Biomedical subjects

S Gambert

Publications and source records attributed to S Gambert.

3 recordsLinked to original sources

PubMed2002

Acute mountain sickness, dehydration, and bicarbonate clearance: preliminary field data from the Nepal Himalaya.

BACKGROUND: In 1999, Basnyat et al. published preliminary data demonstrating an inverse correlation between hydration status and acute mountain sickness during an epidemiological study performed in the vicinity of Mount Everest. To expand on these findings, we have re turned to the Langtang area of the Nepal Himalaya to perform more specific studies of altitude illness related to dehydration and hypoxemia using urine studies, pulse oximetry, and physical examination. HYPOTHESIS: Dehydration will incite physiological changes aimed at the preservation of vascular volume homeostasis characterized by the production of sodium and water sparing hormones. As sodium is reabsorbed in the kidney, bicarbonate anion is also reabsorbed resulting in insufficient bicarbonate anion excretion by the kidney leading to an incomplete compensation for altitude induced hypocapnic alkalosis and the development of clinical disease. METHODS: Estimates of intravascular volume (urine specific gravity), oxygen saturation (pulse oximetry), urinary bi carbonate excretion (urine pH), and AMS (Lake Louise Score) were collected from Hindu pilgrims at 4243 m during an annual sacred festival at Lake Gosinkunda. RESULTS: Worsening altitude illness approx imated by increasing Lake Louise Score was associated with increasing urine specific gravity (p = 0.043), decreasing oxygen saturation (p = 0.020), and decreasing urine pH (p = 0.040) after rapid ascent to 4243 m. CONCLUSIONS: Worsening altitude illness, indicated by increasing Lake Louise score, was associated with increasing measures of dehydration, hypoxemia, and urine acidity.

Acid-Base Equilibrium↗

PubMed2001

Modification of the rat aortic wall during ageing; possible relation with decrease of peptidergic innervation.

Structural changes of the male rat aorta were followed from birth to old age in male and female rats. In males, the vessel media width and area progressively increase concomitantly with a decrease of nuclei density during ageing, suggesting an hypertrophy of the smooth muscle cells. These correlations were however not evidenced in females. TUNEL-positive cells were found in media of 4 and 6 months in both sexes, mainly on the luminal side and in the adventitia. When biochemical markers were investigated with immunohistochemistry, media was uniformly stained by the anti-vimentin and anti-alpha-smooth actin at all stages investigated. On the contrary, the surface of media stained with anti-desmin decreased during ageing, especially on the luminal side. As observed with electron microscopy, with ageing the endothelium is replaced by small cells with pseudopodia adhering to the vestigial elastic lamina and infiltrating into the extracellular matrix left after the disappearance of smooth muscle cells. In addition, in the older rats (25-29 months) the elastic laminae are completely disorganised. Hypertrophy of the smooth muscle cells was confirmed by this approach. In parallel to this study, perivascular peptidergic innervation was stained with antibodies against calcitonin gene-related peptide (CGRP), substance P (SP), neuropeptide Y (NPY), and vasoactive intestinal polypeptide (VIP) at different ages during the whole life of rats. These peptides are present in stages younger than 6 months, then gradually disappear. In one year animals and older, the peptidergic innervation has totally disappeared. We discuss the possible role of peptidergic innervation in the control of the vessel wall cellular stability during ageing.

Actins↗

PubMed1979

Adipose tissue development, growth, and food consumption in protein-malnourished rats.

Effects of protein malnutrition on adipose tissue development were studied in weanling male Sprague-Dawley rats fed isocaloric diets ad libitum containing either 22% (controls) or 8% (protein-malnourished rats) casein, and in rats pair-fed to the protein-malnourished rats with the 22% casein diet. After 32 days on the diet, protein-malnourished rats were 37% and pair-fed 67% the weight of the controls, while torso length was 37% and 73% of controls, respectively. Food consumption relative to body weight was greatest in protein-malnourished rats. Compared to control rats, the distal epididymal adipocyte number in the protein-malnourished rats was decreased in proportion to the decrease in body size and was more closely related to the protein intake than to the total calories consumed. After 32 days on diet, mean adipocyte number per 2 distal pads was 11.7 x 10(6) in controls and 4.3 x 10(6) in protein-malnourished rats. In pair-fed rats, cell number lagged behind controls at 4 and 11 days, but was normal at 32 days (11.4 x 10(6) cells). The distal epididymal pad adipocyte size and percent lipid were similar in all groups during the first 25 days of dietary treatment. Adipocyte size was increased significantly in controls at day 32 compared to the other two groups. At each time studied through day 25 on diet, epididymal pad weight was related to the adipose cell number rather than the cell size. It is concluded that severe restriction of dietary protein during the postweaning period of growth in rats results in decreased epididymal adipocyte proliferation and/or differentiation concomitant with generalized growth retardation, whereas isocaloric feeding of a diet of normal protein content is associated with only a transient delay in adipose tissue development.

Adipose Tissue↗