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1.
Age Ageing ; 52(1)2023 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-36729468

RESUMEN

BACKGROUND: there is a trend across Europe to enable more care at the community level. The Acute Geriatric Community Hospital (AGCH) in the Netherlands in an acute geriatric unit situated in a skilled nursing facility (SNF). It provides hospital-level care for older adults with acute medical conditions. The aim of this study is to identify barriers and facilitators associated with implementing the AGCH in a SNF. METHODS: semi-structured interviews (n = 42) were carried out with clinical and administrative personnel at the AGCH and university hospital and stakeholders from the partnering care organisations and health insurance company. Data were analysed using thematic analysis. RESULTS: facilitators to implementing the AGCH concept were enthusiasm for the AGCH concept, organising preparatory sessions, starting with low-complex patients, good team leadership and ongoing education of the AGCH team. Other facilitators included strong collaboration between stakeholders, commitment to shared investment costs and involvement of regulators.Barriers to implementation were providing hospital care in an SNF, financing AGCH care, difficulties selecting patients at the emergency department, lack of protocols and guidelines, electronic health records unsuited for hospital care, department layout on two different floors and complex shared business operations. Furthermore, transfer of acute care to the community care meant that some care was not reimbursed. CONCLUSIONS: the AGCH concept was valued by all stakeholders. The main facilitators included the perceived value of the AGCH concept and enthusiasm of stakeholders. Structural financing is an obstacle to the expansion and continuation of this care model.


Asunto(s)
Hospitales Comunitarios , Instituciones de Cuidados Especializados de Enfermería , Humanos , Anciano , Países Bajos , Investigación Cualitativa , Europa (Continente)
2.
N Engl J Med ; 364(2): 136-45, 2011 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-21226579

RESUMEN

BACKGROUND: In mice, the scavenger receptor class B type I (SR-BI) is essential for the delivery of high-density lipoprotein (HDL) cholesterol to the liver and steroidogenic organs. Paradoxically, elevated HDL cholesterol levels are associated with increased atherosclerosis in SR-BI-knockout mice. It is unclear what role SR-BI plays in human metabolism. METHODS: We sequenced the gene encoding SR-BI in persons with elevated HDL cholesterol levels and identified a family with a new missense mutation (P297S). The functional effects of the P297S mutation on HDL binding, cellular cholesterol uptake and efflux, atherosclerosis, platelet function, and adrenal function were studied. RESULTS: Cholesterol uptake from HDL by primary murine hepatocytes that expressed mutant SR-BI was reduced to half of that of hepatocytes expressing wild-type SR-BI. Carriers of the P297S mutation had increased HDL cholesterol levels (70.4 mg per deciliter [1.8 mmol per liter], vs. 53.4 mg per deciliter [1.4 mmol per liter] in noncarriers; P<0.001) and a reduced capacity for efflux of cholesterol from macrophages, but the carotid artery intima-media thickness was similar in carriers and in family noncarriers. Platelets from carriers had increased unesterified cholesterol content and impaired function. In carriers, adrenal steroidogenesis was attenuated, as evidenced by decreased urinary excretion of sterol metabolites, a decreased response to corticotropin stimulation, and symptoms of diminished adrenal function. CONCLUSIONS: We identified a family with a functional mutation in SR-BI. The mutation carriers had increased HDL cholesterol levels and a reduction in cholesterol efflux from macrophages but no significant increase in atherosclerosis. Reduced SR-BI function was associated with altered platelet function and decreased adrenal steroidogenesis. (Funded by the European Community and others.).


