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Biomedical subjects

G Luisetto

Publications and source records attributed to G Luisetto.

At least 37 records · Page 2Linked to original sources
PubMed1994

Sexual influence on bone metabolism in uremic patients on regular dialytic treatment.

In order to evaluate the influence of sex on bone metabolism in patients on regular dialytic treatment, 82 patients (51 males and 31 females) were studied. All the women were amenorrheic and none of them took estrogens. Women showed radiological features of hyperparathyroidism more frequently than men and, in addition, higher bone GLA protein and lower calcitonin serum levels. In both sexes a significant positive correlation was observed between PTH and BGP, but the slope was higher in females, even though not significant. These results suggest that the uremic females show an increased skeletal sensitivity to PTH, probably due to the lack of protective effect of estrogens.

Aged↗
PubMed1994

Glucose-induced insulin secretion in uremia: role of 1 alpha,25(HO)2-vitamin D3.

To evaluate the role and mechanism of action of calcitriol on glucose-induced insulin secretion in uremia, 17 patients with severe chronic renal failure were studied. Glucose metabolism was investigated by the intravenous glucose tolerance test (IVGTT) before and after treatment for 21 days with 0.5 microgram/day of calcitriol and 500 mg/day of calcium (C+Ca) (6 cases) or 0.5 microgram/day of calcitriol alone (C) (11 cases). After these evaluations the patients on C+Ca were shifted to C and 6 patients on C were shifted to C+Ca, and IVGTT was repeated 21 days after the shift. For each test plasma glucose (G), immunoreactive insulin (IRI) and C-peptide (C-p) were measured at -30, 0, 2, 5, 15, 30, 45, 60 min, and baseline plasma values of 1 alpha,25(HO)2-vitamin D3, C-terminal parathyroid hormone (PTH-C), intact parathyroid hormone (PTH-I), calcitonin, and serum values of total and ionized calcium were dosed. Also, glucose constant decay (K-G), insulin response (IRI area), C-p production (C-p area), insulinogenic index (IGI) and insulin resistance index (RI) were calculated. A historical group of 21 healthy volunteers formed the normal controls. 1 alpha,25(HO)2-vitamin D3 plasma levels in uremic patients before treatment were significantly lower than normal range. As compared to controls, uremic patients showed significantly lower K-G, IRI area and IGI values and significantly higher RI values. After treatment with C or C+Ca, the insulin response improved significantly at 2 and 5 min and G decrement was more marked at 30, 45 and 60 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Influence of aging and menopause in determining vertebral and distal forearm bone loss in adult healthy women.

In order to assess the relative influence of aging and menopause in determining the decrease of bone mass in adult women, two groups of normal subjects were examined in this retrospective, cross-sectional study. In group A, bone mineral density (BMD) was evaluated at spine (L2-L4) by dual X-ray absorptiometry (DXA) (Hologic QDR-1000); in group B, BMD was measured at the distal forearm by single photon absorptiometry (SPA) (Osteometer DT 100). Both groups were further divided into two subgroups: A1 and B1 included women with the same postmenopausal, but different chronological age; A2 and B2 included women with the same chronological, but different postmenopausal age. BMD and BMI-corrected BMD (cBMD) were plotted versus age and years since menopause, respectively. Mathematical analysis of the correlation curves between BMD and chronological age showed that the decrease of BMD is very similar at spine and forearm, and is better fitted by a quadratic function. Age-related fractional bone diminution shows a progressive increase with aging (at spine: -0.38%/year at 45 years, -0.81%/year at 50, -1.3%/year at 55 and -1.9%/year at 60. At forearm: -0.5%/year at 50 years, -1.1%/year at 55 and -1.68%/year at 60). On the other hand, menopause-related BMD decrement is very evident during the first year since menopause (at spine: -8.1%/year; at forearm: -3.4%/year), and progressively decreases, according to a logarithmic function. Ten years later, yearly diminution of BMD is below 1%/year and 0.4%/year at spine and forearm, respectively. At this time, age contributes to determine bone loss for 2/3 and menopause for 1/3.

Absorptiometry, Photon↗
PubMed1991

Hypophosphatemia and renal tubular dysfunction in alcoholics. Are they related to liver function impairment?

The study was designed to evaluate (a) the role of reduced renal phosphate reabsorptive capacity assessed as the ratio of maximum capacity for renal phosphate reabsorption (TmPO4) to glomerular filtration rate (GFR) in the pathogenesis of hypophosphatemia in alcoholics, (b) possible mechanisms leading to reduced TmPO4/GFR, and (c) the effect of liver function impairment on TmPO4/GFR. The TmPO4/GFR, its major extrarenal determinants, ratios of urinary excretion gamma-glutamyl transpeptidase and of alpha-glucosidase to GFR (uGGT/GFR and uAGL/GFR), indices of structural damage of renal tubular cells, and fractional clearance of lysozyme, an index of proximal renal function, were evaluated in 31 alcoholics with alcohol-related liver disease, 24 alcoholics without alcohol-related liver disease, 14 patients with non-alcohol-related liver disease, and 25 control subjects. Hypophosphatemia was found in 35% of alcoholics with alcohol-related liver disease, 29% of alcoholics without alcohol-related liver disease, and no patients with non-alcohol-related liver disease. A reduced TmPO4/GFR was the major determinant of hypophosphatemia in both groups of alcoholics. No difference in extrarenal determinants of TmPO4/GFR was found between alcoholics with and without hypophosphatemia. Alcoholics with and without alcohol-related liver disease had increased uGGT/GFR and normal uAGL/GFR regardless of serum phosphate level. Fractional clearance of lysozyme, instead, was increased only in hypophosphatemic alcoholics with and without alcohol-related liver disease. The TmPO4/GFR correlated inversely with the fractional clearance of lysozyme in both groups of alcoholics (P less than 0.01). The TmPO4/GFR and urinary enzymes were normal in patients with non-alcohol-related liver disease. It was concluded that a reduced TmPO4/GFR is involved in the pathogenesis of hypophosphatemia in alcoholics. A proximal tubular dysfunction seems to be responsible for the reduced TmPO4/GFR. Liver function impairment is not required for the expression of this tubular dysfunction.

