El salto de la doble hélice. Consecuencias del Proyecto Genoma Humano en la medicina del siglo XXI (Segunda parte) / The leap of the double helix. Consequences of the Human Genome Project in medicine of the 21st century (Part II

El Proyecto Genoma Humano, iniciado en octubre de 1990, ha permitido desentrañar, 12 años después, la secuencia nucleotídica del ADN humano. Este hecho ha producido un avance singular en la medicina moderna, posibilitando a través de la detección de las variaciones nucleotídicas en la secuencia del ADN, el desarrollo de estudios genéticos, la determinación de pronósticos y guías terapéuticas con fármacos, y el desarrollo de nuevas drogas gracias al avance de la farmacogenómica. Todo esto permitiría, en un futuro cercano, la predicción de respuestas a maniobras terapéuticas en los procedimientos de anestesia, cuidados críticos y tratamiento del dolor. Este desarrollo introduce también problemas éticos, específicamente en los campos de la terapia génica y la clonación.

Local regulation of the axonal phenotype, a case of merotrophism

In this essay, we show that several anatomical features of the axon, namely, microtubular content, caliber and extension of sprouts, correlate on a local basis with the particular condition of the glial cell, i.e., the anatomy of axons is dynamic, although it is seen usually in its `normal' state. The occurrence of ribosomes and messenger RNAs in the axon suggests that axoplasmic proteins are most likely synthesized locally, at variance with the accepted notion that they are supplied by the cell body. We propose that the supporting cell (oligodendrocyte or Schwann cell) regulates the axonal phenotype by fine-tuning the ongoing axonal protein synthesis.

The Proteomics Approach to Find Biomarkers in Gastric Cancer

Gastric cancer is a very serious disease and is naturally resistant to many anticancer drugs. To reduce the mortality and improve the effectiveness of therapy, many studies have tried to find key biomarkers. Proteomic technologies are providing the tools needed to discover and identify disease-associating biomarkers. The proteomic study of gastric cancer establishes any specific events that lead to cancer, and it provides a direct way to define the true function of genes. Using two dimensional (2-D) electrophoresis of the stomach cancer tissue, we have gained about 1,500 spots in each gel, and 140 protein spots also were identified. Among the identified proteins, there were seven over-expressed proteins in stomach cancer tissue: NSP3, transgelin, prohibitin, heat shock protein (hsp) 27 and variant, protein disulfide isomerase A3, unnamed protein product and glucose regulated protein. There were also seven under-expressed proteins in stomach cancer: Apolipoprotein A-1, p20, nucleoside diphosphate isomerase A, alpha 1 antitrypsin, desmin, serum albumin and sero-transferrin.

Purificação de glicose-6-fosfato desidrogenase (G6PDH) em sistemas de duas fases aquosas utilizando PEG/citrato / Purification of glucose-6-phosphate dehydrogenase (G6PDH) by aqueous two-phase system by using PEG/citrate

Foi estudada, neste trabalho, a purificação por extração líquido-líquido da enzima glicose-6-fosfato desidrogenase (G6PDH), de Saccharomyces cerevisiae, em sistemas de duas fases aquosas, preparados com polietilenoglicol (PEG) e sal citrato. Foram avaliados, também, a estabilidade e o equilíbrio do sistema, além do efeito da concentração de citrato de sódio, concentração e massa molar do PEG na partição desta enzima, com auxílio de um planejamento experimental do tipo fatorial 2ü. Os resultados das extrações mostraram que é possível purificar a G6PDH nesse tipo de sistema, com a condução do processo em duas etapas. A primeira delas, conduzida com 17 porcento (p/p) de PEG 400 e 20 porcento (p/p) de citrato...

Utilização de surimi para a obtenção de hidrolisados protéicos com baixo teor de fenilalanina / Surimi utilization for protein hydrolysates with low phenylalanine tenor acquisition

Neste estudo foi avaliada, durante o período de um ano, a composição química de surimi comercial, produzido com espécies de peixes de baixo valor comercial, "Maria-Luiza" (Paralonchurus brasiliensis) e "Perna-de-moça" (Cynoscion virescens), encontrados na costa sudeste brasileira. Realizamos a comparação de alguns aspectos químicos deste surimi com outro produzido em escala laboratorial a partir de "Pescada-branca" (Cynoscion leiarchus), espécie de grande demanda. O surimi comercial apresentou teor lipídico inferior a 1 porcento, embora variável (0,12-0,61 porcento), obedecendo a sazonalidade de acordo com o período de desova dos peixes. O teor de proteína no surimi comercial flutou entre 9,9 porcento-18 porcento...

