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1.
Heliyon ; 10(6): e27686, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38509936

RESUMO

Rationale and objectives: The potential of breast microcalcification chemistry to provide clinically valuable intelligence is being increasingly studied. However, acquisition of crystallographic details has, to date, been limited to high brightness, synchrotron radiation sources. This study, for the first time, evaluates a laboratory-based system that interrogates histological sections containing microcalcifications. The principal objective was to determine the measurement precision of the laboratory system and assess whether this was sufficient to provide potentially clinical valuable information. Materials and methods: Sections from 5 histological specimens from breast core biopsies obtained to evaluate mammographic calcification were examined using a synchrotron source and a laboratory-based instrument. The samples were chosen to represent a significant proportion of the known breast tissue, mineralogical landscape. Data were subsequently analysed using conventional methods and microcalcification characteristics such as crystallographic phase, chemical deviation from ideal stoichiometry and microstructure were determined. Results: The crystallographic phase of each microcalcification (e.g., hydroxyapatite, whitlockite) was easily determined from the laboratory derived data even when a mixed phase was apparent. Lattice parameter values from the laboratory experiments agreed well with the corresponding synchrotron values and, critically, were determined to precisions that were significantly greater than required for potential clinical exploitation. Conclusion: It has been shown that crystallographic characteristics of microcalcifications can be determined in the laboratory with sufficient precision to have potential clinical value. The work will thus enable exploitation acceleration of these latent microcalcification features as current dependence upon access to limited synchrotron resources is minimized.

3.
J Biomed Inform ; 95: 103225, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31195101

RESUMO

Culturally- and linguistically-tailored health communication is needed for vulnerable populations to manage their health and the health of their families. This presents a significant design challenge. The use of collages is an increasingly popular technique with the flexibility to capture the needs and experiences of individuals with various cultural and language preferences. Collage analysis has typically remained qualitative in nature. We introduce a novel, objective, semi-automated approach that enhances collage analysis to elucidate pattern differences that may not be detectable by natural perception. We present a case scenario of collage analysis based on the expressed experience and self-management needs of Hispanic dementia caregivers (n = 24). We demonstrate how our innovative approach may reveal cultural differences between language groups that could have otherwise been missed using traditional techniques.


Assuntos
Cuidadores , Visualização de Dados , Demência/terapia , Saúde da Família , Gestão da Informação em Saúde/métodos , Idoso , Idoso de 80 Anos ou mais , Feminino , Hispânico ou Latino , Humanos , Masculino , Pessoa de Meia-Idade
4.
J Hepatol ; 69(5): 1015-1024, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29886155

RESUMO

BACKGROUND & AIMS: Advancing liver disease results in deleterious changes in a number of critical organs. The ability to measure structure, blood flow and tissue perfusion within multiple organs in a single scan has implications for determining the balance of benefit vs. harm for therapies. Our aim was to establish the feasibility of magnetic resonance imaging (MRI) to assess changes in Compensated Cirrhosis (CC), and relate this to disease severity and future liver-related outcomes (LROs). METHODS: A total of 60 patients with CC, 40 healthy volunteers and 7 patients with decompensated cirrhosis were recruited. In a single scan session, MRI measures comprised phase-contrast MRI vessel blood flow, arterial spin labelling tissue perfusion, T1 longitudinal relaxation time, heart rate, cardiac index, and volume assessment of the liver, spleen and kidneys. We explored the association between MRI parameters and disease severity, analysing differences in baseline MRI parameters in the 11 (18%) patients with CC who experienced future LROs. RESULTS: In the liver, compositional changes were reflected by increased T1 in progressive disease (p <0.001) and an increase in liver volume in CC (p = 0.006), with associated progressive reduction in liver (p <0.001) and splenic (p <0.001) perfusion. A significant reduction in renal cortex T1 and increase in cardiac index and superior mesenteric arterial blood flow was seen with increasing disease severity. Baseline liver T1 (p = 0.01), liver perfusion (p <0.01), and renal cortex T1 (p <0.01) were significantly different in patients with CC who subsequently developed negative LROs. CONCLUSIONS: MRI enables the contemporaneous assessment of organs in liver cirrhosis in a single scan without the requirement for a contrast agent. MRI parameters of liver T1, renal T1, hepatic and splenic perfusion, and superior mesenteric arterial blood flow were related to the risk of LROs. LAY SUMMARY: This study assesses the changes to structure, blood flow and perfusion that occur in the key organs (liver, spleen and kidney) associated with severe liver disease (Compensated Cirrhosis), using magnetic resonance imaging. The magnetic resonance imaging measures which changed with disease severity and were related to negative liver-related clinical outcomes are described.


