Bone mineral density in young women of the city of São Paulo, Brazil: correlation with both collagen type I alpha 1 gene polymorphism and clinical aspects.

Osteoporosis is a multifactorial disease with great impact on morbidity and mortality mainly in postmenopausal women. Although it is recognized that factors related to life-style and habits may influence bone mass formation leading to greater or lower bone mass, more than 85% of the variation in bone mineral density (BMD) is genetically determined. The collagen type I alpha 1 (COLIA1) gene is a possible risk factor for osteoporosis. We studied a population of 220 young women from the city of São Paulo, Brazil, with respect to BMD and its correlation with both COLIA1 genotype and clinical aspects. The distribution of COLIA1 genotype SS, Ss and ss in the population studied was 73.6, 24.1 and 2.3%, respectively. No association between these genotypes and femoral or lumbar spine BMD was detected. There was a positive association between lumbar spine BMD and weight (P<0.0001), height (P<0.0156), and body mass index (BMI) (P<0.0156), and a negative association with age at menarche (P<0.0026). There was also a positive association between femoral BMD and weight (P<0.0001), height (P<0.0001), and BMI (P<0.0001), and a negative correlation with family history for osteoporosis (P<0.041). There was no association between the presence of allele s and reduced BMD. We conclude that a family history of osteoporosis and age at menarche are factors that may influence bone mass in our population.

Bone mineral density in young women of the city of Säo Paulo, Brazil: correlation with both collagen type I alpha 1 gene polymorphism and clinical aspects

Osteoporosis is a multifactorial disease with great impact on morbidity and mortality mainly in postmenopausal women. Although it is recognized that factors related to life-style and habits may influence bone mass formation leading to greater or lower bone mass, more than 85 percent of the variation in bone mineral density (BMD) is genetically determined. The collagen type I alpha 1 (COLIA1) gene is a possible risk factor for osteoporosis. We studied a population of 220 young women from the city of Säo Paulo, Brazil, with respect to BMD and its correlation with both COLIA1 genotype and clinical aspects. The distribution of COLIA1 genotype SS, Ss and ss in the population studied was 73.6, 24.1 and 2.3 percent, respectively. No association between these genotypes and femoral or lumbar spine BMD was detected. There was a positive association between lumbar spine BMD and weight (P<0.0001), height (P<0.0156), and body mass index (BMI) (P<0.0156), and a negative association with age at menarche (P<0.0026). There was also a positive association between femoral BMD and weight (P<0.0001), height (P<0.0001), and BMI (P<0.0001), and a negative correlation with family history for osteoporosis (P<0.041). There was no association between the presence of allele s and reduced BMD. We conclude that a family history of osteoporosis and age at menarche are factors that may influence bone mass in our population

Y-chromosome identification by PCR and gonadal histopathology in Turner's syndrome without overt Y-mosaicism.

OBJECTIVE: The frequency of gonadoblastoma is high in patients with Turner's syndrome bearing cells with Y or partial Y-chromosome. About 60% of patients with Turner's syndrome have a 45,X karyotype. In 30% of them a Y-sequence is disclosed by DNA analysis. To identify patients at risk of developing gonadoblastoma, a PCR based assay with SRY, ZFY and DYZ3 specific primers was carried out to detect different Y-sequences in the DNA of peripheral lymphocytes from patients with Turner's syndrome. DESIGN AND PATIENTS: Peripheral blood karyotypes from 36 patients with Turner's syndrome were studied. Patients with proven Y-chromosomal material were excluded. Genomic DNA was extracted from peripheral blood. SRY and ZFY genes and DYZ3 repetion of Y-chromosome were amplified by PCR. Patients with clinical signs of hyperandrogenism or with positive Y-sequences by PCR underwent gonadectomy. The gonadal tissues were examined for Y-sequences using PCR, morphology and immunohistochemical study. MEASUREMENTS: Turner's syndrome and signs of hyperandrogenism were evaluated both clinically and through laboratory tests. Haematoxylin and eosin staining was employed in gonadal morphology studies. The presence of testosterone was detected by immunohistochemistry using a monoclonal antibody. RESULTS: Two patients who had Y-positive blood samples and three hyperandrogenic (2 hirsutes, 1 virilized) Y-negatives underwent gonadectomy. PCR was carried out on their gonadal tissue. The tissue from the two patients without hyperandrogenism was Y-positive. The gonadal tissue from the three hyperandrogenics was Y-negative. Gonadal morphology disclosed hilus cell hyperplasia in the 3 hyperandrogenic Y-negatives and in one Y-positive patient; stromal luteoma and hyperthecosis in the virilized patient, cystadenofibroma in one hirsute patient and gonadoblastoma in one Y-positive. Testosterone was detected immunohistochemically in the hilus cell hyperplasia, stromal luteoma and hyperthecosis found in the hyperandrogenic patients. CONCLUSIONS: The molecular study was sensitive and useful in the evaluation of patients at risk of developing gonadoblastoma. Other nontumour, gonadotrophin-dependent and Y-independent mechanisms which deserve the same medical approach may be involved in the genesis of hyperandrogenic signs in Turner's syndrome.

