Effects of treadmill training on myelin proteomic markers and cerebellum morphology in a rat model of cuprizone-induced toxic demyelination.

BACKGROUND: Multiple sclerosis (MS) is the most common demyelinating disease of the central nervous system (CNS). If demyelination is persistent, it will result in irreversible axonal injury and loss. The purpose of the current study was to investigate the effects of treadmill training on myelin proteomic markers and cerebellum morphology in a rat model of cuprizone-induced toxic demyelination. METHODS: Thirty male rats were randomly assigned to five groups (n = 6 per group), consisting of a healthy control group (Control), a cuprizone (CPZ) group, and three exercise training groups: exercise training before and during the CPZ administration (EX-CPZ-EX), exercise training before the CPZ administration (EX-CPZ), and exercise training during the CPZ administration (CPZ-EX). A rat model of CPZ-induced toxic demyelination consisted of feeding the rats cuprizone pellets (0.2%) for 6 weeks. All exercise groups performed a treadmill training protocol 5 days/week for 6 weeks. Levels of Myelin proteolipid protein (PLP), Myelin oligodendrocyte glycoprotein (MOG), axonal injury in the cerebellar tissue, and volume, weight, and length of the cerebellum were determined. RESULTS: Results indicated a significant decrease in PLP and MOG in the CPZ groups compared to the Control group (****p < 0.0001). There was a significant increase in PLP and MOG and a significant decrease in axonal injury in the EX-CPZ-EX group as compared to other CPZ groups (****p < 0.0001), and CPZ-MS and CPZ-EX were not significantly different from one another. However, there were no significant differences between the groups for the volume, weight, or length of the cerebellum. CONCLUSION: Treadmill training improved myelin sheath structural proteins and axonal injury in cerebellar tissue in a rat model of CPZ-induced toxic demyelination.

Astaxanthin Reduces Demyelination and Oligodendrocytes Death in A Rat Model of Multiple Sclerosis.

OBJECTIVE: Astaxanthin (AST) is a carotenoid with anti-oxidative, anti-inflammatory, and anti-apoptotic properties. It has also been reported that AST exerts protective effects against neurodegenerative diseases and reduces oxidative stress-induced the central nervous system (CNS) injury. In this study, we aimed to evaluate the protective potential of AST in inhibiting demyelination and oligodendrocyte death in a rat model of multiple sclerosis (MS). MATERIALS AND METHODS: In this experimental study, forty Wistar rats were randomly assigned to four experimental groups: control group (with normal feeding), cuprizone (CPZ group) that daily received 0.6% CPZ for 4 weeks, sham group that daily received 0.6% CPZ plus dimethyl sulfoxid (DMSO) for 4 weeks, and AST group that daily received 0.6% CPZ and after 12 hours were treated with AST (3 mg/kg), for 4 weeks. Muscle strength was evaluated by the behavioral basket test at the end of every week for 4 weeks. Luxol Fast Blue (LFB) staining was utilized for the identification of myelination and demyelination. Myelin density was evaluated by the ImageJ software. The expression of A2B5 (oligodendrocyte precursor protein) and myelin oligodendrocyte protein (MOG) were assessed by immunohistochemistry (IHC) and the expression of myelin basic protein (MBP), MOG, and platelet-derived growth factor-alpha (PDGFR-α) genes was examined by the real-time polymerase chain reaction (RT-PCR) technique. RESULTS: The administration of AST reduced the oligodendrocyte damage and myelin sheath disruption in a rat model of MS. The basket behavioral test showed the improvement of muscle strength in the AST group compared with CPZ and sham groups. Besides, the results of real-time PCR and IHC indicated the beneficial effects of AST in declining demyelination and oligodendrocyte death in a rat model of MS. CONCLUSION: AST reduces damages to the myelin sheath and oligodendrocyte death in a rat model of MS.

Prevalence of Associated Anomalies in Cleft Lip and/or Palate Patients.

