence of UA could induce obvious color fading of the TpBpy COF-based sensing system, a smartphone-based platform was further developed for instrument-free and on-site detection of UA. The high-resolution photos of the sensing system with different UA concentrations under white-light irradiation were captured and converted into color intensity based on RGB mode by the “Color Grab” app. The YUV color space method with a weighted average of R, G, and B components recommended by the International Telecommunication Union (ITU) was adopted to construct luminance and color-difference signals , and theTo verify the practicability of this TpBpy COF-based sensing system, UA content in human urine and serum samples were determined via the colorimetric procedure and the smartphone-based platform.As shown in In this study, we successfully synthesized a two-dimensional covalent organic framework TpBpy COF via the Schiff-base condensation reaction. The as-synthesized TpBpy COF exhibited excellent oxidase-like activity under visible light irradiation that could efficiently catalyze the TMB into blue oxTMB. Based on the ability of UA to reduce oxTMB, we proposed two modes  for UA sensing. The UA contents determined by the smartphone-based signal readout platform are consistent with the theoretic UA contents in healthy human serum and urine , suggest