Association of airborne particulate matter with pollen, fungal spores, and allergic symptoms in an arid urbanized area.

Studies focused on the seasonal distribution of pollen and spores in semiarid cities are scarce. At these sites, climate change potentiates the emission and transport of fine (PM10) to ultrafine particles (PM2.5), easily attached to pollen surfaces, causing allergen's release. This study examines the potential correlation of seasonal variations of pollen, fungal spores, PM10, and meteorological parameters with allergic reactions of 150 people living in a Sonoran desert city. We collected PM10, airborne pollen, and spores during a year. We also studied topsoil and road dust samples as potential PM-emission sources. We obtained dust-mineralogy, chemistry, and particle size attached to pollen by X-ray diffraction and scanning electron microscope. Results show that seasonal high PM-loading in the urban atmosphere coincides with aeroallergens promoting micro- to nanoparticles' attachment to pollen's surface. A collapsed membrane was observed in several samples after individual grains show the following maximum wall coverage: Poaceae 28%, Asteraceae 40%, Chenopodiaceae-Amaranthacea 29%, Fabaceae 18%. Most of the particles covering pollen's surface have a geogenic origin mixed with metals linked to traffic (bromide, chlorine, and antimony). Mineralogical, granulometric analysis, and main wind-direction show that two local soil-types are the main contributors to PM. A high frequency of positive sensitization to pollen with high particle loading was detected. These results suggest that climate-driven dust emissions may alter pollen and spore surfaces' physicochemical characteristics with the further consequences in their allergenic potential.

Draft Genome Sequence of a Mycobacterium africanum Clinical Isolate from Antioquia, Colombia.

Mycobacterium africanum is a member of the Mycobacterium tuberculosis complex. Most commonly found in West African countries, it has scarcely been described in South America. Here, we report the first genome sequence of a Colombian M. africanum clinical isolate. It is composed of 4,493,502 bp, with 4,069 genes.

Implementación de un Demodulador Heterodino para la Discriminación del Sentido del Flujo Sanguíneo en un Detector Doppler Ultrasónico Bi-direccional / Implementation of a heterodyne demodulator for blood flow sense discrimination in a bi-directional ultrasonic Doppler detector

Los sistemas Doppler ultrasónicos han sido utilizados ampliamente en el diagnóstico médico, en general en el estudio de flujo sanguíneo y en particular en el diagnóstico de padecimientos vasculares. Esto se debe principalmente a su carácter no invasivo y su relativo bajo costo. Una característica importante de los sistemas Doppler ultrasónicos es la de poder detectar la señal asociada con el flujo sanguíneo y discriminar la dirección del mismo. La señal Doppler ultrasónica contiene información asociada con la velocidad de los componentes de la sangre, y su espectro en frecuencia representa el perfil de velocidad del flujo sanguíneo, que puede ser de sentido directo o inverso. Típicamente los sistemas Doppler ultrasónicos que detectan el sentido de la dirección de flujo sanguíneo de la señal, se basan en métodos de demodulación homodina en cuadratura. Sin embargo las señales producidas por este tipo de detectores requieren de un proceso adicional de separación. Este trabajo aborda la implementación de un demodulador heterodino que forma parte de un detector Doppler ultrasónico para la medición de flujo sanguíneo bi-direccional. Se describe el principio de la detección de la señal Doppler ultrasónica de flujo sanguíneo y su representación en la forma de un espectrograma de dos dimensiones, así como también los dispositivos detectores Doppler de flujo sanguíneo, su clasificación de acuerdo a su modo de operación y tipo de demodulación. Finalmente se presentan pruebas de funcionalidad y se analizan los resultados obtenidos contrastándolos con los resultados teóricos.