Asunto(s)
Insuficiencia Suprarrenal/genética , Aterosclerosis/genética , HDL-Colesterol/sangre , Colesterol/metabolismo , Mutación Missense , Receptores Depuradores de Clase B/genética , Adolescente , Glándulas Suprarrenales/fisiología , Adulto , Anciano , Anciano de 80 o más Años , Animales , Arterias Carótidas/anatomía & histología , Colesterol/sangre , Análisis Mutacional de ADN , Femenino , Heterocigoto , Homeostasis/genética , Humanos , Hidrocortisona/metabolismo , Macrófagos/metabolismo , Masculino , Ratones , Ratones Noqueados , Persona de Mediana Edad , Linaje , Activación Plaquetaria/genética , Triglicéridos/sangre , Adulto Joven
3.
J Am Med Dir Assoc ; 25(4): 704-710, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38159913

RESUMEN

OBJECTIVES: Hospital admission in older adults is associated with unwanted outcomes such as readmission, institutionalization, and functional decline. To reduce these outcomes, the Netherlands introduced an alternative to hospital-based care: the Acute Geriatric Community Hospital (AGCH). The AGCH is an acute care unit situated outside of a hospital focusing on early rehabilitation and comprehensive geriatric assessment. The objective of this study was to evaluate if AGCH care is associated with decreasing unplanned readmissions or death compared with hospital-based care. DESIGN: Prospective cohort study controlled with a historic cohort. SETTING AND PARTICIPANTS: A (sub)acute care unit (AGCH) and 6 hospitals in the Netherlands; participants were acutely ill older adults. METHODS: We used inverse propensity score weighting to account for baseline differences. The primary outcome was 90-day readmission or death. Secondary outcomes included 30-day readmission or death, time to death, admission to long-term residential care, occurrence of falls and functioning over time. Generalized logistic regression models and multilevel regression analyses were used to estimate effects. RESULTS: AGCH patients (n = 206) had lower 90-day readmission or death rates [odds ratio (OR) 0.39, 95% CI 0.23-0.67] compared to patients treated in hospital (n = 401). AGCH patients had a lower risk of 90-day readmission (OR 0.38, 95% CI 0.21-0.67) but did not differ on all-cause mortality (OR 0.89, 95% CI 0.44-1.79) compared with the hospital control group. AGCH patients had lower 30-day readmission or death rates. Secondary outcomes did not differ. CONCLUSIONS AND IMPLICATIONS: AGCH patients had lower rates of readmission and/or death than patients treated in a hospital. Our results support further research on the implementation and cost-effectiveness of AGCH in the Netherlands and other countries seeking alternatives to hospital-based care.


Asunto(s)
Hospitales Comunitarios , Alta del Paciente , Humanos , Anciano , Estudios Prospectivos , Países Bajos , Hospitalización , Readmisión del Paciente
4.
J Lipid Res ; 54(7): 1964-71, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23650622

RESUMEN

Atheroprotection by high density lipoprotein (HDL) is considered to be mediated through reverse cholesterol transport (RCT) from peripheral tissues. We investigated in vivo cholesterol fluxes through the RCT pathway in patients with low plasma high density lipoprotein cholesterol (HDL-c) due to mutations in APOA1. Seven carriers of the L202P mutation in APOA1 (mean HDL-c: 20 ± 19 mg/dl) and seven unaffected controls (mean HDL-c: 54 ± 11 mg/dl, P < 0.0001) received a 20 h infusion of (13)C2-cholesterol ((13)C-C). Enrichment of plasma and erythrocyte free cholesterol and plasma cholesterol esters was measured. With a three-compartment SAAM-II model, tissue cholesterol efflux (TCE) was calculated. TCE was reduced by 19% in carriers (4.6 ± 0.8 mg/kg/h versus 5.7 ± 0.7 mg/kg/h in controls, P = 0.02). Fecal (13)C recovery and sterol excretion 7 days postinfusion did not differ significantly between carriers and controls: 21.3 ± 20% versus 13.3 ± 6.3% (P = 0.33), and 2,015 ± 1,431 mg/day versus 1456 ± 404 mg/day (P = 0.43), respectively. TCE is reduced in carriers of mutations in APOA1, suggesting that HDL contributes to efflux of tissue cholesterol in humans. The residual TCE and unaffected fecal sterol excretion in our severely affected carriers suggest, however, that non-HDL pathways contribute to RCT significantly.


