Retroviral RNA identified in the cerebrospinal fluids and brains of individuals with schizophrenia

Schizophrenia is a serious brain disease of uncertain etiology. A role for retroviruses in the etiopathogenesis of some cases of schizophrenia has been postulated on the basis of clinical and epidemiological observations. We found sequences homologous to retroviral pol genes in the cell-free cerebrospinal fluids (CSFs) of 10 of 35 (29%) individuals with recent-onset schizophrenia or schizoaffective disorder. Retroviral sequences also were identified in the CSFs of 1 of 20 individuals with chronic schizophrenia. However, retroviral sequences were not identified in any of the CSFs obtained from 22 individuals with noninflammatory neurological diseases or from 30 individuals without evidence of neurological or psychiatric diseases (χ2 = 19.25, P < 0.001). The nucleotide sequences identified in the CSFs of the individuals with schizophrenia or schizoaffective disorder were related to those of the human endogenous retroviral (HERV)-W family of endogenous retroviruses and to other retroviruses in the murine leukemia virus genus. Transcription of RNA homologous to members of the HERV-W family of retroviruses also was found to be up-regulated differentially in the frontal cortex regions of brains obtained postmortem from individuals with schizophrenia, as compared with corresponding tissue from individuals without psychiatric diseases. The transcriptional activation of certain retroviral elements within the central nervous system may be associated with the development of schizophrenia in at least some individuals. The further characterization of retroviral elements within the central nervous system of individuals with schizophrenia might lead to improved methods for the diagnosis and management of this disorder.

Identification of peptides specific for cerebrospinal fluid antibodies in multiple sclerosis by using phage libraries.

The study of the origin and pathogenetic relevance of the oligoclonal antibodies present in the cerebrospinal fluid (CSF) of multiple sclerosis (MS) patients has been hampered by a lack of specific ligands. We recently reported a general strategy, based on phage-displayed random peptide libraries, to identify ligands for disease-specific antibodies even in the absence of any information on the nature of the pathologic antigen. With this procedure, we identified several peptides specifically recognized by antibodies present in the CSF of MS patients. Using these peptides as reagents, we demonstrated that they mimic different natural epitopes and react with antibodies enriched in the CSF of MS patients. Antibodies recognizing the selected peptides are commonly found with equal frequency in the sera of MS patients and of normal individuals. In contrast, the repertoire of CSF antibodies appears to be individual-specific and is probably the result of a nonspecific immunodysregulation rather than a stereotyped response to a single antigen/agent.

Glycoprotein 330/megalin: probable role in receptor-mediated transport of apolipoprotein J alone and in a complex with Alzheimer disease amyloid beta at the blood-brain and blood-cerebrospinal fluid barriers.

A soluble form of Alzheimer disease amyloid beta-protein (sA beta) is transported in the blood and cerebrospinal fluid mainly complexed with apolipoprotein J (apoJ). Using a well-characterized in situ perfused guinea pig brain model, we recently obtained preliminary evidence that apoJ facilitates transport of sA beta (1-40)-apoJ complexes across the blood-brain barrier and the blood-cerebrospinal fluid barrier, but the mechanisms remain poorly understood. In the present study, we examined the transport process in greater detail and investigated the possible role of glycoprotein 330 (gp330)/megalin, a receptor for multiple ligands, including apoJ. High-affinity transport systems with a Km of 0.2 and 0.5 nM were demonstrated for apoJ at the blood-brain barrier and the choroid epithelium in vivo, suggesting a specific receptor-mediated mechanism. The sA beta (1-40)-apoJ complex shared the same transport mechanism and exhibited 2.4- to 10.2-fold higher affinity than apoJ itself. Binding to microvessels, transport into brain parenchyma, and choroidal uptake of both apoJ and sA beta (1-40)-apoJ complexes were markedly inhibited (74-99%) in the presence of a monoclonal antibody to gp330/megalin and were virtually abolished by perfusion with the receptor-associated protein, which blocks binding of all known ligands to gp330. Western blot analysis of cerebral microvessels with the monoclonal antibody to gp330 revealed a protein with a mass identical to that in extracts of kidney membranes enriched with gp330/megalin, but in much lower concentration. The findings suggest that gp330/megalin mediates cellular uptake and transport of apoJ and sA beta (1-40)-apoJ complex at the cerebral vascular endothelium and choroid epithelium.

Persistent elevations of cerebrospinal fluid concentrations of corticotropin-releasing factor in adult nonhuman primates exposed to early-life stressors: implications for the pathophysiology of mood and anxiety disorders.

