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Biomedical subjects

P Dupuy

Publications and source records attributed to P Dupuy.

At least 55 records · Page 3Linked to original sources

[Natural history of duodenal ulcer].

The authors have studied the natural history of duodenal ulcer from published data, in an attempt to determine precisely the evolutive potential of this disease both spontaneously and during its treatment. They deal successively with the risk of complication and the short- or long-term influence of medical and surgical treatment on the occurrence of exacerbations and complications. The role played by Helicobacter pylori in healing of the ulcer and in the long-term course of the ulcerous disease, as well as the problems concerning its duration and mortality, are discussed. The data clearly show that the medical and surgical treatment of duodenal ulcer can slow down, at least temporarily, the course of the disease. Other studies are needed before drawing firm conclusions concerning the relationship between H. pylori and duodenal ulcer, even though numerous studies seem to have demonstrated that eradication of this micro-organism is associated with a substantial decrease in the risk of recurrent ulcer.

Duodenal Ulcer↗

Exocrine pancreatic secretion in normal controls and chronic calcifying pancreatitis patients from Burundi: possible dietary influences.

Pure pancreatic juice composition was studied, after secretin and cerulein stimulation in 29 people from Burundi (Central Africa): 17 controls and 12 alcoholic chronic pancreatitis (CP) patients. Results were compared to similar data in France. African controls had a similar pancreatic response to hormones apart from a much lower lipase secretion than French controls. In the early non-calcified stage of African CP water and bicarbonate secretion were markedly diminished while protein and lipase concentrations were enhanced. In the late stage, secretion was exhausted except that of calcium. Nutritional data were obtained under the same conditions in 40 African controls and in 34 CP patients (including all patients tested for secretion). African controls had a very low fat intake (35.2 +/- 2.6 g/day), and patients had a higher protein and fat intake (144.7 +/- 5.9 and 66.2 +/- 4.8 g/day, respectively) than local controls: as in other countries, CP was associated with a diet enriched in alcohol, fat and protein.

Adult↗

Topical tiacrilast, a potent mast cell degranulation inhibitor, does not improve adult atopic eczema.

Tiacrilast is a potent mast cell degranulation inhibitor in vitro and in animal studies. Since mast cells and their mediators are possibly involved in atopic eczema, we have studied a topically applied 3% hydrogel formulation of tiacrilast against vehicle in a multicenter, double-blind, placebo-controlled trial. Drug or vehicle were applied on involved skin for 28 days. Efficacy was assessed weekly using a 4-point scale for erythema, scaling, induration, exudation and pruritus. An overall assessment of the sites for efficacy and site preference was performed at the end of treatment. In the 32 patients evaluable for efficacy, > 33% improvement was noted on 78% of the drug- and 75% of the vehicle-treated sites, with no statistically significant differences for any of the parameters tested. Treatment was generally well tolerated by all patients. These data suggest that mast cells may not play a major role in the maintenance of atopic eczema lesions.

Administration, Cutaneous↗

Inhaled nitric oxide reverses pulmonary vasoconstriction in the hypoxic and acidotic newborn lamb.

We determined whether inhaling low levels of nitric oxide (NO) gas could selectively reverse hypoxic pulmonary vasoconstriction in the near-term newborn lamb and whether vasodilation would be attenuated by respiratory acidosis. To examine the mechanism of air and NO-induced pulmonary vasodilation soon after birth, we measured plasma and lung cGMP levels in the newly ventilated fetal lamb. Breathing at FIO2 0.10 nearly doubled the pulmonary vascular resistance index in newborn lambs and decreased pulmonary blood flow primarily by reducing left-to-right blood flow through the ductus arteriosus. Inhaling 20 ppm NO at FIO2 0.10 completely reversed hypoxic pulmonary vasoconstriction within minutes. Maximum pulmonary vasodilation occurred during inhalation of > or = 80 ppm NO. Breathing 8% CO2 at FIO2 0.10 elevated the pulmonary vascular resistance index to a level similar to breathing at FIO2 0.10 without added CO2. Respiratory acidosis did not attenuate pulmonary vasodilation by inhaled NO. In none of our studies did inhaling NO produce systemic hypotension or elevate methemoglobin levels. Four minutes after initiating ventilation with air in the fetal lamb lung, cGMP concentration nearly doubled without changing preductal plasma cGMP concentration. Ventilation with 80 ppm NO at FIO2 0.21 increased both lung and preductal plasma cGMP concentration threefold. Our data suggest that inhaled NO gas is a rapid and potent selective vasodilator of the newborn pulmonary circulation with an elevated vascular tone due to hypoxia and respiratory acidosis that acts by increasing lung cGMP concentration.

