Haze in the Klang Valley of Malaysia

Continuous measurements of dry aerosol light scattering (Bsp) were made at two sites in the Klang Valley of Malaysia between December 1998 and December 2000. In addition 24-h PM2.5 samples were collected on a one-day-in-six cycle and the chemical composition of the aerosol was determined. Periods of excessive haze were defined as 24-h average Bsp values greater than 150 Mm-1 and these occurred on a number of occasions, between May and September 1999, during May 2000, and between July and September 2000. The evidence for smoke being a significant contributor to aerosol during periods of excessive haze is discussed and includes features of the aerosol chemistry, the diurnal cycle of Bsp, and the coincidence of forest fires on Sumatra during the southwest (SW) monsoon period, as well as transport modelling for one week of the southwest Monsoon of 2000. The study highlights that whilst transboundary smoke is a major contributor to poor visibility in the Klang Valley, smoke from fires on Peninsular Malaysia is also a contributor, and at all times, the domestic source of secondary particle production is present

Can self-affirmation exacerbate adverse reactions to stress under certain conditions?

OBJECTIVE: Self-affirmation has repeatedly been shown to reduce adverse psychological and physiological responses to stress. However, it is plausible that self-affirmation could exacerbate negative reactions to stress under certain conditions. The current research explored whether self-affirmation would increase negative psychological responses to a stressor occurring in a central life domain characterised by low levels of control. DESIGN: Female participants (Study 1 N = 132; Study 2 N = 141) completed baseline measures of anxiety and mood. They were then randomly allocated to complete a self-affirmation or control task, before reading a narrative documenting a stressful birth and imagining themselves in the place of the woman giving birth. After completing this task, participants again reported their levels of anxiety and positive mood. MAIN OUTCOME MEASURES: Anxiety and positive mood assessed at follow-up. RESULTS: Study 1 demonstrated that self-affirmed women experienced increased anxiety and less positive mood at follow-up, compared both to baseline and to women in the control condition. Study 2 revealed that the effect of self-affirmation on outcomes was moderated by fear of childbirth. CONCLUSION: These results provide preliminary evidence that self-affirmation may worsen negative responses to stressors under certain conditions and for certain individuals

Defining an International Standard Set of Outcome Measures for Patients With Hip or Knee Osteoarthritis: Consensus of the International Consortium for Health Outcomes Measurement Hip and Knee Osteoarthritis Working Group

OBJECTIVE: To define a minimum Standard Set of outcome measures and case-mix factors for monitoring, comparing, and improving health care for patients with clinically diagnosed hip or knee osteoarthritis (OA), with a focus on defining the outcomes that matter most to patients. METHODS: An international working group of patients, arthroplasty register experts, orthopedic surgeons, primary care physicians, rheumatologists, and physiotherapists representing 10 countries was assembled to review existing literature and practices for assessing outcomes of pharmacologic and nonpharmacologic OA therapies, including surgery. A series of 8 teleconferences, incorporating a modified Delphi process, were held to reach consensus. RESULTS: The working group reached consensus on a concise set of outcome measures to evaluate patients\u27 joint pain, physical functioning, health-related quality of life, work status, mortality, reoperations, readmissions, and overall satisfaction with treatment result. To support analysis of these outcome measures, pertinent baseline characteristics and risk factor metrics were defined. Annual outcome measurement is recommended for all patients. CONCLUSION: We have defined a Standard Set of outcome measures for monitoring the care of people with clinically diagnosed hip or knee OA that is appropriate for use across all treatment and care settings. We believe this Standard Set provides meaningful, comparable, and easy to interpret measures ready to implement in clinics and/or registries globally. We view this set as an initial step that, when combined with cost data, will facilitate value-based health care improvements in the treatment of hip and knee OA

The unique chemistry of Eastern Mediterranean water masses selects for distinct microbial communities by depth

Peer reviewedPublisher PD

Age-dependent Changes in the Articular Cartilage and Subchondral Bone of C57BL/6 Mice after Surgical Destabilization of Medial Meniscus

