Modulation of angiogenic factor VEGF by DNA-hsp65 vaccination in a murine CNS tuberculosis model.

Tuberculosis (TB) is a serious public health problem. Development of experimental models and vaccines are essential to elucidate physiopathological mechanisms and to control the disease. Vascular endothelial growth factor (VEGF) is a potent activator of vascular permeability and angiogenesis. VEGF seems to participate in breakdown of the blood brain-barrier (BBB) in tuberculous meningitis (TBM), contributing to worsening of disease. Therefore, the objective here was to extent the characterization of our previously described murine model of central nervous system TB (CNS-TB) by describing the VEGF participation in the CNS disease, and suggesting a vaccination plan in mice. Plasmid encoding DNA protein antigen DNA-hsp65 has been described as a protector against TB infection and was used here to test its effectiveness in the prevention of VEGF production and TB disease. Vaccinated mice and its controls were injected with Mycobacterium bovis bacillus Calmette-Guerin (BCG) in cerebellum. Four weeks after BCG injection, mice were perfused and brains were paraffin-embedded for VEGF expression analysis. We observed VEGF immunohistochemical expression in TBM and granulomas in non-vaccinated mice. The DNA-hsp65 treatment blocked the expression of VEGF in mice TBM. Therefore, our murine model indicated the VEGF participation in the physiopathology of CNS-TB and the potential prevention of the DNA-hsp65 in the disease progression.

The contribution of a murine CNS-TB model for the understanding of the host-pathogen interactions in the formation of granulomas.

Central nervous system (CNS) tuberculosis (TB) is the most severe form of TB, characterized morphologically by brain granulomas and tuberculous meningitis (TBM). Experimental strategies for the study of the host-pathogen interaction through the analysis of granulomas and its intrinsic molecular mechanisms could provide new insights into the neuropathology of TB. To verify whether cerebellar mycobacterial infection induces the main features of the disease in human CNS and better understand the physiological mechanisms underlying the disease, we injected bacillus Calmette-Guerin (BCG) into the mouse cerebellum. BCG-induced CNS-TB is characterized by the formation of granulomas and TBM, a build up of bacterial loads in these lesions, and microglial recruitment into the lesion sites. In addition, there is an enhanced expression of signaling molecules such as nuclear factor-κB (NF-κB) and there is a presence of inducible nitric oxide synthase (iNOS) in the lesions and surrounding areas. This murine model of cerebellar CNS-TB was characterized by cellular and biochemical immune responses typically found in the human disease. This model could expand our knowledge about granulomas in TB infection of the cerebellum, and help characterize the physiological mechanisms involved with the progression of this serious illness that is responsible for killing millions people every year.

Screening for mutations in the RYR1 gene in families with malignant hyperthermia.

Malignant hyperthermia (MH) is a potentially lethal pharmacogenetic predisposition associated with a susceptibility to volatile anesthetics and depolarizing muscle relaxants that lead to a fulminant anesthetic crisis with hyperthermia, skeletal muscle rigidity, respiratory and metabolic acidosis, and muscle rhabdomyolysis. Malignant hyperthermia crises are caused by an abnormal regulation of the calcium release mechanism, which reflects the consequences of disturbed skeletal muscle calcium homeostasis. We screened 64 individuals of 27 unrelated families for the most frequently described mutations associated with MH in the genes RYR1 and CACNL1A3. We identified only one family with the Arg614Cys mutation but with a discordant segregating pattern to the in vitro contracture test (IVCT). To elucidate which other mechanism could lead to susceptibility in the members of this family, we tested it for further MH susceptibility loci. The same haplotype was shown to segregate with the individuals carrying the Arg614Cys mutation in chromosome 19; however, the other susceptible and equivocal individuals do not share this haplotype. Markers for the susceptible locus in chromosome regions 17q, 7q, 3q, and 5p did not segregate with the IVCT phenotype in the susceptible individuals, suggesting that the positivity of the IVCT could be attributable to other ambient factors.

[Experimental tumors of the central nervous system: standardisation of a model in rats using the 9L glioma cells]. / Tumores experimentais do sistema nervoso central: padronização de modelo em roedores utilizando a linhagem 9L.

