Biomedical subjects

Akiyoshi Nishimura

Publications and source records attributed to Akiyoshi Nishimura.

10 recordsLinked to original sources

PubMed2006

Differences in characteristics between suicide victims who left notes or not.

BACKGROUND: Suicide notes (SN) are one of markers of the severity of a suicide attempt and are said to provide a valuable insight into the thinking of suicide victims before the fatal act [Shah, A., De, T., 1998. Suicide and the elderly. Int. J. Psychiat. Clin Pract. 2, 3-18]. To examine whether suicide victims who wrote notes (note writers: NW) differ from those who did not, we investigated the characteristics of a sample of more than 5000 Japanese suicides using multiple logistic regression analysis. METHODS: For all suicide victims (5161 cases), we examined the following information: gender, age, suicide method, reason for suicide, marital status, residential status, history of psychiatric disorders, previous suicidal behavior, physical disease, and content of suicide notes. RESULTS: Mean incidence of NW was 30.1% (male: 29.7%, female: 30.8%). NW in Japan had the following characteristics; higher proportion in female and living alone, suicide by more lethal methods such as carbon monoxide, hanging or sharp instruments. On the other hand, non-NW had tendencies to commit suicide for reasons of physical illness and psychiatric disorder, and/or history of previous psychiatric disorders. LIMITATIONS: This study is observational and discusses only completed, not attempted, suicide. Medical and psychiatric comorbidity are judged only by the history of diagnosis and the information about the problems in relationships is based not on valid criteria for inclusion. CONCLUSIONS: Although these findings show ethnic differences, it is possible that SN may be considered an indicator of a serious suicide attempt. Further studies of SN are needed to confirm this.

Adult↗

PubMed2005

Incidence of note-leaving remains constant despite increasing suicide rates.

Suicide notes (SN) are potentially valuable sources of information about the psychological states of the suicidal person. It was hypothesized that there was a significant relation between suicide rate and note-leaving rate and that the incidence of note-leaving was increased during prolonged economic recession. During 21 years (1981-2001) in Kobe, of a total of 18 558 violent deaths, 5161 were due to suicide (27.8%), with 3417 male cases (66.2%) and 1754 female cases (33.8%). For each year the annual suicide rates and note-leaving rates were calculated, and this represents the percentage of committed suicides in which SN were left, among all suicide victims. In spite of the prolonged economic slump, the note-leaving rate remained almost constant (23.4-36.2%). Pearson's correlation coefficient showed no significant correlation between suicide rate and note-leaving rates (r = 0.27, P = 0.23). The finding that the incidence of note-leaving remains constant despite increasing suicide rates may suggest that the reasons for suicide do not affect note-leaving. There are cross-cultural, ethnic, and racial variations in suicidal behaviors. Although this finding may be specific in Japan, further studies of SN are needed to help clarify the suicidal states of mind.

Communication↗

PubMed2004

Economic slump and suicide method: preliminary study in Kobe.

During the recent half decade, Japan's suicide rate at approximately 25 deaths per 100 000 people has been one of the highest rates in the world. From the perspective of suicide prevention by restricting access to suicidal means, the aim of the present study was to examine what kind of suicidal method increased during prolonged economic slump. During 21 years (1981-2001), for all suicide victims (5161 cases) the gender, age, and suicide methods were investigated. The yearly full unemployment rate was also used as a representative socioeconomic factor during the same periods in Japan using government statistics, and the relationship between methods of suicide and full unemployment rate was investigated. Pearson's correlation suggested that there was a significant correlation only for hanging rate (r = 0.736, P < 0.001), but not for the percentages of other methods of suicide. This finding that unemployed persons may have a susceptibility towards certain suicide methods could help in the prevention of suicides. Mental health in Japan should be given more attention, especially for the working population, and social programs offering help should be considered widely.

Adolescent↗

PubMed2003

Number of striatal D-neurons is reduced in autopsy brains of schizophrenics.

