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Biomedical subjects

R U Peter

Publications and source records attributed to R U Peter.

138 records · Page 8Linked to original sources

[Treatment of seborrhoeic eczema with ketoconazole in comparison with an active agent-free cream].

Both systemic and topical application of ketoconazole (CAS 65277-42-1) have been found effective in seborrhoeic dermatitis. The topical application of 2% ketoconazole in a cream base in particular has so far only once been compared to the application of the vehicle. Statistical analysis, however, has only been descriptive. In the present trial including 60 patients 2% ketoconazole cream (Nizoral) and a bland cream have been compared in a randomised, controlled fashion. Both erythema and scaling were found markedly more reduced in the verum group (p = 0.003 and p = 0.006, resp.). Hence the topical application of 2% ketoconazole cream can be considered as rational treatment of seborrhoeic dermatitis the more so as the application of the drug was well tolerated.

Administration, Topical↗

Progressive growth of fish tumors after transplantation into thymus-aplastic (nu/nu) mice.

The nude mouse does not reject xenografts of malignant and nonmalignant tissues of mammalian or avian origin, due to a deficiency of functional T-lymphocytes. In this study, tissue from a cold-blooded vertebrate, a teleost fish, was for the first time successfully transplanted to Swiss albino nu/nu mice. Malignant melanotic melanoma of Xiphophorus transplanted to nude mice showed progressive growth and could be serially passaged. In vitro culture experiments revealed that the fish tumor cells adapt to the physiological conditions of the mammalian host, most obviously to the body temperature. On the other hand, fish-specific morphological characters and biochemical features, e.g., expression of a melanoma-associated antigen, were retained. This experiment demonstrates the enormous capacity of the melanoma cells to adapt to severe changes in their environment, which even enables them to overcome the physiological barriers between such taxonomically distant vertebrate groups as fish and mammals.

Animals↗

Chromosome 7 aneusomy. A marker for metastatic melanoma? Expression of the epidermal growth factor receptor gene and chromosome 7 aneusomy in nevi, primary malignant melanomas and metastases.

Receptor tyrosine kinases such as the epidermal growth factor receptor (EGFR) play an important role in a variety of malignant neoplasias, making the search for aberrations in the relevant chromosomes an important issue. Differential expression of the EGFR gene was investigated by reverse transcriptase (RT)-PCR on tissue samples of normal skin, nevi, primary melanomas, and melanoma metastases. The EGFR gene is located on chromosome 7p12.3-p12.1. To determine the number of chromosomes 7 in cell nuclei of the mentioned tissue samples we performed fluorescence in situ hybridization (FISH) on touch preparations, using a DNA probe that hybridizes specifically to the centromeric region of chromosome 7. Additionally, chromosome 7 number in interphase nuclei was determined in short-term primary cell cultures of nevi, primary melanomas, and metastases. The highest EGFR gene expression frequency was found in melanoma metastases. By FISH we detected the highest fraction of cell nuclei with more than two chromosomes 7 in the group of metastases. Our results suggest that overexpression of the EGFR gene might play an important role in metastasis of malignant melanoma. This is well reflected by polysomy 7, possibly accounting for an increased EGFR gene copy number.

Aneuploidy↗

Male reproductive system in patients exposed to ionizing irradiation in the Chernobyl accident.

Twelve men with different forms and stages of chronic radiation dermatitis caused by accidental exposure to beta and gamma irradiation during and after the Chernobyl atomic power plant accident were examined. Two patients had impotentia coeundi, and the others reported various impairments of sexual function. One patient had aspermia, two patients had azoospermia, one had oligospermia, and four had normal sperm counts. In three samples abnormal forms of spermatozoa were increased. Sperm motility was decreased in 3 samples and was normal in another. Hormonal analyses demonstrated low testosterone plasma levels in two patients, an increase of follicle stimulating hormone (FSH) levels in six patients, and a decrease of luteinizing hormone (LH) in one patient. In one patient who showed an increase of plasma prolactin level, associated with low testosterone and LH, a microadenoma of the pituitary gland (prolactinoma) was detected. It would appear that there is an association between accidental exposure to ionizing radiation of varying severity and the impairment of exocrine and endocrine testicular function, sometimes resulting in long-lasting physiological and psychological problems.

Accidents↗

Accidental radiation exposure and azoospermia.

