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Biomedical subjects

A Michel

Publications and source records attributed to A Michel.

At least 199 records · Page 11Linked to original sources
PubMed1986

Animal pharmacology of the selective histamine H1-receptor antagonist tazifylline.

3,7-Dihydro-7-[2-hydroxy-3-[4-[3-(phenylthio) propyl]-1-piperazinyl]propyl]-1,3-dimethyl-1H-purine-2,6-dione dihydrochloride (tazifylline, RS-49014) potently inhibited contractions evoked by stimulation of histamine H1-receptors in isolated guinea pig ilea and exhibited high affinity for these receptors in radioligand binding studies in vitro. In rats, guinea pigs and dogs the antihistaminic effect of tazifylline was rapid in onset and long-lived. In anesthetized guinea pigs, tazifylline markedly inhibited histamine-induced bronchoconstriction and protected conscious animals from the lethal effect of large doses of the amine. In conscious rats, tazifylline was more potent in reducing the inflammatory effects of intradermal histamine than that evoked by anaphylactic reaction. In conscious dogs, orally administered tazifylline inhibited histamine-induced skin inflammation for long periods of time and in anesthetized animals attenuated that portion of the histamine-evoked hypotension attributable to stimulation of H1-receptors. Results obtained from a variety of in vitro and in vivo experimental preparations showed that tazifylline had much lower affinity for histamine H2-receptors, alpha- and beta-adrenoceptors, 5-hydroxytryptamine and muscarinic receptor subtypes. Tazifylline poorly inhibited the release of histamine from rat peritoneal mast cells. Large oral doses of tazifylline did not reduce spontaneous locomotor activity in mice, nor did they produce overt symptoms of behavioral depression in conscious rats. Therefore, tazifylline is a potent, selective and long-acting histamine H1-receptor antagonist that does not appear to produce central depression in animals.

Animals↗
PubMed1985

Cardiac adenylate cyclase activity in streptozotocin-treated rats after 4 months of diabetes: impairment of epinephrine and glucagon stimulation.

Adenylate cyclase (AC) activities of cardiac membranes prepared (a) from rats that had been made diabetic 4 months previously by a single i.v. injection (50 mg/kg) of streptozotocin (STZ), and (b) from diabetic rats which had been treated during the same period by a daily dose of long-acting insulin (2-4 U/animal), were compared with the AC activity of cardiac membranes prepared from age-matched control animals. Basal (Mg++-dependent) and Mn++ (7 mM)-dependent activities, as well as Gpp(NH)p (3 X 10(-7) M) stimulation and Ca++ (pCa = 3.9) inhibition of cardiac AC were not significantly different in the three groups. At the EC50 concentration epinephrine (5 X 10(-7) M) stimulation of AC was reduced in diabetic animals but no change was observed at higher concentrations (10(-4) M). Glucagon stimulation was impaired at both the EC50 concentration (10(-7) M) and at higher concentrations (10(-5) M). Insulin treatment of the diabetic animals partially prevented the impairment of hormone stimulation. These results confirm observations that alterations of cardiac AC activity in STZ-treated rats are indeed due to diabetes and not to STZ-toxicity and suggest that AC-coupled receptors are altered either by an diabetes-induced alteration of cardiac sarcolemma.

Adenylyl Cyclases↗
PubMed1985

The proprietary hospital industry: a financial analysis 1972-1982.

This paper evaluates the performance of both specific firms within the American for-profit hospital industry and the industry as a whole. First, traditional financial analysis is used to evaluate individual publicly traded for-profit chains. Then, industry performance from 1973 to 1982 is evaluated using a set of measures based on Modern Portfolio Theory. The traditional financial analysis indicates that the industry seems increasingly profitable as well as increasingly healthy from the perspective of utilizing its assets and reducing its collection period. However, the industry's rapid growth rate has strained its ability to use additional debt funding and has created a potentially dangerous liquidity position. Measures based on Modern Portfolio Theory indicate that the average return of the industry has improved over the past 5 years. However, its risk has also increased. Nevertheless, the increase in risk is more than offset by the increased average return. In addition, recent legislation designed 'to reward the efficient' has introduced a significant degree of uncertainty into the industry's performance for the coming years. Thus, hospitals' ability to maintain the substantial profitability and rate of growth they have experienced over the past decade will depend on how well they will adapt to the changing environment.

