ROR1 is essential for proper innervation of auditory hair cells and hearing in humans and mice

Hair cells of the inner ear, the mechanosensory receptors, convert sound waves into neural signals that are passed to the brain via the auditory nerve. Little is known about the molecular mechanisms that govern the development of hair cell–neuronal connections. We ascertained a family with autosomal recessive deafness associated with a common cavity inner ear malformation and auditory neuropathy. Via whole-exome sequencing, we identified a variant (c.2207G>C, p.R736T) in ROR1 (receptor tyrosine kinase-like orphan receptor 1), cosegregating with deafness in the family and absent in ethnicity-matched controls. ROR1 is a tyrosine kinase-like receptor localized at the plasma membrane. At the cellular level, the mutation prevents the protein from reaching the cellular membrane. In the presence of WNT5A, a known ROR1 ligand, the mutated ROR1 fails to activate NF-κB. Ror1 is expressed in the inner ear during development at embryonic and postnatal stages. We demonstrate that Ror1 mutant mice are severely deaf, with preserved otoacoustic emissions. Anatomically, mutant mice display malformed cochleae. Axons of spiral ganglion neurons show fasciculation defects. Type I neurons show impaired synapses with inner hair cells, and type II neurons display aberrant projections through the cochlear sensory epithelium. We conclude that Ror1 is crucial for spiral ganglion neurons to innervate auditory hair cells. Impairment of ROR1 function largely affects development of the inner ear and hearing in humans and mice.Sensorineural hearing loss (SNHL) is diagnosed in approximately 1 per 500 newborns (1). A genetic etiology is present in more than half of the cases. Inner ear anomalies (IEAs), demonstrated with computerized tomography or magnetic resonance imaging, are associated with SNHL in about one-third of individuals (2). Although IEAs can be diagnosed in patients with other clinical manifestations, such as those seen in Waardenburg [Mendelian Inheritance in Man (MIM) 193500], Pendred (MIM 274600), or BOR (MIM 113650) syndromes, the majority of cases fall into the category of nonsyndromic deafness. Despite recent progress in identifying genes that determine many forms of hearing loss (hereditaryhearingloss.org/), the genetic basis of IEAs in humans remains largely unknown.The inner ear is a complex organ that is built from a simple structure, referred to as the otocyst, through a series of morphogenetic events. Roughly, it consists of a dorsal vestibular and a ventral auditory component (3). Studies in model organisms have identified a number of genes that play roles in proper development of the inner ear. Mouse models have been particularly relevant because the anatomy and physiology of the murine auditory system are similar to those of humans. Mutations in human orthologs of many of these genes have been reported to cause deafness in humans as well (4).Next-generation sequencing technologies have allowed rapid identification of novel human deafness genes. Approximately 85% of disease-causing mutations in Mendelian disorders have been found in the protein-coding regions, despite the fact that this portion accounts for less than 2% of the entire human genome (5). Accordingly, whole exome sequencing (WES) has been frequently used because it allows for a targeted enrichment and resequencing of nearly all exons of protein-coding genes.In this study, via WES, we detected a mutation in ROR1 (receptor tyrosine kinase-like orphan receptor 1; MIM 602336), encoding receptor tyrosine kinase-like orphan receptor 1, that associates with an IEA and nonsyndromic deafness in a family. Further characterization of Ror1 mutant mice revealed that Ror1 deficiency results in defective hair cell innervation and abnormal cochlear development.     

Incidence,risk factors and causes of death in an HIV care programme with a large proportion of injecting drug users

