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Biomedical subjects

C Villabona

Publications and source records attributed to C Villabona.

At least 37 records · Page 2Linked to original sources
PubMed1993

[Basal cortisol and ACTH in the immediate postoperative period in ACTH-producing hypophyseal adenomas].

BACKGROUND: Evaluate the usefulness of basal cortisol and ACTH during the immediate postoperative period following hypophyseal surgery, as early indicators of remission in patients with Cushing's disease. METHODS: Nine patients with Cushing's disease and on whom selective transphenoidal adenomectomy was performed were included in the study. Basal cortisol and ACTH levels were compared the first week after surgery, with definitive results being obtained after a month's time during which basal cortisol levels below 165 nmol/l indicated patients cured of Cushing's disease. RESULTS: Cortisol levels determined post-op, in five patients in remission, were found to be lower than those in patients who were not cured (63 +/- 55.8 versus 606 +/- 267 nmol/l, p < 0.01). However, ACTH levels were not lower. All the patients in remission had initial cortisol levels lower than 182 nmol/l, whereas the uncured patients had levels higher than 404 nmol/l. There was a correlation between cortisol measured in the first week and the definitive value (r = 0.81, p < 0.01). CONCLUSION: Cortisol in the immediate postoperative period following hypophyseal surgery is a good indicator of definitive adrenocorticotropic function and permits the identification of those patients in remission.

Adenoma↗
PubMed1990

Abnormalities of lipoprotein metabolism in patients with the nephrotic syndrome.

BACKGROUND AND METHODS: Patients with the nephrotic syndrome characteristically have multiple abnormalities of lipoprotein metabolism, but the cause and exact nature of these abnormalities are uncertain. In this study, we measured serum lipids and apoproteins in 57 patients with the nephrotic syndrome. We also determined the kinetic indexes of low-density lipoprotein (LDL) metabolism in six patients, and again in three of the six after recovery. RESULTS: The patients with the nephrotic syndrome had elevated serum concentrations of cholesterol, triglycerides, and phospholipids, which were confined to the lipoproteins containing apoprotein B. The serum concentrations of high-density lipoproteins and the associated A-I and A-II apoproteins were similar in the patients with the nephrotic syndrome and normal subjects. The relative proportions of lipids and their positive association with the increased serum concentrations of apoproteins B, C-II, C-III, and E suggest quantitative rather than qualitative differences in the lipoproteins. All the patients had lipiduria, which probably reflected the excretion of high-density lipoproteins, although no intact immunoreactive apoprotein A-I was found in urine. Serum albumin concentrations were inversely related to serum lipid concentrations in the patients, the severity of the hypoalbuminemia corresponding to the degree of change in serum lipoprotein concentrations. The kinetic studies of lipoprotein metabolism revealed an overproduction of LDL apoprotein B that returned to normal after recovery. CONCLUSIONS: The elevated serum concentrations of LDL cholesterol, other lipids, and apoprotein B in patients with uncomplicated nephrotic syndrome are due to reversible increases in lipoprotein production.

Adolescent↗
PubMed1990

Toxicity of lovastatin in rats with experimentally induced nephrotic syndrome.

The effect of lovastatin on the hyperlipidemia induced in rats with experimental nephrotic syndrome was investigated; toxicity and the effects on common blood chemistry parameters were also assessed. Hyperlipoproteinemia in this particular model is associated with an increase in hepatic synthesis of lipoproteins, and treatment with lovastatin could be the most suitable, since the drug inhibits cellular cholesterol synthesis. Lovastatin treatment resulted in a considerable reduction in plasma cholesterol and triglyceride levels. The decrease in cholesterol levels with treatment was mainly confined to the low-density lipoproteins (LDL) although there was a reduction in the nephrotic-syndrome-induced incremental level of high-density lipoprotein cholesterol. Other lipoprotein fractions were unaffected by lovastatin. LDL apoprotein B was increased in both groups of rats, but to a lesser degree in the lovastatin-treated group, suggesting a double effect, inhibition of both, cholesterol and apoprotein synthesis. Both groups of rats showed a certain degree of renal impairment as shown by significant elevations in plasma urea and creatinine levels. Hepatic damage was also observed, chemically and microscopically, in both groups of rats, being more pronounced in those rats treated with lovastatin in which a 50% mortality ensued after 2 weeks of treatment. At the dosage used this may have some implications in its therapeutic use in certain conditions.