Assuntos
Cirrose Hepática/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Idoso , Feminino , Humanos , Rim/diagnóstico por imagem , Fígado/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Fluxo Sanguíneo Regional , Índice de Gravidade de Doença , Baço/diagnóstico por imagem
5.
J Am Heart Assoc ; 7(11)2018 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-29853444

RESUMO

BACKGROUND: Significant heterogeneity exists in practice patterns and algorithms used for cardiac screening before kidney transplant. Cardiorespiratory fitness, as measured by peak oxygen uptake (VO2peak), is an established validated predictor of future cardiovascular morbidity and mortality in both healthy and diseased populations. The literature supports its use among asymptomatic patients in abrogating the need for further cardiac testing. METHODS AND RESULTS: We outlined a pre-renal transplant screening algorithm to incorporate VO2peak testing among a population of asymptomatic high-risk patients (with diabetes mellitus and/or >50 years of age). Only those with VO2peak <17 mL/kg per minute (equivalent to <5 metabolic equivalents) underwent further noninvasive cardiac screening tests. We conducted a retrospective study of the a priori dichotomization of the VO2peak <17 versus ≥17 mL/kg per minute to determine negative and positive predictive value of future cardiac events and all-cause mortality. We report a high (>90%) negative predictive value, indicating that VO2peak ≥17 mL/kg per minute is effective to rule out future cardiac events and all-cause mortality. However, lower VO2peak had low positive predictive value and should not be used as a reliable metric to predict future cardiac events and/or mortality. In addition, a simple mathematical calculation documented a cost savings of ≈$272 600 in the cardiac screening among our study cohort of 637 patients undergoing evaluation for kidney and/or pancreas transplant. CONCLUSIONS: We conclude that incorporating an objective measure of cardiorespiratory fitness with VO2peak is safe and allows for a cost savings in the cardiovascular screening protocol among higher-risk phenotype (with diabetes mellitus and >50 years of age) being evaluated for kidney transplant.


Assuntos
Aptidão Cardiorrespiratória , Doenças Cardiovasculares/diagnóstico , Teste de Esforço , Falência Renal Crônica/cirurgia , Transplante de Rim , Consumo de Oxigênio , Liberação de Cirurgia/métodos , Adulto , Idoso , Doenças Cardiovasculares/fisiopatologia , Análise Custo-Benefício , Teste de Esforço/economia , Feminino , Custos de Cuidados de Saúde , Humanos , Falência Renal Crônica/diagnóstico , Falência Renal Crônica/fisiopatologia , Transplante de Rim/efeitos adversos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Liberação de Cirurgia/economia
6.
Scand J Gastroenterol ; 53(12): 1611-1618, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30600732

RESUMO

BACKGROUND: Patient outcomes in gastric adenocarcinoma are poor due to late diagnosis. Detecting and treating at the premalignant stage has the potential to improve this. Helicobacter pylori is also a strong risk factor for this disease. AIMS: Primary aims were to assess the diagnostic accuracy of magnified narrow band imaging (NBI-Z) endoscopy and serology in detecting normal mucosa, H. pylori gastritis and gastric atrophy. Secondary aims were to compare the diagnostic accuracies of two classification systems using both NBI-Z and white light endoscopy with magnification (WLE-Z) and evaluate the inter-observer agreement. METHODS: Patients were prospectively recruited. Images of gastric mucosa were stored with histology and serum for IgG H. pylori and Pepsinogen (PG) I/II ELISAs. Blinded expert endoscopists agreed on mucosal pattern. Mucosal images and serological markers were compared with histology. Kappa statistics determined inter-observer variability for randomly allocated images among four experts and four non-experts. RESULTS: 116 patients were prospectively recruited. Diagnostic accuracy of NBI-Z for determining normal gastric mucosa was 0.87(95%CI 0.82-0.92), H. pylori gastritis 0.65(95%CI 0.55-0.75) and gastric atrophy 0.88(95%CI 0.81-0.94). NBI-Z was superior to serology at detecting gastric atrophy: NBI-Z gastric atrophy 0.88(95%CI 0.81-0.94) vs PGI/II ratio < 3 0.74(95%CI 0.62-0.85) p<.0001. Overall NBI-Z was superior to WLE-Z in detecting disease using two validated classifications. Inter-observer agreement was 0.63(95%CI 0.51-0.73). CONCLUSIONS: NBI-Z accurately detects changes in the GI mucosa which currently depend on histology. NBI-Z is useful in the detection of precancerous conditions, potentially improving patient outcomes with early intervention to prevent gastric cancer.


