Search PubMed⌕ Search

Biomedical subjects

J Lemoine

Publications and source records attributed to J Lemoine.

48 records · Page 3Linked to original sources
PubMed1988

Altered drinking responses in dogs with chronic metabolic alkalosis.

Chronic chloride depletion alkalosis in dogs causes a lowered osmotic threshold and increased sensitivity for vasopressin (AVP) release. Since AVP release and drinking behavior normally are closely associated over a narrow range of changes in plasma osmolality (Posm), we investigated whether alkalotic dogs would also show an altered responsiveness to the dipsogenic effects of angiotensin II (ANG II) and osmotic stimuli. Dogs made chronically alkalotic by a combination of chloride-free diet and furosemide injections developed polydipsia in the absence of any increase in solute intake and in the presence of a significant reduction in Posm. The animals were chronically hypochloremic, hyponatremic and hypokalemic, and appeared to be extracellular fluid (ECF) contracted. Plasma renin activity (PRA) was 10-fold higher in alkalotic dogs than controls. When Posm was increased by a slow 2 hr infusion of hypertonic sodium sulfate, alkalotic dogs were found to have a significantly lower osmotic threshold for inducing drinking (289.8 +/- 1.1 mOsm/kg/H2O vs. 305.1 +/- 1.3 mOsm/kg/H2O in controls), but the slope or sensitivity of the water intake/Posm relationship was not significantly different. Finally, compared to normal animals, alkalotic dogs were unresponsive to the dipsogenic effects of IV ANG II. These data indicate that the central mechanisms which mediate drinking in response to cellular and extracellular thirst stimuli are altered in chronic metabolic alkalosis.

Alkalosis↗
PubMed1987

Central mechanisms for apomorphine-induced emesis in the dog.

In order to investigate whether different receptor populations mediate emesis induced by intracerebroventricular (i.c.v.) and intravenous (i.v.) apomorphine, adult beagle dogs were tested with various doses of the drug with and without central and peripheral pretreatment with the dopamine antagonist sulpiride. The threshold dose of apomorphine to induce emesis by i.c.v. injections was 30-50 times lower than via the i.v. route, while the response latencies after i.c.v. administration were typically longer and the number of bouts of vomiting greater. I.v. pretreatment with sulpiride was more effective than i.c.v. pretreatment in blocking emesis induced by i.v. apomorphine, whereas both i.v. and i.c.v. sulpiride effectively blocked vomiting after i.c.v. apomorphine. Finally, in separate experiments, surgical interruption of blood flow in the region of the area postrema permanently abolished the emetic response to i.c.v. apomorphine, but only transiently disrupted emesis induced by i.v. apomorphine. These data suggest the possibility that i.v. and i.c.v. apomorphine-induced emesis may be mediated by separate dopamine receptors on the cerebrospinal fluid-side and blood-side of the area postrema.

Animals↗
PubMed1985

Fluid regulation and reproductive cyclicity in female rats treated neonatally with testosterone and methandrostenolone.

Female rats injected with 1 mg of testosterone propionate on day 5 after birth weighed significantly more during the immediate postpubertal period than methandrostenolone-treated (1 mg) or vehicle-injected control females. There were no differences between groups in 24-hour intakes of food or water, when expressed on a per unit body weight basis. Testosterone- and methandrostenolone-treated rats ingested less water than controls in response to acute extracellular dehydration but not after cellular dehydration. The volume of the 'sexually dimorphic nucleus' of the preoptic area was significantly greater in brains taken from the two steroid-injected groups compared to control females. Testosterone had a stronger androgenic effect than methandrostenolone in terms of disrupting the estrous cycle.

Animals↗
PubMed1984

Central angiotensin-induced water intake and salt appetite in the pig.

Single intracranial injections of the peptide analogues of angiotensin and the enzyme renin induced drinking of water and 1.8% NaCl solution in prepubertal female pigs maintained ad libitum on a sodium-free diet with unrestricted access to both fluids. Over the dose range 10(-12)-10(-9) mol angiotensin (AI), angiotensin II (AII), angiotensin III (AIII), and renin substrate (RS), the volumes of water and salt solution ingested were dose-dependent. As in other vertebrates, AII was the most potent and rapidly acting dipsogen. However, unlike in the rat, dog and pigeon, AIII was highly effective in stimulating both water intake and salt appetite, whereas AI and RS were relatively weak. Pretreatment of intracranial sites with 10(-9) mol of the AII competitive antagonist, Sar1-Ala8-angiotensin, had no effect on the volume of water or 1.8% NaCl ingested after 10(-10) mol AIII, suggesting that in the pig AIII can exert its dipsogenic effects without acting on central AII receptors. Single microinjections of 1 and 10 mU of renin also elicited dose-dependent drinking of water and 1.8% NaCl, but compared with the peptide analogues of angiotensin the responses had a longer latency and duration and were more variable between individual animals.

Angiotensins↗
PubMed1983

Surgical management of gallstones in cirrhotic patients.

Among the cirrhotic patients admitted to our department, 64 (17 percent) were found to have cholelithiasis. In 14 patients (22 percent), cholelithiasis caused cholecystitis, obstructive jaundice, or biliary pain. These 14 patients were operated on and underwent cholecystectomy. There was one postoperative complication (gastrointestinal bleeding from esophageal varices) and one death (due to acute respiratory failure). In 50 patients (78 percent) cholelithiasis was asymptomatic. Ten of the 50 patients died from liver failure and the stones were discovered at necropsy. Seven of the patients had radiographically demonstrated stones that were not operated on. They are alive at the present time, more than 2 years later. In the remaining 33 patients, the stones were discovered during portasystemic shunt procedures. In these patients, cholelithiasis was systematically treated by cholecystectomy (8 patients) or cholecystolithotomy (25 patients). Postoperative mortality and morbidity rates were not different in these 33 patients when compared with the rates in 170 patients who underwent portal surgery alone during the same period. Our results confirm the high incidence of cholelithiasis in cirrhotic patients. Complications of gallstones are not frequent but require an emergency operation that carries a high risk in these patients. On the other hand, elective surgical treatment of asymptomatic cholelithiasis at the time of portal diversion does not bear any peculiar risk. In such a situation, cholecystolithotomy is easier and probably safer than cholecystectomy.

Cholecystectomy↗
PubMed1983

Microlithiasis of the gallbladder.

Patients with microlithiasis represent a small group compared with the general population of patients with gallstones. However, it is a group which deserves particular attention because of the risk of acute pancreatitis. For this reason, cholecystectomy should be advocated in patients considered to be at low anesthetic risk in which echography or roentgenography detects the presence of minute stones in the gallbladder, even in the absence of biliary disorders.

Acute Disease↗