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Biomedical subjects

A Bouvet

Publications and source records attributed to A Bouvet.

At least 73 records · Page 4Linked to original sources
PubMed1988

Open canalicular system of platelets in porcine stress syndrome.

A study was undertaken to test whether a previously reported alteration in platelet morphology could be of predictive value for the detection of stress-susceptibility in pigs. Platelets from 20 normal pigs, nine pigs classified as stress-susceptible on the basis of their response to halothane challenge, and 11 siblings of halothane reactors belonging to two different breeds were subjected to electron microscopic examination. A quantitative analysis of electron micrographs, based on the extent of dilatation of the open canalicular system in platelets and the percentage of affected platelets, revealed that halothane reactor pigs could be distinguished from normal animals on the basis of their open canalicular system score. The discrete nature of the score categories in siblings indicates that platelet alteration may be an inherent component of the porcine stress syndrome and suggests that some of the false negatives in the halothane test may be identified as stress-susceptible on this criterion. Further studies involving a larger number of halothane reactors and siblings are needed to ascertain the consistency of the open canalicular system features and eventually, to develop a simple test system based on platelet alterations for the detection of stress-susceptibility in pigs.

Animals↗
PubMed1987

Platelet alterations in porcine stress syndrome.

Platelets in blood collected from pigs identified as normal (21) or stress susceptible (25) on the basis of their response to halothane challenge, were subjected to electron microscopic examination in order to test whether the ultrastructural features of stress susceptible pigs exhibit any deviation from those of normal. The most striking feature of the platelets from stress susceptible pigs was the extent of dilatation of the open canalicular system (OCS). The difference in platelet morphology between normal and stress susceptible pigs was consistent regardless of the anticoagulants used for blood collection indicating that the platelet alteration may be an inherent component of the porcine stress syndrome.

Animals↗
PubMed1987

Predominance of capsular polysaccharide type 5 among oxacillin-resistant Staphylococcus aureus.

The relationship between capsular polysaccharide types 5 and 8 and resistance of Staphylococcus aureus to oxacillin was studied with a collection of 406 clinical isolates from six French hospitals. Of 175 type 5 isolates, 84 (48%) were resistant to oxacillin. In contrast, only 8 of 160 type 8 isolates (5%) and 5 of 71 nontypeable isolates (7%) were resistant to oxacillin. Therefore, capsular typing of clinical isolates of S. aureus may facilitate the choice of first-line antibiotic therapy.

Bacterial Capsules↗
PubMed1986

[Cryptosporidiosis in grafting of allogeneic bone marrow].

Cryptosporidiosis may cause diarrhea after a conditioning regimen for allogeneic bone marrow transplantation. The case reported here suggests resurgence of latent cryptosporidiosis in early post-graft period, since other causes of immunosuppression such as graft-versus-host disease or transfusional LAV/HTLV III retroviral infection, were absent. The diagnosis was confirmed by rectal biopsy and ultrastructural analysis. Good response to spiramycin was obtained.

Adolescent↗
PubMed1986

Enzyme-linked immunosorbent assay for the detection of antibodies to nutritionally variant streptococci in patients with endocarditis.

The viridans streptococci are responsible for 50%-55% of microbial endocarditis. Among these varied species, the nutritionally variant streptococci (NVS) have recently been associated with culture-negative endocarditis and are responsible for 5%-10% of all streptococcal endocarditis. The isolation and identification of these bacteria has been hampered by the extremely fastidious nature of their growth requirements as well as by their slow growth rate. In addition, their antibiotic sensitivity varies greatly, a characteristic leading to a higher rate of morbidity and mortality than is found in patients with non-NVS endocarditis. For these reasons sera from patients with NVS endocarditis were examined for antibodies to the NVS serotype I antigen by using an enzyme-linked immunosorbent assay. Seventy-four percent of patients with NVS endocarditis had elevated titers to this antigen. None of the sera from controls and only 6.7% of the sera from patients with non-NVS streptococcal endocarditis showed increased titers. These results indicate that antibody to the NVS serotype I antigen can serve as a marker for NVS endocarditis.

