3,033 research outputs found

    Haze in the Klang Valley of Malaysia

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    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

    The Varus Knee Reveals Differential Expression Patterns of miRNAs in Spared vs. Non-spared Compartments

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    Introduction MicroRNAs (miRNAs) function by repressing cellular protein levels to provide a sophisticated level of gene regulation that coordinates a broad spectrum of biological processes. MiRNA inhibition of mRNA translation has emerged as an important regulator of chondrogenic and osteogenic development, osteoblast, osteoclast and chondrocyte cell growth and differentiation, and tissue homeostasis in the adult skeleton. MiRNAs control many layers of regulation in adult tissues connected to both normal biological and pathologic cellular activities. The study of miRNAs in skeletal disorders is in its infancy. Osteoarthritis (OA) is a disease that progresses from degeneration of the articular cartilage to remodeling of the underlying subchondral bone over many years. While miRNAs have been identified with the inflammatory pathogenesis of rheumatoid arthritis (RA), only a few studies have been performed on OA tissue (1,2) . Here we performed a systematic analysis of the articular cartilage from varus OA knee replacements, comparing multiple tissue samples from the lateral (spared) and medial (diseased) compartments. Before proceeding to a miRNA profiling, each sample was analyzed for expression of a small set of miRNAs that have been reported in association with RA, OA and cartilage formation. These preliminary findings have identified a spectrum of changes in surface cartilage between control and diseased tissue. Methods Human tissues: 6 individual articular cartilage samples were harvested from a total of 5 osteoarthritic varus human knees. Cartilage samples were exempt from IRB review as they are discarded materials. Samples were removed with a biopsy punch and were approximately 6 x 2mm (diameter x thickness). Cartilage specimens were harvested from the more normal-appearing lateral (‘spared’) compartments and from the more OA-affected, medial compartments of the knees. This sampling technique allows direct comparison of more significantly OA-affected cartilage samples with those of lower OA grade from the same set of individuals. Knee ages ranged from 53-74 years old and averaged 65 years old. RNA and miRNA Isolation: Each osteochondral specimen was placed in RNA Later (Sigma) immediately following surgical removal, in order to preserve the integrity of the total RNA. Specimens were transported to the lab where individual samples were removed carefully with RNase-treated tools and were transferred intofresh RNA Later solution and incubated overnight at 4C to allow penetration and maximal inhibition of RNase activity. Samples were then removed from RNA Later, blotted briefly and frozen in liquid N2, and then pulverized using a Bessman tissue pulverizer (Fisher). The pulverized samples were immediately placed into Trizol (InVitrogen) and homogenized using a polytron device. Total RNA was isolated to include small RNAs of \u3e17 nucleotides, according to the manufacturer’s protocol (InVitrogen). Purified RNA was obtained using precipitated total RNAs filtered through glass columns according to the manufacturer’s protocol (Zymo Research). RNAs were reverse-transcribed into DNA using 900ng of each purified RNA sample using the TaqMan microRNA Reverse Transcription Kit (Applied Biosystems). TaqMan qPCR analysis for small RNAs was performed using the following human primer-probe sets from Applied Biosystems: hsa-miRs-: 9, 22, 27a, 29a and 34a. Human U6 was used to normalize all qPCR data and data was plotted as normalized relative values. Normalized relative values were averaged for each of the complement of medial vs. lateral samples. Results MiRs were found to be either up- or down-regulated in a manner that suggests a mechanism of de-repression of pro-inflammatory cytokine signaling and repression of pro-inflammatory events in medial vs. lateral varus knee OA cartilage samples, respectively. MiRs 9, 27a, and 29a were found to up-regulated in lateral varus knee cartilage samples vs. medial varus knee cartilage samples (Fig.1. A,C,E,F). Conversely, miRs 22 and 34a were found to upregulated in medial vs. lateral cartilage samples (Fig1, B, D). Discussion The functional characterization of global gene expression patterns through miRNAs in OA is lacking. Particularly, the roles of miRs in OA disease development, as biomarkers, and in disease outcomes are at question. A few large-scale microarray approaches have previously identified expression signatures of potential OA-involved miRNAs (2). By comparing cartilage samples that derive from more advanced (medial) vs. less advanced (lateral) OA stages in varus human knees, we seek to combine miRNA expression analysis with clinicopathologic features. MiRs -9, -22 and -34a are known to be involved in regulating pro-inflammatory events in OA. Higher levels of miRs, -9, -27a & -140 in less-affected lateral compartment cartilage are consistent with previous reports of reduced TNFa, MMP-13 & ADAMTS-5 expression events, respectively (Fig.1, F, E & A) (3,4,5). MiRs -22 and -34a have been shown to be associated with promoting tissue catabolism by their presence and are here shown to be increased in more affected medial compartment cartilage (Fig.1, B, D) (4). In addition, miR-34a deficiency has been previously shown to inhibit chondrocyte apoptosis, consistent with the lower expression level found in lateral cartilage (Fig.1, D) (6). MiR-29a was found in a previous microarray analysis to be the highest-fold down-regulated miRNA in OA vs. normal cartilage, consistent with our finding of under-expression in medial cartilage samples (Fig.1, C) (1). The goal of these studies is to begin to understand how miRNAs can both contribute to and protect against OA. Here we show that the comparison of cartilage-derived miRNAs in medial and lateral compartment pairs from the same knee may facilitate validation of candidate OA miRNAs. Significance The aims of this project are to provide an internally-controlled platform of study for the miRNAs of OA using the natural disease differences inherent in spared vs. non-spared cartilage compartments from a varus OA knee. Such efforts may provide an alternative methodology when compared to the significant barrier of obtaining age-matched, non-OA control knee cartilage. References 1.) Iliopoulus D. PLoS One. 2008;3(11):e3740. Epub 2008 Nov 17. 2.) Goldring MB. Curr Opin Rheumatol. 2011 Jul 22. [Epub]. 3.) Yu C. J Int Med Res. 2011;39(1):1-9. 4.) Alcaraz MJ. Biochem Pharmacol. 2010 Jul 1;80(1):13-21. 5.) Miyaki S. Genes Dev. 2010 Jun 1;24(11):1173-85. 6.) Abouheif MM. Rheumatology. 2010 Nov;49(11):2054-60

