PubMed Health⌕ Search

Biomedical subjects

S Muzzo

Publications and source records attributed to S Muzzo.

At least 19 recordsLinked to original sources
PubMed1999

Single and multiple selenium-zinc-iodine deficiencies affect rat thyroid metabolism and ultrastructure.

This study was conducted to evaluate the effects of single and combined deficiencies of Se, Zn and I on thyroid function in rats. Rats were fed amino acid-based diets for 6 wk starting from weaning. The diets contained either low or adequate amounts of these minerals. In addition to the control and control pair-fed groups, seven experimental groups were formed: Se deficient (Se-); I deficient (I-); Zn deficient (Zn-); Se and I deficient (Se-I-); Zn and I deficient (Zn-I-); Se and Zn deficient (Se-Zn); and Se, I and Zn deficient (Se-I-Zn-). Serum triiodothyronine (T3) was significantly lower than in controls in Zn-, Se-Zn- and Se-I- groups. Serum total thyroxine (T4) and free T4 were significantly lower and thyroid-stimulating hormone (TSH) greater in all iodine-deficient groups, regardless of Se or Zn status. Thyroid glutathione peroxidase activity was significantly reduced in Se- and Se-Zn- groups. Nevertheless, in the groups with a concurrent I deficiency, the activity of this enzyme was significantly greater than in controls. Severe alterations of the follicle cellular architecture, including signs compatible with apoptosis, were observed in the Zn- and Se-Zn- groups. These alterations appeared to be less severe when iodine deficiency was simultaneously present. Single and multiple deficiencies of Se, Zn and I have distinct effects on thyroid metabolism and structure.

Animals↗
PubMed1997

[Iodine nutrition in school children of four census areas of Chile].

BACKGROUND: Although endemic goiter is an easily controlled chronic disease, it continues to be a serious global public health problem. AIM: To study iodine nutrition in school age children from different areas of Chile. SUBJECTS AND METHODS: Thyroid gland was palpated in 4181 school age children from Calama, Santiago, Temuco and Punta Arenas. Urinary iodine excretion was measured to 9% of these children and iodine concentration in salt for human consumption obtained in each of these areas was determined. RESULTS: A 9% goiter prevalence in boys and 11% prevalence in girls was detected. The prevalence of goiter Ia was 6.5% and the figure in different geographic areas was similar. Iodine concentration in salt for human consumption was adequate according to Chilean legislation (82.6, 95.7, 96.8 and 93.2 micrograms ugI/g salt in Calama, Santiago, Temuco and Punta Arenas respectively). Urinary iodine excretion in boys and girls was 1695 and 1802 micrograms l/g creatinine in Calama, 680 and 732 in Santiago, 574 and 690 in Temuco, 570 and 528 in Punta Arenas. These values are well above recommendations. CONCLUSIONS: Endemic goiter is no longer a problem in Chile. The importance of a continuous surveillance of iodine nutrition in Chile and the reduction of salt iodine concentration required by Chilean legislation is underscored.

Censuses↗
PubMed1996

[Bone mass in celiac patients].

Bone mineral content was measured in the whole body, the spine (L2-L4) and hip by Dual Photonic Absorpciometry (densitometer Norland 2600 Gd-153), in seventeen celiac patients, aged 6 to 12 years, with good adherence to the gluten free diet. The diagnosed was made before 30 months of age in 50% of cases. Average treatment duration was 69.8 +/- 36 months. The randomly selected control group was composed of 48 school age children, of the same age and sex of patients. Total bone mass (TBM) and bone mineral density (BMD) were expressed as Z scores on the basis of normal values established by the authors in Chilean children. Celiac patients had lower TBM and BMD of whole body, than controls (-1.11 +/- 0.94 vs 0.00 +/- 0.85 and -0.59 +/- 0.76 vs 0.06 +/- 0.84, respectively) and at the spine (-0.79 +/- 1.04 vs 0.003 +/- 0.92 and -1.49 +/- 0.99 vs 0.06 +/- 0.87 respectively). A lower TBM was founded at the hip (-0.62 +/- 1.28 vs -0.08 +/- 0.82) without differences in BMD. Celiac patients had a lower bone mass than controls despite early diagnosis and good compliance with the gluten-free diet. These differences could not be atributed entirely to the lower height of celiac patients. These results suggest that celiac patients constitute a risk group for development of osteoporosis later in life. This fact should be taken into consideration in the treatment of this condition.

Bone Density↗
PubMed1995

[Psychosocial and familial variables associated with teenage pregnancy].

Preventive measures for teenage pregnancy (TP), would decrease infant mortality, early undernutrition and statal social expenditure. The cost of programs for TP would decrease with a sensitive risk indicator. We searched some pysoshocial and familial parameters, useful to built up this indicator. Self esteem (Piers-Harris test), intrafamilial relationship (Familial Apgar of Magdaleno) and the use of break time were studied in 60 pregnant teenagers (PT), 60 non pregnant teenagers at a low risk of pregnancy (LRP) and 60 non pregnant teenagers at a high risk of pregnancy (HRP). PT and HRP showed lower self esteem than LRP (88.3, 70.0 Y 41.6% respectively, under 7 points) lower familial Apgar (61.6, 50 y 8.3% under score 6) and lower the quality of use of break time (66.7, 74.1 y 31.7% respectively with regular or deficient quality). The self esteem, intrafamilial relationship hand use of break time were associated to early pregnancy and high risk of pregnancy. These parameters are important to built up a sensitive risk indicator of early pregnancy in order to decrease the prevalence of this serious problem.