Adult↗
PubMed1990

Renal function during calcitriol therapy in chronic renal failure.

Some authors have reported that vitamin D treatment worsens renal function. We studied 10 patients with stable renal function, who were given calcitriol (0.5 micrograms/day) for a 4-month period. Creatinine and inulin clearance were performed at the beginning and at the end of the treatment. Although serum creatinine increased and creatinine clearance decreased, inulin clearance did not show significant variations. Furthermore, serum creatinine fell to the baseline value within 60 days after discontinuation of vitamin D therapy. The increased serum creatinine may be explained by an augmented release from muscular tissue, probably due to the improvement of uremic myopathy induced by calcitriol.

Adult↗
PubMed1989

Aldosterone and pressor responses to angiotensin II in primary hyperparathyroidism.

The aim of this study was to assess the effect of hypercalcaemia due to primary hyperparathyroidism on the pressor and aldosterone responses to angiotensin II (Ang II) infusion. Five patients with hyperparathyroidism were studied, before and after parathyroidectomy, and were compared with five normal subjects. After 30 min of equilibration, Asp1-Val5 Ang II was infused in all subjects at stepwise increasing dose rates of 2 and 4 ng/kg per min for 30 min each. In the hyperparathyroid patients the baseline levels of plasma parathyroid hormone and calcium were significantly higher than in the controls, and returned to normal after the parathyroidectomy; plasma aldosterone and renin activity were normal both before and after the parathyroidectomy. Two hyperparathyroid patients had high blood pressure levels, which were normalized after surgery. The increase in the aldosterone response from baseline at each time point of the Ang II infusion was greater in the hyperparathyroid patients before than after the operation (P less than 0.05), and greater than in the normals (P less than 0.05). No difference in the increased response of systolic or diastolic blood pressure was observed between the hyperparathyroid patients, either before or after the parathyroidectomy, and the normal subjects. High levels of extracellular calcium or parathyroid hormone, or both, might play a primary role in the aldosterone hyper-responsiveness to Ang II in the hyperparathyroid patients. The similar pressor response to Ang II in hyperparathyroid patients and the normal subjects suggests that hypercalcaemia does not potentiate the vasoconstrictive action of Ang II.

Adult↗
PubMed1986

Serum levels of calcitonin in Cushing's syndrome.

Serum levels of calcitonin (CT) were studied in 21 patients with Cushing's syndrome (CS), 18 females and 3 males aging from 16 to 59 years, and in 70 age and sex matched normal subjects. Patients with CS showed CT values significantly lower than those found in controls (9.9 +/- 5.0 pg/ml vs. 15.9 +/- 6.3 pg/ml, mean +/- SD; p less than 0.01), while no difference was observed in total serum calcium and phosphate and calcium corrected for albumin. No correlation between CT and serum calcium and phosphate, serum cortisol and urinary free cortisol was found. It is possible that low CT levels are involved in the pathogenesis of bone loss observed in CS.

Adolescent↗
PubMed1984

High serum calcitonin levels in heroin addicts.

An involvement of calcitonin in the mechanism of pain perception has recently been hypothesized. In order to collect information about the relationship between this hormone and well known analgesic substances such as opioids, we have studied the serum levels of calcitonin in a group of heroin addicts, finding higher average concentrations than in normal subjects of matched age and sex. In these addicts there were no severe signs of impaired renal or hepatic function, or alterations of the serum levels of calcium and phosphate. So we think that opioids, in a direct or indirect way, can stimulate the secretion of calcitonin.

Adolescent↗
PubMed1978

[Calcitonin, gastrin, parathyroid hormone and the autonomic nervous system].

Stimulation of the beta-adrenergic terminations was employed to determine whether calcitonin-secreting thyroid C cells are derived from the neural crest. Calcitonin secretion was increased, whereas parathormone, insulin and gastrin values were not significantly changed. In addition, administration of a beta-blocking drug before ethanol led to a marked fall in calcitonin with respect to the baseline. Once again, other hormone levels were not affected.

Calcitonin↗
PubMed1977

[Blood calcitonin in alcoholic cirrhosis].

In spite of an important metabolic role of the liver in the synthesis and degradation of hormonal peptides and seco-steroïds, the clinical occurrence of disturbed regulation of calcium and phosphorus metabolism is rare in hepatic disorders. 23 patients suffering from alcoholic cirrhosis were studied. All had normal plasma calcium and phosphorus concentration as well as immunoreactive parathyroid hormone levels. 25 hydroxyvitamin D3 levels were decreased. Immunoreactive calcitonin were increased in relation to the increase in plasma alkaline phosphatase activity. The causes and consequences of these endocrine disturbances are discussed.

Calcitonin↗