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1.
mBio ; 12(2)2021 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-33906927

RESUMO

SARS-CoV-2 infection causing the COVID-19 pandemic calls for immediate interventions to avoid viral transmission, disease progression, and subsequent excessive inflammation and tissue destruction. Primary normal human bronchial epithelial cells are among the first targets of SARS-CoV-2 infection. Here, we show that ColdZyme medical device mouth spray efficiently protected against virus entry, excessive inflammation, and tissue damage. Applying ColdZyme to fully differentiated, polarized human epithelium cultured at an air-liquid interphase (ALI) completely blocked binding of SARS-CoV-2 and increased local complement activation mediated by the virus as well as productive infection of the tissue model. While SARS-CoV-2 infection resulted in exaggerated intracellular complement activation immediately following infection and a drop in transepithelial resistance, these parameters were bypassed by single pretreatment of the tissues with ColdZyme mouth spray. Crucially, our study highlights the importance of testing already evaluated and safe drugs such as ColdZyme mouth spray for maintaining epithelial integrity and hindering SARS-CoV-2 entry within standardized three-dimensional (3D) in vitro models mimicking the in vivo human airway epithelium.IMPORTANCE Although our understanding of COVID-19 continuously progresses, essential questions regarding prophylaxis and treatment remain open. A hallmark of severe SARS-CoV-2 infection is a hitherto-undescribed mechanism leading to excessive inflammation and tissue destruction associated with enhanced pathogenicity and mortality. To tackle the problem at the source, transfer of SARS-CoV-2, subsequent binding, infection, and inflammatory responses have to be avoided. In this study, we used fully differentiated, mucus-producing, and ciliated human airway epithelial cultures to test the efficacy of ColdZyme medical device mouth spray in terms of protection from SARS-CoV-2 infection. Importantly, we found that pretreatment of the in vitro airway cultures using ColdZyme mouth spray resulted in significantly shielding the epithelial integrity, hindering virus binding and infection, and blocking excessive intrinsic complement activation within the airway cultures. Our in vitro data suggest that ColdZyme mouth spray may have an impact in prevention of COVID-19.


Assuntos
Antivirais/farmacologia , Mucosa Respiratória/efeitos dos fármacos , SARS-CoV-2/efeitos dos fármacos , Brônquios/citologia , COVID-19/prevenção & controle , COVID-19/virologia , Complemento C3/imunologia , Células Epiteliais , Humanos , Imunidade Inata/efeitos dos fármacos , Mucosa Nasal/efeitos dos fármacos , Mucosa Nasal/imunologia , Mucosa Nasal/virologia , Sprays Orais , Mucosa Respiratória/imunologia , Mucosa Respiratória/virologia , SARS-CoV-2/fisiologia , Ligação Viral/efeitos dos fármacos
2.
Int J Infect Dis ; 81: 210-214, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30794940

RESUMO

Dalbavancin, a lipoglycopeptide with prolonged half-life approved for the treatment of acute bacterial skin and soft tissue infections, can be used for the treatment of infections caused by gram-positive bacteria requiring long term treatment such as endocarditis, prosthetic joint infections (PJI) or osteomyelitis. Clinical data are limited in these settings. OBJECTIVES: To evaluate indications, safety, tolerability and long-term outcomes of dalbavancin-treated patients. Patients and methods Our multicenter, retrospective study includes patients who received dalbavancin in Austria from September 2016 to March 2018. 90-day outcomes and tolerability were determined. RESULTS: A total of 101 patients were included in 3 centers (57% male, median age 65 years). The treated infections were PJI (31%), osteomyelitis (29%), endocarditis (25%) and acute bacterial skin and soft tissue infections (12%). Concomitant use of other antimicrobial substances was common (63%). The mean total cumulative dose of dalbavancin was 3,357mg (±2,283mg). Clinical success rate was 89%. Side effects occurred in 3/101 patients. CONCLUSION: In this real-life study dalbavancin was primarily used in off-label indications for treatment of PJI, osteomyelitis and endocarditis. Success rate was high (89%), tolerability and safety were excellent in this setting. Dalbavancin may therefore be used in these off-label indications as alternative treatment approach.


