The P2X7 receptor (P2X7R) is a membrane receptor for the extracellular adenosine triphosphate (ATP). It functions as a ligand-gated non-selective cation channel and can mediate formation of a large non-selective membrane pore. Activation of the P2X7R induces multiple downstream events, including oxidative stress, inflammatory responses and cell death. Although the P2X7R has been identified in the retinal pigment epithelium (RPE) and different layers of retina, its biological and pathological functions as well as its downstream signaling pathways in the RPE and retina are not yet fully understood. Better understanding of the function of P2X7R in the RPE and retina under normal and disease states might lead to novel therapeutic targets in retinal diseases, including age-related macular degeneration (AMD). This brief review will mainly focus on recent findings on in vitro and in vivo evidence for the role of the P2X7R in the RPE and AMD. Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly in developed countries, affecting tens of millions of people worldwide. It has two forms: dry AMD (geographic atrophy) and wet AMD (neovascular AMD). The dry AMD is the most common form (80%–90%), while wet AMD is less common 10%–20%) and more severe. In dry AMD, small white or yellowish deposits, termed drusen, typically accumulate between the retinal pigment epithelium (RPE) monolayer and Bruch’s membrane, followed by RPE and photoreceptor degeneration 0%–20% an. In wet The P2X7 receptor (P2X7R), first discovered in immune cells  and thenThe P2X7R has been localized to different layers of retina and the RPE. The vertebrate retina is a structure of ten-layers from closest to farthest from the vitreous body: (1) inner limiting membrane (ILM); (2) nerve fiber layer (NFL); (3) ganglion cell layer (GCL); (4) inner plexiform layer (IPL); (5) inner nuclear layer (INL); (6) outer plexiform layer (OPL); (7) outer nuclear layer (ONL); (8) external limiting membrane (ELM); (9) photoreceptor layer; and (10) the RPE layer. The P2X7R has been detected in the human, monkey and rodent retina and localized to specific cell types and different layers of the retina. In the monkey retina, immunoreactivity for P2X7R was observed in the INL, IPL, and GCL. In the INL, horizontal cells were strongly immunopositive; in the IPL, fine processes were immunopositive; and in the GCL, the majority of ganglion cells were immunopositive . AnotherIn the rodent retina, the P2XR is widely expressed in both inner and outer retina. Retinal ganglion cells, amacrine cells, horizontal cells, microglia and photoreceptors all express P2X7R or functional P2X7R ,23,24,25Independent research groups have demonstrated that the P2X7R is expressed in the RPE at both mRNA and protein levels . The P2X−/− mice, a model of Stargardt’s retinal degeneration, when compared with control wild type mice . Ou. Ou65]. In summary, the P2X7R mediates AMD-like defects in several animal models of dry and wet AMD. Genetically knocking out P2X7R or pharmacologically inhibiting P2X7R can improve outcomes in these animal models.The recent findings have demonstrated the presence of the P2X7R in the RPE and different layers of retina. The P2X7R in the RPE and retina is functional in vitro and in vivo. This receptor mediates AMD-like defects in in vitro models of AMD and in animal models of both dry and wet AMD.In addition to acting as either an ion channel or a non-selective large membrane pore, the P2X7R mediates many biological effects such as oxidative stress, inflammation, and three modes of cell death: apoptosis, necrosis and autophagic cell death. Its expression is highly regulated. The function of the P2X7R is also determined by its polymorphisms, splice variants, and interacting proteins. Better understanding of the P2X7R’s functions and regulations in the RPE and retina under normal, aging and AMD conditions may lead to the development of novel preventive and therapeutic strategies for AMD.


Hearing function was evaluated by measuring the auditory brainstem response before VGCV treatment and at 6 months. Hearing dysfunction, defined as a V-wave threshold >40 dB, was categorized into: most severe, ≥91 dB; severe, 61–90 dB; and moderate, 41–60 dB. Hearing improvement was defined as a decrease of ≥20 dB from the pretreatment V-wave threshold. Of 52 ears in 26 infants with congenital CMV infection, 29 (56%) had hearing dysfunction, and of 29 ears, 16 (55%) improved after VGCV treatment. Although, 16 (84%) of 19 ears with moderate or severe hearing dysfunction improved after treatment (p < 0.001), 10 ears with the most severe form did not. In conclusion, VGCV treatment is effective in improving moderate and severe hearing dysfunction in infants with congenital CMV infection.Although earlier studies have shown that antiviral treatment regimens using valganciclovir (VGCV) improved hearing function in some infants with congenital cytomegalovirus (CMV) infection; its efficacy on the severity of hearing dysfunction is unclear. We conducted a prospective study among 26 infants with congenital CMV infections from 2009 to 2018. Oral VGCV (32 mg/kg/day) was administered for 6 weeks (November 2009 to June 2015;  SLC26A4 and GJB2, the latter most frequently originates from congenital cytomegalovirus (CMV) infection. A study in the United States (US) reported that congenital CMV infection accounted for 21% of congenital hearing loss [Congenital sensorineural hearing loss can be caused by hereditary or non-hereditary factors. Although the former is caused by gene mutations such as ing loss ,4,5. HowTo address these limitations, we decided to determine the therapeutic efficacy of oral VGCV monotherapy (32 mg/kg/day) by using a prospective design, comparing a 6-week regimen with a 6-month regimen, with a uniform timing of 6 months after birth for the post-treatment hearing assessment. To minimize confounders due to inter-rater error and methodology, we defined hearing improvement or deterioration more strictly as a respective decrease or increase of ≥20 dB in the wave V threshold of the ABR. Our objective was to conduct the first prospective study to determine if the efficacy of VGCV is dependent on the severity of hearing dysfunction in symptomatic infants with congenital CMV infection.n = 20; 6-month group, n = 6). n = 23, 88%) and abnormal ABR . Adverse events were observed in 11 children (42%); with neutropenia as the most common, affecting 10 (38%) of the subjects. Adverse events occurred in 10/20 (50%) and 1/6 (17%) of infants in the 6-week and 6-month group, respectively (p = 0.33). Neutropenia, which led to a temporary discontinuation of treatment was observed in 8 children (31%); 5 (19%) required granulocyte colony-stimulating factor (G-CSF), 3 (12%) continued at half-dosage (16 mg/kg/day), and 1 (4%) required the drug change to foscarnet. No infant with neutropenia developed any additional severe bacterial infection. Additionally, the blood and urine CMV loads were reduced from baseline by VGCV therapy in 25/26 infants (96%). At the end of treatment, residual CMV DNA was detected in the blood and urine of 3 (12%) and 6 (23%) infants, respectively. Both cases belonged to the 6-week group; neither viremia nor viruria was detected in the 6-month group .From 2009 to 2018, 26 symptomatic infants with congenital CMV infection received VGCV therapy at Kobe University Hospital , 29 ears (56%) were classified as abnormal , and 23 (44%) was considered non-abnormal . Based on the baseline ABR (p = 1.00); the hearing function was improved or maintained with the same degree in 22 (92%) of 24 abnormal ears in the 6-week regimen and 5 (100%) of 5 abnormal ears in the 6-month regimen. Furthermore, the hearing function was maintained in 14 (88%) of 16 non-abnormal ears in the 6-week regimen and 6 (86%) of 7 non-abnormal ears in the 6-month regimen. Hearing deterioration was observed in 4 children  across both groups; residual CMV was detected in the urine of 1/4, and the blood of 0/4.We compared the differences in therapeutic efficacy observed between the two VGCV regimens (6-week vs. 6-month), and found no statistically significant differences in efficacy as follows (p < 0.01 vs. most severe) and in 11 (85%) of 13 ears with baseline “moderate” hearing dysfunction (p < 0.001 vs. most severe). Out of 29 abnormal ears, 10 ears with the “most severe” form of hearing dysfunction at baseline did not show significant improvement (0%); however, hearing improved in 5 (83%) of 6 ears with “severe” hearing dysfunction , and neutropenia was observed in 10 38%). Kimberlin et al. observed neutropenia in 29/46 (63%) of their cohort treated with IV GCV %, and ne. However%. KimberThe study by Bilavsky et al.  showed oVGCV treatment duration was not associated with differential treatment effects in our cohort. Kimberlin et al.’s study in 2015 , a randoIn our cohort, whereas hearing function improved in 84% of ears with “severe” or “moderate” impairment at baseline, no such reversals were observed among ears rated “most severe” (0%). A lot remains uncertain about the pathogenic mechanism of congenital CMV infection-induced hearing loss . However(1)Treatment duration was modified midway through the study period in July 2015, from 6 weeks of oral VGCV (32 mg/kg/day) to 6 months. However, ethical considerations about choosing the optimal treatment option for our patients dictated this decision, based on the evidence presented by Kimberlin et al. in 2015 supporting the superiority of 6-month versus 6-week regimens of VGCV . As indi(2)Our decision to measure our main outcome at 6 months after birth could only capture the relatively short-term effects. It is critical for future studies to pursue longer-term follow-up; this would enable the assessment of any deterioration or progressive deafness. However, we achieved our original goal of assessing VGCV’s effects at a consistent time point for all patients. Hearing assessments during long-term follow-up can be affected by other factors besides CMV infection, such as otitis media. Therefore, we believe our choice of 6 months after birth as the assessment time point was appropriate for focusing on VGCV’s efficacy in treating congenital CMV infection.