Ilda S. Kunii

Desenvolvimento de um método para a determinação da iodúria e sua aplicação na excreção urinária de iodo em escolares brasileiros

In this study we developed a semi-automated method for the measurement of urinary iodine using firstly ammonium persulfate for digestion of urine followed by estimation of iodine content in the Sandell-Kolthoff reaction, in which iodine acts as a catalyst for the reduction of cerium. This method was validated in the 3rd Brazilian National Survey of iodine deficiency in 1994. We studied 16,803 casual urine samples from schoolchildren of 401 cities and found 4 moderately-deficient towns (Almas, Arraias, and Parana, in the State of Tocantins, and Cocos, in the State of Bahia), and 116 mildly-deficient. This work suggests that despite the salt iodization program, there was some iodine-deficient areas in Brazil in 1994. Recent surveys, involving less cities, are indicating an excess of iodine ingestion. Therefore, in a country of continental dimensions and very heterogeneous in terms of public health, periodical evaluations are necessary to monitor the real situation of iodine nutrition in Brazil. The method developed in this paper is suitable for these surveys.

Increases in summer serum 25-hydroxyvitamin D (25OHD) concentrations in elderly subjects in São Paulo, Brazil vary with age, gender and ethnicity

BackgroundHypovitaminosis D is a common condition among elderly individuals in temperate-climate countries, with a clear seasonal variation on 25 hydroxyvitamin D levels, increasing after summer and decreasing after winter, but there are few data from sunny countries such as Brazil. Many factors can interfere on vitamin D cutaneous synthesis. We aimed at studying the 25OHD variations during winter and summer in an outdoor physically active elderly population living in São Paulo city, and analysed their determining factors.MethodsNinety-nine individuals (52 women and 47 men, from 55 to 83 years old) from different ethnic groups were selected from an outdoor physical activity group. Data are reported as Mean ± SD, and we used Pearson Linear Correlation, Students t-test for non-related samples, Chi-square (χ²) test and One-way ANOVA for analysis.ResultsMean 25OHD value for the whole group was 78.9 ± 30.9 nmol/L in the winter and 91.6 ± 31.7 nmol/L in the summer (p = 0.005). Mean winter serum 25OHD concentrations were not different between men and women (81.2 ± 30.1 nmol/L vs. 76.7 ± 31.8 nmol/L, respectively), and 19.2% of the individuals showed values < 50 nmol/L. In the summer, we noticed an increase only for men (107.6 ± 31.4 nmol/L) compared to women (76.7 ± 24.0 nmol/L), and 6.5% showed values < 50 nmol/L. A decrease in the mean PTH in the summer compared to the winter was noticed, with PTH levels showing a relationship with 25OHD concentrations only in the winter (r = -0.208, p = 0.041). White individuals showed an increase in mean serum 25OHD in the summer (p = 0.016) which was not noticed for other ethnic groups (Asians, native Brazilians and blacks). An increase in 25OHD values in the summer was observed in the age groups ranging from 51-60 and 61-70 years old (p < 0.05), but not in the age group from 71 years old on.Conclusions25OHD values increased during the summer in elderly residents of São Paulo, but to different extents depending on ethnicity, gender and age. This season-dependent increase was noticed only among men, white and who were in the youngest group of individuals.

Ion channelopathies in endocrinology: recent genetic findings and pathophysiological insights

Ion channels serve diverse cellular functions, mainly in cell signal transduction. In endocrine cells, these channels play a major role in hormonal secretion, Ca(2+)-mediated cell signaling, transepithelial transport, cell motility and growth, volume regulation and cellular ionic content and acidification of lysosomal compartments. Ion channel dysfunction can cause endocrine disorders or endocrine-related manifestations, such as pseudohypoaldosteronism type 1, Liddle syndrome, Bartter syndrome, persistent hyperinsulinemic hypoglycemia of infancy, neonatal diabetes mellitus, cystic fibrosis, Dents disease, hypomagnesemia with secondary hypocalcemia, nephrogenic diabetes insipidus and, the most recently genetically identified channelopathy, thyrotoxic hypokalemic periodic paralysis. This review briefly recapitulates the membrane action potential in endocrine cells and offers a short overview of known endocrine channelopathies with focus on recent progress regarding the pathophysiological mechanisms and functional genetic defects.

