Dietary-derived vitamin B12 protects Caenorhabditis elegans from thiol-reducing agents.

BACKGROUND: One-carbon metabolism, which includes the folate and methionine cycles, involves the transfer of methyl groups which are then utilised as a part of multiple physiological processes including redox defence. During the methionine cycle, the vitamin B12-dependent enzyme methionine synthetase converts homocysteine to methionine. The enzyme S-adenosylmethionine (SAM) synthetase then uses methionine in the production of the reactive methyl carrier SAM. SAM-binding methyltransferases then utilise SAM as a cofactor to methylate proteins, small molecules, lipids, and nucleic acids. RESULTS: We describe a novel SAM methyltransferase, RIPS-1, which was the single gene identified from forward genetic screens in Caenorhabditis elegans looking for resistance to lethal concentrations of the thiol-reducing agent dithiothreitol (DTT). As well as RIPS-1 mutation, we show that in wild-type worms, DTT toxicity can be overcome by modulating vitamin B12 levels, either by using growth media and/or bacterial food that provide higher levels of vitamin B12 or by vitamin B12 supplementation. We show that active methionine synthetase is required for vitamin B12-mediated DTT resistance in wild types but is not required for resistance resulting from RIPS-1 mutation and that susceptibility to DTT is partially suppressed by methionine supplementation. A targeted RNAi modifier screen identified the mitochondrial enzyme methylmalonyl-CoA epimerase as a strong genetic enhancer of DTT resistance in a RIPS-1 mutant. We show that RIPS-1 is expressed in the intestinal and hypodermal tissues of the nematode and that treating with DTT, ß-mercaptoethanol, or hydrogen sulfide induces RIPS-1 expression. We demonstrate that RIPS-1 expression is controlled by the hypoxia-inducible factor pathway and that homologues of RIPS-1 are found in a small subset of eukaryotes and bacteria, many of which can adapt to fluctuations in environmental oxygen levels. CONCLUSIONS: This work highlights the central importance of dietary vitamin B12 in normal metabolic processes in C. elegans, defines a new role for this vitamin in countering reductive stress, and identifies RIPS-1 as a novel methyltransferase in the methionine cycle.

A report of congenital adrenal hyperplasia due to 17α-hydroxylase deficiency in two 46,XX sisters.

Congenital adrenal hyperplasia (CAH) is a group of rare orphan disorders caused by mutations in seven different enzymes that impair cortisol biosynthesis. The 17α-hydroxylase deficiency (17OHD) is one of the less common forms of CAH, corresponding to approximately 1% of the cases, with an estimated annual incidence of 1 in 50,000 newborns. Cases description - two phenotypically female Ecuadorian sisters, both with primary amenorrhea, absence of secondary sexual characteristics, and osteoporosis. High blood pressure was present in the older sister. Hypergonadotropic hypogonadism profile was observed: decreased cortisol and dehydroepiandrosterone sulfate (DHEAS), increased adrenocorticotropic hormone (ACTH) and normal levels of 17-hydroxyprogesterone, extremely high deoxycorticosterone (DOC) levels, and a tomography showed bilateral adrenal hyperplasia in both sisters. Consanguinity was evident in their ancestors. Furthermore, in the exon 7, the variant c.1216T > C, p.Trp406Arg was detected in homozygosis in the CYP17A1 gene of both sisters. We report a homozygous missense mutation in the CYP17A1 gene causing 17OHD in two sisters from Loja, Ecuador. According to the authors, this is the first time such deficiency and mutation are described in two members of the same family in Ecuador.

Effect of CYP4F2, VKORC1, and CYP2C9 in Influencing Coumarin Dose: A Single-Patient Data Meta-Analysis in More Than 15,000 Individuals.

The cytochrome P450 (CYP)4F2 gene is known to influence mean coumarin dose. The aim of the present study was to undertake a meta-analysis at the individual patients level to capture the possible effect of ethnicity, gene-gene interaction, or other drugs on the association and to verify if inclusion of CYP4F2*3 variant into dosing algorithms improves the prediction of mean coumarin dose. We asked the authors of our previous meta-analysis (30 articles) and of 38 new articles retrieved by a systematic review to send us individual patients' data. The final collection consists of 15,754 patients split into a derivation and validation cohort. The CYP4F2*3 polymorphism was consistently associated with an increase in mean coumarin dose (+9% (95% confidence interval (CI) 7-10%), with a higher effect in women, in patients taking acenocoumarol, and in white patients. The inclusion of the CYP4F2*3 in dosing algorithms slightly improved the prediction of stable coumarin dose. New pharmacogenetic equations potentially useful for clinical practice were derived.