(3)Despite the impressive length of our study, spanning around 9 years, our subgroups were relatively small after classifying them by hearing severity. We consider this final limitation as characteristic of any single-center prospective studies for this subject with congenital CMV infection.Our study had several limitations:From November 2009 to March 2018, a single-center prospective study was conducted at Kobe University Hospital to investigate the efficacy of VGCV treatment on hearing dysfunction in infants with symptomatic congenital CMV infection. Because antiviral treatment is off-label for congenital CMV infection, we fully explained the risks and benefits of its use to the legal guardians of each subject, and their written consent was obtained before starting treatment. All subjects with congenital CMV infection were authorized to undergo VGCV therapy. This study was conducted in accordance with the Declaration of Helsinki, and the protocol was approved by the Ethics Committee of Kobe University Graduate School of Medicine (no. 1214). (1)A positive result of a filter paper-based screening to detect CMV DNA in urine, a method developed previously by our team  or a pre(2)a positive result of real-time quantitative PCR for CMV DNA in the urine as a confirmed diagnosis, as previously established . DiagnosCongenital CMV infection was definitively diagnosed based on the following methods:Following a confirmed diagnosis, symptoms were determined based on the findings of the physical exams, hematological testing, chest X-rays, abdominal ultrasound, fundoscopy, ABR testing, and brain imaging . Congenital CMV infection was considered “symptomatic” if one or more of the following symptoms were present: microcephaly, hepatosplenomegaly/hepatitis, thrombocytopenia, brain imaging abnormalities, eye complications such as retinal choroiditis, and abnormal ABR ,17,18. M6 white blood cells, with a negative cut-off of 1 × 102 CN/106 white blood cells. CMV DNA in urine was expressed in terms of CN/mL, with a negative cut-off of 3 × 103 CN/mL [Using a previously reported method , DNA was03 CN/mL .ABR was measured using the Neuropack S1 system . First, we tested the ability of the stimuli at amplitudes 90 dB, 60 dB, and 30 dB to evoke ABR. Hearing status was classified as “normal” if the auditory stimulus evoked a detectable wave V at 30 dB. However, if wave V was undetectable at a given loudness, the test was repeated with a stimulus 10 dB higher in amplitude. The wave V threshold was defined as the lowest amplitude to evoke the ABR. Based on the classification of the Japan Audiological Society, hearing dysfunction was defined as a V-wave threshold and categorized as: most severe, ≥91 dB; severe, 61–90 dB; moderate, 41–60 dB; 31–40 dB, mild; and normal, ≤30 dB. The abnormal ears were classified as: most severe, severe, or moderate for analysis; while the non-abnormal ears were classified as mild or normal .3) is a common side effect of VGCV [Symptomatic infants with congenital CMV infection were hospitalized for the first 6 weeks of VGCV therapy to monitor drug effects and adverse events. Depending on their conditions, the patients were released to continue treatment in an outpatient setting after 6 weeks. The subjects enrolled from November 2009 to June 2015 were administered 6 weeks of oral VGCV 32 mg/kg/d), while those enrolled from July 2015 onward were administered the same dose for 6 months 2 mg/kg/d,8. The iWave-V threshold was determined before the start of treatment (baseline) and 6 months after birth using the method mentioned above. Hearing improvement/exacerbation was defined as a ≥20 dB decrease/increase in this value from baseline to the sixth-month time point; hearing maintenance was defined when the wave-V threshold was the same, or the change was within 20 dB . Our primary outcomes were the improvement rates in the abnormal ear group and each severity group of hearing dysfunction at baseline. Our secondary outcome was the rate at which hearing was maintained in the non-abnormal ear group.p < 0.05 was considered significant.Data were organized in 2 × 2 contingency tables and statistically analyzed using Fisher’s exact test. We concluded that VGCV treatment for either 6 weeks or 6 months is effective in improving hearing dysfunction and maintaining the hearing degree in infants with congenital CMV infection, except for those with the most severe form. Subsequently, further studies using multiple center-based prospective cohorts will be needed to confirm our results.


Hearing preservation is a major goal in the treatment of neurofibromatosis type 2 (NF2) associated vestibular schwannoma (VS), particularly in children and adolescents. In this study, we retrospectively reviewed hearing and volumetry data sets of 39 operated tumors (ears) in 23 patients under the age of 25 and in a follow-up period of 21 to 167 months. Hearing data over a compatible period on 20 other tumors, which did not receive surgery due to their less aggressive nature, were included for comparison. Surgery was carried out via a retrosigmoid approach with the brainstem auditory evoked potential (BAEP) guide. Immediately after surgery, functional hearing was maintained in 82% of ears. Average hearing scores were better in the non-surgery ears. However, the hearing scores in both groups worsened gradually with a similar dynamic during the 42-month postoperative follow-up period. No accelerated impairment of hearing was evident for the operated cases. Rather, the gap between the two hearing deterioration lines tended to close at the end of the follow-up period. Our result suggested that the BAEP-guided surgery did not cause additional hearing deterioration in the long-term and seemed to slow down hearing deterioration of those tumors that were initially more aggressive. NF2 tumor-suppressor gene on chromosome 22q12 [Neurofibromatosis Type 2 (NF2) is a rare autosomal-dominant tumor predisposition syndrome, with a prevalence of 1:56,000, an incidence of 1 case in 33,000 to 40,000 live births per year [me 22q12 ,8. Genotme 22q12 ,10.Due to the bilateral nature of VS in NF2 patients, hearing preservation is extremely important to prevent total deafness, especially for young patients. For hearing preservation, several strategies have been proven to be effective for NF2-associated VS—(1) partial resection mainly for decompression of the internal auditory canal and (2) electrophysiological guidance with brainstem auditory evoked potential (BAEP) and motor evoked potentials (MEP) of the facial nerve, by experienced interpreters ,12,13. NThe aim of this study is to investigate the hearing function before surgery, immediately after surgery, and in the years following surgery, in young NF2 patients under 25 years of age, during diagnosis. Furthermore, confounding factors such as tumor volume and mutations are also investigated.Detailed clinical and demographic data are provided in Partial resection was achieved in a majority of the tumors—32/39; 82%. We did not record any major surgical complications in the short- and long-term follow-up  other than deterioration of hearing or facial nerve function. Minor complications directly after surgery occurred in 8 cases, such as wound healing disorders (2/8) and severe neck pain/headache (6/8) and could be successfully treated conservatively.Facial nerves function was preserved in 37/39 (95%) tumors. In two cases, an improvement from the House–Brackmann Classification System (H–B) grade II to I was achieved by surgery . 3 versus 1.6 ± 2.0 cm3 (p = 0.027) and 66% ± 38% versus 38% ± 32% (p = 0.024), respectively.Seven resections resulted in postoperative deafness . HoweverFor 32 (82%) ears, functional hearing could be preserved after surgery. Slightly significant reduction in pure-tone average (PTA) and in the speech discrimination score (SDS) was measured, which, however, were functionally not relevant . One earPreservation of the preoperative hearing grade could be achieved in 29 (74%), 28 (72%), and 24 (62%) ears, with regards to the Gardner and Robertson Scale (G–R), American Association of Otolaryngology–Head and Neck Surgery (AAO–HNS) and the BAEP classification, respectively. Three (8%) ears improved in BAEP. A better preoperative G–R grade correlated with a higher preservation rate in the same grades—81%, 50%, and 33% for grade I, II, and III, respectively.Three bony decompression surgeries without tumor resection resulted in hearing preservation. One subtotal resection led to a BAEP drop from 2 to 5. All other subtotal and near total resections were in ears with poor preoperative BAEP scores of 4 and 5. Interestingly, the only total resection  resulted in a hearing preservation with a BAEP remaining in score 1. The majority (32) of resections were partial with various outcomes of hearing .Correlations of the additional parameters with postoperative hearing are summarized in p < 0.05) in a similar dynamic over the 42-month postoperative follow-up period. No accelerated hearing deterioration was evident for the operated cases, despite a worse hearing starting point; instead, the gap between the decreasing lines in the two groups tended to close at the end of the follow-up period  hearing deterioration became similar in cases with and without surgery. The variation of hearing deterioration was large but equal in both groups of tumors, regardless of surgery. This observation suggests that the surgery of VS did not accelerate hearing loss but rather modified the initial, more rapid hearing deterioration (caused by the aggressively growing VS) toward a slower hearing deterioration, which was similar to that of the non-operated less aggressive VS. Hearing preservation is more likely to be achieved in patients that had a good hearing before the surgery ,16,21. ODue to the high risk of bilateral deafness over the time, hearing preserving surgery has a much higher value for NF2 patients than for patients with unilateral sporadic VS. Consequently, total resection should not be the intended goal, as such a surgery has a much lower hearing preservation rate of 30%, compared to the 73% achieved by subtotal resection . AdditioThus, our study confirmed again, and this is of major importance, that the surgeon needs to be conscious with regard to the intraoperative BAEP behavior and needs to show a defensive surgical behavior to preserve functional hearing. This results in smaller resection amounts in the majority of cases. A similar experience of better hearing preservation by deliberate partial resection has been reported by Wigand et al. , using aA potential disadvantage of the retrosigmoid approach is the high rate of longer lasting neck pain or occipital headache (still existing at the time of discharge) from damage and irritation to the oblique neck muscles . HoweverIn summary, results of the present study suggest that early surgery of VS in NF2 patients, which is strictly oriented at functional hearing preservation and is not aimed at tumor removal, has a long-term beneficial effect of slowing down the dynamics of hearing impairment. In our overall management strategy, this type of surgery is, therefore, often chosen as the first step, followed by a bevacizumab treatment at a later delayed timepoint, for surgery, when hearing deteriorates again. Thus, the side effects of this treatment can be postponed by several years and its costs are avoided.A total of 23 NF2 patients under 25 years during diagnosis were included in this retrospective analysis. Operations were performed on 39 tumors between 2004 and 2018, at the Department of Neurosurgery and Centre of Neurofibromatosis in Tübingen.A total of 20 control ears in 15 NF2 patients with the same cut-off age at time of diagnosis were chosen as a control group. These patients had stable hearing and tumor growth and, therefore, had no indication for a surgical intervention during the observation period. Neither the operated nor the non-operated patients were treated with chemotherapy during the time intervals under investigation. The Ethics Board of the Medical Faculty and the University Hospital of Tübingen approved this retrospective analysis (No 018/2019BO2). All operations were performed at our institution via the retrosigmoid approach, by decompression of the internal auditory canal (IAC) with various resection amounts, under continuous neurophysiological monitoring by two experienced neurosurgeons . Indications for surgery were (a) large tumors (T4 Hannover Classification ) on bothThe main influencing factors evaluated for impact of surgery on hearing included, (1) age at diagnosis, (2) preoperative tumor growth rate, (3) preoperative tumor volume, (4) resection volume, and (5) type of constitutional mutation. The data were obtained from clinical reports and MRI. Tumor volumetry, growth rate, and resection amount were performed, classified, and calculated in 579 data sets, as previously described . For 21 Patients with hearing aids or implants  were excluded. Hearing was assessed in all patients by regular determination of 4-frequency PTA, SDS, and BAEP, within 4 weeks before surgery and then every three-to-six months after surgery. Hearing data were classified using the Gardner and Robertson Scale (G–R) , Americat-test with a two-tailed hypothesis. Pearson’s correlation coefficient was used to analyze the relationship between hearing values/classifications and the VS growth rate, volume, and resection amount. After normalization of the pre- and postoperative hearing data, an analysis of variance (ANOVA) with the Games–Howell post-hoc test was carried out with PTA and SDS values with a comparison of the age of patients. To investigate the long-term course of PTA and SDS values before (until 24 months) and after (until 42 months) surgery, an analysis of covariance (ANCOVA) was performed and data were compared to the 20 control ears. Hearing before and after surgery was compared using paired by BAEP-guided partial resection via the retrosigmoid approach for the VSs enabled a high rate of functional hearing preservation (74–82%). In the long term, such surgery does not negatively impact hearing and, therefore, provides a preferred primary treatment option for NF2-associated VS.


