Lifetime prevalence of schizophrenia among individuals prenatally exposed to atomic bomb radiation in Nagasaki City

OBJECTIVE: The aim of this study was to examine the relationship between prenatal exposure to atomic bomb (A-bomb) radiation and the development of schizophrenia in adulthood. METHOD: We investigated the lifetime prevalence of schizophrenia among people prenatally exposed to the 1945 Nagasaki A-bomb, using the schizophrenia register and the A-bomb survivors' database. RESULTS: Among 1867 prenatally exposed individuals, 18 subjects (0.96%) had developed schizophrenia later in life. The prevalence was significantly higher in people exposed in the second trimester of pregnancy than in those exposed in the third trimester. The closer they had been to the hypocentre, the higher was the prevalence, but no statistically significant linear relationship was seen. CONCLUSION: This investigation could not clarify the nature of exposure to A-bomb radiation as a risk factor for schizophrenia in the prenatal period.     

Psychological effect of the Nagasaki atomic bombing on survivors after half a century

In 1997 a mental health survey using a 30-item General Health Questionnaire (GHQ-30) and an interview survey of an atomic bombing experience were conducted in survivors of the Nagasaki atomic bombing. Overall psychological distress measured on the basis of the GHQ-30 was greater in the atomic bombing survivors than in the controls. As for the contents of psychological distress, those concerning emotion such as anxiety and depression were milder in survivors than in the controls, but those related to social activities such as apathy, disturbance of human relations, loss of enjoyment of living were more severe. Furthermore, recurring and distressing recollection of the experience of the atomic bombing, suspicion over the relationship between the atomic bombing and an unhealthy physical condition, and the experience of witnessing death or severe injury of close relatives due to the atomic bombing were significantly related to the degree of psychological distress of the survivors.     

Effects of gamma radiation on the shark brain

Summary A comparison was made between the effects of gamma radiation on the elasmobranch and the mammalian brain. Thirty-seven nurse sharks (ginglymostoma cirratum) received a single exposure, in a range of 1 000 to 30 000 rads, to the brain. The animals remained seemingly unaffected in their behavior and at their sacrifice, between one day and 28 months after irradiation, no histological changes could be detected with the exception of one shark (exposed to 30 000 and sacrificed after 12 months) which showed two small necrotic lesions in the tegmentum. No detectable difference in amount and distribution of glycogen in the brain could be demonstrated between irradiated and non-irradiated sharks. Also, the irradiated sharks showed no changes of the blood-brain barrier to protein tracer.Rats irradiated with 25 000 to 30 000 rads to the brain from the same source died shortly after exposure or showed extensive necrotic lesions in the brain. These was also an intense accumulation of glycogen mostly in the astrocytes and a widespread disturbance of the bloodbrain barrier to Evans Blue-albumin tracer.     

Cerebrovascular diseases in a fixed population of Hiroshima and Nagasaki, with special reference to relationship between type and risk factors

A study was made of the incidence of cerebrovascular disease, the chronological trends, and the relationship between the disease types and risk factors in 16,491 citizens of Hiroshima and Nagasaki. The subjects underwent medical examination at least once between 1958-74, and were free of cerebrovascular disease at the initial examination. During the 16-year period, 1.162 cases of cerebrovascular disease developed in the study population, with diagnosis definite in 621. By type, there were 108 cases of cerebral hemorrhage, 469 cases of cerebral infarction, 33 cases of subarachnoid hemorrhage, and 11 cases of other unclassifiable types. As a risk factor of cerebral hemorrhage, elevation of systolic and diastolic blood pressure was the most closely related to onset, and left ventricular hypertrophy on electrocardiogram (ECG), and proteinuria were also related. However, a tendency was seen for the risk to be higher when the levels of serum cholesterol were lower. In cerebral infarction, aging like systolic blood pressure, was a most important risk factor. Left ventricular hypertrophy on ECG, proteinuria, and diabetes could also be risk factors. However, the relation to blood pressure, especially diastolic blood pressure, was not so great as in the case of cerebral hemorrhage.     

Effects of cocaethylene on dopamine and serotonin synthesis in Long–Evans and Sprague–Dawley brains

We examined the behavioral and neurochemical effects of cocaethylene treatment in Long–Evans (LE) and Sprague–Dawley (SD) rats. Cocaethylene-induced behaviors were significantly less in LE rats. Cocaethylene caused an inhibition of dopamine synthesis in the caudate nucleus and nucleus accumbens that was equivalent in both rat lines. Serotonin synthesis was also suppressed by cocaethylene treatment, however this phenomenon was less pronounced when compared with the effects on dopamine synthesis.     