Adutos de DNA gerados por produtos da lipoperoxidaçäo: caracterizaçäo, detecçäo, incorporaçäo em oligonucleotídeos e implicaçöes biológicas / Adducts of DNA generated by products of the lipid peroxidation: caracterization, detection, incorporation in oligonucleotides and biological implications

Compostos carcinogênicos estruturalmente diversos ligam-se covalentemente ao DNA formando adutos que, se não reparados, provocam mutações. Inicialmente relacionados apenas a compostos exógenos, atualmente há várias evidências de que compostos gerados endogenamente poderiam modificar o DNA gerando adutos. Dentre os compostos endógenos, os produtos carbonílicos `alfaï,ßinsaturados destacam-se pois reagem como agentes alquilantes bifuncionais com as bases do DNA, formando adutos exocíclicos. O 2,4-decadienal (DDE) é um aldeído `alfaï,ß-insaturado que além de estar presente em alimentos e poluentes, é um dos mais importantes produtos da lipoperoxidação. Embora há várias indicações sobre a ação genótoxica do DDE, nenhum aduto deste composto com nucleobases havia sido caracterizado...

Proteínas y enzimas como posibles mensajeros en la comunicación química interneuronal: parte III / Proteins and enzymes as chemical messengers regulatin neuronal transmission and basal ganglia: part III

La comunicaicón química interneuronal está basada en la transmisión y decodificación de señales químicas a través de la liberación de neurotransmisores y péptidos bioactivos. Asimismo, durante más de dos décadas también se ha estudiado el papael funcional de componentes protéicos de alta masa molecular que son libradas al espacio sináptico donde ejercen acciones biológicas en las neuronas posinápticas. Estas protéinas son sintetizadas en el rER y segregadas dentro de sistemas intracelulares de transporte para su neurosecreción por mecanismo molecualres definidos. Adicionalmente esta macromoléculas también parecen tener relevancia funcional en el mantenimiento estructural de la sinápsis, mediante la interacción dual neuron-glía, además de modular eventos regulatorios en neuronas blanco durante su transporte transneuronal en sistemas de transmisión específicos

Ideal concentration of growth factors in rabbit's flexor tendon culture

Growth factors have the ability to stimulate matrix synthesis and cell proliferation in rabbit flexor tendon. Maximal stimulation effects of growth factors have a wide variation. It depends upon the different anatomic sites of the tendon segment, the kinds of growth factor, the concentration of growth factors, and the time sequence. Since proliferation was an early component of intrinsic tendon healing, we investigated the short-term dose response to four different growth factors on in vitro rabbit's tendon culture. We evaluated the effects according to the various concentrations of recombinant human insulin-like growth factor 1 (IGF), recombinant human epidermal growth factor (EGF), fibroblast growth factor (FGF), and recombinant human platelet-derived growth factor-BB (PDGF). Fetal calf serum was the most potent stimulator of cell proliferation and protein synthesis in in vitro rabbit's tendon culture. Matrix synthesis and cell proliferation were stimulated dose-dependently by IGF between the doses of 50 and 150 ng/ml. The maximum mitogenic effect of EGF was observed at the concentration of 100 ng/ml (1.3 times more than the media-only control culture). The rabbit's tendon responded significantly dose-dependently to PDGF, whereas there was no significant response to FGF.

La medicina molecular: ¿es una utopía pensar en su aplicación clínica? / The molecular medicine: is it an utopia to think in it clinical application?

