Predictive performance of a genetic risk score using 11 susceptibility alleles for the incidence of Type 2 diabetes in a general Japanese population: a nested case-control study.

AIMS: To assess the predictive ability of a genetic risk score for the incidence of Type 2 diabetes in a general Japanese population. METHODS: This prospective case-control study, nested within a Japan Public Health Centre-based prospective study, included 466 participants with incident Type 2 diabetes over a 5-year period (cases) and 1361 control participants, as well as 1463 participants with existing diabetes and 1463 control participants. Eleven susceptibility single nucleotide polymorphisms, identified through genome-wide association studies and replicated in Japanese populations, were analysed. RESULTS: Most single nucleotide polymorphism loci showed directionally consistent associations with diabetes. From the combined samples, one single nucleotide polymorphism (rs2206734 at CDKAL1) reached a genome-wide significance level (odds ratio 1.28, 95% CI 1.18-1.40; P = 1.8 × 10-8 ). Three single nucleotide polymorphisms (rs2206734 in CDKAL1, rs2383208 in CDKN2A/B, and rs2237892 in KCNQ1) were nominally significantly associated with incident diabetes. Compared with the lowest quintile of the total number of risk alleles, the highest quintile had a higher odds of incident diabetes (odds ratio 2.34, 95% CI 1.59-3.46) after adjusting for conventional risk factors such as age, sex and BMI. The addition to the conventional risk factor-based model of a genetic risk score using the 11 single nucleotide polymorphisms significantly improved predictive performance; the c-statistic increased by 0.021, net reclassification improved by 6.2%, and integrated discrimination improved by 0.003. CONCLUSIONS: Our prospective findings suggest that the addition of a genetic risk score may provide modest but significant incremental predictive performance beyond that of the conventional risk factor-based model without biochemical markers.

Association of plasma concentrations of branched-chain amino acids with risk of colorectal adenoma in a large Japanese population.

Background: Available evidence from animal studies suggests that branched-chain amino acids (BCAAs) may have a protective effect against colorectal carcinogenesis. However, a possible effect of BCAAs against colorectal neoplasia has not been evaluated in humans. Here, we aimed to evaluate whether plasma concentrations of BCAA are associated with the risk of colorectal adenoma (CRA), a precursor lesion of colorectal cancer. Patients and methods: CRA cases and controls were identified from examinees who underwent total colonoscopy as part of a cancer screening program between 2004 and 2005 and responded to self-administered dietary and lifestyle questionnaires. We measured plasma concentrations of leucine, isoleucine and valine in 629 patients with adenoma and 584 controls. Unconditional logistic regression models were used to estimate odds ratio (OR) and 95% confidence interval (CI) for the association between BCAA and CRA risk after adjustment for potential confounders. Results: High plasma concentrations of leucine, valine and total BCAA were inversely associated with CRA risk after adjustment of potential confounders. The multivariate-adjusted ORs for the highest versus lowest quartiles were 0.60 (95% CI 0.42-0.87, Ptrend = 0.006) for leucine, 0.68 (95% CI 0.48-0.97, Ptrend = 0.09) for valine and 0.68 (95% CI 0.48-0.98, Ptrend = 0.10) for total BCAA. Further analysis by gender revealed that this inverse association was clearly evident in men, but not in women: the corresponding OR for leucine, valine and total BCAA was 0.50 (95% CI 0.32-0.80, Ptrend = 0.003), 0.60 (95% CI 0.38-0.95, Ptrend = 0.01) and 0.58 (95% CI 0.37-0.93, Ptrend = 0.04), respectively, in men and 0.78 (95% CI 0.42-1.45, Ptrend = 0.44), 0.77 (95% CI 0.41-1.43, Ptrend = 0.85) and 0.84 (95% CI 0.45-1.57, Ptrend = 0.81), respectively, in women. Conclusion: Our finding suggests that BCAAs may have a beneficial influence against the process of colorectal carcinogenesis, at least in the early stage. The mechanisms underlying this potential association between BCAA and colorectal carcinogenesis warrant further investigation.

