Enfermedades respiratorias en México. Análisis del estudio Global Burden of Disease 2021 / Respiratory diseases in Mexico. Analysis from the Global Burden of Disease study 2021

Resumen Antecedentes: Las enfermedades respiratorias (ER) se analizan individualmente, posiblemente con subestimación de su carga total. Objetivo: Analizar la carga de las ER en México para población de 20 años o más de 1990 a 2021. Material y métodos: Se presenta la carga de ER en México a partir de estimaciones del estudio Global Burden of Disease en cuanto a mortalidad y años de vida saludable (AVISA) perdidos que comprenden recuentos, tasas por 100 000 y tasas estandarizadas por edad. Las ER se categorizaron en enfermedades respiratorias crónicas (ERC), infecciones respiratorias y cánceres respiratorios. Resultados: En 2021, las ER causaron la muerte de 336 728 adultos mayores de 20 años, lo que representó 30.5 % del total de defunciones, incremento cercano al triple respecto a 2019, principalmente debido a COVID-19. Las ERC contribuyeron con 3.4 % del total de muertes, las infecciones respiratorias con 25.9 % y los cánceres respiratorios con 1.2 %. La mortalidad y AVISA perdidos por ERC se incrementaron persistentemente, con variaciones entre los estados. Las tasas de mortalidad ajustadas por edad de las ERC disminuyeron desde 1990, excepto las enfermedades pulmonares intersticiales, que se incrementaron constantemente. Conclusión: Los significativos niveles de mortalidad y discapacidad debidos a enfermedades respiratorias en México exigen mejorar la prevención, investigación y abordar factores de riesgo como tabaquismo y contaminación, además de fomentar la capacitación médica continua.

Abstract Background: Respiratory diseases (RD) are often analyzed separately rather, possibly leading to an underestimation of their total burden. Objective: To analyze the burden of RD in Mexico for population aged 20 or older from 1990 to 2021. Material y methods: We present the burden of RD in Mexico based on estimates of the Global Burden of Disease study for mortality and disability-adjusted life years (DALYs), comprising counts, rates per 100,000, as well as age-standardized rates. RDs were categorized into three key groups: chronic respiratory diseases (CRD), respiratory infections (RI), and respiratory cancers. Results: In 2021, among those aged 20+, RDs were responsible for 336,728 deaths, which accounts for 30.5% of total deaths— a nearly threefold increase since 2019, primarily due to the COVID-19 pandemic. CRDs contributed with 3.4% of total deaths; RIs, with 25.9%; and respiratory cancers, with 1.2%. CRDs showed a continuous rise in deaths, crude mortality, and DALY rates across genders, with no signs of leveling. RD burden varied widely across states. Age-standardized CRD mortality rates have generally declined since 1990, except for interstitial lung diseases, which have consistently increased. Conclusion: The significant burden of mortality and disability due to RDs in Mexico underscores the necessity for enhanced prevention, research, and for addressing risk factors such as smoking and pollution. Ongoing healthcare training can help reduce RD burden.

Respiratory diseases in Mexico: analysis from the Global Burden of Disease study 2021.

BACKGROUND: Respiratory diseases (RD) are often analyzed separately rather than collectively, possibly leading to an underestimation of their total burden. OBJECTIVE: To analyze the burden of RD in Mexico for population aged 20 or older from 1990 to 2021. MATERIAL AND METHODS: We present the burden of RD in Mexico based on estimates of the Global Burden of Disease study for mortality and disability-adjusted life years (DALYs), comprising counts, rates per 100,000, as well as age-standardized rates. RDs were categorized into three key groups: chronic respiratory diseases (CRD), respiratory infections (RI), and respiratory cancers. RESULTS: In 2021, among those aged 20+, RDs were responsible for 336,728 deaths, which accounts for 30.5% of total deaths -a nearly threefold increase since 2019, primarily due to the COVID-19 pandemic. CRDs contributed with 3.4% of total deaths; RIs, with 25.9%; and respiratory cancers, with 1.2%. CRDs showed a continuous rise in deaths, crude mortality, and DALY rates across genders, with no signs of leveling. RD burden varied widely across Mexican states. Age-standardized CRD mortality rates have generally declined since 1990, except for interstitial lung diseases, which have consistently increased. CONCLUSION: The significant burden of mortality and disability due to RDs in Mexico underscores the n|ecessity for enhanced prevention, research, and for addressing risk factors such as smoking and pollution. Ongoing healthcare training can help reduce RD burden.

