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Biomedical subjects

F Denis

Publications and source records attributed to F Denis.

At least 163 records · Page 9Linked to original sources

[Prevalence of antibodies to the hepatitis C virus in pregnant foreign residents in France].

Blood transfusion and intravenous drug use are the two main modes of transmission of the hepatitis C virus (HCV). Sexual intercourse seems to play a less significant part in transmission of the HCV and data are still lacking on vertical mother-to-offspring transmission. HCV seroprevalence was determined in 1,084 pregnant foreign residents of France living in a single city (Limoges). Antibodies to the HCV were detected in sera using both the first and second generation Abbott ELISA kits. Sera yielding reproducible positive results with either kit were retested with a blocking test (HCV EIA Neutralization, Abbott) and a second generation RIBA (Ortho) for confirmation. For screening, use of tests detecting both nonstructural and structural antibodies improved results noticeably (5 of 16 sera). Use of confirmation tests was found to be indispensable. Overall seroprevalence was 1.47%. However, results varied across geographic regions or origin, ranging from 0% for Europe, 1.9% for North Africa and 1.78% for South-East Asia, to 4.76% for black Africa. These findings demonstrated the potential for mother-to-offspring transmission among women from high prevalence areas. A prospective study in African an Asian women is being considered to evaluate ineffectiveness and transmission using serial serologic tests and viral genome detection by polymerase chain reaction studies (PCR).

Adult↗

[Maternal-infant transmission of the HTLV-1 virus].

The virus is transmitted horizontally via the bloodstream or sexual intercourse but vertical transmission is also believed to be a major mode of contamination. Between 20 and 25% of children born to seropositive mothers are believed to be infected and more than 90% of mothers whose children are found to be seropositive are themselves infected. If transplacental route appears to be exceptional or poorly documented, transmission by breast-feeding has been proved by virological, experimental and epidemiological arguments and is a major mode of contamination.

Animals↗

Lateral distraction injuries to the thoracic and lumbar spine. A report of three cases.

Three patients sustained a lateral distraction injury to the thoracic or lumbar spine. These injuries were associated with multiple fractures of the ribs and extremities as well as with thoracic and abdominal visceral injuries. No patient had an injury to the spinal cord or cauda equina. The injuries to the spine were successfully treated with open reduction of the unilateral subluxation of the facet joint and with internal fixation with Harrington instrumentation. Fusion was achieved with the spine in anatomical alignment, without any complications, in all three patients.

Accidents, Traffic↗

[Seroprevalence of hepatitis C in human immunodeficiency virus infected patients].

Prevalence of antibodies against hepatitis C virus (HCV) was evaluated using Ortho and Abbott HCV Elisa assays and the Abbott EIA Neutralization assay in 150 human immunodeficiency virus (HIV)-seropositive patients and compared with the prevalence of hepatitis B virus (HBV) and hepatitis D virus (HDV) markers. Overall prevalence of hepatitis C virus antibodies was 29.3%; significant variations were seen across human immunodeficiency virus risk factor subgroups: prevalence was 10.2% in homosexual men, 12.0% in bisexual men, 73.5% in intravenous drug users, 13.3% in blood transfusion recipients, and 16.6% in frequent travellers. Seroprevalence was higher in the 20 to 40 year-old age group and in patients stage II or III according to the Center for Disease Control classification. Prevalence of hepatitis B virus and hepatitis D virus markers (75.7% and 17.5% respectively) was analyzed according to hepatitis C virus marker status; patients with HBcAb were more likely to have antibodies against hepatitis C virus than their HBcAb-negative counterparts. Further studies are needed to investigate the influence of coexposure to human immunodeficiency virus and hepatitis C virus on liver lesions. Data from this study show that coinfection or coexposure is common.

Adult↗

[In vitro activity of beta-lactam antibiotics in combination with sulbactam against enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter. Results of a multicenter study].

The in vitro antimicrobial activity of ticarcillin (TICAR), mezlocillin (MEZLO), piperacillin (PIPER), cefoperazone (CPZ), cefotaxime (CTX) and ceftazidime (CAZ), alone and in combination with 8 micrograms/ml of sulbactam (SULB), was studied by agar dilution against TICAR resistant strains isolated in 8 hospitals over a period of 3 months in 1989 (747 enterobacteria, 110 Ps. aeruginosa and 48 Acinetobacter sp.). SULB did not modify the activity of beta-lactam antibiotics against Ps. aeruginosa. The 6 beta-lactam antibiotics SULB combinations were only active for 27% of Acinetobacter SULB sensitive. SULB restored the activity of: MEZLO, PIPER, CPZ in Enterobacteria producing a penicillinase; PIPER, CTX and CAZ in Enterobacteria producing a broad-spectrum beta-lactamase; MEZLO, PIPER, CTX and CAZ in M. morganii producing a derepressed cephalosporinase.

