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Biomedical subjects

L Beccaria

Publications and source records attributed to L Beccaria.

At least 19 recordsLinked to original sources
PubMed2000

GH/IGF-I axis in Prader-Willi syndrome: evaluation of IGF-I levels and of the somatotroph responsiveness to various provocative stimuli. Genetic Obesity Study Group of Italian Society of Pediatric Endocrinology and Diabetology.

Basal IGF-I levels and the GH response to at least two among provocative stimuli such as clonidine (CLO, Catapresan, 150 mcg/m2 p.o.), GHRH (1 mcg/kg i.v.)+arginine (ARG, 0.5 g/kg i.v. infusion during 30 min) and GHRH+pyridostigmine (PD, Mestinon cpr 60 mg p.o.) have been evaluated in 43 children with Prader-Willi syndrome (PWS, 17 males and 26 females, age 3-22 yr, 7 normal weight and 36 obese PWS), in 25 normal short children (NC, 17 males and 8 females, 7.7-18.5 yr) and in 24 children with simple obesity (OB, 14 males, 10 females, 7.7-21.5 yr). Both normal weight and obese PWS had mean IGF-I levels lower than those recorded in NC (p<0.001) and OB (p<0.001). The GH responses to GHRH+ARG and GHRH+PD in NC were similar and higher than that to CLO (p<0.001). In PWS the GH response to GHRH+ARG was higher than that to GHRH+PD (p<0.001) which, in turn, was higher than that to CLO (p<0.001); these responses in PWS were lower than those in normal children (p<0.02) and similar to those in OB. In normal weight PWS the GH responses to GHRH+ARG and to GHRH+PD were similar and higher than to CLO (p<0.05); however, each provocative stimulus elicited a GH rise lower than that in NC (p<0.05). In obese PWS as well as in OB the GH response to GHRH+ARG was higher than that to GHRH+PD (p<0.02) which, in turn, was higher than that to CLO (p<0.001); all GH responses in obese PWS and OB were lower than those in NC (p<0.001) but similar to those in normal weight PWS. In conclusion, patients with PWS show clear reduction of IGF-I levels as well as of the somatotroph responsiveness to provocative stimuli independently of body weight excess. These results strengthen the hypothesis that PWS syndrome is frequently connotated by GH insufficiency.

Adolescent↗
PubMed1999

Persisting obesity starting before puberty is associated with stable intraabdominal fat during adolescence.

OBJECTIVES: To observe the evolution of intraabdominal adipose tissue (IAT) in obese prepubertal children, who did not change their degree of obesity during adolescence and to evaluate its relationship with metabolic risk indexes (RI). DESIGN: Longitudinal study of 16 obese adolescents (eight male and eight female) in whom relative body weight (RBW) did not change significantly and pubertal development was completed during the study period. MEASUREMENTS: Magnetic resonance imaging (MRI) scan at lumbar level (L4) three times during a 4 y period. At basal and at four years biochemical assays for metabolic indexes. RESULTS: IAT did not differ significantly over the three measurement times and showed significant correlations between first and second (r = 0.66, P < 0.005), first and third (r = 0.61, P < 0.01) and second and third values (r = 0.84, P < 0.0001). Subcutaneous adipose tissue (SAT) increased significantly from basal to third evaluation (P < 0.002). At baseline, IAT correlated significantly with lipids (total and LDL cholesterol r = 0.72, P < 0.004), while at the end of the study, IAT correlated positively with insulin (fasting insulin r = 0.55, P < 0.008, insulin area after oral glucose tolerance test (OGTT) r = 0.60, P < 0.03, fasting insulin/glucose r = 0.67 P < 0.006) and negatively with high density lipoprotein (HDL) cholesterol (r = -0.55, P < 0.04). CONCLUSIONS: Obesity achieved before puberty, and stable during adolescence, showed a relatively stable amount of IAT. In post pubertal children the relationship of IAT to clinically significant risk factors resemble the pattern in obese adults.

Abdomen↗
PubMed1999

[Prader-Willi syndrome].

Prader-Willi syndrome (PWS) is the most frequent cause of secondary obesity, characterized by neonatal hypotonia, dysmorphic facies, acromicria, hypogonadism, stunted growth, obesity, behavioural disturbances and cognitive impairment. Clinical diagnosis is confirmed by alteration of imprinted genes on the proximal long arm of chromosome 15 (15q11-13) for deletion, translocation, uniparental disomy for maternal chromosome 15 or imprinting center defect. Methylation test is the most reliable test for diagnosis. This issue explains diagnostic tests, clinical, metabolic, endocrinological features, and the most frequent complications observed in this syndrome. Precocious diagnosis and multidisciplinary approach allow in these patients to prevent the severe obesity and linked complications.

Diagnosis, Differential↗
PubMed1999

Body composition during GH treatment in Prader-Labhardt-Willi syndrome.

Prader-Labhardt-Willi syndrome (PLWS) is a model to study GH secretion, body composition and consequences of GH therapy. Twenty-seven patients were studied by dual-energy X-ray absorptiometry (DXA) and were each compared to two age- and sex-matched controls (obese and normal weight). Fat mass (FM) was significantly greater in PLWS than in patients with simple obesity; lean body mass (LM) and bone mineral content (BMC) were significantly lower compared to both controls. The peculiar body composition of PLWS patients seems to be similar to that found in GH deficiency. In six PLWS children treated with GH, LM increased after 6 months (p<0.02) up to 12 months (p<0.03); FM decreased in 5/6 patients. Obese adult PLWS patients treated with GH for 6 months showed a reduction in adiposity; LM increased significantly only in the leg compartment. Abdominal CT scan did not show a significant reduction of intrabdominal fat area. In conclusion, GH therapy might improve final stature and exert a positive influence on body composition in patients with PLWS.

Adipose Tissue↗
PubMed1998

Prader-Willi syndrome: relationship of adiposity to plasma leptin levels.

OBJECTIVE: Prader-Willi syndrome (PWS) is an autosomal dominant disorder involving the proximal long arm of chromosome 15, in which obesity is common. However, there is limited information on the underlying physiological mechanisms promoting obesity in this population. We tested whether there was a significant positive association between leptin and total body fat (TBF) in subjects with PWS, and whether this association was stronger among subjects with than without PWS. RESEARCH METHODS AND PROCEDURES: We studied 21 PWS patients and 64 non-PWS controls on whom we measured serum leptin, total body fat, glucose, insulin, and resting energy expenditure. We tested whether the slope of the regression line between leptin and TBF (in kg), measured by dual energy X-ray absorptiometry, was the same for PWS patients and non-PWS controls. RESULTS: Regression analyses indicated that the leptin-TBF association was significantly stronger among PWS patients. In contrast, the slope of the leptin-body mass index association did not significantly differ between PWS patients and non-PWS controls. None of the other outcome variables showed associations with leptin. DISCUSSION: Results suggest that the role of leptin in promoting obesity may be greater among subjects with PWS than among non-PWS controls.

Absorptiometry, Photon↗
PubMed1997

Peculiar body composition in patients with Prader-Labhart-Willi syndrome.

Prader-Labhart-Willi syndrome (PWS)-characterized by severe obesity, short stature, hypogonadism, and muscle hypotonia-appears to be an interesting model for body-composition abnormalities. Twenty-seven PWS patients (15 males and 12 females) aged 6-22 y underwent total-body analysis by dual-energy X-ray photon absorptiometry (DXA). For each PWS patient two age- and sex-matched control subjects were studied: one obese subject with a relative body weight (RBW > 120%) and body mass index (BMI) similar to that of the patient and one normal-weight subject (RBW < 120%). Percentage body fat was significantly greater in PWS patients than in obese subjects (47.4 +/- 7.2% compared with 41.9 +/- 9.9%, P < 0.0001) and the same difference was evident for arms and legs but not for the trunk. Lean mass was significantly lower in PWS patients (26.4 +/- 8.2 kg) than in normal-weight subjects (32.9 +/- 10.2 kg) and even more so than in obese subjects (40.3 +/- 13.2 kg) (P < 0.0001). The most affected regions were limbs; thus, the ratio of lean mass in the trunk to that in the limbs was significantly higher in PWS patients (1.19 +/- 0.15) than in obese (1.07 +/- 0.13) and normal-weight (1.07 +/- 0.09) subjects (P < 0.002). The ratio of fat mass to lean mass was significantly higher in PWS patients than in obese subjects (0.90 +/- 0.32 and 0.74 +/- 0.27, P < 0.05). Bone mineral content (BMC) was significantly lower in PWS patients (1503 +/- 46 g) than in normal-weight (1876 +/- 677 g) and obese (2322 +/- 773 g) subjects (P < 0.0001); this difference was most pronounced in the limb region. Bone mineral density (BMD) in PWS patients (0.993 +/- 0.116 g/cm2) did not differ significantly from that of normal-weight subjects (1.033 +/- 0.147 g/cm2) but was significantly lower than that of obese subjects (1.154 +/- 0.139 g/cm2). The influence of age on body composition was assessed by comparing two age subgroups (< 12 y, n = 10; and > or = 12 y, n = 17). The older PWS patients had higher adiposity, lower BMC, and dramatically lower BMD. Also, the lean mass deficit increased with age so that the ratio of fat mass to lean mass was close to 1. In conclusion, PWS patients showed a peculiar body composition, to some extent similar to that found in subjects deficient in growth hormone or even to sedentary and elderly people. These results suggest the importance of an accurate analysis of body composition in PWS patients.

Adipose Tissue↗
PubMed1996

Impairment of growth hormone responsiveness to growth hormone releasing hormone and pyridostigmine in patients affected by Prader-Labhardt-Willi syndrome.

In order to evaluate the impairment of GH response in patients affected by Prader-Labhardt-Willi (PLW) syndrome, in 18 patients we studied GH response to clonidine and to GHRH + pyridostigmine, a cholinergic drug which enhances GHRH induced GH responsiveness in obese patients. After clonidine GH response was abnormal in 14/18 subjects (mean GH peak: 4.1 +/- 1.3 micrograms/l; area under curve: 208.1 +/- 74.2 micrograms/l.h) while all but 5 patients showed an inadequate GH response to GHRH + pyridostigmine (mean GH peak: 13.4 +/- 2.5 micrograms/l; area under curve: 903.4 +/- 171.0 micrograms/l.h). However, in the three patients with low adiposity index, GH response to GHRH + pyridostigmine was significantly higher than that observed in fatter subjects. In addition, GH response to GHRH + pyridostigmine was negatively correlated to age and adiposity index. In conclusion, our data are consistent with the hypothesis of the existence of a complex derangement of GH neuroendocrine regulation in these subjects.

Adolescent↗
PubMed1996

Influence of body composition on bone mineral content in children and adolescents.

Excess fat and fat-free mass have been extensively described in obese children, whereas few data about bone mineral content (BMC) variations are available in children. Dual-energy X-ray absorptiometry (DXA) allows a direct and accurate measurement of three body compartments (fat, lean, and BMC), subdivided into three regions (arms, trunk, and legs). The aim of our study was to evaluate the influence of body compartments on total BMC (TBMC) and regional BMC (RBMC) in obese and normal-weight subjects. Sixty-five obese and 50 normal-weight children and adolescents (age range: 5-18 y relative body weight: 160 +/- 23% and 101 +/- 12%, respectively), matched for sex and pubertal stage underwent a DXA total-body analysis. Obese subjects had significantly greater fat and lean compartments than normal-weight subjects (P < 0.0001). TBMC was larger in obese children (1930 +/- 670 g compared with 1480 +/- 490 g, P < 0.0001) as was RBMC (arms: 182 +/- 81 g compared with 151 +/- 65 g; trunk: 560 +/- 223 g compared with 433 +/- 169 g; legs: 788 +/- 341 g compared with 539 +/- 231 g, P < 0.0001). We found lean mass to be the best correlate with TBMC (r = 0.91 in obese and 0.94 in normal-weight children). Multiple-regression analysis confirmed lean mass as one of the major determinants of TBMC and RBMC in children. However, differences in TBMC and RBMC were no longer present after correction for age, sex, and body-composition variables. There were no differences in TBMC and RBMC between obese and normal-weight children after correction for the confounding variables age and sex.

Absorptiometry, Photon↗
PubMed1995

Relative expansion of extracellular water in obese vs. normal children.

This preliminary communication reports data regarding the distribution between intracellular (ICW) and extracellular (ECW) water compartments in a group of 21 prepubertal young obese children of both sexes in comparison with a group of 18 normal children weight matched for age. Our data indicate that obesity is associated with a highly significant relative expansion of extracellular water (ECW/ICW = 0.61 +/- 0.19 and 0.76 +/- 0.09 in control and obese subjects, respectively; P < 0.0015). This observation, which has been already reported in adult women, suggests that some disturbances of water homeostasis have an early onset and stress the need for an early control of energy imbalance in children. These findings are of great concern also in the field of human body composition, suggesting the opportunity for a critical reevaluation of the assumed constancy of some human body characteristics. Body composition methodologies developed for "normal" populations would require adjustment for use in the obese population, since a considerable error would be introduced.

Body Water↗
PubMed1992

A case of familial nesidioblastosis: prenatal diagnosis of foetal hyperinsulinism.

Persistent neonatal hyperinsulinaemic hypoglycaemia due to nesidioblastosis is a rare condition probably transmitted by an autosomal recessive inheritance. Recurrent hypoglycaemic episodes become evident after birth and cause severe neurological damage without intensive treatment. The intrauterine detection of hypoglycaemia and hyperinsulinism in newborns subsequently diagnosed as affected by nesidioblastosis has not yet been reported. We describe a case of familial nesidioblastosis in which an intrauterine diagnosis could be suggested by high levels of insulin and C-peptide and low values of glucose in the amniotic fluid.

Amniocentesis↗
PubMed1991

[The usefulness of measuring fructosamine in the cord blood of the newborn infants of diabetic mothers].

The aim of our study was to evaluate the usefulness of fructosamine measurement (Fram) in cord blood as an index of glucose metabolism in the last week of pregnancy in infants of diabetic mothers. In newborns and their respective mothers Fram values were surprisingly greater in N than in IDM and IGDM and neonatal and maternal values appeared to be strictly related. While intrauterine growth was associated with metabolic control indexes of 2nd and 3rd trimester gestation. Fram value appeared positively correlated to cord insulin. In conclusion Fram level appears as a good index of glucose metabolic control of the last week of pregnancy and it is associated to cord insulin level and to neonatal hypoglycemia.

Blood Glucose↗
PubMed1990

Bone mass in young patients with type I diabetes.

We measured bone mineral content (BMC) with single photon absorptiometry in two groups of young patients with type I diabetes: the first group (prospective study) consists of 48 patients followed from onset to the third year of diabetes and the second group (cross-sectional study) consists of 66 long-term diabetics. Bone mineral content at onset of disease was lower than normal in only two cases. After 3 years of diabetes no male revealed BMC below the normal range but two females (6.6%) had low BMC values. In our cross-sectional study we found a BMC reduction in 12% of the cases. We did not find a relationship between bone deficit and duration of diabetes, or bone mass values and HbA1.

Adolescent↗
PubMed1990

Regulation of pancreatic endocrine function by cholecystokinin: studies with MK-329, a nonpeptide cholecystokinin receptor antagonist.

A cholecystokinin (CCK) receptor antagonist, MK-329, was used to explore the physiological role of CCK in regulating pancreatic endocrine function in humans. The ability of CCK to increase plasma pancreatic polypeptide (PP) concentrations and blockade of this effect with MK-329 were evaluated in a double blind, balanced, four-period cross-over study. Eight subjects received single oral doses of 0.5, 2, or 10 mg MK-329 or placebo, followed by an iv infusion of CCK-8 (34 ng/kg.h). In placebo-treated subjects, PP increased from basal levels of 70 +/- 15 (+/- SE) to peak values of 291 +/- 58 pg/mL after CCK infusion (P less than 0.05 compared to basal). This increase in plasma PP concentration was inhibited in a dose-dependent fashion by MK-329, with 10 mg antagonizing the stimulatory effect of CCK infusion by nearly 80%. Second, the effect of MK-329 on meal-stimulated pancreatic endocrine responses was evaluated by giving placebo or 10 mg MK-329 2 h before ingestion of a mixed meal. Eight subjects were treated in a randomized two-period cross-over fashion. With placebo treatment, peak postprandial plasma insulin, glucagon, and glucose concentrations were 101 +/- 8 microU/mL, 195 +/- 15 pg/mL, and 150 +/- 10 mg/dL, respectively (all P less than 0.05). The integrated PP response following the meal was 56.3 +/- 11.1 ng/mL.minute. With MK-329 treatment, the integrated PP concentration was reduced to 33.9 +/- 2.2 ng/mL.min (P less than 0.05 compared to placebo treatment). Mean postprandial insulin, glucagon, and glucose concentrations did not differ between placebo and MK-329 treatments. We conclude that CCK receptor blockade with 10 mg MK-329 does not alter plasma insulin, glucagon, or glucose responses to a mixed meal. However, the observation that physiological concentrations of CCK increase plasma levels of PP, and the finding that CCK receptor blockade selectively attenuates the postprandial increase in plasma PP concentrations support a physiological role for CCK in regulating PP secretion.

Administration, Oral↗
PubMed1989

Effects of a novel cholecystokinin (CCK) receptor antagonist, MK-329, on gallbladder contraction and gastric emptying in humans. Implications for the physiology of CCK.

To explore the physiology of cholecystokinin (CCK) in humans, we investigated the effect on gallbladder contraction and gastric emptying of a recently developed CCK receptor antagonist, MK-329. In a double-blind, four-period crossover study eight subjects received single doses of 0.5, 2, or 10 mg MK-329, or placebo, followed by an intravenous infusion of CCK-8 (30 pmol/kg.h). In placebo-treated subjects gallbladder volumes decreased on average to 43% of initial volumes after 2 h of CCK infusion. MK-329 caused a dose-dependent inhibition of CCK-stimulated gallbladder contraction with 10 mg producing complete blockade (P less than 0.01, cf. placebo). Gallbladder contraction and gastric emptying rates after a mixed meal were then measured in a two-period crossover study. Subjects received placebo or 10 mg of MK-329 2 h before eating. Gastric emptying of both solids and liquids was measured simultaneously by gamma scintigraphy. In placebo-treated subjects plasma CCK levels increased postprandially to 2.3 pM, gallbladder volumes decreased 68.4 +/- 3.8% (SE), and the times for 50% emptying of liquids and solids from the stomach were 58 +/- 10 and 128 +/- 8 min, respectively. In MK-329-treated subjects there was a marked elevation in peak CCK levels to 13.8 pM (P less than 0.01, cf. placebo), and gallbladder contraction was completely inhibited. Solid and liquid emptying rates were unaffected. These findings demonstrate that (a) MK-329 is a potent, orally active antagonist of CCK in humans, and (b) CCK is the major regulator of postprandial gallbladder contraction. These data also support the concept of negative feedback regulation of CCK secretion and suggest that mechanisms other than CCK play a dominant role in the regulation of postprandial gastric emptying rates.

Adult↗