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BACKGROUND: Although telehealth is becoming more popular for delivery of care for individuals with musculoskeletal pain, to our knowledge telehealth has not been used to manage Achilles tendinopathy. This research aimed to explore the experience of participants and physiotherapists with gym-based exercise interventions for Achilles tendinopathy monitored via videoconference. METHODS: A qualitative, interpretive description design was performed using semi-structured interviews (8 participants) and a focus group (7 physiotherapists). Participants and physiotherapists were interviewed about their experiences of the use of telehealth during a gym-based exercise intervention incorporating different calf load parameters for Achilles tendinopathy. We employed an inductive thematic analysis approach to analyse the data. RESULTS: Three themes identified from both participants and physiotherapists included i) acceptability of telehealth; ii) enablers to adherence with telehealth; and iii) barriers to adherence with telehealth. Two extra themes arose from participants regarding adherence with gym-based exercise, including enablers to adherence with the exercise intervention, and barriers to adherence with the exercise intervention. Both participants and physiotherapists expressed overall satisfaction and acceptability of telehealth monitoring of gym-based exercise. CONCLUSION: Gym-based exercise intervention for Achilles tendinopathy involving weekly telehealth monitoring was acceptable to both participants and physiotherapists. Potential enablers and barriers were identified that may improve adherence to this type of intervention.
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Tendão do Calcâneo , Fisioterapeutas , Telemedicina , Tendinopatia , Exercício Físico , Terapia por Exercício , Humanos , Tendinopatia/terapiaRESUMO
We report the first measurement of the neutron cross section on argon in the energy range of 100-800 MeV. The measurement was obtained with a 4.3-h exposure of the Mini-CAPTAIN detector to the WNR/LANSCE beam at LANL. The total cross section is measured from the attenuation coefficient of the neutron flux as it traverses the liquid argon volume. A set of 2631 candidate interactions is divided in bins of the neutron kinetic energy calculated from time-of-flight measurements. These interactions are reconstructed with custom-made algorithms specifically designed for the data in a time projection chamber the size of the Mini-CAPTAIN detector. The energy averaged cross section is 0.91±0.10(stat)±0.09(syst) b. A comparison of the measured cross section is made to the GEANT4 and FLUKA event generator packages, where the energy averaged cross sections in this range are 0.60 and 0.68 b, respectively.
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BACKGROUND: Falls remain common for community-dwelling older people and impose a substantial economic burden to the healthcare system. RESPOND is a novel falls prevention programme that aims to reduce secondary falls and fall injuries among older people who present to a hospital emergency department (ED) with a fall. The present protocol describes a prospective economic evaluation examining the incremental cost-effectiveness of the RESPOND programme, compared with usual care practice, from the Australian health system perspective. METHODS AND DESIGN: This economic evaluation will recruit 528 participants from two major tertiary hospital EDs in Australia and will be undertaken alongside a multisite randomised controlled trial. Outcome and costing data will be collected for all participants over the 12-month trial. It will compare the RESPOND falls prevention programme with usual care practice (current community-based falls prevention practices) to determine its incremental cost-effectiveness according to three intermediate clinical outcomes: (1) falls prevented, (2) fall injuries prevented and (3) injurious falls prevented. In addition, utilities will be derived from a generic quality-of-life measure (EQ-5D-5L) and used to calculate the 'incremental cost per quality-adjusted life years gained'. DISCUSSION: The results of this study will provide healthcare decision makers with evidence to assist with setting spending thresholds for preventive health programmes and inform selection of emergency and community service models of care. TRIAL REGISTRATION NUMBER: The protocol for this study is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12614000336684); Pre-results.
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Acidentes por Quedas/prevenção & controle , Serviço Hospitalar de Emergência/estatística & dados numéricos , Hospitalização/estatística & dados numéricos , Serviços Preventivos de Saúde , Ferimentos e Lesões/prevenção & controle , Acidentes por Quedas/economia , Idoso , Idoso de 80 Anos ou mais , Austrália , Protocolos Clínicos , Análise Custo-Benefício , Serviço Hospitalar de Emergência/economia , Feminino , Hospitalização/economia , Humanos , Masculino , Serviços Preventivos de Saúde/economia , Serviços Preventivos de Saúde/organização & administração , Avaliação de Programas e Projetos de Saúde , Estudos Prospectivos , Anos de Vida Ajustados por Qualidade de Vida , Medição de Risco , Ferimentos e Lesões/economiaRESUMO
BACKGROUND: Temporal and dose-response relationships between allied health (AH) and recovery in the acute phase following lower limb (LL) arthroplasty are unclear. This systematic review investigates whether early commencement, additional therapy and/or weekend AH affects length of stay (LOS) and patient outcomes in the acute phase following LL arthroplasty. METHODS: Electronic databases were searched in February 2015. Studies were included if they evaluated any of the following aspects of AH for adults following LL arthroplasty in the acute phase: Early compared to later therapy commencement; Additional therapy; or a 6- or 7-day service compared to a lesser service. RESULTS: Twenty-four studies met the inclusion criteria, of which 19 investigated effects of physical therapy (PT) alone. Earlier PT reduced LOS (WMD = -1.23 days; 95% CI, -2.16 to -0.30) and resulted in higher probability of discharge directly home (relative risk = 1.45; 95% CI, 1.26-1.67). Addition of weekend PT reduced LOS (WMD = -1.04 days; 95% CI, -1.66 to -0.41) and improved function (SMD = 0.37; 95% CI, 0.02-0.73). Increasing PT from once to twice daily did not affect LOS (WMD = -0.35 days; 95% CI, -0.96-0.26) or function (SMD = 0.31; 95% CI, -0.06-0.71). DISCUSSION: Early PT commencement and a weekend service may produce favorable outcomes following LL arthroplasty when baseline LOS is 4 days or more. Redistributing PT resources to commence as early as day of surgery regardless of weekday may accelerate postoperative recovery. Current, high quality research is needed to confirm these findings.
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Modalidades de Fisioterapia , Artroplastia do Joelho , Humanos , Tempo de Internação , Extremidade Inferior , Alta do PacienteRESUMO
OBJECTIVES: To determine associations of inter- and intra-muscular adipose tissue (IMAT) with cardiometabolic health and physical function in older adults. METHODS: 48 community-dwelling older adults aged â65 years (mean 71.6±4.8 years; 52% women) underwent whole-body dual-energy X-ray absorptiometry, to assess appendicular lean mass (ALM), and peripheral quantitative computed tomography (pQCT; 66% tibia), to assess calf IMAT cross-sectional area ([CSA]; cm2) and muscle density (mg/cm(3); higher values indicate lower fat infiltration). Fasting glucose, lipids, triglycerides and C-reactive protein (CRP) were analysed. Physical function was assessed by postural sway (computerised posturography; N=41), and gait analysis (GAITRite Electronic Walkway; N=40). RESULTS: Higher IMAT CSA and muscle density were associated with significantly higher (B=0.85 95%CI [0.34, 1.36]) and lower (-2.14 [-4.20, -0.08]) CRP and higher (0.93 [0.56, 1.30]) and lower postural sway (-3.12 [-4.74, -1.50]), respectively, after adjustment for age, sex and ALM/BMI. Higher IMAT CSA was associated with slower gait speed and cadence, and greater step time and step width (all P<0.03), while higher muscle density was associated with smaller step width (P<0.01) only. CONCLUSIONS: Older adults with higher calf IMAT have poorer balance, mobility and inflammatory status. Interventions aimed at improving physical function in older adults should incorporate strategies to reduce IMAT.
