Parathyrin and calcium homeostasis in the fetus

The response of plasma parathyrin (PT) in cattle fetuses to changes in plasma calcium was investigated in utero. Resting plasma calcium levels for 4 fetuses averaged 3.1 mg/dl higher than for their mothers. Fetal PT levels (0.67 ng/ml) were half those of the mother (1.40 ng/ml). Hypocalcemia induced by EDTA infusion evoked a rise in plasma PT in 2 or 3 fetuses. The relationship between plasma PT and calcium levels in these fetuses was curvilinear, PT rising from about 0.7 ng/ml at 13 mg calcium/dl to a plateau of about 1.6 ng/ml below 10 mg calcium/dl. This contrasted with one of the mothers in which PT rose above 3 ng/ml when plasma calcium fell from 9 to 7 mg/dl. During infusion of EDTA to mother or fetus there were no changes in plasma calcium or PT levels in the respective fetus or mother.     

Children with atopic eczema. I: Clinical response to food elimination and subsequent double-blind food challenge.

The role of foods in the exacerbation of atopic eczema was studied by offering a food elimination diet and subsequent random order, double-blind food challenges to 91 eczematous patients, [49 males and 42 females, median age 4.5 years (range 0.5-15)]. Eczema improved in 49 of 66 (74 per cent) (skin score fall greater than or equal to 3) after stopping cows' milk, eggs and various other foods, with significant decreases in erythema, excoriation, lichenification and extent of eczema. One hundred and ninety-four food challenges were given to 64 patients who had shown objective or subjective improvement. Eczema and associated symptoms were significantly worse after cows' milk and tomato compared with placebo. Egg did not worsen eczema, but 48 per cent of 44 challenges were incomplete, mainly due to hypersensitivity reactions and challenge refusal. The longer a food had been avoided, the less likely was the chance of a positive food reaction. Clinical history did not predict response to dietary manipulation. A standard elimination diet avoiding cows' milk, egg, tomatoes and possibly colours and preservatives should help up to three-quarters of patients, and is easy to implement with the help of a dietician. This diet may be considered in all children with moderate or severe eczema.     

The Effects of Acute Bouts of Whole Body Vibration on Central Hemodynamics in Frail Older Adults: A Pilot Study

Abstract

Introduction: This study investigates whether an acute bout of whole body vibration (WBV): (i) improves measures of central hemodynamics and (ii) can be completed without inducing orthostatic intolerance in frail older adults. Methods: Nine rest home residents participated in a cross-over design incorporating WBV and non-vibrational control conditions (CON) on 2 separate testing days. The order of the two testing conditions was randomized. Participants completed 10 sets of 60?seconds of WBV training or CON with an inter-set rest period of 60?seconds. Results: During training, no interaction or between-condition effects were observed for any variable. Following training, there was an interaction effect reported for augmentation index (AIx) (P?<?0.019) and a significant large increase in AIx for WBV (P?=?0.020, Eta = 0.202). Three participants exhibited one-off notable decreases in either central systolic or diastolic blood pressure. Conclusion: An acute bout of WBV is a safe training method for frail older adults.     

45Ca uptake and the actions of Bay K 8644 on aortic strips from rabbits with perinephritis hypertension

Uptake of 45Ca was measured in rings of thoracic aorta from rabbits with hypertension, induced by cellophane perinephritis (Page hypertension: one-kidney, one wrap). Basal 45Ca uptake was increased significantly in the hypertensive group (sham: 100 +/- 3, hypertensive: 133 +/- 11 nmol/g wet weight, n = 6). 45Ca uptake was increased by KCl (30 mmol/l), norepinephrine (50 nmol/l) and Bay K 8644 (14 or 56 nmol/l) by the following amounts: 152, 15, 28 and 36%, respectively. Stimulated 45Ca uptake was less in hypertensive animals for all agonists. The augmenting effect of Bay K 8644 on 45Ca uptake, stimulated by norepinephrine or by KCl, was also reduced in hypertension. It is concluded that in hypertension there are alterations in the Ca regulatory process and in the properties of the Ca channel in arterial muscle.     

The persisting effect of unemployment on health and social well-being in men early in working life.

In our studies of the effects of unemployment in the early working life of men in a British national birth cohort we have shown elsewhere that this experience was part of a longer term accumulation of social and health disadvantage. This present study asks whether men's unemployment also inflicted potential longterm damage to future socio-economic chances and health. We therefore constructed indicators of socio-economic circumstances and health at 33 years from factors already shown to be associated with health in later life. For the socio-economic indicator we used a combination of income, occupational status and home ownership and described this as socio-economic capital. For the health indicator we combined scores of body mass index, leisure time exercise, frequency of eating fresh fruit and of smoking, and described this as health capital. After controlling for pre-labour market socio-economic and health factors, prolonged unemployment is shown here to reduce significantly both socio-economic and health capital by age 33 years. We conclude that the experience of prolonged unemployment early in the working life of this population of young men looks likely to have a persisting effect on their future health and socio-economic circumstances.     

Origin and selection of peripheral CD4-CD8- T cells bearing alpha/beta T cell antigen receptors in autoimmune gld mice

We have analyzed the origin and development of unusual CD4-CD8- alpha/beta T cell receptor-positive peripheral T cells produced in large numbers by mice homozygous for the gld mutation (C3H-gld/gld). These mice may be an important model for investigating processes controlling T cell development. Bone marrow transfers demonstrated that the gld defect was intrinsic to bone marrow-derived cells. Clonal deletion of potentially autoreactive cells was observed in peripheral gld CD4-CD8-, CD4+CD8-, and CD4-CD8+ T cells, as well as mature thymocytes. This suggests that gld CD4-CD8- T cells have passed through the thymus in ontogeny and that gld autoimmunity does not result from a general defect in elimination of self-reactive thymocytes. These observations, combined with demethylation of the CD8 gene in the CD4-CD8- population, support prior expression of CD4 and/or CD8 in gld CD4-CD8- T cell ontogeny, perhaps at a CD4+CD8+ stage. Steroid sensitivity of gld thymocytes and CD4-CD8- T cells was normal. Therefore, we found no gross abnormalities in two major mechanisms of inducible cell death in the gld thymus, the clonal deletion process associated with tolerance and the steroid-inducible endogenous endonuclease thought to be involved in apoptosis of unselected thymocytes. The data suggest that if gld CD4-CD8- T cells arise via escape from normal elimination in the thymus, they must do so by a novel defect in thymic selection (perhaps related to aberrant positive signals) and/or are expanded by an extrathymic process which allows clonal deletion to occur.