A novel mutation, Ser143Pro, in the lamin A/C gene is common in finnish patients with familial dilated cardiomyopathy.

AIMS: The mutations most frequently associated with dilated cardiomyopathy (DCM) have been reported in the lamin A/C gene. The role of variants of the lamin A/C gene was investigated in patients with DCM from eastern and southern Finland. METHODS AND RESULTS: All 12 exons of the lamin A/C gene were screened in 18 well-characterised familial DCM patients from eastern and southern Finland and in 72 sporadic DCM patients from eastern Finland using the PCR-SSCP method. A novel mutation, Ser143Pro (S143P), was detected in the lamin A/C gene in 24 subjects from 5 unrelated families and in one sporadic case of DCM. Sinus or atrioventricular nodal dysfunction occurred in the majority of the affected subjects, many of which required pacemaker implantation. Seven patients (28%) with the S143P mutation died suddenly or from progressive heart failure, or underwent heart transplantation. The haplotypes 5-5-5-3, 5-5-5-2, and 5-5-5-1 co-segregated with the Ser143Pro mutation, suggesting a founder effect of this mutation. CONCLUSIONS: A novel mutation S143P in the lamin A/C gene was found to be common among Finnish DCM patients. Haplotype analysis strongly suggests a founder effect of this mutation. The phenotype is characterised by severe heart failure, progressive atrioventricular conduction defects, and sudden death. Screening for the lamin A/C gene and, particularly, the S143P mutation seems warranted when patients with DCM have conduction system disturbances.     

Plantar shear stress measurements — A review

Background

Mechanical stress at the plantar surface has two components, pressure acting normal to the surface and shear stress acting tangential to the surface. Typically only pressure is measured and reported. However, plantar shear stress also plays a major role, especially in diabetic ulceration.

Methods

During the last few decades, a variety of methods have been developed for the measurement of plantar shear stress. This paper reviews the technologies used in plantar shear stress measurements.

Findings

Several technologies have been used, e.g. magneto-resistors, strain gauges, optical methods, piezoelectric materials and capacitive sensors. Examples of plantar shear stress values measured with the developed devices are also collected here and the relationship between sensor characteristics and the measured plantar shear stress distribution is discussed.

Interpretation

Even with the limitations of current plantar shear stress measurement technologies, they can provide useful information on the plantar stress distribution.     

The Clinical Presentation of Puumala Hantavirus Induced Hemorrhagic Fever with Renal Syndrome Is Related to Plasma Glucose Concentration

Puumala hantavirus (PUUV) causes a hemorrhagic fever with renal syndrome characterized by thrombocytopenia, increased capillary leakage, and acute kidney injury (AKI). As glucosuria at hospital admission predicts the severity of PUUV infection, we explored how plasma glucose concentration associates with disease severity. Plasma glucose values were measured during hospital care in 185 patients with PUUV infection. They were divided into two groups according to maximum plasma glucose concentration: P-Gluc < 7.8 mmol/L (n = 134) and P-Gluc ≥ 7.8 mmol/L (n = 51). The determinants of disease severity were analyzed across groups. Patients with P-Gluc ≥7.8 mmol/L had higher hematocrit (0.46 vs. 0.43; p < 0.001) and lower plasma albumin concentration (24 vs. 29 g/L; p < 0.001) than patients with P-Gluc < 7.8 mmol/L. They presented with higher prevalence of pulmonary infiltrations and pleural effusion in chest radiograph, higher prevalence of shock and greater weight change during hospitalization. Patients with P-Gluc ≥ 7.8 mmol/L were characterized by lower platelet count (50 vs. 66 × 10⁹/L; p = 0.001), more severe AKI (plasma creatinine 272 vs. 151 µmol/L; p = 0.001), and longer hospital treatment (8 vs. 6 days; p < 0.001) than patients with P-Gluc < 7.8 mmol/L. Plasma glucose level is associated with the severity of capillary leakage, thrombocytopenia, inflammation, and AKI in patients with acute PUUV infection.     

Human leukocyte antigen-B8-DR3 is a more important risk factor for severe Puumala hantavirus infection than the tumor necrosis factor-alpha(-308) G/A polymorphism

The tumor necrosis factor (TNF)-alpha(-308) G/A polymorphism (TNF-2) is in linkage disequilibrium with the human leukocyte antigen (HLA)-B8-DR3 haplotype. Both factors have been associated with severe Puumala hantavirus-induced nephropathia epidemica (NE). To examine which part of this extended haplotype might show the strongest association with the outcome of NE, the HLA-B, HLA-DRB1, and TNF-alpha(-308) alleles in 116 hospital-treated patients with NE were analyzed. The findings pointing to clinically severe NE were strongly associated with HLA-B8-DR3 haplotype. There was a trend toward severe disease in persons positive for TNF-2. This was probably due to strong linkage disequilibrium with HLA-B8-DR3, since there were no differences in the clinical severity of NE when TNF-2-positive/B8-DR3-negative persons were compared with TNF-2-negative/B8-DR3-negative persons. It is concluded that the HLA-B8-DR3 haplotype is an important contributor to the course of NE. The data indicate that the TNF-2 allele is not an independent risk factor for severe NE but a passive component in the extended haplotype.     