Asunto(s)
Apolipoproteína A-I/metabolismo , HDL-Colesterol/metabolismo , Adolescente , Adulto , Anciano , Apolipoproteína A-I/genética , Transporte Biológico , HDL-Colesterol/sangre , Humanos , Masculino , Persona de Mediana Edad , Mutación , Adulto Joven
5.
Arterioscler Thromb Vasc Biol ; 29(9): 1336-41, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19667106

RESUMEN

OBJECTIVE: The purpose of this study was to investigate the mechanism by which the nonnucleoside reverse transcriptase inhibitor (NNRTI) nevirapine (NVP) increases high-density lipoprotein cholesterol (HDLc) in treatment-experienced human immunodeficiency virus-1 (HIV-1)-infected patients. METHODS AND RESULTS: Twelve HIV-1 infected patients, with stably suppressed HIV-1 viral load using AZT/3TC/abacavir for > or =6 months, added NVP to their current antiretroviral regimen. Patients received a primed bolus infusion of the stable isotope L-[1-(13)C]-valine for 12 hours before, as well as 6 and 24 weeks after, the addition of NVP to study apolipoprotein A-I (apoA-I) kinetics. Absolute production rate (APR) and fractional catabolic rate (FCR) of apoA-I were calculated using SAAM-II modeling. Major HDLc-modulating enzymes were assessed. Plasma apoA-I and HDLc levels increased significantly after 24 weeks of treatment by, respectively, 13+/-4% (P=0.01) and 16+/-6% (P=0.015). Concomitantly, apoA-I production rate at 24 weeks increased by 17+/-7% (P=0.04). ApoA-I catabolism did not change. A modest increase of lecithin:cholesterol acyltransferase and cholesteryl ester transfer protein activity was observed. CONCLUSIONS: NVP increases apoA-I production, which contributes to the HDLc increase after introduction of NVP-containing regimens. In view of the potent antiatherogenic effects of apoA-I, the observed increase may contribute to the favorable cardiovascular profile of NVP.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Apolipoproteína A-I/sangre , HDL-Colesterol/sangre , Infecciones por VIH/tratamiento farmacológico , VIH-1/aislamiento & purificación , Nevirapina/uso terapéutico , Inhibidores de la Transcriptasa Inversa/uso terapéutico , Adulto , Terapia Antirretroviral Altamente Activa , Didesoxinucleósidos/uso terapéutico , Infecciones por VIH/sangre , Infecciones por VIH/virología , VIH-1/genética , Humanos , Cinética , Londres , Espectroscopía de Resonancia Magnética , Masculino , Persona de Mediana Edad , Países Bajos , ARN Viral/sangre , Resultado del Tratamiento , Regulación hacia Arriba , Carga Viral
6.
Arterioscler Thromb Vasc Biol ; 29(6): 956-62, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19304573

RESUMEN

OBJECTIVE: GPIHBP1 is an endothelial cell protein that binds lipoprotein lipase (LPL) and chylomicrons. Because GPIHBP1 deficiency causes chylomicronemia in mice, we sought to determine whether some cases of chylomicronemia in humans could be attributable to defective GPIHBP1 proteins. METHODS AND RESULTS: Patients with severe hypertriglyceridemia (n=60, with plasma triglycerides above the 95th percentile for age and gender) were screened for mutations in GPIHBP1. A homozygous GPIHBP1 mutation (c.344A>C) that changed a highly conserved glutamine at residue 115 to a proline (p.Q115P) was identified in a 33-year-old male with lifelong chylomicronemia. The patient had failure-to-thrive as a child but had no history of pancreatitis. He had no mutations in LPL, APOA5, or APOC2. The Q115P substitution did not affect the ability of GPIHBP1 to reach the cell surface. However, unlike wild-type GPIHBP1, GPIHBP1-Q115P lacked the ability to bind LPL or chylomicrons (d < 1.006 g/mL lipoproteins from Gpihbp1(-/-) mice). Mouse GPIHBP1 with the corresponding mutation (Q114P) also could not bind LPL. CONCLUSIONS: A homozygous missense mutation in GPIHBP1 (Q115P) was identified in a patient with chylomicronemia. The mutation eliminated the ability of GPIHBP1 to bind LPL and chylomicrons, strongly suggesting that it caused the patient's chylomicronemia.


