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Biomedical subjects

A Fournier

Publications and source records attributed to A Fournier.

At least 541 records · Page 30Linked to original sources
PubMed1984

[Primary hyperparathyroidism. Lack of effect of cimetidine on plasma levels of parathyroid hormone and calcium].

Because of the contradictory results formerly published as regards the effect of cimetidine in primary hyperparathyroidism, we have studied the effect of cimetidine at the daily dose of 1200 mg in 14 cases of primary hyperparathyroidism. The diagnosis was ascertained in all cases by the coexistence of an otherwise unexplained hypercalcemia and of a concomitantly elevated plasma concentration of immunoreactive parathyroid hormone (PiPTH) measured by 2 different antibodies and confirmed in 10 cases by surgical neck exploration. In 5 cases with severe hypercalcemia (greater than 12.0 mg/l) cimetidine was discontinued after 5 days because of its lack of effect on both plasma concentrations of calcium and PiPTH, and the patients were successfully operated. In 8 cases with milder hypercalcemia, cimetidine was given for 1.5-6 months. There was no significant change in both plasma concentrations of calcium (PCa) and PiPTH but a regression analysis showed that PCa was negatively correlated to time with a correlation coefficient which would have become significant if the follow-up had been 9 months. In the last patient severe hypercalcemia was controlled by simultaneous administration of phosphate, indomethacin and cimetidine without concomitant decrease of PiPTH; and 6 weeks after cimetidine discontinuation no significant increase of PCa and PiPTH occurred. These data show that cimetidine has no clinically therapeutic value in primary hyperparathyroidism.

Adolescent↗
PubMed1984

Structure and in vitro transcription of a glycine tRNA gene from Bombyx mori.

We report the sequences of a Bombyx mori tRNA1Gly gene, its flanking regions, and its in vitro transcription products. The 5' flanking DNA contains the sequences TATAC, TATTTT and TTC located 30, 18 and 4 nucleotides, respectively, in front of the transcription initiation site. These resemble, in both position and composition, sequences preceding other RNA polymerase III genes of B. mori. A deletion mutant retaining these conserved sequences and an additional 8 bp of flanking DNA is transcribed better than the wild-type gene in cell-free extracts from Xenopus laevis and B. mori. A mutant lacking the conserved sequences is expressed in the frog extract, but is inactive in the homologous system.

Animals↗
PubMed1984

A dual assay for the specific screening of 3-methylcholanthrene- and phenobarbital-like chemical inducers of cytochrome P-450 monooxygenases.

We present and evaluate a dual assay, the CYPIA (Cytochrome P-450 induction assay) for the detection and the simultaneous identification of chemicals belonging either to the 3-methylcholanthrene or phenobarbital classes of cytochrome P-450 monooxygenase inducers. These inducers play an important role in the mutagenic activation of chemical compounds as well as in many pharmacological and toxicological events and therefore should be screened by drug and chemical designers. After treatment of male rats or mice by chemicals, the liver preparations (S9) have been used in the Salmonella typhimurium test, to activate either ethidium bromide or cyclophosphamide into mutagenic metabolites. These transformations are specifically catalyzed by cytochrome P-450-dependent monooxygenases induced by 3-methylcholanthrene-like and phenobarbital-like chemical inducers, respectively. The mutagenicity data were strikingly correlated with other methods (production of [3H]benzo[a]pyrene bay-region metabolites, benzphetamine demethylase activity, immunological double-diffusion analysis). Compared to the latter methods, the CYPIA, based on a single and widespread technology, introduces an interesting simplification, and improves the specificity and the sensitivity of the responses.

Animals↗
PubMed1984

Characterization and localization of vasoactive intestinal peptide receptors in the rat lung.