Assuntos
Antibacterianos/administração & dosagem , Bactérias Gram-Positivas/efeitos dos fármacos , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Teicoplanina/análogos & derivados , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/efeitos adversos , Antibacterianos/uso terapêutico , Áustria , Criança , Feminino , Bactérias Gram-Positivas/genética , Bactérias Gram-Positivas/isolamento & purificação , Bactérias Gram-Positivas/fisiologia , Infecções por Bactérias Gram-Positivas/microbiologia , Humanos , Masculino , Pessoa de Meia-Idade , Osteomielite/microbiologia , Estudos Retrospectivos , Infecções dos Tecidos Moles/tratamento farmacológico , Infecções dos Tecidos Moles/microbiologia , Teicoplanina/administração & dosagem , Teicoplanina/efeitos adversos , Adulto Jovem
3.
Neuroscience ; 388: 191-202, 2018 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-30048782

RESUMO

Retinal horizontal cells (HCs) are inhibitory neurons, which modulate the transmission of light-elicited signals from photoreceptors to bipolar cells in the outer retina. HCs of the same physiological type are extensively coupled via gap junctions. In the zebrafish retina, the population of HCs comprises up to four morphologically distinct subtypes. Four different connexins (Cx52.6, Cx52.7, Cx52.9 and Cx55.5) were detected in these cells with overlapping expression patterns. In this study, we show that Cx52.6 is alternatively spliced in the retina, resulting in an additional isoform, designated as Cx53.4, which differs from the originally described Cx52.6 only by the final C-terminal peptide (12 vs. 4 aa). Further protein sequence alignments revealed that Cx53.4 represents the counterpart of alternatively spliced mouse Cx57 and human Cx62. RT-PCR analyses of mRNA expression in different adult zebrafish tissues showed that Cx53.4 is expressed exclusively in the retina. The localization of Cx53.4 protein within the retina was analyzed using a specific antibody. Immunofluorescence analyses demonstrated that the expression of Cx53.4 is restricted to HCs of all four subtypes. Further, immunoelectron microscopy confirmed the presence of Cx53.4 in gap junctions between HC dendrites and between their axon terminals.


Assuntos
Conexinas/metabolismo , Células Horizontais da Retina/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/metabolismo , Processamento Alternativo , Animais , Animais Geneticamente Modificados , Axônios/metabolismo , Células Cultivadas , Conexinas/genética , Dendritos/metabolismo , Junções Comunicantes/metabolismo , Isoformas de Proteínas/metabolismo , RNA Mensageiro/metabolismo , Células Horizontais da Retina/citologia , Alinhamento de Sequência , Peixe-Zebra/anatomia & histologia , Proteínas de Peixe-Zebra/genética
4.
AJR Am J Roentgenol ; 210(6): 1323-1329, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29702022

RESUMO

OBJECTIVE: The purpose of this study was to compare findings of ultrasound (US) with dual-energy CT (DECT) findings in patients presenting with suspected gouty knee arthritis. SUBJECTS AND METHODS: This prospective study included 65 patients (52 men and 13 women; median age, 61.7 years [range, 38-87 years]) with an initial clinical diagnosis of acute gouty knee arthritis who underwent DECT performed using a 128-MDCT scanner and US performed using a 5-18-MHz transducer. Both intra- and extraarticular findings obtained using each modality were tabulated. RESULTS: DECT identified gout as the final diagnosis for 52 of 65 patients (80.0%). An alternative diagnosis was confirmed for the remaining 13 patients. US detected gout in 31 of 52 patients (sensitivity, 59.6%) and produced findings negative for gout in seven of 13 patients (specificity, 53.8%). The double contour sign on US was positive for gout in 23 of 52 patients (44.2%) and negative in 12 of 13 patients (92.3%). Extraarticular urate deposition was identified by DECT in 44 of 52 patients, compared with identification by US in 11 of 52 patients (p < 0.001). CONCLUSION: The sensitivity of US for the diagnosis of gouty knee arthritis is limited, particularly with respect to extraarticular urate deposition. The double contour sign is the single most valuable sign for the assessment of gouty knee arthritis by US.


