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C Sultan

Publications and source records attributed to C Sultan.

At least 127 records · Page 7Linked to original sources
PubMed1989

[Bioluminescence assay of luteinizing hormone in plasma and urine].

The authors describe a bioluminescent immunoassay of LH in plasma and urine. It uses two monoclonal antibodies, one is labelled with glucose-6-phosphate-dehydrogenase, the other one is coimmobilized together with bioluminescent enzymes from marine bacteria on the same adsorbent (Sepharose). This assay can be performed directly on 20 microliters plasma or 10 microliters urine. The protocol is very fast, no separation step is required to remove the excess labeled antibodies. The inhibitory effect of the biological sample on luminescent reaction is determined by adding NADH to the assay tubes. The working range of this assay is 3 to 300 Ul/l, with a sensitivity of detection of 0.5 Ul/l. Recovery, linearity, within and between assay precision were evaluated and appeared to be satisfactory. The authors have observed a good correlation between results obtained with our method and with radioimmunoassay.

Female↗
PubMed1988

Correlations between free plasma estradiol and estrogens determined by bioluminescence in saliva, plasma, and urine during spontaneous and FSH stimulated cycles in women.

Estrone and estradiol (E1 + E2) concentrations in saliva were compared with four other parameters of estrogen status in five normal ovulatory women and ten FSH stimulated women selected for an in vitro fertilization program. E1 + E2 in saliva, plasma, and urine were assessed by a rapid, specific and sensitive enzymatic assay using bioluminescence. The free fraction of plasma estradiol was determined by equilibrium dialysis and total plasma estradiol by conventional radioimmunoassay. The pattern of E1 + E2 variation in saliva was similar to that of free plasma estradiol and the two parameters were correlated in both spontaneous and stimulated cycles. However, the lower correlation coefficient (r = 0.52, P less than 0.001) in spontaneous cycles compared with the high (r = 0.96, P less than 0.001) in the stimulated cycles shows that salivary E1 + E2 could be representative of plasma free estradiol in stimulated cycles but not in normal cycles. The free fraction of plasma estradiol reproduced the variation of total plasma estradiol in spontaneous as well as in FSH stimulated cycles and both parameters were strongly correlated (r = 0.91, P less than 0.001 and r = 0.90, P less than 0.001), respectively. The data show that salivary E1 + E2 concentrations are highly representative of the free fraction of E2 in plasma and at a lesser extend (r = 0.72, P less than 0.001) of total plasma E2 in FSH stimulated cycles.

Adult↗
PubMed1988

Androgen and erythropoiesis: evidence for an androgen receptor in erythroblasts from human bone marrow cultures.

The techniques for culturing erythroid precursors made possible the study of the effect of steroids on these cells, and it has been well established that androgens and 5 beta-steroids have a direct effect on erythroid precursor cells from animal or human bone marrow. By contrast, their mechanisms of intracellular action remain poorly understood. We used tritiated methyltrienolone (R1881), a synthetic androgen that binds strongly to the androgen receptor, to characterize the binding activity in nuclear extracts of erythroblasts from human bone marrow cultures. The nuclear extracts contained binding sites that were saturable at low concentrations of 3H-R1881 (8-12 nM). Scatchard analysis revealed that the dissociation constant of the hormone-receptor complexes (Kd) was 10-20 nM, and the number of binding sites was 64-103 fmol/mg of protein. On linear sucrose density gradient analysis (5-20%), the hormone-receptor complexes sedimented in the region of 3.9 S. Finally, 5 beta-dihydrotestosterone had also a strong affinity for the binding sites. The nuclear component binding has all the physicochemical characteristics usually attributed to androgen receptors. These data strongly suggest that androgen action on erythropoiesis is mediated by a nuclear androgen receptor.

Bone Marrow Cells↗
PubMed1988

Congenital adrenal hyperplasia associated with hyperphosphatemic rickets.

The authors describe a boy with precocious puberty due to adrenal hyperplasia associated with rickets, hypocalcemia, hyperphosphatemia, elevated PTH and alkaline phosphatase levels, and concentrations of 25-OH-D and 1,25-(OH)2D at the upper limit or above normal range. Treatment with hydrocortisone for 9 months did not normalize hypocalcemia and hyperphosphatemia. The addition of 1,25-(OH)2D3 (0.5-2 micrograms/day) to the corticoid treatment for 1 year was followed by a progressive normalization of plasma calcium, phosphorus, PTH and alkaline phosphatase concentrations with improvement of the osteomalacia on bone biopsy.