ANTECEDENTES: Las enfermedades respiratorias (ER) se analizan individualmente, posiblemente con subestimación de su carga total. OBJETIVO: Analizar la carga de las ER en México para población de 20 años o más de 1990 a 2021. MATERIAL Y MÉTODOS: Se presenta la carga de ER en México a partir de estimaciones del estudio Global Burden of Disease en cuanto a mortalidad y años de vida saludable (AVISA) perdidos que comprenden recuentos, tasas por 100 000 y tasas estandarizadas por edad. Las ER se categorizaron en enfermedades respiratorias crónicas (ERC), infecciones respiratorias y cánceres respiratorios. RESULTADOS: En 2021, las ER causaron la muerte de 336 728 adultos mayores de 20 años, lo que representó 30.5 % del total de defunciones, incremento cercano al triple respecto a 2019, principalmente debido a COVID-19. Las ERC contribuyeron con 3.4 % del total de muertes, las infecciones respiratorias con 25.9 % y los cánceres respiratorios con 1.2 %. La mortalidad y AVISA perdidos por ERC se incrementaron persistentemente, con variaciones entre los estados. Las tasas de mortalidad ajustadas por edad de las ERC disminuyeron desde 1990, excepto las enfermedades pulmonares intersticiales, que se incrementaron constantemente. CONCLUSIÓN: Los significativos niveles de mortalidad y discapacidad debidos a enfermedades respiratorias en México exigen mejorar la prevención, investigación y abordar factores de riesgo como tabaquismo y contaminación, además de fomentar la capacitación médica continua.

Image Registration Measures and Chronic Osteoarthritis Knee Pain Prediction: Data from the Osteoarthritis Initiative / Métricas de Registro de Imágenes y Predicción de Dolor de Rodilla por Osteoartritis Crónica: Datos de la Osteoarthritis Initiative

Abstract Osteoarthritis (OA) is the most common type of arthritis, is a growing disease in the industrialized world. OA is an incapacitate disease that affects more than 1 in 10 adults over 60 years old. X-ray medical imaging is a primary diagnose technique used on staging OA that the expert reads and quantify the stage of the disease. Some Computer-Aided Diagnosis (CADx) efforts to automate the OA detection have been made to aid the radiologist in the detection and control, nevertheless, the pain inherits to the disease progression is left behind. In this research, it's proposed a CADx system that quantify the bilateral similarity of the patient's knees to correlate the degree of asymmetry with the pain development. Firstly, the knee images were aligned using a B-spline image registration algorithm, then, a set of similarity measures were quantified, lastly, using this measures it's proposed a multivariate model to predict the pain development up to 48 months. The methodology was validated on a cohort of 131 patients from the Osteoarthritis Initiative (OAI) database. Results suggest that mutual information can be associated with K&L OAI scores, and Multivariate models predicted knee chronic pain with: AUC 0.756, 0.704, 0.713 at baseline, one year, and two years' follow-up.

Resumen La osteoartritis (OA) es el tipo de artritis más común. OA es una enfermedad limitante que afecta a 1 de 10 adultos con 60 años o más. Las imágenes de rayos-x son una técnica de diagnóstico primario que permite conocer el estado de OA, las cuales el experto lee y cuantifica así la etapa de la enfermedad. El Diagnóstico Asistido por Computadora (CADx, por sus siglas en inglés) ha buscado automatizar el diagnóstico de OA para ayudar al radiólogo en la detección y control; sin embargo, el dolor provocado por la progresión de la enfermedad es dejado atrás. En este trabajo se propone un sistema de CADx que cuantifica la similitud bilateral de las rodillas de los pacientes, con el fin de correlacionar el grado de asimetría con el dolor. Inicialmente, las imágenes de las rodillas fueron alineadas usando el algoritmo B-spline para su registro, después, un conjunto de métricas estándar fue cuantificado; finalmente, con estas métricas se propone un modelo multivariado para predecir el dolor de rodilla desarrollado en 48 meses. La metodología fue validada con 131 pacientes obtenidos de la base de datos de la Osteoarthritis Initiative (OAI). Los resultados sugieren que las métricas pueden ser asociadas con los puntajes de KellgrenLawrence; además, los modelos predicen significativamente el dolor crónico de rodilla con: AUC 0.756, 0.704 y 0.7113, al inicio, un año y dos años después, respectivamente.