Assuntos
Artrite Gotosa/diagnóstico por imagem , Articulação do Joelho/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Ultrassonografia/métodos , Doença Aguda , Adulto , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Feminino , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sensibilidade e Especificidade
5.
Neuroscience ; 340: 8-22, 2017 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-27793781

RESUMO

In the vertebrate retina, horizontal cells (HCs) reveal homologous coupling by gap junctions (gj), which are thought to consist of different connexins (Cx). However, recent studies in mouse, rabbit and zebrafish retina indicate that individual HCs express more than one connexin. To provide further insights into the composition of gj connecting HCs and to determine whether HCs express multiple connexins, we examined the molecular identity and distribution of gj between HCs of the carp retina. We have cloned four carp connexins designated Cx49.5, Cx55.5, Cx52.6 and Cx53.8 with a close relationship to connexins previously reported in HCs of mouse, rabbit and zebrafish, respectively. Using in situ hybridization, Cx49.5 expression was detected in different subpopulations of retinal neurons including HCs, whereas the Cx52.6 transcript was localized exclusively in HCs. Using specific antibodies, Cx55.5 and Cx53.8 were detected on dendrites of all four HC subtypes and axon terminals. Immunoelectron microscopy confirmed the presence of Cx55.5 and Cx53.8 in gap junctions between these processes and Cx55.5 was additionally observed in HC dendrites invaginating cone pedicles, suggesting its participation in the modulation of photoreceptor output in the carp retina. Furthermore, using single-cell RT-PCR, all four connexins were detected in different subtypes of HCs, suggesting overlapping expression patterns. Thus, the composition of gj mediating homologous coupling between subtypes of carp HCs appears to be more complex than expected. Moreover, BLAST searches of the preliminary carp genome, using novel sequences as query, suggest that most of the analyzed connexin genes are duplicated in carp.


Assuntos
Carpas/anatomia & histologia , Carpas/metabolismo , Junções Comunicantes/metabolismo , Células Horizontais da Retina/citologia , Células Horizontais da Retina/metabolismo , Sequência de Aminoácidos , Animais , Axônios/metabolismo , Western Blotting , Linhagem Celular Tumoral , Conexinas/metabolismo , Dendritos/metabolismo , Proteínas de Peixes/metabolismo , Imuno-Histoquímica , Hibridização In Situ , Camundongos , Microscopia Imunoeletrônica , Reação em Cadeia da Polimerase , Isoformas de Proteínas , Alinhamento de Sequência
6.
BMJ Open Sport Exerc Med ; 1(1): e000026, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-27900124

RESUMO

BACKGROUND/AIMS: Surface electromyography (sEMG) is a commonly used technique to investigate muscle activation and fatigue, which is non-invasive and can allow for continuous measurement. Systematic research on the use of sEMG in the sporting environment has been on-going for many years and predominantly based on cycling and rowing activities. To date there have been no reviews assessing the validity and reliability in sEMG exclusively in running activities specifically during on-field testing. The purpose of this review is to evaluate the use of sEMG in the practical context and whether this be translated to on-field testing. METHODS: Electronic literature searches were performed using the Cochrane Library, PUBMED, CINAHL and PeDro without restrictions on the study date to identify the relevant current English language literature. RESULTS: 10 studies were relevant after title and content review. All the studies identified were all level three evidence based. The general trends of the sEMG activity appear to correlate with running velocity and muscle fatigue seems almost always the consequence of prolonged, dynamic activity. However, these changes are not consistently measured or statistically significant throughout the studies raising the question of the accuracy and reliability when analysing sEMG measurements and making assumptions about the cause of fatigue. CONCLUSIONS: An agreed consensus when measuring and analysing sEMG data during running activities particularly in field testing with the most appropriate study design and reliable methodology is yet to be determined and further studies are required.

