Arbolado urbano, calidad del aire y afecciones respiratorias en seis comunas de la provincia de Santiago, Chile / Urban trees, air quality and respiratory diseases in six communes of the province of Santiago, Chile

Ozone (O3) is a secondary pollutant, often above the norm in some areas of Santiago in the spring-summer period. It is formed in the atmosphere by photochemical reactions, between nitrogen oxides (NOx) and volatile organic compounds (VOCs), which have an important biogenic contribution (BVOCs). In this research the interrelationship between urban trees, their contribution to atmospheric ozone formation and particulate matter, and respiratory diseases in 6 communes in the province of Santiago was analyzed. The choice of the communes considered the number of inhabitants, the existence of stations monitoring air quality, the percentage of green areas and the geographical distribution. The results showed correlation between the type of species of urban trees, ozone, particulate matter and respiratory diseases: asthma and pneumonia. Necessity for replacement of exotic trees species by native species is concluded.

El ozono (O3) es un contaminante secundario, frecuentemente sobre la norma en algunas áreas de Santiago en el período primavera-verano. Se forma en la atmósfera por reacciones fotoquímicas, a partir de óxidos de nitrógeno (NOx) y compuestos orgánicos volátiles (COVs), los cuales tienen un aporte biogénico (COVsB) importante. En esta investigación se analizó la interrelación entre el arbolado urbano, su contribución a la formación de ozono y material particulado atmosféricos, y las afecciones respiratorias en 6 comunas de la provincia de Santiago. La elección de las comunas consideró el número de habitantes, la existencia de estaciones de monitoreo de calidad del aire, el porcentaje de áreas verdes y la distribución geográfica. Los resultados muestran que existe relación entre el tipo de especies del arbolado urbano, el ozono, el material particulado y las enfermedades respiratorias: asma y neumonía. Se concluye la necesidad de considerar el remplazo de especies exóticas por especies nativas.

Frecuencia de los polimorfismos CYP1A1*2A y deleción del gen GSTM1 en pacientes con carcinoma de células escamosas de laringe en relación al hábito tabáquico: estudio piloto en Chile / Frequency of CYP1A1*2A and GSTM1 gene polymorphisms in Chilean patients with squamous cell carcinoma of the larynx in relation to smoking habit: a pilot study

Introducción: Entre los factores de riesgo para cáncer laríngeo (CL) son relevantes el consumo de tabaco y alcohol. Estos xenobióticos son metabolizados por un grupo de enzimas, entre las cuales están CYP1A1 y GSTM1, cuyas variantes polimórficas se postulan como factores de riesgo para esta enfermedad. Objetivos: Describir la frecuencia de las variantes de los polimorfismos de CYP1A1 y GSTM1 en un grupo de pacientes diagnosticados con CL. Analizar la posible correlación entre las variantes genéticas de ambas enzimas y la presencia de CL. Evaluar la influencia del hábito tabáquico en el riesgo de aparición de cáncer escamoso de laringe en pacientes con genotipos de riesgo. Material y método: Se seleccionaron 35 pacientes con CL entre los años 2000 y 2010 en Servicio de Otorrinolaringología del HBLT y 124 controles reclutados en el Centro de Investigaciones Farmacológicas y Toxicológicas (IFT). A todos los individuos se les registraron datos demográficos y extrajo una muestra de sangre para analizar las variantes polimórficas de CYP1A1 y GSTM1, mediante PCR-RFLP. Resultados: De un total de 35pacientes 54,3% presentan el genotipo GSTM1 (-/-) y 17,1% el genotipo CYP1A1*2A C/C. En el grupo control (n =140) estas frecuencias fueron de 19,35°% y 10,48%o, respectivamente. Se observó una correlación entre GSTM1 y el CL, estratificado por el hábito tabáquico y alcohólico. No se encontraron relaciones estadísticamente significativas con el hábito alcohólico y/o tabáquico. No se observaron asociaciones entre la patología y la combinación de genotipos o entre genotipos y el hábito tabáquico o alcohólico. Conclusiones: Los resultados muestran una asociación estadísticamente significativa entre la deleción de GSTM1 (-/-) y el riesgo de presentar CL, lo que refleja el importante papel que juega esta enzima en la desintoxicación de compuestos cancerígenos. Sin embargo, se requiere incrementar el número de pacientes para establecer apropiadamente la relación genético-ambiental que permite adjudicar un papel relevante a estos biomarcadores.

