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1.
J Am Water Works Assoc ; 110(12): E44-E51, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30713343

RESUMO

A 2016 incident that resulted in damage to a water storage tank's roof motivated pilot-scale experiments to be conducted to determine the impact of mesh on tank overflow capacity. A clean mesh installed near the outlet of an overflow system did not reduce the capacity during the weir dominated flow regime. The impact of a mesh was found to be a reduction in the area available to flow, which was found to lower the achievable capacity through the system. Considering only the head loss or pressure drop associated with the mesh and not area reduction resulted in an overestimation of achievable capacity, which could lead to an undersized overflow system. The results and formulas presented will help water utilities ensure overflow systems with mesh are appropriately sized.

2.
J Clin Neurosci ; 44: 269-273, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28709837

RESUMO

Thoracic disc herniation is a rare pathology for which surgical treatment is difficult. The discovery of asymptomatic or only slightly symptomatic lesions can be problematic, especially in cases of marked canal stenosis. The possibility of spontaneous resorption has been documented by a few case reports but there is no study on this subject. Our objective was to compare the clinical and radiological data for two groups of patients with significant thoracic herniation (occupying more than 20% of the spinal canal): one showing spontaneous resorption (group 1) and the other persistence of the lesion during follow up (group 2). The physiological processes of thoracic herniation are also discussed. We present a retrospective study of our database of patients with thoracic hernia. Only subjects who initially showed signs of slight or absent myelopathy (Frankel D or E) were included. Group 1 and 2 are composed of 12 and 17 patients respectively. The clinical and radiological data are compared. The two groups were not different for the following parameters: age, sex ratio, disc calcification, size, trajectory, side, hernia level. Other parameters were evaluated and were not associated with a higher rate of resorption: disc calcification, intramedullary hypersignal in T2 sequence, calcification of the posterior common vertebral ligament, calcification of another disc and Scheuerman's disease. Asymptomatic thoracic disc herniation is a condition that can disappear spontaneously, even in the case of a large lesion. To date, there are no clinical or radiological data that can predict such an evolution.


Assuntos
Doenças Assintomáticas , Deslocamento do Disco Intervertebral/patologia , Remissão Espontânea , Canal Medular/patologia , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Deslocamento do Disco Intervertebral/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos
3.
Glob Chang Biol ; 23(6): 2154-2165, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-27801975

RESUMO

Eddy covariance (EC) continues to provide invaluable insights into the dynamics of Earth's surface processes. However, despite its many strengths, spatial replication of EC at the ecosystem scale is rare. High equipment costs are likely to be partially responsible. This contributes to the low sampling, and even lower replication, of ecoregions in Africa, Oceania (excluding Australia) and South America. The level of replication matters as it directly affects statistical power. While the ergodicity of turbulence and temporal replication allow an EC tower to provide statistically robust flux estimates for its footprint, these principles do not extend to larger ecosystem scales. Despite the challenge of spatially replicating EC, it is clearly of interest to be able to use EC to provide statistically robust flux estimates for larger areas. We ask: How much spatial replication of EC is required for statistical confidence in our flux estimates of an ecosystem? We provide the reader with tools to estimate the number of EC towers needed to achieve a given statistical power. We show that for a typical ecosystem, around four EC towers are needed to have 95% statistical confidence that the annual flux of an ecosystem is nonzero. Furthermore, if the true flux is small relative to instrument noise and spatial variability, the number of towers needed can rise dramatically. We discuss approaches for improving statistical power and describe one solution: an inexpensive EC system that could help by making spatial replication more affordable. However, we note that diverting limited resources from other key measurements in order to allow spatial replication may not be optimal, and a balance needs to be struck. While individual EC towers are well suited to providing fluxes from the flux footprint, we emphasize that spatial replication is essential for statistically robust fluxes if a wider ecosystem is being studied.


Assuntos
Dióxido de Carbono , Ecossistema , África , Austrália , Interpretação Estatística de Dados , América do Sul
4.
Glob Chang Biol ; 21(10): 3712-25, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25969925