7.
Occup Med (Lond) ; 64(8): 580-2, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25149118

RESUMO

BACKGROUND: Little is known about rates of alcohol consumption in career firefighters. AIMS: To assess the quantity and frequency of alcohol consumption among career firefighters and the covariates that influence consumption levels. METHODS: A convenience sample of career firefighters completed an online, self-administered, health assessment survey. Hierarchical binary logistic regression assessed the ability of several covariates to predict binge drinking status. RESULTS: The majority of the sample (n = 160) consumed alcohol (89%), with approximately one-third (34%) having a drinking binge in the past 30 days. The regression model explained 13-18% of the variance in binge drinking status and correctly classified 71% of cases. Race (P < 0.05) and time of service (P < 0.01) were the only covariates that made a statistically significant contribution to the model. After controlling for other factors in the model, white respondents were ~4.5 times more likely to binge drink than non-white respondents (95% CI: 1.15-17.4). For each additional year of service, firefighters were 1.08 times less likely to binge drink (95% CI: 0.87-0.97). CONCLUSIONS: Drinking levels observed in this study exceed those of the general adult population, including college students. Thus, it appears that firefighters represent an at-risk drinking group. Further investigations addressing reasons for alcohol use and abuse among firefighters are warranted. This study and subsequent research will provide information necessary for the development and testing of tailored interventions aimed at reducing firefighter alcohol consumption.


Assuntos
Consumo de Bebidas Alcoólicas/epidemiologia , Bombeiros/estatística & dados numéricos , Adulto , Consumo de Bebidas Alcoólicas/prevenção & controle , Consumo de Bebidas Alcoólicas/psicologia , Feminino , Bombeiros/psicologia , Florida/epidemiologia , Inquéritos Epidemiológicos , Humanos , Modelos Logísticos , Masculino , Fatores de Risco , Comportamento de Redução do Risco
8.
Br J Sports Med ; 47(17): 1080-4, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24045906

RESUMO

Despite thoracic outlet syndrome (TOS) being first described early in the 19th century, the subsequent literature seems limited, focusing on case reports and investigations providing little assistance in the management of equivocal presentations. Best practice clinical management, with little evidence base, poses great challenges for clinicians in deciding how to manage TOS, when to operate and which procedure should be undertaken. Furthermore, the implications of TOS and its surgical effects are poorly documented, with little evidence in the literature as to the impact of surgical intervention on athletes and their physiology or function. This paper describes a clinical example of TOS highlighting salient issues and examining the evidence to guide clinical management at each stage, in the case of a 26-year-old professional football player who suffered an acute onset of unilateral right shoulder to bicep pain associated with tingling in the hand. Clinicians managing similar cases in the future will have a reference point to assist their diagnosis, management and promote much needed research to further our understanding of this difficult syndrome.


Assuntos
Dor de Ombro/etiologia , Síndrome do Desfiladeiro Torácico/complicações , Doença Aguda , Adulto , Analgésicos/uso terapêutico , Diagnóstico Diferencial , Diagnóstico por Imagem , Humanos , Masculino , Parestesia , Dor de Ombro/terapia , Futebol , Síndrome do Desfiladeiro Torácico/diagnóstico , Síndrome do Desfiladeiro Torácico/terapia
10.
Ultraschall Med ; 32 Suppl 2: E31-7, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21894599

RESUMO

PURPOSE: To compare joint inflammation assessment using subjective grading of power Doppler ultrasonography (PDUS) and contrast-enhanced ultrasonography (CEUS) versus computer-aided objective CEUS quantification. MATERIALS AND METHODS: 37 joints of 28 patients with arthritis of different etiologies underwent B-mode ultrasonography, PDUS, and CEUS using a second-generation contrast agent. Synovial thickness, extent of vascularized pannus and intensity of vascularization were included in a 4-point PDUS and CEUS grading system. Subjective CEUS and PDUS scores were compared to computer-aided objective CEUS quantification using Qontrast® software for the calculation of the signal intensity (SI) and the ratio of SI for contrast enhancement. RESULTS: The interobserver agreement for subjective scoring was good to excellent (κ = 0.8 - 1.0; P < 0.0001). Computer-aided objective CEUS quantification correlated statistically significantly with subjective CEUS (P < 0.001) and PDUS grading (P < 0.05). The Qontrast® SI ratio correlated with subjective CEUS (P < 0.02) and PDUS grading (P < 0.03). Clinical activity did not correlate with vascularity or synovial thickening (P = N. S.) and no correlation between synovial thickening and vascularity extent could be found, neither using PDUS nor CEUS (P = N. S.). CONCLUSION: Both subjective CEUS grading and objective CEUS quantification are valuable for assessing joint vascularity in arthritis and computer-aided CEUS quantification may be a suitable objective tool for therapy follow-up in arthritis.


Assuntos
Artrite/diagnóstico por imagem , Meios de Contraste/administração & dosagem , Diagnóstico por Computador/métodos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Articulações/irrigação sanguínea , Articulações/diagnóstico por imagem , Fosfolipídeos , Hexafluoreto de Enxofre , Ultrassonografia Doppler em Cores/métodos , Ultrassonografia Doppler/métodos , Ultrassonografia/métodos , Adulto , Idoso , Artrite Reumatoide/diagnóstico por imagem , Diagnóstico Diferencial , Feminino , Tecido de Granulação/irrigação sanguínea , Tecido de Granulação/diagnóstico por imagem , Humanos , Hipertrofia , Masculino , Pessoa de Meia-Idade , Osteoartrite/diagnóstico por imagem , Fluxo Sanguíneo Regional/fisiologia , Software , Espondilartrite/diagnóstico por imagem , Membrana Sinovial/irrigação sanguínea , Membrana Sinovial/diagnóstico por imagem , Membrana Sinovial/patologia , Gravação em Vídeo/métodos
11.
Clin Microbiol Infect ; 17(2): 235-7, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20384708

RESUMO

To evaluate the clinical reliability of two rapid influenza detection tests (RIDTs), we analyzed 107 specimens from patients with clinically suspected pandemic influenza A/H1N1v by these tests as well as by real-time PCR as a standard. Both RIDTs had a moderate sensitivity (28-32%), a high specificity (93-99%) and a negative predictive value of 80%. These results will impact on the clinical management and isolation precautions in patients with suspected infection. Although a positive RITD is mostly confirmatory, a negative result in the presence of high clinical likelihood of infection should be interpreted with caution and be re-evaluated by PCR.


Assuntos
Antígenos Virais/análise , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Humana/diagnóstico , Virologia/métodos , Áustria , Humanos , Vírus da Influenza A Subtipo H1N1/imunologia , Sistemas Automatizados de Assistência Junto ao Leito , Sensibilidade e Especificidade
12.
Biosens Bioelectron ; 26(2): 596-601, 2010 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-20688508

RESUMO

A biocompatible device for the voltage dependent uptake and release of the neural transmitter L-glutamate in neutral pH solutions is demonstrated. The device consists of a gold electrode coated with molecularly imprinted, overoxidised polypyrrole (oPPy). It is shown here that oPPy can behave as an anion exchanger in neutral pH. The voltage dependent uptake and release of glutamate from the oPPy as well as the enantioselectivity of the polymer layer for L-glutamate over D-glutamate are investigated in neutral pH solutions using electrochemical quartz crystal microbalance techniques. The biocompatibility of the oPPy layer is demonstrated using retinae from young rats. The retinae were isolated and the dissociated cells were kept in culture for up to 1-week. The cells were exposed to the oPPy layers for 3 days, and there is no significant difference in the survival rate between the cells cultured on the oPPy layers and the control samples. Additionally the cell-polymer interface from cells grown directly on the oPPy layers is investigated using electron microscopy.


Assuntos
Materiais Biocompatíveis/química , Materiais Biocompatíveis/efeitos da radiação , Eletrodos , Ácido Glutâmico/química , Sistemas Microeletromecânicos/instrumentação , Polímeros/química , Polímeros/efeitos da radiação , Pirróis/química , Pirróis/efeitos da radiação , Animais , Campos Eletromagnéticos , Concentração de Íons de Hidrogênio , Teste de Materiais , Ratos , Soluções , Propriedades de Superfície
14.
Curr Drug Metab ; 8(3): 225-36, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17430111