Animals↗
PubMed1989

Low density lipoprotein metabolism in rats with puromycin aminonucleoside-induced nephrotic syndrome.

With puromycin aminonucleoside-induced nephrotic syndrome (NS) in rats, twofold elevated levels of lipoproteins were observed. These levels were not related to proteinuria or to plasma albumin levels. Ultrastructural lesions induced in the kidneys by puromycin aminonucleoside were consistent with NS, while there was little or no hepatic involvement. Apolipoprotein B (apo B) kinetic measurements using homologous 125I-labeled low density lipoproteins (LDL) demonstrated a higher synthetic rate in nephrotic rats relative to controls (6.18 +/- 1.86 micrograms x g-1 x d-1 v 3.94 +/- 0.66 micrograms x g-1 x d-1 respectively, P less than .005), while the fractional catabolic rate was only marginally reduced (1.64 +/- 0.28 pools x day-1 in NS v 1.83 +/- 0.37 pools x day-1 in controls, P less than 0.4). These results indicate that in rats with experimentally induced NS, the expanded apo B-LDL pool results from increased synthesis of this apoprotein while no significant role can be ascribed to alterations in its catabolism. These data are consistent with our preliminary findings in NS in humans.

Animals↗
PubMed1987

Potassium disturbances as a cause of metabolic neuromyopathy.

We report two cases of ascending muscular weakness progressing to areflexic quadriplegia caused by severe derangement of potassium homeostasis. The first patient presented with a 17-alpha-hydroxylase deficiency and severe hypokalemia. The second case had primary adrenocortical deficiency (Addison's disease) and extreme hyperkalemia. Complete recovery ensued after correction of the metabolic disorder in both cases. The role of potassium in the pathophysiology of neuromuscular excitation is discussed. We conclude that when neuromyopathy is present, metabolic causes should be considered and the serum potassium determined.

Addison Disease↗
PubMed1985

Hormonal profile and serum zinc levels in uraemic men with gonadal dysfunction undergoing haemodialysis.

Serum gonadal hormones, gonadotrophins and zinc levels were studied in thirteen men aged 29-62 yr with chronic renal failure undergoing haemodialysis. All patients had decreased libido and impotence. Serum testosterone levels in patients (18.5 +/- 1.3 (SEM) nmol/l) were significantly lower (p less than 0.05) than in the control group (24.1 +/- 2.2 (SEM) nmol/l) although salivary testosterone levels were strictly within the normal range. Mean serum 17-beta-oestradiol and luteinizing hormone levels (0.19 +/- 0.03 (SEM) nmol/l, and 57.4 +/- 13.1 (SEM) IU/l, respectively) were significantly higher (p less than 0.05 and p less than 0.005, respectively) than in the control group (0.11 +/- 0.02 (SEM) nmol/l and 14.8 +/- 1.9 (SEM) IU/l, respectively). Mean progesterone and follicle-stimulating hormone levels in patients were not significantly different from those of control subjects. Mean prolactin values in patients (1,019 +/- 285 (SEM) mIU/l) were significantly higher (p less than 0.01) than in the control group (211 +/- 24 (SEM) mIU/l). Serum prolactin levels in five patients were extremely high (above 1,200 mIU/l). There was no statistically significant difference in serum zinc levels between patients and controls. As salivary testosterone is normal, it seems that hyperprolactinaemia and raised serum 17-beta-oestradiol levels may be responsible, at least in part, for sexual dysfunction in male patients with chronic renal failure receiving haemodialysis.

Adult↗