HypercHolesterolemia is a commonly experienced metabolic disorder and it causes arteriosclerosis. Recently, new therapeutic reagents such as statins have been created and primary hypercholesterolemia is effectively treated with these reagents. However, statins are not low priced and may induce rare but serious side effects such as rhabdomyolysis. abstract. To evaluate the prevalence of dyslipidemia in the population of Hashimoto thyroiditis, we reviewed medical records on the consecutive 1181 cases with adult Hashimoto thyroiditis and 830 cases were adopted for the study. First, the serum TSH level increased and serum free T4 level decreased, slightly but significantly, with increasing age. There were significant positive correlations between serum TSH levels and lipid parameters such as total cholesterol (TC), triglyceride (TG), HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C), non-HDL-C and LDL-C/HDL-C ratio (L/H). In contrast, there were significant negative correlations between serum free T4 levels and all of these lipid parameters. According to the thyroid function, the cases were classified into 4 groups such as thyrotoxicosis (TT), euthyroidism (EU), subclinical hypothyroidism (SH) and overt hypothyroidism (OH). TC, HDL-C, non-HDL-C and LDL-C of TT were significantly lower than those in EU. In contrast, TC, TG, non-HDL-C, LDL-C, L/H and age of OH were significantly higher than those in EU. Interestingly, LDL-C and L/H of SH were significantly higher compared with EU. Thirty-two of SH patients were treated with small doses of levothyroxine and the effects on the lipid profile were examined. The TC, non-HDL-C, LDL-C and L/H were significantly decreased after treatment. In conclusion, the prevalence of dyslipidemia increases along with hypofunction of the thyroid and T4 replacement therapy may improve lipid profile in the cases of SH with Hashimoto thyroiditis.

Germline mutations of the tumor suppressor gene MEN1 are found not only in typical multiple endocrine neoplasia type 1 (MEN1) but also in its incomplete forms such as familial isolated hyperparathyroidism (FIHP) and apparently sporadic parathyroid tumor (ASPT). No definitive genotype-phenotype correlation has been established between these clinical forms and MEN1 gene mutations. We previously demonstrated that mutant menin proteins associated with MEN1 are rapidly degraded by the ubiquitin-proteasome pathway. To examine whether the intracellular stability of mutant menin is correlated with clinical phenotypes, we developed a method of evaluating menin stability and examined 20 mutants associated with typical MEN1 (17 missense, two in-frame deletion, one nonsense) and 21 mutants associated with FIHP or ASPT (19 missense, two in-frame deletion). All tested mutants associated with typical MEN1 showed reduced stability. Some missense and in-frame deletion mutants (G28A, R171W, T197I, E255K, E274A, Y353del and E366D) associated with FIHP or ASPT were almost as stable as or only slightly less stable than wild-type menin, while others were as unstable as those associated with typical MEN1. Some stable mutants exhibited substantial biological activities when tested by JunD-dependent transactivation assay. These findings suggest that certain missense and in-frame mutations are fairly stable and retain intrinsic biological activity, and might be specifically associated with incomplete clinical phenotypes. The menin stability test will provide useful information for the management of patients carrying germline MEN1 mutations especially when they have missense or in-frame variants of ambiguous clinical significance. (Cancer Sci 2011; 102: 2097-2102 M enin is a tumor suppressor protein encoded by MEN1, a gene responsible for multiple endocrine neoplasia type 1 (MEN1), a familial cancer syndrome typically characterized by the development of multiple tumors in the pituitary, parathyroid and enteropancreatic endocrine tissues.(1,2) Menin is a nuclear protein having C-terminal nuclear localizing signal sequences, (3) and exhibits modulatory activity on gene expression such as repression of JunD-dependent transcription. (4) Diverse roles have been implicated for menin, including cell cycle control, cell differentiation and DNA repair, which are likely to be conferred by interaction with various menin-binding proteins.(2) Menin is considered to be a scaffold protein tethering such proteins to specific gene loci.(5) Although the mechanism of how menin is involved in gene regulation has been elucidated to some extent, the basis for tissue-specific tumorigenesis in MEN1 remains unknown.Heterozygous germline mutations of the MEN1 gene are found in 70-90% of patients clinically diagnosed as MEN1. (6) More than 500 different loss-of-function mutations have been identified, which are distributed throughout the gene with no apparent hot spot.(2,6,7) Germline MEN1 mutations have also been found in a subset of familial isolated hyperparathy...