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Tecido Adiposo/patologia , Envelhecimento/patologia , Composição Corporal/fisiologia , Músculo Esquelético/patologia , Aptidão Física/fisiologia , Sarcopenia/patologia , Absorciometria de Fóton , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Perna (Membro) , MasculinoRESUMO
INTRODUCTION: Participation in falls prevention activities by older people following presentation to the emergency department (ED) with a fall is suboptimal. This randomised controlled trial (RCT) will test the RESPOND programme, an intervention designed to improve older persons' participation in falls prevention activities through delivery of patient-centred education and behaviour change strategies. DESIGN AND SETTING: A RCT at two tertiary referral EDs in Melbourne and Perth, Australia. PARTICIPANTS: 528 community-dwelling people aged 60-90â years presenting to the ED with a fall and discharged home will be recruited. People who require an interpreter or hands-on assistance to walk; live in residential aged care or >50â km from the trial hospital; have terminal illness, cognitive impairment, documented aggressive behaviour or a history of psychosis; are receiving palliative care or are unable to use a telephone will be excluded. METHODS: Participants will be randomly allocated to the RESPOND intervention or standard care control group. RESPOND incorporates (1) a home-based risk factor assessment; (2) education, coaching, goal setting and follow-up telephone support for management of one or more of four risk factors with evidence of effective interventions and (3) healthcare provider communication and community linkage delivered over 6â months. Primary outcomes are falls and fall injuries per person-year. DISCUSSION: RESPOND builds on prior falls prevention learnings and aims to help individuals make guided decisions about how they will manage their falls risk. Patient-centred models have been successfully trialled in chronic and cardiovascular disease; however, evidence to support this approach in falls prevention is limited. TRIAL REGISTRATION NUMBER: The protocol for this study is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12614000336684).
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Acidentes por Quedas/prevenção & controle , Serviços de Saúde Comunitária/organização & administração , Serviço Hospitalar de Emergência/estatística & dados numéricos , Serviços Preventivos de Saúde/organização & administração , Ferimentos e Lesões/prevenção & controle , Acidentes por Quedas/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Protocolos Clínicos , Planejamento Ambiental , Feminino , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Alta do Paciente , Avaliação de Programas e Projetos de Saúde , Medição de Risco , Fatores de Risco , Austrália Ocidental/epidemiologia , Ferimentos e Lesões/epidemiologiaRESUMO
BACKGROUND: Musculoskeletal physiotherapy practice rapidly adopted telehealth during the COVID-19 pandemic, providing a unique opportunity to evaluate the experiences and attitudes of people who would not usually engage with these services. METHODS: A sequential mixed-methods study recruited people with musculoskeletal pain conditions accessing Australian private practice physiotherapist services. Part 1 involved an online survey of telehealth services accessed, treatments and resources provided, self-reported global change in condition, and attitudes toward telehealth. Part 2 involved semi-structured interviews with a subset of survey participants, exploring experiences and attitudes towards telehealth. Quantitative data was reported descriptively. Qualitative data was evaluated using inductive thematic analysis. RESULTS: 172 participants responded to the survey, and 19 were interviewed. 95% accessed video-based telehealth, and 85% reported condition improvement. 84% agreed it was an efficient use of their time, 75% agreed it was financially viable, and 73% agreed their condition was accurately diagnosed. 62% percent believed telehealth should be less expensive than in-person services. Qualitative analysis revealed four themes (17 subthemes), including (i) telehealth had value, but generally perceived as inferior to in-person care; (ii) challenges related to assessment, diagnosis, 'hands on' treatment, observation, communication, and technology; (iii) advantages to access safe, expert, and convenient care; and (iv) importance of supportive technology, including video and supplementary resources. CONCLUSION: Physiotherapist telehealth services provided to people with musculoskeletal pain during the pandemic was valued. However, telehealth was generally perceived as inferior to traditional in-person care, and may be best used as part of a hybrid model of care.
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COVID-19 , Dor Musculoesquelética , Fisioterapeutas , Telemedicina , Atitude , Austrália , Humanos , Dor Musculoesquelética/terapia , Pandemias , Telemedicina/métodosRESUMO
BACKGROUND: The ENJOY project (Exercise interveNtion outdoor proJect in the cOmmunitY for older people) is a community-based research project actively promoting physical activity engagement through the delivery of an exercise program using outdoor multimodal exercise equipment. This study investigated the impact of the physical activity program on falls in older people. METHOD: This study was a multi-site prospective study with a pre-post intervention design and 12-month follow up. Eighty older people with increased falls risk underwent a 12-week supervised outdoors exercise program followed by a 6-month maintenance phase. The proportion of fallers and falls incidence were compared between the preceding and the prospective years. RESULTS: A sample of 54 (age 72.4±7.3, 79.6% women) was available for the 12 months analysis (due to COVID19 lockdowns, data of 19 participants were excluded and 4 dropped out). Number of fallers (from 51.8% to 31.4%, p=0.03) and falls incidence (from 42 to 29 falls, p<0.01) were significantly reduced at the 12-months follow up. CONCLUSION: The ENJOY Seniors Exercise Park program integrates outdoor multimodal exercise stations including specific exercises designed to challenge dynamic balance during functional daily movements. The outcomes provide preliminary evidence for the potential positive impact of the ENJOY Seniors Exercise Park in reducing falls for older people.
