Risk behaviors and STI prevalence among people with HIV in El Salvador.

To date, there are no studies from El Salvador among people with HIV to inform prevention programs. We conducted a study in El Salvador in 2008 among people with HIV using audio computer-assisted interviews on risk behaviors and access to health care. Blood was tested for syphilis and herpes simplex type 2 (HSV-2). Active syphilis was defined as RPR titer ≥1:8. Genital specimens were tested for other sexually transmitted infections (STI) by PCR. We evaluated factors associated with unprotected sex with last stable partner of HIV-negative or unknown status among those reporting a stable partner. A total of 811 HIV-positive individuals participated: 413 men and 398 women. Prevalence of Chlamydia and gonorrhea was low (≤1%), while prevalence of other STI was high: Mycoplasma genitalium (14%), syphilis (15% seropositivity, active syphilis 3%) and HSV-2 (85%). In multivariate analysis, disclosing HIV status to partner (OR 0.2, 95% CI: 0.1-0.3, p<0.001), participation in HIV support groups (OR 0.3, 95% CI: 0.1-0.8, p=0.01), easy access to condoms (OR 0.4, 95% CI: 0.2-0.9, p=0.04) were protective factors for unprotected sex. Reporting a casual partner in the last 12 months (OR 3.6, 95% CI: 1.5-8.5, p=0.004). and having an STI (OR 2.6, 95% CI:1.3-5.5, p=0.02) were associated with an increased odds of unprotected sex. Prevention interventions among HIV-positives in El Salvador should focus on increasing condom access, promoting HIV disclosure and couples testing and reducing the number of partners. The positive role of support groups should be used to enhance behavioral change.

A pathological study of experimental long-standing Schistosoma bovis infection in sheep.

The pathological response of sheep to two dose levels (400 or 10,000 cercariae) of Schistosoma bovis was evaluated 24 weeks after infection. The results confirmed that a single low or high dose causes lesions in the liver and intestine, and that the lungs, lymph nodes, pancreas and abomasum are affected in sheep given a single high dose. In addition, the study showed that pathological changes (mainly a granulomatous inflammatory reaction) were induced not only by eggs but also by adult worms, and that their severity was in general related to the dose of S. bovis. Hoeppli reaction product, observed on the surface of adult schistosomes in some parasitic granulomas, showed no immunoreaction for IgG, IgA or IgM.

Optimization of the immunohistochemical demonstration of keratins in paraffin wax-embedded mouse skin.

The purpose of this study was to develop an immunoperoxidase technique for the detection of cytokeratins in samples of paraffin wax-embedded adult and fetal skin from NMRI mice, with various antibodies (Troma-1, LL001, 8.60, MCK5, MCK6, AF129) that have been tested mainly on fresh-frozen sections. Each antibody was tested with three different fixatives (10% neutral buffered formalin, Bouin's fluid, and 70% ethanol) and two distinct pretreatments (enzymatic digestion with trypsin, or heat treatment). The best results, in terms of non-specific background labelling, morphological preservation and intensity of specific labelling, were obtained (1) for adult skin, by the use of Bouin's fluid, heat pretreatment and antibodies LL001, MCK5, MCK6 or AF129, and (2) for fetal skin, by the use of 70% ethanol, heat pretreatment and antibody Troma-1. Monoclonal antibody 8.60 gave the best results when the use of 70% ethanol was combined with either enzymatic digestion or heat pretreatment.

Spontaneous mouse mammary tumours: incidence and cytokeratin expression.

The purpose of this study was to advance our knowledge of the histogenesis of spontaneous mammary tumours in laboratory mice. Normal mammary tissue and 19 spontaneous mammary tumours from adult female mice were examined using monoclonal and polyclonal antibodies differing in their recognition of various cytokeratin intermediate filament proteins (CKs). All neoplasms were intraductal and were invasive carcinomas with a tubular, papillary, cystic or solid growth pattern. CK8-positive reactions were detected in the normal alveolar and ductal epithelia and CK5- and CK14-positive reactions were seen in myoepithelial cells of nonlactating mammary glands. Positive staining for CK5 and CK8 was detected in all tumours and CK14 was expressed in those with a papillary pattern. Comparisons between non-lactating glands and tumours indicated that the neoplasms were well or moderately differentiated, there was no squamoid differentiation and that they arose from the alveoli and duct system, not the myoepithelial cells.

Effects of in utero exposure to nonsteroidal estrogens on mouse testis.

