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Biomedical subjects

M Staroukine

Publications and source records attributed to M Staroukine.

At least 19 recordsLinked to original sources

Increased angiotensin II in ascites during severe ovarian hyperstimulation syndrome: role of early pregnancy and ovarian gonadotropin stimulation.

OBJECTIVE: To investigate the implications of the ovarian renin-angiotensin system (RAS) in the pathophysiology of the ovarian hyperstimulation syndrome (OHSS) in relation to gonadotropin stimulation and early pregnancy. DESIGN: A controlled clinical study comparing blood and simultaneously sampled peritoneal fluid (PF) from patients with severe OHSS and from controls without OHSS. SETTING: University Hospitals. PATIENT(S): Eleven patients with severe OHSS, 8 patients with ascites of other origin, 9 patients with a first-trimester pregnancy, and 15 patients stimulated with gonadotropins for IVF. MAIN OUTCOME MEASURE(S): Angiotensin II immunoreactivity was measured in blood and PF and analyzed by high-performance liquid chromatography (HPLC) in ascites from OHSS. RESULT(S): Angiotensin II immunoreactivity (pg/mL; mean +/- SE) was highest in the ascites from pregnant OHSS (1,669 +/- 418), reaching levels 5 times higher than in the plasma (331 +/- 61) and 100 times higher than in control ascites (17 +/- 6.7). Angiotensin II immunoreactivity was elevated in the PF during early pregnancy (211 +/- 68) and after gonadotropin stimulation (244 +/- 41) and was higher than in the plasma in both groups. Analysis by HPLC showed that the majority of Ang II immunoreactivity in the ascites of OHSS was because of true Ang II. CONCLUSION(S): Severe forms of OHSS, especially those associated with pregnancy, are consistently characterized by huge concentrations of Ang II immunoreactivity in the ascites, proved to be true Ang II by HPLC analysis. This may be due to the synergistic effects of exogenous and endogenous hCG on the ovarian RAS.

Adult

[Biliary ileus].

A case of gallstone ileus in an elderly woman is described and attention is drawn to the insidious clinical presentation and the significance of the often subtle radiological signs. The data from the literature specifies these aspects and allows a more complete review of this relatively rare pathology in order to remind its importance in differential diagnosis to emergency clinicians and radiologists.

Biliary Fistula

Chronic angiotensin-converting enzyme inhibition and endothelial function of rat aorta.

To determine whether chronic angiotensin-converting enzyme (ACE) inhibition produces functional changes in the aorta normotensive rats, four groups of rats were studied in parallel for 6 weeks. Group 1 orally received ramipril and beta 2-kinin antagonist HOE140 500 micrograms/kg per day s.c. by injection for the remaining 2 weeks; group 3, hydralazine 100 mg/kg per day PO for 6 weeks; group 4 (control), subcutaneous injections of saline solution during the last 2 of 6 weeks. In aorta isolated from group 1 the relaxations induced by bradykinin, acetylcholine, and histamine were significantly potentiated compared with those of group 4. In group 3, despite a decrease in systolic blood pressure similar to that induced by ramipril treatment, the responses to these three endothelium-dependent vasodilators were not different from those of group 4. In group 2, bradykinin-induced relaxations were completely abolished whereas acetylcholine-induced and histamine-induced relaxations were to those of group 4. The inhibitory effect of the endothelium on serotonin-induced contractions was significantly increased in preparations of group 1 compared with those of groups 2 through 4. Indirect measurements of nitric oxide formation such as contractions evoked by NG-monomethyl-L-arginine (L-NMMA) and aortic cGMP content were also significantly enhanced in preparations from group 1 compared with those of groups 2 through 4. Moreover, because the relaxations to nitroglycerin and nitroprusside were similar in groups 1, 2, and 4 an alteration of the guanylate cyclase activity by ramipril treatment is quite unlikely. Thus long-term treatment with ramipril potentiates the endothelium-dependent responses in the rat aorta by enhancing nitric oxide availability.