Necesidades de formación para el desarrollo integral de la primera infancia: perspectiva desde un estudio regional / Training needs for comprehensive early childhood development: perspective from a regional study

Objetivo: Caracterizar las fortalezas y debilidades de los programas de formación de profesionales de la salud para el desarrollo de competencias en cuidado de la salud para el desarrollo integral (CSDI) de niños menores de 6 años, en 16 municipios de Cundinamarca y Boyacá (Colombia). Métodos: Estudio descriptivo mixto (cuantitativo y cualitativo) mediante entrevistas (n=126) y grupos de discusión (n=3) con profesionales en formación, entrevistas a informantes clave (n=3), revisión de contenidos de planes de estudio (n=9), encuestas a profesionales de la salud (n=111) y acompañantes (n=111) y revisión de historias clínicas (n=54) relacionadas con la atención de niños menores de 6 años. Los resultados se analizaron según cuatro dominios: Preparación para la vida, Prácticas cotidianas para el cuidado de la salud, Seguridad e integridad corporal y Educación inicial. Resultados: Se destaca la inclusión de contenidos sobre preparación para la vida y prácticas cotidianas para el cuidado de la salud, como también la orientación del currículo hacia la atención integral; así como la ausencia de contenidos sobre seguridad e integridad corporal y sobre educación inicial. Un elemento importante de la atención integral hace referencia al conocimiento de los signos de alarma por parte de las familias; pero un 40 % de estas familias no han recibido esta información por parte de profesionales de la salud. Por último, el entorno, redes de apoyo y otras vulnerabilidades son poco exploradas en los servicios de salud. Conclusiones: En programas de formación en salud se destaca la orientación hacia la atención integral. Atención integral que se puede fortalecer en el profesional de la salud en formación desde las capacidades del ser y saber.

Objective: To characterize the strengths and weaknesses of the training programs of health professionals for the development of skills in Healthcare for Integral Development (HID) in early childhood, in 16 municipalities of Cundinamarca and Boyacá (Colombia). Methods: A mixed-methods descriptive study (quantitative and qualitative), carried out through interviews (n = 126) and focus groups (n = 3) with health professionals in training, key informant interviews (n = 3), revision of curriculum content (n = 9), surveys of health professionals (n = 111) and companions (n = 111), and medical record review (n = 54), related to the care of early childhood. The results were analyzed according to four domains: preparation for life, everyday practices for health care, safety and bodily integrity and early education. Results: It is highlighted the inclusion of content on life skills and daily practices for health care, as well as the orientation of the curriculum toward comprehensive care; and the absence of contents on security and bodily integrity, and early education. An important element of comprehensive care refers to the knowledge of the warning signs on the part of families, but 40 % of these families have not received this information from health professionals. Finally, the environment, support networks and other vulnerabilities are little explored in health services. Conclusions: It is highlighted the orientation toward comprehensive care in health training programs. Comprehensive care can strengthen the health professional training from the capabilities of being and knowing.

Determinación de trihalometanos en aguas de consumo humano por microextracción en fase sólida- cromatografía de gases en Pereira, Colombia / Determination of trihalomethanes in drinking water by solid phase microextraction- gas chromatography in Pereira, Colombia / Determinação de trihalometanos na água para consumo humano por microextração em fase sólida -cromatografia em fase gasosa em Pereira, Colômbia

La desinfección del agua con cloro genera subproductos como los trihalometanos (THM´s), a los cuales se les atribuyen propiedades cancerígenas y con efecto adverso en el sistema reproductivo. Se estandarizó un método simple, rápido y libre de solventes fue para la determinación de THM´s en aguas para consumo humano utilizando microextracción en fase sólida con espacio de cabeza combinada con cromatografía de gases con detector de microcaptura de electrones (HS-SPME-GC-µECD). Fueron estudiados y optimizados parámetros experimentales. Las condiciones optimizadas fueron: 20 min de extracción a 37 °C en presencia de 25% de NaCl y con una agitación de 200 rpm; con tiempo de desorción de 4 min a 250 °C. Se determinaron los límites de detección y cuantificación del método y se realizó el análisis de los trihalometanos de 75 muestras de agua de la planta de tratamiento de Aguas y Aguas de la ciudad de Pereira. El rango lineal de 5-100 mg/L fue establecido con una desviación estándar relativa (%RSD) en el rango 6,1-10,1 %. Los límites de detección estuvieron en el rango 3,8-7,8 mg/L. El promedio de la concentración de THM´s fue de 55,5 mg/L.

Water disinfection with chlorine generates byproducts such as trihalomethanes (THM's), to which cancer risk and a potential adverse effect on the reproductive system properties are attributed. The maximum permitted level of THM's in the United States is 80-100 µg/L, while in Colombia it is 200 µg/L. In this study a simple, fast and solvent-free method was developed for the determination of THM's in drinking water using solid phase microextraction in combination with head space gas chromatography microcapture electron detector (HS-SPME-GC-µECD) and used for quantification of THM's in drinking water. Experimental parameters such as extraction time, extraction temperature, desorption temperature, magnetic stirring, and addition of salt were studied. Limits of detection and quantification were determined and the analysis of THM´s in 75 samples of water from the treatment plant of Pereira city were performed. Optimized conditions were 20 min extraction at 37 °C in the presence of 25% NaCl and with stirring at 200 rpm; with a desorption time of 4 min at 250 °C. Linear range of 5-100 µg/L was established with a relative standard deviation (% RSD) in the range 6.1-10.1%. Detection limits ranged from 3.8 to 7.8 µg/L. Average concentration of THMs was 55.5 µg/L which was within International and National requirements.

