Ponencia en XX Reunión ALPA, XXX Reunión APPA-Cusco-Perú

Bios es una publicación de Performance SAC

Las ciencias biomédicas se han desarrollado principalmente en los países occidentales, por lo que no es sorpresa que haya un sesgo excesivo de representación de europeos o descendientes de europeos como sujetos de las ciencias médicas. Se calcula que alrededor del 20 % de los humanos son de origen europeo, distribuidos en Europa, por supuesto, pero también en otros continentes como América, con Estados Unidos y Canadá en el norte, o Argentina y Brasil en el sur, si se desea citar algunos ejemplos de la gran representación poblacional de este origen (1). Asimismo, se encuentran en mayoría en Oceanía, en los países más grandes que son Australia y Nueva Zelanda. Sin embargo, este 20 % de la población global está representado en cerca del 80 % de los estudios poblacionales si se tiene en cuenta el origen genético o racial (1). Es importante recalcar que, inclusive en estudios ...

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La encefalitis equina es una enfermedad viral, que afecta el sistema nervioso de caballos y otros mamíferos (incluyendo humanos)

The micronuclei test in lymphocyte culture is a validated procedure to study mutagenicity. It consists in detecting damaged interphasic nuclear material produced by chromosome fragmentation or nuclear division errors in 2000 binucleated cells with well defined cytoplasm. Standard protocol derives from blood chromosome preparation with hypotonic and fixing solutions as well as preparing slides by dropping fixed cells. We modified the protocol to improve the number and quality of micronuclei. First, lymphocytes are separated from red cells before culture. After 72 hours, hypotonic and repeated fixer washing steps are eliminated. Cells are put onto slides by spreading instead of dropping. With these modifications we obtained more (about 8 times per slide) and better defined binucleated cells to help micronuclei detection.

El test de micronúcleos en cultivo de linfocitos es una prueba validada para estudiar mutagenicidad. Consiste en detectar material nuclear interfásico dañado, producto de fragmentación cromosómica o errores de división nuclear en 2000 células binucleadas con citoplasma definido. El protocolo estándar deriva de la preparación citológica de cromosomas de sangre periférica con solución hipotónica, lavados de fijador y goteo de láminas. Nosotros proponemos modificaciones para mejorar el número y la observación de los micronúcleos. Primero se purifica linfocitos de glóbulos rojos antes del cultivo, luego de 72 horas, se elimina la solución hipotónica y los lavados repetidos con fijador, y finalmente se coloca las muestras en láminas por frotis en vez de goteo. Con las modificaciones obtenemos mas células binucleadas bien definidas (un promedio de 8 veces más por lámina...

La Revista Peruana de Biología es una publicación de la Universidad Nacional Mayor de San Marcos

We have analized the combination of variants at 4 sites of the gene MBL (mannose binding lectin) which is part of the immune system, in 19 normal individuals from the islands of Anapia-Suana in the Lake Titicaca. OnIy 3 combinations (haplotypes) were registered: LYPB, HYPA and LYPA; the proportion of the pressumed defective haplotype LYPB is 0.58 being the highest ever recorded. This haplotype is rare among European, Asian and African populations. It predisposes to infectious diseases as tuberculosis and AIDS as well as autoimmune diseases like reumatoid arthritis and lupus erithematosumo This finding lead our future efforts to elucidate the reason of this high frequency of LYPB and to determine its proportion in other islands of the Titicaca Lake.

Molecular genetics is an important tool to elucidate the cause of hereditary diseases. One of the strategies used in this type of studies, is to map the gene responsible of the disease to a specific chromosome region. This has helped in the characterization of some genes, but others remain to be identified. Primau Open Angle Glaucoma (POAG) is a hereditary disease that can lead to blindness if untreated. There are six loci for POAG: GLClA on chromosome region lq24.3-q25.2, GLClB (2cenq13), GLClC (3q21-q24), GLClD (8q23), GLClE (10p14p15) y GLClF (7q35-q36). In a study of several POAG Peruvian families we have characterized one that cosegregates with markers of chromosome 2 corresponding to a new reported family for GLCIB located at 2cen-2q13. One additional individual in the family reveals genetic recombination that refines the position to a smaller region in 2cen-q12 eliminating several...

We evaluate the use of SSCP (single strand conformational polymorphism), a relatively easy and inexpensive technique for the detection of point mutations with a sensibility around 80% under ideal conditions. To test the technique, we used samples of volunteers whose DNA had been previously characterized for the presence or absence of 5 mitochondrial RFLPs. Optimization of the tests included variations in TBE (1X and 0,5X) and of glycerol concentration (10%, 5% and no glycerol) in polyacrylamide gels. Four out of five RFLPs were detected under the conditions used and could be applied routinely without using restriction enzymes. In addition, the SSCP technique allowed detection of unknown mutations in a 394 bp nucleotide segment of the hypervariable (HVI) region of mtDNA. Differences corresponding to different haplotypes were detected, helping to distinguish groups within the same subtype....

