Astroglial cells: glucocorticoid target cells in the brain

Glutamine synthetase (GS), an enzyme localized in astroglial cells in the brain, is directly implicated in brain detoxification. An ontogenic study of GS activity was performed in homogenates from four distinct brain areas in comparison with the respective astrocytes obtained in primary cultures. GS was induced by hydrocortisone in the astrocytes of all brain areas studied; only cerebellum and cerebral hemisphere astroglial cells had a higher specific activity when compared with the corresponding homogenates. N6O2-Dibutyryl adenosine 3',5'-cyclic monophosphate (dBc AMP), insulin, soluble brain factors, and noradrenaline (NA) were also able to modulate GS activity. Brain factors as well as dBc AMP interfered with hydrocortisone induction of GS. Regulation by hydrocortisone paralleled the variation in its concentration in brain during development. We conclude that astroglial cells are target cells for glucocorticoids, which may modulate ammonia detoxification in these cells.     

长期住院稳定期精神分裂症患者认知功能及脑灰质密度的对照研究

目的:探讨长期住院稳定期精神分裂症患者大脑结构形态学改变及其与精神病理学症状的关系. 方法:对68例稳定期精神分裂症住院患者(患者组)与17名正常对照(对照组)采用中文版精神分裂症认知功能成套测验共识版(MCCB)作为评价工具进行认知功能测评,以阳性与阴性症状量表(PANSS)评定患者精神症状,Pearson相关分析探讨二者之间的相关性.患者组与对照组均进行磁共振扫描. 结果:研究组PANSS阴性症状评分平均(18.19 ±7.29)分高于阳性症状(13.12±5.44)分.MCCB认知功能评估中,研究组在符号编码、言语流畅、持续操作、言语记忆、迷宫、情绪管理及总测验成绩与正常对照组差异有统计学意义(t=2.82 ～5.99,P＜0.05或P＜0.01).Pearson相关分析显示,研究组PANSS总分及阴性症状与MCCB中符号编码、言语流畅、持续操作、言语记忆、情绪管理及总测验成绩等呈显著负相关(r=-0.25～-0.42,P＜0.05或P＜0.01).基于体素的形态学方法(VBM)分析显示,研究组的左侧额上回,左侧额中回、左额内侧回、右侧楔叶、左侧颞中回的灰质密度显著低于正常对照(Z=3.16 ～4.08,P＜0.05或P＜0.01). 结论:稳定期精神分裂症患者以阴性症状为主,阴性症状越重,认知损害越明显;阴性症状持续与认知功能损害可能与左侧额叶灰质密度下降有关.     

Influence of reserpine on all-night sleep pattern in nonlobotomized and lobotomized chronic schizophrenic patients.

This study was performed on two groups of schizophrenic patients. One group consisted on nine nonlobotomized patients and the other of nine lobotomized ones. The groups were matched for age, sex, duration of illness, clinical symptoms, type and dose of psychopharmacological treatment. The patients of both groups were administered 1 mg of reserpine half an hour before bedtime, for three successive days. Before reserpine administration the mean percentage time of the NREM stage 4 was significantly higher in the lobotomized group. There was no significant difference in the REM parameters. After three days of reserpine administration in the nonlobotomized group, there was no significant difference in the mean percentage of the NREM stage 4, whereas the mean REM percentage significantly increased and REM latency decreased. In the lobotomized group the same procedure, i.e., three days of reserpine administration, provoked a significant decrease in the mean percentage of the NREM stage 4 and no significant changes in the REM parameters. This difference in reserpine action on sleep in the lobotomized group is discussed.     

Facial affect decoding in schizophrenic disorders: a study using event-related potentials

Deficits in emotional processing are evident in schizophrenia, but the underlying processes are still under debate. In this study we tried to replicate findings of diminished prefrontal electroencephalographic response during facial affect recognition in healthy controls and subsequently in schizophrenic patients. As a first step, we analysed the event-related potentials (ERPs) of 36 healthy subjects during emotional expression decoding compared with neutral face viewing. Subsequently, the ERPs of 22 patients with schizophrenia were compared with the ERPs of 22 healthy subjects matched for age and sex. The hypothesised increase in the negative component at 200 ms over frontal brain regions during facial affect decoding was not found in this study. Instead we found increased positive amplitudes at 300 ms over parietal brain areas for the active affect-decoding task compared with the passive neutral face-viewing task. Interestingly, schizophrenic patients had higher amplitudes in the neutral condition than did healthy controls. This effect was more pronounced in the paranoid subgroup of patients.     

