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Biomedical subjects

M Chalet

Publications and source records attributed to M Chalet.

At least 19 recordsLinked to original sources
PubMed1997

Cytomegalovirus detection in cryopreserved semen samples collected for therapeutic donor insemination.

The presence of cytomegalovirus (CMV) in semen was retrospectively evaluated in 178 cryopreserved semen samples obtained from 97 donors recruited by two sperm banks. Thirty-three (34.0%) donors were CMV-seronegative, 51 (52.6%) were CMV-seropositive and 13 (13.4%) had an unknown serological status. CMV was detected in sperm specimens by cell culture and polymerase chain reaction (PCR). CMV was detected in five (2.8%) samples from two (2.0%) donors by cell culture and in 10 samples (5.6%) from five donors (5.1%) by PCR; all the samples which were positive by cell culture were also positive by PCR. Our data indicate that cryopreserved semen specimens obtained from healthy volunteer donors represent a potential source of CMV infection through therapeutic donor insemination. PCR, which is more sensitive than cell culture, should be used for direct and rapid identification of CMV in semen samples collected from volunteer donors. CMV detection in semen by PCR could be advantageously compared to CMV-antibody tests in serum which are only indicative of a former CMV infection.

Adult↗
PubMed1995

Infraorbital pigmented skin. Preliminary observations of laser therapy.

BACKGROUND: The presence of infraobital dark skin, often known as dark circles under the eyes, is a frequent cosmetic concern. There has been little reported on therapy of this condition. One group of patients was determined to have dermal melanin deposition, which we treated with a Q-switched ruby laser. OBJECTIVE: Our study evaluated the clinical and histological appearance of infraobital skin pigment in 17 patients with dermal melanin deposition treated with a Q-switched ruby laser. METHODS: Seventeen patients with melanin deposition were treated with the Q-switched ruby laser (694 nm) with a pulse width of 28 nanoseconds and fluences of 7.5 J/cm2. Response to treatment was assessed by an independent investigator with patient and photograph evaluation. Skin Biopsies were obtained in nine of the 17 patients. RESULTS: Of those patients treated with one Q-switched ruby session, 23.5% achieved a greater than 50% response. Of those treated twice, 88.9% achieved greater than 50% response. In postreatment skin biopsies there was reduction of dermal melanin deposition. CONCLUSIONS: Patients with infraobital pigmented skin due to dermal melanin deposition may be considered candidates for Q-switched Ruby laser treatment.

Adult↗
PubMed1993

Nevus of Ota: treatment with high energy fluences of the Q-switched ruby laser.

BACKGROUND: The nevus of Ota is a benign dermal melanocytic lesion that has previously proved difficult to treat. Recently, the Q-switched ruby laser has been reported to be successful in treating benign pigmented lesions and tattoos. OBJECTIVE: Our study evaluates the treatment of 16 patients with nevus of Ota with the Q-switched ruby laser (694 nm). METHODS: Sixteen patients with nevus of Ota were treated with the Q-switched ruby laser with a pulse width of 28 nsec and energy fluences ranging from 7.5 to 10 J/cm2. Response to treatment was assessed by an independent investigator with photographs. RESULTS: The average number of treatments was 3.8 per patient. After two treatments, 44% of patients showed a 50% or greater improvement. After three treatments, 85% of patients showed a 50% or greater improvement; after four treatments, 100% of patients showed 50% or greater improvement. No patients had permanent textural changes or scarring. CONCLUSION: High-energy fluences of the Q-switched ruby laser lead to significant improvement without scarring of nevus of Ota after a few treatments.

Adolescent↗
PubMed1992

[Cytochemical ultrastructural study of adenosine 5'monophosphate hydrolysis in human spermatozoa].

A specific 5'nucleotidase activity (pH 7.4) is localized by cytochemical technics, in the head (nuclear membrane, periacrosomal cytoplasm) and in the mitochondrial membrane of human spermatozoa. The effect of different effectors (manganese, nickel, fluoride, tartrate, tetramisole), studied in the head by rate assessment of cells with or without hydrolysis sites, changes the cellular distribution, the depth of reactions and their localization. The 5'nucleotidase interferences with some unspecific phosphatases are discussed.

5'-Nucleotidase↗
PubMed1986

[Subcutaneous grafts of fresh or cryopreserved testis in castrated rats and mice: comparison of the histologic aspects of the grafts].

