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Biomedical subjects

Y Guiguen

Publications and source records attributed to Y Guiguen.

28 records · Page 2Linked to original sources
PubMed1996

[Human papillomavirus 6/11 in conjunctival papilloma].

INTRODUCTION: Human papilloma virus is highly prevalent, but rarely localized in the conjunctiva. CASE REPORT: A 19-year-old man with no past history of skin or mucosal disease consulted for tumefaction of the conjunctiva. Exeresis revealed a viral papilloma. In situ hybridization was positive for human papilloma virus 6/11. DISCUSSION: Conjunctival lesions of human papilloma virus are often located in the caroncula as in our patient. The papillomatous aspect of the tumour may suggest squamous cell carcinoma (sometimes induced by human papillomavirus 16/18). Contamination may be manual or occur at birth via the maternal genital mucosa. Treatment usually is based on wide exeresis with cryo-application although spontaneous regression is possible.

Adult↗
PubMed1995

Gonadal in vitro androstenedione metabolism and changes in some plasma and gonadal steroid hormones during sex inversion of the protandrous sea bass, Lates calcarifer.

Steroidogenesis in the gonad of the protandrous sea bass, Lates calcarifer, was examined in vitro in spermiating testis, previtellogenic ovary, and transitional gonads. Gonadal tissues were incubated with tritiated androstenedione. Metabolites were analyzed by thin-layer chromatography, high-performance liquid chromatography, microchemical reactions, and crystallization to constant specific activity. 17 beta-Hydroxysteroid dehydrogenase, 5 beta-reductase, and 3 alpha-hydroxysteroid dehydrogenase activities were found in all of the sex types. On the other hand, 11 beta-hydroxysteroid dehydrogenase and 11 beta-hydroxylase activities were found only when testicular tissue was present, i.e., in testis and early transitional gonad. A low aromatase activity leading to estrone synthesis was detected in the previtellogenic ovary. In late transitional gonads, a major metabolite (metabolite X) was suggestively identified as a 3-ester of 17 beta-estradiol according to its chemical and immunological characteristics. Levels of 17 beta-estradiol (E2), the metabolite X, testosterone (T), and 11-ketotestosterone (11KT) were also measured by radioimmunoassay in plasma, before (January and February) and during (March and April) the sex inversion process. Plasma E2 was virtually undetectable (means below 25 pg/ml), although higher levels of metabolite X were found in transitional fish (485 +/- 432 pg/ml in March). Throughout this period, plasma levels of T and 11KT and the androgens/estrogens ratio were significantly higher in males than in transitional fish, where these levels decreased during the sex inversion period. The level of in vitro synthesis of metabolite X was high in transitional gonads, but their concentrations were very low (0.07 +/- 0.09 ng of equivalent E2/g in transitional gonads against 0.22 +/- 0.37 ng of equivalent E2/g in testes and 2.16 +/- 2.7 ng of equivalent E2/g in ovaries).

11-beta-Hydroxysteroid Dehydrogenases↗
PubMed1995

T-->A transversion 11 bp from a splice acceptor site in the human gene for steroidogenic acute regulatory protein causes congenital lipoid adrenal hyperplasia.

Congenial lipoid adrenal hyperplasia (lipoid CAH) is the most severe form of CAH. Affected individuals can make no adrenal or gonadal steroids. All affected individuals are phenotypic females irrespective of gonadal sex, and frequently die in infancy if mineralocorticoid and glucocorticoid replacements are not instituted. Recent data implicate the steroidogenic acute regulatory (StAR) protein in this disorder. We now describe a 46,XY patient of Vietnamese ancestry with lipoid CAH who had a somewhat milder form of the disease. Diagnosis was at 10 weeks of age, and low levels of plasma progesterone, corticosterone, 180H-corticosterone and androstenedione were detectable. Testicular RNA for StAR was reverse transcribed, amplified, cloned and sequenced, revealing a 185 bp deletion corresponding to all of exon 5. The corresponding mRNA did not encode active protein in transfected cells. Cloned genomic DNA from the patient revealed only a T-->A transversion in intron 4,11 bp from the splice acceptor site of exon 5. This transversion destroys an NcoI site; digestion of PCR-amplified genomic DNA from the patient and both parents confirmed that the patient was homozygous and the parents were heterozygous. Expression vectors for StAR minigenes were constructed containing all StAR exons plus introns 4, 5 and 6 either with or without the T-->A mutation in intron 4. RNase protection assays showed that expression of the vector with normal intron 4 yielded correctly spliced StAR mRNA in transfected COS-1 cells, while most, but not all StAR mRNA from the vector with the T-->A transversion in intron 4 was abnormally spliced. RNase protection of the patient's testicular RNA confirmed that most, but not all StAR mRNA was similarly spliced abnormally. Splicing errors appear to be a rare cause of genetic diseases, but subtle intronic mutations may be missed when genomic DNA is the only material available for study. The low level of normal StAR mRNA produced may account for the later clinical presentation and low levels of steroid hormones detected in this patient.

Adrenal Hyperplasia, Congenital↗
PubMed1993

Changes in plasma and gonadal steroid hormones in relation to the reproductive cycle and the sex inversion process in the protandrous seabass, Lates calcarifer.

