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1.
Mon Not R Astron Soc ; 492(4): 6105-6119, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33867587

RESUMO

Most of the major planets in the Solar System support populations of co-orbiting bodies, known as Trojans, at their L4 and L5 Lagrange points. In contrast, Earth has only one known co-orbiting companion. This paper presents the results from a search for Earth Trojans using the DECam instrument on the Blanco Telescope at CTIO. This search found no additional Trojans in spite of greater coverage compared to previous surveys of the L5 point. Therefore, the main result of this work is to place the most stringent constraints to date on the population of Earth Trojans. These constraints depend on assumptions regarding the underlying population properties, especially the slope of the magnitude distribution (which in turn depends on the size and albedo distributions of the objects). For standard assumptions, we calculate upper limits to a 90% confidence limit on the L5 population of N ET < 1 for magnitude H < 15.5, N ET =60-85 for H < 19.7, and N ET = 97 for H=20.4. This latter magnitude limit corresponds to Trojans ∼300 m in size for albedo 0.15. At H=19.7, these upper limits are consistent with previous L4 Earth Trojan constraints and significantly improve L5 constraints.

2.
S. Afr. med. j. (Online) ; 109(11): 872-875, 2019. tab
Artigo em Inglês | AIM (África) | ID: biblio-1271211

RESUMO

Background. Sickle cell disease (SCD) is an inherited haemoglobinopathy in which homozygous individuals suffer from numerous complications including vaso-occlusion, infection and haemolytic anaemia. Patients therefore often require blood transfusions, which may lead to elevated levels of allogeneic antibodies. In South Africa (SA), the number of patients with SCD has risen significantly owing to migration and changing demographics, leading to an increased need for blood products.Objectives. Against the above background, to determine the incidence of alloimmunisation and the presence of clinically significant antibodies in SCD patients requiring transfusions in Cape Town, SA.Methods. Information on SCD patients receiving blood products between 2010 and 2012, including demographics, number of units transfused and the presence and type of alloantibodies, was collected. The results were compared with those for non-SCD controls who had received a similar number of transfusions.Results. Of 182 patients analysed, 91 had SCD. Twenty-two percent of the SCD patients and 13.2% of the controls had become alloimmunised (p=0.12), while the proportions of those receiving transfusions and acquiring clinically significant antibodies were similar between the two groups (p=0.17 and p=0.19, respectively). However, the total number and amount of unidentified antibodies were significantly increased in patients with SCD (p=0.02 and p<0.001, respectively).Conclusions. This study concluded that patients with SCD develop increased numbers of unidentified antibodies, which may be important in the selection of suitable donors


Assuntos
Anemia Falciforme , Anticorpos , Transfusão de Sangue , África do Sul
3.
Cardiovasc Diabetol ; 16(1): 114, 2017 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-28915818

RESUMO

BACKGROUND: Good glycaemic control in type 2 diabetes (T2DM) protects the microcirculation. Current guidelines suggest glycaemic targets be relaxed in advanced diabetes. We explored whether disease duration or pre-existing macrovascular complications attenuated the association between hyperglycaemia and microvascular function. METHODS: 743 participants with T2DM (n = 222), cardiovascular disease (CVD = 183), both (n = 177) or neither (controls = 161) from two centres in the UK, underwent standard clinical measures and endothelial dependent (ACh) and independent (SNP) microvascular function assessment using laser Doppler imaging. RESULTS: People with T2DM and CVD had attenuated ACh and SNP responses compared to controls. This was additive in those with both (ANOVA p < 0.001). In regression models, cardiovascular risk factors accounted for attenuated ACh and SNP responses in CVD, whereas HbA1c accounted for the effects of T2DM. HbA1c was associated with ACh and SNP response after adjustment for cardiovascular risk factors (adjusted standardised beta (ß) -0.096, p = <0.008 and -0.135, p < 0.001, respectively). Pre-existing CVD did not modify this association (ß -0.099; p = 0.006 and -0.138; p < 0.001, respectively). Duration of diabetes accounted for the association between HbA1c and ACh (ß -0.043; p = 0.3), but not between HbA1c and SNP (ß -0.105; p = 0.02). CONCLUSIONS: In those with T2DM and CVD, good glycaemic control is still associated with better microvascular function, whereas in those with prolonged disease this association is lost. This suggests duration of diabetes may be a better surrogate for "advanced disease" than concomitant CVD, although this requires prospective validation.