General Linear Models for Pain Prediction in Knee Osteoarthritis: Data from the Osteoarthritis Initiative / Modelos Lineales Generales para Predecir Dolor en Osteoartritis de Rodilla: Datos de la "Osteoarthritis Initiative"

Abstract: Knee pain is the most common and disabling symptom in Osteoarthritis (OA). Joint pain is a late manifestation of the OA. In earlier stages of the disease changes in joint structures are shown. Also, formation of bony osteophytes, cartilage degradation, and joint space reduction which are some of the most common, among others. The main goal of this study is to associate radiological features with the joint pain symptom. Univariate and multivariate studies were performed using Bioinformatics tools to determine the relationship of future pain with early radiological evidence of the disease. All data was retrieved from the Osteoarthritis Initiative repository (OAI). A case-control study was done using available data from participants in OAI database. Radiological data was assessed with different OAI radiology groups. We have used quantitative and semi-quantitative scores to measure two different relations between radiological data in three different time points. The goal was to track the appearance and prevalence of pain as a symptom. All predictive models were statistically significant (P ≤ 0,05), obtaining the receiving operating characteristic (ROC) curves with their respective area under the curves (AUC) of 0.6516, 0.6174, and 0.6737 for T-0, T-1 and T-2 in quantitative analysis. For semi-quantitative an AU C of 0.6865, 0.6486, and 0.6406 for T-0, T-1 and T-2. The models obtained in the Bioinformatics study suggest that early joint structure changes can be associated with future joint pain. An image-based biomarker that could predict future pain, measured in early OA stages, could become a useful tool to improve the quality of life of people dealing OA.

Resumen: El dolor de rodilla es el síntoma más común y limitante de la Osteoartritis (OA), además de presentarse como una manifestación tardía de la enfermedad. Los cambios que ocurren en las estructuras de las articulaciones se presentan en las primeras etapas de la OA. Algunos de los cambios más comunes son la formación de osteofitos óseos, degradación del cartílago, y la reducción del espacio en la articulación, entre otros. El principal objetivo de este estudio es la asociación de características radiológicas con el síntoma de dolor de las articulaciones, para lo que fueron realizados dos estudios: univariado y multivariado, usando herramientas bioinformáticas para determinar la relación de futuro dolor con la evidencia radiológica temprana de la enfermedad. Todos los datos fueron recuperados de la Osteoarthritis Initiative repository (OAI). Este estudio de caso-control se llevó a cabo utilizando los datos disponibles de los participantes de la base de datos de la OAI. Los datos radiológicos fueron evaluados con diferentes grupos de radiología de la OAI. Fueron usadas puntuaciones cuantitativas y semi- cuantitativas para medir las dos diferentes relaciones entre los datos radiológicos en tres diferentes puntos de tiempo. El objetivo fue seguir la trayectoria de la aparición y prevalencia del dolor como síntoma. Todos los modelos predictivos fueron estadísticamente significativos (P ≤ 0,05). Para el análisis cuantitativo se calcularon las áreas bajo la curva (AUC): 0.6516, 0.6174, y 0.6737 para T-0, T-1 y T-2, y para el análisis semi-cuantitativo se calcularon las AU C: 0.6865, 0.6486, y 0.6406 para T-0, T-1 y T-2. Los modelos obtenidos en el estudio bioinformático sugieren que los cambios tempranos en la estructura de las articulaciones pueden estar asociados con el futuro dolor de rodilla. Un biomarcador basado en imágenes que pueda predecir el futuro dolor, medido en las primeras etapas de OA, podría convertirse en una herramienta útil para mejorar la calidad de vida de la gente que padece OA.

Prevalence of premature ovarian failure in patients with systemic lupus erythematosus.

OBJECTIVE: To estimate the prevalence of premature ovarian failure (POF) and its associated factors in patients with systemic lupus erythematosus (SLE). METHODS: Cross-sectional study including consecutive SLE women <60 years of age attending a rheumatology clinic. A face-to-face interview was undertaken to obtain demographic, gynaecological and lupus characteristics. Additional rheumatologic and endocrine data were retrieved from patients' medical records. POF prevalence was estimated in the study sample and in a subgroup of patients aged <40 years at interview. Associations between POF and selected variables were assessed by logistic regression analyses. RESULTS: A total of 961 patients were analysed. Prevalence of POF, secondary amenorrhea of known cause, menopause and hysterectomy were 5.4%, 0.8%, 7.8% and 4.4%, respectively. In 674 (70%) patients who had not been exposed to cyclophosphamide (CYC) the prevalence of POF was 0.6%. Disease activity over time (OR 1.4 (CI 95% 1.0-1.8, p < 0.05)) and CYC treatment (OR 5.9 (CI 95% 1.8-18.8, p < 0.01)) were associated with higher prevalence. Association between POF and endocrine autoimmune diseases was not found. CONCLUSIONS: In the absence of CYC treatment, the prevalence of POF in lupus patients is consistent with that reported in the general population. The existence of autoimmune processes at the ovary seems unlikely in most lupus patients.