RESUMO

Quantifying landscape-scale methane (CH4 ) fluxes from boreal and arctic regions, and determining how they are controlled, is critical for predicting the magnitude of any CH4 emission feedback to climate change. Furthermore, there remains uncertainty regarding the relative importance of small areas of strong methanogenic activity, vs. larger areas with net CH4 uptake, in controlling landscape-level fluxes. We measured CH4 fluxes from multiple microtopographical subunits (sedge-dominated lawns, interhummocks and hummocks) within an aapa mire in subarctic Finland, as well as in drier ecosystems present in the wider landscape, lichen heath and mountain birch forest. An intercomparison was carried out between fluxes measured using static chambers, up-scaled using a high-resolution landcover map derived from aerial photography and eddy covariance. Strong agreement was observed between the two methodologies, with emission rates greatest in lawns. CH4 fluxes from lawns were strongly related to seasonal fluctuations in temperature, but their floating nature meant that water-table depth was not a key factor in controlling CH4 release. In contrast, chamber measurements identified net CH4 uptake in birch forest soils. An intercomparison between the aerial photography and satellite remote sensing demonstrated that quantifying the distribution of the key CH4 emitting and consuming plant communities was possible from satellite, allowing fluxes to be scaled up to a 100 km(2) area. For the full growing season (May to October), ~ 1.1-1.4 g CH4  m(-2) was released across the 100 km(2) area. This was based on up-scaled lawn emissions of 1.2-1.5 g CH4  m(-2) , vs. an up-scaled uptake of 0.07-0.15 g CH4  m(-2) by the wider landscape. Given the strong temperature sensitivity of the dominant lawn fluxes, and the fact that lawns are unlikely to dry out, climate warming may substantially increase CH4 emissions in northern Finland, and in aapa mire regions in general.


Assuntos
Florestas , Metano/metabolismo , Áreas Alagadas , Regiões Árticas , Mudança Climática , Finlândia
5.
Bioanalysis ; 3(19): 2171-5, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21985412

RESUMO

This University of Wisconsin School of Pharmacy bioanalytical conference is presented each year by the Extension Services in Pharmacy, the professional development department within the school. The purpose of this 4-day conference is to provide an educational forum to discuss issues and applications associated with the analysis of xenobiotics, metabolites, biologics and biomarkers in biological matrices. The conference is designed to include and encourage an open exchange of scientific and methodological applications for bioanalysis. To increase the interactive nature of the conference, the program was a mixture of lectures, poster sessions, round table discussions and workshops. This article summarizes the presentations at the 12th Annual Conference.


Assuntos
Biomarcadores/análise , Técnicas de Química Analítica , Química Analítica/tendências , Humanos , Xenobióticos/análise
6.
Bioanalysis ; 3(7): 735-43, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21452991

RESUMO

BACKGROUND: The fast-paced nature of the pharmaceutical industry requires robust bioanalytical methods to endure the high-throughput sample demands of the production environment. RESULTS: A rapid, accurate and precise LC-MS/MS method was developed for the quantitation of a diastereomer quartet in human plasma. Virtually all of the phosphatidylcholine and most of the lysophosphatidylcholine from human plasma were removed using a phospholipid-removing protein precipitation 96-well plate. An Agilent Poroshell SB-C18 2.1 × 50 mm superficially porous column was used at 100°C and 1.2 ml/min to separate a diastereomer quartet in <2.5 min. Peak shape, retention and resolution were maintained over nearly 200 extracted bioanalytical samples under these separation conditions. The method was tested for accuracy and precision; the assay inter-run accuracy and precision were minus 7.2-0.7% and 2.1-11.9%, respectively (n = 18). CONCLUSION: The application of the superficially porous column resulted in twofold response increase and a 2.6-fold reduction in cycle time compared with a 3.5-µm column performing under comparable resolution conditions.


Assuntos
Análise Química do Sangue/instrumentação , Cromatografia Líquida de Alta Pressão/instrumentação , Dipeptídeos/sangue , Sulfonas/sangue , Espectrometria de Massas em Tandem/instrumentação , Tecnologia Farmacêutica/instrumentação , Análise Química do Sangue/métodos , Cromatografia Líquida de Alta Pressão/métodos , Ciclopropanos , Humanos , Leucina/análogos & derivados , Lisofosfatidilcolinas/sangue , Fosfatidilcolinas/sangue , Prolina/análogos & derivados , Estereoisomerismo , Espectrometria de Massas em Tandem/métodos , Tecnologia Farmacêutica/métodos , Temperatura , Ureia
7.
J Pharm Biomed Anal ; 55(2): 349-59, 2011 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-21353434

