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Biomedical subjects

Toru Nakajima

Publications and source records attributed to Toru Nakajima.

At least 19 recordsLinked to original sources
PubMed2006

Coronary aneurysm reduced after coronary stenting.

We describe as case of a 70-year-old man who underwent a percutaneous coronary intervention with stenting, for a severe stenosis complicated by a coronary aneurysm just distal to the stenotic site. Notably, coronary angiogram showed an immediate and progressive reduction in the size of coronary aneurysm. Curved planar reconstruction images of the enhanced CT showed no thrombus and no dissection of the coronary aneurysm. We speculate that coronary stenting might decrease the velocity of coronary flow through the stenosis. Consequently, stenting might attenuate the hydrodynamic wall stress on the aneurysm, and, in addition, improve the degradation of the extracellular matrix structure through the regulation of matrix metalloproteinases. Regression of coronary aneurysm after stenting requires further investigations, because stenting may become a potential means for treating post-stenotic aneurysms.

Aged↗
PubMed2005

Effect of benzodiazepine hypnotic triazolam on relationship of blood pressure and Paco2 to cerebral blood flow during human non-rapid eye movement sleep.

We sought to clarify the effect of short-acting benzodiazepine hypnotic on the relationship of arterial blood pressure and arterial partial pressure of carbon dioxide (Paco2) to regional cerebral blood flow (rCBF) during human non-rapid-eye-movement (non-REM) sleep. Nine young normal volunteers were treated in a randomized, crossover design with triazolam or placebo and underwent positron emission tomography at night. During wakefulness and stage 2 and slow wave (stages 3 and 4) sleep, we measured mean arterial blood pressure (MAP), Paco2, and absolute CBF. With triazolam compared to placebo, MAP reduced gradually. During stage 2 sleep, Paco2 increased and whole-brain mean CBF decreased. With triazolam, relative rCBF of the left orbital basal forebrain decreased more during stage 2 than slow wave sleep, whereas absolute CBF of the occipital cortex and cerebral white matter remained constant. During triazolam-induced stage 2 sleep, absolute CBF of the cerebral white matter correlated more strongly to both MAP and Paco2 than during placebo sleep and also correlated more strongly to both MAP and Paco2 than absolute CBF of the occipital cortex. In the frontal white matter, during triazolam-induced stage 2 sleep compared to wakefulness, absolute CBF was significantly better correlated to MAP, but not to Paco2. During triazolam-induced stage 2, the cerebral white matter may receive a modulated CBF regulation having the strengthened relationship of Paco2 to CBF and, more locally, the frontal white matter may depend precariously on CBF regulation.

Adult↗
PubMed2005

Effect of zolpidem on sleep architecture and its next-morning residual effect in insomniac patients: a randomized crossover comparative study with brotizolam.

This study was conducted to determine the effect of zolpidem (ZOL) 10 mg orally on the sleep architecture and the next-morning residual effect in patients with non-organic insomnia (ICD-10) as compared to the effect of brotizolam (BTM) 0.25 mg orally, a widely used short-acting benzodiazepine (BZD) hypnotic in Japan, in a randomized, crossover comparative study. Fourteen patients with non-organic insomnia (3 males and 11 females; mean age of 54.9+/-S.D. 8.9 years). First three nights with placebo, middle three nights with either ZOL 10 mg or BTM 0.25 mg, and last three nights again with placebo in each session (a total of two sessions). Primary endpoints were polysomnography findings of sleep stages, sleep parameters, and sleep latency (SL) in the morning to examine calculable sleepiness as a residual effect. Secondary endpoint was sleep quality assessed by self-assessment questionnaire. At 150 min after Tmax, both ZOL and BTM significantly increased stage 2 (S2), and ZOL showed significantly longer slow wave sleep (SWS; stage 3+4) as compared to BTM. Stage wake was significantly increased by ZOL at the first withdrawal night and by BTM at the second withdrawal night. ZOL did not affect SL after rising, whereas BTM showed significantly shorter SL. Both drugs reduced the number of nocturnal awakenings and improved subjective sleep quality. The common adverse drug reaction (ADR) was sleepiness (3 patients) in each treatment. All events were mild. No serious adverse events occurred. ZOL is as effective as BTM in improving subjective sleep quality in patients with psychophysiological insomnia (PPI). ZOL has advantages over BTM in having a unique profile of increasing SWS with less next-morning residual effect.

