The aim of this respective study was to assess the graft signal/noise quotient (SNQ) value and associated factors based on magnetic resonance imaging (MRI) after lateral meniscal allograft transplantation (LMAT). Patients with LMAT were included. The SNQ, width of the anterior horn (WAH), width of the midbody (WMB), width of the posterior horn (WPH) of each lateral meniscus, coronal graft extrusion (CGE), the anterior cartilage meniscus distance (ACMD) and the posterior cartilage meniscus distance (PCMD) were measured using MRI and tested by multivariate stepwise regression analysis. The relative percentage of extrusion (PRE) was calculated. Seventy-one male patients were examined, and 7 patients were lost to follow-up. The SNQ of the meniscus increased from immediately after surgery to 6 months postoperatively, decreased from 6 to 12 months, increased from 12 to 24 months, and increased from 24 to 36 months. The mean SNQ had a significant negative association with the WPH and CGE at 6 months (p < 0.05), the WPH at 1 year (p < 0.05), the PRE of CGE (CPRE) at 2 years (p < 0.05), and the PCMD, CPRE, and PRE of the PCMD (PPRE) at 3 years (p < 0.01) postoperatively. Multivariate stepwise regression analysis showed that the WPH at 6 months, WPH at 1 year, WMD and PCMD at 2 years, and WMD, ACMD and CGE at 3 years were significant independent factors correlated with the mean SNQ of grafts in different periods. Maturation of meniscal grafts fluctuated with time. The maturation process occupied the main role before 1 year postoperatively, but after the maturation process, tearing of the meniscal allograft played the leading role. Changes in an allograft’s location had an obvious association with the SNQ. The WPH influenced the graft SNQ value at 6 months and 1 year postoperatively, but after the maturation process, the WMB and graft extrusion played the same roles. Acute meniscal tears are the second most common athletic knee injury following anterior cruciate ligament (ACL) tears2. For irreparable meniscal injury, meniscectomy is a common surgery. The long-term results of total meniscectomy have been shown to be closely associated with rapid degenerative changes and decreased clinical function and activity levels3. In the late 1980s, clinical meniscal allograft transplantation (MAT) emerged as a logical approach to provide pain relief and functional improvement of the knee joint4. Compared to meniscectomized knee joints, MAT increases the contact area and decreases the contact pressure on the cartilage surface5.Fibrocartilaginous menisci play an essential role in the complex biomechanics of the knee joint, such as load distribution, joint stability, articular cartilage lubrication and shock absorption6. Magnetic resonance imaging (MRI) is commonly used as a noninvasive tool to evaluate graft status after implantation. The sagittal allograft position, morphologic features, shrinkage, extrusion, intrameniscal signal intensities and degeneration of adjacent articular cartilage are often measured9. However, few studies have investigated intrameniscal signal intensities after MAT, and their clinical relevance remains unknown6.The increased number of MATs has led to the need for better postoperative evaluation of the reconstructed graft. The International Meniscus Reconstruction Experts Forum (IMREF) does not recommend routine second-look arthroscopy after MAT13. Potential risk factors influencing the failure incidence of MAT, including graft placement, shrinkage, extrusion, and degeneration of adjacent articular cartilage, have been investigated11. The presence of severe cartilage damage at the time of MAT can cause an increased failure rate11. However, little is known about the correlations of these factors with the maturity of transplanted meniscal allografts6.In addition, an increasing number of studies on the failure rate of MAT have been conductedThe purpose of this study was to identify factors that influence graft maturity after lateral MAT (LMAT) based on 3.0-T MRI. We hypothesized that graft maturity is critical in the prevention and management of graft failure, and that some factors based on MRI are significantly correlated with increased graft maturity after LMAT.At the final follow-up time point, 7 cases had been lost. No infection or synovitis was observed in any of the participants. However, one case of treatment failure and one case of meniscus allograft dislocation were noted, which were treated with a second operation for meniscal restoration.The intraclass correlation coefficients (ICCs) of intraobserver reliabilities for the signal/noise quotients (SNQs) of the grafts, which were calculated immediately and at 6 months, 1 year, 2 years and 3 years postoperatively, were 0.836, 0.878, 0.827, 0.826 and 0.951, respectively. The ICC of interobserver reliability for the graft SNQ value in the overall sample was 0.77. Generally, the mean SNQ of the meniscal grafts increased from immediately after surgery to 6 months postoperatively, decreased from 6 to 12 months, then increased from 12 to 24 months, and increased slowly from 24 to 36 months. In addition, the peak SNQ occurred at 6 months postoperatively, and the lowest SNQ occurred at 12 months postoperatively. The SNQ values of the anterior horn site, midbody site, and posterior horn site had similar curves. The only difference was that the SNQ of the posterior horn site decreased slowly from 24 to 36 months , midbody (WMB) and posterior horn (WPH) of each lateral meniscus decreased with time (p < 0.05) Fig. , and theSimilarly, the influence of different surgery techniques was also analyzed. From postoperation to 24 months after surgery, SNQs after LMAT with different surgical techniques had similar curves, and no obvious difference was observed between the 2 groups immediately after surgery or at 6 months, 1 year, and 2 years after surgery P > 0.05), but at 3 years after surgery, the SNQ after LMAT with the bone bridge technique was obviously higher than after LMAT with the modified bone plug technique  of the allograft and its SNQ value was positive, indicating that the intrameniscal SI is higher in cases with wider allografts. This effect might be caused by a wider graft bearing more load between the tibial plateau and femoral condyle. This stress causes variations in the SNQ value. However, until recently, relevant literature to confirm our speculation was lacking.In addition, we found that the widths of the anterior horn, midbody and posterior horn of each lateral meniscus decreased with time, but the WPH changed the slowest, the WMB decreased quickly in the early healing period, and the WAH decreased quickly in the midterm period. The study by Lee et al.22 showed that in the sagittal plane, the mean absolute ACMDs were 2.59 ± 1.75, 2.58 ± 1.85, and 2.37 ± 1.60 mm, and the mean relative ACMDs were 20.7% ± 13.1%, 20.6% ± 13.8%, and 19.0% ± 12.2% at the 3 follow-up time points. The mean absolute PCMDs were − 1.23 ± 3.34, − 1.28 ± 3.08, and − 1.42 ± 2.77 mm, and the mean relative PCMDs were − 10.3% ± 25.9%, − 11.0% ± 24.6%, and − 12.2% ± 23.2% at the same time points. In the coronal plane, the mean absolute meniscal extrusion values at 6 weeks, 1 year, and the final follow-up were 2.90 ± 0.94, 2.85 ± 0.97, and 2.83 ± 0.89 mm, respectively, and the mean PREs were 27.0% ± 9.4%, 27.1% ± 10.1%, and 27.8% ± 9.7%, respectively. These findings suggest that extrusion of a meniscal allograft in either the coronal or sagittal plane does not progress after LMAT, which differs from our results. In our study, extrusion of meniscal allografts in either the coronal or sagittal plane obviously changed with time; the anterior horn and the posterior horn both moved anteriorly because they belong to an integral unit. These areas had synergic movement similar to that in the studies by Rankin et al.23 and Scholes et al.24In our study, CGE and the CPRE increased with time but became steady after 2 years postoperatively; however, changes in the ACMD, APRE, PCMD and PCRE were more complicated but varied in a contrary manner, indicating that the sagittal locations of allografts were constantly changing. A study by Kim et al.26. After meniscal maturation, CGE and the CPRE had negative associations with the SNQ of the MBS and the mean SNQ of the grafts at 2 years and 3 years. Movement toward the center of the tibial plateau corresponded to more load-bearing, degeneration and abrasion, and additionally, a higher SNQ value was observed.In addition, the correlations of the SNQ values of the grafts with the ACMD, APRE, CGE, CPRE, PCMD and PPRE were very complicated, indicating changes in the allografts’ locations, and our study showed that location changes have an obvious association with the SNQ after the maturation process (at 2 years and 3 years postoperatively) Tables  and 2. I27 compared a patient series with full-thickness chondral defects who underwent MAT with a patient series with no chondral defects and found no differences in changes in individual patient-reported outcomes (PROs) from the preoperative period to the final follow-up period. However, Kempshall et al.28 showed that outcome measures after MAT in cases with minimal chondral damage continued to improve at 2 and 3 years postoperatively, with slightly greater improvement than that in cases with significant chondral damage.The SNQ changed more quickly in the modified bone plug technique (MBP) group than in the bone bridge technique (BBT) group and had similar peak and lower bottommost values. At 2 years and 3 years postoperatively, the SNQ in the BBT group was higher, showing that better cartilage was good for vascularization at 6 months and for faster organizational dehydration and better tissue maturation at 1 year. The cases with a worse cartilage status showed lower SNQ values of the grafts after the maturation process. Previously, Saltzman et al.Only some factors based on MRI were analyzed in this study. Whether other factors influence graft maturation, such as clinical outcomes and lower limb power lines, is unclear. Only males were recruited in this study. No females were included to avoid any influence of differences in hormone levels on graft maturity. Therefore, our results are representative of only some patients and not the entire population. Future studies in this field will provide valuable information regarding sex differences and the influence of other factors on graft maturity. Only 64 LMAT cases were ultimately investigated, and the number of studies was small. A larger sample size for further investigations should be utilized in the future. Finally, this study was limited by our use of the SNQs of some graft sites to represent the SNQ of the entire graft, and this method might have limitations.20. More than 3 years of follow-up and assurance of the uniformity of surgery-related factors were necessary. The inclusion criteria were as follows: (1) unilateral MAT, (2) no history of reinjury of the affected knee, and (3) 18–50 years of age. Participants were excluded if they had osteoarthritis (confirmed by surgery), combined ligament injuries, or a severe synovial reaction at the time of surgery.This retrospective study was performed after ethical approval was received from the ethics committee of Peking University Shenzhen Hospital. All methods were carried out in accordance with relevant guidelines and regulations. All subjects included provided informed consent. From January 2008 to December 2015, male patients who underwent unilateral MAT by the same senior doctor were included. Females were excluded due to concerns about different hormonal levels, which might influence graft maturity29 (BBT group) and 41 patients who underwent the modified bone plug technique30 (MBP group). After surgery, all patients followed the same rehabilitation principles: Early range of motion (ROM) movements in the range of 0° to 60° for 15 min daily were encouraged beginning 1 week postoperatively to minimize the deleterious effects of immobilization; gradual progression to full weight-bearing was permitted by 6 weeks postoperatively; a double upright hinged brace was used during the designated protection phase; flexion was limited to 90° for 14 weeks postoperatively; gentle jogging was allowed between 4 and 6 months, but running was not advised before 6 months postoperatively; and finally, a return to sports was anticipated between 6 and 9 months30. The patient demographic data are shown in Table A total of 71 patients were recruited for this study . Sagittal oblique fat-saturated proton density images were obtained as follows: repetition time, 3,000 ms; echo time, 45 ms; flip angle, 160°; matrix, 320 × 320; field of view, 15 × 15 cm; slice thickness, 3 mm; and scan time, 2 min 41 s. The image data were transferred to Siemens workstation software  for calculation. All calculations at the midbody of each lateral meniscus were evaluated on midcoronal sections, and those at the posterior and anterior horns were measured on midsagittal sections of T2-weighted images and midcoronal or midsagittal sections, which were determined as the middle cuts among the serial coronal images from the anterior to the posterior meniscocapsular junction of the lateral meniscus and the serial sagittal images from the lateral tibial eminence to the lateral meniscocapsular junction of the lateral meniscus31.The SI was calculated at the graft sites as well as two other sites (the quadriceps tendon site at approximately 2 cm at the top of the patella and the background at approximately 2 cm anterior to the patellar tendon) using a region of interest (ROI) Fig. . The mea32.In addition, we also measured many other factors, including the following: the WAH, the WMB, the WPH of each lateral meniscus, the grade of cartilage lesions before surgery, CGE, the CPRE, the ACMD (defined as the distance from the anterior articular margin to the anterior border of the anterior horn of the meniscus), anterior graft extrusion, the APRE, the PCMD (defined as the distance from the posterior articular margin to the posterior border of the meniscus), posterior graft extrusion, and the PPRE20 study. Calculation of the sample size yielded 62 patients.Statistical analysis was performed with SPSS software for Windows , and the results were reported as the mean and standard deviation. The data were tested for normality using the Shapiro–Wilk test. ICCs were assessed by examining intraobserver reliabilities. The coefficients were interpreted as poor if ICC < 0.4, marginal if 0.4 < ICC < 0.75, and good if ICC > 0.75. Spearman’s correlation coefficients were calculated between the graft SNQ value and potential risk factors, including graft shrinkage, CGE, the grade cartilage lesions before surgery, the ACMD, and the PCMD. Multivariate stepwise regression analysis was performed to further assess the independent factors correlated with the graft SNQ value. The level of significance was set as P < 0.05;β < 0.2, and the expected correlation coefficients were referenced from Li’s et al.The SNQ values of meniscal grafts fluctuated with time because the maturation process occupied the main role before 1 year postoperatively, but after the maturation process, tearing of the meniscal allograft played the leading role. LMAT with the MBP resulted in better midterm maturation than LMAT with the BBT. The WPH was a significant independent factor correlated with the graft SNQ value at 6 months and 1 year after surgery, but after maturation of the WMB, graft extrusion was a significant independent predictor of the graft SNQ value.


