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Biomedical subjects

J L Ruibal

Publications and source records attributed to J L Ruibal.

8 recordsLinked to original sources
PubMed2000

Serum leptin concentrations in children with Prader-Willi syndrome and non-syndromal obesity.

There is limited information on the underlying physiological mechanisms promoting obesity in patients with Prader-Willi syndrome (PWS). The aim of this study was to investigate whether body fat regulation in children with PWS is similar to that in children with non-syndromal obesity and non-obese children. We studied three groups: 1) 72 non-obese children and adolescents; 2) 68 children with non-syndromal obesity; and 3) 11 patients with PWS. Height and weight were measured and body mass index (BMI) and BMI SDS were calculated. Fasting serum leptin concentrations were determined. Median leptin serum concentrations were similar in PWS patients and children with non-syndromal obesity. Median leptin serum concentrations were higher in these two groups than in the non-obese group. Log leptin serum concentrations and BMI SDS showed significant correlations in the three groups of patients; correlation coefficients were 0.525, 0.285 and 0.854, respectively. In conclusion, median leptin serum concentrations are similar in PWS patients and children with non-syndromal obesity. The relationship between log serum leptin concentrations and BMI SDS was different in the three groups of patients studied.

Adolescent↗
PubMed1996

Analysis of the blood-retinal barrier: its relation to clinical and metabolic factors and progression to retinopathy in juvenile diabetics. A 4-year follow-up study.

BACKGROUND: The study was carried out to evaluate the correlation between blood-retinal barrier (BRB) permeability and the development of diabetic retinopathy (DR) and to assess the metabolic and clinical factors related to DR over a 4-year period by means of vitreous fluorophotometry (VF). METHODS: Thirty-five type I diabetics with no retinopathy, age 7-21 years (mean 14.32 +/- 2.1 years) were enrolled in this longitudinal study. Two visits included standard ophthalmological examination, fluorescein angiography and VF were performed, on entry into the study and 4 years later. The following risk factors in DR were analyzed: age, duration of diabetes, blood pressure, cholesterol, triglycerides, fasting blood glucose levels, glycosylated hemoglobin (HbA1c), insulin dose/kg body weight (IDBW), fructosamine and albuminuria. To estimate the BRB permeability we adopted the vitreous penetration ratio transmittance (VPRt) value. RESULTS: At 4-year follow-up the mean VPRt had significantly increased. During that time 13 patients developed DR and their final mean VPRt was significantly higher than that in non-DR patients. Additionally, the initial mean VPRt was higher but not significantly so, in patients that later developed DR than in non-DR subjects. A constant linear correlation was found between VPRt and duration of diabetes, HbA1c and microalbuminuria. CONCLUSION: VF is a quantitative method that could measure and predict the breakdown of the BRB before angiographic retinopathy in type I diabetics. The major clinical and metabolic factors related to alterations in the BRB are duration of diabetes, HbA1c and microalbuminuria.

Adolescent↗
PubMed1994

[Inhibition of growth hormone in insulin-dependent diabetics after oral administration of pirenzepine. Fluorophotometric study of the vitreous body].

The purpose of our study was to quantify the blood-retinal barrier permeability in five patients with insulin-dependent diabetic (mean age 14.96 +/- 2.45 years) without retinopathy, after six month with oral pirenzepine, a growth hormone inhibitor. Blood-retinal barrier permeability was determined by vitreous fluorophotometry before and after treatment with a nocturnal oral dose of pirenzepine (0.6 mg/kg the first month and 1 mg/kg the following five months). We found a significant diminution (p < 0.05) in growth hormone levels (10.48 +/- 4.94 ng/ml before treatment and 4.35 +/- 2.53 ng/ml after treatment), nevertheless, no changes in the blood-retinal barrier permeability values were observed (4.84 +/- 2.08 x 10(-6) min-1 before treatment and 4.53 +/- 2.54 x 10(-6) min-1 after treatment). We found no modifications in the levels of somatomedin C or HbA1c either. It can be concluded that oral pirenzepine used at this dose for six months, in spite of a significant decrease in growth hormone secretion, does not decrease the permeability of the blood-retinal barrier.

Administration, Oral↗
PubMed1993

An 18-month vitreous fluorophotometric follow-up study in juvenile diabetics.

The authors assessed a fluorophotometry follow-up study of 18 months in 24 juvenile insulin-dependent diabetic patients with no retinopathy. The initial duration of diabetes was 5.96 +/- 3.44 years and the glycosylated hemoglobin (HbA1c) was 10.12 +/- 2.27%. The baseline Vitreous Penetration Ratio transmittance value (VPRt) was 4.13 +/- 1.31 x 10-6 min-1 and after 18 months was 5.36 +/- 1.85 x 10-6 min-1, yielding a statistically significant difference (p < 0.01). The average HbA1c during the follow-up term was 9.80 +/- 1.72%. VPRt values were significantly correlated with the duration of diabetes and HbA1c. During the follow-up 3 patients developed foveal background diabetic retinopathy with respect to a high initial VPRt value (6.22 +/- 0.27 x 10-6 min-1), nevertheless, the other 7 patients with high baseline VPRt did not do so. We suggest that vitreous fluorophotometry could be a beneficial procedure in the management of insulin-dependent diabetic patients; however, there is not a cut-off value for VPRt values to help distinguish patients prone to develop retinopathy.

Adolescent↗
PubMed1993

Evolution of height and bone age in primary congenital hypothyroidism.

Thyroid hormones are fundamental for growth and bone maturity. Retarded physical and osseous development signals congenital hypothyroidism. This study assessed the evolution of height and bone age and final height after hormone replacement treatment in 25 patients with primary congenital hypothyroidism. Bone ages, measured periodically for 12 years after treatment began, were expressed as standard deviation scores (SDS) corresponding to chronologic age. Heights were expressed as SDS and related to standardized curves and genetic height. All patients experienced height recovery during the first year. Of 19 patients who reached their final height, 16 surpassed the expected mean for genetic height. Bone age accelerated progressively, with total recovery toward the third year, and remained accelerated, reaching +1.43 +/- 1.27 in relation to chronologic age 12 years after hormone replacement began. Thus, early diagnosis and adequate treatment of congenital hypothyroidism improved growth and osseous development, although progressive acceleration of bone age may have limited final height in some children.

Age Determination by Skeleton↗