Risk of bipolar disorder and psychotic features in patients initially hospitalised with severe depression.

OBJECTIVE: Severe depression may be a risk factor for diagnostic conversion into bipolar disorder (BD), and psychotic depression (PD) has been consistently associated with BD. The aims of the present study were to investigate the stability of the diagnosis of severe depression and the differences between PD and non-psychotic severe depression (non-PD), as well as to assess the effectiveness of electroconvulsive therapy (ECT). METHODS: Patients who were hospitalised for severe depression (diagnosed according to ICD-10) both with and without psychotic symptoms (n=89; mean age=55.6 years, SD=13.9) from 2001 to 2010 were retrospectively assessed. RESULTS: By the 75th month of follow-up assessments, 11(12.4%) patients had developed BD. Among these 11 converters, nine had developed BD within 1 year after admission. Only sub-threshold hypomanic symptoms were significantly related to developing BD. The number of depressive episodes and history of physical diseases were significantly increased in non-PD compared with PD patients, whereas ECT was significantly increased in PD compared with non-PD patients. There was a significant association between length of stay at the hospital and the number of days between admission and ECT. CONCLUSION: Sub-threshold hypomanic symptoms may represent a prodrome of BD or an indicator of an already manifest phenotype, especially in older patients, which suggests cautious use of antidepressants. In severe depression, non-PD may often occur secondary to physical diseases and patients may experience increased recurrences compared with PD patients, which may be a more 'primary' disorder and often requires ECT treatments. ECT is effective for severe depression regardless of the presence of any psychotic feature; the earlier ECT is introduced, the better the expected treatment outcome.

Reliability and validation of the Japanese version of the cognitive distortion scale.

The cognitive distortion scale (CDS) is a self-rated measure to assess the degree of cognitive distortion which is 10 thinking errors commonly seen in depression. However, there is no scale to measure 10 types cognitive distortions specific to depression in Japan. Therefore, this study translated the CDS into Japanese (CDS-J), and examined its factor structure, validity, and reliability in a Japanese population. A total of 237 healthy individuals and 39 individuals with depression participated in this study. Confirmatory factor analysis indicated the appropriateness of the CDS-J's 10-factor structure. Regarding convergent validity, CDS-J was significantly correlated with dysfunctional attitudes, negative automatic thoughts, and depression. Regarding discriminant validity, the CDS-J showed no significant correlation with positive automatic thoughts. The total CDS-J scores of the healthy participants and of those with major depression were compared. The results showed significant differences between groups. Finally, the CDS-J was found to have a high test-retest reliability. Therefore, the CDS-J is a valid and reliable tool for assessing cognitive distortions in Japan.

Trends in Primary Tooth Emergence Pattern and Associated Factors in Japanese Infants.

OBJECTIVE: The purposes of this study were to analyse trends in primary tooth emergence patterns and to identify physical factors potentially associated with them. METHODS: The participants were 27,454 infants who underwent routine 18-month-old health examinations in Ebetsu City, Japan, between 1980 and 2012. This study was conducted using data from infants' 18-month-old health examinations over a 33-year period. The mean number of emerged primary teeth was analysed by sex using a general linear model. For logistic regression analysis, the proportion of infants with 16 emerged teeth or more at 18 months old was used as a dependent variable. Examination year; birth order; birth weight; weight, height, and chest girth at 18 months old; number of fused teeth; and mother's age were used as independent variables. RESULTS: The mean number of emerged primary teeth decreased over the 33-year period. Birth weight and weight and height at 18 months old decreased, and the proportion of low-birth-weight (<2500 g) infants increased over the 33-year period. On general linear model analysis, the yearly change in the mean number of emerged primary teeth was -0.0188 for boys and -0.0181 for girls. Birth weight and weight and height at 18 months old were significantly associated with the presence of 16 emerged primary teeth or more, according to the logistic regression analysis. CONCLUSIONS: The results demonstrated that, over the 33-year period examined, the mean number of emerged primary teeth decreased and birth weight and weight and height at 18 months old were associated with the pattern of tooth emergence.

Relationships between oral conditions and physical performance in a rural elderly population in Japan.