Ontogeny of pineal melatonin rhythm in rats under 12: 12-hr and 14: 14-hr lightdark conditions

Abstract: The aim of the study was to determine whether a discrepancy between the genetically determined endogenous circadian period and an abnormally long Zeitgeber period disturbs the development of melatonin synthesis. Breeding pairs of rats were kept under 12: 12- or 14: 14-hr light: dark (LD) conditions. Pineal melatonin contents in the offspring were measured by radioimmunoassay. At 2 weeks of age high melatonin contents were found from lights-off to lights-on in both conditions suggesting dominance of the photic regulation. At 3 weeks of age the signs of the circadian regulation in the melatonin profiles were evident: a lag period after the light offset in control conditions and a significant decline before the light onset in both conditions. However, in 14: 14-hr LD conditions the melatonin content did not decrease to daytime levels until the lights were on. This could suggest incomplete maturation of the circadian system. The phase relationships between the melatonin peak and LD cycle were different in the two conditions. A statistically significant LD difference was first found at the age of 8–10 days in male pups and at 14 days in female pups under both lightings. The results suggest that the abnormally long LD cycle did not cause any major disorders in the development of photic or circadian regulation of the melatonin synthesis.     

The effect of polyol-combinant saliva stimulants on S. mutans levels in plaque and saliva of patients with mental retardation

The effect of chewable saliva-stimulants on Streptococcus mutans levels in dental plaque and paraffin-stimulated whole saliva among participants who were mentally disabled was investigated. Over 64-days, 98 participants chewed one of four saliva-stimulating tablets five times/day. The tablets contained one of the following: xylitol (X) or sorbitol (S), or 1:1 mixtures of xylitol and erythritol (XE) or sorbitol and erythritol (SE). Consumption of xylitol and sorbitol in Groups X and S was 5.4 grams/day/ subject, and of each polyol in Groups XE and SE, consumption was 2.7 g/day/subject. Interproximal dental plaque and stimulated whole saliva were sampled at baseline, at Day 36, and Day 64. There was a statistically significant reduction of S. mutans in plaque and saliva counts in Groups X and XE. The percentage of S. mutans in total streptococci increased significantly in dental plaque in Group S but decreased in the other groups. The results suggest that xylitol-containing saliva stimulants may be more effective than sorbitol-containing products in controlling some caries-associated parameters in people who are mentally disabled. Also a relationship may exist between the pentitol-type xylitol and S. mutans , and erythritol may exert a specific biochemical effect on this organism, although further studies are needed.     

Granulocytopenia in Cohen syndrome

Cohen syndrome is an autosomal recessive disorder characterized by mental retardation, microcephalia and typical craniofacial features, myopia and chorioretinal dystrophy. As some patients were reported to have leucopenia, we collected the haematological data of 26 Finnish Cohen patients. They all had experienced periods of isolated granulocytopenia from an early age. Granulocytopenia was mild to moderate, non-cyclic and never fatal. Most patients suffered from prolonged or repeated gingival or skin infections. We restudied 16 patients. Bone marrow examination revealed in all patients a normo- or hypercellular marrow, with a left-shifted granulopoiesis in 8/16 patients. The response to adrenaline stimulation was subnormal in 12/14 and to hydrocortisone in 8/16 patients, but administration of rhG-CSF caused granulocytosis in the three patients studied. No bone marrow malignancies were seen.     

Mechanism of Cisplatin Ototoxicity: Antioxidant System

Abstract: The dose and duration limiting toxic effects of cisplatin are ototoxicity and nephrotoxicity. While several studies have attempted to shed some light on the causes of nephrotoxicity, the reasons for ototoxicity induced by cisplatin are poorly understood. Therefore, this investigation was undertaken to delineate the potential mechanisms underlying cisplatin ototoxicity. The role of glutathione (GSH), oxidized glutathione (GSSG) and malondialdehyde levels, and antioxidant enzyme activities [superoxide dismutase, catalase, GSH peroxidase, and GSH reductase] were examined in cochlear toxicity following an acute dose of cisplatin. Male Wistar rats were treated with various doses of cisplatin. Pretreatment auditory brain stem evoked responses (ABR) were performed and then post-treatment ABRs and endocochlear potentials were also performed after three days. Acute cochlear toxicity (ototoxicity) was evidenced as elevated hearing thresholds and prolonged wave I latencies in response to various stimuli (clicks and tone bursts at 2, 8, 16 and 32 kHz) on ABRs. The endocochlear potentials were reduced (50% control) in cisplatin-treated rats as compared to control animals. The rats were sacrified and cochleae isolated. The GSH, GSSG and malondialdehyde levels, and antioxidant enzyme activities were determined. Cisplatin ototoxicity correlated with a decrease in cochlear GSH [0.45±0.012 nmol/mg] after cisplatin administration compared to 0.95±012 nmol/mg in control cochleae (P<0.05). Superoxide dismutase, catalase activities and malondialehyde levels were significantly increased in the cochleae of cisplatin injected rats. Cochlear GSH-peroxidase and GSH reductase activity significantly decreased after cisplatin administration. Alterations in the activity of antioxidant enzymes, an increase in malondialdehyde levels, and depletion of cochlear GSH suggest a role for reactive oxygen species mediated damage of the cochlea in cisplatin toxicity. These biochemical changes were accompanied by the elevation of ABR threshold that appears to correlate well with alterations in antioxidant systems which could be the cause of cisplatin ototoxicity.