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Biomedical subjects

L Dumitriu

Publications and source records attributed to L Dumitriu.

70 records · Page 4Linked to original sources
PubMedDate not supplied

The role of the renin-angiotensin system in arterial hypertension in hypercorticism.

The authors have studied on 25 cases of hypercorticism, one of the mechanisms of producing arterial hypertension, the renin-angiotensin system. The study showed that in only 20% of the cases plasma renin activity was high whereas in the remaining 80% other mechanisms were responsible for the hypertension. In the cases in which the plasma activity of renin was high, by studying the changes in the value of electrolytes we were able to derive some understanding of the mechanism of action of the RA2A system. Thus, the literature data show that sometimes the excess of glucocorticoids causes hypertension by activating directly the RA2A system and concomitently inhibiting the renin-kalikrein system (RKKS) and PgS; at other times, the excess of glucocorticoids is exerted on the same renin-angiotensin system, but via ACTH and ADH, the electrolytes values being those that demonstrate the borrowed mechanism.

17-Ketosteroids↗
PubMedDate not supplied

Plasma renin activity (PRA) and plasma aldosterone in the adrenal cortex hyperactivity. Studies on 50 hypertensive patients.

The authors have studied on 50 patients hospitalized in the Adrenal Pathology unit of the Institute of Endocrinology, the etiopathogeny of arterial hypertension (AH) in hypercorticism and the therapeutic implications, arriving at the conclusion that in 20% of the cases AH was probably due to an increased activity of renin-angiotensin and in 47% to elevated levels of aldosterone. The authors hypothesize that AH in the remaining 30% of the hypercorticism cases in this study is due to other mineralocorticoids in excess and suggest that the treatment should be pathogenic and strictly individualized.

Adrenocortical Hyperfunction↗
PubMedDate not supplied

Fine-needle aspiration biopsy of the thyroid correlated with clinical scintigraphic, echographic and pathologic data in nodular and diffuse goiter.

In order to make thyroid aspiration biopsy, a routine diagnostic and therapeutic procedure in the "C. I. Parhon" Institute of Endocrinology, the authors carried out a study on 100 patients with nodular or diffuse goiter. The results were corroborated by clinical, scintigraphic and echographic data. The cytologic diagnosis was compared with the histopathologic one in 50 operated cases and confirmed by the post-therapeutic clinical course in the remaining 50. The study of the cases classified as benign (83%), suspect (6%) and malignant lesions (11%) was made for each individual diagnosis, taking into account the specific clinical, scintigraphic, echographic, and cytologic aspects. The cytology of cold nodules showed that only 30% of the patients required surgery, the rest of them having benign lesions that benefited from puncture and drug therapy. The cytohistologic concordance in malignant tumors was 93.3% (73.3% for certain, 20% with suspicion). The proportion of false negative diagnoses was 6.6% (one case). None of the findings was falsely positive. The advantages of this procedure are discussed.

Biopsy, Needle↗
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

Diagnosis and treatment of hyperthyroidism in elderly patients.

The clinical signs of hyperthyroidism in the elderly are often atypical and have an insidious onset. The hyperkinetic form and the exophthalmic syndrome are rare. Apathetic thyreotoxicosis occurs, with few exceptions, in the elderly. Part of the clinical signs of hyperthyroidism may be erroneously attributed to the normal aging process. Most authors consider radioiodine as the treatment of choice in elderly hyperthyroid patient.

Age Factors↗
PubMedDate not supplied

Turner's syndrome with sympathoblastoma.

A case of Turner's syndrome clinically and cytogenetically diagnosed in a 15-year old girl is reported. At age 4 the girl was hospitalized for renal malformations (doubling of the urethra and its ectopic opening). Laparatomy revealed a small tumoral formation which was removed. The diagnosis established anatomo-histologically was of sympathoblastoma. Since the tumor is genetically conditioned by an autosomal mutation, association of the gonosomial anomaly and sympathoblastoma is supposed to be fortuitious though it is not improbable that the tumor be the result of an embryonar disorder favourized by the chromosomal anomaly.

Adolescent↗
PubMedDate not supplied

Results of 131I therapy in hyperthyroidism at 7-18 years of age.

