Biomedical subjects

M C Vigone

Publications and source records attributed to M C Vigone.

7 recordsLinked to original sources

PubMed2003

Thyroid function and puberty.

Thyroid hormones are essential for normal growth, sexual development and reproductive function. During puberty, changes in thyroid functions and an increase in thyroid volume occur as an adaptation to body and sexual development. Hypothyroidism diagnosed late in prepubertal years, usually due to Hashimoto's thyroiditis, can cause a delay of puberty or incomplete isosexual precocity (development of breast and internal genitalia in girls and increased testis volume in boys without adrenarche). In contrast, normal pubertal development and adequate menarche have been documented in congenital hypothyroidism detected by neonatal screening and treated early. The effect of hyperthyroidism on pubertal development is not well known, but a short period of hyperthyroidism seems not to have major negative effects. In adolescence or young adulthood, menstrual dysfunction, infertility, and stillbirth or premature birth are associated with thyroid dysfunction.

Female↗

PubMed2000

Crying abnormalities in congenital hypothyroidism: preliminary spectrographic study.

The aim of this preliminary study was to evaluate the acoustic patterns of the cries of hypothyroid newborns at the time of diagnosis and after the beginning of therapy. Cries were recorded at the nursery of the San Raffaele Hospital, Milan, Italy from 12 full-term subjects (three boys and nine girls) affected by congenital hypothyroidism. Results show that untreated hypothyroid infants at first recording had fewer voiceless and partially voiced cries than normal controls. The percent distribution of this pattern did not change at the second recording after the onset of substitutive therapy. Also, untreated hypothyroid infants had many more cry units showing a vibrato contour than did controls, and this pattern did not change after the onset of treatment. Starting, maximum, minimum, and end frequencies measured on the fundamental were significantly lower in the hypothyroid sample. Four hypothyroid subjects recorded before therapy and within 4 weeks after therapy onset significantly augmented their fundamental frequency parameters; however, in 25% of the sample, sound parameters remained unaltered after 3 or more weeks of treatment. To our knowledge the present preliminary study is the first one performed on follow-up of hypothyroid newborns and indicates that both central and peripheral damage might influence the pattern of crying in untreated hypothyroid infants.

Congenital Hypothyroidism↗

PubMed1998

Comparison of clinical-radiological and molecular findings in hypochondroplasia.

Hypochondroplasia is an autosomal dominant skeletal dysplasia characterized by disproportionate short stature. A mutation (N540K) in the fibroblast growth factor receptor 3 (FGFR3) gene was described in some patients with this condition. The aims of the study were to identify the frequency of the FGFR3 gene mutation, to define the salient clinical and radiological abnormalities of the affected subjects, and to verify the contribution of molecular findings to the clinical and radiological definition of hypochondroplasia. Based on the most common radiological criteria, we selected 18 patients with a phenotype compatible with hypochondroplasia. Height, sitting height, and cranial circumference were measured in all patients. Radiographs of the lumbar spine, left leg, pelvis, and left hand were also obtained. The presence of the N540K mutation was verified by restriction enzyme digestions. Half of our patients carried the N540K mutation. Although similar in phenotype to the patients without the mutation, they showed in addition relative macrocephaly. The association of the unchanged/narrow interpedicular distance with the fibula longer than the tibia was more common in patients with gene mutation. Although we did not find a firm correlation between genotype and phenotype, in our study the N540K mutation was most often associated with disproportionate short stature, macrocephaly, and with radiological findings of unchanged/narrow interpedicular distance and fibula longer than tibia.

Adolescent↗

PubMed1998

Assessment of skeletal maturation in infants: comparison between two methods in hypothyroid patients.

BACKGROUND: Conventional skeletal radiography is the standard technique for assessing skeletal age. However, radiography cannot demonstrate cartilage and is therefore of lesser value in infancy when the ossification centres are composed mainly of cartilage. By comparison, US clearly demonstrates cartilage and bone. OBJECTIVE: In the present study, we compared radiography and sonography for the assessment of skeletal age in neonates and infants. MATERIALS AND METHODS: Because delayed skeletal maturation is a feature of congenital hypothyroidism and assessment of skeletal age is routinely performed in our centre, we studied 55 hypothyroid infants (aged 7-66 days). AP radiographs and sonograms, acquired using high-frequency scanners, were obtained and dimensions of the distal femoral epiphyseal ossification centre (DFE) were compared. RESULTS: Measurements of DFE by the two methods showed excellent correlation (R = 0.94, P = 0.0001). Radiographs did not demonstrate a DFE in 11 infants, and US did not show it in 6. In no infant did radiography demonstrate DFE not seen by US. Moreover, DFE dimensions on US were larger than those measured on radiographs. Infants with absent thyroid gland had a DFE significantly smaller than those infants with ectopic or normally placed glands (P < 0.001), on both radiographs and sonograms. CONCLUSION: Our data suggest that sonography is a valid alternative to standard radiography for the assessment of skeletal age in infants.

Age Determination by Skeleton↗

PubMed1998

Neonatal transient hypothyroidism: aetiological study. Italian Collaborative Study on Transient Hypothyroidism.

AIMS: To define the aetiology of neonatal transient hypothyroidism (NTH) and recommend preventive measures. METHODS: Maternal and perinatal clinical data on the use of antiseptics, drugs, and contrast agents containing iodine were collected from 40 subjects. Thyroid stimulating hormone (TSH), free thyroxine (FT4), thyroxine (T4), thyroglobulin (TG), TSH receptor antibodies, thyroid peroxidase antibodies and urinary iodine were measured in random neonatal samples. In the mothers with known or suspected thyroid disorders, TSH, FT4, TSH receptor antibodies and thyroid peroxidase antibodies were also measured. RESULTS: The NTH aetiology was identified in 85% of cases. More than 50% of the babies with transient hypothyroidism had been exposed to iodine; maternal transfer of antibodies had occurred in a third of them. CONCLUSIONS: It is suggested that the practice of using iodine containing disinfectants should be withdrawn, and chlorhexidine substituted instead; that pregnant women should be advised of the adverse effects of using iodine products; and that thyroid function should be monitored whenever iodine is used.

Adult↗

PubMed1996

Congenital hypothyroidism: auxological retrospective study during the first six years of age.

We examined length, height and weight from birth to six years of age and head circumference during the first two years in 89 children with congenital hypothyroidism (CH). The patients were divided in two groups: children diagnosed by clinical criteria during the first year of life (group A) and children detected by neonatal screening (group B). Group A showed a complete catch up growth for height and weight 10 months after the beginning of the replacement therapy; to the contrary, group B did not show any difference for height and weight compared to normal standards. Head circumference, evaluated only in group B, was significantly higher in comparison with normal standards. When etiology of CH was taken into consideration, children with athyreosis showed a significantly lower length at birth and at three months of age and their growths curves normalized after institution of replacement therapy. In conclusion our data suggest a direct relationship between severity and duration of hormone deficiency and growth retardation and confirm that replacement therapy started within the first year of live in CH patients clinically diagnosed allows a catch up growth.

Body Height↗

PubMedDate not supplied

Measurement of urinary iodine excretion to reveal iodine excess in neonatal transient hypothyroidism.

This study was undertaken to confirm the importance of iodine excess in neonatal transient hypothyroidism. In 30 transient hypothyroid newborns at screening we measured urinary iodine excretion and TSH. They were divided into two groups: group A consisted of 21 newborns who had been exposed to iodine; group B of 9 non-exposed newborns. The two groups were significantly different only for median urinary iodine excretion (p = 0.001). In 61.5% of newborns of group A, iodine exposure caused iodine excess (urinary iodine excretion higher than 185 micrograms/l); this correlated with a higher prevalence of prematurity and a lower mean gestational age. Clinical records should reveal iodine exposure, but only urinary iodine excretion shows iodine excess. We suggest that evaluation at birth of urinary iodine excretion in every newborn with high TSH could help in predicting a good prognosis, since hypothyroidism due to the Wolff-Chaikoff effect is always spontaneously reversible, even if treatment may be suggested.

Female↗