Search PubMed⌕ Search

Biomedical subjects

F Capani

Publications and source records attributed to F Capani.

At least 55 records · Page 3Linked to original sources
PubMed1993

Prediabetes: genetic, immunological and metabolical aspects.

There is mounting evidence from experimental animal diabetes and from human epidemiological studies that a long period of "prediabetes" precedes the clinical onset of type 1 (Insulin Dependent) Diabetes Mellitus. In this review, the authors evaluate the main informations concerning the genetic, immunological and metabolic aspects of this phase of prediabetes and the relationship of prediabetes with the onset of the disease. Prediabetes is a long period; in this period the destruction of beta cells can be caused by many factors and by many pathogenetic mechanisms. Nowadays, we begin to understand some of these mechanisms and the central role of the activation of the immune system; this activation results in various humoral and cellular abnormalities detectable in the prediabetic phase. These abnormalities, together with metabolic ones, have been reported in many studies. Consequently, we have at our disposal some genetic, immunological and metabolical markers which can be useful in the detection of the person at risk of developing diabetes mellitus.

Animals↗
PubMed1992

Circadian variations in antioxidant defences and lipid peroxidation in the rat heart.

Circadian variations in antioxidant defences and lipid peroxidation were investigated in 12 rat hearts perfused during light (i.e., at 08.00, n = 6) and dark cycle (i.e., at 19.00, n = 6). Higher levels of non proteic thiol compounds (P < 0.01), glutathione transferase activity (P < 0.05) and lipid peroxidation (P < 0.01) were detected in evening-excised hearts, associated with a lower (P < 0.05) selenium-dependent glutathione peroxidase activity; superoxide dismutase and glutathione reductase activities, as well as vitamin E content, were similar in the two groups. Moreover, a greater release of thiobarbituric acid reactive substances (P < 0.01) and proteins (P < 0.05) was detected in the myocardial effluent of another group of 5 evening-excised hearts perfused with Krebs-Henseleit buffer containing 30 microM cumene hydroperoxide, as compared to 5 light-cycle hearts. In conclusion, a higher oxidative stress seems to be operative in the rat heart during early stages of the dark phase, in spite of the increase level of non proteic thiol compounds (namely, glutathione). An imbalance of antioxidant defences, and/or higher radical generation and unsaturation degree of biomembranes lipids, may be hypothesized to favour myocardial oxidative stress at the beginning of the motor activity phase in rats.

Animals↗
PubMed1992

[Echographic evaluation of pancreatic dimensions in type 1 diabetes mellitus].

Aim of this study was to determine whether pancreatic size is altered in patients suffering from type I diabetes mellitus. Twenty-five diabetics (14 males and 11 females) and twenty-five healthy controls entered the study. All patients and controls were scanned by the same operator with the same US equipment after overnight fasting. The longitudinal and antero-posterior diameters of the head, body and tail and the transverse diameter of the head as well as the total area of the gland were measured through longitudinal and axial scans. The two groups were homogeneous relative to age, sex, distribution, height, weight and body mass index. All measured diameters as well as the total area of the gland were significantly smaller in diabetic patients than in controls (1-way ANOVA: p less than 0.001). These results may open new perspectives to US identification of possible changes in pancreatic size by a new US study including high-risk subjects without clinical signs.

Adult↗
PubMed1990

Circadian time structure of pituitary and adrenal response to CRF, TRH and LHRH.

In six healthy males, aged 25.3 +/- 0.66, the pituitary and adrenal simultaneous response to CRF (1 microgram/kg), TRH (200 micrograms) and LH-RH (100 micrograms) was studied at the following times of different days: 0400, 0800, 1200, 1600, 2000 and 0000. Each test was preceded by a 8-hr fast after a meal containing 600 cal (CHO 50%, lipid 30%, protein 20%). The interval between two consecutive tests was 52 hrs and the starting time was randomized. The serum cortisol was measured before and after 60, 120, 180, 240 min. Serum TSH, Prolactin, FSH and LH were measured before and after 5, 10, 15, 30, 60, 90 and 120 min. The statistical analysis was reported by both mean chronograms (as absolute values and relative change or absolute difference from mesor) and mean cosinor on basal values and total (T.A.) or incremental (I.A.) areas after RH stimulus. Serum cortisol: a statistically significant circadian rhythm was found for basal values with a peak in the morning (phi at 1040; 95% C.L. 0808-1438). T.A. after RH stimulus as well appeared statistically higher again in the morning, whereas the I.A. presented an opposite phase with higher values at night (phi at 2133; 95% C.L. 2055-0312). Serum Prolactin: mean chronogram analysis showed significantly higher basal values at 0800 and lower values at 1600, whereas I.A. were significantly lower in the morning. Serum LH: basal values were statistically higher in the morning, while T.A. and I.A. showed an opposite behaviour with peaks in the night (T.A.: phi at 2015, 95% C.L. 1710-0035; I.A.: 0 2033; 95% C.L. 1736-0004).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Can the chronobiological approach better evaluate the relationship between diabetes mellitus and arterial hypertension?

This work evaluates by a chronobiological approach the relationship between arterial hypertension and diabetes mellitus. Sixteen type II (non-insulin-dependent) diabetic hypertensive males (age 50-60 years, BMI 26 +/- 1, without nephropathy) were selected for the study. Blood pressure (BP) was considered borderline, mild or moderate, systolic and/or diastolic by a single measurement (occasional measurement) according to the Report of the Joint National Committee on Detection, Evaluation and Treatment of High Blood Pressure (1984). Then both dynamic ambulatory BP through a 24-hr span (5300 ABPS Spacelabs) and an oral glucose-tolerance test (100 gm) with serum glucose and insulin measures were carried out. Total insulin area (TIA) and total glucose area (TGA) were computed. Blood-pressure values were analyzed by the Cosinor method, and then percent time of elevation (PTE) and the hyperbaric impact (HBI) were calculated. A statistically significant positive correlation was found between TIA and the mesors of both systolic BP/diastolic BP (p less than 0.05) and HBI (p less than 0.05 and p less than 0.01, respectively).

Blood Pressure↗
PubMed1989

Circadian variation in renal sodium and potassium handling in cirrhosis. The role of aldosterone, cortisol, sympathoadrenergic tone, and intratubular factors.

Renal sodium and potassium handling, plasma aldosterone and cortisol concentrations, and urine free norepinephrine excretion were determined every 4 h for 24 h in 15 cirrhotics (7 without ascites, group 1; 8 with ascites, group 2) and 7 healthy controls during controlled salt intake and recumbency. Renal sodium excretion was significantly reduced in group 2, whereas it exceeded threefold the salt intake in group 1. Its circadian rhythm was disrupted in both groups of patients. Significant inverse correlations with plasma aldosterone were found erratically in controls, never in group 1, and at every 4-h interval in group 2. In the latter, the indexes of tubular activity and effectiveness of aldosterone were also significantly increased. Urine norepinephrine excretion was never related to sodium excretion in either controls or patients; in group 2 it was directly correlated with glomerular filtration rate in many instances. The cortisol-related circadian rhythm of kaliuresis was retained only in group 1. The 24-h renal potassium excretion of controls and patients was comparable, in spite of the striking hyperaldosteronism, and the more than doubled contribution of aldosterone to kaliuresis shown in group 2. The influence of aldosterone on potassium excretion was also witnessed by the direct correlation between these variables found in group 1 and, when kaliuresis was corrected by the distal sodium delivery, group 2. Renal sodium handling in cirrhosis is altered even before ascites formation and compensated patients can undergo "spontaneous natriuresis." Aldosterone is the main cause of sodium retention in nonazotemic ascitic patients, while sympathoadrenergic hyperactivity may contribute to preserve renal perfusion. The influence of aldosterone on kaliuresis is enhanced, but renal potassium wasting in patients with ascites and hyperaldosteronism is prevented by reduced distal tubular availability of sodium.

Adult↗
PubMed1989

Circadian rhythm of proteinuria: effects of an evening meat meal.

Ten healthy volunteers were studied to test the effect of a meat meal on the circadian rhythm of urinary proteins. All subjects were kept at bed-rest during the whole 24-h evaluation period. An oral protein load (0.6 g/kg bodyweight) was given at supper-time (19.00 hours). Urinary and serum samples were collected every 3 h and examined for total protein, albumin, retinol-binding protein, and creatinine. All these variables and glomerular filtration rate (GFR), as measured by creatinine clearance, showed circadian rhythms. Acrophases were located at 14.21 hours (range 11.11-16.25) for urinary total protein, at 17.27 hours (13.14-22.31) for serum total protein, at 15.13 hours (13.01-18.04) for urinary albumin, at 14.18 hours (11.13-19.20) for serum albumin, at 21.22 hours (18.42-02.41) for urinary retinol-binding protein, at 14.51 hours (08.52-19.57) for serum retinol-binding protein, and at 16.17 hours (13.38-19.25) for creatinine clearance. Thus, the acrophases of urinary total protein and urinary albumin excretion rates occurred before the supper protein load, in a time span common to the acrophases of their serum levels and maximal GFR, whereas the acrophase of urinary retinol-binding protein occurred after the supper meat meal, concomitantly with the lowest value of serum retinol-binding protein. These findings suggest that circadian rhythms of urinary total protein and urinary albumin are influenced by changes in GFR, which occur also independently from an oral protein load. In fact, the latter did not modify creatinine clearance when administered at supper time.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Predominant role of gluconeogenesis in increased hepatic glucose production in NIDDM.

Excessive hepatic glucose output is an important factor in the fasting hyperglycemia of non-insulin-dependent diabetes mellitus (NIDDM). To determine the relative contributions of gluconeogenesis and glycogenolysis in a quantitative manner, we applied a new isotopic approach, using infusions of [6-3H]glucose and [2-14C]acetate to trace overall hepatic glucose output and phosphoenolpyruvate gluconeogenesis in 14 postabsorptive NIDDM subjects and in 9 nondiabetic volunteers of similar age and weight. Overall hepatic glucose output was increased nearly twofold in the NIDDM subjects (22.7 +/- 1.0 vs. 12.0 +/- 0.6 mumol.kg-1.min-1 in the nondiabetic volunteers, P less than .001); phosphoenolpyruvate gluconeogenesis was increased more than threefold in the NIDDM subjects (12.7 +/- 1.4 vs. 3.6 +/- 0.4 mumol.kg-1.min-1 in the nondiabetic subjects, P less than .001) and was accompanied by increased plasma lactate, alanine, and glucagon concentrations (all P less than .05). The increased phosphoenolpyruvate gluconeogenesis accounted for 89 +/- 6% of the increase in overall hepatic glucose output in the NIDDM subjects and was significantly correlated with the fasting plasma glucose concentrations (r = .67, P less than .01). Glycogenolysis, calculated as the difference between overall hepatic glucose output and phosphoenolpyruvate gluconeogenesis, was not significantly different in the NIDDM subjects (9.9 +/- 0.06 mumol.kg-1.min-1) and the nondiabetic volunteers (8.4 +/- 0.3 mumol.kg-1.min-1). We conclude that increased gluconeogenesis is the predominant mechanism responsible for increased hepatic glucose output in NIDDM.

Adult↗
PubMed1987

Chronobiological evaluation of sympathoadrenergic function in cirrhosis. Relationship with arterial pressure and heart rate.

Intraday activity of the adrenergic system was investigated in 7 healthy controls and in cirrhotic patients without ascites (group 1, 7 cases) and with ascites (group 2, 9 cases) by determining the urinary norepinephrine and vanillylmandelic acid excretions at 4-h intervals for 24 h. Mean arterial pressure and heart rate were also recorded. In controls, the statistical evaluation by the cosinor method showed a circadian rhythm of such variables, with zenith in the morning and nadir at night. Intraday changes of urinary excretion of norepinephrine were closely related to arterial pressure and heart rate in most subjects. The most important change in cirrhotic patients was the achronia [no detection of a statistically significant (p greater than 0.05) rhythm] in urinary excretion of norepinephrine and arterial pressure. This occurred not only in group 2 patients, who had lower arterial pressure and higher NE mesors than controls (p less than 0.05), but also in group 1 patients, whose mesors were comparable to controls. The statistical significance of heart rate rhythmicity was preserved in patients, but its zenith was progressively displaced toward evening (group 1) and night hours (group 2, whose mesor was increased). Changes in urinary excretion of vanillylmandelic acid roughly paralleled those of norepinephrine both in controls and patients, but they did not significantly increase even in the group with ascites. In both groups of cirrhotic patients, the correlation between urinary excretion of norepinephrine, arterial pressure, and heart rate within the same subject was lost in most cases. This chronobiological study showed that the sympathoadrenergic activity can be deranged also in the early stages of cirrhosis, and suggested that an altered control of cardiovascular homeostasis is present even under steady state conditions. This alteration might blunt adrenergic responses to stress conditions.

Adrenergic Fibers↗
PubMed1987

Chronobiological aspects of weight loss in obesity: effects of different meal timing regimens.

A series of short- and long-lasting experimental protocols of different meal timing regimes were performed in obese subjects to assess the possible occurrence of (1) a different metabolic fate of nutrients; (2) a phase shift of circadian rhythms of metabolic and hormonal parameters strictly related to nutrition; (3) a different weight loss. (A) In a short-lasting protocol (3 days) 15 obese subjects were fed a hypocaloric diet (684 kcal/day) (a) at 10 hr only, (b) at 1800 hr only; (c) at 1000 hr, 1400 hr and 1800 hr, or (d) studied during a 36-hr fasting. Measures of calorimetry (R.Q., CHO and lipid oxidations, energy expenditure), hormones (plasma cortisol, insulin, HGH, urinary catecholamines), urinary electrolytes (Na, K) and vital parameters (body temperature, heart rate, blood pressure) were carried out at 4-hr intervals for three days. A significantly higher lipid oxidation and a lower CHO oxidation were documented with the meal at 1800 hr, in comparison with the meal at 1000 hr. CHO and lipid oxidation circadian rhythms appeared the most affected by meal timing. (B) In a long-lasting protocol (18 days) 10 obese subjects were fed the same hypocaloric diet (a) at 1000 hr only and (b) at 1800 hr only. Calorimetric measures were performed every other day for 2 hr preceding each meal. Before and after the 18-days single meal period, body temperature, plasma cortisol, PRL and TSH were recorded (delta t = 4 hr). A higher lipid oxidation and a lower CHO oxidation were again demonstrated with the meal at 18 hr. Minimal changes of hormonal circadian rhythms were documented suggesting that the hypothalamus-hypophysis network is scarcely affected by meal timing. Weight loss did not vary in both short- and long-term protocol.