Twenty-seven patients aged 7-18 years, with hyperthyroidism and diffuse goite received 131I and 125I in doses of 200-350 muCi/gm of gland. The drug was given in a unique dose to 14 patients and fractioned (maximum 4 doses) to the rest. The total maximum dose was 15 mCi. Doubtless recovery was obtained in 25 cases and probable improvement in another 2 (the patients were lost track of). Exophthalmometric values did not increase in any of the patients and in 2 cases of edematous exophthalmos the protrusion and edema disappeared after this treatment. Clear improvement in the nutritional state occurred and puberty followed a normal course. The incidence of both early and late transient hypothyroidism was 1/25, while permanent hypothyroidism occurred in 5/25. In 5 cases administration of 125I in doses of 500 muCi/gm of gland was not effective and necessitated 131I readministration. It was concluded that radioactive iodine (131 isotope) is an effective radiopharmaceutical for radical treatment of hyperthyroidism in children and adolescents. The therapeutical innocuity of 131I was perfect and the dose of 200-350 muCi/gm of gland was the most adequate. A follow-up of the functional status is however advocated in these patients for detection of late hypothyroidism.

Adolescent↗
PubMedDate not supplied

Circadian rhythm of TSH in adult onset non-insulin dependent (type II) diabetics with altered thyroid state.

Twenty adult onset non-insulin dependent (Type II) diabetic patients and twenty non-diabetic subjects matched for sex, age, height and weight were studied. The diabetes was controlled by diet only in 10 patients and by oral hypoglycemic agents in 10. All patients were diurnally active and rested at night. Blood was sampled at 4-hour intervals over a 24-hour span (6 samples). TSH, total T3 and total T4 were determined by radioimmunoassay. The circadian rhythm in TSH was statistically significant by cosinor analysis and was comparable in all rhythm parameters in diabetics and non-diabetics. The rhythms of total T3 and T4 also seem to persist with comparable timing although the small number of subjects did not allow rhythm detection at the 5 per cent level in all groups. The circadian mean of the total T3 plasma concentration in the diabetics, however, was statistically significantly lower than the usual range of this laboratory and the total T4 was elevated but within the usual range. The changes in total T3 and T4 were most pronounced in the patients on oral hypoglycemic agents. This study indicates persistence of a circadian rhythm in TSH (and presumably also in the plasma concentrations of total T3 and T4) in non-insulin dependent diabetic patients in spite of a lowered circadian mean concentration of total T3 and a slightly but statistically significantly higher total T4 than in the matched non-diabetic subjects. The altered thyroidal state in the diabetic patients thus does not interfere with the circadian periodic secretion of TSH.

Age Factors↗
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 anaplastic transformation of differentiated thyroid carcinoma. An ultrastructural study.

The authors studied 60 thyroid carcinomas (29 folliculo-papillary carcinomas, 20 follicular carcinomas and 11 undifferentiated carcinomas), using ultrastructural, morphometrical and immunohistochemical methods. The anaplastic transformation correlates with the following aspects: decrease of intercellular junctions and of microvilli together with alteration of cell organelles. Immunohistochemically, thyroglobulin is present in various amounts in differentiated carcinoma, but it is absent in undifferentiated tumors. A good correlation is found between the pattern of thyroglobulin and the ultrastructural aspects of neoplastic cells. The authors consider that anaplastic tumors originate from differentiated carcinomas. The decrease of junctions, the modifications in the number and shape of microvilli, the alterations of cell organelles and the changes of thyroglobulin pattern are the principal parameters involved in the anaplastic transformation. These criteria can be also used in order to ascertain an early diagnosis in the thyroid carcinoma evolving anaplastic changes.

Adenocarcinoma↗
PubMedDate not supplied

Mutagenic effect of 131I in the mouse assessed by the transplacentar micronuclei test.

The incidence of chromosomal aberrations induced by 131I in the mouse foetus was assessed using the transplacentar micronuclei test (the incidence of the micronuclei in foetal liver). For comparison the standard micronuclei test was applied to the maternal bone marrow. A distinct quantitative difference was found with respect to the incidence of micronuclei in the foetus and the mother in response to doses of 131I as low as those used in clinical investigation. The less marked mutagenic effect of 131I on the foetus may be accounted for by the massive concentration of 131I in the mothers' thyroid and its increased renal clearance. A protective role might be also played by the placenta.

Animals↗