Experiments were performed to characterize vasoactive intestinal peptide (VIP) receptors in rat lung and to study their localization by means of light and electron microscope autoradiography. [125I]Iodo-VIP binding to lung homogenate was inhibited by synthetic VIP, [Val5]secretin, secretin, and 7-27 secretin with half-maximal inhibition (ID50) values of 1.62, 13, 121 nmol/liter and up to 0.1 mmol/liter, respectively. The relative potency of [Val5]secretin and 7-27 secretin to displace the tracer indicated that [125I]iodo-VIP binds to specific VIP receptors. Kinetic studies showed two sites of binding, a site of high affinity with equilibrium dissociation constant (KD) values of 0.32 +/- 0.09 nM and Bmax of 88.7 +/- 28.6 fmol/mg protein and a lower affinity binding site with a KD value of 23.0 +/- 2.9 mM and Bmax of 584 +/- 136.9 fmol/mg protein. The localization of VIP receptors was performed by radioautography both in vivo after iv injection of [125I]iodo-VIP and in vitro by the direct application of the radiolabeled peptide to cryostat sections of unfixed lung tissue. After iv injection of label, silver grains were detected only over alveoli. Electron microscopy indicated that radioactivity was mostly associated with alveolar capillaries. In vitro localization studies showed specific binding not only to alveoli but also to bronchi. These studies suggest that VIP can act at different sites and that the peptide could gain access to alveoli via the general circulation.

Animals↗
PubMed1984

[Monitoring therapeutic arteriovenous fistulas in chronic hemodialysis patients. Value of the continuous Doppler test combined with real-time echotomography].

Continuous doppler investigation of functioning of therapeutic arteriovenous fistula is a well-established routine. The availability for the last few years of high frequency (10 mg/Hz) real-time ultrasound has enabled visualization of superficial arteries and veins. Total afferent and efferent branches of these therapeutic fistulae can be visualized. Examination should therefore include continuous doppler recordings combined with real-time ultrasound of both transverse and sagittal sections of the different arteries and veins participating in the fistula. The indication for examination is clinical in cases with low or high output or during the immediate postoperative period to detect early thrombosis.

Arteriovenous Shunt, Surgical↗
PubMed1984

[Renin-angiotensin-aldosterone system, blood volume, serum uric acid and urinary excretion of prostaglandins and kallikrein in the arterial hypertension induced by pregnancy].

The plasma renin activity (PRA), plasma volume (PV), urinary excretion of Kallikrein (UK) and PGE2, PGF2 alpha, 6-keto PGF1 alpha and TXB2 were measured in 24 ambulant patients without treatment on normal sodium diets with pregnancy-induced hypertension (HT) (diastolic BP greater than or equal to 90 mmHg, appearing after 20 weeks' pregnancy and absent 2 months after delivery). The UK was measured by an esterase technique, prostaglandins by radioimmunological assay and PV by dye dilution (Evans blue). Two subgroups of patients were identified according to the evolution of their blood pressure at rest at home; the first (7 patients) with labile HT, and the second (14 patients) with permanent HT. The PRA was significantly lower (p less than 0,001) in patients with permanent compared to labile hypertension (4,7 +/- 0,3 compared to 12,2 +/- 0,8 ng/ml/h) and compared to a control group of normotensive pregnant women (6,5 +/- 0,5). The PV, expressed as a percentage of the theoretical volume with respect to the stage of pregnancy and body surface area was low in both groups. In permanent HT: 1) there was no correlation between PV and PRA, 2) a positive correlation between UK and urinary 6-keto PGF1 alpha (r = 0,62; p less than 0,001) and PGE2 (r = -0,51, p less than 0,05). Discriminative linear analysis showed that urinary 6-keto PGF1 alpha was mainly related to PRA and to a lesser degree to UK.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1984

[Physiopathology of pregnancy-induced hypertension].

Even though multiple factors are involved in arterial blood pressure elevation, during pregnancy-induced hypertension normal physiologic processes are occurring in the uteroplacental unit. These appear probably very early in pregnancy. Treatment of pregnancy-induced hypertension at the present time is directed simply at lowering the blood pressure. It should be emphasized that only one placebo-controlled study has demonstrated a beneficial effect of antihypertensive treatment for the fetus in moderate pregnancy-induced hypertension. Future treatment very likely will be preventive, administered from the onset of pregnancy in a high-risk patient.

Catecholamines↗
PubMed1983

Evaluation of the contribution of mast cell mediators to the hypotensive activity of various peptides in rats.

