Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 79
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Antimicrob Agents Chemother ; 68(4): e0172823, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38470133

RESUMO

Left ventricular assist devices (LVAD) are increasingly used for management of heart failure; infection remains a frequent complication. Phage therapy has been successful in a variety of antibiotic refractory infections and is of interest in treating LVAD infections. We performed a retrospective review of four patients that underwent five separate courses of intravenous (IV) phage therapy with concomitant antibiotic for treatment of endovascular Pseudomonas aeruginosa LVAD infection. We assessed phage susceptibility, bacterial strain sequencing, serum neutralization, biofilm activity, and shelf-life of phage preparations. Five treatments of one to four wild-type virulent phage(s) were administered for 14-51 days after informed consent and regulatory approval. There was no successful outcome. Breakthrough bacteremia occurred in four of five treatments. Two patients died from the underlying infection. We noted a variable decline in phage susceptibility following three of five treatments, four of four tested developed serum neutralization, and prophage presence was confirmed in isolates of two tested patients. Two phage preparations showed an initial titer drop. Phage biofilm activity was confirmed in two. Phage susceptibility alone was not predictive of clinical efficacy in P. aeruginosa endovascular LVAD infection. IV phage was associated with serum neutralization in most cases though lack of clinical effect may be multifactorial including presence of multiple bacterial isolates with varying phage susceptibility, presence of prophages, decline in phage titers, and possible lack of biofilm activity. Breakthrough bacteremia occurred frequently (while the organism remained susceptible to administered phage) and is an important safety consideration.


Assuntos
Bacteriemia , Bacteriófagos , Coração Auxiliar , Terapia por Fagos , Infecções por Pseudomonas , Humanos , Pseudomonas aeruginosa , Coração Auxiliar/efeitos adversos , Infecções por Pseudomonas/terapia , Infecções por Pseudomonas/microbiologia , Antibacterianos/uso terapêutico , Prófagos , Bacteriemia/tratamento farmacológico
2.
Clin Endocrinol (Oxf) ; 100(5): 488-501, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38037493

RESUMO

OBJECTIVE: Thyroid hormone under-replacement and over-replacement are associated with adverse health outcomes. This systematic review aimed to evaluate the extent of thyroid hormone replacement adequacy for patients with known hypothyroidism in real-word settings, excluding those receiving thyroid hormone suppressive therapy as thyroid cancer treatment. DESIGN: Four electronic databases (Embase [Ovid], Medline [Ovid], PubMed and SCOPUS) were searched for published and unpublished observational studies until 12 December 2022. The results of the studies were meta-analysed to calculate pooled prevalence estimates for thyroid hormone supplementation adequacy, over-replacement and under-replacement. Quality assessment of studies was performed using the Joanna-Briggs appraisal tool for prevalence studies. RESULTS: Seven studies with a total of 4230 patients were eligible for quantitative synthesis. The pooled prevalence estimates of adequate thyroid replacement, over-replacement and under-replacement were 0.55 (95% confidence interval [CI]: 0.49-0.60, p = .001), 0.20 (95% CI: 0.14-0.27, p = .001) and 0.24 (95% CI: 0.13-0.36, p = .001), respectively. Four studies subclassified hypothyroidism and hyperthyroidism into overt and subclinical. The pooled prevalence of overt and subclinical hyperthyroidism was 0.04 (95% CI: 0.00-0.11, p = .01) and 0.17 (95% CI: 0.09-0.27 p = .001), respectively. For overt and subclinical hypothyroidism, the pooled prevalence was 0.02 (95% CI: 0.01-0.03, p = .001) and 0.20 (95% CI: 0.12-0.29, p = .001), respectively. CONCLUSIONS: On average, approximately half of patients with hypothyroidism are only treated to target euthyroidism. In real-world practice, a significant number of patients are over-treated or under-treated, leading to adverse healthcare outcomes. It is imperative that more effective thyroid monitoring strategies be implemented, with an emphasis on primary care thyroid function monitoring, to minimise inappropriate thyroid replacement treatments and optimise healthcare outcomes at a population level.


