Mental illness in England,in Scotland and in Scots living in England

Summary Beginning from the observation that Scots living in England have much higher rates of mental hospital admission than do the English, several hypotheses are proposed to account for this. Much of the excess in rates of mental illness is accounted for by those diagnosed as having alcohol-related disorders and behaviour and personality problems. The results of an examination of offical statistics in the two countries enabled some explanations to be offered. It was found that rates of admissions to mental hospitals are higher in Scotland than in England but not as high as those found among Scots migrants who have a much higher rate of readmission to hospitals than either of the other groups. In fact, if first admissions only are considered the rates of admission in Scotland are not only higher than rates for English natives but also higher than for Scottish migrants. It seems that Scots living in England are somewhat less likely to become mental patients than Scots in Scotland but that once they do achieve this status they are very much more likely to be readmitted on subsequent occasions. It was concluded that there might be two fairly distinct groups of migrants from Scotland to England who have different backgrounds, different reasons for migrating and different psychological characteristics. On the one hand there are stable, economically motivated migrants who move south for definite employment related reasons and who show few psychological symptoms. While on the other hand there is a group of migrants who perhaps have psychological problems and who move more in hope than expectation without definite prospects and who account for the high rates of mental hospital admission found in Scottish migrants.     

Prostacyclin release in the coronary circulation during sustained stimulation in in vitro and in in vivo experimental systems

Prostacyclin release from rat isolated perfused hearts and from dog coronary circulation was studied by measuring immunoreactive 6-keto-PGF1 alpha (6-keto-PGF1a) in heart perfusate and in plasma obtained from the great cardiac vein respectively. Continuous infusion of arachidonic acid at constant concentration in isolated perfused hearts induced an increased prostacyclin release. This release showed a rapid peak within 10 min and a subsequent decrease. Low-flow ischemia induced an increased perfusate concentration of 6-keto-PGF1a but, considering the decreased flow, prostacyclin release was actually reduced. During the whole period of ischemia (60 min) prostacyclin release was constant. In open-chest anesthetized dogs 6-keto-PGF1a concentration in the great cardiac vein was increased after ligation of the left anterior descending coronary artery. A prolonged period of coronary occlusion (4.5 hours) resulted in a progressive rise of prostacyclin release. 6-keto-PGF1a determinations in the femoral vein and in the aorta did not show relevant variations during the observation period.     

癫痫与抑郁关系的研究进展

抑郁是癫痫患者中常见的精神障碍,严重地影响了患者的生活质量。传统的观点认为癫痫患者因为存在着诸多社会学问题易出现抑郁倾向,癫痫和抑郁是单向的联系,但大量的研究已经证明癫痫和抑郁之间存在双向的联系,一种异常状态的存在可能易转化为另一种异常状态的发展。癫痫和抑郁存在着共同的发病机制。本文主要就癫痫和抑郁的双向联系以及抗抑郁药物在癫痫患者中的应用进行阐述。     

Neuroimaging in epilepsy in tropics

Epilepsy is a major public health problem in many tropical countries. Also, some of the tropical diseases are major contributors to the higher prevalence of epilepsy in these countries. The etiologic factors responsible for epilepsy in these countries are quite different from those in the developed world. This article discusses the etiologic factors and neuroimaging of epilepsy in light of the conditions in these tropical countries.     

Sudanophilic lipid accumulation in astrocytes in periventricular leukomalacia in monkeys

Summary Sudanophilic lipid accumulation is a characteristic feature of periventricular leukomalacia (PVL) of infants. At least two types of lipid-containing cells have been identified, one being the macrophage, the other the pre-myelin glial cell. A third type of lipid-containing cell has been seen in two monkeys with spontaneous PVL. Electron microscopically this cell appears to be an astrocyte. This probably represents a reaction of the astrocyte to hypoxia and may be the equivalent of the hypertrophic astrocytes found in human infants.Supported in part by NIH grant HDO 8633 and the Regional Primate Research Center Grant RR-00166     

Increase in cathepsin D activity in rat brain in aging

Cathepsin D-like activity in homogenates of five brain areas of 3-month-old and 24-month-old Fischer 344 rats was measured. With hemoglobin as substrate at pH 3.2, more than 90% of the activity was inhibited by pepstatin. In each area studied, activity was more than twice as high in the old rat brain: 140-160% higher in the cortex, cerebellum, pons-medulla, and striatum and 90-100% higher in the hippocampus and spinal cord. The greatly increased metabolic capacity in the absence of an increase in protein turnover may have a role in age-related pathological degeneration in the brain.     

Abnormalities in MRI-measured signal intensity in the corpus callosum in schizophrenia

The microstructural integrity of the corpus callosum (CC) in first-episode schizophrenia patients was assessed by measuring the signal intensity (SI) in T1-weighted MRI images. Analyses revealed that compared to both healthy controls and non-schizophrenic patients, schizophrenia patients showed reductions in SI in all the callosal subregions, the genu, body, isthmus and splenium in first-episode schizophrenia. These results indicate that schizophrenia is characterized by pathology of this principal interhemispheric commissure; the abnormalities may reflect distributed (rather than localized) interhemispheric disconnectivity that extends beyond the heteromodal association cortices.     

Characteristics of nociceptors in the periodontium--an in vitro study in rats

Recent studies have indicated that nociceptors can be classified into various types according to their physiological properties. These studies have clarified that the frequency distribution of various nociceptor types is different among body sites and animal species. In the present study, we investigated the physiological properties of rat's periodontal nociceptors in an in vitro jaw-nerve preparation. Responses were recorded from functional single filaments in the inferior alveolar nerve. To determine the nociceptor type, calibrated von Frey filaments, heat, and bradykinin (BK) stimuli were used. We found five subtypes of nociceptors in the periodontal ligaments of the lower incisor: Adelta-high threshold mechanonociceptors (Adelta-HTM, n=28), Adelta-mechanoheat nociceptors (Adelta-MH, n=6), Adelta-polymodal nociceptors (Adelta-POLY, n=26), C-high threshold mechanonociceptors (C-HTM, n=3) and C-polymodal nociceptors (C-POLY, n=4). Most nociceptors were Adelta-innervated, while only a small number of C-innervated nociceptors were found. The present results suggest that periodontal nociceptors transmit mainly fast pain, and may thus play a role in rapid detection of injure-related stimuli during mastication.     

Defects in Bioenergetic Coupling in Schizophrenia

Synaptic neurotransmission relies on maintenance of the synapse and meeting the energy demands of neurons. Defects in excitatory and inhibitory synapses have been implicated in schizophrenia, likely contributing to positive and negative symptoms as well as impaired cognition. Recently, accumulating evidence has suggested that bioenergetic systems, important in both synaptic function and cognition, are abnormal in psychiatric illnesses such as schizophrenia. Animal models of synaptic dysfunction demonstrated endophenotypes of schizophrenia as well as bioenergetic abnormalities. We report findings on the bioenergetic interplay of astrocytes and neurons and discuss how dysregulation of these pathways may contribute to the pathogenesis of schizophrenia, highlighting metabolic systems as important therapeutic targets.