To compare the hearing thresholds obtained with auditory brainstem response (ABR) and auditory steady state response (ASSR) audiometry in children with hearing loss.Hearing thresholds were obtained by ABR and ASSR in children who presented with suspicion of deafness at Ear, nose & throat department of Al-Nafees Medical College Hospital Islamabad, between January to August 2018. The mean hearing thresholds obtained by two tests were compared within each category of severity of deafness. Time taken by both tests was also compared.A total of 57 patients (114 ears) were included in the study. Among them 27 (47.4%) were male and 30 (52.6%) were female. The mean age of patients at presentation was 42 months (±30.9) with age range from one to 12 years. Mean hearing thresholds obtained by click ABR, chirp ABR, ASSR  & ASSR  was 56.25 (±27.61), 58.88 (±27.44), 58.03 (±21.26) & 56.35 (±22.86) respectively. Mean thresholds were comparable between click ABR & ASSR  and between chirp ABR & ASSR  in all degrees of hearing loss categories except in those patients with normal hearing thresholds. The mean time taken by clicks ABR, chirp ABR and ASSR were four minutes seven seconds, three minutes 15 seconds and 16 minutes and 7 seconds respectively.Hearing thresholds obtained by ABR and ASSR are comparable in all categories of severity of hearing loss. The time taken by ABR is less as compared to ASSR. Early identification of hearing loss in infants and children is of utmost importance because normal hearing is essential for speech and intellectual development.After the introduction of ASSR in clinical audiological practice, attempts have been made to compare its various aspects with ABR, a test which is already well established clinically. International literature provides few studies that compared the two techniques but no work has yet been done on this subject in our country. The purpose of this study was to compare hearing thresholds obtained by these two objective audiological tests in children with varying severity of hearing loss and to compare time taken by each test.This study included all those children from birth till 12 years of age regardless of gender, who due to suspicion of hearing loss, were referred for hearing evaluation to the Audiology section of Department of Otolaryngology, Al-Nafees Medical College Hospital Islamabad, between January to August, 2018. Non-probability convenient sampling technique was used. After taking targeted history from the parents, child’s ear was examined by performing otoscopy. Tympanometry was performed to rule out any conductive cause of hearing loss. Those children who had any congenital anomaly of ear or were suffering from active external and middle ear disease were excluded from the study.Hearing evaluation was done by ABR & ASSR under natural sleep or sedation  in a purpose build sound treated room. The ambient noise level during the tests was <30 decibels (dB). The equipment used for the test was Sentiero Advanced . Supra aural head phones (TD-39) were used to deliver the auditory stimuli to both ears simultaneously. Vertical electrode montage was used & electrode impedance was kept below 5 kohms.ABR testing was conducted first by click stimuli and then by chirp stimuli using rarefaction polarity. The stimulus rate was 37.1 Hz. Number of averages were 2000. A 10 dB increment or decrement was used to determine the threshold. The upper limit of stimulus intensity was 90 dB HL for click stimuli and 95 dB HL for chirp stimuli. Hearing threshold was defined as the lowest intensity level at which well-defined wave V can be identified by visual inspection.ASSR was then conducted after the completion of ABR. Adaptive threshold method was used with stimulus intensity range from 10 to 100 dB HL (hearing level). Modulation frequency was 80 Hz. Each ear was tested for four frequencies  simultaneously.The data obtained was evaluated with statistical package SPSS 21.0 version. Results obtained by both ABR (click & chirp) and ASSR were compared according to the response obtained or not till the maximum upper limit of stimulus intensity. Hearing thresholds obtained by click ABR and ASSR  and chirp ABR and ASSR  were compared within each category of degree of hearing loss. Mean thresholds obtained by click and chirp ABR were also compared. Those cases in which no response was obtained till the upper limit of stimulus presentation of our equipment were not included in the statistical analysis for calculation of mean. Paired sample t test was utilized to compare the means. P value of < 0.01 was interpreted as a statistically significant variation. Pearson correlation test was used to find correlation between the mean thresholds obtained by two techniques. Both the techniques were also evaluated for the mean time taken by each technique.The study protocol was approved by institutional review board committee of Isra University. Written informed consent was obtained from the parents of each subject. The confidentiality of the participant data was maintained.A total of 57 patients (114 ears) were included in the study. Among them, 27 (47.4%) were male and 30 (52.6%) were female. The mean age of patients included in the study was 42 months (3.5 years) SD±30.9 (Range 1 to 12 years). The distribution of patients among various age groups is as follows: 29 in 0-3 years, 18 in 4-6 years, 8 in 7-9 years & only 2 in 10-12 years age groups.With both click & chirp ABR stimuli, response was observed  in 43 ears (37.7%) whereas in 71 ears (63.3%) there was no response till the upper limit of stimulus intensity that can be presented with our equipment. With ASSR at four frequencies , response was observed in 58 ears (50.9%) whereas in 56 ears (49.1%), no response was recorded on any of the four frequencies up to 100 dB stimulus.The distribution of results according to the degree of deafness with click ABR, chirp ABR & ASSR are shown in Both ABR (click & chirp) and ASSR were compared according to the response obtained or not. The results are shown in None of the ears with no response on ASSR showed response with ABR (either click/chirp) whereas in 15 (13.1%) ears in which click ABR showed no response till the limit of equipment showed response with ASSR and 11 (9.6%) ears in which there was no response with chirp ABR showed response with ASSR. Correlation of mean hearing thresholds obtained with ABR (click and chirp) & ASSR are shown in Hearing thresholds obtained with both the click and chirp ABR were compared with ASSR with in each category of severity of hearing loss. The results are shown in Hearing thresholds obtained by ABR utilizing click and chirp stimuli were also compared with each other. The results are shown in Both the techniques were compared with respect to mean time taken by each technique. Mean time taken by click ABR is four minutes and seven seconds and by chirp ABR is three minutes and 15 seconds. Mean time by ASSR test is 16 minutes and seven seconds.About half of the patients 50.8%) in this study were in age group of one to three years with mean age at the time of presentation for hearing evaluation was 3.5 years which is considerably higher if we compare it with the same in developed countries.0.8% in tABR and ASSR are the most commonly used objective tests for hearing evaluation in pediatric population. In the present study, hearing thresholds were detected in 37.7% of our patients with ABR utilizing click and chirp stimuli whereas ASSR detected response in about half of the cases 50.9%). One of the reason for this finding is that the upper limit of stimulus presentation with our equipment is 90, 95 and 100 dB for click ABR, chirp ABR and ASSR respectively. There is not a single case in which ABR detected the response but ASSR failed to detect it whereas there were 15 cases tested by click ABR and 11 cases with chirp ABR in which no response was detected but ASSR detected hearing thresholds in all these cases. The possible explanation for these results is that with ASSR technique, higher stimulus levels can be presented which is not possible with ABR. In most auditory evoked potential testing equipment that are clinically available, upper limit of stimulus intensity that can be presented in ABR testing is 90 to 95 dB HL whereas in ASSR, up to 120 dB HL stimulus intensity can be presented. Therefore, ASSR can detect hearing thresholds at a much higher degree of deafness as compared to ABR. This aspect of ASSR is highlighted in many other studies which also suggested that not only the hearing can be tested with higher stimulus intensity but the results of ASSR become more reliable as the severity of hearing loss increases.0.9%. One9The results of hearing evaluation in our study showed that two thirds of our patients had profound degree of hearing loss. This may be due to the fact that our study included only those children that presented with suspicion of deafness or non-development of speech. This again highlight the need to implement a hearing screening program, as these cases can be diagnosed at birth and appropriate auditory rehabilitation program can be started much earlier.A high positive correlation r=0.9) was found when the mean hearing thresholds obtained by click and chirp ABR were compared with ASSR. This finding is in accordance with many other studies in which the two tests were compared. was founASSR test took considerable more time to complete the test as compared to ABR but it give frequency specific hearing thresholds information which is not available with click or chirp ABR. This feature is also observed in many other studies.18The hearing thresholds obtained by both the ABR and ASSR are comparable in subjects with varying severity of hearing loss. The time taken to complete the test is much less with ABR than ASSR.MAA: Conceived and designed the study, analysis and interpretation of data, critically reviewed the manuscript before submission to journal. He also takes responsibility and is accountable for all aspects of the work in ensuring that questions related to the accuracy and integrity of any part of the work are appropriately investigated and resolved.AJ & AM: Both of them did data collection & data analysis. They were also involved in manuscript writing.AM: Did statistical analysis and interpretation of data.


