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Biomedical subjects

S Kanba

Publications and source records attributed to S Kanba.

At least 19 recordsLinked to original sources

Deficit in theory of mind is a risk for relapse of major depression.

BACKGROUND: Recently, we reported that patients with depression have theory of mind (ToM) deficit during remission from acute episodes. ToM deficit means difficulty in social adjustment and thus may indicate a poorer prognosis. METHODS: We evaluated ToM ability of 50 patients during remission from major depressive episodes. The patients were followed for 1 year and their outcome observed. RESULTS: After 1 year, patients who had ToM deficit in a second order false question relapsed significantly more frequently as compared with patients who did not have a deficit (Fisher's exact test p < 0.0001; relative risk (RR) = 8.105; CI 2.020, 32.524). Significant differences were shown in scores of the Global Assessment of Functioning Scale (p < 0.0001) between the two groups. CONCLUSIONS: Patients with ToM deficit in second order false belief during remission may be a high risk group for recurrence and lower social function 1 year after recovering from a major depressive episode.

Adult↗

Cross-cultural equivalence in depression assessment: Japan-Europe-North American study.

OBJECTIVE: Worldwide use of the Hamilton Rating Scale for Depression (HRSD) presupposes that depression symptomatology can be measured the same way across countries but no empirical study has yet examined this issue. We therefore examined cross-cultural consistency of factor structure of HRSD. METHOD: A 17-item HRSD data were sought for 5,185 individuals diagnosed with major depression in Japan, Europe and North America. Candidate factor structures were obtained with simultaneous component analysis (SCA) across the three cultures. They were then submitted to multiple-group confirmatory factor analysis (CFA). RESULTS: According to SCA, 3-, 4- or 5-factor solutions were found to optimally and adequately summarize the variables for all the three populations. When submitted to CFA, the 5-factor solution was the best fitting and the most parsimonious: they were 'anhedonia/retardation,''guilt/agitation,''bodily symptoms,''insomnia' and 'appetite.' CONCLUSION: Common underlying factors exist for HRSD among Japanese, European and American patients with major depression.

Adult↗

Plasma orexin-A is lower in patients with narcolepsy.

Recently identified hypothalamic peptides called orexins (or hypocretins) have been implicated in the sleep-wake cycle and in sleep disorder narcolepsy. Neuropathological studies have shown that in patients with narcolepsy, global reduction in the expression of orexins occurs due to the loss of orexin neurons in the hypothalamus. Cerebrospinal fluid analysis has confirmed a reduced or undetectable level of orexin-A in most narcolepsy patients. In this study, measurement of plasma orexin showed significantly lower concentrations in patients with narcolepsy than in age- and gender-matched normal controls. These data suggest that low levels of orexin-A in plasma could serve as a biological marker for narcolepsy.

Adult↗

Dimensions of temperament as vulnerability factors in depression.

In order to evaluate the hypothesis that one set of genetic risk factors may be common to disorders and dimensions of temperament, whereas environmental risk factors are disorder specific, we have conducted a genetic analysis of dimensions of temperament and symptoms of depression in about 201 pairs of monozygotic and dizygotic twins. Dimensions of temperament associated with novelty seeking, harm avoidance, reward dependence, and persistence were measured by using the Temperament and Character Instruments developed by Cloninger, and depressive symptoms were measured using the Hospital Anxiety and Depression Scale. Differences among individuals on these measures can be explained by differences in their genes and in their environmental experiences. There are no differences between the sexes in gene action affecting temperament. Each dimension of temperament is genetically dependent, and genetic variations in symptoms of depression are largely dependent on the same factors that affect the temperament. Temperament is closely associated with vulnerability to depressive symptoms.

Adolescent↗

Mice lacking serum amyloid P component do not necessarily develop severe autoimmune disease.

Serum amyloid P component (SAP) is a major acute-phase reactant in mice. Recently, it was reported that SAP-deficient mice spontaneously developed anti-nuclear antibodies and severe glomerulonephritis. Because the SAP-deficient mice we generated display no obvious phenotypic abnormalities, we investigated whether our SAP-deficient mice would also spontaneously develop autoimmune responses. In accordance with the report, our mice produced high titers of anti-nuclear antibody but did not develop severe glomerulonephritis. On the other hand, it was recently reported that SAP bound to gram-negative bacteria via lipopolysaccharide (LPS) prevented LPS-mediated activation of a classical complement pathway. Thus, we asked if SAP-deficient mice would show altered responses to an intraperitoneal injection of LPS from Salmonella typhimirium. SAP-deficiency did afford resistance to lethality induced by high-dose LPS. Our experiments clearly showed that contrary to documented data, SAP-deficient mice do not develop serious autoimmune disease and we suggest that SAP has a critical role in LPS toxicity.