A desinfecção da água com cloro gera subprodutos como trihalometanos (THM´s), aos quais são atribuídos o risco de câncer e efeitos adversos sobre o sistema reprodutivo. Foi estandardizado um método simples, rápido e livre de solventes para a determinação de THM´s nas águas para consumo humano usando microextração em fase sólida com espaço de cabeça em combinação de cromatografia gasosa com microcaptura de eletrões (HS-SPME-GC-µECD). Foram estudados e otimizados os parâmetros experimentais. As condições optimizadas foram de 20 minutos de extração, a 37 °C na presença de 25% de NaCl, com agitação de 200 rpm e com tempo de dessorção de 4 min a 250 °C. Os limites de detecção e quantificação do método foram determinados e foi realizada a análise de trihalometanos em 75 amostras de água da estação de tratamento da cidade de Pereira. A gama linear de 5-100 mg/L foi estabelecida com um desvio-padrão relativo (%RSD) na gama de 6,1-10,1%. Os limites de detecção foram de 3,8 a 7,8, mg/L. A média de concentração de THM´s foi de 55,5 mg/L.

Evaluación del programa de mantenimiento con metadona del Hospital Mental de Risaralda / Evaluation of the Methadone Maintenance Program of the Risaralda Mental Hospital

Introducción: La atención psicosocial y el tratamiento de mantenimiento con metadona (TMM) son las estrategias preferidas para el manejo de adictos a heroína, pero los resultados siguen siendo insatisfactorios, lo que justifica la búsqueda e intervención sobre los factores que influyen en la respuesta al tratamiento. Métodos: Con el propósito de determinar la contribución de una serie de variables demográficas, clínicas y genéticas en las concentraciones séricas y la respuesta a la metadona, estudiamos a pacientes del TMM que estuvieran recibiendo metadona con supervisión y sin cambios en las dosis por lo menos durante las últimas 2 semanas. Se les registró edad, sexo, índice de masa corporal (IMC), tiempo de abuso de heroína, adicción a otras drogas, antecedentes delictivos, dosis diaria actual de metadona, tiempo de permanencia en el TMM, comorbilidad y comedicación. Se les tomaron muestras de sangre para determinar concentraciones séricas de metadona racémica y sus enantiómeros R-y S-, y para la tipificación de alelos candidatos de los genes POR, CYP2B6, ABCB1, GRIN1, OPRM1, SLC6A3, DßH y ARRB2, todos ellos asociados con el metabolismo, la distribución tisular y el mecanismo de acción de la metadona. La cuantificación de metadona se hizo mediante HPLC-DAD y la detección de los marcadores genéticos por los métodos de PCR en tiempo real y VNTR. Resultados: Se incluyó a 80 personas de 23,5 ± 5a ˜nos (el 86% varones), todos policonsumidores de sustancias adictivas, el 60% con antecedentes delictivos, con 5,1 ± 2,9 años de consumo de heroína y 5,3 ± 4 meses de ingreso al TMM, con 41 ± 12 mg/día de meta-dona tomada con supervisión. Las concentraciones valle de RS-, R-y S-metadona fueron, respectivamente, 168 ± 77, 84 ± 40 y 84 ± 42 ng/ml. Todos los genotipos estuvieron en equilibrio de Hardy-Weinberg. Las dos pruebas de orina fueron negativas para heroína en el 61,3% (49/80) de los voluntarios; el descenso en el consumo de cocaína/basuco fue del 83%; el de marihuana, del 30% y el de otros psicoactivos (inhalantes, benzodiacepinas, anfetaminas) bajó a cero, mientras el consumo de tabaco permaneció en el 93,5% (75/80). Las concentraciones de metadona racémica y sus enantiómeros se correlacionaron significativamente con las dosis diaria del fármaco, pero ninguna de las demás variables demográficas, clínicas o genéticas incidió en la concentración sérica de metadona. En cuanto a los resultados del TMM, los no consumidores y los consumidores ocasionales de heroína, así como los que abandonaron el consumo de otros psicoactivos y los que no, tuvieron características similares con respecto a las variables demográficas, genéticas y clínicas, incluidas las concentraciones sanguíneas de metadona, con excepción de los individuos que no disminuyeron el consumo de otros psicoactivos distintos de heroína, quienes tuvieron significativamente (p = 0,03) mayores concentraciones sanguíneas de S-metadona que quienes sí abandonaron el consumo. Conclusiones: Hubo importante reducción en los consumos de heroína y otros psicoactivos y reinserción social de los pacientes; sin embargo, la amplia superposición entre las dosis efectivas e inefectivas de metadona apunta a la presencia de variables personales y sociales que trascienden el simple manejo farmacológico y probablemente deban ser abordadas con más éxito desde lo psicosocial, particularmente en lo que tiene que ver con la identificación y superación de las experiencias detonantes de recaídas y con ciertos rasgos del paciente, tales como su nivel de estrés psicológico o sus trastornos psiquiátricos.