Diplostomum sp. infection in the eye retina of fish (i.e. Arctic charr). Histological sections showed that the trematodes caused mechanical disengagement between the retinal pigmentary epithelium and the neurosensory retina, with damaged cones and rods in the outer segment and epithelium reduced to a single layer of pigmentary cells. The metacercariae were “floating” in possibly fluid-filled vesicles together with several round cells, mostly located in the anterio-dorsal and anterio-ventral areas of the eye near the iris. The round cells may indicate internal retinal damage repair mechanisms, without connections to the general immune system. Metacercariae intestines contained pigmented cellular debris indicating that they feed on retinal epithelium. These retinal lesions may have similar vision effects as focal retinal detachment in vertebrates. Diplostomum metacercaria alters fish visual acuity but may in a lesser degree lead to a severe or total visual impairment because of repairing mechanisms. The pathology in the retina seems thereby to be dependent on fish size, age and dose.The eye represents an immune privileged organ where parasites can escape host reactions. This study provides the first systematic evidence of the pathology associated with   •Diplostomum in the eye of Arctic charr Salvelinus alpinus.Histological description of the distribution of •Metacercaria specifically located in spaces formed between the retinal pigmentary epithelium and the neurosensory retina.•Lesions display closer similarities with those observed in retinal detachment in other species.•Changes in the frequency and distribution of the lesions between morphs are suggested. There aDiplostomum von Nordmann, 1832  represent one of the most frequently reported  , brown trout , three-spines stickleback (Gasterosteus aculeatus) and European perch (Perca fluviatilis)  . The Arcnditions . Wild ponditions  as responditions . These dnditions . The deenditions  but theinditions . These cnditions . Thus, tDiplostomum spp. in the eye retina of Arctic charr. We study fish from recently discovered polymorphic populations in Skogsfjordvatn, Northern Norway . Skogsfjordvatn is an open lake system with elevation of 20 m a.s.l., a 2 km long outlet river with migratory Atlantic salmon , brown trout, Arctic charr and European eel (Anguilla anguilla). Additionally, there is freshwater resident brown trout, three-spined stickleback, and three Arctic charr morphs that differ in resource use, trophic morphology, parasite infection, life-history traits and are genetically differentiated  gill-nets  placed in the littoral zone (0–12 m depth) and the profundal zone (at 25–45 m depth). Fish length (fork-length) was measured (mm), and all Arctic charr were visually assigned to one of the three morphs, the LO-, the PB- and the PP-morphs  at different levels were performed from each half eye. Sections were stained with Haematoxylin and Eosin and mounted in DPX.3Diplostomum, with 100% prevalence in all three morphs . Metacercaria were observed exclusively within the retina and no metacercaria were detected in other locations in the eye. After sectioning, 0.5–1 mm single vesicles within the retina and between the pigmentary layer and the inner retinal layers could be observed under the binocular microscope at low magnifications . Preliminary data confirmed the metacercariae in the retina of Arctic charr from this lake correspond to a single species of ications . In mostications . These vVesicles and parasites were always detected between the retinal pigmentary epithelium (RPE) and the neurosensory retina (NSR). In Arctic charr, as well as in other fish species, the outermost retinal layers are formed by epithelial cells with large amounts of pigments arranged on a thin membrane resembling Bruch's membrane . The RPEHistological sections also revealed the presence of single metacercaria within the posterior retina in 10.3% of the fish but, in these cases with scarce or no vesicle development. Such alterations may vary from simple mechanical compression in the RPE and the cones and rods layer due to the presence of the parasite , to moreParasites localized in the different sections were easily recognized as metacercaria. In each vesicle, they were observed as “floating” organisms within a fluid-filled empty space. Typical structures recognized, such as oral sucker, pseudosuckers, intestinal caeca and also digested material were commonly seen within the metacercaria , Fig. 6.4Diplostomum sp. eye infection has been detected and confirmed in all Arctic charr morphs from Lake Skogsfjordvatn suggesting a potential impairment of the vision of these fishes. The histopathological changes in the retina associated to infection of Diplostomum sp. in Arctic charr indicates that metacercaria display a specific tropism towards the transition zone between the neurosensory retina (NSR) and the retinal pigmentary epithelium (RPE). A similar specific tropism to this zone was described in Perca flavescens infected by Diplostomum adamsi . Groups of melanosomes are frequently observed inside the digestive tube of the metacercaria and also in some cases vesicles with amorphous material was observed within the parasite bodies. These observations suggest actively feeding of the metacercaria on intertissular fluids, on cellular debris from damaged RPE and probably NSR. Active feeding has been previously proposed in other unencysted metacercariae of Diplostomum spp. (Diplostomum cercariae used melatonin (produced in the fish eye retina) as cue to reach the eye among several other compounds tested. Since Vitamin A is abundant in the retina, this compound could also work as a target for orientation within the fish host for Diplostomum spp. cercariae.Vesicles or blister-like lesions where parasites are found aggregated can be associated to enlarged spaces filled with liquids. Retina plays a major role in the transport of ions and nutrients from the choroid, so liquid accumulation within these vesicles can be expected. Large numbers of parasites can be seen ‘floating’ in these spaces suggesting a suitable microhabitat for mum spp. , particumum spp.  active fThe proposed moderate impact of parasites on the retina suggests that the pathology thereby seem to be dependent on several factors. First, the size of the fish as smaller fish will have smaller eyes/habitats. Second, the age of the fish as metacercariae generally accumulate over the life span of the host (no sign of parasite death has been observed in our samples). The damages are also highly dose-dependent and therefore will be accentuated with a persistent high infection pressure over time. Fish seem generally to suffer from diplostomiasis as highly infected individuals have lower capture rate of prey compared with less infected fish e.g. . Thus, tDiplostomum sp. infections. The PB-morph has to detect small, sediment buried prey in addition to spot predators visually at deep-waters (Diplostomum-host interactions.The three morphs present in our study, have relevant differences in head and eye morphology as well as important ecological adaptations . The uppp-waters . These dp-waters , in partp-waters . These hDiplostomum larvae and the retina of Arctic charr at the histological level. This observation suggests a unique and specific placement of the parasites within the retina, causing damages similar to the retinal detachment in other vertebrate species but also suggesting a particular benefit for the parasite. The lesions caused by the parasite in the eye retina of the fish suggest that visual capacity can be impaired. Furthermore, the presence and also the absence of severe damages or responses such as inflammation suggests that retinal structures are constantly regenerating from parasites action, but implies an additional physiological cost of infection for the host.To sum up, in this paper we describe specific interactions and pathological events established between None.