Adolescent↗
PubMed1995

[Bone mineralization and calcium intake in Chilean school children].

Bone mineralization was evaluated in 36 school age children with calcium intake below 50% of Recommended Dietary Allowances (RDA), and compared with 28 school age children with calcium intake higher than 100% of the RDA. The total group was aged between 86 and 178 months. The calcium intake was evaluated by 24 hours recordatory survey. Height for age and weight for height were evaluated according to WHO tables. Puberal development was evaluated according to Tanner stages. Bone mineral density (BMD) and total bone mass (TBM) of whole body, spine and femoral neck were measured with Norland 2600 densitometer. School age children with intakes below 50% of RDA had lower height for age adequation (97.7 +/- 4.0%), whole body TBM adequation (98.9 +/- 17.9%) and BMD adequation (97.8 +/- 7.9%) than those ingesting more than 100% of the RDA (115.9 +/- 17.4%), (109.7 +/- 18.0%) and (104.7 +/- 11.1%) respectively. In spine, however, there was a clear tendency to be lower, there were no significant differences between both groups. There were no differences in femoral necks BMD adequation, or TBM adequation between both groups. These results show that children with calcium intake below 50% of the recommendation has lower adequation of statural growth and bone mineralization. The role of calcium in the differences found in this study is discussed.

Adolescent↗
PubMed1995

[Bone mineralization in adolescents suffering from postnatal malnutrition].

The bone mineralization of 6 male and 18 female adolescents with a mean age of 12 years and 11 months, who had suffered severe, early, postnatal protein-energy undernutrition, was analyzed. These patients have been followed up at our Institute since their nutritional rehabilitation. Bone mineralization was measured by bone dual isotopic densitometry (Gd 153). These results were compared with those of normal school-age Chilean children of the same age and sex. Weight for height of adolescent who had suffered from undernutrition was similar to the controls, and both were over 100% of the standard. Adequation of height for age was significantly less in those with previous history of undernutrition. Densitometries showed that adolescents with a past history of undernutrition had lower total bone mass in whole body, spine and femoral neck; differences disappeared when expressed per 100 cm of body height. There were no differences in bone mineral density in the different area measurements. It is concluded that the possible alterations that undernutrition produces in bone mineralization probably recover after nutritional rehabilitation, adequate nutritional follow up and health support.

Calcification, Physiologic↗
PubMed1994

[Early pregnancy risk: development and validation of a predictive instrument].

An early pregnancy risk scale, with scores ranging from 11 to 66 points from lower to higher risk, was constructed using variables associated with teenager's pregnancy. This scale was applied to 3000 female teenagers, coming from Metropolitan Santiago public schools. The sample was divided in three risk groups: group A (high risk) with scores equal or over 35 points, group B (low risk) with scores equal or below 20 points and group B (intermediate risk) with scores between 20.1 and 34.9 points. These girls were followed during 2 years. During this period, 84 girls became pregnant, 24 of 184 (13%) in group A, 60 of 2332 (2.6%) in group C and none of 307 in group B. There were 104 school desertions in group A and 37 in group B. To study associations and analyze risk, the sample was divided in two risk groups: high, with scores over 27 and low, with scores below 27. There was a high association between pregnancy risk score and the occurrence of pregnancy (RR 5.25 p < 0.0001) and school desertion (RR 3.32 p < 0.0001). Pregnancy was predicted with a 78% sensitivity and 55.6% specificity. School desertion was predicted with a 74% sensitivity and 56% specificity. The importance variable weighing using multiple regression models, to improve the predictor's sensitivity and specificity, is discussed.

Adolescent↗
PubMed1994

[Endemic goiter in three census areas of Chile].

The goal of the present study was to evaluate the current status of endemic goiter in Chile. 3500 students of basic education from public schools in three censor areas of the country were studied: 1000 in Calam (North), 1000 in Temuco (South) and 1500 in Santiago (Center). Socio-economic level was evaluated according to the Graffar scale. Two trained physicians determined body weight, height and size of the goiter through palpation of the thyroid gland (according to W.H.O. classification). Iodine in urine was determined in 20% of the students. Iodine insalt was determined in samples obtained in the three areas. A goiter prevalence of goiter of 11.4% in males and 12% in females was found, with a higher prevalence in females during puberty. A higher prevalence in the medium-low and low socio-economical levels was observed (12.4% and 14.4% respectively). The level of salt iodination was variable in the three areas (1/3 with concentration > than 100 parts per million (ppm), 1/3 between 60-100 ppm and 1/3 with < 60 ppm of iodine content). According to W.H.O. criteria, Chile has presently a low goiter prevalence, but the salt iodine concentration indicate the importance of a permanent surveillance of iodine nutrition.