Background: Psychosocial care and methadone maintenance treatment (MMT) are the preferred strategies for the management of heroin addicts, but the results are still unsa-tisfactory, justifying the search and intervention of the factors influencing the response to treatment. Methodology: In order to determine the contribution of demographic, clinical and genetic variables on serum concentrations and response to methadone, we investigated patients on MMT, who were receiving methadone in supervised and unchanged doses at least during the previous two weeks. The age, gender, body mass index (BMI), duration of heroin abuse, addiction to other drugs, criminal background, current daily methadone doses, time spent in the TMM, comorbidity and concomitant medication were recorded. Blood samples were taken for the determination of serum levels of racemic methadone and its R and S-enantiomers, and for typing of candidate alleles of POR, CYP2B6, ABCB1, GRIN1, OPRM1, SLC6A3, DßH and ARRB2 genes, all associated with the metabolism, tissue distribution and mechanism of action of methadone. Methadone quantification was by HPLC-DAD, and the detection of genetic markers by Real Time PCR and VNTR methods. Results: A total of 80 subject volunteers were enrolled, with a mean age of 23.5 (5) years (86% male), all of them were addicts of multiple drugs, 60% with a criminal background, 5.1 (2.9) years taking heroin, and 5.3 (4) months on MMT, and taking a supervised dose of 41 (12) mg/day methadone. The (R), (S) and (R, S) methadone enantiomer trough plasma levels were, 84 (40), 84 (42), and 168 (77) ng/mL, respectively. All genotypes were in Hardy-Weinberg equilibrium. The two urine tests were negative for heroin in 61.3% (49/80) of the volunteers, the decline in cocaine/crack use was 83%, 30% of marijuana, and other psychoactives (inhalants, benzodiazepines, amphetamines) decreased to zero, while the consumption of snuff remained at 93.5% (75/80). Blood concentrations of racemic methadone and its enantiomers were significantly associated with the dose/day of the medication, but none of the other demographic, clinical or genetic variables impacted on serum levels of methadone. As for the results of the MMT, non-users and occasional users of heroin, as well as those who stopped taking other psychoactive drugs, and the ones who did not, were similar as regards the demographic, genetic and clinical variables. This included the blood metahdone concentrations, except for individuals who did not reduce their consumption of other psychoactives other than heroin, who had significantly (P = .03) higher blood levels of S-methadone, compared with those who did stop taking them. Conclusions: There was a significant reduction in the consumption of heroin and other psychoactives, and social rehabilitation of patients. However, the extensive overlap between effective and ineffective doses of methadone suggests the presence of personal and social variables that transcend the simple pharmacological management. These probably need to be addressed more successfully from the psychosocial features, particularly as regards to identifying and overcoming relapse-trigger experiences, as well as certain features of the patient, such as their psychological distress level or their psychiatric disorders.

[Evaluation of the Methadone Maintenance Program of the Risaralda Mental Hospital]. / Evaluación del programa de mantenimiento con metadona del Hospital Mental de Risaralda.

BACKGROUND: Psychosocial care and methadone maintenance treatment (MMT) are the preferred strategies for the management of heroin addicts, but the results are still unsatisfactory, justifying the search and intervention of the factors influencing the response to treatment. METHODOLOGY: In order to determine the contribution of demographic, clinical and genetic variables on serum concentrations and response to methadone, we investigated patients on MMT, who were receiving methadone in supervised and unchanged doses at least during the previous two weeks. The age, gender, body mass index (BMI), duration of heroin abuse, addiction to other drugs, criminal background, current daily methadone doses, time spent in the TMM, comorbidity and concomitant medication were recorded. Blood samples were taken for the determination of serum levels of racemic methadone and its R and S-enantiomers, and for typing of candidate alleles of POR, CYP2B6, ABCB1, GRIN1, OPRM1, SLC6A3, DßH and ARRB2 genes, all associated with the metabolism, tissue distribution and mechanism of action of methadone. Methadone quantification was by HPLC-DAD, and the detection of genetic markers by Real Time PCR and VNTR methods. RESULTS: A total of 80 subject volunteers were enrolled, with a mean age of 23.5 (5) years (86% male), all of them were addicts of multiple drugs, 60% with a criminal background, 5.1 (2.9) years taking heroin, and 5.3 (4) months on MMT, and taking a supervised dose of 41 (12) mg/day methadone. The (R), (S) and (R, S) methadone enantiomer trough plasma levels were, 84 (40), 84 (42), and 168 (77) ng/mL, respectively. All genotypes were in Hardy-Weinberg equilibrium. The two urine tests were negative for heroin in 61.3% (49/80) of the volunteers, the decline in cocaine/crack use was 83%, 30% of marijuana, and other psychoactives (inhalants, benzodiazepines, amphetamines) decreased to zero, while the consumption of snuff remained at 93.5% (75/80). Blood concentrations of racemic methadone and its enantiomers were significantly associated with the dose/day of the medication, but none of the other demographic, clinical or genetic variables impacted on serum levels of methadone. As for the results of the MMT, non-users and occasional users of heroin, as well as those who stopped taking other psychoactive drugs, and the ones who did not, were similar as regards the demographic, genetic and clinical variables. This included the blood metahdone concentrations, except for individuals who did not reduce their consumption of other psychoactives other than heroin, who had significantly (P=.03) higher blood levels of S-methadone, compared with those who did stop taking them. CONCLUSIONS: There was a significant reduction in the consumption of heroin and other psychoactives, and social rehabilitation of patients. However, the extensive overlap between effective and ineffective doses of methadone suggests the presence of personal and social variables that transcend the simple pharmacological management. These probably need to be addressed more successfully from the psychosocial features, particularly as regards to identifying and overcoming relapse-trigger experiences, as well as certain features of the patient, such as their psychological distress level or their psychiatric disorders.

