A Low Percentage of Patients Satisfy Typical Indications for Single-stage Exchange Arthroplasty for Chronic Periprosthetic Joint Infection.

BACKGROUND: Periprosthetic joint infection (PJI) is a leading cause of revision arthroplasty. Considerable controversy still exists whether single- or two-stage exchange is the better approach for patients with chronic PJI. Historically, single-stage exchange arthroplasty was thought to have an unacceptably high risk of reinfection compared with two-stage exchange but recent studies have demonstrated that this may not be the case. To be considered for single-stage exchange, patients should meet certain criteria including a preoperatively identified nonvirulent pathogen in an immunocompetent host with an uncompromised soft tissue envelope. It is unclear what proportion of patients with chronic PJI actually meet these criteria. Additionally, patients who meet the criteria for single-stage exchange are selected because, in principle, they may be more likely to be able to overcome the infection, but it is unknown what the reinfection risk is in patients undergoing two-stage exchange who might have met selection criteria for single-stage exchange. QUESTIONS/PURPOSES: (1) What percentage of patients with chronic PJI treated at our institution met the International Consensus Meeting criteria for single-stage exchange arthroplasty? (2) Is the risk of persistent or recurrent infection lower for patients treated with two-stage exchange who met International Consensus Meeting criteria for single-stage exchange than it is among those who did not meet those inclusion criteria? METHODS: Between 2012 and 2016, one referral center treated 120 patients with chronic PJI as determined by Musculoskeletal Infection Society (MSIS) criteria. During this time, we used single-stage exchange only rarely in patients with chronic PJI (3%; four of 120), and only in oncologic patients with mega-prosthesis implants; 7% (eight of 120) underwent other procedures (resection arthroplasty or arthrodesis). Of the remaining 108, 16% (17) were lost to follow-up; the remaining 91 were evaluated in this retrospective study. To answer our first question, we applied the International Consensus Meeting indications for single-stage exchange, which were a known nonvirulent preoperative organism, an immunocompetent host, and a healthy soft-tissue envelope without a sinus tract; we then calculated the percentage of patients who would have met those criteria. To answer our second question, we compared those who would and would not have met those criteria in terms of the proportion who were determined to be infection-free at 2 years using the MSIS criteria. RESULTS: Only 19% (20 of 108) of patients met the International Consensus Meeting criteria for single-stage exchange. With the numbers available, there was no difference between those who met and did not meet those criteria in terms of the proportion of patients who had persistent or recurrent infection 2 years after treatment (three of 15 versus 32% [24 of 76]; p = 0.38). CONCLUSIONS: We found that only a small proportion of patients who presented with chronic PJI to a referral center would have been suitable for single-stage direct exchange; with the numbers available, we found no difference in the reinfection risk after two-stage revision in those patients compared with those who would not have met those criteria. Consequently, it is possible that a small proportion of patients may benefit from single-stage exchange, but our small sample size may have missed important differences in reinfection risk, and so our findings on that question must be considered preliminary. Larger studies randomizing patients who meet single-stage criteria to either single- or two-stage exchange will better elucidate the true reinfection risk in this patient population. LEVEL OF EVIDENCE: Level III, therapeutic study.

Getting the fundamentals of movement: a meta-analysis of the effectiveness of motor skill interventions in children.

