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Biomedical subjects

L Simionescu

Publications and source records attributed to L Simionescu.

At least 91 records · Page 5Linked to original sources
PubMedDate not supplied

The hormonal pattern in alcoholic disease. I. Luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testosterone.

The study included 48 male chronic alcoholics, aged 20 through 50 years, classified in two groups according to the presence (22 patients) or absence (26 patients) of clinically evident sexual disorders. The blood samples were collected the first 2-3 days after hospitalization, before any anti-alcoholic treatment. The control group included 10 adult male normal subjects. By comparison to the control group, the basal level of LH was significantly (p less than 0.01) lower in both groups of alcoholic patients while the FSH level was significantly higher (p less than 0.01) in the group with sexual disorders. The serum levels of testosterone were increased (p less than 0.05) only in the group having sexual disorders. Our data suggest that the feedback regulation of the hypophyseal LH release seems to be impaired by defects in the peripheral metabolization of testosterone.

Adult↗
PubMedDate not supplied

Studies on the action of pesticides upon the endocrines using in vitro human thyroid cells culture and in vivo animal models. I. Herbicides--aminotriasole (amitrol) and atrazine.

The action of aminotriasole (amitrol) and atrazine in doses of 0.001--1 mg and 0.0001--.01 mg/1.5 ml medium, respectively, upon cell cultures of human thyroid was studied in order to find out their influence on cell multiplication, proteic synthesis, enzymatic activity of thyroid cells, and hormonal synthesis. The results varied according to the dose utilized and the type of thyroid cell studied. The acute experiment carried out on rats treated 15 days with 500 ppm amitol and 50 ppm atrazine revealed variations in the T3, T4 and LH synthesis. Amitrol showed a strong inhibitory action on T3 and T4 secretion, whereas atrazine stimulated it.

Amitrole↗
PubMedDate not supplied

The radioimmunological measurement of thyroglobulin secretion in vitro under the influence of some herbicides.

A radioimmunoassay (RIA) technique of human thyroglobulin (Tgl) was developed using 125I-Tgl and a rabbit anti-Tgl serum at the initial dilution of 1:100,000. The sensitivity of the technique was of 2.5 ng/ml. The RIA of Tgl was applied as a screening test for the in vitro secretory activity of human thyroid cells under the influence of two herbicides of the heterocyclic group (Amitrol and Atrazin). Three levels of concentration of Amitrol and Atrazin were administered to the tissue culture tubes containing in the first series of experiments perinodular tissue (Typ), and in the second one nodular tissue (TyN). The thyroid gland was surgically obtained from a patient with the diagnosis of polynodular goiter. Only the high levels (10 mg and 1.0 mg/tube, respectively) of herbicide concentration inhibited the secretion and release of Tgl, the nodular tissue being more resistant to the toxic. However, parallel studies including the dosage of the active hormones (T3, T4) are necessary in order to appreciate the value of Tgl determination as an indicator of hormogenesis in this type of experiments.

Amitrole↗
PubMedDate not supplied

The action of chlorpromazine upon the serum and hypophyseal levels of prolactin and TSH in the pinealectomized male rat.

The action of chlorpromazine (CPZ) administered intraperitoneally (i.p.) in a single dose of 1.0 mg (0.2 ml) upon the serum and hypophyseal levels of prolactin and TSH was investigated in sham-operated (Sh-O) and pinealectomized (Px) male rats. Fourteen days after surgery the animals received 0.2 ml of CPZ or 0.2 ml of isotonic natrium chloride solution and were killed one hour after. The following data were obtained: a) CPZ released pituitary prolactin in both Sh-O and Px groups; b) The TSH circulating levels were increased in the Px group receiving CPZ (p less than 0.01); however, the same sense of variation was observed also in the Sh-O group. The results are suggesting the lack of intervention of the pineal in the mechanism of action of CPZ on the pituitary hormones with or without target gland.

Animals↗
PubMedDate not supplied

Release of growth hormone, prolactin, LH, FSH and IRI in serum through orally administered 1-proline in high dosage.

