Evolution of specific antibodies and proviral DNA in milk of small ruminants infected by small ruminant lentivirus.

The diagnosis of Small Ruminant Lentivirus (SRLV) is based on clinical signs, pathological lesions and laboratory testing. No standard reference test for the diagnosis of maedi visna has been validated up to the present, and it is puzzling that tests which detect antibodies against the virus and tests which detect the proviral genome may render opposite results. The aim of this study was to evaluate the presence in milk throughout a lactation period of specific antibodies by ELISA and of SRLV proviral DNA by a PCR of the highly conserved pol region. A six-month study was conducted with the milk of 28 ewes and 31 goats intensively reared. The percentage of animals with antibodies against SRLV increased throughout the study period. Seroprevalence in sheep was 28% at the beginning of the study and by the end it had increased up to 52.4%. In goats, initial seroprevalence of 5.6% increased to 16%. The percentage of PCR positive ewes was stable throughout the study period. Of the positive sheep, 21.4% were PCR-positive before antibodies could be detected and most of them became PCR-negative shortly after the first detection of antibodies. This might suggest that antibodies have a neutralizing effect. In addition, an equal percentage of sheep were always PCR-negative but either became ELISA-positive or was always ELISA-positive, which might support this hypothesis. On the other hand, the PCR results in goats did not follow any pattern and oscillated between 35.3% and 55.6% depending on the month. Most goats positive by PCR failed to develop antibodies in the 6 months tested. We may conclude that the infection and the antibody response to it follow a different trend in sheep and goats.

Study of the telomerase hTERT fraction, PCNA and CD34 expression on pituitary adenomas. Association with clinical and demographic characteristics.

To determine the frequency of human telomerase reverse transcriptase (hTERT) catalytic fraction expression and its association with clinical and demographic characteristics of the patient, as well as with the expression of CD34 and proliferating cell nuclear antigen (PCNA) indexes on adenohypophyseal hormone tissues. A transverse study was realized with 49 cases of hypophyseal adenoma with analysis type cases and controls. The different adenohypophyseal hormones [prolactin (PRL), growth hormone (GH), follicle stimulating hormone, luteinizing hormone, thyroid gland stimulant hormone, adrenocorticotropic hormone (ACTH)], the catalytic fraction of the telomerase hTERT, the PCNA index and the CD34 density were determined by means of immunohistochemical techniques. The clinical, demographic and histopathological characteristics of the patients with and without hTERT expression were compared by means of Pearson's Chi-squared, Fisher's exact test and Mann-Whitney's U. Twenty-eight point six percent of the adenomas had positive expression for hTERT. The variables significantly correlated with hTERT's expression were younger age of presentation, diagnostic of adenoma producer, higher PCNA index, higher CD34 density, increased GH on serum and the expression on PRL tissue, GH and ACTH. Tobacco history had a negative association with hTERT's expression. The telomerase could be a marker of cellular proliferation associated with angiogenesis and hormonal activity. Evaluation of these variables could provide information about their biological behavior.

Human telomerase and alpha-methylacyl-coenzyme A racemase in prostatic carcinoma. A comparative immunohistochemical study.

Human telomerase detected by in situ hybridization has been demonstrated to be a useful tool for the diagnosis of malignancy and has also been tested by reverse transcriptase-polymerase chain reaction in several tumors such as hepatic cell carcinoma, melanoma, colonic carcinoma, gastric carcinoma, biliary carcinoma, breast carcinoma, mesothelioma, lung carcinoma, female tract carcinoma, and prostatic carcinoma. A monoclonal antibody (clone Tel-24) that allows for the detection of human telomerase reverse transcriptase (hTERT) in paraffin blocks of archival material has recently been developed. Carcinomas of cervix, endometrium, and breast have been studied by this method, but its value in prostatic carcinoma has not been explored; for that reason, we studied benign and malignant prostatic lesions by immunohistochemistry using paraffin embedded tissue. The aim of the study was to define the sensitivity and specificity of hTERT in prostate cancer, in comparison with alpha-methylacyl-coenzyme A racemase (AMACR) (P504-S). Fifty-five specimens of diverse prostatic lesions were selected for study (43 needle biopsies and 12 transurethral resections); there were 61 malignancies (47 infiltrating carcinomas and 14 high-grade prostatic intraepithelial neoplasias [PIN]) and 29 benign lesions (10 basal cell hyperplasias, 12 nodular hyperplasias, 4 chronic prostatitis, and 3 atrophic glands). Signal for hTERT nucleolar was detected in 31 of 47 infiltrating adenocarcinomas, in 11 of 14 PIN, and in none of 27 benign lesions (sensitivity, 71%; specificity, 100%). Diffuse cytoplasmic positivity for AMACR was found in 37 of 41 infiltrating adenocarcinomas, in 7 of 7 PIN, and in 6 of 22 benign lesions (sensitivity, 91%; specificity, 72%). These results indicate that hTERT is highly specific of malignancy, with no false-positive cases; however, it had lower sensitivity than AMACR.

Unusual outbreak of clinical mastitis in dairy sheep caused by Streptococcus equi subsp. zooepidemicus.

This work describes an outbreak of clinical mastitis affecting 13 of 58 lactating ewes due to Streptococcus equi subsp. zooepidemicus. S. equi subsp. zooepidemicus was isolated in pure culture from all milk samples. All the clinical isolates had identical biochemical profiles and antimicrobial susceptibility patterns and also exhibited indistinguishable macrorestriction patterns by pulsed-field gel electrophoresis, indicating that all cases of mastitis were produced by a single strain.