Objectives To identify factors influencing mortality in an HIV programme providing care to large numbers of injecting drug users (IDUs) and patients co‐infected with hepatitis C (HCV). Methods A longitudinal analysis of monitoring data from HIV‐infected adults who started antiretroviral therapy (ART) between 2003 and 2009 was performed. Mortality and programme attrition rates within 2 years of ART initiation were estimated. Associations with individual‐level factors were assessed with multivariable Cox and piece‐wise Cox regression. Results A total of 1671 person‐years of follow‐up from 1014 individuals was analysed. Thirty‐four percent of patients were women and 33% were current or ex‐IDUs. 36.2% of patients (90.8% of IDUs) were co‐infected with HCV. Two‐year all‐cause mortality rate was 5.4 per 100 person‐years (95% CI, 4.4–6.7). Most HIV‐related deaths occurred within 6 months of ART start (36, 67.9%), but only 5 (25.0%) non‐HIV‐related deaths were recorded during this period. Mortality was higher in older patients (HR = 2.50; 95% CI, 1.42–4.40 for ≥40 compared to 15–29 years), and in those with initial BMI < 18.5 kg/m² (HR = 3.38; 95% CI, 1.82–5.32), poor adherence to treatment (HR = 5.13; 95% CI, 2.47–10.65 during the second year of therapy), or low initial CD4 cell count (HR = 4.55; 95% CI, 1.54–13.41 for <100 compared to ≥100 cells/μl). Risk of death was not associated with IDU status (P = 0.38). Conclusion Increased mortality was associated with late presentation of patients. In this programme, death rates were similar regardless of injection drug exposure, supporting the notion that satisfactory treatment outcomes can be achieved when comprehensive care is provided to these patients.     

A giant ovarian cyst in a neonate with classical 21-hydroxylase deficiency with very high testosterone levels demonstrating a high-dose hook effect

Congenital adrenal hyperplasia (CAH) is a group of disorders affecting the adrenal steroid synthesis. The most common form, 21-hydroxylase deficiency (21-OHD), leads to decreased production of cortisol and aldosterone with increased androgen secretion. In classic CAH, glucocorticoid treatment can be life-saving and serves to bring the symptoms under control. However, the treatment challenge is to effectively control the excess androgen effect by using the lowest possible glucocorticoid dose. Previous studies suggested a relationship between ovarian cyst formation and adrenal androgen excess, but neonatal large ovarian cysts have been very rarely reported in newborns with CAH. Here, we present the unique case of a neonate with classical 21-OHD who underwent surgery for a giant (10x8x7 cm) unilateral solitary ovarian follicular cyst on the 2nd postnatal day. Hormonal evaluation of the patient revealed high-dose hook effect for serum testosterone levels for the first time by a two-site immunoradiometric assay. Possible mechanisms by which androgen excess may cause ovarian cyst formation are discussed.     

Acute presentation of autoimmune hepatitis in a patient with myasthenia gravis, thymoma, Hashimoto thyroiditis and connective tissue disorder

Myasthenia gravis is an antibody-mediated autoimmune disease at the neuromuscular junctions. It can be associated with many other autoimmune diseases. We report a case of acute presentation of autoimmune hepatitis with myasthenia gravis, thymoma, Hashimoto thyroiditis and connective tissue disorder.     

Deficiency of a New Protein Associated with Cardiac Syndrome X; Called Adropin

The pathophysiology of cardiac syndrome X (CSX) is still unclear, but most patients with CSX have endothelial dysfunction. It has been shown that adropin uniquely effects the regulation of endothelial function. The purpose of the study was to evaluate the role of adropin in CSX. Eighty‐six consecutive cardiac syndrome X‐diagnosed patients and 86 age‐sex matched healthy subjects were enrolled into the study. Serum adropin levels, nitrite/nitrate levels were measured in each subject. The adropin levels were significantly lower in patients with CSX than healthy subjects (1.7 ± 0.8 ng/mL and 3.4 ± 1.8 ng/mL, respectively; P < 0.001). The BMI values of patients with CSX were significantly higher than control subjects (28.1 ± 2.4 kg/m² and 26.0 ± 3.7 kg/m², respectively; P < 0.001). Plasma nitrite/nitrate levels were lower in patients with CSX than control subjects (15.9 ± 1.6   μmol/L vs. 25.4 ± 2.8 μmol/L, respectively; P < 0.001), and they have a significantly positive correlation with plasma adropin levels (r = 0.463, P < 0.001). In the multiple linear regression analysis, nitrite/nitrate levels, BMI, and adropin were found to be independent risk factors for CSX. A ROC curve is used to identify the ability of adropin levels to predict the cardiac syndrome X. The area under the ROC curve was 0.854 for adropin levels (P = 0.0001). The sensitivity and specificity values of adropin levels were 90.7 and 70.9%, respectively (cut‐off value 2.73). In conclusion, lower serum adropin levels were associated with CSX. Adropin is an independent risk factor for CSX.     