INTRODUCTION: Orofacial clefts are among the most common congenital anomalies. Patients presenting with orofacial clefts often require surgery or other complex procedures. A cleft lip or palate can be a single anomaly or a part of multiple congenital anomalies. The reported prevalence of cleft disease and associated anomalies varies widely across the literature, and is dependent on the diagnostic procedure used. In this study we determined the prevalence of associated anomalies in patients with a cleft lip and/or palate, with a specific focus on cardiac anomalies. MATERIALS AND METHODS: In this cross-sectional study, 526 patients with a cleft lip and /or palate admitted to the children's referral hospital between 2006 and 2011 were evaluated. All associated anomalies were detected and recorded. Patient information collected included age, gender, type and side of cleft, craniofacial anomalies and presence of other anomalies, including cardiac anomalies. Data were analyzed using SPSS version 16. RESULTS: Of the 526 patients enrolled in the study, 58% (305) were male and 42% (221) were female. In total, 75% of patients (396) were aged between 4 and 8 years and 25% (130) were aged less than 4 years. The most common cleft type in our study was bilateral cleft palate. The most commonly associated anomaly among cleft patients, in 12% of cleft patients, was a cardiac anomaly. The most common cardiac anomaly was atrial septal defect (ASD). CONCLUSION: The prevalence of associated anomalies among orofacial cleft patients is high. The most common associated anomaly is cardiac anomaly, with ASD being the most common cardiac anomaly. There are no significant relationships between type of cleft and associated cardiac anomalies.

Serum Level of Matrix Metalloproteinase-2 and -9 in Patients with Laryngeal Squamous Cell Carcinoma and Clinical Significance.

BACKGROUND: Laryngeal cancer is an important malignancy in head and neck area and squamous cell carcinoma (SCC) is the most common type accounting for 95% of cases. Increase in matrix metalloproteinases (MMPs) in different tumors and their correlation with tumor invasiveness has been documented. However, most studies have evaluated MMP-2 and MMP-9 expression and few have evaluated serum levels. The aim of current study was to evaluate serum levels in patients with laryngeal SCC compared to normal subjects and assess any relation with tumor clinicopathological findings. MATERIALS AND METHODS: In this case control study, 20 patients with oral SCC and 20 healthy subjects were included. Serum levels of MMP-2 and MMP-9 were compared between groups and correlations with findings including grade (T) and node involvement (N) were evaluated. RESULTS: Patients with laryngeal SCC had significantly higher serum levels of MMP-2 (p=0.01) and MMP-9 (p=0.03) compared to healthy subjects. Patients with higher T stage (T3,4) had significantly higher MMP-2 (p=0.04) and MMP-9 (p=0.01). There was significant positive correlation between serum levels of MMP-2 with T stage (r=0.45, p=0.04) and lymph node involvement (r=0.563, p=0.01) and between levels of MMP-9 with T stage (r=0.527, p=0.01). CONCLUSIONS: Our results showed that compared to healthy subjects, both MMP-2 and MMP-9 are significantly increased in serum of laryngeal SCC cases. MMP-2 was correlated with lymph node involvement while MMP-9 has stronger correlation with T stage compared to MMP-2.

Effect of adenotonsillectomy on ADHD symptoms of children with adenotonsillar hypertrophy and sleep disordered breathing.

BACKGROUND: Adenotonsillar hypertrophy is the most common etiologic agent for the obstruction of the upper airways in children, which might be associated with attention-deficit hyperactivity disorder (ADHD), one of the most common psychiatric disorders of childhood. Despite the concurrence of these two conditions, i.e., obstruction of the airways and ADHD, no exact etiologic relationship has been established between adenotonsillectomy (AT) and ADHD symptoms. This study was undertaken to evaluate the effect of AT on the ADHD symptoms in children with adenotonsillar hypertrophy and sleep disordered breathing (SDB). METHODS: The design of the present study consisted of pre-test and post-test, followed by post hoc tests. Fifty-three children aged 3-12 were included in this study, selected from those referring to the Pediatric Hospital of Tabriz University of Medical Sciences, with SDB, adenotonsillar hypertrophy and ADHD based on DSM-IV criteria, by availability of the subjects undergoing adenotonsillectomy after evaluation of the severity of ADHD symptoms. The scores of ADHD symptoms were evaluated before AT and at 3- and 6-month postoperative intervals based on Conner's Parent Rating Scale-Revised (CPRS-R) Questionnaire. Repeated-measures ANOVA and Fisher's exact test were used for data analysis. RESULTS: AT resulted in a significant decrease in the severity of ADHD symptoms (oppositional behavior, cognitive disorders, inattention, hyperactivity and ADHD index) at 3- and 6-month postoperative intervals (P<0.001), with more significant decreases at 6-month postoperative interval compared to 3-month interval (P<0.001). CONCLUSIONS: Based on the results of this pilot study, AT in children with SDB associated with ADHD resulted in a significant decrease in the severity of ADHD symptoms.

Serum Level of Interleukin-6 in Patients with Oral Tongue Squamous cell Carcinoma.

INTRODUCTION: The clinical outcome of patients with squamous cell carcinoma (SCC) located in the head and neck has remained poor despite ongoing advances in diagnosis and management. Interleukin-6(IL-6) is a multi-functional cytokine that plays an important role in the process of cell differentiation and is increased in several malignancies. The aim of this study was to investigate the serum levels of interleukin-6 in patients with oral tongue SCC. MATERIALS AND METHODS: In a cross-sectional study, 17 patients with oral tongue SCC were compared with the same number of age- and gender-matched healthy subjects. Serum IL-6 level fluctuation was determined using an immunological technique, before detecting its possible association with the subjects' age, gender, drinking and smoking history, cancer site, and disease severity. RESULTS: The intensity of serum IL-6 in patients with oral tongue SCC was statistically significantly higher than that in healthy subjects (P<0.001). Serum IL-6 level was independent of the patients' age, gender, smoking and drinking history as well as cancer stage. CONCLUSION: IL-6 is a valuable biomarker in the diagnosis of oral tongue SCC. Its high sensitivity makes prediction of this condition possible, while this biomarker can also be used to screen high-risk patients.

Serum levels of MMP9 and MMP2 in patients with oral squamous cell carcinoma.

BACKGROUND: Squamous cell carcinoma (SCC) is the most common cancer in the oral area. Matrix metalloproteinases (MMPs) and especially MMP-2 and MMP-9 are increased in malignancy and lymph node involvement in oral SCCs. We aimed to evaluate the serum levels of MMP-2 and MMP-9 in patients with oral SCC compared to normal subjects and their relation with clinicopathological findings. MATERIALS AND METHODS: In this case control study, 20 patients with oral SCC and 20 healthy subjects were included and serum levels of MMP-2 and MMP-9 were compared between groups. Also, the correlation between these markers with clinicopathological findings including grade (T) and node (N) were evaluated. RESULTS: Patients with oral SCC had significantly higher serum levels of MMP-2 (p=0.01) and MMP-9 (p<0.001) compared to healthy subjects. With increase in grade T, MMP-2 was significantly increased (p=0.001), but in the MMP-9 case this was not significant (p=0.27). The levels of MMP-2 (p=0.002) and MMP-9 (p=0.01) in cases with lymph node involvement and that of MMP-2 in subjects with smoking history (p=0.001) were significantly high. There was significantly positive correlation between MMP-2 with grade T tumor (r=0.598, p=0.005), lymph node involvement (r=0.737, p<0.001) and smoking (r=0.674, p=0.001) and also between MMP-9 and lymph node involvement (r=0.474, p=0.03). CONCLUSIONS: Both markers are significantly increased in oral SCC compared to healthy subjects. However, MMP-2 was better for evaluating lymph node involvement and tumor grade.

Effects of peptidic growth hormone secretagogue receptor (GHS-R) antagonist [D-Lys3] on some of serum hormonal and biochemical parameters in Wistar rat model.

OBJECTIVE: The present study investigated the effects of different dosages of a GHS-R antagonist [D-Lys3] on some serum hormonal (cortisol, T3 and T4) and biochemical parameters in a rat. MATERIALS AND METHODS: Thirty-six 60-day-old male rats were assigned to four treatments. [D-Lys3]-GHRP-6 solutions were infused via intraperitoneal injections. Blood was collected and analyzed. RESULTS: The large dosages of a GHS-R antagonist (200 ng/kg BW) caused increases in cortisol, whereas no significant changes occurred when low dosages were injected. There were no significant changes in T3 and T4 following the administration of the GHS-R antagonist, but a considerable increase was observed in blood glucose levels of the groups (G50, G100, and G200 ng/kg BW). There was a significant increase in total protein when the greatest dose was administrated (G200 ng/kg BW). However, total cholesterol, triglycerides, and albumin showed no significant changes. CONCLUSIONS: Exogenous GHS-R antagonist can cause an increase in glucose and moderate increases in cortisol and total protein, yet it has no significant effect on T3 and T4 levels or on the concentrations of serum lipids. The effect of GHS-R antagonist is not completely adverse to the effects of ghrelin. Further molecular studies are necessary to identify the physiological effects of the peptidic GHS-R antagonist.