To calculate the rate of tuberculosis cases per prison unit in Espírito Santo; present the individual, clinical, and institutional characteristics of the cases in persons deprived of liberty (PPL); and analyze the association between these characteristics and treatment outcome in this population. The study included cases of tuberculosis in the PPL of Espírito Santo from 2014 to 2016. Rate calculation, descriptive analysis and hierarchical logistic regression were performed considering the individual, clinical and institutional levels. The rate of diagnosed cases per prison unit in the state ranged from 0 to 17.3 cases per 1,000 inmates. Of all reported cases, 218 (72.6%) healed, 21 (7.0%) dropped out, 1 (0.3%) died of tuberculosis, 2 (0.7%) died from other causes, 56 (18.7%) transferred the treatment site and 2 (0.7%) developed drug-resistant tuberculosis. The adjusted analysis showed that supervised treatment ensures success . The study highlighted the importance of knowing the TB treatment outcome in the PPL to implement measures to reduce failure, and the contribution of supervised treatment in this process. Besides the diseases already observed in the general population, dermatoses, mental illness, trauma, infectious diarrhea, STDs, and respiratory diseases such as pneumonia and tuberculosis (TB) are often prevalent in PPL2. Some factors effectively contribute to the PPL high endemicity of tuberculosis. They may be related to individuals and their living conditions before incarceration — being young, male and with low education; using drugs; having associated injuries; exhibiting previous treatment for TB and having a history of incarceration; or to incarceration — overpopulation, poorly ventilated and poorly lit cells, frequent exposure to the bacillus in a confined environment, lack of information and lack of health services access in prison3.Monitoring TB indicators in the PPL of Brazil showed an increase in the incidence rate from 627.6 cases to 904.9 cases per 100,000 prisoners from 2007 to 2013, while mortality reached 18.0 deaths per 100,000 prisoners in 2007 and 16.0 deaths per 100,000 prisoners in 2013Política Nacional de Atenção Integral à Saúde das Pessoas Privadas de Liberdade no Sistema Prisional , instituted by Interministerial Ordinance no. 1, of January 2, 2014, to expand the health measures of the Brazilian Unified Health System (SUS) for PPL. Among its multiple guidelines, PNAISP also included a specific measure for TB control4.In 2014, the Ministry of Health launched the Thus, besides quantifying TB cases in PPL, we must investigate which factors permeate this context and interfere in the dynamics of disease outbreak and treatment. This study aimed to calculate the rate of tuberculosis cases per prison unit in Espírito Santo (ES) from 2014 to 2016; to present the individual, clinical, and institutional characteristics of the cases; and to analyze the association between these characteristics and the interruption of tuberculosis treatment in this population.5. These units refer to provisional, closed, semi-open and mixed prison systems, excluding police stations or the like.The sample of this study comprised the tuberculosis cases registered in persons deprived of liberty in the State of Espírito Santo from 2014 to 2016, including new cases, relapses, readmission after dropping out, transfer or unknown entry method (“does not know”). Espírito Santo has 34 prison units, which in 2014 housed 16,234 prisoners, accounting for an imprisonment rate of 417.9 PPL per 100,000 inhabitants, higher than the country’s rate—299.7 per 100,0006 and the literature on the subject. Thus, the theoretical model used consisted of the levels and respective variables  as: cure, dropping out, death from tuberculosis, death from other causes, transfer, multidrug-resistant tuberculosis, treatment change, failure, and primary default. In the hierarchical logistic model, this variable was reclassified as success (cure) and failure (other categories).The variable studied was the tuberculosis treatment outcome, classified by the Sistema de Informação de Agravos de Notificação  and the Levantamento Nacional de Informações Penitenciárias5, as well as databases and reports from the State health and justice departments, stored in a single database for statistical analysis.Data were collected from the Statistical analysis estimated the TB diagnosis rate per prison unit in Espírito Santo, considering only the cases diagnosed during incarceration, and excluding transfers and unknown entry method (“does not know”). Then a descriptive analysis was performed according to the variables ranked by level and categorized per TB treatment outcome.Logistic regression estimated the gross and adjusted odds ratio (OR) and respective 95% confidence intervals (95%CI). Multivariate analysis used the hierarchical model defined according to the established levels. Initially, the variables associated with the interest outcome (p ≤ 0.20) were included in the model, to account for possible confounding variables. In the modeling stage, independent variables were included from the distal to the proximal level. Variables with p < 0.20 were kept at each hierarchical level and in the final model for adjustment. In the final model, a significance level of 5% was adopted to determine the variables associated with treatment failure.6. Statistical analyses were performed using the R programming, version 3.4.1.Hierarchical models are used when distal factors influence intermediate factors, which, in turn, influence more proximal factors, directly impacting the outcome. Thus, this model allows including variables in their sequential order, even with dependency on observationsThis research was approved by the Research Ethics Committee of the Escola Nacional de Saúde Pública Sérgio Arouca da Fundação Oswaldo Cruz (Fiocruz) under opinion no. 1,866,469 on December 14, 2016.Centro de Triagem de Viana (CTV – Viana Triage Center), located in Grande Vitória, had the highest diagnosis rate and an occupancy rate above 200%. Other institutional characteristics proved to be heterogeneous among the units  healed, 21 (7.0%) dropped out, 1 (0.3%) died of tuberculosis, 2 (0.7%) died from other causes, 56 (18.7%) transferred the treatment site and 2 (0.7%) developed drug-resistant TB.We evaluated these cases for their individual, clinical and institutional characteristics  and cateThe cases were mostly male, young (18 to 29 years), mixed race, with five to eight years of schooling. Women and individuals aged 30 to 39 years, with one to four years of schooling, showed more treatment failure.Among comorbidities and associated conditions, the most prevalent was alcoholism, reported in 24% of cases, followed by Aids (6.0%), diabetes (2.0%) and mental illness (1.2%). Results show that most treatment failures occurred in cases with Aids and mental illness. The percentage of cure (success) was similar between alcohol users (72.2%) and non-users (74.2%).The most observed types of admission were new case (71.7%) and pulmonary tuberculosis (88.3%). Cases of extrapulmonary TB showed less treatment success when compared to pulmonary TB.Most X-ray examinations were suspected, while sputum smear and sputum culture tests were positive. Those treated with medication showed a success rate above 80%, approaching 60% in cases without the supervised dose.Regarding institutional aspects, most cases occurred in provisional units, managed by the state, with an occupancy rate between 100.00 and 199.99%. The infrastructure assessment showed the prevalence of cases in institutions built for incarceration, with an expanded health (74.7%), education (70.0%) and visit (46.0%) structure. We also highlight the presence of a differentiated expanded health team, comprising a nursing team, general practitioner, dentist, social worker and psychologist or occupational therapist, or psychiatrist, or physiotherapist for 63.0% of cases. The work rate was 0.10 to 14.99% in the prison units where 65.6% of TB cases were diagnosed, and the most prevalent education rate was 15.00 to 29.99%, representing 32.3% of them. This study had some limitations. It left out variables on time of incarceration during diagnosis or related to previous history of incarceration, which could influence diagnosis, although there are still little data showing any association with treatment outcome. The impact of TB on persons deprived of liberty in the general burden of the disease may be underestimated when considering the situations in which the PPL develop it after release, albeit acquiring the bacillus during incarceration. Thus, other studies should address these questions.7. The established flow foresees that these newcomers remain for a maximum period of 48 hours in the unit, awaiting transfer according to profile and legal situation, identified by an initial registration. However, this deadline is not met, with prisoners remaining for up to 30 days8.In the period studied, the CTV had the highest rate of TB diagnosed cases, with 17.3 per 1,000 persons deprived of liberty. The CTV is singular if compared with other institutions, working as a gateway to the ES prison system and therefore has a high turnover, with an average of 690 entries each monthProtocolo de Controle de Tuberculose Pulmonar da População Prisional (Protocol for Controlling Pulmonary Tuberculosis in the Prison Population) of Espírito Santo based on the Ministry of Health guidelines, an active search for respiratory symptoms, using a specific screening form, must be performed when entering the prison system9—which may be responsible for the greater number of TB cases identified in the CTV compared with the other units. Once transferred, these individuals already have an initial screening for TB. However, although the diagnosis occurs during incarceration, we must reflect on the transmission mechanism of the TB bacillus and its incubation time. From our data, it is unclear if the prison unit was the place of TB contagion, since the PPL could already be infected, progressing to the active disease during this period. Although not the source, the prison environment would have contributed to the disease evolution3. Genetic studies could provide a better understanding on the dynamics of M. tuberculosis transmission, enlightening this issue. Knowledge of how the microorganism is dispersed in the prison and general population aids in disease prevention and control strategies10.According to the 11.Tuberculosis cases recorded in ES prison population in 2014, 2015 and 2016 represented 7.5%, 6.1% and 7.8% of all reported cases, respectively. In 2014, 8.4% of all cases in Brazil were found among PPL, although this group represented only 0.3% of the country’s total population in that year12. Our data on cure (72.6%) and dropping out (7.0%) rates were similar to this study, but the transfer rate (18.7%) was superior, probably due to the logistics adopted by the ES Department of Justice, which elected one prison unit as the gateway to the prison system, from which the allocation is made.According to the Ministry of Health, comparative data on TB treatment outcome in 2015 showed cure, dropping out, and