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Biomedical subjects

P Vannini

Publications and source records attributed to P Vannini.

At least 37 records · Page 2Linked to original sources
PubMed1987

Investigation of insulin resistance associated with Werner's syndrome.

The tissue sensitivity to insulin and the metabolic clearance rate of insulin were evaluated in a new case of Werner's syndrome, by means of the euglycemic clamp technique using an artificial endocrine pancreas. The possible contribution of pancreatic insulin secretion and of reduced hepatic insulin breakdown to the peripheral hyperinsulinism was also studied by simultaneous determination of C-peptide and insulin levels and by analysis of the C-peptide/insulin molar ratio. The data obtained are consistent with the presence of marked insulin resistance and of reduced metabolic clearance rate of insulin in our patient, confirming what has been observed previously using other techniques. The finding of a reduced C-peptide to insulin ratio during the intravenous glucose tolerance test suggests that hepatic extraction of insulin could also be altered in Werner's syndrome, as found in several hyperinsulinism conditions, therefore contributing to peripheral hyperinsulinism.

Adult↗
PubMed1986

Tinea capitis in the adult: two case studies.

The authors describe two cases of tinea capitis in adults, one due to Microsporum canis and the other to Trichophyton rubrum. The atypical clinical presentation of the dermatophytosis in these two cases is stressed. It is hypothesized that in both cases the disease spread from primary lesion on the face.

Aged↗
PubMed1986

Comparison between monocomponent human insulin U-40 and U-100 in CSII treatment of type 1 diabetics.

A multicentric study has been carried out to compare the efficacy and the safety of monocomponent human insulins of different concentration (Novo Actrapid HM U-40 and U-100) in CSII-treated Type 1 diabetics. 15 males, all of whom had been diabetic for at least 2 yr, had been treated by CSII and were skillful in the self-monitoring of diabetes were selected for observation at 3 different clinical centres (Bologna, Chieti and Torino). After a 1-week period of insulin dose optimization, the patients were asked not to modify either basal or pre-prandial insulin infusion during the following 2 weeks in which they were treated alternately by U-40 or by U-100 insulin (7 days for each treatment in random sequence). Each day or at least every other day, patients recorded at home a 9-point blood glucose profile by means of glucose-sensitive strips and photometric reading (Reflocheck System-BOEHRINGER MANNHEIM, FRG). The patients used the microinfuser Miles Microjet Bolus 2 for the U-40 infusion and the same model with appropriate modifications for the U-100 infusion. On the last day of each study period, blood samples were drawn after the pre-breakfast insulin bolus. Paired Student's t-test analyses between blood glucose values obtained with different regimens did not show a significant difference in metabolic control. Similarly no difference could be observed in insulin absorption after an identical bolus of U-40 or U-100 insulin. In conclusion human U-100 insulin seems to be as effective and safe as U-40 and is recommended in order to reduce the size of microinfusers.

Adult↗
PubMed1986

Therapeutic experience with ketoconazole.

The efficacy of ketoconazole was evaluated in forty-five patients with dermatophytoses, in twelve with candidosis, in two with fixed cutaneous sporotrichosis, in one with primary cutaneous cryptococcosis and in one with pulmonary aspergillosis. Patients received 200 mg daily of ketoconazole until complete cure, except for patients with vulvovagnitis who received 400 mg daily for five days. All patients with dermatophytoses were cured within 20 to 40 days. No recurrences were observed at post-therapy follow-up. Patients with candidosis were also cured, with only one recurrence. Patients with deep mycoses recovered, except for one with fixed cutaneous sporotrichosis, who showed slight improvement. No significant side-effects were observed during therapy. In conclusion, ketoconazole is an effective therapeutic agent for fungal infections.

Candidiasis, Vulvovaginal↗
PubMed1985

The artificial endocrine pancreas in the surgical treatment of insulinoma. Usefulness and limits.

