Biomedical subjects
Publications and source records attributed to C Sultan.
In addition to the conventional classification, based on the nature of the gonads, it is possible to compile a physiopathologic classification based instead on the mass of androgens secreted by the fetal testicle, the receptivity of the target tissues and the coexistence of estrogen and androgen secretion.
Cholesterol biosynthesis in cultured human skin fibroblasts was studied by [14C]acetic acid incorporation into non-saponifiable lipids and quantification of labeled cholesterol among its precursors. Synthesis was slow, in spite of a high 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA) activity and led to an accumulation of unexpected non-polar metabolites identified as C-30 sterones, but not C-27 sterol precursors. This supports a post-HMG-CoA regulation at the lanosterol demethylation step. Cholesterol biosynthesis was stimulated by cell culture in lipid depleted medium and was inhibited by pentadecane-2-one which acts mainly at two post-HMG-CoA steps: lanosterol demethylation and lathosterol isomerisation to cholesterol. A parallel pentadecane-2-one inhibition of cell growth was also observed, even when cells were cultured in the presence of whole serum. This indicates the existence of a relationship between endogenous cholesterol synthesis and cell growth and sheds additional light on the role of post-HMG-CoA regulation in this phenomenon.
Some patients present borderline features between acute myeloid leukemia (AML) and typical myelodysplastic syndromes (MDS): an excess of blasts insufficient to conclusively diagnose AML, yet above the figures usually compatible with MDS or the presence of Auer rods associated with a moderate excess of blasts. This presents considerable difficulties in diagnosis and management. The authors studied 28 such cases using the French-American-British Co-operative Group (FAB) classification, which groups them into a separate category termed "refractory anemia with excess of blasts in transformation" (RAEB-T). This was found to be a heterogenous group. Certain patients (4/28) had a previously established myelodysplasia, but most presented directly as RAEB-T. Two very different pictures emerged: a few patients (4/28) were young, with presentation and evolution similar to classic AML, for whom combination chemotherapy was effective; the majority (20/28) were older, with more varied clinical and cytologic presentation, for whom chemotherapy was of little effect and who presented a picture resembling classic RAEB with a median survival of 10 months.
In 90%-hepatectomized rats, the plasma testosterone level (0.34 +/- 0.07 ng.ml, mean +/- SEM) is significantly lower (P less than 0.001) than in sham operated male rats (1.7 +/- 0.26 ng.ml, mean +/- SEM). In dogs, after 90% hepatectomy, the mean plasma testosterone concentration fell to 1/10 of the plasma testosterone level measured in sham operated animals either 24 or 72 h after surgery. In hepatectomized men, plasma testosterone is markedly decreased in contrast to what is observed after duodeno-pancreatectomy performed under the same conditions of anesthesia. These results suggest that 90% hepatectomy severely alters the Leydig cell function.
The development of technical innovations which has taken place during the last 10 years in the medical field, has resulted in a rapid growth of laboratory investigations. The diffusion of these techniques has induced the systemacy in the prescription of certain tests without reconsidering the information they give. The analysis that has been made in Henri Mondor Hospital on the case of the white blood cells differential deals with this question. Has the white blood cells differential to be considered as a systematic test? What are the technological implications at stake? Can we propose strategies in this field for the use of equipment? A study has been made in order to answer these different questions. The study concerns 1514 requests for hematologic tests and 863 patients in order to characterize the prescriptions, to measure their interest and to evaluate their opportuneness. Furthermore, the contribution of decision-making aids in rationalizing the prescriptions has been evaluated in parallel to this study.
The syndrome of isosexual precocious puberty (PP) associated with a primary malignant hepatic tumor is rare and previously reported in only 17 cases with poor prognosis. Twelve cases are well-documented gonadotropin-producing tumors. We here describe a new case of virilizing hepatoblastoma in a 2-year-10-month-old boy with evidence of testosterone (T) production by the tumor itself, and survival with a 3 1/2-year follow-up after an extended right hepatic lobectomy. Preoperative laboratory findings showed high levels of serum alpha-fetoprotein (AFP) and T:350,000 ng/mL and 4.92 ng/mL, respectively, which normalized after surgery. There was no circulating gonadotropin nor stimulation of the hypothalamic-pituitary axis. Testicular biopsy showed neither interstitial-cell maturation nor Leydig-cell hyperplasia. Moreover, demonstration of T secretion by tumor cells and T synthesis in presence of C14 progesterone was performed in an in vitro culture system. These data seem to provide supportive evidence of a T-producing hepatoblastoma.