Genetic variants associated with addictive behavior in Colombianaddicted and non-addicted to heroin or cocaine / Variantes genéticas asociadas con conducta adictiva en colombianos adictos y no adictos a heroína o cocaína

Objective:Determine the prevalence and compare somegenetic markers involved in addictive behavior in a groupof addicts to derivative of coca (cocaine/crack) or heroinand a control group of non-addicted people matched forgender, age and ethnicity.Methods:A 120 addicts and 120 non-addicts Colombianmale were surveyed and genotyped for 18 polymorphismof the OPRM1, DRD2, DRD4, SLC6A3, SLC6A4, ABCB1,DβH and CYP2B6 genes. For the identification of allelesmarkers were used mini-sequencing and fragment multi-plex PCR techniques; ethnicity of cases and controls wasanalyzed with 61 AIMs.Results:The age of onset use of heroin or coca derivati-ves (cocaine/crack) was 16,5±6 years and 99,2 percent of themconsume several illicit drugs. It showed that controlsand addicts belong to the same ethnic group. Significantdifferences between addicts and controls in relation toschooling, marital status, social security family historyof substance abuse (p<0,001), Int8-VNTR SLC6A3 gene(p=0,015) and SNP 3435C>T ABCB1 gene (p=0,001) werefound.Conclusion:The present results indicate that the VNTR-6R polymorphism of the gene SLC6A3 and the genoty-pe 3435CC in the ABCB1 gene, are both associated withaddictive behavior to heroin or cocaine.

Genetic variants associated with addictive behavior in Colombian addicted and non-addicted to heroin or cocaine.

OBJECTIVE: Determine the prevalence and compare some genetic markers involved in addictive behavior in a group of addicts to derivative of coca (cocaine/crack) or heroin and a control group of non-addicted people matched for gender, age and ethnicity. METHODS: A 120 addicts and 120 non-addicts Colombian male were surveyed and genotyped for 18 polymorphism of the OPRM1, DRD2, DRD4, SLC6A3, SLC6A4, ABCB1, DßH and CYP2B6 genes. For the identification of alleles markers were used mini-sequencing and fragment multiplex PCR techniques; ethnicity of cases and controls was analyzed with 61 AIMs. RESULTS: The age of onset use of heroin or coca derivatives (cocaine/crack) was 16.5±6 years and 99.2% of them consume several illicit drugs. It showed that controls and addicts belong to the same ethnic group. Significant differences between addicts and controls in relation to schooling, marital status, social security family history of substance abuse (p <0.001), Int8-VNTR SLC6A3 gene (p= 0.015) and SNP 3435C>T ABCB1 gene (p= 0.001) were found. CONCLUSION: The present results indicate that the VNTR- 6R polymorphism of the gene SLC6A3 and the genotype 3435CC in the ABCB1 gene, are both associated with addictive behavior to heroin or cocaine.

OBJETIVO: Determinar la prevalencia y comparar marcadores genéticos involucrados en conducta adictiva en un grupo de adictos a cocaína/crack o heroína y en un grupo control de no adictos apareados por g énero, edad y etnicidad. METODOLOGÍA: 120 varones adictos y 120 no adictos fueron encuestados y genotipificados para 18 alelos de los genes OPRM1, DßH, DRD2, DRD4, SLC6A3, SLC6A4, ABCB1 y CYP2B6. Para la identificación de los diferentes alelos se utilizaron las técnicas de minisecuenciaci ón y multiplex PCR. La etnicidad de casos y controles fue analizada con 61 marcadores ancestro-informativos. RESULTADOS: La edad de inicio en el consumo de heroína o derivados de la coca fue de 16.5±6 años y el 99.2% de ellos eran policonsumidores. Los controles y los adictos pertenecen al mismo grupo étnico. Diferencias significativas entre adictos y controles fueron encontradas en relación con escolaridad (p <0.001), estado civil (p <0.001), seguridad social (p <0.001) e historia familiar de drogadicción (p <0.001), genotipo int8-VNTR del gen SLC6A3 (p= 0.015) y al SNP 3435C>T (rs1045642) del gen ABCB1 (p= 0.001). CONCLUSIÓN: Los resultados indican que el polimorfismo VNTR-6R del gen SLC6A3 y el genotipo 3435CC en el gen ABCB1, están asociados con conducta adictiva a heroína o cocaína.

Losartan hydroxylation phenotype in an Ecuadorian population: influence of CYP2C9 genetic polymorphism, habits and gender.