RESUMO

Human immunodeficiency virus type 1 (HIV) infection is characterized by progressive immunodeficiency despite of an overwhelming cellular immune activation. Patients show highly elevated serum/plasma concentrations of the proinflammatory cytokine interferon-gamma (IFN-gamma), which induces human monocytes to form neopterin, to produce reactive oxygen species (ROS) and in parallel, to degrade tryptophan. Enhanced tryptophan degradation by the enzyme indoleamine-2, 3-dioxygenase (IDO) contributes importantly to disease progression and "complications" of HIV infection: By a subsequent impairment of protein metabolism and serotonin formation, the development of neuropsychiatric disorders and weight loss in HIV infected patients can be enforced. Furthermore, increased IDO-activation efficiently suppresses the growth and proliferation of pathogens as well as host T-cells. IDO and other IFN-gamma-mediated pathways are strongly induced in patients with HIV infection and are also linked with disease progression: Neopterin formation by GTP-cyclohydrolase I sensitively reflects the stage of the disease, and determination of the pteridine in body fluids is useful to monitor the efficacy of antiretroviral therapy. Neopterin is an independent prognostic factor for the outcome of disease, and well suited to estimate the degree of immune activation in vivo and the responsiveness of immunocompetent cells to stimulation in vitro. ROS formation may contribute to the development of oxidative stress in HIV infection, resulting in depletion of antioxidants. The cause-effective role of an overwhelming Th1-type immune response together with the activation of IDO and other IFN-gamma-mediated biochemical pathways for the course of HIV infection, the development of immunodeficiency, anemia and weight loss in HIV patients is discussed.


Assuntos
Infecções por HIV/imunologia , Indolamina-Pirrol 2,3,-Dioxigenase/imunologia , Interferon gama/imunologia , Infecções por HIV/metabolismo , Humanos , Neopterina/metabolismo , Triptofano/metabolismo
15.
Int J Clin Pharmacol Ther ; 40(4): 142-9, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11996208

RESUMO

OBJECTIVES: Pharmacokinetic data on levofloxacin in critically ill patients are sparse and conflicting. Aim of the study was to assess the clearance of levofloxacin in critically ill patients treated with continuous veno-venous hemofiltration (CVVH). METHODS: Pharmacokinetics of levofloxacin were studied in 11 critically ill patients. Four patients were treated with CVVH because of renal failure, 4 patients had moderately impaired renal function but were not on hemofiltration, and 3 patients had approximately normal renal function. Patients received 0.5 g levofloxacin infused over 0.5 hours. Plasma levels of levofloxacin were determined by HPLC and pharmacokinetic parameters were calculated using a non-compartmental model. RESULTS: Levofloxacin clearance in critically ill patients with approximately normal renal function was similar to that in healthy subjects. In critically ill patients with impaired renal function not on CVVH, mean half-life was prolonged by a factor of about 3 (20-25 hours). The mean residence time and the volume of distribution were also increased. In renal failure treated with CVVH, a wide variability in pharmacokinetics was seen. The half-life was about 30 hours and the mean levofloxacin clearance was raised by a factor of 2. The area under the concentration-time curve was reduced by hemofiltration, while the volume of distribution was increased. There was a positive correlation between blood flow through the hemofilter and levofloxacin clearance. Variable amounts of the drug were recovered from the hemofilter. Most plasma levels, however, were in the therapeutic range and drug accumulation to toxic plasma concentrations was not observed in renal failure patients undergoing CVVH and receiving single daily administration of 0.5 g of levofloxacin i.v. CONCLUSIONS: During CVVH using polysulfone membrane hemofilters, plasma concentrations of levofloxacin are not easily predictable. Levofloxacin clearance may be affected by binding to secondary membranes formed in hemofilters during CVVH and blood flow rates have a significant impact on the pharmacokinetics of levofloxacin.


Assuntos
Anti-Infecciosos Urinários/farmacocinética , Hemofiltração , Levofloxacino , Ofloxacino/farmacocinética , Insuficiência Renal/terapia , Adulto , Idoso , Estado Terminal , Feminino , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade
16.
Vis Neurosci ; 19(5): 621-32, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12507328

RESUMO

The resistances of the horizontal cell syncytium in the vertebrate retina are modulated in a time-dependent fashion during light stimulation. Therefore, the spatial properties of horizontal cells are expected to change with time after the illumination conditions are altered. This study was designed to investigate time- and intensity-dependent changes in the receptive-field properties of L1-type horizontal cells in the turtle Mauremys caspica. Photoresponses were elicited by monochromatic (650 nm) light stimuli of 2-s duration covering retinal spots of different radii. The length constants were derived from the relationships between amplitude and spot radius that were constructed for different time intervals after onset of the light stimulus. For a given stimulus intensity, the length constant transiently increased to a peak value and then slowly recovered to a plateau level. When the length constant was compared to the amplitude of the response to full-field illumination for the entire duration of the light stimulus, an ellipse-like curve was obtained indicating that for a given membrane potential, two different values of the length constant could be obtained. Dopamine considerably reduced the size of the receptive fields but did not affect the time-dependent changes in the length constant. These results indicate that changes in the membrane resistance underlie short-term modulation of the receptive-field properties of turtle L1-type horizontal cells after onset of a light stimulus.