It has been suggested that rate of estrogen formation was higher in patients with androgen insensitivity syndrome (AIS). This work was designed to find out if peripheral aromatase activity could be related to a defect in androgen action in prepubertal children with male pseudohermaphroditism. Fibroblast estrogen production was assayed by a highly specific enzymatic determination. Foreskin fibroblast strains were raised from 17 children with partial androgen insensitivity (PAIS) as defined by dihydrotestosterone binding activity in cells. Results are expressed as pmol estrogens/mg proteins synthetized/day when cultured fibroblasts are incubated with D4-androstenedione. In normal prepubertal boys (n = 19), aromatase activity ranged between 5 and 10 pmol estrogens/mg proteins/day, while in postpubertal boys it varied between 15 and 34 pmol estrogens/mg proteins/day. In prepubertal boys with PAIS (n = 17) aromatase activity is highly elevated: 19.4 +/- 8.4 pmol/mg proteins/day. These results show that (a) peripheral aromatase activity is low before puberty and (b) fibroblast estrogen synthesis is significantly (p less than 0.001) increased in prepubertal children with PAIS. Our data suggest that low utilization of androgens by target cells stimulates the production of estrogen. Peripheral aromatase activity can thus be considered as a 'marker' of androgen insensitivity in prepubertal children with male pseudohermaphroditism.
For the diagnosis of M7, the bone marrow aspirate shows a leukemic cell infiltrate that comprises 30% or more of all cells. These cells are identified as being of megakaryocyte lineage by the platelet peroxidase reaction on electron microscopy or by tests with monoclonal or polyclonal platelet-specific antibodies. Myelofibrosis or increased bone marrow reticulin are a prominent aspect in most patients with M7. In patients with increased reticulin, the bone marrow sample may be difficult to obtain and the counts done on the marrow films may be misleading. In these patients, the diagnosis of M7 should be based on excellent bone marrow biopsy sections that show an excess of blasts and, at times, increased numbers of maturing megakaryocytes; and on the presence of unequivocal megakaryoblasts in the peripheral blood or bone marrow (or both) as shown by immunologic techniques.
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The new techniques of culture of bone marrow have shown that androgens and 5 beta steroids exert a direct effect on erythroid precursor cells from human or animal bone marrow. By contrast, the mechanisms of the intracellular actions of those compounds are poorly understood. Tritiated methyltrienolone (R 1881), a synthetic androgen that highly binds to androgen receptor, has been used for the study of a binding activity in nuclear extracts of cultured erythroblasts from human bone marrow. The nuclear extracts contain binding sites saturable at low concentrations of 3H-R 1881 (20-30 nM). Scatchard analysis revealed that the R 1881-nuclear complex has a dissociation constant (Kd) of 25-50 nM, and the number of binding sites was 235-370 fmoles/mg protein. The complex sedimented on 5-20% sucrose gradient in the 3.9 S region and 5 beta dihydrotestosterone compete strongly with R 1881 for binding sites. This binding component has characteristics of high affinity, low-capacity, sedimentation behaviour, and specificity commonly attributed to "androgen receptors".
Recent progress in the study of the hormonal regulation of spermatogenesis justifies endocrine examination in the case of male sterility. The most important complementary investigation are the assays of FSH, LH and plasmatic testosterone. Radioimmunoassay of FSH is the fundamental examination, since this hormone is considered to be an indicator of germinal function. Thus, in the case of oligospermia, or even azoospermia, FSH assay is decisive. When the FSH levels (in conjunction with LH levels) are high and combined with azoospermia, there is a possibility of testicular dysgenesis linked with a karyotype anomaly (XXY etc.). In some cases the germinal affection is secondary to cryptorchidism, orchitis, torsion, medicinal alteration, or radiotherapy. Decreased testosterone values combined with an insufficient FSH and LH response to stimulation tests indicate a gonadotrophic deficit, which is the best indication for substitution therapy using gonadotrophins or LH-RH. An increase in LH, contrasting with a normal FSH value, evokes the exceptional case of a disturbance of androgen receptivity. Normal FSH (and LH) values suggest excretory sterility. Lastly, when hyperprolactinemia is suspected, an assay of plasmatic prolactin is necessary. A "simple" hormonal evaluation allows a routine etiological approach to the diagnosis of sterility, and is thus an important element in the investigative strategy applied to male sterility, used along with the other complementary and indispensible examinations.
A macromolecular component which specifically binds tritium-labeled-dihydrotestosterone is present in cultured amniotic fluid cells. The androgen-binding complex is characterized by a 3.6S sedimentation coefficient, an apparent dissociation constant of 1 nmol/L, a mean binding capacity of 243 +/- 140 fmol/mg of DNA, and a specificity for testosterone and dihydrotestosterone. Similar properties have been reported for the androgen receptor of the fetal genital skin fibroblast, which suggests that the tritium-labeled-dihydrotestosterone-binding component in amniotic fluid cells is the androgen receptor. Amniotic fluid cell monolayers incubated with serum-free medium containing testosterone are able to transform testosterone into dihydrotestosterone. The 5 alpha-reduced product has been characterized by thin-layer chromatography and capillary column gas-liquid chromatography. Androgen receptors and 5 alpha-reductase activity are expressed in amniotic fluid cells. The prenatal diagnosis of 5 alpha-reductase deficiency or complete androgen insensitivity syndrome (testicular feminization) is thus theoretically possible and obviously prenatal testing would be indicated in the family at high risk.