Acidosis, Respiratory↗

[Renal lithostathine: a new protein inhibitor of lithogenesis].

Lithostathine is a protein of pancreatic secretion inhibiting calcium carbonate crystal growth. Antibodies to lithostathine were used to identify a related protein in urine and kidney stones. Western blot analysis of proteins extracted from concentrated normal urine or kidney stones demonstrated the presence of a protein with an apparent molecular weight of 23 kDa. The same antibodies were used in immunolocalization experiments on fresh human nephrectomy specimens cryosections. A positive signal was observed in the cells of proximal tubules and thick ascending limbs of Henle's loop. Protein extracts of renal stones inhibited calcium carbonate crystal growth. Because of its structural and functional similarities with pancreatic lithostathine, it was called renal lithostathine.

Animals↗

Evidence that human kidney produces a protein similar to lithostathine, the pancreatic inhibitor of CaCO3 crystal growth.

Pancreatic juice is supersaturated in calcium carbonate. CaCO3 crystal growth is controlled by lithostathine, a secretory protein synthesized by pancreatic acinar cells, first described as a constituent of pancreatic stones. It was recently reported that, in the thin descending limb of the Henle's loop, urine was supersaturated in CaCO3 (Coe FL, Parks JH: Defenses of an unstable compromise: crystallization inhibitors and the kidney's role in mineral regulation. Kidney Int. 1990: 38, 625-631. This observation suggested the presence in kidney of a similar inhibitor. In this study, we show that a protein immunologically related to lithostathine is actually present in urine of healthy subjects and in renal stones. Immunocytochemistry of kidney sections localized the protein to cells of the proximal tubules and thick ascending limbs of the Henle's loops. Protein extracts of renal stones inhibited CaCO3 crystal growth in vitro and this inhibition was significantly lifted by incubating the extracts with antibodies to lithostathine. The protein is not immunologically related to nephrocalcin. Because of its structural and functional similarities with pancreatic lithostathine, it was called renal lithostathine.

Calcium Carbonate↗

[The metastatic liver: a rare cause of hepatocellular insufficiency].

Liver metastases are frequent, often large and sometimes very late in skin or choroid metastatic melanoma. Hepatic failure is a rarely described complication in metastatic liver melanoma. We report a case of liver failure in a metastatic liver melanoma in a woman 76 years old, treated 16 years before for a choroid melanoma. About this case, we discuss the frequency, the location of primitive tumors and mechanism of liver failure in metastatic liver.

Aged↗

Preliminary treatment of urinary proteins improves electrophoretic analysis and immunodetection.

Analysis of urinary protein composition is an important tool in studies on renal physiology and physiopathology. Urine is, however, a complex mixture containing, besides protein, a variety of compounds such as salts, peptides, oligosaccharides, and glycosaminoglycans. Some of these compounds interfere with the electrophoretic migration of protein in sodium dodecyl sulfate-polyacrylamide gels and prevent correct analysis of the protein pattern. We describe a simple method for extracting urinary proteins that considerably improves their electrophoretic migration and subsequent immunodetection. This treatment involves ammonium sulfate fractionations (for precipitating proteins), EDTA (for inhibiting protein aggregation), and HCl hydrolysis (for removing glycosylaminoglycans). Recovery during extraction was found to be almost quantitative for total protein and three representative proteins: albumin, alpha 1-glycoprotein acid, and beta 2-microglobulin.

Albuminuria↗

Change in bile salt dependent lipase in human breast milk during extended lactation.