Coping strategies and risk of cardiovascular disease incidence and mortality: the Japan Public Health Center-based prospective Study.

AIMS: Coping strategies may be significantly associated with health outcomes. This is the first study to investigate the association between baseline coping strategies and cardiovascular disease (CVD) incidence and mortality in a general population cohort. METHODS AND RESULTS: The Japan Public Health Center-based prospective Study asked questions on coping in its third follow-up survey (2000-04). Analyses on CVD incidence and mortality included 57 017 subjects aged 50-79 without a history of CVD and who provided complete answers on approach- and avoidance-oriented coping behaviours and strategies. Cox regression models, adjusted for confounders, were used to determine hazard ratios (HRs) according to coping style. Mean follow-up time was 7.9 years for incidence and 8.0 years for mortality.The premorbid use of an approach-oriented coping strategy was inversely associated with incidence of stroke (HR = 0.85; 95% CI, 0.73-1.00) and CVD mortality (HR = 0.74; 95% CI, 0.55-0.99). Stroke subtype analyses revealed an inverse association between the approach-oriented coping strategy and incidence of ischaemic stroke (HR = 0.79; 95% CI, 0.64-0.98) and a positive association between the combined coping strategy and incidence of intra-parenchymal haemorrhage (HR = 2.03; 95% CI, 1.01-4.10). Utilizing an avoidance coping strategy was associated with increased mortality from ischaemic heart disease (IHD) only in hypertensive individuals (HR = 3.46; 95% CI, 1.07-11.18). The coping behaviours fantasizing and positive reappraisal were associated with increased risk of CVD incidence (HR = 1.24; 95% CI, 1.03-1.50) and reduced risk of IHD mortality (HR = 0.63; 95% CI, 0.40-0.99), respectively. CONCLUSION: An approach-oriented coping strategy, i.e. proactively dealing with sources of stress, may be associated with significantly reduced stroke incidence and CVD mortality in a Japanese population-based cohort.

Soy food and isoflavone intake and endometrial cancer risk: the Japan Public Health Center-based prospective study.

OBJECTIVE: Compared with western populations, the consumption of soy foods among Japanese is very high and the incidence of endometrial cancer very low. We evaluated the association of soy food and isoflavone intake with endometrial cancer risk in Japanese women. DESIGN: Prospective cohort study. SETTING: Ten public health centre areas in Japan. POPULATION: Forty nine thousand one hundred and twenty-one women of age 45-74 years who responded to a 5-year follow-up survey questionnaire. METHODS: Intakes of soy foods as well as other covariates were assessed in 1995-1998 by a self-administered food frequency questionnaire. Cox proportional hazards regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI). MAIN OUTCOME MEASURE: Incidence of endometrial cancer. RESULTS: During an average of 12.1 years of follow up, 112 newly diagnosed endometrial cancer cases were identified. Energy-adjusted intakes of soy food and isoflavone were not associated with the risk of endometrial cancer. The multivariate-adjusted HR per 25 g/day increase in the intake of soy food was 1.02 (95% CI 0.94-1.10), and the corresponding value for isoflavone intake per 15 mg/day was 1.01 (95% CI 0.84-1.22). CONCLUSION: In this population-based prospective cohort study of Japanese women, we observed no evidence of a protective association between soy food or isoflavone intake and endometrial cancer risk.

Rice, bread, noodle and cereal intake and colorectal cancer in Japanese men and women: the Japan Public Health Center-based prospective Study (JPHC Study).

BACKGROUND: Colorectal cancer (CRC) incidence rate increased rapidly in Japan between the 1950s and 1990s. We examined the association between rice intake and CRC risk in comparison with bread, noodles and cereal among Japanese adults enrolled in the Japan Public Health Center-based prospective Study. METHODS: A total of 73,501 Japanese men and women were followed-up from 1995 to 1999 until the end of 2008 for an average of 11 years. During 801,937 person-years of follow-up, we identified 1276 incident cases of CRC. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) of CRC for rice, noodle, bread and cereal intake were calculated by Cox proportional hazards model. RESULTS: Overall, no significant association was observed for the highest quartile of rice intake compared with the lowest and the risk of CRC and its subsites in men (HR, 0.77; 95% CI, 0.56-1.07) and women (HR, 1.10; 95% CI, 0.71-1.68). However, a non-significant inverse trend was observed between rice intake and rectal cancer in men. No clear patterns of association were observed in bread, noodle and cereal intake. CONCLUSION: Our findings suggest that the consumption of rice does not have a substantial impact on the risk of CRC in the Japanese population.