UNLABELLED: The development of fundamental movement skills (FMS) is associated with positive health-related outcomes. Children do not develop FMS naturally through maturational processes. These skills need to be learned, practised and reinforced. The objective was to determine the effectiveness of motor skill interventions in children. The following databases were searched for relevant articles: Academic Search Premier, PsycArticles, PsycInfo, SportDiscus and ERIC. No date range was specified and each search was conducted to include all possible years of publication specific to each database. Key terms for the search included motor, skill, movement, intervention, programme or children. Searches were conducted using single and combined terms. Pertinent journals and article reference lists were also manually searched. INCLUSION CRITERIA: (1) implementation of any type of motor skill intervention; (2) pre- and post-qualitative assessment of FMS; and (3) availability of means and standard deviations of motor performance. A significant positive effect of motor skill interventions on the improvement of FMS in children was found (d= 0.39, P < 0.001). Results indicate that object control (d= 0.41, P < 0.001) and locomotor skills (d= 0.45, P < 0.001) improved similarly from pre- to post-intervention. The overall effect size for control groups (i.e. free play) was not significant (d= 0.06, P= 0.33). A Pearson correlation indicated a non-significant (P= 0.296), negative correlation (r=-0.18) between effect size of pre- to post-improvement of FMS and the duration of the intervention (in minutes). Motor skill interventions are effective in improving FMS in children. Early childhood education centres should implement 'planned' movement programmes as a strategy to promote motor skill development in children.

Sexual revictimization prevention: an outcome evaluation.

This investigation tested a program to reduce women's risk for sexual revictimization. Participants were 66 women with histories of sexual victimization as adolescents or adults who were randomly assigned to a preventive intervention group or a no-treatment control group. They completed initial measures assessing history of sexual assault, self-efficacy, and psychological functioning, returning approximately 2 months later for follow-up assessment using the same measures. Results suggest that the prevention program may be effective in reducing the incidence of sexual assault revictimization in this population. In addition, participants in the intervention group displayed significant improvement in psychological adjustment and self-reported self-efficacy.

From chump to champ: people's appraisals of their earlier and present selves.

The authors present and test a theory of temporal self-appraisal. According to the theory, people can maintain their typically favorable self-regard by disparaging their distant and complimenting their recent past selves. This pattern of appraisals should be stronger for more important attributes because of their greater impact on self-regard and stronger for self-ratings than for ratings of other people. Studies 1 and 2 demonstrated that participants are more critical of distant past selves than of current selves, and Study 3 showed that this effect is obtained even when concurrent evaluations indicate no actual improvement. Studies 4 and 5 revealed that people perceived greater improvement for self than for acquaintances and siblings over the same time period. Study 6 provided support for the predicted effects of temporal distance and attribute importance on people's evaluation of past selves.

Identification and characterization of two neuromedin U receptors differentially expressed in peripheral tissues and the central nervous system.

Two structurally related, G-protein-coupled receptors were identified as receptors for the neuropeptide, neuromedin U. This peptide is found in highest levels in the gut and genitourinary system where it potently contracts smooth muscle but is also expressed in the spinal cord and discrete regions of the brain. Binding sites for neuromedin U have been characterized in rat uterus, however, little is known about the activity of this peptide in the regions of the central nervous system where it is expressed. The receptors characterized in this report are activated by neuromedin U at nanomolar potency in heterologous expression systems and bind radiolabeled neuromedin U with high affinity. Localization of the receptor RNA by quantitative reverse transcription-polymerase chain reaction in a variety of human tissues shows distinct expression patterns for the two receptors. NMU1 is expressed predominantly in peripheral tissues, whereas NMU2 is more highly expressed in the central nervous system. Identification of neuromedin U receptor subtypes will greatly aid in the determination of the physiological roles of this peptide.

NMR and mutagenesis evidence for an I domain allosteric site that regulates lymphocyte function-associated antigen 1 ligand binding.

