Electrical stimulation structurally affects the tissues of the rectum and anus of nulliparous rats.

Considering that the muscles of the anus perform a critical role in maintaining continence, losses in their structure can negatively affect the physiological control of the intestinal contents. Anorectal electro-stimulation (ARES) has been reported to have a positive effect on the functionality of treated patients, but how ARES affects the structural tissues of the anorectal segment remains unknown. Because the study of how ARES structurally affects human tissues is not possible, this study aimed to clarify these effects in a murine model, which has a similar anorectal segment (structure and physiology) to humans. For the descriptive and comparative study, randomly selected nulliparous adult Wistar rats (n = 5) were submitted to 30 anorectal sessions of ARES with a biphasic current (700 µs, 50 Hz from 2 to 4 mA). After treatment, the animals were euthanized, and the anorectal segments were dissected and processed for histopathological analysis. Our results showed that ARES increased the widths of the mucosal, submucosal and muscle layers of the rectum, as well as the number of leukocytes in the mucosa. ARES also caused hyperplasia of the smooth muscle of the internal anal sphincter and hypertrophy of the external anal sphincter muscle. In conclusion, our results showed that ARES had not only a positive effect on the structure (morphology) of all tissues associated with the rectum and anus but, more importantly, on the structural gain of the muscles (hyperplasia and hypertrophy), which could point to a functional gain of the anal sphincter, reinforcing the applicability of ARES as a non-invasive treatment for anal incontinence.

Bone mineral density and respiratory muscle strength in male individuals with mental retardation (with and without Down Syndrome).

The purpose of this study was to assess the respiratory muscle strength (RMS) in individuals with mental retardation (MR), with or without Down Syndrome (DS), and its association with bone mineral density (BMD). Forty-five male individuals (15 with DS, 15 with mental retardation (MR) and 15 apparently healthy controls), aged 20-35, participated in this study. Subject assessment included pulmonary function tests, RMS (maximal inspiratory pressure, MIP, and maximal expiratory pressure, MEP) and BMD of the second and fourth lumbar vertebrae. ANOVA was used to test differences amongst groups. Tukey post hoc test was utilized when significant differences were detected with ANOVA. Bivariate correlation for BMD and respiratory muscle strength was calculated with Pearson's coefficient of correlation. Individuals with MR, both with and without DS, have lower FEV1, FVC, MIP and MEP (p<0.001) compared to controls. Individuals with DS also had lower BMD, which was associated with lower MIP and MEP. Hypotonia, sedentary lifestyle and obesity are factors that may explain lower MIP and MEP in DS. Strategies to increase RMS could decrease the risk of osteoporosis in the DS population.