The usefulness and the limits of the artificial endocrine pancreas in the surgical management of insulinoma has been evaluated in three male patients who underwent pancreatic resection because of previously detected adenoma. In particular, blood glucose and contemporary levels of insulin and C-peptide were continuously monitored before, during and after surgery, to record the temporal relationship between the removal of insulinomas and the variations of these parameters. In the pre-resection phase, only two cases revealed hypoglycemia and required dextrose infusion to correct hypoglycemia and reach euglycemic levels, whereas all the patients showed elevated insulin and C-peptide levels. After anesthesia and surgical incision, the pancreas was observed and manipulated in search of adenoma. In all patients this manoeuvre caused an increase of insulin and C-peptide levels and in two cases a slight decrease of blood glucose levels. After adenoma resection, a prompt increase of glycemia was observed only in one patient, in the other two the time which elapsed before significant blood glucose changes was more prolonged (55 and 80 min. respectively). On the contrary, a rapid fall in insulin and C-peptide levels was observed in all cases. We conclude that artificial endocrine pancreas has the advantage of maintaining the normoglycemia before and during surgery, preventing the risk of dangerous hypoglycemia in basal conditions and following manipulation of pancreas while localizing adenoma. However, the prolonged interval elapsed before significant blood glucose variations limits the usefulness of the artificial endocrine pancreas in localizing intraoperatively previously undetected adenomas.

Adenoma, Islet Cell↗
PubMed1985

Effect of long-term near-normoglycemia on the progression of diabetic nephropathy.

The effect of prolonged restoration of near-normoglycemia on the progression of diabetic nephropathy was evaluated in a controlled study in which 10 insulin-dependent (type 1) diabetic patients with clinical proteinuria were randomized to continue with conventional insulin treatment (CIT) or to undertake more intensive diabetic therapy using continuous subcutaneous insulin infusion (CSII). The patients, mean age 33 +/- 8 yr, mean duration of diabetes 15 +/- 4 yr, were studied before and during 12 months of either CIT or CSII therapy. Glycemic control was assessed by means of mean blood glucose (MBG) +/- Standard deviation (SD), urinary glucose excretion and glycosylated hemoglobin, while renal function was assessed by albumin, IgG and beta-2-microglobulin urinary excretion rates, serum creatinine and creatinine clearance. Blood glucose level, urinary glucose excretion and glycosylated hemoglobin fell significantly in the CSII group, while no differences were found in the CIT group after the 12 months observation period. Both groups showed a deterioration in all indices of renal function, as illustrated by an increase of protein excretion rates and of serum creatinine, and by a decline in creatinine clearance. Comparison of the rate of increase of urinary albumin and IgG excretion and of serum creatinine and of the rate of fall in creatinine clearance between CIT and CSII groups demonstrated that the rate of progression of diabetic nephropathy may be slowed by correction of hyperglycemia. Our study, with due reservations because of the small number of examined patients and differences in kidney function at the beginning of the trial shows that intensive diabetic care may play a role in the proteinuric stage of diabetes in slowing further destruction of residual glomerular structure and in delaying end stage renal failure.

Adult↗
PubMed1984

Insulin-dependent metabolism of branched-chain amino acids in obesity.

The effect of euglycemic hyperinsulinism on branched-chain amino acids (BCAA; valine, isoleucine and leucine) was evaluated in five obese subjects and five controls. A continuous intravenous insulin infusion raised plasma insulin to a steady-state level. An artificial endocrine pancrease that infused glucose was used to sustain euglycemia. Basal and steady-state insulin levels were significantly higher in the obese subjects than in the controls. The amount of glucose infused to maintain euglycemia and its ratio to steady-state insulin levels was significantly lower in the obese subjects, suggesting an impaired insulin action on glucose metabolism. Basal BCAA levels were similar in the two groups of subjects. During insulin infusion the decremental areas of BCAA below basal levels were significantly lower in the obese patients (63 +/- 5 nmol/mL X min v 143 +/- 8 nmol/mL X min, P less than 0.001), as was the ratio of the decremental areas of BCAA to the incremental areas of insulin (1.11 +/- 0.05 nmol/microU v 3.30 +/- 0.24 nmol/microU, P less than 0.001). Our data suggest that insulin resistance in obesity reduces hormonal effects on glucose as well as on BCAA metabolism.

Amino Acids, Branched-Chain↗
PubMed1984

The euglycemic clamp technique in patients with liver cirrhosis.