Vitamin D receptor gene polymorphism: correlation with bone mineral density in a Brazilian population with insulin-dependent diabetes mellitus.

Patients with insulin-dependent diabetes mellitus (IDDM) are at higher risk of developing osteoporosis. Among the genetic factors related to the development of osteoporosis, a possible association between vitamin D receptor (VDR) gene polymorphism and bone mineral density (BMD) has been described in some populations. We characterized the VDR gene polymorphism in a healthy adult Brazilian population and in a group of patients with IDDM and correlated these findings with densitometric values in both groups. The Brazilian population is characterized by an important racial heterogeneity and therefore is considered an ethnically heterogeneous population. We recruited 94 healthy adult Brazilian volunteers (63 women and 31 men), mean (+/- SD) age 32.4 +/- 6.5 years (range 18-49 years), and 78 patients with IDDM (33 women and 45 men) diagnosed before 18 years of age, mean (+/- SD) age 23.3 +/- 5.5 years (range 18-39 years). VDR genotype was assessed by polymerase chain reaction amplification followed by BsmI digestion on DNA isolated from peripheral blood leukocytes. Statistical analysis included Bonferroni t-test to compare densitometric values within different genotypes in both groups and multiple regression analysis of bone density adjusted for potential confounding factors. The IDDM group had a lower BMD compared with the control group. The VDR genotype distribution in the control group was 43 Bb (45.7%), 39 bb (41.5%) and 12 BB (12.8%). This distribution did not differ from that observed in the IDDM group: 39 Bb (50%), 26 bb (33.3%) and 13 BB (16.7%). In the IDDM group, patients with the Bb genotype had a higher body weight when compared with the BB genotype (p = 0.02). However, when diabetic patients were controlled for age, sex and body mass index, BB genotype was associated with a lower mean BMD at lumbar spine and femoral neck than in Bb and bb patients. BB patients had a shorter duration of IDDM than bb and Bb patients. These findings suggest a small influence of VDR gene polymorphism on BMD of a racially heterogeneous population with IDDM.

Calcitonina monomérica plasmática e hipercalcemia em pacientes portadores de neoplasia pulmonar / Monomeric plasmatic calcitonin and hypercalcemia in lung cancer patients

A calcitonina (CT) é um hormonio peptídico relacionado ao metabolismo de calcio produzido pelas células C da tiróide. Encontra-se com níveis plasmaticos bastante elevados no carcinoma medular de tiróide e mostra-se como excelente marcador dessa doença. No entanto, existem relatos na literatura que demonstraram níveis elevados deste peptídio em pacientes portadores de outras neoplasias, principalmente no carcinoma de pulmao. Objetivo. Avaliar a validade da dosagem da CT sérica como possível marcador tumoral em pacientes portadores de tumor de pulmao de diferentes tipos histológicos. Métodos. Foram dosados CT plasmatica e calcio ionizado sanguíneo em 56 pacientes portadores de tumores malignos de pulmao. Para as dosagens de CT os autores utilizaram um método de radioimunoensaio específico, realizado após extraçao prévia do soro em coluna de sílica. Resultados. Observou-se prevalência de hipercalcemia de 21,4 por cento; apenas três (5,4 por cento) dos 56 pacientes investigados apresentaram níveis pouco elevados de calcitonina, e o restante manteve níveis normais ou identectaveis do peptídio. Conclusao. Os resultados demonstram que, com a utilizaçao de um método bastante específico para dosagem da calcitonina em sua forma monomérica, nao se encontram níveis elevados deste hormonio em pacientes portadores de neoplasia pulmonar, desestimulando sua utilizaçao como marcador tumoral nesta patologia.

[Monomeric plasmatic calcitonin and hypercalcemia in lung cancer patients]. / Calcitonina monomérica plasmática e hipercalcemia em pacientes portadores de neoplasia pulmonar.