Assuntos
Hipertireoidismo , Hipotireoidismo , Humanos , Hipotireoidismo/tratamento farmacológico , Hipotireoidismo/complicações , Hipertireoidismo/complicações , Hormônios Tireóideos , Tiroxina/uso terapêutico
3.
Clin Infect Dis ; 73(1): e144-e151, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32699879

RESUMO

BACKGROUND: Prosthetic joint infection (PJI) is a potentially limb-threatening complication of total knee arthroplasty. Phage therapy is a promising strategy to manage such infections including those involving antibiotic-resistant microbes, and to target microbial biofilms. Experience with phage therapy for infections associated with retained hardware is limited. A 62-year-old diabetic man with a history of right total knee arthroplasty 11 years prior who had suffered multiple episodes of prosthetic knee infection despite numerous surgeries and prolonged courses of antibiotics, with progressive clinical worsening and development of severe allergies to antibiotics, had been offered limb amputation for persistent right prosthetic knee infection due to Klebsiella pneumoniae complex. Intravenous phage therapy was initiated as a limb-salvaging intervention. METHODS: The patient received 40 intravenous doses of a single phage (KpJH46Φ2) targeting his bacterial isolate, alongside continued minocycline (which he had been receiving when he developed increasing pain, swelling, and erythema prior to initiation of phage therapy). Serial cytokine and biomarker measurements were performed before, during, and after treatment. The in vitro anti-biofilm activity of KpJH46Φ2, minocycline and the combination thereof was evaluated against a preformed biofilm of the patient's isolate and determined by safranin staining. RESULTS: Phage therapy resulted in resolution of local symptoms and signs of infection and recovery of function. The patient did not experience treatment-related adverse effects and remained asymptomatic 34 weeks after completing treatment while still receiving minocycline. A trend in biofilm biomass reduction was noted 22 hours after exposure to KpJH46Φ2 (P = .063). The addition of phage was associated with a satisfactory outcome in this case of intractable biofilm-associated prosthetic knee infection. Pending further studies to assess its efficacy and safety, phage therapy holds promise for treatment of device-associated infections.


Assuntos
Artroplastia do Joelho , Terapia por Fagos , Infecções Relacionadas à Prótese , Antibacterianos/uso terapêutico , Artroplastia do Joelho/efeitos adversos , Biofilmes , Humanos , Klebsiella pneumoniae , Masculino , Pessoa de Meia-Idade , Infecções Relacionadas à Prótese/tratamento farmacológico
4.
Biotechnol Bioeng ; 118(1): 481-490, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32865815

RESUMO

Chinese hamster ovary (CHO) cells are widely used in biopharmaceutical production. Improvements to cell lines and bioprocesses are constantly being explored. One of the major limitations of CHO cell culture is that the cells undergo apoptosis, leading to rapid cell death, which impedes reaching high recombinant protein titres. While several genetic engineering strategies have been successfully employed to reduce apoptosis, there is still room to further enhance CHO cell lines performance. 'Omics analysis is a powerful tool to better understand different phenotypes and for the identification of gene targets for engineering. Here, we present a comprehensive review of previous CHO 'omics studies that revealed changes in the expression of apoptosis-related genes. We highlight targets for genetic engineering that have reduced, or have the potential to reduce, apoptosis or to increase cell proliferation in CHO cells, with the final aim of increasing productivity.


Assuntos
Apoptose , Proliferação de Células , Proteômica , Animais , Células CHO , Cricetulus , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética
5.
Biotechnol Bioeng ; 117(4): 1187-1203, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31930480

RESUMO

Chinese hamster ovary (CHO) cells are the predominant host cell line for the production of biopharmaceuticals, a growing industry currently worth more than $188 billion USD in global sales. CHO cells undergo programmed cell death (apoptosis) following different stresses encountered in cell culture, such as substrate limitation, accumulation of toxic by-products, and mechanical shear, hindering production. Genetic engineering strategies to reduce apoptosis in CHO cells have been investigated with mixed results. In this review, a contemporary understanding of the real complexity of apoptotic mechanisms and signaling pathways is described; followed by an overview of antiapoptotic cell line engineering strategies tested so far in CHO cells.