Adrenal Hyperplasia, Congenital↗
PubMed1988

[Malignant arterial hypertension disclosing late congenital adrenal hyperplasia due to 17 alpha-hydroxylase deficiency].

17 alpha-hydroxylase deficiency is a rare form of congenital abnormality in steroid synthesis, usually associated with moderate arterial hypertension and suppression of the renin-angiotensin system in a young adult. We report on a 45 years old woman with malignant hypertension (220/135 mmHg, severe retinopathy with papilledema, progressive renal insufficiency with serum creatinine over 300 mumol/l) of recent onset. Biological exploration revealed a metabolic alkalosis, a moderate hypokalemia (3 mmol/l), with elevated urinary excretion of potassium. Plasma aldosterone concentration (33 ng/dl) and plasma renin activity (17 ng/ml/h) were elevated. Acute captopril administration was followed by a marked (-29 p. 100) decrease in mean arterial pressure. In this 46 XX patient, a primary amenorrhea had never been explored; clinical examination disclosed the absence of female secondary sex characteristics. Plasma cortisol was low (203 mmol/l) as were plasma androgens (testosterone 0.55, androstene dione 0.19, delta HEA less than 0.1 nmol/l respectively) and oestrogens (oestradiol 59 nmol/l). Elevated levels of progesterone and pregnenolone sulfate (12.1 and 2027 nmol/l respectively) contrasted with decreased levels of 17 OH progesterone (0.35 nmol/l). Computed tomography revealed a subnormal right adrenal gland and a pseudo-tumoral aspect on the left side. Treatment with dexamethasone and combined antihypertensive drugs (captopril, nifedipine and atenolol) resulted in normalisation of blood pressure and secretion of renin and aldosterone but renal function did not fully recovered. Thus, the hypertension of 17 alpha-hydroxylase deficiency can follow a malignant course in association with a marked activation of the renin-angiotensin system.

Adrenal Hyperplasia, Congenital↗
PubMed1988

Decision-making system (DMS) applied to hematology. Diagnosis of 180 cases of anemia secondary to a variety of hematologic disorders.

We have developed a new decision-making system which includes interpretation of complete blood count (CBC). The system works using Bayes' rule. We tested the CBC program for the diagnosis of 180 cases of anemia covering 20 benign and malignant hematological disorders. The data entered were obtained from a Coulter S + IV/HD and the interpretation of blood smears. Clinical information was not used. In 64.5% of cases, the correct diagnosis was displayed in first rank and in 20%, in second or third rank, giving a total of 84% of quite satisfactory responses. There were only 5% incorrect responses, but the proposed complementary tests rectified the error. Computer-aided diagnosis can help pathologists, clinicians, students, and technicians to make rapid correct diagnoses and choose the appropriate tests to perform. These programs run on IBM PC or similar microcomputers and are available from Coulter Electronics, Hialeah, FL.

Anemia↗
PubMed1987

[An aid in decision-making in hematology: characteristics and performances of the program. 200 cases of anemia].

An aid to decision programme has been applied to 200 cases of anaemia. Evaluation by the bayesian method rested on clinical data (age, sex, race) and laboratory data (blood count and differential, erythrocyte morphology). An accurate diagnosis was made initially in 107 cases, and for the first 5 diseases in 173 cases. The programme proved more effective than two clinicians recently trained in haematology. Devised for micro-computers, it can be used in routine practice and for teaching purposes.

Anemia↗
PubMed1987

Partial androgen receptor deficiency and mixed gonadal dysgenesis in Drash syndrome.

Drash syndrome associates a nephropathy characterized by a diffuse mesangial sclerosis of early onset, Wilms tumor, and male pseudohermaphroditism (MPH). A patient with Drash syndrome is reported with the following: karyotype 46,XY, external genitalia near normal female, mixed gonadal dysgenesis, severe androgen receptor deficiency demonstrated for the first time in this syndrome. The possibility of a common genetic denominator with the del 11p13 WAGR complex is suggested. MPH/nephroblastoma association is common. Androgen receptor deficiency has been observed in one case of each syndrome, respectively.

Disorders of Sex Development↗
PubMed1987

Determination of glycogen and enzymes of glycogen metabolism in human hair follicles.

The skin epithelium and its organelles use glycogen as well as glucose as source of energy. Therefore the characterisation of glycogen metabolism and the enzymes involved is important in the study of mechanisms regulating the normal or abnormal differentiation of skin organelles such as sebaceous glands and hair follicles. The present paper describes fluorimetric methods for the determination of glycogen and for the measurements of phosphorylase and phosphorylase kinase activity in one and the same lysate of minute tissue samples. The methods were tested for their suitability on freshly isolated human hair follicles and cultured hair follicle cells. The possible use of these techniques for studies on the pathophysiology of acne and hirsutism is discussed.

Cells, Cultured↗
PubMed1987

Bioluminescence: an improvement in the enzymatic assay of dehydroepiandrosterone sulfate in biological fluids.

Dehydroepiandrosterone sulfate (DHEAS) determination in biological fluids was carried out by enzymatic hydrolysis and conversion into estrogens [estrone (E1) and estradiol (E2)] by the multienzyme system of human placental microsomes. The enzymatic complex consists of sulfatase, 3 beta-hydroxysteroid oxido reductase and 5en----4en isomerase which converts DHEAS into androstenedione (A); the latter component is further converted into estrogens by the aromatase. The resulting estrogens were determined from the NADH formed by the transhydrogenation reactions of human placental dehydrogenase. NADH was measured by bioluminescence. As little as 4 pg was assayable by this rapid enzymatic method, with a coefficient of variation of 8%. The results are in good agreement with radioimmunoassay and the method is suitable for routine use.

Dehydroepiandrosterone↗
PubMed1987

[Somatomedin C/insulin-like growth factor I and in vitro erythropoiesis].

The effect of human somatomedin C/insulin-like growth factor I(SM-C/IGF-1) and human growth hormone (hGH) on colony formation by erythroid precursor cells (CFU-E and BFU-E) from children's bone marrow or blood was studied by methylcellulose cloning assay. We found that physiological concentrations of IGF-1, but not of hGH, stimulated erythropoiesis in vitro in the presence of erythropoietin, as demonstrated by the increased activity of a cytosolic enzyme of the heme pathway (uroporphyrinogen I synthase). The results suggest that IGF-I could be involved in the regulation of erythroid differentiation.

Bone Marrow↗
PubMed1987

Is increased 5 alpha-reductase activity a primary phenomenon in androgen-dependent skin disorders?

Testosterone metabolism was investigated in fractions of human skin, enriched in epidermis, dermis, sebaceous glands, and sweat glands, by histologic sectioning of skin punch biopsies, and the results were compared with two culturable skin cells, i.e., keratinocytes and fibroblasts. Since sebocytes could not be brought in culture, metabolism was also investigated in the hamster flank model. In the epidermal tissue of the skin biopsies the predominant metabolite was androstenedione, formed by the enzyme 17 beta-hydroxysteroid dehydrogenase. The same was true for cultured hair follicle keratinocytes. In the deeper skin layers the formation of androstenedione was markedly reduced, whereas the formation of 5 alpha-reduced metabolites was highly increased, with a maximum in the skin fractions containing large sebaceous glands. Cultured shoulder skin fibroblasts showed a markedly different testosterone metabolism compared with the sectioned skin biopsies, suggesting that dermal fibroblasts play a less important role in the overall skin testosterone metabolism. The present approach, allowing the comparison of testosterone metabolism in different substructures of the same skin biopsy provides new evidence that the high 5 alpha-reductase activity in the specific skin fractions must be mainly ascribed to the sebaceous glands. These results render a previous hypothesis, stating that the elevated level of 5 alpha-reductase and subsequent formation of dihydrotestosterone in androgenetic alopecia and acne (usually accompanied by seborrhea) could therefore simply be the consequence of sebaceous gland enlargement, much stronger. This hypothesis is further evaluated by quantitative correlation of sebaceous gland size with enzyme activity in the hamster flank model.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1987

Myelodysplastic syndromes.

