[Post-exposure HIV prevention: eligibility of patients recently infected by sexual exposure]. / Prophylaxie post exposition au VIH: éligibilité des patients récemment infectés par voie sexuelle.

QUESTION: Post-exposure prophylaxis (PEP) is effective in preventing HIV infection after professional exposure. PEP is also recommended after inadvertent sexual exposure if two conditions are met: the source person is known to be HIV infected, and exposure to this person occurred only once or is accidental. The objective of this study is to describe the circumstances of sexual exposure and determine how frequently these conditions were present among patients diagnosed during primary HIV infection. METHODS: Physicians of 35 patients diagnosed with primary HIV infection provided detailed information on the circumstances of infection as well as on the patients and source persons. RESULTS: Most patients were homosexual (71%), and 91% were male. Only one patient (3%) had a single exposure with a known HIV-infected person and was therefore eligible for PEP. Eight patients (23%) who did not know the HIV status of their partner would have been eligible considering single exposure as a sufficient criterion for PEP. Oro-genital contact appears to account for transmission in four instances. Eleven persons (31%) were infected after sexual contact with their stable partner, of whom 7 did not known his/her HIV status. Twelve patients (34%) were infected after multiple unprotected sexual contact with unknown partners. CONCLUSION: The direct impact of PEP in terms of HIV infections prevented is likely to be small. PEP will not make up for the failure of other prevention methods. It may, however, contribute to the disclosure and the discussion of risk situations and help physicians provide individual counselling taking into account the precise context of risk behavior.

[HIV infection, tuberculosis and tuberculin test in Switzerland. The Swiss HIV Cohort Study]. / Infection VIH, tuberculose et test tuberculinique en Suisse. The Swiss HIV Cohort Study.

BACKGROUND: The usefulness of the tuberculin skin test (TST) for HIV-infected subjects may be questioned because false-negative results are increasingly common with advanced immune deficiency. The objectives of this research were thus to describe the use and the results of TST among patients with HIV infection in Switzerland and to measure the usefulness of isoniazid preventive chemotherapy and the incidence of tuberculosis (TB) relative to TST and CD4 cell count at the time of TST. DESIGN: Prospective multicentric cohort study of HIV infected patients; comparison of patients tested and non-tested, and of those with positive and negative TST. Multivariate comparison (Cox model) of TB incidence taking into account TST results and CD4 cell count at the time of TST. RESULTS: Out of 5802 patients followed up in the Swiss HIV cohort study as of September 1994, 34.6% were tested. Native Swiss were more likely to be tested than patients from high TB prevalence countries (36% vs 21% of native Africans). Patients registered after 1990 were more often tested than before (50% vs 26%). Of 2010 tested patients, 6.8% had a > 5 mm induration. African patients were more frequently TST positive (26%) than Swiss nationals (6%). Among patients with CD4 > 500 per mm3 at the time of the test, 16% were TST positive compared to 1% of those with CD4 < 200 per mm3. Out of 25 cases of tuberculosis among tested patients, 84% (21) occurred among TST-negative patients. Tuberculosis incidence among TST-negative patients with CD4 > or = 200 per mm3 at the time of the test was 0.3 per person-year. In comparison, the adjusted relative risk of tuberculosis among TST-positive patients with CD4 > or = 200 per mm3 was 5.5 (95% confidence interval [CI]: 1.2-23.9) and 6.6 (CI: 2.3-19.0) among TST-negative patients with CD4 < 200 per mm3. CONCLUSION: Despite its usefulness, TST is often performed too late and is therefore difficult to interpret. TST should be done as early as possible. TST should be done as early as possible. Among patients with CD4 < 200 per mm3, a negative TST should not preclude the use-of preventive chemotherapy, particularly in those originally from countries with a high incidence of tuberculosis.

Tuberculosis among European patients with the acquired immune deficiency syndrome. The AIDS in Europe Study Group.

OBJECTIVES: To describe the characteristics of acquired immune deficiency syndrome (AIDS) patients with tuberculosis in Europe; to assess the incidence and risk factors of tuberculosis after AIDS; to compare survival of AIDS patients with and without extra-pulmonary tuberculosis (EPTB) at the time of AIDS diagnosis. DESIGN: Multicentric retrospective cohort study of 6544 AIDS patients diagnosed in 52 clinical centres and 17 European countries. METHODS: Description of patient characteristics and comparisons of tuberculosis incidence and mortality after AIDS with multivariate Cox proportional hazard models. RESULTS: 14.6% of AIDS patients had tuberculosis and 78% of those with tuberculosis had EPTB. EPTB was the AIDS-defining condition in 8.7% of the patients. Tuberculosis incidence after AIDS was 3.1 per 100 person-years. Age, gender and HIV-transmission category were not significantly associated with an increased risk of tuberculosis and the strongest risk factor for both EPTB and pulmonary tuberculosis (PTB) was the region of origin. The adjusted hazard ratio of EPTB and PTB in Southern Europe compared to Northern Europe were 5.5 (95% confidence interval [CI]: 5.0-6.1) and 2.0 (CI: 1.4-2.7) respectively. The apparent survival advantage of AIDS patients with EPTB compared to patients diagnosed with other conditions (median survival time: 22 vs 16 months) was statistically not significant when confounding variables were adjusted for (Hazard ratio: 0.85; CI: 0.62-1.07). CONCLUSIONS: In Europe, there are large differences in the incidence of tuberculosis among AIDS patients in different countries. They do not seem to be due to differences in age or in the prevalence of injecting drug use and likely reflect differences in the prevalence of tuberculosis infection. The role of recent transmission should also be considered, and national tuberculosis control efforts and Europe-wide surveillance need to be reinforced accordingly.