The human striatum, especially its ventral part, the nucleus accumbens, contains numerous neurons immunoreactive for aromatic L-amino acid decarboxylase (AADC, the second-step monoamine synthesizing enzyme, =DDC: dopa decarboxylase), but not for tyrosine hydroxylase (TH, the first-step catecholamine synthesizing enzyme) or tryptophan hydroxylase (TPH, the first-step serotonin synthesizing enzyme) (Neurosci Lett 232 (1997) 111-114). These AADC (+)/TH (-)/TPH (-) neurons are named as D-neurons (Jaeger CB, Ruggiero DA, Albert VR, Joh TH, Reis DJ. Immunocytochemical localization of aromatic-L-amino acid decarboxylase. In: Bjorklund A, Hokfelt T, editors. Classical transmission in the CNS, Part I, Handbook of chemical neuroanatomy, vol. 2. Amsterdam: Elsevier, 1984. pp. 387-418). The nucleus accumbens is one of the brain regions that is involved in the pathogenesis of schizophrenia. We examined the distribution of striatal D-neurons using AADC immunohistochemistry and postmortem brains obtained by legal and pathological autopsies (nine controls (27-75 years old) and nine schizophrenics (32-78 years old), postmortem interval to fixation (PMI): 2-30 h). Because the number of AADC-positive neurons per section had a tendency to reduce in the case with longer PMI, we analyzed specimens of five controls (27-64 years old) and six schizophrenics (51-78 years old) in which the PMI was less than 8 h. The number of AADC-positive neurons was reduced in the striatum of schizophrenics compared to that of controls. The reduction was significant in the nucleus accumbens (P<0.05, t-test). D-Neurons might be involved in the pathogenesis of schizophrenia. Further studies using sex-, age- and PMI-matched controls are essential.

Adult↗

PubMed2003

Utilization of lectin-histochemistry in forensic neuropathology: lectin staining provides useful information for postmortem diagnosis in forensic neuropathology.

We have investigated the deposition of glycoconjugates in human brain tissue with or without brain disorders. In this review we describe the application of lectin-histochemistry techniques to forensic neuropathology. Lectin staining is able to reveal several kinds of carbohydrate-related depositions in addition to the conventional degenerative changes including senile plaques, neurofibrillary tangles and corpora amylacea. The senile plaques and neurofibrillary tangles were clearly stained by Con A, PSA and GSI lectins, the corpora amylacea which is relevant to repeated brain hypoxia and mitochondrial damage was also easily detected by these and many other kinds of lectins. Amorphous spaces were detected around blood vessels and independently from blood vessels by lectin staining in the white matter from patients with brain disorders or severe edema. The white matter lesions were not considered relevant for forensic pathology, until a large group of cerebral white matter lesions were detected in the elderly with increasing frequency by modern neuro-imaging methods. The spherical deposits were newly detected by lectin staining in the molecular layer of the dentate gyrus of the hippocampal formation chiefly from patients with schizophrenia or cognitive dysfunctions.

Alzheimer Disease↗

PubMed2003

Two cases of monostotic Paget's disease: effects of bisphosphonate.

We report two cases of monostotic Paget's disease which were effectively treated with bisphosphonate. Case 1 was a 60-year-old female. Medical examination revealed high alkaline phosphatase (ALP) levels making her visit our clinic. Hematological examination showed high levels of ALP isozyme 3 and bone metabolism markers, and bone scintigraphy demonstrated strong accumulation of 99mTc on the skull. With the diagnosis of monostotic Paget's disease of the skull, treatment with bisphosphonate (etidronate) was started. The response to etidronate was good and after 12 weeks of treatment, the ALP levels decreased to about 26% of the levels before treatment, without the appearance of any symptoms or lesion development. One year and three months later, ALP increased again, and etidronate administration was resumed. However, four years after the diagnosis of the disease, etidronate became ineffective and oral administration of alendronate, a stronger bisphosphonate, was started at 5 mg/day. The patient responded favorably to the bisphosphonate and is still under observation. Case 2 was a 71-year-old female. High ALP levels were found during the follow-up of type 2 diabetes, and the case was diagnosed as monostotic Paget's disease of the pelvis based on bone metabolism markers and bone scintigraphy. Etidronate treatment at 200 mg/day resulted in the improvement of bone metabolism markers and bone scintigraphy findings. When she died of colon cancer twelve months later, with no marked progress of the Paget's disease of bone observed clinically.

Aged↗

PubMed2002

Localization of sepiapterin reductase in the human brain.