Inhibition of PKC-dependent extracellular Ca2+ entry contributes to the depression of contractile activity in long-term pressure-overloaded endothelium-denuded rat aortas

We examined the contractile responsiveness of rat thoracic aortas under pressure overload after long-term suprarenal abdominal aortic coarctation (lt-Srac). Endothelium-dependent angiotensin II (ANG II) type 2 receptor (AT2R)-mediated depression of contractions to ANG II has been reported in short-term (1 week) pressure-overloaded rat aortas. Contractility was evaluated in the aortic rings of rats subjected to lt-Srac or sham surgery (Sham) for 8 weeks. ANG I and II levels and AT2R protein expression in the aortas of lt-Srac and Sham rats were also evaluated. lt-Srac attenuated the contractions of ANG II and phenylephrine in the aortas in an endothelium-independent manner. However, lt-Srac did not influence the transient contractions induced in endothelium-denuded aortic rings by ANG II, phenylephrine, or caffeine in Ca2+-free medium or the subsequent tonic constrictions induced by the addition of Ca2+ in the absence of agonists. Thus, the contractions induced by Ca2+ release from intracellular stores and Ca2+ influx through stored-operated channels were not inhibited in the aortas of lt-Srac rats. Potassium-elicited contractions in endothelium-denuded aortic rings of lt-Srac rats remained unaltered compared with control tissues. Consequently, the contractile depression observed in aortic tissues of lt-Srac rats cannot be explained by direct inhibition of voltage-operated Ca2+ channels. Interestingly, 12-O-tetradecanoylphorbol-13-acetate-induced contractions in endothelium-denuded aortic rings of lt-Srac rats were depressed in the presence but not in the absence of extracellular Ca2+. Neither levels of angiotensins nor of AT2R were modified in the aortas after lt-Srac. The results suggest that, in rat thoracic aortas, lt-Srac selectively inhibited protein kinase C-mediated activation of contraction that is dependent on extracellular Ca2+ entry.

Inhibition of PKC-dependent extracellular Ca2+ entry contributes to the depression of contractile activity in long-term pressure-overloaded endothelium-denuded rat aortas.

We examined the contractile responsiveness of rat thoracic aortas under pressure overload after long-term suprarenal abdominal aortic coarctation (lt-Srac). Endothelium-dependent angiotensin II (ANG II) type 2 receptor (AT2R)-mediated depression of contractions to ANG II has been reported in short-term (1 week) pressure-overloaded rat aortas. Contractility was evaluated in the aortic rings of rats subjected to lt-Srac or sham surgery (Sham) for 8 weeks. ANG I and II levels and AT2R protein expression in the aortas of lt-Srac and Sham rats were also evaluated. lt-Srac attenuated the contractions of ANG II and phenylephrine in the aortas in an endothelium-independent manner. However, lt-Srac did not influence the transient contractions induced in endothelium-denuded aortic rings by ANG II, phenylephrine, or caffeine in Ca2+-free medium or the subsequent tonic constrictions induced by the addition of Ca2+ in the absence of agonists. Thus, the contractions induced by Ca2+ release from intracellular stores and Ca2+ influx through stored-operated channels were not inhibited in the aortas of lt-Srac rats. Potassium-elicited contractions in endothelium-denuded aortic rings of lt-Srac rats remained unaltered compared with control tissues. Consequently, the contractile depression observed in aortic tissues of lt-Srac rats cannot be explained by direct inhibition of voltage-operated Ca2+ channels. Interestingly, 12-O-tetradecanoylphorbol-13-acetate-induced contractions in endothelium-denuded aortic rings of lt-Srac rats were depressed in the presence but not in the absence of extracellular Ca2+. Neither levels of angiotensins nor of AT2R were modified in the aortas after lt-Srac. The results suggest that, in rat thoracic aortas, lt-Srac selectively inhibited protein kinase C-mediated activation of contraction that is dependent on extracellular Ca2+ entry.