Assuntos
Glicemia/metabolismo , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/diagnóstico por imagem , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/diagnóstico por imagem , Microcirculação/fisiologia , Idoso , Doenças Cardiovasculares/epidemiologia , Estudos de Casos e Controles , Comorbidade , Diabetes Mellitus Tipo 2/epidemiologia , Feminino , Índice Glicêmico/fisiologia , Humanos , Fluxometria por Laser-Doppler/métodos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
4.
Urologe A ; 55(10): 1309-1316, 2016 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-27620184

RESUMO

Urological and surgical treatment of urinary stones are highly technological and technology-driven disciplines in present-day surgery. German medical engineering has always been recognized for its technical innovations in endoscopic surgery. Current and future trends are indicative of further miniaturization and automation of surgical instruments and assist systems to facilitate endourological procedures as well as improvements in the quality of results and ergonomics. These technologies include, e. g. 3D-tracking to facilitate access to the pelvicaliceal system for percutaneous nephrolithotomy (PNL) or robotic master-slave systems for endourology. The aim of all future stone treatment should be complete stone removal. This could be achieved by improved stone fragmentation ("micron-sized debris") or complete removal of fragments (e. g. using a "stone glue"). Integration of diagnostic procedures and treatments will constitute a key aspect of future developments in medical engineering. Intelligent laser systems may be capable of distinguishing stones from mucosa and artificial surfaces and may be used for immediate stone analysis during surgery. A simpler and faster availability of metabolic ("metabolomics") and genetic ("genomics") diagnostics will help to facilitate and improve individual metaphylaxis, e. g. in patient self-management. Nanotechnology and microrobots that may be used for endoluminal diagnostics and treatment of the urinary tract are already in development.


Assuntos
Litotripsia/tendências , Nefrostomia Percutânea/tendências , Assistência Centrada no Paciente/tendências , Cirurgia Assistida por Computador/tendências , Ureteroscopia/tendências , Urolitíase/terapia , Terapia Combinada/tendências , Previsões , Humanos , Procedimentos Cirúrgicos Minimamente Invasivos/tendências , Resultado do Tratamento , Urolitíase/diagnóstico , Urologia/tendências
5.
J Intern Med ; 278(3): 291-302, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25752315

RESUMO

BACKGROUND: There is a need to develop and validate surrogate markers of cardiovascular disease (CVD) in subjects with diabetes. The macrovascular changes associated with diabetes include aggravated atherosclerosis, increased arterial stiffness and endothelial dysfunction. The aim of this study was to determine which of these factors is most strongly associated with clinically manifest cardiovascular events. METHODS: Vascular changes were measured in a cohort of 458 subjects with type 2 diabetes (T2D) and CVD (myocardial infarction, stroke or lower extremity arterial disease), 527 subjects with T2D but without clinically manifest CVD and 515 subjects without T2D and with or without CVD. RESULTS: Carotid intima-media thickness (IMT) and ankle-brachial pressure index were independently associated with the presence of CVD in subjects with T2D, whereas pulse wave velocity and endothelial function provided limited independent additive information. Measurement of IMT in the carotid bulb provided better discrimination of the presence of CVD in subjects with T2D than measurement of IMT in the common carotid artery. The factors most significantly associated with increased carotid IMT in T2D were age, disease duration, systolic blood pressure, impaired renal function and increased arterial stiffness, whereas there were no or weak independent associations with metabolic factors and endothelial dysfunction. CONCLUSIONS: Measures of atherosclerotic burden are associated with clinically manifest CVD in subjects with T2D. In addition, vascular changes that are not directly related to known metabolic risk factors are important in the development of both atherosclerosis and CVD in T2D. A better understanding of the mechanisms involved is crucial for enabling better identification of CVD risk in T2D.