Adult↗
PubMed1987

Circadian rhythm of proteinuria in normal subjects but not in patients with glomerulonephritis.

The existence of circadian variations in the urinary excretion of total protein, albumin and creatinine was investigated in subjects with normal and impaired renal function. All individuals were kept at bedrest for 24 hours. Eight consecutive urine specimens were collected every 3 hours and examined. In normal subjects the urinary total protein, albumin and creatinine excretion showed a significant increase during the 12 daytime hours compared with the night-time. The diurnal variations with peak occurrence at 13.26 h (range 09.58-16.43 h) for total protein, at 12.37 h (range 10.33-15.18 h) for albumin, at 16.33 h (range 13.22-19.24 h) for creatinine are temporally related to the ingestion of meat. In patients, by contrast, total protein, albumin and creatinine excretion in the urine were not modified significantly throughout the 24 hours period. Thus, impaired renal function is associated with the loss of the physiological circadian rhythm.

Adult↗
PubMed1987

Circadian time structure in the endocrine system of elderly subjects.

Six young, healthy males (mean age 27 +/- 0.8 years) and six healthy elderly men (mean age 75 +/- 2.0 years) underwent an evaluation of their circadian rhythms in cortisol, PRL, and TSH; oral body temperature and heart rate also were recorded. In the two groups no differences in the circadian patterns of cortisol, PRL, and body temperature were found. We consider it remarkable that the mesor of PRL values did not differ significantly between young and elderly subjects. A markedly advanced TSH acrophase was found in the elderly compared to the young controls. This change in acrophase could be important, because the hormone is known to be a marker of the function of the hypothalamus-hypophysis axis. In addition, an advance of the acrophase of the heart rate in the elderly compared to the younger age group was observed.

Adult↗
PubMed1986

Chronobiological study of factors affecting plasma aldosterone concentration in cirrhosis.

We studied the mechanisms leading to derangement of aldosterone secretion in cirrhosis. The circadian patterns of plasma renin activity (PRA), aldosterone, cortisol, sodium, and potassium were studied in 16 nonazotemic cirrhotics (group 1 without ascites, 7 cases; group 2 with ascites, 9 cases) and 7 healthy controls. Group 1 did not differ from controls in aldosterone, sodium, and potassium mean daily levels (mesors), but had reduced PRA mesor (p less than 0.05). Moreover, minor derangements in circadian patterns of PRA, aldosterone, and potassium were also found. Group 2 not only showed an increased mesor of PRA (p less than 0.05), aldosterone (p less than 0.001), and reduced sodium (p less than 0.005), but also achronia in daily fluctuations of PRA, aldosterone, and potassium. In all groups the mesors of PRA and aldosterone were correlated (r greater than or equal to 0.82; p less than 0.01 or less), but the regression line slopes of patients were steeper than those of controls (group 1, p less than 0.05; group 2, p less than 0.01). Moreover, although in controls and some group 1 patients aldosterone paralleled cortisol rhythmicity, most group 2 patients had aldosterone daily patterns correlated with those of PRA. Finally, no relationships between plasma potassium and aldosterone concentrations were found in patients, whereas they were strictly related in controls. These results suggest that the renin-angiotensin system is the prevalent determinant of aldosterone secretion in cirrhosis.

Adult↗
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↗
PubMed1985

[Insulin secretion after a protein and lipid meal in healthy subjects].

Previous studies suggested that insulin requirement in type I diabetics could be split in a "basal" insulin requirement, mainly related to body weight and in a "post-prandial" insulin requirement, mainly related to carbohydrates intake. In the present study we wanted to investigate the occurrence and the magnitude of insulin response to protein only or fat only meals in normal subjects, trying to obtain some evidences for an insulin requirement possibly related to these substrates in diabetic subjects. Fat only meals did not evoke any insulin response while a small but significant increase in plasma insulin was observed after a protein only meal (from 16.6 +/- 2.85 to 25.83 +/- 2.52 microU at 90', p less than 0.05). Blood glucose remained unchanged after fat or protein meals. It is concluded that a small sovrabasal insulin dose would be probably required by diabetic patients after a protein meal: this is however so small that a carbohydrates related insulin dose given before a normal mixed meal would be able to normalize aminoacids as well as glucose metabolism.

Adult↗