The revision partial knee classification system: understanding the causative pathology and magnitude of further surgery following partial knee arthroplasty.

AIMS: Joint registries classify all further arthroplasty procedures to a knee with an existing partial arthroplasty as revision surgery, regardless of the actual procedure performed. Relatively minor procedures, including bearing exchanges, are classified in the same way as major operations requiring augments and stems. A new classification system is proposed to acknowledge and describe the detail of these procedures, which has implications for risk, recovery, and health economics. METHODS: Classification categories were proposed by a surgical consensus group, then ranked by patients, according to perceived invasiveness and implications for recovery. In round one, 26 revision cases were classified by the consensus group. Results were tested for inter-rater reliability. In round two, four additional cases were added for clarity. Round three repeated the survey one month later, subject to inter- and intrarater reliability testing. In round four, five additional expert partial knee arthroplasty surgeons were asked to classify the 30 cases according to the proposed revision partial knee classification (RPKC) system. RESULTS: Four classes were proposed: PR1, where no bone-implant interfaces are affected; PR2, where surgery does not include conversion to total knee arthroplasty, for example, a second partial arthroplasty to a native compartment; PR3, when a standard primary total knee prosthesis is used; and PR4 when revision components are necessary. Round one resulted in 92% inter-rater agreement (Kendall's W 0.97; p < 0.005), rising to 93% in round two (Kendall's W 0.98; p < 0.001). Round three demonstrated 97% agreement (Kendall's W 0.98; p < 0.001), with high intra-rater reliability (interclass correlation coefficient (ICC) 0.99; 95% confidence interval 0.98 to 0.99). Round four resulted in 80% agreement (Kendall's W 0.92; p < 0.001). CONCLUSION: The RPKC system accounts for all procedures which may be appropriate following partial knee arthroplasty. It has been shown to be reliable, repeatable and pragmatic. The implications for patient care and health economics are discussed. Cite this article: Bone Jt Open 2021;2(8):638-645

Gender, school and academic year differences among Spanish university students at high-risk for developing an eating disorder: An epidemiologic study

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to assess the magnitude of the university population at high-risk of developing an eating disorder and the prevalence of unhealthy eating attitudes and behaviours amongst groups at risk; gender, school or academic year differences were also explored.</p> <p>Methods</p> <p>A cross-sectional study based on self-report was used to screen university students at high-risk for an eating disorder. The sample size was of 2551 university students enrolled in 13 schools between the ages of 18 and 26 years. The instruments included: a social-demographic questionnaire, the Eating Disorders Inventory (EDI), the Body Shape Questionnaire (BSQ), the Symptom Check List 90-R (SCL-90-R), and the Self-Esteem Scale (RSE). The sample design is a non-proportional stratified sample by academic year and school. The prevalence rate was estimated controlling academic year and school. Logistic regression analysis was used to investigate adjusted associations between gender, school and academic year.</p> <p>Results</p> <p>Female students presented unhealthy weight-control behaviours as dieting, laxatives use or self-induced vomiting to lose weight than males. A total of 6% of the females had a BMI of 17.5 or less or 2.5% had amenorrhea for 3 or more months. In contrast, a higher proportion of males (11.6%) reported binge eating behaviour. The prevalence rate of students at high-risk for an eating disorder was 14.9% (11.6–18) for males and 20.8% (18.7–22.8) for females, according to an overall cut-off point on the EDI questionnaire. Prevalence rates presented statistically significant differences by gender (p < 0.001) but not by school or academic year.</p> <p>Conclusion</p> <p>The prevalence of eating disorder risk in university students is high and is associated with unhealthy weight-control practices, similar results have been found in previous studies using cut-off points in questionnaires. These results may be taken into account to encourage early detection and a greater awareness for seeking treatment in order to improve the diagnosis, among students on university campuses.</p

BR-squared: a practical solution to the winner’s curse in genome-wide scans

The detrimental effects of the winner’s curse, including overestimation of the genetic effects of associated variants and underestimation of sufficient sample sizes for replication studies are well-recognized in genome-wide association studies (GWAS). These effects can be expected to worsen as the field moves from GWAS into whole genome sequencing. To date, few studies have reported statistical adjustments to the naive estimates, due to the lack of suitable statistical methods and computational tools. We have developed an efficient genome-wide non-parametric method that explicitly accounts for the threshold, ranking, and allele frequency effects in whole genome scans. Here, we implement the method to provide bias-reduced estimates via bootstrap re-sampling (BR-squared) for association studies of both disease status and quantitative traits, and we report the results of applying BR-squared to GWAS of psoriasis and HbA1c. We observed over 50% reduction in the genetic effect size estimation for many associated SNPs. This translates into a greater than fourfold increase in sample size requirements for successful replication studies, which in part explains some of the apparent failures in replicating the original signals. Our analysis suggests that adjusting for the winner’s curse is critical for interpreting findings from whole genome scans and planning replication and meta-GWAS studies, as well as in attempts to translate findings into the clinical setting

