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Biomedical subjects

P Marchand

Publications and source records attributed to P Marchand.

At least 19 recordsLinked to original sources
PubMed1992

The MgATP-binding site on chicken gizzard myosin light chain kinase remains open and functionally competent during the calmodulin-dependent activation-inactivation cycle of the enzyme.

An ATP-like affinity labeling reagent, 5'-[p-(fluorosulfonyl)benzoyl]adenosine (FSBA), was used to probe the MgATP-binding site of smooth muscle myosin light chain kinase from chicken gizzard (smMLCK) and its calmodulin (CaM) complex. Native smMLCK has an absolute requirement for the binding of the calcium complex of CaM for expression of its catalytic activity. FSBA reacted with smMLCK-CaM and with the CaM-free, inactive enzyme as well. Both reactions were dependent on time and FSBA concentration. Reaction was accompanied by the incorporation of covalently bound [14C]FSBA into smMLCK protein at a molar ratio of approximately 1:1 in each case. p-(Fluorosulfonyl)benzoic acid, an analogue of FSBA lacking the adenosine targeting group, did not react at a significant rate with either form of smMLCK. Reaction of CaM-free and CaM-bound smMLCK with FSBA displayed saturation kinetics. The first-order rate constants for the conversion of the reversible, noncovalent enzyme-FSBA complex to form the irreversibly inhibited, covalently modified enzyme were similar for both smMLCK and smMLCK-CaM, 0.15 and 0.07 min-1, respectively. The concentrations of FSBA yielding the half-maximal rate of inactivation, KI, were essentially identical--0.65 and 0.64 mM, respectively--for smMLCK and smMLCK-CaM. MgATP, but not MgGTP or a substrate peptide, potently inhibited reaction with FSBA. Inhibition by MgATP was competitive. The measured inhibitory constant for MgATP was essentially the same--33 versus 34 microM--for both smMLCK and smMLCK-CaM. It therefore is concluded that the MgATP-binding site on smMLCK remains accessible and recognizable as such when the enzyme becomes inactivated upon dissociation of CaM.

Adenosine Triphosphate↗
PubMed1992

Rapid diagnosis of influenza A. Comparison with ELISA immunocapture and culture.

The Directigen Flu-A is an enzyme immunoassay for detecting in 15 min the influenza A nucleoproteinic antigen directly from specimens after passive adsorption on a cellulose membrane. The test was assessed using 160 frozen (-20 degrees C) specimens collected during the 1988-1989 A/H1N1 influenza epidemic and the 1989-1990 A/H3N2 epidemic. Compared to the ELISA immunocapture test, the sensitivity of the commercial test was 87.8% and the specificity was 97.6%. When compared to isolation of viruses on LLCMK2 cells and/or chicken embryo, the sensitivity was 84%. No cross-reaction was found with other respiratory disease viruses. The feasibility, practicability and rapidity of the test make it a test of choice for rapid diagnosis of influenza A.

Antigens, Viral↗
PubMed1991

Comparative study of biosynthetic human growth hormone immunogenicity in growth hormone deficient children.

The immunogenicities of six recombinant human growth hormone (rhGH) preparations, from KABI (A rhGH191 and B rhGH192), Eli Lilly (C), Nordisk (D), Sanofi (E) and Serono (F), used to treat 260 GH-deficient children, have been compared using a common specific and sensitive procedure for antibody determination. For this purpose we developed two immunoassays: a competitive liquid radioimmunoassay using 125I-rhGH, and an immunometric solid enzymoimmunoassay in which the rhGHs were immobilized. Blood samples were collected from the GH-deficient children before treatment and after 3, 6, 9, 12, 18 and 24 months of therapy. Human GH antibodies were detected in children treated with 3 of the 6 rhGH preparations. Seven percent of the patients treated with hormone A, 14% with hormone B and 22% with hormone C formed antibodies against the respective rhGH. Differences in capacity and affinity of the hGH antibodies were observed between these anti-GH-positive groups. They could be divided into 2 groups according to their immunopotency. One group (7, 14 and 6% of the patients treated with hormones A, B and C, respectively) developed anti-hGH antibodies with very low binding capacities (30-100 fmol/ml). The other group (16% of the patients treated with hormone C) developed IgG-type antibodies to hGH with higher binding capacities (200-1,200 fmol/ml) and a measurable binding affinity (Ka = 10(8) M-1). These hGH antibodies partially inhibited the binding of labeled GH to its specific liver membrane receptor. However, because of their low titer, they did not inhibit growth in the treated children.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

[Esophagectomy without thoracotomy using a stripping method: technic, results, indications in benign and malignant diseases of the esophagus].

A technique of esophagectomy without thoracotomy using a stripper with limited dissection of the mediastinum has been applied to 48 patients: neoplasia in 41 (squamous-cell carcinoma of the esophagus: 34, carcinoma of the gastric cardia: 5, pharyngeal carcinoma: 2) and non-malignant pathology in 7 (2 caustic necroses, 2 ruptured esophagus, 2 anastomotic leakages after gastro-esophageal resection, 1 caustic stenosis). There were 3 post-operative deaths. The best indications of this procedure are extended tumors of the lower esophagus in poor-risk patients, and perhaps superficial carcinomas of the esophagus whatever the site. The usefulness of this technique in such situations as perforations and mediastinitis is emphasized.

Adult↗
PubMed1987

Selective tropism of bovine leukemia virus (BLV) for surface immunoglobulin-bearing ovine B lymphocytes.