Assuntos
Gastrite Atrófica/diagnóstico por imagem , Gastroscopia/métodos , Imagem de Banda Estreita , Lesões Pré-Cancerosas/diagnóstico por imagem , Neoplasias Gástricas/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Detecção Precoce de Câncer , Feminino , Mucosa Gástrica/patologia , Gastrite Atrófica/microbiologia , Gastrite Atrófica/patologia , Infecções por Helicobacter/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Lesões Pré-Cancerosas/patologia , Estudos Prospectivos , Sensibilidade e Especificidade , Neoplasias Gástricas/patologia , Reino Unido , Adulto Jovem
7.
Proc Natl Acad Sci U S A ; 114(43): 11368-11373, 2017 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-29073058

RESUMO

Maintaining a robust blood product supply is an essential requirement to guarantee optimal patient care in modern health care systems. However, daily blood product use is difficult to anticipate. Platelet products are the most variable in daily usage, have short shelf lives, and are also the most expensive to produce, test, and store. Due to the combination of absolute need, uncertain daily demand, and short shelf life, platelet products are frequently wasted due to expiration. Our aim is to build and validate a statistical model to forecast future platelet demand and thereby reduce wastage. We have investigated platelet usage patterns at our institution, and specifically interrogated the relationship between platelet usage and aggregated hospital-wide patient data over a recent consecutive 29-mo period. Using a convex statistical formulation, we have found that platelet usage is highly dependent on weekday/weekend pattern, number of patients with various abnormal complete blood count measurements, and location-specific hospital census data. We incorporated these relationships in a mathematical model to guide collection and ordering strategy. This model minimizes waste due to expiration while avoiding shortages; the number of remaining platelet units at the end of any day stays above 10 in our model during the same period. Compared with historical expiration rates during the same period, our model reduces the expiration rate from 10.5 to 3.2%. Extrapolating our results to the ∼2 million units of platelets transfused annually within the United States, if implemented successfully, our model can potentially save ∼80 million dollars in health care costs.


Assuntos
Modelos Estatísticos , Transfusão de Plaquetas/estatística & dados numéricos , Atenção Terciária à Saúde , California , Registros Eletrônicos de Saúde , Custos de Cuidados de Saúde , Humanos , Transfusão de Plaquetas/economia , Atenção Terciária à Saúde/economia
8.
J Hepatol ; 65(6): 1131-1139, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27475617

RESUMO

BACKGROUND & AIMS: Hepatic venous pressure gradient (HVPG) measurement is currently the only validated technique to accurately evaluate changes in portal pressure. In this study, we evaluate the use of non-contrast quantitative magnetic resonance imaging (MRI) as a surrogate measure of portal pressure. METHODS: Thirty patients undergoing HVPG measurement were prospectively recruited. MR parameters of longitudinal relaxation time (T1), perfusion of the liver and spleen (by arterial spin labelling), and blood flow in the portal, splanchnic and collateral circulation (by phase contrast MRI) were assessed. We estimated the liver stiffness measurement (LSM) and enhanced liver fibrosis (ELF) score. The correlation of all non-invasive parameters with HVPG was evaluated. RESULTS: The mean (range) HVPG of the patients was 9.8 (1-22) mmHg, and 14 patients (48%) had clinically significant portal hypertension (CSPH, HVPG ⩾10mmHg). Liver T1 relaxation time, splenic artery and superior mesenteric artery velocity correlated significantly with HVPG. Using multiple linear regression, liver T1 and splenic artery velocity remained as the two parameters in the multivariate model significantly associated with HVPG (R=0.90, p<0.001). This correlation was maintained in patients with CSPH (R=0.85, p<0.001). A validation cohort (n=10) showed this linear model provided a good prediction of HVPG. LSM and ELF score correlated significantly with HVPG in the whole population but the correlation was absent in CSPH. CONCLUSIONS: MR parameters related to both hepatic architecture and splanchnic haemodynamics correlate significantly with HVPG. This proposed model, confirmed in a validation cohort, could replace the invasive HVPG measurement. LAY SUMMARY: In patients with cirrhosis, the development and progression of portal hypertension is related to worse outcomes. However, the standard technique of assessing portal pressure is invasive and not widely used in clinical practice. Here, we have studied the use of non-invasive MRI in evaluating portal pressure. The MRI measures of liver architecture and blood flow in the splenic artery correlated well with portal pressure. Therefore, this non-invasive method can potentially be used to assess portal pressure in clinical trials and monitoring treatment in practice.