Animals↗

Elevated plasma nitrate levels in depressive states.

BACKGROUND: Previous studies have shown that nitric oxide (NO) synthase inhibitors show preclinical antidepressant-like properties, suggesting that NO is involved in the pathogenesis of depression. The purpose of this study is to examine whether or not NO production increases in depressed patients. METHODS: Plasma nitrate concentrations, an index of NO production, were measured by high-performance liquid chromatography in depressed patients (n=17) and compared with patients suffering anxiety (n=6) and with healthy controls (n=12). RESULTS: Plasma nitrate concentrations were significantly higher in depressed patients than in patients with an anxiety disorder (P<0.05) or in controls (P<0.01). LIMITATIONS: The study group was small. The source of the surplus production of NO in patients with major depressive episode remains unclear. CONCLUSIONS: These results suggest that NO production is increased in depression.

Adult↗

Genetics of cognition: outline of a collaborative twin study.

A multidisciplinary collaborative study examining cognition in a large sample of twins is outlined. A common experimental protocol and design is used in The Netherlands, Australia and Japan to measure cognitive ability using traditional IQ measures (i.e., psychometric IQ), processing speed (e.g., reaction time [RT] and inspection time [IT]), and working memory (e.g., spatial span, delayed response [DR] performance). The main aim is to investigate the genetic covariation among these cognitive phenotypes in order to use the correlated biological markers in future linkage and association analyses to detect quantitative-trait loci (QTLs). We outline the study and methodology, and report results from our preliminary analyses that examines the heritability of processing speed and working memory indices, and their phenotypic correlation with IQ. Heritability of Full Scale IQ was 87% in the Netherlands, 83% in Australia, and 71% in Japan. Heritability estimates for processing speed and working memory indices ranged from 33-64%. Associations of IQ with RT and IT (-0.28 to -0.36) replicated previous findings with those of higher cognitive ability showing faster speed of processing. Similarly, significant correlations were indicated between IQ and the spatial span working memory task (storage [0.31], executive processing [0.37]) and the DR working memory task (0.25), with those of higher cognitive ability showing better memory performance. These analyses establish the heritability of the processing speed and working memory measures to be used in our collaborative twin study of cognition, and support the findings that individual differences in processing speed and working memory may underlie individual differences in psychometric IQ.

Adolescent↗

[Symptomatology and diagnosis of depression].

It is characterized by mainly depressive mood and psychomotor retardation. Another symptoms are retardation of thought, diurnal change, anxiety, irritability, delusion of belittlement, etc. There are often somatic symptoms as loss of appetite, sleep disturbance, loss of body weight, constipation, etc. Depressive symptoms are often seen in schizophrenia, brain injury, endocrinosis illness and other somatic illness. Diagnosis of depression is carefully carried out by detailed interviews and symptoms. Recently diagnosis of depression is determined mechanically by DSM-IV or ICD-10. Neuro-endocrine tests as DST or Dex-CRH test, are useful strategies in examination of depression.

Depression↗

Effect of a 5-HT(1A) receptor agonist, flesinoxan, on the extracellular noradrenaline level in the hippocampus and on the locomotor activity of rats.

We have studied effects of 5-hydroxytryptamine 1A (5-HT(1A)) receptor-selective compounds on the extracellular noradrenaline (NA) level in the hippocampus of rats using microdialysis and on their locomotor activity. A selective 5-HT(1A) receptor agonist, flesinoxan (5 mg/kg, i.p.) increased the extracellular NA level in the hippocampus, and increased the locomotor activity. Both responses were blocked by pretreatment with a 5-HT(1A) receptor antagonist, WAY100635 (1 mg/kg, i.p.) and an alpha(2) adrenoceptor agonist, clonidine (50 microg/kg, i.p.). Bilateral intrahippocampal injection of flesinoxan (200 nmol in 2 microl, respectively) increased the locomotor activity of rats and the intrahippocampal perfusion of flesinoxan (1 mM, 2 microl/min) increased the extracellular NA level in the hippocampus. Bilateral intrahippocampal injections of a small amount of WAY100635 (0.1 nmol in 2 microl, respectively) blocked the flesinoxan (5 mg/kg, i.p.)-induced hyperactivity. Flesinoxan (5 mg/kg, i.p.) did not significantly influence the level of serotonin or its major metabolite in the hippocampus, or dopamine or its metabolites in the striatum. In conclusion, these behavioral as well as pharmacological results indicate that postsynaptic 5-HT(1A) receptor activation by flesinoxan increase the extracellular NA level in the hippocampus, which may be the cause of the increase of the locomotor activity.

Animals↗

Seasonal changes in human sleep-wake rhythm in Antarctica and Japan.