Gender difference in the association of insulin and the insulin-like growth factor axis with colorectal neoplasia.

OBJECTIVE: Accumulating evidence has implicated insulin and the insulin-like growth factor (IGF) axis in colorectal carcinogenesis. Of interest, adiposity is likely to impose a greater risk on men than on women, which indicates that the association of insulin and the IGF axis with colorectal neoplasia may differ by gender. However, epidemiological evidence for this possible gender difference is limited to date. METHODS: We measured plasma concentrations of C-peptide, IGF-I and IGF-binding proteins (IGFBPs) 1 and 3 in 1520 healthy volunteer examinees who underwent total colonoscopy between February 2004 and February 2005, and cross-sectionally investigated the association of these biomarkers with colorectal adenoma by gender. An unconditional logistic regression model was used to estimate odds ratios (ORs) and their 95% confidence intervals (CIs) for colorectal adenoma after adjustment for potential confounders. RESULTS: We observed a positive association of C-peptide and IGF-I (P (trend)<0.001 and 0.02, respectively) and an inverse association of IGFBP-1 (P (trend)=0.002) with colorectal adenoma in men. Adjusted ORs of colorectal adenoma for the highest compared with the lowest quartile were also statistically significant for C-peptide (OR: 2.62, 95% CI: 1.71-4.01), IGF-I (OR: 1.63, 95% CI: 1.08-2.46) and IGFBP-1 (OR: 0.49, 95% CI: 0.32-0.75). In contrast, no measurable association was seen in women. Corresponding ORs for C-peptide, IGF-I and IGFBP-1 were 0.98 (95% CI: 0.56-1.71), 0.79 (95% CI: 0.44-1.43) and 1.05 (95% CI: 0.60-1.86), respectively. The gender difference was statistically significant for C-peptide (P (interaction)=0.03) and marginally significant for IGF-I and IGFBP-1 (P (interaction)=0.14 and 0.12, respectively). CONCLUSION: Our observations suggest that insulin and the IGF axis act differently by gender in colorectal carcinogenesis, at least in its early stage. The findings of this study further our understanding of the complexities of the gender difference in the association between adiposity and colorectal neoplasia.

Dietary isoflavone and the risk of colorectal adenoma: a case-control study in Japan.

We conducted a case-control study in a Japanese population to investigate the association between dietary isoflavone intake and the risk of colorectal adenoma. Participants who underwent magnifying colonoscopy with dye spreading as part of a cancer screening programme responded to a self-administered questionnaire, which included lifestyle information and intake of 145 food items, before the colonoscopy. A total of 721 case and 697 control subjects were enrolled. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using unconditional logistic regression models. We found a significant inverse association between dietary isoflavone intake and the risk of colorectal adenoma in men and women combined. However, the inverse association was not linear; rather, all quartiles above the first showed a similar decrease in risk, with multivariable-adjusted ORs and 95% CIs compared with the lowest quartile of 0.77 (0.57-1.04), 0.76 (0.56-1.02) and 0.70 (0.51-0.96) in the second, third and highest quartiles, respectively (P for trend=0.03). Of interest, the observed association was more prominent in women than in men. The observed ceiling effect associated with higher isoflavone intake suggests that a lower intake of dietary isoflavone might be associated with an increased risk of colorectal adenoma in Japanese populations.

Inhibition of cytokinesis by a lipid metabolite, psychosine.