Assuntos
Retina/fisiologia , Tartarugas/fisiologia , Animais , Simulação por Computador , Dopamina/farmacologia , Células Gigantes/fisiologia , Técnicas In Vitro , Luz , Modelos Biológicos , Estimulação Luminosa/métodos , Retina/citologia , Retina/efeitos dos fármacos , Retina/efeitos da radiação , Fatores de Tempo
17.
Health Educ Behav ; 28(5): 547-59, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11575685

RESUMO

This study examined the feasibility of collecting health risk behavior data from undergraduate students using a Web-based survey. Undergraduates were randomly selected and assigned randomly to a mail survey group and a Web survey group. There were no statistically significant differences between the two groups for demographics, response rates, item completion, and item completion errors. Yet differences were found for response time and sensitive item completion. This is the first study to demonstrate the feasibility of collecting health risk behavior data from undergraduates using the Web. Undergraduates are just as likely to respond to a Web survey compared with a mail survey and more likely to answer socially threatening items using this method. Also, the Web format and protocol required less time to administer. Researchers and practitioners conducting health survey research with college students or other homogeneous populations who have access to e-mail and the Web should consider using a Web-based survey design as an altemative to a mail, self-administered survey. In such a population, a Web-based survey should not discourage participation, particularly if participants are interested in the questionnaire content.


Assuntos
Comportamentos Relacionados com a Saúde , Inquéritos Epidemiológicos , Internet , Vigilância da População/métodos , Assunção de Riscos , Estudantes/psicologia , Adolescente , Adulto , Demografia , Estudos de Viabilidade , Feminino , Florida , Humanos , Masculino , Estudantes/estatística & dados numéricos , Inquéritos e Questionários , Fatores de Tempo
18.
J Neurosci ; 21(16): 6036-44, 2001 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-11487627

RESUMO

In the mammalian retina, rods feed into the cone pathway through electrotonic coupling, and recent histological data suggest the involvement of connexin36 (Cx36) in this pathway. We therefore generated Cx36 null mice and monitored the functional consequences of this deficiency on early visual transmission. The homozygous mutant mice had a normally developed retina and showed no changes in the cellular organization of the rod pathway. In contrast, the functional coupling between AII amacrine cells and bipolar cells was impaired. Recordings of electroretinograms revealed a significant decrease of the scotopic b-wave in mutant animals and an increased cone threshold that is compatible with a distorted, gap junctional transmission between AII amacrine cells and cone bipolar cells. Recordings of visual evoked potentials showed extended latency in mutant mice but unaffected ON and OFF components. Our results demonstrate that Cx36-containing gap junctions are essential for normal synaptic transmission within the rod pathway.


Assuntos
Conexinas/deficiência , Junções Comunicantes , Transmissão Sináptica , Transtornos da Visão/fisiopatologia , Visão Ocular , Vias Visuais/fisiopatologia , Animais , Relógios Biológicos , Linhagem Celular , Conexinas/genética , Conexinas/metabolismo , Eletrorretinografia , Potenciais Evocados Visuais , Proteínas do Olho/genética , Proteínas do Olho/metabolismo , Junções Comunicantes/metabolismo , Junções Comunicantes/patologia , Marcação de Genes , Homozigoto , Camundongos , Camundongos Knockout , Microscopia Confocal , Estimulação Luminosa/métodos , Tempo de Reação , Retina/patologia , Retina/fisiopatologia , Células Fotorreceptoras Retinianas Cones/patologia , Células Fotorreceptoras Retinianas Cones/fisiopatologia , Células Fotorreceptoras Retinianas Bastonetes/patologia , Colículos Superiores/citologia , Transtornos da Visão/genética , Transtornos da Visão/patologia , Vias Visuais/patologia , Proteína delta-2 de Junções Comunicantes
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