ABSTRACT INTRODUCTION Alzheimer disease is the main cause of dementia associated with aging in Cuba and the world. Development of methods for early diagnosis is vital to increasing intervention effectiveness and improving patient quality of life. Recent studies have shown associations between alterations in serum levels of antineuronal antibodies and Alzheimer disease pathology. However, the specific relationship between such antineuronal antibodies and Alzheimer pathogenesis remains unclear because of the great variety of antibodies identified and their heterogeneity among patients and nondemented controls. OBJECTIVE Assess the association between serum levels of antibodies against neuronal antigens (total brain protein, aldolase and amyloid beta protein) and cognitive performance in older Cuban adults. METHODS A cross-sectional pilot study was conducted of adults aged ≥65 years living in Havana’s Playa Municipality and Artemisa Province (southwest of Havana). A sociodemographic and risk factor questionnaire was administered, neuropsychological assessment conducted, and physical and neurological examinations performed. A relative or caregiver was also interviewed. Laboratory tests included: complete blood count, glycemia, lipid panel, and apolipoprotein E genotype. Of 143 individuals studied, 33 were cognitively normal, 52 had mild cognitive impairment, and 58, probable Alzheimer disease. Serum antibody levels were determined by ELISA and compared using covariance analysis with a significance level of 0.05. ELISA specificity, sensitivity and predictive value were assessed by analyzing their respective diagnostic performance curves. RESULTS Patients with probable Alzheimer disease performed least well on the mini mental state examination (cognitively normal 28.8, SD 1.2; mild cognitive impairment 27.4, SD 2.2; probable Alzheimer disease 12.9, SD 6.5; ANOVA p <0.001). The percentage of Apo E4 carriers was seven times greater in the group with probable Alzheimer disease than in the cognitively normal group. Among the antibodies studied, only those against amyloid beta peptide had levels significantly higher in the Alzheimer disease group than in the cognitively normal group (p = 0.007) and the group with mild cognitive impairment (p = 0.002). CONCLUSIONS Results support the presence of an autoimmune component in Alzheimer disease and suggest that serum anti–amyloid-beta could be used for its diagnosis.

A review of S-adenosylmethionine, considered as the fundamental donor of methyl groups in the organism, was made. S-adenosylhomocysteine, which is a powerful inhibitor of transmethylases depending on S-adenosylmethionine, is obtained by a transmethylation reaction. The inhibition of the reactions of transmethylation depending on SAM, is revealed by the metabolic conversion of S-adenosylhomocysteine into adenosine and L-homocysteine by a reversible reaction catalyzed by S-adenosylhomocysteine hydrolase. This enzyme is present in the liver, pancreas, and kidney. It is composed of two a and two b chains, which are joined by four disulphure bonds. It also has sulphidril residuals. The enzyme is regulated by its substrates, adenosine, L-homocysteine, in vitro purines and other metabolites. The S-adenosylhomocysteine hydrolase is irreversibly inhibited by 5-desoi-5-difluoromethyl tioadenosine and 5-deoxy-5-trifluoromethyl tioadenosine.

Se realizó una revisión de la S-adenosil metionina, considerado como el donante fundamental de grupos metilo en el organismo. Por una reacción de transmetilación es obtenida la S-adenosil homocisteína, que es un potente inhibidor de transmetilasas dependientes de S-adenosil metionina. La inhibición de las reacciones de transmetilación dependientes de esta última, es revelada por la conversión metabólica de S-adenosil homocisteína en adenosina y L-homocisteína mediante una reacción reversible, catalizada por la enzima S-adenosil homocisteína hidrolasa. Esta enzima se encuentra fundamentalmente localizada en hígado, páncreas y riñón, en el organismo. Está compuesta por 2 cadenas alfa y 2 beta, unidas por 4 puentes disulfuro y contiene residuos sulfidrilos. Se encuentra regulada por sus sustratos, adenosina y L-homocisteína, además, por purinas y otros metabolitos in vitro. La S-adenosil homocisteína hidrolasa se encuentra inhibida de forma irreversible por 5-desoí-5-difluorometil tioadenosina y 5-deoxy-5-trifluorometil tioadenosina.