Objective: Dopamine agonists normalize prolactin (PRL) levels and reduce tumour size in responsive prolactinoma. However, several cases have shown resistance to dopamine agonists upon initial treatment. Infrequently, prolactinoma initially responds, but then becomes refractory to prolonged treatment (secondary resistance). We investigated the possible mechanisms of resistance to dopamine agonists. Subjects and methods: Twelve cases of prolactinoma were surgically resected and classified according to the responsiveness of PRL levels and tumour size to dopamine agonists: good responders (nZ5), poor responders (nZ5), or secondary resistance (nZ2). We examined the expression of dopamine D 2 receptor (D 2 R) isoform (short: D 2 S and long: D 2 L) mRNA and protein. We investigated DNA methylation patterns in the promoter region of the DRD2 gene. Results: The predominant D 2 R isoform expressed in prolactinoma was D 2 L. Levels of D 2 L mRNA were significantly lower in secondary resistance and poor responders than in good responders. Expression of D 2 R protein was variable among cases. Almost no CpG sites of the DRD2 gene promoter region were methylated. Conclusion: Resistance of prolactinoma to dopamine agonists is correlated with a reduction in D 2 L isoform mRNA levels. Silencing of the DRD2 gene by methylation in the promoter region is unlikely to play a role in dopamine agonist resistance in prolactinoma.

Objective β-adrenergic antagonists (β-blockers) are often used to attenuate the hyperadrenergic symptoms of Graves' disease (GD), including palpitation. Although β-blockers reduce the heart rate, cardiac output and oxygen consumption, no firm evidence exists regarding the effects of combined therapy with β-blockers and anti-thyroid drugs. The objective is to elucidate the effects of β-blockers on anti-thyroid drug therapy in GD. Methods Patients newly diagnosed with mild GD were randomly assigned to receive methimazole with or without β-blockers in a prospective multi-center survey. The heart rate and thyroid function were measured and the quality of life was assessed using original and SF-36 questionnaires at 0 and 4 weeks. Results A total of 28 patients were enrolled in the study. Fourteen patients (one man, 13 women) were randomly assigned to the group treated with β-blockers and 14 patients (one man, 13 women) were randomly assigned to the group not treated with β-blockers. Although no significant differences in the improvement of thyroid function were observed between the two groups, the heart rates improved more significantly in the group treated with β-blockers. Specific symptoms, such as easy fatigability and shortness of breath, also improved more significantly with the β-blocker treatment. In addition, 'physical functioning' assessed with the SF-36 questionnaires significantly improved only in the group treated with β-blockers. Conclusion Although β-blockers may not reinforce the effects of anti-thyroid drugs on thyroid function, at least during the course of one month, they are effective in reducing heart rates and ameliorating specific symptoms in patients with mild GD.

Multiple endocrine neoplasia type 1 (MEN1) is a relatively rare autosomal dominantly inherited condition characterized by hyperplastic and neoplastic disorder of endocrine organs such as the parathyroid, anterior pituitary and gastroenteropancreatic endocrine tissues [1]. Primary hyperparathyroidism (PHPT) is the most common disorder, and is usually the initial manifestation in MEN1. Its prevalence in MEN1 patients during lifetime is nearly 100%, and the average age of onset is during the third decade of life, which is much earlier than that of sporadic primary hyperparathyroidism [2,3] abstract. Heterozygous germline mutation of the tumor suppressor gene MEN1 is responsible for multiple endocrine neoplasia type 1 (MEN1), a familial cancer syndrome characterized by pituitary, parathyroid and enteropancreatic tumors. Various mutations have been identified throughout the entire gene region in patients with MEN1 and its incomplete forms often manifested as familial isolated hyperparathyroidism and apparently sporadic parathyroid tumor. Mutation analysis of the MEN1 gene is a powerful tool for the early diagnosis of MEN1; however, the clinical significance of the identified mutations is not always obvious. In this study, a previously unreported missense MEN1 mutation, c.824G>T was identified in a patient with primary hyperparathyroidism and evaluated for its pathogenicity. This mutation was predicted to generate a putative missense menin protein, R275M. A stability test of the menin protein demonstrated that the stability of R275M mutant was reduced only slightly as compared with wild type menin, and therefore could not preclude the possibility that it was a rare benign polymorphism. However, further analysis of leukocyte mRNA and minigene experiments indicated that the mutant c.824G>T allele gives rise to abnormally spliced menin mRNA, and thereby confirmed that c.824G>T mutation is causative for MEN1. Thus, leukocyte mRNA analysis has been demonstrated useful to identify a splicing mutation of the MEN1 gene.

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