Hyperhomocysteinemia and low B vitamin levels are independently associated with venous thromboembolism: results from the EDITH study: a hospital-based case-control study.

BACKGROUND: Moderate hyperhomocysteinemia and B vitamins deficiency are thought to be risk factors for venous thromboembolism (VTE). The causality and independence of those associations are still questioned. METHODS: We measured fasting serum total homocysteine, folates, and vitamin B12 levels as well as 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T genotypes in 467 patients hospitalized with a first well-documented deep vein thrombosis and/or pulmonary embolism not related to a major acquired risk factor and 467 controls matched for gender and age. RESULTS: Mild hyperhomocysteinemia, low serum folates, and vitamin B12 were associated with VTE independently of each other. In multivariate analysis, odds ratios (OR) (95% CI) for VTE associated with mild hyperhomocysteinemia (>15 micromol L(-1)), low serum folates (< or = 4.9 nmol L(-1)), and vitamin B12 (< or = 253 pmol L(-1)) were 1.48 (1.05-2.08), 3.14 (1.35-7.32) and 1.42 (1.03-1.98), respectively. An MTHFRC677T genotype was not significantly associated with VTE; OR (95% CI): 1.13 (0.70-1.81) CONCLUSIONS: The current data provides further knowledge in the complex relationship between hyperhomocysteinemia, low vitamin levels, and VTE.

Ontogeny of steroid metabolizing enzymes in rat oligodendrocytes.

Rat oligodendroglial cells were isolated from newborn and developing brains and used immediately after, for quantification of steroid metabolizing activities. Oligodendrocytes (Ol) and their progenitor cells were incubated with [(14)C] testosterone, [(14)C] progesterone, [(14)C] pregnenolone or [(14)C] dehydroepiandrosterone (DHEA). Oligodendrocytes and their progenitor cells expressed different steroid metabolizing enzymes. The main activities were 5 alpha reduction of testosterone and progesterone and 3 beta hydroxy steroid dehydrogenase-isomerase which transformed pregnenolone into progesterone and DHEA into Delta 4 androstenedione. 5 alpha reductase activity increased in male and female rats in parallel with testosterone or progesterone. Contrary to this, 3 beta hydroxysteroid dehydrogenase-isomerase activity was found to be high in the young rat and to decrease when testosterone and progesterone plasma concentration increased.

Methylenetetrahydrofolate reductase C677T genotype and venous thromboembolic disease.

BACKGROUND: Many studies have suggested an increased risk of venous thromboembolism (VTE) in patients with mild hyperhomocysteinemia. The C677T mutation in the MTHFR gene has recently been described as a cause of mild hyperhomocysteinemia. OBJECTIVES: To investigate the potential of the C677T mutation in the MTHFR gene in its homozygous state as a risk factor for VTE. METHODS: Case-control study design. The presence of the mutation was determined in all consecutive patients referred from July 1994 to September 1997 and in whom the diagnosis was duly confirmed. Analysis was carried out in a subgroup of VTE patients free from both acquired and genetic risk factors (factor-V mutation and/or prothrombin gene mutation). A control group consisted of 105 volunteer blood donors. RESULTS: In the 366 patients with a confirmed VTE, 253 presented acquired risk factors and 58 were carriers of the factor-V Leiden mutation and/or G20210A mutation of the prothrombin gene. In the remaining 55 patients, VTE was considered as 'unexplained', and the frequency of the C677T mutation MTHFR was 21.8% in its homozygous state and 34.5% in its heterozygous state. In the control group, 9.5% were found homozygous and 34.3% heterozygous. The odds ratio for having VTE in the presence of the mutation in its homozygous state was 2.9 (95% CI 1. 0-8.6). CONCLUSION: This study suggests that the homozygous C677T mutation in the MTHFR gene might be a risk factor of VTE in patients with spontaneous events and without other common genetic risk factors.

Levels of collagen degradation products (telopeptides) in the tear film of patients with keratoconus.