Assuntos
Apoptose , Produtos Biológicos/metabolismo , Células CHO , Engenharia Celular , Animais , Técnicas de Cultura de Células , Cricetinae , Cricetulus
7.
Am J Transplant ; 19(9): 2631-2639, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31207123

RESUMO

Bacteriophage therapy (BT) uses bacteriophages to treat pathogenic bacteria and is an emerging strategy against multidrug-resistant (MDR) infections. Experience in solid organ transplant is limited. We describe BT in 3 lung transplant recipients (LTR) with life-threatening MDR infections caused by Pseudomonas aeruginosa (n = 2) and Burkholderia dolosa (n = 1). For each patient, lytic bacteriophages were selected against their bacterial isolates. BT was administered for variable durations under emergency Investigational New Drug applications and with patient informed consent. Safety was assessed using clinical/laboratory parameters and observed clinical improvements described, as appropriate. All patients received concurrent antibiotics. Two ventilator-dependent LTR with large airway complications and refractory MDR P. aeruginosa pneumonia received BT. Both responded clinically and were discharged from the hospital off ventilator support. A third patient had recurrent B. dolosa infection following transplant. Following BT initiation, consolidative opacities improved and ventilator weaning was begun. However, infection relapsed on BT and the patient died. No BT-related adverse events were identified in the 3 cases. BT was well tolerated and associated with clinical improvement in LTRs with MDR bacterial infection not responsive to antibiotics alone. BT may be a viable adjunct to antibiotics for patients with MDR infections.


Assuntos
Infecções Bacterianas/prevenção & controle , Infecções Bacterianas/terapia , Farmacorresistência Bacteriana Múltipla , Pneumopatias/cirurgia , Transplante de Pulmão , Terapia por Fagos/métodos , Adulto , Idoso , Antibacterianos/uso terapêutico , Burkholderia , Feminino , Humanos , Pneumopatias/complicações , Pneumopatias/microbiologia , Transplante de Pulmão/efeitos adversos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Pseudomonas aeruginosa , Infecções Respiratórias/microbiologia , Transplantados
8.
Phys Chem Chem Phys ; 21(20): 10449-10456, 2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-31069358

RESUMO

A new state of radical thermal non-equilibrium in surface adsorbed molecules is discovered that enables rapid surface diffusion of energized adatoms with a negligible effect on the substrate surface temperature. Due to enhanced surface diffusion, growth rates can be achieved that improve the feasibility of many nanofabrication techniques. Since the adatom temperature cannot be directly measured without disturbing its thermodynamic state, the first principle hard-cube model is used to predict both the adatom effective temperature and the surface temperature in response to gaseous particle impingement in a vacuum. The validity of the approach is supported by local, spatially-resolved surface temperature measurements of the thermal response to supersonic microjet gas impingement. The ability to determine and control the adatom effective temperature, and therefore the surface diffusion rate, opens new degrees of freedom in controlling a wide range of nanofabrication processes that critically depend on surface diffusion of precursor molecules. This fundamental understanding has the potential to accelerate research into nanoscale fabrication and to yield the new materials with unique properties that are only accessible with nanoscale features.