Assuntos
Arteriosclerose/diagnóstico por imagem , Doenças Cardiovasculares/patologia , Diabetes Mellitus Tipo 2/complicações , Idoso , Artérias Carótidas/diagnóstico por imagem , Espessura Intima-Media Carotídea , Estudos Transversais , Diabetes Mellitus Tipo 2/patologia , Endotélio Vascular/fisiopatologia , Europa (Continente) , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Regressão , Fatores de Risco , Rigidez Vascular/fisiologia
6.
Biomed Res Int ; 2015: 968302, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25710038

RESUMO

Red blood cells undergo a series of biochemical fluctuations during 35-42-day storage period at 1°C to 6°C. The sodium/potassium pump is immobilised causing a decrease in intracellular potassium with an increase in cytoplasmic sodium levels, glucose levels decline, and acidosis occurs as a result of low pH levels. The frailty of stored erythrocytes triggers the formation of haemoglobin-containing microparticles and the release of cell-free haemoglobin which may add to transfusion difficulties. Lipid peroxidation, oxidative stress to band 3 structures, and other morphological and structural molecular changes also occur leading to spheroechinocytes and osmotic fragility. These changes that transpire in the red cells during the storage period are referred to as "storage lesions." It is well documented that gamma irradiation exacerbates storage lesions and the reports of increased potassium levels leading to adverse reactions observed in neonates and infants have been of particular concern. There are, however, remarkably few systematic studies comparing the in vitro storage lesions of irradiated and nonirradiated red cell concentrates and it has been suggested that the impact of storage lesions on leucocyte reduced red blood cell concentrate (RBCC) is incomplete. The review examines storage lesions in red blood cells and their adverse effects in reference to blood transfusion.


Assuntos
Preservação de Sangue/métodos , Eritrócitos/metabolismo , Eritrócitos/efeitos da radiação , Animais , Células Cultivadas , Relação Dose-Resposta à Radiação , Transfusão de Eritrócitos , Eritrócitos/citologia , Humanos , Doses de Radiação , Manejo de Espécimes
7.
Nutr Metab Cardiovasc Dis ; 25(3): 287-94, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25455721

RESUMO

BACKGROUND AND AIMS: Low 25-hydroxyvitamin D levels are common in patients with chronic fatigue syndrome; such patients also manifest impaired vascular health. We tested whether high-dose intermittent oral vitamin D therapy improved markers of vascular health and fatigue in patients with chronic fatigue syndrome. METHODS AND RESULTS: Parallel-group, double-blind, randomised placebo-controlled trial. Patients with chronic fatigue syndrome according to the Fukuda (1994) and Canadian (2003) criteria were randomised to receive 100,000 units oral vitamin D3 or matching placebo every 2 months for 6 months. The primary outcome was arterial stiffness measured using carotid-femoral pulse wave velocity at 6 months. Secondary outcomes included flow-mediated dilatation of the brachial artery, blood pressure, cholesterol, insulin resistance, markers of inflammation and oxidative stress, and the Piper Fatigue scale. As many as 50 participants were randomised; mean age 49 (SD 13) years, mean baseline pulse wave velocity 7.8 m/s (SD 2.3), mean baseline office blood pressure 128/78 (18/12) mmHg and mean baseline 25-hydroxyvitamin D level 46 (18) nmol/L. 25-hydroxyvitamin D levels increased by 22 nmol/L at 6 months in the treatment group relative to placebo. There was no effect of treatment on pulse wave velocity at 6 months (adjusted treatment effect 0.0 m/s; 95% CI -0.6 to 0.6; p = 0.93). No improvement was seen in other vascular and metabolic outcomes, or in the Piper Fatigue scale at 6 months (adjusted treatment effect 0.2 points; 95% CI -0.8 to 1.2; p = 0.73). CONCLUSION: High-dose oral vitamin D3 did not improve markers of vascular health or fatigue in patients with chronic fatigue syndrome. TRIAL REGISTRATION: www.controlled-trials.com, ISRCTN59927814.


