Variation of the anal resting pressure induced by postexpiratory apnea effort in patients with constipation

CONTEXT: Intestinal constipation - a common symptom among the general population - is more frequent in women. It may be secondary to an improper diet or organic or functional disturbances, such as dyskinesia of the pelvic floor. This is basically characterized by the absence of relaxation or paradoxical contraction of the pelvic floor and anal sphincter during evacuation. OBJECTIVE: To analyze, by manometric data, the anal pressure variation at rest, during evacuation effort by using the Valsalva maneuver and forced post-expiratory apnea in subjects with secondary constipation. METHODS: Twenty-one patients (19 females - 90.4%) with a mean age of 47.5 years old (23-72) were studied. The diagnosis was performed using anorectal manometry, with a catheter containing eight channels disposed at the axial axis, measuring the proximal (1) and distal (2) portions of the anal orifice. The elevation of the pressure values in relation to the resting with the evacuation effort was present in all patients. The Agachan score was used for clinical evaluation of constipation. The variables studied were: mean anal pressure of the anal orifice for 20 seconds at rest, the effort of evacuation using Valsalva maneuver and the effort of evacuation during apnea after forced expiration, as well as the area under the curve of the manometric tracing at moments Valsalva and apnea. RESULTS: The analysis of the mean values of the anal pressure variation at rest evidenced difference between proximal and distal channels (P = 0.007), independent of the moment and tendency to differ during moments Valsalva and apnea (P = 0.06). The mean of values of the area under the manometric tracing curve showed differences between moments Valsalva and apnea (P = 0.0008), either at the proximal portion or at the distal portion of the anal orifice. CONCLUSION: The effort of evacuation associated with postexpiratory apnea, when compared with the effort associated with the Valsalva maneuver, provides lower elevation of anal pressure at rest by the parameter area under the curve

Social network correlates of HIV risk-related behaviors among male migrants in China

Abstract Background Significant domestic and global research has focused on HIV risk among China’s large internal migrant population. Much of this work takes an individual behavior approach while ignoring the critical role social networks play in shaping HIV risk. Methods Based on past studies among migrant men in China of yingchou activities (activities that build and reinforce social networks such as eating, drinking alcohol and patronizing commercial sex), we constructed ego-centric networks for a sample of 385 male migrants recruited from multiple worksites in Beijing. We used a nested-model approach to examine the contribution of social network characteristics to HIV risk at both the variable and model levels. Results As compared to an individual-level model, addition of social network variables significantly improved the fit of the models. Commercial sex norms and condom use norms of core yingchou networks were significantly associated with egos’ commercial sex and condom use respectively. The size of yingchou network was associated with egos’ commercial sex. The network models became more sensitive after network norm measures took into account the intimacy of network ties and allowed for egos’ uncertainty when reporting their alters’ sexual behaviors. Conclusion Results suggest the importance of social network factors and core network members in HIV transmission and risk-reduction interventions for male migrants. Future studies could explore other important social networks among male migrants, consider the intimacy of network ties and egos’ uncertainty about alters’ situations in constructing network norms, and refine the measurement of network size and density