transfer rates of 73.2%, 7.7% and 5.5% for PPL, while in the general population they reached 71.0%, 9.8% and 5.0%, respectively13. Although the rate of incarcerated women increased by 10.7% per year from 2005 to 2014, men are still most of PPL, with an average of 5.8% women to 94.2% men5. In Espírito Santo, men represented 93.6% of the all arrests in 20145, supporting the high percentage of TB cases in men observed in this study. Despite being a minority, the research showed a higher proportion of treatment failure in women (71.4%) than in men (26.3%). A study assessing TB in the Brazilian PPL from 2009 to 201411 showed that women deprived of liberty had HIV co-infection rates (24.1%) higher than men (15.2%). In this study, co-infection appeared in 28.6% of women and 5.5% of men, and may contribute significantly to the observed failure scenario, though associated with other characteristics.Frequent transfers between units influence follow-up loss; thus, communication between safety and health professionals must be agile and constant, aiming to minimize treatment drop out and ensuring that the medical records accompany the patient when changing prisons. The Ministry of Health states that mobility in the prison system increases the risk of TB infection, given the circulation between different penal institutions, health services and the general population, during and after incarceration6, age group of most TB cases recorded in the study (64%). A wider age group, from 18 to 39 years, accounts for 90.7% of the recorded cases. Previous studies also show that the age group 18 to 39 years (74.7%) comprises most TB cases recorded in the PPL, although only 39.8% of TB cases in the general population show up in this age range11. In 2014, 25.6% of TB cases in men aged 20 to 29 years registered in Brazil were deprived of liberty11.Infopen data show that approximately 55% of the Brazilian PPL is between 18 and 29 years of age11. The results showed a higher percentage of treatment success for pulmonary TB (74.3%) than for extrapulmonary (59.3%). Extrapulmonary TB diagnosis presents a higher degree of difficulty, since some forms show unspecific signs and symptoms, requiring tests of restricted access to PPL and delaying treatment, which may explain this finding13.Extrapulmonary tuberculosis rate, observed in 9.0% of all cases in the PPL, was similar to the country’s, 8.2%14, according to the literature.The institutional description observed refers to the characteristics of the prison units where TB cases were located during diagnosis and reflects the prison context experienced in the state in general. In 2016, the occupancy rate of prisons in the country was 197.4% and 144.7% in Espírito Santo, while the rate of prisoners without charge in Brazil was 40.2% and 42.3% in the ESConselho Nacional de Política Criminal e Penitenciária , restructured the ES prison system by building 26 prison units, which included infrastructure for visit, education, work, and health. State management aimed to implement policies in security and resocialization, including health care, formal study provision, training and work15. The ES currently has work and education rates among the best recorded in the country16. Building ventilated and illuminated prisons contributes to reducing the transmission of respiratory infections, according to the Manual de Intervenções Ambientais para o Controle da Tuberculose nas Prisões , which proposes solutions to improve environmental conditions for preserving peoples’ health without compromising safety17.In 2006, the ES prison system underwent overpopulation, violent rebellions, homicides, and breakouts, resulting in the absence of a minimum structure that could enable security management or resocialization policy. Thus, in 2009, a federal intervention carried out by the Programa de Saúde Prisional  in ES was 75.2% in 201418, reaching 100.0% in 2018. This study highlighted the importance of the health team’s performance for treatment success. The PNAISP, established by the Ministry of Health in 2014, aims to ensure access for persons deprived of liberty to comprehensive care in the SUS, focus of the Rede de Atenção à Saúde . This national policy and its ordinances standardize the types of teams and resource funding. The Equipe de Atenção Básica Prisional (EABp – Prison Primary Care Team) is multidisciplinary, and its modality and workload are determined by the number of inmates and the epidemiological profile of the units4.Regarding health, the coverage of the 19. One research showed that supervised treatment reduces unfavorable tuberculosis treatment outcomes by 25%, and that patients who did not receive DOT were more likely to abandon treatment , die from TB  and have unknown treatment results 20. The Ministry of Health recommends directly observed treatment for PPL, as it strengthens the bond with the health professional, guarantees quick access to health service regarding adverse effects, prevents using medication as an element of exchange and pressure, offers to exchange information and establish care, among others13.Performing directly observed treatment (DOT) was associated with treatment success, reaffirming the beneficial effect of DOT shown in other studies13.The ministry also lists as main obstacles to implementing control strategies in the prison environment: the lack of knowledge about TB by PPL and security professionals; undervaluation of TB symptoms by PPL, hindering early diagnosis; difficulty of PPL access to health services, and its scarcity of human and financial resources; low adherence of PPL to treatment and prevention measures; and the stigmatization and segregation created by TB, considering the importance of protection by belonging to a groupDespite the challenges, the study showed that we must examine the components influencing the outcome of tuberculosis treatment in PPL, to implement measures that provide cure and reduce failure rates. Knowing what leads to drop out contributes to interrupt the chain of transmission of the disease and its prevention, not only among the PPL, but between family members and workers who circulate in the prison environment. 1.O ambiente prisional favorece o adoecimento da população privada de liberdade (PPL) devido às consequências do confinamento e da dificuldade de acesso aos serviços de saúde. Além dos agravos já observados na população em geral, são frequentemente prevalentes na PPL dermatoses, transtornos mentais, traumas, diarreias infecciosas, doenças sexualmente transmissíveis e ainda doenças respiratórias como pneumonia e tuberculose (TB), principalmente2. Alguns fatores contribuem efetivamente para alta endemicidade da tuberculose na PPL. Eles podem ser atribuídos aos indivíduos e sua condição de vida antes do encarceramento, como ser jovem, do sexo masculino e com baixa escolaridade, fazer uso de drogas, apresentar agravos associados, ter feito tratamento anterior para TB e ter antecedente de encarceramento; ou ainda aos fatores relacionados ao encarceramento, como celas superpopulosas, mal ventiladas e com pouca iluminação solar, exposição frequente ao bacilo em ambiente confinado, falta de informação e dificuldade de acesso aos serviços de saúde na prisão3.O monitoramento dos indicadores da TB na PPL no Brasil mostrou um aumento na taxa de incidência de 627,6 casos para 904,9 casos por 100 mil presos de 2007 para 2013, enquanto a taxa de mortalidade nesse período foi de 18,0 óbitos por 100 mil presos em 2007 e 16,0 óbitos por 100 mil presos em 20134.Em 2014, o Ministério da Saúde (MS) lançou a Política Nacional de Atenção Integral à Saúde das Pessoas Privadas de Liberdade no Sistema Prisional (PNAISP), instituída pela portaria interministerial nº 1, de 2 de janeiro de 2014, com o objetivo de ampliar as ações de saúde do Sistema Único de Saúde (SUS) para a PPL. Entre as múltiplas diretrizes do PNAISP, também foi incorporada uma linha de ação específica para o controle da TBDiante disso, é de extrema importância, além de quantificar os casos de TB na PPL, conhecer os fatores que permeiam esse contexto e que interferem na dinâmica do adoecimento e tratamento da doença. Os objetivos deste estudo foram: calcular a taxa de casos diagnosticados com tuberculose por unidades prisionais do Espírito Santo no período de 2014 a 2016, apresentar as características individuais, clínicas e institucionais dos casos de TB na PPL do ES no período de 2014 a 2016 e analisar a associação entre essas características e a situação de encerramento do tratamento da tuberculose na PPL do ES.5. Essas UP referem-se a estabelecimentos de regime do tipo provisório, fechado, semiaberto e misto, sendo excluídas delegacias ou similares.A população total do estudo foram os casos de tuberculose registrados na PPL do ES de 2014 a 2016, incluindo casos novos, recidivas, reingressos após abandono, transferência ou método de entrada desconhecido (“não sabe”). O ES possui 34 unidades prisionais (UP), que em 2014 abrigavam 16.234 presos, contabilizando uma taxa de aprisionamento de 417,9 pessoas privadas de liberdade por 100 mil habitantes, superior à taxa do Brasil, que é de 299,7 por 100 mil6 e na literatura acerca do tema. Sendo assim, o modelo teórico utilizado foi constituído pelos níveis e respectivas variáveis, conforme a As variáveis do estudo foram categorizadas em níveis hierarquizados construídos baseando-se nos modelos propostos por MacielA variável de desfecho estudada foi a situação de encerramento do tratamento da tuberculose, classificada pelo Programa Nacional de Controle da Tuberculose como cura, abandono, óbito por tuberculose, óbito por outras causas, transferência, tuberculose multidrogarresistente, mudança de esquema, falência e abandono primário. No modelo logístico hierarquizado, essa variável foi reclassificada em sucesso (cura) e insucesso (demais categorias).5, além de bancos de dados e relatórios das secretarias de saúde e de justiça do ES, armazenados em uma base de dados única para análise estatística.Os dados utilizados foram extraídos do Sistema de Informação de Agravos de Notificação (SINAN) e do Levantamento Nacional de Informações PenitenciáriasNa análise estatística foi realizado o cálculo das taxas de diagnóstico com TB por unidade prisional do ES. Para esse cálculo foram considerados somente os casos diagnosticados durante o encarceramento, excluindo-se os casos de transferências e método de entrada desconhecido (“não sabe”). Em seguida realizou-se a análise descritiva dos casos na PPL do ES, segundo as variáveis estabelecidas nos níveis e categorizadas de acordo com a situação de encerramento da TB.A regressão logística foi utilizada para calcular as razões de chances (RC) brutas e ajustadas e respectivos intervalos de confiança de 95% (IC95%). Na análise multivariável, foi empregado o modelo hierarquizado definido de acordo com os níveis estabelecidos. Inicialmente, as variáveis associadas com o desfecho de interesse  foram incluídas no modelo, a fim de considerar a inclusão de possíveis variáveis de confusão. Na etapa de modelagem, as variáveis independentes foram incluídas a partir do nível distal até o proximal. Foram mantidas em cada nível hierarquizado e no modelo