RESUMO

SCH 530348 is a safe and effective oral anti-platelet agent for patients with acute coronary syndrome. Clinical study results suggest that SCH 530348 dosage at 20 mg or 40 mg is feasible to achieve rapid maximum platelet inhibition following an acute coronary event or intervention procedure. To permit accurate determinations of circulating SCH 530348 in plasma following dosing, a method for measuring SCH 530348 concentrations in human plasma was validated using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The method utilized semi-automated 96-well protein precipitation with gradient chromatography using an ACQUITY™ UPLC BEH C18 (2.1 mm×50 mm, 1.7 µm) column. The retention time of SCH 530348 was approximately 1.5 min. This method was validated for routine quantitation of SCH 530348 over the concentration range of 1.00-1000 ng/mL. Inter-run accuracy based on mean percent theoretical for replicate quality control samples was better than 95.2%. Inter-run precision based on percent relative deviation for replicate quality control samples was ≤3.3%. SCH 530348 quality control samples were stable in human plasma for up to three freeze/thaw cycles, for at least 467 days when frozen at -20 °C and for at least 7 h when stored at room temperature. The lower limit of quantitation was 1.00 ng/mL for a 100 µL plasma aliquot.


Assuntos
Cromatografia Líquida/métodos , Lactonas/sangue , Piridinas/sangue , Receptores de Trombina/antagonistas & inibidores , Espectrometria de Massas em Tandem/métodos , Algoritmos , Humanos , Limite de Detecção , Padrões de Referência , Reprodutibilidade dos Testes
8.
J Pharm Biomed Anal ; 54(1): 179-85, 2011 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-20837385

RESUMO

A rugged and reproducible liquid chromatographic tandem mass spectrometric bioanalytical method was developed for the quantitation of drug stereoisomers in human plasma. Column temperature was shown to be an important variable toward optimizing diastereomer selectivity, resolution and analysis cycle time. Non-linear Van't Hoff plots and changes in peak shape with temperature suggested that selectivity was governed by multiple retention mechanisms. The high temperature chromatography method was validated and used to analyze samples from human clinical trials. Utilization of high temperature chromatography offered alternative selectivity and is a viable approach for difficult separations in regulated bioanalysis.


Assuntos
Técnicas de Química Analítica , Cromatografia Líquida/métodos , Dipeptídeos/análise , Sulfonas/análise , Espectrometria de Massas em Tandem/métodos , Química Farmacêutica/métodos , Cromatografia/métodos , Cromatografia Líquida de Alta Pressão/métodos , Ciclopropanos , Dipeptídeos/química , Humanos , Leucina/análogos & derivados , Prolina/análogos & derivados , Reprodutibilidade dos Testes , Estereoisomerismo , Sulfonas/química , Temperatura , Fatores de Tempo , Ureia
10.
J Appl Physiol (1985) ; 108(4): 933-40, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20133431

RESUMO

Obesity increases the incidence of cardiac arrhythmias and impairs wound healing. However, it is presently unknown whether a high-fat diet affects arrhythmic risk or wound healing before the onset of overt obesity or hyperlipidemia. After 8 wk of feeding a high-fat diet to adult female rats, a nonsignificant increase in body weight was observed and associated with a normal plasma lipid profile. Following ischemia/reperfusion injury, scar length (standard diet 0.29 +/- 0.09 vs. high-fat 0.32 +/- 0.13 cm), thickness (standard diet 0.047 +/- 0.02 vs. high-fat 0.059 +/- 0.01 cm), and collagen alpha(1) type 1 content (standard diet 0.21 +/- 0.04 vs. high-fat 0.20 +/- 0.04 arbitrary units/mm(2)) of infarcted hearts were not altered by the high-fat diet. However, the mortality rate was greatly increased 24 h postinfarction (from 5% to 46%, P < 0.01 for ischemia/reperfusion rats; from 20% to 89%, P < 0.0001, in complete-occlusion rats) in high-fat fed rats, in association with a higher prevalence of ventricular arrhythmias. Ventricular arrhythmia inducibility was also significantly increased in noninfarcted rats fed a high-fat diet. In the hearts of rats fed a high-fat diet, connexin-40 expression was absent, connexin-43 was hypophosphorylated and lateralized, and neurofilament-M immunoreactive fiber density (standard diet 2,020 +/- 260 vs. high-fat diet 2,830 +/- 250 microm(2)/mm(2)) and tyrosine hydroxylase protein expression were increased (P < 0.05). Thus, in the absence of overt obesity and hyperlipidemia, sympathetic hyperinnervation and an aberrant pattern of gap junctional protein expression and regulation in the heart of female rats fed a high-fat diet may have contributed in part to the higher incidence of inducible cardiac arrhythmias.