We previously suggested [Steroids 33, (1979) 3; Steroids 37, (1981) 6] that cultured genital skin fibroblasts should prove useful for screening of potential antiandrogens in human and living target cells. "Serenoa repens" lipidic extract (S.R.E.) was recently reported (Br. J. Pharmacol., in press) to inhibit androgen action in animals. The present investigation was designed to study the antiandrogenicity of this compound in human cells: we therefore analyzed the effects of S.R.E. on the intracellular conversion of testosterone (T) to 5 alpha-reduced derivatives, and we investigated interaction of S.R.E. with the intracellular androgen-receptor complex. Since the chemical structure of the active component of S.R.E. is still unknown, results are expressed in U/ml (one unit is defined as the amount of S.R.E. required to inhibit 50% of the specific binding (IC50) of [3H]1881 to rat prostate cytosol). S.R.E. at different dilutions (5.7 to 28.6 U/ml) is added to culture media containing [3H]T or [3H]dihydrotestosterone (DHT) and incubated at 37 degrees C with cultured fibroblasts. 28.6 U/ml S.R.E. significantly alters the formation of DHT and strongly inhibits 3 ketosteroid reductase mediated conversion of DHT to 5 alpha-androstane-3 alpha, 17 beta-diol, characterized radiochemically by thin-layer chromatography. S.R.E. is a good competitor for the whole cell androgen receptor: 7.1 U/ml S.R.E. gives 50% inhibition of the binding of 2 X 10(-9) M [3H]DHT to its receptor. Competitive binding assays after cell fractionation indicate that S.R.E. is less potent in nuclear than in cytosol receptors. Sucrose gradient centrifugation of the radioactive cell lysate of fibroblasts demonstrates that 28.6 U/ml S.R.E. abolishes 70% of the 3.6 S receptor-complex radioactive peak. The present studies show that S.R.E. inhibits 5 alpha-reductase, 3-ketosteroid reductase and receptor binding of androgens in cultured human foreskin fibroblasts. As the search for the ideal antiandrogen continues, S.R.E. appears to be a new type of antiandrogenic compound as therapeutics for the treatment of benign prostatic hypertrophy, hirsutism and so forth.
The benign hyperplasia of the prostate is a manifestation of aging, involving the accumulation, within the gland, of dihydrotestosterone, the probable mediator of the hyperplasia. Binding studies were performed on the cytosolic androgenic receptor of the rat prostate using [3H]methyltrienolone as a ligand. The binding of [3H]methyltrienolone at 5 nM, was inhibited by various drugs, such as methyltrienolone and cyproterone acetate. Permixon, a liposterolic extract of the plant, Serenoa Repens B, inhibits competitively the binding to the cytosolic receptor of the rat prostate. Various vegetable and mineral oils, the plant steroid: beta sitosterol and the antiprostatic drug: Tadenan, were all found to be inactive. The antiprostatic activity of Permixon shown in animal studies and controlled clinical trials, may thus result from a direct action at the cytosolic receptor.
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Serum cobalamin (vitamin B12) and unsaturated B12 binding capacity (UBBC) have been measured in 24 cases of hypereosinophilia: 16 were cases of hypereosinophilic syndrome (HES) and 8 of secondary eosinophilia. The two groups were similar with respect to absolute eosinophil counts. Serum cobalamin and UBBC were found to be markedly increased in most cases of HES and normal in secondary eosinophilia. This elevation of UBBC was mainly related to the increase of R binders (transcobalamins I and III). The elevated serum cobalamin and R binders in HES were due neither to a higher intracellular content of R binders nor to an increased release of these binders from eosinophils of HES. Pure fractions of eosinophils obtained from HES and secondary eosinophilia did not exhibit any difference in vitamin B12 binders. On the other hand, neutrophil-rich fractions from the same patients showed a higher content of intracellular B12 binding proteins than pure eosinophil fractions, irrespective of the cause of eosinophilia. These findings suggest that the increased serum vitamin B12 and UBBC could reflect an expanded pool of both eosinophils and neutrophils in HES and, thus, provide an additional argument for the inclusion of this syndrome in the group of myeloproliferative disorders.
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In male pseudo-hermaphroditism due to end organ unresponsiveness, partial androgen insensitivity can usually be related to low but detectable dihydrotestosterone (DHT) binding activity in cultured sexual skin fibroblasts. We have studied two patients with partial virilization and total absence of androgen receptors in cultured fibroblasts. A lack of DHT binding could be related to a selection of a fibroblast strain with no androgen receptor activity, to insufficient sensitivity of the method in detecting very low receptor concentrations or to an instability of the receptor or the androgen-receptor complex. However, these observations raise the question of masculinization of external genitalia with undetectable androgen receptor.