Introduction: Tobacco and alcohol consumption are recognized risk factors for squamous cell carcinoma of the larynx. These xenobiotics are metabolized by numerous enzymes, among which, CYP1A1 and GSTM1 gene polymorphisms have been identified as risk factors for developing tobacco related cancers as lung and laryngeal carcinomas. Nevertheless, these polymorphisms have not been studied in Chilean patients with squamous cell carcinoma of the larynx. Aim: To describe, for the first time, the frequency of CYP1A1 and GSTM1 gene polymorphisms in Chilean patients with squamous cell carcinoma of the larynx. Material and method: We conducted a case-control study. The case group consisted of 35 Chilean patients with squamous cell carcinoma of the larynx; the control group was formed by 124 Chilean subjects without cancer diagnosis. Demographic data as age, sex and quantification of tobacco smoking and alcohol consumption were recorded in all individuals. CYP1A1 and GSTM1 gene polymorphisms were evaluated by polymerase chain reaction and restriction enzymes (PCR-RFLP). Results: The frequency of CYP1A1*2A C/C genotype was 54, 3°% among laryngeal cancerpatients and 17,1%% among control subjects. The frequency ofGSTM1 (-/-) genotype was 19,35 %% among laryngeal cancer patients and 10,48%% among control subjects. There were no statistically significant relationships between this gene polymorphisms and tobacco smoking or alcohol consumption. There were no associations between the presence of both gene polymorphisms in the same individual and the presence of laryngeal cancer. Interestingly we found an OR of 8.69 (CI 2.90 to 26.01) for GSTM1 (-/-) polymorphism and laryngeal cancer, stratified by tobacco smoking and alcohol consumption. Conclusions: Our work shows that the deletion of GSTM1 could be an important risk factor for squamous cell carcinoma of the larynx in Chilean patients. This finding reflects the important role that detoxification of carcinogenic compounds plays in Chilean population. However, it is necessary to increase the number of studied patients to properly establish the genetic-environmental relationship ascribed to these biomarkers.

Perfil epidemiológico del paciente con antígeno prostático específico sobre 4 ng/mL: Región del Bío Bío, Chile / Epidemiological profile of the patient with prostate specific antigen over 4 ng/mL: Bio Bio Region, Chile

Objetivo: Describir el perfil epidemiológico de una muestra de pacientes beneficiarios del Servicio de Salud Bío Bío con examen de antígeno prostático sobre 4 ng/mL. Método: Se realizó un estudio transversal descriptivo donde se revisaron 436 fichas clínicas de pacientes con niveles APE > 4,0 ng/ml determinado en el Laboratorio Clínico del Hospital Dr. Víctor Ríos Ruiz, entre enero y junio del año 2006. También se obtuvo información a partir de los certificados de defunción y de anatomía patológica. Resultados: El 42,4 por ciento pertenecía a la comuna de Los Ángeles y el 57,6 por ciento restante se distribuye homogéneamente dentro de la región de Bío Bío. El promedio de edad de los pacientes fue de 72 años (31 a 98 años). El 75,6 por ciento pertenece a los grupos A y B del Fondo Nacional de Atención de Salud (FONASA), habiendo 10 por ciento sin afiliación conocida. El 63,4 por ciento presentaba hipertensión arterial. El 24,8 por ciento tuvo como diagnóstico cáncer de próstata (CaP) y el 58,2 por ciento hiperplasia benigna prostática. El 58,26 por ciento de los pacientes tuvo un valor de APE entre 4,00 a 10,00 ng/ml, el 34,59 por ciento entre 10,01 a 50,00 ng/ml y el 7,57por ciento un valor de APE >50,00 ng/ml. Conclusiones: El mayor porcentaje de los pacientes se concentra en la ciudad de Los Ángeles, siendo la mayoría del segmento A y B del fondo nacional de salud. La edad promedio fue de 72 años. La hipertensión arterial, la diabetes mellitus y el cáncer de próstata fueron las patologías más prevalentes en estos pacientes.

Objective: To describe the epidemiologic profile of a sample of patient beneficiaries of the Bio Bio Health Service with prostate specific antigen (PSA) up 4 ng/mL. Method: A descriptive cross-sectional study was made between January and June of 2006, where436 clinical histories of patients with levels APE up 4.0 ng/ml were reviewed. Also information from certificates of death and pathological anatomy was obtained. Results: The 42.4 percent belonged of Los Angeles province and the rest were distributed homogenous within Bio Bio region. The average of age of the patients was of 72 years old (31 to 98 years). The 75.6 percent belong to the groups A and B of the National Found of Health Attention (FONASA), being a 10.0 percent without well-known affiliation. The 63.4 percent presented arterial hypertension. The 24.8 percent present prostate cancer diagnostic (CaP) and the 58.2 percent had benign prostatic hyperplasia. 58.26 percent of the patients had a value of PSA between 4.0 to.10.0 ng/ml, the 34.59 percent between 10.01 to 50.00 ng/ml and the 7.57 percent a value of APE>50.00 ng/ml. Conclusions: The larger percentages of the patients live in the urban area of Los Angeles city, belonging most of the segment A and B of the National Found of Health Attention (FONASA). The average age was of 72 years. The hypertension arterial, the diabetes mellitus and the prostate cancer were the most prevalent pathologies in these patients.