Assuntos
Gorduras na Dieta/administração & dosagem , Hiperlipidemias/complicações , Obesidade/complicações , Sistema Nervoso Simpático/efeitos dos fármacos , Taquicardia Ventricular/induzido quimicamente , Disfunção Ventricular Esquerda/induzido quimicamente , Animais , Peso Corporal/efeitos dos fármacos , Conexinas/efeitos dos fármacos , Conexinas/metabolismo , Feminino , Coração/efeitos dos fármacos , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/metabolismo , Ventrículos do Coração/patologia , Hemodinâmica , Hiperlipidemias/fisiopatologia , Lipídeos/sangue , Longevidade/efeitos dos fármacos , Obesidade/fisiopatologia , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/fisiopatologia , Sistema Nervoso Simpático/fisiopatologia , Taquicardia Ventricular/fisiopatologia , Disfunção Ventricular Esquerda/fisiopatologia , Remodelação Ventricular/efeitos dos fármacos , Remodelação Ventricular/fisiologia , Cicatrização/efeitos dos fármacos
11.
Atmos Environ (1994) ; 44(16)2010 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24339727

RESUMO

Using proton transfer reaction mass spectrometry equipped with a quadrupol mass analyser to quantify the biosphere-atmosphere exchange of volatile organic compounds (VOC), concentrations of different VOC are measured sequentially. Depending on how many VOC species are targeted and their respective integration times, each VOC is measured at repeat rates on the order of a few seconds. This represents an order of magnitude longer sample interval compared to the standard eddy covariance (EC) method (5-20 Hz sampling rates). Here we simulate the effect of disjunct sampling on EC flux estimates by decreasing the time resolution of CO2 and H2O concentrations measured at 20 Hz above a temperate mountain grassland in the Austrian Alps. Fluxes for one month are calculated with the standard EC method and compared to fluxes calculated based on the disjunct data (1, 3 and 5 s sampling rates) using the following approaches: i) imputation of missing concentrations based on the nearest neighbouring samples (iDECnn), ii) imputation by linear interpolation (iDECli), and iii) virtual disjunct EC (vDEC), i.e. flux calculation based solely on the disjunct concentrations. It is shown that the two imputation methods result in additional low-pass filtering, longer lag times (as determined with the maximum cross-correlation method) and a flux loss of 3-30 % as compared to the standard EC method. A novel procedure, based on a transfer function approach, which specifically corrects for the effect of data treatment, was developed, resulting in improved correspondence (to within 2 %). The vDEC method yields fluxes which approximate the true (20 Hz) fluxes to within 3-7 % and it is this approach we recommend because it involves no additional empirical corrections. The only drawback of the vDEC method is the noisy nature of the cross-correlations, which poses problems with lag determination - practical approaches to overcome this limitation are discussed.

12.
J Appl Physiol (1985) ; 107(4): 1241-8, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19679743

RESUMO

Nestin+ cardiac myocyte-like cells were detected in the peri-infarct/infarct region of the ischemically damaged heart. The present study was undertaken to elucidate the phenotype and potential origin of nestin+ cardiac myocyte-like cells and identify stimuli implicated in their appearance. In the infarcted human and rat heart, nestin+ cardiac myocyte-like cells were morphologically and structurally immature, exhibited a desmin-immunoreactive striated phenotype, expressed the beta(1)-adrenergic receptor, and associated with an aberrant pattern of connexin-43 expression and/or organization. Nestin+ cardiac myocyte-like cells were detected 24 h postischemic injury and persisted in the infarcted rat heart for 9 mo. In the normal rat heart, cardiac progenitor transcriptional factors Nkx2.5/GATA4 were detected in a subpopulation of nestin+ neural stem cells. Following an ischemic insult, nestin+/Nkx2.5+ neural stem cells migrated to the peri-infarct/infarct region and appeared to be in a primordial state of differentiation to a nestin+ cardiac myocyte-like cell. The exposure of adult male rats to normobaric hypoxia (12% O2) for 10 days failed to promote the appearance of nestin+ cardiac myocyte-like cells. Following osmotic pump delivery of isoproterenol to normal adult rats, nestin+ cardiac myocyte-like cells were detected, albeit the response was modest and secondary to tissue loss. Thus ischemia-induced appearance of nestin+ cardiac myocyte-like cells apparently represents an adaptive response to heal the infarcted heart. Nkx2.5/GATA4 expression in a subpopulation of resident neural stem cells provides the appropriate phenotype for their potential differentiation to a nestin+ cardiac myocyte-like cell.