Assuntos
Hipertensão Portal , Humanos , Cirrose Hepática , Imageamento por Ressonância Magnética , Pressão na Veia Porta
9.
Am Heart J ; 176: 83-92, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27264224

RESUMO

BACKGROUND: Statin-mediated low-density lipoprotein cholesterol (LDL-C) lowering fails to prevent more than half of cardiovascular events in clinical trials. Serial plaque imaging studies have highlighted the benefits of aggressive LDL-C lowering, with plaque regression evident in up to two-thirds of patients with achieved LDL-C levels <70 mg/dL. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors permit LDL-C-lowering by a further 54% to 75% in statin-treated patients. The impact of achieving very low LDL-C levels with PCSK9 inhibitors on coronary atherosclerosis has not been investigated. AIMS: To test the hypothesis that incremental LDL-C lowering with the PCSK9 inhibitor, evolocumab, will result in a significantly greater change from baseline in coronary atheroma volume than placebo in subjects receiving maximally tolerated statin therapy. METHODS: A phase 3, multicenter, double-blind, randomized, placebo-controlled trial evaluating the impact of evolocumab on coronary atheroma volume as assessed by serial coronary intravascular ultrasound at baseline in patients undergoing a clinically indicated coronary angiogram with angiographic evidence of coronary atheroma, and after 78 weeks of treatment. Subjects (n = 968) were randomized 1:1 into 2 groups to receive monthly either evolocumab 420 mg or placebo subcutaneous injections. CONCLUSIONS: The GLAGOV trial will explore whether greater degrees of plaque regression are achievable with ultrahigh-intensity LDL-C lowering after combination statin-PCSK9 inhibitor therapy. GLAGOV will provide important mechanistic, safety, and efficacy data prior to the eagerly anticipated clinical outcomes trials testing the PCSK9 inhibitor hypothesis (www.clinicaltrials.gov identifier NCT01813422).


Assuntos
Anticorpos Monoclonais/administração & dosagem , LDL-Colesterol/sangue , Doença da Artéria Coronariana , Placa Aterosclerótica , Pró-Proteína Convertase 9 , Ultrassonografia de Intervenção/métodos , Idoso , Anticorpos Monoclonais Humanizados , Anticolesterolemiantes/administração & dosagem , Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/tratamento farmacológico , Vasos Coronários/diagnóstico por imagem , Progressão da Doença , Método Duplo-Cego , Monitoramento de Medicamentos/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inibidores de PCSK9 , Placa Aterosclerótica/diagnóstico por imagem , Placa Aterosclerótica/tratamento farmacológico , Pró-Proteína Convertase 9/imunologia
10.
Med Care ; 52(6): 469-78, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24699236

RESUMO

BACKGROUND: Most catheter-associated urinary tract infections (CAUTIs) are considered preventable and thus a potential target for health care quality improvement and cost savings. OBJECTIVES: We sought to estimate excess Medicare reimbursement, length of stay, and inpatient death associated with CAUTI among hospitalized beneficiaries. RESEARCH DESIGN: Using a retrospective cohort design with linked Medicare inpatient claims and National Healthcare Safety Network data from 2009, we compared Medicare reimbursement between Medicare beneficiaries with and without CAUTIs. SUBJECTS: Fee-for-service Medicare beneficiaries aged 65 years or older with continuous coverage of parts A (hospital insurance) and B (supplementary medical insurance). RESULTS: We found that beneficiaries with CAUTI had higher median Medicare reimbursement [intensive care unit (ICU): $8548, non-ICU: $1479) and length of stay (ICU: 8.1 d, non-ICU: 3.6 d) compared with those without CAUTI controlling for potential confounding factors. Odds of inpatient death were higher among beneficiaries with versus without CAUTI only among those with an ICU stay (ICU: odds ratio 1.37). CONCLUSIONS: Beneficiaries with CAUTI had increased Medicare reimbursement and length of stay compared with those without CAUTI after adjusting for potential confounders.


Assuntos
Infecções Relacionadas a Cateter/economia , Infecção Hospitalar/economia , Hospitalização/economia , Reembolso de Seguro de Saúde/economia , Medicare Assignment/economia , Medicare Part A/economia , Infecções Urinárias/economia , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Infecção Hospitalar/mortalidade , Infecção Hospitalar/prevenção & controle , Feminino , Mortalidade Hospitalar , Humanos , Unidades de Terapia Intensiva/economia , Tempo de Internação/economia , Masculino , Medicare Part B , Melhoria de Qualidade/economia , Estudos Retrospectivos , Estados Unidos , Infecções Urinárias/mortalidade , Infecções Urinárias/prevenção & controle
11.
J Am Coll Cardiol ; 63(5): 430-3, 2014 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-24161333

RESUMO

OBJECTIVES: This study sought to define the ability of AMG 145, a monoclonal antibody directed against proprotein convertase subtilisin kexin type 9 (PCSK9), to enable subjects at high risk for major adverse cardiovascular events to achieve National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP III) parameters for low-density lipoprotein cholesterol (LDL-C) and other lipid goals. BACKGROUND: Many patients at high risk for adverse cardiovascular events are unable to achieve the NCEP-ATP III LDL-C goal of <70 mg/dl, even with high-potency statin therapy. METHODS: In 282 subjects from the LAPLACE-TIMI 57 (LDL-C Assessment with PCSK9 monoclonaL Antibody Inhibition Combined With Statin thErapy-Thrombolysis In Myocardial Infarction 57) trial at high risk according to NCEP-ATP III criteria, we compared the proportion of subjects achieving the NCEP-ATP III recommended LDL-C goal of <70 mg/dl across treatment arms. Other outcomes included the triple goals of LDL-C <70 mg/dl, non-high-density lipoprotein cholesterol (HDL-C) <100 mg/dl, and apolipoprotein B (ApoB) <80 mg/dl. RESULTS: During the dosing interval, more than 90% of subjects in both of the top dose groups every 2 weeks and every 4 weeks attained this lipid target over the dosing interval, with similar success rates for the triple lipid goal. CONCLUSIONS: PCSK9 inhibition with AMG 145 enables high-risk patients to achieve established lipid goals. If this therapy demonstrates efficacy for reducing cardiovascular events with a favorable safety profile in ongoing phase 3 trials, we believe it will have major public health implications.


Assuntos
Anticorpos Monoclonais/administração & dosagem , LDL-Colesterol/sangue , Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , Infarto do Miocárdio/tratamento farmacológico , Educação de Pacientes como Assunto , Pró-Proteína Convertases/antagonistas & inibidores , Terapia Trombolítica/métodos , Adulto , Idoso , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais Humanizados , Relação Dose-Resposta a Droga , Esquema de Medicação , Quimioterapia Combinada , Feminino , Seguimentos , Humanos , Hipercolesterolemia/sangue , Hipercolesterolemia/complicações , Hipercolesterolemia/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/sangue , Infarto do Miocárdio/complicações , Pró-Proteína Convertase 9 , Pró-Proteína Convertases/imunologia , Serina Endopeptidases/imunologia , Fatores de Tempo , Resultado do Tratamento
12.
Circulation ; 128(9): 962-9, 2013 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-23884353

RESUMO

BACKGROUND: Lipoprotein(a) [Lp(a)] is an emerging risk factor for cardiovascular disease. Currently, there are few available therapies to lower Lp(a). We sought to evaluate the impact of AMG145, a monoclonal antibody against proprotein convertase subtilisin kexin type 9 (PCSK9), on Lp(a). METHODS AND RESULTS: As part of the LDL-C Assessment With PCSK9 Monoclonal Antibody Inhibition Combined With Statin Therapy (LAPLACE)-Thrombolysis in Myocardial Infarction (TIMI) 57 trial, 631 patients with hypercholesterolemia receiving statin therapy were randomized to receive AMG145 at 1 of 3 different doses every 2 weeks or 1 of 3 different doses every 4 weeks versus placebo. Lp(a) and other lipid parameters were measured at baseline and at week 12. Compared with placebo, AMG145 70 mg, 105 mg, and 140 mg every 2 weeks reduced Lp(a) at 12 weeks by 18%, 32%, and 32%, respectively (P<0.001 for each dose versus placebo). Likewise, AMG145 280 mg, 350 mg, and 420 mg every 4 weeks reduced Lp(a) by 18%, 23%, and 23%, respectively (P<0.001 for each dose versus placebo). The reduction in Lp(a) correlated with the reduction in low-density lipoprotein cholesterol (ρ=0.33, P<0.001). The effect of AMG145 on Lp(a) was consistent regardless of age, sex, race, history of diabetes mellitus, and background statin regimen. Patients with higher levels of Lp(a) at baseline had larger absolute reductions but comparatively smaller percent reductions in Lp(a) with AMG145 compared with those with lower baseline Lp(a) values. CONCLUSIONS: AMG145 significantly reduces Lp(a), by up to 32%, among subjects with hypercholesterolemia receiving statin therapy, offering an additional, complementary benefit beyond robust low-density lipoprotein cholesterol reduction with regard to a patient's atherogenic lipid profile.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hipercolesterolemia/sangue , Hipercolesterolemia/tratamento farmacológico , Lipoproteína(a)/sangue , Pró-Proteína Convertases/imunologia , Serina Endopeptidases/imunologia , Idoso , Anticorpos Monoclonais Humanizados , Biomarcadores/sangue , LDL-Colesterol/sangue , Relação Dose-Resposta a Droga , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/tratamento farmacológico , Pró-Proteína Convertase 9 , Fatores de Risco , Terapia Trombolítica
13.
J Thromb Thrombolysis ; 27(4): 438-46, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-18521540

RESUMO

BACKGROUND: Oxidative stress play an important role triggering platelet/endothelial activation. AGI-1067 is a novel, phenolic antioxidant, and vascular protectant which dose-dependently inhibits PEA biomarkers in vitro. Whether treatment with AGI-1067 alters platelets in vivo is not known. We serially assessed release of established PEA biomarkers in subjects treated with AGI-1067 versus placebo in the frame of Assessment of Lipoprotein Profiles Randomized Trial (ALPS). METHODS: Healthy subjects (18-65 years) with multiple risk factors for coronary artery disease were randomized 1:1 to receive 300 mg AGI-1067 (n = 112) or matching placebo (n = 117) daily for 12 weeks. Anticoagulants, aspirin, NSAIDS, and COX inhibitors were not permitted in this study. Plasma samples were collected at baseline, and at week 12 after randomization. Platelet factor 4 (PF4), beta-thromboglobulin (betaTG), P-selectin, thromboxane (TxB2), and prostacyclin (6-keto-PGF1a) were measured by ELISA. RESULTS: Treatment with AGI-1067 was associated with a highly significant reduction of TxB2 release (P < 0.0001) when compared to the placebo. There were no differences in PF4, betaTG, P-selectin, and 6-keto-PGF1a between and within groups. AGI-1067 also inhibits TxB2 release from calcium ionophore (A23187)-stimulated human platelets with the IC50 equals 1 microM; but does not interfere with 6-keto-PGF1alpha release in either A23187-, or TXA2-stimulated human aortic endothelial cells. CONCLUSION: AGI-1067 selectively reduces TxB(2 )production from stimulated platelets, and diminishes plasma TxB2 levels in ALPS participants. These data support earlier in vitro, and pilot ex vivo experiments suggesting antiplatelet properties of AGI-1067. Lack of 6-keto-PGF1a down regulation may represent an attractive advantage of AGI-1067 over currently available antiplatelet regimens.


Assuntos
Doença da Artéria Coronariana/prevenção & controle , Lipoproteínas/sangue , Probucol/análogos & derivados , Tromboxanos/antagonistas & inibidores , Tromboxanos/sangue , Adolescente , Adulto , Idoso , Biomarcadores/sangue , Células Cultivadas , Doença da Artéria Coronariana/sangue , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Probucol/uso terapêutico , Fatores de Risco , Doenças Vasculares/sangue , Doenças Vasculares/prevenção & controle , Adulto Jovem
14.
Med Sci Sports Exerc ; 39(11): 1985-8, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17986906

RESUMO

PURPOSE: To determine the frequency of the ACTN3 R577X polymorphism (functional R allele and nonfunctional X allele) in a variety of African populations and to examine its influence on the success of elite East African endurance runners and West African sprinters. METHODS: The R577X polymorphism was genotyped in 198 Ethiopian controls and 76 elite Ethiopian endurance athletes, 158 Kenyan controls and 284 elite Kenyan endurance runners, and 60 Nigerian controls and 62 elite Nigerian power athletes. Statistical analyses were performed by exact tests of population differentiation, using Arlequin, version 3. Analyses were carried out using 1 x 10(6) Markov chain steps, and 1 x 10(5) dememorization steps. RESULTS: The frequency of the X allele was extremely low among Kenyans and Nigerians (approximately 1% homozygosity) and higher in Ethiopians (approximately 11% homozygosity). The low baseline frequencies of the three populations tested mean that any associations with sprint performance would likely be obscured. In Ethiopians, where baseline levels of 577XX were about 11%, there was no increased frequency in the endurance athletes. CONCLUSION: Our data suggest that alpha-actinin-3 deficiency is not a major influence on performance in African athletes.


Assuntos
Actinina/genética , Polimorfismo Genético , Esportes , África Oriental , África Ocidental , Alelos , Cromossomos Humanos X , Frequência do Gene , Humanos , Cadeias de Markov
15.
Med J Aust ; 186(10): 513-8, 2007 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-17516898

RESUMO

OBJECTIVE: To gain some understanding of the attitudes and behaviours of Indigenous young people in Townsville concerning relationships, contraception and safe sex. DESIGN: Cross-sectional study using a computer-assisted self-administered survey and single-sex focus group discussions designed by a Young Mums' Group operating on participatory action principles and acting as peer interviewers. PARTICIPANTS AND SETTING: 171 Indigenous students in Years 9-11 at three high schools and 15 residents of a homeless youth shelter in Townsville, Queensland, 27 April - 8 December 2004. MAIN OUTCOME MEASURES: Self-reported attitudes and behaviour about relationships, sexual intercourse and contraception. RESULTS: 84/183 participants (45.9%) reported past sexual intercourse, with 56.1% commencing intercourse at age 13-14 years. The likelihood of having had sex increased with being male (P=0.001), increasing age, increased perceived sexual activity of peer group (both P=0.000), and drinking alcohol at least weekly (P=0.015). Young women were more likely to report unwanted sexual touching (P=0.031), and less likely to report enjoying sexual intercourse (P=0.001). The main qualitative themes concerned females' reputations, coercion, and denial of female desire. Only 49/80 participants (61.3%) reported always using condoms. The main reasons for not using contraception were "just not thinking about it", shame, and problems with access. Despite having reasonable knowledge about contraception, most lacked the confidence and negotiation skills to communicate with partners about condom use. CONCLUSIONS: Like teenagers elsewhere, Indigenous teenagers in Townsville are becoming sexually active at a young age, and not practising safe sex reliably. The need to protect their reputations puts young women at risk by not being prepared for safe sex by carrying condoms.


Assuntos
Comportamento do Adolescente , Atitude Frente a Saúde/etnologia , Comportamento Contraceptivo/etnologia , Conhecimentos, Atitudes e Prática em Saúde , Havaiano Nativo ou Outro Ilhéu do Pacífico , População Urbana , Adolescente , Estudos Transversais , Feminino , Grupos Focais , Humanos , Relações Interpessoais , Relações Mãe-Filho , Narração , Grupo Associado , Queensland , Educação Sexual/métodos , Fatores Sexuais , Inquéritos e Questionários
16.
J Clin Lipidol ; 1(4): 271-9, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21291691

RESUMO

BACKGROUND: AGI-1067 (succinobucol) is a phenolic derivative of probucol that inhibits the vascular oxidative-inflammatory cascade and is intended to have an improved clinical profile. OBJECTIVE: The Assessment of Lipoprotein Profiles (ALPS) study evaluated the effects of AGI-1067 on lipid, antioxidant, antiinflammatory and safety profiles in healthy subjects. METHODS: This was a double-blind, placebo-controlled, 12-week, multicenter trial. Eligible subjects, aged 18 to 65 years, had low-density lipoprotein cholesterol (LDL-C) ≤ 190 mg/dL, triglyceride (TG) ≤ 600 mg/dL and Framingham risk <10%. Subjects were randomized 1:1 to oral 300 mg AGI-1067 (n = 127) or matching placebo (n = 127) once daily. RESULTS: AGI-1067 and placebo treatment had small changes (mean) in: LDL-C (+2.98 vs -1.52 mg/dL, respectively; P = 0.057), apolipoprotein B (+1.48 vs -1.91 mg/dL; P = 0.267), high-density lipoprotein cholesterol (HDL-C) [-3.69 vs -0.29 mg/dL; P < 0.001], and apolipoprotein (Apo) A-I (-10.43 vs -6.14 mg/dL; P = 0.021). Subjects with baseline LDL-C > 130 mg/dL showed the largest decreases in HDL-C and ApoA-I, while subjects with LDL-C ≤130 mg/dL had insignificant changes in both parameters. Changes in cholesteryl ester transfer protein mass were significantly correlated (P < 0.0001) with LDL-C changes, but not HDL-C. Paraoxonase activity increased with AGI-1067 vs little change in placebo (+1.78 vs +0.15 U/L, respectively; P = 0.077). HDL particles isolated from AGI-1067 treated subjects showed significant antioxidant potency vs HDL particles from placebo subjects (thiobarbituric acid reactive substances in a LDL oxidation assay decreased -25.88% vs +7.88, respectively; P = 0.011). CONCLUSION: The ALPS study demonstrated that AGI-1067 had minor effects on LDL and HDL cholesterol. More dramatic effects were observed for HDL-associated paraoxonase and thiobarbituric acid reactive substances activity, suggesting that the antiatherosclerotic properties of AGI-1067 may involve an HDL antioxidant mechanism consistent with inhibition of the oxidative-inflammatory cascade, rather than involving a lipid regulating pathway.

17.
J Sports Sci ; 24(4): 415-22, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16492605

RESUMO

Kenyan athletes have dominated international distance running in recent years. Explanations for their success include favourable physiological characteristics, which could include favourable genetic endowment, and advantageous environmental conditions. The aim of this study was to compare the demographic characteristics of elite Kenyan runners with those of the general Kenyan population. Questionnaires, administered to 404 elite Kenyan runners specializing in distances ranging from the 800 m to the marathon and 87 Kenyan controls, obtained information on place of birth, language, and distance and method of travel to school. Athletes were separated into two groups according to athletic success: those who competed in international competition and those who competed in national competition. The athletes differed from controls in regional distribution, language, and distance and method of travel to school; athletes also differed from each other with the exception of method of travel to school. Most national and international athletes came from the Rift Valley province (controls 20%, national athletes 65%, international athletes 81%), belonged to the Kalenjin ethnic group (controls 8%, national athletes 49%, international athletes 76%) and Nandi sub-tribe (controls 5%, national athletes 25%, international athletes 44%), and spoke languages of Nilotic origin (controls 21%, national athletes 60%, international athletes 79%). A higher proportion of all athletes ran to school each day (controls 22%, national athletes 73%, international athletes 81%) and covered greater distances. In conclusion, Kenyan runners are from a distinctive environmental background in terms of geographical distribution, ethnicity and travelled further to school, mostly by running. These findings highlight the importance of environmental and social factors in the success of Kenyan runners.