Papel de las enzimas citocromo p450 en el metabolismo de fármacos antineoplásicos: situación actual y perspectivas terapéuticas: [revisión] / Role of cytochrome P450 enzymes in the metabolism of antineoplastic drugs: [review]

Cytochrome P450 enzymes are very important to metabolize anti-carcinogenic agents. Therefore, understanding the role of these enzymes and their allele variants in the bioactivation or detoxification of drugs could greatiy benefit antineoplastic pharmacotherapy. The aim of thís manuscrípt is to give information about metabohzing enzymes for antineoplastic agents and to relate the current situation in antitumoral pharmacotherapy with recent knowledge about cytochrome P450 enzymes. This is crucial for the future perspectives towards personalized pharmacotherapy. We summarize the role of cytochrome P450 enzymes in the resistance and bioactivation of several antitumor agents, their induction and repression mechanisms and the effect of genetic polymorphisms on variability of drug metabolization. The understanding of genetic variability will help to develop new research Unes on innovative therapeutic possibilities.

[Role of cytochrome P450 enzymes in the metabolism of antineoplastic drugs]. / Papel de las enzimas citocromo p450 en el metabolismo de fármacos antineoplásicos: situación actual y perspectivas terapéuticas.

Cytochrome P450 enzymes are very important to metabolize anti-carcinogenic agents. Therefore, understanding the role of these enzymes and their allele variants in the bioactivation or detoxification of drugs could greatly benefit antineoplastic pharmacotherapy. The aim of this manuscript is to give information about metabolizing enzymes for antineoplastic agents and to relate the current situation in antitumoral pharmacotherapy with recent knowledge about cytochrome P450 enzymes. This is crucial for the future perspectives towards personalized pharmacotherapy. We summarize the role of cytochrome P450 enzymes in the resistance and bioactivation of several antitumor agents, their induction and repression mechanisms and the effect of genetic polymorphisms on variability of drug metabolization. The understanding of genetic variability will help to develop new research lines on innovative therapeutic possibilities.

Prevalencia de la resistencia a metrodinazol, claritromicina y tetraciclina en Helicobacter pylori aislado de pacientes de la Región Metropolitana / Prevalence of metronidazole, clarithromycin and tetracycline resistance in Helicobacter pylori isolated from Chilean patients

Background: Helicobacter pylori is a pathogenic bacterium that infects a significant number of individuals. At present, therapeutic strategies to eradicate this bacterium depend on our knowledge of its resistance to antimicrobials. Aims: To evaluate the primary resistance of H pylori to metronidazole (Mtz), clarithromycin (Cla), and tetracycline (Tet) in symptomatic out-patients. Material and Methods: Fifty independent isolates of H pylori were obtained by endoscopy-assisted gastric biopsy from patients attending the University of Chile Clinical Hospital, that previously had not been treated with an eradication regime against this bacterium. The minimal inhibitory concentration of each antimicrobial was determined by agar dilution method. Results: Forty five and 27 percent of the isolates were found to be resistant to Mtz and Tet, respectively; the majority of these resistant isolates were from patients older than 21 years. Twenty percent of isolates were resistant to Cla; these were distributed evenly among different ages. Thirty two percent of the isolates were resistant to two or more of the antimicrobials. Conclusions: The high frequency of naturally occurring, antimicrobial-resistant strains of H pylori poses a national and world-wide problem for public health.

Prevalencia de la infección por helicobacter pylori según ensayo de la ureasa en pacientes derivados a la Unidad de Endoscopía del Hospital Clínico de la Universidad de Chile / Prevalence of infection by helicobacter pylori by urease test in patients derivates to the endoscopic section of Hospital Clínico de la Universidad de Chile

Helicobacter pylori is a pathogenic bacterium that infects a significant number of individuals. In Chile about 79 percent of the population is colonized. Aims: This study evaluate the prevalence of the H. pylori infection in symptomatic outpatients. Materials and Methods: 276 non selected patients were enrolled from Endoscopic Unit of Clinical Hospital of the University of Chile. The bacterium was detected by urease test. Results: H. pylori infection was found in 44,9 percent patients. Infection was higher in younger patients, 53,8 percent between 21-60 years, and was lower in older patients, 25,6 percent in older than 60 years. The risk of being H. pylori carrier is twofold higher in persons younger than 60 years as compared to those older than 60 years. Conclusion: The age would be modifier factors for H. pylori infection risk.