9.
Artigo em Inglês | MEDLINE | ID: mdl-28807909

RESUMO

Widespread antibiotic use in clinical medicine and the livestock industry has contributed to the global spread of multidrug-resistant (MDR) bacterial pathogens, including Acinetobacter baumannii We report on a method used to produce a personalized bacteriophage-based therapeutic treatment for a 68-year-old diabetic patient with necrotizing pancreatitis complicated by an MDR A. baumannii infection. Despite multiple antibiotic courses and efforts at percutaneous drainage of a pancreatic pseudocyst, the patient deteriorated over a 4-month period. In the absence of effective antibiotics, two laboratories identified nine different bacteriophages with lytic activity for an A. baumannii isolate from the patient. Administration of these bacteriophages intravenously and percutaneously into the abscess cavities was associated with reversal of the patient's downward clinical trajectory, clearance of the A. baumannii infection, and a return to health. The outcome of this case suggests that the methods described here for the production of bacteriophage therapeutics could be applied to similar cases and that more concerted efforts to investigate the use of therapeutic bacteriophages for MDR bacterial infections are warranted.


Assuntos
Infecções por Acinetobacter/terapia , Acinetobacter baumannii/efeitos dos fármacos , Antibacterianos/uso terapêutico , Bacteriófagos/classificação , Pseudocisto Pancreático/terapia , Pancreatite Necrosante Aguda/terapia , Terapia por Fagos/métodos , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/isolamento & purificação , Acinetobacter baumannii/virologia , Idoso , Farmacorresistência Bacteriana Múltipla , Cálculos Biliares/patologia , Humanos , Masculino , Minociclina/uso terapêutico , Pseudocisto Pancreático/microbiologia , Pancreatite Necrosante Aguda/microbiologia
10.
Antimicrob Agents Chemother ; 60(10): 5806-16, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27431214

RESUMO

Multidrug-resistant bacterial pathogens are an increasing threat to public health, and lytic bacteriophages have reemerged as a potential therapeutic option. In this work, we isolated and assembled a five-member cocktail of wild phages against Acinetobacter baumannii and demonstrated therapeutic efficacy in a mouse full-thickness dorsal infected wound model. The cocktail lowers the bioburden in the wound, prevents the spread of infection and necrosis to surrounding tissue, and decreases infection-associated morbidity. Interestingly, this effective cocktail is composed of four phages that do not kill the parent strain of the infection and one phage that simply delays bacterial growth in vitro via a strong but incomplete selection event. The cocktail here appears to function in a combinatorial manner, as one constituent phage targets capsulated A. baumannii bacteria and selects for loss of receptor, shifting the population to an uncapsulated state that is then sensitized to the remaining four phages in the cocktail. Additionally, capsule is a known virulence factor for A. baumannii, and we demonstrated that the emergent uncapsulated bacteria are avirulent in a Galleria mellonella model. These results highlight the importance of anticipating population changes during phage therapy and designing intelligent cocktails to control emergent strains, as well as the benefits of using phages that target virulence factors. Because of the efficacy of this cocktail isolated from a limited environmental pool, we have established a pipeline for developing new phage therapeutics against additional clinically relevant multidrug-resistant pathogens by using environmental phages sourced from around the globe.


Assuntos
Infecções por Acinetobacter/terapia , Acinetobacter baumannii/virologia , Bacteriófagos , Infecção dos Ferimentos/terapia , Infecções por Acinetobacter/virologia , Acinetobacter baumannii/química , Acinetobacter baumannii/patogenicidade , Animais , Farmacorresistência Bacteriana Múltipla , Feminino , Camundongos Endogâmicos BALB C , Mariposas/microbiologia , Esgotos/virologia , Análise Espectral Raman , Infecção dos Ferimentos/virologia
11.
Stress ; 18(1): 107-14, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25338193