Adolescent↗
PubMed1994

[Bone mineralization in Chilean children determined by dual photon bone densitometry].

In 198 school age children, aged 6 to 13 years, the bone mineral density (BMD) and total bone mass (TBM) was measured in total body, lumbar spine and hip, using a double beam photon densitometer with a Gd 153 source. An increase with age of BMD and TBM was found in all the analyzed areas. At 12 years of age, TBM and BMD of total body were higher in girls than in boys. BMD of lumbar spine was significantly higher in girls than in boys at ages between 11 to 13 years. BMD of lumbar spine and femoral neck of 9 years old females were 36% and 18% respectively, lower than values of young adult Chilean females. The importance of normal values of bone mineralization for the diagnosis of bone diseases and for the evaluation of programmes directed to solve this problems is emphasized.

Absorptiometry, Photon↗
PubMed1990

The hypothalamic-pituitary-adrenal axis in infantile malnutrition.

We studied the circadian rhythm and the response of the hypothalamic-pituitary-adrenal (HPA) axis to ovine corticotrophin releasing hormone (oCRH) stimulation and dexamethasone suppression in 32 children with grade II-III marasmus. Children were studied prior to and after nutritional rehabilitation. Mean baseline plasma cortisol concentrations were elevated at admission and decreased significantly after nutritional rehabilitation. Mean +/- SEM plasma cortisol response to oCRH increased from a basal of 480 +/- 41 to a peak of 582 +/- 58 nmol/l at the time of admission, and from a basal of 234 +/- 27 to a peak of 532 +/- 41 nmol/l after caloric rehabilitation. Dexamethasone suppression in the malnourished group was associated with a decrease in the mean +/- SEM basal plasma cortisol concentration from 397 +/- 44 to 171 +/- 44 nmol/l. After caloric rehabilitation, basal cortisol levels decreased from 259 +/- 27 to 22 +/- 5 nmol/l following dexamethasone. Our results support the concept that malnutrition is associated with decreased responsiveness to oCRH and incomplete dexamethasone suppression, and that these abnormalities are restored after nutritional rehabilitation.

Child, Preschool↗
PubMed1988

Histological maturation of astroglial cells in the archicortex of young hypothyroid rats.

The maturation of fibrous astrocytes was studied in the archicortex (hippocampus) of rats rendered hypothyroid by perinatal administration of propylthiouracil (PTU). A decrease in the number of protoplasmic processes and end-feet in fibrous astrocytes from the cortical molecular layer was observed. The diameter of the perikaryon and length of the prolongations were also decreased. In animals rehabilitated after weaning, the diameter of the perikaryon and length of protoplasmic processes returned to normal while that of number of prolongations per astroglial cell remained unchanged. It is postulated that hypothyroidism induced immediately after birth impairs differentiation of astroglia in the archicortex of the rat brain, probably as a response secondary to altered neuronal and capillary development.

Animals↗
PubMed1987

Sociocultural characteristics of pregnant and nonpregnant adolescents of low socioeconomic status: a comparative study.

The objective of this study was to compare the sociocultural characteristics of pregnant adolescents of low SES with a nonpregnant adolescent group from the same area of Santiago, Chile. The sample was composed of 229 adolescents, 129 of whom were pregnant for the first time (group A), and 100 who were not pregnant (group B). Each pregnant girl was matched with a nonpregnant girl of the same age and from the same neighborhood. Several differences between the groups were found. Group A had less schooling, a lower level of aspirations, and tended to live in "the present." In addition, norms of behavior were more permissive, they did not practice any religion, and their peer group had more liberal attitudes. The importance of breaking these patterns in order to prevent adolescent pregnancy is discussed.

Adolescent↗
PubMed1986

Physical growth and bone age of survivors of protein energy malnutrition.

Early postnatal malnutrition produces delay in growth and developmental processes, and children from a low socioeconomical level where undernutrition is prevalent are shorter than those from higher socioeconomic levels. We examined the effects of severe and early protein energy malnutrition on growth and bone maturation. We studied 40 preschool children who had been admitted to hospital in infancy with protein energy malnutrition and 38 children from the same socioeconomic level, paired for age and sex, who had never been malnourished. Growth measurements were made over a period of 4-6 years, and bone age was determined in a subgroup through wrist roentgenograms. Results showed a correlation between protein energy malnutrition, birth weight of infants, and mother's height and head circumference. The group with protein energy malnutrition showed a significant delay in stature after four years, especially the girls (p less than 0.001). Weight:height ratio was reduced in boys compared with controls but not in girls. Both groups showed a delay in bone maturation, but there were no significant differences between them. We found a positive correlation between bone age and arm fat area in control boys and between bone age and height for age in boys with protein energy malnutrition. The finding that rehabilitated children were shorter than the control group but had similar bone age at follow up suggests that genetic or prenatal factors were important in their later poor growth, and this suggestion is supported by their smaller birth size and the smaller size of their mothers.

Age Determination by Skeleton↗