精神分裂症脑功能不平衡视觉P300研究

目的　从神经生理学角度探索精神分裂症患者脑区域功能的不平衡。方法　对 2 1例精神分裂症患者在发病期及两年缓解期后 ,采用视觉图像辨认作业引出Fz、Cz、Pz、Oz、T3 、T4 点P3 0 0 ,并与 2 4名正常人对比P3 波幅值。结果　病例组发病期与缓解期六个采样点 (Oz 例外 )均有P3 波幅下降 ;两颞侧相比 ,仅发病期存在P3 波幅左 <右的偏侧性 ,且有统计学意义。结论　精神分裂症存在普遍稳定的认知电位异常。左右采样点的异常不对称性可能是功能性的 ,决定于受检时的临床状态     

精神分裂症患者认知功能的纵向研究

目的:探讨在精神分裂症的纵向病程中认知功能的改变.方法:对64例精神分裂症患者,分别在住院期间和5年后随访观察时的精神症状,信知功能等进行评定.结果:5年后随访时阳性,阴性症状群均明显改善.操作智商和全量表智商有所改善,且与阴性症状群相关,神经心理测验中,循环字母A删除测验和自由联想成绩也有改善,但双手手指敲击速度减慢,结论:本组精神分裂症患者在良好的维持治疗下,在5年病程中精神症状得到改善,认知功能也部分得到改善.     

Functional brain asymmetry and attentional modulation in young and stabilised schizophrenic patients: a dichotic listening study

Impaired functional brain asymmetry has been shown in schizophrenic patients, in addition to attentional deficits related to this laterality impairment. However, it has usually been shown in older patients with frequent positive symptoms. This is a matter of concern because previous studies have suggested that such deficits interact with subgroup characteristics, especially positive symptoms like hallucinations and age/duration of the illness. Thus, in this study, we tested a homogeneous group of young and stabilised schizophrenic patients. We used a verbal dichotic listening test with consonant-vowel syllables to study brain asymmetry and attentional modulation. Nineteen patients were compared with healthy subjects with the same age, handedness and gender distribution. All subjects were tested during a divided and two focused attention conditions. The patient and reference group showed the same performance pattern. This indicates that young and stabilised patients show normal functional brain asymmetry and normal ability to modulate attention. It is suggested that impairments in functional asymmetry and attentional modulation may follow a continuum related to symptomatology and age/duration of illness.     

Astroglial plasticity and glutamate function in a chronic mouse model of Parkinson's disease

Astrocytes play a major role in maintaining low levels of synaptically released glutamate, and in many neurodegenerative diseases, astrocytes become reactive and lose their ability to regulate glutamate levels, through a malfunction of the glial glutamate transporter-1. However, in Parkinson's disease, there are few data on these glial cells or their regulation of glutamate transport although glutamate cytotoxicity has been blamed for the morphological and functional decline of striatal neurons. In the present study, we use a chronic mouse model of Parkinson's disease to investigate astrocytes and their relationship to glutamate, its extracellular level, synaptic localization, and transport. C57/bl mice were treated chronically with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and probenecid (MPTP/p). From 4 to 8 weeks after treatment, these mice show a significant loss of dopaminergic terminals in the striatum and a significant increase in the size and number of GFAP-immunopositive astrocytes. However, no change in extracellular glutamate, its synaptic localization, or transport kinetics was detected. Nevertheless, the density of transporters per astrocyte is significantly reduced in the MPTP/p-treated mice when compared to controls. These results support reactive gliosis as a means of striatal compensation for dopamine loss. The reduction in transporter complement on individual cells, however, suggests that astrocytic function may be compromised. Although reactive astrocytes are important for maintaining homeostasis, changes in their ability to regulate glutamate and its associated synaptic functions could be important for the progressive nature of the pathophysiology associated with Parkinson's disease.     

Hypofrontality and cognitive impairment in schizophrenia: dynamic single-photon tomography and neuropsychological assessment of schizophrenic brain function

Regional cerebral blood flow (rCBF) was assessed in 40 chronic male schizophrenic patients (20 medicated, 20 unmedicated) and 31 matched normal controls with Dynamic Single-photon Emission Computed Tomography (D-SPECT). Blind analyses of normalized color-coded tomograms revealed significant bifrontal and bitemporal rCBF deficits in the patient group. Frontal flow deficits were most prominent in paranoid patients (n = 21) and right temporal deficits were most prominent in nonparanoid patients (n = 19). These relative regional declines were observed within the context of significantly elevated hemispheric blood flow in schizophrenics compared with controls. Reduced left frontal rCBF was associated with neuropsychological impairment on the Wisconsin Card Sorting Test and Luria-Nebraska Battery. Increased hemispheric CBF was correlated with the presence of positive schizophrenic symptoms. Medication status was unrelated to rCBF. These findings demonstrate that hypofrontality has important implications for cognitive function in some schizophrenic individuals.     

精神分裂症伴迟发性运动障碍认知功能的对照研究

目的 了解慢性精神分裂症TD患者是否存在认知功能损害。方法 符合持续性TD诊断标准且年龄低于65岁的慢性精神分裂症患者纳入TD组,对照组为同期住院慢性精神分裂症患者。其性别与TD组配对,年龄、文化程度、目前抗精神病药物各类分别与TD组匹配。两组患者认知功能测验包括:韦氏成人智力量表(WAIS-RC)、韦氏记忆量表(WMS)及威期康星卡片分类测验(WCST)。结果 WAIS-RC测验TD组和对照组语言智商、作业智商、总智商成绩无显著差异,但数字广度、数字符合测验TD组得分明显低于对照组。WMS测验结果显示TD组顺数数、累积、背数测验得分明显低于对照组,TD组记忆商数较低。WCST测验结果显示:两组持续错误数无差异,TD组总反应数、正确数、随机错误数、分类完成数的成绩均关于对照组。二元变量相关分析显示:AIMS得分与记忆商数、总反应数、正确数、随机错误数、分类完成数相关。多元逐步回归分析显示:文化程度、TD、年龄是影响患者认知功能的主要因素。结论 有无TD的慢性精神分裂症患者的智商无显著差异;TD患者存在记忆损害,特别是工作记忆损害;TD患者额叶执行功能差于无TD者;除文化程度、年龄外,TD对患者的认知功能损害有影响。     

