Neuroprotection, excitotoxicity and NMDA antagonists.

PURPOSE: To analyze the main aspects of neuroprotection and excitotoxicity. DISCUSSION: This is a significant theory on the pathophysiology of cerebral ischemia; it is based on the release of excitatory aminoacid (EAA), mainly glutamate. The sequence starts with a decrease of the blood flow and ends in neuronal death. The main stages of this reaction are herein presented and discussed. An in depth study of the effects of the excessive intracellular calcium is undertaken. Neuroprotectors (NP) are a group of drugs that reduce the excitotoxicity, opposing the excessive release of EAA and its intracellular effects. Neuroprotectors represent a rational approach to stroke treatment and offer a number of potential advantages. They prevent or limit ischemia-induced damage. CONCLUSION: There are many experimental and clinical NP trials. A minimum of 800 trials are currently under study worldwide. The most important NP subgroups are: N-methyl D-aspartate (NMDA) antagonists, gamma-amino butyric acid (GABA) agonists, amino-hydroxy-methyl-isoxalone propionic acid (AMPA) antagonists, reducers of intracellular Ca++ inhibitors of nitric oxide modulation pathway free radicals scavengers, sodium channel antagonists, glutamate release inhibitor, growth factors, hypothermia and potassium channel activators.

[Comparison between HDL and LDL cholesterol as risk factors for carotid atherosclerosis]. / Comparação das frações HDL e LDL colesterol como fatores de risco para a aterosclerose carotídea.

In order to find out whether there exists a relationship between HDL and LDL serum levels and atherosclerotic plaques in the carotid artery (CA), a prospective study was carried out involving 125 patients. They were aleatorily included, of both sexes and age between 45-75 years old. HDL and LDL serum levels were measured as well CA ultrasonographic mode B investigated. It was verified that the number of patients having atherosclerotic plaques in CA was inversely proportional to the HDL levels. We came up with the same ratio when the HDL levels were compared to the number of patients having CA stenosis. These results were statistically significant (x2 = 6.57 and x2 = 9.24 respectively; critical x2 = 5.99 to alpha = 5%). A direct ratio was also found out in the relationship between the presence of atherosclerotic plaques in the CA and the LDL serum levels (greater in patients with plaques). However no relationship between LDL levels and the occurrence or not of CA stenosis in patients having plaques was demonstrated. The results were not statistically significant (x2 = 0.97 and x2 = 0.41, respectively, critical x2 = 5.99 to alpha = 5%). The obtained results seem to be at least in part in agreement with literature findings. Statistically significative results in the comparison of HDL and LDL levels with the grade of stenosis of the CA were not found out (x2 = 11.78 and x2 = 4.03, respectively; critical x2 = 12.59 to alpha = 5%).

Estudio de los niveles de CD23 soluble, IgE y eosinofilia en la respuesta inflamatoria del asma bronquial / Study of the levels of soluble CD23, I and E and eosinophile in the inflammatory reply of bronchial asthma

El CD23, descripto como una glucoproteína de 45 kDa, está relacionado con la activación de los linfocitos B y la regulación de la síntesis de IgE. Se degrada en fragmentos solubles (CD23s). Es una multicitocina involucrada en patologías con predominio de linfocitos TH2, tales como las enfermedades alérgicas, leucemia B crónica o en injerto de médula ósea. El 70 por ciento de los asmáticos presenta niveles de IgE aumentados. El eosinófilo es la célula central de la inflamación asmática. Objetivo: se evaluó la corrrelación entre niveles de CD23s, IgE sérica, eosinofilia sanguínea y esputo en asmáticos atópicos y por aspirina, frente a un grupo control de individuos normales. Pacientes: se estudiaron 27 pacientes atópicos: 14m, 13f, 10 asmáticos por AAS: 4m, 6f. Un grupo control de 10 sujetos: 5m, 5f. Nadie recibió corticoides en los dos meses previos. Se determinaron IgE total por ELISA Kabi-Pharmacia, CD23s por ELISA, Binding Site, MK112. Recuentos de eosinófilos en esputo y sangre periférica. Resultados: IgE:asmáticos atópicos: 500I252kU/l. Asmáticos por AAS: 68I27 kU/l. Controles: 51I20 kU/l<0.0005. CD23s: asmáticos atópicos: 7.65I2.25 ng/ml. Asmáticos por AAS: 3.4I0,95 ng/ml. Controles: 3.73I1.08 ng/ml; p<0.0005. Eosinófilos en esputo: asmáticos atópicos: 25I13 por ciento. Asmáticos por AAS: 23I13 por ciento. NS. Eosinofilia sanguínea: asmáticos atópicos: 685I316/mm3. Asmáticos por AAS: 555I190/mm3 NS. Control: 255I90mm3; p<0.0005. Conclusiones: nuestro estudio demuestra un incremento de la IgE y CD23s en los asmáticos atópicos. Los sensibles a aspirina no presentaron cambios significativos respecto del grupo control. La eosinofilia positiva se encontró en ambos grupos de asmáticos. Esto sugiere diferentes mecanismos inflamatorios en asma bronquial, con una vía común representada por los eosinófilos

