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Biomedical subjects

Toshiaki Hanafusa

Publications and source records attributed to Toshiaki Hanafusa.

At least 19 recordsLinked to original sources

Functional single-nucleotide polymorphisms in the secretogranin III (SCG3) gene that form secretory granules with appetite-related neuropeptides are associated with obesity.

CONTEXT: Genetic factors are important for the development of obesity. However, the genetic background of obesity still remains unclear. OBJECTIVE: Our objective was to search for obesity-related genes using a large number of gene-based single-nucleotide polymorphisms (SNPs). DESIGN AND SETTING: We conducted case-control association analyses using 94 obese patients and 658 controls with 62,663 SNPs selected from the SNP database. SNPs that possessed P < or = 0.02 were further analyzed using 796 obese and 711 control subjects. One SNP (rs3764220) in the secretogranin III (SCG3) gene showed the lowest P value (P = 0.0000019). We sequenced an approximately 300-kb genomic region around rs3764220 and discovered SNPs for haplotype analyses. SCG3 was the only gene within a haplotype block that contained rs3764220. The functions of SCG3 were studied. PATIENTS: Obese subjects (body mass index > or = 30 kg/m(2), n = 890) and control subjects (general population; n = 658, body mass index < or = 25 kg/m(2); n = 711) were recruited for this study. RESULTS: Twelve SNPs in the SCG3 gene including rs3764220 were in almost complete linkage disequilibrium and significantly associated with an obesity phenotype. Two SNPs (rs16964465, rs16964476) affected the transcriptional activity of SCG3, and subjects with the minor allele seemed to be resistant to obesity (odds ratio, 9.23; 95% confidence interval, 2.77-30.80; chi(2) = 19.2; P = 0.0000067). SCG3 mRNA and immunoreactivity were detected in the paraventricular nucleus, lateral hypothalamic area, and arcuate nucleus, and the protein coexisted with orexin, melanin-concentrating hormone, neuropeptide Y, and proopiomelanocortin. SCG3 formed a granule-like structure together with these neuropeptides. CONCLUSIONS: Genetic variations in the SCG3 gene may influence the risk of obesity through possible regulation of hypothalamic neuropeptide secretion.

Adult↗

Fulminant type 1 diabetes: a novel clinical entity requiring special attention by all medical practitioners.

Fulminant type 1 diabetes is a recently discovered subtype of type 1 diabetes. It is defined as diabetes in which the process of beta-cell destruction and the progression of hyperglycemia and ketoacidosis are extremely rapid. The pathogenesis of this disease remains to be clarified, but the involvement of both genetic background-especially human leukocyte antigen genes-and viruses has been suggested. Fulminant type 1 diabetes has the following clinical characteristics: duration of hyperglycemic symptoms is 4 days on average; there is a high prevalence of preceding common-cold-like and gastrointestinal symptoms; there is a near-normal level of glycated hemoglobin in spite of very high plasma glucose levels associated with ketoacidosis; the disease is sometimes related to pregnancy; and there are increased serum pancreatic enzyme levels, absent C-peptide levels, but virtually no detectable autoantibodies against constituents of pancreatic beta cells. The presence of the above characteristics strongly indicates the diagnosis of fulminant type 1 diabetes. Once the diagnosis of this disease is suspected, treatment of diabetic ketoacidosis must be started immediately, as in all other cases of type 1 diabetes. Otherwise, the death of the patient is likely to occur within 24 h. All medical practitioners must remember that this extremely rapidly progressing type of diabetes does exist, and they must pay special attention not to overlook it.

Acute Disease↗

Physiologically high concentrations of 17beta-estradiol enhance NF-kappaB activity in human T cells.

