Intrinsic aerobic capacity sets a divide for aging and longevity

<p><b>Rationale:</b> Low aerobic exercise capacity is a powerful predictor of premature morbidity and mortality for healthy adults as well as those with cardiovascular disease. For aged populations, poor performance on treadmill or extended walking tests indicates closer proximity to future health declines. Together, these findings suggest a fundamental connection between aerobic capacity and longevity.</p> <p><b>Objectives:</b> Through artificial selective breeding, we developed an animal model system to prospectively test the association between aerobic exercise capacity and survivability (aerobic hypothesis).</p> <p><b>Methods and Results:</b> Laboratory rats of widely diverse genetic backgrounds (N:NIH stock) were selectively bred for low or high intrinsic (inborn) treadmill running capacity. Cohorts of male and female rats from generations 14, 15, and 17 of selection were followed for survivability and assessed for age-related declines in cardiovascular fitness including maximal oxygen uptake (VO<sub>2max</sub>), myocardial function, endurance performance, and change in body mass. Median lifespan for low exercise capacity rats was 28% to 45% shorter than high capacity rats (hazard ratio, 0.06; P<0.001). VO<sub>2max</sub>, measured across adulthood was a reliable predictor of lifespan (P<0.001). During progression from adult to old age, left ventricular myocardial and cardiomyocyte morphology, contractility, and intracellular Ca<sup>2+</sup> handling in both systole and diastole, as well as mean blood pressure, were more compromised in rats bred for low aerobic capacity. Physical activity levels, energy expenditure (Vo<sub>2</sub>), and lean body mass were all better sustained with age in rats bred for high aerobic capacity.</p> <p><b>Conclusions:</b> These data obtained from a contrasting heterogeneous model system provide strong evidence that genetic segregation for aerobic exercise capacity can be linked with longevity and are useful for deeper mechanistic exploration of aging.</p&gt

A complex and severe encephalitis associated with four co-existing neuronal cell-surface autoantibodies

Many forms of autoimmune encephalitis are mediated by neuronal cell-surface directed autoantibodies. The co-occurrence of four neuronal cell-surface antibodies in a single patient is exceptionally rare. We report a patient who had a severe encephalitis associated with antibodies to NMDA, Glycine, GABAA and GABAB receptors. Case: A 28-year-old man on tacrolimus presented with a first seizure. Thereafter, he developed confusion, cerebellar signs, opsoclonus, neuromyotonia and medication-refractory seizures. CSF sampling revealed 826 white cells and NMDA, glycine and GABAB receptor antibodies: all were also detected in serum along with additional GABAA receptor antibodies. Neural antibodies were detected using fixed (NMDA, GABAA, GABAB receptor) or live (glycine receptor) cell-based assays at Oxford Neuroimmunology Laboratory, Oxford, UK. MRI brain demonstrated cerebellar leptomeningeal enhancement and a hyperintense lesion in the cerebellar vermis. EEG revealed extreme delta brush and needle EMG confirmed neuromyotonia. No underlying malignancy was detected. Methylprednisolone, IVIG, Rituximab, therapeutic plasma exchange, cyclophosphamide and bortezomib were administered sequentially, with minimal clinical improvement. Death secondary to respiratory sepsis occurred on the 714th hospital day. Postmortem revealed pan-cerebellar atrophy with Purkinje cell loss; dentate nucleus ganglionopathy, and thoracolumbar cord myelopathy. In summary, the detection of multiple neuronal cell-surface antibodies in autoimmune encephalitis is unusual and may result in a complex overlap syndrome with a poor response to immunotherapy

The American Society of Pain and Neuroscience (ASPN) Guidelines and Consensus on the Definition, Current Evidence, Clinical Use and Future Applications for Physiologic Closed-Loop Controlled Neuromodulation in Chronic Pain: A NEURON Group Project.

INTRODUCTION: Neuromodulation has been a staple of treatment for moderate-to-severe chronic refractory pain since the introduction of the first spinal cord stimulator by Norman Shealy in 1967. Appreciating the dynamic nature of electrical modulation of the nervous system from the epidural space, the goal has been consistent, reliable, and therapeutic neural activation of the spinal cord. This has proven to be extremely difficult. Recently, the Food and Drug Administration (FDA) released a guidance on physiologic closed loop controlled (PCLC) devices, highlighting the potential for these therapies to deliver accurate, consistent, real-time therapy, enhancing medical care and reducing variability. Because of the growing neuromodulation market focus on PCLC strategies, the American Society of Pain and Neuroscience (ASPN) sought to develop guidance on safety and efficacy, along with a taxonomy surrounding PCLC systems (PCLCSs) and to develop an evidence-based best practice review. METHODS: A librarian-assisted literature search was performed to identify manuscripts relevant to the topic of PCLC stimulation for management of chronic pain. Initial literature search was performed utilizing MEDLINE, EMBASE, Cochrane database, BioMed Central, and Web of Science. Included manuscripts encompassed meta-analyses, systematic reviews, randomized controlled trials (RCTs), prospective or retrospective studies with follow-up to 12 months, limited to the English language. MESH terms utilized included closed-loop, physiologic closed loop controlled, spinal cord stimulation, closed loop feedback, feedback controlled, neuromodulation, pain, persistent pain, neuropathic pain, and chronic pain. The modified USPSTF evidence and recommendation grading strategy previously utilized was again employed. RESULTS: Four studies were identified for review, 2 prospective, one retrospective, and one randomized controlled study with at least 12-month follow-up. CONCLUSION: PCLC neuromodulation is an innovation that requires a responsible introduction. As commercial access grows, there is a responsibility that requires consistency with definition, evidence generation, focused on safety and efficacy

Disparities in preventive procedures: comparisons of self-report and Medicare claims data

BACKGROUND: Racial/ethnic disparities are assessed using either self-report or claims data. We compared these two data sources and examined contributors to discrepancies in estimates of disparities. METHODS: We analyzed self-report and matching claims data from Medicare Beneficiaries 65 and older who participated in the Medicare Current Beneficiary Survey, 1999–2002. Six preventive procedures were included: PSA testing, influenza vaccination, Pap smear testing, cholesterol testing, mammography, and colorectal cancer testing. We examined predictors of self-reports in the absence of claims and claims in the absence of self-reports. RESULTS: With the exception of PSA testing, racial/ethnic disparities in preventive procedures are generally larger when using Medicare claims than when using patients' self-report. Analyses adjusting for age, gender, income, educational level, health status, proxy response and supplemental insurance showed that minorities were more likely to self-report preventive procedures in the absence of claims. Adjusted odds ratios ranged from 1.07 (95% CI: 0.88 – 1.30) for PSA testing to 1.83 (95% CI: 1.46 – 2.30) for Pap smear testing. Rates of claims in the absence of self-report were low. Minorities were more likely to have PSA test claims in the absence of self-reports (1.55 95% CI: 1.17 – 2.06), but were less likely to have influenza vaccination claims in the absence of self-reports (0.69 95% CI: 0.51 – 0.93). CONCLUSION: These findings are consistent with either racial/ethnic reporting biases in receipt of preventive procedures or less efficient Medicare billing among providers with large minority practices