PURPOSE: Levels of collagen degradation products (telopeptides) in the tear film of patients with keratoconus were measured to study the release of telopeptides in the tears. METHODS: Tear samples were collected from 26 keratoconus patients and 36 age-similar human control subjects. Levels of telopeptides were quantified and compared between the two groups. RESULTS: The telopeptide level in tears from keratoconus patients was 2.5-fold higher than in tears from the control group. The telopeptide concentration was age-dependent in both groups. In tears from young people, telopeptide level was 2-fold higher than in tears from the older people. CONCLUSION: The tear film of patients with keratoconus contains higher levels of telopeptides than those of control subjects. Determination of telopeptide levels in tears could be useful for the follow-up of keratoconus development in patients.

Cloning, sequencing and expression of Pseudomonas testosteroni gene encoding 3 alpha-hydroxysteroid dehydrogenase.

We describe the cloning, sequencing and expression of the 3 alpha-hydroxysteroid dehydrogenase (3 alpha-HSD) gene of Pseudomonas testosteroni. A genomic library of P. testosteroni total DNA constructed from SauIIIA digests ligated to an lambda gt11 vector was probed with a polyclonal antibody raised against purified enzyme. Subclones derived from a recombinant phage containing a 1746 bp insert were sequenced and found to contain an open reading frame of 696 bp that corresponds to a protein of 231 amino acid residues. A search for homologous proteins was performed. No similarity was observed when comparing 3 alpha-HSD with known members of the short-chain dehydrogenase family. However a small proteic fragment (80 amino acids) shows homology with the N-terminal sequence of bacterial L7/L12 ribosomal proteins.

Gene amplifications in advanced-stage human prostate cancer.

Gene amplification is a model of proto-oncogene alterations occasionally observed in human tumors. This amplification can, in some cases, have prognostic value (N-myc in neuroblastoma, c-erbB2 and int-2 in breast cancer, etc.). Amplifications of the proto-oncogenes c-myc, c-erbB2 and int-2 have not yet been report in prostate adenocarcinoma, which, like breast cancer, is hormone dependent. We sought amplifications of these three proto-oncogenes by means of Southern blotting in 15 human prostate adenocarcinoma specimens, most of which were advanced (7 stage C and 6 stage D1 or D2). We confirmed the lack of c-myc and c-erbB2 amplification, regardless of the stage, in contrast to the case of breast cancer. Int-2 amplification was observed in one advanced tumor with bone metastases, out of a total of six stage D tumors. The precise frequency of int-2 amplification and its role in prostate carcinogenesis remain to be determined.

[Cloning of genes coding for 3-alpha-hydroxysteroid dehydrogenase and for (3-17)-beta-hydroxysteroid dehydrogenase from Pseudomonas testosteroni]. / Clonage des gènes codant pour la 3 alpha-hydroxystéroïde déshydrogénase et pour la (3-17)beta-hydroxystéroïde déshydrogénase de Pseudomonas testosteroni.

A genomic library of Pseudomonas testosteroi total DNA constructed from SauIIIA digests ligated to a lambda gt11 vector was probed with different polyclonal antibodies raised against purified 3 alpha-HSD and (3 beta-17 beta)-HSD. Two different clones reacting with one antibody were selected. The clone reacting with (3-17)beta-HSD antibody contained a 2,661-base pair insert and was found to contained an open reading frame of 765 base pair that corresponds to a protein of 254 amino-acid residues. A 1,492-base pair was inserte in pBR 322 plasmid vector; the recombinant bacterie over expressed the (3-17)beta-HSD gene. The clone reacting with 3 alpha-HSD antibody contained a 1746 base pair insert which contained an open reading frame of 696 base pairs that corresponds to a protein of 231 amino-acid residues. A search for homologous proteins was performed. Distant similarities were found between (3-17)beta-HSD and members of the short-chain alcool dehydrogenase (SCAD) family but no similarity was observed between 3 alpha-HSD and proteins of this family.

Purification of testosterone 5 alpha-reductase from human prostate by a four-step chromatographic procedure.