Cost Control↗
PubMed1985

Characterization of trypsin stimulation of cardiac adenylate cyclase.

The activity of adenylate cyclase present in a purified dog heart sarcolemmal preparation in the presence of magnesium as cosubstrate is biphasically influenced by increasing concentrations of trypsin: Stimulation at low concentrations (0.5 to 1 microgram/mL) is followed by inhibition at higher concentrations. In the presence of manganese in place of magnesium, the stimulation phase is abolished but the inhibition is still observed at the same trypsin concentrations. The trypsin stimulatory effect does not occur when trypsin is preincubated with cardiac membranes prior to the addition of ATP. When trypsin is added with ATP, the stimulation is expressed by an increase in the Maximal Velocity (Vmax) rather than a decrease in the Michaelis constant (Km). The stimulatory effect of trypsin on AC activity is rapid, linear and irreversible. GTP, Gpp(NH)p and adrenaline stimulatory curves are shifted to the left in the presence of trypsin. These results suggest that protease stimulation of cardiac AC involves the GTP-binding protein (N) activity, but the exact mechanism remains to be determined.

Adenylyl Cyclases↗
PubMed1985

[Aortocaval fistulas. Apropos of 5 cases].

UNLABELLED: 5 cases of aorto-iliac aneurysms which fistulised into the inferior vena cava are described. They illustrate the problems encountered in this condition. - DIAGNOSIS: although a classical diagnosis, it is only recognised in 27 p. 100 of cases because the clinical presentation can be very variable. A pulsating, expansive, abdominal mass very suggestive of an aneurysm of the abdominal aorta should alert to the possibility of a fistula within the inferior vena cava when the patient has unexplained cardiac failure, shock, lower limb deep vein thrombosis, urinary or psychological problems. In the absence of a continuous abdominal murmur, the diagnosis may be confirmed by complementary investigations; the investigations of choice are non-invasive. Abdominal ultrasonography showing an aneurysm of the abdominal aorta associated with dilatation of the inferior vena cava is very suggestive of the diagnosis. - The only treatment is surgery. The operative risk depends on the presence of absence of associated retroperitoneal rupture of the aneurysm, the respective mortalities being 83 p. 100 and 15 p. 100. - The principal causes of death are pulmonary embolism and renal failure which necessitate special prophylactic measures (surgical and anaesthetic).

Aged↗
PubMed1984

Circadian changes in carrageenin-induced edema: the anti-inflammatory effect and bioavailability of phenylbutazone in rats.

The circadian variations in paw-edema produced by carrageenin and the anti-inflammatory effect of phenylbutazone were studied, in rats kept under a 12 light-12 dark regimen, in comparison with the variations of plasma phenylbutazone and oxyphenbutazone levels. When the experiment was performed during the light span (08.00 and 14.00 h), the rats were highly sensitive to the phlogistic effect of carrageenin, the plasma levels of phenylbutazone and oxyphenbutazone were lower, and the anti-inflammatory effect of phenylbutazone, weaker. Opposite results were obtained when the experiment was performed during the dark span (02.00 and 20.00 h). The results indicate that the chronoeffectiveness of phenylbutazone is influenced by both its chronokinetics and the chronesthesy of the biosystem involved.

Animals↗
PubMed1984

[Infertility caused by uterus bipartitus. Value of the Bret-Palmer operation].

Among the uterine malformations responsible for infertility, uterus bipartitus is one of the most amenable to surgery. The operation devised by Bret and Palmer is intended for those cases where the malformation is due to non-resorption of the medial septum and not for those where it is due to lack of fusion of the Mullerian ducts. The results are excellent, since 70% or 80% of previously infertile women subsequently became pregnant.

Female↗
PubMed1983

Synthesis and biological activities of [beta-Malyl1]- and [beta-Malyl1, Leu8]-angiotensin II analogues.

The synthesis of [beta-Malyl1]- and [beta-Malyl1, Leu8]-angiotensin II using a solid phase procedure is reported. The replacement of the N-terminal amino group of aspartic acid by a hydroxyl group gives analogues with lower affinity than [Asn1]- and [Asn1, Leu8]-AII. However, the isoster [beta-Malyl1]-AII shows higher potency than [Asn1]-AII and this may be due to metabolic or enzymatic resistance.