Bovine leukemia virus (BLV) is experimentally infectious for sheep. Virus production does not occur in the animals, but only after in vitro cultivation of infected lymphocytes in the presence of phytohemagglutinin. Lipopolysaccharide or dextran sulfate 500 had no effect. After panning separation, it was possible to demonstrate that, in peripheral blood lymphocytes, BLV was integrated in the B lymphocytes only and that BLV expression took place in a fraction of this population. The ovine leukemia may constitute a good experimental model for understanding the virus-induced leukemias of the BLV-human T cell leukemia virus group.

Animals↗
PubMed1987

[Chemoembolization of hepatic metastases. Preliminary study].

Twenty-one patients with hepatic metastases were treated by chemoembolization over a 2-year period, the technique consisting of selective injection of a mixture of Spongel powder and Adriamycin plus 5-FU into the hepatic artery. Indications and results are discussed as a function of clinical, biologic and radiologic criteria.

Adult↗
PubMed1986

[Acute pancreatitis caused by lithiasis in a dilated ampulla of Vater].

Unusual features in a case of dilatation of ampulla of Vater were in the existence of biliary calculi in the diverticulum and lithiasis complicated by a revealing acute pancreatitis. Diagnosis was suggested from barium meal followed through images and confirmed by perioperative cholangiography. Surgical treatment of such cases is simple, allows recovery without sequelae and avoids risks of recurrence.

Acute Disease↗
PubMed1986

[Functional studies of the esophagus in gastroesophageal reflux: application to anti-reflux surgery].

A functional exploration of the esophagus, an acid reflux test, a manometry and an endoscopic examination were performed on 56 patients in succession, who had undergone a complete fundoplication for gastro-esophageal reflux. These tests were done pre-operatively as well as post-operatively at short term (1 year) and long term (4 years). The functional and endoscopic pre-operative work-up did not enable to isolate a group of patients likely to present a therapeutic failure. 54 patients were seen again at 1 year, with a good clinical result in 50 of them (92 per cent). At 4 years, 39 out of 48 patients (81 per cent) maintained that result. The acid reflux test was abnormal in all cases of clinical recurrence. Two asymptomatic patients had an abnormal test. One presented a clinical recurrence subsequently, the other had a severe esophagitis confirming the recurrence. On manometry, a significant and stable increase of the pressure of the lower esophageal sphincter was noticed after fundoplication (8.1 +/- 1.8 mmHg pre-operatively, 15.5 +/- 1.4 mmHg at 1 year, 14.5 +/- 1.5 mmHg at 4 years). In case of recurrence, the pressures were in an average lower although values within normal limits could not exclude a recurrence. A complete fundoplication is therefore a reliable long term procedure. The functional exploration of the esophagus post-operatively enables to select asymptomatic patients with a high recurrence risk and gives an objective evaluation of the operative results.

Adolescent↗
PubMed1985

[Evaluation of the activity and quality of care in a digestive surgery department].

Since 1980, details of all patients operated upon in a digestive surgery unit have been entered on record-cards with the view of obtaining information on the activity of the unit and improving post-operative care. Over a 3-year period, 2005 patients underwent surgery, 25% of them for cancerous lesions. Biliary tract operations (385 patients), fundoplication by the abdominal route for gastro-oesophageal reflux (58 patients) and curative resection of the colon for carcinoma (100 patients) were set apart for evaluation. For each of the above pathologies, morbidity, mortality and duration of stay in hospital in cases with uneventful or complicated post-operative course were analyzed. Annual audits of this kind result in accurate evaluation and periodical reappraisal of the therapeutic habits of the medico-surgical team.

Adolescent↗
PubMed1985

[Completed calibrated fundoplication].

Complete fundoplication at present is the most effective surgical treatment of gastro-oesophageal reflux. However, it has a number of side-effects, including post-operative dysphagia, inability to eructate and painful gastric distension. Fifty-five patients were operated upon using a technique which comprises wide gastric release and fabrication of a tension-free valve around a 50F probe introduced through the mouth. After 1 year, 94% of patients were free of reflux and 22% had mild dysphagia. After 3 years, the proportion of reflux-free patients still was 94%; 12% suffered from mild dysphagia and 6% had problems with eructation. Thus, calibration of the oesophagus with a 50F probe reduces the side-effects of complete fundoplication while remaining effective against gastro-oesophageal reflux.

Esophagus↗
PubMed1985

[The irrigraphic profile, an orienting element in the indications for lumbar sympathectomy].

A retrospective study of 108 case-reports of patients treated by lumbar sympathectomy was conducted to determine irrigraphic parameters possessing possible predictive value for the indication of sympathectomy. The value of the Index 6 (distal irrigation index) must be certainly taken into account; the Index 1 (proximal index) appears to be of interest when analyzing data with a view to sympathectomy in diffuse forms of arteritis. Three profile-types were distinguished; statistical analysis showed no significant difference in these profiles, with respect to the sympathectomy, in relation to the clinical results obtained. Irrigraphic modifications after sympathectomy were analyzed in 72 cases; results confirmed the improved efficacy of sympathectomy at Stage 2 than at Stages 3 and 4, but also showed that at Stage 2 the profile II appeared to react more favorably and that at Stages 3 and 4 the profile I appears to react less well than the other profiles. Also studied were patients with diabetes, who react less favorably to sympathectomy, patients who fail-to respond to sympathectomy, and those with worsening of irrigraphic profiles after sympathectomy, mainly in diabetics with profile I. These findings show that it is not possible to define a precise irrigraphic profile more favorable to sympathectomy, but that they provide interesting elements to be confronted with clinical and arteriographic data when deciding on the need for sympathectomy.

Adult↗