Radix et Rhizoma Nardostachyos include Nardostachys jatamansi and N. chinensis. Traditionally, the two plants have been used to treat many diseases. Because of their special aroma, they are also commonly used in the food and cosmetics industry. Recently, N. jatamansi and N. chinensis have been overexploited due to their economic importance, resulting in a sharp decline in their wild resources. Predicting potential distributions of the genus Nardostachys under different climate scenarios and understanding its preferred habitat are of great significance for their conservation, artificial cultivation, and assessment of their value.The medicinal plants of Nardostachys under current and future climatic conditions based on two representative concentration pathways (RCP2.6 and RCP8.5) for the 2050s and 2070s. These data were used to study the effects of climate variables.The Maxent model was used to predict the potential geographical distributions of the genus N. chinensis presents a relatively stable growth compared to N. jatamansi. In addition, precipitation plays a crucial role in modeling the effects of climate change on the genus Nardostachys. This study provides theoretical guidance for the cultivation of N. chinensis.The results show that the potential distribution of the two species will increase, thus more suitable habitats will be present in China. The suitable habitat for  Radix et Rhizoma Nardostachyos include Nardostachys jatamansi and N. chinensis   .Fritillaria cirrhosa, Lilium nepalense, Phellodendron amurense Rupr, and Atractylodes lancea , Specimen Resources Sharing Platform for Education (http://mnh.scu.edu.cn/), and Global Biodiversity Information Facility (https://www.gbif.org/). The literature used was open-source and available worldwide. In the absence of specific geographical coordinate records, Google Earth 7.0 was utilized to find the approximate latitude and longitude according to the described geographical location. After duplicate and invalid records were removed, the sampling points of N. jatamansi and N. chinensis were 183 and 60, respectively. We obtained sampling points from the specimen database and literature, and all the specimens collected in the specimen database are wild. In accordance with the requirements of the Maxent software, the distribution records of N. jatamansi and N. chinensis were organized into .csv format files including the species name and distribution point longitude and latitude, with the east and north latitudes positive and the west and south latitudes negative.Occurrence records of N. jatamansi and N. chinensis. Refer to other literature, 19 bioclimatic variables with 2.5-min resolution of the current conditions and future conditions (2050s and 2070s) were downloaded from the WorldClim-Global Climate Data (http://worldclim.org/)  . The 2.5im.org/) . These vim.org/) . The 19 im.org/) .https://github.com/mrmaxent/Maxent/blob/master/ArchivedReleases/3.3.3k/maxent.jar). Maxent was used to predict the current and future potential distributions of N. jatamansi and N. chinensis based on the occurrence records and climate data. The logical output (results are expressed in terms of probability) was selected to assess the likelihood of the presence of a species in each grid cell. A total of 25% of the occurrence records were chosen as the test set, and the remaining parameters were the default settings  of N. jatamansi under the RCP2.6 emission scenario will continue to grow. However, the range of suitable areas under the RCP8.5 emission scenario was significantly reduced and was significantly lower than the current level. The results showed that the climate-suitable area decreased in the 2070s under the RCP8.5 climate scenario compared to the current period.By 2070, the area of suitable habitats for N. chinensis under RCP2.6 also continued to increase, relative to the 2050s and the present. Suitable areas of N. chinensis under RCP8.5 still increased compared to the present. However, suitable areas of N. chinensis under RCP8.5 decreased from the 2050s.Suitable areas of N. jatamansi and N. chinensis were simulated by the Maxent model, which automatically predicted the contribution percentage of each variable to the forecasted results. N. jatamansi and N. chinensis in their current distribution range. Among them, precipitation of the driest period (Bio14) was the largest contributing factor when modeling the distributions of N. jatamansi and N. chinensis.A total of 19 bioclimatic variables from the BIOCLIM climate dataset were used as the background environmental data, such as temperature and rainfall. These variables are comprehensive conclusions and quantitative descriptions of the climatic environment in the regions containing the targeted species. The potential distributions of N. chinensis , precipitation of the driest quarter (Bio17), and precipitation of the driest period (Bio14) were the main variables in the simulation of hinensis . Howeveratamansi .N. jatamansi and N. chinensis. Response curves indicated the correlation between the environmental variables used for prediction and the probability of the presence of N. jatamansi and N. chinensis. In N. jatamansi and N. chinensis. The distribution probability of N. jatamansi and N. chinensis increased with the increase of variable value. After exceeding this peak, the distribution probability decreased with the increase of the value for environmental factors, indicating that N. jatamansi and N. chinensis have some adaptability to these variables. When the probability is greater than 0.5, the corresponding ecological factor value is more suitable for the growth of the plant.N. chinensis and 0–10 mm for N. jatamansi. The optimum range of precipitation of the driest month is very narrow, indicating that N. jatamansi and N. chinensis were sensitive to precipitation.The prediction showed that the best ranges for these indicators were precipitation of the driest month, one to five mm for 2 concentration, and the changes in certain climatic resources changed the dynamics and balance of different species, thereby affecting their productivity , the density of N. jatamansi has increased significantly with altitude was revealed on a west-facing slope. And the north and west-facing slopes in the alpine zone of this region are broadly considered as the shady areas with low light and high moisture (valerian species (N. jatamansi and N. chinensis compared to temperature and other environmental variables.According to the results of above forecase, we can conclude that precipitation of the driest period is the most important environmental factor affecting the growth of moisture . The adv species . These rN. jatamansi and N. chinensis were sensitive to precipitation. Thus, this showed that research on water management should be strengthened for future cultivation practices.The analysis for the response curves showed that the probability of species presence changed as a result of the dominant environmental variables. The results indicated that Nardostachys species and prediction of their potential distributions under current and future climate conditions are reliable. Considering the effects of climate change, N. chinensis is more suitable for cultivation. In addition, precipitation of the driest period is an important factor in the impact of climate change on N. jatamansi and N. chinensis. It is of great significance to study the impact of climate change on the genus Nardostachys to predict their potential distribution in the future for the protection, sustainable use, and value assessment of these biological resources. It is essential to conduct future studies on the effect of watering of N. chinensis for developing effective techniques to cultivate N. chinensis. The study will provide references for the cultivation planning and resource utilization of N. jatamansi and N. chinensis.The results of this Maxent simulation of climate change impacts on the distribution of two


Noise pollution is one of the most important occupational pollutants in heavy-vehicle drivers. Therefore, this epidemiological research was conducted with the aim of determining the prevalence of hearing loss in heavy-vehicle drivers in Iran.t test.This cross-sectional research was conducted on 65,533 heavy-vehicle drivers including truck and intercity bus drivers from February 2006 to March 2016. The air and bone threshold of pure tone was measured for each ear at 0.5, 1, 2, 3, 4, 6, and 8 kHz by a skillful radiology expert. The obtained data from this research was analyzed in SPSS software using statistical tests such as descriptive analysis and paired t test showed that hearing loss difference in left and right ears was significant (P < 0.001). Mean and standard deviation of paired t test showed that hearing loss difference in left and right ears was significant in all frequencies except 1000 Hz (P < 0.001).Mean (standard deviation) of hearing loss in left and right ears of all people was 23.02 (8.25) and 22.48 (7.86), respectively. Paired The findings of this research generally showed that 26.8% of the studied drivers have hearing loss. Hearing loss in the left ear was more than right ear. Noise pollution is one of the most important jobs and environmental pollutants , World HThe noise of the vehicle can influence various groups including dwellers around heavy traffic roads and vehicle drivers. Many studies have been conducted on the environmental effects of noise pollution. The national research in the US shows that 18% of people suffer from road traffic noise in their lives . HoweverAccording to the importance of preventing hearing loss in developing countries, bus and truck drivers are examined annually in Iran for hearing loss, but there is no comprehensive epidemiological study to analyze these findings. Therefore, this epidemiological research was conducted with the aim of determining the prevalence of hearing loss in heavy-vehicle drivers of Iran.This cross-sectional research was conducted on heavy-vehicle drivers including truck and intercity bus drivers from February 2006 to March 2016. This study is a part of a national survey program. Isfahan province, as one of the industrial cities with high traffic of heavy vehicles in center of Iran, was selected to perform the study. Therefore, all intercity drivers referred to occupational medical centers of Isfahan province to obtain a health card during these 10 years were included in the study. The date of the drivers extracted and the date of the subjects with the inclusion criteria entered to the study. Inclusion criteria include: older than 20 years, no other diseases except musculoskeletal disorders or back pain, no congenital hearing impairment and diagnosis of guided or combined hearing loss, no background of ear discharge, and no extra secretion or wax. For the collection of the driver’s data during the last 10 years, their demographic information including age, height, and weight was collected at first. Then, their general health was studied. Finally, they passed a pure turn audiometry. The data of 65533 drivers were collected in this period. All participants