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Biomedical subjects

J Boyer

Publications and source records attributed to J Boyer.

At least 271 records · Page 15Linked to original sources
PubMed1979

[Plasma cortisol response to intravenous beta 1-24 corticotropin as related to the fat mass and its topographic localisation (author's transl)].

Plasma cortisol response induced by 2.5 microgram/kg beta 1-24 corticotropin (1 hour infusion) in obese females was not related to fat mass. The response was increasingly pronounced as fat predominated in the upper body segment, i.e. android obesity. This phenomenon may be interpreted as indicating an increased adrenal capacity to secrete cortisol in such obese patients. Low level but longstanding excess cortisol secretion is probably the cause of the android features of obesity.

Adipose Tissue↗
PubMed1978

[Unusual digestive manifestations during rheumatoid purpura. Apropos of 2 cases].

We have observed two unusual forms of rheumatoid purpura with digestive symptoms in two young girls aged 16 years. In the first case, the signs of complete duodenal stenosis led to a surgical operation which led to the discovery of an infiltrated mesenteric band of adhesions containing numerous lymph nodes, with on the oedematous loops of small intestine, numerous ecchymoses. In the second case, the duodenal-jejunal radiological abnormalities suggested protein-losing enteropathy. especially as this patient like the first, had major hypoproteinemia without albuminuria. The Cr51 radioisotope test confirmed this quite exceptional diagnosis in this disease.

Adolescent↗
PubMed1978

Post-heparin plasma lipolytic activity in acute hepatitis.

Post-heparin plasma lipolytic activity (PHLA) was measured in 21 patients with acute viral hepatitis. PHLA was significantly reduced in all patients (p less than 0.0005), whose mean activity was only 32% of the control subjects. An inverse correlation (p less than 0.05) was found between PHLA values and serum triglycerides levels. During recovery, the normalization of PHLA was much slower than that of the usual tests of liver function. PHLA measurement may represent a new and sensitive test of liver function.

Acute Disease↗
PubMed1977

[The relationship between zinc levels in blood and the activity of delta-amino-levulinic acid dehydratase in human erythrocytes (author's transl)].

The blood levels of zinc, lead, copper and albumin and the activity of erythrocyte delta-aminolevulinic acid dehydratase (ALA D), with and without addition of zinc in vitro, were measured in healthy subjects and in patients with cirrhosis. In cirrhosis there was a decrease, of zinc (-40%) albumin (-38%) and of activity of ALA D (-48%) and an increase in blood lead (+80%). Correlation between these results has been studied. The increase of blood lead is probably the result of zinc decrease. Moreover, as the urinary excretion of zinc is enhanced by chelation therapy, the prescription of zinc in lead intoxication is to be recommended. The activity of ALA D in patients with cirrhosis is less enhanced by addition of zinc in vitro than is the activity in patients intoxicated with lead. Probably in cirrhosis there is especially a decrease in the synthesis of ALA D, and lead intoxication the enzyme is inhibited.

Copper↗
PubMed1977

Hydrolysis and uptake of an aliphatic fatty ester by whole isolated fat cells.

During 9-min incubations at 37 degrees C, whole isolated fat cells are able to hydrolyze a water-insoluble ester, ethyl [3H]oleate, added as an emulsion to the extracellular medium. The monoester lipase exerts its activity as a membrane-bound enzyme and is not releasable by heparin. Variation of the reaction rate with substrate concentration suggests a diffusion-limited process, consonant with the fact that enzyme and substrate are associated with particles of enormous sizes (the fat cell and the lipid droplet, respectively). Variation of lipase activity with increasing temperature in the incubation medium shows a break at 46 degrees C +/-1 degrees C, most probably related to a phase transition in the membrane structure. During incubation, 30-60% of the amount of [3H]oleic chains formed by hydrolysis are incorporated into the cell, mainly as triacylglycerols. Controls of cell viability indicate that under the experimental conditions the framework of the membrane and the internal organization of the cell appear to be maintained. Such an experimental model might duplicate physiological conditions since aliphatic fatty esters are thought to be hydrolyzed at the cell surface during uptake.

Adipose Tissue↗
PubMed1977

[Extrinsic compression of the celiac trunk by the arcuate ligament of the diaphragm. Apropos of 5 cases].

The authors report 5 cases (3 women and 2 men) of extrinsic stenosis of the coeliac axis by the arcuate ligament of the diaphragm. In one of the latter, the stenosis of the coeliac axis was associated with chronic calcific pancreatitis. These 5 patients were operated on. Division of the arcuate ligament gave on the whole very favourable results. (3 excellent results, one good and one average result). The authors then recall the clinical, angiographic and pathogenic data in this disease which remains exceptional. The diagnosis should be made and operation decided only after a fairly long period of observation during which one has elimiatned the diagnoses of gastro-intestinal, gall bladder, pancreatic and above all psychiatric disease by endoscopy, radiography and symptomatic medical treatment.