Assuntos
Demografia , Resistência Física/fisiologia , Corrida/fisiologia , Corrida/estatística & dados numéricos , Adolescente , Adulto , Estudos de Casos e Controles , Países em Desenvolvimento , Feminino , Humanos , Incidência , Quênia/epidemiologia , Masculino , Aptidão Física/fisiologia , Probabilidade , Inquéritos e Questionários
18.
Congest Heart Fail ; 9(3): 176-8, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12826777

RESUMO

Pulmonary hypertension is a daunting accompaniment of advanced heart failure. Efforts to safely and consistently lower pulmonary vascular resistance are necessary but fraught with challenges. In this report the authors explore the novel use of sildenafil, an inhibitor of phosphodiesterase-5, in tackling pulmonary hypertension in heart failure. The salutary effects of this agent deserve further study.


Assuntos
3',5'-GMP Cíclico Fosfodiesterases/uso terapêutico , Hipertensão Pulmonar/tratamento farmacológico , Piperazinas/uso terapêutico , Insuficiência Cardíaca/complicações , Humanos , Hipertensão Pulmonar/etiologia , Masculino , Pessoa de Meia-Idade , Purinas , Citrato de Sildenafila , Sulfonas
19.
Transplantation ; 74(11): 1568-73, 2002 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-12490790

RESUMO

BACKGROUND: Black American heart transplant recipients receiving cyclosporine-based primary immunoprophylaxis suffer higher rates of allograft rejection with hemodynamic compromise, infections, and posttransplant coronary artery disease. We examined the hypothesis that a combination of tacrolimus and mycophenolate mofetil "resurrects" clinical outcome of black Americans to those seen in white heart transplant recipients. METHODS: Sixty-three adult primary heart transplant recipients were included in this study. Twenty black American and 21 white patients who received tacrolimus-based primary immunoprophylaxis were enrolled in this prospective, observational parallel cohort investigation. A separate group of 22 black American patients were randomly allocated to receive cyclosporine-microemulsion-based primary prophylaxis and served as the control population for assessing outcomes in the black American group. Adjunctive immunosuppression included mycophenolate mofetil and corticosteroids. The primary end-point was the freedom from allograft rejection requiring treatment at 1 year. Secondary end-points included rejection with hemodynamic compromise, and patient or graft survival. Adverse events evaluated included development of infections requiring hospitalization and nonimmunological outcomes including hyperlipidemia, hypertension, and diabetes mellitus (new onset or worsened). RESULTS: Tacrolimus-treated black American patients had greater freedom from allograft rejection requiring treatment at 1 year than those treated with cyclosporine (64% vs. 37%, P=0.01). No differences were noted between tacrolimus-treated black Americans and whites in the primary end point (64% and 67% respectively, P=nonsignificant [NS]). Tacrolimus-based immunosuppression was associated with better 1-year survival in black Americans compared with cyclosporine (95% vs. 73%, P=0.04), and this end point was similar to that achieved in tacrolimus-treated white heart transplant recipients (95%). No differences in infection rates were noted among either group. Cyclosporine-treated black Americans suffered more hyperlipidemia and worse hypertension than tacrolimus-treated patients. CONCLUSIONS: Compared with cyclosporine, an immunosuppressive strategy using tacrolimus in black Americans achieves superior efficacy with regard to allograft rejection, higher allograft survival, and similar safety. Furthermore, tacrolimus-based immunosuppression is similar in immunological efficacy and safety in black Americans and in white heart transplant recipients.


Assuntos
População Negra , Transplante de Coração , Imunossupressores/uso terapêutico , Ácido Micofenólico/uso terapêutico , Tacrolimo/uso terapêutico , População Branca , Adulto , Negro ou Afro-Americano , Idoso , Peso Corporal , Creatinina/sangue , Infecções por Citomegalovirus/epidemiologia , Infecções por Citomegalovirus/etiologia , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Feminino , Rejeição de Enxerto/epidemiologia , Rejeição de Enxerto/fisiopatologia , Rejeição de Enxerto/prevenção & controle , Transplante de Coração/efeitos adversos , Hemodinâmica , Humanos , Hiperlipidemias/etiologia , Hipertensão/etiologia , Imunossupressores/administração & dosagem , Imunossupressores/sangue , Incidência , Masculino , Pessoa de Meia-Idade , Ácido Micofenólico/análogos & derivados , Tacrolimo/administração & dosagem , Tacrolimo/sangue , Transplante Homólogo , Resultado do Tratamento
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