Age is the primary risk factor for osteoarthritis (OA), yet surgical OA mouse models such as destabilization of the medial meniscus (DMM) used for evaluating disease-modifying OA targets are frequently performed on young adult mice only. This study investigates how age affects cartilage and subchondral bone changes in mouse joints following DMM. DMM was performed on male C57BL/6 mice at 4 months (4 M), 12 months (12 M) and 19+ months (19 M+) and on females at 12 M and 18 M+. Two months after surgery, operated and unoperated contralateral knees were harvested and evaluated using cartilage histology scores and muCT quantification of subchondral bone plate thickness and osteophyte formation. The 12 M and 19 M+ male mice developed more cartilage erosions and thicker subchondral bone plates after DMM than 4 M males. The size of osteophytes trended up with age, while the bone volume fraction was significantly higher in the 19 M+ group. Furthermore, 12 M females developed milder OA than males as indicated by less cartilage degradation, less subchondral bone plate sclerosis and smaller osteophytes. Our results reveal distinct age/gender-dependent structural changes in joint cartilage and subchondral bone post-DMM, facilitating more thoughtful selection of murine age/gender when using this surgical technique for translational OA research

Changes in Patient Reported Symptoms During the Natural Progression of Osteoarthritis

Background: Arthritis is the leading cause of disability among adults in the United States affecting twenty-one million adults[1]. In addition, osteoarthritis is the second most costly chronic condition in the U.S[2]. Physical activity is a challenge in all patients and is associated with fewer functional limitations and lower risk for developing illness[3]. Currently, there are no objective measures of physical activity in advanced knee OA. Objectives: The purpose of this study was to quantify patient-reported changes in pain and function during the natural progression of osteoarthritis at 3, 6, and 9 months, and to correlate these metrics with objective activity monitors. Methods: 50 patients who were undergoing non-operative management of OA were enrolled. Patients were seen at baseline, 3 months, 6 months, and 9 months. At each visit, basic demographics and patient-reported measures (SF-36, WOMAC, and Charlson Co-morbidity index) were recorded. In addition, patients wore ActiGraph and activPal activity monitors for 7 days following the visit. Results: The average age of the enrolled participants was 57 with 82% of participants being less than 65 years of age. Most participants were female (64%), and 80% of participants had 1 or fewer medical co-morbidities on the Charlson Co-morbidity Index. Only 4% of patients were using assistive devices. The average WOMAC pain score was 68 and did not change from one time period to the next. The average SF-36 PCS score was 38 and the MCS was 54, and neither changed over time. The average SF-36 PCS score in patients with a WOMAC pain score less than 80 was 36, while in those with a WOMAC pain score greater than 80 it was 42.5. In contrast, analyses of the activPal found a decline in activity over the time period. In the first 19 patients wearing the activPal who were analyzed, 12 of 19 increased sedentary time at 9 months by an average of 18%. In addition, 15 of 19 participants decreased minutes of moderate to vigorous physical activity (MVPA) at 9 months by an average of 26%. Conclusions: In our study of 50 participants with osteoarthritis, patient-reported function did not change over a 9-month period. However, preliminary activity data suggests a decline. Further work will correlate patient-reported measures to the objective measures recorded by activity monitors to determine if objective monitors are preferable to detect early changes in activity due to OA. [1] (CDC), Centers for Disease Control and Prevention. Prevalence of arthritis—United States, 1997. MMWR Morb Mortal Wkly Rep 2001. May 4; 50:334-6. [2] Druss BG, Marcus SC, Olfson M, Pincus HA. The most expensive medical conditions in America. Health Affairs. 2002; 21:105-11. [3] Centers for Disease Control and Prevention (CDC). Physical activity among adults with a disability—United States, 2005. MMWR Morb Mortal Wkly Rep 2007. Oct 5;56(39):1021-4

A Prospective Randomized Comparison of Patient Specific Instruments with Standard TKA Instrumentation

Introduction: Patient specific instruments (PSI), an alternative to standard total knee arthroplasty (TKA) technology, have shown mixed results regarding effectiveness in previous studies. This study evaluated the accuracy of the predicted PSI plan, compared incremental cost savings with PSI, and compared outcomes of PSI and standard TKA patients. Patients and Methods: This randomized, prospective feasibility study included 19 primary TKA patients receiving a cruciate-retaining cemented prosthesis from a single surgeon (DCA). 9 patients randomized to PSI received a pre-operative knee MRI for PSI fabrication using proprietary software.10 standard TKAs were completed. Operative data collected included operating times, implant details, femoral (medial/lateral distal and posterior) and tibial (medial/lateral) resections, and instrument trays used. Hospitalization data collected included length of stay, blood loss, drain output, and transfusions. SF-36 and WOMAC scores, routine radiographic analysis, and femoral-tibial angles were collected pre- and post-operatively. Costs of operating room use and anesthesia, implants, and hospitalization were collected. Statistical analyses included t-tests and chi-square tests. Results: All implant sizes matched surgical team adjusted PSI software plans. Flexion gap resection (posterior medial/lateral femur) was extremely accurate (averagemm). Sagittal plane tibial component posterior slope was larger in PSI TKA (mean 7.3 degrees) than standard instrumentation (mean 4.2 degrees) (p0.05). There were no differences in operating room times or hospitalization data, and there were no significant differences in functional outcomes between the two groups (p\u3e0.05). PSI patients used 4 fewer instrument trays per case (p\u3c0.0001). Conclusion: PSI TKA demonstrated outstanding accuracy in bone resection when compared with the pre-operative plan, and resulted in appropriate limb and component alignment with primary TKA. The number of instrument trays used in PSI TKA was significantly less than standard TKA, which led to less cost for instrument sterilization and assembly