    Post-traumatic stress disorder following childbirth: an update of current issues and recommendations for future research

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    Objective: This paper aimed to report the current status of research in the field of post-traumatic stress disorder following childbirth (PTSD FC), and to update the findings of an earlier 2008 paper. Background: A group of international researchers, clinicians and service users met in 2006 to establish the state of clinical and academic knowledge relating to PTSD FC. A paper identified four key areas of research knowledge at that time. Methods: Fourteen clinicians and researchers met in Oxford, UK to update the previously published paper relating to PTSD FC. The first part of the meeting focused on updating the four key areas identified previously, and the second part on discussing new and emerging areas of research within the field. Results: A number of advances have been made in research within the area of PTSD FC. Prevalence is well established within mothers, several intervention studies have been published, and there is growing interest in new areas: staff and pathways; prevention and early intervention; impact on families and children; special populations; and post-traumatic growth. Conclusion: Despite progress, significant gaps remain within the PTSD FC knowledge base. Further research continues to be needed across all areas identified in 2006, and five areas were identified which can be seen as ‘new and emerging’. All of these new areas require further extensive research. Relatively little is still known about PTSD FC

    Randomized trial of polychromatic blue-enriched light for circadian phase shifting, melatonin suppression, and alerting responses.

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    Wavelength comparisons have indicated that circadian phase-shifting and enhancement of subjective and EEG-correlates of alertness have a higher sensitivity to short wavelength visible light. The aim of the current study was to test whether polychromatic light enriched in the blue portion of the spectrum (17,000 K) has increased efficacy for melatonin suppression, circadian phase-shifting, and alertness as compared to an equal photon density exposure to a standard white polychromatic light (4000 K). Twenty healthy participants were studied in a time-free environment for 7 days. The protocol included two baseline days followed by a 26-h constant routine (CR1) to assess initial circadian phase. Following CR1, participants were exposed to a full-field fluorescent light (1 × 10 14 photons/cm 2 /s, 4000 K or 17,000 K, n = 10/condition) for 6.5 h during the biological night. Following an 8 h recovery sleep, a second 30-h CR was performed. Melatonin suppression was assessed from the difference during the light exposure and the corresponding clock time 24 h earlier during CR1. Phase-shifts were calculated from the clock time difference in dim light melatonin onset time (DLMO) between CR1 and CR2. Blue-enriched light caused significantly greater suppression of melatonin than standard light ((mean ± SD) 70.9 ± 19.6% and 42.8 ± 29.1%, respectively, p \u3c 0.05). There was no significant difference in the magnitude of phase delay shifts. Blue-enriched light significantly improved subjective alertness (p \u3c 0.05) but no differences were found for objective alertness. These data contribute to the optimization of the short wavelength-enriched spectra and intensities needed for circadian, neuroendocrine and neurobehavioral regulation

    Etiology of Experimental Osteoarthritis: Early Events and Potential Clinical Implications

