Genetic Analyses of the Mouse Deafness Mutations Varitint-Waddler (Va) and Jerker (Espnje)

Genetic studies on spontaneous mouse mutants with hearing defects have provided important insights into the function of genes expressed in inner ear hair cells. Here we report on our genetic analyses of the deaf mutants varitint-waddler (Va) and jerker (Espnje). A high-resolution genetic map localizes VaJ to a 0.14 ± 0.08 cM region between D3Mit85 and D3Mit259 on distal chromosome 3. By comparative mapping, the human ortholog resides at 1p22.3 between markers D1S3449 and D1S2252. To study the effect of different genetic backgrounds on the hearing phenotype, Espnje and VaJ were crossed to various inbred strains. Auditory-evoked brainstem response tests on F2 progeny demonstrate that expression, inheritance, and penetrance of the hearing phenotype are solely controlled by the mutant allele. To test for a genetic interaction between Espnje and Cdh23v, auditory function was analyzed in double heterozygotes; no significant increases of thresholds of sound pressure levels were observed. The results establish the framework for cloning the Va gene and provide valuable insights into the genetics of deafness mutations in the mouse.     

Natural killer cell activity and CSF monoamine metabolites in suicide attempters

The aim of this study was to investigate markers of serotonin and immune function in suicidal patients. Cytotoxic activity of natural killer cells (NK) and CD16 lymphocytes were studied in 28 suicide attempters and 26 healthy controls, and related in patients to 5-hydroxyindoleacetic acid (5-HIAA) in cerebrospinal fluid (CSF). Patients with CSF 5-HIAA below the median had significantly lower NK cell activity than other patients. CD16 cell frequency was significantly lower in patients than in controls, and patients also tended to have lower NK cell cytotoxicity than healthy controls. There were no statistically significant correlations between 4-hydroxy-3methoxyphenyl glycol (HMPG), homovanillic acid (HVA), CSF cortisol and NK cell activity. The results support the hypothesis of compromised immune function in suicidal patients with evidence of disordered serotonin function.     

Advanced systemic sclerosis complicated by pulmonary hypertension and complete atrioventricular block: a case report.

BACKGROUND: Systemic sclerosis (SSc) is a connective tissue disorder of unknown etiology characterized by fibrosis of the skin and visceral organs, in which the heart is frequently (40-70% of patients) and severely involved. Pulmonary hypertension affects 10-15% of patients with SSc and is one of the most important complications adversely influencing their survival. CASE REPORT: The case report presents a 59-year-old male patient with advanced systemic sclerosis whose initial examination revealed pulmonary hypertension, rhythm and atrioventricular conduction disturbances, and elevated level of NT-proBNP. After six months the patient deteriorated; an increase in NT-proBNP level and progression of pulmonary hypertension were observed. CONCLUSIONS: The described case is followed by a discussion of cardiovascular involvement in systemic sclerosis and emphasizes that heart involvement in SSc may have very serious clinical implications.     

Application of the Minnesota Code in evaluating electrocardiographic features of ischemic heart disease in patients exposed to carbon disulphide

Summary We examined 81 men exposed for a long time to carbon disulphide (CS₂) and tested the possible electrocardiographic (ECG) changes of ischemic heart disease (I.H.D.). The subjects were examined twice in two years. In order to make the ECG evaluation more objective, the Minnesota Code was applied. Two obligatory ECG examinations and only one submaximal effort test were carried out. For comparative evaluation, the control group was examined once. We proved that, in spite of the accepted opinion concerning the atheromatous action of CS₂, this compound does not cause ECG symptoms of I.H.D. in a higher percentage of exposed persons. It also does not cause any significant increase in I.H.D. symptoms in dynamic ECG observations.