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.     

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。     

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.     

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 noradrenaline-synthesizing enzyme activity in medulla oblongata in Parkinson's disease

Summary Dopamine beta hydroxylase (DBH), the noradrenaline-synthesizing enzyme, and phenylethanolamine-N-methyltransferase (PNMT), the adrenaline-synthesizing enzyme, were assayed in 18 areas of brain stem in eight cases of parkinsonian syndromes and of four age- and postmortem delay-matched controls. Dissection was performed by the punch technique and enzyme activities assayed by radiometric methods. No significant change was found for PNMT activity. DBH activity was significantly increased in the A2-C2 area of the medulla oblongata (including the nucleus tractus solitarius) in the cases of Parkinson's disease.The A2-C2 area is known to be implicated in the control of blood pressure in rats. These findings are discussed in relation to orthostatic hypotension and the influence ofl-dopa therapy.Supported by grants from INSERM ATP 657897, ATP 8179113, CRL 79-1-356-6, DGRST (80 E 0882), FRMF, and Sandoz-France France     

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.     

Issues in evaluation of cognition in the elderly in developing countries

Background:

Developing regions of the world host the majority of elderly subjects who are at risk for dementia. Reliable epidemiological data from these countries is invaluable in tackling this global problem. Scarcity of such data in literature is largely attributable to problems that are unique to developing communities worldwide.

Objective:

To classify and describe the problems that interfere with the collection of reliable epidemiological data on cognitive impairment in the elderly in developing communities, and to suggest practical solutions for some of them.

Methods:

Inferring from the experiences of a large, ongoing, population-based study on the cognitive impairments in the elderly in South India and from the review of literature.

Conclusion:

A fatalistic attitude regarding aging in the communities, significant heterogeneity in educational abilities and activities of daily living, high illiteracy among rural subjects, and lack of an organized health care system and updated demographic figures are some of the major factors that contribute to technical, namely, methodology-related problems and practical, namely, subject-related problems in such epidemiological studies.     

Progress in neuroprotection in Parkinson's disease

Slowing or aborting the progress of neurodegeneration in Parkinson's disease (PD) remains the most important unmet need of this disorder. There are several recent developments in trial design and also in drugs under investigation for possible neuroprotective effect. Emphasis has been placed on clinical as opposed to imaging end-points and these include change in a clinical rating scale, e.g. United Parkinson's disease Rating Scale (UPDRS), or time to additional therapy. The introduction of the delayed-start, or wash-in, trial design adds an additional dimension to drug evaluation for neuroprotection. Compounds that have been recently tested in clinical trial include the monoamine oxidase-B inhibitor rasagiline, the anti-apoptotic agents TCH346 and CEP1347, and the promitochondrial agent creatine. The dopamine agonists have been evaluated for a neuroprotective effect using imaging end-points. Perhaps the most important and simplest concept for neuroprotection has been the theory that early dopaminergic support for the degenerating dopaminergic system per se provides significant long-term clinical benefit for PD patients.     

Suicide in the elderly in Austria

In most countries men and women have the highest suicide rates in age groups over 60 years. We investigated suicide rates for the elderly in Austria, a country with one of the highest suicide rates in the world, for the period 1980–1991, using data from the Federal Statistical Division. Suicide rates remained stable over the last decade at a very high level. The mean rate for men was 85.2, for women 28.6/100 000. In men and women rates rise with age. The mean rate of men rises from 51.2 (60–64 years) to 117.3/100 000 (over 85 years); in women there is an increase from 21.4 (60–64 years) to 32.8/100 000 (over 85 years). We did not confirm findings in other countries, where suicide rates have increased in recent years.     

Gender in Voice Perception in Autism

Deficits in the perception of social stimuli may contribute to the characteristic impairments in social interaction in high functioning autism (HFA). Although the cortical processing of voice is abnormal in HFA, it is unclear whether this gives rise to impairments in the perception of voice gender. About 20 children with HFA and 20 matched controls were presented with voice fragments that were parametrically morphed in gender. No differences were found in the perception of gender between the two groups of participants, but response times differed significantly. The results suggest that the perception of voice gender is not impaired in HFA, which is consistent with behavioral findings of an unimpaired voice-based identification of age and identity by individuals with autism. The differences in response times suggest that individuals with HFA use different perceptual approaches from those used by typically developing individuals.     

Ethnic disparities in problem behaviour in adolescence contribute to ethnic disparities in social class in adulthood

BACKGROUND: It is important for prevention of social class disparities to know how ethnic disparities in social class arise among migrant children. We contribute to this understanding by examining the role of problem behaviour in adolescence. METHODS: Prospective observational study with 753 Dutch native and 217 Turkish migrant adolescents (11-18 year) followed for 10 years. Internalising and externalising problems were assessed in adolescence and employment status and occupational level were assessed in adulthood. The difference in odds ratios (OR) before and after adjustment for internalising and externalising problems was an indication of the predictive value of disparities in internalising and externalising problems for the development of social class disparities. RESULTS: A total of 135 (62%) of the Turkish and 602 (80%) of the Dutch adults were employed. Internalising and externalising problems were not associated with employment status. Of the employed, 65 (48%) Turkish and 179 (30%) Dutch adults worked in low-level occupations (p < 0.0001). Internalising and externalising problems were associated with both ethnicity and occupation. The OR for low-level occupation for Turkish adults was 1.78 (1.19-2.65), indicating ethnic disparities. Adjustment for internalising problems lowered the OR with 36% to 1.50 (0.97-2.31), and adjustment for externalising problems lowered it with 8% to 1.72 (1.15-2.57). Findings were similar for men and women and did not vary by age. CONCLUSIONS: Ethnic disparities in occupational level in adulthood could partly be attributed to disparities in mental health between Turkish migrants and Dutch natives in adolescence. Prevention of ethnic disparities in mental health at young age may therefore also contribute to the prevention of occupational differences in adulthood.     

Changes in parasympathetic system in medulla oblongata in male pigs in the course of tachycardia-induced cardiomyopathy

Background

Autonomic imbalance constituting a fundamental feature of heart failure (HF) has been assessed mainly at the periphery. Changes in the functioning of autonomic centers in the brain remain unclear. We investigated the molecular elements of parasympathetic system, i.e. α7 nicotinic acetylcholine receptor (α7nAChR) and enzymes metabolizing acetylcholine (acetylcholinesterase, AChE, choline acetyltransferase, ChAT) in medulla oblongata (MO) of male pigs with chronic tachycardia-induced cardiomyopathy.

Methods

The mRNA levels of AChE, ChAT, α7nAChR and X-box binding protein 1 (spliced form, XBP1s) in MO were analyzed using qPCR, AChE and ChAT activities using spectrophotometry, proteasome activity using fluorometry, and the protein level of α7nAChR using Western blotting.

Results

The development of systolic HF was accompanied by an increase in circulating catecholamines, a decrease in the AChE and α7nAChR mRNA in MO, an increase in AChE activity (all p < 0.05), and no change in either the mRNA or activity of ChAT. Both circulating catecholamine levels and AChE activity were inversely related to systolic function of left myocardial ventricle (p < 0.05). The level of α7nAChR protein in MO and its cytoplasmatic fraction were higher in pigs with moderate and severe HF as compared to the other animals (p < 0.01). There was no difference in proteasome activity in MO between diseased and healthy animals, whereas the XBP1s mRNA decreased during HF progression (p < 0.05).

Conclusions

Molecular elements of parasympathetic system are changed within the medulla oblongata during the progression of systolic non-ischemic heart failure in male pigs, indicating a functional link between MO and heart in HF.     

事件相关电位在精神分裂症中的应用及研究进展

事件相关电位（event related potentials,ERP）是根据现代心理学原理发展起来的一种与刺激事件呈“锁时”关系的脑电活动分析技术,临床常规ERP包括失匹配负波（MMN）、P300、关联负变（CNV）、感觉门控（P50）等,现就近年来事件相关电位在精神分裂症方面的研究作一综述。     

Reduction in cholecystokinin-like immunoreactivity in the basal ganglia in Huntington''s disease

In the intact hindlimb, flexion reflexes are most easily obtained when the knee is extended. Movement of the knee joint after the muscles have been tenotomized and held at fixed lengths still modulates flexion reflex excitability. After anaesthesia of the joint capsule movement of the limb no longer affects flexion reflex excitability.     

Increase in thickness of cerebral cortex in response to environmental enrichment in brattleboro rats deficient in vasopressin

Changes in cortical thickness were observed in male Brattleboro rats killed at 60 and 90 days of age from standard environmental conditions, and at 90 days of age after 30 days in an enriched condition. When 60- and 90-day-old standard animals were compared, both homozygous Brattleboro rats with diabetes insipidus and also heterozygous nondiabetic rats showed reduction in cortical thickness with age. When 90-day-old enriched animals were compared with the 90-day-old standard group: the homozygous rats with enrichment showed statistically significant thickening in frontal, parietal, and occipital cortices, and the heterozygous rats showed statistically significant thickening with enrichment in parietal and occipital regions. In both heterozygous and homozygous Brattleboro rats the most significant increases were in the occipital cortex. These results are in general agreement with previously reported developmental and enrichment studies in the normal Long-Evans strain of rats, with an important difference: both heterozygous and homozygous animals showed greater and more generalized response to enrichment. We speculate that this greater responsiveness to environmentally induced cortical thickening in the Brattleboro rats is due to increased arousal, and it may be related to alterations in norepinephrine concentration and/or turnover associated with absence of, or abnormalities in, vasopressin in the brain.     

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.     

Photophobia in primary headaches,in essential blepharospasm and in major depression

Objectives: Although photophobia is a well-known symptom in various disorders, it has rarely been studied explicitly and its definition in a clinical setting can be somewhat elusive. Here, we assessed photophobia with a common psychometric tool in different conditions, in which light intolerance is considered part of the syndrome. Patients and methods: A prospective study was undertaken in patients with migraine (MH), cluster headache (CH), tension-type headache (TH), essential blepharospasm (BS) and major depression (MD). Photophobia was assessed by the photophobia questionnaire (range 0–8). Symptom severity was measured in each patient group with appropriate scales. Finally, depression was assessed explicitly in each condition. Results: Hundred and six subjects met the inclusion criteria (MH: 27, CH: 21, TH: 20, BS: 18, MD: 20). Photophobia scores differed between patient groups, with migraineurs showing the highest (6.63) and TH patients the lowest (2.10) scores (ranking: MH, BS, CH, MD and TH). Symptom severity as well as depression had little, if any, influence on the degree of photophobia. Discussion: Photophobia is a core symptom of migraine but also constitutes a feature of other neurological conditions. The relative independence from other, disease-specific features, suggests that photophobia is a rather autonomous symptom.