There is increasing evidence for an important role of adverse early experience on the development of major psychiatric disorders in adulthood. Corticotropin-releasing factor (CRF), an endogenous neuropeptide, is the primary physiological regulator of the mammalian stress response. Grown nonhuman primates who were exposed as infants to adverse early rearing conditions were studied to determine if long-term alterations of CRF neuronal systems had occurred following the early stressor. In comparison to monkeys reared by mothers foraging under predictable conditions, infant monkeys raised by mothers foraging under unpredictable conditions exhibited persistently elevated cerebrospinal fluid (CSF) concentrations of CRF. Because hyperactivity of CRF-releasing neurons has been implicated in the pathophysiology of certain human affective and anxiety disorders, the present finding provides a potential neurobiological mechanism by which early-life stressors may contribute to adult psychopathology.

Degradação de atrazina por processo foto-Fenton monitorado por injeção seqüencial e cromatografia a líquido de alta eficiência

Processos de fotodegradação de compostos orgânicos tóxicos têm sido bastante estudados. Este trabalho trata da aplicação do processo foto-Fenton para a degradação de atrazina em água (composto modelo). O efeito das concentrações dos seguintes compostos foi avaliado: peróxido de hidrogênio (2 a 6 mmol L-1) e ferrioxalato de potássio (0,2 a 1 mmol L-1). Os experimentos foram realizados em um reator com lâmpada UV - 8W (254nm). O processo de fotodegradação foi monitorado por medidas de espectrofotometria de absorção molecular automatizada por injeção seqüencial (SIA) para determinação de peróxido de hidrogênio e por cromatografia a líquido de alta eficiência (CLAE) para determinação de atrazina e metabólitos. Os experimentos demonstram que o processo de foto-Fenton é viável para o tratamento de atrazina em água.

Caracterização morfológica e imunofenotípica dos linfomas caninos através de citologia de meio líquido e imunocitoquímica em emblocado celular

O linfoma canino é uma das neoplasias mais prevalentes em cães, diagnosticado frequentemente através de exame citológico de aspirados. A imunofenotipagem para diferenciação entre linfomas de células B e T é importante para definição prognóstica e tratamento, entretanto, dificilmente é realizada em materiais provenientes de aspirados citológicos. A citologia em meio líquido (CML) é uma metodologia automatizada de produção de esfregaços citológicos, que permite a conservação de todo o material da aspiração, e utilização do material residual para, por exemplo, produção de emblocado celular (EC) e imunocitoquímica. Este trabalho teve como objetivo aplicar a CML e EC com imunocitoquímica em amostras de linfonodos caninos suspeitos para linfoma. Além disso, pretendeu caracterizar morfologicamente as células linfoides neste tipo de preparado, comparando ao esfregaço convencional. Para isto, foram selecionados 54 cães com linfadenomegalia, 10 deles sorologicamente positivos para leishmaniose canina. Comparou-se a CML com a citologia convencional, quanto às características técnicas e testou-se dois métodos diferentes de EC: Bouin e agarose com formalina. Aplicou-se painel imunocitoquímico de anticorpos anti-CD3, anti-CD79a, anti-Pax-5 e anti-Ki67, para imunofenotipagem e determinação da proliferação celular. Adicionalmente, realizaram-se análises estatísticas para avaliação do desempenho e concordância interobservador comparada entre citologia convencional, CML e o uso conjunto de CML e imunocitoquímica do emblocado celular. Como resultado, as células linfoides apresentaram-se preservadas, com melhor definição de cromatina e nucléolos, porém com tamanho reduzido e pior definição citoplasmática, na CML. O EC de Bouin revelou grupos densos e bem definidos, que permitiram a aplicação da imunocitoquímica. Por outro lado, os emblocados de agarose, apresentaram-se frouxos, com células marcadamente dispersas, revelando-se inadequados para preparados de células linfoides. O anticorpo anti-Pax-5 mostrou-se mais adequado do que o anti-CD79a para marcação de células B em emblocados, por produzir menos fundo e pela marcação nuclear ser mais distinguível do que a citoplasmática. A concordância interobservadores da CML foi moderada (k= 0,434), enquanto a da citologia convencional foi boa (k=0,762). Ambas as técnicas exibiram a mesma acurácia e, com aplicação da CML, houve redução do percentual de amostras insatisfatórias. A CML em conjunto com EC e imunocitoquímica apresentou maior sensibilidade (75%), especificidade (99%) e acurácia (89,47%). Como conclusão, a CML em conjunto com EC e imunocitoquímica pode ser aplicada para diagnóstico de linfoma canino, com maior sensibilidade, especificidade e acurácia