Optimizing nucleic acid extraction from thyroid fine-needle aspiration cells in stained slides, formalin-fixed/paraffin-embedded tissues, and long-term stored blood samples

OBJECTIVE Adequate isolation of nucleic acids from peripheral blood, fine-needle aspiration cells in stained slides, and fresh and formalin-fixed/paraffin-embedded tissues is crucial to ensure the success of molecular endocrinology techniques, especially when samples are stored for long periods, or when no other samples can be collected from patients who are lost to follow-up. Here, we evaluate several procedures to improve current methodologies for DNA (salting-out) and RNA isolation. MATERIALS AND METHODS We used proteinase K treatment, heat shock, and other adaptations to increase the amount and quality of the material retrieved from the samples. RESULTS We successfully isolated DNA and RNA from the samples described above, and this material was suitable for PCR, methylation profiling, real-time PCR and DNA sequencing. CONCLUSION The techniques herein applied to isolate nucleic acids allowed further reliable molecular analyses.

Three Years Follow-up of Pamidronate Therapy in Two Brothers with Osteoporosis-Pseudoglioma Syndrome (OPPG) Carrying an LRP5 Mutation

UNLABELLED Osteoporosis-pseudoglioma (OPPG) is a rare syndrome characterized by severe osteoporosis and ocular defects caused by homozygotic inactivation mutations in the LRP5 gene. Bisphosphonate has been demonstrated to improve bone mineral density (BMD) in children with OPPG. We present here a 3 years follow-up of two brothers with OPPG carrying a novel mutation in the LRP5 gene, who were treated with intravenous pamidronate. PATIENT REPORT We looked for a mutation in the LRP5 gene in two brothers (12 and 4 years old) with clinical features of OPPG (blindness, low BMD and fragility fractures) and in their consanguineous parents to confirm the diagnosis of OPPG. The patients were treated with bisphosphonate for 3 years. They received 1 mg/kg/day of pamidronate for 2 consecutive days, every 3 months during the first year, and every 4 months in subsequent years. Calcium, phosphorus, total alkaline phosphatase, parathyroid hormone, hepatic transaminases, creatinine and hemogram tests were performed before each infusion. Bone densitometry was performed at baseline and at the end of the follow-up. RESULTS AND CONCLUSION The affected brothers carry a missense mutation in the third codon of exon 8 (AAT-->ATT) that led to the exchange of an asparagine for an isoleucine (N531I). Both parents were found to be heterozygous for this mutation. The intravenous pamidronate therapy was safe for up to 3 years of use. Moreover, increased BMD and decreased fracture rate were observed in our patients with OPPG.

Early Diagnosis of Multiple Endocrine Neoplasia Type 2B: a Challenge for Physicians

BACKGROUND The hereditary form of medullary thyroid carcinoma may occur isolated as a familial medullary thyroid carcinoma (FMTC) or as part of Multiple Endocrine Neoplasia 2A (MEN2A) and 2B (MEN2B). MEN2B is a rare syndrome, its phenotype may usually, but not always, be noted by the physician. In the infant none of the MEN2B characteristics are present, except by early gastrointestinal dysfunction caused by intestinal neuromas. When available, genetic analysis confirms the diagnosis and guides pre-operative evaluation and extent of surgery. Here we report four cases of MEN2B in which the late diagnosis had a significant impact in clinical evolution and, potentially, in overall survival. CASE REPORT We report four cases, 2 men and 2 women, with differences in their phenotypes and with a late diagnosis. The first case has a history of severe gastrointestinal obstruction requiring a surgery intervention two days after his birth. The second told had nodules in the oral mucosa and constipation since childhood. The third case referred a history of constipation from birth until 5 months of life. The fourth has had a history of chronic constipation since childhood. DISCUSSION New concepts have emerged since the RET oncogene was identified in 1993 as the responsible gene for hereditary medullary thyroid carcinoma. The majority of MEN2B individuals have M918T mutation in the exon 16 of RET, with a few cases having a mutation A883F or the association of V804M with E805K, Y806C or S904C mutations. The consensus classifies the RET mutation in codon 918 as of highest risk and recommends total thyroidectomy and central lymph node dissection until 6 months after birth. A fast and precise diagnosis is essential to reach these goals. The identification of early manifestations such as intestinal ganglioneuromatosis and oral mucosal neuromas should prompt the physician to initiate an investigation for multiple endocrine neoplasia type 2B. CONCLUSION The diagnosis of MEN2B is very important to allow appropriate investigation of associated diseases and to allow counseling and appropriate screening of relatives for a RET mutation. Even patients with MEN2B, which often have typical physical features, may not be properly recognized and be followed as a sporadic case. Based on this, all suspicious cases of multiple endocrine neoplasia should undergo a molecular genetic test.