Adrenergic beta-Antagonists

Comparison of the hemodynamic responses to molsidomine and isosorbide dinitrate in congestive heart failure.

To evaluate the mechanisms involved in nitrate tolerance, we randomized 23 patients with congestive heart failure resulting from coronary artery disease to an isosorbide dinitrate or a molsidomine infusion. The drugs were titrated to decrease pulmonary capillary wedge pressure by > or = 30% or > or = 10 mm Hg. Then isosorbide dinitrate, molsidomine, or placebo was infused in a double-blind randomized manner for 24 hours. In all patients, treatment with enalapril was begun > or = 48 hours before the beginning of the protocol and was continued throughout the study to avoid renin-angiotensin activation. The pulmonary capillary wedge pressure remained significantly decreased at 24 hours during molsidomine infusion only. No significant increase in catecholamines occurred. Because molsidomine differs from organic nitrates by its property of directly stimulating guanylate cyclase without depending on thiol group availability, these results suggest that impaired biotransformation of nitrates is involved in tolerance induced by high doses of isosorbide dinitrate in congestive heart failure.

Biotransformation

Angiotensin II immunoreactivity is elevated in ascites during severe ovarian hyperstimulation syndrome: implications for pathophysiology and clinical management.

OBJECTIVE: To investigate the ovarian renin-angiotensin system (RAS) during severe ovarian hyperstimulation syndrome (OHSS). DESIGN: Simultaneous sampling of blood and ascitic or peritoneal fluid (PF) during therapeutic paracentesis or laparoscopy. SETTING: University Hospital. PATIENTS: Twelve patients were investigated: three patients presenting severe OHSS, three patients with a spontaneous first trimester pregnancy, three normally cycling women during the early luteal phase, and three patients with ascites of nonovarian origin. MAIN OUTCOME MEASURE: Renin-like activity and angiotensin II (ANG II) immunoreactivity were measured simultaneously in the plasma and the ascites or PF. RESULTS: Angiotensin II immunoreactivity was much higher in the ascites or PF than in corresponding plasma during severe OHSS, first trimester pregnancy, and in the early luteal phase, while it was lower in ascites of nonovarian origin. Renin-like activity and ANG II immunoreactivity were the highest in the ascites of severe OHSS and in the PF from part of the patients with a spontaneous first trimester pregnancy. CONCLUSIONS: The present findings argue for the ovarian origin of the elevated renin-like activity and ANG II immunoreactivity in the ascites of severe OHSS and suggest a stimulatory role of hCG on the ovarian RAS whether during severe OHSS or first trimester spontaneous pregnancy. The vasoactive peptide ANG II may contribute to the maintenance of the ascites in severe OHSS but is probably not responsible for the formation of the ascites. The efficiency of paracentesis during severe OHSS could be explained at least partially by the removing of great amounts of ANG II from the peritoneal cavity.

Adult

Hemodynamic response to molsidomine in patients with ischemic cardiomyopathy tolerant to isosorbide dinitrate.

Unlike nitrates, molsidomine is able to relax vascular smooth muscle without depending on the availability of sulfhydryl groups. To assess the clinical relevance of this property, the hemodynamic effects of a 24-h i.v. infusion of molsidomine were studied in 14 patients with ischemic cardiomyopathy rendered tolerant to i.v. isosorbide dinitrate. In order to determine the role of neurohormonal activation, six of these patients were studied in the presence of an angiotensin-converting enzyme (ACE) inhibitor (enalapril, 5 mg, b.i.d.) (group 2). Six patients out of eight in group 1 (without ACE inhibition) and all patients in group 2 responded to molsidomine with a marked reduction of pulmonary artery wedge pressure (PAWP) (49% +/- 5 and 50% +/- 4 versus baseline value, respectively). However, the reduction of PAWP in group 1 was no longer significant at 12 h, and at 24 h the loss of the peak effect reached 67% +/- 7. On the contrary, PAWP remained persistently reduced in group 2 (loss of peak effect, 20% +/- 3 at 24 h, p less than 0.005). In addition, a significant decrease in hematocrit and increase in epinephrine occurred in group 1 but not in group 2. These results suggest that both the absence of dependence on sulfhydryl groups and the blockade of neurohormonal reactions are needed to avoid nitrate tolerance.

Aged

Legionellosis and "torsades de pointes".

Myocarditis, pericarditis and endocarditis are rare manifestations of Legionella pneumophila infection. We describe a case of myocarditis complicated with a potentially fatal arrhythmia: "torsades de pointes".

Aged

Interaction between nonsteroidal anti-inflammatory drugs and loop diuretics: modulation by sodium balance.

Nonsteroidal anti-inflammatory drugs have been shown to decrease the natriuretic response to loop diuretics in many but not all studies. Recently, indomethacin was shown not to affect the natriuretic response to the new loop diuretic torasemide in healthy volunteers. Inasmuch as sodium balance has been reported to modify the effect of indomethacin on furosemide-induced natriuresis in dogs, we investigated the effect of indomethacin, under two sodium balances (50 and 150 mEq/day), on the natriuretic response to two doses of torasemide in six healthy volunteers. Under the low sodium diet, indomethacin reduced the natriuretic response to torasemide like that to furosemide. In contrast, on the normal sodium diet, indomethacin failed to affect the natriuretic response to torasemide. Indomethacin reduced base-line and diuretic-induced increase in plasma renin activity, plasma angiotensin II levels and urinary excretion of prostaglandin 6-keto F1 alpha to a similar extent under the two sodium diets. Our data show that indomethacin reduces the natriuretic response to torasemide in humans. Dietary sodium restriction is a significant determinant of the interaction between nonsteroidal anti-inflammatory drugs and loop diuretics in healthy volunteers, presumably because it allows loop diuretics to provoke an increase in renal blood flow which participates in their natriuretic action and is blocked by nonsteroidal anti-inflammatory drugs.

Adult

Indirect evidence of glomerular/tubular mixed-type postexercise proteinuria in healthy humans.

Hypothetical mechanisms have been postulated to explain the presence of proteins in urine after severe exercise. Recently, it has been shown that several amino acids inhibit tubular protein reabsorption. Seven healthy men, hyperhydrated, were studied during a 2-min bicycle exercise at supramaximal load. The subjects were tested without or with lysine perfusion (0.4 g/kg body wt iv). In both testing conditions, blood lactate increased to 13.8 mmol/l. Total protein urinary excretion increased to 1.10 and 1.67 mg/min, without and with lysine perfusion, compared with 79 micrograms/min at rest. In the meantime, albumin excretion increased 48- and 74-fold, respectively, while beta 2-microglobulin excretion increased 97- and 1,043-fold compared with basal values. The renal clearance of albumin increased to 8.4 microliters/min without lysine and to 12.0 microliters/min with lysine perfusion (rest 0.18). beta 2-Microglobulin clearance increased to 10.0 and 39.3 ml/min, respectively (rest 0.05). These data clearly demonstrate that postexercise proteinuria is of mixed type after exhaustive short-term exertion. Both increased glomerular permeability and partial tubular reabsorption inhibition to proteins appear to be involved.

Adult

Failure of indomethacin to impair the diuretic and natriuretic effects of the loop diuretic torasemide in healthy volunteers.

The effects of torasemide, a new potent loop diuretic, on renin release, water and sodium excretion were investigated in young healthy volunteers before and after 3 days of treatment with indomethacin. Torasemide 20 mg i.v. induced a rapid and biphasic increase both in plasma renin activity and plasma angiotensin II levels, which was almost completely abolished by pretreatment with indomethacin. Torasemide also increased urine volume, sodium excretion and, during the first hour after dosing, the creatinine clearance. None of the latter effects was impaired by indomethacin pretreatment. It is concluded that, like other loop diuretics, torasemide stimulates renin release by increasing renal prostaglandin production. However, at variance with what is observed with other loop diuretics, the diuretic and natriuretic effects of torasemide as well as the change in creatinine clearance do not appear to be inhibited by indomethacin.

Adult