Gender and BMI Differences in Physical Activity after Total Knee Replacement

Background Total knee replacement (TKR) is an effective procedure to eliminate knee pain due to osteoarthritis. However variation in functional outcome persists. Patient attributes, including age, gender, body mass index (BMI), and emotional health, influence degree of functional gain. The level of daily physical activity (PA) is important to weight management, knee OA care, and overall health. As the arthritis population becomes more overweight and inactive, it is important to understand the physical activity benefits accrued following TKR. Health promotion programs, conducted in community dwelling adults, have called attention to the use of accelerometers (step activity monitor devices) as a measure of general activity. The device, worn around the leg, gives an accurate number of daily steps (mean steps/ day), as well as, walking rate (mean steps/ minute). Unfortunately, there are limited data on the use of accelerometers in patients with knee OA. It is unknown if self-reported physical function correlates with objectively measured physical activity (e.g., steps/day) or if patient attributes influence the level of physical activity in patients with osteoarthritis before and after TKR. We hypothesized that patient physical activity at 6 months post-TKR varies with the two patients attributes, gender and body mass index (BMI). Materials and Methods A consecutive series of 89 TKR patients wore a small ankle accelerometer (StepWatch Activity Monitor/SAM; CYMA, Inc.) above the ankle of the operative leg before TKR and again at 6 months after surgery. Demographic attributes, self-reported function measured with SF36 and WOMAC, and physical activity as measured by accelerometer as quantity of steps/day and % of day inactive were recorded. Descriptive statistics and mean differences were calculated. Results Patients had a mean age of 67 years, mean BMI of 30, and 71% were women. Overall, physical activity significantly improved from a mean of 6600 steps/day before TKR to 7690 steps/day at 6 months. Women walked fewer steps/day than men before and after TKR (6,218 before, 7,150 after; a 15% increase). Non-obese patients improved steps/day, obese did not. While male reduced their inactive time after TKR, women did not. After adjusting for BMI and age, gender differences persisted in objectively measured physical activity. The number of steps/day was moderately but significant correlated with PCS and WOMAC function (r=0.28 – 0.4). Conclusions Physical activity as measured by accelerometer improved after TKR, varied with patient attributes, including gender and BMI, and was moderately correlated with self-reported function. A 15% increase in pre to post TKR patient steps/day is highly significant and contributes to the health status improvement of patients with advanced arthritis. Women‘s lower physical activity levels before surgery persists after TKR, despite significant pain relief. Physical activity differences should be considered when designing TKR patient pathways and rehabilitation programs

Clinical Profile and Disability Levels of Younger vs. Older TKR and THR Patients in a National Research Consortium

Introduction: A growing number of patients under 65 years old undergo total knee replacement (TKR) and total hip replacement (THR).1 This trend has raised concerns that younger patients may receive surgery prematurely. We examined demographic and clinical factors in younger versus older patients in a national sample of THR and THR patients. Methods: Patients undergoing primary TKR and THR from 7/1/11 through 12/03/12 were identified from a national research consortium that gathers demographics, comorbid conditions (Charlson Comorbidity Index), Short Form 36 Physical Component Score (PCS) and Mental Component Score (MCS), burden of musculoskeletal disease using the Knee injury and Osteoarthritis Outcome Score (KOOS) or the Hip injury and Osteoarthritis Outcome Score (HOOS) and the Oswestry Low Back Pain Disability Questionnaire. Descriptive statistics were performed. Results: TKR patients included 1326 younger ( Conclusion: Younger patients have fewer medical illnesses at the time of TKR or THR, but have greater functional impairment and higher rates of obesity and smoking as well as lower mental health scores