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Biomedical subjects

M Vanelli

Publications and source records attributed to M Vanelli.

At least 37 records · Page 2Linked to original sources
PubMed1997

Oral environment temperature changes induced by cold/hot liquid intake.

The use of NiTi shape memory alloys, introduced into orthodontics because of their ability to develop light continuous forces that prove more effective than heavy intermittent forces in the teeth movement, requires the mastering of the functional properties of NiTi wires. More specifically, the recovery force acting on the teeth is a sensitive function of temperature: knowledge of oral temperature modifications is therefore required to understand the stress state modification felt during orthodontic therapy. The temperature modifications induced by cold or hot drink intake in the oral cavity were investigated by using arch wires, fixed to removable Hawley retainers, similar to those currently used in orthodontic practice, by means of six temperature sensors placed in correspondence with specific teeth. Similarly, the temperature changes were detected on a metallic frame, fixed onto the palatal zone to a Hawley retainer, where a palatal expander was placed to correct unilateral or bilateral crossbites in deciduous or in early mixed dentition. The maximum temperature change was observed in the interincisor area: The temperature modification on other teeth depends on the modality of drink intake, with the highest temperature variations being detected in the palatal zone. Hence modifications in the stress state during orthodontic therapy with NiTi wires are to be expected.

Beverages↗
PubMed1997

Management of insulin-dependent diabetes mellitus in adolescents.

There are many reasons for a specific management plan for adolescents with insulin-dependent diabetes mellitus (IDDM). Although most new patients can be managed initially on an outpatient basis, as they reach their teenage years, blood glucose control deteriorates and insulin requirements increase. Eating disorders, missing insulin injections, excess of alcohol all contribute to poor glycaemic control. Teenagers who have had diabetes for a number of years may have developed microvascular complications and disturbances of growth can occur, more often in girls than in boys. The transition to adult care continues to be a significant problem both for paediatricians and patients. Diabetes management during adolescence requires a team effort involving nurse educator, dietitian, paediatric diabetologist and, possibly, a social worker, with referral to specialists if necessary. Organizing this type of care requires a Regional Paediatric Diabetes Centre.

Adolescent↗
PubMed1997

Spontaneous thyrotropin and cortisol secretion interactions in patients with nonclassical 21-hydroxylase deficiency and control children.

Both exogenous and endogenous hypercortisolism result in reduced TSH secretion and mild hypothyroidism. However, little is known about the relation between endogenous TSH and cortisol secretion under physiological or slightly disturbed conditions. To examine this, we evaluated the pulsatility and circadian rhythmicity and time-cross-correlated the 24-h secretory patterns of cortisol and TSH in eight prepubertal children with nonclassical congenital adrenal hyperplasia (NCCAH) and eight age-matched short normal children. In both groups, TSH and cortisol were secreted in a pulsatile and circadian fashion, with a clear nocturnal TSH surge. Although no difference in mean 24-h TSH levels was observed between the two groups, daytime TSH levels were lower in the NCCAH group than in control children (P < 0.05). The cross-correlation analysis of the 24-h raw data showed that TSH and cortisol were negatively correlated, with a 2.5-h lag time for both groups, with cortisol leading TSH. This correlation might reflect a negative glucocorticoid effect exerted on the hypothalamic-pituitary-thyroid axis under physiological conditions. A significant positive correlation with TSH leading cortisol was observed at 8.5 and 5.5 h lag times for the control and NCCAH groups, respectively. The substantially shorter lag time of this positive correlation in NCCAH children than in controls suggests that in the latter, the nocturnal TSH peak occurs temporally closer to their compromised morning cortisol peak. These data indicate that the hypothalamic-pituitary-adrenal axis has a primarily negative influence on endogenous TSH secretion and that even mild disturbances in cortisol biosynthesis are associated with slight alterations in TSH secretion.

Adrenal Hyperplasia, Congenital↗
PubMed1997

Ovarian 17 alpha-hydroxyprogesterone responses to GnRH analog testing in oligomenorrheic insulin-dependent diabetic adolescents.

OBJECTIVE: To investigate the pituitary-ovarian function in adolescent girls with insulin-dependent diabetes mellitus (IDDM). DESIGN: Clinical case-control study. METHODS: The GnRH analog leuprolide acetate was administered subcutaneously to 16 adolescents with IDDM (seven eumenorrheic and nine oligomenorrheic) and 13 controls between 0800 and 0900 h. Blood samples were collected at baseline and 0.5, 3, 6 and 24 h after leuprolide to measure levels of gonadotropins, 17 alpha-hydroxyprogesterone (17-OHP), androgens and estradiol. RESULTS: Mean baseline serum LH levels were significantly higher in eumenorrheic compared with oligomenorrheic IDDM patients, while peak LH responses to GnRH analog testing were similar in all subjects. Oligomenorrheic IDDM girls showed, as a group, a distinct 17-OHP response to GnRH analog stimulation, which in five out of nine girls was in the range of functional ovarian hyperandrogenism (> or = 8.6 nmol/l). Androgen and estradiol levels were not significantly altered in any group. No correlation was found between steroid levels and HbA1c levels, although the latter were significantly higher in oligomenorrheic than in eumenorrheic patients. CONCLUSION: About 50% of the oligomenorrheic IDDM adolescents had an increased ovarian 17-OHP response to GnRH analog stimulation in the range of functional ovarian hyperandrogenism. Factors other than metabolic control, such as stress, may play an etiologic role in IDDM ovarian dysfunction.

17-alpha-Hydroxyprogesterone↗
PubMed1995

A multicenter randomized trial of comprehensive geriatric assessment and management: experimental design, baseline data, and six-month preliminary results.

Between October 1992 and July 1993, 11 Northern Italian geriatric departments systematically screened 1386 inpatients hospitalized for at least 10 days. Of those screened, 74% (N = 1019) were excluded by one or more of 7 exclusion criteria; 32% (N = 118) of the 367 remaining subjects failed to meet more than 1 of 8 inclusion criteria. The 11 Geriatric Evaluation Units (GEUs) examined the remaining eligible 249 inpatients with a uniform comprehensive geriatric assessment (CGA) plan, which included a number of validated assessment scales. Of those evaluated, 39% (N = 97) were ineligible for the study because of being unwilling, noncompliant, too sick or "not truly frail", and the remaining 152 (11% of all patients screened) were randomly enrolled in two groups; 79 were assigned to the GEU (experimental group), and 73 to standard care in the National Health Care System (control group). At entry there was no statistically significant difference between the two groups. At 6 months, preliminary results are encouraging; GEU patients had a lower mortality than controls (2 vs 8, 2.5% vs 10.9%; p < 0.05). Slight differences were seen in both clinical-cognitive-affective-functional status and the use of health and social care resources. Only 3 subjects dropped out, 8 refused further follow-up, and 3 went to a nursing-home. We conclude that a standardized selection plan can recognize frail elderly inpatients and that GEU care seems to achieve good results.

Aged↗
PubMed1994

Transient neonatal diabetes mellitus: a relapse after 10 years of complete remission.

The follow-up study of a patient with permanent diabetes (DM) unrelated to islet cell antibody and anti-insulin antibodies and occurring 10 years after a transient neonatal DM episode is reported. A latent defect in insulin release was proved. It produced transient glucosuria during intercurrent illnesses and permanent hyperglycaemia and a decrease in growth velocity [with high stimulated growth hormone and low insulin-like growth factor I (IGF-I)] at the onset of puberty. After insulin therapy was re-introduced, catch-up growth and normalization of the blood glucose and IGF-I levels were noted.

Autoantibodies↗
PubMed1994

Blood pressure tracking in adolescents with insulin-dependent diabetes mellitus.

Hypertension, one of the most frequent and important complications of insulin-dependent diabetes mellitus (IDDM), usually begins in the second decade of the disease and is rare in childhood. We analysed the blood pressure (BP) levels of 106 patients (48 males, 58 females, aged 2-16 years) in relation to sex and age and we studied the modification of BP with years (tracking). BP levels, registered every three to six months, were compared with the local standard levels for age and expressed as standard deviation scores (SDS) of the means. For each subject a regression line describing the change of the SDS over time was calculated by the method of least squares. The slope of this line is called trend and represents the tendency of BP to increase or decrease with time, i.e. to develop (or not) hypertension. All patients, except one 16 year old girl, had normal BP and no microalbuminuria but ten of them presented with mean levels in the upper quartile and/or a constantly upward BP trend and were considered at risk. After a three year follow-up four of these ten patients became frankly hypertensive with increased microalbuminuria. These results agree with previous findings and with the hypothesis that an increase of intraglomerular and/or systemic BP may precede the appearance of (and even could be responsible for) microalbuminuria. The BP tracking study in IDDM children and adolescents could be useful for an early recognition of patients at risk of developing hypertension and diabetic nephropathy.

Aging↗
PubMed1994

[Some clinical, psycho-emotional and cognitive aspects in insulin- dependent diabetic young patients at the end of educative camps].

The "campus" represents a good instrument to improve the independence of the child and adolescent with diabetes. What are the expectation of children taking part in it? For them, will it be a vacation or a period of hospitalization? To evaluate these aspects we have studied, in addition to the theoretical and practical knowledge, the emotional life of 53 young diabetics (31 males and 22 females, age 8.1-15.7 years, duration of disease 2 months 10 years, and HbA1c 6.5-12.6%). We observed that 80% of the patients improved the injection technique; we also found an increase of correct answers (from 60% to 73%, x = 3.8, p < 0.05) to a list of questions on different aspects of diabetes asked at the beginning and at the end of the campus. From the drawings collected at the end of the stay, we observed that 78% of the children lived the experience in a playful way, 11% in a medical and 11% in a educational way. It must be pointed out that the children who perceived the educational aspect of the stay were older than the others (11.5 +/- 2 vs. 13.9 +/- 1; p < 0.05). Consequently, we believe that educational programs on diabetes, like the "campus", should be reserved to children older than 12 years of age.

Adolescent↗
PubMed1993

Adrenal steroid and adrenocorticotropin responses to human corticotropin-releasing hormone stimulation test in adolescents with type I diabetes mellitus.

To determine whether abnormalities of hypothalamic-pituitary-adrenal axis function occur in type I diabetes mellitus, corticotropin, cortisol, 17-hydroxyprogesterone (17-OHP), androstenedione (D4-A), dehydroepiandrosterone (DHEA), and DHEA sulfate (DS) levels were measured after an intravenous (IV) injection of 1 microgram/kg human corticotropin-releasing hormone (CRH) in diabetic adolescents and normal age-matched subjects. CRH produced a consistent increase in corticotropin blood levels that was comparable in the two groups. In contrast, both baseline and stimulated cortisol concentrations were greater in diabetic patients. Levels of 17-OHP increased after CRH administration, and the magnitude of increase was similar in all subjects. Stimulation with CRH determined an attenuated integrated DS response in diabetics compared with normal subjects with a different pattern of the hormone secretion, whereas no differences in D4-A concentrations were detected between the two groups. DHEA serum levels of subjects from both groups underwent similar changes following administration of CRH. In conclusion, patients with type I diabetes have a discrete response of adrenal steroids to CRH stimulation that appears to be independent of corticotropin secretion. This phenomenon might be related to a direct effect of insulin on enzyme systems involved in the biosynthetic pathway of adrenal steroids or, alternatively, to an intra-adrenal CRH/corticotropin mechanism acting on the adrenal cortex in a paracrine manner.

Adolescent↗
PubMed1993

[Performance and utility of a quick immunological method for the measurement of HbAlc in a pediatric diabetes unit].

This study compares the results of a new immunoassay method (DCA2000, Ames) used to measure HbAlc concentration in 9 min using 1-microliter capillary blood sample with those obtained with an ion exchange traditional method (HPLC, DIAMAT, Biorad) in both a non-diabetic and a diabetic pediatric population. All HbAlc values were measured in the two methods on the same whole-blood venous aliquot after we had excluded differences in HbAlc values measured by DCA2000 on venous and capillary blood samples (8.5 +/- 1.4 vs 8.6 +/- 1.4%). Data analysis shows an excellent correspondence between the two assays (r = 0.97; p < 0.0001). HbAlc values obtained by DCA2000 method in diabetic patients are related to the mean value of the blood glucose levels collected at home in the last two months (r = 0.74; p < 0.003). The percentile distribution of the HbAlc values is similar both in DCA2000 (3-- = 4.4; 50-- = 5.3; 97-- = 6.0%) and in HPLC method (3-- = 4; 50-- = 5; 97-- = 5.9%). Within-run precision for DCA2000 ranges from 3.7 to 1.9% and between-run precision from 4.5 to 0.9%. The new immunoassay method gives accurate and reliable HbA1c values and compared with HPLC methodology has at least three advantages: it does not require venipuncture, provides HbA1c value within 9 miy and allows both physician and patient to verify in virtually' real time the degree of blood glucose control.

Adolescent↗
PubMed1992

Clinical data regarding the growth of diabetic children.

Many authors have reported retarded growth in children with diabetes, though this has been a somewhat variable finding. However, with the newer treatment regimens for diabetes the problem of reduced growth rates has largely been solved.

Adolescent↗
PubMed1992

Blood pressure tracking in juvenile insulin dependent diabetes mellitus: preliminary data.

One of the most frequent and important complications of IDDM is hypertension. It begins usually in adulthood and is rare in children. In order to study the behaviour and control of BP in IDDM children and adolescents we analyzed the BP levels of 106 patients (48 males, 58 females; age 1.5-16 yrs) in relation to sex, age, duration of the disease, and different parameters of metabolic control; moreover we studied the modifications of BP levels with years (tracking). BP levels, registered every 3-6 mos, were compared to the standard levels for age of the local population (2000 students between 7 and 16 yrs of age) and expressed as standard deviation scores (SDS) of the means. For each subject a line describing the change of the SDS over time was calculated by the method of least squares: the slope of this line is called trend and represents the tendency of the BP to increase or maintain stable or decrease with time, i.e to develop or not hypertension. All patients, except one 16 y. old girl, had normal BP and no microalbuminuria, but 10 of them presented with mean levels in the upper quartile and a constantly upward BP trend. Two of these patients showed after a 2 year follow-up stable hypertension and microalbuminuria. Moreover, an analytical and statistical study pointed out that BP levels of IDDM children seem to be influenced in addition to age, sex, height, weight, ponderal excess, as the general population, by the duration of the disease the insulin dose and some metabolic parameters (HbA1, HbA1c, glycemia, creatininemia).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Vitreous fluorophotometry in juvenile diabetics after oral fluorescein.

Vitreous fluorophotometry was performed in young patients (8 to 19 years old) affected by insulin-dependent diabetes mellitus, with no signs of diabetic retinopathy. Oral fluorescein was administered, and measures were used to prevent hypoglycemia during the examination. The results showed a breakdown of the blood-retinal barrier in nine (43%) of the 21 patients. The oral fluorescein method allows a satisfactory evaluation of ocular fluorescence profiles, with minimal risk of systemic side effects.

Administration, Oral↗
PubMed1986

Effects of intravenous TRH on growth hormone and cortisol serum levels in children and adolescents with insulin dependent diabetes mellitus.

The effects of an iv thyrotropin releasing hormone (TRH) bolus on serum growth hormone (GH) and cortisol levels were evaluated in 59 children and adolescents with insulin dependent diabetes mellitus (IDDM) and in 24 healthy, age-matched control subjects. In the IDDM group GH baseline levels sharply rose within 30 min after TRH and successively normalized. On the contrary, TRH injection failed to affect GH serum concentrations in the control group. The GH increase after TRH in IDDM patients was positively correlated to age, but unrelated to other variables, such as sex, pubertal stage, duration of disease, glycemia, glycosylated hemoglobin, thyrotropin and T4 concentrations. Twenty-one out of 59 diabetics and only 1/24 controls exhibited a paradoxical GH response to TRH, arbitrarily defined as a precocious increase (within 30 min), of more than 100% with respect to the baseline value, associated with a GH peak greater than 10 ng/ml. Eighteen IDDM patients underwent a second TRH test 12 to 24 months later and substantially exhibited the same GH pattern documented the first time. The mechanism responsible for such anomalous GH responsiveness to TRH in IDDM is unclear. However, it cannot be attributed to a nonspecific stress reaction, as proven by the lack of a concomitant increase of cortisol serum levels in the same subjects.

Adolescent↗
PubMed1986

Blood pressure behaviour and control in Turner syndrome.

UNLABELLED: Adult Turner syndrome (TS) patients frequently present hypertension. To clarify the pathogenesis of this hypertension we examined the blood pressure (BP) behaviour and the renin-angiotensin-aldosterone system in 31 TS patients (2-22 years of age). BP levels were occasionally elevated in 47% of the subjects and constantly elevated in 23%. Most of the patients were on estrogen replacement therapy, but 26% of them presented with elevated levels since childhood. Supine and upright plasma renin activity (PRA) values were higher in TS compared to controls and more elevated in hypertensive TS than in the normotensive ones. At Captopril challenge TS showed different PRA responses regardless of the karyotype and clinical features. Patients on estrogen therapy, however, exhibited higher increments of PRA after Captopril. CONCLUSIONS: TS patients show high frequency of hypertension in pediatric age. Estrogen therapy is an outbreaking and worsening factor. An estrogen independent role of the renin-angiotensin-aldosterone system in the pathogenesis of TS hypertension is still uncertain.

Adolescent↗