were male.Pure tone air and bone conduction audiometry parameter was used to test the hearing condition of people. Hearing was tested using the Welton 1300 clinical audiometer equipped with AD-19 supra-aural in a noise-insulated room based on the American Speech-Language-Hearing Association , 15. TheHearing loss was calculated as mean threshold pure tune at 0.5, 1, 2, 3, 4, 6, and 8 kHz in each ear. Classification of people was based on hearing loss as people with healthy ears (HL less than 25), people with weak hearing loss (higher HL than 25 and similar/lower than 40), people with medium hearing loss (HL higher than 40 and similar/lower than 60), and people with high hearing loss (higher than 60) . Moreovet test. Paired t test was used to evaluate the difference of hearing loss between the right and left ears. P value below 0.05 was considered as statistically significant.The obtained data from this research was analyzed in SPSS software using statistical tests such as descriptive analysis and paired t test showed that hearing loss difference in the left and right ears was significant (P < 0.001). As well, Table t test in all frequencies have been presented in Table Mean (standard deviation), age, height, weight, and body mass index of the participants were 38.2 12.2), 1.73 (0.06), 76.69 (12.95), and 25.58 (9.64). All participants were male. The results of statistical analysis showed that 47,998 out of 65,533 (73.2%) were without significant hearing loss, 2891 (4.4%) with hearing loss just in right ear, 5081 people (7.8%) with hearing loss just in the left ear, and 9563 (14.6%) had hearing loss in both ears. Frequency and frequency percentage of people with various hearing loss degrees in the left and right ears are presented in Table 2.2, 1.73t test also indicated that difference of mean hearing loss between left and right ears was significant in all frequencies except 1000 Hz (P < 0.001). Figure The results of paired Results of this research generally showed that 26.8% of drivers had hearing loss. Meanwhile, the maximum percentage (14.6%) is related to people with hearing loss in both ears. Among those who had hearing loss just in one ear, hearing loss in the left ear was 7.8% more than the ones with hearing loss in the right ear with 4.4%. Janghorbani et al. in a research with the aim of estimating the prevalence of hearing loss in truck drivers concluded that the prevalence of hearing loss in both ears, in the left ear, and in the right ear among drivers was 18.1, 6.5, and 3%, respectively . ResultsMoreover, the high volume of the decrepit trucks and busses with high noise in Iranian roads can also be a reason for this finding. Head of Iran's Road and Rail Transport Organization in 2017 announced that there are 252000 trucks younger than 15 years, 96000 trucks of 15–35 years old, and 75000 trucks older than 35 years working in the state . AnotherMoreover, results of this research showed that the mean hearing loss in Iranian drivers in left and right ears is 23.02 and 22.48. Results of Krishman Kumar and Jain research in India show that noise pressure level of trucks and busses is 83-90 and 77-92 dB, respectively . ResultsAccording to the high volume of samples in this research, the limitations of this research can be the non-consideration of people’s working background, the exact type of vehicle model, and the condition of its air conditioning system. Moreover, the studied blood parameters are fewer than the other research and more blood parameters can be evaluated in future research.The findings of this research generally showed that 26.8% of the studied drivers have hearing loss. Hearing loss in the left ear was more than that in the right ear. In addition, people with hearing loss just in left ear were more than those just in the right ear. According to the hearing importance of drivers’ safety and life quality, it is suggested to reduce people facing this noise by innovation of the decrepit trucks, installation of suitable ventilation systems on old trucks to avoid opening the windows, isolation of the holes and vents of the truck chamber, periodic maintenance of trucks, use of personal protective equipment, decrease of driving time duration, and periodic health check for early detection of individuals with hearing loss and work restrictions for them to prevent further progression.


GJB2, which encodes Cx26) cause approximately half of all cases of congenital hearing loss in newborns. Great progress has been made in understanding GJ function and the molecular mechanisms for the role of Cxs in the cochlea. Data reveal that multiple types of Cxs work together to ensure normal development and function of the cochlea. These findings include many aspects not proposed in the classic K+ recycling theory, such as the formation of normal cochlear morphology , the fine-tuning of the innervation of nerve fibers to the hair cells (HCs), the maturation of the ribbon synapses, and the initiation of the endocochlear potential (EP). New data, especially those collected from targeted modification of major Cx genes in the mouse cochlea, have demonstrated that Cx26 plays an essential role in the postnatal maturation of the cochlea. Studies also show that Cx26 and Cx30 assume very different roles in the EP generation, given that only Cx26 is required for normal hearing. This article will review our current understanding of the molecular structure, cellular distribution, and major functions of cochlear GJs. Potential implications of the knowledge of cochlear GJs on the design and implementation of translational studies of cochlear gene therapies for Cx mutations are also discussed.Connexins (Cxs) are ubiquitous membrane proteins that are found throughout vertebrate organs, acting as building blocks of the gap junctions (GJs) known to play vital roles in the normal function of many organs. Mutations in Cx genes (particularly  Connexins (Cxs) are ubiquitous membrane proteins that are present throughout the vertebrate organs. Six Cx subunits are assembled into a connexon, a hexameric structure in the cell membrane  of K+, the EP, and the onset of hearing  have more than two exons, with exon 3 encoding the CDS  changes] of GJs , while exon two contains the complete coding sequence (CDS) and the 3′-UTR. However, Gjb2>Gjc3>Gjb6≈Gja1). Multiple studies have demonstrated that major subtypes of Cxs expressed in the cochlea are Cx26  have been linked to hearing loss in Chinese families with recessive deafness  as detected by Cohen-Salmon et al.  were theExpression of Cx45 is detected in the mouse cochlea by E17.5, in fibrocytes of the spiral limbus and ligament, mesenchymal cells under the basilar membrane and lining the scala vestibule, and in capillary cells  may be associated with sensorineural hearing loss + that needs to be removed, this observation is not compatible with that expected by the K+ recycling theory.OHC degeneration starts days before the degeneration of IHCs +, EP, and onset of hearing in mice  and functional maturation  of the cochlea + recycling theory.Conditional knockout of Cx26 before early postnatal stages  results in severe hearing loss in mice + recycling pathway , that play important cochlear functions that are clearly not linked to K+ recycling at all.There are other GJ systems in the cochlea, but not in the proposed K+ fluxes by ion channels, membrane transporters/co-transporters and GJs in all types of cells in the SV  mice show a delay in the maturation of hearing thresholds and an early loss of high-frequency sensitivities. In addition, a prolongation in latency and distortion in the wave I of the auditory brainstem responses and elevated sensitivity to noise damages are found. However, the morphology of sensory HCs and DPOAE that depend on the integrity of outer HCs are normal in Gjc3−/− mice, indicating that the organ of Corti is not directly affected. The phenotypes in Gjc3−/− mice are explained by proposing that Cx29 hemichannels provide a pathway for removing accumulated K+ in peri-axonal space during high-frequency firings of the auditory nerve GJB2 (MIM 121011), COL11A2 (MIM 120290), MYH9 (MIM 160775), MY07A (MIM 601317), PDS (MIM 274600), CDH23 (MIM 605516), and WFS1 (MIM 606201)]. Different mutations in the same gene may cause either dominant or recessive forms of non-syndromic hearing loss . Treatment designs will need to be considerably different  in humans to restore normal hearing  Turnover rate of Cxs. Many Cxs, including Cx26, exhibit limited stability and degrade within 1–5 h  give only mild-to-moderate hearing loss  have indicated that the appropriate time window of gene therapy of Cx26 seems to be in early development, possibly necessitating surgery in human embryos. The ramifications of such aggressive intervention will need to be carefully analyzed.Our current knowledge about GJ structure and functions in the cochlea indicates that Cxs play essential roles in the structure and functional maturation of the cochlea. Both Cx26 and Cx30 play vital roles in EP generation and maintenance. Reduced Cx26 expression is the likely cause of deafness even in cases of Cx30-null mutations since Cx26 expression at WT levels is sufficient for normal GJ function in the cochlea and the preservation of hearing. Before we can make a conclusion, one needs to keep in mind that studies have also shown that results obtained from mouse models may not necessarily be extrapolated to humans (and vice versa). Thus, larger animal models such as pig or non-human primates may be needed for further studies. Many human XW and XL designed this article and generated The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


This cohort study conducted in Japan showed that severe age-related kyphosis was visually detected. The visual assessment of kyphosis was associated with declines in ADL, suggesting that we can easily identify people at high risk to develop future ADL reduction in the community setting.Age-related kyphosis is related with declines in activities of daily living (ADL). Its conventional diagnosis has been made by orthopedic surgeons and trained examiners using specialized equipment such as X-rays. We investigated whether visual classification of kyphosis by laypersons accurately predicted future ADL decline.This study was part of the Kurabuchi Study, a cohort study of community-dwelling elderly Japanese. Between 2009 and 2010, three layperson raters used reference illustrations to classify 532 participants without ADL decline at study baseline into four categories. Other examiners used conventional methods to assess kyphosis in the same participants: curve ruler, Spinal Mouse, and the block method. ADL decline was defined as the development of dependence according to the Katz Index, admission to a nursing home, or certification of long-term care need.Thirty-five of the participants (6.6%) were classified with the most severe degree of kyphosis at baseline by visual assessment. Interrater agreement was high (Kappa = 0.73) for the most severe group. During 4.5 years of follow-up, 106 participants (19.9%) showed ADL decline. On the basis of visual assessment, the adjusted risk ratio for ADL decline among the participants with the most severe kyphosis was 2.6 (95% CI: 1.4–4.6). Assessments of kyphosis made with the Spinal Mouse also accurately predicted ADL decline.Visual assessment of kyphosis predicted future declines in ADL in this study. Since our method requires no special tools or training, it may be useful for identifying those at high risk of ADL decline.The online version of this article (10.1007/s11657-018-0551-4) contains supplementary material, which is available to authorized users. Scientific advances have led to longer lifespans and aging societies. According to United Nations data, more than 40% of the populations of several Asian and European countries will be over the age of 60 by 2050; among these countries, Japan has the highest aging rate . ClearlyAs the number of healthy elderly people increases, it becomes more difficult to predict functional deterioration only on the basis of age. Therefore, to identify those who would benefit from preventive intervention, effective predictive measures are needed. Various conditions like dementia, depression , pain 44, and viSome 20 to 30% of elderly people reportedly develop age-related kyphosis . DiagnosThe purpose of this study was to investigate whether visual classification of kyphosis by laypersons is useful. We hypothesized that this classification method would predict the future ADL decline of community-dwelling elderly.This study was performed as part of the Kurabuchi Study –7, 13–15In 2009 and 2010 (the baseline for the present study), an extra item—classification of kyphosis by visual assessment—was included in the health examinations performed at the eight community centers. Among the residents, 560 participated in this baseline survey, 406 of whom were original participants from the 2005–2006 survey, 81 of whom had newly entered the 65-year-old age bracket, and 73 of whom had newly decided to participate in the study since the first survey. At this point, we excluded 25 participants with ADL decline at baseline: 21 with certification of long-term need of support, 9 with dependence in ADL (Katz ADL) , 4 who hThe study protocol was approved by the Ethics Committees of Keio University School of Medicine   and Faculty of Medicine, Toho University  , and written informed consent was obtained from all participants.For the purposes of this study, we developed a simple evaluation method in which the rater uses reference illustrations Fig.  to visuaThe degree of kyphosis was also assessed by three different conventional methods: the kyphosis index , Spinal Mouse (standing position), and the block method (supine position). All three types of conventional assessment were performed by trained examiners.For KI assessments, the participants were asked to relax and stand naturally, and the thoracic curvature between the spinous processes of the seventh cervical and fourth lumber vertebrae was traced onto paper with an adjustable curve ruler; KI was then calculated according to the formula proposed by Milne and Lauder . Since nIn the second conventional method, the participants were again asked to stand in a relaxed position, and spinal posture was evaluated with a Spinal Mouse , a computer-assisted, noninvasive device to measure spinal shape; measurements were made as described elsewhere . From thFor the block method, the distance between the participant’s occiput and the table was measured with blocks, each measuring 1.5 cm in height. The blocks were placed under the neck with the participants in the supine position, lying with their face parallel to the floor, and the number of blocks used for each participant was recorded , 18. We The participants were followed up annually and assessed for any dependence in ADL. We defined dependence in ADL as previously reported : admissiInformation on nursing home admission, certification of a need for long-term care/support, and death was collected from the Kurabuchi Branch Office of Takasaki City Hall. Information relevant to Katz ADL classification was collected during the annual home-visit surveys.Information was collected during the baseline survey in 2009 and 2010 on age, sex, current smoking status (yes/no), current drinking status (yes/no), living status , history of life-threatening diseases , current knee joint pain , current back pain . The demi-span  was usedSTATA version 14  was used for all data analyses.The participants were divided into four groups according to the visual classification of kyphosis by each rater. The Chi-square test or Fisher’s exact test was used to compare the baseline variables among the four kyphotic classifications. The observer agreement between the raters was assessed using Fleiss’s Kappa .The association of each kyphosis category, as classified visually, with ADL decline, was assessed by crude analysis, and then by three multivariate analyses using Poisson regression models, with category 2 (into which the largest number of participants fell) used as the reference. The first model was adjusted for age categories and sex. Model 1 included marital status, education, drinking, smoking, BMI, vision impairment, hearing handicap, knee joint pain, depressive symptoms, and history of life-threatening diseases, which were considered a priori confounders or were associated with visual kyphotic classification, as well as age categories and sex. In addition to the variables adjusted for in Model 1, back pain and bone stiffness (categories) were added in Model 2. The strengths of associations were indicated by the RRs and 95% confidence intervals (CIs).Finally, the association of each conventional kyphotic measure  with ADL decline was assessed by crude analyses, and then by the same three multivariate analyses, with Poisson regression models used for the visual classification. In assessing KI and inclination, the second quantile was used as the reference. For the block method, the 0–2 block category was used as the reference.Rater A (the representative rater) rated all 532 participants, rater B assessed 485, and rater C 396. Rater A put 98 18.4%) of the participants in category 1 (no kyphosis), 294 (55.3%) in category 2 (slight kyphosis), 105 (19.7%) in category 3 (between 2 and 4), and 35 (6.6%) in category 4 (severe kyphosis). Observer agreement between the three raters showed a high rate of agreement (Kappa = 0.73) for category 4, and moderate agreement across all four categories (Kappa = 0.36)  participants showed ADL decline , and 47 (8.8%) died. The adjusted RRs of ADL decline or death according to the representative rater’s kyphotic classifications are shown in Table Table Our simple method of having untrained raters use reference pictures to visually classify kyphosis and allowed us to show an association between kyphosis and future ADL decline. There was good agreement among the raters in classifying participants in the most severe category of kyphosis.Previous studies, most of which were cross-sectional, used various methods to assess kyphosis and also showed an association between kyphosis and ADL decline. For example, Ryan et al.  used botOur results were consistent with those of studies using conventional methods to classify kyphosis, which generally show the most significant levels of ADL decline in subjects falling into the most severe kyphotic group , 26, 27.With our visual classification method, 6.6% of the participants were classified in category 4, the most severe kyphosis group, which places them among the 20 to 30% of the elderly population reportedly affected by hyper-kyphosis due to aging ; this isAnother notable feature of our method is that it allows the subjects to be evaluated while they are moving around normally, meaning that evaluations are based on the posture they adopt in their daily activities. When subjects are asked to stop and stand up straight, their efforts to maintain the position are likely to result in their adopting a posture that is different from their normal one, resulting in an incorrect assessment of kyphosis severity and risk of ADL decline. In addition, in assessing subjects while they are in motion, our visual classification method may be capable of evaluating not only spinal kyphosis, but also muscle strength and the degree of inclination. Inclination in sagittal posture is also reported to be associated with future dependence in ADL , and it Our study showed no association between the degree of kyphosis and death, although such an association has been reported . It is rThe major strength of our study is that the participants were community-dwelling elderly people and not patients, which makes the results applicable to the general public. It should also be noted that our follow-up rate was very high. On the other hand, there are three limitations. One is that we lacked information on whether any of the participants received intervention for ADL decline during the follow-up period, and we acknowledge that some may have maintained their ADL levels through effective intervention. Another limitation is that our results could to some extent be Japan-specific: the evaluation criteria for admission to nursing homes or certification of the need of assistance at home, for example, could vary from country to country, and the third limitation is that our visual classification of kyphosis was performed by non-experienced people in our research. Actually, we think it is a good point of our research that our method can be performed at anywhere, and by any person, although, misclassification of kyphosis might reduce if the classification was performed by experienced people such as orthopedic surgeons.Japan is now experiencing a “super-aging society,” so maintaining the health of its elderly is becoming more and more important, as is the need to involve the community in preventing health impairment in people who are ever more vulnerable to it as they age. Identifying people at high risk is the first step in prevention, and our simple visual method of kyphosis classification can play a role in this. The next step is research to develop interventions that will be effective in helping elderly people with kyphosis maintain good levels of ADL. There are cases that treatable diseases such as Parkinson’s disease, degenerative diseases of lower limbs, or lumber canal stenosis, which accompanies postural change, underlie the condition of kyphosis. In these cases, we should diagnose them sooner in order to make the treatment outcome better. Also, when muscle weakness underlies the condition of kyphosis, approaches to strengthen back extensor muscles may help improve the development of progression of kyphosis, and also improving their QOL –39. HoweESM 1(PDF 29 kb)ESM 2(PDF 49 kb)ESM 3(PDF 50 kb)


