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Biomedical subjects

M Dumont

Publications and source records attributed to M Dumont.

At least 181 records · Page 10Linked to original sources
PubMed1987

[The priority of the surgical treatment of ovarian cysts or dispute with the Anglo-Saxons].

It seems likely the first oophorectomy which was carried out in France must have been in the years 1847-1848 (Woyeikowsky and Vaullegard). This surgical procedure, however, was carried out much earlier. In Germany Chrysmar carried out the operation in 1819 and Ephraim McDowell in America, in Kentucky, did it in 3 cases between 1809 and 1816. Whereas Robert Houstoun operated on a woman in Glasgow in 1701, he did not carry out oophorectomy but punctured the cyst through a laparotomy incision.

Female↗
PubMed1986

Synthesis and biological activity of dynorphin-(1-13) and analogs substituted in positions 8 and 10.

Dynorphin-(1-13) (Dyn-(1-13)) and various analogs substituted in positions 8 and 10 were synthesized by the solid-phase technique and analyzed for their ability to inhibit the electrically evoked contraction of the guinea pig ileum (GPI) and to compete with the binding of [3H]-ethylketocyclazocine (EKC, kappa ligand), [3H]-[D-Ala2, MePhe4-Gly-ol5]-enkephalin (DAGO, mu ligand) and [3H]-[D-Ser2, Thr6]-Leu-enkephalin (DSLET, delta ligand) to membrane preparations of the guinea pig cerebellum or rat brain. Introduction of Ala in position 8 decreased the activity of the peptide on the GPI by 50% but induced a 2.22-fold increase in its affinity for the kappa receptor ([3H]-EKC binding displacement from guinea pig cerebellum; Ki of 0.05 nM as compared with 0.11 nM for Dyn-(1-13)). On the other hand, the ability of [Ala8] Dyn-(1-13) to displace the binding of [3H]-DSLET from rat brain membranes was decreased by a factor of 1.7 while its affinity for the mu receptor was not greatly affected ([3H]-DAGO displacement; Ki of 0.44 nM as compared with 0.50 nM for Dyn-(1-13)). Replacement of position 8 by D-Ala caused similar changes in the activity of the peptide but the increase in its affinity for the kappa site was somewhat smaller (Ki of 0.08 nM as compared with 0.11 nM). [D-Pro10]-Dyn-(1-13) was equipotent to [Ala8]-Dyn-(1-13) in the GPI but its affinity for the mu binding site was decreased by a factor of 2.7 as compared with Dyn-(1-13).(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1986

14-beta-Methyl-8-oxacyclorphan (BC-3016), a morphinan derivative with high affinity for kappa opioid receptor: comparison with dynorphin-A(1-13).

14-beta-Methyl-8-oxacyclorphan (BC-3016) was tested for its ability to depress the electrically evoked contractions of the guinea pig ileum (GPI) and of the mouse vas deferens (MVD) and to compete with the binding of prototype ligands selective for kappa-, mu-, or delta-opioid receptors in membrane preparations of rat brain and guinea pig cerebellum. BC-3016 was a very potent agonist in the GPI and MVD preparations, with ID50 of 0.7 and 31 nM, respectively. The activity of levorphanol, a standard alkaloid related to BC-3016, was much lower in both assays with ID50 values of 44 and 86 nM, respectively. Conversely, the activity of BC-3016 was quite comparable to that of dynorphin-A(1-13) in both preparations. In the GPI assay, a putative kappa-receptor antagonist, MR-2266, was 6.6 and 5.5 times more potent than naloxone in blocking the activity of BC-3016 and dynorphin-A(1-13), respectively. BC-3016 was also very potent in displacing bound [3H]ethylketocyclazocine ([3H]EKC) to membrane preparations of the guinea pig cerebellum, a brain component containing predominantly kappa-opioid receptors (Ki of 0.58 nM). Its potency in the displacement of the bound mu-ligand, 3H-labelled (D-Ala2,MePhe4,Gly-OH5)-enkephalin ([3H]DAGO), to rat brain homogenates was somewhat lower (Ki of 0.8 nM) but still high when compared with its ability to displace the delta-ligand, 3H-labelled (D-Ser2, Thr6)-Leu-enkephalin ([3H]DSLET) to rat brain homogenates (Ki of 4.45 nM). The affinity of BC-3016 for the opioid receptor was 2.1-fold higher than that of U-50488H, a selective kappa-opioid ligand.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

[Ectopia cordis: early echographic diagnosis in utero].

Having had a case of ectopia cordis which was diagnosed early in utero, the authors have analysed the information they have obtained and they have suggested what steps to take according to the features revealed by the ultrasound pictures and taking into account the different anatomical forms. They have also considered the lesions that are associated with this condition and the principal prognostic features.