Acinetobacter↗

Immunoblot analysis of IgG subclasses of circulating antibodies in bullous pemphigoid.

Sera from 20 patients with bullous pemphigoid (BP) were analyzed for the subclass distribution of IgG autoantibodies by Western immunoblotting of normal human heat-separated epidermal extracts. Strips were sequentially probed with patient sera, monoclonal antibodies (Mab) anti-human IgG1-4, and a labeled anti-mouse Ig. The relative dilutions of each subclass-specific Mab were determined in dot immunobinding experiments in order to give uniform reactivity to the corresponding human IgG subclass. Circulating BP autoantibodies reacting with the major BP antigen of 220 kDa and/or a 165-kDa band showed a stricking predominance of IgG4. Overall, IgG4 was the major subclass reactive with the 220-kDa band, whereas, in addition to IgG4, IgG1 and IgG2 were frequently represented in the response to the 165-kDa band. Complement fixation of circulating BP antibodies was studied by complement indirect immunofluorescence using human serum as source of complement and FITC goat anti-human C3, C1q, and C4, on normal human skin substrate. When circulating BP antibodies contained IgG1 or IgG2 in addition to IgG4, they fixed C3 and, in some cases, C1q and C4, suggesting complement activation by either the classical or the alternate pathway.

Blotting, Western↗

Competitive enzyme-immunoassays using native viral antigens to discriminate between HIV-1 and HIV-2 infections.

Human immunodeficiency virus (HIV) strains can be separated into two serotypes: HIV-1 and HIV-2. In the study reported herein, we developed and evaluated competitive enzyme-immunoassays (CEIA-1 for the detection of antibody to HIV-1, CEIA-2 for the detection of antibody to HIV-2) to discriminate serologically between HIV-1 and HIV-2 infections. In most of the cases, the serotyping of known reactive serum samples was done easily with the CEIAs, showing a similar specificity to the Western blot. Such competitive assays could represent alternative procedures for serotyping HIV infection and would limit the need for expensive Western blots, especially in economically poor countries.

Antibodies, Viral↗

Confirmatory tests for human T-cell leukemia virus type 1 (HTLV-1): western blot compared with RIPA on African sera.

Confirmation of human T-Cell leukemia virus type 1 (HTLV-1) seropositivity calls for reactivity against at least 2 proteins encoded by 2 different genes, revealed by Western blot (WB) and/or radioimmuno-precipitation assay (RIPA). To evaluate the use of WB as a basis for applying these criteria, we conducted a study of two types of WB and compared them with RIPA patterns. The first part of the work, performed with 40 African sera, used Dupont de Nemours commercialized WB and an 'in-house' WB. Both WB detected antibody to proteins encoded by 2 different genes: antibody to gag products were revealed equally by both WB, but commercialized WB detected antibody to tax protein whereas the 'in-house' WB detected antibody to env protein (gp46) more efficiently. The second part of the work, conducted with 158 African sera, compared results of an 'in-house' virus lysate WB and RIPA. Our data show a perfect concordance between the two procedures when sera were clearly positive by WB (gag + env reaction). Sera reacting to p19 and p24 (both gag) by WB were confirmed positive by RIPA in 75% of the cases. The majority of the indeterminate WB profiles not confirmed by RIPA presented isolated gag reactivity (p15 or p19 or p24).

Blotting, Western↗

Multicenter evaluation of a new recombinant enzyme immunoassay for the combined detection of antibody to HIV-1 and HIV-2.

A newly developed recombinant antigen-based anti-HIV-1/HIV-2 enzyme immunoassay (Abbott Recombinant HIV-1/HIV-2 EIA) was evaluated against a second generation anti-HIV-1 EIA (Abbott Recombinant HIV-1 EIA). Five thousand and twenty-nine sera from European blood donors and 403 sera from central African blood donors were used in the evaluation, along with four panels and one cohort. The panels included 99 'problem' sera, 733 sera with antibodies to HIV-1 from asymptomatic people and from patients at different disease stages, 25 serial bleeds from five plasmapheresis donors seroconverting for antibodies to HIV-1, and 202 sera with antibodies to HIV-2 collected from healthy and diseased people of European or west African origin. In addition, 734 sera collected from a west African cohort were tested. Using Western blot as the reference standard, the specificity obtained by the recombinant anti-HIV-1 EIA (HIV-i EIA) was 99.90% [99.81-99.99%; 95% confidence limits (95% CL)] with European blood donor sera; 99.50% (98.78-100%) with Central Africa blood donor sera; 92.93% (87.78-98.08%) with 'problem' sera and 99.43% (98.87-100%) with sera from a west African cohort. Using the same samples, the recombinant anti-HIV-1/HIV-2 EIA (HIV-1/HIV-2 EIA) yielded a specificity of 99.84% (99.73-99.95%), 99.50% (98.78-100%), 95.96% (92.00-99.92%) and 98.58% (97.69-99.47%), respectively. All 776 Western blot-confirmed anti-HIV-1 sera were reactive in both EIAs, and the EIA-reactive samples from seroconverting plasma donors were always observed for both assays in the same serial bleed. For HIV-2, the HIV-1 EIA yielded an overall sensitivity of 75.83% (69.93-81.72%) compared with 99.53% (98.58-100%) for HIV-1/HIV-2 EIA. The addition of a recombinant env-protein of HIV-2 to the recombinant env and core proteins of HIV-1 on the solid phase of HIV-1 EIA improved the detection of anti-HIV-2 while preserving the assay's overall specificity and sensitivity for the detection of anti-HIV-1.