Amino Acids↗
PubMed1983

Response to secondary therapy in patients with adenocarcinoma of the breast previously treated with adjuvant chemotherapy.

The response to secondary therapy, chemotherapy or hormonal, is examined in 26 patients with adenocarcinoma of breast who failed adjuvant chemotherapy. Response rates to tamoxifen or combination chemotherapy, cyclophosphamide, methotrexate, and 5-FU (CMF) or Adriamycin and vincristine (AV) were similar to response rates reported for Stage IV patients, never exposed to cytotoxic agents. Survivals in these 26 patients were similar to those reported for Stage IV patients never exposed to cytotoxics. It is concluded that adjuvant chemotherapy does not lessen future response to secondary therapies or decrease survival.

Adenocarcinoma↗
PubMed1983

Multimodality therapy of stage III adenocarcinoma of the breast.

The results of a pilot multimodality program (surgery + radiotherapy + chemotherapy) are reported in 34 women with advanced stage III and IV adenocarcinoma of the breast. The median relapse-free survival for all patients was 24 months, with 74% of the premenopausal patients and 37% of the postmenopausal alive at five years (P = 0.18). The relapse rate was significantly lower in premenopausal patients when compared to the postmenopausal subgroup. Estrogen receptor status was not predictive for relapse or survival.

Adenocarcinoma↗
PubMed1983

[Not Available].

Explore the source record for details and available documents.

History of Medicine↗
PubMed1982

The conformational properties of somatostatin. IV. The conformers contributing to the conformation equilibrium of somatostatin in aqueous solution as found by semi-empirical energy calculations and high-resolution NMR experiments.

The results of a conformational study by 1H and 13C high-resolution NMR at 270 and 500 MHz on the peptide hormone somatostatin have been compared with a series of conformers generated by semi-empirical energy calculations. The use of specifically deuterated phenylalanine residues has enabled us to confirm and supplement the identification of all but the phenylalanine aromatic resonances in the proton spectra of somatostatin. In order to minimize the risk of overlooking some low-energy conformations, four different strategies have been used for the generation of the conformers: two based on combinations of conformations of fragments that had been studied before, one on a random procedure and one on the conformational constraints existing in bicyclic analogs with high biological activity. The experimental values of 3JNH-C alpha H and 3J alpha beta coupling constants and the existence of several ring current shifts allowed us to select from the calculations those families of low-energy conformers that are compatible with the NMR results. The NH temperature coefficients do not warrant the existence of any stable beta or gamma turns in the molecule, although the region SRIF8-12 seems to be the most stable in this respect. In addition there are several upfield shifts: 0.2-0.4 ppm on the Lys9 side-chain, 0.3-0.5 ppm on the Phe6 alpha, beta and Phe7 alpha protons, as well as some 0.2-0.3 ppm shifts on parts of two phenylalanine ring systems. Almost all of these shifts decrease considerably with increasing temperature. Most of the observed NMR results are compatible with the properties of one family of low-energy conformations whose main features are a double beta II bend Trp8-Lys9, Thr10 -Phe11, a close proximity of the Trp8 and Lys9 side chains and an orientation of Phe7 towards the Phe6 alpha, beta protons. We conclude that this set of conformations forms a major contribution to the conformational equilibrium at room temperature. The properties of this and several other sets of low-energy conformations that do not dominate in aqueous solution are discussed in relation to al available experimental evidence.

Magnetic Resonance Spectroscopy↗
PubMed1982

Prognostic value of the estrogen receptor level in pathologic stage I and II adenocarcinoma of the breast.

The relationship between estrogen receptor levels and recurrence of breast cancer was examined in 302 patients with adenocarcinoma of the breast, pathologic stage (PS) I and II. All 117 patients with PS II adenocarcinoma of the breast received adjunctive chemotherapy. In this series, there was no association between the estrogen receptor level and recurrence in either the 185 patients with PS I adenocarcinoma of the breast or the 117 patients with PS II adenocarcinoma of the breast. The most important prognostic variable was the presence or absence of axillary metastases.

Adenocarcinoma↗