We have tested the effects of intravenous injections of substance P (SP), bradykinin (BK), somatostatin (SS) and vasoactive intestinal peptide (VIP) on the blood pressure, histaminemia and hematocrit in pentobarbital-anesthetized rats. The four peptides elicited a decrease of the mean arterial blood pressure which varied both in amplitude and in duration depending both on the peptide and on the doses utilized. The hypotensive effects of SP and VIP were more persistent than those caused by BK or SS. Only SP evoked an increase of histaminemia. Both SP and BK caused an increase of hematocrit. The change of hematocrit was more prominent and of longer duration after Sp than after BK. Pretreatment of rats with the antiinflammatory drug dexamethasone inhibited markedly the changes of blood pressure, histaminemia and hematocrit caused by SP. The hypotensive effects of BK, SS and VIP as well as the transient change of hematocrit evoked by BK were not affected by dexamethasone. The results suggest that part of the hypotensive activity and changes of hematocrit evoked by SP in rats is due to the release and action of histamine and possibly of other vasoactive substances, of mast cell origin. The results also indicate that mast cell mediators, particularly histamine, are unlikely to be instrumental in the hypotensive activity of BK, SS or VIP in rats.

Animals↗
PubMed1983

Effect of calcium restriction on renal excretion of oxalate and the probability of stones in the various pathophysiological groups with calcium stones.

To evaluate the adequacy of simple calcium restriction for patients with idiopathic calcium stones the effect of 5 days of calcium restriction without oxalate restriction on renal excretion of calcium and oxalate, and the corresponding probability of stones were assessed in 50 controls and 48 patients. Renal excretion of calcium decreased and that of oxalate increased significantly in all groups but the importance of the changes was critically dependent upon the underlying pathophysiological condition. The probability of stones decreased only in patients with absorptive hypercalciuria type II owing to the usual excessive calcium intake and increased in those with absorptive hypercalciuria type I and renal hypercalciuria, which are associated with true hyperabsorption of calcium and represent the 2 forms of idiopathic hypercalciuria. We believe that simple calcium restriction is beneficial for patients with idiopathic calculi only when the hypercalciuria is caused by exaggerated intake of calcium, since it increases the probability of stones in patients with idiopathic hypercalciuria. Calcium restriction always is associated with an increase in oxalate excretion, suggesting that simultaneous oxalate restriction should be added in all cases to decrease the probability of stones.

Adult↗
PubMed1983

Monoclonal antibodies to rabbit progesterone receptor: crossreaction with other mammalian progesterone receptors.

A mouse was immunized with purified rabbit uterine cytosolic progesterone receptor (specific activity: 3 nmol of steroid bound per mg of protein). After fusion of its spleen cells with Sp2-OAg myeloma cells, supernatants of 11 hybrid cultures were found to react in both an immunoenzymatic test and a double-immunoprecipitation test with the progesterone receptor. Clones were obtained from the five hybrid cells that gave the strongest response in both tests. Antibodies from cell culture supernatants and ascitic fluids were characterized. Three are of the IgG1 and two of the IgG2a isotype. Their apparent affinity for the progesterone receptor was measured by immunoprecipitation in physiological salt conditions. The equilibrium dissociation constants were between 0.1 and 4 nM. All five monoclonal antibodies crossreacted with the rabbit nuclear receptor, the human cytosolic receptor, and other mammalian (rat, guinea pig) but not avian (chicken) cytosolic progesterone receptors. There was no interaction with the glucocorticoid receptor and corticosteroid binding globulin.

Animals↗
PubMed1983

Advantage of hand bone calcium content measurement by local neutron activation analysis for following up hemodialysis patients.