Orally given 1-proline in high dosage (500 mg/kg b.w.) resulted in growth hormone (GH) release in 9 healthy, sexually immature children investigated (5 boys and 4 girls). A slight, unsignificant decrease of the mean prolactin level was also noted. Serum immunoreactive insulin (IRI), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) concentrations in serum were not influenced. The possible use of proline loading in high dosage for the detection of GH deficiency especially in small children and in infants is suggested.

Child↗
PubMedDate not supplied

Insulin radioimmunoassay measurement by the polyethyleneglycol separation technique using the ROTOP kit reagents. Some clinical applications.

The technique described in the instructions booklet of the radioimmunoassay Insulin kit commercially known as the ROTOP-Insulin kit (CCR) tested both in our and in other laboratories did not show the desired reproducibility. Using the main ROTOP reagents (anti-insulin serum and 125I-Insulin) in radioimmunoassay (RIA) systems with other separation techniques (double antibody, dextran-charcoal and polyethyleneglycol) we observed that these reagents are suitable for a sensitive and precise RIA system. The intra-assay variations observed were caused by the separation technique with 86% ethanol as proposed by the procedure. This work describes an insulin-RIA system modified in order to be able to use the ROTOP reagents with the polyethyleneglycol (PEG) separation technique. This variant is used for more than three years in our laboratory but was adopted also in other RIA laboratories in Romania.

Charcoal↗
PubMedDate not supplied

The action of chlorpromazine upon the serum and hypophyseal variations of growth hormone, prolactin and TSH in the male adult rat under continuous-lighting stress.

The influence of chlorpromazine (CPZ) on the serum and hypophyseal levels of growth hormone (GH), prolactin and TSH was studied in the male adult rat occurring under normal light-dark-rhythm conditions and under continuous 24-hour lighting, respectively. The serum and hypophyseal concentrations of GH decreased significantly (p less than 0.01 and p less than or equal to 0.02) one hour after the administration of 1.0 mg of CPZ in the animals under continuous light by comparison with the animals maintained on the same conditions. In the animals under normal light-dark rhythm, CPZ did not influence the peripheral or central concentrations of GH. The animals maintained either in normal or in continuous lighting conditions released prolactin under the influence of CPZ. The increased values of circulating TSH in light-exposed animals by comparison with the diurnal group (p less than 0.001) were some more augmented under the influence of CPZ, while this drug remained unefficient in the animals under normal light-dark-rhythm conditions. The mechanism of CPZ action upon the secretion of GH and prolactin, which are hormones lacking target gland, is discussed.

Animals↗
PubMedDate not supplied

Studies of cellular immunity in Graves' disease.

Cell immunity aspects were studied in patients with untreated Graves' disease or thyreotoxicosis relapsing after anti-thyroid drug therapy interruption. The peripheral blood T-lymphocyte count was significantly low (p less than 0.05) in the untreated patients. The leucocyte inhibition factor (LIF) test showed only a slight sensibilization of lymphocytes to thyroglobulin in the untreated patients, whereas in those with relapsed thyreotoxicosis there was a marked sensitization to thyroglobulin and microsomal antigen. Our observations suggest that part of the untreated patients have some abnormalities in the function of their lymphocytes. All the relapsed cases showed an intense sensitization of lymphocytes in the direct LIF test. The possibility of using the LIF test as an indicator of thyreotoxicosis release after interruption of the anti-thyroid drug therapy is suggested.

Adult↗
PubMedDate not supplied

Immunohistochemical demonstration of thyroglobulin in thyroid pathology.

Thyroglobulin (Tg) was detected by the immunoperoxidase method in the following thyroid diseases: euthyroid goiter, Graves' disease, Hashimoto's thyroiditis, folliculo-papillary carcinoma, follicular carcinoma, anaplastic carcinoma and medullary carcinoma. Thyroglobulin was present in all benign lesions. The highest immunohistochemical staining reaction was found in Graves' disease. In euthyroid goiter, some colloid-distended macrofollicles did not show any Tg staining. A heterogeneous pattern of Tg staining was displayed especially by thyroid carcinomas. In most cases of papillary and follicular carcinomas Tg was detected in some neoplastic cells and sometimes in the colloid. There were differences in Tg content between different fields of the same tumor. In all anaplastic carcinomas a negative Tg staining was found. Vizualization of Tg in thyroid carcinomas is important for estimating the degree of differentiation and for indicating the thyroidal origin of metastases of adenocarcinomas.

