Andrés Felipe Betancur Pérez

Bio: Andrés Felipe Betancur Pérez is an academic researcher from University of Antioquia. The author has contributed to research in topics: Broadband networks & Genetic linkage. The author has an hindex of 3, co-authored 5 publications receiving 14 citations.

Análisis de ligamiento genético de la diabetes mellitus tipo 1, a marcadores de los cromosomas 2 y 11 en familias antioqueñas

Abstract: Diabetes mellitus (DM) comprises e heterogeneous group of hypoglycemic disorders, that are grouped according to their physiopathology and etiology; the most notorious ones are type 1 DM (DM1) and type 2 DM (DM2); DM1 is characterized by early onset and absolute lack of insulin; therefore, patients suffering from it depend on insulin since the beginning of their symptoms; in contrast, DM2 manifests during adult life and not all patients depend on insulin. DM1 is classified as DM1A when it results from an autoimmune response of pancreatic b cells, and DM1B if it is of unknown origin (idiopathic). Studies on the etiology of DM1 have revealed that both types have a strong genetic component but their inheritance pattern is complex since its pathogenesis may result from the interaction with environmental factors of variants in multiple genes. By means of genetic studies on DM1, susceptibility loci known as IDDM have been identified, namely: for DM1A the first locus (IDDM1) was found in the HLA-DR/QD region, located in 6p21, that modulates the effect of other genes involved in the disease; the second one (IDDM2) is located in 11p15, the site of the insulin gene. That means, DM1 exhibits wide genetic heterogeneity so that more than 18 loci involved in susceptibility to this disease have been identified, among them, 3 on chromosome 2 (IDDM 7, 12, and 13), and 1on chromosome 14 (IDDM11), the latter being associated to DM1B. The aim of this study was the search for loci on chromosomes 2 and 11 involved in the susceptibility to DM, in three families from Antioquia, Colombia; for that purpose, parametric linkage analysis was performed to 23 microsatellite markers on chromosome 2, and to 18 on chromosome 11. In order to determine the power for making linkage analysis, simulation was carried out on the families, coded as DM1 (11 affected members), family 1 (2 affected members), and family 10 (3 affected members); results demonstrated power enough for that purpose since in DM1 the maximum odds ratio (Lod score or Z maximum) was 3.57 without recombination (=0=0), above 3, the accepted value for determining linkage; when the three families were taken together, a maximum Z of 5.76 was obtained. With the linkage analysis for chromosome 11, it was found that only in family 10 there was a positive Z value, 1.18 to marker D11S925 with =0=0, above the simulation value for this family (0.75); as regards chromosome 2, positive Z values were obtained to marker D2S319 in DM1 and family 10: 2.08 and 0.88, respectively, with =0=0. When the three families were taken as a whole and Z values were calculated for markers D11S925 and D2S319, a value of 2.5 was obtained, with =0=0, which confirms that in the analysed families 2 loci are involved, located in the regions of chromosomes 11 and 2 signaled by such markers. If it is taken into account that the D1S925 marker is located in the region 11q23-3, and the D2S319 marker, in the region 2qter, it may be said that in this work two new loci of susceptibility to DM1 have been identified in three families from Antioquia, Colombia, since these regions do not agree with those so far reported; besides, since results were negative in linkage analysis to IDDM1(data not shown), the studied cases of DM1 could be classified as DM1B.