Two hundred eighty-one milk samples collected from Zaïrian nonprivileged, undernourished mothers, in series of nine groups from 1 month to 18 months after parturition, and 66 milk samples collected from French privileged mothers in series of four groups from 2 days to 16 months postpartum, were analyzed for their lactose, lipid and protein contents. In addition, the activity of bile salt-dependent lipase (esterase), which may play an important role in the newborn infant's lipids digestion, was measured. After the first month postpartum, independent of the nutritional state of the mother, sugar and protein concentrations were identical. Lipid content of French mothers' milk was lower in transitional milk, but appeared constant in mature milk with an average value of 29.1 +/- 5.8 mg/mL of milk. In Zaïrian mothers' milk, the lipid content of mature milk plateaued at around 50-55 mg/mL independent of the stage of lactation. Bile salt-dependent lipase showed constant esterase activity within the lactation stage in privileged mothers' milk, but decreased by almost 80-90% during the first four months of lactation in undernourished mothers. The data suggest that milk from nonprivileged mothers may lose some of its ability to hydrolyze milk lipid esters, which could also be of consequence to the infant's normal growth in view of its effect on the esters of the lipid-soluble vitamins A, E and D.

Adult↗

Cyclosporin A inhibits the antigen-presenting functions of freshly isolated human Langerhans cells in vitro.

Cyclosporin A (CsA) is a strong inhibitor of skin allograft rejection. It has been also reported to act, not only on helper T cells, but also on the antigen-presenting functions of mouse epidermal cells (EC) enriched in Langerhans cells (LC). We tested the effects of CsA on the human allogeneic mixed epidermal cell-lymphocyte reaction (MECLR) using whole EC and freshly isolated LC as stimulator cells. Results were as follows. 1) CsA inhibited the lymphocyte proliferative response in a dose-dependent fashion, by about 80% for a CsA concentration of 10(-7) M. To evaluate the effects of the drug on the two cell populations involved in MECLR, stimulator EC and responder PBMC were separately pulsed for 2 h with CsA, washed, and combined to form MECLR. Inhibition by CsA of the alloantigen-dependent lymphocyte proliferation appeared to be multifactorial, because CsA-pulsed EC and CsA-pulsed effector PBMC led to identical reductions of 40% each in proliferation. 2) The nature of EC sensitivity to CsA during MECLR was then analyzed after freshly separating highly purified CD1-positive LC (greater than 95%) and LC-depleted EC (mainly keratinocytes), using an immunomagnetic particle technique. When responder PBMC were cultured with CsA-pulsed LC, a highly significant reduction of lymphocyte proliferation was observed, indicating that CsA has direct effects on LC. 3) Some of the possible mechanisms by which CsA might act on LC were studied. Substantial IL-1 activity and PGE2 amounts were induced during MECLR by LC and keratinocytes, but CsA did not act via these factors. Neither did it significantly modify HLA-DR, DQ, or DP antigen expressions on EC. In conclusion, CsA directly inhibits antigen presentation by human LC. This inhibition may partly explain the beneficial effects of CsA on skin allografts and certain cutaneous immune reactions.

Adolescent↗

Changes in pancreatic exocrine secretion with age: pancreatic exocrine secretion does decrease in the elderly.

Pancreatic exocrine secretion was estimated in 180 normal control patients, free of abdominal and pancreatic disease, aged from 16 to 83 years. Duodenal juice was collected in two 15-min fractions after a single intravenous injection of 1 U/kg secretin + 3 U/kg CCK. Volume, maximal concentration and output of bicarbonate, lipase, phospholipase and chymotrypsin were estimated as well as minimal concentration and output of chloride and calcium. Each parameter was plotted against age, either individually or after separation into two age groups. Volume linearly increased up to the 3rd decade, and thereafter linearly decreased. Bicarbonate secretion paralleled fluid secretion and also decreased after the 3rd decade. The changes in chloride and calcium concentrations were different: concentrations linearly increased after the 3rd decade. Calcium concentration linearly increased with age (p less than 0.02) while chloride output was unchanged. The three enzymes that were studied linearly decreased in concentration as well as in output with age from the 3rd decade (p less than 0.02). Protein secretion decreased before water and bicarbonate secretion. One can conclude that pancreatic secretion changes in humans with age. Aging alters pancreatic secretion, through a decrease in flow rate, bicarbonate and enzyme secretion while calcium concentration is enhanced. Although not requiring substitutive therapy in the whole population, individual cases of pancreatic exocrine insufficiency might be explained by aging, without malnutrition.