Asunto(s)
Proteínas Portadoras/genética , Quilomicrones/genética , Hiperlipoproteinemia Tipo I/genética , Hipertrigliceridemia/genética , Lipoproteína Lipasa/metabolismo , Mutación Missense , Adulto , Animales , Células CHO , Proteínas Portadoras/metabolismo , Quilomicrones/metabolismo , Cricetinae , Cricetulus , Homocigoto , Humanos , Hiperlipoproteinemia Tipo I/sangre , Hiperlipoproteinemia Tipo I/enzimología , Hipertrigliceridemia/sangre , Hipertrigliceridemia/enzimología , Masculino , Ratones , Ratones Noqueados , Fenotipo , Unión Proteica , Transporte de Proteínas , Receptores de Lipoproteína/deficiencia , Receptores de Lipoproteína/genética , Índice de Severidad de la Enfermedad , Transfección
7.
Ann Intern Med ; 150(2): 84-93, 2009 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-19153411

RESUMEN

BACKGROUND: High-density lipoprotein (HDL) cholesterol levels are inversely related to risk for coronary artery disease (CAD). Because HDL particles are heterogeneous in size and composition, they may be differentially associated with other cardiovascular risk factors and with cardiovascular risk. OBJECTIVE: To study the independent relationships of HDL size and particle concentration to risk for future CAD. DESIGN: Nested case-control study within the EPIC (European Prospective Investigation into Cancer and Nutrition)-Norfolk cohort; baseline survey between 1993 and 1997, follow-up until November 2003. SETTING: Norfolk, United Kingdom. PARTICIPANTS: Case patients were 822 apparently healthy men and women who developed CAD during follow-up. Control participants were 1401 participants who remained without CAD and were matched to case patients by sex, age, and enrollment time. MEASUREMENTS: First CAD event leading to either hospitalization or death. RESULTS: Nuclear magnetic resonance spectroscopy-measured HDL particle concentration (mean, 33.9 micromol/L [SD, 5] vs. 32.9 micromol/L [SD, 6]; P < 0.001) and HDL size (mean, 8.9 nm [SD, 0.5] vs. 8.8 nm [SD, 0.5]; P < 0.001), as well as gradient gel electrophoresis-measured HDL size (mean, 8.9 nm [SD, 0.4] vs. 8.8 nm [SD, 0.4]; P = 0.005) were lower in case patients than in control participants. High-density lipoprotein size and HDL particle concentration were only weakly correlated (r = 0.08, for those measured with nuclear magnetic resonance spectroscopy; r = 0.10, for those measured with gradient gel electrophoresis). High-density lipoprotein size was strongly associated with risk factors characteristic of the metabolic syndrome, including waist-to-hip ratio, triglyceride level, and apolipoprotein B level, whereas HDL particle concentration was not. Both HDL size and HDL particle concentration were independently associated with CAD risk. The association between HDL size and CAD risk was abolished on adjustment for apolipoprotein B and triglyceride levels (adjusted odds ratio, 1.00 [95% CI, 0.71 to 1.39] for top vs. bottom quartile), whereas HDL particle concentration remained independently associated with CAD risk (adjusted odds ratio, 0.50 [CI, 0.37 to 0.66]). LIMITATION: Measurements were performed in nonfasting blood samples, and residual confounding cannot be excluded. CONCLUSION: Both HDL size and HDL particle concentration were independently associated with other cardiovascular risk factors and with the risk for CAD. The relationship between HDL size and CAD risk was explained by markers associated with the metabolic syndrome, indicating that part of the relationship between HDL cholesterol and CAD risk is merely a reflection of this metabolic risk.


