Central somatosensory changes and altered muscle synergies in subjects with anterior cruciate ligament deficiency

To clarify the mechanisms of compensation in subjects with anterior cruciate ligament deficiency (ACL-D), we examined proprioception, quadriceps strength, somatosensory evoked potentials (SEPs) and muscle responses during gait in varied combinations of speed and incline. Seventeen subjects with ACL-D were grouped by functional level and report of giving way. Seven subjects without ACL-D served as a control sample for muscle response measures. ACL-D subjects with quadriceps weakness experienced giving way and could not resume sport activities. Those without weakness fell into one of two groups: (1) copers, who had full return to previous activity and no giving way despite proprioceptive loss and altered SEPs, and (2) adapters, who were unable to return to previous activity level and experienced giving way despite neither proprioceptive loss or altered SEPs. The unique muscle pattern in copers during inclined fast walking included larger and earlier hamstring activation. These results suggest that in individuals with ACL-D without a strength deficit, altered SEPs and altered neuromuscular patterns are the factors that enable resumption of pre-injury functional levels. Loss of proprioception may drive the central changes, which in turn drives the development of altered muscle patterns.     

Expression of heterologous antigens in commensal Neisseria spp.: preservation of conformational epitopes with vaccine potential

Commensal neisseriae share with Neisseria meningitidis (meningococcus) a tendency towards overproduction of the bacterial outer envelope, leading to the formation and release during growth of outer membrane vesicles (OMVs). OMVs from both meningococci and commensal neisseriae have shown promise as vaccines to protect against meningococcal disease. We report here the successful expression at high levels of heterologous proteins in commensal neisseriae and the display, in its native conformation, of one meningococcal outer membrane protein vaccine candidate, NspA, in OMVs prepared from such a recombinant Neisseria flavescens strain. These NspA-containing OMVs conferred protection against otherwise lethal intraperitoneal challenge of mice with N. meningitidis serogroup B, and sera raised against them mediated opsonophagocytosis of meningococcal strains expressing this antigen. This development promises to facilitate the design of novel vaccines containing membrane protein antigens that are otherwise difficult to present in native conformation that provide cross-protective efficacy in the prevention of meningococcal disease.     

Use of primary prevention services among male adults with cerebral palsy, multiple sclerosis, or spinal cord injury in managed care and fee-for-service

Future research needs to clarify the biases in clinical practice and potential barriers that may exist at both the provider and health plan levels that exclude men with physical disabilities from routine preventive services. As the population of people with disabilities ages and lives longer, it is necessary that routine preventive services are accessible and made available to them, regardless of gender, disability, or health insurance type.     

Ribosomal alterations contribute to bacterial resistance against the dipeptide antibiotic TAN 1057

TAN 1057-resistant Staphylococcus aureus and Escherichia coli strains were selected to elucidate the mechanism of resistance and the mode of action of this dipeptide antibiotic. Cell-free translation with isolated ribosomes and S150 fractions from sensitive and resistant S. aureus strains demonstrated that alterations in the ribosomes contribute to the resistance of the bacteria.     

Recall and recognition in mild hypoxia: using covariance structural modeling to test competing theories of explicit memory

To test theories of explicit memory in amnesia, we examined the effect of hypoxia on memory performance in a group of 56 survivors of sudden cardiac arrest. Structural equation modeling revealed that a single-factor explanation of recall and recognition was insufficient to account for performance, thus contradicting single-process models of explicit memory. A dual-process model of recall in which two processes (e.g., declarative memory and controlled search) contribute to recall performance, whereas only one process (e.g., declarative memory) underlies recognition performance, also failed to explain the results adequately. In contrast, a dual-process model of recognition provided an acceptable account of the data. In this model, two processes--recollection and familiarity--underlie recognition memory, whereas only the recollection process contributes to free recall. The best-fitting model was one in which hypoxia and aging led to deficits in recollection, but left familiarity unaffected. Moreover, a controlled search process was correlated with recollection, but was not associated with familiarity or the severity of hypoxia. The results support models of explicit memory in which recollection depends on the hippocampus and frontal lobes, whereas familiarity-based recognition relies on other brain regions.