Nuclear membrane bound testosterone 5 alpha-reductase solubilized in active form from human prostatic tissue by 0.5% n-octyl beta-D-glucopyranoside was purified by a four-step chromatographic procedure including DEAE-Trisacryl ion exchange, hydroxylapatite adsorption, testosterone-Sepharose affinity and Sepharose 4B gel filtration. A purification of approximately 30-fold was achieved judging from the increase in the specific enzymatic activity. We have purified the acidic pH-optimum 5 alpha-reductase type 2 isoenzyme. The apparent molecular weight of the purified enzyme was estimated as 42,000 by SDS-PAGE. At the same time we isolated a 38 kDa protein characterized by a real affinity for testosterone and by a possible association to the 5 alpha-reductase enzyme.

Glycosylated nature of testosterone 5 alpha-reductase 2 purified from human prostate.

5 alpha-reductase 2 from human prostate solubilized into an active and stable form using a non-ionic detergent octyl glucoside was successfully purified using a four-step chromatographic procedure. The enzyme was obtained as an apparently homogeneous protein exhibiting an apparent molecular weight of 42 kDa upon SDS-PAGE. Con A, DBA, UEA-I, and RCA60 lectins recognized this protein. After treatment with O-glycosidase and neuraminidase, a protein of an apparent molecular weight about 30 kDa appeared. On the other hand, N-glycosidase treatment of this enzyme had no effect. These results indicate that the human prostate testosterone 5 alpha-reductase 2 is an O-glycosylated sialoglycoprotein with a peptide moiety of about 30 kDa; the oligosaccharide side chains contain mannose, N-acetyl galactosamine, fucose, galactose and sialic acids.

Characterization and solubilization of testosterone 17 beta-hydroxysteroid dehydrogenase in human hyperplastic prostate.

17 beta-Hydroxysteroid dehydrogenase is a membrane-bound enzyme in human prostate. Solubilization of this enzyme can only be obtained in the presence of detergents. The optimal solubilization mixture contained 50 mM Tris-HCl buffer pH 9.0, 20% glycerol, 0.1 M KCl and 5 mg/ml of the non-ionic detergent N-octyl glucoside. In these conditions, the soluble fraction contained more than 90% of the enzymatic activity. A 2.5-fold increase of specific activity was obtained during solubilization under optimal conditions.

Cloning, DNA sequencing and expression of (3-17)beta hydroxysteroid dehydrogenase from Pseudomonas testosteroni.

We describe the cloning, sequencing and overexpression of the (3-17)beta hydroxysteroid dehydrogenase gene of Pseudomonas testosteroni. A genomic library of Ps. testosteroni total DNA constructed from SauIIIA digests ligated to a lambda gt11 vector was probed with polyclonal antibody raised against purified enzyme. Subclones derived from a recombinant phage containing a 2661-base-pair insert were sequenced and found to contain an open reading frame of 765 base pairs that corresponds to a protein of 254 amino acid residues. A 1492-base-pair fragment was inserted into pBR322 plasmid vector and used to construct a strain of E. coli HB101 that overexpressed the steroid dehydrogenase gene.

Oestrogen secreting Leydig cell tumour and GnRH agonist in-vivo and in-vitro studies.

OBJECTIVE: The purposes of our study concerning two patients with oestrogen secreting Leydig cell tumour were to determine whether endogenous LH levels are involved in testicular tumour steroidogenesis and whether aromatase activity of oestrogen secreting Leydig cell tumours is directly or indirectly dependent on LH levels. MEASUREMENTS: E2 and T were evaluated after hCG injection (5000 IU) during 96 hours. Bio and immuno LH, T, E2, were determined at the basal state and after administration of D-Trp-6-GnRH agonist (3.75 mg) every 3 weeks. The abnormal testis was removed after the third injection and testicular venous blood was collected during the operation. Testicular tumour was incubated with 4-14C-T. RESULTS: Oestradiol (E2) response to hCG injection (5000 IU) was prolonged and exaggerated while that of testosterone (T) was similar to that of the controls. The aromatase index (E2/T) remained elevated even 96 hours after hCG. Intramuscular injection of the GnRH agonist, D-Trp-6-GnRH (3.75 mg) resulted in a reduction of immunoreactive and bioactive LH. T was decreased to about 10% of baseline levels and E2 fell from 240 to 36 pmol/l. In the blood of the spermatic veins collected in the course of surgery, E2 levels were found to be lower in comparison with the controls. E2 was found to be twofold higher in the spermatic vein draining the tumoral side than in that of the contralateral testis. Incubation of the testicular tumours with 4-14C-T, displayed a reduced aromatase activity (conversion of T to E2: 0.3 and 0.1% in patients 1 and 2 respectively). CONCLUSIONS: The kinetics of E2 response to hCG administration would suggest a modification of the regulation of the aromatase activity in this type of oestrogen secreting tumour. A certain endogenous LH level may be necessary to supply a sufficient quantity of T substrate, and to maintain aromatase activity of such Leydig cell tumours secreting oestrogens. These tumours seem to be responsive to endogenous LH levels.

Partial purification of 3 alpha- and 3 beta-hydroxysteroid dehydrogenases from human hyperplastic prostate. Comparison between the two enzymes.

3 alpha-Hydroxysteroid dehydrogenase (3 alpha-HSD) activity has been purified to homogeneity, the enzyme is a monomer with a Mw of 32,000 Da. 3 beta-Hydroxysteroid dehydrogenase (3 beta-HSD) activity has been partially purified and has an apparent Mw of 30,000 Da. Both enzymes have the same cofactor requirements, optimal pH. However, 3 beta-HSD appeared to be an integral protein dependent on protein environment for its activity while 3 alpha-HSD activity is a protein more loosely associated to membranes.

Unusually high rates of metabolism of DHT in cytosols of the quail uropygial gland.

The metabolism of DHT in the cytosol of the quail uropygial gland was found to be so high that the steroid was almost completely inactivated within 2 hours of incubation at 0 C. In these conditions, DHT cannot be used for the characterization of androgen receptors. By contrast, R 1881 and mibolerone, which are not metabolized, can be used as alternative ligands. Moreover, the extremely high metabolism of DHT questions the physiologic role of this steroid in the quail uropygial gland.

Metabolism of androgens in human hyperplastic prostate: evidence for a differential localization of the enzymes involved in the metabolism.

The subcellular distribution of 5 alpha-reductase, 17 beta-hydroxy steroid dehydrogenase, 3 alpha- and 3 beta-hydroxysteroid dehydrogenase activities was studied in human hyperplastic prostate. 5 alpha-reductase and 17 beta-hydroxysteroid dehydrogenase activities are located in the nuclear envelope. 3 alpha-hydroxysteroid dehydrogenase activity was almost equally distributed between cytosol and membranes, 3 beta-hydroxysteroid dehydrogenase activity was linked to all membranes. Direct testosterone metabolism (transformation into its active metabolite 5 alpha-DHT and into androstenedione, an inactive androgen) takes place only in the nucleus whereas indirect metabolism takes place mainly in the cytoplasm. These findings add new evidence for the mechanism of action of testosterone in prostatic tissue. Testosterone diffuses into the cell, migrates toward the nucleus and is transformed at the nuclear envelope level into two metabolites, DHT and androstenedione. After transformation into its active form, the hormone enters the nucleus whereas the inactive form is released into the cytoplasm. This metabolism could be seen as a control of the amount of active hormone entering the nucleus and being able to bind the androgen receptor.

Androgen regulation of the androgen receptor of the quail uropygial gland: application of a [3H]mibolerone exchange assay.

