Influence of surface morphology and internal structure on the mechanical properties and tribological response of Boa Red Tail and Python Regius snake skin.

The understanding of the tribological behavior of natural structures has been used as inspiration to design and optimize surfaces for diverse applications in engineering. In the present work, morphological, microstructural, mechanical and tribological characterization of the shed skin of two snake species, namely Boa Red Tail and Python Regius was carried out. Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) analyses showed the existence of deterministic patterns, i.e., ordered arrays of geometrical features at the surface, while Transmission Electron Microscopy (TEM) allowed studying the internal structure and chemical composition of the skin sheds. Nanoindentation measurements showed significant variations in hardness and elastic modulus from the surface to the inner layers of the skin, and pin-on-disc tests revealed anisotropic behavior of the friction coefficient (COF) as a function of the sliding direction against balsa wood in dry conditions. Correlations between the friction data, nano-indentation mechanical properties and subsurface skin structure were established for both species taking into account the ways in which the skins' deterministic patterns influence the tribological performance.

PIMA: A population informative multiplex for the Americas.

We describe an ancestry-informative autosomal SNP multiplex designed to be a small-scale, flexible panel that can complement uniparental markers in assessing the American variability (i.e. pre-Colombian) found in contemporary indigenous American populations. This study centered on choosing SNPs with the specific characteristics of: 1) extreme allele frequency differences between indigenous Americans and the African, European and East Asian population groups that contribute to present-day population variation in the Americas; 2) high informativeness-for-assignment In values; and 3) well-spaced genomic distribution and chromosomal separation from existing small-scale forensic ancestry marker sets. The resulting capillary electrophoresis SNaPshot single base extension test was named: PIMA (Population Informative Multiplex for the Americas), comprising 26 autosomal SNPs, a single X-chromosome SNP plus the amelogenin sex marker adapted for SNaPshot. PIMA complements the established 34plex forensic ancestry panel to provide a powerful and simple tool for the analysis of American populations, including those with admixed histories, commonly encountered in America. Comparing the results obtained with the combined marker panels of PIMA and 34plex to SNP data from a much larger ancestry panel allowed us to gauge their relative efficiency. PIMA+34plex gives equivalent power to the 314-SNP 'LACE' genomic ancestry control panel, while requiring a much smaller genotyping effort. The ancestry profiles and genetic structure of 22 populations spread across the American continent were estimated using PIMA+34plex data, and those estimates were contrasted with information provided by uniparental markers (mtDNA and Y-chromosome loci) for a small set of admixed individuals from Venezuela. Our results indicate that an American genetic component is efficiently detected in contemporary American populations using a small set of ancestry informative SNPs, and these co-ancestry estimates are consistent with the known history and demography of the Americas. The small scale and high population differentiation power of PIMA, particularly when combined with 34plex, provides a practical and powerful tool for genetic studies of American populations as well as forensic DNA analyses.

[Ellis van Creveld. Case report]. / Ellis van Creveld: reporte de caso.

INTRODUCTION: Ellis-van Creveld (EVC) (OMIM # 225500) syndrome is a rare skeletal dysplasia disorder transmitted by autosomal recessive inheritance. The diagnosis is made based on phenotypic characteristics such as chondrodysplasia, heart defects and polydactyly. The prognosis depends mainly on the severity of the disease, diagnosis and comprehensive management of the condition. OBJECTIVE: To describe a patient diagnosed with EVC syndrome. CASE REPORT: Newborn diagnosed with EVC syndrome who presented dysmorphic facies, shortened long bones, rhizomelic shortening, small hands, brachydactyly, single transverse palmar crease, postaxial polydactyly in the upper limbs, bilateral preaxial polysyndactyly in lower limbs and hypoplastic nails, complex heart defects and narrow thorax. The evolution was unfavorable; the patient died 8 weeks after birth from complications due to heart defects. CONCLUSIONS: EVC syndrome is rare and unknown; therefore, it is important to spread its characteristics within the pediatric community, emphasizing that it affects multiple organ systems and requires a multidisciplinary approach to treat individually each patient, to provide genetic and reproductive counseling to couples and to give information regarding child development expectations.

Primer caso de síndrome de Moebius-Poland en niño expuesto prenatalmente a misoprostol / First case of Moebius-Poland syndrome in child prenatally exposed to misoprostol

No disponible

Posible caso de síndrome de Morquio en la cerámica de la cultura tumaco-tolita / Possible case of Morquio syndrome in the pottery of Tumaco-Tolita culture

No disponible

El caso de los sobrevivientes del deslizamiento de Villatina (Medellín): Estudio etnográfico, 2005 / The case of the survivors from the ground sliding in Villatina in 1987. ethnographic research, 2005