The subjects were eight men of the Japanese Antarctic Research Expedition (average age 35.8 years), and 10 healthy people living around Kofu, Japan (28.9 years). They completed a sleep log for 12 to 18 months, and the sleep-wake state was scored in 10-min epochs. Q24 values calculated by chi2 periodgram were low in the Antarctic midwinter. This means that there was difficulty in synchronizing to a 24-h period in the Antarctic midwinter. In Antarctica, sleep onset and offset times were delayed mostly in the midwinter. In Japan, sleep offset time was delayed mostly around the winter solstice.

Adult↗

Bright light treatment for night-time insomnia and daytime sleepiness in elderly people: comparison with a short-acting hypnotic.

Night-time bright light (BL) treatment and triazolam (0.125 mg/day) were given to three healthy elderly people in a cross-over design. They kept a daytime sleepiness test and a sleep log, and their wrist-activity was monitored simultaneously. Subjectively, BL increased daytime sleepiness and naps, and decreased night-time sleep. Triazolam decreased daytime sleepiness and naps, and increased night-time sleep. Actigraphic night-time sleep and naps on the first day were similar to these results. However, on the fourth day night-time insomnia induced by BL had recovered, and naps were shorter than the baseline. Triazolam increased actigraphic naps as the days passed.

Aged↗

Genetic structure of the five-factor model of personality in a Japanese twin population.

Dimensional approaches have been used to describe the fundamental dimensions that underlie the entire domain of normal and pathological personality. We tested the five factor model of personality structure in a sample of Japanese twins, to clarify the contributions of genetic and environment. The revised NEO personality inventory (NEO-PI-R) was administered to 251 twin pairs, ranging in age from 15 to 27 years of age. The NEO-PI-R is a 240-item questionnaire which was developed to assess the dimensions of personality. Univariate genetic analysis showed that the AE model in which phenotypic covariances are explained only by additive genetic (A) and nonshared environment (E) is still a plausible model, and that the relative proportion of genetic influence was comparable to that reported by Loehlin (1992). Multivariate genetic analysis of the Japanese data suggested/revealed that the five factors are genetically dependent on each other and one common genetic factor mediates their interdependence. Previous studies have assumed that they are phenotypically independent and robust. Although there are sampling biases in the present study, it is noteworthy that the results for all five factors depicted by the NEO-PI-R were comparable to those reported by Western researchers, and the genetic structure of the five-factor model is complex.

Adolescent↗

Distribution of prolactin-releasing peptide-immunoreactive neurons in the rat hypothalamus.

A newly identified hypothalamic peptide whose specific receptors are present in the anterior pituitary gland is a selective and potent stimulator of prolactin secretion and is therefore termed prolactin-releasing peptide (PRP). We investigated the distribution of PRP-containing neurons in the hypothalamus of female rats by immunocytochemical techniques. Immunocytochemistry using a specific antibody raised to PRP revealed that PRP-immunoreactive perikarya were located in the posteroventral part of the dorsomedial nucleus of the hypothalamus. PRP-immunoreactive nerve terminals were present in high concentrations in a region ventral to the bed nucleus of the stria terminalis, but scarcely observed in the external layer of the median eminence in which well known hypothalamic hormones such as growth hormone-releasing hormone and somatostatin were abundantly detected. This specific distribution in the hypothalamus suggests a novel route of the hypophysiotropic action of PRP.

Animals↗

Validity of sleep log compared with actigraphic sleep-wake state II.

Twenty-five young people (Y group), three elderly people and seven people with various sleep disorders (SD group) kept a sleep log for 2-7 days, and their wrist-activity was monitored simultaneously. The sensitivity and specificity of the sleep log, and the ratio of agreement between the sleep log and actigraphic sleep-wake state were calculated. The sensitivity and specificity in Y group were 87.93+/-6.49% and 96.51+/-2.37%, respectively. The sensitivity in SD group was significantly lower than in Y group. Even in Y group one-hour agreement ratios dropped during the sleep onset period.

Adult↗

Environmental and possible genetic contributions to character dimensions of personality.

The relationship between dimensions of personality characteristics and the perceived rearing attitude of parents in the Japanese population were investigated. The scores on a measure of perceived parental attitude of 153 normal female students, measured on the Parker Parental Bonding Instrument, were correlated with personality features from the Japanese version of the Cloninger Temperament and Character Inventory. Self-directedness, especially the subclasses of Responsibility vs Blaming and Congruent Second Nature vs Incongruent Habits, was significantly related to high scores on Maternal Care and low scores on Maternal Overprotection. The subscale of Self-acceptance vs Self-striving correlated only with low scores on Maternal Overprotection. Paternal Care was only related to the total scale scores on Self-directedness. Results suggest that some personality traits may be related to the perceived attitudes of parents, especially of the mother, during childhood.

Adolescent↗