Adult↗
PubMed2005

Time-course changes in the expression of heme oxygenase-1 in human subcutaneous hemorrhage.

To determine the time-course of human subcutaneous hemorrhage, heme oxygenase (HO)-1 expression and macrophage infiltration were observed using an immunohistochemical technique and semiquantitative analysis. The number of immunoreactive cells and the number of all infiltrating cells of each microscopic field were counted, and the ratio of the former to the latter was calculated as the positive cells ratio. An increase in the HO-1-positive cells ratio was observed starting at 3 h after injury, and the maximum ratio was observed 3 days after injury. The pattern of the increase in the macrophage ratio was similar to that of the HO-1-positive cells ratio in the early period after injury. Observation of serial sections revealed that the expression of HO-1 in the cells corresponded to the localization of macrophage. The present results suggest that the determination of HO-1 expression, as derived from macrophages, might be useful for the estimation of the time-course of subcutaneous hemorrhage.

Adolescent↗
PubMed2005

Detection of right to left shunting through a patent foramen ovale in Japanese patients with ischemic stroke by transesophageal echocardiography using a standardized Valsalva maneuver.

We attempted to clarify the usefulness of transesophageal echocardiography performed using a standardized Valsalva maneuver to detect the presence of a patent foramen ovale in Japanese patients with ischemic stroke. Four hundred ninety six patients with ischemic stroke who were admitted to the Yokohama City Brain and Stroke Center between September 1999 and February 2002 were enrolled for the study. All the enrolled patients underwent transesophageal echocardiography with contrast injection and color Doppler imaging. During the procedure, a standardized Valsalva maneuver was performed to induce right to left shunting through a patent foramen ovale. Other related structural abnormalities, such as atrial septal aneurysm and the Chiari network anomaly, were also detected by the test. Transesophageal echocardiography without the Valsalva maneuver revealed a functional right to left communication in only 8.2% of the ischemic stroke patients, whereas the procedure conducted using a standardized Valsalva maneuver to provoke shunting revealed a patent foramen ovale in 15.3% of the patients. The presence of an atrial septal aneurysm or the Chiari network anomaly was not sensitive or specific enough to predict the presence of a patent foramen ovale as diagnosed by transesophageal echocardiography using the standardized Valsalva maneuver. Our results suggest that the standardized Valsalva maneuver is a safe and useful technique to detect the presence of a patent foramen ovale, which is potentially known to be associated with paradoxical embolism.

Aged↗
PubMed2004

Cerebral white matter blood flow is constant during human non-rapid eye movement sleep: a positron emission tomographic study.

This study aimed to identify brain regions with the least decreased cerebral blood flow (CBF) and their relationship to physiological parameters during human non-rapid eye movement (NREM) sleep. Using [(15)O]H(2)O positron emission tomography, CBF was measured for nine normal young adults during nighttime. As NREM sleep progressed, mean arterial blood pressure and whole brain mean CBF decreased significantly; arterial partial pressure of CO(2) and, selectively, relative CBF of the cerebral white matter increased significantly. Absolute CBF remained constant in the cerebral white matter, registering 25.9 +/- 3.8 during wakefulness, 25.8 +/- 3.3 during light NREM sleep, and 26.9 +/- 3.0 (ml.100 g(-1).min(-1)) during deep NREM sleep (P = 0.592), and in the occipital cortex (P = 0.611). The regression slope of the absolute CBF significantly differed with respect to arterial partial pressure of CO(2) between the cerebral white matter (slope 0.054, R = - 0.04) and frontoparietal association cortex (slope - 0.776, R = - 0.31) (P = 0.005) or thalamus (slope - 1.933, R = - 0.47) (P = 0.004) and between the occipital cortex (slope 0.084, R = 0.06) and frontoparietal association cortex (P = 0.021) or thalamus (P < 0.001), and, with respect to mean arterial blood pressure, between the cerebral white matter (slope - 0.067, R = - 0.10) and thalamus (slope 0.637, R = 0.31) (P = 0.044). The cerebral white matter CBF keeps constant during NREM sleep as well as the occipital cortical CBF, and may be specifically regulated by both CO(2) vasoreactivity and pressure autoregulation.