Estudio etnográfico que pretende comprender desde la percepción de individuos sobrevivientes del deslizamiento de Villatina de 1987, los procesos sociales asociados a este y las consecuencias que permanecen aún en la vida comunitaria de los barrios Villatina y Héctor Abad Gómez, de la ciudad de Medellín. La discusión giró en torno a la información recolectada en 16 entrevistas semiestructuradas, revisión de fuentes secundarias y la observación. Se encontraron consecuencias negativas y positivas originadas por el desastre, de las cuales varias continúan presentes. Entre las negativas están: pérdida de familiares y amigos manifestada en duelos no resueltos, manejo y representación del camposanto, falta de claridad con relación a las versiones del origen de la tragedia y desacuerdo con la declaratoria de la zona de alto riesgo. Por otro lado, se reconocen como ganancias sociales: procesos organizativos consolidados, nuevos liderazgos surgidos, espacios organizativos y de encuentro, la familia como apoyo social aportes del proceso de reubicación y aumento de la sensibilidad social. Para terminar, los sobrevivientes esperan: trato digno, por parte de los investigadores, que las instituciones sean correspondientes a la hora de intervenir en la comunidad y que el Estado clarifique la causa de la tragedia.

This ethnographic research tries to understand the perception of the individuals who survived after the landslide of Villatina in 1987, the social processes related to it and the outcomes that still remain in the communitarian life of the Villatina and Héctor Abad Gómez suburbs in the city of Medellín. The discussion was focused in the information gathered from 16 semi-structured interviews, the revision of secondary sources and direct observation. Positive and negative outcomes were the result of the disaster, some of which still prevail. Among the negative causes are the lost of family members and friends which is shown in unsolved grief, handling and representation of the cemetery, lack of clarity due to the versions about the real causes of the tragedy and disagreement with the nomination of the place as a high risk zone. On the other hand, some other aspects are recognized as a social gain, such as organized social processes, new leaderships, organized meeting places; the family as a social support, contributions to the relocation process and an increasing social sensitivity. Finally, the survivors look forward to deserve worthy treatment from the investigators; in the hope that institutions taking part in the community be correspondent and that the government will clarify the causes of the tragedy.

Polymorphic variants of the beta2-adrenergic receptor (ADRB2) gene and ADRB2-related propanolol-induced dyslipidemia in the Colombian population.

Different polymorphisms of the ADRB2 gene encoding the beta-adrenergic receptor (ADRB2) are associated with changes in a variety of responses of the sympathetic nervous system (SNS). In this study, we have investigated the distribution of frequencies of ADRB2-related allelic variants (Arg16Gly, Gln27Glu, Thr164Ile) in the Colombian population, as well as the influence of the Gln27Glu polymorphism as a risk factor for the development of dyslipidemia following propranolol administration. Genotyping was performed in unrelated Colombian volunteers, using PCR-RFLP methods. To examine the association between the Gln27Glu polymorphism of the ADRB2 gene and dyslipidemia induced by propranolol, we recruited 19 healthy individuals who were homozygous for either the Gln27 (wild-type, N = 11) or the Glu27 (homozygous mutant, N = 8) genotype. Electrocardiography (ECG), heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI), serum lipid levels (T-CHO, HDL-CHO, TG), and fibrinogen were determined before and after propranolol administration. The distribution of genotypes was as follows: Arg16Arg 46%, Arg16Gly 47.4%, Gly16Gly 6.6%, Gln27Gln 44.7%, Gln27Glu 48.2%, and Glu27Glu 7.1%, with allelic frequencies of 69.7% for Arg16, 30.3% for Gly16, 68.8% for Gln27, and 31.2% for Glu27. The Thr164Ile polymorphism was found only in one subject, who was heterozygous for the isoleucine variant. Significant changes in physiological parameters (HR, SBP, DBP) have been found in association with ADRB2 variants in both native and mutant subgroups after propranolol intake. HDL-CHO levels diminished (p = 0.005) in native homozygous individuals (Gln27Gln), whereas TG levels were found increased (p = 0.012) in the mutant homozygous individuals (Glu27Glu). T-CHO levels and serum fibrinogen levels remained unaltered in both subgroups. The evidence that subjects homozygous for Gln27 in the ADRB2 gene show a significant reduction of HDL-CHO levels, as well as the increased TG levels in subjects homozygous for Glu27 after propranolol administration, suggest that the Gln27Glu polymorphism represents a risk factor for dyslipidemia induced by propranolol. These results may contribute to a better understanding of the mechanisms underlying dyslipidemia induced by ADRB2 antagonists.

Allelic variants of the thiopurine methyltransferase (TPMT) gene in the Colombian population.

