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Biomedical subjects

M Oprescu

Publications and source records attributed to M Oprescu.

At least 37 records · Page 2Linked to original sources

[The etiopathology of phacoantigenic uveitis and phacolytic glaucoma].

The phacoantigenic uveitis is a self-immune affection at the lens proteins, which may be determined by a 3rd-type hypersensitivity, and some sterner forms by a 4th-type hypersensitivity. In phacolytic glaucomas, the macrophagic reaction at degraded lens proteins obstructs the trabecular gaps, determining the raise of ocular tension with the appearance of secondary glaucomas.

Animals↗

[The microbial flora in septic corneal ulcers].

The researching of the microbial flora for 101 septic ulcer of the cornea shows the highest frequency of gram-positive embryos, the golden Streptococcus has been met for 83 cases of which. The Streptococcus was for 7 cases, Pneumococcus for 2 cases, gram-positive Bacillus of superinfections for 14 cases. Among the gram-negative embryos might be mentioned Moraxella for 7 observations, Proteus for 4 obs., Klebsiella for 2 obs., Pseudomonas for 2 obs., Enterobacter for one case. For all the ulcers of the cornea it is obliged to be done the researching of the permeability of the lacrimal ways, the main source for infection of the cornea.

Anti-Bacterial Agents↗

[Ocular manifestations in Stevens-Johnson syndrome].

A patient woman, 45 years old, showed bilateral corneal ulcers, symblepharon, milkish-white scars, cicatricial entropion, trichiasis, lacrimal hyposecretion within a Stevens-Johnson syndrome. Histological examination of the conjunctiva shows a necrosis process of epithelium with phlyctenular cavities and abundant subepithelial inflammatory infiltrate. The affection etiopathogenesis is discussed.

Conjunctiva↗

Anti LH and FSH activity of the human urinary antisteroid substance.

The antisteroid urinary substance was checked out for its effect on LH and FSH under endogenous (castrated animal) and exogenous (administration of releasing hormone-GnRH) stimulation of the rat hypophysis. Administration of this substance partly blocked the castration induced LH and FSH serum increase by 65% and 37% respectively (p less than 0.01) and inhibited the GnRH stimulating effect depressing serum LH by 50% and FSH by 33% (p less than 0.05). In both experiments the LH and FSH content of the hypophysis was not influenced.

Animals↗

Action of some pesticides on T4 to T3 conversion in cultured kidney and liver cells in the presence or absence of cysteine.

The influence of aminotriazole (ATA), atrazine (ATZ), prometryne (P) and ATC on T4 to T3 conversion in kidney and liver cell cultures in the presence or absence of cysteine was studied. The experiment was carried out on cell cultures (rat renal cells and human embryo cells) and organotypic cultures (rat liver cells), treated with the above mentioned pesticides in 2 doses each, in the presence of 1 microgram and 10 micrograms T4 in the culture medium. This experiment was reproduced in the same conditions supplementing the culture medium with 30 mg cysteine per 100 ml culture medium. T3 and T4 in the culture medium were measured by RIA. The proteins in the monolayer cultures were also assayed. Cysteine proved to stimulate T4 to T3 conversion at the level of human and rat kidney cells with little variation depending on the pesticide and the dose applied. Between the activities of the human and the rat cells in the presence of the same pesticide, there were clear differences. The latter are also expressed in the values of proteic synthesis taking place in the renal human embryo cells and rat renal cell cultures under the same influences.

Animals↗

Reactivity of cold thyroid nodule under hormonal influences: study on cell cultures.

The authors have studied the reactivity of cold thyroid nodule cells (CN) by comparison with the reactivity of normal thyroid cells (Ty), hot nodules cells (N), Graves' disease cells (G) and cells from the area proximal to cold nodules (TyC), under the influence of increased amounts of T3, TSH, STH, insulin, estradiol and KI present in the culture medium. The experiment lasted for 9-10 days. The study was carried out on monolayer cultures of cells obtained by tripsinization and on organocultures. Proteic synthesis, cytochemical and cytoenzymatic activities in the culture under the influence of the above substances were examined comparatively. After interruption of the treatment, the monolayer cultures were stained with Giemsa and examined by light microscopy. Proteic synthesis and release of Tg, T3 and T4 into the culture medium, were also examined. The organocultures were used in evaluating 125I uptake from the medium under the influence of the treatment. The results showed variation in relation to the tissue and hormone dose applied. It was especially found that TSH and estradiol cause enlargement of CN cell nuclei and an increased number of mitoses and polyploidia which might be premises for possible malignization.

Cells, Cultured↗

LH and FSH in human cerebrospinal fluid.