Significance of orbital fatty tissue for exophthalmos in thyroid-associated ophthalmopathy

PURPOSE: To correlate exophthalmos with the volume of extraocular muscle and orbital fatty tissue in thyroid-associated ophthalmopathy (TAO), using MRI that enables the orbital soft tissues to be well defined. METHODS: Thirty-three orbits, 20 from 10 patients with TAO and 13 from 13 controls, were employed. T1-weighted orbital MR slices 2 or 3 mm thick were obtained in axial, coronal and sagittal planes. Tracing the outlines of each structure, we measured the total sectional areas. Volumes of the extraocular muscle, of the fatty tissue and of the bony orbital cavity were calculated by multiplying the slice thickness. Exophthalmos was also measured using axial MRI. RESULTS: In TAO the volume increment of orbital fatty tissue (6.19 cm(3)) was much greater than that of extraocular muscle (1.16 cm(3)). Increase of exophthalmos by 1 mm needed a total orbital volume increment of 0.92 cm(3). The total orbital fatty tissue volume (correlation coefficient 0.70, P=0.06%) and the anterior orbital fatty tissue volume (0.64, P=0.23%) were more closely correlated with the degree of exophthalmos than was extraocular muscle volume (0.58, P=0.8%). Moreover, the volume increment of extraocular muscle and orbital fatty tissue was not always proportional. CONCLUSION: The results show that the orbital fatty tissue involvement is closely related to the degree of exophthalmos. For studying exophthalmos in TAO, the volumetric change, not only in ocular muscles, but also in orbital fatty tissue, should be taken into consideration.     

MicroRNA-381 increases radiosensitivity in esophageal squamous cell carcinoma

Background: Radiation resistance poses a major clinical challenge in treatment of esophageal squamous cell carcinoma (ESCC). However, the mechanisms of radioresistance has not been fully elucidated. Since accumulating evidence demonstrates that aberrant expression of microRNAs (miRNAs) contributes to cancer sensitivity to radiation, we aimed to identify miRNAs associated with radioresistance of ESCC. Methods: In this study, we used GeneChip miRNA Array to perform an comparison of miRNAs expression in tissues from primary ESCC and recurrent ESCC in situ after radiotherapy. Differential expressions of miRNAs were comfirmed by quantitative Real-Time PCR in tissues and six ESCC cell lines. Cell radiosensitivity were determined by colony formation assay. Functional analyses of miRNA-381 in ESCC cells growth and metastasis were performed by MTT and Transwell Assays. In vivo assays of the functions of miRNA-381 were performed in tumor xenografts. Results: One miRNA candidate, miRNA-381, was found to be downregulated in radiation resistance tissues and cells. Enforced expression of miRNA-381 increased radiosensitivity of ESCC cells and promoted nonaggressive phenotype including decreased cellular proliferation and migration. In contrast, inhibition of miRNA-381 in ESCC cells promoted radiation resistance and development of an aggressive phenotype. In vivo assays extended the significance of these results, showing that miRNA-381 overexpression decreased the tumor growth and the resistance to radiation treatment in tumor xenografts. Conclusions: Together, our work reveals miRNA-381 expression as a critical determinant of radiosensitivity in esophageal cancer cells.     

Hypermethylation of repetitive DNA elements in livers of mice fed an atherogenic diet

ObjectiveDNA methylation status was examined in C57BL/6J obese mice fed an atherogenic diet (AD) to establish the correlation between epigenetic alterations and obesity-related abnormalities.MethodsSix-week-old male C57BL/6J mice were fed a normal diet (ND) or AD for 8 wk. Methylation levels of global DNA and repetitive DNA elements in livers of ND-fed mice and AD-fed mice were examined.ResultsThe total amounts of 5-MeC genomic contents in livers of AD-fed mice were increased as compared with those of ND-fed mice. Hypermethylation of repetitive DNA elements was observed in livers of AD-fed mice.ConclusionHypermethylation of repetitive DNA elements in livers of AD-fed mice proposes epigenetic changes by nutritional intervention.