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    Introduction Osteoarthritis (OA) is the most common form of arthritis and accounts for 50% of all chronic conditions in the elderly. One in two adults reported a chronic musculoskeletal condition in 2005, twice the rate of reported chronic heart or respiratory conditions(2). In addition, persons aged 45 to 64 account for an increasingly greater proportion of total musculoskeletal disease treatment costs and lost wages, a trend that will continue for the next several decades(3). Surgical treatment culminating in total joint replacement (TJR) remains the most effective therapy for late stage OA. Current treatment of pre-surgical OA consists of pain relieving medications (i.e. NSAIDs), physical therapy, and mechanical supports (i.e. braces, canes, and walkers). Despite the wealth of clinical data on OA, there is currently no cure for the disease. Our previous work in developing potential disease-modifying osteoarthritis drugs (DMOADs) had yielded promising results, showing a decrease in OA cartilage lesion areas and histological grades (Figure 1). Interestingly, we noted that animals treated for only the first 3 weeks demonstrated near 6-week levels of OA reduction. These differences in treatment responsiveness necessitate a better characterization of the specific cellular phases of OA throughout the natural disease progression. The current study was undertaken to clarify this progression of early OA events. Methods OA was induced in the right knees of 10-week-old male 129 S6/SvEv (Taconic) mice via DMM surgery. Mice receiving sham surgery with no destabilization were used as negative controls. Both groups were sacrificed at 4, 8, 12, 16, and 20-day intervals in order to evaluate OA progression. Knees were harvested, processed, and sectioned at 6um intervals. Sections were stained for cartilage composition (Safranin-O) and scored for progression and severity of OA by 3 blinded observers using a 0-5 scale (modified Mankin System)(4). Both ‘mean maximal’ scores (highest scores per knee), and ‘mean summed scores (sum of scores per knee) were generated using this scale. All scores were averaged across observers. Cartilage lesion area, subchondral bone area (sclerosis), and apoptosis (TUNEL method) were measured using a histomorphometric analysis package (ImageJ)(5). Conclusions Measurable osteoarthritic changes in articular cartilage and underlying bone following meniscal injury occur far earlier than previously described. Some changes are clearly degenerative (OA grade, stage & lesion area), however, some changes (subchondral bone thickening) could be regarded as compensatory supportive mechanisms. Cell death (apoptosis) is an acute event following relatively minor changes to knee biomechanics. Our results suggest an opportunity for intervention early on in OA before the resulting articular changes become irreversible. Specifically, consideration of anti-apoptosis based therapies could prevent much of the subsequent structural changes in articular cartilage. Future Directions Apoptosis data suggests pursuing an anti-apoptotic therapy strategy in the DMM model of OA Early bone sclerotic events suggest bone tissue as a target for anti-OA therapy. Translationally, preventing or delaying OA due to soft tissue injuries (e.g., sports injuries) may be possible with early medical treatment of OA proximal to the time of injury. References (1) International Bone and Joint Decade 2000-2010 Organization, 1999. (2) National Center for Health Statistics, National Health Interview Survey, 2005. (3) Kurtz, SM, Lau, E, et al. Future Young Patient Demand for Primary and Revision Joint Replacement: National Projections from 2010 to 2030. Clinical Orthopaedics and Related Research, April 2009. (4) Kurtz, SM, Ong, K, et. al. Projections of Primary and Revision Hip and Knee Arthroplasty in the United States from 2005 to 2030. The Journal of Bone and Joint Surgery, 2007;89:780-5. (5) http://rsbweb.nih.gov/ij

    Mutations underlying Episodic Ataxia type-1 antagonize Kv1.1 RNA editing

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    © The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Scientific Reports 7 (2017): 41095, doi:10.1038/srep41095.Adenosine-to-inosine RNA editing in transcripts encoding the voltage-gated potassium channel Kv1.1 converts an isoleucine to valine codon for amino acid 400, speeding channel recovery from inactivation. Numerous Kv1.1 mutations have been associated with the human disorder Episodic Ataxia Type-1 (EA1), characterized by stress-induced ataxia, myokymia, and increased prevalence of seizures. Three EA1 mutations, V404I, I407M, and V408A, are located within the RNA duplex structure required for RNA editing. Each mutation decreased RNA editing both in vitro and using an in vivo mouse model bearing the V408A allele. Editing of transcripts encoding mutant channels affects numerous biophysical properties including channel opening, closing, and inactivation. Thus EA1 symptoms could be influenced not only by the direct effects of the mutations on channel properties, but also by their influence on RNA editing. These studies provide the first evidence that mutations associated with human genetic disorders can affect cis-regulatory elements to alter RNA editing.This work was supported by the Vanderbilt Molecular Endocrinology Training Program (T32DK007563; E.A.F.K.), a Ruth L. Kirschstein National Research Service Award (F31NS087911; E.A.F.K), a Vanderbilt Dissertation Enhancement Grant (E.A.F.K.), and the Vanderbilt Joel G. Hardman Chair in Pharmacology (R.B.E). Additional support for J.J.C.R. included NINDS (R0111223855, R01NS64259) and the Cystic Fibrosis Foundation Therapeutics (Rosent14XXO). Infrastructural support for J.J.C.R. was provided by NIGMS (P20GM103642), NIMH (G12-MD007600), and NSF (DBI 0115825, DBI 1337284)

    Culex tarsalis is a competent vector species for Cache Valley virus

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    Background: Cache Valley virus (CVV) is a mosquito-borne orthobunyavirus endemic in North America. The virus is an important agricultural pathogen leading to abortion and embryonic lethality in ruminant species, especially sheep. The importance of CVV in human public health has recently increased because of the report of severe neurotropic diseases. However, mosquito species responsible for transmission of the virus to humans remain to be determined. In this study, vector competence of three Culex species mosquitoes of public health importance, Culex pipiens, Cx. tarsalis and Cx. quinquefasciatus, was determined in order to identify potential bridge vector species responsible for the transmission of CVV from viremic vertebrate hosts to humans. Results: Variation of susceptibility to CVV was observed among selected Culex species mosquitoes tested in this study. Per os infection resulted in the establishment of infection and dissemination in Culex tarsalis, whereas Cx. pipiens and Cx. quinquefasciatus were highly refractory to CVV. Detection of viral RNA in saliva collected from infected Cx. tarsalis provided evidence supporting its role as a competent vector. Conclusions: Our study provided further understanding of the transmission cycles of CVV and identifies Cx. tarsalis as a competent vector

    Differential burden of musculoskeletal pain in African Americans and whites patients at the time of total joint replacement surgery

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    Objective: African Americans patients have greater operative joint pain and functional limitation at the time of total joint replacement (TJR) compared to white patients. We examined the factors associated with this apparent disparity. Methods: A consecutive sample of 5745 patients with advanced knee and hip osteoarthritis [who elected to undergo TJR in 2011-201] reported, preoperatively, medical comorbidities, operative and non-operative hip/ knee pain using Hip and Knee Disability and Osteoarthritis Outcome Scores (HOOS/KOOS), function using Short Form 36 Physical Component Score (PCS). Total burden of musculoskeletal pain was quantified as moderate/severe pain in non-operative hip and knee joints and lumbar back pain using Oswestry Disability Index (ODI). Associations among race, medical co-morbidites (modified Charlson), total musculoskeletal pain burden, operative joint pain, and functional limitations were examined using multivariable regression models. Results:Compared to Whites, African Americans (143 hips and 201 knees) reported worse surgical joint pain (mean pain: 39.3 vs. 49.2 [hip]; 43.4 vs. 53.2 [knee]), poorer surgical joint function (mean function: 38.9 vs. 45.7 [hip]; 45.9 vs. 53.4 [knee]), poorer global function (mean PCS: 30.0 vs. 31.6 [hip]; 31.3 vs. 33.1 [knee]), and more non-operative joints pain (p Conclusions: Greater burden of musculoskeletal pain explains differences in pre-operative pain and function between African American and white patients and likely impacts rehabilitation and subsequent TJR outcomes

    Total Joint Replacement Prehabilitation: A Feasibility Study

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    Objectives: Pre-operative physical therapy has been shown to reduce post-acute care service utilization. Shifting rehabilitation to the presurgical period, referred to as prehabilitation, could result in reduced recovery time and cost. Limited access to physical therapy may prevent patients from achieving the benefits, and a standard set of independent exercises may be an alternative. We aim to assess the feasibility of an independent exercise program as a pre-surgical intervention for total hip and knee replacement. Design: Participants were taught two exercises for hip or knee arthritis at least one week prior to surgery and instructed to perform them independently at home. Subjects were contacted three days to one month post-operatively and surveyed about discharge, frequency of exercise, and living status of alone or with others. No adverse effects were reported. Additional information was collected from the subjects’chart including age, BMI, and sex. Discharge outcomes were compared with pre-existing independent factors using univariate and multivariate analyses. Results: A total of 80 subjects were followed with a home discharge rate of 78.75%. Univariate analyses showed that the presence of other people in the home showed a slight, but non-significant, association with differences of discharge destination. 82.1%-83.3% of patients who live with others were discharged home versus 57.1% of patients living alone (LR chi-square: 3.84, p=0.15). Multivariate analyses showed a slight, but non-significant, association between frequency of prehabilitation and discharge destination (OR=1.212; 95% CI, 0.960-1.530). BMI showed no associated difference in discharge destination. Conclusions: Increased frequency of prehabilitation and presence of others at home showed slight associations with increased discharges to home, but were non-significant. Increased exposure to prehabilitation (duration times frequency) trends toward more frequent home discharge. Independently performed prehabilitation may be offered as an alternative pre-surgical intervention with likely little to no adverse effect. Larger numbers are needed to determine likelihood of discharge home
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