Clinical subtypes of schizophrenic disorders: a cluster analytic study

Two hundred and fifty-five psychiatric inpatients with a definite diagnosis of DSM-IV schizophrenic disorder were examined by means of the Structured Clinical Interview and rated on the 30 main items of the Positive and Negative Syndrome Scale (PANSS). Patients' scores were subjected to a cluster analysis, using Ward's method. Cluster analysis indicated the existence of five groups. The first group (n = 46) comprised patients with overall psychopathology of minimal severity, the second group (n = 39) patients with severe positive symptoms along with symptoms of psychomotor excitement, the third group (n = 58) patients with severe positive psychopathology only, the fourth group (n = 34) patients with severe positive negative depressive and cognitive symptoms and, finally, the fifth group (n = 78) patients with severe negative symptoms only. Patients in the first and third groups were older and their illnesses were of longer duration compared to those of the remaining groups. With respect to DSM-IV clinical types of schizophrenic disorders, the paranoid type predominated in the second and the third groups, whereas the disorganized and catatonic types were markedly overpresented in the fifth group.     

精神分裂症患者脑部CT临床对照研究

为探讨精神分裂症患者脑ＣＴ结果与临床的相关性，对１９９５年１月～１９９６年５月住院符合ＣＣＭＤ—２—Ｒ诊断标准的精神分裂症患者进行脑部ＣＴ检查，以同期门诊神经症患者的脑ＣＴ检查报告作对照，并与临床相关因素进行对照分析。结果发现精神分裂症组脑ＣＴ异常６９例（３２．４％），与对照组比较有极显著差异；前者病程＞５年，年龄４０岁以上，以阴性症状为主患者的脑萎缩发生率最高。     

Mortality among chronic schizophrenic patients: a prospective 14-year follow-up study of 150 schizophrenic patients

OBJECTIVE: The aim of this study was to quantify the mortality risk in chronic schizophrenic patients, ten to 14 years after the initial evaluation. Furthermore, using sociodemographical, clinical and psychometrical variables evaluated at inclusion, predictors of global or mortality by suicide were explored. METHODS: One hundred and fifty subjects meeting the research diagnostic criteria (RDC) for chronic schizophrenia were included in the study between 1991 and 1995. At the initial assessment, the following variables were assessed: sex, age, level of education, number of hospitalisations, mean duration of the illness, scores on the physical anhedonia scale, the brief psychiatric rating scale (BPRS), the positive and negative syndrome scale (PANSS), and Beck's depression inventory (BDI). In May 2005, all the subjects were assessed using direct or indirect methods. Survival analysis was conducted using the Kaplan-Meier product-limit estimator and a standardized mortality ratio (SMR) was calculated. Multivariate Cox regression was performed to detect predictive factors associated with mortality. RESULTS: The absolute mortality rate was of 18.57% and the RSM of 4.83. The absolute mortality rate for suicide was 6.98%. Multivariate Cox regression analyses showed that two factors (high rate of males, high dose of antipsychotics) were related to an increase in global mortality risk. Moreover, high dose of antipsychotics and a high rate of "positive" subjects, as evaluated by the PANSS, were related to an increase in mortality risk by suicide. CONCLUSION: High dose of neuroleptics could characterize the severe form of schizophrenia, the risk of mortality of which was higher than that of the less severe forms. Another explanation was that high doses of neuroleptics could lead to severe side effects and thus an increase in the vulnerability of schizophrenics to organic diseases. Positive, contrary to negative, symptoms could increase the risk of suicide. This 14-year follow-up study confirmed the increased mortality rates by natural and non natural causes observed in chronic schizophrenic subjects.     

精神分裂症患者机体抗氧化功能指标的实验研究

目的 探讨机体抗氧化能力在精神疾病发病机理中的作用及其临床意义。方法 采用化学比色法检测176例精神分裂症患者血清中SOD、MDA、GSH－Px、VC、VE和NO含量。结果 精神分裂症患者血清中SOD、MDA、NO含量均高于对照组（P＜0．05或0．01）;GSH－Px、VC含均低于对照组（P＜0．01）;VE两者无显著差异（P＞0．05）;精神分裂症家族史阳性者血清中NO高于精神分裂症阴性家族史者（P＜0．05）;精神分裂症患者抗氧化能力含量可因病程、性别、年龄的不同而不同;精神分裂症患者治疗后SOD、MDA低于治疗前（P＜0．01）。结论 精神分裂症患者体内自由基代谢异常可能是精神分裂症发病的生物学因素之一。