Asunto(s)
HDL-Colesterol/sangre , HDL-Colesterol/química , Enfermedad de la Arteria Coronaria/sangre , Anciano , Estudios de Casos y Controles , Femenino , Humanos , Espectroscopía de Resonancia Magnética , Masculino , Persona de Mediana Edad , Tamaño de la Partícula , Estudios Prospectivos , Factores de Riesgo
8.
Endocrinol Metab Clin North Am ; 37(3): 623-33, viii, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18775355

RESUMEN

The alarming and still increasing prevalence of obesity and associated cardiovascular risk raises much concern. The increase in cardiovascular risk depends to a significant extent on the changes in lipid profiles as observed in obesity. These changes are decreased high-density lipoprotein cholesterol and increased triglyceride levels. Much effort has already been expended into the elucidation of the mechanisms behind these obesity-associated lipid changes. Insulin resistance certainly plays a central role and, in addition, both hormonal and neurologic pathways have recently been found to play an important role. This article focuses on the mechanisms involved in the development of the proatherogenic lipid changes associated with obesity.


Asunto(s)
Enfermedades Cardiovasculares/etiología , Dislipidemias/complicaciones , Obesidad/complicaciones , Adipocitos/fisiología , Animales , Humanos , Metabolismo de los Lípidos , Obesidad/metabolismo
10.
Cholesterol ; 2012: 610741, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22611487

RESUMEN

HDL provides atheroprotection by facilitating cholesterol efflex from lipid-laden macrophages in the vessel wall. In vitro studies have suggested impaired efflux capacity of HDL following inflammatory changes. We assessed the impact of acute severe sepsis and mild chronic inflammatory disease on the efflux capacity of HDL. We hypothesize that a more severe inflammatory state leads to stronger impaired cholesterol efflux capacity. Using lipid-laden THP1 cells and fibroblasts we were able to show that efflux capacity of HDL from both patients with severe sepsis or with Crohn's disease (active or in remission), either isolated using density gradient ultracentrifugation or using apoB precipitation, was not impaired. Yet plasma levels of HDL cholesterol and apoA-I were markedly lower in patients with sepsis. Based on the current observations we conclude that inflammatory disease does not interfere with the capacity of HDL to mediate cholesterol efflux. Our findings do not lend support to the biological relevance of HDL function changes in vitro.

11.
Med Clin North Am ; 95(5): 893-902, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21855698

RESUMEN

Dyslipidemia associated with obesity and the metabolic syndrome is one of the central features contributing to the increased CV risk in these patients. In view of the pandemic of the metabolic syndrome, it is imperative to fully understand the mechanisms leading to the metabolic lipid phenotype before embarking upon optimal treatment strategies. The traditional concept that insulin resistance causes increased FFA flux via increased TG hydrolysis in adipose tissue is still of a central theme in the general hypothesis. The combination of increased hepatic VLDL secretion with impaired LPL-mediated TG clearance explains the hypertriglyceridemia phenotype of the metabolic syndrome. Hence, central IR may be an important factor contributing to peripheral hypertriglyceridemia. Recently recognized regulatory systems include the profound impact of the hypothalamus on TG secretion and glucose control. In addition, dysfunctional (or inflamed) intra abdominal adipose tissue has emerged as a potent regulator of dyslipidemia and IR. It will be a challenge to design novel treatment modalities that target "dysfunctional" fat or central IR to attempt to prevent the epidemic of CV disease secondary to the metabolic syndrome.


