Periprosthetic fractures of the femur after hip arthroplasty: an analysis of 99 patients.

The medical records and radiographs of 99 patients treated for a periprosthetic femur fracture after total hip arthroplasty over a 17-year period at a single institution were prospectively reviewed. Fractures were classified according to the Vancouver system and stratified as to treatment method. Sixty-six patients had complete records available and a minimum of 12 months follow-up.

Energy expenditure and activity of transfemoral amputees using mechanical and microprocessor-controlled prosthetic knees.

Objective: To quantify the energy efficiency of locomotion and free-living physical activity energy expenditure of transfemoral amputees using a mechanical and microprocessor-controlled prosthetic knee.

Design: Repeated-measures design to evaluate comparative functional outcomes.

Setting: Exercise physiology laboratory and community free-living environment.

Essential roles of the acetylcholine receptor gamma-subunit in neuromuscular synaptic patterning.

Formation of the vertebrate neuromuscular junction (NMJ) takes place in a stereotypic pattern in which nerves terminate at select sarcolemmal sites often localized to the central region of the muscle fibers. Several lines of evidence indicate that the muscle fibers may initiate postsynaptic differentiation independent of the ingrowing nerves. For example, nascent acetylcholine receptors (AChRs) are pre-patterned at select regions of the muscle during the initial stage of neuromuscular synaptogenesis.

Engagement and retention in services among formerly homeless adults with co-occurring mental illness and substance abuse: voices from the margins.

This qualitative study analyzed 72 interviews with 39 formerly homeless psychiatric consumers to develop a grounded theory model of engagement and retention in mental health and substance abuse services. Person-centered themes included severity of mental illness and substance abuse (the latter also conflicting with programmatic abstinence requirements). System-related themes inhibiting service use included program rules and restrictions and a lack of one-on-one therapy.

Podoplanin is a better immunohistochemical marker for sarcomatoid mesothelioma than calretinin.

Immunohistochemistry using a broad panel of markers is an invaluable tool for diagnosing sarcomatoid mesothelioma. Membranous podoplanin staining has been proposed as a specific and sensitive marker to distinguish epithelioid mesothelioma from adenocarcinoma. We found that cytoplasmic podoplanin staining was present in sarcomatoid mesotheliomas, and wanted to explore the reproducibility and specificity of this staining pattern.

Remelting of highly cross-linked polyethylene worn under laboratory conditions.

It has been suggested that apparent wear damage in highly cross-linked polyethylene acetabular liners can be removed with subsequent remelting of retrieved liners. To test this hypothesis, we remelted liners that had been previously tested under controlled laboratory conditions and that had experienced nonzero wear rates and visible wear damage. Five liner groups were examined: three with a range of irradiation doses without heat treatment, and two irradiated to 100 kGys, one with remelting, and the other annealing.

The inflammatory response to social defeat is increased in older mice.

KINSEY, S. G., BAILEY, M.

Arthroscopic versus open osteoplasty of the head-neck junction: a cadaveric investigation.

Purpose: Femoroacetabular impingement can be successfully treated by open osteoplasty, although arthroscopic osteoplasty is growing in popularity. We compared the precision and accuracy of arthroscopic versus open osteoplasty.

Methods: We randomly assigned 8 paired fresh-frozen cadaveric pelvises to an open or arthroscopic technique and performed osteoplasty on both anterior femoral head-neck junctions.

Subordinate social status modulates the vulnerability to the immunological effects of social stress.

Social stress has long been known to affect physical and psychological health in humans and a variety of animal species. In mice, disruption of the social hierarchy (social disruption, SDR) resulted in significant changes in the phenotype and function of immune cells taken from the spleen. Interestingly, there were considerable individual differences in the development of this splenic response to SDR.

Species boundaries within Saprolegnia (Saprolegniales, Oomycota) based on morphological and DNA sequence data.

Saprolegnia is a common and widespread genus of Oomycetes, however species identifications are difficult and uncertain. To test whether keys based on morphological characters could identify species as determined by molecular characters we determined partial DNA sequences for the 28S rRNA gene and the complete internal transcribed spacer (ITS) region for 55 isolates belonging to Saprolegnia and one isolate of Protoachlya hypogyna that exhibited saprolegnoid zoospore discharge in water culture. Phylogenetic analyses of the combined sequence data yielded 10 robustly supported clades that probably represent separate species.

Gait and balance of transfemoral amputees using passive mechanical and microprocessor-controlled prosthetic knees.

Background: Microprocessor-controlled knee joints appeared on the market a decade ago. These joints are more sophisticated and more expensive than mechanical ones. The literature is contradictory regarding changes in gait and balance when using these sophisticated devices.

Stress and wound healing.

Over the past decade it has become clear that stress can significantly slow wound healing: stressors ranging in magnitude and duration impair healing in humans and animals. For example, in humans, the chronic stress of caregiving as well as the relatively brief stress of academic examinations impedes healing. Similarly, restraint stress slows healing in mice.

Vascular preservation during arthroscopic osteoplasty of the femoral head-neck junction: a cadaveric investigation.

Purpose: The goal of this study was to evaluate the risk of vascular injury with arthroscopic osteoplasty of the femoral head-neck junction in a cadaveric model.

Methods: Eight fresh-frozen cadaveric pelvi were used for arthroscopic osteoplasty of a predetermined 150 degrees arc of resection along the anterior femoral head-neck junction. Postoperatively, injection studies of the deep femoral arteries were performed on all specimens to identify local extravasation of neoprene latex before polymerization as a reproducible indicator of vascular injury.

Reevaluating the self-medication hypothesis among the dually diagnosed.

