Clinical features of symptomatic patellofemoral joint osteoarthritis

Introduction

Patellofemoral joint osteoarthritis (OA) is common and leads to pain and disability. However, current classification criteria do not distinguish between patellofemoral and tibiofemoral joint OA. The objective of this study was to provide empirical evidence of the clinical features of patellofemoral joint OA (PFJOA) and to explore the potential for making a confident clinical diagnosis in the community setting.

Methods

This was a population-based cross-sectional study of 745 adults aged ≥50 years with knee pain. Information on risk factors and clinical signs and symptoms was gathered by a self-complete questionnaire, and standardised clinical interview and examination. Three radiographic views of the knee were obtained (weight-bearing semi-flexed posteroanterior, supine skyline and lateral) and individuals were classified into four subsets (no radiographic OA, isolated PFJOA, isolated tibiofemoral joint OA, combined patellofemoral/tibiofemoral joint OA) according to two different cut-offs: ''any OA'' and ''moderate to severe OA''. A series of binary logistic and multinomial regression functions were performed to compare the clinical features of each subset and their ability in combination to discriminate PFJOA from other subsets.

Results

Distinctive clinical features of moderate to severe isolated PFJOA included a history of dramatic swelling, valgus deformity, markedly reduced quadriceps strength, and pain on patellofemoral joint compression. Mild isolated PFJOA was barely distinguished from no radiographic OA (AUC 0.71, 95% CI 0.66, 0.76) with only difficulty descending stairs and coarse crepitus marginally informative over age, sex and body mass index. Other cardinal signs of knee OA - the presence of effusion, bony enlargement, reduced flexion range of movement, mediolateral instability and varus deformity - were indicators of tibiofemoral joint OA.

Conclusions

Early isolated PFJOA is clinically manifest in symptoms and self-reported functional limitation but has fewer clear clinical signs. More advanced disease is indicated by a small number of simple-to-assess signs and the relative absence of classic signs of knee OA, which are predominantly manifestations of tibiofemoral joint OA. Confident diagnosis of even more advanced PFJOA may be limited in the community setting.     

Diet of bluegill Lepomis macrochirus in a South African reservoir during winter and summer

Alien fishes are considered a major threat to aquatic biodiversity in South Africa, yet relatively little regional information on their biology and ecology is available for many of these species. Seasonal changes in the diet of the bluegill Lepomis macrochirus in Howieson’s Poort Dam, Grahamstown, were assessed during summer and winter in 2014–2015, using stomach content analysis. In winter, juvenile and adult fish diets were dominated by crustacean zooplankton and insects, respectively. In summer, juvenile fish fed on crustaceans and insects, whereas adults consumed mostly fish eggs, indicating a potential impact by these invasive fish on native fish through oophagy.     

A novel Atg5-shRNA mouse model enables temporal control of Autophagy in vivo

Macroautophagy/autophagy is an evolutionarily conserved catabolic pathway whose modulation has been linked to diverse disease states, including age-associated disorders. Conventional and conditional whole-body knockout mouse models of key autophagy genes display perinatal death and lethal neurotoxicity, respectively, limiting their applications for in vivo studies. Here, we have developed an inducible shRNA mouse model targeting Atg5, allowing us to dynamically inhibit autophagy in vivo, termed ATG5i mice. The lack of brain-associated shRNA expression in this model circumvents the lethal phenotypes associated with complete autophagy knockouts. We show that ATG5i mice recapitulate many of the previously described phenotypes of tissue-specific knockouts. While restoration of autophagy in the liver rescues hepatomegaly and other pathologies associated with autophagy deficiency, this coincides with the development of hepatic fibrosis. These results highlight the need to consider the potential side effects of systemic anti-autophagy therapies.     

An improved method using densitometry for evaluating severity of laser photocoagulation induced CNV

Laser photocoagulation induced choroidal neovascularization currently is the most effective model available for the study of this disease in terms of efficacy of new drugs and therapies. Previously, evaluating the extent of choroidal neovascularization using this model was time- consuming and required the use of experienced personnel. We describe a new method for simple and rapid evaluation of laser induced choroidal neovascularization using densitometry. Fluorescein angiograms of a laser photocoagulated rat eye were scanned into a computer. Densitometry software subsequently was used to calculate the severity of the laser lesions. The densitometry method proved effective for calculating the extent of laser induced choroidal neovascularization. In addition, this method was more rapid than visual evaluations and less likely to produce errors.     

Noncontact dipole effects on channel permeation. III. Anomalous proton conductance effects in gramicidin

Proton transport on water wires, of interest for many problems in membrane biology, is analyzed in side-chain analogs of gramicidin A channels. In symmetrical 0.1 N HCl solutions, fluorination of channel Trp(11), Trp-(13), or Trp(15) side chains is found to inhibit proton transport, and replacement of one or more Trps with Phe enhances proton transport, the opposite of the effects on K(+) transport in lecithin bilayers. The current-voltage relations are superlinear, indicating that some membrane field-dependent process is rate limiting. The interfacial dipole effects are usually assumed to affect the rate of cation translocation across the channel. For proton conductance, however, water reorientation after proton translocation is anticipated to be rate limiting. We propose that the findings reported here are most readily interpreted as the result of dipole-dipole interactions between channel waters and polar side chains or lipid headgroups. In particular, if reorientation of the water column begins with the water nearest the channel exit, this hypothesis explains the negative impact of fluorination and the positive impact of headgroup dipole on proton conductance.     

Lifestyle modifications to prevent and control hypertension. 4. Recommendations on physical exercise training. Canadian Hypertension Society,Canadian Coalition for High Blood Pressure Prevention and Control,Laboratory Centre for Disease Control at Health Canada,Heart and Stroke Foundation of Canada

OBJECTIVE: To provide updated, evidence-based recommendations for health care professionals concerning the effects of regular physical activity on the prevention and control of hypertension in otherwise healthy adults. OPTIONS: People may engage in no, sporadic or regular physical activity that may be of low, moderate or vigorous intensity. For sedentary people with hypertension, the options are to undertake or maintain regular physical activity and to avoid or moderate medication use; to use another lifestyle modification technique; to commence or continue antihypertensive medication; or to take no action and remain at increased risk of cardiovascular disease. OUTCOMES: The health outcomes considered were changes in blood pressure and in morbidity and mortality rates. Because of insufficient evidence, no economic outcomes were considered. EVIDENCE: A MEDLINE search was conducted for the period 1966-1997 with the terms exercise, exertion, physical activity, hypertension and blood pressure. Both reports of trials and review articles were obtained. Other relevant evidence was obtained from the reference lists of these articles, from the personal files of the authors and through contacts with experts. The articles were reviewed, classified according to study design and graded according to level of evidence. VALUES: A high value was placed on avoidance of cardiovascular morbidity and premature death caused by untreated hypertension. BENEFITS, HARMS AND COSTS: Physical activity of moderate intensity involving rhythmic movements with the lower limbs for 50-60 minutes, 3 or 4 times per week, reduces blood pressure and appears to be more effective than vigorous exercise. Harm is uncommon and is generally restricted to the musculoskeletal injuries that may occur with any repetitive activity. Injury occurs more often with jogging than with walking, cycling or swimming. The costs include the costs of appropriate shoes, garments and equipment, but these were not specifically measured. RECOMMENDATIONS: (1) People with mild hypertension should engage in 50-60 minutes of moderate rhythmic exercise of the lower limbs, such as brisk walking or cycling, 3 or 4 times per week to reduce blood pressure, (2) Exercise should be prescribed as an adjunctive therapy for people who require pharmacologic therapy for hypertension, especially those who are not receiving beta-blockers. (3) People who do not have hypertension should participate in regular exercise as it will decrease blood pressure and reduce the risk of coronary artery disease, although there is no direct evidence that it will prevent hypertension. VALIDATION: These recommendations agree with those of the World Hypertension League, the American College of Sports Medicine, the report of the US Surgeon General on physical activity and health, and the US National Institutes of Health Consensus Development Panel on Physical Activity and Cardiovascular Health. These guidelines have not been clinically tested. SPONSORS: The Canadian Hypertension Society, the Canadian Coalition for High Blood Pressure Prevention and Control, the Laboratory Centre for Disease Control at Health Canada, and the Heart and Stroke Foundation of Canada.