We evaluate the use of SSCP (single strand conformational polymorphism), a relatively easy and inexpensive technique for the detection of point mutations with a sensibility around 80% under ideal conditions. To test the technique, we used samples of volunteers whose DNA had been previously characterized for the presence or absence of 5 mitochondrial RFLPs. Optimization of the tests included variations in TBE (1X and 0,5X) and of glycerol concentration (10%, 5% and no glycerol) in polyacrylamide gels. Four out of five RFLPs were detected under the conditions used and could be applied routinely without using restriction enzymes. In addition, the SSCP technique allowed detection of unknown mutations in a 394 bp nucleotide segment of the hypervariable (HVI) region of mtDNA. Differences corresponding to different haplotypes were detected, helping to distinguish groups within the same subtype....

The molecular characterization of the mutations causing hereditary diseases are important tools for diagnosis, prognosis and eventually treatment. Huntington's disease is a neurodegenerative disease producing spastic uncontrolled movements and is caused by the expansion of a trinucleotide (CAG)n within the first exon of the gene HD located at 4p16. Hemocromatosis is a liver disease causing cirrosis, diabetes and heart problems, in addition one third of patients dies of hepatocarcinoma. Almost all cases of hemocromatosis are due to mutations in the gene HFE at 6p21, being C282Y and H63D the mutations most frequently detected in Europe and USA. We are establishing the molecular diagnosis of different diseases starting with Huntington disease and hemochromatosis as the begining of a service to the Peruvian comunity.

Los tumores estromales gastrointestinales (GIST) son neoplasias mesenquimales que típicamente surgen a nivel del estómago, intestino delgado, colon, y otros sitios en la cavidad abdominal y su identificación se ha incrementado por mejoras en los criterios de detección. La mayor parte de los tumores GIST son causados por mutaciones activadoras en los genes de receptores transmembranares tirosina quinasa c-KIT y receptor alpha del factor de crecimiento derivado de plaquetas (PDGFRA). Las mutaciones causales de GIST se restringen solo a ciertas regiones del gen que corresponden a importantes zonas funcionales de c-KIT o PDGFRA. Se reporta que hasta 70% de casos de GIST se debe a mutaciones en el exón 11 del gen c-Kit que corresponde a la región yuxtamembrana del receptor. La región y el tipo de mutación determinan diferencialmente cómo se desarrolla la neoplasia, el pronóstico y s...

Genetics and Molecular Biology es una publicación de la Sociedade Brasileira de Genética

La Revista de Gastroenterología del Perú es una publicación de la Sociedad de Gastroenterología del Perú

Mannose-binding lectin (MBL) is a collagen-like serum protein that mediates activation of the complement system and is of importance for host defence. Common variant alleles situated both in the promoter and structural region of the human MBL gene (MBL2) influence the stability and the serum concentration of the protein. Epidemiological studies have suggested that genetically determined variation in MBL serum concentration influences the susceptibility to and the course of different types of infections, autoimmune, metabolic and cardiovascular diseases, but this is still a subject of debate. The fact that these genetic variations are very frequent indicates a dual role for MBL in host defence. In this survey, we summarize the current molecular understanding of human MBL genetics.

We analyzed mitochondrial DNA haplotypes from 144 samples of islanders of the Taquile and Amantani (Quechua speakers) and Los Uros and Anapia (Aymara speakers) of the Lake Titicaca, Peru. We have found the highest frequency of B1 mtDNA haplotype ever reported: 100% in Taquile (n= 57); 88,6% in Amantani (n= 35); 87,5% in Anapia (n= 24) and 75% in Los Uros (n= 28). There are other haplotypes but in low frequencies: 11,4% of C1 in Amantani; 17,9% of A2 and 7,1% of D1 in Los Uros; 4,2% of C1, C2 and D1 haplotypes in Anapia. The high frequency of the B1 haplotype indicates that Taquile, Amantaní and Anapia islands have been populated by a reduced founder group. Although the genetic affinity between islanders of Anapia and Los Uros, the proportion of some alleles in the latter suggest the persistence of the uru genetic background.

We analyzed mitochondrial DNA haplotypes from 144 samples of islanders of the Taquile and Amantani (Quechua speakers) and Los Uros and Anapia (Aymara speakers) of the Lake Titicaca, Peru. We have found the highest frequency of B1 mtDNA haplotype ever reported: 100% in Taquile (n= 57); 88,6% in Amantani (n= 35); 87,5% in Anapia (n= 24) and 75% in Los Uros (n= 28). There are other haplotypes but in low frequencies: 11,4% of C1 in Amantani; 17,9% of A2 and 7,1% of D1 in Los Uros; 4,2% of C1, C2 and D1 haplotypes in Anapia. The high frequency of the B1 haplotype indicates that Taquile, Amantaní and Anapia islands have been populated by a reduced founder group. Although the genetic affinity between islanders of Anapia and Los Uros, the proportion of some alleles in the latter suggest the persistence of the uru genetic background.