LH and FSH of cerebrospinal fluid (CSF) and serum were radioimmunologically measured. Samples were obtained simultaneously from 116 subjects of the following groups: A. 22 patients with non-endocrine diseases, B. 18 patients with cranial diabetes insipidus (DI) of whom 4 with metastatic carcinomas, C. 5 patients with primary empty sella syndrome, D. one with hydatiform mole, and E. 70 patients with pituitary adenomas, i.e. growth hormone--or prolactin-secreting or "non-secreting" adenomas, of whom 38 patients with invasive and 32 with enclosed adenomas. LH and FSH are normal constituents of CSF and their CSF levels poorly correlates with the serum ones (LH r = 0.477 p less than 0.01). Enclosed adenomas with SSE showed low levels of LH in CSF. High CSF-gonadotropins concentrations (above 4.0 mIU/ml) with a low serum/CSF ratio (below 3) was frequently, but not constantly found in patients with invasive adenomas and are not indicative per se of this diagnosis. Some patients with brain metastasis from breast carcinoma and DI, or with non-tumoral diseases and DI showed similar high patterns of CSF gonadotropins though the serum levels were within normal range. This suggests that local vascular mechanisms, including the retrograde circulation of gonadotropins from the pituitary to the hypothalamus, influence the blood-brain barrier much more than the release of gonadotropins into the systemic blood circulation.

Acromegaly↗

LH and FSH levels in serum and cerebrospinal fluid (CSF) of human fetus.

The concentration of LH and FSH was measured in the fetal blood and cerebrospinal fluid (CSF) of 4 human fetuses between 21 and 24 weeks old. A comparison was made with 6 post menopausal females. In one fetus the serum and CSF levels of both hormones were determined after administration of 200 micrograms LRH and 400 micrograms TRH. The mean serum fetal levels of LH and FSH of 76.6 mIU/ml (range, 29.5-152.0) and 30.5 mIU/ml (range 3.1-60.3), respectively, were not significantly different from those of postmenopausal females, whereas the fetal CSF levels of these hormones were significantly higher (p less than 0.02) than those of post menopausal females. The serum to CSF ratios for the fetal LH and FSH were 4.6 +/- 1.1 and 2.4 +/- 0.61 respectively, significantly different (p less than 0.02 and p less than 0.001 respectively) from those of post menopausal females (29.1 +/- 6.6 for LH and 50.9 +/- 10.9 for FSH). In one fetus LRH did not provoke any change in circulating FSH and LH level 20 min. after administration, while a slight increase of these hormone in the CSF was observed. These data suggest that the permeability of blood-CSF barrier to gonadotropins in the fetus seems to be higher than in the adult who has no blood-CSF barrier (B--CSF--B) alterations.

Blood-Brain Barrier↗

Altered specificity of the blood-cerebrospinal fluid barrier for pituitary hormones in patients with tumoral hypothalamo-hypophyseal diseases as proved by releasing hormones stimulation.

Growth hormone (GH), prolactin (PRL) and gonadotropins (LH and FSH) of cerebrospinal fluid (CSF) and serum were radioimmunologically measured in basal condition in 75 cases and during the stimulation with releasing hormones in 24 of cases, i.e. with TRH plus LRH i.v. Samples were obtained from 75 patients of the following groups: A. control group of 9 patients without endocrine diseases; B. 8 patients with nontumoral diseases, of whom 4 with organic cranial diabetes insipidus and 4 with empty sella syndromes; C. 36 patients with invasive tumors i.e. 6 hypothalamic metastatic carcinomas and 300 invasive pituitary adenomas; D. 22 patients with enclosed tumors, i.e. 1 suprasellar dermoid cyst and 21 enclosed pituitary adenomas. Minimum 3 pituitary hormones were measured in each analyzed sample, and only those hormones, not secreted by the tumoral cells, were analyzed for their differential penetration into the CSF. An increase of the permeability of the blood-CSF barrier (BCB) was frequently observed in the group of invasive tumors and occasionally in the other tumoral or non-tumoral groups. The serum/CSF ratios of gonadotropins become significantly lower than the ratios of GH and PRL in the invasive groups (p less than 0.02), and here the CSF level was correlated to the increases of the serum levels during LRH plus TRH i.v. test only for gonadotropins. These data suggest that the specificity of BCB is not lost, but altered by the tumors of the hypothalamo-hypophyseal region, with an increase of the permeability for gonadotropins more than for GH or PRL.

Adult↗

Angiotensin I-like immunoreactive substance in pineal gland of normal and Brattleboro rats with hereditary diabetes insipidus.

An angiotensin I-like immunoreactive substance (AI) was evidenced by a radioimmunoassay technique in the rat brain. The concentration of AI was significantly greater in the pineal tissue as compared to the hypothalamic or cerebral cortex tissue (p less than 0.001); its concentration was also higher in the pineal of the homozygous rats with hereditary diabetes insipidus (Brattleboro strain) as compared to the same tissue of the normal rats (p less than 0.001). The possible role of a pineal angiotensin system in the hydrosaline regulation is discussed.

Angiotensin II↗