RESUMO

Exposure to social and environmental stressors may influence behavior as well as autonomic and cardiovascular regulation, potentially leading to depressive disorders and cardiac dysfunction including elevated sympathetic drive, reduced parasympathetic function, and ventricular arrhythmias. The cellular mechanisms that underlie these interactions are not well understood. One mechanism may involve alterations in the expression of Connexin43 (Cx43) and Connexin45 (Cx45), gap junction proteins in the heart that play an important role in ensuring efficient cell-to-cell coupling and the maintenance of cardiac rhythmicity. The present study investigated the hypothesis that long-term social isolation, combined with mild environmental stressors, would produce both depressive behaviors and altered Cx43 and Cx45 expression in the left ventricle of prairie voles - a socially monogamous rodent model. Adult, female prairie voles were exposed to either social isolation (n = 22) or control (paired, n = 23) conditions (4 weeks), alone or in combination with chronic mild stress (CMS) (1 week). Social isolation, versus paired control conditions, produced significantly (p < 0.05) increased depressive behaviors in a 5-min forced swim test, and CMS exacerbated (p < 0.05) these behaviors. Social isolation (alone) reduced (p < 0.05) total Cx43 expression in the left ventricle; whereas CMS (but not isolation) increased (p < 0.05) total Cx45 expression and reduced (p < 0.05) the Cx43/Cx45 ratio, measured via Western blot analysis. The present findings provide insight into potential cellular mechanisms underlying altered cardiac rhythmicity associated with social and environmental stress in the prairie vole.


Assuntos
Arritmias Cardíacas/etiologia , Arvicolinae , Comportamento Animal , Conexina 43/metabolismo , Conexinas/metabolismo , Depressão/etiologia , Meio Ambiente , Ventrículos do Coração/metabolismo , Isolamento Social , Estresse Psicológico/etiologia , Animais , Arritmias Cardíacas/metabolismo , Arritmias Cardíacas/psicologia , Arvicolinae/metabolismo , Arvicolinae/psicologia , Doença Crônica , Depressão/metabolismo , Depressão/psicologia , Modelos Animais de Doenças , Feminino , Atividade Motora , Fatores de Risco , Estresse Psicológico/metabolismo , Estresse Psicológico/psicologia , Natação , Fatores de Tempo
12.
Microb Cell Fact ; 14: 91, 2015 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-26112740

RESUMO

BACKGROUND: Predictable control of gene expression is necessary for the rational design and optimization of cell factories. In the yeast Saccharomyces cerevisiae, the promoter is one of the most important tools available for controlling gene expression. However, the complex expression patterns of yeast promoters have not been fully characterised and compared on different carbon sources (glucose, sucrose, galactose and ethanol) and across the diauxic shift in glucose batch cultivation. These conditions are of importance to yeast cell factory design because they are commonly used and encountered in industrial processes. Here, the activities of a series of "constitutive" and inducible promoters were characterised in single cells throughout the fermentation using green fluorescent protein (GFP) as a reporter. RESULTS: The "constitutive" promoters, including glycolytic promoters, transcription elongation factor promoters and ribosomal promoters, differed in their response patterns to different carbon sources; however, in glucose batch cultivation, expression driven by these promoters decreased sharply as glucose was depleted and cells moved towards the diauxic shift. Promoters induced at low-glucose levels (P(HXT7), P(SSA1) and P(ADH2)) varied in induction strength on non-glucose carbon sources (sucrose, galactose and ethanol); in contrast to the "constitutive" promoters, GFP expression increased as glucose decreased and cells moved towards the diauxic shift. While lower than several "constitutive" promoters during the exponential phase, expression from the SSA1 promoter was higher in the post-diauxic phase than the commonly-used TEF1 promoter. The galactose-inducible GAL1 promoter provided the highest GFP expression on galactose, and the copper-inducible CUP1 promoter provided the highest induced GFP expression following the diauxic shift. CONCLUSIONS: The data provides a foundation for predictable and optimised control of gene expression levels on different carbon sources and throughout batch fermentation, including during and after the diauxic shift. This information can be applied for designing expression approaches to improve yields, rates and titres in yeast cell factories.


