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Biomedical subjects

F Bricaire

Publications and source records attributed to F Bricaire.

At least 109 records · Page 6Linked to original sources

Tumor necrosis factor-alpha, microglia and astrocytes in AIDS dementia complex.

The pathogenesis of HIV-associated cognitive changes is poorly understood. Cytokines such as tumor necrosis factor-alpha (TNF-alpha) have been postulated to contribute to the mechanism of the neurological complications of HIV infection. One of the effects of TNF-alpha is to induce astrocyte proliferation in vitro. The purpose of this study was to look for a correlation between the expression of TNF-alpha, astrogliosis and the degree of cognitive impairment in 12 prospectively assessed AIDS cases without focal brain lesion, 8 of whom were demented. They were compared with 6 control patients without neurological disease. Neuropathological examination showed myelin pallor in 5 of the 8 demented patients. TNF-alpha expression was detected by immunohistochemistry in the midfrontal cortex, subcortical and deep white matter, and basal ganglia. Not only perivascular macrophages but also some microglial and endothelial cells were labeled. Most TNF-alpha-positive cells were in close contact with glial fibrillary acidic protein-positive astrocytes. They were more numerous than gp41-positive cells. Their density increased with increasing cognitive impairment and in parallel to the astrogliosis in the frontal cortex, basal ganglia and deep white matter. These findings further support the hypotheses that lesions of the deep white matter, driven by TNF-alpha, are associated with cognitive alteration, and that indirect effects of HIV infection in the brain participate in the development of HIV-associated dementia through a diffuse immune activation, mediated by cytokines.

AIDS Dementia Complex↗

Human immunodeficiency virus type 1 DNA and RNA load in brains of demented and nondemented patients with acquired immunodeficiency syndrome.

The relationship between dementia and human immunodeficiency virus type 1 (HIV-1) cerebral load is not clearly understood. We used immunohistochemistry and competitive polymerase chain reaction to evaluate the density ofgp 41 immunostained cells and the amount of HIV-1 DNA and RNA in the midfrontal gyrus of 21 HIV-1 infected patients, nine of whom were demented. The amounts of HIV-1 DNA and RNA, and the density of gp 41-positive cells were significantly linked. In this small series of cases, (1) although as a mean, there was a larger viral load in demented patients than in nondemented, this did not reach the significance level (2) discrepancies appeared in the population under study, some demented patients having low viral loads.

AIDS Dementia Complex↗

Efficacy and safety of desensitization with sulfamethoxazole and trimethoprim in 48 previously hypersensitive patients infected with human immunodeficiency virus.

OBJECTIVE: To study the safety and efficacy of desensitization with the use of a combination product of sulfamethoxazole and trimethoprim in previously hypersensitive patients infected with the human immunodeficiency virus. DESIGN: Prospective survey, with a median follow-up of 16 months (range, 5-24 months). SETTING: Day-care hospital in a referral center. PATIENTS: All human immunodeficiency virus-infected patients who had a history of allergic reactions (eg, rash) to sulfamethoxazole-trimethoprim and who required sulfamethoxazole-trimethoprim prophylaxis. INTERVENTION: The desensitization procedure took 2 days. The full dose (sulfamethoxazole-trimethoprim, 400-80 mg) was reached on the third day according to the following schedule: day 1--4-0.8 mg at 9 AM, 8-1.6 mg at 11 AM, 20-4 mg at 1 PM, and 40-8 mg at 5 PM; day 2--80-16 mg at 9 AM, 160-32 mg at 3 PM, and 200-40 mg at 9 PM; and day 3--400-80 mg at 9 AM. MAIN OUTCOME MEASURE: The onset of cutaneous adverse effects attributable to sulfamethoxazole-trimethoprim therapy within 3 months after desensitization. RESULTS: Of the 48 evaluable patients, 37 (77%) tolerated sulfamethoxazole-trimethoprim desensitization without toxic effects and continued to take sulfamethoxazole-trimethoprim daily. Desensitization failed in 11 cases (5 on day 1, 3 on day 2, and 1 each on days 9, 11, and 90). Acute hypotension and a nonfatal myocardial infarction developed in 1 of these patients. The factors that were predictive of failure were a relatively high CD4+ cell percentage (11% vs 8%; P = .008) and a relatively high CD4+/CD8+ ratio (0.27 vs 0.12; P = .02). CONCLUSIONS: The efficacy of desensitization with sulfamethoxazole-trimethoprim was confirmed; this desensitization procedure was more often successful in patients with lower CD4+ cell percentages and CD4+/CD8+ ratios. However, sulfamethoxazole-trimethoprim therapy should be reintroduced carefully.