Male mice exposed in utero to alpha-zearalanol (zeranol) or diethylstilbestrol (DES) were analyzed postnatally to evaluate the possible changes on their testicular morphology as part of an examination of the effects of transplacental exposure to non-steroidal estrogens on sensitive tissues. Pregnant NMRI mice were injected subcutaneously with ethyl oleate (0.1 mL) alone (negative control) or with 150 micrograms/kg of body weight of zeranol or DES (positive control) on days 9 and 10 of gestation. Experimental and control male offspring were euthanized at days 45 (n = 47), 90 (n = 44), 180 (n = 40) and 365 (n = 26) after birth and their gonads were examined by light and electron microscopy. The results suggested that prenatal zeranol or DES exposure induced more severe and earlier (at 45 d) testicular abnormalities than in negative control (at 6 mo). These age-related alterations were characterized by regressive changes in the germinal epithelium and Sertoli's cells as well as foci of Leydig's cells around atrophied seminiferous tubules and dysplasia of the rete testis epithelium. On the contrary, the presence of Leydig's cells with immature morphology and their arrangement in sheet could be attributable exclusively to estrogen treatment. The presence of no neoplasm was confirmed.

Effects of in-utero exposure to zeranol or diethylstilboestrol on morphological development of the fetal testis in mice.

The morphological development of the fetal mouse testis exposed to alpha-zearalanol (zeranol) or diethylstilboestrol (DES) was evaluated as part of an examination of the effects of transplacental exposure to non-steroid oestrogens on susceptible tissues. On days 9 and 10 of gestation, pregnant NMRI mice were given subcutaneous injections of ethyl oleate alone (0.1 ml) or zeranol or DES (150 micrograms/kg body weight) in ethyl oleate. The mice were killed from days 12 to 18 of gestation and the male fetuses were examined. Microscopical examination of the gonads indicated that the onset of testicular differentiation was earlier in the oestrogen-treated fetuses than in controls. Abnormal differentiation of gonocytes and foci of hyperplasia of fetal Leydig cells were observed in the oestrogen-treated mice. Male fetuses from female mice treated with DES showed a delay in testicular descent and progressive decrease in reactivity for cytokeratin (CK) 8 in fetal Sertoli cells. These morphological findings suggest that prenatal exposure to zeranol or DES induces abnormal testicular differentiation in the mouse.

Effect of diethylstilbestrol or zeranol on fetal development, gestation duration, and number of offspring in NMRI mice.

OBJECTIVE: To evaluate the effects of diethylstilbestrol (DES) or alpha-zearalanol (zeranol) on fetal development, gestation duration, and number of offspring. DESIGN: Study effects of prenatal administration of DES or zeranol on various pre- and perinatal variables in an experimental group of mice, compared with effects in a control group. ANIMALS: Pregnant NMRI mice. PROCEDURE: Diethylstilbestrol or zeranol (150 mg/kg of body weight) or vehicle (controls) was administered SC to pregnant mice on days 9 and 10 of gestation. Fetuses from pregnant mice of each group were counted and weighed, and their size and head length were recorded. Additional pregnant mice delivered their fetuses naturally, and pups from each group were counted and their sex was determined. At the end of gestation, abortions were evaluated. All data were statistically analyzed. RESULTS: Mean number of fetuses was significantly lower (P < 0.0001) in DES-treated (4.59 +/- 0.48) than in control mice (8.33 +/- 0.49). Both estrogenic substances significantly reduced fetal size and weight (P < 0.0001), compared with control mice. Diethylstilbestrol significantly increased abortion frequency (P < 0.0001) and gestation duration (P < 0.0001), compared with values for control mice. A reduced number of live pups (P < 0.0001) from pregnant mice administered DES (5.48 +/- 0.38) or zeranol (5.97 +/- 0.49) was observed, compared with control mice (8.52 +/- 0.50), because of reduced number of male offspring (P < 0.0001). CONCLUSIONS: Diethylstilbestrol or zeranol administered during mid-pregnancy leads to decreased fetal weight and size and lower numbers of male offspring at birth. Likewise, DES induced a significant increase in abortions and gestation duration.

Incidence and pathomorphology of uterine tumours in the cow.

A statistical and pathological study on uterine tumours during the examination of 1489 female bovines at slaughter was carried out. A 0.4% (n = 6) incidence of uterine neoplasms, being 50% adenocarcinomas and the other 50% leiomyomas, was diagnosed. With regard to age groups, tumours were more frequent in the 11-15-year-old group. Two animals affected by adenocarcinoma were not fertile and they had ovarian metastasis that, to the author's knowledge, has been cited as extremely rare in cows. An ultrastructural study of these carcinomas and their metastasis was also made. Two leiomyomas were intramural and another one was pedunculated and subserous located. All leiomyomas showed the features of old tumours.