Assuntos
Proteínas de Filamentos Intermediários/metabolismo , Infarto do Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Células-Tronco/metabolismo , Agonistas Adrenérgicos beta/administração & dosagem , Animais , Diferenciação Celular , Movimento Celular , Conexina 43/metabolismo , Modelos Animais de Doenças , Fator de Transcrição GATA4/metabolismo , Proteína Homeobox Nkx-2.5 , Proteínas de Homeodomínio/metabolismo , Humanos , Hipóxia/metabolismo , Hipóxia/patologia , Infusões Subcutâneas , Isoproterenol/administração & dosagem , Masculino , Infarto do Miocárdio/patologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , Nestina , Neurônios/efeitos dos fármacos , Neurônios/patologia , Fenótipo , Ratos , Ratos Sprague-Dawley , Receptores Adrenérgicos beta 1/metabolismo , Células-Tronco/efeitos dos fármacos , Células-Tronco/patologia , Sistema Nervoso Simpático/metabolismo , Fatores de Tempo , Fatores de Transcrição/metabolismo
13.
Can J Physiol Pharmacol ; 87(6): 460-70, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19526041

RESUMO

Rapamycin represents a recognized drug-based therapeutic approach to treat cardiovascular disease. However, at least in the female heart, rapamycin may suppress the recruitment of putative signalling events conferring cardioprotection. The present study tested the hypothesis that rapamycin-sensitive signalling events contributed to the cardioprotective phenotype of the female rat heart after an ischemic insult. Rapamycin (1.5 mg/kg) was administered to adult female Sprague-Dawley rats 24 h after complete coronary artery ligation and continued for 6 days. Rapamycin abrogated p70S6K phosphorylation in the left ventricle of sham rats and the noninfarcted left ventricle (NILV) of 1-week postmyocardial-infarcted (MI) rats. Scar weight (MI 0.028 +/- 0.006, MI+rapamycin 0.064 +/- 0.004 g) and surface area (MI 0.37 +/- 0.08, MI+rapamycin 0.74 +/- 0.03 cm2) were significantly larger in rapamycin-treated post-MI rats. In the NILV of post-MI female rats, rapamycin inhibited the upregulation of eNOS. Furthermore, the increased expression of collagen and TGF-beta3 mRNAs in the NILV were attenuated in rapamycin-treated post-MI rats, whereas scar healing was unaffected. The present study has demonstrated that rapamycin-sensitive signalling events were implicated in scar formation and reactive fibrosis. Rapamycin-mediated suppression of eNOS and TGF-beta3 mRNA in post-MI female rats may have directly contributed to the larger infarct and attenuation of the reactive fibrotic response, respectively.


Assuntos
Cicatriz/patologia , Infarto do Miocárdio/patologia , Miocárdio/patologia , Sirolimo/farmacologia , Remodelação Ventricular/efeitos dos fármacos , Animais , Western Blotting , Cicatriz/prevenção & controle , Colágeno/biossíntese , Modelos Animais de Doenças , Feminino , Fibrose , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/enzimologia , Ventrículos do Coração/metabolismo , Ventrículos do Coração/patologia , Infarto do Miocárdio/enzimologia , Infarto do Miocárdio/prevenção & controle , Miocárdio/enzimologia , Miocárdio/metabolismo , Óxido Nítrico Sintase Tipo III/antagonistas & inibidores , Fosforilação , Ratos , Ratos Sprague-Dawley , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Sirolimo/administração & dosagem , Sirolimo/efeitos adversos , Sirolimo/uso terapêutico , Fator de Crescimento Transformador beta3/biossíntese
14.
J Pharm Biomed Anal ; 50(1): 46-52, 2009 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-19442473

RESUMO

A rapid and robust liquid chromatographic tandem mass spectrometric (LC-MS/MS) method for the determination of posaconazole concentrations in human plasma was validated. Posaconazole was extracted from human plasma using mixed-mode cation exchange solid phase extraction in a 96-well plate format followed by gradient separation on a fused-core Halo C18 column. The analyte and its corresponding internal standard were detected using a Sciex API 4000 triple quadrupole LC-MS/MS system equipped with a TurboIonSpray ionization source operated in the positive ion mode. The calibration range of the method was 5.00-5000ng/mL using a 50microL aliquot of plasma. The assay inter-run accuracy and precision were-4.6-2.8% and 2.3-8.7%, respectively (n=18). The results from method validation indicate the method to be sensitive, selective, accurate, and reproducible. The method was successfully applied to the routine analysis of clinical samples with the fused-core silica columns providing excellent reproducibility for greater than 1000 injections per column.


Assuntos
Antifúngicos/sangue , Cromatografia Líquida/métodos , Espectrometria de Massas em Tandem/métodos , Triazóis/sangue , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
15.
J Cell Physiol ; 220(2): 440-9, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19388005

RESUMO

Neural stem cells were identified in the rat heart and during scar formation and healing participated in sympathetic fiber sprouting and angiogenesis. In the setting of diabetes, impaired wound healing represents a typical pathological feature. These findings provided the impetus to test the hypothesis that experimental diabetes adversely influenced the phenotype of cardiac neural stem cells. Streptozotocin (STZ)-induced diabetic rats were associated with elevated plasma glucose levels, significant loss of body weight and left ventricular contractile dysfunction. In the heart of STZ-diabetic rats, the density of nestin immunoreactive processes emanating from cardiac neural stem cells were reduced. The latter finding was reaffirmed as nestin protein expression was significantly decreased in the heart of STZ-diabetic rats and associated with a concomitant reduction of nestin mRNA. Employing the TUNEL assay, the loss of nestin expression in STZ-diabetic rats was not attributed to widespread cardiac neural stem cell apoptosis. Insulin administration to STZ-diabetic rats with established hyperglycaemia led to a modest recovery of nestin protein expression in cardiac neural stem cells. By contrast, the administration of insulin immediately after STZ injection improved plasma glucose levels and significantly attenuated the loss of nestin protein expression. These data highlight the novel observation that nestin protein expression in cardiac neural stem cells was significantly reduced in STZ-induced type I diabetic rats. The aberrant cardiac neural stem cell phenotype may compromise their biological role and predispose the diabetic heart to maladaptive healing following ischemic injury.


Assuntos
Cardiomiopatias , Diabetes Mellitus Experimental , Miocárdio/citologia , Neurônios/citologia , Fenótipo , Células-Tronco/fisiologia , Animais , Apoptose/fisiologia , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Peso Corporal , Cardiomiopatias/etiologia , Cardiomiopatias/patologia , Dexametasona/farmacologia , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/patologia , Glucocorticoides/farmacologia , Humanos , Insulina/metabolismo , Proteínas de Filamentos Intermediários/genética , Proteínas de Filamentos Intermediários/metabolismo , Masculino , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Nestina , Neurônios/fisiologia , Tamanho do Órgão , Ratos , Ratos Sprague-Dawley , Ratos Zucker , Células-Tronco/citologia , Função Ventricular Esquerda/fisiologia , Remodelação Ventricular
16.
J Mol Cell Cardiol ; 45(5): 694-702, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18718475

RESUMO

Nestin-expressing cells were identified in the normal rat heart characterized by a small cell body and numerous processes and following an ischemic insult migrated to the infarct region. The present study was undertaken to identify the phenotype, origin and biological role of nestin-expressing cells during reparative fibrosis. A neural stem cell phenotype was identified based on musashi-1 expression, growth as a neurosphere, and differentiation to a neuronal cell. Using the Wnt1-cre; Z/EG transgenic mouse model, which expresses EGFP in embryologically-derived neural crest cells, the reporter signal was detected in nestin-expressing cells residing in the heart. In infarcted human hearts, nestin-expressing cells were detected in the viable myocardium and the scar and morphologically analogous to the population identified in the rat heart. Following either an ischemic insult or the acute administration of 6-hydroxydopamine, sympathetic sprouting was dependent on the physical association of neurofilament-M immunoreactive fibres with nestin-positive processes emanating from neural stem cells. To specifically study the biological role of the subpopulation in the infarct region, neural stem cells were isolated from the scar, fluorescently labelled and transplanted in the heart of 3-day post-MI rats. Injected scar-derived neural stem cells migrated to the infarct region and were used as a substrate for de novo blood vessel formation. These data have demonstrated that the heart contains a resident population of neural stem cells derived from the neural crest and participate in reparative fibrosis. Their manipulation could provide an alternative approach to ameliorate the healing process following ischemic injury.


Assuntos
Coração/fisiologia , Neovascularização Fisiológica , Animais , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Miocárdio/metabolismo , Crista Neural/metabolismo , Proteínas de Neurofilamentos/metabolismo , Neurônios/metabolismo , Oxidopamina/farmacologia , Ratos , Ratos Sprague-Dawley , Células-Tronco/metabolismo
17.
J Pharmacol Exp Ther ; 325(3): 961-8, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18356487

