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1.
J Occup Rehabil ; 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38739344

RESUMO

PURPOSE: Electronic Health Records (EHRs) can contain vast amounts of clinical information that could be reused in modelling outcomes of work-related musculoskeletal disorders (WMSDs). Determining the generalizability of an EHR dataset is an important step in determining the appropriateness of its reuse. The study aims to describe the EHR dataset used by occupational musculoskeletal therapists and determine whether the EHR dataset is generalizable to the Australian workers' population and injury characteristics seen in workers' compensation claims. METHODS: Variables were considered if they were associated with outcomes of WMSDs and variables data were available. Completeness and external validity assessment analysed frequency distributions, percentage of records and confidence intervals. RESULTS: There were 48,434 patient care plans across 10 industries from 2014 to 2021. The EHR collects information related to clinical interventions, health and psychosocial factors, job demands, work accommodations as well as workplace culture, which have all been shown to be valuable variables in determining outcomes to WMSDs. Distributions of age, duration of employment, gender and region of birth were mostly similar to the Australian workforce. Upper limb WMSDs were higher in the EHR compared to workers' compensation claims and diagnoses were similar. CONCLUSION: The study shows the EHR has strong potential to be used for further research into WMSDs as it has a similar population to the Australian workforce, manufacturing industry and workers' compensation claims. It contains many variables that may be relevant in modelling outcomes to WMSDs that are not typically available in existing datasets.

2.
J Occup Rehabil ; 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38536622

RESUMO

PURPOSE: Through electronic health records (EHRs), musculoskeletal (MSK) therapists such as chiropractors and physical therapists, as well as occupational medicine physicians could collect data on many variables that can be traditionally challenging to collect in managing work-related musculoskeletal disorders (WMSDs). The review's objectives were to explore the extent of research using EHRs in predicting outcomes of WMSDs by MSK therapists. METHOD: A systematic search was conducted in Medline, PubMed, CINAHL, and Embase. Grey literature was searched. 2156 unique papers were retrieved, of which 38 were included. Three themes were explored, the use of EHRs to predict outcomes to WMSDs, data sources for predicting outcomes to WMSDs, and adoption of standardised information for managing WMSDs. RESULTS: Predicting outcomes of all MSK disorders using EHRs has been researched in 6 studies, with only 3 focusing on MSK therapists and 4 addressing WMSDs. Similar to all secondary data source research, the challenges include data quality, missing data and unstructured data. There is not yet a standardised or minimum set of data that has been defined for MSK therapists to collect when managing WMSD. Further work based on existing frameworks is required to reduce the documentation burden and increase usability. CONCLUSION: The review outlines the limited research on using EHRs to predict outcomes of WMSDs. It highlights the need for EHR design to address data quality issues and develop a standardised data set in occupational healthcare that includes known factors that potentially predict outcomes to help regulators, research efforts, and practitioners make better informed clinical decisions.

3.
Respir Res ; 20(1): 290, 2019 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-31864360

RESUMO

BACKGROUND: Several small molecule corrector and potentiator drugs have recently been licensed for Cystic Fibrosis (CF) therapy. However, other aspects of the disease, especially inflammation, are less effectively treated by these drugs. We hypothesized that small molecule drugs could function either alone or as an adjuvant to licensed therapies to treat these aspects of the disease, perhaps emulating the effects of gene therapy in CF cells. The cardiac glycoside digitoxin, which has been shown to inhibit TNFα/NFκB signaling in CF lung epithelial cells, may serve as such a therapy. METHODS: IB3-1 CF lung epithelial cells were treated with different Vertex (VX) drugs, digitoxin, and various drug mixtures, and ELISA assays were used to assess suppression of baseline and TNFα-activated secretion of cytokines and chemokines. Transcriptional responses to these drugs were assessed by RNA-seq and compared with gene expression in AAV-[wildtype]CFTR-treated IB3-1 (S9) cells. We also compared in vitro gene expression signatures with in vivo data from biopsied nasal epithelial cells from digitoxin-treated CF patients. RESULTS: CF cells exposed to digitoxin exhibited significant suppression of both TNFα/NFκB signaling and downstream secretion of IL-8, IL-6 and GM-CSF, with or without co-treatment with VX drugs. No evidence of drug-drug interference was observed. RNA-seq analysis showed that gene therapy-treated CF lung cells induced changes in 3134 genes. Among these, 32.6% were altered by digitoxin treatment in the same direction. Shared functional gene ontology themes for genes suppressed by both digitoxin and gene therapy included inflammation (84 gene signature), and cell-cell interactions and fibrosis (49 gene signature), while genes elevated by both were enriched for epithelial differentiation (82 gene signature). A new analysis of mRNA data from digitoxin-treated CF patients showed consistent trends in expression for genes in these signatures. CONCLUSIONS: Adjuvant gene therapy-emulating activities of digitoxin may contribute to enhancing the efficacy of currently licensed correctors and potentiators in CF patients.