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Acidentes por Quedas , COVID-19 , Acidentes por Quedas/prevenção & controle , Idoso , Controle de Doenças Transmissíveis , Exercício Físico , Feminino , Humanos , Masculino , Estudos ProspectivosRESUMO
BACKGROUND: Telehealth services have helped enable continuity of care during the coronavirus pandemic. We aimed to investigate use and views towards telehealth among allied health clinicians treating people with musculoskeletal conditions during the pandemic. METHODS: Cross-sectional international survey of allied health clinicians who used telehealth to manage musculoskeletal conditions during the coronavirus pandemic. Questions covered demographics, clinician-related factors (e.g. profession, clinical experience and setting), telehealth use (e.g. proportion of caseload, treatments used), attitudes towards telehealth (Likert scale), and perceived barriers and enablers (open questions). Data were presented descriptively, and an inductive thematic content analysis approach was used for qualitative data, based on the Capability-Opportunity-Motivation Behavioural Model. RESULTS: 827 clinicians participated, mostly physiotherapists (82%) working in Australia (70%). Most (71%, 587/827) reported reduced revenue (mean (SD) 62% (24.7%)) since the pandemic commenced. Median proportion of people seen via telehealth increased from 0% pre (IQR 0 to 1) to 60% during the pandemic (IQR 10 to 100). Most clinicians reported managing common musculoskeletal conditions via telehealth. Less than half (42%) of clinicians surveyed believed telehealth was as effective as face-to-face care. A quarter or less believed patients value telehealth to the same extent (25%), or that they have sufficient telehealth training (21%). Lack of physical contact when working through telehealth was perceived to hamper accurate and effective diagnosis and management. CONCLUSION: Although telehealth was adopted by allied health clinicians during the coronavirus pandemic, we identified barriers that may limit continued telehealth use among allied health clinicians beyond the current pandemic.
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Pessoal Técnico de Saúde/estatística & dados numéricos , Atitude do Pessoal de Saúde , COVID-19/reabilitação , Doenças Musculoesqueléticas/reabilitação , Telemedicina/estatística & dados numéricos , Adulto , Pessoal Técnico de Saúde/psicologia , Austrália , COVID-19/epidemiologia , Estudos Transversais , Feminino , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Padrões de Prática Médica/estatística & dados numéricosRESUMO
BACKGROUND: Rotator cuff related shoulder pain is the most common cause of shoulder pain. Whilst guidelines recommend conservative management prior to imaging, injection or surgical management, recent findings suggest that patients experience management contrary to guideline recommendations. OBJECTIVES: The aim of this study was to investigate self-reported management among people with rotator cuff related shoulder pain (RCRSP) and their beliefs towards management. MATERIALS AND METHODS: Cross-sectional survey of people with RCRSP recruited when referred for imaging (n = 120). Electronic survey about demographic factors, management people had had (including imaging, injections, surgery, exercise, adjuncts), and beliefs about treatments. The frequency of various treatments was reported (separately for each cohort and traumatic onset) as well as the timing of interventions related to first-line care. RESULTS: Most people had tried exercise (99/120, 82.5%) but only one in five people reported exercise was helpful, and one in six reported it was unhelpful or made their symptoms worse. Approximately a third of the cohort reported not receiving activity modification advice (34.2%, 41/120), those that did received inconsistent information. People with both traumatic (imaging 31/43, 72.1%; injections 13/24, 54.2%, surgery 8/21, 38.1%) and atraumatic onset pain (imaging 43/77, 55.8%; injections 31/51, 60.8%, surgery 4/19, 21.1%) had similarly high rates of intervention prior to trialling conservative management. Patient beliefs in regards to management showed trends towards interventionalist care. CONCLUSION: Patient reported management of RCRSP is often inconsistent with guideline recommended management.