Assuntos
Fenômenos Fisiológicos Cardiovasculares/efeitos dos fármacos , Colecalciferol/administração & dosagem , Síndrome de Fadiga Crônica/tratamento farmacológico , Adulto , Biomarcadores/sangue , Pressão Sanguínea/efeitos dos fármacos , Artéria Braquial/efeitos dos fármacos , Artéria Braquial/metabolismo , Canadá , Colecalciferol/sangue , Colesterol/sangue , Suplementos Nutricionais , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Inflamação/sangue , Inflamação/tratamento farmacológico , Resistência à Insulina , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo/efeitos dos fármacos , Análise de Onda de Pulso , Resultado do Tratamento , Rigidez Vascular , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/complicações
8.
Phys Chem Chem Phys ; 16(43): 23908-14, 2014 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-25277596

RESUMO

An experimental study of Xe and Kr adsorption in metal-organic frameworks CPO-27-Ni, CPO-27-Mg, and ZIF-8 was carried out. In situ synchrotron X-ray powder diffraction experiments allowed precise determination of the adsorption sites and sequence of their filling with increasing of gas pressure at different temperatures. Structural investigations were used for interpretation of gas adsorption measurements.


Assuntos
Criptônio/química , Compostos Organometálicos/química , Xenônio/química , Adsorção , Gases Nobres/química , Compostos Organometálicos/síntese química , Temperatura , Difração de Raios X
9.
Science ; 343(6174): 988-90, 2014 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-24526313

RESUMO

Observations with the Interstellar Boundary Explorer (IBEX) have shown enhanced energetic neutral atom (ENA) emission from a narrow, circular ribbon likely centered on the direction of the local interstellar medium (LISM) magnetic field. Here, we show that recent determinations of the local interstellar velocity, based on interstellar atom measurements with IBEX, are consistent with the interstellar modulation of high-energy (tera-electron volts, TeV) cosmic rays and diffusive propagation from supernova sources revealed in global anisotropy maps of ground-based high-energy cosmic-ray observatories (Milagro, Asγ, and IceCube). Establishing a consistent local interstellar magnetic field direction using IBEX ENAs at hundreds to thousands of eV and galactic cosmic rays at tens of TeV has wide-ranging implications for the structure of our heliosphere and its interactions with the LISM, which is particularly important at the time when the Voyager spacecraft are leaving our heliosphere.

10.
Horm Metab Res ; 44(4): 306-11, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22274718

RESUMO

Type 2 familial partial lipodystrophy (FPLD2) patients show impaired glucose and lipid metabolism resulting from lipodystrophic 'lipid pressure' and an intrinsic defect in skeletal muscle metabolism. Since mutated lamin A may interfere with peroxisome proliferator activator gamma (PPARγ) expression, we hypothesized that PPARγ stimulation improves fat distribution and metabolic abnormalities in these patients. 5 nondiabetic FPLD2 patients were treated with rosiglitazone over 12 months. We assessed body composition, body fat distribution, and skinfold thickness/subcutaneous tissue thickness. We also determined venous glucose, insulin, and free fatty acid (FFA) concentrations, and respiratory quotient (RQ) before and during oral glucose tolerance testing. Adipose tissue and muscle fasting and postprandial metabolism were studied by microdialysis. Within 12 months treatment, hip circumference increased from 93.6±2.78 cm to 96.2±2.3 cm (p<0.05). Rosiglitazone reduced fasting glucose levels and liver transaminases. Baseline and postprandial FFA concentrations were significantly lower after 12 months treatment. RQ and muscle interstitial pyruvate and lactate did not respond to treatment. We conclude that PPARγ stimulation with rosiglitazone modestly improves glucose metabolism in FPLD2 patients presumably through proximal adipose tissue expansion. The intrinsic muscular metabolic defect does not respond to rosiglitazone.