A review of the neurotrophic substances as therapeutics in retinitis pigmentosa, one the most studied retinal dystrophies, was made. It is a chronic and noncommunicable disease with great clinical and genetical heterogeneity that is characterized by the progressive loss of the photoreceptors, which leads to blindness. Its treatment is one the serious problems that have not been solved yet at the world level. There have been published scientific papers on new substances that may have a neuroprotective, angiogenic, and mitogenic effect on the nervous system, specifically on the cellular elements of the retina. These neurotrophic substances suggest a therapeutic alternative on the short term in the neurodegenerative diseases of the retina with great success and recovery of the visual function of the cells that have not died by the modulation of the apoptosis process in animal models with retinitis pigmentosa. It is expected that in a future they will be used combined with other techniques of larger scope as, for example, the genic therapy.

Se hizo una revisión sobre las sustancias neurotróficas como terapéutica en la retinosis pigmentaria, una de las distrofias retinianas más estudiadas. Es una enfermedad crónica no transmisible, con gran heterogeneidad clínica y genética, la cual se caracteriza por la pérdida progresiva de los fotorreceptores, lo que conduce a la ceguera. Su tratamiento constituye uno de los graves problemas no resueltos aún a escala mundial. Recién se han publicado trabajos científicos sobre nuevas sustancias que pueden tener efecto neuroprotector, angiogénico y mitogénico, sobre el sistema nervioso, específicamente en los elementos celulares de la retina. Estas sustancias neurotróficas sugieren una alternativa terapéutica, a corto plazo, en las enfermedades neurodegenerativas de la retina, con gran éxito y recuperación de la función visual de las células que no han muerto, mediante la modulación del proceso de apoptosis en modelos animales con retinosis pigmentaria. Se espera que en un futuro se utilicen en combinación con otras técnicas de mayor alcance, como por ejemplo la terapia génica.

An assessment of the present criteria to define death and its link with organ transplant, as well as of some related bioethical aspects, was made. As the complexity of the topic makes difficult the bioethical elaboration of the problem and the definition and determination of death, it is necessary to establish a specific conception as integral as possible. According to the potential of applications that could be obtained from cellular and tissue therapy in a near future, it was deduced that the current concept of brain death as a criterion of human death for organ donation should be modified. It was considered that in the context of the present debate the adoption of one or the other position is transcendent, not only due to the importance of the topic, but to its implications as regards the design and implementation of policies or programs of great relevance in the social sphere

Se hizo una valoración de los criterios actuales para definir la muerte y su vinculación con el trasplante de órganos, así como de algunos aspectos bioéticos relacionados. De la complejidad del tema, deriva lo difícil de la elaboración bioética del problema, de la definición y determinación de la muerte, y por tanto la necesidad de fundamentar una concepción determinada con la mayor integralidad posible. Con el potencial de aplicaciones que podría aportar la terapia celular y tisular en un futuro cercano, se deduce que el concepto actual de muerte cerebral como criterio de muerte humana para la donación de órganos tendrá que ser modificado. Se consideró que en el contexto del debate actual adquiere gran trascendencia la adopción de una u otra posición, no solo debido a la importancia del tema, sino dadas sus implicaciones en relación con el diseño y la implementación de políticas y programas de gran relevancia en el plano social

A total of 100 sera from patients with autoimmune diseases and sound individuals were indistinctly studied by the methods of indirect immunofluorescence (IIF) and the immunohistochemical technique by using enzimatic conjugates with peroxidase (IP) in order to detect antinuclear antibodies (ANA). The results of the study of each sample by IIF and IP were compared taking into account their positivity or not, as well as the marking pattern presented by the positive cases. The sensitivity and specificity studies showed an elevated index of reliability. Taking into account the high concordance between the IIF and IP studies, it was concluded that the application of the IP method for the detection of ANA is feasible, and that as it is more sensitive and economic than the IFI, it is recommended as the election method

Se estudiaron indistintamente, por los métodos de la inmunofluorescencia indirecta (IFI) y la técnica de inmunohistoquímica mediante el uso de conjugados enzimáticos con peroxidasa (IP), un total de 100 sueros provenientes de pacientes con enfermedades autoinmunes y personas sanas para la detección de anticuerpos antinucleares (AAN). Los resultados del estudio de cada muestra empleando IFI e IP fueron comparados teniendo en cuenta su positividad o no, así como el patrón de marcaje que presentaron los casos positivos. Los estudios de sensibilidad y especificidad mostraron un elevado índice de confiabilidad. Teniendo en cuenta la elevada concordancia entre los resultados de IFI e IP, se pudo concluir que la aplicación del método de IP para la detección de AAN resulta factible; además, este método posee mayor sensibilidad que IFI y por resultar más económico, se propone que constituya el método de elección