Although a number of cellular components of cytokinesis have been identified, little is known about the detailed mechanisms underlying this process. Here, we report that the lipid metabolite psychosine (galactosylsphingosine), derived from galactosylceramide, induced formation of multinuclear cells from a variety of nonadherent and adherent cells due to inhibition of cytokinesis. When psychosine was added to the human myelomonocyte cell line U937, which was the most sensitive among the cell lines tested, cleavage furrow formed either incompletely or almost completely. However, abnormal contractile movement was detected in which the cellular contents of one of the hemispheres of the contracting cell were transferred into its counterpart. Finally, the cleavage furrow disappeared and cytokinesis was reversed. Psychosine treatment also induced giant clots of actin filaments in the cells that probably consisted of small vacuoles with filamentous structures, suggesting that psychosine affected actin reorganization. These observations could account for the formation of multinuclear globoid cells in the brains of patients with globoid cell leukodystrophy, a neurological disorder characterized by the accumulation of psychosine due to galactosylceramidase deficiency.

Direct effects of catecholamines, thyrotropin-releasing hormone, and somatostatin on growth hormone and prolactin secretion from adenomatous and nonadenomatous human pituitary cells in culture.

To determine the mechanism and the site of action of catecholamines as well as hormones including thyrotropin-releasing hormone (TRH)1 and somatostatin on pituitary hormone release in patients with acromegaly and in normal subjects, the effects of these substances on growth hormone (GH) and prolactin (PRL) secretion from adenomatous and nonadenomatous human pituitary cells in culture were examined. When dopamine (0.01-0.1 microM) or bromocriptine (0.01-0.1 microM) was added to the culture media, a significant inhibition of GH and PRL secretion from adenoma cells from acromegalic patients was observed. This inhibition was blocked by D2 receptor blockade with metoclopramide or sulpiride, but not by D1 receptor blockade. Similarly, dopamine suppressed GH and PRL release by nonadenomatous pituitary cells in a dose-dependent manner, which was again blocked by D2 receptor blockade. The minimum effective concentration of dopamine required for a significant inhibition of PRL secretion (0.01 microM) was lower than that for GH release (0.1 microM). Norepinephrine, likewise, caused a suppression of PRL secretion from adenomatous and nonadenomatous pituitary cells. This effect was blocked by sulpiride, phentolamine, however, was ineffective. When TRH was added to the media, both GH and PRL secretion were enhanced in adenoma cells, while only the stimulation of PRL release was observed in nonadenomatous pituitary cells. Coincubation of TRH and dopamine resulted in variable effects on GH and PRL secretion. Somatostatin consistently lowered GH and PRL secretion in both adenomatous and nonadenomatous pituitary cells and completely blocked the TRH-induced stimulation of GH and PRL secretion from adenoma cells. Opioid peptides (1 microM) failed to affect hormone release. These results suggest that no qualitative difference in GH and PRL responses to dopaminergic agonists or to somatostatin exists between adenoma cells of acromegalic patients and normal pituitary cells, and that the direct effect of catecholamines on GH and PRL secretion from human pituitary cells is mediated mainly through dopamine receptor activation.

Direct effects of thyrotropin-releasing hormone, cyproheptadine, and dopamine on adrenocorticotropin secretion from human corticotroph adenoma cells in vitro.

In an attempt to delineate the mechanism and the site of action of cyproheptadine and dopaminergic agonists as well as hormones including thyrotropin-releasing hormone (TRH) and hydrocortisone, the effects of these substances on ACTH secretion from corticotroph adenoma cells in culture were examined. Dispersed cells of pituitary adenomas obtained at surgery from four patients with Nelson's syndrome and one subject with Cushing's disease formed a monolayer and actively secreted ACTH into the medium. When TRH (0.1 microM) was added to the medium, a significant increase in ACTH secretion was demonstrated by adenoma cells from two patients who responded to TRH preoperatively. Moreover, a dose-response relationship between TRH concentrations and ACTH secretion was observed. Incubation of cells with cyproheptadine (1 or 0.1 microM) resulted in a significant decrease in ACTH release, and inhibited stimulation produced by TRH in one experiment. This effect of cyproheptadine was blocked when equimolar concentrations of serotonin was coincubated, whereas serotonin by itself did not affect ACTH secretion. Dopamine (0.1 microM) lowered ACTH accumulation in the medium, which was blocked by the addition of haloperidol. When hydrocortisone was added to the culture, dose-dependent suppression of ACTH secretion was demonstrated. TRH at an equimolar concentration reversed this effect, but, failed to overcome the inhibition induced by a higher concentration of hydrocortisone in cells from one adenoma studied. Cultured normal corticotrophs obtained from a patient with metastatic breast cancer, on the other hand, did not show any response to these substances, except for hydrocortisone. We suggest that TRH, cyproheptadine, dopamine affect ACTH secretion in patients with ACTH-producing pituitary adenomas by their direct action on the adenoma.