Assuntos
Lamina Tipo A/genética , Lipodistrofia Parcial Familiar/tratamento farmacológico , Lipodistrofia Parcial Familiar/genética , Mutação , Tiazolidinedionas/uso terapêutico , Adulto , Glicemia/metabolismo , Composição Corporal/efeitos dos fármacos , Colesterol/metabolismo , Feminino , Humanos , Lipodistrofia , Lipodistrofia Parcial Familiar/metabolismo , Masculino , Pessoa de Meia-Idade , Adulto Jovem
12.
Eur J Clin Nutr ; 64(7): 704-13, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20372175

RESUMO

OBJECTIVES: Drinking green tea is associated with many health benefits, including increased fat oxidation. We tested the hypothesis that epigallocatechin-3-gallate (EGCG), the main green tea catechin, increases fat oxidation in obese men. METHODS: Ten healthy overweight/obese males (body mass index 31.3+/-0.8 kg/m(2)) were studied in a randomized, placebo-controlled, double-blind crossover trial. Study supplements were low EGCG (300 mg), high EGCG (600 mg), caffeine (200 mg), EGCG/caffeine (300 mg/200 mg) or placebo and were taken orally for 3 days. At the third day of supplementation, O(2) consumption and CO(2) production was measured by indirect calorimetry to assess energy expenditure and fat oxidation over 4 h each after overnight fasting and after a standardized test meal. RESULTS: Energy expenditure was not affected by any supplementation, neither after overnight fasting nor after the test meal. During the first 2 h after overnight fasting, fat oxidation increased by 7.7 (not significant, NS), 15.2 (NS), 26.3 (P<0.05 vs placebo) and 35.4% (P<0.01 vs placebo and low EGCG), for low EGCG, high EGCG, caffeine and EGCG/caffeine, respectively. During the first 2 h after the meal, the mean increase in fat oxidation was 33.3 (P<0.05 vs placebo), 20.2 (NS), 34.5 (P<0.05 vs placebo) and 49.4% (P<0.05 vs placebo) for low EGCG, high EGCG, caffeine and EGCG/caffeine, respectively. CONCLUSIONS: Low EGCG increases postprandial fat oxidation in obese men and this to the same extent as 200 mg caffeine, whereas high EGCG does not exert this effect. Fasting fat oxidation is increased only by caffeine (with or without EGCG). There is no synergism of low EGCG and 200 mg caffeine. Energy expenditure is not affected by EGCG.


Assuntos
Antioxidantes/farmacologia , Catequina/análogos & derivados , Peroxidação de Lipídeos/efeitos dos fármacos , Obesidade/metabolismo , Extratos Vegetais/farmacologia , Adulto , Cafeína/farmacologia , Catequina/farmacologia , Estudos Cross-Over , Suplementos Nutricionais , Relação Dose-Resposta a Droga , Método Duplo-Cego , Metabolismo Energético/efeitos dos fármacos , Jejum , Humanos , Masculino , Sobrepeso/metabolismo , Projetos Piloto , Período Pós-Prandial , Adulto Jovem
13.
Rev Sci Instrum ; 78(8): 085101, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17764349

RESUMO

A simple design for a cesium sputter ion source compatible with vacuum and ion-optical systems as well as with electronics of the commercially available Cameca IMS-4f instrument is reported. This ion source has been tested with the cluster primary ions of Si(n)(-) and Cu(n)(-). Our experiments with surface characterization and depth profiling conducted to date demonstrate improvements of the analytical capabilities of the secondary ion mass spectrometry instrument due to the nonadditive enhancement of secondary ion emission and shorter ion ranges of polyatomic projectiles compared to atomic ones with the same impact energy.


Assuntos
Césio , Desenho Assistido por Computador , Íons Pesados , Espectrometria de Massas por Ionização por Electrospray/instrumentação , Transdutores , Desenho de Equipamento , Análise de Falha de Equipamento , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria de Massas por Ionização por Electrospray/métodos
14.
Bol. Asoc. Méd. P. R ; 99(1): 46-50, jan.-mar. 2007.
Artigo em Inglês | LILACS | ID: lil-471878

RESUMO

Malpositioning of a permanent pacemaker lead in the left ventricle is rare. Usually, a paced right bundle branch pattern is the initial finding that fosters other confirmatory studies such as chest films and transthoracic echocardiogram. We describe the unusual case of an asymptomatic 83-year-old male patient who was incidentally found with a permanent pacemaker lead placed through the atrial septum into the left ventricle. This patient had contraindications for chronic anticoagulation and was placed on antiplatelet therapy instead. He has been well after three years without evidence of embolic episodes.