BACKGROUND: Calcitonin (CT) is a peptidic hormone produced by the thyroid C cells and related to calcium metabolism. High plasmatic levels of this hormone are found in patients with medullary thyroid carcinoma, what makes it an excellent tumor marker for this disease. However, there are reports that showed an increase of plasmatic CT levels in patients with other tumors, mainly in lung cancer. PURPOSE: These data prompt us to investigate the validity of the CT level determinations as a potential tumor marker in different histologic lung cancer, and its correlation with hypercalcemia, a very common complication in these tumors. METHOD: Blood were sampled from 56 patients with malignant lung disease for the CT and ionized calcium determinations. Calcitonin was measured using a specific radioimmunoassay for the monomeric form of the molecule, in a previous silica extracted serum probe. RESULTS: We did not find elevated levels of monomeric CT in lung cancer. Only 3 patients had mild elevated levels, while in the others CT was normal or undetectable. Hypercalcemia was found in 21.4% of these patients, but only one with supranormal CT levels. CONCLUSION: Monomeric CT serum levels are normal in lung cancer, what makes the latter use an unreliable tumor marker.

Monoclonal antibodies specific for the free alpha subunit of glycoprotein hormones and their use in the development of a sensitive immunofluorometric assay.

Glycoprotein hormone free alpha subunit has been used as a marker for some pituitary tumors and to study the reactivity of glycoprotein hormone-producing cells under different circumstances. We describe a highly sensitive and specific immunofluorometric assay for the measurement of serum free alpha subunit levels. The assay is based on a monoclonal antibody, specific for free alpha subunit, bound to microtiter plates. As tracer antibody we employed an europium-labelled free/complexed alpha subunit specific monoclonal antibody. Using overnight incubation and 50-microliters samples, the least detectable dose was of the order of 4 ng/l. Cross-reactivity with LH, TSH, FSH and hCG was 6.5, 1.2, 4.3 and 1.1%, respectively. Normal adult males showed values ranging from 120 to 790 ng/l, not different from normal adult premenopausal females (88 to 604 ng/l). In post-menopausal females, serum concentrations were significantly higher, ranging from 341 to 4071 ng/l. In 56 patients with untreated pituitary tumors (18 "non-secreting", 25 GH-producing and 13 prolactin-producing tumors), 10 showed high values, 3 of them from the first group, 3 from the second and 4 from the third. We conclude that this highly sensitive assay can be a valuable tool for the diagnosis and follow-up of selected patients with pituitary tumors and in other circumstances in which the glycoprotein hormone-producing cells of the pituitary require evaluation.

Monoclonal antibodies specific for the free alpha subunit of glycoprotein hormones and their use in the development of a sensitive immunofluorometric assay

Glicoprotein hormone free alpha subunit has been used as a marker for some pituitary tumors and to study the reactivity of glycoprotein hormone-producing cells under different circunstances. We describe a highly sensitive ans specific immunofluorometric assau for the measurement of serum free alpha subunit levels. The assay is based on a monoclonal antibody, specific for free alpha subunit, bound to microtiter plates. As tracer antibody we employed an europium-labelled free/complexed alpha subunit specific monoclonal antibody. Using overnight incubation and 50µl samples, the least detectable dose was of the order of 4 ng/1. Cross-reactivity with LH, TSH, FSH, and hCG was 6.5, 1.2, 4.3 and 1.1 percent, repectively. Normal adult males showed values ranging from 120 to 790ng/l, not different from normal adult premenopausal females (88 to 604 ng/l). In post-menopausal females, serum concentrations were significantly highler, ranging from 341 to 407 ng/l. In 56 patients with untreated pituitary tumors (18 "non-secreting", 25 GH-producing and 13 prolactin-producing tumors), 10 showed high values, 3 of them from the first group, 3 from the second and 4 from the third. We conclude that this highly sensitive assay can be a valualbe tool for the diagnosis and follow-up of selected patients with pituatary tumors and in other circumstances in which the glycoprotein hormone-producing cells of the pituitary require evaluation

Development and clinical application of an immunofluorometric assay for intact parathyroid hormone.

Parathyroid hormone (PTH) is a linear peptide of 84 amino acids that is found in serum mainly in the form of carboxyl-terminal fragments. The biological activity of PTH depends on the presence of the amino-terminal portion and in circulation is limited to the intact molecule. We describe an immunofluorometric assay for the measurement of PTH-(1-84) based on a chicken egg yolk-derived amino-terminal antibody bound to microtiter plates by an anti-chicken Ig monoclonal antibody. As tracer antibody we employed a Europium-labelled carboxyl-terminal specific monoclonal antibody produced from a mouse immunized with hPTH-(53-84)-BSA conjugate. The assay included an initial overnight incubation of the sample and the solid phase-bound amino-terminal antibody, followed by washing and addition of the tracer antibody, and an additional two hours of incubation prior to fluorescence reading. The least-detectable dose was in the order of 2.5 pg/ml and preliminary studies in 40 normal adults showed values in the range of 4 to 70 pg/ml; for 12 patients with surgery-proven primary hyperparathyroidism values ranged from 109 to 743 pg/ml and for 34 patients with humoral hypercalcemia of malignancy from 2.5 to 66 pg/ml. We conclude that this assay, with its increased sensitivity and specificity, will be a valuable tool in the study of PTH secretion in normal and pathological situations.