ﬁnal as variáveis com p < 0,20 para ajuste. No modelo final, adotou-se o nível de significância de 5% para determinação das variáveis associadas ao insucesso do tratamento.6. As análises estatísticas foram realizadas no programa R na versão 3.4.1.Modelos hierarquizados são utilizados quando fatores distais influenciam fatores intermediários, que, por sua vez, influenciam fatores mais proximais, agindo diretamente no desfecho. Dessa maneira, este modelo permite incluir variáveis de acordo com sua ordenação temporal, mesmo que haja dependência das observaçõesEsta pesquisa foi aprovada pelo Comitê de Ética em Pesquisa da Escola Nacional de Saúde Pública Sérgio Arouca da Fundação Oswaldo Cruz (Fiocruz) sob o parecer nº 1.866.469 em 14 de dezembro de 2016.A taxa de casos de tuberculose diagnosticados nas unidades prisionais do ES de 2014 a 2016 variou de 0 a 17,3 casos por 1.000 presos. As unidades que não contabilizaram casos de TB eram em sua maioria localizadas em cidades do interior do estado e tinham taxa de ocupação inferior a 100%, enquanto o Centro de Triagem de Viana (CTV), que apresentou a maior taxa de diagnóstico, localiza-se na Grande Vitória e tinha taxa de ocupação acima de 200%. Outras características institucionais mostraram-se heterogêneas entre as unidades .Nos anos de 2014, 2015 e 2016, foram notificados no SINAN respectivamente 103, 91 e 106 casos de tuberculose na PPL do ES, totalizando 300 casos no período. Do total de casos na PPL, 218  se curaram, 21  abandonaram o tratamento, 1  morreu por tuberculose, 2  morreram por outras causas, 56  foram transferidos de local de tratamento e 2  desenvolveram TB drogarresistente.Esses casos foram avaliados quanto às suas características individuais, clínicas e institucionais  e categoOs casos foram em sua maioria homens, jovens (18 a 29 anos), da raça/cor parda e tinham de cinco a oito anos de estudo. Observou-se mais insucesso no tratamento entre as mulheres, nos indivíduos com a faixa etária de 30 a 39 anos e com um a quatro anos de estudo.Entre as comorbidades e agravos associados, o mais prevalente foi o alcoolismo, relatado em 24% dos casos, seguido da aids , diabetes  e doença mental . Nota-se que o insucesso do tratamento foi mais frequente entre os casos com aids e doença mental. O percentual de cura (sucesso) foi semelhante entre os indivíduos que faziam  ou não uso do álcool .O tipo de entrada mais observado foi o caso novo , assim como a forma pulmonar da tuberculose . Os casos de TB extrapulmonar mostraram menos sucesso no tratamento quando comparados aos pulmonares.Os exames de raios x foram em sua maioria suspeitos assim como os exames de baciloscopia e cultura de escarro foram positivos. Entre os que receberam o tratamento observado com medicação, observou-se um percentual de sucesso acima de 80%, enquanto este se aproximou dos 60% nos casos que não receberem a dose supervisionada.Quanto às características institucionais, nota-se que a maioria dos casos se encontravam em estabelecimentos provisórios, administrados pela gestão estadual e com taxa de ocupação entre 100,00 e 199,99%. A avaliação da estrutura física mostrou que prevaleceram os casos que estavam em instituições construídas para a finalidade de encarceramento, com estrutura ampliada de saúde , educação  e visita . Destaca-se também a presença de equipe de saúde ampliada diferenciada, composta por equipe de enfermagem, clínico geral, dentista, assistente social e psicólogo ou terapeuta ocupacional, ou psiquiatra, ou fisioterapeuta para 63,0% dos casos. A taxa de trabalho foi de 0,10 a14,99% nas unidades em que foram diagnosticados 65,6% dos casos de TB, e a taxa de educação mais predominante foi de 15,00 a 29,99%, representando 32,3% deles. Esses dados diferenciados por situação de encerramento (sucesso e insucesso) são detalhados na A Este estudo apresentou algumas limitações. Não foram incluídas variáveis que permitissem conhecer o tempo de privação de liberdade no momento do diagnóstico ou relativas à história pregressa de encarceramento, que poderiam influenciar principalmente no diagnóstico da doença, apesar de ainda serem escassos dados que mostrem alguma associação com o desfecho do tratamento. Além disso, pode estar subestimado o impacto da TB na PPL na carga geral da doença quando consideradas as situações em que os indivíduos a desenvolvem após sua soltura, embora tenham adquirido o bacilo durante o encarceramento. Sugere-se que sejam realizados outros estudos, que sejam capazes de avaliar essas questões.7. O fluxo estabelecido prevê que esses ingressantes permaneçam nessa unidade pelo prazo máximo de 48 horas até que seja realizada sua transferência, de acordo com perfil e situação jurídica, identificados por meio de um cadastro inicial. No entanto, esse prazo não é cumprido, sendo observada a permanência de presos por até 30 dias8.No período estudado, o CTV apresentou a maior taxa de casos diagnosticados para TB, com 17,3 por 1.000 indivíduos privados de liberdade. Destaca-se que o CTV possui características diferenciadas em relação às demais instituições, por se tratar de uma porta de entrada para o sistema prisional do ES e por isso apresentar altíssima rotatividade, com uma média de 690 ingressos a cada mês9, o que possivelmente contribuiu para a identificação do número superior de casos de TB no CTV comparado com as demais unidades. Além disso, quando esses indivíduos são transferidos para outras unidades, já foram triados inicialmente para TB. No entanto, apesar de o diagnóstico ser realizado durante o encarceramento, é importante refletir sobre o mecanismo de transmissão do bacilo da TB e seu tempo de incubação. A partir dos dados deste estudo, não é possível afirmar que a unidade prisional foi o local de contágio da TB, já que a pessoa privada de liberdade poderia já ser portadora do bacilo antes do encarceramento e ter apenas progredido para a doença ativa durante esse período. Dessa forma, embora não seja a fonte, o ambiente prisional teria contribuído para a evolução da doença3. Estudos genéticos poderiam fornecer uma melhor compreensão da dinâmica da transmissão de M. tuberculosis e esclarecer essa questão. O conhecimento das formas em que o microrganismo está disperso na população intra e extramuros é importante para as estratégias de prevenção e controle da doença10.Segundo o Protocolo de Controle de Tuberculose Pulmonar da População Prisional do ES, baseado nas diretrizes do MS, deve ser realizada a busca ativa de sintomáticos respiratórios por meio de um formulário de triagem específico aplicado no ingresso no sistema prisional11.Os casos de TB registrados na PPL do ES nos anos de 2014, 2015 e 2016 representaram respectivamente 7,5%, 6,1% e 7,8% do total de casos notificados. Em 2014, 8,4% do total de casos no Brasil foram encontrados entre a PPL, embora esse grupo representasse aproximadamente 0,3% da população total do país nesse ano12. As taxas de cura  e abandono  foram semelhantes às observadas neste estudo, porém os índices de transferência  foram superiores, o que pode ser explicado pela logística adotada pela Secretaria de Justiça do ES, que elegeu uma unidade prisional como porta de entrada para o sistema penitenciário, a partir da qual é realizada a alocação para as outras unidades.Segundo o MS, dados comparativos da situação de encerramento do tratamento da TB em 2015 mostraram para a PPL taxas de cura, abandono e transferência de 73,2%, 7,7% e 5,5%, enquanto na população em geral essas taxas foram de 71,0%, 9,8% e 5,0%, respectivamente13. Embora a taxa de mulheres presas tenha aumentado 10,7% ao ano de 2005 a 2014, os homens ainda são a grande maioria da PPL, sendo a média brasileira de 5,8% mulheres presas para 94,2% de homens5. No ES, os homens representaram 93,6% do total de pessoas presas em 20145, corroborando o alto percentual de casos de TB no sexo masculino observado neste estudo. No entanto, apesar de serem minoria, a pesquisa mostrou uma proporção maior de insucesso do tratamento nas mulheres  que nos homens . Uma pesquisa que avaliou a TB na PPL no Brasil de 2009 a 201411 mostrou que as mulheres privadas de liberdade apresentaram taxa de coinfecção pelo HIV  superior à taxa correspondente entre homens . Neste estudo a coinfecção estava presente em 28,6% das mulheres e em 5,5% dos homens, podendo contribuir de forma importante para o cenário de insucesso observado, ainda que associada a outras características.As frequentes transferências entre as unidades prisionais são uma importante causa de perda de seguimento; dessa forma, a comunicação entre os profissionais de segurança e saúde deve ser estabelecida de forma ágil e constante, visando a minimizar os casos de abandono de tratamento. É essencial que o prontuário de saúde acompanhe o paciente nas transferências entre as unidades prisionais. Além disso, o MS destaca que a mobilidade no sistema prisional aumenta o risco de adoecer por TB, haja vista a circulação entre as diferentes instituições penitenciárias, serviços de saúde e comunidade geral, durante e após o encarceramento6, sendo essa a faixa etária em que mais se registraram casos de TB no estudo (64%). Considerando a faixa etária mais ampla, de 18 a 39 anos, observam-se 90,7% dos casos registrados. Estudos anteriores mostram também o registro da maioria dos casos de TB na PPL na faixa etária de 18 a 39 anos , embora apenas 39,8% dos casos de TB sejam registrados nessa faixa etária na população em geral11. No ano de 2014, 25,6% dos casos de TB em homens de 20 a 29 anos registrados no Brasil estavam privados de liberdade11.Dados do Infopen mostram que aproximadamente 55% da PPL no Brasil tem de 18 a 29 anos de idade11. Os resultados apontaram um percentual maior de sucesso do tratamento para a forma pulmonar  que para a extrapulmonar . A realização do diagnóstico da TB extrapulmonar apresenta um grau mais elevado de dificuldade, visto que algumas formas apresentam sinais e sintomas inespecíficos e exigem exames diferenciados de acesso restrito à PPL, com consequente atraso do início do tratamento, podendo explicar esse achado13.A tuberculose extrapulmonar, observada em 9,0% do total de casos na PPL do ES, mostrou-se semelhante à registrada no país, de 8,2%14, de acordo com o observado na maioria dos casos notificados no estudo.A descrição institucional observada refere-se às características das unidades prisionais de localização do caso de TB no momento do diagnóstico e reflete o contexto prisional vivenciado no ES de uma maneira geral. Em 2016, a taxa de ocupação dos estabelecimentos prisionais no país era 197,4% e no ES era 144,7%, enquanto a taxa de presos sem condenação no Brasil era de 40,2% e de 42,3% no ES15. O ES atualmente apresenta índices de trabalho e educação entre os melhores registrados no país16. A construção de unidades ventiladas e iluminadas contribui de forma benéfica para a redução da transmissão de infecções respiratórias, conforme tratado pelo Manual de Intervenções Ambientais para o Controle da Tuberculose nas Prisões, que apresenta soluções de melhoria das condições ambientais para a preservação da saúde dos que frequentam o espaço prisional sem comprometer a segurança17.No ano de 2006, o sistema penitenciário do ES viveu