Antibodies, Bacterial↗
PubMed1986

[Operative mortality and morbidity in pelvic exenteration. Technical aspects].

Postoperative complications in a continuous series of 23 pelvic exenterations for female genital tumor are analyzed, together with specific technical improvements capable of reducing morbidity and mortality of this major surgery. Emphasis is placed on the use of automatic suturing to improve hemostasis and to facilitate performance of digestive anastomoses. The preferred urinary bypass operation is ureterosigmoidostomy into an excluded loop, cutaneous ureterostomy being reserved for patients in a poor general condition. The only satisfactory procedure for filling of the pelviperineal cavity appears to be internal epiploplasty combined with perineal reconstruction by means of a musculus gracilis flap, which also allows the confection of a new vaginal cavity.

Adult↗
PubMed1985

[Gracilis muscle flaps for covering losses of perineal substance in cancer surgery].

Myocutaneous or purely muscular flaps were used in 14 patients after extended surgical excision in the perineal region. When taking out the flap, its one-pedicle and relatively weak blood supply must be taken into account. With this precaution, this technics can always be used for perineal resurfacing, particularly after total vulvectomy. In pelvic exenteration and amputation for anorectal cancer, it enables surgeons to fill the muscular gap, which seems to improve the post-operative course. It can also be used for vaginal, penile or sphincteric reconstruction.

Anus Neoplasms↗
PubMed1985

Comparison of penicillin and vancomycin, individually and in combination with gentamicin and amikacin, in the treatment of experimental endocarditis induced by nutritionally variant streptococci.

Six different antibiotic treatment regimens were compared for efficacy in rabbits with endocarditis induced by inoculation with a nutritionally variant strain of streptococcus. Seven untreated animals, sacrificed at day 11, had vegetations containing 8.89 +/- 1.35 log10 CFU/g, none of which was sterile. The vegetations from the rabbits in all treated groups had bacterial titers significantly lower than those of the controls (P less than 0.001). Vegetations from penicillin-treated animals averaged 5.14 +/- 1.00 log CFU/g, and no vegetations were sterile. Treatment with penicillin plus gentamicin or amikacin was more effective than treatment with penicillin alone, resulting in 3.99 +/- 0.94 log CFU/g of vegetation and sterile lesions in 5 of 12 animals. Treatment with vancomycin alone was as least as efficient as that with penicillin plus an aminoglycoside, resulting in an average of 3.33 +/- 0.96 log CFU/g of vegetation and sterile lesions in five of eight animals. Treatment with vancomycin plus an aminoglycoside was not superior to treatment with vancomycin alone, resulting in an average of 3.68 +/- 1.37 log CFU/g of vegetation and sterile lesions in 8 of 13 animals. These in vivo results correlated poorly with the in vitro susceptibility of the strain to the various antibiotics, as measured by the time-kill method. These results support the current practice of using vancomycin as alternative therapy when a penicillin-aminoglycoside combination is ineffective or contraindicated in patients with endocarditis caused by nutritionally variant streptococci.

Amikacin↗
PubMed1985

Characterization of nutritionally variant streptococci by biochemical tests and penicillin-binding proteins.

A comparative study of 60 strains of nutritionally variant streptococci (NVS) with 34 strains of Streptococcus mitis and 37 strains of Streptococcus sanguis II showed the presence of a red chromophore which was absent in the other streptococcal species. By using the conventional microbiological tests, only small differences were found between the NVS and the two other related species. In contrast a clear-cut delineation was found by the API 20 Strep system of identification. All NVS contained pyrrolidonylarylamidase, an enzyme which was absent in S. mitis and S. sanguis II strains, and lacked the alkaline phosphatase enzyme which was present in 56% of S. mitis strains and 62% of S. sanguis II strains. According to the additional enzymatic and biochemical tests of the API 20 Strep system, there were three biotypes among NVS. The major biotype included 33 of 60 strains which were characterized by the presence of both alpha- and beta-galactosidases and the capacity to hydrolyze trehalose. This biotype also showed a specific pattern of penicillin-binding proteins. These results show that NVS are recognized as a separate variety distinct from S. mitis and S. sanguis II species, despite some common biochemical properties. Moreover, the delineation of 33 strains with a specific biotype and a specific penicillin-binding protein pattern strongly suggests that a large part of NVS strains belong to an individual species.