AIM: To describe for the first time CYP2C9 hydroxylation phenotype with CYP2C9 genotypes in a Hispanic (Ecuadorian) population using losartan; and the relevance of gender, tobacco, ethanol and caffeine consumption on the enzyme hydroxylation capacity. METHODS: Ecuadorian healthy volunteers (n = 194) received a single oral dose of 25 mg losartan. Losartan metabolic ratio was defined as losartan:E3174 concentration. CYP2C9 alleles *2, *3, *4, *5 and *6 were analyzed. RESULTS: No phenotypically poor metabolizers were found. The metabolic ratio (mean ± standard deviation) was higher (p < 0.05) in CYP2C9*1/*3 carriers (12.4 ± 13.8; n = 6) versus CYP2C9*1/*1 (4.9 ± 7.0; n = 167), as well as in females versus males (6.72 ± 9.72 and 3.76 ± 4.48, respectively; p < 0.05). Only the following genotypes, CYP2C9*1/*1, CYP2C9*1/*2 and CYP2C9*1/*3, were found with a frequency of 86.1%, 10.8% and 3.1%, respectively. CONCLUSION: Despite the mean metabolic ratio being higher in this population than in others previously studied across genotypes, no poor metabolizers, either phenotypically or genotypically, were found.

ß(2) -adrenoreceptor polymorphisms in asthmatic and non-asthmatic schoolchildren from Colombia and their relationship to treatment response.

Asthma is a chronic and recurrent disease. Its high prevalence around the world is the result of a complex interaction between genetic and environmental factors. The genetic aspects of susceptibility, severity, and response to treatment in asthma are of great scientific interest. The purpose of the study was to establish the relationship between the Gln27Glu and Arg16Gly alleles of the ß(2) -adrenergic receptor (ADRB2) gene with respect to the susceptibility to and severity of asthma, as well as the response to treatment in mestizo schoolchildren. 109 schoolchildren with asthma diagnosis and 137 asymptomatic controls were genotyped for the Arg16Gly and Gln27Glu alleles of the ADRB2 gene by minisequencing. Allele, genotype, and haplotype frequencies of the ADRB2 gene between asthmatic and non-asthmatic as well as demographic, clinical, and spirometric variables among asthmatic patients according to their genotype were compared. ADRB2 gene expression was determined by real-time quantitative PCR. No statistical differences were found in allele, genotype, and haplotype frequencies of the ADRB2 gene between cases and controls. We did not find differences between asthmatic patients classified according to their ADRB2 genotypes and haplotypes when evaluating demographic, clinical, and spirometric variables. The ADRB2 genotype and haplotype are not associated with spirometric responses or ADRB2 gene expression after administration of a ß-(2) agonist plus a glucocorticoid. These results suggest that in the group of mestizo schoolchildren studied, the Arg16Gly and Gln27Glu polymorphisms are not markers of susceptibility or severity of asthma and do not affect ADRB2 gene expression during the rescue therapy.

Factores genéticos y ambientales asociados con la respuestaa warfarina en pacientes colombianos / Genetic and bioenvironmental factors associated with warfarin response in Colombian patients

Introducción. La warfarina es un anticoagulante de difícil manejo por su estrecho margen terapéutico y los numerosos factores que influyen en la respuesta. Objetivo. Determinar la contribución de variables demográficas, clínicas y genéticas sobre las dosis de mantenimiento de warfarina en pacientes colombianos. Materiales y métodos. Se incluyeron 145 adultos de ambos sexos, en anticoagulación estable con International Normalized Ratio (INR) entre 2 y 3, al menos, durante dos meses, sin cambio en las dosis de warfarina ni en el preparado comercial. Previa firma del consentimiento informado de cada voluntario, se registró su edad, sexo, peso, talla, tabaquismo, enfermedades concomitantes, medicación simultánea, INR, dosis de warfarina, su indicación y nombre comercial. Cada paciente se tipificó para los genes CYP2C9, VKORC1, CYP4F2 y PROC, y en 59 de ellos, se cuantificaron las concentraciones séricas de warfarina. La genotipificación y la cuantificación sanguínea se hicieron mediante minisecuenciación y HPLC, respectivamente. Resultados. Los factores de edad, medicación simultánea con inhibidores (amiodarona, sertralina, fluoxetina) o inductores enzimáticos (fenitoína, carbamacepina), los alelos rs1799853 (*2) y rs1057910 (*3) del gen CYP2C9, así como rs9923231 del gen VKORC1, se asociaron con las dosis de warfarina requeridas para conseguir anticoagulación con INR de 2 a 3.Dichas variables se incluyeron en un modelo de regresión lineal múltiple que permitiera predecir la dosis semanal de warfarina, y se obtuvo un algoritmo que explica el 47,4% de la variabilidad en las dosis. Conclusión. La consideración de las variables clínicas y las farmacogenéticas puede mejorar la relación entre seguridad y eficacia de la warfarina, aunque la adopción de un algoritmo de dosificación farmacogenético requiere información obtenida con ensayos clínicos.