In order to know better the diagnostics and the physiopathology of molecular, it's necessary to incorporate molecular biology techniques to an important group of illnesses, some of them are infectious pathologies and genetic illnesses. The knowledge of human metabolic ways or the specific enzymes that can be of molecular basis of the several man pathologies, is the molecular medicine. Actually, at least exist three lines that use the molecular biology in order to understand medical problems. These main lines are: 1. hereditary illnesses, II. viral and bacteriology diagnoses, and III. identification and the studies of paternity

Overexpression of tissue inhibitors of metalloproteinase-1 and -2 in the stroma of gastric cancer

The fundamental event of cancer invasion and metastasis is the complicated interaction of cancer cells with host cells, in which event, a number of proteases and their inhibitors are involved. Matrix metalloproteinases are the potent proteases in degrading the basement membrane and extra cellular matrix and are inhibited by specific endogeneous inhibitors, tissue inhibitors of metalloproteinases-1(TIMP-1) and TIMP-2. The expression of mRNA for TIMP-1 and -2 was investigated by Northern blot analysis in specimens taken from 27 patients with primary gastric adenocarcinoma; 25 samples from the primary site, six from the metastatic lymph nodes and two from the peritoneal fluids. The expression for TIMP-1 and -2 was compared in primary gastric cancer tissues, metastatic lymph nodes and normal gastric mucosae. TIMP-1 mRNA was overexpressed in 24 (96%) out of 25 primary cancer tissues compared with the paired normal mucosae, while TIMP-2 was in 10 (40%). In six specimens of metastatic lymph nodes, TIMP-1 and -2 were overexpressed in 6 (100%) and 4 (67%) specimens, respectively. Of two specimens prepared from the peritoneal fluids, all specimens overexpressed TIMP-1 compared with the those of primary cancer tissues, while one (50%) specimen overexpressed TIMP-2. Immunohistochemical staining was done to investigate the localization of TIMP-1 and -2, demonstrating that the immunoreactivity for TIMP-1 and -2 was clearly detected in the cytoplasm of the stromal cells. These results suggest that both TIMP-1 and -2 are overexpressed by stromal cells in most of primary and some metastatic gastric cancer tissues and that TIMP-1 and TIMP-2, produced by stromal cells, may play an important role in inhibiting the proteolytic activity of matrix metalloproteinases originated from cancer cells, in gastric cancer.

Overexpression of tissue inhibitors of metalloproteinase-1 and -2 in the stroma of gastric cancer

The fundamental event of cancer invasion and metastasis is the complicated interaction of cancer cells with host cells, in which event, a number of proteases and their inhibitors are involved. Matrix metalloproteinases are the potent proteases in degrading the basement membrane and extra cellular matrix and are inhibited by specific endogeneous inhibitors, tissue inhibitors of metalloproteinases-1(TIMP-1) and TIMP-2. The expression of mRNA for TIMP-1 and -2 was investigated by Northern blot analysis in specimens taken from 27 patients with primary gastric adenocarcinoma; 25 samples from the primary site, six from the metastatic lymph nodes and two from the peritoneal fluids. The expression for TIMP-1 and -2 was compared in primary gastric cancer tissues, metastatic lymph nodes and normal gastric mucosae. TIMP-1 mRNA was overexpressed in 24 (96%) out of 25 primary cancer tissues compared with the paired normal mucosae, while TIMP-2 was in 10 (40%). In six specimens of metastatic lymph nodes, TIMP-1 and -2 were overexpressed in 6 (100%) and 4 (67%) specimens, respectively. Of two specimens prepared from the peritoneal fluids, all specimens overexpressed TIMP-1 compared with the those of primary cancer tissues, while one (50%) specimen overexpressed TIMP-2. Immunohistochemical staining was done to investigate the localization of TIMP-1 and -2, demonstrating that the immunoreactivity for TIMP-1 and -2 was clearly detected in the cytoplasm of the stromal cells. These results suggest that both TIMP-1 and -2 are overexpressed by stromal cells in most of primary and some metastatic gastric cancer tissues and that TIMP-1 and TIMP-2, produced by stromal cells, may play an important role in inhibiting the proteolytic activity of matrix metalloproteinases originated from cancer cells, in gastric cancer.

Analise conformacional de modelos de peptidios para a proteina aderente do mexilhao, Mytilus edulis L / Conformational analyses of model peptides for the adhesive protein of the mussel, Mytilus edulis L