Estrogen has diverse effects on inflammation and immune responses. That pregnancy is associated with remission of some autoimmune diseases and exacerbation of others suggests that physiological fluctuation in estrogen levels could affect the immune responses in humans. However, the molecular basis for these phenomena is poorly understood. We hypothesized that fluctuations of estrogen levels modulate intracellular signaling for immune responses via estrogen receptors (ERs). In reporter assays, 17beta-estradiol (E2) at a physiologically high concentration increased the activity of NF-kappaB in Jurkat cells stimulated by PMA/ionomycin or TNF-alpha. Overexpression and RNA interference experiments suggested that the effects were mediated through ERbeta. Immunoprecipitation assay showed that both ERalpha and ERbeta are directly associated with NF-kappaB in the cell nucleus. Using chromatin immunoprecipitation assay, we confirmed that ERalpha and ERbeta associated with NF-kappaB and steroid hormone coactivators at the promoter region of NF-kappaB regulated gene. Considering that NF-kappaB regulates the expression of various genes essential for cell growth and death, estrogen could regulate the fate of T cells by affecting the activity of NF-kappaB. To determine whether E2 alters the fate of T cells, we investigated E2 actions on T cell apoptosis, a well-known NF-kappaB-mediated phenomenon. E2 increased apoptosis of Jurkat cells and decreased that of human peripheral blood T cells. Our results indicate that E2 at a physiologically high concentration modulates NF-kappaB signaling in human T cells via ERbeta and affects T cell survival, suggesting that these actions may underlie the gender differences in autoimmune diseases.

Apoptosis↗

Effect of levo-thyroxine replacement on non-high-density lipoprotein cholesterol in hypothyroid patients.

CONTEXT: Recently, non-high-density lipoprotein cholesterol (non-HDL-C), a measure of total cholesterol minus HDL-C, has emerged as a predictor of cardiovascular disease. OBJECTIVE: We evaluated the effect of L-T4 replacement on non-HDL-C levels in patients with primary hypothyroidism. METHODS: Thirteen patients with overt hypothyroidism and 26 patients with subclinical hypothyroidism participated in the study. The lipid profiles, including non-HDL-C, were measured in patients with hypothyroidism before and 3 months after L-T4 replacement was started. RESULTS: After L-T4 replacement, the serum concentrations of all lipoproteins, exclusive of lipoprotein (a) [Lp(a)], were significantly decreased in patients with overt hypothyroidism. In patients with subclinical hypothyroidism, the serum concentrations of total cholesterol, non-HDL-C, remnant-like particle cholesterol, and apolipoprotein B (Apo B) were significantly decreased, whereas no significant changes in the serum concentrations of low-density lipoprotein cholesterol, HDL-C, triglycerides, apolipoprotein A-I, and Lp(a) were observed. In all 39 patients, the reduction in the non-HDL-C levels correlated with the reduction in the low-density lipoprotein cholesterol, remnant-like particle cholesterol, and Apo B levels. However, the reduction in the non-HDL-C levels did not correlate with the reduction in the HDL-C, Lp(a), and apolipoprotein A-I levels. CONCLUSIONS: This study is the first to show that L-T4 replacement may reduce serum concentrations of non-HDL-C in patients with hypothyroidism. The study also suggests that such altered serum concentrations of non-HDL-C in hypothyroidism may be related to the disturbed metabolism of low-density lipoprotein, remnant lipoprotein, and Apo B.

Adult↗

Vascular Behçet's disease with coronary artery aneurysm.

A 33-year-old man with a 4-year history of Behçet's disease was hospitalized with acute myocardial infarction. Percutaneous coronary intervention (PCI) treated 99% stenosis of the right coronary artery but follow-up coronary arteriography clearly revealed a coronary artery aneurysm (CAA) at the lesion proximal to the PCI site and intravascular ultrasound confirmed that it was a true aneurysm. We speculated that Behçet's disease might be involved in coronary lesion, especially in CAA formation. We decided to increase the dose of prednisolone and to add warfarin. The size of the CAA was not altered after 6 months.

Adult↗

Successful treatment of multi-agent chemotherapy with rituximab for IgM plasma cell leukemia.