Development and clinical application of an immunoflurometric assay for intact parathyroid hormone

Parathyroid hormone (PTH) is a linear peptide of 84 amino acids that is found in serum mainly in the form of carboxyl-terminal fragments. The biological activity of PTH depends on the presence of the amino-terminal portion and in circulation is limited to the intact molecule. We describe an immunmofluorometric assay for the measurement of PTH-(1-84) based on a chicken egg yolk-derived amino-terminal antibody bound to microtiter plates by an anti-chicken Ig monoclonal antibody. As tracer antibody we employed a Europium-labelled carboxyl-terminal specific monoclonal antibody produced from a mouse immunized with hPTH-(53-84)-BSA conjugate. The assayincluded an initial overnight incubation of the sample and the solid phase-bound amino-terminal antibody, followed by washing and addition of the tracer antibody, and an additional two hours of incubation prior to fluorescence reading. The least-detectable dose was in the order of 2.5 pg/.ml and preliminary studies in 40 normal adults showed values in the range of 4 to 70 pg/ml; fo 12 patients with surgery-proven primary hyperparathyroidism values ranged from 109 to 743 pg/ml and for 34 patients with humoral hypercalcemia of malignancy from 2.5 to 66 pg/ml. We conclude that this assay, with its increased sensitivity and specificity, will be a valuable tool in the study of PTH secretion in normal and pathological situations

[Parathyroid function in hyperthyroidism: implications for bone metabolism and effect of the treatment]. / Função paratiroidiana no hipertiroidismo: implicações no metabolismo ósseo e efeito do tratamento.

PURPOSE: using bone densitometry, to evaluate bone loss of hyperthyroidism patients, and to study the possible contribution of parathyroid hormone (PTH) in the genesis of this osteopenia. TYPE: prospective study of patients with hyperthyroidism before and after treatment. PLACE: Division of Endocrinology, Escola Paulista de Medicina. São Paulo, SP. PATIENTS: 14 outpatients with clinical and laboratory diagnosis of toxic diffuse goiter (Basedow-Graves disease). Six of these patients were studied again after treatment, with at least 6 months of clinical and laboratory euthyroidism. METHOD: bone mineral content of the lumbar vertebral bodies was evaluated by dual-photon bone densitometry. Parathyroid hormone secretion was studied with an amino-terminal specific assay after EDTA-induced hypocalcemia; results were compared to those obtained from a group of 10 normal controls. RESULTS: there was a significant increase in bone mineral density after treatment (1.300 +/- 0.079 g/cm2) as compared to the pre-treatment condition (1.229 +/- 0.091 g/cm2, p less than 0.001). Decrement rate of serum calcium during EDTA infusion was significantly lower (p less than 0.001) in hyperthyroid (-0.698 x 10(-3) +/- 0.12 x 10(-5)) than in normal control individuals (-1.486 x 10(-3) +/- 9.33 x 10(-5)), and went back to normal after treatment. EDTA-induced calcium lowering was sufficient to induce a PTH plateau of maximum response. Maximum PTH response in hyperthyroidism patients (2.34 +/- 0.45pmol) was significantly lower (p less than 0.001) than that observed in normal controls (7.51 +/- 0.40), PTH response was normal after six months of euthyroidism. CONCLUSIONS: bone mineral density showed a significant increment in treated patients, suggesting that these patients had suffered some degree of bone loss during the course of thyrotoxicosis. The lower PTH secretory reserve found in untreated hyperthyroid patients suggests that hyperthyroid state-induced bone loss may be a consequence of a direct action of thyroid hormones. This conditions was reverted after 6 months of euthyroidism.

Parathyroid hormone secretory reserve in patients submitted to 131-iodine therapy for hyperthyroidism.