In the castrated rat, only testis taken in one to two week-old donors observed three months after sub-cutaneous isograft contain a well developed interstitial tissue and some seminiferous tubules with germinal cells. On the contrary in castrated mice, testicular grafts taken in adult animals show some Leydig cells and degenerating seminiferous tubules. These grafts permit the restoration of androgenic activity in previously castrated recipients.

Animals↗
PubMed1986

Isolation of Bipolaris australiensis from a lesion of viral vesicular dermatitis on the scalp.

Bipolaris australiensis is recorded as an opportunistic pathogen of humans. The fungus was recovered from a biopsy specimen of skin taken from an area of viral vesicular dermatitis on the scalp. Hyphal elements of B. australiensis were seen in the tissues. The taxonomy of the genera Bipolaris, Drechslera, Exserohilum and Helminthosporium is discussed with particular reference to published case reports.

Aged↗
PubMed1984

[Modification of splenic 5'-nucleotidase activity during proliferative processes in the spleen. Histoenzymatic study in the rat].

In the rat spleen, periarteriolar lymphocyte sheath and the external area of the germinal center in the white pulp and the Billroth's cords in the red pulp possess a strong 5'Nucleotidase activity. During antigenic stimulation a lymphocyte proliferation occurs in the white pulp, while 5'Nucleotidase activity is weak. In the germinal center there is inverse relationship between development of the mitotic internal area and the 5'Nucleotidase external zone. Likewise in the myeloid metaplasia of the red pulp induced by fibrosarcoma development, the 5'Nucleotidase of the Billroth's cords is decreased. 5'Nucleotidase might exert a negative control on cell proliferation probably through adenosine production. On the other hand this enzymatic activity might gave back available nucleosides for cellular proliferation, lymphocytes being especially impermeable to nucleotides.

5'-Nucleotidase↗
PubMed1984

[Effect of an acidic sulfated polysaccharide on whole blood coagulability. In vivo study in rats].

Armatan, an acid sulphated polysaccharide isolated from a red marine seaweed Asparagopsis armata (Harv.), increases the coagulation time of the rat plasma in vivo assays. This property presents, with administration, time and dose, some variations. Among the three ways studied, subcutaneous injection gives more interesting results than the others. At high concentrations (10, 20 and 50 mg/kg), intravenous administration induces plasma and organic (liver-spleen) diseases.

Animals↗
PubMed1983

[Characteristics of the action of an acidic sulfated polysaccharide on global blood coagulation in vitro. Preliminary study in various species of mammals and in man].

An acid sulphated polysaccharide, isolated from a red marine seaweed, Asparagopsis armata ( Harv .), increases the coagulation time of the plasma in vitro studies. This property, compared with the anticoagulant activity of pentosan polysulphate and heparin, pr esents , with concentration and temperature, some variations in man and other mammals . The rat and human plasma seem to behave in the same way with this substance.

Animals↗
PubMed1983

[Survival of motile spermatozoa in a medium based on lactate, glucose and phosphate].

Suspensions of motile human spermatozoa, plasma seminal-free, were incubated several days into synthetic medium (C2) with lactate, glucose and phosphate as principal components. Maintenance of forward motility was compared in C2 medium and in known B2 I.N.R.A. medium. C2 medium entertain survival of motile spermatozoa during some days at 20 degrees C. This method of conservation should allow many homologous artificial inseminations by ovulatory cycle avoiding injurious effects of repeated ejaculations or low-temperature conservation.

Cell Survival↗
PubMed1983

[Effects of a fixed mixture of lactate, glucose and phosphate on the survival of human spermatozoa].

It is admitted that selection of human motile spermatozoa improves chances of conception by homologous artificial insemination. Effect of media constituted by different concentrations of glucose, lactate and phosphate in the maintenance of vitality and forward motility (positively correlated with penetrating capacity) was studied in human spermatozoa after washing. Lactate optimal concentrations appear necessary in the maintenance of progressive motility. The vitality is little affected in the various media. To complete this minimum medium various substances known to improve spermatozoa survival should be added. This complete media should allow to dispose of suitable spermatozoa suspensions during several days permitting many inseminations by cycle.

Cell Survival↗
PubMed1983

Inhibition of ultraviolet-B skin carcinogenesis by all-trans-retinoic acid regimens that inhibit ornithine decarboxylase induction.