superlotação, rebeliões violentas, homicídios e fugas, gerando a ausência de uma estrutura mínima que possibilitasse a gestão da segurança ou política de ressocialização. Sendo assim, em 2009, houve uma intervenção federal realizada pelo Conselho Nacional de Política Criminal e Penitenciária, o que motivou uma restruturação no sistema prisional do ES por meio da construção de forma padronizada de 26 unidades prisionais, que incluíam estrutura física para visita, educação, trabalho e saúde. A gestão estadual objetivou implementar políticas nas áreas de segurança e ressocialização, abrangendo assistência à saúde, oferta de estudo formal, capacitação e trabalho18, sendo ampliada para 100,0% no ano de 2018. Este estudo mostrou a importância da atuação da equipe de saúde para o sucesso do tratamento. A PNAISP, instituída pelo Ministério da Saúde em 2014, objetiva garantir o acesso das pessoas privadas de liberdade ao cuidado integral no SUS, como ponto de atenção da Rede de Atenção à Saúde (RAS). A PNAISP e suas portarias normatizam os tipos de equipes e financiamento dos recursos. A Equipe de Atenção Básica Prisional (EABp) apresenta composição multiprofissional, e sua modalidade e carga horária de atuação são determinadas pelo número de pessoas custodiadas e o perfil epidemiológico das unidades4.No que tange à saúde, a cobertura do Programa de Saúde Prisional no ES era de 75,2% em 201419. Uma pesquisa mostrou que o tratamento supervisionado reduz em 25% os desfechos desfavoráveis do tratamento da tuberculose, e que pacientes que não receberam o TDO foram mais propensos ao abandono do tratamento , óbito por TB  e resultados de tratamento desconhecidos 20. O TDO é preconizado pelo MS para a PPL, destacando como benefícios o fortalecimento do vínculo com o profissional de saúde, a garantia de acesso rápido ao serviço em caso de efeitos adversos pelo tratamento, o estabelecimento de barreiras para que a medicação seja usada como elemento de troca e pressão, a oferta de troca de informações e estabelecimento do cuidado, entre outros13.A realização do tratamento diretamente observado (TDO) mostrou-se associada ao sucesso do tratamento, reafirmando o efeito benéfico do TDO já demostrado em outros estudos13.Além dos aspectos já discutidos no artigo, o MS lista como principais obstáculos para a implementação de estratégias de controle no ambiente prisional: o desconhecimento sobre a TB pela PPL e profissionais de segurança que atuam nas prisões; a subvalorização dos sintomas da doença pela PPL, dificultando o diagnóstico precoce; a dificuldade de acesso da PPL aos serviços de saúde, assim como a escassez de recursos humanos e financeiros destinados a esses serviços; a baixa adesão da PPL ao tratamento e ações de prevenção; e a estigmatização e segregação geradas pela TB, considerando a importância da proteção pelo pertencimento ao grupoApesar dos desafios, o estudo mostrou que é de extrema importância buscar conhecer quais componentes influenciam no desfecho do tratamento da tuberculose na PPL, com vistas à implementação de ações que proporcionem a cura do tratamento e reduzam índices de insucesso. Conhecer as características que levam principalmente ao abandono contribui para interromper a cadeia de transmissão da doença e para sua prevenção, não somente entre a PPL, mas entre o grupo de familiares e trabalhadores que convivem com o ambiente prisional.


Molecules. On the one hand, I have now been involved with Molecules in one way or another since 1998, so it has been a feature of over 2/3 of my professional life. On the other hand, as I retire from the position—effective the end of the year—I am extremely pleased that MDPI has access to an outstanding superb pool of candidates and Prof. Farid Chemat , the current Green Chemistry Section Editor-in-Chief of Molecules, has kindly accepted MDPI’s offer to replace me, effective Jan 2021. I have no doubts whatsoever that under his guidance and with the help of the journal’s excellent editorial staff in the MDPI offices around the world, Molecules will go on to even more and better accomplishments. It is with mixed feelings that I put fingers to keyboard to write this, perhaps my last Editorial as Editor-in-Chief of Molecules and MDPI, seeking someone to help the then Editor-in-Chief of Molecules, Dr. Esteban Pombo-Villar, run what was one of the first ever online chemistry journals. Intrigued by this new technology, I responded and was soon working in my spare time as editorial assistant, a fancy name for a one person editorial office handling manuscript receipt, peer review layout and editing, while the founding editor handled the publishing and administrative tasks, uploading the journal to the server of the University of Basel which had kindly donated some network space to host it. That first year we published 74 papers and the Molbank section of Molecules was introduced, publishing one-compound-per-paper short notes. That section (a predecessor of the 28 or so current and past sections that now make up Molecules) would eventually become an independent journal with its own ISSN (1422-8599) in 2003. The first annual ECSOC e-conference (http://www.mdpi.org/ecsoc/) was also held this year. Little could I imagine when in 1998, I answered an online ad from Dr Shu Kun Lin, the visionary founder of IJMS and Entropy in 1999, Sensors in 2001 and Marine Drugs in 2003). Dr. Shu-Kun Lin took over as Editor-in-Chief of Molecules, replacing Dr. Pombo-Villar whose senior management duties with Novartis no longer allowed him to dedicate the necessary attention to the growing journal and I was formally appointed its Managing Editor, a position I would hold during the expansion of MDPI and the founding of the first formal MDPI editorial office to handle manuscripts in 2002. In 2005, the year Molecules celebrated its 10th anniversary, I was honored to be offered and accept the role of Editor-in-Chief.Those first few years I would also come to be the editorial assistant for other MDPI journals as they were launched  in Paris. Francis also ran several mirrors of the MDPI website (some still running today). A true Renaissance man , Francis was an fervent and tireless defender of the concept of free and open access to scientific content, chairing the Civil Society Scientific Information Working Group, and coordinating the patents, trademarks and copyrights workgroup at the United Nations World Summit on the Information Society in 2003. He also designed the global patronage pattern to answer the legal arguments raised against the global license under the Berne Convention. The last few years until his untimely and sudden death he was a consultant to the International Telecommunication Union (ITU) and the University of Geneva. His contributions to the modern scientific information world we now take for granted cannot be overstated and he is sorely missed by all who knew him. I would be remiss if I did not mention here our dear colleague Dr. Francis Muguet (1955–2009), who joined MDPI in 2001 as an Associate Editor for There have been many milestones that I have had the pleasure of witnessing in the ensuing years. The introduction of the automated manuscript submission and manuscript handling system (SuSy) in 2011, the same year MDPI took its first baby steps on social media with a Facebook page. The first 100 employees in the various editorial offices in 2012 (a number that would reach 1000 five years later and now stands at just over 3500) and the iPhone and Android app versions of the MDPI platform made available via the iTunes and Google Play stores. Our 6000th paper, published in 2014. The 10,000th one only two years later. The first Tu Youyou Award announced in 2016, our most prestigious prize, that joined our Best Paper and Travel Awards. The journal’s highest Impact Factor (3.098) for the year 2017 (the 5-year impact factor is 3.268). Our move to semi-monthly issues in 2019 to handle the sheer volume of papers being submitted and published, and finally, our 20000th paper published earlier this year . Molecules to a new colleague, I can truthfully state what I will miss most are the daily interactions with all the people involved, from my dear friend and colleague Dr. Shu Kun Lin, the founder of Molecules and MDPI, to our many authors and peer reviewers, readers and the Molecules Section Editors, the Managing Editors and Editorial Assistants from the MDPI offices around the globe with whom I have the honor of interacting all these years. I know I leave the journal in their very capable hands, and I can truly look back with admiration at our progress and say it has been a fun ride.While it may sound like a cliché, as I hand over the pleasure and honor of being Editor-in-Chief of                     Derek McPhee                    MoleculesEditor in Chief,


Population PKs and potential effects of PPL were then analyzed using NONMEM software. Lastly, these results were extrapolated from rats to humans using the allometric scaling and the liver blood flow method. PPL  exerts a statistically significant increase in DLX exposures at steady state, with a 20.2% and 24.6% increase in DLX Duloxetine (DLX) is a potent drug investigated for the treatment of depression and urinary incontinence. DLX is extensively metabolized in the liver by two P450 isozymes, CYP2D6 and CYP1A2. Propolis (PPL) is one of the popular functional foods known to have effects on activities of CYPs, including CYP1A2. Due to the high probability of using DLX and PPL simultaneously, the present study was designed to investigate the potent effect of PPL on pharmacokinetics (PKs) of DLX after co-administration in humans. A PK study was first conducted in 18 rats ( Propolis (PPL) is a resin-like material made by honeybees from the buds of poplar and cone-bearing trees and is used in beehive construction and maintenance. PPL has been used in traditional medicine for centuries worldwide ,2. A sigN-acetyl-p-benzoquinoneimine (an active metabolite of acetaminophen), which was produced by cytochrome P450 (CYP) enzymes [in vitro in a concentration-dependent manner [in vitro and in vivo have also been reported in our recently study [Previous literature has reported that PPL has protective effects against chemical-induced liver injury ,11,12. F enzymes . Changes enzymes ,14,15,16t manner . The inhDuloxetine (DLX), (+)-(S)-N-methyl-γ-(1-naphthyloxy)-2-thiophenrpropylamine, administered as duloxetine hydrochloride, is a potent and selective serotonin and norepinephrine reuptake inhibitor. This drug is used clinically in many countries for the treatment of disorders related to norepinephrine and serotonin, including major depressive disorder, diabetic peripheral neuropathic pain, and generalized anxiety disorder ,18. The Since only DLX has pharmacological effects, while all its circulating metabolites are inactive, any interaction resulting in a variation in DLX metabolism may alter its therapeutic effects, safety, and/or adverse events . Nowaday2 > 0.99). During the method validation, all the test results met the required criteria according to the U.S Food and Drug Administration (FDA) guidelines for bioanalytical method validation [Plasma concentration of DLX and 