Stereochemical Insignificance Discovered in Acinetobacter baumannii Quorum Sensing

Stereochemistry is a key aspect of molecular recognition for biological systems. As such, receptors and enzymes are often highly stereospecific, only recognizing one stereoisomer of a ligand. Recently, the quorum sensing signaling molecules used by the nosocomial opportunistic pathogen, Acinetobacter baumannii, were identified, and the primary signaling molecule isolated from this species was N-(3-hydroxydodecanoyl)-l-homoserine lactone. A plethora of bacterial species have been demonstrated to utilize 3-hydroxy-acylhomoserine lactone autoinducers, and in virtually all cases, the (R)-stereoisomer was identified as the natural ligand and exhibited greater autoinducer activity than the corresponding (S)-stereoisomer. Using chemical synthesis and biochemical assays, we have uncovered a case of stereochemical insignificance in A. baumannii and provide a unique example where stereochemistry appears nonessential for acylhomoserine lactone-mediated quorum sensing signaling. Based on previously reported phylogenetic studies, we suggest that A. baumannii has evolutionarily adopted this unique, yet promiscuous quorum sensing system to ensure its survival, particularly in the presence of other proteobacteria

Batrachochytrium dendrobatidis Shows High Genetic Diversity and Ecological Niche Specificity among Haplotypes in the Maya Mountains of Belize

The amphibian pathogen Batrachochytrium dendrobatidis (Bd) has been implicated in amphibian declines around the globe. Although it has been found in most countries in Central America, its presence has never been assessed in Belize. We set out to determine the range, prevalence, and diversity of Bd using quantitative PCR (qPCR) and sequencing of a portion of the 5.8 s and ITS1-2 regions. Swabs were collected from 524 amphibians of at least 26 species in the protected areas of the Maya Mountains of Belize. We sequenced a subset of 72 samples that had tested positive for Bd by qPCR at least once; 30 samples were verified as Bd. Eight unique Bd haplotypes were identified in the Maya Mountains, five of which were previously undescribed. We identified unique ecological niches for the two most broadly distributed haplotypes. Combined with data showing differing virulence shown in different strains in other studies, the 5.8 s - ITS1-2 region diversity found in this study suggests that there may be substantial differences among populations or haplotypes. Future work should focus on whether specific haplotypes for other genomic regions and possibly pathogenicity can be associated with haplotypes at this locus, as well as the integration of molecular tools with other ecological tools to elucidate the ecology and pathogenicity of Bd

The Reinforcing Therapist Performance (RTP) experiment: Study protocol for a cluster randomized trial

<p>Abstract</p> <p>Background</p> <p>Rewarding provider performance has been recommended by the Institute of Medicine as an approach to improve the quality of treatment, yet little empirical research currently exists that has examined the effectiveness and cost-effectiveness of such approaches. The aim of this study is to test the effectiveness and cost-effectiveness of providing monetary incentives directly to therapists as a method to improve substance abuse treatment service delivery and subsequent client treatment outcomes.</p> <p>Design</p> <p>Using a cluster randomized design, substance abuse treatment therapists from across 29 sites were assigned by site to either an implementation as usual (IAU) or pay-for-performance (P4P) condition.</p> <p>Participants</p> <p>Substance abuse treatment therapists participating in a large dissemination and implementation initiative funded by the Center for Substance Abuse Treatment.</p> <p>Intervention</p> <p>Therapists in both conditions received comprehensive training and ongoing monitoring, coaching, and feedback. However, those in the P4P condition also were given the opportunity to earn monetary incentives for achieving two sets of measurable behaviors related to quality implementation of the treatment.</p> <p>Outcomes</p> <p>Effectiveness outcomes will focus on the impact of the monetary incentives to increase the proportion of adolescents who receive a targeted threshold level of treatment, months that therapists demonstrate monthly competency, and adolescents who are in recovery following treatment. Similarly, cost-effectiveness outcomes will focus on cost per adolescent receiving targeted threshold level of treatment, cost per month of demonstrated competence, and cost per adolescent in recovery.</p> <p>Trial Registration</p> <p>Trial Registration Number: NCT01016704</p

Genome Wide Association (GWA) Study for Early Onset Extreme Obesity Supports the Role of Fat Mass and Obesity Associated Gene (FTO) Variants

