Gilberto González

High prevalence of vitamin D deficiency in Chilean healthy postmenopausal women with normal sun exposure: additional evidence for a worldwide concern.

Objective:To assess the prevalence of vitamin D deficiency in healthy postmenopausal women with normal sun exposure but without vitamin D fortification in their diets. Design:We studied 90 healthy ambulatory women who were residents of Santiago, Chile (latitude 33°S); 30 were premenopausal (32.6 ± 7.4 y), and 60 were postmenopausal (63.7 ± 9.7 y). Half of the women were studied during the winter and the other half during the following summer. Each provided a fasting blood sample to measure biochemical parameters, parathyroid hormone, and 25-hydroxyvitamin D and completed a questionnaire to estimate sunlight exposure. A first morning urine sample was collected in postmenopausal women to measure deoxypyridinoline. Various cutoff points of 25-hydroxyvitamin D were used to assess the prevalence of vitamin D deficiency (<9, <15, and <20 ng/mL). Results:All of the women had normal renal and liver parameters. Sunlight exposure was adequate in almost all of the volunteers (93% in both groups, P > 0.05). In postmenopausal women, serum 25-hydroxyvitamin D was less than 9 ng/mL in 12%, less than 15 ng/mL in 40%, and less than 20 ng/mL in 60%, compared with 0%, 13%, and 27%, respectively, in premenopausal women. Deoxypyridinoline was 75% higher during winter than summer (9.8 ± 2.5 vs 5.6 ± 1.4 nmol/mmol creatinine, P < 0.0001). Conclusions:Vitamin D deficiency is very common in Chilean healthy postmenopausal women with normal sun exposure but without vitamin D fortification in their diets. This finding is associated with higher bone resorption during winter time and emphasizes the need to increase vitamin D intake in healthy postmenopausal women.

Higher latitude and lower solar radiation influence on anaphylaxis in Chilean children

Recent studies suggest an association between higher latitude, a proxy of vitamin D (VD) status, and allergic diseases. Chile provides an ideal setting to study this association due to its latitude span and high rates of VD deficiency in southern regions. The aim of this study is to explore the associations of latitude and solar radiation with anaphylaxis admission rates.

Anticuerpos anti-tiroglobulina en el seguimiento de pacientes con cáncer diferenciado de tiroides: ¿Marcadores de enfermedad residual o recidivante?

Background: Anti thyroglobulin antibodies are present in 25% of patients treated for a differentiated thyroid cancer, invalidating thyroglobulin determination. Those patients subjected to total thyroidectomy and free of disease, should reduce the production of these antibodies, due to the lack of antigenic stimulus. Therefore, anti thyroglobulin antibodies could be useful to detect early relapses. Aim: To assess the relationship between anti thyroglobulin antibodies and the evolution of the disease in patients treated for thyroid cancer. Material and methods: Retrospective analysis of 26 patients treated for thyroid cancer with positive anti thyroglobulin antibodies, followed for three years. These were divided in those with or without lymphocytic thyroiditis (19 and 7 respectively). Results: At the first year of follow up, anti thyroglobulin antibody concentration was 401±94.9 UI/ml (x±sem) in patients with thyroiditis and 38.9±8.9 UI/ml in those without thyroiditis (p < 0.005). During the three years of follow up, no differences in anti thyroglobulin antibodies were observed between patients with or without tumor relapse. Conclusions: Concentration of anti thyroglobulin antibodies was higher in patients with thyroiditis and did not differentiate patients with tumor relapse (Rev Med Chile 2002; 130: 167-72)

Feeding and bone turnover in gastric bypass.

CONTEXT Roux-en-Y gastric bypass (RYGB) is associated with high bone turnover. In healthy subjects, feeding causes acute reduction of bone resorption, which is regulated by several intestinal and pancreatic peptides. OBJECTIVE Our objective was to assess bone turnover after feeding in patients with RYGB. DESIGN AND SETTING This was a cross-sectional case-control study at a university hospital. PARTICIPANTS Fifteen postmenopausal women who underwent RYGB 7.4 ± 4.1 years previously were matched by age and body mass index with 15 nonoperated women (controls). MAIN OUTCOMES Serum PTH, calcium, phosphorus, insulin, carboxy telopeptide (CTX), procollagen type I N-terminal propeptide (P1NP), and glucagon-like peptide 2 (GLP-2) were measured while fasting and after a standard meal (SM). RESULTS The fasting calcium, phosphorus, and PTH were similar in both groups and exhibited similar decreases after an SM. The fasting CTX level was higher in the RYGB than in the control group (0.589 ± 0.18 vs 0.382 ± 0.11 ng/mL; P < .05) and fell to a nadir of 42.2% of the basal value in the RYGB and 53.9% in controls (P < .05). The fasting and postprandial P1NP levels were similar in both groups and fell to a nadir of 85.8% in the RYGB and 89.3% in controls. Insulin and GLP-2 levels were similar during fasting in both groups. RYGB patients had exaggerated postprandial insulin and GLP-2 response compared with the controls with the insulin and GLP-2 area under the curve being significantly higher in the RYGB group. There was a significant negative correlation between the peak of insulin levels and the CTX changes. CONCLUSION The acute reduction in bone resorption after feeding is preserved in RYGB and is even higher than in nonoperated subjects. This phenomenon is related to the increase of postprandial levels of insulin. These findings suggest a bone-protecting mechanism in RYGB that may counteract the elevated bone resorption that occurs during fasting.