Abnormalities, Multiple↗
PubMed1986

[Rare or little known syndromes in gynecology and obstetrics].

The author presents fourty-three years' experience of rare syndromes or those which he considers are poorly understood in the area of gynecologic obstetrics. He briefly reviews: spontaneous post-cesarian perforation of the cecum, post-partum paralysis of the external popliteal sciatic, carpal canal syndrome in pregnacy, meralgia paresthetica in pregnant women, diaphragmatic hernia and its complications during pregnancy and labor, post-mortem cesarian, the "molar lung", early pregnancy and late pregnancy, fulguration and electroshock in pregnant women, the "acrobatic fetus", the rupture of an aneurysm of the splenic artery, geophagia or "pica", extramucous ruptures of the uterus, "virtually pure" type XX familial gonadic dysgenesis with deaf-muteness, gynecologic pathomimesis, genital perihepatitis or Fitz-Hugh-Curtis syndrome, vulvar mammary ectopism, post-hysterectomic pregnancy, recurrent hydramnios, locoregional ecchymatosis.

Cesarean Section↗
PubMed1986

[Assessment of the risk of postpartum thromboembolism by measuring antithrombin III levels. A false hope].

In order to predict better thrombo-embolic complications that sometimes occur after delivery, we studied the variations of antithrombin III levels (A.T. III) in 703 women, at the 8th month pregnancy (275 levels), on the first day (609 levels) and the 5th day (516 levels) after delivery. The average antithrombin III levels were respectively 90.8%, 83.4% and 98.7%. We found 120 levels (8.5%) lower than 80% (normal range for A.T. III = 80-120%), 107 of which on the first day after delivery were followed by a rapid increase to the normal range; these women however were satisfactory in the post-partum period. Therefore predicting thrombo-embolic complications in the post-partum period through A.T. III levels determination would seem to be pointless.

Adult↗
PubMed1986

[A case of hepatic and splenic peliosis occurring in the puerperium after normal pregnancy].

The authors report a case of Peliosis of the liver and of the spleen that occurred at term after a normal pregnancy that lasted 38 weeks. The delivery was complicated by amniotic infection with hemorrhagic shock and uterine inertia that gave rise to the need for a sub-total hysterectomy in order to stop the bleeding. The progress of the case was made worse by the development of the disseminated intra-vascular coagulation syndrome with septicaemia and pulmonary oedema. When the operation was carried out to stop the bleeding it was noted that the liver was enlarged, hard, smooth and dark in colour and the histological specimen showed a major degree of Peliosis hepatis. The same lesions were found in the region of the spleen and a lymph node. The patient died 14 days after delivery of acute renal failure together with cerebral oedema and septic shock. The authors consider that the aetiology of the Peliosis could be due to hormone changes of pregnancy associated with septicaemia. The anatomical evolution of Peliosis hepatis to widespread necrosis of the parenchyma makes it possible to understand that the condition of diffuse intra-vascular coagulation will not improve in the presence of hepato-cellular insufficiency.

Adult↗
PubMed1985

Interaction of dynorphin with kappa opioid receptors in bovine adrenal medulla.

Dynorphin (Dyn) and various prototypic kappa opioid ligands were tested for their ability to bind to opioid receptors in a membrane preparation of bovine adrenal medulla and to modulate the release of catecholamines (CA) from isolated adrenal chromaffin cells. Saturation binding studies with [3H]-ethylketocyclazocine ([3H]-EKC) were performed at 37 degrees C for 30 min in the presence of [D-Ala2,Me-Phe4,Gly-ol5]-enkephalin (DAGO) and [D-Ser2,Thr6]-Leu-enkephalin (DSLET), two specific ligands for crossreacting mu and delta opioid receptors, respectively. Scatchard plot analysis of the data revealed the presence of two receptor sites: a high affinity binding site (kappa) with a KD of 0.66 nM and a Bmax of 12 pmoles/g protein and a low affinity binding site (kappa 2) with a KD of 11.1 nM and a Bmax of 56 pmoles/g protein. The presence of kappa opioid receptors in the membrane preparation was also supported by competition studies. U-50, 488H and Dyn-(1-13), two selective kappa opioid ligands, were potent inhibitors of [3H]-EKC binding with Ki (high affinity binding sites) of 2.5 and 2.3 nM, respectively. Among the various ligands tested for each class of opioid receptors (mu, delta, kappa), U-50, 488H and Dyn-(1-13) were the most potent inhibitors of the acetylcholine-evoked CA secretions from isolated adrenal chromaffin cells with IC50 of 0.31 and 1.14 microM, respectively. The inhibitory effect of U-50, 488H was significantly antagonized by diprenorphine and MR-2266, two opioid antagonists with a high affinity for the kappa opioid receptor.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗
PubMed1985

Effect of acid-base balance and acetazolamide on ursodeoxycholate-induced biliary bicarbonate secretion.