Seven Georgian male soldiers (19-25 years old) had accidentally been exposed to radiation by Cs-137 between April 1996 and May 1997. No information about the exact time and duration of exposure was available. All patients presented with the subacute stage of Cutaneous Radiation Syndrome with deep painful ulcers on different body sites, predominantly on the legs. Semen analyses showed complete azoospermia in 4 patients, with elevated follicle-stimulating hormone (FSH) in 3 and elevated luteinizing hormone (LH) in 2 of them. One patient had severe oligozoospermia of 7 million sperm per mL, with normal sperm motility and morphology; his FSH and LH levels were elevated. One patient had complete normozoospermia, and the seventh patient had polyzoospermia of 340 million per mL; both of these patients had normal serum hormone levels. Only the patient with oligozoospermia reported a history of delayed testicular descent; his physical examination showed relatively soft and small testicles and a varicocele with considerable reflux. The physical andrological examinations were normal in the other 6 patients. It is very likely that the azoospermia in the 4 patients can be attributed to the radiation accident. In conclusion, it is essential to perform andrological examinations in patients who have been exposed to radiation even if there are only cutaneous injuries detectable, as a high percentage of them can show azoospermia.

Adult↗

Detection of cutaneous varicella zoster virus infections by immunofluorescence versus PCR.

Detection of localized, clinically atypical cutaneous infections with varicella zoster virus (VZV) has proven difficult, as serum antibody tests sometimes are not sensitive and specific enough for that purpose. Therefore immunofluorescence and an internally controlled PCR for VZV are compared for sensitivity. Detection of PCR products was done by ELISA, and if positive, additionally by agarose gel electrophoresis. Of 60 samples 44 were PCR-positive by ELISA (44 = 100%), of which 37 (84%) were also positive on the agarose gel. Thirty-four samples (77%) were positive by immunofluorescence. No sample was positive by immunofluorescence and negative by PCR. A combination of immunofluorescence and PCR with agarose gel analysis detected 42 samples out of 44 positive by PCR ELISA (95%). These results demonstrate that immunofluorescence is a suitable, fast and inexpensive method for routine diagnostics. Additional sensitivity can be achieved by screening immunofluorescence-negative samples by PCR, which is extremely sensitive but time-consuming and labor-intensive.

Antigens, Viral↗

Soluble p185/her2 and S100 in yolk sac blood from human melanoma metastases xenotransplanted to chick embryo chorioallantoic membrane.

BACKGROUND: The chorionallantoic membrane (CAM) of the chick embryo has been used as an experimental model for studying tumor invasion and metastasis of human malignant melanoma. In search for a model to show graft-host-interactions in vivo, tumor markers in peripheral blood of the host were investigated. MATERIALS AND METHODS: Before collecting melanoma metastasis xenografts, blood samples were taken from CAM and a control group. S100 and sp185/her2 in peripheral blood were evaluated in a blinded manner. RESULTS: 23/28 samples deriving from successfully performed human melanoma metastasis CAM xenografts were positive for S100 versus 2/22 samples for sp185/her2. CONCLUSION: Regarding melanoma, in this model sp185/her2 gave no additional information. S100 levels corresponded to clinical and immunohistological findings concerning adherence of tumors and extravasation of human melanoma cells. Based on these data S100 levels in the peripheral blood could help to determine the effect of exogenous stimuli such as radiation and therapeutic agents on metastatisation of the xenografts.

Animals↗

S100 beta is a more reliable tumor marker in peripheral blood for patients with newly occurred melanoma metastases compared with MIA, albumin and lactate-dehydrogenase.

Lactate-dehydroxynase (LDH) has been described as a leading blood parameter in patients with melanoma metastases. However, recent data indicates that levels of S100 as well as melanoma inhibiting activity (MIA) in peripheral blood, correlate with melanoma progression. The aim of this study was to evaluate tumor markers S100, MIA, LDH and albumin in peripheral blood of 373 melanoma patients. 284 patients presented with in-situ or UICC stage I/II, and 89 with stage III/IV (54 tumor-free, 29 with newly occurred metastases). For newly occurred metastases, sensitivity was highest for S100 in peripheral blood (0.86), followed by MIA (0.80), LDH (0.48), and albumin (0.15). Specificity for albumin (0.99) and LDH (0.98) was higher than for S100 (0.91) and MIA (0.62). This data indicate that S100 in peripheral blood as compared to MIA, LDH and albumin appears to be the most appropriate tumor marker for newly occurred melanoma metastases.

Albumins↗