Effects of Exercise Training on Neuromuscular Junction Morphology and Pre- to Post-Synaptic Coupling in Young and Aged Rats

The objective of this study was to determine whether pre- to post-synaptic coupling of the neuromuscular junction (NMJ) could be maintained in the face of significant morphological remodeling brought about by exercise training, and whether aging altered this capacity. Eighteen young adult (8 mo) and eighteen aged (24 mo) Fischer 344 rats were randomly assigned to either endurance trained (treadmill running) or untrained control conditions resulting in four groups (N = 9 / group). After the 10-week intervention rats were euthanized and hindlimb muscles were surgically removed, quickly frozen at approximate resting length and stored at - 85 degrees C. The plantaris and EDL muscles were selected for study as they have different functions (ankle extensor and ankle flexor, respectively) but both are similarly and overwhelmingly comprised of fast-twitch myofibers. NMJs were stained with immunofluorescent procedures and images were collected with confocal microscopy. Each variable of interest was analyzed with a 2-way ANOVA with main effects of age and endurance training; in all cases significance was set at P \u3c = 0.05. Results showed that no main effects of aging were detected in NMJs of either the plantaris or the EDL. Similarly, endurance training failed to alter any synaptic parameters of EDL muscles. The same exercise stimulus in the plantaris however, resulted in significant pre- and post-synaptic remodeling, but without altering pre- to post-synaptic coupling of the NMJs. Myofiber profiles of the same plantaris and EDL muscles were also analyzed. Unlike NMJs, myofibers displayed significant age-related atrophy in both the plantaris and EDL muscles. Overall, these results confirm that despite significant training-induced reconfiguration of NMJs, pre- to post-synaptic coupling remains intact underscoring the importance of maintaining proper apposition of neurotransmitter release and binding sites so that effective nerve to muscle communication is assured. (C) 2015 IBRO. Published by Elsevier Ltd. All rights reserved

Is 30-Day Posthospitalization Mortality Lower Among Racial/Ethnic Minorities?: A Reexamination

BackgroundMultiple studies have reported that risk-adjusted rates of 30-day mortality after hospitalization for an acute condition are lower among blacks compared with whites.ObjectiveTo examine if previously reported lower mortality for minorities, relative to whites, is accounted for by adjustment for do-not-resuscitate status, potentially unconfirmed admission diagnosis, and differential risk of hospitalization.Research designUsing inpatient discharge and vital status data for patients aged 18 and older in California, we examined all admissions from January 1, 2010 to June 30, 2011 for acute myocardial infarction, heart failure, pneumonia, acute stroke, gastrointestinal bleed, and hip fracture and estimated relative risk of mortality for Hispanics, non-Hispanic blacks, non-Hispanic Asians, and non-Hispanic whites. Multiple mortality measures were examined: inpatient, 30-, 90-, and 180 day. Adding census data we estimated population risks of hospitalization and hospitalization with inpatient death.ResultsAcross all mortality outcomes, blacks had lower mortality rate, relative to whites even after exclusion of patients with do-not-resuscitate status and potentially unconfirmed diagnosis. Compared with whites, the population risk of hospitalization was 80% higher and risk of hospitalization with inpatient mortality was 30% higher among blacks. Among Hispanics and Asians, disparities varied with mortality measure.ConclusionsLower risk of posthospitalization mortality among blacks, relative to whites, may be associated with higher rate of hospitalizations and differences in unobserved patient acuity. Disparities for Hispanics and Asians, relative to whites, vary with the mortality measure used

Disparities in Potentially Preventable Hospitalizations: Near-National Estimates for Hispanics

© Health Research and Educational Trust Objective: To obtain near-national rates of potentially preventable hospitalization (PPH)—a marker of barriers to outpatient care access—for Hispanics; to examine their differences from other race-ethnic groups and by Hispanic national origin; and to identify key mediating factors. Data Sources/Study Setting: Data from all-payer inpatient discharge databases for 15 states accounting for 85 percent of Hispanics nationally. Study Design: Combining counts of inpatient discharges with census population for adults aged 18 and older, we estimated age-sex-adjusted PPH rates. We examined county-level variation in race-ethnic disparities in these rates to identify the mediating role of area-level indicators of chronic condition prevalence, socioeconomic status (SES), health care access, acculturation, and provider availability. Principal Findings: Age-sex-adjusted PPH rates were 13 percent higher among Hispanics (1,375 per 100,000 adults) and 111 percent higher among blacks (2,578) compared to whites (1,221). Among Hispanics, these rates were relatively higher in areas with predominantly Puerto Rican and Cuban Americans than in areas with Hispanics of other nationalities. Small area variation in chronic condition prevalence and SES fully accounted for the higher rates among Hispanics, but only partially among blacks. Conclusions: Hispanics and blacks face higher barriers to outpatient care access; the higher barriers among Hispanics (but not blacks) seem mediated by SES, lack of insurance, cost barriers, and limited provider availability

Massachusetts health reform and disparities in joint replacement use: difference in differences study

Objective: To estimate the impact of the insurance expansion in 2006 on use of knee and hip replacement procedures by race/ethnicity, area income, and the use of hospitals that predominantly serve poor people (“safety net hospitals”). Design: Quasi-experimental difference in differences study examining change after reform in the share of procedures performed in safety net hospitals by race/ethnicity and area income, with adjustment for patients’ residence, demographics, and comorbidity. Setting: State of Massachusetts, United States. Participants: Massachusetts residents aged 40-64 as the target beneficiaries of reform and similarly aged residents of New Jersey, New York, and Pennsylvania as the comparison (control) population. Main outcomes measures Number of knee and hip replacement procedures per 10 000 population and use of safety net hospitals. Procedure counts from state discharge data for 2.5 years before and after reform, and multivariate difference in differences. Poisson regression was used to adjust for demographics, economic conditions, secular time, and geographic factors to estimate the change in procedure rate associated with health reform by race/ethnicity and area income. Results: Before reform, the number of procedures (/10 000) in Massachusetts was lower among Hispanic people (12.9, P<0.001) than black people (28.1) and white people (30.1). Overall, procedure use increased 22.4% during the 2.5 years after insurance expansion; reform in Massachusetts was associated with a 4.7% increase. The increase associated with reform was significantly higher among Hispanic people (37.9%, P<0.001) and black people (11.4%, P<0.05) than among white people (2.8%). Lower income was not associated with larger increases in procedure use. The share of knee and hip replacement procedures performed in safety net hospitals in Massachusetts decreased by 1.0% from a level of 12.7% before reform. The reduction was larger among Hispanic people (−6.4%, P<0.001) than white people (−1.0%), and among low income residents (−3.9%, p<0.001) than high income residents (0%). Conclusions: Insurance expansion can help reduce disparities by race/ethnicity but not by income in access to elective surgical care and could shift some elective surgical care away from safety net hospitals

Inter-Observer Agreement on Subjects' Race and Race-Informative Characteristics

Health and socioeconomic disparities tend to be experienced along racial and ethnic lines, but investigators are not sure how individuals are assigned to groups, or how consistent this process is. To address these issues, 1,919 orthodontic patient records were examined by at least two observers who estimated each individual's race and the characteristics that influenced each estimate. Agreement regarding race is high for African and European Americans, but not as high for Asian, Hispanic, and Native Americans. The indicator observers most often agreed upon as important in estimating group membership is name, especially for Asian and Hispanic Americans. The observers, who were almost all European American, most often agreed that skin color is an important indicator of race only when they also agreed the subject was European American. This suggests that in a diverse community, light skin color is associated with a particular group, while a range of darker shades can be associated with members of any other group. This research supports comparable studies showing that race estimations in medical records are likely reliable for African and European Americans, but are less so for other groups. Further, these results show that skin color is not consistently the primary indicator of an individual's race, but that other characteristics such as facial features add significant information

Pilot survey of oral health-related quality of life: a cross-sectional study of adults in Benin City, Edo State, Nigeria

BACKGROUND: Oral health studies conducted so far in Nigeria have documented prevalence and incidence of dental disease using traditional clinical measures. However none have investigated the use of an oral health-related quality of life (OHRQoL) instrument to document oral health outcomes. The aims of this study are: to describe how oral health affects and impacts quality of life (QoL) and to explore the association between these affects and the oral health care seeking behavior of adults in Benin City, Edo State, Nigeria. METHODS: A cross-sectional survey recruited 356 adults aged 18–64 years from two large hospital outpatient departments and from members of a university community. Closed-ended oral health questionnaire with "effect and impact" item-questions from OHQoL-UK(© )instrument was administered by trained interviewers. Collected data included sociodemographic, dental visits, and effects and impact of oral health on QoL. Univariate and bivariable analyses were done and a chi-square test was used to test differences in proportions. Multivariable analyses using ANOVA examined the association between QoL factors and visits to a dentist. RESULTS: Complete data was available for 83% of the participants. About 62% of participants perceived their oral health as affecting their QoL. Overall, 82%, 63%, and 77% of participants perceived that oral health has an effect on their eating or enjoyment of food, sleep or ability to relax, and smiling or laughing, respectively. Some 46%, 36%, and 25% of participants reported that oral health impact their daily activities, social activities, and talking to people, respectively. Dental visits within the last year was significantly associated with eating, speech, and finance (P < 0.05). The summary score for the oral health effects on QoL ranged from 33 to 80 with a median value of 61 (95% CI: 60, 62) and interquartile range of 52–70. Multivariable modeling suggested a model containing only education (F = 6.5, pr>F = 0.0111). The mean of effects sum score for those with secondary/tertiary education levels (mean = 61.8; 95% CI: 60.6, 62.9) was significantly higher than those with less than secondary level of education (mean = 57.2; 95% CI: 57.2, 60.6). CONCLUSION: Most adults in the study reported that oral health affects their life quality, and have little/no impact on their quality of life. Dental visits within the last year were associated with eating, speech, and finance