Atrial natriuretic factor in human blood.

To determine whether atrial natriuretic factor (ANF) is a circulating hormone in men, a radioimmunoassay suitable for the estimation of ANF in human plasma was developed and the nature of plasma ANF was characterized. Plasma ANF was extracted before radioimmunoassay by affinity chromatography on a column of ANF antibody-coupled agarose. When plasma ANF extract was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, with the radioimmunoassay of the eluted gel slices for ANF, almost all of the ANF activities ran in the 3,000-mol-wt area, while three peaks of ANF were observed in human atrial tissue extract, molecular weights of which corresponded to 14,000, 6,000, and 3,000, respectively. Reversed-phase high performance liquid chromatography of atrial tissue extract resolved multiple forms of ANF. In contrast, one major peak was observed in human plasma extract, and its retention time coincided with that of synthetic human alpha-atrial natriuretic polypeptide. When 500 ml of 0.9% saline was infused into six healthy subjects over 45 min, plasma levels of ANF were unequivocally elevated. The mean plasma ANF concentrations rose from the baseline (23.0 +/- 2.5 pg/ml, mean +/- SEM, n = 6) to the peak (41.8 +/- 4.9 pg/ml, mean +/- SEM) at 75 min postinfusion. No significant change in plasma ANF, on the other hand, was found in the control group. These results suggest that ANF is a circulating hormone in men and is secreted in response to isotonic volume expansion.

Nature of the immunoreactive neurophysins in ectopic vasopressin-producing oat cell carcinomas of the lung. Demonstration of a putative common precursor to vasopressin and neurophysin.

In an attempt to delineate the nature of the immunoreactive neurophysins in oat cell carcinomas of the lung with ectopic vasopressin production, tumor neurophysins were characterized by gel filtration and by electrophoresis. In all of the five tumor tissues, activities of both vasopressin and nicotine-stimulated neurophysin (NSN) determined by radioimmunoassay were demonstrated. A small amount of oxytocin as well as estrogen-stimulated neurophysin was detected in three of the tissues. When tissue extract was subjected to Sephadex G-50 gel filtration in 0.2 N acetic acid, the major portion of immunoreactive NSN emerged in the fractions corresponding to the molecular size of 10,000. The migration pattern of NSN in these fractions on electrophoresis was qualitatively the same as that of NSN extracted from human posterior pituitary glands. In addition to this major neurophysin, immunoreactive NSN with the molecular size of 20,000 was consistently demonstrated in three tumor extracts. This high molecular weight form of neurophysin represented 6.5--8.7% of total NSN immunoactivities in each tumor extract and its elution profile was not changed when analyzed under denaturating conditions in 6 M guanidine hydrochloride. On electrophoresis, it migrated near the gamma globulin region; however, the peak was broad suggesting that it consists of more than two different molecular populations. A substantial portion of the high molecular weight NSN appears to be a glycoprotein judging from its binding to concanavalin A. When the high molecular weight from of neurophysin was incubated with trypsin, essentially all of the activities were converted into NSN with the molecular size of 10,000. Moreover, an equimolar amount of vasopressin was liberated after the treatment, the elution pattern of which closely resembled that of synthetic arginine vasopressin. When a lower concentration of trypsin was used, some of the 20,000-dalton neurophysin exhibited activities of both NSN and vasopressin. Since the antivasopressin serum used in this study appeared to be directed toward the ring portion side of vasopressin, these results suggest that this 20,000-dalton neurophysin is, in all probability, a common precursor to vasopressin and neurophysin, and that vasopressin may be located in the middle of the precursor molecule.

