The Role of the Crista Terminalis in Atrial Flutter and Fibrillation: A Computer Modeling Study

Although atrial fibrillation is a common arrhythmia, the underlying mechanisms are incompletely understood. Recent studies have determined the role of the crista terminalis in the mechanisms of a simpler arrhythmia, atrial flutter. We hypothesize that as transverse coupling across the crista terminalis increases, the activation pattern that results is less like typical atrial flutter and more like atrial fibrillation. 6480 Van Capelle elements were coupled in an icosahedron, simulating the right atrium. Atrial simulations were created which incorporated no heterogeneity, heterogeneous coupling, heterogeneous effective refractory periods, and both heterogeneous coupling and effective refractory periods. When the entire crista terminalis was uncoupled, typical atrial flutter occurred. When transverse coupling allowed activation to propagate across the crista terminalis, the flutter cycle length decreased (p < 0.0001). In addition, when heterogeneity was present, both the coefficient of variation of cycle length and the number of activation wavelets increased (p < 0.0001). Thus, a more rapid reentrant circuit in the superior right atrium drove fibrillatory activity in the remainder of the atrium, as predicted by the mother wavelet hypothesis. While awaiting in vivo validation, our study indicates that transverse coupling along the crista terminalis may play an important role in the development of atrial fibrillation from atrial flutter. © 2000 Biomedical Engineering Society. PAC00: 8719Hh, 8710+e     

Sustained remission of schizophrenia among community-dwelling older outpatients

OBJECTIVE: The frequency and nature of sustained remission of schizophrenia are controversial. METHOD: The authors assessed the prevalence of sustained remission among 155 middle-aged and elderly outpatients living independently. They compared patients with sustained remission to symptomatic schizophrenia patients and normal comparison subjects using standardized psychopathological, cognitive, and functional measures. RESULTS: Eight percent of the older schizophrenia patients living independently met criteria for sustained remission. Their level of psychopathology was similar to that in normal subjects and lower than that in symptomatic patients. On cognition, quality of well-being, and everyday functioning, the group with sustained remission was intermediate between the normal and symptomatic groups and differed significantly from the normal subjects. CONCLUSIONS: Sustained remission can occur even in older patients with very chronic illness, but its prevalence is lower than that in several published reports. Remission may reflect a return to premorbid functioning, consistent with neurodevelopmental hypotheses of schizophrenia.     

Improving dietary behavior in African Americans: the Parents As Teachers High 5, Low Fat Program

BACKGROUND: The High 5, Low Fat Program (H5LF) for African American parents was developed in partnership with the Parents As Teachers program, and was designed to test a dietary intervention appropriate for national adoption. METHODS: H5LF used a group randomized, nested cohort design with 738 parents. Consistent with organizational goals and methods, parent educators delivered a dietary change program via personal visits, newsletters, and group meetings. Primary outcomes were reducing percentage calories from fat and increasing fruit and vegetable consumption among participating parents; intermediate aims included improving in nutrition-related skills and parental modeling of dietary behaviors. RESULTS: H5LF parents achieved a 0.53 increase in fruit and vegetable consumption (P = 0.03), and a higher proportion of H5LF parents reduced their intake to less than 30% calories from fat (chi(2) = 4.8, P < 0.03; -1.7% calories from fat, p = 0.07) and improved performance of dietary behaviors (F = 14.2, P = 0.004). Improvements in parental modeling were not statistically significant. CONCLUSIONS: H5LF is an effective intervention that is appropriate for national adoption by over 2000 Parents As Teachers sites with the potential to impact dietary intake of African American parents nationwide.     

Craniofacial microsomia in a parasite of a heteropagus conjoined twin: a clinical and histopathologic evaluation

This report evaluates a rare case of craniofacial microsomia in a partially developed, malformed heteropagus conjoined twin. In this instance, several major components of the craniofacial complex were involved: bones, cartilage, teeth, salivary glands, auditory apparatus, cerebrum, cranial nerves, and ocular neuroepithelium. In addition, cervical vertebrae and appendicular long bones were markedly affected. To date, the underlying disorder (whether genetic, metabolic, or environmental) responsible for the development of this congenital malformation is not fully understood. Our clinical and pathologic examinations tend to suggest that an apparent lack of an adequate arterial blood supply to the growing embryo could have contributed to the elaboration of this complex syndrome. The fact that the parasite's blood supply relied mainly upon a single, medium-sized artery (1.5 mm in diameter) could have brought about local ischemic milieus during the critical phases of embryogenesis; hence, impeding the preprogrammed migration of neural crest cells to their end targets in the upper branchial arches. In such a case, the normal sequence of cell differentiation is damaged, which in turn imposes a severe impact on the morphogenesis of the various tissues composing the craniofacial complex.     