The association between Self-Reported Medication Adherence scores and systolic blood pressure control: a SPRINT baseline data study

We examined baseline data from the Systolic Blood Pressure Intervention Trial (SPRINT) to investigate whether medication adherence, measured by the 8-item Morisky Medication Adherence Scale (MMAS-8), was associated with systolic blood pressure (SBP) and whether MMAS-8 score and number of antihypertensive medications interacted in influencing SBP. A total of 8435 SPRINT participants were included: 21.2% had low adherence (MMAS-8: 160 mm Hg in 8.8%. In multivariable regression, medium vs. low adherence weakly associated with lower SBP (odds ratio: 1.17; confidence interval: 1.04, 1.31). SPRINT eligibility criteria should be considered when interpreting results. Efforts to understand and enhance adherence are crucial to improve population health, and using self-report instruments might be considered for predicting treatment adherence and response in future efficacy trials and for identifying patients for adherence support in clinical practice

Pathologic and Phenotypic Alterations in a Mouse Expressing a Connexin47 Missense Mutation That Causes Pelizaeus-Merzbacher–Like Disease in Humans

Gap junction channels are intercellular conduits that allow diffusional exchange of ions, second messengers, and metabolites. Human oligodendrocytes express the gap junction protein connexin47 (Cx47), which is encoded by the GJC2 gene. The autosomal recessive mutation hCx47M283T causes Pelizaeus-Merzbacher–like disease 1 (PMLD1), a progressive leukodystrophy characterized by hypomyelination, retarded motor development, nystagmus, and spasticity. We introduced the human missense mutation into the orthologous position of the mouse Gjc2 gene and inserted the mCx47M282T coding sequence into the mouse genome via homologous recombination in embryonic stem cells. Three-week-old homozygous Cx47M282T mice displayed impaired rotarod performance but unchanged open-field behavior. 10-15-day-old homozygous Cx47M282T and Cx47 null mice revealed a more than 80% reduction in the number of cells participating in glial networks after biocytin injections into oligodendrocytes in sections of corpus callosum. Homozygous expression of mCx47M282T resulted in reduced MBP expression and astrogliosis in the cerebellum of ten-day-old mice which could also be detected in Cx47 null mice of the same age. Three-month-old homozygous Cx47M282T mice exhibited neither altered open-field behavior nor impaired rotarod performance anymore. Adult mCx47M282T expressing mice did not show substantial myelin alterations, but homozygous Cx47M282T mice, additionally deprived of connexin32, which is also expressed in oligodendrocytes, died within six weeks after birth and displayed severe myelin defects accompanied by astrogliosis and activated microglia. These results strongly suggest that PMLD1 is caused by the loss of Cx47 channel function that results in impaired panglial coupling in white matter tissue

Racial and ethnic differences in general health status and limiting health conditions among American children: parental reports in the 1999 National Survey of America's Families

Working PaperObjectives: This research investigates the association between race/ethnicity and child health and examines the role of family structure, family SES, and healthcare factors in this association. Five major racial/ethnic groups in the United States are studied. Two child health outcomes including parent-rated health and limiting health condition are examined. The analysis is stratified into three age groups: age 0 to 5, age 6 to 11, and age 12 to 17. Design: Cross-sectional study using data from a large nationally representative sample collected in 1999 in the United States. Results: For general health, older age groups tend to exhibit larger racial/ethnic disparities. With few exceptions, minority groups showed higher risk of poor health relative to Whites among children age 6 to 17. In the youngest group (age 0 to 5), only Latinos have significant health disadvantage. As to limiting health condition, black children prior to adolescence are slightly disadvantaged, Native American adolescents are significantly more likely to have limiting conditions, whereas Asian adolescents are better off than Whites. Family SES explains some black, Latino, and Native American effects but not all; and SES does not explain the Asian effects. Family structure and healthcare factors generally do not contribute much to the racial/ethnic differences but they can have significant effects on child health in their own right. We also find that economic resources play a more salient role in child health than parental education especially in younger children. And healthcare factors to some extent explain why children from higher SES family fare better. Conclusion: Racial/ethnic disparities in health start early in life. Except for Asians, class explains a substantial amount but not all of these disparities. Healthcare factors play a prominent role in explaining disparities by class. Structural solution is needed to reduce disparities by race and ethnicity particularly in younger children