Anatomical significance of a posterior horn of medial meniscus: the relationship between its radial tear and cartilage degradation of joint surface

<p>Abstract</p> <p>Background</p> <p>Traumatic injury and surgical meniscectomy of a medial meniscus are known to cause subsequent knee osteoarthritis. However, the difference in the prevalence of osteoarthritis caused by the individual type of the medial meniscal tear has not been elucidated. The aim of this study was to investigate what type of tear is predominantly responsible for the degradation of articular cartilage in the medial compartment of knee joints.</p> <p>Methods</p> <p>Five hundred and forty eight cadaveric knees (290 male and 258 female) were registered in this study. The average age of cadavers at death was 78.8 years old (range: 52-103 years). The knees were macroscopically examined and their medial menisci were classified into four groups according to types of tears: "no tear", "radial tear of posterior horn", "other types of tear" and "worn-out meniscus" groups. The severity of cartilage degradation in their medial compartment of knee joints was evaluated using the international cartilage repair society (ICRS) grading system. We statistically compared the ICRS grades among the groups using Mann-Whitney U test.</p> <p>Results</p> <p>The knees were assigned into the four groups: 416 "no tear" knees, 51 "radial tear of posterior horn" knees, 71 "other types of tear" knees, and 10 "worn-out meniscus" knees. The knees with substantial meniscal tears showed the severer ICRS grades of cartilage degradation than those without meniscal tears. In addition, the ICRS grades were significantly severer in the "radial tear of posterior horn" group than in the "other types of tear" group, suggesting that the radial tear of posterior horn in the medial meniscus is one of the risk factors for cartilage degradation of joint surface.</p> <p>Conclusions</p> <p>We have clarified the relationship between the radial tear of posterior horn in the medial meniscus and the severer grade of cartilage degradation. This study indicates that the efforts should be made to restore the anatomical role of the posterior horn in keeping the hoop strain, when patients' physical activity levels are high and the tear pattern is simple enough to be securely sutured.</p

Weak Polygyny in California Sea Lions and the Potential for Alternative Mating Tactics

Female aggregation and male territoriality are considered to be hallmarks of polygynous mating systems. The development of genetic parentage assignment has called into question the accuracy of behavioral traits in predicting true mating systems. In this study we use 14 microsatellite markers to explore the mating system of one of the most behaviorally polygynous species, the California sea lion (Zalophus californianus). We sampled a total of 158 female-pup pairs and 99 territorial males across two breeding rookeries (San Jorge and Los Islotes) in the Gulf of California, Mexico. Fathers could be identified for 30% of pups sampled at San Jorge across three breeding seasons and 15% of sampled pups at Los Islotes across two breeding seasons. Analysis of paternal relatedness between the pups for which no fathers were identified (sampled over four breeding seasons at San Jorge and two at Los Islotes) revealed that few pups were likely to share a father. Thirty-one percent of the sampled males on San Jorge and 15% of the sampled males on Los Islotes were assigned at least one paternity. With one exception, no male was identified as the father of more than two pups. Furthermore, at Los Islotes rookery there were significantly fewer pups assigned paternity than expected given the pool of sampled males (p<0.0001). Overall, we found considerably lower variation in male reproductive success than expected in a species that exhibits behavior associated with strongly polygynous mating. Low variation in male reproductive success may result from heightened mobility among receptive females in the Gulf of California, which reduces the ability of males to monopolize groups of females. Our results raise important questions regarding the adaptive role of territoriality and the potential for alternative mating tactics in this species

Right drug, right patient, right time: aspiration or future promise for biologics in rheumatoid arthritis?

Individualising biologic disease-modifying anti-rheumatic drugs (bDMARDs) to maximise outcomes and deliver safe and cost-effective care is a key goal in the management of rheumatoid arthritis (RA). Investigation to identify predictive tools of bDMARD response is a highly active and prolific area of research. In addition to clinical phenotyping, cellular and molecular characterisation of synovial tissue and blood in patients with RA, using different technologies, can facilitate predictive testing. This narrative review will summarise the literature for the available bDMARD classes and focus on where progress has been made. We will also look ahead and consider the increasing use of ‘omics’ technologies, the potential they hold as well as the challenges, and what is needed in the future to fully realise our ambition of personalised bDMARD treatment

Educational change, inertia and potential futures

The point of departure of the paper is that there are profound social, cultural, technological, scientific and environmental changes which occur at most local but also at global levels of the modern world. From these will stem huge challenges in all spheres of life. These demand changes in education, not necessarily in the system or how it operates, but perhaps in its aims, and most certainly in its content. Knowledge that was once powerful to understand the world, to develop as a person and address the challenges of life, should be replaced with new knowledge which may often be outside the traditional disciplines. Moreover, a host of new skills may be relevant for the world of tomorrow. There are, however, many obstacles to change, both reasonable and unreasonable ones. The thrust of the paper is to provide a discussion of nine categories of inertia or constraints that are seen to stifle change, in particular, as it relates to the content of education. The categories are discussed under the headings of general conservativism, system stability, standards, fuzziness of new ideas, the strength of old ideas, vested interests, teacher education, lack of space and motivation for initiative, and lack of consequence of no change. Added to this there are serious logistic problems for those who want to foster change. It is argued that very little change in content will be seen if these inertial constraints are not recognised. Assuming there is a will to change, the institutional infrastructures that should facilitate sustained change must be scutinised and it must be ensured that the teachers, i.e. the professionals that operate the system, are involved.Peer Reviewe

Complement receptor 1 gene (CR1) intragenic duplication and risk of Alzheimer’s disease

Single nucleotide variants (SNVs) within and surrounding the complement receptor 1 (CR1) gene show some of the strongest genome-wide association signals with late-onset Alzheimer’s disease. Some studies have suggested that this association signal is due to a duplication allele (CR1-B) of a low copy repeat (LCR) within the CR1 gene, which increases the number of complement C3b/C4b-binding sites in the mature receptor. In this study, we develop a triplex paralogue ratio test assay for CR1 LCR copy number allowing large numbers of samples to be typed with a limited amount of DNA. We also develop a CR1-B allele-specific PCR based on the junction generated by an historical non-allelic homologous recombination event between CR1 LCRs. We use these methods to genotype CR1 and measure CR1-B allele frequency in both late-onset and early-onset cases and unaffected controls from the United Kingdom. Our data support an association of late-onset Alzheimer’s disease with the CR1-B allele, and confirm that this allele occurs most frequently on the risk haplotype defined by SNV alleles. Furthermore, regression models incorporating CR1-B genotype provide a better fit to our data compared to incorporating the SNV-defined risk haplotype, supporting the CR1-B allele as the variant underlying the increased risk of late-onset Alzheimer’s disease

Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe