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Biomedical subjects

C Varela

Publications and source records attributed to C Varela.

70 records · Page 4Linked to original sources
PubMed1984

Prolactin as a marker of dopaminergic activity at different levels of thyroid function in man.

To investigate the hypothesis of an altered dopaminergic activity in hypothyroidism, seven patients without thyroid tissue were studied by means of three consecutive tests: an iv bolus of TRH (200 micrograms); a continuous iv infusion (5 mg during 30 min) of metoclopramide (MCP); and a second, post-MCP, iv bolus of TRH (200 micrograms). The study was performed three times: (A) without treatment; (B) on the 15th day while on L-T4 (150 micrograms i.d.); and (C) on the 30th day with the same treatment. Each time was a different situation of thyroid function; on the basis of basal serum TSH (P less than 0.001, A vs B vs C). The response of PRL to the first (non-primed) TRH, expressed as the sum of increments in ng/ml (mean +/- SE), was significantly higher in A (659 +/- 155) than in C (185 +/- 61). Individual PRL responses correlated with circulating T3 (P less than 0.02), but not with T4. A significant increase of PRL occurred after MCP in the three situations, but there were no differences among them. Likewise, the responses to the second (MCP-primed) TRH showed no differences. Although there was an expected high correlation (P less than 0.001) between basal TSH and circulating thyroid hormones, the maximal response of TSH to both non-primed and MCP-primed TRH was in B. After MCP, no measurable increase of TSH could be demonstrated at any of the three levels of thyroid function. These results do not support the hypothesis of an altered dopaminergic activity in hypothyroidism.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Dopaminergic modulation of aldosterone secretion: effect of sodium balance and postural changes.

The influence of an increased endogenous production of angiotensin II and of sodium homeostasis upon the response of plasma aldosterone to metoclopramide administration has been investigated in 5 normal volunteers. Our results show that the increase of plasma aldosterone after metoclopramide administration is independent of angiotensin II, ACTH and potassium, and that it increases even further due to the endogenous production of angiotensin II induced by postural changes. The state of sodium balance seems to influence the response of plasma aldosterone to metoclopramide administration as it occurs with other stimuli of aldosterone secretion.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

A randomized cross-over study comparing cabergoline and quinagolide in the treatment of hyperprolactinemic patients.

Quinagolide (QUI) and cabergoline (CAB) are dopamine agonists recently introduced for the treatment of hyperprolactinemia. In the present study, these drugs have been compared in terms of effectiveness and tolerability. Twenty patients (18 females and 2 males) with hyperprolactinemia (8 with microprolactinomas, 6 with idiopathic hyperprolactinemia and 6 with empty sella turcica syndrome) were treated with oral QUI (75 microg once daily) and CAB (0,5 mg twice weekly), in a randomized cross-over trial with placebo between both drugs. Each drug was administered for 12 weeks, separated by other 12 weeks with placebo. PRL levels decreased with both drugs at 2 or 4 weeks of starting the treatment, without differences between both drugs at weeks 4, 8 and 12. At week 12, normal PRL levels (<20 ng/ml) were attained in 90% patients with CAB and only in 75% patients with QUI (p<0.05). After discontinuation of treatment, significant increase in serum PRL was higher after QUI withdrawal than after CAB. Clinical efficacy of both treatments was similar in terms of improvement amenorrhea, oligomenorrhea, galactorrhea, and impotence. All patients completed both cycles of treatment, and the most frequent side-effects were nausea, headache and dizziness, without significant differences between CAB (30%) and QUI (55%). Our study indicates that, at the doses employed here, CAB showed a high percentage of patients with normal PRL at the end of treatment and long-lasting efficacy in the levels of PRL. Clinical response and side-effects were similar in both drugs.

Adult↗
PubMedDate not supplied

Comparisons of activity measurements with radionuclide calibrators.

The correct administration to a patient of the prescribed activity of a radiopharmaceutical is an important factor to ensure the confidence in the diagnosis or the therapeutic efficiency, while at the same time keeping the unnecessary human exposure as low as possible. Comparisons of activity measurements for 131I, 201Tl and 99mTc with radionuclide calibrators were organized the first time in Cuba during 2002 with the aim of obtaining information about the quality of administration of radiopharmaceuticals. Ten Cuban nuclear medicine departments and the laboratories involved in the production of these kinds of compounds participated in the comparison runs. The results presented in this paper facilitated the identification of several problems and initiated corrective actions. In addition, they indicate the necessity of establishing Quality Systems in nuclear medicine in Cuba.

Calibration↗
PubMedDate not supplied

Hypothyroidism and primary open-angle glaucoma.

OBJECTIVE: To test if there is an association between hypothyroidism and primary open-angle glaucoma (POAG) and the utility of routine study of thyroid function in these patients. METHODS: The study was conducted in a case-control fashion. Seventy-five consecutive patients with a previous diagnosis of POAG and 75 control patients were prospectively evaluated for hypothyroidism. The levels of thyroid-stimulating hormone and free thyroxin were measured. RESULTS: Hypothyroidism was revealed in only 2 patients with previous diagnosis of POAG (2.67%) and 3 patients of the control group (4%). CONCLUSIONS: As we have not been able to demonstrate the previously reported relationship between hypothyroidism and POAG, we cannot recommend the systematic screening for hypothyroidism in patients with POAG.

Adult↗
PubMedDate not supplied

[Diagnostic process and management of schizophrenia in Spain: the ACEE project].

INTRODUCTION: Although schizophrenia has a great impact on the health care, social and family levels, there is little epidemiological information on patients with schizophrenia, its diagnosis and treatment in Spain. The ACEE (Abordaje Clínico de la Esquizofrenia en España; Clinical Approach to Schizophrenia in Spain) study was designed with the primary objective of defining the management of schizophrenia in Spain from the perspective of current clinical practice. METHOD: ACEE is a descriptive cross-sectional multicenter observational study with data collected in the setting of current clinical practice by means of a specifically designed questionnaire. RESULTS: A total of 1,937 patients have been studied (83% pertaining to the public sector and 17% to private one). Most subjects had paranoid schizophrenia in the stabilization phase, and did not work because of their illness. Most (96%) were receiving antipsychotic treatment and 55% also received some non-drug treatment. Negative symptoms were more frequent than positive symptoms (88% versus 63%). Significant differences were observed for type of patients and diagnostic procedures involved between the public and private health care sectors. CONCLUSIONS: The ACEE study shows that schizophrenic patients attending Spanish psychiatric centers are mainly single, non-working males who are living in their family setting. Treatment basically consists of antipsychotics combined with other drugs, and few complementary examinations are performed.

Combined Modality Therapy↗