Effects of peptidic growth hormone secretagogue receptor (GHS-R) antagonist [D-Lys3] on some of serum hormonal and biochemical parameters in Wistar rat model / Efeitos do antagonista [D-Lys3] do receptor do peptídeo secretagogo do hormônio do crescimento (GHS-R) sobre alguns parâmetros bioquímicos e hormonais séricos em um modelo em ratos Wistar

Objective : The present study investigated the effects of different dosages of a GHS-R antagonist [D-Lys3] on some serum hormonal (cortisol, T3 and T4) and biochemical parameters in a rat.Materials and methods : Thirty-six 60-day-old male rats were assigned to four treatments. [D-Lys3]-GHRP-6 solutions were infused via intraperitoneal injections. Blood was collected and analyzed.Results : The large dosages of a GHS-R antagonist (200 ng/kg BW) caused increases in cortisol, whereas no significant changes occurred when low dosages were injected. There were no significant changes in T3 and T4 following the administration of the GHS-R antagonist, but a considerable increase was observed in blood glucose levels of the groups (G50, G100, and G200 ng/kg BW). There was a significant increase in total protein when the greatest dose was administrated (G200 ng/kg BW). However, total cholesterol, triglycerides, and albumin showed no significant changes.Conclusions : Exogenous GHS-R antagonist can cause an increase in glucose and moderate increases in cortisol and total protein, yet it has no significant effect on T3 and T4 levels or on the concentrations of serum lipids. The effect of GHS-R antagonist is not completely adverse to the effects of ghrelin. Further molecular studies are necessary to identify the physiological effects of the peptidic GHS-R antagonist. Arq Bras Endocrinol Metab. 2014;58(3):288-91.

Objetivo : O presente estudo investigou os efeitos de diferentes doses do antagonista do GHS-R [D-Lys3] sobre alguns parâmetros hormonais (cortisol, T3 e T4) e bioquímicos em ratos.Materiais e métodos : Trinta e seis ratos machos com 60 dias de idade foram alocados para quatro tratamentos. Soluções de [D-Lys3]-GHRP-6 foram administradas por meio de injeções intraperitoneais e foram coletadas e analisadas amostras.Resultados : Doses altas de antagonista de GHS-R (200 ng/kg PC) levaram a aumento do cortisol, enquanto não houve diferença significativa quando foram injetadas doses baixas. Não houve alterações significativas em T3 e T4 depois da administração do antagonista do GHS-R, mas foi observado aumento considerável nos níveis de glicose sanguínea dos grupos (G50, G100 e G200 ng/kg PC). Houve aumento significativo na proteína total quando foi administrada a maior dose (G200 ng/kg PC), entretanto, não foram observadas alterações no colesterol total, nos triglicérides e na albumina.Conclusões : O antagonista do GHS-R exógeno pode causar aumento da glicose e aumento moderado do cortisol e proteína total, embora não haja efeitos significativos nos níveis de T3 e T4 ou na concentração de lipídios séricos. O efeito do antagonista de GHS-R não é completamente adverso aos efeitos da grelina. Devem ser feitos outros estudos moleculares para se identificar os efeitos fisiológicos do peptídeo antagonista do GHS-R. Arq Bras Endocrinol Metab. 2014;58(3):288-91.

Does adenotonsillectomy alter IGF-1 and ghrelin serum levels in children with adenotonsillar hypertrophy and failure to thrive? A prospective study.

OBJECTIVES: Adenotonsillar hypertrophy (ATH) contributes to upper airway obstruction and recurrent tonsillitis in children. The aim of this study was to evaluate the effect of adenotonsillectomy on serum IGF-1 and ghrelin levels in children with ATH failure to thrive. METHODS: Forty pre-pubertal children with more than 5 years of age (6.57 ± 1.284 years) suffering from ATH, sleep disorder breathing, snoring, open mouth breathing and growth retardation were studied. Blood samples were taken eight hours after fasting and weight and height were measured by SECA instrument. Blood samples were centrifuged immediately and the extracted sera were stored at -70 °C in Eppendorf vials. IGF-1 and ghrelin were measured by ELISA kit. Patients with adenotonsillectomy indication underwent adenotonsillectomy and serum levels of IGF-1 and ghrelin were measured 12 months after operation. RESULTS: Weight, height and BMI were increased significantly after operation (P < 0.001). Serum IGF-1 and ghrelin levels increased significantly after operation compared to before operation (P < 0.001). CONCLUSION: Growth retardation in children with adenotonsillar hypertrophy is related to lower serum IGF-1 levels. Ghrelin levels increase before the meals and ghrelin increases hunger and food intake. The results obtained from our study confirmed that weight, height and BMI increase significantly following adenotonsillectomy; this could in turns prevent undesirable and irreversible physiological changes that occur due to adenotonsillar hypertrophy. Adenotonsillectomy in children with adenotonsillar hypertrophy and failure to thrive increases IGF-1 and Ghrelin serum levels which might contribute to the improvement in the growth pattern of the children.