Hyperbilirubinemia is a common neonatal problem with toxic effects on the nervous system that can cause hearing impairment. This study was conducted to assess the risk factors for sensorineural hearing loss and other coexisting problems in icteric infants. In a case-control study, 200 term infants with bilirubin levels higher than 20 mg/dl admitted to the neonatal intensive care unit of Ghaem Hospital, Mashhad during 2007–2015 were investigated. Profiles of infants with hearing impairment (n=60) were compared with those of icteric newborns with normal hearing (140 newborns) as the control group. After confirming the clinical diagnosis of jaundice by laboratory findings, a validated questionnaire containing mother and infant profiles were used for data collection. The auditory brainstem response test was used for assessment of infant hearing status after discharge.Sensorineural hearing loss among infants with severe hyperbilirubinemia was found to be 4.8%. Serum total bilirubin (P=0.001), creatinine levels (P=0.002), direct Coombs test results (P=0.001), etiology (P=0.000) and treatment for jaundice (P=0.000), eye movement disorders (P=0.001), opisthotonos (P=0.001), and microcephaly (P=0.001) were found to be significantly different between the two groups (P<0.005). The prognostic predictability of sensorineural hearing loss based on total bilirubin level was found to be 82%.Hearing impairment occurs about 10–50 times more frequently in neonates with severe jaundice. Total bilirubin level has the highest predictability for infant hearing status. Blood group and Rhesus (Rh) incompatibilities between mother and child and G6PD deficiency are important known causes for hearing impairment due to jaundice.  Neonatal jaundice is the most common cause of hospitalization in the first month after birth ,2. BilirRisk factors for hearing loss vary at different ages. A family history of hearing loss, congenital infections, auditory-pharyngeal disorders, meningitis, ototoxic medications, and bilirubin levels higher than 20 mg/dl are involved in hearing loss in children under 2.5 years old ,8. The aThe otoacoustic emission (OAE) test is one of the routine after-birth screening procedures for risk-factor-free infants ,13. The auditory brainstem response (ABR) is another test used to detect hearing loss and neural type in particular , and hasIn this case-control study conducted between 2007 and 2015, 200 term infants with bilirubin levels higher than 20 mg/dl admitted to the neonatal intensive care unit of Ghaem Hospital, Mashhad were investigated. Profiles of infants with hearing impairment (n=60) were compared with those of icteric newborns with normal hearing (140 newborns) as the control group. The exclusion criteria included multiple anomalies, chromosomal diseases, history of hearing impairment in the family members, and asphyxia. Convenience sampling was done from all icteric neonates admitted to Ghaem Hospital, Mashhad. Data collection was performed using a questionnaire. The validity and reliability of the questionnaire was confirmed according to reliable sources and the judgment of five experts using alpha Cronbach’s reliability test (r=0.8). The questionnaire consisted of maternal and infant demographic data as well as the Denver II developmental screening test. Patients were evaluated after obtaining their parents' consent. The study was performed after ethical approval from the Vice Chancellor for Research, Mashhad University of Medical Sciences.Complete physical examination of infants as well as medical history, age, gender, birth weight, gestational age, and Apgar score were recorded, together with the mother's age and blood type. In addition, the infant’s bilirubin, hematocrit, direct and indirect Coombs levels, reticulocytes count, glucose-6-phosphate dehydrogenase (G6PD) enzyme levels, and both the mother's and infant's blood type and complete blood cell count were determined. ABO incompatibility was suspected when the mother's blood group was type O and the baby's blood group was either A or B, with at least two of the following conditions: jaundice on the first day, positive direct Coombs test, microspherocytosis in the peripheral blood or positive indirect Coombs test ,19. In the absence of Rhesus (Rh) or ABO incompatibility, but a positive direct Coombs test, the incompatibilities were considered as a sub-group . The poiHearing assessmentThe hearing status of the neonates was investigated using the ABR method after discharge. ABR is a non-invasive method for early detection of impaired hearing pathways. The efficiency of the test increases with prolonged exposure to hyperbilirubinemia, even after effective treatment. ABR is also capable of detecting subclinical encephalopathy before the manifestation of signs and symptoms of kernicterus. ABR test impairment is usually transient in most patients and improves with rapid and effective treatment. Thus, performing serial ABR tests can be a useful, non-invasive and necessary technique to diagnose disorders ranging from secondary neurodevelopmental disorders to hyperbilirubinemia . The ABRStatistical analysesSPSS (16.5) software was used for data analysis. Data are expressed as the mean ± standard deviation (SD). The Student t-test or Chi-square test was used to analyze the relationships between variables with normal distribution and nominal scale, respectively. A P<0.05 was considered statistically significant.Of 200 icteric neonates who participated in this study, 60 newborns suffered from sensorineural hearing loss (case group), whose characteristics were compared with 140 infants with a history of a bilirubin level of over 20 mg/dl having a normal hearing status (control group). Of the 200 icteric infants studied, 58% were males and 42% were females. The average referral ages of icteric infants in the control and test groups were 7.07 ± 3.53 and 5.71 ± 3.02 days, respectively. The mean birth weights of infants in the control and case groups were 3.13 ± 0.54 and 2.87 ± 0.51 kg, respectively. The mean gestational ages of infants in the control and case groups were 39.1 ± 0.86 and 38.6 ± 1.31 weeks, respectively. The mean Apgar scores of infants in the control and case groups were 8.9 ± 1.11 and 8.6 ± 1.31, respectively. Other characteristics of the studied infants are given in There was no significant difference between the two study groups regarding the following factors: parity (P<0.630), maternal age (P<0.725), T4 (P<0.132), thyroid-stimulating hormone (TSH) (P<0.413), or blood urea nitrogen (BUN) (P<0.580). However, the differences were statistically significant between the two groups in the following parameters: birth weight (P<0.002), admission weight (P<0.009), age (P<0.06), direct bilirubin (P<0.001), total bilirubin (P<0.001), hematocrit (P<0.003), reticulocyte count (P<0.004), and creatinine (P<0.002) .No significant statistical association was found between the infant's hearing status and sex (P<0.962). The direct Coombs test result was significantly associated with hearing status (P<0.001), meaning that the newborns with sensorineural hearing loss had the highest value of positive direct Coombs results. However, no significant association was seen between hearing loss and indirect Coombs results (P<0.101). The rate of G6PD deficiency was significantly different between the study and control groups (P<0.04). The etiology of jaundice in infants with sensorineural hearing loss was one of the following conditions: unknown (16 cases), blood group (ABO) and Rh incompatibility (nine cases each), G6PD deficiency (seven cases) and sepsis (two cases); while in icteric infants with normal hearing status, the etiology of jaundice was as follows: unknown (44 cases), ABO incompatibility (five cases), urinary tract infection (one case), G6PD deficiency (case case), and sepsis (two cases). Significant differences were seen in abnormal eye movements (P<0.001), opisthotonos (P<0.001), and microcephaly (P<0.001) between the two groups, indicating that eye movement disorder, opisthotonos and microcephaly were seen with a higher rate in jaundiced infants with sensorineural hearing loss . The paiLong-term final outcomes of infants with hearing impairment at 12 months of age are shown in Comparison of icteric infants with and without normal hearing based on three various levels of bilirubin revealed a significant relationship between the bilirubin levels among the three groups (P< 0.001) .According to our study results, the risk of hearing impairment in icteric infants with a bilirubin level higher than 20 mg/dl was 10–50 times higher. Sensorineural hearing loss was found to be related to severity of hyperbilirubinemia, cause of jaundice, and treatment approach. In addition, an increased rate of complications including microcephaly, abnormal eye movements, and developmental delay was seen in icteric infants with hearing loss. While other studies have reported a diverse range of incidence rates for abnormal ABR test results among infants with hyperbilirubinemia ,19,23-27Our findings indicating a higher risk of developing hearing loss with increased severity of hyperbilirubinemia confirm the results of previous studies ,19,31.The most common causes of jaundice among infants with sensorineural hearing loss in our study include unknown causes, ABO and Rh incompatibility, G6PD deficiency, and sepsis. The most common causes of hyper-bilirubinemia in infants with normal hearing were unknown, ABO incompatibility, urinary tract infections, G6PD deficiency, and sepsis. Idiopathic causes (30%), ABO incompatibility (18%), Rh incompatibility (14.8%), G6PD deficiency (12.6%), and sepsis (3.3%) have been described in other studies as the most common predisposing factors for jaundice complications, including hearing loss disorders .Routine G6PD deficiency was the third etiology leading to hearing impairments. As a result of lack of a proper screening system for the G6PD enzyme, as well as the parents' lack of knowledge, the affected newborns are usually presented late to the hospital and have already developed higher jaundice complications, including hearing impairment.According to this study, more icteric infants with sensorineural hearing loss have undergone a combination of phototherapy and blood exchange transfusions, which is in line with other similar studies ,33. Low Icteric infants with sensorineural hearing loss in this study had lower admission ages and higher bilirubin levels, while ABR has been shown to be independent of age, weight, bilirubin levels, and blood group in other studies . The impIn this study, the rate of hearing loss sensorineural was equal to 4.76%. In addition, icteric infants with sensorineural hearing impairment compared to icteric babies with normal hearing status are at risk of low birth weight, the need for blood exchange transfusions, eye movement disorder, opisthotonos, and microcephaly disorders. Blood group and Rh incompatibilities and G6PD deficiency are the important known causes for hearing impairment due to jaundice. Bilirubin levels have a high predictive power (82%) for prognosis of sensorineural hearing disorders in icteric neonates. Higher levels of bilirubin are associated with a greater risk of developing hearing losses. Over 90% of icteric infants with bilirubin levels of 38-47 mg/dl develop hearing impairments. Great emphasis must be laid upon screening the hearing status of infants with hyperbilirubinemia due to the importance of hearing performance in child learning processes.