4-HD after a single oral dose of 40 mg/kg DLX or a single oral dose of 40 mg/kg DLX with 500 or 1500 mg/kg PPL in rats were determined using a high-performance liquid chromatography-tandem mass spectrometer (HPLC-MS/MS) method. The calibration curves established by plotting the peak area ratio vs. concentration were linear in the range of 5–1000 ng/mL for both of these two analytes (Rlidation . Individp < 0.000) on the fraction of 4-HD converted from DLX  changes and goodness of fit (GOF) plots. A summary of building steps for covariate models resulting in statistical significance in the OFV during the model development is listed in  as well as statistical methods . The predicted concentrations from 1000 simulated datasets using the final model for DLX and 4-HD after a single oral dose of 40 mg DLX and a variable dose of PPL in rats are shown in ) of DLX was 55.9 L/h and 1022 L, respectively. Following conversion, the predicted apparent total clearance  from zero to last time  and 2.6 h (from 12.7 to 15.3 h) when the drug was co-administered with PPL at doses of 5000 or 15,000 mg/day, respectively, comparing to when the drug was administered alone. Correspondingly, when DLX was administered once daily, the presence of PPL resulted in an increase by 11.6% and 28.0% in PK profiles of DLX and 4-HD after administration of multiple DLX 40 or 60 mg doses given once or twice daily co-administered with difference PPL doses  in the first day and at the steady state condition are illustrated in Drug interactions are one of the most common causes of medical adverse events. Therefore, evaluating potential drug interaction is an integral part of drug development. It is also important for making dosing recommendations for co-administered drugs. PK drug interactions may occur if a drug, a supplement, or food affects any one of the following four processes of another drug: absorption, distribution, metabolism, or elimination (ADME) ,30,31.PPL has been found to inhibit more than 50% activities of many enzymatic CYPs in a concentration-dependent manner, including CYP1A2. Changes in activity of CYP enzymes is thought to be a factor in interactions between supplements and drugs that may cause adverse events. While DLX has been reported to be a substrate of CYP450, the drug is rapidly and extensively metabolized by CYP1A2 and, to a lesser degree, metabolized by CYP2D6 to form multiple oxidative metabolites . Consequin vitro and/or PK profiles in preclinical species, utilizing both physiological and empirical approaches, are highly desirable [CL, Vd, and 1/2t, due to its simplicity [1/2t of DLX in humans was estimated to be 136 L/h, 2487 L, and 12.7 h, respectively. They are all in agreement with published literature [Approaches to predict human PK profiles from esirable ,37,38,39mplicity ,24,25,26mplicity ,41,42. Dterature ,45,46,47terature . In the terature .Up until now, there have been no official criteria for extrapolated data from animals to humans. However, the criteria that the prediction of PK parameters within the range of one-half and twice  of the observed data are determined to be acceptable predictions has been suggested and applied in many published studies ,48,49,50The absorption rate constant of DLX in humans was predicted based on the relationship between Given that DLX is acid labile, it therefore must be formulated with enteric-coated pellets to protect DLX from degradation in the acidic stomach environment by preventing DLX dissolution in the acidic stomach but allowing immediate release and rapid absorption at the small intestine. Consequently, after oral administration, there is a median 2-h lag time  exerts a statistically significant increase in DLX exposures at steady state, with a 20.2% and 24.6% increase in DLX ed alone . These rThe present study had some limitations. The inhibitory CYP1A2 effect of PPL on PKs of DLX was conducted in rats, followed by extrapolation into healthy human subjects directly. The extrapolation was conducted with the assumption that there are anatomical, physiological, and biochemical similarities among rats and humans. However, animal populations may not exactly represent human populations in these conditions. In addition, healthy subjects also may not well represent the patient populations. Therefore, to make future decisions about using a treatment combination of DLX and PPL, for instance, whether the combination should be avoided or patient safety should be monitored during co-administration in humans, future clinical studies should be conducted in diverse human populations, especially patients with liver or renal failures and patients treated with DLX. Importantly, as we mentioned above, the biological activities in PPL depend mainly upon the chemical composition of the constituents, which vary considerably depending on the type of plants accessible to the bees as well as the sites of collection. As the results of the drug interaction between PPL and duloxetine could be different depending on the major ingredients and its respective contents of PPL, its interpretation should be paid attention to.w/w). The PPL capsules contained only PPL extract from beehives of the honey bee without additives. PPL capsules were dissolved to 200 μg/mL in 0.1 M phosphate buffer (pH 7.4) containing 0.5% dimethyl sulfoxide (DMSO). Major ingredients in the PPL extract were then determined by a HPLC–MS/MS system as described in our previous report [PPL capsules were purchased from Natural Immix Health Ltd.  and Country Life Ltd.  and pooled at the ratio 1:1  and Santa Cruz Biotechnology , respectively. Carbamazepine, used as an internal standard (IS) for analyzing DLX and 4-HD, was purchased from Sigma Chemical .n = 6 rats/group). Each was orally administered the same DLX dose (40 mg/kg) and a different PPL dose . PPL doses in the present study were the equivalent amounts of natural PPL. Blood samples (0.3 mL) were collected in Vacutainer® tubes  at pre-dose (0 h) and at various predetermined time-points  post-dose. Samples were centrifuged; the plasma was then transferred to polyethylene tubes and stored at −70 °C until analysis.The present study was approved by the Animal Ethics Committee of Chungnam National University (no. CNU-00721). It was conducted in 18 SD rats divided into 3 groups . Separation was performed using an Atlantis C18  column operated at 40 ± 5 °C. The mobile phase was a mixture of methanol with 5 nM ammonium acetate at a volume ratio of 60:40 and a flow rate of 0.3 mL/min.DLX and 4-HD were extracted from the plasma by a liquid-liquid extraction method, followed by analysis with a validated HPLC–MS/MS method as described in our previous report . In detaiP is the parameter value for the ith individual, TVP is the typical population parameter, and iƞ (IIV) is the difference between iP and TVP that is assumed to be normally distributed with a mean of zero and a variance of ωƞ2. A proportional error model was applied to describe the residual random error (ε) that contains contributions from IIV, assay error, and model misspecification, as expressed by Equation (7):ij and Cijpred, present the jth observed and predicted concentrations for the ith individual, respectively; ε,ijpro is the proportional component that has normally distributed residual random effects with a mean of zero and a variance of σ2pro.PK analysis was conducted using a software package for nonlinear mixed-effects modeling  . The PK The proposed disposition compartment model for DLX and its metabolite, 4-HD, is schematically presented in The estimated population PK parameters for DLX were apparent oral clearance (p < 0.05) and stepwise backward elimination (p < 0.01) based on change in the OFV using a likelihood ratio test within NONMEM, as well as reductions in IIV of PK parameters, GOF plots, and precision of estimates. Effects of PPL on the metabolism of DLX were modeled using a Michaelis Menten equation. For example, the effects of PPL on Second, a covariate model to describe the possible effect of PPL on the PKs of DLX through its interaction with CYP1A2 was developed based on the base model. Covariate model building was accomplished by mixed stepwise forward addition  for all parameters to assess parameter uncertainty.Evaluation and selection of the models were based on graphical analysis as well as statistical methods. A nonparametric bootstrap analysis and a VPC were performed by simulating 1000 replicates each group using NONMEM. The final model assumed the same study design with same parameter estimates and their variances. Concentrations predicted from the VPC simulations were plotted against time for a 95% CI of the median, 5Vd of DLX and 4-HD in humans was extrapolated from the PK parameters in rats using a simple inter-species allometric scaling method [Y is the parameter of interest, W is the average body weight of a species, and a and b are the allometric coefficient and exponent of the equation, respectively. In the case of Vd, a fixed value of 1.0 was used for the exponent in the equation [Vd in humans was predicted from the rat PK parameter, as presented in Equation (11):Assuming that an adult human has an average body weight of 70 kg, g method ,24,25,26equation ,24,25,26CL) in humans was extrapolated from rats following a method described by Ward and Smith [CL is considered to be proportional to LBF. Accordingly, human CL was predicted following the Equation (12) below:LBF values for rats and humans are 85 and 21 mL/min per kg of body weight, respectively [Clearance  40 or 60 mg once daily and (2) 40 or 60 mg twice daily. For PPL, the supplement was co-administered with DLX at a total dose of (1) 0 mg, (2) 5000 mg, or (3) 15,000 mg of PPL per day. The potential effects of PPL on the PKs of DLX were assessed by comparing After a single oral dose of DLX 40 mg/kg in rats, PKs of DLX and its metabolite 4-HD were modeled well by a one-compartment disposition model with first-order absorption and first-order elimination. While the metabolism from DLX to 4-HD was described by both pre-systemic (first-pass effect) and systemic metabolic pathways, a Michaelis-Menten equation was used to model the CYP1A2 inhibition kinetics of PPL on the metabolism of DLX converted to 4-HD. The PK profiles of DLX, as well as the interaction of PPL with the PKs of DLX in humans, were successfully extrapolated from the corresponding PK parameters in rats by applying an allometric scaling method (for predicting volume of distribution), an LBF method (for predicting clearance), and other PK parameters in humans extracted from experimental literature, with the final developed population model in rats. In conclusion, at the DLX doses less than 120 mg, the presence of PPL exerts a statistically significant increase in DLX exposures but does not seem to exert clinically significant changes in the PKs of DLX, even at the maximum dose of PPL . At the maximum therapeutic dose of DLX (60 mg twice daily), safety issues are required to be attended to, and the possibility of interaction between DLX and PPL might be noted. Future studies further investigating these findings should be conducted in diverse human populations to provide a better representation.