Adult↗

[Antropyloric lithiasic obstruction. A variant of Bouveret's syndrome].

We report about one case of cholecystoduodenal fistula complicated by antropyloric lithiasic obstruction, which was treated surgically with gastrotomy and extraction of the calculus, in an 82-year-old woman. This case represents an anatomic variant of Bouveret's syndrome, which is classically defined as a duodenal lithiasic obstruction. On the basis of this case, the authors discuss the diagnostic and possibly therapeutic merits of digestive endoscopy and define the main clinical, anatomical and evolutive characteristics of this unfrequent complication of biliary lithiasis.

Aged↗

Characterization of a monoclonal antibody against a mucin-type glycoprotein in human sweat.

We report the preparation and characterization of an IgG2 monoclonal antibody (MAb), HSMA, prepared against a human pooled sweat extract (HPSE). The major component of HPSE was a mucin-type molecule, as revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) stained with periodic acid-Schiff (PAS) reagent. By immunoblotting, HSMA revealed a smear in the high molecular weight range, typical of mucins. In enzyme-linked immunosorbent assay (ELISA), HSMA failed to react with HPSE fractions isolated after anionic exchange gel chromatography. Similarly, radio-immunobinding assays demonstrated no reactivity between HSMA and A, B, H, and Lewis blood group-related structures. The immunohistological labeling on normal skin showed that HSMA reacted with the cells of eccrine sweat glands, and to a lesser extent, with sebaceous glands and epidermal cells. Periodate treatment in situ abolished these reactions, thus suggesting the carbohydrate structure of the HSMA-epitope. In indirect immunofluorescence (IF) studies, HSMA also reacted with other exocrine glands, e.g. mammary glands, sublingual glands, mixed sero-mucous glands of the trachea, and in the pancreas. Sparse positive cells were also observed in the testis, kidney, thyroid and digestive tract.

Animals↗

T-cell receptor-gamma/delta bearing lymphocytes in normal and inflammatory human skin.

Murine dendritic epidermal T cells (DETC) were recently reported to express T-cell receptor (TCR)-gamma/delta chains. In a search for the human equivalent of these cells, we tested normal and lesional skin with MoAb which react with the TCR-gamma/delta heterodimer. We performed indirect immunofluorescence (IF) on epidermal sheets, and alkaline-phosphatase-anti-alkaline-phosphatase complex (APAAP) on epidermal cell smears. Frozen skin sections from normal skin and various cutaneous lymphocyte infiltrates were also studied. A few CD3+ T lymphocytes were consistently found in normal epidermis. Most of these cells appeared to be TCR-alpha/beta +, and some CD4+ or CD8+. On epidermal sheets and cell smears, only a very small TCR-gamma/delta + cell population was visualized (less than 0.1% of the total). On normal skin sections, we observed 0 to 3 gamma/delta + cells per section. When present, they were often located in the epidermal basal layer, and were round or dendritic. Double immunolabeling revealed that gamma/delta + cells differed from CD1+ Langerhans cells, and that they had a similar phenotypic pattern as gamma/delta + peripheral lymphocytes (PBL): CD2+, CD3+, CD4-, and CD8-. Immunostaining from various inflammatory skin lesions showed that the dermal infiltrates included CD3+ T lymphocytes but virtually no gamma/delta + cells. Only a few gamma/delta + cells were found in some end-evolutive infiltrates. Taken together, these results strongly suggest that normal human epidermis occasionally harbors TCR-gamma/delta complex bearing lymphocytes, which constitute a small fraction of the CD3+ cutaneous T lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗

[Postoperative enoximone in coronary surgery. Systemic and coronary hemodynamics and regional systolic function].

The effects of Enoximone (50 mg in 20 minutes) on systemic, pulmonary and coronary haemodynamics and on regional systolic function were examined after surgical myocardial revascularisation in 5 patients without overt cardiac failure. The flow in mammary artery grafts and the study of regional systolic function were assessed by Doppler probes implanted during the operation. Enoximone increased Qc and Qco without changing blood pressure or cardiac output, due to arterial vasodilatation and inotropic stimulation. Pulmonary vasodilatation resulted in hypoxemia which must be prevented. The increase in VO2 was unrelated to oxygen transport suggesting a specific drug related effect.

Cardiotonic Agents↗