The self-medication hypothesis (SMH) is an intuitively appealing explanation for substance use. Conceptually, however, it is not always clear what the hypothesis entails, particularly when applied to persons with mental and substance use disorders. This makes empirical support for SMH difficult to evaluate.

Repeated social defeat increases the bactericidal activity of splenic macrophages through a Toll-like receptor-dependent pathway.

Phagocytes of the innate immune system, such as monocytes/macrophages, represent a first line of defense against invading microorganisms. Psychological stress is often thought to suppress the functioning of these cells, in part due to the immunosuppressive activity of stress-induced glucocorticoid hormones. However, exposure to the stressor social disruption (SDR) has been shown to increase cytokine production by monocytes/macrophages and to reduce their sensitivity to corticosterone.

Giant cell tumor of the lumbar spine: operative management via spondylectomy and short-segment, 3-column reconstruction with pedicle recreation.

Background: Giant cell tumors of the lumbar spine are uncommon lesions. Aggressive management of such lesions via spondylectomy to obtain local control and prevent recurrence is often necessary. Spinal reconstruction after total spondylectomy can be challenging.

Exploring the diversity of marine-derived fungal polyketide synthases.

Using an approach based on polymerase chain reaction (PCR), we examined the diversity of polyketide synthase (PKS) genes present in 160 marine fungal isolates, representing 142 species. We obtained ketosynthase (KS) domain PCR products from 99 fungal isolates, representing Dothideomycetes, Sordariomycetes, Eurotiomycetes, and incertae sedis. Sequence similarity searches and phylogenetic analysis of 29 marine partial-KS-encoding sequences revealed domains predicted to encode reducing, nonreducing, and 6-methylsalicylic acid PKSs.

There's no place like (a) home: ontological security among persons with serious mental illness in the United States.

As the homelessness 'crisis' in the United States enters a third decade, few are as adversely affected as persons with serious mental illness. Despite recent evidence favoring a 'housing first' approach, the dominant 'treatment first' approach persists in which individuals must climb a ladder of program requirements before becoming eligible for an apartment of their own. Drawing upon the concept of 'ontological security', this qualitative study examines the subjective meaning of 'home' among 39 persons who were part of a unique urban experiment that provided New York City's homeless mentally ill adults with immediate access to independent housing in the late 1990s.

Care or scare: the safety of youth in congregate care in New York City.

Objective: This qualitative study examined stakeholders' perceptions of the safety of youth ages 12 and older living in congregate care facilities within the New York City foster care system. The study explored the youth's physical safety, the safety of their personal belongings, the physical conditions of congregate care settings, and the relationship between staff quality and youth safety.

Method: The study involved interviews with family court judges, representatives of private child welfare agencies, attorneys who represent children in foster care, social workers, representatives of advocacy and other relevant organizations in New York City, and former foster youth who had been placed in congregate care settings.

Impingement contributes to backside wear and screw-metallic shell fretting in modular acetabular cups.

Eighty-six polyethylene liners and 56 metallic shells of acetabular components were evaluated by visual and stereomicroscopic examination for impingement, backside polyethylene wear, creep, and fretting at the screw-metallic shell interface using a subjective scoring system. Medical records and radiological data were available in 65 and 46 patients, respectively. Impingement was found in 62 components (75%).

Contributions of histamine, prostanoids, and neurokinins to edema elicited by edema toxin from Bacillus anthracis.

Bacillus anthracis edema toxin (ET), composed of protective antigen and an adenylate cyclase edema factor (EF), elicits edema in host tissues, but the target cells and events leading from EF-mediated cyclic-AMP production to edema are unknown. We evaluated the direct effect of ET on several cell types in vitro and tested the possibility that mediators of vascular leakage, such as histamine, contribute to edema in rabbits given intradermal ET. ET increased the transendothelial electrical resistance of endothelial monolayers, a response that is mechanistically inconsistent with the in vivo vascular leakage induced by ET.

In their own words: trauma and substance abuse in the lives of formerly homeless women with serious mental illness.

In-depth interviews were conducted with 13 formerly homeless mentally ill women to capture their individual life trajectories of mental illness, substance abuse, and trauma in their own words. Cross-case analyses produced 5 themes: (a) betrayals of trust, (b) graphic or gratuitous nature of traumatic events, (c) anxiety about leaving their immediate surroundings (including attending group treatment programs), (d) desire for one's own space, and (e) gender-related status loss and stigmatization. Findings suggest formerly homeless mentally ill women need (and want) autonomy, protection from further victimization, and assistance in restoring status and devalued identity.

Moderate exercise early after influenza virus infection reduces the Th1 inflammatory response in lungs of mice.

We have previously shown that moderate exercise significantly increased survival after influenza virus (A/PR/8/34) infection in mice. We hypothesized that this brief duration of exercise would either increase innate immune defences and/or shift the immune response from a Th1 inflammatory to a Th2 anti-inflammatory response resulting in decreased lung pathology. Adult male BALB/cByJ mice (5-6 months old) were infected with 50 microL of A/PR/8/34 virus (40HAU) intranasally and randomized to either an exercise (EX) or sedentary (SED) group.

Synaptotagmin-2 is essential for survival and contributes to Ca2+ triggering of neurotransmitter release in central and neuromuscular synapses.

Biochemical and genetic data suggest that synaptotagmin-2 functions as a Ca2+ sensor for fast neurotransmitter release in caudal brain regions, but animals and/or synapses lacking synaptotagmin-2 have not been examined. We have now generated mice in which the 5' end of the synaptotagmin-2 gene was replaced by lacZ. Using beta-galactosidase as a marker, we show that, consistent with previous studies, synaptotagmin-2 is widely expressed in spinal cord, brainstem, and cerebellum, but is additionally present in selected forebrain neurons, including most striatal neurons and some hypothalamic, cortical, and hippocampal neurons.