Immunohistochemical study of placental form of glutathione S-transferase in human brain tumors and fetal brains

The activity of glutathione S-transferase placental form (GST-pi) was examined in 100 cases including various histologic subtypes and grading of human brain tumors and 10 cases of fetal brains by immunohistochemical studies. The 69% of cases with brain tumors were shown to be positive for GST-pi. This activity in neuroepithelial tumors tended to increase in order to tumor grading, however, medulloblastoma and primitive neuroectodermal tumor (PNET) were not immunoreactive with GST-pi. Embryonal carcinoma showed strong staining, although fetal brains were negative. The metastatic brain tumors showed the same reactivity with GST-pi as those of original carcinomas. Moreover, the difference of GST-pi activity was investigated on some brain tumors treated with or without antitumor drug, such as 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU). The 85% of recurrent cases showed strong staining with GST-pi, and GST-pi activity seemed to be increased after treated with ACNU. The present study indicated that GST-pi might be a useful marker for human brain tumor, as the same conclusion was applicable to other neoplastic lesions examined previously. It is suggested that the increased GST-pi activity with malignancy of tumor may indicate the tendency to recurrence. The presence of such activity in tumor cells may also imply their acquired multidrug resistance. Our findings suggest that the evaluation of GST-pi activity in brain tumors will offer a predictive value for eventual behavior of the tumor.     

Reduced brain size and gyrification in the brains of dyslexic patients

Dyslexia is a specific learning disability that affects the way in which a person acquires reading skills. The pathologic substrate of the condition has been debated in the literature. Conclusions from postmortem studies remain controversial because series have been based on few and often ill-characterized cases. The present article expands on one of the reported neuropathologic findings in dyslexia, that is, wider minicolumns. Measurements were made of magnetic resonance images in a series of 16 dyslexic and 14 age- and sex-matched controls. Dyslexic patients had significantly smaller total cerebral volume (P = .014) and reduced gyrification index (P = .021). No changes were noted in cortical thickness, the ratio of gray to white matter, or the cross-sectional areas of the corpus callosum and medulla oblongata. The findings, although not conclusive, are in keeping with a minicolumnar defect in dyslexia. The decreased gyrification and preserved cortical thickness can alter the information processing capacity of the brain by providing a greater degree of cortical integration at the expense of a slower response time. The article also emphasizes the contrast between findings in dyslexia and in autism.     

Distribution of RNA during neuronal migration in developing normal and dysplastic brains in man. Acridine orange study

Acridine orange, a fluorochrome stain of nucleic acids, was used to study neuronal maturation in human brains during development. The central nervous system in 15 normal fetuses and neonates of 16 to 44 weeks gestational age were examined, as well as 24 dysplastic brains exhibiting abnormal cellular migrations. The increase in cytoplasmic RNA of neurons coincides with the onset of neurotransmitter synthesis, temporally synchronized to begin after migration in the cerebral hemispheres but before migration of the external granular layer of the cerebellum. The presence or absence of orange fluorescence in heterotopic nerve cells serves as a marker of the state of maturity by indicating whether the cell was still migrating at the time of death or had already arrived at its definitive site in the brain, whether normal or abnormal. Furthermore, the type of neurotransmitter produced by a given neuron influences ribosomal concentration and hence the intensity of orange RNA fluorescence. Neurons that secrete peptides, acetylcholine, or monoamines show stronger fluorescence than do those synthesizing simple amino acids as transmitters. Transitory transmitters of developing brain may account for stronger fluorescence in certain neurons of the fetus than in the adult, an example being the granule cells of the cerebellar cortex. Acridine orange is a useful supplementary tool in pediatric neuropathology.     

U0126对缺血性脑损伤大鼠脑内水通道蛋白-4表达的影响

目的研究水通道蛋白-4(aquaporin4,AQP4)在缺血性脑损伤大鼠脑内的表达,及丝裂原活化蛋白激酶(MAPKs)信号转导通路抑制剂U0126对其表达的影响。方法用线栓法建立缺血性脑损伤大鼠模型,测定脑组织含水量及伊文斯蓝含量,并采用免疫组织化学、Westernblot和逆转录-聚合酶链反应技术,检测AQP4的表达。测定预先经侧脑室给予U0126后MAPKs信号通路关键蛋白ERK1/2和ELK1磷酸化水平,同时观察U0126对脑水肿和AQP4表达的影响。结果正常组AQP4表达较低[蛋白(吸光度值,下同):123·1±1·0,mRNA(吸光度比值,下同):0·173±0·017],在缺血损伤后表达升高(蛋白:153·6±0·8,mRNA:0·400±0·015),脑组织含水量及伊文斯蓝含量增加,给予U0126后AQP4的表达和脑组织含水量降低(蛋白:149·0±1·1,mRNA:0·328±0·010,P<0·01),同时ERK1/2和ELK1磷酸化水平降低。结论缺血性损伤后AQP4表达上升,脑水肿明显,预先给予U0126可抑制AQP4的表达,减轻脑水肿。     