There is a correlation between the ability to induce the polyamine-biosynthetic enzyme ornithine decarboxylase (ODC) and the tumor-promoting ability of various carcinogens in mouse epidermis. Some agents which inhibit skin carcinogenesis also inhibit ODC induction. In this study, all-trans-retinoic acid (RA) regimens that inhibited the induction of epidermal ODC by ultraviolet-B (UVB) were tested for their ability to inhibit UVB skin carcinogenesis. Hairless mice were irradiated once daily with UVB for 20 days, receiving a total dose of UVB (17.1 kJ/sq m). Topical RA was applied immediately (RA, one dose) or applied 0, 1, 2, 3, and 4 hr (RA, five doses) after each irradiance. The mice were maintained for 52 weeks and then sacrificed. Groups treated with RA tended to have fewer mice with tumors, fewer tumors per mouse, smaller tumor diameters, and slower growing tumors than did appropriate irradiated control groups. RA given five times was more effective than was RA given one time at inhibiting UVB skin carcinogenesis. These results show that RA treatments that inhibit epidermal ODC induction may be effective in reducing the carcinogenicity of UVB.

Animals↗
PubMed1982

Inhibition of ultraviolet-B epidermal ornithine decarboxylase induction and skin carcinogenesis in hairless mice by topical indomethacin and triamcinolone acetonide.

Modulation of ultraviolet-B (UVB) skin carcinogenesis by topical treatment with two antiinflammatory drugs expected to have different mechanisms of action has been studied in the hairless mouse. Indomethacin is a nonsteroidal antiinflammatory agent which may act by inhibiting prostaglandin biosynthesis. Triamcinolone acetonide is a steroidal antiinflammatory agent. Both of these drugs inhibited the induction of epidermal ornithine decarboxylase by UVB when applied topically in a acetone vehicle. A UVB skin tumor study was designed. Groups of mice were irradiated daily with UVB for 20 days, each mouse receiving a total of 17.1 kJ UVB per sq m. Group 1 was treated with acetone immediately after each irradiation; Group 2 received 700 nmol indomethacin in acetone immediately after each irradiation; Group 3 received 14.4 nmol triamcinolone acetonide in acetone immediately after each irradiation. Mice were killed after 52 weeks, and the tumors were excised and examined histologically. Both topical indomethacin and topical triamcinolone acetonide were effective in reducing the incidence and size of the skin tumors induced by UVB. This evidence supports the hypothesis that the induction of ornithine decarboxylase may be a critical component of UVB skin carcinogenesis and that inhibition of ornithine decarboxylase induction can be used as a screen for agents which will inhibit UVB skin carcinogenesis.

Animals↗
PubMed1982

Psoriasiform dermatosis in a rhesus monkey. Epidermal labeling indexes, polyamines, and histopathologic findings.

We have previously described the clinical and dermatopathologic features of a psoriasiform dermatosis in a rhesus monkey (Macaca mulatta). This animal has been studied further in attempts to characterize its skin disease. Epidermal cell DNA synthesis was measured following the intradermal injection of tritiated thymidine. Epidermal cell labeling indexes in the involved and uninvolved skin of the affected monkey and in the skin of a normal monkey were compared. The labeling indexes in the involved skin were significantly increased as compared with uninvolved skin; they were also significantly higher than in normal skin. Epidermal polyamine assays showed increased epidermal putrescine in involved skin together with increased spermidine and an increased spermidine-spermine ratio compared with uninvolved and normal skin sites.

Animals↗
PubMed1980

[Effects of a polysaccharide extracted from a red alga (Bonnemaisonales) on mononucleate phagocytes in several rodents].

"Armatan" an acidic sulfated polysaccharide isolated from a red algae (Asparagopsis Armata), has a marked affinity for the Mononuclear Phagocytes System. Its activity seems fairly well established. Indeed, it sets off a series of evolutionary cellular processes beginning with an accumulation of monocytes at the inflammatory injection site; these cells are then replaced by macrophages over several weeks which are progressively substituted by fibroblasts, thereby inducing a final fibro-cicatricial reaction. The inductive effect of Armatan in this cellular evolution is discussed.

Animals↗
PubMed1979

[Hematopoiesis and changes in the RES of the spleen pulp in fibrosarcoma-bearing rats].

The transplantable fibrosarcoma of the Rat gives birth to different modifications in the splenic structures, and a strong perturbation is found within the enzymatic activities. The macrophages have an altered acid phosphatase activity. This is in marked contrast to the increase in number of the alkaline phosphatase polymorphonuclear cells, which are originated from myeloid areas in the red pulp. Lymphoïd-reticular cells, possessing one 5'nucleotidase activity, seem to be responsible, possibly, by forming numerous clonal systems during the development of this fibrosarcoma. The role of this separate system is discussed.

5'-Nucleotidase↗