Interacciones genéticas y genético-ambientales como efecto modificador del riesgo de cáncer de próstata: un diseño case-only / Gene-gene and gene-environment interactions as modifier factors of prostatic cancer risk: a case-only design study

Background: The role of susceptibility low penetrance genes and environmental factors in the etiology of prostate cancer (PCa) is unclear, but may involve in some cases multiple alleles at multiple loci. Aim: To evaluate the association of gene-gene and gene-environment interactions with PCa. Patients and methods: One hundred three subjects with biopsy proven PCa were studied, using a case-only design. All were interrogated about smoking habits. Polymorphisms for Glutathione-S-transferase (GST) and Cytochrome P4501A1 (CYP1A1), were measured in DNA extracted from peripheral Iymphocytes, using a restriction fragment length polymorphism analysis. Results: Our findings suggest that gene-gene interactions between GSTT1 and CYP1A1 high risk genotypes were positive modifiers and had a high predictive value for the presence of PCa, compared with non-susceptibility genotypes. The interaction between susceptibility genotypes and smoking did not modify the risk for PCa. Conclusions: Gene-gene interactions may play a role modulating the susceptibility to PCa in a proportion of affected individuals (Rev Méd Chile 2004; 132: 961-66).

Contaminación intradomiciliaria en un sector de extrema pobreza de la comuna de La Pintana / Indoor air pollution in a zone of extreme poverty at La Pintana community, Santiago

Background: Indoor pollution can be an important risk factor for human health, considering that people spend more than 60 percent of their time in their houses. Aim: To investigate indoor pollution in a zone of extreme poverty in Metropolitan Santiago. Material and methods: During 24h, carbon monoxide (CO), sulfur dioxide (SO2), respirable particulate matter (PM10), polycyclic aromatic hydrocarbons absorbed in PM5, temperature and humidity, were measured in the interior of 24 houses in La Pintana, Santiago. Results: The higher pollutant concentrations were observed during hours when heating was used, in houses that used coal (mean PM10 250 µg/m3, CO 42 ppm, SO2 192 ppb) or firewood (mean PM10 489 µg/m3, CO 57 ppm, SO2 295 ppb). In all houses, polycyclic aromatic hydrocarbons were detected and they came from the interior of the house and not from external filtered air. Coal, firewood and cigarette smoke were important sources of carcinogenic and kerosene and gas were sources of non carcinogenic polycyclic aromatic hydrocarbons. Conclusions: In the houses studied, the population was exposed to an accumulation of highly toxic pollutants, caused by a lack of ventilation. A high relative humidity also contributed to the growth of biological pollutants

Influencia de la contaminación atmosférica en la calidad de aire de interiores / Influence of outdoor pollution on indoor air quality

The influence of outdoor pollution on indoor air quality was studied in downtown Santiago (Bandera street). Carbon monoxide (CO), nicotine, particulate matter, respirable fraction (PM5) and total and carcinogenic polyaromatic hydrocarbons (PAHs) were simultaneously monitores indoors and outdoors and indoors in restaurants, offices and other places. The levels of CO changed simultaneously outdoors and indoors (r=0.89) specially during traffic rush hours, demonstrating the importance of outdoor infiltration into the indoor air quality and masking the contribution of other CO indoor sources. The maximun CO concentrations were over 800 percent and over 1000 percent higher indoors and outdoors respectively than the 9 ppm CO National Ambient Air Quality. The PM5 concentrations were very high and showed no significant differences (p>0.05) from indoor to outdoors, or between indoor levels in restaurants, offices and other places. Total ans carcinogenic PAHs levels were also very high, outdoors and indoors, outodoor levels being generally higher than those indoors and no significant; differences (p>0.05) were found for the indoor levels between restaurants, offices and other places. Nicotine levels showed significant differences (p<0.05) between indoor and outdoor levels. In addition, great differences (p<0.05) in indoor levels, were found between offices and restaurants, and offices and other places. Among indoor sources cigarrete smoke seems to be a minor source since nicotine concentrations, bieng 2.3 times higher in restaurants and other places than in offices, do not contribute to enhance significantly PM5 and total and carcinogenic HAPs in the first ones. These results suggest that in downtown Santiago, infiltration might be the main source of indoor pollution. This is supported by 2 evidences: a) coronene, a tracer of vehicle emissions was found in high concentraion indoors and b) in restaurants (in wich PAHs emissions might be higher indoor) a correlation coefficient of 0.987 for the indoor and outdoor concentrations of carcinogenic PAHs was found. Furthermore a survey asking for different symptoms and effects probably related to air pollution was made to people working in Bandera and in a rural area located 40 Km from Santiago. The results showed that excluding smoking as a confounded factor, people working in Bandera showed a significantly greater (p<0.05) risk of ill effects on their health than people working in the rural area