A number of experimental models have been established during the last decades in order to study tumor biology and the effects of treatment or manipulation of the microenvironment of malignant glial tumors. Even though those models have been well characterised and are, to a certain extent, easily reproducible, there are limitations as to their use and to the interpretation of the results. The aim of this study is to standardize a model of a malignant glial tumor and detect possible events able to modify its development. 9L cells were inoculated intracerebrally in 48 Sprague-Dawley rats; from these, 25 animals were also implanted with a device containing electrodes for the registration of the electroencephalogramm. Animals were daily evaluated by neurologic examination. Twenty four animals developed tumor - 10 animals died either in the immediate pos-operatory period or during evolution; 14 animals did not develop tumor. Macroscopically the tumor was well demarcated from the adjacent brain; by light microscopy the tumor exhibited malignant characteristics as well as extensive infiltration of the brain parenchyma. Diagnosis was that of a malignant astrocytoma. The use of the stereotaxic frame and care to infuse a small volume of liquid containing cells during a period of 120 seconds were the most important procedures to obtain sucess in the model. Additional care should be taken in counting cells in the Neubauer camera and in maintaining cells in constant agitation before injecting the tumor-containing solution. The model here developed was efficient besides being of low cost and of relatively easy execution.

Tumores experimentais do sistema nervoso central: padronização de modelo em roedores utilizando a linhagem 9L / Experimental tumors of the central nervous system: standardisation of a model in rats using the 9L glioma cells

Grande variedade de modelos experimentais foram estabelecidos em neuro-oncologia durante as últimas décadas, a fim de estudar a biologia tumoral e a eficiciência de novas drogas e novos tratamentos em gliomas malignos humanos. Embora estes modelos estejam bem caracterizados e sejam facilmente reproduzíveis e aplicáveis, háá limitações quanto ao seu uso e a resposta obtida, principalmente quando utilizados para monitorização de tratamentos. A proposta deste estudoé padronizar modelo de tumor cerebral glial experimental e detectar variáveis que possam influenciar o seu desenvolvimento. Células 9L foram inoculadas na substância branca do cérebro em 48 ratos machos Sprague-Dawley; destes, 25 animais receberam eletrodos corticais para realização de eletroencefalografia. Os animais eram avaliados diariamente por observação neurológica. Vinte e quatro ratos desenvolveram tumor - 10 animais morreram ou no pós-operatório imediato ou durante a evolução; 14 animais não desenvolveram tumor. Macroscopicamente, o tumor parecia bem delimitado; características de malignidade e extensa infiltração foram observadas a microscopia de luz; o diagnóstico foi o de astrocitoma maligno. A utilização de técnica estereotóxica e a infusão de pequeno volume de suspensão celular por um tempo longo de infusão foram considerados importantes para o bom desenvolvimento do tumor. Procedimentos que merecem atenção são: contagem precisa das células na camara de Neubauer, agitação constante da suspensão de células a serem inoculadas e fixação precisa da profundidade de inoculação. O modelo experimental desenvolvido no presente trabalho mostrou ser de execução relativamente fácil, com custo razoável e reprodutível

Diagnósticos alternativos em pacientes com suspeita de encefalite por Herpes simplex e negativos à reaçäo em cadeia por polimerase (PCR) / Alternative diagnoses among suspected Herpes simplex encephalitis patients with negative polymerase chain reaction (PCR)

O objetivo do presente estudo é analisar os diagnósticos encontrados em uma série de pacientes cuja suspeita clínica inicial era de encefalite herpética (HSE), mas que tiveram este diagnóstico afastado através de resultado negativo à reaçäo em cadeia por polimerase (PCR) para detecçäo do Herpes simples (HSV) em líquido cefalorraqueano (LCR). Em 43 dos 61 pacientes com suspeita de HSE estudados (70,5 por cento) o resultado à PCR foi negativo. O diagnóstico diferencial foi elucidado em 41,9 por cento dos 43 casos em que a PCR para HSV resultou negativa. Nestes, as patologias diagnosticadas foram infecçöes virais (2 casos-11,1 por cento) e näo virais (5 casos-27,2 por cento), doenças vasculares (4 casos-22,2 por cento), desmielinizantes (3 casos-16,7 por cento), distúrbios tóxico-metabólicos (3 casos-16,7 por cento) e tumor do sistema nervoso central (1 caso-5,6 por cento). A pouca especificidade do quadro clínico e a disponibilidade de tratamento eficaz e seguro para a HSE justificam a grande quantidade de casos tratados com aciclovir, mas cujo diagnóstico de encefalite pelo HSV näo foi confirmado. A utilizaçäo da PCR no LCR contribuiu para melhor avaliaçäo etiológica dos quadros de encefalite aguda aqui estudados