Bacterial Proteins↗
PubMed1985

[Prevention of bacterial endocarditis].

Prevention of bacterial endocarditis is aimed at limiting the frequency, size, and duration of transient bacteremia with subsequent bacterial implantation on valvular endothelium in patients with cardiopathy. Any procedure involving mucosa rich in normal flora or an infectious site can result in bacteremia, which can be minimized by selecting diagnostic and therapeutic procedures which are least traumatic. In addition, proper antibiotic prophylaxis should be administered according to the most frequently encountered bacteria: Streptococcus viridans during dental manipulations, enterococci during urogenital or intestinal procedures, and staphylococcal species from skin lacerations or cardiac surgery. The different antibiotic prophylactic regimens suggested at the present time vary according to the patient and the particular circumstances surrounding his illness. These regimens should be modified according to future epidemiologic findings in bacterial endocarditis.

Anti-Bacterial Agents↗
PubMed1984

Characterization of a pH-dependent chromophore from nutritionally variant streptococci.

Strains of nutritionally variant streptococci and Streptococcus mitis produce a chromophore when they are heated at acid pH. No other strains of streptococci elaborated this chromophore. Furthermore, the nutritionally variant streptococci produced approximately twice the amount of chromophore as the S. mitis strains. The chromophore was localized in the cell wall of these streptococcal strains and appeared to be resistant to trypsin treatment. Hydrolysis apparently is required because elevated temperatures at pH 2 are necessary for demonstration of the chromophore. The chromophore has a maximal absorbance at 504 nm with a pKa of 3.6. The chromophore absorbance spectrum showed an isosbestic point at 400 nm. This is the first example of a pH-dependent chromophore to be found in streptococci and serves as a positive characteristic for the description of nutritionally variant streptococci as well as S. mitis.

Chromogenic Compounds↗
PubMed1981

Nutritionally variant streptococci from patients with endocarditis: growth parameters in a semisynthetic medium and demonstration of a chromophore.

Nutritionally variant streptococci have been characterized in the past by their growth as satellite colonies and by their nutrient requirements of cysteine or vitamin B6 for growth in complex media. To further understand the growth characteristics of these strains, we studied fresh isolates from patients with endocarditis by using chemically defined medium enriched with 2% Todd-Hewitt dialysate. Under anaerobic conditions, growth yields of the strains in this medium were comparable to those obtained from a complex medium supplemented with vitamin B6, whereas under aerobic conditions, most of the strains had higher growth yields in the semisynthetic medium. Furthermore, the requirement for cysteine and vitamin B6 in the semisynthetic medium was no greater than that of other Streptococcus species. Electron microscopic studies demonstrated normal cell wall structures in organisms grown in the semisynthetic medium as compared with abnormal and irregular cell wall thickening in organisms grown in supplemented complex medium. Finally, these strains appeared to contain a common component when grown in the semisynthetic medium as demonstrated by the appearance of a chromophore after boiling the bacteria at pH 2. Therefore, the demonstration of a medium which permits adequate growth with a normal ultrastructure of nutritionally variant streptococci will permit the further study of this group of important streptococci.

Culture Media↗
PubMed1979

[Role of the anesthetic consultation in an organization model of the anesthesia-resuscitation department].

The anaesthetic consultation is essential to give patients a sense of security. It should be organised taking into account the needs and resources of the department. In the light of the experience of the authors in an anti-cancer center, three main principles can be enumerated for this to be properly organised: the detachment of doctors from the surgical departments, a rotation in the department and a timetable for the consultations. The part played by the departments requesting help and the different secretarial offices is important. In this way one can anticipate and eliminate the improvisation which always occurs, to the detriment of the patient. Collaboration between the different departments involved is naturally indispensable. These general principles have beeen stated for at least a dozen or so years by a certain number of anaesthetists. It was quite easy to stranspose these principles and to adapt them to the organisation of the anti-cancer struggle. Such applications should be generalised.

Anesthesia Department, Hospital↗