Comparison of gastric reactance with commonly used perfusion markers in a swine hypovolemic shock model.

BACKGROUND: The gut has been hypothesized to be a protagonist tissue in multiple organ dysfunction syndrome (MODS) for the past three decades. Gastric reactance (XL) is a potential perfusion marker derived from gastric impedance spectroscopy (GIS), which is an emerging tool through which living tissue can be continuously measured to determine its pathophysiological evolution. This study aimed to compare the performance of XL [positive predictive values (PPV), negative predictive values (NPV), and area under the curve (AUC)] against commonly used perfusion markers before and during hypovolemic shock in swine subjects. METHODS: Prospective, controlled animal trial with two groups, control group (CG) N = 5 and shock (MAP ≤ 48 mmHg) group (SG) N = 16. Comparison time points were defined as T-2 (2 h before shock), T-1 (1 h before shock), T0 (shock), T1 (1 h after shock), and T2 (2 h after shock). Shock severity was assessed through blood gases, systemic and hemodynamic variables, and via histological examination for assessing inflammation-edema and detachment in the gastric mucosa. Macroscopic assessment of the gastric mucosa was defined in five levels (0-normal mucosa, 1-stippling or epithelial hemorrhage, 2-pale mucosa, 3-violet mucosa, and 4-marmoreal mucosa). Receiver Operating Characteristic (ROC) curves of perfusion markers and XL were calculated to identify optimal cutoff values and their individual ability to predict hypovolemic shock. RESULTS: Comparison among the CG and the SG showed statistically significant differences in XL measurements at T-1, T0, T1, and T2, while lactate showed statistically significant differences until T1 and T2. Statistically significant differences were detected in mucosa class (p < 0.001) and in inflammation-edema in the gastric body and the fundus (p = 0.021 and p = 0.043). The performance of the minimum XL value per subject  per event (XL_Min) was better (0.81 ≤ AUC ≤ 0.96, 0.93 ≤ PPV ≤ 1.00, 0.45 ≤ NPV ≤ 0.83) than maximum lactate value (Lac_Max) per subject per event (0.29 ≤ AUC ≤ 0.82, 0.82 ≤ PPV ≤ 0.91, 0.24 ≤ NPV ≤ 0.82). Cutoff values for XL_Min show progressive increases at each time point, while cutoff values for Lac_Max increase only at T2. CONCLUSIONS: XL proved to be an indirect and consistent marker of inadequate gastric mucosal perfusion, which shows significant and detectable changes before commonly used markers of global perfusion under the hypovolemic shock conditions outlined in this work.

Migration intentions and illicit substance use among youth in central Mexico.

This study explored intentions to emigrate and substance use among youth (ages 14-24) from a central Mexico state with high emigration rates. Questionnaires were completed in 2007 by 702 students attending a probability sample of alternative secondary schools serving remote or poor communities. Linear and logistic regression analyses indicated that stronger intentions to emigrate predicted greater access to drugs, drug offers, and use of illicit drugs (marijuana, cocaine, inhalants), but not alcohol or cigarettes. Results are related to the healthy migrant theory and its applicability to youth with limited educational opportunities. The study's limitations are noted.

Gender differences in drug resistance skills of youth in Guanajuato, Mexico.

Research is limited or absent on Mexican adolescents' exposure to substance offers, ways of dealing with these offers, and possible gender differences in responses to offers. Extending U.S.-based research, this study examines how youth living in the Mexican state of Guanajuato employ the four drug resistance strategies-refuse, explain, avoid, and leave-that are part of the Keepin' It REAL evidence-based drug prevention intervention. The analysis uses cross-sectional survey data from 702 students enrolled in eight alternative secondary education sites in 2007. Participants reported the drug resistance behaviors they used to deal with offers of alcohol, cigarettes, and marijuana. Using multivariate regression, findings indicate most youth had developed repertoires of drug resistance strategies that involved multiple REAL strategies and some other strategy as well. For those receiving offers, the most common strategy was to refuse the offer with a simple "no." However, males used all the strategies significantly more often than females for situations involving cigarettes and marijuana as well as when using refuse and non-REAL strategies for alcohol. Possible reasons for the gender difference in use of strategies are discussed. The findings can help inform effective prevention programs based on teaching culturally appropriate drug resistance and communication skills.

The socialization of prosocial behavioral tendencies among Mexican American adolescents: The role of familism values.

This study investigates the role of familism values in fostering socialization experiences that promote prosocial behavioral tendencies among Mexican American adolescents. Two hundred and four Mexican American mothers and their adolescent children (104 girls, age M = 10.91 years) completed measures of familism values, prosocial parenting practices, and prosocial behavioral tendencies. Structural equation modeling tests indicated that mothers' familism values are related to parenting behaviors that promote prosocial behavioral tendencies, which in turn are related to adolescents' perception of prosocial parenting practices. Furthermore, adolescents' perception of prosocial parenting practices is related to familism values and prosocial behavior tendencies. Last, the relation between adolescents' perception of prosocial parenting practices and prosocial behavioral tendencies is partially mediated by familism values. These findings are consistent with the theoretical suggestion that the transmission of traditional familism values may serve as a social medium through which prosocial behavioral tendencies are fostered among Mexican American adolescents.