Neurophysin biosynthesis in vitro in oat cell carcinoma of the lung with ectopic vasopressin production.

The incorporation of labeled compounds into neurophysins of a transplantable human oat cell carcinoma of the lung with ectopic vasopressin production was studied in vitro. Neurophysins in cell extracts and in incubation media were isolated by immunoprecipitation and analyzed by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. When cells were incubated with L-[35S]cysteine for 12 h, SDS-polyacrylamide gel electrophoresis of the immunoprecipitates from cell extract and medium resolved two forms of neurophysins with apparent molecular mass of 10,000 (10K) and 20,000 (20K). Both forms of [35S]-neurophysins were completely displaced from the immunoprecipitates by excess human neurophysin. Incubation of cells with L-[35S]cysteine and D-[3H]-glucosamine hydrochloride revealed that glucosamine was incorporated into the 20K neurophysin region, but not into 10K species. To observe the kinetics of labeling of the two forms of neurophysins, cells were incubated with L[35S]cysteine for varying periods of time. After short labeling periods, most of the radioactivity resided in 20K species, which plateaued after 1 h, whereas 10K neurophysin progressively increased in its height. When cells were chased with unlabeled cysteine after the exposure to a short pulse of labeling, 20K neurophysin peak gradually decreased with an apparent initial half-life of 1 h. In contrast, the label in 10K neurophysin steadily increased, which exceeded the former by 3 h of chase. Analysis of 20K neurophysin in cell extract by isoelectric focusing on polyacrylamide gel demonstrated that it was principally composed of a protein with an apparent isoelectric point (pI) of 5.7. These results suggest that neurophysin is synthesized in ectopic vasopressin-producing tumors by post-translational processing from a glycosylated proneurophysin with an apparent molecular mass of 20,000 daltons and a pI of 5.7.

Glucocorticoid receptor activation is involved in producing abnormal phenotypes of single-prolonged stress rats: a putative post-traumatic stress disorder model.

Post-traumatic stress disorder (PTSD) is a stress-related mental disorder caused by traumatic experience, and presents with characteristic symptoms, such as intrusive memories, a state of hyperarousal, and avoidance, that endure for years. Single-prolonged stress (SPS) is one of the animal models proposed for PTSD. Rats exposed to SPS showed enhanced inhibition of the hypothalamo-pituitary-adrenal (HPA) axis, which has been reliably reproduced in patients with PTSD, and increased expression of glucocorticoid receptor (GR) in the hippocampus. In this study, we characterized further neuroendocrinologic, behavioral and electrophysiological alterations in SPS rats. Plasma corticosterone recovered from an initial increase within a week, and gross histological changes and neuronal cell death were not observed in the hippocampus of the SPS rats. Behavioral analyses revealed that the SPS rats presented enhanced acoustic startle and impaired spatial memory that paralleled the deficits in hippocampal long-term potentiation (LTP) and depression. Contextual fear memory was enhanced in the rats 1 week after SPS exposure, whereas LTP in the amygdala was blunted. Interestingly, blockade of GR activation by administering 17-beta-hydroxy-11-beta-/4-/[methyl]-[1-methylethyl]aminophenyl/-17-alpha-[prop-1-ynyl]estra-4-9-diene-3-one (RU40555), a GR antagonist, prior to SPS exposure prevented potentiation of fear conditioning and impairment of LTP in the CA1 region. Altogether, SPS caused a number of behavioral changes similar to those described in PTSD, which marks SPS as a putative PTSD model. The preventive effects of a GR antagonist suggested that GR activation might play a critical role in producing the altered behavior and neuronal function of SPS rats.

Sli2 (Ypk1), a homologue of mammalian protein kinase SGK, is a downstream kinase in the sphingolipid-mediated signaling pathway of yeast.