The leukocyte integrin, lymphocyte function-associated antigen 1 (LFA-1) (CD11a/CD18), mediates cell adhesion and signaling in inflammatory and immune responses. To support these functions, LFA-1 must convert from a resting to an activated state that avidly binds its ligands such as intercellular adhesion molecule 1 (ICAM-1). Biochemical and x-ray studies of the Mac-1 (CD11b/CD18) I domain suggest that integrin activation could involve a conformational change of the C-terminal alpha-helix. We report the use of NMR spectroscopy to identify CD11a I domain residues whose resonances are affected by binding to ICAM-1. We observed two distinct sites in the CD11a I domain that were affected. As expected from previous mutagenesis studies, a cluster of residues localized around the metal ion-dependent adhesion site (MIDAS) was severely perturbed on ICAM-1 binding. A second cluster of residues distal to the MIDAS that included the C-terminal alpha-helix of the CD11a I domain was also affected. Substitution of residues in the core of this second I domain site resulted in constitutively active LFA-1 binding to ICAM-1. Binding data indicates that none of the 20 substitution mutants we tested at this second site form an essential ICAM-1 binding interface. We also demonstrate that residues in the I domain linker sequences can regulate LFA-1 binding. These results indicate that LFA-1 binding to ICAM-1 is regulated by an I domain allosteric site (IDAS) and that this site is structurally linked to the MIDAS.

The frequency of temporal-self and social comparisons in people's personal appraisals.

Although past literature emphasizes the importance of social comparisons, in this study it was predicted that participants would often mention temporal comparisons in their self-descriptions. The first 3 studies revealed that participants report as many or more temporal-past comparisons than social comparisons. It was predicted that people would particularly favor temporal-past comparisons when they are interested in enhancing themselves. Temporal-past comparisons are gratifying, because they tend to indicate improvement over time. Social comparisons may be preferred when people are motivated to evaluate themselves accurately. These predictions were supported when self-evaluation and self-enhancement goals were explicitly manipulated (Study 4) or primed (Study 5).

Effects of method, orientation, and size of angle on the Ponzo illusion.

The Ponzo figure was used to test predictions based upon Pressey's 1971 concept of attentive fields. Subjects made judgements using either the method of successive reproduction (n = 18) or the method of reproduction (n = 17). Size of the acute angle between the oblique and test lines (30 degrees, 45 degrees, and 60 degrees) and orientation of test figures (apex pointed up, left, right, and down) were varied. It was predicted with the method of successive reproduction that illusions of shrinkage would occur and that the variable of orientation would not affect size of illusion. With the method of reproduction the prediction was made that illusions of expansion would occur when the apex pointed up and that illusions of shrinkage would occur when the apex pointed down. Analysis showed that with the method of successive reproduction illusions of shrinkage occurred when the apex was pointed either up or down. When the apex pointed either to the right or left nonsignificant illusions were found. With the method of reproduction the classical illusion of expansion occurred when the apex pointed up but changed to one of shrinkage when the apex pointed down. Size of expansion illusion diminished as the acute angle formed between the oblique and standard lines decreased. In general, some of the results were consistent with Pressey's concept of attentive fields.

Rapid activation of MDR1 gene expression in human metastatic sarcoma after in vivo exposure to doxorubicin.

Overexpression of P-glycoprotein (Pgp), a multidrug transporter encoded by the MDR1 gene, is associated with chemoresistance in some human solid tumor malignancies. To date, analyses of MDR1 levels in solid tumors have examined constitutive increases in expression at relapse. In the present study, we have evaluated the acute induction of MDR1 gene expression in a solid human tumor as a function of time in response to in vivo exposure to chemotherapy. Five patients with unresectable sarcoma pulmonary metastases underwent isolated single lung perfusion with doxorubicin. Relative MDR1 gene expression was measured in metastatic tumor nodules and normal lung specimens after initiation of chemoperfusion. In four of five patients, a 3-15-fold (median, 6.8) increase in MDR1 RNA levels was detected in tumors at 50 min after administration of doxorubicin. In contrast, normal lung samples had very low levels of MDR1 RNA prior to perfusion, and no acute increases were observed after therapy. These findings demonstrate, for the first time, that MDR1 gene expression can be rapidly activated in human tumors after transient in vivo exposure to cytotoxic chemotherapy.

Risk recognition and trauma-related symptoms among sexually revictimized women.