Humans↗
PubMedDate not supplied

The entrapment of biological active substances into liposomes. II. Effects of oral administration of liposomally entrapped insulin in normal and alloxanized rats.

Insulin (I) was entrapped into liposomes of various lipid compositions. After oral administration, some of the normal rats treated with neutral liposomes (c) and (d) having egg yolk lecithin, prepared with 2 or 4 mg I/ml respectively, showed a decrease in blood glucose at 2 and 4 hrs. In alloxanized rats (75 mg alloxan/kg body weight) the positive liposomes (f) have induced in some animals a decrease in blood glucose at both time intervals after oral treatment. When neutral liposomes (c) were administered to diabetic rats (125 mg alloxan/kg body) the blood glucose decreased in 9 of 12 animals from 391 to 125 mg/100 ml blood, at 3 hrs after oral treatment. At 1 h, the effect had appeared in 3 of 14 animals. The neutral liposomes (g) having synthetic lecithin, induced a decrease in blood glucose in 5 of 10 animals. A good correlation was observed between decreased glucose and increased insulin levels with the same variability throughout the treated group. No increased insulin levels were observed in diabetic control and normal rats. By the RIA method, the insulin entrapment was 8%. Histological studies have shown that at 35 min after oral administration, neutral liposomes (c) penetrate deeply into the intestinal wall of alloxanized rats as compared both to the neutral liposomes with synthetic lecithin (g) or to the positive ones (f).

Administration, Oral↗
PubMedDate not supplied

Comparative study of the effects of lisuride and pimozide on the preovulatory surge of FSH, LH and prolactin in rat.

In experiments conducted on adult female Wistar rats, lisuride hydrogen maleate, injected before the critical period of proestrus (between 11 h-13 h) in a single s.c. dose of 0.125 mg/kg body, significantly elevated the preovulatory gonadotropin surge and slightly, non-significantly lowered that of prolactin (assessed between 15-16 h). Pimozide, a selective antidopaminergic neuroleptic, injected according to the same schedule in a dose of 2.5 mg/kg body, strongly augmented the LH surge and also prolactin secretion. Thus, stimulation of gonadotropin secretion by lisuride cannot be ascribed to its dopaminergic agonistic action, but may be attributed to its antiserotoninic activity or to the action on the presynaptic dopamine receptors of the tuberoinfundibular neurons, reducing their inhibitory influence on the gonadotropin surge. The results plead for the inhibitory role of DA in the LH and prolactin secretion; 5-HT may have a similar action in the preovulatory gonadotropin surge and a stimulatory one in the surge of prolactin.

Animals↗
PubMedDate not supplied

Down's syndrome 47, XX,+21 with agonadism.

A girl with 47, XX,+21 Down's syndrome presenting labio-scrotal fusion and clitoral hypertrophy is reported. Anatomo-pathologic examination of the patient revealed the absence of the gonads and rudimentary Fallopian tubes. Botal's orifice was also present. This association, the first to be encountered so far, seems fortuitious.

Chromosome Mapping↗
PubMedDate not supplied

Familial Down's syndrome.

Investigation of an intensely consanguinized family in which three children were born with Down's syndrome (in one of them the diagnosis was uncertain) suggests the existence of a gene that favours chromosomal non-disjunction. In the same family there were two children with multiple malformations and two with neoplasia.

Abnormalities, Multiple↗
PubMedDate not supplied

The simultaneous isolation of the human pituitary hormones. II. The luteinizing hormone.

The main purpose of the work is the isolation of luteinizing hormone (LH) from frozen human pituitaries. The procedure for the processing of the glands included the steps described by P. Roos [22] for the preparation of the follicle stimulating hormone (FSH) slightly modified and adapted to our conditions. After thawing, the pituitaries were homogenized in 0.03 N Naphosphate buffer, pH 5.7. The protein bulk containing growth hormone (GH) was separated by precipitation with saturated ammonium sulfate (v/v). The supernatant containing gonadotrophins, obtained by centrifugation, was fractionated by chromatography on DEAE cellulose, the first peak being further fractionated by column gel-filtration on Sephadex G-100 after a previous concentration by dialysis against polyvinylpyrolidone 10%. The first peak obtained by this last fractionation was considered for the time being, as pure LH. The extraction and fractionation steps were followed by disc polyacrylamide gel electrophoresis and by radioimmunoassay measurement of the LH concentration. Studies concerning the homogeneity and the biological activity of our LH preparation by comparison to the LH preparations recommended by WHO, are in progress in our laboratory.

Chromatography, DEAE-Cellulose↗
PubMedDate not supplied

A radioimmunoassay system for human myoglobin: method development and applications.

double antibody radioimmunoassay (RIA) system for human myoglobin (hMb) was developed using our own reagents. The antigen (hMb) was isolated from human muscle, purified and stored frozen until needed for immunization, radiolabeling or reference preparation. The anti-hMb serum raised in rabbits was used at 1:2.10(4) dilution (initial). The Chloramine-T method was used for the hMb labeling obtaining at 10-15 muCi/micrograms (370-550 KBq/micrograms) specific activity. Working standards were prepared having concentrations in the range of 2.0 to 500 ng/ml. The reagents were incubated at +4 degrees C for 48 plus 24 hrs. The specificity and accuracy of our hMb-RIA system were validated using for parallel assays an already validated immunochemical system, the hemagglutination inhibition (HI) technique and the parallelism test using serum dilutions from patients with acute myocardial infarction (AMI). The serum hMb concentration in normal subjects (no = 23) was 54.14 +/- 15.08 ng/ml (X +/- SD), being higher in short-term hypothyroidism (no = 13), 87.95 +/- 20.90 ng/ml (p less than 0.0005) or in treated hyperthyroidism (no = 5), 80.03 +/- 21.81 ng/ml. In AMI (no = 6) the serum hMb concentration varied in the range of 123 to 1510 ng/ml. The sensitivity of our hMb-RIA system is 2 ng/ml and the intraassay average error (coefficient of variability % in %B) is 2.26%. Trials to shorten the incubation time showed that adequate binding of labelled Mb may be obtained with 2 plus 4 hr intervals at room temperature. It is necessary to establish, in our conditions, the variation limits for serum hMb in normal subjects according to sex and age as a comparison basis for the study of its physiological and pathological variations.

Animals↗
PubMedDate not supplied

The method of multilayer gel plates for the analytical immunochemical techniques.

A new analytical immunochemical method using gel film copies obtained by means of multilayer gel plates is described. The method is suitable for any variant of immunochemical gel technique. Perfect identity of the copies as well as some advantages are exemplified. In comparison with the already known monolayer gel plate method, the multilayer plate is more advantageous for the study of the dynamics of the antigen-antibody reaction, for the discovery of the nature of some unknown biological products available in very low quantities and for the discovery of the nature of some unknown biological products available in very low quantities and for the economy of certain costly reagents. Moreover, its high reproductibility recommends it as a reference method for the control of quality, especially of the precision and accuracy of the monolayer immunofiltration techniques.

Counterimmunoelectrophoresis↗
PubMedDate not supplied

The influence of thiol derivatives on synthesis of thyroid hormones in human thyroid cultured cells.

The experiments were carried out on 26 lots of thyroid cell cultures treated with sodium sulphate, lithium sulphate, lithium carbonate, cystine, cysteine, and methionine, in 2 doses each, in the presence or absence of iodine in the culture medium. The monolayer culture was used in morphologic, cytochemical and cytoenzymatic studies, and the culture medium was used for assay of thyroglobulin and thyroxin. We found that addition of aminoacids with SH or S--S groups to the culture medium causes stimulation of protein synthesis overstrain on the oxydases system at the expense of dehydrogenases. Stimulation of protein synthesis in the thyroid cell cultures under study is not accompanied by a corresponding hormonal secretory activity, the process of hormonal biosynthesis being inhibited as compared to the control culture.

Cells, Cultured↗