Assuntos
Fibrose Cística/metabolismo , Digitoxina/farmacologia , Terapia Genética/métodos , Mediadores da Inflamação/antagonistas & inibidores , Mediadores da Inflamação/metabolismo , Mucosa Respiratória/metabolismo , Animais , Cardiotônicos/farmacologia , Células Cultivadas , Fibrose Cística/patologia , Fibrose Cística/terapia , Relação Dose-Resposta a Droga , Humanos , Ratos , Ratos Endogâmicos F344 , Mucosa Respiratória/efeitos dos fármacos , Resultado do Tratamento
4.
Gene Ther ; 22(11): 908-16, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26133785

RESUMO

Cystic fibrosis (CF) is due to mutations in the CFTR gene, which prevents correct folding, trafficking and function of the mutant cystic fibrosis transmembrane conductance regulator (CFTR) protein. The dysfunctional effect of CFTR mutations, principally the F508del-CFTR mutant, is further manifested by hypersecretion of the pro-inflammatory chemokine interleukin-8 into the airway lumen, which further contributes to morbidity and mortality. We have hypothesized that microRNA (miR)-based therapeutics could rescue the dysfunctional consequences of mutant CFTR. Here we report that a miR-16 mimic can effectively rescue F508del-CFTR protein function in airway cell lines and primary cultures, of differentiated human bronchial epithelia from F508del homozygotes, which express mutant CFTR endogenously. We also identify two other miRs, miR-1 and miR-302a, which are also active. Although miR-16 is expressed at basal comparable levels in CF and control cells, miR-1 and miR-302a are undetectable. When miR mimics are expressed in CF lung or pancreatic cells, the expression of the F508del-CFTR protein is significantly increased. Importantly, miR-16 promotes functional rescue of the cyclic AMP-activated apical F508del-CFTR chloride channel in primary lung epithelial cells from CF patients. We interpret these findings to suggest that these miRs may constitute novel targets for CF therapy.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/genética , Fibrose Cística/genética , Fibrose Cística/terapia , MicroRNAs/genética , Linhagem Celular , Células Cultivadas , Fibrose Cística/metabolismo , Fibrose Cística/patologia , Células Epiteliais/patologia , Terapia Genética/métodos , Humanos , MicroRNAs/administração & dosagem , MicroRNAs/biossíntese , Mutação , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Mucosa Respiratória/patologia
5.
Science ; 209(4453): 274-7, 1980 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-17807116

RESUMO

Estimates based on potential maize crops and maize consumption patterns of the 15th-century Mesoamerican protohistoric Tarascan population living within its geopolitical core (Lake Páttzcuaro Basin) indicate that this population had not maintained itself through agricultural- and lacustrine-carrying capacity alone. It was through having to obtain basic resources such as maize from outside the basin that the Tarascans developed mechanisms that formed the particular character of their state.