Teriparatide increases bone mineral density in a man with osteoporosis pseudoglioma

Osteoporosis Pseudoglioma (OPPG) is characterized by severe juvenile‐onset osteoporosis and ocular abnormalities. It is caused by one of several inactivating mutations in LRP5, a gene importantly involved in bone formation. The objective of this study was to evaluate the efficacy of teriparatide in a young man with OPPG. The subject of this case report is a 19‐year‐old man with congenital blindness and low trauma fractures because of OPPG. A 2‐year course of teriparatide, 20 µg/day, was initiated after a 6‐year course of intravenous pamidronate infusions, the latter 3 years of which had minimal effects on bone mineral density (BMD). Measurements in serum were made of C‐terminal telopeptide of type I collagen (CTX), N‐terminal propeptide of type I collagen (P1NP), total and ionized calcium, phosphate, uric acid, complete blood count, and renal and liver function tests. Urinary calcium/creatinine ratio was determined. BMD was measured by DXA yearly. BMD increased by 9.7% in lumbar spine and 10.2% in right femur hip. CTX rose early, peaking in month 3, followed by an increase in P1NP, peaking in month 9. Both indices returned to baseline by month 24. The increase in CTX followed by P1NP is an unusual time course when teriparatide is used to treat osteoporosis but may be typical of low bone turnover states. There were no adverse events. In a patient with OPPG, teriparatide markedly increased BMD in the lumbar spine and femur hip.

Extended RET gene analysis in patients with apparently sporadic medullary thyroid cancer: clinical benefits and cost.

RET sequencing has become an important tool in medullary thyroid cancer (MTC) evaluation and should be performed even in the absence of family history of MTC. The most commonly studied exons in index cases are 8, 10, 11, and 13–16. To address the ATA guidelines regarding the sequencing of the entire coding region of RET, we selected 50 patients with sporadic MTC (sMTC) without mutations in the hot spot regions of RET for extended investigation of exons 1–7, 9, 12, 17, 18, and 19. Twenty-seven of 50 patients presented with one or more features suggesting familial disease. We found only a new RET variant (p.Gly550Glu) in one patient with MTC. Several polymorphisms were observed, and their frequency was histogram scaled by exons and introns. Eight patients were also included for somatic mutation search. We estimated the sequencing cost by stratifying into four investigation approaches: (1) hot spot exons in a new patient, (2) the remaining exons if the hot spots are negative in a patient with suspected familial disease, (3) a relative of a carrier for a known RET mutation, and (4) tumor sequencing. In spite of the increasing number of variants being described in MTC, it appears that there is no direct clinical benefit in extending RET germ line analysis beyond the hot spot regions in sMTC. The cost evaluation in apparent sMTC using a tiered approach may help clinicians make more suitable decisions regarding the benefits of investigating only the hot spots against the entire coding region of RET.

Parathyroid hormone: an early predictor of symptomatic hypocalcemia after total thyroidectomy

OBJECTIVE The purpose of this study was to evaluate if the measurement of peri-operative parathyroid hormone (PTH) is able to identify patients with increased risk of developing symptoms of hypocalcemia. SUBJECTS AND METHODS Forty patients who underwent total thyroidectomy were studied prospectively. Ionized serum calcium and PTH were measured after induction of anesthesia, one hour (PTH1) and one day after surgery (PTH24). Patients were evaluated for symptoms of hypocalcemia and treated with calcium and vitamin D supplementation as necessary. RESULTS Symptomatic hypocalcemia developed in 16 patients. Symptomatic patients had significant lower PTH1 and greater drops in PTH levels. The selection of 12.1 ng/L as PTH1 level cutoff level divided patients with and without symptoms with 93.7% sensitivity and 91.6% specificity. The selection of 73.5% as the cutoff value for PTH decrease resulted in 91.6% sensitivity and 87.5% specificity. CONCLUSION PTH1 levels and the drop in PTH levels are reliable predictors of developing symptomatic hypocalcemia after total thyroidectomy.

A novel glucokinase deletion (p.Lys32del) and five previously described mutations co-segregate with the phenotype of mild familial hyperglycaemia (MODY2) in Brazilian families.

Six Brazilian families with mild familial hyperglycaemia have been screened for glucokinase (GCK) mutations. All had mutations that co-segregated with the phenotype. One of the mutations, the deletion 96_98delAAG (p.Lys32del), had not been previously described, reinforcing the worldwide prevalence of GCK MODY and widespread existence of undetected new mutations.