[Modification of a hydraulic device for controlled banding of the trunk of the pulmonary artery in dogs]. / Modificación de un dispositivo hidráulico para el bandaje controlado del tronco de la arteria pulmonar en caninos.

UNLABELLED: Different congenital or acquired diseases increase the right ventricular systolic pressure. The elevation is achieved by pulmonary artery banding with linen tape or hydraulic devices. We introduce a new hydraulic device to be used in experimental subjects of less than 15 kilograms. METHODS: An experimental laboratory phase was conducted. In this phase, the hydraulic devices were tested against pressures as high as 80 mm Hg; later on the hydraulic devices were placed on the dogs' main pulmonary artery; the right ventricular systolic pressure, pulmonary artery pressure, and their differences were obtained. The values are expressed in average +/- standard deviation. RESULTS: The average weight of the dogs was 12.6 +/- 2.2 kg. The average diameter found in the main pulmonary artery was 12.4 +/- 1.4 mm and 27.5 +/- 1.6 mm length. Right ventricular systolic pressure of basal condition to maximum pressure obtained was 25.5 +/- 1.9 mm Hg vs 50.3 +/- 6.9 mm Hg, p < 0.0001; pulmonary artery pressures under the same conditions were 24.7 +/- 2 mm Hg vs 21.5 +/- 6.9 mm Hg, p < 0.043; and the differences between them were 0.8 +/- 1.4 mm Hg vs 28.8 +/- 4.2 mm Hg, p < 0.0001, developed by the hydraulic device respectively. CONCLUSIONS: The hydraulic device allows attaining a controlled acute increase in right ventricular systolic pressure.

Modificación de un dispositivo hidráulico para el bandaje controlado del tronco de la arteria pulmonar en caninos / Modification of a hydraulic device for controlled banding of the trunk of the pulmonary artery in dogs

Diversas enfermedades congénitas o adquiridas incrementan la presión sistólica del ventrículo derecho. Este incremento se ha realizado con el bandaje del tronco arterial pulmonar con cintas de lino o dispositivos hidráulicos. Presentamos un nuevo dispositivo hidráulico para ser usado en sujetos experimentales menores a 15 kilogramos. Material y métodos: Se realizó una fase experimental de laboratorio donde los dispositivos hidráulicos fueron probados contra presiones hasta de 80 mm Hg; posteriormente se colocaron en el tronco de la arteria pulmonar de perros donde se les determinó la presión sistólica del ventrículo derecho, la de la arteria pulmonar y el gradiente de ambos. Los valores se expresaron en medias ± desviación estándar. Resultados: El peso de los perros fue 12.6 ± 2.2 kilogramos. El diámetro del tronco de la arteria pulmonar encontrado en los perros fue de 12.4 ± 1.4 mm y 27.5 ± 1.6 mm de largo. Las presiones sistólicas ventriculares derechas en condición basal y de máxima elevación fueron: 25.5 ± 1.9 mm Hg vs 50.3 ± 6.9 mm Hg, p < 0.0001; las presiones sistólicas de la arteria pulmonar para estas mismas condiciones fueron: 24.7 ± 2 mm Hg vs 21.5 ± 6.9 mm Hg, p < 0.043; y el respectivo gradiente de ambas para estas presiones fueron: 0.8 ± 1.4 mm Hg vs 28.8 ± 4.2 mm Hg, p < 0.0001. Conclusiones: El DH permite el incremento agudo controlado de la presión sistólica del ventrículo derecho.

Different congenital or acquired diseases increase the right ventricular systolic pressure. The elevation is achieved by pulmonary artery banding with linen tape or hydraulic devices. We introduce a new hydraulic device to be used in experimental subjects of less than 15 kilograms. Methods: An experimental laboratory phase was conducted. In this phase, the hydraulic devices were tested against pressures as high as 80 mm Hg; later on the hydraulic devices were placed on the dogs' main pulmonary artery; the right ventricular systolic pressure, pulmonary artery pressure, and their differences were obtained. The values are expressed in average ± standard deviation. Results: The average weight of the dogs was 12.6 ± 2.2 kg. The average diameter found in the main pulmonary artery was 12.4 ± 1.4 mm and 27.5 ± 1.6 mm length. Right ventricular systolic pressure of basal condition to maximum pressure obtained was 25.5 ± 1.9 mm Hg vs 50.3 ± 6.9 mm Hg, p < 0.0001; pulmonary artery pressures under the same conditions were 24.7 ± 2 mm Hg vs 21.5 ± 6.9 mm Hg, p < 0.043; and the differences between them were 0.8 ± 1.4 mm Hg vs 28.8 ± 4.2 mm Hg, p < 0.0001, developed by the hydraulic device respectively. Conclusions: The hydraulic device allows attaining a controlled acute increase in right ventricular systolic pressure.