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Lesões do Manguito Rotador , Manguito Rotador , Estudos Transversais , Humanos , Lesões do Manguito Rotador/terapia , Autorrelato , Dor de Ombro/terapiaRESUMO
BACKGROUND: Rotator cuff tendinopathy is a common and disabling cause of shoulder pain. While conservative treatment is recommended as initial management, recent findings suggest that general practitioners and rheumatologists do not consistently align with recommended care. This study aimed to survey Australian physiotherapists to explore the extent to which recommended management is being applied. METHODS: A cross-sectional online survey. RESULTS: Five hundred and two Australian physiotherapists completed the survey. Results demonstrated the majority of physiotherapists provide conservative management consistent with guideline recommendations, through delivery of exercise and education, comparable to management by physiotherapists in the United Kingdom, Belgium and the Netherlands. Parameters and construction of exercise treatment programs were highly variable within the cohort, qualitative analysis highlighting varied reasoning underpinning these management decisions. CONCLUSIONS: Australian physiotherapists are broadly consistent with providing recommended management, however heterogeneity exists in the methods and parameters of treatment delivery.
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Terapia por Exercício/métodos , Terapia por Exercício/normas , Doenças Musculoesqueléticas/terapia , Modalidades de Fisioterapia/normas , Guias de Prática Clínica como Assunto , Lesões do Manguito Rotador/terapia , Tendinopatia/terapia , Adolescente , Adulto , Idoso , Atitude do Pessoal de Saúde , Austrália , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fisioterapeutas/psicologia , Inquéritos e Questionários , Adulto JovemRESUMO
The Aerogel Cherenkov Detector for Cygnus (ACD/C) is a time-dependent, x-ray spectral detector that uses SiO2 aerogels spanning an index of refraction (n = 1.02-1.07) corresponding to a 1.1-2.3 MeV x-ray energy threshold. The ACD/C was developed for pulsed power x-ray sources like Cygnus located at the Nevada National Site and Mercury located at the Naval Research Laboratory (NRL). Aerogels sit between the measurement capabilities of gas (>2 MeV) and solids such as fused silica (>0.3 MeV). The detector uses an aluminum converter to Compton scatter incoming x-rays and create relativistic electrons, which produce Cherenkov light in an aerogel or a fused silica medium. The ACD/C was fielded at the NRL when Mercury was tuned to produce up to 4.8 MeV endpoint bremsstrahlung. Despite a high radiation and electromagnetic interference background, the ACD/C was able to achieve high signal over noise across five aerogel densities and fused silica, including a signal to noise for a 1.1 MeV aerogel threshold. Previous experiments at Cygnus observed a signal that was comparable to the noise (1×) at the same threshold. The ACD/C observed time-resolved rise and fall times for different energy thresholds of the photon spectrum. Monte Carlo simulations of the ACD/C's aerogel response curves were folded with a simulation of Mercury's photon energy spectrum and agree within the error to the observed result.
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BACKGROUND: Controversy persists regarding medicinal therapies and injections. OBJECTIVES: To determine the effects of medication and injections on primary outcomes (e.g. pain) for adults with mechanical neck disorders and whiplash. SEARCH STRATEGY: We searched CENTRAL, MANTIS, CINAHL from their start to May 2006; MEDLINE and EMBASE to December 2006. We scrutinised reference lists for other trials. SELECTION CRITERIA: We included randomised controlled trials with adults with neck disorders, with or without associated headache or radicular findings. We considered medicinal and injection therapies, regardless of route of administration. DATA COLLECTION AND ANALYSIS: Two authors independently selected articles, abstracted data and assessed methodological quality. When clinical heterogeneity was absent, we combined studies using random-effects models. MAIN RESULTS: We found 36 trials that examined the effects of oral NSAIDs, psychotropic agents, steroid injections, and anaesthetic agents. Trials had a mean of 3.1 on the Jadad Scale for methodological quality; 70% were high quality. For acute whiplash, administering intravenous methylprednisolone within eight hours of injury reduced pain at one week (SMD -0.90, 95% CI -1.57 to -0.24), and sick leave but not pain at six months compared to placebo in one trial. For chronic neck disorders at short-term follow-up, intramuscular injection of lidocaine was superior to placebo (SMD -1.36, 95% CI -1.93 to -0.80); NNT 3, treatment advantage 45% and dry needling, but similar to ultrasound in one trial each. In chronic neck disorders with radicular findings, epidural methylprednisolone and lidocaine reduced neck pain and improved function more than when given by intramuscular route at one-year follow-up, in one trial. In subacute and chronic neck disorders, muscle relaxants, analgesics and NSAIDs had limited evidence and unclear benefits. In participants with chronic neck disorders with or without radicular findings or headache, there was moderate evidence from five high quality trials that Botulinum toxin A intramuscular injections had similar effects to saline in improving pain (pooled SMD: -0.39, 95%CI -1.25 to 0.47), disability or global perceived effect. AUTHORS' CONCLUSIONS: The major limitations are the lack of replication of the findings and sufficiently large trials. There is moderate evidence for the benefit of intravenous methylprednisolone given within eight hours of acute whiplash, from a single trial. Lidocaine injection into myofascial trigger points appears effective in two trials. There is moderate evidence that Botulinum toxin A is not superior to saline injection for chronic MND. Muscle relaxants, analgesics and NSAIDs had limited evidence and unclear benefits.
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Anestésicos Locais/administração & dosagem , Anti-Inflamatórios não Esteroides/administração & dosagem , Cervicalgia/tratamento farmacológico , Psicotrópicos/administração & dosagem , Traumatismos em Chicotada/tratamento farmacológico , Toxinas Botulínicas Tipo A/administração & dosagem , Doença Crônica , Humanos , Lidocaína/administração & dosagem , Metilprednisolona/administração & dosagem , Fármacos Neuromusculares/administração & dosagem , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Proton and/or sodium electrochemical gradients are critical to energy handling at the plasma membranes of all living cells. Sodium gradients are used for animal plasma membranes, all other living organisms use proton gradients. These chemical and electrical gradients are either created by a cation pumping ATPase or are created by photons or redox, used to make ATP. It has been established that both hydrogen and sodium ions leak through lipid bilayers at approximately the same rate at the concentration they occur in living organisms. Although the gradients are achieved by pumping the cations out of the cell, the plasma membrane potential enhances the leakage rate of these cations into the cell because of the orientation of the potential. This review proposes that cells use certain lipids to inhibit cation leakage through the membrane bilayers. It assumes that Na(+) leaks through the bilayer by a defect mechanism. For Na(+) leakage in animal plasma membranes, the evidence suggests that cholesterol is a key inhibitor of Na(+) leakage. Here I put forth a novel mechanism for proton leakage through lipid bilayers. The mechanism assumes water forms protonated and deprotonated clusters in the lipid bilayer. The model suggests how two features of lipid structures may inhibit H(+) leakage. One feature is the fused ring structure of sterols, hopanoids and tetrahymenol which extrude water and therefore clusters from the bilayer. The second feature is lipid structures that crowd the center of the bilayer with hydrocarbon. This can be accomplished either by separating the two monolayers with hydrocarbons such as isoprenes or isopranes in the bilayer's cleavage plane or by branching the lipid chains in the center of the bilayers with hydrocarbon. The natural distribution of lipids that contain these features are examined. Data in the literature shows that plasma membranes exposed to extreme concentrations of cations are particularly rich in the lipids containing the predicted qualities. Prokaryote plasma membranes that reside in extreme acids (acidophiles) contain both hopanoids and iso/anteiso- terminal lipid branching. Plasma membranes that reside in extreme base (alkaliphiles) contain both squalene and iso/anteiso- lipids. The mole fraction of squalene in alkaliphile bilayers increases, as they are cultured at higher pH. In eukaryotes, cation leak inhibition is here attributed to sterols and certain isoprenes, dolichol for lysosomes and peroxysomes, ubiquinone for these in addition to mitochondrion, and plastoquinone for the chloroplast. Phytosterols differ from cholesterol because they contain methyl and ethyl branches on the side chain. The proposal provides a structure-function rationale for distinguishing the structures of the phytosterols as inhibitors of proton leaks from that of cholesterol which is proposed to inhibit leaks of Na(+). The most extensively studied of sterols, cholesterol, occurs only in animal cells where there is a sodium gradient across the plasma membrane. In mammals, nearly 100 proteins participate in cholesterol's biosynthetic and degradation pathway, its regulatory mechanisms and cell-delivery system. Although a fat, cholesterol yields no energy on degradation. Experiments have shown that it reduces Na(+) and K(+) leakage through lipid bilayers to approximately one third of bilayers that lack the sterol. If sterols significantly inhibit cation leakage through the lipids of the plasma membrane, then the general role of all sterols is to save metabolic ATP energy, which is the penalty for cation leaks into the cytosol. The regulation of cholesterol's appearance in the plasma membrane and the evolution of sterols is discussed in light of this proposed role.
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Membrana Celular/metabolismo , Bicamadas Lipídicas/metabolismo , Bombas de Próton , Sódio/metabolismo , Esteróis/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Colesterol/metabolismo , Evolução Molecular , Transporte de Íons , Potenciais da Membrana/fisiologia , Modelos Biológicos , Fitosteróis/metabolismo , Esqualeno/metabolismoRESUMO
A method has been developed for making large unilamellar vesicles (LUV) with low polydispersity. The LUV, constituted of dioleoylphosphatidic acid (DOPA), 300 nm in diameter are made by a modification of the pH adjustment technique (Hauser, H. and Gains, N. (1982) Proc. Natl. Acad. Sci. USA 79, 1683-1687). This size is 10 times that (30 nm) of vesicles prepared by prolonged sonication. Vesicle size is increased stepwise by adding cholesterol (to a maximum of 40 mol% cholesterol) to form vesicles in 0.15 M KCl with up to 600 nm diameter. The vesicle size is measured by photon correlation spectroscopy, electron microscopy, and by measurement of the internal volume with cyanocobalamin while calculating the number of DOPA molecules per vesicle. Vesicles are stable for at least three weeks. Sepharose 4B column chromatography of the preparation yields a peak of fractions with the same polydispersity as the original sample and shows that 30 to 40% of the original lipid in a sample is recovered as LUV. Less than 2% of the sample forms small unilamellar vesicles (SUV) (diameter = 30 nm), which emerge from the column in a separate peak. Since the remaining lipid is not suspended in the buffer during vesicle formation, for most purposes the vesicles may be used immediately after titration so that they can be prepared in less than 40 min.
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Lipossomos , Ácidos Fosfatídicos , Fosfolipídeos , Concentração de Íons de Hidrogênio , Microscopia Eletrônica , Cloreto de Potássio , Soluções , Sonicação , Sacarose , Vitamina B 12/administração & dosagemRESUMO
BACKGROUND: Medicinal therapies and injections are commonly recommended for neck pain, yet controversy persists over their effectiveness. OBJECTIVES: To determine the effect of medicines and injections on pain, function/disability, patient satisfaction and range of motion in participants with mechanical neck disorders (MND). SEARCH STRATEGY: We searched CENTRAL (Issue 4, 2002), and MEDLINE, EMBASE, MANTIS, CINHAL from their start to March 2003. We scrutinized reference lists for other trials. SELECTION CRITERIA: We included randomized controlled trials with adults with MND, with or without associated headache or radicular findings. We considered medicinal and injection therapies, regardless of route of administration. DATA COLLECTION AND ANALYSIS: Two authors independently selected articles, abstracted data and assessed methodological quality using the Jadad criteria. Consensus was used to resolve disagreements. When clinical heterogeneity was absent, we combined studies using random-effects meta-analysis models. MAIN RESULTS: We found 32 trials that examined the effects of oral NSAIDs, psychotropic agents, injections of steroids, and anaesthetic agents. Overall, methodological quality had a mean of 3.2/5 on the Jadad Scale. For acute whiplash, administering intravenous methylprednisolone within eight hours reduced pain at one week, and sick leave but not pain at six months compared to placebo. For chronic MND at short-term follow-up, intramuscular injection of lidocaine was superior to placebo or dry needling, but similar to ultrasound. In chronic MND with radicular findings, epidural methylprednisolone and lidocaine reduced neck pain and improved function at one-year follow-up compared to the intramuscular route. In subacute/chronic MND, we found conflicting evidence of pain reduction for oral psychotropic agents compared to placebo or control. Single trials of eperison hydrochloride and tetrazepam showed positive results. Results for cyclobenzaprine were mixed. Diazepam did not show benefit. Other treatments including NSAIDS and nerve blocks had unclear or limited evidence of benefit. In participants with chronic MND with or without radicular findings or headache, there was moderate evidence from five high quality trials showing that Botox A intramuscular injections were not better than saline in improving pain (pooled SMD: -0.39 (95%CI: -1.25 to 0.47), disability or global perceived effect. AUTHORS' CONCLUSIONS: Intra-muscular injection of lidocaine for chronic MND and intravenous injection of methylprednisolone for acute whiplash were effective treatments. There was limited evidence of effectiveness of epidural injection of methylprednisolone and lidocaine for chronic MND with radicular findings. Oral psychotropic agents had mixed results. There was moderate evidence that Botox A intramuscular injections for chronic MND were no better than saline. Other medications, including NSAIDs, had contradictory or limited evidence of effectiveness.
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Anestésicos Locais/administração & dosagem , Anti-Inflamatórios não Esteroides/administração & dosagem , Cervicalgia/tratamento farmacológico , Psicotrópicos/administração & dosagem , Traumatismos em Chicotada/tratamento farmacológico , Doença Crônica , Humanos , Lidocaína/administração & dosagem , Metilprednisolona/administração & dosagem , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
BACKGROUND: Hospital length of stay and discharge destination are important outcome measures in evaluating effectiveness and efficiency of health services. Although hospital administrative data are readily used as a data collection source in health services research, no research has assessed this data collection method against other commonly used methods. OBJECTIVE: Determine if administrative data from electronic patient management programs are an effective data collection method for key hospital outcome measures when compared with alternative hospital data collection methods. METHOD: Prospective observational study comparing the completeness of data capture and level of agreement between three data collection methods; manual data collection from ward-based sources, administrative data from an electronic patient management program (i.PM), and inpatient medical record review (gold standard) for hospital length of stay and discharge destination. RESULTS: Manual data collection from ward-based sources captured only 376 (69%) of the 542 inpatient episodes captured from the hospital administrative electronic patient management program. Administrative data from the electronic patient management program had the highest levels of agreement with inpatient medical record review for both length of stay (93.4%) and discharge destination (91%) data. CONCLUSION: This is the first paper to demonstrate differences between data collection methods for hospital length of stay and discharge destination. Administrative data from an electronic patient management program showed the highest level of completeness of capture and level of agreement with the gold standard of inpatient medical record review for both length of stay and discharge destination, and therefore may be an acceptable data collection method for these measures.
Assuntos
Coleta de Dados/métodos , Tempo de Internação/estatística & dados numéricos , Alta do Paciente/estatística & dados numéricos , Mineração de Dados , Tomada de Decisões , Feminino , Política de Saúde , Administração Hospitalar/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de SaúdeRESUMO
The rate of the lateral diffusion of straight-chain phospholipids predicts the rate of water diffusion through bilayers. A new model of lipid dynamics integrates these processes. Substances such as cholesterol that reduce water diffusion proportionally reduce lateral diffusion. The model yields a number of predictions about the dynamics of the lipids at the Tm and suggests different mechanisms for how water diffuses across bilayers of other-than-straight-chain lipids, and how proteins bind to membranes. A second recent development in water transport across biological membranes is the discovery of a ubiquitous family of water transport proteins that facilitate large-volume water translocation. Like water diffusion through lipid bilayers, water transport by these proteins is directed by osmosis and is therefore under the control of ATP and ion pumps. The presence of water transport proteins in membranes is often regulated by hormones.
Assuntos
Membrana Celular/metabolismo , Água/metabolismo , Transporte Biológico , Fenômenos Químicos , Físico-Química , Colesterol/farmacologia , Cristalização , Difusão , Bicamadas Lipídicas/química , Bicamadas Lipídicas/metabolismo , Modelos Biológicos , SoluçõesRESUMO
10-N-Nonyl acridine orange (NAO) has been used at low concentrations as a fluorescent indicator for cardiolipin (CL) in membranes and bilayers. The mechanism of its selective fluorescence in the presence of CL, and not any other phospholipids, is not understood. The dye might recognize CL by its high pK (pK(2)>8.5). To investigate that, we established that NAO does not exhibit a pK in a pH range between 2.3 and 10.0. A second explanation is that the dye aggregates at hydrophobic domains on bilayers exposed by the CL. We found that a similar spectral shift occurs in the absence of CL in a concentrated solution of the dye in methanol and in the solid state. A model is proposed in which the nonyl group inserts in the bilayer at the hydrophobic surface generated by the presence of four chains on the phospholipid.