Hand bone calcium content [Ca] has been measured by local neutron analysis in hemodialyzed patients free of signs of osteomalacia before and 6-12 months after treatment with vitamin D metabolites, and it has been compared to some iliac bone histomorphometric parameters. With 1,25-(OH)2D3 alone, [Ca] increases significantly at the 6th month of treatment (p less than 0.001) but not from the 6th to the 12th month. With 1 alpha-(OH)D3 + 25-(OH)D3 the same phenomenon is observed at the 6th and 12th months of treatment. Before treatment, [Ca] was correlated negatively with the osteoid surfaces (OS) (r = -0.62, p = 0.01) and the number of osteoclasts per square millimeter (Ocl/mm2) (r = -0.79, p less than 0.001). At the 6th month of treatment, [Ca] was still correlated negatively with OS (r = -0.42, p = 0.05) and with Ocl/mm2 (r = -0.60, p less than 0.005). At the 12th month, the two negative correlations decreased but remained significant (r = -0.42, p = 0.05; r = -0.45, p = 0.05). These data suggest that (1) hand bone calcium analysis by neutron activation permits to follow up the peripheral bone mineral content in hemodialyzed patients and (2) the [Ca] increase only observed during the first months of treatment with vitamin D metabolites probably result from an attenuation of secondary hyperparathyroidism.

Adult↗
PubMed1983

Renovascular hypertension: easier diagnosis and treatment with intravenous renal arteriography and percutaneous transluminal dilatation.

For the diagnosis of renovascular disease, the authors propose the use of intravenous arteriography with photographic subtraction as the method of choice and advise the use of pyelogram wash-out to assess the functional significance of the stenosis. Furthermore they report their experience with percutaneous transluminal dilatation in 41 patients (10 fibrotic--31 atherosclerotic renal artery stenoses) and suggest that this method is valid alternative to surgery specially in poor risk patients. A controlled trial of this method versus surgery needs however to be undertaken to define the respective roles of these treatments.

Adolescent↗
PubMed1983

[Treatment of peritonitis in peritoneal dialysis. Comparison between continuous lavage with a machine and intermittent lavage with 4 CAPD bags/day].

Since 1978, 54 episodes of PT occurred in patients treated by PD, first 26 PT (group A) were treated by CLM (40 l/day) and in situ antibiotics (AB): in the absence of Candida, the association of sulfamethoxazol (SMZ: 80 mg/l) and trimethoprime (TMP: 16 mg/l) was used. Only when a Candida was present amphotericine B (AMB: 5 mg/l) was used. CLM was continued until PT was cured. The last 29 PT (group B) were treated by 4 bags/day of CAPD with in situ AB: SMZ: 200 mg/l and TMP 40 mg/l and a systematic oral prophylaxis of Candida was performed by AMB 1,5 g/day. In group A, 5 patients died and 2 others in group B. Complications were more frequent in group A (14) than in group B (6): p less than 0.02. In group A, the AB was changed in 7 cases because of initial resistance (1) or bacterial superinfection (2) or Candida superinfection (4). In group B, AB was changed in 9 cases because of initial resistance (7) or Candida superinfection (2). In conclusion the treatment of PT by 4 bags per day with in situ AB cure PT as rapidly as CLM in spite of lower doses of SMZ - TMP. However, this method is easier to perform and give less complication than CLM. It must be the treatment of choice of PT from peritoneal dialysis.

Anti-Bacterial Agents↗
PubMed1983

[Hyperaluminemia in chronic hemodialysis patients. Evaluation of the respective roles of dialysate aluminum and oral aluminum hydroxide].

UNLABELLED: In order to evaluate the respective role of dialysate aluminium and of oral aluminium hydroxide in the occurrence of hyperaluminemia in patients on chronic hemodialysis, plasma aluminium was measured in 19 of them selected for their reliability, before and then 6 and 12 months after the use of a double step reverse osmosis system which allowed to have dialysate aluminium always below 20 micrograms/l, whereas before it was between 20 and 120 micrograms/l. No significant decrease of their plasma aluminium concentration was observed (81 +/- SEM 12, 81 +/- 12 and 75 +/- 12 micrograms/l respectively). But a significant correlation between plasma aluminium and the total or daily prescribed dose of Al (OH)3 was found before and after 12 months of reverse osmosis. A significant negative correlation was observed between plasma aluminium and the mean corpuscular volume, before and 12 months after reverse osmosis. No correlation was found between plasma aluminium and the plasma PTH levels or with the administration of active vitamin D metabolites. CONCLUSIONS: These data suggest that oral Al (OH)3 plays a predominant role in the hyperaluminemia of hemodialyzed patients and that hyperaluminemia may contribute to their microcytic anemia.

Administration, Oral↗