Assuntos
Humanos , Masculino , Idoso de 80 Anos ou mais , Bloqueio de Ramo/terapia , Marca-Passo Artificial , Corpos Estranhos/diagnóstico , Corpos Estranhos/terapia , Marca-Passo Artificial/efeitos adversos
15.
Biochem Pharmacol ; 72(12): 1724-9, 2006 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-17027670

RESUMO

Regional adrenergic function is difficult to assess in humans. Tyramine given through a microdialysis probe may be a useful tool in this regard. However, tyramine data is hard to interpret given the drug's complex mode of action. We characterized the response to tyramine, isoproterenol, and dopamine in adipose tissue with microdialysis probes in normal subjects. We measured glycerol concentrations to follow changes in lipolysis and monitored tissue perfusion with ethanol dilution. During perfusion with tyramine, dialysate glycerol concentration increased dose-dependently from 83+/-8 microM at baseline to 181+/-18 microM at 3.5 mM tyramine (p<0.001) followed by a fall down to 121+/-9 microM at 35 mM tyramine (p<0.001). Propranolol almost completely blocked this response. A similar lipolytic response was not observed in isolated human adipocytes. Dopamine <35 microM did not replicate the tyramine-induced lipolysis; however, dopamine >35 microM potently inhibited lipolysis. We conclude that tyramine-induced lipolysis is explained by a pre-synaptic mechanism. Tyramine applied through a microdialysis probe in concentrations up to 3.5 mM can be used to assess pre- and post-synaptic mechanisms regulating lipid mobilization.


Assuntos
Adipócitos/efeitos dos fármacos , Tecido Adiposo/efeitos dos fármacos , Inibidores da Captação Adrenérgica/farmacologia , Glicerol/metabolismo , Tiramina/farmacologia , Adipócitos/metabolismo , Tecido Adiposo/metabolismo , Adulto , Dopamina/metabolismo , Dopamina/farmacologia , Relação Dose-Resposta a Droga , Feminino , Humanos , Isoproterenol/farmacologia , Lipólise/efeitos dos fármacos , Masculino , Microdiálise , Pessoa de Meia-Idade , Perfusão , Dobras Cutâneas , Gordura Subcutânea/efeitos dos fármacos , Gordura Subcutânea/metabolismo
16.
Horm Metab Res ; 38(5): 323-9, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16718629

RESUMO

AT1 receptor blockers and ACE inhibitors decrease the risk for new onset diabetes mellitus. The phenomenon could be related to a direct angiotensin II effect on tissue metabolism. To address the issue, we recruited eighteen obese hypertensive patients. Patients were randomized to double-blind treatment with either valsartan (n = 8) or atenolol (n = 10) for thirteen weeks. They underwent an oral glucose tolerance test before and during active treatment, while metabolism was monitored through subcutaneous and intramuscular microdialysis and indirect calorimetry. After glucose ingestion, venous glucose and insulin concentrations increased rapidly while systemic free fatty acid concentrations were suppressed. Dialysate glucose and lactate concentrations increased briskly in adipose tissue and in skeletal muscle. Dialysate glycerol decreased profoundly in both tissues. Respiratory quotient increased markedly after glucose ingestion. These responses were identical at baseline and during active treatment either drug. We conclude that AT1 receptor blockade in obese hypertensive patients has no effect on interstitial glucose supply, lipolysis, and substrate oxidation. One possible explanation is that angiotensin II levels in obese hypertensives are not sufficient to elicit the metabolic changes that have been observed after direct angiotensin II application. The exact mechanism by which inhibition of the renin-angiotensin-aldosterone system decreases the diabetes risk remains unresolved and requires further study.


