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Biomedical subjects

P Vincent

Publications and source records attributed to P Vincent.

At least 163 records · Page 9Linked to original sources
PubMed1986

Urinary N-nitrosamino acids as indices of endogenous formation of N-nitroso compounds.

Exposure to their precursors (e.g., amines, nitrate/nitrite, NOx) can lead to formation in the human body of N-nitroso compounds (NOC), a class of potent animal carcinogens, which are also suspected of being carcinogenic in man. A non-invasive method, the 'N-nitrosoproline (NPRO) test', for estimating endogenous nitrosation in man was developed in our laboratory. This test, which monitors 24-hr-excretion of urinary N-nitrosamino acids, is now applied in clinical and field studies, with the aim of measuring nitrosamine exposure and of identifying dietary, life-style, and host factors, or disease states, that affect nitrosation in man. Results from such studies are used to identify populations/individuals at high risk for cancers of the stomach, oesophagus, and oral cavity possibly caused by endogenous nitrosamines, and to indicate preventive measures by which the body burden of endogenous nitroso carcinogens can be lowered efficiently.

Amino Acids↗
PubMed1986

Scanning fluorometer for the rapid assessment of pyridine nucleotide and flavoprotein fluorescence changes in tissues in vivo.

This paper describes a scanning fluorometer which produces images in real time of the distribution of pyridine nucleotide or flavoprotein fluorescence at the surface of tissues in vivo. The basic difference between this device and others reported in the literature is that fluorescence changes at any selected point within the image can be quantified as they occur. We suggest that the apparatus has potential application in those areas of surgery where vascular replacement or repair is required and where it would be advantageous to have an immediate measure of the cellular response to a return of blood flow.

Animals↗
PubMed1985

[Clinical value of rapid bacteriological results in nosocomial infections. Comparison with traditional methods].

With automated analysers, bacterial identification and susceptibility testing can be performed in 4-5 hours instead of 12-18 hours with conventional methods. A controlled trial was carried out in the surgical ward of a university hospital to evaluate the clinical repercussions of these rapid methods. The automated analyser reduced delays in the laboratory by about 25%, and optimizing information transfer from laboratory to ward brought the reduction up to 50%. It was found that earlier results of susceptibility testing modified prescriptions and this may be expected to result in a more rational use of antibiotics.

Autoanalysis↗
PubMed1985

The medical and economic consequences of automation in bacteriology: a case study in a French university hospital.

In a bacteriology laboratory where automated and non-automated procedures co-existed during the study period (1 year), patients were randomly assigned to each type of procedure and we observed the physicians behaviour as well as patients well-being in a surgical service using the results from the laboratory. Contrary to our expectations, the reduction in the time delay necessary to obtain information did not alter either the prescribing behaviour of physicians nor the welfare of patients. Besides, the gain in time was significantly lower than expected. We also discuss in detail the meaning and relevance of the results.

Automation↗
PubMed1985

Screening of microorganisms for nitrosation catalysis at pH 7 and kinetic studies on nitrosamine formation from secondary amines by E. coli strains.

Thirty-eight strains of microorganisms isolated from infected human trachea, urine, blood and faeces were examined for their ability to form N-nitrosomorpholine from morpholine and nitrite at pH 7.25. Twenty-five bacterial strains exhibited nitrosation activity, including 18 out of 19 strains of Escherichia coli and three out of nine Pseudomonas aeruginosa, Proteus morganii, Proteus mirabilis, Klebsiella pneumoniae and Neisseria strains; E. coli A10 strain showed the highest activity. Formation of N-nitrosomorpholine was proportional to the incubation time up to 2 h and to the number of resting E. coli A10 cells; the reaction followed Michaelis-Menten kinetics. Nitrosation rate appeared to be dependent on the pKa value of several amines studied. As the nitrosation catalysis was heat-labile, our data suggest that N-nitrosation is catalysed by a bacterial enzyme(s). This reaction may lead to enhanced endogenous nitrosation in subjects suffering from an achlorhydric stomach or from chronic urinary tract infections.

Amines↗
PubMed1985

Factors related to length of stay of laminectomy patients.

A retrospective record audit was done to address the following research question: Are there factors associated with the length of hospital stay of laminectomy patients? According to the information on their records, patients with the following characteristics tended to have longer stays: were of the black race, had other medical diagnoses, had cervical region procedure, had "partial" procedure, had "extensive" pathology, and had greater use of pain medications. Those who were employed prior to admission, who were permitted to be more active, and who had muscle spasms had significantly shorter stays. The implications for nursing practice are discussed.

Adult↗
PubMed1985

Pefloxacin: evolution of in vitro activity during 18 months of use in an intensive care unit.

