Alberto Gómez

AMOXICILLIN AND CLAVULANIC ACID IN THE TREATMENT OF ACTINOMYCETOMA

Background. Mycetoma is a relatively frequent disease in tropical countries. Drugs commonly used need a long period of treatment, and some cases are resistant to these drugs, especially those with bone or visceral involvement. The combination of amoxicillin‐clavulanic acid has shown effectiveness against strains of Nocardia brasiliensis in vitro.

De Novo Disruption of the Proteasome Regulatory Subunit PSMD12 Causes a Syndromic Neurodevelopmental Disorder

Degradation of proteins by the ubiquitin-proteasome system (UPS) is an essential biological process in the development of eukaryotic organisms. Dysregulation of this mechanism leads to numerous human neurodegenerative or neurodevelopmental disorders. Through a multi-center collaboration, we identified six de novo genomic deletions and four de novo point mutations involving PSMD12, encoding the non-ATPase subunit PSMD12 (aka RPN5) of the 19S regulator of 26S proteasome complex, in unrelated individuals with intellectual disability, congenital malformations, ophthalmologic anomalies, feeding difficulties, deafness, and subtle dysmorphic facial features. We observed reduced PSMD12 levels and an accumulation of ubiquitinated proteins without any impairment of proteasome catalytic activity. Our PSMD12 loss-of-function zebrafish CRISPR/Cas9 model exhibited microcephaly, decreased convolution of the renal tubules, and abnormal craniofacial morphology. Our data support the biological importance of PSMD12 as a scaffolding subunit in proteasome function during development and neurogenesis in particular; they enable the definition of a neurodevelopmental disorder due to PSMD12 variants, expanding the phenotypic spectrum of UPS-dependent disorders.

Lymphocyte subtypes and adhesion molecules in actinic prurigo: observations with cyclosporin A

Background Actinic prurigo is a photodermatitis in which UV light is implicated by an unknown mechanism.

HLA-DPB 1 POLYMORPHISM IN SEVEN SOUTH AMERICAN INDIAN TRIBES IN COLOMBIA

HLA‐DPB 1 allele frequencies were investigated in seven geographically and linguistically distinct Amerindian tribes of Colombia. Allele *1301 was found only in the Embera tribe living along the Pacific coast, while allele *0101 was found only in two individuals of the Wayuu tribe inhabiting the Guajira desert. Significant geographical variation was observed in the other two alleles (*1401 and *0402), which were found in all seven tribal groups. The possible reasons for this restricted polymorphism and the genetic diversity found in the investigation are discussed.

A Colombian Caribbean population study of 16 Y-chromosome STR loci

Allelic frequencies and haplotypic composition of 305 male unrelated individuals from the Caribbean Colombian states of Atlántico, Bolívar, Cesar, Córdoba, Guajira, Magdalena and Sucre, were determined using 16 Y-chromosome STR loci. Two hundred and ninety three (293) haplotypes were identified, of which 283 were unique and the other 10 were found twice or thrice in the Caribbean population tested. Haplotypic diversity surpassed the values obtained in other populations, ranging from 99.66% in the population of Sucre to 99.99% in the population of Córdoba. We also calculated the overall haplotypic diversity (99.97%) and the discrimination power of these haplotypes (96.1%) in these groups. Analysis of molecular variance (AMOVA) for 10 Colombian and Spanish populations (3139 haplotypes) reveals low differentiation between the Colombian populations of mainly European descent and large distance to Afroamerican populations living in Colombia.

Differential Th1/Th2 balance in peripheral blood lymphocytes from patients suffering from flea bite-induced papular urticaria.

BACKGROUND The Th1/Th2 balance has not been characterized in patients suffering from flea bite-induced papular urticaria (FBPU). Our aim was to improve understanding of the immunopathogenesis of CD4+ and CD8+ T-cells in humans suffering from flea bite-induced papular urticaria. METHODS Peripheral blood mononuclear cells were obtained from 18 pediatric patients and 10 age-matched healthy controls. Cellular phenotypes, intracellular production of interferon gamma (IFNgamma) and interleukin-4 (IL-4) in T-cells stimulated with polyclonal stimuli was determined by flow cytometry following short-term in vitro stimulation. RESULTS The results revealed lower frequencies of IFNgamma-secreting (p = 0.02) and higher frequencies of IL-4-secreting (p = 0.03) CD4+ T-cells in patient lymphocyte cultures compared to healthy control cultures in the presence of polyclonal stimuli. This is the first description of differential cytokine patterns in papular urticaria patients. CONCLUSION Patients suffering from papular urticaria have an atopic status compared to healthy children.

HLA ANTIGENS IN AMERINDIAN GROUPS OF TWO DIFFERENT LINGUISTIC FAMILIES FROM COLOMBIA

Serological HLA types (A, B, C, DR and DQ loci) were studied in five different Indian tribes (Cubeo, Tucano, Coreguaje, Embera and Noanama) belonging to two distinct linguistic families. For all the MHC loci, the range of variation among the five tribes was enormous. Two tribes, Cubeo and Tucano, showed a wide spectrum of antigenic specificities which seemed to be due to admixture from non‐tribal groups, while in the other three tribes the polymorphisms of various HLA loci showed restricted distributions. The gene frequency data, when converted to a kinship matrix and a two‐dimensional eigenvector plot, indicated that members of the same linguistic family tend to have greater genetic affinity.