Synchronous phase-demodulation and harmonic rejection of 9-step pixelated dynamic interferograms.

We propose a novel synchronous phase-demodulation of pixelated interferograms using squared 3x3 phase-shifted unit-cells. This 3x3 unit-cell is tiled over the CCD image sensor to create a two-dimensional (2D) pixelated carrier. Our synchronous phase-demodulation uses this 2D carrier to demodulate the pixelated interferogram as in the standard 2x2 unit-cell case. The main motivation behind the use of a 3x3 pixelated carrier (instead of the usual 2x2) is its higher harmonic robustness, allowing one to demodulate intensity-distorted fringe patterns. The harmonic rejection robustness of our spatial 3x3 configuration equals the robustness of the temporal least-squares 9-step phase-shifting algorithm (PSA). In other words, extending from the usual 2x2 phase-shifting unit-cell to 3x3 unit-cells, one extends the harmonic rejection of the demodulation algorithm. Finally we also prove that our proposed 9-step, 3x3 pixelated carrier uses the 2D available spectral space more efficiently than using these 9-steps in a linear spatial-carrier configuration.

Temporary morphological changes in plus disease induced during contact digital imaging.

OBJECTIVE: To compare and quantify the retinal vascular changes induced by non-intentional pressure contact by digital handheld camera during retinopathy of prematurity (ROP) imaging by means of a computer-based image analysis system, Retinal Image multiScale Analysis. METHODS: A set of 10 wide-angle retinal pairs of photographs per patient, who underwent routine ROP examinations, was measured. Vascular trees were matched between 'compression artifact' (absence of the vascular column at the optic nerve) and 'not compression artifact' conditions. Parameters were analyzed using a two-level linear model for each individual parameter for arterioles and venules separately: integrated curvature (IC), diameter (d), and tortuosity index (TI). RESULTS: Images affected with compression artifact showed significant vascular d (P<0.01) changes in both arteries and veins, as well as in artery IC (P<0.05). Vascular TI remained unchanged in both groups. CONCLUSIONS: Non-adverted corneal pressure with the RetCam lens could compress and decrease intra-arterial diameter or even collapse retinal vessels. Careful attention to technique is essential to avoid absence of the arterial blood column at the optic nerve head that is indicative of increased pressure during imaging.

Retinopathy of prematurity as a major cause of severe visual impairment and blindness in children in schools for the blind in Guadalajara city, Mexico.

AIM: To determine the causes of blindness in students attending schools for the blind in Guadalajara city, Mexico and to assess the availability of screening for retinopathy of prematurity (ROP) in local neonatal intensive care units. METHODS: Information on causes of blindness was obtained by interview with parents and teachers, review of records and examination. Causes of visual loss in children with a distance visual acuity of <6/60 (ie, severely visually impaired or blind) were determined and classified according to the WHO's classification system for children. RESULTS: Of 153 children in the two participating schools, 144 were severely visual impaired or blind. Their ages ranged from 4 months to 15 years and 58% were female. ROP was the most common cause of visual loss (34.7%), followed by optic nerve lesions (17.4%) and glaucoma (14.6%). 25/59 (42.3%) children aged 0-4 years were blind from ROP compared with 6/32 (18.8%) children aged 10-15 years. 78% of children blind from ROP had psychomotor delay and less than half (46%) had not received treatment for ROP. All five privately funded neonatal intensive care units in the city regularly screen for ROP compared with only four of the 12 units in the public sector. CONCLUSIONS: ROP is the leading cause of blindness in children in Mexico despite national guidelines being in place. Health policies promoting primary prevention through improved neonatal care need to be implemented. Advocacy is required so that the time ophthalmologists spend screening and treating ROP is included in their job description and hence salaried.

[Nutrition iodine status in pregnant women in the sanitary district Sierra de Huelva-Andévalo, South of Spain]. / Deficiencia nutricional de yodo en gestantes pertenecientes al distrito sanitario Sierra de Huelva-Andévalo, sur de España.