This study used experimental methodology to investigate the differential impact of various levels of sexual victimization on women's perceptions of risk and evaluative judgments of sexual assault within a dating interaction. Single- and multiple-incident victims were compared with nonvictims. Results supported the hypothesis that revictimized women would exhibit longer latencies than either single-incident victims or nonvictims in signaling that an audiotaped date rape should be halted. Revictimized women with greater posttraumatic stress disorder (PTSD) symptoms, arousal symptoms in particular, exhibited latencies similar to those of nonvictims, whereas revictimized women with lower levels of PTSD symptoms had significantly longer latencies. Dissociative symptoms were not related to latency. These findings suggest that PTSD-related arousal symptoms may serve a buffering effect, increasing sensitivity to threat cues that portend a sexually coercive interaction.

Sexual coercion history, calloused sexual beliefs and judgments of sexual coercion in a date rape analogue.

This study compared men with and without a history of coercive sexual behavior on their judgments of how far a man should go in using coercion in an audiotaped date rape simulation. Calloused sexual beliefs (CSB) and a "token resistance" manipulation were expected to differentially interact with coercion history. Results showed no effect for "token resistance." Calloused sexual beliefs interacted with coercion group, such that sexually coercive men high in CSB took significantly longer to stop the date rape interaction than coercive men low in CSB, who did not differ from noncoercive men. These findings support a model of sexual coercion in which a cognitive set consisting of rape-supportive beliefs may serve as a disinhibitor of behavior.

Physiological and phylogenetic diversity of bacteria growing on resin acids.

Resin acids are tricyclic diterpenes which are synthesized by trees and are a major cause of toxicity of pulp mill effluents. Bacterial strains isolated from three different sources and which grow on resin acids were physiologically characterized. Eleven strains, representating distinct groups, were further characterized physiologically and phylogenetically. The isolates had distinct specificities for use, as growth substrates, of the different resin acids tested. The isolates also used fatty acids but were generally limited in use of other diverse substrates tested. According to their 16S rDNA sequences, the representative isolates are related to members of the genera, Sphingomonas, Zoogloea, Ralstonia, Burkholderia, Pseudomonas and Mycobacterium. Analysis of whole-cell fatty acid profiles generally supported those phylogenetic relationships. However, most of the isolated did not have high similarities to reference strains in the Microbial Identification System database of fatty acid profiles or in the Biolog database of substrate oxidation patterns. Described species of Sphingomonas, Zoolgoea, Burkholderia Pseudomonas, most closely related to the isolates we characterized, failed to grow on, or degrade, resin acids. We propose recognition of Zoogloea resiniphila sp. nov., Pseudomonas vancouverensis sp. nov., P. abietaniphila sp. nov. and P. multiresinivorans sp. nov.

Evidence-based practice in primary care: past, present and future.

As in other health care specialities, evidence-based practice is beginning to have an impact on the philosophy and workings of primary care. Some practising clinicians, however, may wish to question its relevance to their everyday work, and whether general practitioners and other members of the primary health care team can realistically adopt a new approach to clinical decision making, at a time of such high workload and competing priorities. Major changes have taken place during the last 20 years as a result of the National Health Service (NHS) reforms, the development of general practice and primary care research, and other health service innovations such as the introduction of new technologies, which have had an important impact on primary care. Issues such as the availability and use of different research methods, the role of experts, and the development of guidelines, audit and evaluation of care, are becoming subject to renewed scrutiny. Within this context, this article explores the potential of an evidence-based approach in the primary care setting, and discusses possible strategies for change to assist the dissemination of research into practice and the implementation of evidence-based health care.

Isolation and characterization of isopimaric acid-degrading bacteria from a sequencing batch reactor.