Warming Endotracheal Tube in Blind Nasotracheal Intubation throughout Maxillofacial Surgeries.

INTRODUCTION: Blind nasotracheal intubation is an intubation method without observation of glottis that is used when the orotracheal intubation is difficult or impossible. One of the methods to minimize trauma to the nasal cavity is to soften the endotracheal tube through warming. Our aim in this study was to evaluate endotracheal intubation using endotracheal tubes softened by hot water at 50 °C and to compare the patients in terms of success rate and complications. METHODS: 60 patients with ASA Class I and II scheduled to undergo elective jaw and mouth surgeries under general anesthesia were recruited. RESULTS: success rate for Blind nasotracheal intubation in the control group was 70% vs. 83.3% in the study group. Although the success rate in the study group was higher than the control group, this difference was not statistically significant. The most frequent position of nasotracheal intubation tube was tracheal followed by esophageal and anterior positions, respectively. CONCLUSION: In conclusion, our study showed that using an endotracheal tube softened by warm water could reduce the incidence and severity of epistaxis during blind nasotracheal intubation; however it could not facilitate blind nasotracheal intubation.

Effect of low level laser application at the end of surgery to reduce pain after tonsillectomy in adults.

INTRODUCTION: Tonsillectomy is among commonest otorhinolaryngologic surgeries. Many methods have been used to control post surgical pain, but despite it, pain is still one of the problems related to this operation. Recently, due to the non invasiveness of low level lasers, this modality has attracted attention. The purpose of this study is to evaluate the effects of low level laser irradiation at the end of surgery on reduction of pain after tonsillectomy in adults. METHODS: In a clinical trial, 60 adult patients, candidates for tonsillectomy were randomly assigned to two groups, A and B, and both groups were anesthetized similarly by the same technique. At the end of surgery, in the case group, the tonsils' bed were irradiated by infrared laser with 980nm wavelength, 100Hz, 4J/cm(2) from the infra mandibular angle. In the control group, the tonsils' bed had laser therapy with a turned off probe. Following laser treatment, the patients were reversed and extubated and consciousness achieved, pain and odynophagia were assessed at 2, 4, 6, 8, 12 and 24h post surgery based on visual analog scale for pain (VAS) and analgesic consumption. RESULTS: In the laser group frequency of patients with pain sensation in each evaluated hour was lower than in the control group. The amount of pain decrease and analgesic consumption reduction was significantly higher in patients who received laser (P=0.01). CONCLUSION: Based on the results of this study, use of low level lasers is effective in reducing tonsillectomy post surgical pain in adults.

Effect of in ovo ghrelin administration on serum malondialdehyde level in newly-hatched chickens.

OBJECTIVE: To investigate effects of in ovo ghrelin administration on serum malondialdehyde (MDA) level in newly-hatched chickens. METHODS: Fertilized eggs were divided into 7 groups: group T1 as control (without injection), group T2 (in ovo injected with 50 ng/egg ghrelin on day 5), group T3 (in ovo injected with 100 ng/egg ghrelin on day 5), group T4 (in ovo injected with 50 ng/egg ghrelin on day 10), group T5 (in ovo injected with 100 ng/egg ghrelin on day 10), group T6 (in ovo injected with solvent: 1% acetic acid, without ghrelin on day 5) and group T7 (in ovo injected with solvent without ghrelin on day 10). After hatching, serum MDA concentrations were determined. RESULTS: Ghrelin administrated groups (T2, T3, T4 and T5) had lower serum MDA level in comparison with control group (T1) or solvent injected groups (T6 and T7). T2 and T3 (ghrelin injection on day 5) had significantly lower MDA concentrations (4.10 and 4.60 nmol/mL, respectively) in comparison with other groups. In T4 and T5, MDA levels were lower than T1, T6 and T7 (non-ghrelin administrated groups) (9.53 and 9.50 in comparison with 10.73, 10.03 and 10.13 nmol/mL) and were higher than T2 and T3. CONCLUSIONS: It can be concluded that in ovo administration of ghrelin can have anti-oxidative protection and reduce serum MDA level. Ghrelin administration on day 5 of incubation is more efficient.

