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Biomedical subjects

P Dor

Publications and source records attributed to P Dor.

At least 37 records · Page 2Linked to original sources
PubMed1980

Regulation of cyclic nucleotide and prostaglandin formation in normal human thyroid tissue and in autonomous nodules.

We have investigated the regulation of the human throid gland based on controls discovered in the dog thyroid gland. TSH and thyroid-stimulating immunoglobulin enhanced cAMP accumulation, which supports the validity of the Sutherland model for the action of TSH on the human thyroid. Iodide inhibited TSH- and thyroid-stimulating immunoglobulin-activated cAMP accumulation and this effect was reduced by methimazole, showing that, in this tissue, iodide, through an oxidized derivative, depresses the TSH-cAMP system. Contrary to the hypothesis of a short feedback loop of thyroid hormone, no thyroid effect of T3 or T4 was found. Adrenergic agents (norepinephrine and isoproterenol) enhanced cAMP accumulation; this effect was inhibited by dl-propranolol but not by d-propranolol or phentolamine. This suggests a positive control of the thyroid cAMP system by beta-adrenergic receptors. Histamine also increased cAMP accumulation. However, the role of these controls is unknown. Acetylcholine, by a muscarinic type effect, enhanced cGMP accumulation and prostaglandin E2 and prostaglandin F2 alpha release. These effects were mimicked by ionophore A23187 and abolished in a calcium-deprived medium, which suggests that they are secondary to a raised Ca++ influx. The results are summarized in a general working model of human thyroid regulation. These biochemical controls have been compared in normal tissue and autonomous nodules. No evidence of increased sensitivity to TSH of the nodular tissue was found. On the other hand, this tissue was less sensitive to acetylcholine (cGMP accumulation) and more sensitive to norepinephrine (cAMP accumulation).

4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone↗
PubMed1978

Malignant lymphomas and undifferentiated small cell carcinoma of the thyroid: a clinicopathological review in the light of the Kiel classification for malignant lymphomas.

The paper reports a re-evaluation--based on the Kiel classification for non-Hodgkin lymphomas--of a group of cases initially diagnosed as undifferentiated small cell carcinomas or primary lymphomas of the thyroid. Twelve such cases were found among the 155 cases of primary malignant tumours of the thyroid recorded at the Institut Jules Bordet between 1955 and 1975. The review of the clinical charts and the histology showed that all the cases were in fact malignant lymphomas fitting easily into one of the groups described in the Kiel classification. These findings support the growing opinion that undifferentiated small cell carcinoma of the thyroid does not exist as a distinctive clinicopathological entity. Furthermore, the Kiel classification proved to be an excellent prognostic indicator, since all the cases classified as highly malignant were indeed fatal, whereas the surviving cases--three of which had shown tumoral extension beyond the thyroid capsule--fell into the group of low malignancy. Lastly, this study acknowledges the frequently observed association of malignant lymphoma of the thyroid with stigmata of Hashimoto's disease, and thus supports the concept that the continuous antigenic stimulation observed in the latter could trigger the development of a malignant lymphoma.

Aged↗
PubMed1977

Steroid sex hormones and prolactin in postmenopausal women with generalized mammary carcinoma during prolonged dexamethasone treatment.

The endocrine response to prolonged dexamethasone treatment was investigated in six postmenopausal women with generalized mammary carcinoma. Plasma cortisol levels decreased rapidly and became undetectable whereas significant concentrations of plasma dehydroepiandrosterone and androstenedione persisted throughout the study, even in two ovariectomized patients, indicating a certain degree of autonomy or a greater resistance of adrenal 'androgens' to the inhibition of ACTH secretion. Except in the ovariectomized patients, plasma testosterone did not fall significantly whereas the plasma oestrogens tended progressively towards undetectable concentrations. A similar response was found in six normal postmenopausal women although the disappearance of their oestrogens was relatively rapid. This indicates that much of the testosterone present after the menopause could still be produced by the ovaries whereas the ovarian production of oestrogens becomes negligible. The delayed disappearance of oestrogens in the patients with mammary carcinoma indicates that the persisting adrenal 'androgens' remained efficient precursors of oestrogen synthesis within the peripheral tissues and presumably within the mammary tumour itself. Plasma dihydrotestosterone behaved like the plasma oestrogens. Despite the fall in plasma oestrogens, plasma gonadotrophins did not increase further but plasma prolactin rose progressively. The persistance of steroid sex hormones and the rise of plasma prolactin might explain the poor response to dexamethasone treatment in mammary carcinoma.

Aged↗
PubMed1976

Output of oestrogens, testosterone and their precursors by isolated human adrenal cells as compared with that of glucocorticosteroids.

The output of oestrogens, testosterone and their precursors was compared with that of glucocorticosteroids under standardized conditions, in a suspension of isolated human adrenal cells. Cortisol, corticosterone, androstenedione, dehydroepiandrosterone and its sulphate all increased in the same proportions after ACTH stimulation. The response to the logarithm of ACTH concentrations had a sigmoid shape but was fairly linear between 5 and 100 to 1000 muu./ml. The output of dehydroepiandrosterone plus that of its sulphate was of the same order of magnitude as the production of cortisol; the output of free dehydroepiandrosterone averaged half that of the sulphate indicating that the adrenal cortex is capable, under certain conditions, of producing large amounts of the free steroid. The output of androstenedione was very low, on average 35 times lower than that of cortisol, suggesting by extrapolation that the adrenal secretion may not be the main source of androstenedione in vivo or that ACTH is not the unique stimulus to adrenal androstenedione secretion. The output of testosterone was small to negligible and that of oestrogens was practically absent. In three additional experiments the influence of prolactin, prostaglandins, FSH and HCG was explored: no selective stimulation of androgen or oestrogen output was observed except in one experiment in which HCG stimulated adrenal testosterone production.

Adrenal Cortex↗
PubMed1976

[Latero-cervical branchial cysts and fistulas].

Twenty-four cases of cysts and fistulae of the lateral part of the neck are presented. They come from the very important modification in the branchial apparatus arising during the embryogenesis of the neck. We found these vestigal anomalies moreover under the mandibula before the sterno-cleido-mastoidean muscle, but every where in the lateral part of the neck too. The differential diagnosis must be done between lymph nodes infections, dermoid cysts, benign and malignant tumors. Therefore the puncture seems very contributive. The best therapy is for everybody the radical removal.

Adolescent↗
PubMed1976

[Comparative study of ticarcillin and of carbenicillin as prophylactic treatment in the oncologic surgery of head and neck (author's transl)].

The frequency of postoperative infections in oncologic head and neck surgery can be reduced by the prophylactic use of antibiotics. In order to assess such preventive treatments as to their advantages and disadvantages, a controlled clinical trial was undertaken. The prophylactic use of antibiotics was used in 107 patients, operated for tumors of the upper airway-digestive tract. According to a previous randomisation, the patients received either carbenicillin either ticarcillin. The efficiency of carbenicillin and ticarcillin proved similar. The results obtained with these antibiotics turned out to be superior to those previously obtained with combined ampicillin and cloxacillin; the number of wound infections, primary and secondary, was lessened. The most frequent complications were thrombophlebitis at the site of intravenous perfusion of the antibiotics and hypokaliemia.

Carbenicillin↗