We isolated two aerobic, gram-negative bacteria which grew on the diterpene resin acid isopimaric acid (IpA) as the sole carbon source and electron donor. The source of the isolates was a sequencing batch reactor treating a high-strength process stream from a paper mill. The isolates, IpA-1 and IpA-2, also grew on pimaric and dehydroabietic acids, and IpA-1 grew on abietic acid. Both strains used fatty acids, but neither strain used camphor, sitosterol, or betulin. Strain IpA-1 grew anaerobically with nitrate as an electron acceptor. Strains IpA-1 and IpA-2 had growth yields of 0.19 and 0.23 g of protein per g of IpA, respectively. During growth, both strains transformed IpA carbon to approximately equal amounts of biomass, carbon dioxide, and dissolved organic carbon. In both strains, growth on IpA induced an enzymatic system which caused cell suspensions to transform all four of the above resin acids. Cell suspensions of IpA-1 and IpA-2 removed IpA at rates of 0.56 and 0.13 mumol mg of protein-1 h-1, respectively. Cultures and cell suspensions of both strains failed to completely consume pimaric acid and yielded small amounts of an apparent metabolite from this acid. Cultures and cell suspensions of both strains yielded large amounts of three apparent metabolites from dehydroabietic acid. Analysis of 16S rDNA sequences indicated that the isolates are distinct members of the genus Pseudomonas sensu stricto.

Effect of backrest position on hemodynamic and right ventricular measurements in critically ill adults.

BACKGROUND: Hemodynamic measurements are often obtained with the patient in a flat, supine position. Reports suggest that these measurements can be reliably obtained at backrest elevations from 0 degree to 45 degrees. However, no study has been performed to evaluate the effects of position change on all the measurements that can be obtained via a pulmonary artery catheter. OBJECTIVE: To investigate the effects of backrest elevation of 0 degree, 30 degrees, and 45 degrees on measurements obtained via a pulmonary artery catheter. METHOD: Thirty-nine patients in an ICU at a university-based hospital, who required a pulmonary artery catheter, were studied. A single-group, repeated-measures design was used. Hemodynamic and volumetric measurements were obtained from all subjects. RESULTS: Repeated-measures analysis of variance revealed that differences in cardiac index were statistically significant, and differences in cardiac output approached statistical significance. However, examination of the means of these measurements indicates a clinically nonsignificant difference in these values. No statistically or clinically significant differences were found for the other hemodynamic or volumetric measurements studied related to the order of backrest elevation. CONCLUSION: Findings support the hypothesis that a patient need not be placed flat to obtain accurate hemodynamic and volumetric measurements. Results of this study are consistent with those of previous research and extend previous results to include the volumetric measurements of end-diastolic volume index and right ejection fraction. In addition, the use of mechanical ventilation and vasoactive drugs did not alter the accuracy of the measurements at backrest elevations from 0 degree to 45 degrees.

Evidence based general practice: a retrospective study of interventions in one training practice.

OBJECTIVES: To estimate the proportion of interventions in general practice that are based on evidence from clinical trials and to assess the appropriateness of such an evaluation. DESIGN: Retrospective review of case notes. SETTING: One suburban training general practice. SUBJECTS: 122 consecutive doctor-patient consultations over two days. MAIN OUTCOME MEASURES: Proportions of interventions based on randomised controlled trials (from literature search with Medline, pharmaceutical databases, and standard textbooks), on convincing non-experimental evidence, and without substantial evidence. RESULTS: 21 of the 122 consultations recorded were excluded due to insufficient data; 31 of the interventions were based on randomised controlled trial evidence and 51 based on convincing non-experimental evidence. Hence 82/101 (81%) of interventions were based on evidence meeting our criteria. CONCLUSIONS: Most interventions within general practice are based on evidence from clinical trials, but the methods used in such trials may not be the most appropriate to apply to this setting.

Spectral analysis of lactoperoxidase. Evidence for a common heme in mammalian peroxidases.