An exchange assay for androgen receptors in the quail uropygial gland using [3H]mibolerone was established. The most efficient exchange conditions were 3 days of incubation at 15 degrees C. Under these conditions, androgen receptors were stable in the presence of sodium molybdate, and the exchange of [3H]mibolerone with endogenous testosterone bound to cytosolic or nuclear androgen receptors was maximal. Less than 5% of [3H]mibolerone-binding sites occurred in the extracted nuclear pellets. Using this exchange technique, it was shown that androgen receptors in the uropygial gland of photostimulated male quail or castrated quail treated with testosterone were activated and that their concentrations in both cytosolic and nuclear fractions were increased. These results confirm the androgen dependency of the quail uropygial gland, and show that it is an organ which can be used as a model for the study of androgen action in sebaceous glands.

[Sensitivity to various antibiotics of spiroplasmas isolated from mosquitoes in France]. / Sensibilité à divers antibiotiques de six souches de spiroplasmes isolés de moustiques en France.

Spiroplasmas are helical mycoplasmas that play a significant role in plant diseases. They are also found in arthropods that are likely to bite humans, such as ticks and mosquitoes. These arthropods can act as vectors and therefore may be of epidemiologic significance. Furthermore, mainly on the grounds of morphologic evidence, spiroplasmas have been incriminated in the genesis of human Creutzfeld-Jacob disease. We recovered six strains of Spiroplasma sp. from 1927 female mosquitoes. In vitro susceptibility of each strain to the following antibiotics was studied: tetracycline, oxytetracycline, doxycycline, erythromycin, chloramphenicol, rifampin, kanamycin, gentamicin and pefloxacin. Minimal inhibitory concentrations (MICs) were determined by dilution in liquid SP4 medium using microtiter plates. Plates were incubated for 24 to 48 hours at 30 degrees C. The inoculum contained approximately 5 X 10(5) CFU/ml. Each of the six strains was found to be highly susceptible to tetracycline, oxytetracycline, doxycycline, erythromycin, chloramphenicol and pefloxacin (MICs less than or equal to 0.16 microgram/ml, 0.63 microgram/ml, 0.08 microgram/ml, 0.16 microgram/ml and 0.32 microgram/ml respectively). On the opposite, the strains exhibited resistance to rifampin and variable degrees of susceptibility to kanamycin (12.5 micrograms/ml less than MIC less than 50 micrograms/ml) and gentamicin (3.12 micrograms/ml less than MIC less than 50 micrograms/ml). From our results, spiroplasmas seem to have more or less the same susceptibility to antibiotics as mycoplasmas.

Testosterone regulation of androgen receptor levels in the uropygial gland of quails (Coturnix coturnix): a further proof for the androgen dependency of the uropygial gland.

In castrated quails supplemented with testosterone by a chronically implanted silastic capsule, removal of the implant resulted in the gradual disappearance of the androgen receptors in both cloacal and uropygial glands. However, after a 7-day time span, the receptors reappeared in both glands but did not reach the original level of implanted birds. On the other hand, the photostimulation of intact birds induced an increase of the receptor content of their uropygial and cloacal glands when compared to sexually quiescent birds. These results show that, the concentration of the androgen receptors of the uropygial and cloacal glands of adult male quails is partly controlled by testosterone. By comparison with the mechanism of the action of testosterone in mammal target organs, our results add weight to the androgen dependency of quails uropygial glands (a sebaceous like organ).

Ultrastructural changes in the uropygial gland of the male Japanese quail, Coturnix coturnix, after testosterone treatment. Comparison with the sebaceous gland of the male rat.

The ultrastructure of the uropygial gland of the male quail was compared to that of the sebaceous gland of the male rat after castration and testosterone treatment of both species. In intact animals, the differentiating cells of these glands displayed almost the same pattern as regards their smooth endoplasmic reticulum, an organelle involved in lipogenesis in both cases. Castration reduced the volume of this organelle, while testosterone administration restored cell morphology to a normal or supranormal level. Finally, this study showed that at ultrastructural level, there is a close functional analogy between the uropygial gland of quail and the sebaceous glands of rats as regards their androgen dependency. Consequently, the uropygial gland might be an attractive model for study of action of androgens on sebaceous-like glands.