Twelve euthyroid patients who had been treated with 131I for hyperthyroidism due to Graves' disease and six normal controls were submitted to an EDTA infusion test. Ionized calcium and parathyroid hormone were measured in serum samples collected every 10 min during the 2-h test. Basal values for calcium (1.22 +/- 0.03 vs 1.23 +/- 0.03 pmol/l, mean +/- SD, controls vs patients) and parathyroid hormone (3.3 +/- 0.65 vs 5.1 +/- 2.32 pmol/l) as well as maximum response during infusion (1.01 +/- 0.04 vs 1.01 +/- 0.05 for calcium and 12.0 +/- 2.2 vs 13.1 +/- 3.7 for parathyroid hormone) were not significantly different. We conclude that 131I treatment for hyperthyroidism due to Graves' disease had no effect on the parathyroid gland secretory reserve of the patients studied.

Parathyroid hormone secretory reserve in patients submitted to 131-iodine therapy for hyperthyroidism

Twelve euthyroid patients who had treated with I for hyperthyroidism due to Fraves' disease and six normal controls were submitted to an EDTA infusion test. Ionized calcium and parthyroid hormone were measured in serum samples collected every 10 min during the 2-h-test. Basal values for calcium (1.22 ñ 0.03 vs 1.23 ñ 0.03 pmol/l, mean ñ SD, controls vs patients) and parathyroid hormone (3.3 ñ 0.65 vs 5.5 ñ 2.32 pmol/l_ as well as maximum response during infusion (1.01 ñ 0.04 vs 1.01 ñ 0.05 for calcium and 12.0 ñ 2.2 vs 13.1 ñ 3.7 for parathyroid hormone) were not significantly different. We conclude that I treatment for hyperthyroidism due to Graves' disease had no effect on the parathyroid gland secretory reserve of the patients studied

Persistent hyperactivity of the parathyroid glands in treated hypothyroid patients.

Twelve untreated hypothyroid patients were submitted to EDTA infusion and the parathyroid hormone response to the induced hypocalcemia was studied with an amino-terminal specific assay. Eight of these patients were retested 6 months after achieving clinical and laboratory euthyroidism. The PTH response in the pretreatment condition was significantly higher than that obtained in a group of 10 normal individuals; this increased response had not normalized after 6 months of euthyroidism. This persisting hyperresponsiveness can be a contributory factor to the bone hypersensitivity to thyroid hormone replacement seen in hypothyroid patients.

Clinical trial of Myrcia uniflora and Bauhinia forficata leaf extracts in normal and diabetic patients.

1. Myrcia uniflora and Bauhinia forficata were compared with placebo for their hypoglycemic effect in randomized cross-over double-blind studies in 2 groups of normal subjects (10 subjects each) and 2 groups of Type II diabetic patients (18 in the M. uniflora group and 16 in the B. forficata group). The protocol with each plant lasted 56 days. 2. After the ingestion of infusions of 3 g leaves/day of M. uniflora and B. forficata leaves, no acute or chronic effects on plasma glucose levels or glycated hemoglobin were found in either group. However, plasma insulin levels in the diabetic group were lower after M. uniflora than after placebo. 3. Among other clinical parameters tested, a statistically significant difference was found only in the alkaline phosphatase level after placebo compared with that after M. uniflora in the normal group. 4. There were no differences in any clinical parameters after the use of placebo or of B. forficata. 5. We conclude that infusions prepared from the leaves of M. uniflora or B. forficata have no hypoglycemic effect on normal subjects or Type II diabetic patients.

Circulating molecular forms of parathyroid hormone in primary and secondary hyperparathyroidism.

To study the circulating forms of parathyroid hormone (PTH), sera from 5 patients with primary hyperparathyroidism (PHP) and 12 patients with secondary hyperparathyroidism due to chronic renal failure (SHP) were submitted to gel filtration chromatography. The eluent samples were analyzed using two sequence-specific radioimmunoassays (RIA), one amino-terminal (NH2), the other carboxyl-terminal (COOH). The results obtained with the NH2 RIA showed a single molecular form in both groups co-eluting with the intact hormone. The COOH assay identified several molecular forms with a broader distribution in the SHP patients. These results confirm the diagnostic superiority of the NH2 assay under both conditions.

Circulating molecular forms of parathyroid hormone in primary and secondary hyperparathyroidism

To study the circulating forms of parathyroid hormone (PTH), sera from 5 patients with primary hyperparathyroidism (PHP) and 12 patients with secondary hyperparthyroidism due the chronic renal failure (SHP) were submitted to gel filtration chromatography. The eluent samples were analyzed using two sequence-specific radioimmunoassays (RIA), one amino-terminal (NH2), the other carboxyl-terminal (COOH). The results obtained with the NH2RIA showed a single molecular form in both groups co-eluting with the intact hormone. The COOH assay identified several molecular forms with a broader distribution in the SHP patients. These results confirm the diagnostic superiority of the NH2 assay under both conditions