Doppler ultrasound systems have been widely used in medical diagnosis, in the study of blood flow, in particular, in the diagnosis of vascular disorders. This is mainly due to its non-invasive method and its relatively low cost. An important feature of the ultrasonic Doppler system is the capability to detect the signal associated with the blood flow and discriminate its direction. The Doppler ultrasound signal contains information associated with the velocity of the blood components, and its frequency spectrum represents the velocity profile of blood flow, which may be direct or reverse. Typically Doppler ultrasound systems which detect the sense of the direction of blood flow signal, are based on methods of homodyne demodulation in quadrature. However the signals produced by these detectors require an additional separation process. This paper addresses the implementation of a heterodyne demodulator as a part of a Doppler ultrasound detector for measuring bi-directional blood flow. We describe the detection process of the Doppler ultrasound blood flow signal and its representation in the form of a two-dimensional spectrogram. Doppler blood flow sensing devices and their classification according to their operation mode and type of demodulation are also described. Finally, functionality tests are presented and results are analyzed.

Epstein-Barr virus-specific CD8(+) T lymphocytes from diffuse large B cell lymphoma patients are functionally impaired.

Epstein-Barr virus (EBV) is a persistent virus with oncogenic capacity that has been implicated in the development of aggressive B cell lymphomas, primarily in immunosuppressed individuals, although it can be present in immunocompetent individuals. Changes in the function and clonal diversity of T lymphocytes might be implied by viral persistence and lymphoma development. The aim of the present study was to evaluate the frequency, phenotype, function and clonotypical distribution of EBV-specific T cells after peripheral blood stimulation with a virus lysate in newly diagnosed patients with diffuse large B cell lymphoma (DLBCL) aged more than 50 years without prior histories of clinical immunosuppression compared with healthy controls. Our results showed impaired EBV-specific immune responses among DLBCL patients that were associated primarily with decreased numbers of central and effector memory CD8(+) T lymphocytes. In contrast to healthy controls, only a minority of the patients showed CD4(+)/tumour necrosis factor (TNF)-α(+) T cells expressing T cell receptor (TCR)-Vß17 and CD8(+)/TNF-α(+) T cells with TCR-Vß5·2, Vß9 and Vß18 in response to EBV. Notably, the production of TNF-α was undetectable among TCR-Vß5·3(+), Vß11(+), Vß12(+), Vß16(+) and Vß23(+) CD8(+) T cells. In addition, we observed decreased numbers of CD4(+)/TNF-α(+) and CD8(+)/TNF-α(+), CD8(+)/interleukin (IL)-2(+) and CD8(+)/TNF-α(+)/IL-2(+) T lymphocytes in the absence of T cells capable of producing TNF-α, IL-2 and IFN-γ after EBV stimulation simultaneously. Moreover, DLBCL patients displayed higher IL-10 levels both under baseline conditions and after EBV stimulation. These findings were also observed in patients with positive EBV viral loads. Prospective studies including a large number of patients are needed to confirm these findings.

On the prediction of Hodgkin lymphoma treatment response.

PURPOSE: The cure rate in Hodgkin lymphoma is high, but the response along with treatment is still unpredictable and highly variable among patients. Detecting those patients who do not respond to treatment at early stages could bring improvements in their treatment. This research tries to identify the main biological prognostic variables currently gathered at diagnosis and design a simple machine learning methodology to help physicians improve the treatment response assessment. METHODS: We carried out a retrospective analysis of the response to treatment of a cohort of 263 Caucasians who were diagnosed with Hodgkin lymphoma in Asturias (Spain). For that purpose, we used a list of 35 clinical and biological variables that are currently measured at diagnosis before any treatment begins. To establish the list of most discriminatory prognostic variables for treatment response, we designed a machine learning approach based on two different feature selection methods (Fisher's ratio and maximum percentile distance) and backwards recursive feature elimination using a nearest-neighbor classifier (k-NN). The weights of the k-NN classifier were optimized using different terms of the confusion matrix (true- and false-positive rates) to minimize risk in the decisions. RESULTS AND CONCLUSIONS: We found that the optimum strategy to predict treatment response in Hodgkin lymphoma consists in solving two different binary classification problems, discriminating first if the patient is in progressive disease; if not, then discerning among complete and partial remission. Serum ferritin turned to be the most discriminatory variable in predicting treatment response, followed by alanine aminotransferase and alkaline phosphatase. The importance of these prognostic variables suggests a close relationship between inflammation, iron overload, liver damage and the extension of the disease.