Adult↗
PubMed2004

A missense variation in human casein kinase I epsilon gene that induces functional alteration and shows an inverse association with circadian rhythm sleep disorders.

Recent studies have shown that functional variations in clock genes, which generate circadian rhythms through interactive positive/negative feedback loops, contribute to the development of circadian rhythm sleep disorders in humans. Another potential candidate for rhythm disorder susceptibility is casein kinase I epsilon (CKIepsilon), which phosphorylates clock proteins and plays a pivotal role in the circadian clock. To determine whether variations in CKIepsilon induce vulnerability to human circadian rhythm sleep disorders, such as delayed sleep phase syndrome (DSPS) and non-24-h sleep-wake syndrome (N-24), we analyzed all of the coding exons of the human CKIepsilon gene. One of the variants identified encoded an amino-acid substitution S408N, eliminating one of the putative autophosphorylation sites in the carboxyl-terminal extension of CKIepsilon. The N408 allele was less common in both DSPS (p = 0.028) and N-24 patients (p = 0.035) compared to controls. When DSPS and N-24 subjects were combined, based on an a priori prediction of a common mechanism underlying both DSPS and N-24, the inverse association between the N408 allele and rhythm disorders was highly significant (p = 0.0067, odds ratio = 0.42, 95% confidence interval: 0.22-0.79). In vitro kinase assay revealed that CKIepsilon with the S408N variation was approximately 1.8-fold more active than wild-type CKIepsilon. These results indicate that the N408 allele in CKIepsilon plays a protective role in the development of DSPS and N-24 through alteration of the enzyme activity.

Adult↗
PubMed2004

Deactivation by benzodiazepine of the basal forebrain and amygdala in normal humans during sleep: a placebo-controlled [15O]H2O PET study.

OBJECTIVE: The authors' goal was to identify differences in regional brain activity between physiological and benzodiazepine-induced sleep to clarify the brain structures involved in the drug's hypnotic effect. METHOD: Using positron emission tomography, they compared regional cerebral blood flow during non-REM sleep in nine volunteers treated with placebo or triazolam, a short-acting benzodiazepine, in a double-blind, crossover design. RESULTS: Blood flow in the basal forebrain and amygdaloid complexes was lower during non-REM sleep when subjects were given triazolam than when they were given placebo. CONCLUSIONS: The hypnotic effect of the benzodiazepines may be mediated mainly by deactivation of the forebrain control system for wakefulness and also by the anxiolytic effect induced by deactivation of the emotional center.

Adult↗
PubMed2003

HLA typing of aortic tissues from unidentified bodies using hot start polymerase chain reaction-sequence specific primers.

This study investigated the identification of unidentified bodies through HLA DNA typing of aortic tissues. Eight aortas were collected at autopsy from six bodies found in water, one burnt body, and one mummified body, respectively. DNA was extracted from 10-20 mg of aortic tissue with a PUREGENE DNA Isolation Kit and phenol/chloroform. HLA (A, B, DR or DQ locus) alleles were typed using the hot start polymerase chain reaction-sequence specific primers (PCR-SSP) method with a Dynal AllSet(+) SSP "low resolution" kit for each locus. The aorta was still retained in degraded samples, those from the drowned, the burnt, and the mummified bodies. In each case, approximately 0.04-3.84 microg of DNA was recovered from 1 mg of fixed tissue. We typed 8/8 for the DR, 4/4 for the DQ, 3/3 for the A, and 3/3 for the B locus from the samples. Based on these results and the finding that DNA extraction is easier from the aorta than from other samples such as bone or tooth, we considered this method to be useful for forensic samples.

Alleles↗
PubMed2003

Sleep and circadian rhythm disturbances in patients with delayed sleep phase syndrome.

STUDY OBJECTIVES: The objective of this study was to clarify sleep characteristics and pathophysiology in patients with delayed sleep phase syndrome (DSPS), which is a major circadian rhythm sleep disorder subtype. DESIGN: Polysomnography was performed for 2 consecutive nights and core body temperature was sampled for 7 consecutive days, including the polysomnography study period, in all subjects. Findings were compared and statistically analyzed between patients with DSPS and matched controls. SETTING: Sleep disorders unit in National Center Hospital. PARTICIPANTS: 11 DSPS patients and 11 age-matched healthy volunteers. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Sleep latency, total sleep time, wakefulness after sleep-onset, and the amount and percentage of Stage 1 sleep were greater in DSPS patients than in volunteers. Sleep efficiency and the amount and percentage of slow wave sleep were lower in DSPS patients than in volunteers. Compared with the healthy volunteers, DSPS patients showed a decreased number and different temporal distribution of high-voltage and low-frequency delta waves. The time of minimum body temperature appeared earlier in the sleep phase for the patients than for the volunteers. Significant correlation was found between the amount of slow wave sleep and the time from sleep onset to minimum body temperature and between the amount and percentage of slow wave sleep and time from minimum body temperature to sleep offset. CONCLUSIONS: Disturbances were found in the sleep structure of patients with DSPS, and these disturbances were related to the discrepancy between patients and controls in the phase relationship difference between sleep and core body temperature rhythms.

Adult↗
PubMed2002

Mutation screening of the human Clock gene in circadian rhythm sleep disorders.

We tested whether the human Clock (hClock) gene, one of the essential components of the circadian oscillator, is implicated in the vulnerability to delayed sleep phase syndrome (DSPS) and non-24-hour sleep-wake syndrome (N-24). Screening in the entire coding region of the hClock gene with PCR amplification revealed three polymorphisms, of which two predicted the amino acid substitutions R533Q and H542R. The frequencies of the R533Q and H542R alleles in patients with DSPS or N-24 were very low and not significantly different from those in control subjects. A T3111C polymorphism in the 3'-untranslated region of hClock, which had been reportedly associated with morning or evening preference for activity, was also investigated; the results showed that the 3111C allele frequency decreased in DSPS. Polymorphisms in the coding region of the hClock gene are unlikely to play an important role in the development of DSPS or N-24. The possible contribution of the T3111C polymorphism to DSPS susceptibility should be studied further.

Adult↗
PubMed2002

Napping predicts responsiveness to hypnotics in patients with primary circadian rhythm disorder.

It is hypothesized that one of the primary abnormalities of primary circadian rhythm disorder (PCRD) is the strong link between any episode of sleep and circadian rhythm. To test this hypothesis, the relationship between napping and responsiveness to hypnotics was examined in 12 patients with PCRD. A significant association was found (P = 0.04, chi2 test). Patients with PCRD who napped were all responders to hypnotics. The results suggest a strong link between episodes of sleep and circadian rhythm in some patients with PCRD, and might also suggest the heterogeneity of PCRD. Napping in patients with PCRD may be a predictor for responsiveness to hypnotics. In addition, napping and responsiveness to hypnotics might have a clinical value to differentiate PCRD from secondary CRD.

Adolescent↗
PubMed2002

Physical symptoms under forced-phase advance treatment in a patient with delayed sleep phase syndrome: a case report.

The physical symptoms that are observed with forced waking in patients with delayed sleep phase syndrome (DSPS) often prevent the successful treatment of patients. Better understanding of these symptoms will assist in providing appropriate treatment in such patients. Herein, a 19-year-old female patient with DSPS is described, in whom headache, fatigue, and dizziness were observed under forced-phase advance treatment. Statistical analysis showed that her headache was dependent on the therapeutic week, and her fatigue was dependent on the period of the day. There was no association between dizziness and either factor. Experience with this patient indicates that the fatigue observed with forced waking is related to the circadian system. This relationship should be explored for other physical symptoms as well.

Adult↗