Electrophysiological study of the rectosigmoid canal: evidence of a rectosigmoid sphincter

Previous studies strongly suggest the presence of a sphincter at the rectosigmoid junction, an area with a mean length of 2.8 cm in adults, called the rectosigmoid canal (RSC). To find supporting evidence of a sphincteric function for the RSC, two recording electrodes were applied to each of the sigmoid colon (SC), RSC and rectum (R) in 11 subjects during operative repair of huge incisional hernias. The RSC, SC and R were individually stimulated by a further electrode and their pressures monitored by a three-channel microtip catheter. The variables of the slow waves or pacesetter potentials, recorded at rest from the RSC and R, were significantly higher than those of the SC. While the frequency and conduction velocity of pacesetter potentials of the RSC and R were similar, the potential pacesetter amplitude of the RSC was significantly higher. The increase of the electrical activity and pressure upon electrostimulation was significantly greater in the RSC than that of the SC or R. Electrostimulation led to an increase in pressure of all three areas, the RSC increase being significantly the greatest. The greater increase of the electrical activity and pressure of the rectosigmoid canal upon electrostimulation, compared to that of the SC or R, strongly supports the presence of a rectosigmoid sphincter.     

Gamma-radiation sensitivity and risk of glioma

BACKGROUND: About 9% of human cancers are brain tumors, of which 90% are gliomas. gamma-Radiation has been identified as a risk factor for brain tumors. In a previous pilot study, we found that lymphocytes from patients with glioma were more sensitive to gamma-radiation than were lymphocytes from matched control subjects. In this larger case-control study, we compared the gamma-radiation sensitivity of lymphocytes from glioma patients with those from control subjects and investigated the association between mutagen sensitivity and the risk for developing glioma. METHODS: We used a mutagen sensitivity assay (an indirect measure of DNA repair activity) to assess chromosomal damage. We gamma-irradiated (1.5 Gy) short-term lymphocyte cultures from 219 case patients with glioma and from 238 healthy control subjects frequency matched by age and sex. After irradiation, cells were cultured for 4 hours, and then Colcemid was added for 1 hour to arrest cells in mitosis. Fifty metaphases were randomly selected for each sample and scored for chromatid breaks. All statistical tests were two-sided. RESULTS: We observed a statistically significantly higher frequency of chromatid breaks per cell from case patients with glioma (mean = 0.55; 95% confidence interval [CI] = 0.50 to 0.59) than from control subjects (mean = 0.44; 95% CI = 0.41 to 0.48) (P<.001). Using 0.40 (the median number of chromatid breaks per cell in control subjects) as the cut point for defining mutagen sensitivity and adjusting for age, sex, and smoking status, we found that mutagen sensitivity was statistically significantly associated with an increased risk for glioma (odds ratio = 2.09; 95% CI = 1.43 to 3.06). When the data were divided into tertiles, the relative risk for glioma increased from the lowest tertile to the highest tertile (trend test, P<.001). CONCLUSION: gamma-Radiation-induced mutagen sensitivity of lymphocytes may be associated with an increased risk for glioma, a result that supports our earlier preliminary findings.     

Parental Ranking of Terms Describing Nonepileptic Events

Paroxysmal nonepileptic events of psychogenic etiology in children and adolescents are common. Patients and their parents are often confused by the terminology used to describe these events. This can lead to frustration and may result in the failure to obtain the necessary nonpharmacologic treatment. Various terms are used to describe such events, some of which might be considered offensive to some individuals. Surveys from 146 parents or guardians of patients identified from a general pediatric clinic, a general neurology clinic, and a pediatric epilepsy monitoring unit were completed with the aim of determining which words and phrases were least offensive. It was determined that nonepileptic events, functional seizures, and nonepileptic attack disorder were the least offensive labels; whereas “it is all in his or her head,” hysterical seizures, and psychogenic seizures were the most offensive terms. This is the only study of its type in the pediatric population. Although each child and family requires individualized communication, we hope that this article will provide useful information to guide the practicing pediatric neurologist in informing families that their children are having events of nonepileptic etiology.     

HIV and HCV prevalence and incarceration-related risks among injecting drug users in three West Bank governorates

In the Middle East, the HIV epidemic among injecting drug users (IDUs) seems to be in an early phase, which increases the importance of prevention and systematic risk surveillance. To gain information about HIV and HCV infection rates among IDUs in the West Bank, a biobehavioral survey was conducted using time-location sampling in the Ramallah, Hebron, and Bethlehem governorates in 2013. The researchers recruited 288 Palestinian IDUs ages 16–64 (M_age?=?39.2, SD?=?11.11). While no HIV cases were found in the sample, 41% of participants tested positive for HCV. Imprisonment was common among participants (83%), so we explored the association of incarceration experience with HCV infection and HIV testing. In multivariate assessments, incarceration was shown to increase the odds of being infected with HCV and ever tested for HIV. HIV prevention should be strengthened in West Bank prisons and correctional facilities, and imprisonment for drug use re-examined.     

Transplantation of the uterus

Most women with uterine factor infertility have today no prospect of carrying a pregnancy to term. The development of a method for transplantation of the human uterus would be a means for many of these women to become both genetic and gestational mothers. In this article we review the literature concerning the history and recent development in the area of uterine transplantation. We describe our newly developed model for heterotopic uterine transplantation in the mouse, which we are using for studies of pregnancy outcome and rejection mechanisms. We also address some of the specific questions that need to be solved before attempts to transplant the human uterus should be performed.     

Mitral valve surgery in patients with ischemic and nonischemic dilated cardiomyopathy

Congestive heart failure (CHF) is a chronic, progressive disease and its central element is the remodeling of the cardiac chamber associated with ventricular dilatation. Secondary mitral regurgitation is a complication of end-stage cardiomyopathy and is associated with a poor prognosis. It is due to progressive mitral annular dilatation and alteration in the geometry of the left ventricle. A vicious cycle of continuing volume overload, ventricular dilatation, progression of annular dilatation, increased left ventricular wall tension and worsening mitral regurgitation and CHF occurs. The mainstays of medical therapy are diuretics and afterload reduction, which are associated with poor long-term survival in these patients. Historically, the surgical approach to patients with mitral regurgitation was mitral valve replacement, but these patients were not considered operative candidates because of their high morbidity and mortality. Heart transplantation is now considered standard treatment for select patients with end-stage heart disease; however, it is applicable only to a small number of patients. Mitral valve replacement in these patients is associated with adverse consequences on left ventricular systolic function resulting from interruption of the annulus-papillary muscle continuity. Preserving the mitral valve apparatus and left ventricle in mitral valve repair enhances and maintains left ventricular function and geometry with an associated decrease in wall stress. Using these operative techniques to alter the shape of the left ventricle, in combination with optimal medical management for heart failure, improves survival and may avoid or postpone transplantation.