Communication of goals and realistic expectations between the surgeon and patient is a crucial step of aesthetic rhinoplasty. Three-dimensional (3D) imaging technology allows for sharing of simulated outcomes in the office setting, thereby facilitating this process. This article highlights the use of 3D rhinoplasty simulation in preoperative assessment and the senior author’s preferred surgical technique in open rhinoplasty. Rhinoplasty can improve the appearance of the nose and its harmony with facial structures while optimizing nasal airflow. Common indications for rhinoplasty include congenital nasal deformity , facial/nasal trauma, dissatisfaction with nasal aesthetics , and difficulty breathing .Various techniques have been described to aid in preoperative planning. Three-dimensional (3D) rhinoplasty simulation is a useful adjunct tool that can aid in operative planning and communication of goals between the patient and surgeon. In this article, we demonstrate the use of preoperative 3D rhinoplasty simulation and the technical aspects of open rhinoplasty in a patient performed by the senior author.The patient is a 30-year-old woman who presented with dissatisfaction with nasal appearance and intermittent breathing difficulty. Physical examination revealed a low radix, dorsal hump, midvault deviation, over-projected nasal tip, slit-like nostrils, and S-shaped deviation of the septum. Inferior turbinates were enlarged bilaterally. An open rhinoplasty approach was planned.Preoperative 3D photogrammetry and rhinoplasty simulation were performed. Aspects of the surgery were simulated and discussed with the patient, including adjustment of tip projection, improvement of dorsal contour, and creation of a supratip break.The patient was brought to the operating room and prepped in a sterile fashion following anesthesia induction. A transcolumellar incision was performed, followed by exposure of the domes and midvault. A limited cephalic trim was performed bilaterally. The septum was accessed, and the upper lateral cartilages separated.The nasal dorsum was lowered using component takedown techniques. Dorsal irregularities were then rasped. The caudal septum was trimmed, and a septoplasty was performed leaving a strong L-strut. Endonasal high-low-high osteotomies were completed. The dorsal upper lateral cartilage margins were carved into 2 autospreader flaps. The spreader flaps and graft were placed into position. Bilateral turbinates were outfractured and coblated. A septal extension graft was placed on the right-hand side, and the tip position was secured. An infralobular tip graft was placed as well. Two articulating alar rim grafts were placed, and the medial crural feet were secured.1 The fat was then mixed with strips of crushed septal cartilage and the combination used as a dorsal onlay graft. Fat was also injected into the sidewall cheek border to alleviate bruising and swelling at the osteotomy sites.2 Kenalog was injected into the inferior turbinates, medial crural footplates, and medial canthal regions to reduce swelling. Incision sites were closed and dressing was placed. Further details on the intraoperative technique can be found in the video content (Video 1). Fat was harvested from the abdomen and processed by Telfa-rolling.The patient was seen for follow-up suture and splint removal at 1 week, and then regular intervals afterward. Typical postoperative care and recommendations were employed. Follow-up images in the video content were provided from 10 weeks postoperative. Three-dimensional analysis demonstrates improved Goode’s ratio, nasolabial angle, and nasofrontal angle postoperatively .4 Requests by the patient to perform multiple modifications or excessive changes on simulation may suggest an underlying body dysmorphic disorder that could contribute to persistent dissatisfaction with appearance following surgery.5 Limitations of 3D simulation include setup costs (equipment and software), pixilation, and simulation limitations on certain views . Three-dimensional technology involving radiography rather than 3D photogrammetry may involve radiation risk to the patient.Three-dimensional rhinoplasty simulation can facilitate communication between the surgeon and patient and help ensure that goals are aligned between both parties. In this process, it is important for the surgeon to display simulated results that are biologically attainable. Proficiency in the technique allows for consistent production of results that do not exceed the actual outcome, thereby preventing false expectations by the patient.7 Several grafts were used to support the tripod complex. The septal extension graft is a powerful technique that improves tip projection and rotation by serving as a secure point of the tripod.8 The graft can create a supratip break when placed at a step off  from the caudal edge of the septum. The articulated alar rim graft is a modified form of the traditional alar rim contour graft that is sutured to the tip complex, rather than free floating in a soft tissue pocket.9 This technique improves upon the possibility of a shrink wrap-like contracture that may occur in the traditional alar rim graft.10 When secured to the caudal septal extension graft and lateral crura, the articulated alar rim graft provides strength to the tripod complex as displayed in the video.A variety of rhinoplasty maneuvers were employed to improve nasal appearance in the presented patient. The high nasal dorsum and tension tip, as well as a short upper lip, were among the patient’s most distressing complaints. A caudal septal trim, tongue-in-groove, and dissection to the anterior nasal spine were performed to correct the tension tip, lip length, and aesthetics at subnasale.11 Septal cartilage is often used in crushed cartilage grafts due to its ease of harvesting during rhinoplasty. When mixed with prepared fat as performed by the senior author, the adipose tissue may serve as a scaffold for cartilage placement as well as further smoothen minor defects in dorsal contour. A limitation of this technique is related to patients with a paucity of septal cartilage, as in the case of revision rhinoplasty patients.Crushed autologous cartilage dorsal onlay grafts are a relatively new technique associated with improved dorsal irregularities and contour and high patient satisfaction.2Finally, harvested fat was injected into the sidewall cheek border/osteotomy sites. This has been shown to reduce postoperative edema and ecchymosis following open rhinoplasty.Preoperative 3D rhinoplasty simulation can foster communication of goals and expectations between the patient and surgeon. The video demonstrates modern rhinoplasty maneuvers, including caudal septal trim, septal extension graft, and articulating alar rim grafts. Crushed cartilage mixed with autologous fat is introduced as an approach to smooth and augment nasal dorsal contour. Autologous fat injections are also used, which has been shown to reduce postoperative edema and ecchymosis and enhance the aesthetic result.


We reconstruct 2D and 3D stiffness distributions in bilayer agarose hydrogels and silicon materials that exhibit heterogeneous displacement/strain responses. We map stiffness in porcine and sheep articular cartilage deep within the bony articular joint space in situ for the first time. Elevated cartilage stiffness localized to the superficial zone is further related to collagen fiber compaction and loss of water content during cyclic loading, as assessed by independent T2 measurements. We additionally describe technical challenges needed to achieve in vivo elastography measurements. Our results introduce new functional imaging biomarkers, which can be assessed nondestructively, with clinical potential to diagnose and track progression of disease in early stages, including osteoarthritis or tissue degeneration.Tissues and engineered biomaterials exhibit exquisite local variation in stiffness that defines their function. Conventional elastography quantifies stiffness in soft  tissue, but robust quantification in stiff  tissues is challenging due to dissipation of high frequency shear waves. We describe new development of  The ability to capture the health and structure of a tissue, manifesting as microscale stiffness, represents a potential functional imaging biomarker with significant clinical utility for diagnosis of disease and repair.The stiffness of a tissue, or its ability to resist deformation when subjected to an applied force, is associated with the structure of the extracellular matrix, a dynamic and biological aggregate of macromolecules that help to regulate the phenotype, expression, and differentiation of embedded cells. Abnormal stiffening or softening of tissue is often a functional hallmark of the pathologic, regenerative, or aging state in most organs in the body, including stiffening in liver fibrosis6 that often leads to pain, disability, and total joint arthroplasty. An unmet medical challenge is the diagnosis of early OA7, when emerging disease-rectifying therapies may be most effective8. However, conventional diagnostic methods for OA are largely insensitive to subtle morphological changes, and only reliably detect advanced OA9. Bulk softening of articular cartilage, attributed to the structural deterioration of the superficial collagen network, altered permeability, and depletion of proteoglycan content, has been linked to early degeneration in OA13. Local structural changes in the tissue, such as cartilage degradation differences through the  thickness, and among regional (e.g. anterior/posterior or load-/non-load-bearing) locations, present an opportunity to noninvasively probe tissue mechanical function and stiffness via imaging. Functional monitoring may be conducted spatiotemporally, especially between superficial and middle zones of cartilage, and may further assist in the design and in situ monitoring of engineered constructs post implantation14. Unfortunately, no conventional methods exist that enable noninvasive stiffness measurements of cartilage within the intact joint space.The stiffness of tissues often changes during degeneration or pathology. In the articular cartilage lining the bony ends in our joints, softening and volumetric loss is a hallmark of osteoarthritis (OA), a degenerative joint disease that affects millions of people in the United States alone15 or indentation16, and high-frequency ultrasound17, have demonstrated the ability to measure mechano-acoustic properties of ex vivo cartilage and revealed its relationship with tissue degradation. However, the weak scattering signals obtained from cartilage and the significant attenuation of the high-frequency ultrasound remains a challenge for imaging within intact joints7. Traditional magnetic resonance elastography (MRE), which is accomplished through synchronized imaging with shear wave excitation18, is able to map the mechanical properties of cartilage explants in vitro20. However, due to the large attenuation of high frequency waves required to probe stiff cartilage  from the underlying subchondral bone of the articular joint21. In addition, unknown  boundary conditions of contacting tissues in the body further complicate measurements. For example, analysis of a separate musculoskeletal tissue, the nucleus pulposus in the intervertebral disc of the spine, demonstrated that shear properties were highly dependent on boundary and preload conditions, chosen frequency range, and wave signal-to-noise ratio (SNR)22. Similarly, articular cartilage contacts numerous complex  boundaries within the native joint space, variable stiffness and preload properties, and consequently reliable elastography strategies are unclear.Elastography provides a spatial map of mechanical quantities, including strain fields and elastic properties, using noninvasive (e.g. often imaging-based) tools to assess intra-tissue mechanics. Current elastography methods based on ultrasound, such as ultrasound elastomicroscopy24. Unlike high-frequency shear wave propagation in MRE, dualMRI utilizes physiological magnitudes of mechanical loading to mimic the walking cycle (e.g. compression magnitude and frequency) and ensure the mechanical stimuli propagate through the cartilage to closely mimic in vivo conditions. By acquisition and analysis of phase contrast data, displacements and strains can be computed with precision on the order of 11 μm and 0.1%, respectively, i.e. approaching the cellular scale25. dualMRI has been applied to investigate the strain pattern of human articular cartilage in vivo26, explanted human and bovine cartilage25, and intact joints and intervertebral discs27. Compared to shear wave based MRE, elastography that utilizes finite deformations imaged by dualMRI does not require wave propagation and specialized gradient coils, and therefore provides a means to study stiff cartilage.In order to directly measure displacement- and strain-based elastography in joint cartilage, we exploit a technique developed in our laboratory termed dualMRI (displacements under applied loading by MRI), which measures tissue deformation under exogenous mechanical loadingfinite deformation elastography, to quantify stiffness in tissues and biomaterials, with a particular emphasis on articular cartilage and analog hydrogels and biomaterials. We utilize a new combination of dualMRI and topology optimization to provide a general framework capable of broad applicability in numerous materials, and in two- and three-dimensional (2D/3D) configurations of material complexity and heterogeneity. We describe development, validation, and application of steady-state, physiological-magnitude cyclic loading to extract