A 67-year-old woman presented with impaired general performance, suffering from fatigue, dyspnea on exertion, and paresthesia of the finger tips. The laboratory findings showed increased white blood cells at 11.37 x 10(3)cells/microl with 26.5% abnormal cells, low haemoglobin and, elevated creatinine, although serum lactate dehydrogenase and calcium levels were normal. Serum immunofixation was positive for monoclonal IgM-kappa paraprotein. Total serum protein and the IgM component were elevated. X-ray examination of the skeleton was normal. Bone marrow aspiration showed 59.5% infiltration of abnormal cells that were characterized by typical mature plasmacytoid morphology. Abnormal cells expressed surface CD20, surface CD138, and cytoplasmic IgM, but not surface CD56 nor surface IgM by flow cytometric immunophenotyping with CD38 gating. Immunohistochemistry showed surface CD38, surface CD20, and cytoplasmic IgM. The clinical findings led to the diagnosis of the IgM Plasma cell leukemia (PCL). The patient received multi-agent chemotherapy (VAD and EDAP with rituximab). The clinical symptoms disappeared, leading to the tumor load reduction. To the best of our knowledge, this is the first report of successful treatment of multi-agent chemotherapy with rituximab for IgM PCL.

Aged↗

Bronchial infiltration with diffuse large B-cell lymphoma.

Non-Hodgkin's lymphoma (NHL) refers to a heterogeneous group of lymphoproliferative diseases with a diversity of clinical courses, including involvement in another organs. NHL frequently involves the thoracic structures, and particularly the mediastinum and lung parenchyma. Several clinical reports have described bronchial-associated lymphoid tissue (BALT) lymphoma as an endobronchial lesion, but endobronchial infiltration with diffuse large B-cell lymphoma is extremely rare. Here, we provide the first report of this condition confirmed by a histopathological study and the presence of an immunoglobulin heavy chain (IgH) gene rearrangement detected by a polymerase chain reaction (PCR).

Antibodies, Monoclonal↗

Wheelchair economy class syndrome in amyotrophic lateral sclerosis.

A wheelchair-bound 61-year-old diabetic man with amyotrophic lateral sclerosis (ALS) developed sudden respiratory failure. Specific findings for hypoxemia and hypocapnia were incompatible with type II respiratory failure seen in the terminal stages of ALS. 'Economy class syndrome' was diagnosed, with massive thrombosis in the pulmonary arteries and deep vein thrombosis. This case offers a warning for long-term wheelchair users, particularly hypoxemic ALS patients, regarding the risks of treatable pulmonary thromboembolism.

Amyotrophic Lateral Sclerosis↗

Differences in heart rate variability in non-hypertensive diabetic patients correlate with the presence of underlying cerebrovascular disease.

We previously showed that diabetes contributes to the development of sclerotic lesions in cerebral arteries. In this study, we attempted to clarify whether differences in heart rate variability in non-hypertensive diabetic patients were dependent on the presence or absence of underlying cerebrovascular disease. Thirty diabetic subjects between 40 and 59 years of age and who had no prior history of hypertension were used in this study. Lacunar lesions (LA) were detected with magnetic resonance imaging and atherosclerotic lesions (AS) were detected using intra- and extracranial magnetic resonance angiography, and by ultrasonographic scanning of the carotid artery. Patients underwent a full clinical laboratory screening and a power spectrum analysis of their heart rate variability. Subjects were divided into two groups: those with and without LA. The low frequency/high frequency ratio (LF/HF ratio) was found to be significantly increased (P<0.01) in subjects with LA (2.2 +/- 0.3) compared to those without LA (1.3 +/- 0.1). When subjects were divided into groups based on their presence or absence of AS, high-frequency power was found to be significantly reduced (P<0.05) in the subjects with AS (12.8 +/- 3.4 ms) compared to those without AS (19.4 +/- 1.7 ms). The LF/HF ratio was found to be significantly increased (P<0.05) in the subjects with AS (2.2 +/- 0.3) compared to those without AS (1.4 +/- 0.1). Our data suggested that atherosclerotic lesions in cerebrovascular diseased linked to decrease of vagal nerve activity in non-hypertensive diabetic patients.

Albuminuria↗