ISP-1 is a new type of immunosuppressant, the structure of which is homologous to that of sphingosine. In a previous study, ISP-1 was found to inhibit mammalian serine palmitoyltransferase, the primary enzyme involved in sphingolipid biosynthesis, and to reduce the intracellular pool of sphingolipids. ISP-1 induces the apoptosis of cytotoxic T cells, which is triggered by decreases in the intracellular levels of sphingolipids. In this study, the inhibition of yeast (Saccharomyces cerevisiae) proliferation by ISP-1 was observed. This ISP-1-induced growth inhibition was also triggered by decreases in the intracellular levels of sphingolipids. In addition, DNA duplication without cytokinesis was detected in ISP-1-treated yeast cells on flow cytometry analysis. We have cloned multicopy suppressor genes of yeast which overcome the lethal sphingolipid depletion induced by ISP-1. One of these genes, SLI2, is synonymous with YPK1, which encodes a serine/threonine kinase. Kinase-dead mutants of YPK1 did not show any resistance to ISP-1, leading us to predict that the kinase activity of the Ypk1 protein should be essential for this resistance to ISP-1. Ypk1 protein overexpression had no effect on sphingolipid biosynthesis by the yeast. Furthermore, both the phosphorylation and intracellular localization of the Ypk1 protein were regulated by the intracellular sphingolipid levels. These data suggest that the Ypk1 protein is a downstream kinase in the sphingolipid-mediated signaling pathway of yeast. The Ypk1 protein was reported to be a functional homologue of the mammalian protein kinase SGK, which is a downstream kinase of 3-phosphoinositide-dependent kinase 1 (PDK1). PDK1 phosphotidylinositol (PI) is regulated by PI-3,4,5-triphosphate and PI-3,4-bisphosphate through the pleckstrin homology (PH) domain. Overexpression of mammalian SGK also overcomes the sphingolipid depletion in yeast. Taking both the inability to produce PI-3,4, 5-triphosphate and PI-3,4-bisphosphate and the lack of a PH domain in the yeast homologue of PDK1, the Pkh1 protein, into account, these findings further suggest that yeast may use sphingolipids instead of inositol phospholipids as lipid mediators.

Plasma 25-hydroxy vitamin D and subsequent prostate cancer risk in a nested Case-Control study in Japan: The JPHC study.

BACKGROUND/OBJECTIVES: Although vitamin D has been experimentally reported to inhibit tumorigenesis, cell growth and prostate cancer invasion, epidemiologic data regarding prostate cancer risk are inconsistent, and some studies have suggested positive but nonsignificant associations. Further, the impact of vitamin D on prostate cancer between Western and Japanese populations may differ due to different plasma vitamin D levels. SUBJECTS/METHODS: We performed a nested case-control study within the Japan Public Health Center-based Prospective (JPHC) Study in 14,203 men (40-69 years) who answered a self-administered questionnaire at baseline (1990-1994) and gave blood samples, and were followed until 2005. We identified 201 prostate cancers which are newly diagnosed during follow-up (mean 12.8 years). We selected two matched controls for each case from the cohort. We used a conditional logistic regression model to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for prostate cancer with respect to levels of 25-hydroxy vitamin D (25(OH)D) in plasma. RESULTS: We did not observe statistically significant association between 25(OH)D level and total prostate cancer (multivariate OR=1.13 (95%CI=0.66-1.94, Ptrend=0.94) for the highest versus lowest tertile) However, 25(OH) levels were slightly positively associated with advanced cancer. The results remained substantially unchanged after stratification by intake of fish or calcium intake. CONCLUSIONS: 25(OH)D level showed no association with overall prostate cancer among Japanese men in this large cohort.

Calreticulin mutant mice develop essential thrombocythemia that is ameliorated by the JAK inhibitor ruxolitinib.