AIDS Serodiagnosis↗

Factors affecting fusion rate in adult spondylolisthesis.

The authors examined factors affecting fusion rate in the surgical treatment of 89 consecutive adult patients with spondylolisthesis. Two factors significantly improved fusion rate: combined anterior and posterior fusion and rigid postoperative immobilization in the cast. In 65 patients with isthmic spondylolisthesis, the fusion rate was raised from 70% when posterior fusion alone was used to 88% when combined anterior and posterior fusion was used. In 20 patients with degenerative spondylolisthesis, frequent use of combined anterior and posterior fusion contributed to a high overall fusion rate of 95%. Among patients with isthmic spondylolisthesis, postoperative cast immobilization resulted in a higher fusion rate of 90% compared with a fusion rate of 63% obtained after brace immobilization.

Adult↗

Comparison of immunofluorescence, particle agglutination, and enzyme immunoassays for detection of human T-cell leukemia virus type I antibody in African sera.

The effectiveness of four screening tests for detecting antibody to human T-cell leukemia virus type I (HTLV-I) was determined by using 2,700 African serum specimens. The tests studied were indirect immunofluorescence, particle agglutination from Fujirebio, and two enzyme immunoassays, one from Abbott Laboratories that used virus lysate from HUT 102 cells and the other from Cambridge BioScience Corp. that used an env recombinant protein. Positive and doubtful sera were confirmed by Western immunoblot and radioimmunoprecipitation assay with Food and Drug Administration seropositivity criteria. The best results were obtained with the two enzyme immunoassays, which were more sensitive (100 and 98.6% [Abbott and Cambridge, respectively]) and more specific (98.7 and 96.5%). Indirect immunofluorescence exhibited difficulties for reading and interpretation. With particle agglutination, prozone was observed for 9 of 78 HTLV-I-positive serum specimens. False-positives in any of the tests were not linked to cross-reactions with human immunodeficiency viruses. However, confirmation tests remain necessary for HTLV-I screening.

Africa↗

Haemophilus influenzae type b cellulitis of the lower extremity in a non-immunocompromised elderly patient.

An 83-year-old non-immunocompromised man who developed Haemophilus influenzae cellulitis on his lower left leg is described. H. influenzae type b was isolated by conventional bacteriological cultures from one blood culture and from a cutaneous blister fluid aspirate, and identified within the dermis by immunofluorescence on a punch biopsy of lesional skin. Evolution was characterized by a slow healing during appropriate systemic antibiotherapy, and absence of any significant increase in antibodies to the capsular polysaccharide of H. influenzae type b.

Aged↗

[Prevalence of hepatitis B (Hbs Ag, Hbe Ag, DNA) and delta virus markers, in about 10,000 pregnant women in Limoges (France)].

The risk of perinatal B virus transmission is well known, but is estimated in France on results obtained from blood donors or from urban populations. In the present study, the screening of HBs Ag was carried out during five years (1984-1988), within a sample population of pregnant women (french women: 8,364, immigrant women: 1,206) seen in the university hospital of Limoges. Positive sera for HBs Ag were also tested for the other markers of B virus including specific DNA, and markers of the delta virus. The total seroprevalence of HBs Ag among these women was 0.54%, and was significantly higher in the immigrant women group (2.57%) when compared to that of french women (0.25%). During the same period (1984-1988), the seroprevalence among females blood donor was 0.03%. Among the HBs Ag chronic carrier pregnant women (n = 52), 27% were HBe Ag positive and four of them (31%) had viral DNA in their serum. Viral DNA was found in three women who were HBe Ag negative. Thirteen per cent of the HBs Ag positive pregnant women were infected by the delta virus.

Adolescent↗

[An unusual germ causing a limp: Eikenella corrodens].

A case of retroperitoneal appendicular abscess due to Eikenella corrodens is reported. This facultative anaerobe is normally found on the respiratory and intestinal mucosa and may be responsible for opportunistic infections. Culture is difficult and growth is slow. There have been few previous reports of the localization reported herein. A limp was the first manifestation of the infection. The differential diagnosis and pathophysiology of this symptom are discussed.

Abscess↗