Specific pattern of flea antigen recognition by IgG subclass and IgE during the progression of papular urticaria caused by flea bite

BACKGROUND Papular urticaria caused by flea bite presents clinical symptoms of a hypersensitivity reaction accompanied by skin lesions. However, the pattern of recognition by different antibody isotypes during the progression of the disease is unknown. This study evaluated variations in immunoglobulin E and immunoglobulin G subclass antibody responses to flea antigens during the progression of papular urticaria caused by flea bite METHODS Twenty-five patients clinically diagnosed with papular urticaria due to flea bite were included. Ten healthy children were included as controls. Recognition of antigens from complete flea body extract by patients and healthy controls was determined using immunoblot assays. RESULTS The results revealed that patients with 2-5 years of papular urticaria evidenced more IgE bands than those with shorter or longer durations of symptoms. In contrast, healthy children showed a predominance of immunoglobulin G1 and immunoglobulin G3. The majority of the recognised antigens were low molecular weight proteins (<90 kDa). Proteins with molecular weights between 16-20, 21-25, and 31-35 kDa showed different patterns of recognition between patients and healthy children. CONCLUSION The predominant specific antibody isotypes vary according to the time elapsed since the onset of symptoms in papular urticaria caused by flea bite.

Análisis de ADN mitocondrial en una muestra de restos óseos arcaicos del periodo Herrera en la sabana de Bogotá

Introducción. Los restos óseos arcaicos son fuente privilegiada de información biológica y su caracterización genética permite confirmar o descartar filiaciones propuestas por otras aproximaciones científicas. La historia precolombina de los Andes orientales se divide en tres periodos principales: i) un poblamiento temprano por parte de grupos cazadores-recolectores; ii) un periodo intermedio (Herrera) de pueblos con agricultura incipiente, y iii) un periodo tardío de pueblos chibchas, agrícolas y alfareros (agroalfarero). Objetivo. Analizar el ADN mitocondrial de restos óseos del periodo Herrera. Materiales y métodos. Se analizaron 11 individuos pertenecientes al yacimiento arqueológico Madrid 2-41, con una edad aproximada de 2.000 años. Un fragmento (192 pb) del segmento hipervariable I fue amplificado y secuenciado, siguiendo criterios estrictos de autenticidad de ADN arcaico. Las secuencias se compararon con las existentes en bases de datos de Norteamérica y Europa usando herramientas bioinformáticas. Resultados. Todas las secuencias resultaron idénticas y fueron clasificadas como haplogrupo B. Esto puede relacionarse con el tipo de entierro ritual practicado en Madrid 2-41, es decir, probablemente los individuos analizados hagan parte de una familia jerárquicamente importante en la antigua sociedad Herrera. La búsqueda de secuencias homólogas en las bases de datos estadounidense y europea no arrojó coincidencias exactas, aunque existe el reporte de un individuo amazónico de ~4.000 años de antigüedad (Brasil) cuya secuencia coincide con la hallada en Madrid 2-41. Conclusión. Los individuos del yacimiento arqueológico Madrid 2-41 están estrechamente emparentados entre sí por línea materna y presentan una secuencia aparentemente ausente en poblaciones actuales.

Conservation Genetics of the Scalloped Hammerhead Shark in the Pacific Coast of Colombia

Previous investigations of the population genetics of the scalloped hammerhead sharks (Sphyrna lewini) in the Eastern Tropical Pacific have lacked information about nursery areas. Such areas are key to promoting conservation initiatives that can protect young sharks from threats such as overfishing. Here, we investigated the genetic diversity, phylogeography, and connectivity of S. lewini found in 3 areas of Colombias Pacific coast: around Malpelo Island and in 2 National Natural Parks on the Colombian Pacific mainland (Sanquianga and Ensenada de Utría). We analyzed mtDNA control region (CR) sequences and genotyped 15 microsatellite loci in 137 samples of adults and juveniles. The mtDNA analyses showed haplotypes shared between the Colombian Pacific individuals sampled in this investigation and other areas in the Eastern Tropical Pacific, the Indo-Pacific, and with sequences previously reported in Colombia (Buenaventura Port), as well as 4 unique haplotypes. Population assignment and paternity analyses detected 3 parent-offspring pairs between Malpelo and Sanquianga and 1 between Malpelo and Utría. These results indicate high genetic connectivity between Malpelo Island and the Colombian Pacific coast, suggesting that these 2 areas are nurseries for S. lewini. This is, to our knowledge, the first evidence of nursery areas identified for the scalloped hammerhead shark anywhere in the world. Additional conservation planning may be required to protect these nursery habitats of this endangered shark species.Previous investigations of the population genetics of the scalloped hammerhead sharks (Sphyrna lewini) in the Eastern Tropical Pacific have lacked information about nursery areas. Such areas are key to promoting conservation initiatives that can protect young sharks from threats such as overfishing. Here, we investigated the genetic diversity, phylogeography, and connectivity of S. lewini found in 3 areas of Colombias Pacific coast: around Malpelo Island and in 2 National Natural Parks on the Colombian Pacific mainland (Sanquianga and Ensenada de Utria). We analyzed mtDNA control region (CR) sequences and genotyped 15 microsatellite loci in 137 samples of adults and juveniles. The mtDNA analyses showed haplotypes shared between the Colombian Pacific individuals sampled in this investigation and other areas in the Eastern Tropical Pacific, the Indo-Pacific, and with sequences previously reported in Colombia (Buenaventura Port), as well as 4 unique haplotypes. Population assignment and paternity analyses detected 3 parent-offspring pairs between Malpelo and Sanquianga and 1 between Malpelo and Utria. These results indicate high genetic connectivity between Malpelo Island and the Colombian Pacific coast, suggesting that these 2 areas are nurseries for S. lewini. This is, to our knowledge, the first evidence of nursery areas identified for the scalloped hammerhead shark anywhere in the world. Additional conservation planning may be required to protect these nursery habitats of this endangered shark species.