Thiopurine methyltransferase (TPMT) catalyzes the inactivation of thiopurine drugs (mercaptopurine, thioguanine and azathioprine) used to treat acute lymphoblastic leukemia, autoimmune diseases and recipients of transplanted organs. No endogenous substrates for this enzyme are known. The TPMT polymorphism is a major determinant of individual differences in the toxicity or therapeutic efficacy of these drugs. The molecular basis of this polymorphism has been established in Caucasians, Africans, African-Americans and Asians, but not yet in the heterogeneous Latin American groups, including the Colombian population. The frequency of the four allelic variants of the TPMT gene, TPMT*2 (G238C), TPMT*3A (G460A and A719G), TPMT*3B (G460A) and TPMT*3C (A719G), were determined in 140 Colombian volunteers of Mestizo origin, using allele-specific PCR and PCR-RFLP assays. The *3A allele was found in 10 samples and the *2 allele in one, all heterozygotes; neither homozygous mutant genotypes nor the *3B and *3C alleles were detected. In agreement with these results, 92.1% and 7.9% of the Colombian population correspond to the phenotypes high and intermediate methylators, respectively. These results show that the frequency of mutations and the allelic distribution of the TPMT gene in the Colombian population are similar to the genetic profile found among US and European Caucasian populations, where the *3A allele is prevalent and the *2 allele is currently present.

Isolation, sequence and genotyping of the drug metabolizer CYP2D6 gene in the Colombian population.

Cytochrome P450 2D6 monooxygenase metabolizes several commonly used drugs, particularly psychotropics and cardiovascular agents. The gene that encodes this isoenzyme is highly polymorphic, with 1-10% of the population carrying mutations that produce an inactive enzyme, and 1-29% of individuals who possess additional copies of functional CYP2D6 genes. The genotypic features of the CYP2D6 gene have already been studied in many ethnic groups; however, the genetic characteristics of this enzyme are unknown in the Colombian population. The allelic variants and mutations of this polymorphic isoenzyme are the main cause of interindividual and interethnic differences in the therapeutic efficacy and adverse effects at standard doses of drugs metabolized by the products of the CYP2D6 gene. In the present study we have isolated, sequenced and genotyped the CYP2D6 gene in the Colombian population. The distribution of allelic frequencies of 10 alleles associated with normal, diminished or increased CYP2D6 activity has been studied in 121 healthy volunteers. The commonest alleles detected in the Colombian people were the functional alleles *1 (38.8%) and *2 (37%). Among the seven nonfunctional alleles studied in our sample, we found frequencies of 19.4%, 1.6%, 1.2% and 0.8%, for the *4, *17, *3 and *5 alleles, respectively. The alleles *6, *7 and *8 could not be identified in any of the subjects studied. The frequency of the duplicate allele was 1.2%. In this Colombian sample, 91.7% of the individuals were normal metabolizers (EM), 6.6% were poor metabolizers (PM), and 1.7% were ultrarapid metabolizers (UM). These results show that the allelic distribution of the CYP2D6 gene in the Colombian population of mestizo-prevalent subjects is compatible with the genomic assembly of the constitutive tri-ethnic origin of this Latin American country.

Description of a project for the production and evaluation of oxygen-carrying hemosubstitutes.

Scarce availability and risk of transmission of infections and diseases (HIV, hepatitis B, Chagas' disease) limit the use and benefits of homologous blood transfusions for surgical purposes. Recent trials of perfluorocarbon-based hemosubstitutes (PFC-HSs) in experimental cardiopulmonary bypass (CPB) have demonstrated their ability to improve brain oxygenation, as compared with conventional crystalloid priming solutions. The objective of the project described here is to test different formulations of PFC-HSs and optimize their formulation and dosage for use in CPB. The project includes: (1) study the feasibility of implementing a laboratory for small scale production of PFC-HSs; (2) evaluate the efficacy of use of PFC-HSs in an animal model of CPB; and (3) evaluate the safety of use of PFC-HSs in an animal model of hemorrhagic shock. Several in-house PFC-HSs and outside PFC-HSs are being evaluated. The current state of the project is: (1) the feasibility study has been completed and several PFCs, emulsifiers and surfactants are being tested; (2) and (3) the animal models have been implemented are being used to test in-house and outside PFC-HSs as priming solutions in CPB and reinfusion fluids in hemorrhagic shock respectively. Some preliminary results are presented.

Tamizaje prenatal de enfermedades fetales genéticas y adquiridas midiendo tres marcadores en suero materno: determinación de AFP, BHcG y E3 no conjugados

La determinación de fetos anormales se ha basado tradicionalmente en la selección de pacientes por edad materna o antecedentes personales y familiares, detectando sólo un pequeño número de fetos anormales. La introducción de la medición y estandarización de tres marcadores en suero materno(Alfafetoproteína, AFP, gonadotropina coriónica, BHcG, y estrioles no conjugados, E3) ha probado ser una herramienta útil en la selección de un grupo importante(54 por ciento a 67 por ciento) de pacientes que sin tener otra indicación para diagnóstico prenatal, gestan fetos anormales y/o tienen gestaciones anormales. La dificultad de la aplicación del triple marcador estriba en : 1. La necesidad de tener curvas estandarizadas para su interpretación. 2. La interpretación cuantitativa de los valores absolutos de la prueba basados en programas de computador complejos y costosos y 3. La interpretación clínica de los resultados basada en un análisis de regresión gaussiano de triple variable, haciendo que los valores obtenidos sean de utilidad al clínico. La presente revisión proporciona las líneas de manejo, indicaciones y protocolos actuales de aplicación del tamizaje con Triple Marcador