Introduction. Warfarin is an anticoagulant that is difficult to administer because of its narrow therapeutic margin and the numerous factors that influence patient response.Objective. Demographic, clinical and genetic variables were characterized to establish the appropriate maintenance dosages of warfarin. Materials and methods. The Colombian patients consisted of 145 adults of both sexes. They were in stable anticoagulation status with international normalized ratio between 2 and 3 for at least two months, and without changes in the warfarin commercial preparation or in the dosage. After signing the informed consent, the following data was recorded for each volunteer: age, gender, weight, height, smoker status, co-morbidity, co-medication, International Normalized Ratio (INR), warfarin dose, and commercial brand. Each patient was typed for genes CYP2C9, VKORC1, CYP4F2 and PROC; for 59 patients, the serum levels of warfarin were quantified. The genotyping and the blood quantification were performed by mini-sequencing and HPLC methods, respectively. Results. Age, co-medication with enzymatic inhibitors (amiodarone, sertraline, fluoxetine) or inducers (phenytoin, carbamazepine), and the alleles rs1799853 (*2) and rs1057910 (*3) of the CYP2C9 gene, as well as rs9923231 of the VKORC1 gene were associated with warfarin dose required to achieve anticoagulation with INR of 2-3. These variables were included in a multiple linear regression model for predicting the optimum dose/week of warfarin. This resulted in an algorithm that explained 47.4% of the variability in the dose responses. Conclusion: Clinical and pharmacogenetic variables provided a basis for improving the safety and effective dosage of warfarin; however, the use of a pharmacogenetic algorithm will require patient data obtained during clinical trials.

Resistencia y sensibilidad a Warfarina / Resistance and sensibility to Warfarina

La warfarina, el anticoagulante oral de mayor prescripci¨®n en el mundo, es unf¨¢rmaco dif¨ªcil de manejar por su estrecho margen terap¨¦utico, amplia gama de interacciones y gran variabilidad inter-individual en la respuesta. De una cohorte de 145 pacientes en anticoagulaci¨®n cr¨®nica con warfarina reportamos una serie de casos de sensibilidad (dosis ¡Ü 15 mg/semana) y de resistencia (dosis ¡Ý 70 mg/semana) al f¨¢rmaco y, tras una breve revisi¨®n de sus aspectos farmacol¨®gicos relevantes, discutimos los posibles factores causantes de estas respuestas exageradas al medicamento.

[Genetic and bioenvironmental factors associated with warfarin response in Colombian patients]. / Factores genéticos y ambientales asociados con la respuesta a warfarina en pacientes colombianos.

INTRODUCTION: Warfarin is an anticoagulant that is difficult to administer because of its narrow therapeutic margin and the numerous factors that influence patient response. OBJECTIVE: Demographic, clinical and genetic variables were characterized to establish the appropriate maintenance dosages of warfarin. MATERIALS AND METHODS: The Colombian patients consisted of 145 adults of both sexes. They were in stable anticoagulation status with international normalized ratio between 2 and 3 for at least two months, and without changes in the warfarin commercial preparation or in the dosage. After signing the informed consent, the following data was recorded for each volunteer: age, gender, weight, height, smoker status, co-morbidity, co-medication, International Normalized Ratio (INR), warfarin dose, and commercial brand. Each patient was typed for genes CYP2C9, VKORC1, CYP4F2 and PROC; for 59 patients, the serum levels of warfarin were quantified. The genotyping and the blood quantification were performed by mini-sequencing and HPLC methods, respectively. RESULTS: Age, co-medication with enzymatic inhibitors (amiodarone, sertraline, fluoxetine) or inducers (phenytoin, carbamazepine), and the alleles rs1799853 (*2) and rs1057910 (*3) of the CYP2C9 gene, as well as rs9923231 of the VKORC1 gene were associated with warfarin dose required to achieve anticoagulation with INR of 2-3. These variables were included in a multiple linear regression model for predicting the optimum dose/week of warfarin. This resulted in an algorithm that explained 47.4% of the variability in the dose responses. CONCLUSION: Clinical and pharmacogenetic variables provided a basis for improving the safety and effective dosage of warfarin; however, the use of a pharmacogenetic algorithm will require patient data obtained during clinical trials.

[Antimicrobial susceptibility of Helicobacter pylori strains isolated in Colombia]. / Resistencia a metronidazol y claritromicina en aislamientos de Helicobacter pylori de pacientes dispépticos en Colombia.

BACKGROUND: Helicobacter pylori antimicrobial resistance rates differ among countries and even between different areas of a country. In Colombia, the most commonly used antimicrobials for the treatment of H pylori infection are amoxicillin, clarithromycin and metronidazole. AIM: To determine antimicrobial susceptibility of H pylori strains isolated in Colombia. MATERIALS AND METHODS: Eighty eight strains of H pylori were isolated and identified by microbiological methods and confirmed with polymerase chain reaction (PCR). The detection of antimicrobial resistance to amoxicillin, clarithromycin, metronidazole and tetraclycline, was conducted by the Etest method. Mutations in the 23S rDNA, involved in resistance to clarithromycin, were detected using PCR and restriction fragment length polymorphism. RESULTS: Eighty eight and 2.2% of the strains were resistant to metronidazole and clarithromycin, respectively. No isolate was simultaneously resistant to amoxicillin or tetracycline. The two clarithromycin resistant strains were homozygous for the A2143G mutation. No mutations were found in the remaining 86 susceptible strains. CONCLUSIONS: The high rate of metronidazole resistance in our population precludes the use of this drug for the empirical treatment of H pylori infection.

Resistencia a metronidazol y claritromicina en aislamientos de Helicobacter pylori de pacientes dispépticos en Colombia / Antimicrobial susceptibility of Helicobacter pylori strains isolated in Colombia

Background: Helicobacter pylori antimicrobial resistance rates differ among countries and even between different areas of a country. In Colombia, the most commonly used antimicrobials for the treatment of H pylori infection are amoxicillin, clarithromycin and metronidazole. Aim: To determine antimicrobial susceptibility of H pylori strains isolated in Colombia. Materials and methods: Eighty eight strains of H pylori were isolated and identified by microbiological methods and confirmed with polymerase chain reaction (PCR). The detection of antimicrobial resistance to amoxicillin, clarithromycin, metronidazole and tetraclycline, was conducted by the Etest method. Mutations in the 23S rDNA, involved in resistance to clarithromycin, were detected using PCR and restriction fragment lenght polymorphism. Results: Eighty eight and 2.2 percent of the strains were resistant to metronidazole and clarithromycin, respectively. No isolate was simultaneously resistant to amoxicillin or tetracycline. The two clarithromycin resistant strains were homozygous for the A2143G mutation. No mutations were found in the remaining 86 susceptible strains. Conclusions: The high rate of metronidazole resistance in our population precludes the use of this drug for the empirical treatment of Hpylori infection.

Phenotype-genotype analysis of CYP2C19 in Colombian mestizo individuals.

BACKGROUND: Omeprazole is metabolized by the hepatic cytochrome P450 (CYP) 2C19 enzyme to 5-hydroxyomeprazole. CYP2C19 exhibits genetic polymorphisms responsible for the presence of poor metabolizers (PMs), intermediate metabolizers (IMs) and extensive metabolizers (EMs). The defective mutations of the enzyme and their frequencies change between different ethnic groups; however, the polymorphism of the CYP2C19 gene has not been studied in Colombian mestizos. The aim of this study was to evaluate the genotype and phenotype status of CYP2C19 in Colombian mestizos, in order to contribute to the use of appropriate strategies of drug therapy for this population. METHODS: 189 subjects were genotyped using the multiplex SNaPshot technique and a subgroup of 44 individuals received 20 mg of omeprazole followed by blood collection at 3 hours to determine the omeprazole hydroxylation index by HPLC. RESULTS: 83.6%, 15.3% and 1.1% of the subjects were genotyped as EMs, IMs and PMs, respectively. The frequencies of the CYP2C29*1 and CYP2C19*2 alleles were 91.3% and 8.7% respectively whereas the *3, *4, *5, *6 and *8 alleles were not found. No discrepancies were found between the genotype and phenotype of CYP2C19. CONCLUSION: The frequency of poor metabolizers (1.1%) in the Colombian mestizos included in this study is similar to that in Bolivian mestizos (1%) but lower than in Mexican-Americans (3.2%), West Mexicans (6%), Caucasians (5%) and African Americans (5.4%). The results of this study will be useful for drug dosage recommendations in Colombian mestizos.

¿Monólogo o diálogo intercultural entre sistemas médicos? Un reto educativo para las ciencias de la salud / Monologue or Intercultural Dialogue between Medical Systems? An Educational Challenge for Medical Sciences

Cada sistema cultural médico construye conocimientos sobre la salud a partir de la especialización y del interculturalismo. El conocimiento construido a partir de las relaciones interculturales ha buscado, principalmente, adecuar la atención en salud a los referentes culturales de los usuarios. Este énfasis ha omitido las oportunidades que representa establecer relaciones entre sistemas culturales médicos basadas en el diálogo; especialmente, las que permitirían ajustar los límites disciplinares de los sistemas en relación, para construir nuevo conocimiento en salud. En esta ausencia de diálogo han incidido tanto las barreras epistemológicas propias de cada sistema, como las relaciones de dominación social. Este artículo expone algunos conceptos relacionados con los procesos cognoscitivos que posibilitan superar dichas barreras, con el fin de que las ciencias de la salud puedan aportar a la puesta en práctica de las recomendaciones de la Organización Mundial de la Salud y del Estado sobre el particular.

Each medical cultural system constructs knowledge about health through specialization or interculturalism. The knowledge constructed through interculturalism has sought, mainly, to adapt the delivery of health care services to the users' cultural referents. This emphasis has overlooked the opportunities embedded in the establishment of intercultural relationships between medical systems based on dialogue, especially in regard to the adjustment of the disciplinary boundaries of medical cultural systems that would allow the construction of new knowledge on health. This absence of dialogue has been determined by epistemological barriers inherent to every system as well as by social domination. This article presents some concepts related to cognition processes which encourage the reflection on the possibilities to overcome such barriers so that the health sciences may contribute to the effective implementation of the World Health Organization and the State's recommendations on the matter. Key words: Medical Anthropology, medical cultural systems, interculturalism, intercultural dialogue, cognition, health policy, education overcome such barriers so that the health sciences may contribute to the effective implementation of the World Health Organization and the State's recommendations on the matter.