Assuntos
Carbono/metabolismo , Regulação Fúngica da Expressão Gênica/genética , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Fermentação
13.
J Bacteriol ; 196(6): 1143-54, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24363347

RESUMO

In order to better characterize the Bacillus anthracis typing phage AP50c, we designed a genetic screen to identify its bacterial receptor. Insertions of the transposon mariner or targeted deletions of the structural gene for the S-layer protein Sap and the sporulation genes spo0A, spo0B, and spo0F in B. anthracis Sterne resulted in phage resistance with concomitant defects in phage adsorption and infectivity. Electron microscopy of bacteria incubated with AP50c revealed phage particles associated with the surface of bacilli of the Sterne strain but not with the surfaces of Δsap, Δspo0A, Δspo0B, or Δspo0F mutants. The amount of Sap in the S layer of each of the spo0 mutant strains was substantially reduced compared to that of the parent strain, and incubation of AP50c with purified recombinant Sap led to a substantial reduction in phage activity. Phylogenetic analysis based on whole-genome sequences of B. cereus sensu lato strains revealed several closely related B. cereus and B. thuringiensis strains that carry sap genes with very high similarities to the sap gene of B. anthracis. Complementation of the Δsap mutant in trans with the wild-type B. anthracis sap or the sap gene from either of two different B. cereus strains that are sensitive to AP50c infection restored phage sensitivity, and electron microscopy confirmed attachment of phage particles to the surface of each of the complemented strains. Based on these data, we postulate that Sap is involved in AP50c infectivity, most likely acting as the phage receptor, and that the spo0 genes may regulate synthesis of Sap and/or formation of the S layer.


Assuntos
Fagos Bacilares/fisiologia , Bacillus anthracis/virologia , Proteínas de Bactérias/metabolismo , Interações Hospedeiro-Parasita , Ligação Viral , Fagos Bacilares/genética , Bacillus cereus/genética , Bacillus thuringiensis/genética , Proteínas de Bactérias/genética , Deleção de Genes , Teste de Complementação Genética , Mutagênese Insercional , Filogenia , Homologia de Sequência de Aminoácidos
15.
ChemMedChem ; : e202400391, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38830117

RESUMO

Concentration-dependent increases in relaxivity (r1) were found to be induced by self-assembly when Fmoc is adjacent to tryptophan in peptide-based MRI contrast agents featuring Gd-DOTA.  A series of di- and tri-peptides were synthesized to test the effect of ionic strength, N-terminal substituent, peptide length, net charge, and relative location of Fmoc and tryptophan on r1 and critical aggregation concentration (CAC) at 1.0 Tesla. Compared to nominal r1 values of 3.5-7.4 mM-1s-1 per Gd(III), r1 values increased dramatically to 13.2-16.9 mM-1s-1 per Gd(III) upon self-assembly, with CACs between 0.22 and 2.59 mM when tested in H2O or PBS. When tested in fetal bovine serum (FBS), the compounds maintained high r1 values of 11.2-13.0 mM-1s-1, but had dramatically lower CAC values below 25 µM. These findings guided the synthesis of two targeted, high-relaxivity MRI contrast agents that contained PSMA-binding ligand, DCL. Their r1 values in H2O or PBS increased from 5.9-7.4 mM-1s-1 to 13.5-14.8 mM-1s-1 with CAC values of 1.65-2.70 mM. In FBS, their r1 values were found to be 11.2-11.9 mM-1s-1, with CAC values below 25 µM. By the conjugation of targeting agents in the last step of synthesis, a broadly applicable route to targeted, high-relaxivity MRI contrast agents is offered.