Adult↗

Astrocytic adhesion molecules are increased in HIV-1-associated cognitive/motor complex.

Half of AIDS dementia cases are associated with HIV-encephalitis or myelin pallor. Another half die with no HIV-related neuropathological changes. Previous observations suggest that cerebral dysfunction may result from more subtle cellular interactions. and that some of them may be mediated by cell adhesion molecules. In the present study the expression by astrocytes and endothelial cells of intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) was analysed as a function of the neuropathological diagnosis, the density of astrogliosis and of HIV-1 positive cells, and of the mental status. Twelve AIDS cases, without focal brain lesion, eight of whom were demented, were selected from a prospective study. They were compared with six control cases with multiple sclerosis, and with six control patients without neurological disease. ICAM-1 and VCAM-1 expression was localized by immunofluorescence and confocal microscopy. HIV protein gp41 was detected by immunohistochemistry on adjacent sections. Endothelial expression of ICAM-1 and VCAM-1 was significantly up-regulated in all AIDS patients. VCAM-1 only was related to myelin pallor. The density of VCAM-1 or ICAM-1 positive astrocytes increased in demented AIDS patients, independently of the neuropathological findings or the density of gp41 positive cells. Expression of cell adhesion molecules, together with other secondary mechanisms such as secretion of cytokines may play a role in the pathogenesis of white matter lesions leading to HIV-1-associated cognitive changes.

AIDS Dementia Complex↗

[Prevention of herpes simplex and varicella zoster infections in patients of HIV infections].

Reactivation of Herpes simplex virus and varicella zoster virus infections occurs frequently in patients infected with human immunodeficiency virus (HIV). Prevention of Herpes simplex recurrences with oral acyclovir (400 mg x 2/day) should be recommended for patients with more than 6 relapses per year. Varicella-zoster immunoglobulin is recommended for prophylaxis of varicella in exposed HIV-infected adults and children who are susceptible. Prevention of varicella-zoster recurrences with oral acyclovir (800 mg x 5/day) should be considered for patients with retinopathy.

AIDS-Related Opportunistic Infections↗

[Apropos of 5 new cases of onchocerciasis edema].

We report 5 cases of onchocerciasis presenting as limb's swelling collected in the tropical disease unit of a parisian hospital between 1982 and 1993. They are 5 men which have lived between 3 weeks and 4 years in forested areas of Cameroon in four cases and Côte d'Ivoire in one case. The incubation period varied from 5 months to 2 years. The limb oedema was always located to one arm. It was associated with a blood eosinophilia above 2000/mm3 in 4 of 5 patients. The skin detection of microfilaria of Onchocerca volvulus was positive in every case. The serodiagnostic tests were negative for indirect immunoflurescent assay and immunoelectrophoresis with exception of one patient. These patients were cured with ivermectine and/or diethylcarbamazine. In addition, 26 other cases described in the literature are discussed.

Animals↗

[Epstein-Barr virus].

The Epstein-Barr virus (EBV), which predominantly infects B-cells, has certain novel features, particularly its ability to remain latent for long periods and its capacity for transformation. Host immune response is complex, varying in intensity and quality. Disease expression results from this conflict between the host and the virus. Clinical manifestations are thus quite variable, ranging from asymptomatic infection, or various aspects of infectious mononucleosis, to malignant lymphoproliferation. This is a perfect illustration of the transition between benign and malignant reactive lymphoproliferation and of the organism's capacity to produce a more or less rapid and effective response to a potentially malignant disorder.

Animals↗

[Cutaneous tuberculosis. A study of 4 cases].