RESUMO

It remains presently unknown whether vascular reactivity is impaired and whether maladaptive cardiac remodeling occurs before the onset of overt obesity and in the absence of hyperlipidemia. Normal female rats were fed a high-fat diet for 8 weeks and were associated with a modest nonsignificant increase of body weight (standard diet, 300 +/- 10, versus high-fat diet, 329 +/- 14 g) and a normal plasma lipid profile. In rats fed a high-fat diet, systolic (171 +/- 7 mm Hg) and diastolic blood pressures (109 +/- 3) were increased compared to a standard diet (systolic blood pressure, 134 +/- 8; diastolic blood pressure, 96 +/- 5 mm Hg), and acetylcholine-dependent relaxation of isolated aortic rings (high-fat diet, 22 +/- 5%, versus standard diet, 53 +/- 8%) was significantly reduced. Furthermore, perivascular fibrosis was detected in the heart of rats fed a high-fat diet. The exogenous addition of resveratrol (trans-3,5,4'-trihydroxystilbene) (0.1 microM) to aortic rings isolated from rats fed a high-fat diet restored acetylcholine-mediated relaxation (47 +/- 9%). The administration of resveratrol (20 mg/kg/day for 8 weeks) to rats fed a high-fat diet prevented the increase in blood pressure and preserved acetylcholine-dependent relaxation of isolated aortic rings. However, resveratrol therapy failed to attenuate the perivascular fibrotic response. These data have demonstrated that a high-fat diet fed to normal female rats can elicit a hypertensive response and induce perivascular fibrosis before the development of overt obesity and in the absence of hyperlipidemia. Resveratrol therapy can prevent the hypertensive response in female rats fed a high-fat diet but is without effect on the progression of perivascular fibrosis.


Assuntos
Antioxidantes/uso terapêutico , Gorduras na Dieta/administração & dosagem , Fibrose/fisiopatologia , Estilbenos/uso terapêutico , Disfunção Ventricular Esquerda/tratamento farmacológico , Acetilcolina/farmacologia , Animais , Aorta/efeitos dos fármacos , Aorta/fisiologia , Pressão Sanguínea , Feminino , Fibrose/patologia , Hiperlipidemias , Miocárdio/patologia , Nitroprussiato/farmacologia , Obesidade , Ratos , Ratos Sprague-Dawley , Resveratrol , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologia , Disfunção Ventricular Esquerda/patologia , Disfunção Ventricular Esquerda/fisiopatologia
18.
J Sep Sci ; 31(2): 242-54, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18246589

RESUMO

A LC-MS/MS method using a LC column packed with sub-2 micron particles and elevated column temperatures was validated for the quantitation of SCH 503034 diastereomers (SCH 534128 and SCH 534129) in human plasma. The method was validated over the concentration range of 2.5 to 1250 ng/mL. Inter-assay precision, based on percent relative deviation for n = 18 replicate quality controls, was 4.5% for SCH 534128 and 4.9% for SCH 534129. Inter-assay accuracy based on n = 18 replicate quality controls was +/- 7.8% for both SCH 534128 and SCH 534129. The method involved the novel application of ion pairing reagents to increase the stereoselectivity of the separation. Temperature, types of ion pairing reagent, and concentration of ion pairing reagent were all found to play significant roles in the resolution of the SCH 534128 and SCH 534129 diastereomers on a LC column packed with sub-2 micron particles. Specifically, a sensitivity increase of five-fold was demonstrated by increasing the column temperature. Without sacrificing resolution, the run time was significantly shortened when the column temperature was elevated to 100 degrees C.


Assuntos
Cromatografia Líquida/métodos , Inibidores de Serina Proteinase/análise , Espectrometria de Massas em Tandem/métodos , Concentração de Íons de Hidrogênio , Indicadores e Reagentes , Padrões de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Estereoisomerismo , Temperatura
19.
J Appl Physiol (1985) ; 104(1): 150-6, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17916672

