PubMed Health⌕ Search

Biomedical subjects

L Díaz

Publications and source records attributed to L Díaz.

At least 55 records · Page 3Linked to original sources
PubMed1984

Preliminary study of hormone determinations during aminoglutethimide therapy for advanced breast cancer.

The aim of this study is to report on Aminoglutethimide-induced hormonal modifications in advanced breast cancer. Estradiol (E2), Testosterone (T), Dehydroepiandrosterone sulphate (DHEA(s] and Aldosterone (A) were determined before, and once every two weeks during treatment with Aminoglutethimide plus Hydrocortisone in 13 menopausal women with advanced breast cancer. The patients were selected either for their E2 and P4-receptor-positive in the original tumor or in metastases or by presenting objective clinical improvement to prior endocrine treatment. On the basis of the response to treatment the patients may be classified in two groups: 1) responders (n = 7) and 2) non-responders. No significant modifications of T concentrations were obtained in group 1 until after the first 8 months of treatment. One spontaneous menopausal patient with a T basal value of 0.80 ng/ml was evaluated during 12 months of treatment. From month 8, T diminished to values below 0.30 ng/ml, indicating a direct action of Aminoglutethimide, hydrocortisone or both drugs on ovarian steroidogenesis. The results obtained from the remaining hormonal parameters, evaluated in all the cases beginning from the second week of treatment, remained unchanged throughout the entire period of study. They were as follows: 1) E2 diminished with respect to basal values between 36 and 60%, thus confirming Aminoglutethimide inhibitory effect upon peripheral aromatization; 2) DHEA(s) diminished between 80 and 90%, indicating an adrenal inhibition due to the combined effect of both drugs, and 3) Aldosterone diminished to values between 80 and 110 pg/ml, these values being within the normal lower range.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1981

Specificity of heme oxygenase: a study with synthetic hemins.

A large number of synthetic iron porphyrins were enzymatically oxidized by a microsomal heme oxygenase preparation from rat liver. They all had in common two vicinal propionic acid residues at C6 and C7. Iron porphyrins of type I were not substrates of the enzyme. Iron porphyrins that carried electron-withdrawing substituents (acyl residues) at C2 and C4 were substrates of heme oxygenase, although the product yields were reduced. Several iron porphyrins, such as hemin XIII (4) and hem III (5), were better substrates of heme oxygenase than the natural substrate hemin IX (1). The enzymatic oxidation was selective for the alpha-methine bridge, and the alpha-biliverdins obtained were reduced by Biliverdin reductase to the corresponding alpha-bilirubins. Preincubation of the enzymatic system with hemin IX (1) and hemin XIII (4) in the absence of NADPH resulted in an inhibition of their oxidation. The iron-free porphyrins which carried two vicinal propionic acid residues at C6 and C7 were also found to be inhibitors of the enzymatic system when preincubated with the latter. The presence of hematochemin IX (18) suppressed the enzymatic oxidation of hemin IX (1).

Animals↗
PubMedDate not supplied

Metastases to the uterine cervix from a gastric carcinoma presenting with obstructive renal failure: a case report.

Metastases to the uterine cervix are infrequent(1-3). Except for cases of endometrial primary carcinoma, the most common origin of neoplastic dissemination to the uterine cervix is the ovary, followed by the breast(1,2). Primary gastrointestinal tumors are rare, and in most of these cases cervical metastases are associated with adnexal bilateral masses (Krukenberg's tumors)(1).

Acute Kidney Injury↗
PubMedDate not supplied

Glomerular hemodynamics in persistent renovascular hypertension in the rat.

We studied the glomerular hemodynamics and activity of the tubuloglomerular feedback system (TGFS) in Wistar rats with persistent hypertension 60 days after removal of the clipped kidney in the Goldblatt (two-kidney, one clip) hypertension model. Ten hypertensive rats (HBP) were compared with 12 normotensive ones (NBP). Micropuncture studies revealed that values for the single nephron glomerular filtration rate (SNGFR), glomerular plasma flow (QA), and afferent oncotic pressure (PAR.A) were similar in both groups, whereas glomerular capillary pressure (PGC) and effective filtration pressure (EFP) were higher in the HBP group (p less than 0.05). A slight but insignificant increase in afferent resistance was present in the HBP group. A positive correlation was found between mean arterial pressure and stop flow pressure (SFP) (r = 0.64, p less than 0.05) but not with SNGFR, suggesting a reduction in the ultrafiltration coefficient in hypertensive rats. This was further supported by studies of the activity of the TGFS, which demonstrated that interrupting flow to the macula densa was followed by a smaller increment in SNGFR in HBP, in spite of a similar rise in SFP. The mechanism responsible for decreasing glomerular permeability is unknown but could be related to structural changes in glomerular capillary or to an increase in intrarenal angiotensin II, as has been demonstrated previously in this model. It is suggested that these adaptations occurring in the kidney exposed to hypertension can contribute to the maintenance of elevated arterial pressure after removing the stenotic kidney.

Angiotensin II↗
PubMedDate not supplied

[Severe hepatotoxicity caused by amiodarone: description of a case].

Amiodarone is useful for the treatment of ventricular and supraventricular arrhythmias, but it has been associated with several adverse effects. Amiodarone-induced hepatotoxicity is a frequent complication and often consist in a mild and asymptomatic elevation of liver function tests, although severe cases have been described. A case of severe amiodarone-induced hepatotoxicity slowly resolving after discontinuation of the drug and in which liver biopsy was crucial for diagnosis is reported. Although there are no pathognomonic histopathological findings, phospholipidosis is the morphologic hallmark of amiodarone hepatotoxicity.

Aged↗
PubMedDate not supplied

[Vitamin D: implications for health and pregnancy].

Vitamin D gained importance since the discovery of its steroid structure. Vitamin D participates in mineral homeostasis, regulation of gene expression, and cell differentiation. Recent advances in the study of the enzyme involved in the conversion of 25-hydroxyvitamin D3 into 1,25-dihydroxyvitamin D3 (calcitriol), as well as the discovery of it's hormone mechanism of action, have led to a better knowledge and understanding of vitamin D endocrine system, as well as it's implication in health and pregnancy.

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