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R Angelopoulou

Publications and source records attributed to R Angelopoulou.

6 recordsLinked to original sources
PubMed2006

Evaluation of gram stain as an alternative in the assessment of human spermatozoa quality.

INTRODUCTION: During spermiogenesis, protaminosis and sperm chromatin condensation are important prerequisites for the preservation of DNA integrity in spermatozoa. The aim of this study is to assess Gram stain as an alternative technique for the evaluation of human sperm chromatin condensation status. PATIENTS AND METHODS: Aniline blue and Gram staining were applied to semen samples from 34 donors in order to determine the relationship between sperm chromatin condensation and infertility. In addition, the possible correlation between morphology and vitality (eosin-Y staining) of spermatozoa compared with their nuclear status (aniline blue and Gram staining) was studied. RESULTS: Chromatin condensation and sperm vitality were significantly higher in fertile men compared to the subfertile. A significant correlation was found between chromatin condensation and (a) sperm vitality (p < 0.01), and (b) nuclear protein status (p < 0.01). CONCLUSIONS: Gram staining may be used as a routine method in assisted reproduction laboratories and could assist in the evaluation of sperm quality as well as in the selection of the appropriate fertilization technique.

Adult↗
PubMed2004

Does octreotide impair anastomotic healing after small bowel resection?

Seventy two rats underwent small bowel resection followed by end-to-end anastomosis. The octreotide group consisted of 36 rats treated with octreotide (subcutaneously, 7 microg/kg/day, in two equal doses), and the control group consisted of 36 rats treated with the same volume saline. Twelve animals from each group were re-explored on the 4th, 8th and 15th postoperative day. Leakages, adhesions, obstructions were the clinical postoperative findings identified and recorded. Anastomotic bursting pressures were measured. Histochemical studies included haematoxylin-eosin and Van Gieson staining techniques and focused on the microscopic characterization of the healing process. Adhesions, leakages and obstructions were not different between octreotide and control groups. Anastomoses of the octreotide group had increased bursting pressures on the 8th and the 15th day (p < .05 , p < .05, respectively). Regarding the histogical results, on the 8th day the octreotide group compared to the control group, showed healing in more layers (p < .05), increased bright red collagen fibers and quantity of fibroblasts (p < .05), and on the 15th day, the octreotide group showed fewer gaps (p < .05), increased bright red collagen fibers and quantity of fibroblasts (p < .05). In this experimental model, it appeared that octreotide does not impair healing of small bowel anastomoses, but in contrast, there is some evidence that it enhances healing on the 8th and the 15th postoperative day.

Anastomosis, Surgical↗
PubMed1996

Metastatic prostate cancer in a transgenic mouse.

We have previously reported the development of a transgenic mouse model for prostate cancer derived from PB-Tag transgenic line 8247, henceforth designated the TRAMP (transgenic adenocarcinoma mouse prostate) model. We now describe the temporal and spatial consequences of transgene expression and report the identification and characterization of metastatic disease in the TRAMP model. TRAMP mice characteristically express the T antigen oncoprotein by 8 weeks of age and develop distinct pathology in the epithelium of the dorsolateral prostate by 10 weeks of age. Distant site metastases can be detected as early as 12 weeks of age. The common sites of metastases are the periaortic lymph nodes and lungs, with occasional metastases to the kidney, adrenal gland, and bone. By 28 weeks of age, 100% harbor metastatic prostate cancer in the lymph nodes or lungs. We have also demonstrated the loss of normal E-cadherin expression, as observed in human prostate cancer, as primary tumors become less differentiated and metastasize. The TRAMP model provides a consistent source of primary and metastatic tumors for histopathobiological and molecular analysis to further define the earliest molecular events involved in the genesis, progression, and metastasis of prostate cancer.

Adenocarcinoma↗
PubMed1994

The rat probasin gene promoter directs hormonally and developmentally regulated expression of a heterologous gene specifically to the prostate in transgenic mice.

An expression cassette carrying 426 basepairs of the rat probasin (PB) gene promoter and 28 basepairs of 5'-untranslated region is sufficient to target the expression of the bacterial chloramphenicol acetyltransferase (CAT) gene specifically to the prostate in transgenic mice. The PB-CAT transgene was expressed in three of five (60%) independent lines of mice, and this expression, as reported previously for the endogenous rat gene, was male specific, restricted primarily to the lateral, dorsal, and ventral lobes of the prostate, with only very low levels of CAT activity detected in the anterior prostate and seminal vesicles. The developmental and hormonal regulation of the transgene also paralleled that reported for the rat gene, with a 70-fold increase in CAT activity in the mouse prostate observed between 2-7 weeks of age, a time corresponding to sexual maturation. PB-CAT activity in the prostate declined after castration to 3.5% of the precastration level, and the CAT activity in castrated males approached precastration levels when mice were supplemented with testosterone. Transgene expression in castrated males was not induced by dexamethasone. Coinjection of PB-CAT with a chicken lysozyme gene matrix attachment region resulted in their cointegration and further restricted the pattern of PB-CAT to the dorsolateral prostate, with suppressed expression observed in the ventral prostate. These studies demonstrate that a minimal rat probasin promoter can target heterologous gene expression specifically to the prostate in a developmentally and hormonally regulated fashion.

Androgen-Binding Protein↗