Broadband optical wavelenght conversion for next generation optical superchannels

Abstract: We propose a broadband all optical wavelength conversion scheme based on a dual driven Mach-Zendher modulator along the entire C band Successful signal demodulation of 5 shifted 100 Gbps Nyquist QPSK channels separated by 50GHz between each other around the original optical modulated signal is reported The propose wavelength conversion schemes enables dynamic bandwidth allocation on next generation optical superchannels

Análisis de asociación entre el trastorno de personalidad antisocial y los trastornos por consumo de sustancias: Estudio de corte transversal

Abstract: INTRODUCCION : existe una asociacion entre el Trastorno de Personalidad Antisocial (TPA) y los Trastornos por Consumo de Sustancias Psicoactivas (TCSP). En la sociedad colombiana un gran numero de delitos estan relacionados directa o indirectamente con el consumo de dichas sustancias. Es posible que los individuos con TPA y TCSP tengan mayor riesgo de transgredir las leyes. MATERIALES Y METODOS : se evaluaron 182 individuos utilizando la Entrevista Diagnostica para Estudios Geneticos en Psiquiatria (Diagnostic Interview for Genetic Studies in Psychiatry) (DIGS) en la carcel Bellavista de Medellin. Fueron seleccionados de manera aleatoria y entrevistados por clinicos expertos. Se hizo diagnostico categorico de TPA y de los TCSP; ademas se evaluaron algunas caracteristicas sociodemograficas. Se realizo un analisis de regresion logistica basado en varios modelos clinicos, se calcularon OR crudos y ajustados con sus respectivos intervalos de confianza del 95%. RESULTADOS : el promedio de la poblacion es menor de 30 anos, con educacion secundaria incompleta y dos terceras partes viven en los estratos socioeconomicos mas bajos: 1 y 2. La prevalencia de TPA es de 63,2%, el TCSP mas prevalente en los internos en general es la dependencia a la marihuana con 57,7%, mientras que las prevalencias de dependencia a la marihuana y a la cocaina en los individuos con TPA son 78,3% y 63,5%, respectivamente; asi mismo, estos TCSP estan mas asociados con el TPA (OR: 12,48; IC 95%: 6,04-25,78) y (OR: 11,2; IC 95%: 6,56-24,88), respectivamente. Los OR ajustados para la asociacion entre el TPA y los TCSP son 9,08 (IC 95%: 4,08-20,17) para la dependencia a la marihuana y 5,98 (IC 95%: 2,48-14,41) en el caso de la dependencia a la cocaina. DISCUSION : es dificil establecer si el TPA lleva a los TCSP o viceversa. La asociacion entre las sustancias psicoactivas y el TPA podria estar relacionada con un efecto neurobiologico directo o por efectos de tolerancia que lleva a una busqueda imperiosa recurriendo a la actividad delincuencial. CONCLUSIONES : existe una fuerte asociacion entre el TPA y los TCSP en la poblacion carcelaria masculina de Medellin. Se necesitan otros estudios con diferentes disenos metodologicos.

Broad-Range tunable optical wavelength converter for next generation optical superchannels

Abstract: A broad-range tunable all optical wavelength conversion scheme that is based on a dual driven Mach-Zehnder modulator with an integrated microwave generator to tune the channel spacing along the entire C band, is proposed. Successful signal demodulation up to 8 wavelength conversions, in steps of 50-400 GHz of 100 Gbps Nyquist QPSK channels with configurable channel spacing is reported. The proposed wavelength conversion scheme enables flexible wavelength routing on gridless optical networks, as can be seen in the Superchannels with a BER lower than 10-13.

Secondary mania following traumatic brain injury

Abstract: OBJECTIVE: In this study patients were examined during the first year after traumatic brain injury to determine the presence of secondary mania. METHOD: A consecutive series of 66 patients with closed-head injury were evaluated in the hospital and at 3-, 6-, and 12-month follow-ups. The patients were examined with a semistructured psychiatric interview and scales for measurement of impairment in activities of daily living, intellectual function, and social functioning. Patients fulfilling the DSM-III-R criteria for mania were compared to patients with major depression and to patients without affective disturbances in regard to their background characteristics, impairment variables, and lesion locations. RESULTS: Six patients (9%) met the criteria for mania at some point during follow-up. The presence of temporal basal polar lesions was significantly associated with secondary mania even when the effect of other lesion locations was taken into account. Secondary mania was not found to be associated with the severity of brain injury, degree of physical or cognitive impairment, level of social functioning, or previous family or personal history of psychiatric disorder. The duration of mania, however, appeared to be brief, lasting approximately 2 months. CONCLUSIONS: The 9% frequency of secondary mania in these patients with traumatic brain injury is significantly greater than that seen in other brain-injured populations (e.g., patients with stroke). The major correlate was the presence of a temporal basal polar lesion. Language: en

Asociación del gen TPO en familias colombianas con la diabetes tipo 1

Abstract: We have found linkage and association of type 1 diabetes (T1D) to 2p25. The TPO gene lies within this region. Our aim was to test the association of this gene with the susceptibility to T1D in a group of Colombian families, all of them originated in Antioquia, a special population in northwestern Colombia. One hundred familial trios with type 1 diabetes (T1D) were analyzed. They had already been studied for anti-glutamic acid descarboxilase (GAD) antibodies and the marker locus D2S319. For further characterization, the probands were tested for autoantibodies against insulin, TPO and thyrosine phosphatase 2 (IA-2). Two single nucleotide polymorphisms (SNPs) (rs4927611 and rs732609) were tested in TPO. These two markers were chosen considering that the polymorphism changes the encoded amino-acid and a minor allele frequency, MAF, ≥ 0.3. SNP typing was carried out by means of the polymerase chain reaction/restriction fragment length polymorphisms (PCR-RFLP) and the tetraprimer amplification refractory mutation system (ARMS-PCR) methods. Hardy-Weinberg equilibrium (HWE) and linkage disequilibrium (LD) analyses were separately tested on both parents and probands. Genetic association was tested by the transmission disequilibrium test (TDT). It was found that 86% of the patients presented at least one of the three auto-antibodies tested. Both parents and probands were found in HWE for both SNPs. In addition, the two markers were found in tight LD (p (p = 0.0116). Autoimmunity was found in a proportion similar to that previously reported. It was found that a haplotype at TPO gene is associated with the disease. Such haplotype is characterized by alleles G and A at rs4927611 and rs732609 SNPs, respectively. Our results suggest a possible causative participation of the TPO gene in T1D. In order to verify them, a sample of equivalent size is currently being collected, from the same population in Colombia.

Chromosome region 2p25 is linked and associated with type 1 diabetes in Colombia.

Abstract: . 1998). Among genetic factors, more than20 loci have been identified in the susceptibility for T1D(Pugliese 1999; Field 2002). These include both HLA andnon-HLA loci. Of these HLA has been more strongly associ-ated with the disease. Nevertheless, several other loci, at least40 additional loci, have also been suggested to be involved inthe genetic susceptibility of T1D.Most of the studies searching for T1D loci are carriedout as association or non-parametric linkage analyses (i.e. sibpair analysis). However, there are few studies reporting theirfindings by a more Mendelian-like approach, some of whichhave statistically significant results (Smyth

Elastic networks of the future: benefits for the Colombian internal telecommunication network

Abstract: The continuous growth in data demand is leading research to bring to light an efficient network using fiber optics and radioelectric spectrum. The next generation of networks will be the result of a convergence between the optical and wireless domain with the purpose to gather all of their virtues in a vast telecommunications network more resilient and more simplified. Colombia will not be marginalized of these advances because actually has deployed optical fiber in most of the country and therefore they must be informed of current progress in terms of new generation of telecommunications networks and guide in a better way the legal guidelines of the Ministry of ICT (Information and Communications Technology) to bring great benefits to the regulation of internal telecommunications network, concerning what was decreed about the immovable of horizontal property. In this paper, research advances are reflected concerning optical fiber transmission, including the new paradigm of hybrid fiber optic networks with wireless networks that will simplify the global telecommunications network. The elastic networks of the future suggest that internal telecommunications networks will be smaller, simple, and versatile, which will facilitate competition between communication service providers, avoiding the monopoly of spaces within horizontal property buildings.