6.
Science ; 224(4649): 619-21, 1984 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-6424235

RESUMO

Cultured chromaffin cells from bovine adrenal medulla were found to contain primarily the B form of monoamine oxidase. This monoamine oxidase B enzyme was somewhat distinct from B enzymes from other sources, in that noradrenaline was a much poorer substrate than serotonin. Nonetheless, studies with selective inhibitors of the A form (clorgyline) and the B form [(-)-deprenyl] confirmed that chromaffin cell monoamine oxidase was the B form. The observation that chromaffin cell monoamine oxidase has poor affinity for catecholamines is consistent with physiological needs that require the cell to synthesize and store large amounts of catecholamines.


Assuntos
Medula Suprarrenal/citologia , Sistema Cromafim/enzimologia , Monoaminoxidase/metabolismo , Medula Suprarrenal/enzimologia , Animais , Plaquetas/metabolismo , Catecolaminas/metabolismo , Bovinos , Clorgilina/farmacologia , Humanos , Norepinefrina/metabolismo , Selegilina/farmacologia , Serotonina/metabolismo
7.
Trends Cancer Res ; 13: 55-62, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30369774

RESUMO

Tumor suppressor function of Annexin-A7 (ANXA7) was demonstrated by cancer-prone phenotype in Anxa7(+/-) mice and ANXA7 profiling in human cancers including prostate and breast. Consistent with its more evident in vivo tumor suppressor role in prostate cancer, wild-type(wt)-ANXA7 in vitro induced similar G2-arrests, but reduced survival more drastically in prostate cancer cells compared to breast cancer cells (DU145 versus MDA-MB-231 and -435). In all three hormone-resistant cancer cell lines, wt-ANXA7 abolished the expression of the oncogenic low-molecular weight (LMW) cyclin E which was for the first time encountered in prostate cancer cells. Dominant-negative nMMM-ANXA7 (which lacks phosphatidylserine liposome aggregation properties) failed to abrogate LMW-cyclin E and simultaneously induced fibroblast growth factor 8 (FGF8) in DU145 that was consistent with the continuing cell cycle progression and reduced cell death. Adenoviral vector alone induced FGF8 in MDA-MB-231/435 cell lines, but not in DU145 cells. Our data indicated that the LMW-Cyclin E expressions in breast cancer and prostate cancer cell-lines were differentially regulated by wild-type and dominant-negative ANXA7 isoforms, demonstrating a different survival mechanism utilized by breast cancer cells. Conventional tumor suppressor p53 failed to completely abolish FGF8 and LMW-cyclin E in breast cancer cells, which were eventually translated into their survival. Thus, ANXA7 tumor suppression could modulate FGF8 and cyclin E expression, and control implying more specific associations with the annexin properties of ANXA7 in prostate tumorigenesis.

8.
Nat Biotechnol ; 18(3): 289-95, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10700143

RESUMO

Hemophilia A and B coagulation defects, which are caused by deficiencies of Factor VIII and Factor IX, respectively, can be bypassed by administration of recombinant Factor VIIa. However, the short half-life of recombinant Factor VIIa in vivo negates its routine clinical use. We report here an in vivo method for the continuous generation of Factor VIIa. The method depends on the implantation of a porous chamber that contains Factor Xa or XIIa, and continuously generates Factor VIIa bypass activity from the subject's own Factor VII, which enters the chamber by diffusion. Once inside, the Factor VII is cleaved to Factor VIIa by the immobilized Factor Xa or XIIa. The newly created Factor VIIa diffuses out of the chamber and back into the circulation, where it can bypass the deficient Factors VIII or IX, and enable coagulation to occur. In vitro, this method generates sufficient Factor VIIa to substantially correct Factor VIII-deficient plasma when assessed by the classical aPTT coagulation assay. In vivo, a Factor XIIa peritoneal implant generates bypass activity for up to one month when tested in rhesus monkeys. Implantation of such a chamber in a patient with hemophilia A or B could eventually provide a viable alternative to replacement therapies using exogenous coagulation factors.