A controlled trial of zidovudine in primary human immunodeficiency virus infection.

BACKGROUND: It is possible that antiretroviral treatment given early during primary infection with the human immunodeficiency virus (HIV) may reduce acute symptoms, help preserve immune function, and improve the long-term prognosis. METHODS: To assess the effect of early antiviral treatment, we conducted a multicenter, double-blind, placebo-controlled trial in which 77 patients with primary HIV infection were randomly assigned to receive either zidovudine (250 mg twice daily; n = 39) or placebo (n = 38) for six months. RESULTS: The mean time from the onset of symptoms until enrollment in the study was 25.1 days. Among the 43 patients who were still symptomatic at the time of enrollment, there was no appreciable difference in the mean (+/- SE) duration of the retroviral syndrome between the zidovudine group (15.0 +/- 4.1 days) and the placebo group (15.8 +/- 3.6 days). During a mean follow-up period of 15 months, minor opportunistic infections developed in eight patients: oral candidiasis in four, herpes zoster in two, and oral hairy leukoplakia in two. Disease progression was significantly less frequent in the zidovudine group (one opportunistic infection) than in the placebo group (seven opportunistic infections; P = 0.009 by the log-rank test). After adjustment for the base-line CD4 cell count, the patients treated with zidovudine had an average gain of 8.9 CD4 cells per cubic millimeter per month (95 percent confidence interval, -1.4 to 19.1) during the first six months of the study, whereas those receiving placebo had an average loss of 12.0 CD4 cells per cubic millimeter per month (95 percent confidence interval, 5.2 to 18.7), for a between-group difference of 20.9 CD4 cells per cubic millimeter per month (95 percent confidence interval, 8.5 to 33.2; P = 0.001). CONCLUSIONS: Antiretroviral therapy administered during primary HIV infection may improve the subsequent clinical course and increase the CD4 cell count.

Cointegrate formation by Tn5, but not transposition, is dependent on recA.

We have studied the effect of the recA-dependent homologous recombination system of Escherichia coli on both Tn5-mediated cointegrate formation and Tn5 transposition. We demonstrate here that, whereas transposition of Tn5 is independent of the recA gene product (as has been shown by other workers), Tn5-mediated cointegrate formation is strongly dependent on recA. The structures of both the simple transposition products and the cointegrates formed in a recA- background seem to be the same as those produced in a recA+ background. These results provide strong evidence that Tn5 does not transpose via an obligate cointegrate intermediate and suggest that the recA effect on cointegrate formation is exerted during the process of transposition.

Inverted repeats of Tn5 are transposable elements.

Experiments presented here show that each of the 1.5-kilobase inverted repeats of the kanamycin-resistance transposon Tn5 is transposable; we designate them IS50-L (left) and IS50-R (right). By DNA sequence analyses, IS50 is 1533 base pairs (bp) long and generates 9-bp direct repeats of target sequences. The ends of IS50 comprise a hyphenated 8-of-9-bp inverted repeat and are not used with equal efficiency; the outside ends are more active than the inside ends, suggesting that a strong transposase recognition site at the outside ends, suggesting that a strong transposase recognition site at the outside end extends beyond the 8 bp common to both ends.

Lactose operon transcription from wild-type and L8-UV5 lac promoters in Escherichia coli treated with chloramphenicol.

In cells treated with chloramphenicol and the inducer isopropyl-beta-D-thiogalacto-pyranoside, messenger ribonucleic acid transcription from the wild-type lac promoter was not detected. Transcription occurred from the mutant UV5-L8 promoter. The transcripts were of variable length; some included the whole Z gene. No major site of transcription arrest within the Z gene was apparent.

Glomerulonephritis associated with hepatitis B. report of a case and review of the literature.

A 45-year old developed membranoproliferative GN seven years after acute hepatitis. He was found to be a chronic carrier of HBsAg, and glomeruli contained granular deposits of immunoglobulins (Ig), complement (C) and HBsAg. Six months later, HN persisted, but HBsAg has disappeared from glomeruli; Ig and C were still present. It was concluded that GN was probably due to a hepatitis B associated antigen, but not necessarily to HBsAg.

Granulation tissue as a contractile organ. A study of structure and function.

CONTRACTING GRANULATION TISSUES CONTAIN FIBROBLASTS THAT DEVELOP CHARACTERISTICS TYPICAL OF SMOOTH MUSCLE: (a) They contain an extensive cytoplasmic fibrillar system. (b) They show immunofluorescent labeling of their cytoplasm with human anti-smooth muscle serum. (c) The nuclei show complicated folds and indentations, indicative of cellular contraction. (d) There are cell-to-cell and cell-to-stroma attachments. (e) It is possible to extract similar quantities of actomyosin (having the same adenosine triphosphatase activity) from granulation tissue and from pregnant rat uterus. (f) Strips of granulation tissue, when tested pharmacologically in vitro, behave similarly to smooth muscle. All these data support the view that, under certain conditions, fibroblasts can differentiate into a cell type structurally and functionally similar to smooth muscle and that this cell, the "myo-fibroblast," plays an important role in connective tissue contraction.

Contraction of granulation tissue in vitro: similarity to smooth muscle.

Strips of granulation tissue from three different experimental models contract in vitro when treated with substances that induce contraction of smooth muscle. Because the fibroblasts in such tissues have some ultrastructural features typical of smooth muscle, our findings indicate that fibroblasts are able to modulate toward a cell type that is morphologically and functionally close to smooth muscle.