Comparing social work's role in renal dialysis in Israel and the United States: the practice-based research potential of available clinical information

This paper demonstrates the use of clinical data-mining in a study of social work interventions with dialysis patients in two countries, the US and Israel. We aimed to examine the role of social workers in improving kidney patient outcomes and to determine the potential of readily available patient information for studying this process. The findings showed considerable differences between the patient samples in both countries, as far as the socio-demographic background was considered. In spite of this, there were numerous similarities in the type of psycho-social problems and reactions, as well as the social workers' interventions. Differences which arose in various patient states and outcomes were examined in light of variations in the health care systems and socio-cultural contexts of renal dialysis in both sites.     

Measurement of microbicide acceptability among U.S. adolescent girls

BACKGROUND AND OBJECTIVE: Topical microbicides will only be effective if they are acceptable to potential users. The purpose of this study is to develop a scale to evaluate characteristics and aspects of topical microbicides that are important to adolescent girls. STUDY DESIGN: Girls (n = 207) completed a questionnaire on perceptions of microbicide-like products. RESULTS: A principal components factor analysis with a varimax rotation produced a 6-factor solution. The mean factor scores suggested that girls saw the products positively. Age was positively correlated with "comparison to condoms" and "comfort while using" factor scores and inversely correlated with "negative impact on interpersonal relationships" factor score. Sexually transmitted infection (STI) history was related to higher scores on the "health benefits" and "pleasure" factors. Age, race/ethnicity, and STI history were not related to the other factor scores. CONCLUSION: The current scale shows promise in assessment of microbicide acceptability, and in general, girls expressed positive views about microbicides.     

Comparison of weight loss achieved after laparoscopic adjustable gastric banding between Afro-Caribbean,Caucasian and South Asian adult female patients in a London bariatric centre

Introduction

It has been shown that following laparoscopic adjustable gastric banding (LAGB) procedures, Afro-Caribbeans achieve poorer weight loss compared with Caucasians. The reasons for this are multifactorial. However, studies have been based on mainly female patients from the US and none to date have been from the UK. Furthermore, South Asians have not previously been compared. The aim of this study was to compare excess weight loss percentage (%EWL) outcomes up to five years following LAGB in Afro-Caribbean, Caucasian and South Asian females in a London-based teaching hospital.

Methods

An analysis was carried out of prospectively collected data of female patients aged ≥16 years of Afro-Caribbean, Caucasian or South Asian origin who underwent LAGB between October 2000 and December 2011. Data included demographics, co-morbidities and anthropometrics.

Results

Overall, 596 females underwent LAGB; 316 Caucasians (53.0%), 64 Afro-Caribbeans (10.8%) and 27 South Asians (4.5%) formed the majority of those who disclosed ethnicities. Age and initial body mass index (BMI) were comparable between Afro-Caribbeans and Caucasians (mean BMI: 47.3kg/m² [standard deviation [SD]: 7.5kg/m², range: 37.0–78.3kg/m²] vs 45.8kg/m² [SD: 7.1kg/m², range: 24.7–79.8kg/m²], p=0.225). A non-significant trend suggested less %EWL in Afro-Caribbeans than in Caucasians at 6 months, and at 1, 2, 3, 4 and 5 years (21.4% vs 24.4%, p=0.26; 27.4% vs 31.3%, p=0.27; 33.0% vs 36.8%, p=0.15; 39.0% vs 45.8%, p=0.14; 34.2% vs 45.3%, p=0.16; 37.1% vs 47.6%, p=0.67). South Asians and Caucasians had a similar age and preoperative BMI (mean BMI: 43.6kg/m² [range: 32.5–59.1kg/m²] vs 45.8kg/m² [range: 24.7–79.8kg/m²], p=0.08). The %EWL was greatest at three and four years among South Asians although numbers were small (n=4 and n=3 respectively).

Conclusions

A non-significant trend suggests poorer weight loss outcomes in Afro-Caribbeans compared with Caucasians in our cohort. Discussion of realistic weight loss outcomes as well as enhanced follow-up and dietary modifications are required for Afro-Caribbean patients. Low numbers prevent definitive conclusions regarding South Asians. Multicentre studies across England are required to better define any differences between ethnicities.