Características de presentación del microcarcinoma papilar del tiroides: Experiencia retrospectiva de los últimos 12 años

BACKGROUND Thyroid microcarcinoma is a tumor of 10 mm or less, that should have a low risk of mortality. However, a subgroup of these carcinomas is as aggressive as bigger tumors. AIM To describe the pathological presentation of these tumors, and compare them with larger tumors. MATERIAL AND METHODS All pathological samples of thyroid carcinoma that were obtained between 1992 and 2003, were studied. In all biopsies, the pathological type, tumor size, the focal or multifocal character, the presence of lymph node involvement and the presence of lymphocytic thyroiditis or thyroid hyperplasia, were recorded. RESULTS One hundred eighteen microcarcinomas and 284 larger tumors were studied. The mean age of patients with microcarcinoma and larger tumors was 42.7+/-14 and 49.3+/-16 years respectively (p <0,001) and 83% were female, without gender differences between tumor types. Mean size of microcarcinomas was 8.6 mm and 116 (98%) were papillary carcinomas. Of these, 109 (94%) were well differentiated and seven (6%) were moderately differentiated. Thirty six (31%) were multifocal and in 10 (8,6%), there was lymph node involvement. The mean size of larger tumors was 23.8 mm and 241 (85%) were papillary carcinomas. Of these, 200 (83%) were well differentiated, and 41 (17%) were moderately differentiated. Eighty five (35%) were multifocal and in 44 (18%) there was lymph node involvement. The prevalence of thyroiditis and hyperplasia was significantly higher among microcarcinomas than in larger tumors (15 and 2.5%, respectively, p <0.001, for the former; 32.4 and 1.7%, respectively, p <0.001, for the latter). CONCLUSIONS In this series, one third of microcarcinomas were multifocal and 10% had lymph node involvement. Therefore, the aggressiveness of these tumors is higher than what is reported in the literature and they should be treated with total thyroidectomy.

Enfermedad de Paget en Chile: una serie de 15 pacientes

Background: Paget disease of bone (PD) is a localized disorder of bone remodeling, which leads to bone fragility and deformity. In Chile PD is uncommon. Aim: To study clinical and demographic characteristics of patients with PD seen in the Clinical Hospital of the Catholic University. Patients and methods: Patients with typical radiological and clinical features of PD referred to our institution during the last decade were included in this review. Results: We obtained data from 15 patients with PD (ten males, eight Chilean, six European and one Asian), eleven of them were diagnosed during the last 3 years. The mean age at diagnosis was 68,7±11,1 years old. No one had first degree relatives with PD. Bone pain was the main complaint in 13 patients and elevated total alkaline phosphatases in the other two. The average duration of the symptoms prior to diagnosis was 38,8 months. Eight patients had monostotic lesions; the most commonly involved sites were the pelvis, spine and femur. Radiological evaluation disclosed sclerotic changes in all patients as well as bone deformity and osteoarthritis in eight patients. Total alkaline phosphatases were elevated in 14 cases (mean: 4 times over the upper normal limit). Conclusions: When compared to series of the Northern hemisphere, PD in Chile is characterized by an older age at diagnosis, a higher frequency of symptomatic presentation, advanced radiological involvement and greater proportion of complications. PD should be suspected in every patient, Chilean or foreigner, with bone pain or elevated alkaline phosphatases (Rev Med Chile 2003; 131: 491-7).

Utilidad de la PTH intraoperatoria como predictor de curación quirúrgica en hiperparatiroidismo primario

Serum PTH was measuredto all patients operated for PHPT between 2003 and 2008, before and five and ten minutes after theexcision of the parathyroid gland causing the disease. The criteria for complete cure were a normalserum calcium at 24 hours and 6 months after surgery and the pathological confirmation ofparathyroid gland excision.

Diseño de una escala ecográfica predictora de malignidad en nódulos tiroideos: Comunicación preliminar

One hundred twenty two biopsies of atotal of 1,498 were conclusive for PTC. Univariate analysis showed associations with PTC for thepresence of micro-calcifications (Odds ratio (OR) 49.2: 95% confidence intervals (CI) 18.7-140.9),solid predominance (OR 25.1; 95% CI 6-220), hypoechogenicity (OR 23.5, 95% CI 6.5-122.6),irregular borders (OR 17, 95% CI 7.2-42.9), lymph node involvement (OR 12.3, 95% CI 2.7-112),central vascularization (OR 12.2, 95% CI 4.8-33.3), local invasion and hyperechogenicity (OR 0.2;CI 95% CI 0.03-0.6). Multivariate analysis disclosed microcalcifications (OR 28.1; CI 95% 8.9-89),hypoechogenicity (OR 9.4; 95% CI 1.5-59.5) and irregular borders (OR 4.7; CI 95% 1.5-15) as thevariables independently associated with the presence of PTC. The prevalence of PTC in the presenceof the three variables was 97.6% (Likelihood ratio (LR) 45) and 5.4% in their absence (LR 0.06).

Carcinoma familiar del tiroides no medular (CFTNM): características de presentación en 17 casos

Retrospective analysis of medical records of patients with thyroid carcinoma. An index case wasdefined as a subject with the diagnosis of differentiated thyroid carcinoma with one or morefirst degree relatives with the same type of cancer. Seventeen such patients were identified andwere compared with 352 subjects with PTC.

Cirugía conservadora de riñón para tumores renales pequeños: papel de la radiofrecuencia

Resumen es: Objetivo: La radiofrecuencia con asistencia laparoscopica es una opcion de tratamiento minimamente invasivo para la conservacion de parenquima renal, esp...