16.
Am J Cardiol ; 218: 102-112, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38432332

RESUMO

There are various devices under clinical investigation for transcatheter mitral valve intervention and transcatheter tricuspid valve intervention (TTVI); however, the exclusion rates remain high. We aimed to investigate the exclusion rates for transcatheter mitral valve repair (TMVr), transcatheter mitral valve replacement (TMVR), transcatheter tricuspid valve repair (TTVr), and transcatheter tricuspid valve replacement (TTVR). There were 129 patients who were referred to St. Francis Hospital & Heart Center valve clinic and completed screening between January 2021 and July 2022. The causes for exclusion were classified into 4 categories: patient withdrawal, anatomic unsuitability, clinical criteria, and medical futility. In 129 patients, the exclusion rates for TMVr, TMVR, TTVr, and TTVR were 81%, 85%, 91%, and 87%, respectively. Patient withdrawal and medical futility were leading etiologies for exclusion, followed by anatomic unsuitability. TMVr had the highest rate of patient withdrawal (64%) and the lowest anatomic unsuitability (5%) because of short posterior leaflet length. Replacement interventions have a higher anatomic unsuitability (33%) than repair interventions (17%) (p = 0.04). Most exclusions of anatomic unsuitability were because of mitral stenosis or small annulus size for TMVR and large annulus size for TTVR. A total of 50% of exclusions from TTVr were because of the presence of pacemaker/defibrillator leads. In patients excluded from their respective trials, patients being referred for TMVr had the highest recurrent hospitalization and repair group had a higher mortality (p <0.01 and p = 0.01, respectively). In conclusion, the exclusion rates for transcatheter mitral valve intervention and TTVI trials remain high because of various reasons, limiting patient enrollment and treatment. This supports the need for further device improvement or exploring alternative means of therapy.


Assuntos
Implante de Prótese de Valva Cardíaca , Insuficiência da Valva Mitral , Humanos , Valva Tricúspide/cirurgia , Cateterismo Cardíaco , Resultado do Tratamento , Insuficiência da Valva Mitral/cirurgia , Hospitais
18.
Am J Physiol Regul Integr Comp Physiol ; 304(5): R362-73, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-23302960

RESUMO

Hindlimb unloading (HU) is a well-established animal model of cardiovascular deconditioning. Previous data indicate that HU results in cardiac sympathovagal imbalance. It is well established that cardiac sympathovagal imbalance increases the risk for developing cardiac arrhythmias. The cardiac gap junction protein connexin 43 (Cx43) is predominately expressed in the left ventricle (LV) and ensures efficient cell-to-cell electrical coupling. In the current study we wanted to test the hypothesis that HU would result in increased predisposition to cardiac arrhythmias and alter the expression and/or phosphorylation of LV-Cx43. Electrocardiographic data using implantable telemetry were obtained over a 10- to 14-day HU or casted control (CC) condition and in response to a sympathetic stressor using isoproterenol administration and brief restraint. The arrhythmic burden was calculated using a modified scoring system to quantify spontaneous and provoked arrhythmias. In addition, Western blot analysis was used to measure LV-Cx43 expression in lysates probed with antibodies directed against the total and an unphosphorylated form of Cx43 in CC and HU rats. HU resulted in a significantly greater total arrhythmic burden during the sympathetic stressor with significantly more ventricular arrhythmias occurring. In addition, there was increased expression of total LV-Cx43 observed with no difference in the expression of unphosphorylated LV-Cx43. Specifically, the increased expression of LV-Cx43 was consistent with the phosphorylated form. These data taken together indicate that cardiovascular deconditioning produced through HU results in increased predisposition to cardiac arrhythmias and increased expression of phosphorylated LV-Cx43.


Assuntos
Arritmias Cardíacas/etiologia , Arritmias Cardíacas/fisiopatologia , Conexina 43/metabolismo , Elevação dos Membros Posteriores/fisiologia , Animais , Anticorpos/farmacologia , Arritmias Cardíacas/diagnóstico , Pressão Sanguínea/fisiologia , Conexina 43/imunologia , Modelos Animais de Doenças , Eletrocardiografia , Frequência Cardíaca/fisiologia , Ventrículos do Coração/metabolismo , Masculino , Miocárdio/metabolismo , Fosforilação/fisiologia , Ratos , Ratos Sprague-Dawley , Sistema Nervoso Simpático/fisiopatologia , Taquicardia Supraventricular/diagnóstico , Taquicardia Supraventricular/etiologia , Taquicardia Supraventricular/fisiopatologia , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/etiologia , Taquicardia Ventricular/fisiopatologia , Nervo Vago/fisiopatologia , Fibrilação Ventricular/diagnóstico , Fibrilação Ventricular/etiologia , Fibrilação Ventricular/fisiopatologia
19.
Virol J ; 10: 165, 2013 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-23714204