Biliary bicarbonate secretion may play an important role in canalicular bile flow. The aim of this study was to examine the effect of disturbances in acid-base balance on ursodeoxycholate (UDCA)-induced choleresis and bicarbonate secretion. Isolated rat livers were perfused with an erythrocyte-free solution in a recirculating system. In the absence of bile acid infusion, bicarbonate concentration in bile varied in parallel with that in the perfusate (15.6-35.1 mM), irrespective of the perfusate pH (7.26-7.55). Bicarbonate concentration in bile was not significantly different from that in the perfusate. Under UDCA infusion (2 mumol/min), bicarbonate concentration in bile and perfusate was correlated (P less than 0.001). Bicarbonate concentration in bile was always higher than that in the perfusate. Perfusate pH changes (7.25-7.56) induced by changes in perfusate carbon dioxide tension had no significant effect on bicarbonate secretion or bile flow. A significant correlation was found between bile flow and bicarbonate secretion both with and without UDCA. Acetazolamide (1 mM) significantly decreased both UDCA-stimulated bile flow (-27.7%) and bicarbonate concentration (-51.8%). These results suggest that canalicular bicarbonate secretion includes an equilibrative component that is possibly linked to diffusion of plasmatic CO2 or HCO3- and a concentrative transport that is stimulated by UDCA, is independent of plasma pH, and involves carbonic anhydrase.

Acetazolamide↗
PubMed1985

Role of H+ transport in ursodeoxycholate-induced biliary HCO-3 secretion in the rat.

Biliary bicarbonate secretion may occur by transport of bicarbonate itself or of H+ (or OH-). To distinguish between these two mechanisms, we have studied the effects of bicarbonate deprivation or substitution by weak acids in the perfusate of isolated rat livers on ursodeoxycholate-induced bicarbonate secretion. Livers were perfused with an erythrocyte-free solution containing either the impermeant buffer Tricine (25 mM) or 25 mM Tricine and 13 mM bicarbonate, acetate, or 5,5-dimethyloxazolidine-2,4-dione (DMO), and ursodeoxycholate was infused. Tauroursodeoxycholate, which does not stimulate bicarbonate secretion, served as a control. During ursodeoxycholate infusion 1) the increase in bile flow, in microliter X min-1 X g liver-1 (+/- SE), was significantly higher in livers perfused with Tricine and bicarbonate (1.29 +/- 0.06), Tricine and acetate (1.46 +/- 0.07), and Tricine and DMO (1.30 +/- 0.04) than in livers perfused with Tricine alone (0.99 +/- 0.04); and 2) biliary bicarbonate, acetate, or DMO concentrations and bile pH were significantly higher than the corresponding perfusate values. In contrast, during tauroursodeoxycholate infusion bile flow was the same whatever the perfusate, and bile pH was lower than pH of the perfusate. Therefore, ursodeoxycholate-induced choleresis and bile alkalinization do not depend on bicarbonate as such (which can be replaced by acetate or DMO). This suggests that ursodeoxycholate-induced biliary bicarbonate secretion is the result of H+ (or OH-) transport rather than transport of bicarbonate itself.

Animals↗
PubMed1985

Mechanism of uptake of dihydroergotamine by isolated rat hepatocytes: effect of troleandomycin.

The mechanism of uptake of dihydroergotamine (DHE) was studied in isolated rat hepatocytes and the effect of troleandomycin on DHE uptake was examined. The uptake was linear for 75 sec and reached an equilibrium at 5 min with an intracellular/extracellular concentration ratio of approximately 65. The initial velocity of uptake was linearly related to the concentration of DHE in the extracellular medium with a diffusion constant of 127 pmol X min-1 X mg of protein-1 X microM-1. Metabolic inhibitors (KCN, carbonylcyanide-M-chlorophenylhydrazone and antimycin A) had no effect on DHE uptake. Replacement of sodium by choline chloride in the extracellular medium decreased slightly but significantly (P less than .02) the uptake of DHE. The addition of troleandomycin (300 microM) in the incubation medium decreased the initial velocity of uptake of DHE (control, velocity of uptake = 88 pmol X min-1 X mg of protein-1 X microM-1; troleandomycin, velocity of uptake = 55 pmol X min-1 X mg of protein-1 X microM-1; P less than .05). These results suggest that DHE enters into the hepatocytes by passive diffusion. The high intracellular/extracellular concentration ratio suggests that intracellular binding occurs and results in an accumulation of DHE in the cells.

Animals↗