Plasma and gonadal levels of several gonadal steroids (testosterone, 11-ketotestosterone, androstenedione, 11 beta-hydroxyandrostenedione, 17 beta-estradiol, and estrone) were measured by RIA in the protandrous seabass, Lates calcarifer, throughout an annual reproductive cycle. Twenty to 25 fish were killed every month for gonadal and plasma sampling. Very low plasma levels of 11-ketotestosterone in females (monthly means always less than 75 pg/ml), and of 17 beta-estradiol (means always less than 68 pg/ml) and estrone (means always less than 42 pg/ml) in males did not fluctuate significantly during the cycle. Conversely, plasma concentrations of testosterone, estrone, and 17 beta-estradiol peaked during vitellogenesis in females (highest mean: 182 +/- 121, 182 +/- 32 and 598 +/- 369 pg/ml, respectively) and testosterone and 11-ketotestosterone peaked during spermiation in males (highest mean: 189 +/- 91 and 223 +/- 94 pg/ml, respectively). When sex type are compared over the whole cycle, females displayed higher 17 beta-estradiol (172 +/- 233.5 pg/ml) and estrone (79.5 +/- 72 pg/ml) levels than males (57 +/- 7.5 and 44 +/- 62.5 pg/ml, respectively), while males had higher 11-ketotestosterone levels (153 +/- 88 pg/ml) and, to a lesser extent, higher testosterone levels (128 +/- 82 pg/ml) than females (51.5 +/- 28 and 91.5 +/- 60 pg/ml, respectively). Transitional fish always exhibit low plasma levels for these four steroids (testosterone 56.5 +/- 12.5 pg/ml, 11-ketotestosterone 59 +/- 23.5 pg/ml, 17 beta-estradiol 65.6 +/- 36 pg/ml, and estrone 61 +/- 47.5 pg/ml). Among gonadal androgens, 11 beta-hydroxyandrostenedione predominated in testes (3.95 +/- 3 ng/g), except during spermiation (0.8 +/- 0.5 ng/g), and remained low in ovaries (1.05 +/- 1.4 ng/g). No differences were detected in gonads, for testosterone and 11-ketotestosterone whatever the sex type, but their concentrations were higher in vitellogenic and atretic ovaries. Androstenedione levels were slightly higher in testes (2.21 +/- 2 ng/g) than in ovaries (1.53 +/- 1.32 ng/g). Transitional gonads always showed low concentrations for these four androgens (testosterone 0.66 +/- 1.77 ng/g, 11-ketotestosterone 0.14 +/- 0.05 ng/g, androstenedione 0.3 +/- 0.34 ng/g, and 11 beta-hydroxyandrostenedione 0.2 +/- 0.23 ng/g). Gonadal 17 beta-estradiol was nearly undetectable in testes (0.06 +/- 0.07 ng/g), low in ovaries (0.42 +/- 0.46 ng/g), and strikingly high in transitional gonads (2.89 +/- 1.64 ng/g) even at the very beginning of sex inversion. This suggests an important role for this estrogen in the protandrous sex inversion process in the seabass L. calcarifer.

Animals↗
PubMed1992

Malignant melanoma and hairy cell leukemia. Two cases.

The authors report two cases of malignant melanoma associated with hairy cell leukemia. Skin neoplasia preceded hematological malignancy in the first observation. Among reports concerning the association of malignant melanoma with hematological diseases, chronic lymphocytic leukemia, Hodgkin's lymphoma and non Hodgkin's lymphoma are preponderant. Epidemiological studies would be of value to predict the expected risk of malignant melanoma in hairy cell leukemia.

Adult↗
PubMedDate not supplied

Cloning of zebrafish cDNA for 3beta-hydroxysteroid dehydrogenase and P450scc.

P450scc and 3beta-HSD cDNA were isolated from a zebrafish lambda gt10 cDNA library using trout SCC and 3beta-HSD cDNA as the probes. The zebrafish SCC cDNA encodes a protein of 509 amino acids, which shares a 78% similarities with the trout SCC and 58% with the human SCC. As for 3beta-HSD, two forms of cDNA were isolated, termed HSD 5 and HSD 17, which may have resulted from alternative splicing. HSD 5 and HSD 17 encode proteins of 374 and 341 amino acids respectively. Both share 77% amino acid similarities with trout 3beta-HSD and 53% similarities with the mouse 3beta-HSD. Zebrafish has been increasingly used as a genetic model system to study organ development and to investigate human diseases. The cloning and the characterization of zebrafish P450scc and 3beta-HSD should facilitate study of steroidogenesis and human disease associated with steroid imbalance.

3-Hydroxysteroid Dehydrogenases↗
PubMedDate not supplied

[Erysipelas in the young population of a military hospital].

INTRODUCTION: Erysipelas usually affects either elderly patients or patients with predisposing factors. We studied erysipelas in a young healthy military population. SUBJECTS AND METHODS: A retrospective study of patients, less than 30 years old, admitted to the Hôpital d'Instruction des Armées Robert Picqué between 1991 and 1997 was performed. RESULTS: Eighty-one patients were studied, 80 were men, mean age was 21.4 years. Localization of erysipelas was: face: 2; leg: 74. Facilitating factors were: portal of entry in 100 p. 100; venous insufficiency in 1 case; alcohol abuse in 1 case. Anti-inflammatory agents had been given at the beginning of treatment in 32.1 p. 100 cases. 7.1 p. 100 patients had a recurrence.. Complications were: abscess in 8 cases and bursitis in 1 case. No facilitating factor was detected. The course was not related with bacterial findings. No thrombo-embolic complication was observed. DISCUSSION: In a young healthy population, erysipelas is not a rare infection. Face is an exceptional localization of erysipelas in relation to older population. The main risk factor for developing this infection is local factor found in 100 p. 100 cases but general factors as repeated hikes, care access, long standing could also be incriminated. Use of anti-inflammatory agents is frequent but role of anti-inflammatory agents in developing complications is not clear. Complications are rare and benign except for frequence of recurrences while the good health.

Abscess↗