Assuntos
Antagonistas Adrenérgicos beta/administração & dosagem , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Glucose/administração & dosagem , Hipertensão/tratamento farmacológico , Metabolismo/efeitos dos fármacos , Obesidade/complicações , Tecido Adiposo/química , Atenolol/administração & dosagem , Glicemia/análise , Diabetes Mellitus Tipo 2/prevenção & controle , Método Duplo-Cego , Etanol/análise , Ácidos Graxos não Esterificados/análise , Ácidos Graxos não Esterificados/sangue , Feminino , Glucose/análise , Teste de Tolerância a Glucose , Glicerol/análise , Humanos , Hipertensão/complicações , Insulina/sangue , Cinética , Ácido Láctico/análise , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/química , Tetrazóis/administração & dosagem , Valina/administração & dosagem , Valina/análogos & derivados , Valsartana
17.
J Neuroimaging ; 15(4): 331-5, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16254397

RESUMO

BACKGROUND AND PURPOSE: Substantial variability in functional outcome and relatively few factors predictive of death or degree of recovery have been observed in patients with lacunar stroke. Such indicators are of great use in the selection of optimal rehabilitation strategies after stroke. Although computed tomography (CT) of patients with a clinical diagnosis of lacunar stroke performed within the first 10 days shows evidence of cerebral infarction in 50% to 60%, the prognostic significance of a visible ischemic lesion on CT is unclear. METHODS: 633 patients who presented with symptoms consistent with lacunar stroke between June 1990 and February 1998 were studied. One hundred fourteen patients imaged with magnetic resonance, 41 patients with nonischemic diagnoses (hemorrhage or tumor), 57 patients imaged within 12 hours of ictus, and 17 patients with incomplete follow-up were excluded from the analysis. The remaining 404 patients were divided into 2 groups, depending on the appearance of the CT scan. Patients with a low-attenuation area on the CT scan consistent with an ischemic lesion in an appropriate region of the brain to explain the presenting symptoms were classified as "CT positive." Patients with either a normal CT scan of the brain or a scan that showed a lesion in an area inconsistent with the presenting symptoms were classified as "CT negative." A series of known or suspected prognostic factors were recorded for each patient: blood pressure, age, smoking, plasma glucose level, serum cholesterol level, and serum triglyceride level. Delay from stroke onset to scanning was also noted. The authors considered 3 outcome measures: survival time, outcome at 6 months after the stroke, and total length of hospital stay for the stroke admission. Six-month outcome was categorized as good (alive at home) or poor (alive in care or dead). RESULTS: There was no difference in survival between the 2 groups (P= .29, log-rank test). After adjusting for other significant prognostic factors (age; relative hazard per additional decade 1.67, P< .0001: plasma glucose level; relative hazard per additional mmol/l 1.08, P= .03) in a proportional hazards model, presence of visible infarction remained nonsignificant (relative hazard 0.84, P= .40). After adjustment for the other significant factor (age, P= .0001), there was no significant difference in 6-month outcome between CT positive and CT negative patients (P= .61). Median total length of hospital stay was not significantly different between the 2 groups (CT positive, 9 days; CT negative, 8 days; Mann-Whitney test, P= .29). CONCLUSION: The authors conclude that in their cohort of patients, having corrected for other prognostic variables, the presence of visible infarction on CT brain scan performed between 12 hours and 30 days of onset of lacunar symptoms is not predictive of duration of hospital stay or of longer term outcome.


Assuntos
Infarto Encefálico/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Idoso , Infarto Encefálico/mortalidade , Feminino , Seguimentos , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Prognóstico , Modelos de Riscos Proporcionais , Taxa de Sobrevida
18.
Horm Metab Res ; 37(2): 68-73, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15778921