Effect of intracerebrovascular injection of ghrelin on some of erythropoietic indicators in 42-day-old broiler chicken

Objective: To evaluate the erythropoietic indicators in 42-day-old broiler chicks following intracerebrovascular injection of exogenous rat ghrelin at 21 day of age. Methods: A total of 90 male chicks were divided into three experimental groups including three replicates (10 chicks for each replicate): group 1 without any ghrelin injection, group 2 subjected to intracerebrovascular injection of 0.5 mg ghrelin/kg b.w. and group 3 subjected to intracerebrovascular injection of 1.0 mg ghrelin/kg b.w. at 21 days of age. Results: Intracerebrovascular injection of 0.5 or 1.0 mg ghrelin/kg b.w. at 21 days of age did not have any significant effect on the measured erythropoietic indicators including red blood cell, hematocrit, haemoglobin, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration. Conclusions:Intracerebrovascular injection of exogenous rat ghrelin does not have any considerable effect on erythropoietic activity of broiler chickens.

Effect of in ovo ghrelin administration on serum malondialdehyde level in newly-hatched chickens

Objective: To investigate effects of in ovo ghrelin administration on serum malondialdehyde (MDA) level in newly-hatched chickens. Methods: Fertilized eggs were divided into 7 groups: group T1 as control (without injection), group T2 (in ovo injected with 50 ng/egg ghrelin on day 5), group T3 (in ovo injected with 100 ng/egg ghrelin on day 5), group T4 (in ovo injected with 50 ng/egg ghrelin on day 10), group T5 (in ovo injected with 100 ng/egg ghrelin on day 10), group T6 (in ovo injected with solvent: 1% acetic acid, without ghrelin on day 5) and group T7 (in ovo injected with solvent without ghrelin on day 10). After hatching, serum MDA concentrations were determined. Results:Ghrelin administrated groups (T2, T3, T4 and T5) had lower serum MDA level in comparison with control group (T1) or solvent injected groups (T6 and T7). T2 and T3 (ghrelin injection on day 5) had significantly lower MDA concentrations (4.10 and 4.60 nmol/mL, respectively) in comparison with other groups. In T4 and T5, MDA levels were lower than T1, T6 and T7 (non-ghrelin administrated groups) (9.53 and 9.50 in comparison with 10.73, 10.03 and 10.13 nmol/mL) and were higher than T2 and T3. Conclusions: It can be concluded that in ovo administration of ghrelin can have anti-oxidative protection and reduce serum MDA level. Ghrelin administration on day 5 of incubation is more efficient.

Mutation analysis of familial GJB2-related deafness in Iranian Azeri Turkish patients.

AIMS: Mutations in the GJB2 gene-encoding connexin 26 protein are the main cause for autosomal recessive nonsyndromic hearing loss worldwide. In this study, we assessed the contributions made by GJB2 and del(GJB6-D13S1830) mutations to the autosomal recessive nonsyndromic deafness genetic load in Iranian Azeri Turkish patients. RESULTS: Probands from 209 different nuclear families were investigated. GJB2 mutations were found in 28% of the patients. Among these patients 44 families had 35delG mutation. The following GJB2 variants, R184P, DelE120, V27I+E114G, W24 x, DelE119, R127H, 235DelC, 290-291 insA, Y155 x, A171T, E147 x, 35insG, G158S, R32H, R143Q, T123N, R143W, H16R, V153I, V27I, M163V, and F154F (a new variant), were identified in 126 of the 418 chromosomes. R143Q mutation was identified as compound heterozygous with 35delG in one profoundly deaf patient. Both parents of this patient were healthy, and one normal sister of this patient was also a carrier for the R143Q, indicating that this mutation has incomplete penetrance. CONCLUSIONS: Our results show that GJB2 mutations are responsible for about 28% of the autosomal recessive nonsyndromic hearing loss in this ethnic group. 35delG is the most prevalent GJB2 mutation accounting for 64.5% of the GJB2 mutations.