Estudio de los niveles de CD23 soluble, IgE y eosinofilia en la respuesta inflamatoria del asma bronquial / Study of the levels of soluble CD23, I and E and eosinophile in the inflammatory reply of bronchial asthma

El CD23, descripto como una glucoproteína de 45 kDa, está relacionado con la activación de los linfocitos B y la regulación de la síntesis de IgE. Se degrada en fragmentos solubles (CD23s). Es una multicitocina involucrada en patologías con predominio de linfocitos TH2, tales como las enfermedades alérgicas, leucemia B crónica o en injerto de médula ósea. El 70 por ciento de los asmáticos presenta niveles de IgE aumentados. El eosinófilo es la célula central de la inflamación asmática. Objetivo: se evaluó la corrrelación entre niveles de CD23s, IgE sérica, eosinofilia sanguínea y esputo en asmáticos atópicos y por aspirina, frente a un grupo control de individuos normales. Pacientes: se estudiaron 27 pacientes atópicos: 14m, 13f, 10 asmáticos por AAS: 4m, 6f. Un grupo control de 10 sujetos: 5m, 5f. Nadie recibió corticoides en los dos meses previos. Se determinaron IgE total por ELISA Kabi-Pharmacia, CD23s por ELISA, Binding Site, MK112. Recuentos de eosinófilos en esputo y sangre periférica. Resultados: IgE:asmáticos atópicos: 500Ï252kU/l. Asmáticos por AAS: 68Ï27 kU/l. Controles: 51Ï20 kU/l<0.0005. CD23s: asmáticos atópicos: 7.65Ï2.25 ng/ml. Asmáticos por AAS: 3.4Ï0,95 ng/ml. Controles: 3.73Ï1.08 ng/ml; p<0.0005. Eosinófilos en esputo: asmáticos atópicos: 25Ï13 por ciento. Asmáticos por AAS: 23Ï13 por ciento. NS. Eosinofilia sanguínea: asmáticos atópicos: 685Ï316/mm3. Asmáticos por AAS: 555Ï190/mm3 NS. Control: 255Ï90mm3; p<0.0005. Conclusiones: nuestro estudio demuestra un incremento de la IgE y CD23s en los asmáticos atópicos. Los sensibles a aspirina no presentaron cambios significativos respecto del grupo control. La eosinofilia positiva se encontró en ambos grupos de asmáticos. Esto sugiere diferentes mecanismos inflamatorios en asma bronquial, con una vía común representada por los eosinófilos

[Cerebral infarction and edema: prognostico-evolutional evaluation by neurologic signs]. / Infarto cerebral e edema: avaliação prognóstico-evolutiva por sinais neurológicos.

The prospective study in question involves 92 patients with cerebral infarction (CI). The follow-up was carried out for 10 days with daily evaluation, and the patients were graded for the different indicators usually researched in such cases. The observations were analysed by comparing the individual indicator averages, taken over all the patients, with the global mean of all the observed values. The analysis shows that the result of the "consciousness" exam alone is the best clinical parameter to ascertain the evolution of the patient after CI.

Nitrate reactive structural gene mutants of Aspergillus nidulans.

Two strains characterized as niaD structural gene mutants in Aspergillus nidulans produce a nitrate reductase which retains the ability to react with nitrate while lacking the ability to oxidize its naturally occurring substrate NADPH. Fifteen such nitrate reactive niaD strains exhibited strong interallelic complementation when tested against strains bearing point mutations in eleven other loci essential to induction and synthesis of nitrate reductase in Aspergillus. Fourteen representatives of this phenotype formed enzyme with a molecular weight equivalent to that of the wild type (200 kD) and also remained inducible by nitrate and repressible by ammonium. The mutation appears to alter the NADPH binding domain of the nitrate reductase since the affinity for the dinucleotide fold in Affigel blue and the dissociation constant (Ks) for enzyme isolated from the mutants on the basis of reduced methyl viologen-nitrate reductase activity is significantly less than that observed for the native enzyme from the wild type.

[Evaluation of glycerol in the treatment of cerebral infarction]. / Avaliação do glicerol no tratamento de infarto cerebral.

A prospective study was undertaken concerning patients with cerebral ischemia for evaluation of glycerol treatment. This medication acts on edema produced by cerebral ischemia; the edema being the main factor that worsens patients with cerebral ischemia. 187 patients were studied specifically for cerebral edema. They were randomly divided into two groups: the first group of 92 patients did not receive anti-edema treatment; the second group of 95 patients was divided into sub-groups according to age and severity of neurological involvement. The use of glycerol was found to be beneficial in all groups treated.

Edema cerebral isquemico. / Ischemic cerebral edema

Saoabordados diferentes aspectos relacionados com o edema cerebral isquemico, como conceituacao, classificacao, fisiopatologica, histologia, papel dos neurotransmissores e tratamento. O edema cerebral isquemico e individualizado das outras formas de edema cerebral por suas caracteristicas proprias. Na fisiopatologia apresentam-se diferentes formas e fases da instalacao e resolucao deste tipo de edema cerebral, correlacionando-as, inclusive, com a terapeutica.A atualizacao no estudo deste evento contribui para sua efetiva identificacao e tratamento

Comportamento do potassio e do sodio no liquido cefalorraquiano, no estado vigil, no coma e no pos-morte. Registro de um caso. / The behavior of the potassium and sodium in cerebrospinal fluid in vigil state, coma and postmorten. Report of a case

E analisado o comportamento do potassio e do sodio no LCR e no sangue, num doente no estado vigil, no coma grau IV, e no posmorte, em um espaco de tempo de aproximadamente 36 horas. Os resultados mostram que o potassio estava em niveis normais no estado vigil, elevou-se no coma irreversivel e acentuou-se ainda mais apos a morte.O sodio nao se alterou significativamente.Estes achados mostram que houve quebra dos mecanismos estaveis e resistentes, responsaveis pelo controle do potassio no LCR.Este fato ocorre em lesoes cerebrais graves, com dano celular intenso. A dosagem do potassio no LCR de doentes em coma e um indice confiavel de avaliacao prognosticoevolutiva deste estado

[Prognostic value of potassium and sodium levels in cerebrospinal fluid and blood in patients with coma. Study of 55 cases]. / Valor prognóstico dos teores de potássio e sódio no líquido cefalorraquiano e no sangue de doentes em coma. Estudo de 55 casos.

This is a prospective study, with 55 patients in coma, in which wasn't chosen sex, age, intensity of coma or etiology. It was measured the concentration of the potassium and the sodium in cerebrospinal fluid, (CSF) and in the serum, to find an auxiliary way to value the prognostic. It is known that the potassium in the CSF is extremely stable, and it maintains the tax without alterations, even when the potassium in CSF is rapid and intensity raised after death. Experimental studies show the potassium raised in CSF in serious damaged brain. Our results show, in patients who recovered consciousness, normal values (means 2,61 mEq/1) of potassium in CSF. The mean of values of potassium in CSF in the group of patients who had bad evolution (they died) show index estatisticaly up of normal values (2,97 mEq/1) and this shows a serious damaged brain and/or irreversible, able to affect the stability of CSF potassium. These index are present in some kind of coma or etiology, showing that raised potassium in CSF, indicates bad prognostic, in some kind of coma. With the sodium, the results show that this ion doesn't serve to this finality, because its concentrations isn't stable in CSF, and change with the blood alterations of natremia.

Valor prognostico dos teores de potassio e sodio no liquido cefalorraquiano e no sangue de doentes em coma: estudo de 55 casos. / Prognostic value of potassium and sodium levels in cerebrospinal fluid and blood in patients with coma: study of 55 cases

Trata-se de um estudo prospectivo com 55 doentes, tomados ao acaso, independentemente da idade, sexo, grau de coma ou da sua etiologia Foi medida a concentracao do potassio e do sodio no LCR e no soro sanguineo destes doentes, visando a um criterio auxiliar de avaliacao prognostica. Os resultados mostraram que as taxas elevadas de potassio no LCR sao indicativo de mau prognostico. No texto sao abordadas os aspectos fisiopatologicos dos achados

[Prognostic-evolutive evaluation of patients in coma based on ocular reflexes]. / Avaliação prognóstico-evolutiva dos doentes em coma mediante os reflexos oculares.

The ocular reflexes (ciliospinal, photomotor, oculocephalic, vestibulo-ocular, corneal) were studied in 84 comatose patients. The scope of the investigation was the assessment of each reflex in terms of its resistance according to the degree of depth of the coma. From the statistical viewpoint it was possible to emphasize the photomotor, corneal and vestibulo-ocular as the most resistant ones. The periodic evaluation in short time intervals of these five reflexes, observing their extinction or their re-appearance, permits a better prognostic assessment in a longitudinal viewpoint of the comatose patient.