Sepiapterin reductase (SPR) is the enzyme that catalyzes the final step of the synthesis of tetrahydrobiopterin (BH4), the cofactor for phenylalanine hydroxylase, tyrosine hydroxylase (TH), tryptophan hydroxylase, and nitric oxide synthase (NOS). Although SPR is essential for synthesizing BH4, the distribution of SPR in the human brain has not yet been clarified. In the present study, we purified recombinant human SPR from cDNA, raised an antibody against human SPR (hSPR), and examined the localization of SPR protein and SPR activity. Human brain homogenates from the substantia nigra (SN), caudate nucleus (CN), gray and white matters of the cerebral cortex (CTX), and dorsal and ventral parts of the medulla oblongata (MO) were subjected to Western blot analysis with anti-hSPR antibody or with anti-TH antibody. Whereas TH protein showed a restricted localization, being mainly detected in the SN and CN, SPR protein was detected in all brain regions examined. SPR activity was relatively high compared with the activity of GTP cyclohydrolase I (GCH), the rate-limiting biosynthetic enzyme of BH4, and was more widely distributed than GCH activity. Immunohistochemistry revealed SPR immunoreactivity in pyramidal neurons in the cerebral CTX, in a small number of striatal neurons, and in neurons of the hypothalamic and brain stem monoaminergic fields and olivary nucleus. Double-staining immunohistochemistry showed that TH and SPR were colocalized in the SN dopamine neurons. Localization of SPR immunoreactive neurons corresponded to monoamine or NOS neuronal fields, and also to the areas where no monoamine or NOS neurons were located. The results indicate that there might be a BH4 biosynthetic pathway where GCH is not involved and that SPR might have some yet unidentified function(s) in addition to BH4 biosynthesis.

Adult↗

PubMed2002

Lack of an association between 5-HT1A receptor gene structural polymorphisms and suicide victims.

A serotonergic dysfunction in the brain has been reported to be involved in suicidal behavior independently of the presence of a specific psychiatric disorder. Serotonin 1A (5-HT1A) receptors are known to be located on serotonergic nerve terminals and to be involved in the presynaptic regulation of serotonin release. Genetic factors partly explain the risks for suicide, and a suicide completion group is thought to be more uniform than a suicide attempt group. To explore the hypothesis that the 5-HT1A receptor-induced serotonergic dysfunction is implicated genetically in suicide, we focused on the structural polymorphisms, Pro16Leu and Gly272Asp, of the 5-HT1A receptor gene, and examined the association between suicide victims who completed suicide and these two polymorphisms. In both polymorphisms, we found no significant difference in genotype distribution or allele frequencies between suicide victims and controls. These findings suggest that neither of these two polymorphisms is associated with suicide victims and it is unlikely that the 5-HT1A receptor gene is implicated in the susceptibility to suicide.

Female↗

PubMed2002

No evidence of an association between a functional monoamine oxidase a gene polymorphism and completed suicides.

Monoamine oxidase A (MAOA) has been implicated in the control of aggression and/or impulsivity in humans and been involved in suicide. This gene has a functional polymorphism in which there is a variable number tandem repeat (VNTR) in the upstream region (MAOA-uVNTR). We hypothesized that MAOA dysfunction due to this polymorphism was associated with suicide genetically through the disinhibition of aggression and/or impulsivity. We performed an association study between completed suicides and the MAOA-uVNTR polymorphism. No significant difference in genotype distribution or allele frequencies was found between completed suicides and comparison groups either in males or females. These results show no evidence of an association between the MAOA-uVNTR polymorphism and completed suicides and suggest that MAOA is not involved in the susceptibility to suicide.

Adult↗

PubMedDate not supplied

Survival and cost analysis of fatalities of the Kobe earthquake in Japan.

OBJECTIVES: The authors investigated the dying patterns, and cause and preventability of deaths in a major earthquake disaster, and estimated the cost needed to enhance emergency medical services (EMS) response to prevent "unnecessary" deaths. METHODS: The authors reviewed autopsy data in the Hanshin-Awaji (Kobe) earthquake of 1995. A survival analysis was performed to determine the time course and pattern of dying of these deaths. A cost analysis to estimate acceptable cost for EMS to reduce fatalities was also performed. Potentially salvageable life-years based on expected life-years among fatalities were calculated and used to simulate an acceptable cost for an enhanced EMS disaster response. RESULTS: The authors analyzed 5,411 fatalities. More than 80% of these patients died within three hours. There were statistically significant differences in survival/dying patterns among causes of death. Thirteen percent of victims experienced a protracted death, which could have been prevented with earlier medical or surgical intervention. The monetary cost of these lost lives was estimated at approximately 600 million US dollars. CONCLUSIONS: Survival analysis revealed a significant population of potentially salvageable patients if more timely and appropriate medical intervention had been available immediately after the earthquake. Based on our cost analysis, and assuming a 1% annual probability of an earthquake and a 30% enhanced lifesaving capability of the EMS effort, approximately $ million dollars annually could be a reasonable expenditure to achieve the goal of reducing preventable deaths in disasters.

Cohort Studies↗