the displacements, followed by inverse modeling to estimate relative stiffness maps.Our objective was to establish and test a workflow, termed Finite deformation elastography, based on dualMRI and topology optimization, allowed for inverse calculation of stiffness in cartilage tissues and biomaterials Fig. . Image amm added to the ideal displacement, similar to noise observed in MRI data, the algorithm was still able to reconstruct a bilayer pattern. Moreover, the stiffness calculation was robust to increasing noise levels from the MRI acquisition  parameters Fig. . This emStiffness distributions were reliably reconstructed in materials with complex stiffness abnormalities, including (stiff) circular inclusions, gradients of elastic properties, or soft, slender inclusion Fig. . AdditioStiffness distributions were reconstructed in bilayer hydrogels and silicone materials, in both 2D and 3D Fig. , and proT2 values in the superficial region that corresponded to regions of elevated stiffness , and are more broadly representative of a wide range of tissues and materials exhibiting gradient and nonuniform stiffness distributions. Moreover, our validation studies revealed that inverse modeling was robust to increasing noise levels. Taken together, the hybrid combination of imaging and topology optimization represents an effective means to reconstruct unknown interior stiffness distributions of complex materials based on noninvasive imaging.Validation studies revealed that our approach was able to reconstruct heterogeneous stiffness distributions, including a bilayer configuration of hydrogels and silicone materials, and in materials with stiff circular and soft slender inclusions. These patterns specifically mimicked different stiffness patterns that could exist in healthy and diseased tissues like articular cartilage  decay. To improve the smoothing technique, we filtered the noise in displacement data using LOWESS, which demonstrated better localized fitting of noise compared to Gaussian fitting27, especially at material edges. Monte Carlo simulation of smoothing techniques showed a smaller bias and precision using LOWESS smoothing. Moreover, the calculated bias of 0.092 and precision of 0.066 were approximately 18% and 13.2%, respectively of the average relative stiffness  indicated that the noise level and the smoothing technique were the most significant factors impacting the technique error. To improve the SNR of the dualMRI system, the number of averages can be used at the cost of longer total imaging time. SNR could additionally be improved by minimizing the loading time to rapidly capture the encoded prior to signal loss, which follows an exponential sec relaxation to be 23 kPa and 112.7 kPa respectively (1:4.9 ratio)27. In both stiffness bi-layer configurations, the inverse-calculated stiffness ratio was close to the bulk testing results. Specifically, the 1:2.0 ratio derived from soft top – stiff bottom configuration was closer to the instantaneous modulus ratio of 1:2.3 than the stiff top – soft bottom configuration. This could be due to the error of the plane stress assumption, since this was a 3D cylindrical gel fixed at the bottom but unconfined at the side. In that way, the out of plane constraints behaves differently in bottom and top and might cause the ratio of stiffness to be different in these two reversed configurations. Besides, the cylindrical indenter should align well with the gel center in ideal scenario, but any error could generate a bias for through-thickness differences. The 3D indentation case showed that with the acquisition of multiple slices of displacement data, it was possible to reconstruct the stiffness distribution without the 2D assumption. Consequently, our workflow was not constrained by complex geometries. Potentially, since topology optimization can also be utilized in contact problems, it is possible to calculate relative stiffness in multiple objects in contact, like the femur and tibia cartilage.Finite deformation elastography successfully reconstructed the bilayer pattern of stiffness in hydrogels and biomaterials. In 2D studies, the stiffness ratio between top and bottom layer were calculated to be 1:2.0 for the first case with 2% layer on top and 1:3.1 for the latter case with 4% on top. As a comparison, an unconfined compression test measured the instantaneous modulus at largest stress of 2% and 4% agarose gels to be 74.6 kPa and 173.4 kPa respectively (1:2.3 ratio), and equilibrium modulus after 30 38 utilizing (1) a forward elasticity problem and finite element analysis, and (2) iterative updates to the stiffness distribution by minimizing the measured displacement distribution. Compared to these techniques, our topology optimization-based method is more computationally efficient and can accommodate different constitutive models including linear elasticity and hyperelasticity, as well as material anisotropies , only a single slice was acquired using dualMRI. Additionally, repeated loading of the cartilage surface was advantageous in our case as it led to collagen fiber compaction and reorientation representing the material response to physiologically-relevant loading, and a stiffer superficial layer40. Cyclic loading before imaging , and during imaging, likely led to lateral tissue deformation and fluid flow, particularly in the superficial zone, further exasperating collagen densification after cyclic loading41. The loading and flow resulted in compaction as a temporary change, similar to what may be expected during a walking cycle, which would be restored by Donnan equilibrium after cyclic loading is ended. Our observations of a stiffer superficial layer, and assumptions of fiber compaction and water loss, were supported by decreased T2 magnitudes in the superficial layer after loading44. Additionally, while cyclic loading was acquired over a long total experimental time, the loading rate within any cycle was considered rapid (0.3 sec to reach one-times body weight), and a nearly incompressible behavior was assumed. Importantly, the compressibility assumption in our workflow relates to potential errors in estimates for mechanical parameters  and additional in situ studies on the effects of preconditioning of healthy and degraded tissue are required. Additionally, finite deformation elastography can be extended to other load-bearing and stiff biomaterials of the musculoskeletal system, including intervertebral disc and ligament.Our in situ, deep within the bony contacting interface of porcine and sheep joints.Finite deformation elastography is based on dualMRI to measure displacements during cyclic loading and topology optimization to calculate internal patterns of stiffness. To develop and validate our workflow, we evaluated how displacement maps determined by experiment or simulation, with predefined stiffness distributions, were used with topology optimization to reconstruct stiffness values. We further evaluated how the sensitivity of a broad space of independent variables (e.g. levels of random noise) influenced method robustness, and to understand how error propagates through the calculation workflow. Using finite deformation elastography, we measured stiffness in unique hydrogel and material model systems in two and three dimensions, and for the first time in cartilage 39. The DENSE sequence sensitized the phase data Δφ to changes in displacement, Δx, according to:xyz displacement encoding, and 45. The whole displacement measurement included phase mapping, phase unwrapping to calculate raw displacement, and displacement smoothing as described previously 37 and optimization software 39, to iteratively update the stiffness of each element representing the material as described . Briefly, the stiffness of each element was associated with a relative density parameter ρk, and the material properties of a given material 49:In our elastography workflow, instead of maximizing the structure stiffness, as is used in traditional applications, we minimized the maximum value of the absolute difference between the measured material deformation and the deformation of a base model at nodes indicated as k. In this study, if not specified, a linear elastic model with Poisson’s ratio 0.49 was used. Because we utilized a displacement boundary simulation, a random Young’s modulus 500 was chosen. For element types, CPS8 was used for 2D meshes, and tetrahedral element C3D4 and brick element C3D8 were used for 3D meshes. A mesh density of 0.6 mm was usually chosen to demonstrate the stiffness heterogeneity and at the same time to keep the computational cost low.Instead of penalizing the density results to reach a 0 (void) to 1 (solid) range, we set the mm. In our finite element models, displacements in all coordinates were predefined at all pixels at boundaries.Following determination of displacements, 2D and 3D models were established using the location of each pixel in the model or sample (MATLAB), and Delaunay triangulations were created to connect each pixel. The boundaries of the model were automatically identified with positive area or volume triangulation, and with a dimension not shorter than 0.5 mm was created . Considering the rapid (0.3 sec) loading ramp and the large water content of the real cartilage, fluid permeation is very minimal by Darcy’s law25 and nearly incompressible behavior (Poisson’s ratio = 0.49) was assumed27. With the bottom edge of the model fully constrained, the top edge was indented to 15% of the thickness, and displacements were calculated, with linear elasticity and plane stress assumptions. To analyze the robustness of the algorithm against noise, different levels of noise were applied and the average stiffness of two layers were calculated  constitutive laws, Poisson’s ratio, 2D assumption, and optimization values. In this analysis, Gaussian smoothing and LOcally WEighted Scatterplot Smoothing (LOWESS) were compared and the analysis provided a ranking for each factor by its impact to the final output.We ranked the model input parameters based on their influence on the model output using a sensitivity analysis (Cotter’s method)mm), were determined from displacement-encoded MRI data27. Within each iteration of the Monte Carlo simulation, experimental level Gaussian random noise (standard deviation = 0.1 mm) was added directly to the ideal displacement not only the internal pixels but also pixels at boundaries. By repeating the random noise generation and inverse simulation for 100 times50, different stiffness maps were reconstructed. Precision was defined as the pooled standard deviation of respective stiffness from all elements between the reconstructed map and the distribution from the ideal model. Bias was calculated by determining the root mean square error of the stiffness value.To analyze the stiffness error (defined by precision and bias) of the whole elastography procedure, we applied Monte Carlo simulations. The pixel number, model dimensions, and data noise  and 4% (stiffer) w/v agarose was mixed in PBS and cured to create uniform and layered constructs with a 6 mm total height, and 10 mm diameter cylindrical implants. There were two gels made to test the stiffness reconstruction accuracy: one gel had 2% agarose (soft) on the top with 2/3 thickness and the second gel was created with 4% agarose (stiff) on the top with 1/3 thickness. In a separate silicone model system, polydimethylsiloxane (PDMS) 38 was used to create a bilayer gel with a 1:2 mix ratio (Sylgard 527) in the top (soft) layer, and a 1:50 mix ratio (Sylgard 184) in the bottom (stiff) layer. These materials allowed us to establish baseline deformation and noise levels commonly observed in small materials or explanted tissues52  or 0.15 × 0.15 mm2 (silicone). For hydrogel samples, the target load was set to be 0.67 N and the gel reached indentation of 6% (configuration: 2% agarose on the top) and 4.6% (configuration: 4% agarose on the top) of the sample depth. As a two-dimensional case, plane stress was assumed for agarose gel and displacement data from the middle section was extracted. For silicone samples, to address the potential bias of the 2D assumption mentioned in the sensitivity analysis, inverse modeling was tested in three dimensions. To test the algorithm on experimental data, we applied 0.33 Hz frequency load to reach 15% indentation and collected the xyz displacement data from 13 consecutive slices . We note that the loading frequency was tuned for ramp loading , which resulted in a steady-state response56. As explained previously, the material was modeled as nearly incompressible material with Poisson’s ratio 0.49, considering the time duration needed to reach  one-times body weight in each loading cycle was only 0.3 sec. Additionally, because we observed a counterintuitive stiffening of the cartilage in the superficial zone (described subsequently), we also acquired an independent measurement of matrix structure using MRI T2 relaxometry mapping. T2 was determined at each volumetric region using monoexponential fitting of data from a multi-echo sequence with parameters: TE/TR = 10.04/4000 ms, number of averages = 1, rare factor = 2, echo spacing = 20.08 ms.To demonstrate finite deformation elastography in a challenging biological system, we measured stiffness in the articular cartilage of intact tibiofemoral joints. dualMRI data describing internal displacements of cartilage juvenile porcine jointsR2) was calculated using linear regression.One-way Analysis of Variance (ANOVA), followed by post hoc Tukey’s test was used to determine statistically significant differences between the groups. The coefficient of regression (Supplementary Information.