The myelodysplastic syndromes (MDS) represent a group of syndromes having in common a defective production of one or more myeloid cell lines. They occur in patients which are more than 50 years old without any sex preponderance. The term MDS is replacing the obsolete and archaic term of 'preleukemia' and/or 'oligoblastic leukemia'. The more striking hematologic features are a discrepancy between a cellular bone marrow and a peripheral blood cytopenia. MDS may be idiopathic or secondary. Some of them precede or predispose to the subsequent development of an acute myeloid leukemia. A correct analysis of peripheral blood and bone marrow smears permits to classify MDS and to establish some prognostic features. Some syndromes are easily recognizable such as acquired idiopathic sideroblastic anemia, refractory anemia with excess of blasts, pure refractory cytopenia and acute myelodysplasia with myelofibrosis. Nevertheless this classification does not cover all these syndromes. Some of them with borderline features will be discussed separately. An analysis of a large series of MDS recently published in the literature will be presented as well as nosologic problems which arise. A conceptual effort should be made to recognize and evaluate the MDS.

Humans↗
PubMed1987

Insulin-like growth factor I stimulates human erythroid colony formation in vitro.

The effects of human GH and insulin-like growth factor I on the proliferation and differentiation of erythroid progenitor cells from the bone marrow and peripheral blood of children were studied in a hormone-depleted culture system. Growth of erythroid progenitors was quantified by directly scoring colonies and by biochemical determination of the activity of a cytosolic enzyme of the heme pathway, uroporphyrinogen I synthase. In the presence of erythropoietin, high concentrations (50-100 ng/mL) of human GH induced an increase in the number of erythroid colonies (and their uroporphyrinogen I synthase activity) formed by bone marrow or peripheral blood erythroid precursors. In the same conditions, physiological concentrations of insulin-like growth factor I (0.5-1 ng/mL) stimulated erythroid cell growth and differentiation (P less than 0.03) from bone marrow or peripheral blood.

Bone Marrow Cells↗
PubMed1987

Gonadotropin and alpha-subunit secretion during long term pituitary suppression by D-Trp6-luteinizing hormone-releasing hormone microcapsules as treatment of precocious puberty.

Short term treatment with GnRH agonists has been reported to increase plasma gonadotropin alpha-subunit (Gn alpha) levels while decreasing plasma immunoreactive LH (IR-LH) levels. In this study we examined the effect of D-Trp6-LHRH (LHRH-A) in microcapsules (60 micrograms/kg, im, every 28 days for 1 yr) in 13 girls suffering from precocious puberty. Plasma IR-Gn alpha was measured by RIA; plasma IR-LH and IR-FSH were measured by both polyclonal RIAs and monoclonal immunoradiometric assays (IRMA). Before treatment, basal IR-LH and IR-FSH levels and peak responses to LHRH measured by both RIA and IRMA were similar, and the Gn alpha response paralleled that of LH. After the first injection of LHRH-A, RIA LH levels were significantly higher than pretreatment levels until day 21, while IRMA LH levels transiently increased, but returned to pretreatment levels by day 7 and became lower thereafter (P less than 0.005). Plasma IR-Gn alpha levels increased from days 3-21 (P less than 0.05). After 1.5 months of treatment, basal RIA LH levels remained detectable and not different from pretreatment levels; IRMA LH levels were very low. The mean RIA and IRMA LH responses to LHRH were decreased at 1.5 and 12 months (P less than 0.01). Basal plasma RIA and IRMA FSH levels were similar during treatment (P greater than 0.05) and significantly lower than pretreatment values (P less than 0.01). The mean RIA and IRMA FSH responses to LHRH decreased significantly at 1.5 months (P less than 0.001). After 12 months, both RIA and IRMA FSH responses were increased, but IRMA values were significantly lower than RIA values. A sustained increase in basal Gn alpha values occurred, but there was a tendency for the peak levels after LHRH treatment to decrease, becoming significantly lower than pretreatment peak levels after 1 yr. The chromatographic analysis on Sephadex G-100 of a pool of plasma samples collected during a LHRH test in three children treated for 6 months indicated that IR-Gn alpha coeluted with [125I]Gn alpha. The large discrepancy between RIA and IRMA LH values suggests the secretion of unusual LH molecules which are recognized by RIA but not by IRMA. The sustained release of large amounts of IR-Gn alpha indicates dissociated effects of LHRH-A on alpha- and beta-subunit secretion by the gonadotrophs. The sustained response of Gn alpha to LHRH demonstrates that gonadotroph cell LHRH receptors are still responsive to LHRH during treatment with a LHRH agonist.

Capsules↗