RESUMO

BACKGROUND: Vibrio cholerae O139 Bengal is the only serogroup other than O1 implicated in cholera epidemics. We describe the isolation and characterization of an O139 serogroup-specific phage, vB_VchP_VchO139-I (ϕVchO139-I) that has similar host range and virion morphology as phage vB_VchP_JA1 (ϕJA1) described previously. We aimed at a complete molecular characterization of both phages and elucidation of their genetic and structural differences and assessment of their genetic relatedness to the N4-like phage group. METHODS: Host-range analysis and plaque morphology screening were done for both ϕJA1 and ϕVchO139-I. Both phage genomes were sequenced by a 454 and Sanger hybrid approach. Genomes were annotated and protein homologies were determined by Blast and HHPred. Restriction profiles, PFGE patterns and data on the physical genome structure were acquired and phylogenetic analyses were performed. RESULTS: The host specificity of ϕJA1 has been attributed to the unique capsular O-antigen produced by O139 strains. Plaque morphologies of the two phages were different; ϕVchO139-I produced a larger halo around the plaques than ϕJA1. Restriction profiles of ϕJA1 and ϕVchO139-I genomes were also different. The genomes of ϕJA1 and ϕVchO139-I consisted of linear double-stranded DNA of 71,252 and 70,938 base pairs. The presence of direct terminal repeats of around 1974 base pairs was demonstrated. Whole genome comparison revealed single nucleotide polymorphisms, small insertions/deletions and differences in gene content. Both genomes had 79 predicted protein encoding sequences, of which only 59 were identical between the two closely related phages. They also encoded one tRNA-Arg gene, an intein within the large terminase gene, and four homing endonuclease genes. Whole genome phylogenetic analyses of ϕJA1 and ϕVchO139-I against other sequenced N4-like phages delineate three novel subgroups or clades within this phage family. CONCLUSIONS: The closely related phages feature significant genetic differences, in spite of being morphologically identical. The phage morphology, genetic organization, genomic content and large terminase protein based phylogeny support the placement of these two phages in the Podoviridae family, more specifically within the N4-like phage group. The physical genome structure of ϕJA1 could be demonstrated experimentally. Our data pave the way for potential use of ϕJA1 and ϕVchO139-I in Vibrio cholerae typing and control.


Assuntos
DNA Viral/química , DNA Viral/genética , Variação Genética , Genoma Viral , Podoviridae/genética , Vibrio cholerae O139/virologia , Análise por Conglomerados , Especificidade de Hospedeiro , Humanos , Dados de Sequência Molecular , Filogenia , Podoviridae/isolamento & purificação , Podoviridae/fisiologia , Análise de Sequência de DNA , Ensaio de Placa Viral
20.
Med Sci Educ ; 33(1): 39-47, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37008425

RESUMO

The implementation of classroom capture and casting technologies has changed how content can be accessed. Students can access live, streaming, and/or recorded formats of material. Broadening this accessibility has, in turn, introduced flexibility for both the learner and the instructor. This flexibility has impacted the necessity of attendance to access classroom-delivered content. There are many reports that investigate the changing attendance climate as well as the potential impact of attendance on student outcomes. Here we investigated the impact of attending classroom activities on student performance with two common content delivery methods in an undergraduate, pre-clinical cardiology course. Electrocardiography (ECG) interpretation was taught using a flipped classroom format which allowed for the practice of interpretive skills with faculty guidance. Other components of the course related to the diagnosis, treatment, and management of cardiovascular disease were delivered using a lecture-based format. The results demonstrate that attendees outperform their classmates in the ability to interpret ECGs and related content. However, the attending student does not appear to have a performance advantage when content is delivered by lecture. The results provide evidence for students to prioritize their time when making decisions about attendance, based on teaching modality, when given a choice. Further, the information can guide curricular change and help colleges and programs identify curricular activities that have a clear attendance benefit for students. Supplementary Information: The online version contains supplementary material available at 10.1007/s40670-022-01689-5.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA