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2.
J Cardiothorac Surg ; 14(1): 51, 2019 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-30845970

RESUMO

BACKGROUND: Cardiac surgery-associated acute kidney injury (CSA-AKI) is a serious postoperative complication of cardiac surgery, an episode of which impacts on patient morbidity and mortality. Pulse wave velocity (PWV; a non-invasive measurement tool to assess arterial stiffness) has been shown to predict kidney disease progression, and cardiovascular and all-cause mortality in patients with chronic kidney disease. We hypothesised that PWV would also predict acute kidney injury in subjects who have undergone non-valve repair elective coronary artery bypass graft (CABG) surgery . METHODS: This was a prospective, observational, exploratory study. PWV was determined with a Vicorder device, together with standard clinical and biochemical parameters. AKI staging was defined according to the Kidney Disease Improving Global Outcomes (KDIGO) Clinical Practice Guidelines. RESULTS: 137 patients were included in the study. 85% were male, and mean age was 66.3 years (SD = 9.7 years). There were 40 episodes (29%) of CSA-AKI. Each 1 unit increase in PWV score was associated with a 1.5 fold greater odds of a CSA-AKI event (p = 0.006(odds ratio = 1.5; confidence interval:1.13-2.10). A 1 unit increase in estimated glomerular filtration rate resulted in an estimated 85% decrease in the odds of developing AKI, each year, men have an odds reduction of 15% of developing AKI compared with females and each 1 year increase in age lowered the odds of developing AKI by 87%. CONCLUSIONS: This pilot exploratory study revealed that PWV, assessed prior to non-valve repair elective CABG surgery, independently predicts CSA-AKI events. PWV is a simple, non-invasive technique that could potentially be used to risk stratify for CSA- AKI following elective cardiac surgery. TRIAL REGISTRATION: ClinTrial.Gov NCT02364427 . Registered 18 February 2015.


Assuntos
Injúria Renal Aguda/etiologia , Ponte de Artéria Coronária/efeitos adversos , Doença das Coronárias/cirurgia , Rigidez Vascular/fisiologia , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/fisiopatologia , Idoso , Doença das Coronárias/fisiopatologia , Feminino , Taxa de Filtração Glomerular , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Valor Preditivo dos Testes , Estudos Prospectivos , Análise de Onda de Pulso , Fatores de Risco
4.
Am J Med ; 131(10): 1251-1256.e2, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29626429

RESUMO

BACKGROUND: Frailty and acute kidney injury are independently associated with an increased risk of morbidity and mortality. The degree of frailty can be assessed by the Clinical Frailty Score (CFS). This study assessed whether an individual's CFS was associated with acute kidney injury in acute elderly medical admissions and recorded the short-term outcomes. METHODS: This was a single-center prospective observational cohort study. All patients aged ≥65 years admitted under an acute medical take over 12 nonconsecutive days were included. Patient demographics, comorbidities, baseline CFS, and renal status on admission were recorded. Outcomes of death, length of stay, and hospital re-attendance were assessed 2 weeks following admission. RESULTS: Of 164 patients (77 males), 19% had acute kidney injury on admission and 22% were considered severely frail. Severe frailty was associated with acute kidney injury (P = .01) and death within 2 weeks (P = .01). Two-week mortality was highest among patients with both (36%). CONCLUSION: The incidence of acute kidney injury in "severely frail" acutely unwell elderly patients is significantly higher and associated with an increased short-term mortality. The CFS may be useful in acute illness to guide clinical decisions in elderly patients.


Assuntos
Injúria Renal Aguda , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/mortalidade , Injúria Renal Aguda/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Feminino , Idoso Fragilizado , Fragilidade/diagnóstico , Fragilidade/epidemiologia , Fragilidade/fisiopatologia , Avaliação Geriátrica/métodos , Mortalidade Hospitalar , Hospitalização/estatística & dados numéricos , Humanos , Incidência , Pacientes Internados/estatística & dados numéricos , Tempo de Internação/estatística & dados numéricos , Masculino , Estudos Prospectivos , Medição de Risco , Reino Unido/epidemiologia
7.
Nature ; 521(7550): 65-9, 2015 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-25951285

RESUMO

Internal gravity waves, the subsurface analogue of the familiar surface gravity waves that break on beaches, are ubiquitous in the ocean. Because of their strong vertical and horizontal currents, and the turbulent mixing caused by their breaking, they affect a panoply of ocean processes, such as the supply of nutrients for photosynthesis, sediment and pollutant transport and acoustic transmission; they also pose hazards for man-made structures in the ocean. Generated primarily by the wind and the tides, internal waves can travel thousands of kilometres from their sources before breaking, making it challenging to observe them and to include them in numerical climate models, which are sensitive to their effects. For over a decade, studies have targeted the South China Sea, where the oceans' most powerful known internal waves are generated in the Luzon Strait and steepen dramatically as they propagate west. Confusion has persisted regarding their mechanism of generation, variability and energy budget, however, owing to the lack of in situ data from the Luzon Strait, where extreme flow conditions make measurements difficult. Here we use new observations and numerical models to (1) show that the waves begin as sinusoidal disturbances rather than arising from sharp hydraulic phenomena, (2) reveal the existence of >200-metre-high breaking internal waves in the region of generation that give rise to turbulence levels >10,000 times that in the open ocean, (3) determine that the Kuroshio western boundary current noticeably refracts the internal wave field emanating from the Luzon Strait, and (4) demonstrate a factor-of-two agreement between modelled and observed energy fluxes, which allows us to produce an observationally supported energy budget of the region. Together, these findings give a cradle-to-grave picture of internal waves on a basin scale, which will support further improvements of their representation in numerical climate predictions.

8.
ACS Appl Mater Interfaces ; 7(1): 738-42, 2015 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-25459154

RESUMO

Battery safety is critical for many applications including portable electronics, hybrid and electric vehicles, and grid storage. For lithium ion batteries, the conventional polymer based separator is unstable at 120 °C and above. In this research, we have developed a pure aluminum oxide nanowire based separator; this separator does not contain any polymer additives or binders; additionally, it is a bendable ceramic. The physical and electrochemical properties of the separator are investigated. The separator has a pore size of about 100 nm, and it shows excellent electrochemical properties under both room and high temperatures. At room temperature, the ceramic separator shows a higher rate capability compared to the conventional Celgard 2500 separator and life cycle performance does not show any degradation. At 120 °C, the cell with the ceramic separator showed a much better cycle performance than the conventional Celgard 2500 separator. Therefore, we believe that this research is really an exciting scientific breakthrough for ceramic separators and lithium ion batteries and could be potentially used in the next generation lithium ion batteries requiring high safety and reliability.

9.
J Chiropr Med ; 12(2): 55-9, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24294146

RESUMO

OBJECTIVE: The purpose of this preliminary study was to determine if a course of chiropractic care would change blood pressure measurements in African American patients and to determine if a study was feasible in a chiropractic teaching clinic. METHODS: Twenty-four African American patients received chiropractic care in a chiropractic teaching clinic over a study period that spanned 23 visits for each patient. Inclusion criteria consisted of patients having a diagnosis of prehypertension (120-139/80-89) or hypertension stage 1 (140-159/90-99). The mean values of 3 baseline blood pressure readings were compared with the mean values of blood pressure readings taken on visits 21, 22, and 23. RESULTS: For the entire sample, reductions for both systolic and diastolic blood pressures were not statistically significant (P > .07). When 4 patients having body mass index values that were considered as outliers were excluded, a statistically significant decrease in diastolic blood pressure was observed (P = .004). By group, a statistically significant reduction occurred in the hypertension stage 1 group for systolic and diastolic blood pressures. CONCLUSION: This study showed that research of this nature may be feasible in chiropractic teaching clinics. The preliminary findings of this study showed that, for a subgroup of African American patients receiving chiropractic care, blood pressure decreased for (a) hypertension stage 1 patients and (b) the sample when those with excessive body mass index were excluded.

10.
Am J Pathol ; 179(2): 661-72, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21704009

RESUMO

Transforming growth factor (TGF)-ß is one of the main fibrogenic cytokines that drives the pathophysiology of progressive renal scarring. MicroRNAs (miRNAs) are endogenous non-coding RNAs that post-transcriptionally regulate gene expression. We examined the role of TGF-ß-induced expression of miR-21, miRNAs in cell culture models and miRNA expression in relevant models of renal disease. In vitro, TGF-ß changed expression of miR-21, miR-214, and miR-145 in rat mesangial cells (CRL-2753) and miR-214, miR-21, miR-30c, miR-200b, and miR-200c during induction of epithelial-mesenchymal transition in rat tubular epithelial cells (NRK52E). miR-214 expression was robustly modulated in both cell types, whereas in tubular epithelial cells miR-21 was increased and miR-200b and miR-200c were decreased by 58% and 48%, respectively, in response to TGF-ß. TGF-ß receptor-1 was found to be a target of miR-200b/c and was down-regulated after overexpression of miR-200c. To assess the differential expression of these miRNAs in vivo, we used the anti-Thy1.1 mesangial glomerulonephritis model and the unilateral ureteral obstruction model in which TGF-ß plays a role and also a genetic model of hypertension, the stroke-prone spontaneously hypertensive rat with and without salt loading. The expressions of miR-214 and miR-21 were significantly increased in all in vivo models, showing a possible miRNA signature of renal damage despite differing causes.


Assuntos
Regulação da Expressão Gênica , MicroRNAs/genética , MicroRNAs/metabolismo , Animais , Modelos Animais de Doenças , Glomerulonefrite/metabolismo , Hipertensão/patologia , Rim/lesões , Rim/metabolismo , Glomérulos Renais/metabolismo , Túbulos Renais/metabolismo , Masculino , Ratos , Ratos Endogâmicos WKY , Fatores de Tempo , Fator de Crescimento Transformador beta/metabolismo , Ureter/patologia
11.
Eur J Med Chem ; 45(9): 3864-9, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20538379

RESUMO

Febrifugine is an alkaloid isolated from Dichroa febrifuga as the active component against Plasmodium falciparum. Adverse side effects have precluded febrifugine as a potential clinical drug. As part of an ongoing malaria chemotherapy project, novel febrifugine analogues were designed and synthesized. Lower toxicity of these newly designed compounds was achieved by reducing or eliminating the tendency to form chemically reactive and toxic intermediates. New compounds possess excellent in vivo antimalarial activity and most of them become less toxic than the natural product febrifugine. Some of the compounds possess a therapeutic index over ten times superior to that of febrifugine and the commonly used antimalarial drug chloroquine. These compounds, as well as the underlying design rationale, may find usefulness in the discovery and development of new antimalarial drugs.


Assuntos
Antimaláricos/síntese química , Antimaláricos/farmacologia , Quinazolinonas/síntese química , Quinazolinonas/farmacologia , Animais , Antimaláricos/química , Antimaláricos/toxicidade , Linhagem Celular , Avaliação Pré-Clínica de Medicamentos , Camundongos , Camundongos Endogâmicos ICR , Plasmodium falciparum/efeitos dos fármacos , Quinazolinonas/química , Quinazolinonas/toxicidade
12.
Int J Cardiol ; 91(1): 107-9, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12957739

RESUMO

Statins are now widely prescribed and without doubt save many lives. However there are rare potentially serious side-effects, including acute renal failure. Patient education and physician vigilence are vital.


Assuntos
Debilidade Muscular/induzido quimicamente , Piridinas/efeitos adversos , Insuficiência Renal/induzido quimicamente , Rabdomiólise/induzido quimicamente , Doença Aguda , Idoso , Humanos , Masculino , Insuficiência Renal/terapia
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