Adult↗
PubMed1977

Estrogen hormones and lipid metabolism. Effect of ethynyl-estradiol on liver lipases.

Lipase activities assayed in liver subcellular fractions from rats given ethynyl-estradiol are lowered, while triglycerides increase and cholesterol decreases in blood. Triester lipase in microsomes is the most altered activity. Such enzymatic changes might play a role in the development of lipid abnormalities in blood of women taking estrogens as oral contraceptives.

Animals↗
PubMed1977

Tissue toxicity of antiseptic solutions. A study of rabbit articular and periarticular tissues.

The gross, histologic, and biochemical effects of four commercially available antiseptic solutions on rabbit knee articular and periarticular connective tissues were investigated. Rabbit knee joints were injected with 2.0 cc of either Betadine prep solution, Betadine scrub solution, pHisohex or 3% hexachlorophene. The opposite knees were injected with sterile saline. All animals were injected three times at 48-hour intervals and sacrificed 10 days after the last injection. The solutions containing detergents, Betadine scrub, and pHisohex caused severe gross and histologic damage to articular cartilage, synovia, and muscle. The hexachlorophene loss solution caused moderate histologic damage, but caused articular cartilage ground substance. Betadine prep solution caused only minimal gross and histologic damage, without any biochemical evidence of articular cartilage damage. If antiseptic solutions are to be used in irrigating or packing joint injuries, the use of Betadine prep is recommended.

Animals↗
PubMed1976

On the individuality of aliphatic and alicyclic monoester lipases in human adipose tissue.

Aliphatic and alicyclic monoester lipase activities from human adipose tissue have been comparatively investigated by using [3H] oleoylethanol and [14C] oleoylcholesterol, respectively, as substrates. A number of specific properties proved to be different for each activity. Different rates of decay of hydrolytic activity towards each substrate were observed during heat denaturation. Stability upon exposure to the cold was different for both activities, and the protective effect of glycerol was less effective for oleoylcholesterol than for oleoylethanol lipase. Serial (NH4)2SO4 fractionation in 5% increments showed that the two activities did not precipitate at identical saturation values. The behaviours of the two activities were compared in an affinity system where monoolein, a substrate molecule, served as a ligand for the enzyme(s) in a covalent complex with CH-Sepharose. During chromatography, both activities followed a comparable adsorption-elution pattern, but the oleoylcholesterol to oleoylethanol lipase activity ratio decreased by a factor of 4. Taken together, these data, along with a differential susceptibility to various surfactants, confirm our earlier hypothesis (Arnaud, J. and Boyer, J (1974) Biochim. Biophys. Acta 337, 165--168) that aliphatic and alicyclic monoester lipase activities in human fat are referable to distinct catalytic proteins.

Adipose Tissue↗
PubMed1976

Lipolytic activity of whole isolated liver cells in aqueous suspension.

1. Liver contains a lipase which catalyzes in vitro the hydrolysis of esters of short-chain normal primary alcohols and fatty acids. It is shown that this enzymatic activity can be measured by using intact liver cells as source of enzyme. During short-term incubations of suspensions of cells isolated from rat liver, the lipase acts as a membrane-bound enzyme and readily attacks [3H] oleoylethanol added as an emulsion into the bathing medium. The lipolytic reaction proceeds linearly for at least 20 min at 37 degrees C, at the pH optimum of 8.5. [3H] Oleic acid, a reaction product, is mostly retained in the medium and is used to monitor the lipolytic process. 2. In the presence of heparin, the bound lipase is released in the medium in amounts representing one-third to one half the total activity contained in the cells. This release is very rapid and associated in all cases with a concomitant release of lactate dehydrogenase activity. Such effects are consistent with the interpretation that heparin, at concentrations comprised between 10 and 100 mug per ml, causes alterations of the plasma membrane of the isolated cells, resulting in the dispersion of membrane-bound and cytoplasmtic material. This action of heparin is totally blocked by protamine sulfate (1 mg/ml). No specific effect of heparin directed towards the selective release of lipase could be demonstrated under these conditions. 3. During incubations in the presence of heparin, it was observed that the release of monoester lipase was quantitatively related to a simultaneous decrease in membrane-bound as well as in total monoester lipase activity measureable in the cells after homogenization. This, along with the reappearance of membrane-bound activity immediately after heparin withdrawal, suggest that under the experimental conditions, the membrane-bound enzyme is replaced from inside the cell in proportion of its release by heparin.

Animals↗
PubMed1976

Lavage of septic joints in rabbits: effects of chondrolysis.

Septic joints were produced in rabbits which were then treated with systemic procaine penicillin. One group of animals also had surgical lavage at four and seven days after bacterial inoculation. In the infected joints there was a significant loss of hexosamine by five days and of collagen by nine days. Lavage delayed the loss of collagen.

Animals↗