Assuntos
Coagulantes/administração & dosagem , Fator XIIa/administração & dosagem , Hemofilia A/tratamento farmacológico , Proteínas Recombinantes/administração & dosagem , Animais , Coagulantes/uso terapêutico , Fator IX/metabolismo , Fator VIII/metabolismo , Fator XIIa/metabolismo , Fator XIIa/farmacologia , Fator XIIa/uso terapêutico , Fibrinogênio/metabolismo , Cobaias , Bombas de Infusão Implantáveis , Macaca mulatta , Masculino , Peritônio , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/uso terapêutico , Fatores de Tempo
9.
Transl Psychiatry ; 7(2): e1025, 2017 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-28170001

RESUMO

Post-traumatic stress disorder (PTSD) is psychiatric disease, which can occur following exposure to traumatic events. PTSD may be acute or chronic, and can have a waxing and waning course of symptoms. It has been hypothesized that proinflammatory cytokines and chemokines in the cerebrospinal fluid (CSF) or plasma might be mediators of the psychophysiological mechanisms relating a history of trauma exposure to changes in behavior and mental health disorders, and medical morbidity. Here we test the cytokine/chemokine hypothesis for PTSD by examining levels of 17 classical cytokines and chemokines in CSF, sampled at 0900 hours, and in plasma sampled hourly for 24 h. The PTSD and healthy control patients are from the NIMH Chronic PTSD and healthy control cohort, initially described by Bonne et al. (2011), in which the PTSD patients have relatively low comorbidity for major depressive disorder (MDD), drug or alcohol use. We find that in plasma, but not CSF, the bivariate MCP4 (CCL13)/ MCP1(CCL2) ratio is ca. twofold elevated in PTSD patients compared with healthy controls. The MCP-4/MCP-1 ratio is invariant over circadian time, and is independent of gender, body mass index or the age at which the trauma was suffered. By contrast, MIP-1ß is a candidate biomarker for PTSD only in females, whereas TARC is a candidate biomarker for PTSD only in males. It remains to be discovered whether these disease-specific differences in circadian expression for these specific immune signaling molecules are biomarkers, surrogates, or drivers for PTSD, or whether any of these analytes could contribute to therapy.


Assuntos
Quimiocina CCL2/metabolismo , Proteínas Quimioatraentes de Monócitos/metabolismo , Transtornos de Estresse Pós-Traumáticos/metabolismo , Adulto , Biomarcadores/sangue , Biomarcadores/líquido cefalorraquidiano , Quimiocina CCL17/metabolismo , Quimiocina CCL4/metabolismo , Doença Crônica , Ritmo Circadiano , Citocinas/metabolismo , Feminino , Humanos , Masculino , Fatores Sexuais
10.
J Sci Med Sport ; 9(1-2): 46-56, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16630745

RESUMO

It was the purpose of this review to document the range, incidence, location and mechanism of injury occurring in the sport of rugby league. Rugby league is a collision sport played in Europe and the Pacific regions including Australia. The sport is well established and has competitions ranging from junior to elite professional. Due to the contact nature of the game, injury is relatively common. The most common injuries are musculotendinous in nature and afflict the lower limb more frequently than elsewhere. Despite the high incidence of minor (sprains/strains) to moderate musculoskeletal injury (fracture, ligament and joint injury) and minor head injuries such as lacerations, nasal fractures and concussions, rare more serious spinal cord and other injuries causing death have also been recorded. The literature on rugby league injury is small but growing and suffers from a lack of consistent definition of what an injury is, thereby causing variability in the nature and incidence/prevalence of injury. Information is lacking on the injury profiles of different age groups. Importantly, there has been little attempt to establish a coordinated injury surveillance program in rugby league in the junior or professional levels. The implementation of such programs would require a universal definition of injury and a focus on important events and competitions. The implementation could provide important information in the identification and prevention of risk factors for injury.


Assuntos
Futebol Americano/lesões , Distribuição por Idade , Traumatismos em Atletas/epidemiologia , Traumatismos em Atletas/etiologia , Humanos , Incidência , Recidiva
11.
Biochim Biophys Acta ; 979(2): 157-65, 1989 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-2923875

RESUMO

Interaction of protein kinase C with chromaffin granule membranes has been studied as a means of investigating the translocation of protein kinase C from cytosol to intracellular membrane surfaces, which is believed to occur during secretion. Protein kinase C in an adrenal medullary soluble fraction was found to bind reversibly to granule membranes in a Ca2+-dependent fashion. Association and dissociation events were sensitive to Ca2+ concentrations in the low micromolar range, and the Ca2+ sensitivity of both processes was increased when the membranes had been preincubated with the protein kinase C-activating phorbol ester, 4 beta-phorbol 12-myristate 13-acetate (TPA). Binding of protein kinase C to granule membranes occurred at 0 and 37 degrees C, irrespective of whether the membranes had been preincubated with TPA. However, dissociation of protein kinase C from granule membranes that had been preincubated with TPA occurred only at 37 degrees C and not at 0 degree C, even though dissociation of the enzyme from membranes which had not been preincubated with TPA would occur at both 37 and 0 degrees C. These effects of TPA were not reproduced by 4 alpha-phorbol 12,13-didecanoate (4 alpha PDD), a phorbol ester which does not activate protein kinase C. Soluble protein kinase C activity also associated with chromaffin granules in a Ca2+-dependent manner in an adrenal medullary homogenate, indicating that granules can compete with other intracellular membranes for the binding of protein kinase C. Results obtained with this model system differ from other systems where the interaction of protein kinase C with plasma membranes has been studied and have general implications for studies performed on the translocation of protein kinase C in intact cells and for the role of protein kinase C in stimulus-secretion coupling in the chromaffin cell.


Assuntos
Cálcio/farmacologia , Grânulos Cromafim/ultraestrutura , Sistema Cromafim/ultraestrutura , Membranas Intracelulares/metabolismo , Proteína Quinase C/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Medula Suprarrenal/ultraestrutura , Animais , Bovinos , Membranas Intracelulares/efeitos dos fármacos , Temperatura
12.
Biochim Biophys Acta ; 903(2): 309-18, 1987 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-2443172

RESUMO

Fusion of chromaffin granule ghosts was induced by synexin at pH 6, 37 degrees C, in the presence of 10(-7) M Ca2+. To study the kinetics and extent of this fusion process we employed two assays that monitored continuously mixing of aqueous contents or membrane mixing by fluorescence intensity increases. In both assays chromaffin granule ghosts were either labeled on the membrane or in the included aqueous phase. The ratios of blank to labeled chromaffin granule ghosts were varied from 1 to 10. The results were analyzed in terms of a mass action kinetic model, which views the overall fusion reaction as a sequence of a second-order process of aggregation followed by a first-order fusion reaction. The model calculations gave fare simulations and predictions of the experimental results. The rate constants describing membrane mixing are more than 2-fold larger than those for volume mixing. The analysis also indicated that the initial aggregation and fusion processes, up to dimer formation, were extremely fast. The rate constant of aggregation was close to the limit in diffusion-controlled processes, whereas the fusion rate constant was about the same as found in fastest virus-liposome fusion events at pH 5. A small increase in volume was found to accompany the fusion between chromaffin granule ghosts. Using ratios of synexin to chromaffin granule ghost protein of 0.13, 0.41 and 1.15 indicated that the overall fusion rate was larger for the intermediate (0.41) case. The analysis showed that the main activity of synexin was an enhancement of the rate of aggregation. At intermediate or excessive synexin concentrations it, respectively, promoted moderately, or inhibited the actual fusion step.