The identity of the non-extractable heme of mammalian lactoperoxidase (LPO) has remained unsolved for over 40 years. Accepted possibilities include a constrained heme b or an 8-thiomethylene-modified heme b. Recent studies of myeloperoxidase (MPO) (Fenna, R., Zeng, J., and Davey, C. (1995) Arch. Biochem. Biophys. 316, 653-656; Taylor, K. L., Strobel, F., Yue, K. T., Ram, P., Pohl, J., Woods, A. S., and Kinkade, J. M., Jr. (1995) Arch. Biochem. Biophys. 316, 635-642) suggest possible prosthetic group similarities between MPO and LPO. To address heme identity for LPO, we used comparative magnetic circular dichroism (MCD) spectroscopy of LPO versus myoglobin (Mb), horseradish peroxidase (HRP), and MPO. MCD spectra of native Fe3+-LPO and Fe3+-CN--LPO are approximately 10 nm red shifted from analogous forms of Mb and HRP, including the formate-Mb adduct. MCD spectra of native LPO and MPO are opposite in sign, and MCD spectra of their cyanoadducts also differ. These data indicate the LPO heme is distinct from heme b of Mb and HRP as well as from "heme m" of MPO. From this work and literature analysis, we suggest that the non-extractable "heme l" of LPO has the two vinyl groups of heme b but lacks the 2-sulfonium-vinyl linkage of heme m. The observed red shifts in LPO spectra may derive from ester linkages to protein as for MPO. Strong spectral analogies between LPO and mammalian peroxidases (e.g. from saliva, eosinophils, thyroid, intestine) indicate similar prosthetic heme moieties.

Can general practice provide useful information?--evaluation of a primary health care information project in northern England.

OBJECTIVE: To develop a computerised primary care information gathering network capable of producing reliable risk factor and morbidity data from a wide diversity of general practice software systems. METHOD: Fourteen practices from the Wakefield and Pontefract district collaborated in sharing information and solving technical difficulties associated with collecting data on coronary heart disease (CHD) risk factors, diabetes, and asthma. Practices also participated in rheumatology and mental health needs assessment projects. RESULTS: Data could be transferred by diskette in only five of the systems and paper reports had to be used to post process the data into a standard format. Not all data were complete or comparable. Crude estimates only of smoking prevalence and smoking cessation interventions were possible, as well as of age and sex specific prevalences for asthma and diabetes. The rheumatology health needs assessment, using the prospective collection of consultation based data, highlighted an unmet need for rheumatology services in the community. CONCLUSIONS: Although practices have been willing to devote considerable time and effort to the project, the diversity of software has precluded a simple methodology for data collection and analysis. The amount of useful information retrieved so far, has been limited but a number of important lessons have been learned which have implications for similar information projects and the use of primary care information in service planning.

ALL-1 gene rearrangements in DNA topoisomerase II inhibitor-related leukemia in children.

We examined clinical, morphologic, and cytogenetic features and ALL-1 (MLL, Htrxl, HRX) gene rearrangements in 17 cases of secondary leukemia that occurred 11 months to 9 years from diagnoses of primary cancers in children who received topoisomerase II inhibitors or developed secondary leukemias typical of those associated with this therapy. Primary diagnoses included nine solid tumors and eight leukemias. Ten secondary leukemias were acute myeloid leukemia (AML), one was of mixed lineage, two were acute lymphoblastic leukemia (ALL), and four presented as myelodysplasia. Of 15 cases with 11q23 involvement, 11 (73%) were cytogenetically identifiable; four cases had molecular rearrangement only. By Southern blot, rearrangements within the ALL-1 gene were similar to sporadic cases. The results of this analysis suggest the following: (1) In most pediatric cases of topoisomerase II inhibitor-associated leukemia, there is disruption of the breakpoint cluster region of the ALL-1 gene at chromosomal band 11q23. (2) Exposure histories vary in secondary 11q23 leukemia, as the only topoisomerase II inhibitor was dactinomycin in one case, and, in another case, no topoisomerase II inhibitor was administered. (3) There is clinical, morphologic, cytogenetic, and molecular heterogeneity in pediatric secondary 11q23 leukemia. (4) There are some survivors of pediatric secondary 11q23 leukemia, but the outcome is most often fatal.