Detección del Sentido del Flujo Sanguíneo Utilizando Demodulación Heterodina para un Sistema Doppler Ultrasónico y su Validación Mediante Simulación / Detection of the Blood Flow Direction Using Heterodyne Demodulation for a Doppler Ultrasound System and its Validation by Simulation

La flujometría Doppler ultrasónica ha sido ampliamente utilizada en el diagnóstico de enfermedades vasculares. Aquellos sistemas que detectan el sentido de la dirección de la señal de flujo, pueden utilizar durante su operación señales producto de la demodulación homodina en cuadratura con el inconveniente de tener que procesar los dos canales (fase y cuadratura) para igualar sus amplitudes y mantener estas características en todo el ancho de banda de las señales. En este artículo se propone un método alternativo para separar el sentido de la dirección de la señal de flujo usando demodulación heterodina, el cual consiste en trasladar la banda de frecuencias de la señal de información Doppler a un origen desplazado al menos el ancho de banda de la señal. Este método tiene la ventaja de simplificar la etapa analógica de la adquisición de la señal Doppler, al utilizar una demodulación en un solo canal. Los resultados de las simulaciones llevadas a cabo en este trabajo muestran la efectividad del método al separar el sentido de la dirección del flujo de forma eficiente en el dominio de la frecuencia, evitando la generación de artefactos en la banda de interés.

Doppler ultrasound blood flow measurement techniques have been widely used for the diagnosis of vascular diseases. In particular, some Doppler systems which may be able to determine the blood flow direction use signals produced by the homodyne quadrature demodulation technique. This approach has a major disadvantage, since it has to process two channels (phase and quadrature), to equalize them (in amplitude) and to maintain these characteristics throughout the complete signal bandwidth. The work presented here, proposes an alternative method to determine the blood flow direction using heterodyne demodulation. The technique involves shifting the complete band of frequencies (where information of interest lies), at least a frequency equal to the bandwidth of the Doppler signal. This method simplifies the analog stage for the acquisition of the Doppler signal since it only needs to process one channel. Results of simulations show the effectiveness of the approach by determining the blood flow direction efficiently, in the frequency domain. It also reduces the generation of artifacts, in the band of interest, caused by differences in the phase and quadrature channels.

The effect of single-file reciprocating systems on Substance P and Calcitonin gene-related peptide expression in human periodontal ligament.

AIM: To quantify the effect of two single-file reciprocating root canal preparation systems on Substance P (SP) and Calcitonin gene-related peptide (CGRP) expression in healthy human periodontal ligament (PDL). METHODOLOGY: Forty PDL samples were obtained from healthy premolars where extraction was indicated for orthodontic reasons. Prior to extraction, 20 of these premolars were divided equally in two groups, and then, root canals were prepared using one of two different single-file systems: WaveOne and Reciproc. Ten premolars were prepared with hand files and served as a positive control group. The remaining 10 premolars where extracted without treatment and served as a negative control group. All PDL samples were processed, and SP and CGRP were measured by radioimmunoassay. RESULTS: Greater SP and CGRP expression were found in the hand instrumentation group (1.220 pmol SP and 0.084 pmol CGRP per mg of PDL), followed by the WaveOne group (0.908 pmol SP and 0.046 pmol CGRP per mg of PDL) and the Reciproc group (0.511 pmol SP and 0.022 pmol CGRP per mg of PDL). The lower SP and CGRP values were associated with the intact control group (0.453 pmol SP and 0.018 pmol CGRP per mg of PDL). The Kruskal-Wallis test revealed significant differences between groups (P < 0.001). Post hoc Tukey HSD tests revealed significant differences in SP and CGRP expression between intact teeth in the control group and all the other groups (P < 0.001) except with the Reciproc group (P = 0.165 and P = 0.42 for SP and CGRP, respectively). Hand instrumentation was associated with significant differences with all the other groups (P < 0.001). Differences between the WaveOne and Reciproc groups were also significant (P < 0.001). CONCLUSION: Substance P and CGRP expression in PDL cells increased when teeth were prepared with WaveOne as well as with hand instrumentation. Reciproc maintained SP and CGRP levels in line with the negative control group.

[Impact of consumption of corn flour with low level enrichment in children of rural zones]. / Impacto del consumo de harina de maíz con un bajo nivel de enriquecimiento en niños de zonas rurales.

INTRODUCTION: Corn has been from the prehispanic era, the most important feeding plant in the Mexican population, particularly in the most important sectors and in marginal areas. In this setting, enriching the product as flour implies an increase in its nutritional quality, especially because corn is the basic food. OBJECTIVE: To assess the effect of the consumption of corn flour enriched with 3% soybean, vitamins, and minerals on the growth and development of infants and preschool children. MATERIAL AND METHODS: experimental study lasting 10 months. The experimental group (n=195) received enriched corn flour whereas the control group (n=200) received non-enriched flour. The indicators were: nutritional status, mental and psychomotor development, and blood hemoglobin levels. RESULTS: in the total sample, there were no differences between the experimental group and the control group. However, there were improvements in the weight-to-height and weight-to-age indexes in the children consuming enriched flour and in children older than one year, who were the babies of indigenous women living in marginal areas. CONCLUSIONS: enriched corn flour appears to be an alternative benefitting the children population with higher nutritional deficiencies. However, a longer intervention is necessary to obtain better results.

Coarsening in potential and nonpotential models of oblique stripe patterns.

We study the coarsening of two-dimensional oblique stripe patterns by numerically solving potential and nonpotential anisotropic Swift-Hohenberg equations. Close to onset, all models exhibit isotropic coarsening with a single characteristic length scale growing in time as t1/2. Further from onset, the characteristic lengths along the preferred directions x and y grow with different exponents, close to 1/3 and 1/2, respectively. In this regime, one-dimensional dynamical scaling relations hold. We draw an analogy between this problem and model A in a stationary, modulated external field. For deep quenches, nonpotential effects produce a complicated dislocation dynamics that can lead to either arrested or faster-than-power-law growth, depending on the model considered. In the arrested case, small isolated domains shrink down to a finite size and fail to disappear. A comparison with available experimental results for electroconvection in nematics is presented.

The effect of social rank on the physiological response during repeated stressful handling in Zebu cattle (Bos indicus).

Although the order of entry to a handling chute is related to social rank, it is still not clear what the consequences are for Zebu cattle of occupying different ranks when being exposed repeatedly to a stressful handling procedure. Eighteen Brahman cows were observed for 243 h to obtain information on social interactions. From that information, indices of success in displacing other individuals of the herd were calculated to reflect social status of each cow. One week after behavioral observations, the cows were forced 19 times to enter a handling chute where they were palpated and 7 ml of blood was collected from their caudal vein. To have an adrenal activity profile along the experimental period, five blood samples (Days 2, 6, 10, 15, and 19) were chosen for cortisol determination. On each sampling day, the average time in the chute, the order of entry, and a value of entrance consistency were calculated. On average, the high-ranking cows entered the chute before the medium- and low-ranking cows. Medium-ranking cows showed higher consistency when entering the race than high- and low-ranking cows. Low-ranking cows had significantly lower cortisol levels than the other two groups since the second sample (Day 6 in the race), and had higher cortisol levels the first time handled than at subsequent sampling days. It is suggested that low-ranking cows adopt a passive strategy that allows them to have a better control over the stressful event, while high-ranking cows respond with higher cortisol levels perhaps because of the need to become aroused to deal with challenges. It was concluded that the herd (a) habituated to repeat handling in a squeeze chute and (b) low-ranking cows responded with lower cortisol concentration to handling.

Algorithms to calculate the AQD distribution with exponential Kernel for ultrasonic doppler blood flow measurement

One of the main goals in ultrasonic Doppler blood flow assessment in the estimation of the mean speed. The aim of this work is focused in Carotid artery blood flow signals...

Hydrodynamic interactions in quasi-two-dimensional colloidal suspensions.

The effects of the hydrodynamic interactions on the short-time dynamics of colloidal, hard-sphere-like particles confined between two parallel walls are measured by digital videomicroscopy. We find that such effects can be described in terms of an effective two-dimensional hydrodynamic function H(k), defined as a straightforward adaptation to two dimensions of the corresponding object describing collective dynamics for the three-dimensional (3D) suspensions. Interestingly, the behavior of H(k) is qualitatively similar to the hydrodynamic function of 3D suspensions of hard spheres. We also found that for values of k where the static structure factor is 1, the dynamics is determined only by self-diffusion.

Some effects of repeated handling and the use of a mask on stress responses in zebu cattle during restraint.

The objective of this investigation was to evaluate the effect of repeated handling and the use of a mask on the order of entry, temperament, cortisol concentration and heart and respiratory rates of Brahman cattle during restraint in a squeeze chute. In the first experiment, 18 cows were restrained in the chute for 10min on 19 test-days and blood samples were collected during five of the trials. Habituation to handling was reflected by a decrease in cortisol concentration as the study advanced (P<0.01). In the second experiment, conducted 6 months later, animals were randomly allotted to two groups, alternating the use of a mask over test-days while restraining the cows in the chute for 3min. Respiratory and heart rates were measured at the beginning and end of each 3min trial. A blood sample was also taken at the end of each trial. Respiratory rates decreased while the animals were restrained and this decrease tended to be greater (P=0.09) when the animals were wearing masks (3.06) than when not (2.2breaths/min). Heart rates also decreased and more so for masked animals (10.6beats/min) than for non-masked (5.0, P<0.01). Cortisol values tended to be higher (9.9 versus 4.7ng/ml, P=0.08) when animals were restrained without a mask. Temperament scores were lower (P>0.01) when cows were masked and have a relative high correlation (r=0.58) with flight distance values, (P<0.05). Finally, the order of entrance was found consistent over test-days, (P<0.01). It is concluded that Brahman cattle: (a) habituate to repeat handling in a squeeze chute; (b) are less emotionally reactive when their eyes were covered during this process and (c) establish a repeatable order of entrance to the chute.

Sexual behavior of Zebu cattle (Bos indicus) following estrous induction by Syncro-Mate B, with or without estrogen injection.

The effect of estrogen administered with norgestomet implants in the expression of behavioral estrous of Zebu cattle was studied in a herd of 18 cycling Brahman cows, in two trials. In the first and second trials, six different cows were treated with progestagen on successive days. In addition, in the first trial, estrogen injection was applied with the treatment. With the purpose of enhancing mounting behavior in treated and/or non-treated animals, on the third day of each trial, three other cows with an active CL were injected with 25 mg of PGF2alpha. All animals were examined three times a week by rectal ultrasound, and a blood sample was also taken for progesterone analysis. Sexual activity was monitored by a closed-circuit TV from 1500 to 0600 h. Direct observation was carried out from 0900 to 1200 h. A total of 15 cows displayed 36 mounting periods (11 with ovulation). Twenty-five annovulatory estrous periods were observed, 77% supported by large follicles. More cows (66% vs. 16%) showed mounting activity when estradiol valerate was used as part of the progestagen treatment (P=.03). Ovulation rate in response to the effect of norgestomet implant was 16%, independent of treatment. It is concluded that estrogen administered with norgestomet implants increases the expression of behavioral estrous in Bos indicus cattle but does not improve ovulation rate.

[Lactose deficient intestinal absorption (LDIA) in a population of healthy Mexican children studied with the hydrogen ion test in air breathing]. / Absorcíon intestinal deficiente de lactosa (AIDL) en una población de niños mexicanos sanos por medio de la prueba de iones hidrogeno en aire espirado.

We studied 100 healthy children looking for lactose malabsortion. We performed in all of them the lactose breath test. We found a 10% with lactose malabsortion. There was no correlation between lactose breath test and fecal reducing substances.

Absorcion intestinal deficiente de lactosa (AIDL) en una poblacion de ninos mexicanos sanos por medio de la prueba de iones hidrogeno en aire espirado / Lactase defficient intestinal absortion (LDIA) in a population of healthy mexican children through the test of hydorgenion in air breathing

Se estudiaron 100 niños sanos, para determinar si presentaban o no absorción intestinal deficiente de lactosa (AIDL), por medio de la prueba de iones hidrógeno en el aire espirado, que asistieron a la consulta externa del servicio de Gastroenterología del Instituto Nacional de Pediatría de la ciudad de México durante el lapso comprendido entre noviembre de 1993 y febrero de 1994. La prevalencia de AIDL encontrada en este estudio fue del 10 por ciento. No existió una asociación estadisticamente significativa entre la prueba de iones hidrógenos y la determinación de pH y azúcares reductores en heces para el diagnóstico de AIDL. (AU)

Absorcion intestinal deficiente de lactosa (AIDL) en una poblacion de ninos mexicanos sanos por medio de la prueba de iones hidrogeno en aire espirado / Lactase defficient intestinal absortion (LDIA) in a population of healthy mexican children through the test of hydorgenion in air breathing

Se estudiaron 100 niños sanos, para determinar si presentaban o no absorción intestinal deficiente de lactosa (AIDL), por medio de la prueba de iones hidrógeno en el aire espirado, que asistieron a la consulta externa del servicio de Gastroenterología del Instituto Nacional de Pediatría de la ciudad de México durante el lapso comprendido entre noviembre de 1993 y febrero de 1994. La prevalencia de AIDL encontrada en este estudio fue del 10 por ciento. No existió una asociación estadisticamente significativa entre la prueba de iones hidrógenos y la determinación de pH y azúcares reductores en heces para el diagnóstico de AIDL.

Gastrostomía endoscópica percutánea: Una experiencia multicéntrica

El objetivo fue presentar la experiencia con dos variantes técnicas de la Gastrostomía Endoscópica Percutánea (GEP). Fueron practicadas 78 GEP, 63 por ciento por la técnica de deslizamiento y 37 por ciento por tracción, 44 mujeres (57 por ciento) y 34 hombres (43 por ciento) de 6 a 94 años, con enfermedades del sistema nervioso central en 89.6 por ciento de los casos. No fueron observadas diferencias estadísticas en los resultados dependientes de la institución ni el uso o no de antibióticos. Las complicaciones fueron más frecuentes durante las primeras 24 horas y después del séptimo día con la técnica por tracción, durante su estandarización. Los pacientes desnutridos tuvieron más complicaciones asociadas al procedimiento. Se concluye que la GEP es una técnica practicable en cualquier servicio de endoscopia, de bajo riesgo, con baja frecuencia de complicaciones y relacionadas con el estado nutricional del paciente y grado de pericia adquirido

Prevalencia de anticuerpos para el virus de la hepatitis C en donadores de sangre, Hospital México / Prevalence of antibodies to hepatitis C virus in blood donors in México Hospital

Se analizaron 2544 sueros de donadores de sangre a los que se les determinó anticuerpos para el virus de la Hepatitis C (HCV). Se obtuvo una prevalencia del 0.24 por ciento, utilizando el método de ELISA. Ninguno de los donadores que dieron la prueba reactiva mostró un patrón de alanina aminotransferasa (ALT) alterado.

Estenosis esofágicas benignas

La estenosis esofágica es una enfermedad común que puede presentarse a cualquier edad. Es más frecuente en ancianos y, a pesar de los avances en el control y tratamiento del reflujo gastroesofágico,continua presentando un serio problema de diagnóstico y manejo. En este trabajo resivimos en concepto general de la enfermedad, su etiología y sus formas de tratamiento más aceptadas hasta el momento