Assuntos
Grânulos Cromafim/ultraestrutura , Sistema Cromafim/ultraestrutura , Fluoresceína-5-Isotiocianato/análogos & derivados , Membranas Intracelulares/fisiologia , Fusão de Membrana/efeitos dos fármacos , Proteínas/farmacologia , Animais , Anexina A7 , Bovinos , Dextranos , Fluoresceínas , Corantes Fluorescentes , Concentração de Íons de Hidrogênio , Membranas Intracelulares/ultraestrutura , Cinética , Espectrometria de Fluorescência
13.
Biochim Biophys Acta ; 905(1): 205-12, 1987 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-2960380

RESUMO

Synexin induces chromaffin granule ghosts to fuse one to another, a process which is followed continuously and quantitatively by monitoring the mixing of the intragranular aqueous compartments. A freeze-thaw technique was used for preparing chromaffin granule ghosts loaded with a self-quenching concentration of the fluorescent, high molecular weight probe FITC-Dextran. When the loaded ghosts were mixed with empty ghosts in the presence of synexin, the two compartments fused, resulting in the dilution of the probe with the concomitant increase in fluorescence. So as to suppress possible leakage signals, anti-fluorescein antibodies which quench probe fluorescence were present in the reaction media. Synexin-mediated fusion of freeze-thaw (F/Th) ghosts and binding of 125I-synexin to these membranes were found to be dependent on Ca2+ concentration, but only in a partial manner. However, these two synexin-mediated properties were demonstrably sensitive to [H+] in the medium. A detailed pH profile of fusion revealed an apparent midpoint of activation at approx. pH 5.2, with asymptotic values at pH 4 (maximum) and pH 7.2 (minimum). In our attempt to determine whether the pH effect was on the synexin or on the membranes, we found that fusion was blocked only by treatment of the membranes with the membrane-impermeant carboxyl group modifier 1-ethyl-3-(4-azonia-4,4-dimethylpentyl)carbodiimide. These data suggest that membrane fusion evoked by synexin seems to be promoted by rendering the F/Th membranes relatively less negatively charged while the synexin becomes more positively charged. The fusion process was entirely dependent upon synexin concentration; the k1/2 under optimal conditions of pCa and pH was 85 nM. Similar to what has been previously found with intact granules, an anti-synexin polyclonal antibody partially (48%) blocked fusion, as did pretreatment of the chromaffin granules ghosts with trypsin (30%). We conclude that the coincident pCa and pH sensitivity of synexin-mediated binding to chromaffin granule membranes and their subsequent fusion might be associated with physiological changes in the concentration of both cations in the cytoplasm of secreting chromaffin cells.


Assuntos
Medula Suprarrenal/ultraestrutura , Grânulos Cromafim/ultraestrutura , Sistema Cromafim/ultraestrutura , Concentração de Íons de Hidrogênio , Membranas Intracelulares/efeitos dos fármacos , Fusão de Membrana/efeitos dos fármacos , Proteínas/farmacologia , Animais , Anexina A7 , Bovinos , Cinética , Estimulação Química
14.
Biochim Biophys Acta ; 1091(3): 417-25, 1991 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-2001423

RESUMO

Calcium transport and catecholamine secretion was measured in cultured bovine chromaffin cells. Calcium ions which entered the cells following stimulation with either nicotine or 50 mM KCl (high potassium) triggered catecholamine release, but then inactivated the secretory process. The nicotine and the high potassium-induced calcium transport mechanisms were mechanistically distinct, but functionally dependent on each other. The specific evidence is that whereas the high potassium-induced Ca2+ influx was found to be inhibited by hyperosmotic medium, the nicotine-stimulated calcium influx was unaffected under these conditions. High potassium and nicotine-stimulated catecholamine release were also differently affected by hyperosmotic medium. While potassium-stimulated catecholamine release was profoundly inhibited by hyperosmolarity, nicotine-stimulated release was only moderately inhibited. Sequential treatments of cells with nicotine and high potassium, under isotonic physiological conditions, indicate that there is a functional, biochemical communication between the otherwise mechanistically distinct calcium channels. Calcium ions which were found to inactivate these channels may be the basis for such communication.