Background. Obesity is a major health problem. Although heritability is substantial, genetic mechanisms predisposing to obesity are not very well understood. We have performed a genome wide association study (GWA) for early onset (extreme) obesity. Methodology/Principal Findings. a) GWA (Genome-Wide Human SNP Array 5.0 comprising 440,794 single nucleotide polymorphisms) for early onset extreme obesity based on 487 extremely obese young German individuals and 442 healthy lean German controls; b) confirmatory analyses on 644 independent families with at least one obese offspring and both parents. We aimed to identify and subsequently confirm the 15 SNPs (minor allele frequency $10%) with the lowest p-values of the GWA by four genetic models: additive, recessive, dominant and allelic. Six single nucleotide polymorphisms (SNPs) in FTO (fat mass and obesity associated gene) within one linkage disequilibrium (LD) block including the GWA SNP rendering the lowest p-value (rs1121980; log-additive model: nominal p = 1.13610 27, corrected p = 0.0494; odds ratio (OR)CT 1.67, 95 % confidence interval (CI) 1.22–2.27; OR TT 2.76, 95 % CI 1.88–4.03) belonged to the 15 SNPs showing the strongest evidence for association with obesity. For confirmation we genotyped 11 of these in the 644 independent families (of the six FTO SNPs we chose only two representing the LD bock). For both FTO SNPs the initial association was confirmed (both Bonferroni corrected p,0.01). However, none of the nine non-FTO SNPs revealed significant transmission disequilibrium

Seafloor character and sedimentary processes in eastern Long Island Sound and western Block Island Sound

Author Posting. © The Author(s), 2006. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Geo-Marine Letters 26 (2006): 59-68, doi: 10.1007/s00367-006-0016-4.Multibeam bathymetric data and seismic-reflection profiles collected in eastern Long Island and western Block Island Sounds reveal previously unrecognized glacial features and modern bedforms. Glacial features include an ice-sculptured bedrock surface, a newly identified recessional moraine, exposed glaciolacustrine sediments, and remnants of stagnant-ice-contact deposits. Modern bedforms include fields of transverse sand waves, barchanoid waves, giant scour depressions, and pockmarks. Bedform asymmetry and scour around obstructions indicate that net sediment transport is westward across the northern par of the study area near Fishers Island and eastward across the southern par near Great Gull Island.This work was supported by the Coastal and Marine Geology Program of the U.S. Geological Survey, the Connecticut Department of Environmental Protection, and the Atlantic Hydrographic Branch of the National Oceanic and Atmospheric Administration

Motor Adaptation Scaled by the Difficulty of a Secondary Cognitive Task

Background: Motor learning requires evaluating performance in previous movements and modifying future movements. The executive system, generally involved in planning and decision-making, could monitor and modify behavior in response to changes in task difficulty or performance. Here we aim to identify the quantitative cognitive contribution to responsive and adaptive control to identify possible overlap between cognitive and motor processes. Methodology/Principal Findings: We developed a dual-task experiment that varied the trial-by-trial difficulty of a secondary cognitive task while participants performed a motor adaptation task. Subjects performed a difficulty-graded semantic categorization task while making reaching movements that were occasionally subjected to force perturbations. We find that motor adaptation was specifically impaired on the most difficult to categorize trials. Conclusions/Significance: We suggest that the degree of decision-level difficulty of a particular categorization differentially burdens the executive system and subsequently results in a proportional degradation of adaptation. Our results suggest

Molecular basis of structure and function of the microvillus membrane of intestinal epithelial cells

Correlation of molecular structure with biochemical functions of the plasma membrane of the microvilli of intestinal epithelial cells has been investigated by biochemical and electron microscopic procedures. Repeating particles, measuring approximately 60 &#197;in diameter, were found on the surface of the microvilli membrane which had been isolated or purified from rabbit intestinal epithelial cells and negatively stained with phosphotungstic acid. These particles were proved to be inherent components of the microvillus membrane, attached to the outer surface of its trilaminar structure, and were designated as the elementary particles of the microvilli of intestinal epithelial cells. Biochemical and electron microscopic identification of these elementary particles has been carried out by isolation of the elementary particles with papain from the isolated microvillus membrane, followed by purification of the particles by chromatographies on DEAE-cellulose and Sephadex columns. The partially purified particles containing invertase and leucine aminopeptidase are similar in size and structure to those of the elementary particles in the microvillus membrane. Evidence indicates that each of the elementary particles coincide with or include an enzyme molecule such as disaccharidase or peptidase, which carry out the terminal hydrolytic digestion of carbohydrates and proteins, respectively, on the surface of the microvillus membrane. Magnesium ionactivated adenosine triphosphatase and alkaline phosphatase cannot be solubilized with papain but remains in the smooth-surface membrane after the elementary particles have been removed. Cytochemical electron microscopic observation revealed that the active site of magnesium ion-activated adenosine triphosphatase is localized predominantly in the inner surface of the trilaminar structure of the microvillus membrane.</p