OBJECTIVES: To show relationships between oral conditions and physical performance in the elderly living independently. METHODS: A total of 821 persons participated. Data on background factors and self-assessed masticatory ability were collected by means of questionnaires. An intraoral examination was performed to examine the pattern of occluding pairs of natural teeth. Handgrip strength and one-leg standing time with eyes open were measured. Step-wise linear regression models were conducted with muscle strength or one-leg standing time as the dependent variables; the pattern of occluding pairs and self-assessed masticatory ability as the principal independent variables. RESULTS: The self-assessed masticatory ability was retained in the final model of the step-wise regression for the handgrip strength, and significant relationships were established in the participants aged 65-74, but the pattern of occluding pairs was not retained. The pattern of occluding pairs, and the self-assessed masticatory ability were retained in the final models for the one-leg standing time, and significant relationships were shown here. CONCLUSION: The self-assessed masticatory ability may be significantly related to muscle strength and static balance function, and the pattern of occluding pairs may be significantly related to the static balance function, particularly in the elderly aged 65-74.

Toll-like receptor 3 ligand-induced antiviral response in mouse osteoblastic cells.

Double-stranded RNA (dsRNA) and its mimic, polyinosinic acid:polycytidylic acid [poly(I):poly(C)], are recognized by toll-like receptor 3 (TLR3) that induces the production of IFN-beta in many cell types. In the present study, we investigated the effects of poly(I):poly(C) on mouse osteoblastic MC3T3-E1 (E1) cells. Poly(I):poly(C) markedly increased IFN-beta mRNA level in a dose-dependent manner. The increase in the IFN-beta mRNA level was apparent as early as 1 h after adding poly(I):poly(C) to the culture and peaked at 12 h. Stimulation with poly(I):poly(C) enhanced the expression of CXCL10 mRNA and TLR3 in E1 cells. Moreover, poly(I):poly(C) induced tyrosine phosphorylation of the transcription factor STAT1 in E1 cells. An anti-IFN-beta neutralizing antibody partially inhibited poly(I):poly(C)-induced CXCL10 mRNA, TLR3 mRNA and STAT1 phosphorylation. These results indicate that osteoblasts secrete IFN-beta in response to viral infection and that endogenous IFN-beta induces both CXCL10 and TLR3 production via an IFN-alpha/beta receptor-STAT1 pathway. It is suggested that osteoblasts are involved in host defense as well as bone metabolism.

Toll like receptor 5 ligand induces monocyte chemoattractant protein-1 in mouse osteoblastic cells.

Flagellin, the ligand of Toll like receptor 5, is the major subunit of bacterial flagella. Flagellin stimulates various cells to release chemokines. Monocyte chemoattractant protein-1 (MCP-1) is a member of the CC chemokine family that is involved in monocyte infiltration in inflammatory diseases. It has been reported that serum MCP-1 levels increase proportionally with the severity of periodontal disease. Inflammatory mediators induce MCP-1 production in various cells, including osteoblasts. However, it remains unclear whether MCP-1 is released from osteoblasts in response to flagellin. In the present study, we investigated the effects of flagellin on the expression of MCP-1 in the mouse osteoblastic cell line, MC3T3-E1 (E1) cells. Flagellin markedly increased MCP-1 mRNA level in a dose-dependent manner. The effect of flagellin on MCP-1 mRNA expression in E1 cells was transient, with a peak at 1 h. Concomitant with MCP-1 mRNA expression, MCP-1 protein levels were clearly elevated at 3 h after flagellin exposure. In addition, we revealed that JNK and MEK-ERK1/2 are involved in flagellin-induced MCP-1 expression in E1 cells. These results indicated that bacterial flagellin may play an important role in the progression of periodontitis. Results of further studies will provide more clues to the prevention of periodontal diseases.

Synthetic double-stranded RNA induces retinoic acid-inducible gene-I in mouse osteoblastic cells.

Retinoic acid inducible gene-I (RIG-I) is a member of the DExH box family of proteins. RIG-I acts as a sensor of viral infections through the recognition of viral double-stranded RNA (dsRNA). Recently, it was demonstrated that polyinosinic acid:polycytidylic acid [poly(I):poly(C)], a synthetic dsRNA analogue, induced the expression of RIG-I in various cell types, such as vascular endothelial cells and gingival fibroblasts. However, it remains unclear whether RIG-I is induced in osteoblasts in response to poly(I):poly(C). In the present study, we investigated the effects of poly(I):poly(C) on the expression of RIG-I in mouse osteoblastic MC3T3-E1(E1) cells. We found that poly(I):poly(C) increased the expression level of RIG-I in E1 cells, and that recombinant interferon-ß (IFN-ß) induced the expression of RIG-I mRNA in E1 cells. An anti-IFN-ß neu-tralizing antibody partially inhibited poly(I):poly(C)-induced RIG-I expression. These results indicate that RIG-I production is induced by poly(I):poly(C)-provoked IFN-ß in mouse osteoblastic E1 cells. We suggest that osteoblasts are involved in antiviral defense as well as in bone metabolism. Results of further studies will provide more clues regarding the molecular function of osteoblasts in viral infection.