Tissue sensitivity to insulin and insulin metabolic clearance rate were assessed by means of the euglycemic clamp technique in 11 controls and 11 patients with liver cirrhosis. The method was carried out using an artificial endocrine pancreas. The amount of glucose infused to keep euglycemia, as well as the ratio of glucose infused to steady-state insulin level, were significantly lower in cirrhotics as compared to controls (p less than 0.001). The metabolic clearance rate of insulin did not show significant differences between the two groups. Our results confirm that a marked insulin resistance is present in cirrhotics, as previously shown by means of different techniques.

Adult↗
PubMed1983

Plasma amino acid response to protein ingestion in patients with liver cirrhosis.

The metabolic effects of a protein-rich meal were studied for 3 h in 10 controls and in 20 cirrhotic patients. After protein ingestion, blood glucose did not vary significantly. Insulin and glucagon levels rose in controls and, more markedly, in cirrhotics. Aromatic amino acids and tryptophan increased more in cirrhotics as a result of their decreased liver function. Similarly, branched-chain amino acids increased by 153 +/- 14 nmol/ml X min (mean +/- SE) in controls and by 259 +/- 27 nmol/ml X min in cirrhotics (p less than 0.02), in the presence of a markedly increased insulin response. Branched-chain amino acid metabolism mainly occurs in skeletal muscle under insulin control; in cirrhosis, it might be reduced as a consequence of insulin resistance. To support this hypothesis, the effects of the protein meal were compared with those of an oral glucose load in 15 cirrhotic patients. Branched-chain amino acid response to protein ingestion significantly correlated with blood glucose response to oral glucose (r = 0.714), and with insulin resistance during the glucose tolerance test, when assessed by the insulinogenic index (r = 0.628). Similarly, in 8 patients, increased branched-chain amino acid response also correlated with the index of tissue sensitivity to insulin obtained by means of the glucose clamp technique during continuous insulin infusion (r = -0.809). We conclude that liver cirrhosis is characterized by an abnormal branched-chain amino acid response to protein ingestion, which matches the well-known intolerance to oral glucose. Both alterations are possibly due to decreased peripheral insulin activity on substrates.

Amino Acids↗
PubMed1982

Muscle protein breakdown in uncontrolled diabetes as assessed by urinary 3-methylhistidine excretion.

In an attempt to evaluate muscle protein catabolism in patients with uncontrolled diabetes, urinary excretion of 3-methylhistidine was measured in eight diabetic subjects, during poor control and after achievement of satisfactory control. The results were compared with the excretion values of ten healthy subjects fed a similar amount of meat. In the diabetic patients in poor metabolic control, 3-methylhistidine excretion was significantly increased compared with the healthy subjects, and returned to normal when a satisfactory glycaemic control was achieved. No significant differences were observed between ketonuric and non-ketonuric uncontrolled patients. Improved glycaemic control reduced 3-methylhistidine excretion in both insulin-dependent and non-insulin-dependent diabetes. These results suggest increased protein catabolism causing muscle protein loss and negative nitrogen balance in diabetic patients with poorly controlled disease.

Adult↗
PubMed1982

Branched-chain amino acids and alanine as indices of the metabolic control in type 1 (insulin-dependent) and type 2 (non-insulin-dependent) diabetic patients.

Alterations in plasma branched-chain amino acids (valine, isoleucine and leucine) and alanine have been described in patients with insulin-dependent diabetes mellitus who have poor metabolic control. To assess the relevance of these abnormalities as indices of metabolic control, we sequentially evaluated plasma amino acids in 14 poorly controlled diabetics (seven Type 1 (insulin-dependent) and seven Type 2 (non-insulin-dependent) patients) until good control was achieved. The sum of branched-chain amino acids in both groups of uncontrolled diabetic patients was significantly increased compared with the values for the same subjects in good metabolic control. No statistically significant differences were present between ketotic and non-ketotic uncontrolled patients. The amelioration of the diabetic state with either insulin treatment or oral hypoglycaemic agents, reduced progressively branched-chain amino acids. The sum of valine, isoleucine and leucine strictly correlated with daily urinary glucose (r = 0.73), but less well with fasting blood glucose (r = 0.43), non-esterified fatty acids (r = 0.46) and glycosylated haemoglobin (r = 0.38). Alanine did not show any statistically significant differences at various stages of diabetic control. Branched-chain amino acids, but not alanine, may be used as indices of short-term diabetic control.

Alanine↗