INTRODUCTION: The recent increase in the incidence of tuberculosis has led to the return of cutaneous forms of this disease. In addition, diagnosis can now be made rapidly using genoma amplification. CASE REPORT: Four cases of cutaneous tuberculosis are described in nonimmunosuppressed patients: two cases of lupus vulgaris, including one due to Mycobacterium africanum, and two others of gummas, including one associated with tuberculosis verrucosa. The diagnosis was suggested by epidemiological, clinical, histological and immunological findings and confirmed by culture of the bacilli in 3 cases and by genoma amplification in 1. DISCUSSION: These observations illustrate the difficulties encountered in determining the tuberculosis nature of skin lesions. The clinical presentation, differential diagnosis, the pathophysiology of this disease and the new interest in genoma amplification are discussed.

Adult↗

Detection of human herpes virus 6 in AIDS-associated retinitis by means of in situ hybridization, polymerase chain reaction and immunohistochemistry.

The ubiquitous nature of HHV-6 and its genomic relationship with cytomegalovirus led us to evaluate an etiological link between HHV-6 and AIDS-associated retinitis in a prospective study. HHV-6 infection was studied in patients with AIDS-associated retinitis and in two control populations. Eye pairs were obtained at necropsy from nine patients with AIDS-associated retinitis, four human immunodeficiency virus (HIV)-sero-positive patients with normal fundus examination and three HIV-seronegative patients. HHV-6 infection was detected by polymerase chain reaction (PCR), in situ hybridization and immunohistochemistry. Human cytomegalovirus (CMV) and HIV-1 infections were detected in parallel by the same methods. HHV-6 infection was detected in three cases of AIDS-associated retinitis. In two of these patients, HHV-6 infection was detected both by immunohistochemistry and PCR while in the third case it was detected by in situ hybridization and PCR. In the three patients, fundus examination showed bilateral retinitis in two of them and unilateral retinitis in one of them. HHV-6 infection was not detected in the retina of the two control groups. CMV was also detected in the three cases positive for HHV-6 by all three methods. HIV DNA was detected by PCR in two of three cases and was confirmed in one of these cases by in situ hybridization. These results confirm that HHV-6 infects the retina but suggests that HHV-6 does not have an exclusive causative role in AIDS-associated retinitis, since CMV coinfection of the retina was detected in all three of the patients positive for HHV-6.

AIDS-Related Opportunistic Infections↗

Dermatoses associated with travel to tropical countries: a prospective study of the diagnosis and management of 269 patients presenting to a tropical disease unit.

The full spectrum of skin diseases related to travel in tropical areas is unknown. We prospectively studied 269 consecutive patients with travel-associated dermatosis who presented to our tropical disease unit in Paris during a 2-year period. The median age of these patients was 30 years; 137 patients were male; 76% of the patients were tourists; 38% had visited sub-Saharan Africa; and 85% had been appropriately vaccinated against tetanus. Cutaneous lesions appeared while the patient was still abroad in 61% of cases and after the patient's return to France in 39%. The diagnosis was definite in 260 cases; 137 of these cases (53%) involved an imported tropical disease. The most common diagnoses were cutaneous larva migrans (25%); pyodermas (18%); pruritic arthropod-reactive dermatitis (10%); myiasis (9%); tungiasis (6%); urticaria (5%); fever and rash (4%); and cutaneous leishmaniasis (3%). Hospitalization was necessary in 27 cases (10%), with a median duration of 5 days (range, 2-21 days). Travelers should be advised on how to avoid exposure to the agents and vectors of infectious dermatoses. Travel first-aid kits should include insect repellents and antibiotics effective against bacterial skin infections.

Adolescent↗

Tuberculosis caused by Mycobacterium africanum associated with involvement of the upper and lower respiratory tract, skin, and mucosa.

Cutaneous tuberculosis is rarely seen in industrialized countries and is usually caused by Mycobacterium tuberculosis. We report a case of cutaneous tuberculosis with bilateral nodular scleritis, nasal sinus invasion, and nasal septum perforation (confirmed by computed tomography scans of the sinuses), associated with pulmonary infiltrates and mediastinal adenopathy, in an African woman. Mycobacterium africanum was recovered from the sputum after 8 weeks of culture in Löwenstein-Jensen medium. To our knowledge, this is the first description of M. africanum associated with cutaneous tuberculosis and nasal sinus invasion.

Adult↗