T-type Ca2+ current contribution to Ca2+-induced Ca2+ release in developing myocardium

In normal adult-ventricular myocardium, Ca2+-induced Ca2+ release (CICR) from the sarcoplasmic reticulum (SR) is activated via Ca2+ entry through L-type Ca2+ channels. However, embryonic-ventricular myocytes have a prominent T-type Ca2+ current (ICa,T). In this study, the contribution of ICa,T to CICR was determined in chick-ventricular development. Electrically stimulated Ca2+ transients were examined in myocytes loaded with fura-2 and Ca2+ currents with perforated patch-clamp. The results show that the magnitudes of the Ca2+ transient, L-type Ca2+ current (ICa,L) and ICa,T, decline with development with the majority of the decline of transients and ICa,L occurring between embryonic day (ED) 5 and 11. Compared to controls, the magnitude of the Ca2+ transient in the presence of nifedipine was reduced by 41% at ED5, 77% at ED11, and 78% at ED15. These results demonstrated that the overall contribution of ICa,T to the transient was greatest at ED5, while ICa,L was predominate at ED11 and 15. This indicated a decline in the contribution of ICa,T to the Ca2+ transient with development. Nifedipine plus caffeine was added to deplete the SR of Ca2+ and eliminate the occurrence of CICR due to ICa,T. Under these conditions, the transients were further reduced at all three developmental ages, which indicated that a portion of the Ca2+ transients present after just nifedipine addition was due to CICR stimulated by ICa,T. These results indicate that Ca2+ entry via T-type channels plays a significant role in excitation-contraction coupling in the developing heart that includes stimulation of CICR.     

Edta and Insulin

Summary Insulin induced hypoglycaemia was enhanced in rats, by the simultaneous administration of disodium EDTA or calcium disodium EDTA but not bmagnesium disodium EDTA. None of these EDTA complexes affected the blood sugar in the absence of insulin.In vitro, both Na and Ca EDTA inhibited the insulin stimulation of glucose uptake by the isolated rat hemidiaphragm, but had no effect upon basal glucose uptake. In contrast, Mg EDTA increased basal glucose uptake with little or no effect upon insulin stimulation. On the isolated epididymal fat pad, both Na and Ca EDTA either did not affect, or slightly reduced, the insulin stimulation of glucose uptake. They sometimes increased the basal glucose uptake. Mg EDTA consistently increased the basal glucose uptake. -It is suggested that thein vivo effect of Ca and Na EDTA is upon the homoeostatic response to hypoglycaemia rather than upon the action of insulin.Based upon a communication to the Medical and Scientific Section of the British Diabetic Association, September, 1965.     

Screening blood glucose values: effects of season and time of day

Summary Blood glucose screening results, obtained using two different screening procedures, are reported from two occupational groups. Post-prandial blood glucose levels were measured in 3346 subjects aged 45 years or more employed by the Greater London Council/Inner London Education Authority. In women, mean blood glucose levels were higher in the afternoon than the morning (p<0.05). Ninety-fifth centile levels were substantially higher in the afternoon in both sexes, though the differences were not constant in all age and sex sub-groups. In both sexes mean glucose levels were highest in the winter (December–February, inclusive), but seasonal variation did not significantly affect the proportion exceeding the ninety-fifth centile for the total population. In the Whitehall study, the blood glucose was measured in men, in the morning, 2h after a 50-g glucose load. Significant seasonal variation in mean blood glucose values occurred, with highest values in winter and lowest in spring (March–May, inclusive). However, there was no significant difference by season in the proportions exceeding the arbitrary cut-off levels of 7.8 and 11.1 mmol/l.     

Molecular epidemiological characterization of respiratory isolates of Moraxella catarrhalis in a pediatric intensive care unit

A perceived increase in the number of isolates of Moraxella catarrhalis from the respiratory secretions of patients intubated in the pediatric intensive care unit prompted a review of the clinical profiles of such patients and restriction enzyme analysis of the strains involved. Over two months, of 192 patients admitted to the unit, 154 were intubated. Of the 46 for whom endotracheal tube specimens were submitted to the laboratory, M catarrhalis was isolated in 12. M catarrhalis was not felt to be a significant respiratory pathogen by the attending medical staff in any of the patients from whom it was isolated. In only two patients (17%) could nosocomial acquisition be firmly invoked. Restriction enzyme analysis of the 12 strains ruled out the presence of an epidemic strain. Isolation of M catarrhalis from intubated children does not necessarily imply pathogenicity nor an outbreak situation.     

Mental Health Service Users’ Perceptions of Stigma,From the General Population and From Mental Health Professionals in Mexico: A Qualitative Study

Community Mental Health Journal - Negative attitudes towards people with mental health disorders have been widely studied and identified in the general population, and even within health care...     

The Prevalence of Left Ventricular Hypertrophy in Obese Children Varies Depending on the Method Utilized to Determine Left Ventricular Mass

Obesity and left ventricular hypertrophy (LVH) have been identified as independent risk factors for cardiovascular events. The definition of LVH depends on the geometric algorithm used to calculate LV mass (LVM) by echocardiography and the method used to normalize LVM for body size. This study evaluates the effect of these methods on the prevalence of LVH in obese children. LVM for 109 obese and 109 age-matched non-obese children was calculated using M-mode or two-dimensional echocardiography (2DE). LVM was then normalized to height 2.7 as indexed LVM (LVMI), to body surface area (BSA), height, and lean body mass (LBM) as LVM Z-scores. LVH was defined as LVMI >95th ‰ using age-specific normal reference values or LVM Z-scores ≥2. The prevalence of LVH by LVMI and LVM Z-scores was compared. There was a correlation between LVM determined by M-mode and by 2DE (R ² = 0.91), although M-mode LVM was greater than 2DE LVM. However, the difference between these values was greater in obese children than in non-obese children. Based on the method of normalization, the prevalence of LVH among obese children was 64 % using LVMI, 15 % using LVM Z-scores for height, 8 % using LVM Z-scores for BSA and 1 % using LVM Z-scores for LBM. Height-based normalization correlates with obesity and hypertension. The methods used to measure and normalize LVM have a profound influence on the diagnosis of LVH in obese children. Further study is needed to determine which method identifies children at risk for cardiovascular morbidity and mortality.