BACKGROUND: Iodine is an essential trace element implicated in synthesis of thyroid hormones. Iodine requirements vary throughout life. This iodine requirement is increased during pregnancy and breastfeeding. In a previous study carried out by our group in 2008, we detected an iodine-deficient area in the province of Huelva, specially in district Sierra de Huelva-Andévalo by means of neonatal TSH determinations. OBJECTIVE: To reinforce the iodine supplementation campaign and its impact on their newborns in order to assess nutrition iodine status in pregnant women using questionnaire and ioduria determination. MATERIAL AND METHODS: This study has been jointly carried out by Congenital Hypothyroidism Unit of the Clinical Biochemistry Department of the Virgen Macarena University Hospital (Seville) and the Gynecology and Clinical Analysis Unit of the Río Tinto Hospital (Huelva) during two years. We studied 313 pregnant women. All of them filled out a personal questionnaire to know the iodine nutritional status in their area. Ioduria was determinated by high-resolution liquid chromatography. Data from pregnant women and results of the studied variables were analyzed with SPSS v13.0. CONCLUSIONS: Pregnant women from the sanitary district Sierra de Huelva-Andévalo present a median for ioduria which corresponds to an insufficient iodine intake according to the WHO classification. The questionnaires suggest that this iodine deficiency is consequence of an insufficient iodine intake and a low adherence to the treatment.

Prevalencia de erosión dental en escolares de Tampico, Madero, Altamira y su relación con el pH salival / Prevalência de erosão dentária em escolares Tampico, Madero, Altamira e sua relação com pH salivar / Prevalence of dental erosion in school children of Tampico Madero Altamira and its relation to the salivary pH

Introducción: La erosión dental es la pérdida de la superficie del diente causada por el ataque ácido y es un problema de salud dental en el mundo moderno; determinar su etiología y factores de riesgo permitirán tratarla y prevenirla correctamente antes de que se presente un daño más severo. Objetivo: Identificar la prevalencia de erosión dental en escolares de Tampico, Madero, Altamira y su relación con el pH salival. Material y Métodos: Fue un estudio observacional y transversal, se examinaron a 510 escolares de Tampico, Madero y Altamira. Se utilizó el índice de erosión de Aine. Resultados: De los 510 escolares, 63 presentaron una frecuencia de erosión dental del 12.35%, de los cuales 35 (13.67%) fueron niñas y 28 (11.02%) niños. No se encontraron diferencias estadísticamente significativas entre niños y niñas (p=.36). En relación con el pH salival no se encontró diferencias estadísticamente significativas. (p=.11). El órgano dental más afectado fue el 46 (7.20%) y el 63 (4.93%). El grado que más prevaleció fue grado 1 (8.03%). En cuanto a la superficie más afectada fue la vestibular. Conclusiones: Es importante para el odontopediatra detectar los signos de erosión en etapas iníciales, identificar la causa y vigilar la nutrición de los niños que presentan erosión para prevenirla oportunamente.

Introdução: Aerosão dentária é a perda da estrutura do dente causada pelo ataque ácido e é um problema de saúde bucal no mundo moderno; determinar sua etiologia e fatores de risco permitirá tratá-la e preveni-la corretamente antes que se desenvolvam danos mais severos. Objetivo: Identificar a prevalência de erosão dentária em escolares de Tampico, Madero, Altamira e sua relação com o pH salivar. Material e Métodos: Através de estudo observacional e transversal, foram examinados 510 escolares de Tampico, Madero e Altamira. Utilizou-se o índice de erosão de Aine. Resultados: Dos 510 escolares, 63 (12,35%) apresentaram erosão dentária, sendo 35 meninas (13,67%) e 28 (11,02%) meninos. Não se encontraram diferenças estatisticamente significantes entre os gêneros (p=0,36). Em relação ao pH salivar não se encontraram diferenças estatisticamente significativas. (p=0,11). Os elementos dentais mais afetados foram o 4.6 (7,20%) e o 6.3 (4,93%). O grau que mais prevaleceu foi o 1 (8,03%) e a superfície vestibular foi a mais afetada. Conclusões: É importante para o odontopediatra detectar os sinais de erosão em etapas iniciais, identificar a causa e vigiar a alimentação das crianças que apresentam erosão para preveni-la oportunamente.

Introduction: Dental erosion is the loss of tooth surface caused by acid attack and is a dental health problem in the modern world, determining its etiology and risk factors will allow properly treating and preventing it before the damage done is more severe. Objective: To identify the prevalence of dental erosion in schoolchildren in Tampico, Madero, Altamira and its relation to salivary pH. Material and Methods: It was a cross-sectional observational study, 510 schoolchildren were examined in Tampico, Madero and Altamira. We used the Aine index for dental erosion. Results: Out of the 510 schoolchildren, 63 had a frequency of dental erosion of 12.35%, of which 35 (13.67%) were girls and 28 (11.02%) boys. There were no statistically significant differences between boys and girls (p =. 36). In relation to salivary pH, no statistically significant differences were found. (P =. 11). The most frequently affected dental organs were 46 (7.20%) and 63 (4.93%). The most prevalent grade was grade1 (8.03%). In regards to the area, the most affected was the vestibular. Conclusions: It is important for the pediatric dentist to detect signs of erosion in its early stages, identify the cause and monitor the nutrition of children with erosion to treat and prevent this condition.

The continuous spread of West Nile virus (WNV): seroprevalence in asymptomatic horses.

West Nile virus (WNV) was probably introduced in southern and northern Mexico from the USA in two independent events. Since then, WNV activity has been reported in several Mexican states bordering the USA and the Gulf of Mexico, but disease manifestations seen there in humans and equids are quite different to those observed in the USA. We have analysed WNV seroprevalence in asymptomatic, unvaccinated equids from two Mexican states where no data had been previously recorded. WNV IgG antibodies were detected in 31.6% (91/288) of equine sera from Chiapas and Puebla states (53.3% and 8.0%, respectively). Analysis by plaque reduction neutralization test (PRNT) showed good specificity (99.4%) and sensitivity (84.9%) with the ELISA results. Further analyses to detect antibodies against three different flaviviruses (WNV, St Louis encephalitis virus, Ilheus virus) by haemagglutination inhibition (HI) tests on a subset of 138 samples showed that 53% of the 83 HI-positive samples showed specific reaction to WNV. These data suggest continuous expansion of WNV through Mexico.

Wood smoke-associated lung disease: a clinical, functional, radiological and pathological description.

BACKGROUND: Approximately half of the world's population, and up to 90% of households in rural areas of developing countries, depend on biomass for cooking and heating. SETTING: The National Institute of Respiratory Diseases, México City. OBJECTIVE: To describe wood smoke-associated lung disease (WSLD). DESIGN: Description of the clinical, functional and radiological manifestations of patients with WSLD, and a comparison of pathological findings of patients who died of WSLD and smokers who died of chronic bronchitis. RESULTS: All patients with WSLD were non-smoking women with chronic bronchitis, in whom asthma, bronchiectasis, tuberculosis, congestive heart failure, extreme obesity and alfa-1 antitrypsin deficiency had been excluded. All patients used wood for cooking and had been exposed to wood smoke for a median of 45 years. Dyspnoea, airway obstruction, air trapping, increased airway resistance, pathological evidence of anthracosis, chronic bronchitis, centrilobular emphysema and pulmonary hypertension were present in most patients with WSLD. Bronchial squamous metaplasia was a common finding. There were no significant differences in the histopathological findings between patients with WSLD and smokers. Diffuse interstitial fibrosis was absent in all patients. CONCLUSIONS: Patients with WSLD have obstructive lung disease, chronic bronchitis, emphysema and pulmonary hypertension comparable to smokers.

Co-ordination between leaf initiation and leaf appearance in field-grown maize (Zea mays): genotypic differences in response of rates to temperature.

BACKGROUND AND AIMS: In maize (Zea mays), early flowering date, which is a valuable trait for several cropping systems, is associated with the number of leaves per plant and the leaf appearance rate. Final leaf number depends upon the rate and duration of leaf initiation. The aims of this study were to analyse the genotypic variation in the response to temperature of leaf appearance rate and leaf initiation rate, and to investigate the co-ordination between these processes under field conditions. METHODS: Sixteen hybrids of different origins were grown under six contrasting environmental conditions. The number of appeared leaves was measured twice a week to estimate leaf appearance rate (leaves d(-1)). Plants were dissected at four sampling dates to determine the number of initiated leaves and estimate leaf initiation rate (leaves d(-1)). A co-ordination model was fitted between the number of initiated leaves and the number of appeared leaves. This model was validated using two independent data sets. KEY RESULTS: Significant (P < 0.05) differences were found among hybrids in the response to temperature of leaf initiation rate (plastochron) and leaf appearance rate (phyllochron). Plastochron ranged between 24.3 and 36.4 degree days (degrees Cd), with a base temperature (Tb) between 4.0 and 8.2 degrees C. Phyllochron ranged between 48.6 and 65.5 degrees Cd, with a Tb between 2.9 and 5.0 degrees C. A single co-ordination model was fitted between the two processes for all hybrids and environments (r2= 0.96, P < 0.0001), and was successfully validated (coefficient of variation < 9 %). CONCLUSIONS: This work has established the existence of genotypic variability in leaf initiation rate and leaf appearance rate in response to temperature, which is a promising result for maize breeding; and the interdependence between these processes from seedling emergence up to floral initiation.

[Altitude, the ratio of PaO2 to fraction of inspired oxygen, and shunt: impact on the assessment of acute lung injury]. / La altitud modifica la relación entre la PaO2/FiO2 y el cortocircuito: impacto en la valoración de la lesión pulmonar aguda.

The ratio of PaO2 to the fraction of inspired oxygen (PaO2/FIO2) is commonly used to determine the severity of acute lung injury and acute respiratory distress syndrome (ARDS). The research presented here used computational models of the lung to analyze the effect of altitude on the PaO2/FIO2 ratio and pulmonary shunt. At a given shunt, the PaO2/FIO2 ratio is lower at higher altitudes. Therefore, when evaluating for ARDS based on a PaO2/FIO2 ratio of <200 mm Hg, patients residing at high altitudes will have less shunt and, presumably, less severe lung injury than patients at sea level. This should be taken into consideration when comparing patients from different altitudes. Shunt should more often be measured directly or be estimated assuming a constant arteriovenous oxygen content difference.

Diabetes modifies the male:female ratio in pulmonary tuberculosis.

SETTING: Socio-cultural factors have been invoked to explain the male predominance among patients with pulmonary tuberculosis, but there is no conclusive evidence of their role. OBJECTIVE: To assess male predominance in a group of diabetics with pulmonary tuberculosis compared with patients with pulmonary tuberculosis alone. DESIGN: Clinical records of in-patients with pulmonary tuberculosis and with (TBDM group, n = 202) or without (TB group, n = 226) diabetes mellitus were reviewed, and the male percentages in each of six age groups (15-29, 30-39, 40-49, 50-59, 60-69, > or = 70 years) calculated. RESULTS: In the TB group, no gender difference (51% males) was found in the first age period, followed by a male predominance thereafter (71%, 68%, 75%, 63% and 58%). The TBDM group showed a similar pattern in the first two age groups (56% and 74%), followed by a steadily decline (r(S) = -0.90, P = 0.04) in male percentage (60%, 44%, 45%, 27%), leading to a female predominance after age 50. The association of age and gender was also corroborated by logistic regression in TBDM (P = 0.02), but not in TB (P = 0.19) patients. CONCLUSIONS: Diabetes was associated with a progressive shift of male predominance in pulmonary tuberculosis. Because diabetes is a disease that affects social activities similarly in men and women, our results suggest that factors other than socio-cultural ones are also important for determining the male predominance in pulmonary tuberculosis.

Estudio serológico de durina y muermo equino / Serological Study dourine and equine glanders

Durine and Glanders are cronic and progressive infectious diseases of horses, donkeys and mules, and human beings in case of glanders. These diseases are caused by a parasite, Trypanosoma equiperdum (T. equiperdum) and a bacteria Burkholderia mallei (B. mallei), respectively. In Peru there are no information about the clinical and serological evidence of durine and glanders. The objective of this study was to detect antibodies against T. equiperdum and B. mallei in serum samples from horses (n=505) of normal appearance, and from different areas of Peru but mainly from Lima by using the complement fixation test. No antibodies against T. equiperdum and B. mallei were detected in the serum samples tested. These results suggest that both diseases are absent or the prevalence are below 1 percent in the studied Peruvian horses.

Treatment of American cutaneous leishmaniasis with miltefosine, an oral agent.

There is no recognized oral treatment for American cutaneous leishmaniasis. A rising-dose, open-label phase I/II trial of the oral agent miltefosine against Colombian cutaneous leishmaniasis was conducted. Seventy-two male Colombian soldiers (mean weight, 67 kg) received miltefosine at 50-100 mg/day for 3 weeks (for 32 evaluable patients) or at 133-150 mg/day for 3-4 weeks (for 32 evaluable patients). The per-protocol cure rate for 50-100 mg/day was 21 (66%) of 32 patients. The per-protocol cure rate for 133-150 mg/day was 30 (94%) of 32 patients (P =.01, by use of Fisher's exact test). The historic per-protocol cure rate for standard injections of antimony is 93%. "Motion sickness" that did not interfere with normal duties was experienced by 40% of patients and was dose related. Vomiting and diarrhea were reported on approximately 2% of treatment days. In this uncontrolled study of oral miltefosine for treatment of patients with American cutaneous leishmaniasis, a dosage of approximately 2.25 mg/kg/day for 3-4 weeks was effective and tolerated.