Assuntos
Medula Suprarrenal/fisiologia , Cálcio/metabolismo , Catecolaminas/metabolismo , Nicotina/farmacologia , Medula Suprarrenal/efeitos dos fármacos , Medula Suprarrenal/metabolismo , Animais , Transporte Biológico Ativo/efeitos dos fármacos , Bovinos , Células Cultivadas , Digitonina/farmacologia , Cinética , Concentração Osmolar , Cloreto de Potássio/farmacologia
15.
Biochim Biophys Acta ; 1234(2): 255-60, 1995 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-7696302

RESUMO

The effects of the protein synthesis inhibitors actinomycin D and cycloheximide on the cellular content of the calcium binding protein synexin, and on the secretory response of cultured bovine adrenal medullary chromaffin cells were determined. Both protein synthesis inhibitors produced a slow decrease in the cellular synexin content. The synexin level was reduced by 50% after 133 h of incubation in the presence of 2 micrograms/ml actinomycin D or 5 micrograms/ml cycloheximide. However, this was partly due to an artefactual stabilization of synexin, since metabolic labelling of synexin with [35S]methionine showed that the half-time of degradation was only 40 h. The secretory response of chromaffin cells was quickly diminished in the presence of protein synthesis inhibitors. Catecholamine secretion induced by membrane depolarization or barium stimulation of intact cells, or by calcium stimulation of digitonin-permeabilized cells was decreased by 77-82% after 24 h of incubation in the presence of 5 micrograms/ml cycloheximide. These results suggest that, in addition to synexin, at least one or more proteins with a shorter half-time of degradation than synexin are involved in the secretory response of adrenal chromaffin cells.


Assuntos
Medula Suprarrenal/fisiologia , Anexina A7/metabolismo , Catecolaminas/metabolismo , Cicloeximida/farmacologia , Dactinomicina/farmacologia , Oligonucleotídeos Antissenso/farmacologia , Medula Suprarrenal/citologia , Medula Suprarrenal/efeitos dos fármacos , Análise de Variância , Animais , Anexina A7/biossíntese , Compostos de Bário/farmacologia , Sequência de Bases , Cloreto de Cálcio/farmacologia , Bovinos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cloretos/farmacologia , Hipotálamo , Cinética , Leucina/metabolismo , Potenciais da Membrana/efeitos dos fármacos , Camundongos , Dados de Sequência Molecular , Neurônios , Células PC12 , Cloreto de Potássio/farmacologia , Ratos , Uridina/metabolismo
16.
Biochim Biophys Acta ; 1742(1-3): 151-60, 2004 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-15590065

RESUMO

Mobilization of intracellular calcium from inositol-1,4,5-triphosphate (IP3)-sensitive endoplasmic reticulum (ER) stores plays a prominent role in brain function. Mice heterozygous for the annexin A7 (Anx7) gene have a profound reduction in IP3 receptor function in pancreatic islets along with defective insulin secretion. We examined IP3-sensitive calcium pools in the brains of Anx7 (+/-) mice by utilizing ATP/Mg(2+)-dependent (45)Ca(2+) uptake into brain membrane preparations and tissue sections. Although the Anx7 (+/-) mouse brain displayed similar levels of IP3 binding sites and thapsigargin-sensitive (45)Ca(2+) uptake as that seen in wild-type mouse brain, the Anx7 (+/-) mouse brain Ca(2+) pools showed markedly reduced sensitivity to IP3. A potent and saturable Ca(2+)-releasing effect of recombinant ANX7 protein was demonstrated in mouse and rat brain membrane preparations, which was additive with that of IP3. We propose that ANX7 mobilizes Ca(2+) from an endoplasmic reticulum-like pool, which can be recruited to enhance IP3-mediated Ca(2+) release.


Assuntos
Anexina A7/fisiologia , Encéfalo/metabolismo , Cálcio/metabolismo , Retículo Endoplasmático/metabolismo , Animais , Anexina A7/genética , Anexina A7/metabolismo , Sequência de Bases , Primers do DNA , Masculino , Camundongos , Ratos , Ratos Sprague-Dawley
17.
Br J Sports Med ; 39(11): 799-804; discussion 799-804, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16244187

RESUMO

In the right hands, the golf swing is a motion that inspires looks of awe from the public. It is a complex movement of the whole body to generate power to a golf ball to propel the ball great distances with accuracy. This movement relies on the coordinated sequence of muscle activation to produce a fluid and reproducible movement. This paper reviews the literature on golf swing related muscle activity. The phases of this activity are discussed with a view to assisting the practitioner in understanding the swing. Such understanding may help in the management of the injured golfer.