Efetuaram-se simulacoes de dinamica molecular a 298 K, usando o programa MOLSIM, para o tridecamero peptidico modelo da proteina aderente do mexilhao Mytilus edulis L. Os resultados estruturais sao comparados aos obtidos com o uso de tecnicas de mecanica molecular e de minimizacao de energia. O tridecamero adota estrutura de dupla volta reversa para as sequencias Lys-Pro-Ser-Tyr e Hyp-Hyp-Thr-Dopa. Na primeira volta, encontrou-se estrutura beta em mais que 50 porcento das simulacoes. Para as trajetorias remanescentes, adotou-se geralmente uma volta gama, composta de residuos de Lys-Pro-Ser. A segunda volta e uma volta beta, que e conservada atraves de simulacoes utilizando modelos e temperaturas diferentes. As duas voltas adjacentes garantem estrutura globular para o modelo da proteina, que e mantida em faixas de constantes dieletricas moleculares entre 1 e 15. Encontrou-se uma conformacao estendida como sendo uma conformacao secundaria, de energia maior em 40-90 kcal tridecamero. Identificaram-se diversas ligacoes de hidrogenio, que mantem a volta dupla estavel. A maioria dessas ligacoes de hidrogenio compreende um grupo OH, que pode explicar a porcentagem extraordinariamente alta de residuos contendo OH, especialmente Hyp e Dopa. A conformacao do modelo de proteina incorpora cadeias laterais de Lys, Dopa e Tyr, que apresentam as funcoes polares proximas umas das outras. Esse arranjo favorece uma geometria de ligacao cruzada na proteina, proposta a partir dos resultados experimentais com a placa aderente

A biochemical comparison between latex from Carica Candamarcensis and C. papaya

1. A group of plant proteinases is present mainly in the unripe fruit of the papaya tree (Carica papaya), which is a member of the genus Carica. C. candamarcensis is another species that belongs to this group. Its latex contains several proteinases displaying high proteolytic activity. 2. We used several electrophoretic techniques to compare the protein composition of the latex from the two species. Acid electrophoresis followed by staining or Western blot revelated a total of 17 proteins in C. candamarcensis and 7 proteins in C. papaya. Some of the proteins observed in C. papaya have been previously reported in the literature. 3. Electrophoresis on denaturing gels, followed by staining or Western blot revealed the presence of 14 proteins in C. candamarcensis and 6 proteins in C. papaya. Non-equilibrium isoelectrofocusing of the latex from both species showed a larger array of proteins in C. candamarcensis. The analysis of esterase and proteolytic activities on gel fractions after electrophoresis revealed the presence of distinct areas presenting enzyme activity. Some proteins detected in C. candamarcensis have different mobilities when compared with from C. papaya. 4. These results support the view that latex from C. candamarcensis contains a wider diversity of proteins compared to C. papaya, and that some of the proteins not in C. papaya present esterase and proteolytic activity

Respuesta metabólica ante la cirugía: modificaciones sistémicas (segunda de tres partes) / Metabolic response to surgery: systemic changes. (seconf o three parts)

En respuesta a la cirugía se producen cambios vasculares periféricos que aseguran una composición corporal, concentración electrolítica, volumen vascular, tonicidad y metabolismo ácido-base adecuados tanto para el trauma quirúrgico como para las características de salud o enfermedad del paciente. Estos cambios están modulados por factores neuroendocrinos hipotálamo-hipofisiarios, renales, suprarrenales y cardiacos

Respuesta metabólica ante la cirugía: modificaciones locales (primera de tres partes) / Metabolic response to surgical intervention: local changes (first of three parts)

En la respuesta inflamatoria local a la cirugía intervienen diversas substancias tales como histamina, kalikreínas, prostaglandinas, leucotrienos, complemento, interleucinas, factor de necrosis tumoral, factor derivado de plaquetas y radicales de oxígeno, que modulan la formación de edema. Migración de leucocitos y reparación tisular necesarios para existencia de condiciones microambientales satisfactorias para la nutrición, crecimiento y regeneración tisulares

Glicosilación de hemoglobinas / Glycosylated hemoglobin

En el organismo existe una gran variedad de proteínas cuyas funciones biológicas son muy diversas. Estas funciones dependen en gran parte del tipo de aminoácidos que las constituyen. Normalmente las proteínas se modifican después de su síntesis. Entre esas modificaciones está la que resulta de la unión de diversos carbohidratos con ciertos aminoácidos a través de reacciones enzimáticas y no enzimáticas. La unión de los carbohidratos a las proteínas se conoce como glicosilación y depende de la concentración de aquellos. Una proteína típica que sufre este fenómeno es la hemoglobina, que se emplea como parámetro para evaluar a largo plazo (cuatro a ocho semanas), el control metabólico de los pacientes con diabetes mellitus y se conoce como hemoglobina glicosilada