Mutations of calreticulin (CALR) are detected in 25-30% of patients with essential thrombocythemia (ET) or primary myelofibrosis and cause frameshifts that result in proteins with a novel C-terminal. We demonstrate that CALR mutations activated signal transducer and activator of transcription 5 (STAT5) in 293T cells in the presence of thrombopoietin receptor (MPL). Human megakaryocytic CMK11-5 cells and erythroleukemic F-36P-MPL cells with knocked-in CALR mutations showed increased growth and acquisition of cytokine-independent growth, respectively, accompanied by STAT5 phosphorylation. Transgenic mice expressing a human CALR mutation with a 52 bp deletion (CALRdel52-transgenic mice (TG)) developed ET, with an increase in platelet count, but not hemoglobin level or white blood cell count, in association with an increase in bone marrow (BM) mature megakaryocytes. CALRdel52 BM cells did not drive away wild-type (WT) BM cells in in vivo competitive serial transplantation assays, suggesting that the self-renewal capacity of CALRdel52 hematopoietic stem cells (HSCs) was comparable to that of WT HSCs. Therapy with the Janus kinase (JAK) inhibitor ruxolitinib ameliorated the thrombocytosis in TG mice and attenuated the increase in number of BM megakaryocytes and HSCs. Taken together, our study provides a model showing that the C-terminal of mutant CALR activated JAK-STAT signaling specifically downstream of MPL and may have a central role in CALR-induced myeloproliferative neoplasms.

Possibility of clinical application of tremor in the upper limb.

A procedure to evaluate the function of the glenohumeral joint (i.e., shoulder joint) for persons with shoulder disorders was proposed by analyzing tremor. In order to compare subjects with shoulder disorders to healthy subjects without disorders, characteristics of tremor for the healthy persons under various angles of glenohumeral joint and under the dominant and no-dominant sides of the upper limb were obtained by peak frequency and power spectrum as basic data. As for the persons with rotator cuff injury, the ratio of total powers for the affected side and the healthy side was obtained as the affective side ratio. The ratio showed the characteristic of the persons with the disorder, and discriminated the total power spectra of persons who were healthy and those with disorders.

Influence of location of acceleration sensor on physiological tremor of upper limb.

The physiological tremor of the upper limb in three positions of pronation, neutrality, and supination due to the movement of forearm was measured on four locations at the tip of the finger, the root of the finger in the hand, the wrist, and the elbow with use of an accelerated sensor. The evaluation of the total power, which was the summation of the power spectrum in the frequency range from 1 to 50 Hz, showed no significant difference in any of the positions. The maintenance of the upper limb at the horizontal level showed the coordination of the central nervous system due to the body parts of the upper arm, forearm, hand, and finger connected by the joint. The coherence spectra showed clear activation of the joint of the wrist in the main peak frequency of around 2.5 and 12.5 Hz in their respective positions. The value of the correlation coefficient in the location between the hand and finger was the largest at over 0.8, and those of the locations which connected the joint of the wrist between the forearm and hand and between the forearm and finger were significantly large with a value from 0.6 to 0.8. The mean time (i.e., arrival time) of the transmission from the proximal side (i.e., upper arm and forearm) to the distal side (i.e., hand and finger) in the upper limb was evaluated quantitatively to be 20 ms for pronation and supination, but the value was small for neutrality.

Inhibition of growth of human small cell lung cancer by bromocriptine.

Bromocriptine, a dopaminergic agonist, inhibited the growth of human small cell lung cancer (SCLC) implanted as tumor xenografts in athymic nude mice; the effect was dose dependent. In mice bearing a SCLC with ectopic vasopressin production, plasma levels of human vasopressin-associated neurophysin decreased concomitantly. Electron microscopy of tumor tissues revealed marked degenerative changes, including pyknosis, densely aggregated chromatin masses, and vacuolization of cytoplasm after bromocriptine treatment. When a SCLC cell line, NCI-H69, was grown in semisolid medium, bromocriptine inhibited its clonal growth in a dose-related manner. Coincubation with dopamine D2 receptor antagonist, metoclopramide, or domperidone, completely blocked the inhibitory effect of bromocriptine. Receptor studies with a dopamine D2 receptor ligand, [125I]iodosulpride, showed high affinity binding sites on the membranes of SCLC cells. These results indicate that SCLC cells are enriched with dopamine D2 receptors, which may mediate the growth-inhibitory effect of bromocriptine on SCLC. Dopaminergic agonists may be useful in the medical treatment of SCLC.