RESUMO

Sympathetic fiber innervation of the damaged region following injury represents a conserved event of wound healing. The present study tested the hypothesis that impaired scar healing in post-myocardial infarction (post-MI) rats was associated with a reduction of sympathetic fibers innervating the infarct region. In 1-wk post-MI rats, neurofilament-M-immunoreactive fibers (1,116 +/- 250 microm(2)/mm(2)) were detected innervating the infarct region and observed in close proximity to a modest number of endothelial nitric oxide synthase-immunoreactive scar-residing vessels. Dexamethasone (Dex) treatment (6 days) of post-MI rats led to a significant reduction of scar weight (Dex + MI 38 +/- 4 mg vs. MI 63 +/- 2 mg) and a disproportionate nonsignificant decrease of scar surface area (Dex + MI 0.54 +/- 0.06 cm(2) vs. MI 0.68 +/- 0.06 cm(2)). In Dex-treated post-MI rats, the density of neurofilament-M-immunoreactive fibers (125 +/- 47 microm(2)/mm(2)) innervating the infarct region was significantly reduced and associated with a decreased expression of nerve growth factor (NGF) mRNA (Dex + MI 0.80 +/- 0.07 vs. MI 1.11 +/- 0.08; P < 0.05 vs. MI). Previous studies have demonstrated that scar myofibroblasts synthesize NGF and may represent a cellular target of Dex. The exposure of 1st passage scar myofibroblasts to Dex led to a dose-dependent suppression of [(3)H]thymidine uptake and a concomitant attenuation of NGF mRNA expression (untreated 3.47 +/- 0.35 vs. Dex treated 2.28 +/- 0.40; P < 0.05 vs. untreated). Thus the present study has demonstrated that impaired scar healing in Dex-treated post-MI rats was associated with a reduction of neurofilament-M-immunoreactive fibers innervating the infarct region. The attenuation of scar myofibroblast proliferation and NGF mRNA expression may represent underlying mechanisms contributing to the diminished neural response in the infarct region of Dex-treated post-MI rats.


Assuntos
Corticosteroides/farmacologia , Dexametasona/farmacologia , Coração/efeitos dos fármacos , Infarto do Miocárdio/fisiopatologia , Miocárdio/patologia , Sistema Nervoso Simpático/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Corticosteroides/efeitos adversos , Animais , Proliferação de Células/efeitos dos fármacos , Dexametasona/efeitos adversos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Proteína GAP-43/metabolismo , Coração/inervação , Coração/fisiopatologia , Masculino , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Miocárdio/metabolismo , Fator de Crescimento Neural/metabolismo , Proteínas de Neurofilamentos/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Óxido Nítrico Sintase Tipo III , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Sistema Nervoso Simpático/metabolismo , Sistema Nervoso Simpático/fisiopatologia , Fatores de Tempo , Função Ventricular Esquerda/efeitos dos fármacos , Remodelação Ventricular/efeitos dos fármacos
20.
J Pharmacol Exp Ther ; 323(3): 916-23, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17875610

RESUMO

Resveratrol (RES; trans-3,5,4'-trihydroxystilbene) has been shown to improve health and slow the progression of disease in various models. Several cardioprotective mechanisms have been identified including antioxidant, anti-inflammatory, and antifibrotic actions. Each of these actions is thought to have the ability to attenuate the pathophysiology underlying the deleterious cardiac structural remodeling that results from acute myocardial infarction (MI). Therefore, we evaluated the effect of resveratrol treatment on the progression of cardiac remodeling after MI. Four groups of rats (sham, n = 6; sham + RES, n = 21; MI, n = 26; MI + RES, n = 24) were treated for 13 weeks, starting 7 days before ligation of the left anterior descending coronary artery. Serial transthoracic echocardiography revealed that resveratrol had no effect on MI-induced left-ventricular and left-atrial dilatation or reduction in left-ventricular fractional shortening. Consistent with these findings, resveratrol did not improve the deterioration of hemodynamic function or reduce infarct size at 12 weeks post-MI. Resveratrol-treated animals did, however, show preserved cardiac contractile reserve in response to dobutamine administration. Radioligand binding revealed that MI reduced beta-adrenergic receptor density. Resveratrol administration increased beta-adrenoceptor density, so that resveratrol-treated MI rats had beta-adrenoceptor densities similar to normal rats. Real-time reverse transcription-polymerase chain reaction revealed that MI-induced changes in sarcoplasmic reticulum Ca2+-ATPase 2 and transforming growth factor beta-1 expression were unaltered by resveratrol, whereas MI-induced increases in atrial natriuretic factor (ANF) and connective tissue growth factor (CTGF) expression were attenuated. Resveratrol treatment does not improve cardiac remodeling and global hemodynamic function post-MI but does preserve contractile reserve and attenuate ANF and CTGF up-regulation.


Assuntos
Cardiotônicos/uso terapêutico , Infarto do Miocárdio/tratamento farmacológico , Estilbenos/uso terapêutico , Remodelação Ventricular/efeitos dos fármacos , Animais , Cardiotônicos/administração & dosagem , Cardiotônicos/farmacologia , Ecocardiografia , Hemodinâmica/efeitos dos fármacos , Masculino , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/fisiopatologia , Ensaio Radioligante , Ratos , Ratos Sprague-Dawley , Receptores Adrenérgicos beta/metabolismo , Resveratrol , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estilbenos/administração & dosagem , Estilbenos/farmacologia
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