Susceptibilidade à hipertermia maligna em três pacientes com síndrome maligna por neurolépticos / Malignant hyperthermia susceptibility in three patients with malignant neuroleptic syndrome

A hipertermia maligna caracteriza-se por hipertermia, rigidez muscular, rabdomiólise, acidose e insuficiência de múltiplos órgaos. A hipertermia maligna anestésica decorre da exposiçao a halogenados e/ou relaxantes musculares despolarizantes. O método padrao para diagnosticar a suscetibilidade à hipertermia maligna é o teste da contratura muscular in vitro em resposta ao halotano e à cafeína. A síndrome maligna por neurolépticos caracteriza-se por hipertermia, síndrome extrapiramidal, acidose, instabilidade neurovegetativa e alteraçoes neurológicas. Descrevemos três pacientes com síndrome maligna por neurolépticos e testes de contratura muscular positivos. Esse achado demonstra que ocasionalmente o músculo de pacientes com síndrome maligna por neurolépticos pode mostrar as alteraçoes encontradas na hipertermia maligna anestésica

Magnetic resonance imaging in five patients with a tumefactive demyelinating lesion in the central nervous system

Five patients with a tumefactive lesion were clinically followed from 1992 to 1993. Four patients were female; age ranged from 32 to 57 years, the duration of symptoms varied from 3 days to 3 years. Neurological examination disclosed dementia in two patients, aphasia in three, hemiparesis in four, hemihypoesthesia in there, optical neuritis in two, tetraparesis with sensitive level and neurogenic bladder in one. MRI disclosed lesions with a hypersignal on images assessed at T2 and hyposignal at T1, and gadolinium heterogeneous enhancement; these lesions were located in the: a) temporooccipital region bilaterally and brain stem, b) frontoparietal white matter, c) basal ganglia, bilateral white matter and brain stem, d) left parietal region, e) cervical spinal cord, with enlargement, of this region. Cerebral biopsy was performed in three patients; acute and subacute demyelinating disease was diagnosed by histological examination. Two patients had an evolutive diagnosis; exclusion of other pathologies and clinical and radiological improvement after corticotherapy, pointed to an inflammatory disease.

Terapêutica intravenosa com metilprednisolona e ciclofosfamida na vasculite do sistema nervoso periférico: avaliaçäo de oito pacientes / Intravenous theraphy with methylprednisolone and cyclophosphamide in vasculitis of peripheral nervous system: evaluation of 8 patients

O comprometimento do sistema nervoso periférico é frequente nas vasculites sistêmicas e contribui decisivamente para o diagnóstico. Oito pacientes foram estudados: sete do sexo feminino e um do sexo masculino; cinco brancos, dois negros, um amarelo; média de idade de 55,9 anos; quatro com poliarterite nodosa, um com lúpus eritematoso sistêmico, um com artrite reumatóide, um com vasculite isolada do sistema nervoso periférico e um com vasculite livedóide. Todos foram submetidos a terapêutica intravenosa com pulsos mensais de metilprednisolona (1 g/dia/3dias) e ciclofosfamida (1 g/dia). Cinco pacientes melhoraram, dois permaneceram inalterados e um faleceu. A melhora neurológica objetiva ocorreu após o terceiro ou quarto pulso e nos pacientes com menor duraçao da doença.

Desproporçäo congênita de fibras: atrofia de fibras tipo I; relato de 11 casos / Congenital fibre disproportion: type I fibres atrophy; report of 11 cases

Relatam-se 11 casos de desproporçäo congênita de fibras, comprovados pelos exames clínicos e complementares, em que as retraçöes fibrotendinosas precoces foram freqüentes, o CPK mostrou-se elevado e, na biópsia muscular, a histoquímica revelou atrofia seletiva das fibras tipo I. Trata-se de distrofia congênita pouco freqüente, de progressäo lenta e evoluçäo benigna