The MIC of pefloxacin against all the strains (3122) isolated in an intensive care unit during 18 months was studied. The MIC of pefloxacin was estimated by standard agar diffusion method in Mueller-Hinton agar. All the strains with a MIC lower than 2 mg/l were considered as sensitive, between 2 and 4 mg/l as "intermediary" and over 4 mg/l as resistant. Geometrical means of MICs were calculated for each month and for different species. The study continued for 18 months from the introduction of the drug which was in widespread and constant use as a first-choice antibiotic. No significant increase was detected in the incidence of resistant strains during the study; on the other hand, small, limited clusters of resistant strains were observed during minor nosocomial epidemics. The general features of quinolone activity, the spectrum of this new quinolone and the slow evolution of the bacterial population are discussed.

Bacteria, Aerobic↗
PubMed1985

[Study of the sensitivity of anaerobic bacteria using 2 dilution technics].

We studied forty-seven anaerobic strains recovered from blood cultures or pus from deep infections over three months. Antibiotic sensitivity was tested using two dilution techniques. For both, a standardized, controlled inoculum was used and strains with known susceptibilities were included. The first method consisted of dilution of antibiotics in Schaedler broth and MIC determination using microplates. In the second method, dilutions in Wilkins-Chalgren broth with 1.5 g/l agar and ATB-API plates were used; these plates are specially designed for anaerobes and have not yet been marketed. Advantages of dilution techniques for antibiotic sensitivity testing of anaerobes are recalled. Our findings establish that, under correct technical conditions, results of both methods studied are consistent.

Anti-Bacterial Agents↗
PubMed1984

Evaluation of the four-hour rapid 20E system for identification of members of the family Enterobacteriaceae.

A study was conducted to compare the API Rapid 20E 4-h system (API System S.A., France; commercially available in the U.S.A. under the name DMS Rapid E System; DMS Laboratories, Darts Mill, Flemington, N.J.), the API 20E 18- to 24-h system (Analytab Products, Plainview, N.Y.), and a conventional media system to measure the ability of each to identify members of the family Enterobacteriaceae. Comparison tables rather than simple percentage agreement tables were generated to define the particular strengths and weaknesses of each system and to allow the laboratory to best use the data. The Rapid 20E compared quite favorably with conventional media. It yielded correct identifications with 95.9% of the isolates tested (API 20E, 98% identification rate). In 2.5% of the isolates, the Rapid 20E gave only genus identifications, and in 1.4% the organisms did not correspond to any key in the code book and could not be identified by the manufacturer's computer service. The ease of inoculation and the 4-h capability make the Rapid 20E system an extremely attractive development in the field of bacterial identification.

Bacteriological Techniques↗
PubMed1984

Combination effect of cefmenoxime with four aminoglycosides on Enterobacteriaceae susceptible and moderately susceptible to this new cephalosporin.

The inhibitory combination effect of cefmenoxime with gentamicin, tobramycin, netilmicin and amikacin against 148 Enterobacteriaceae was compared using the checkerboard agar dilution technique. On average 41% of cefmenoxime-moderately susceptible (MIC between 2 and 32 micrograms/ml) or cefmenoxime-resistant (MIC greater than 32 micrograms/ml) strains were inhibited by synergistic, and 23,5% by partial synergistic cefmenoxime-aminoglycosides combinations. Against cefmenoxime-susceptible strains, these rates of synergy or partial synergy were twofold lower, but only one isolate was not susceptible to these combinations. The amikacin-cefmenoxime interaction was the most performant.

Amikacin↗
PubMed1984

[Exudative enteropathy and residual tricuspid insufficiency following repair of tetralogy of Fallot. Regression following tricuspid valvuloplasty].

Chronic right ventricular failure was observed in a young female operated at 25 years of age for Fallot's tetralogy despite surgical refixation of the patch closing the ventricular septal defect which had previously worked loose. The signs of right ventricular failure were due to severe tricuspid incompetence, confirmed at catheterisation and selective right ventricular angiography. They were associated with major hypoproteinaemia which was not due to urinary loss nor hepatic dysfunction, but which was attributed to an exudative enteropathy. The correction of the valvular defect by valvuloplasty was followed by rapid correction of the biological abnormality. The authors review the relationship between serum proteins and cardiac disease, discuss those cardiac affections with known associations with exudative enteropathy, and also the possibilities of reversing the biological abnormality after surgical cure of the causal cardiac lesion.

Adult↗
PubMed1984

[Corrected transposition of the great vessels with stenosis of the left atrioventricular valve in a 40-year-old woman].

The authors reports the detection of a rare and remarkably well tolerated cardiac malformation in a 40 year old woman whose clinical presentation would have suggested an ordinary mitral stenosis, had there not been a number of very unusual signs. Cardiac catheterisation and angiography showed a corrected transposition of the great arteries with stenosis of the systemic atrioventricular valve. This case is used to illustrate the principal malformations observed in association with corrected transposition of the great arteries, especially the common and very variable abnormalities of the systemic atrioventricular valve. The unusual feature of the reported case was the stenotic nature of the valvular lesion and the fact that this was the only associated intracardiac abnormality, simulating, at first sight, a rheumatic mitral stenosis.

Adult↗