RESUMO

Blood flow in subcutaneous adipose tissue is reduced in obese compared to lean subjects. Limitations in vascular supply might interfere with adipose tissue function as a metabolic and endocrine organ. We tested the hypothesis that nutritive blood flow and tissue metabolism depends on subcutaneous adipose tissue thickness even in normal-weight subjects. Sixteen young, healthy, normal-weight subjects (8 men, 8 women) were included in the study. Abdominal subcutaneous adipose thickness was assessed by skin-fold measurements. The microdialysis technique was applied for monitoring basal adipose tissue blood flow (ethanol dilution technique) and metabolism. An increase in skin-fold thickness from 15 to 45 mm and from 8 to 37 mm was associated with a linear increase in basal ethanol ratio from 0.19 to 0.63 and 0.25 to 0.75 and linear decreases in dialysate glucose concentrations from 1.95 to 0.24 mM and 1.68 to 0.29 mM, and 152 to 42 microM and 172 to 49 microM for glycerol concentrations in men and women, respectively (p < 0.05). Isoproterenol-stimulated blood flow also inversely correlated to skin-fold thickness (p < 0.05). We conclude that increased adipose tissue thickness is associated with reduced tissue perfusion and metabolism, even in lean subjects. Skin-fold thickness is an important confounding variable in metabolic studies, particularly in microdialysis experiments.


Assuntos
Tecido Adiposo/irrigação sanguínea , Pele/irrigação sanguínea , Tecido Adiposo/metabolismo , Agonistas Adrenérgicos beta , Adulto , Etanol/administração & dosagem , Etanol/metabolismo , Feminino , Glucose/metabolismo , Glicerol/metabolismo , Humanos , Isoproterenol/administração & dosagem , Masculino , Microdiálise , Pele/metabolismo , Solventes/administração & dosagem , Solventes/metabolismo
20.
Nutrition ; 19(9): 733-40, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12921882

RESUMO

OBJECTIVES: We wanted to establish optimum protein and glucose intakes during total parenteral nutrition by using a constant caloric but changing protein intake in critically ill, ventilated, anuric patients on continuous renal replacement therapy and measuring amino acid and glucose losses across the hemofilter. METHODS: Eleven consecutive, critically ill patients (eight male, age, 43.5 +/- 21.8 y; Acute Physiology and Chronic Health Evaluation II score, 20.5 +/- 7.0; Acute Physiology and Chronic Health Evaluation risk of death: 36.5% +/- 23.0 and 6 +/- 1 impaired organ systems) entered this study. Patients were fed by continuous infusion of a total parenteral mixture consisting of Synthamin (a mixture of essential and non-essential amino acids), 50% dextrose, and intralipid (long-chain triglycerides) to meet caloric requirements as predicted by Schofield's equation corrected by stress factors. The amount of protein infused was varied (1 to 2.5 g. kg(-1). d(-1)) by increments of 0.25 g. kg(-1). d(-1). Patients were stabilized on each feeding regimen for at least 24 h before paired samples of blood and dialysate were taken for amino acid and glucose measurements. Continuous renal replacement therapy was performed by using a blood pump with a blood flow of 100 to 175 mL/min. Dialysate was pumped in and out counter-currently to the blood flow at 2 L/h. A biocompatible polyacrylonitrile hemofilter was used in all cases. RESULTS: With protein intakes below 2.5 g. kg(-1). d(-1), blood levels of 14% to 57% of the measured amino acids were below the lower limits of the normal range. At 2.5 g. kg(-1). d(-1), all measured amino acids were within the normal range. Amino acid balance became more positive as protein input increased (P = 0.0001). Glucose and amino acid losses were dependent on blood concentration. Overall, 17% (range, 13% to 24%) of infused amino acids and 4% of infused glucose were lost in the dialysate. CONCLUSIONS: This study of critically ill, ventilated, anuric patients on continuous renal replacement therapy suggested that increases in protein and glucose are required to account for the increased losses across the hemofilter. A protein intake of 2.5 g. kg(-1). d(-1) appeared to optimize nitrogen balance and correct amino acid deficiencies.


Assuntos
Aminoácidos/metabolismo , Estado Terminal , Glucose/metabolismo , Nutrição Parenteral Total/métodos , Insuficiência Renal/terapia , Adulto , Aminoácidos/administração & dosagem , Anuria , Estado Terminal/terapia , Soluções para Diálise/análise , Feminino , Glucose/administração & dosagem , Humanos , Masculino , Necessidades Nutricionais , Terapia de Substituição Renal
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