Assuntos
Golfe/fisiologia , Movimento/fisiologia , Músculo Esquelético/fisiologia , Eletromiografia , Humanos , Postura/fisiologia
18.
Br J Sports Med ; 39(2): e9, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15665194

RESUMO

Quadrilateral space syndrome is an uncommon injury. The true prevalence is unknown because of a lack of literature and possible misdiagnosis. Prevalence may increase as knowledge of the syndrome increases. The case is presented of a recreational triathlete who had a spontaneous onset of quadrilateral space syndrome. The diagnosis was made by physical examination and confirmed with magnetic resonance imaging. A conservative, yet aggressive rehabilitation programme resulted in functional improvement within six weeks. Results have been maintained for eight weeks.


Assuntos
Síndromes de Compressão Nervosa/diagnóstico , Dor de Ombro/etiologia , Diagnóstico Diferencial , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Síndromes de Compressão Nervosa/reabilitação , Modalidades de Fisioterapia , Amplitude de Movimento Articular/fisiologia , Ombro/inervação , Dor de Ombro/reabilitação , Síndrome , Resultado do Tratamento
19.
FEBS Lett ; 217(1): 25-31, 1987 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-2954851

RESUMO

The mechanism by which synexin mediates calcium-dependent aggregation of medullary cell chromaffin granules and fusion of granule ghosts involves specific interactions with the lipid component of the membrane. To study the details of these interactions we measured synexin-induced changes in capacitance of phosphatidylserine bilayers formed at the tip of a patch pipet using the double-dip method. Provided calcium was present in the solution filling the pipet (10-50 mM) stable phosphatidylserine bilayers were easily formed. Addition of synexin (0.1 microgram/ml) to an external medium lacking added calcium induced no measurable changes in either bilayer resistance (10-30 G omega) or displacement current across the membrane. However, addition of calcium (0.1-2.5 mM) in the presence of synexin in the external solution caused a marked increase in the size and time constant of decay of the displacement current. From the steady-state value of the current we calculated a 5-fold decrease in resistance and from the charge displaced during the voltage-clamp pulses we calculated a 10-fold increase in membrane capacitance (from 20 to 200 fF). The size of the synexin-specific charge displacement in one direction during a pulse was always equal to the charge returning to the original configuration after the pulse. The synexin-specific transfer of charge reached saturation when the pipet potential was taken to a sufficient positive or negative value. These properties of the extra charge movement support our view that in the presence of calcium the cytosolic protein synexin penetrates into the bilayer. It is possible that these properties may be related to the mechanism by which synexin promotes membrane fusion in natural membranes.


Assuntos
Cálcio/farmacologia , Bicamadas Lipídicas/metabolismo , Fusão de Membrana/efeitos dos fármacos , Fosfatidilserinas/metabolismo , Proteínas/farmacologia , Anexina A7 , Condutividade Elétrica , Potenciais da Membrana/efeitos dos fármacos
20.
FEBS Lett ; 234(2): 439-45, 1988 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-3391283

RESUMO

Pertussis toxin was found to stimulate catecholamine release from bovine adrenal chromaffin cells in a Ca2+-dependent manner and in the absence of any stimulatory or inhibitory agonists for this cell. The release of catecholamine was associated with the ADP-ribosylation of an approx. 40 kDa protein present in the total membrane fraction. These results are consistent with the existence of an exocytosis-linked G-protein.


Assuntos
Adenosina Difosfato Ribose/metabolismo , Medula Suprarrenal/metabolismo , Cálcio/farmacologia , Toxina Pertussis , Proteínas/metabolismo , Fatores de Virulência de Bordetella/farmacologia , Medula Suprarrenal/efeitos dos fármacos , Animais , Catecolaminas/metabolismo , Bovinos , Células Cultivadas , Cinética
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