Epidemiological study of schizophrenia on the Island of Tsushima in Nagasaki Prefecture]

The epidemiology of schizophrenia has been studied with regard to the incidence, prevalence, and morbid risk, and there have been comprehensive reviews. However, the incidence and prevalence have not been analyzed simultaneously in many studies. In the present study, which was performed on a remote island, the number of patients could be determined, and they could be followed up by the same observer. This permitted us to conduct comprehensive epidemiological research while providing local mental health care. The subjects were patients diagnosed with schizophrenia according to the DSM-III-R in Tsushima, Nagasaki Prefecture, between April 1, 1988 and March 31, 1996. The incidence of schizophrenia was 2.3 (2.5 in males, 2.1 in females) per 10,000 people of the population, and the age-adjusted incidence was 2.4. Its prevalence was 5.8 (6.1 in males, 5.7 in females) per 1,000 people of the population, and the age adjusted prevalence was 6.2. In both sexes, the number of patients and the prevalence increased annually. The morbid risk was 0.95% (1. 01% in males, 0.89% in females) by the direct method (calculated from the incidence) and 0.85% (0.90% in males, 0.81% in females) by the indirect method (calculated from the prevalence), showing similarity. These incidence, prevalence, and morbid risk results did not markedly differ from the values reported to date. It is important to establish preventive measures for schizophrenia on the basis of the basic data obtained in this study, and to serially evaluate changes in epidemiological parameters of schizophrenia after their application. Furthermore, by comparing these epidemiological findings with those of other mental disorders and other regions, methods are expected to be utilized comprehensively for local mental health care.     

全脑照射后血脑屏障改变对放射性脑损伤的影响

目的 探讨全脑照射后血脑屏障通透性的改变对放射性脑损伤的影响.方法 80只昆明小鼠随机分对照组、5 Gy、15 Gy和30 Gy剂量组,每组20只,分别于照射后1周和4周,各组随机取出10只小鼠采用Morris水迷宫测试其空间记忆能力,行为测试结束后,随机抽取7只测量其脑内伊文思蓝的含量,3只在电镜下观察血脑屏障结构的改变.结果 照射后1周,15 Gy和30 Gy剂量组脑内依文思蓝明显升高;照射后4周,15 Gy剂量组恢复到对照组水平,而30 Gy剂量组仍未见恢复.照射后1周,15 Gy和30 Gy剂量组小鼠第1次穿越平台的时间延长和穿越次数明显减少;照射后4周,15 cy剂量组恢复到对照组水平,而30 Gy剂量组仍未见恢复.电镜结果显示15 Gy剂量组照射后1周血脑屏障基膜周围出现透亮区,照射后4周恢复;30 Gy剂量组照射后1周血脑屏障基膜周围也出现透亮区,而照射后4周除血脑屏障基膜继续透亮区外,尚出现内皮细胞核固缩、神经元凋亡和脱髓鞘等现象.结论 放射后血脑屏障的通透性的改变是放射损伤的结果,可能也是放射后继发性脑损伤的原因.     

Effects of dexamethasone on peritumoural oedematous brain: a DT-MRI study

OBJECTIVES: Glucocorticoids (dexamethasone) are thought to reduce peritumoural brain oedema by decreasing the permeability of neoplastic capillaries and/or enhancing the clearance of extracellular water. Diffusion tensor magnetic resonance imaging (DT-MRI) was used to measure the water diffusion parameters of oedematous and normal brain in a group of patients with intracranial tumours before and after steroid treatment. METHODS: Fifteen patients with intracranial tumours (seven with high-grade glioma, four with metastatic carcinoma and four with meningioma) were examined before and 48-72 h after dexamethasone treatment (16 mg/day). The mean diffusivity () and fractional anisotropy (FA) were measured for oedematous brain and apparently normal contralateral white matter before and after steroid therapy. RESULTS: In all three patient groups there was a significant decrease in of oedematous brain after steroid treatment (p<0.01). There was no significant change in FA of oedematous brain after treatment in any of the three groups. There was also no significant change in either or FA of apparently normal contralateral white matter after treatment. CONCLUSION: These data indicate that dexamethasone produces a localised reduction in the magnitude of extracellular water molecule mobility, and hence water content, in peritumoural oedematous brain. Furthermore, the magnitude of these changes is similar for both intra- and extra-axial tumours.