Asunto(s)
Enfermedades Cardiovasculares/fisiopatología , Dislipidemias/fisiopatología , Obesidad/fisiopatología , Adipocitos/metabolismo , Adipoquinas/biosíntesis , Índice de Masa Corporal , Enfermedades Cardiovasculares/metabolismo , Colesterol/metabolismo , Dislipidemias/metabolismo , Humanos , Resistencia a la Insulina , Síndrome Metabólico/metabolismo , Síndrome Metabólico/fisiopatología , Obesidad/metabolismo , Triglicéridos/metabolismo
12.
J Am Coll Cardiol ; 58(1): 40-4, 2011 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-21700087

RESUMEN

OBJECTIVES: We hypothesize that increasing high-density lipoprotein cholesterol (HDL-C) shortens cardiac repolarization. BACKGROUND: HDL-C is inversely associated with sudden death. The relation between HDL-C and repolarization of the heart is unexplored. METHODS: HDL-C was elevated with reconstituted high-density lipoprotein (rHDL). Cardiac repolarization was studied by recording cardiac transmembrane potentials with the patch clamp technique from isolated rabbit cardiomyocytes that were superfused with rHDL. Infusions with rHDL (40 mg/kg body weight) were performed in dyslipidemic patients and healthy volunteers. Electrocardiograms were recorded to assess cardiac repolarization before and 24 h after infusion with rHDL. RESULTS: rHDL as well as purified human apolipoprotein AI shortened repolarization of isolated rabbit cardiomyocytes by ∼25% (p < 0.05). rHDL infusion shortened the heart rate-corrected QT interval on surface electrocardiograms in all participants (p < 0.001). CONCLUSIONS: rHDL shortens cardiac repolarization. These data provide evidence for a novel mechanism of HDL infusion that may contribute to reduction of sudden cardiac death.


Asunto(s)
HDL-Colesterol/metabolismo , Enfermedad Coronaria/fisiopatología , Sistema de Conducción Cardíaco/fisiopatología , Corazón/fisiología , Miocitos Cardíacos/citología , Adulto , Anciano , Animales , Apolipoproteína A-I/metabolismo , Aterosclerosis/metabolismo , Estudios de Casos y Controles , Muerte Súbita , Dislipidemias/metabolismo , Electrocardiografía/métodos , Femenino , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Técnicas de Placa-Clamp , Conejos , Fibrilación Ventricular/metabolismo
13.
Atherosclerosis ; 211(1): 1-8, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20117784

RESUMEN

Peripheral lipoprotein lipase (LPL)-mediated lipolysis of triglycerides is the first step in chylomicron/VLDL clearance involving heparan sulfate proteoglycans (HSPGs) displayed at the cell surface of the capillaries in adipose tissue, heart and skeletal muscle. The newly generated chylomicron remnant particles are then cleared by the liver, whereas VLDL remnant particles are either further modified, through the action of hepatic lipase (HL) and cholesteryl ester transfer protein (CETP), into LDL particles or alternatively directly cleared by the liver. Two proteins, lipase maturation factor 1 (LMF1) and glycosylphosphatidylinositol-anchored high density lipoprotein binding protein 1 (GPIHBP1), have been recently identified and have revised our current understanding of LPL maturation and LPL-mediated lipolysis. Moreover, new insights have been gained with respect to hepatic remnant clearance using genetically modified mice targeting the sulfation of HSPGs and even deletion of the most abundant heparan sulfate proteoglycan: syndecan1. In this review, we will provide an overview of novel data on both peripheral TG hydrolysis and hepatic remnant clearance that will improve our knowledge of plasma triglyceride metabolism.


Asunto(s)
Lipoproteína Lipasa/metabolismo , Lipoproteínas/metabolismo , Proteínas de la Membrana/fisiología , Receptores de Lipoproteína/fisiología , Triglicéridos/metabolismo , Secuencia de Aminoácidos , Animales , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Quilomicrones/metabolismo , Proteoglicanos de Heparán Sulfato/fisiología , Humanos , Lipólisis , Ratones , Modelos Moleculares , Datos de Secuencia Molecular
14.
Circ Cardiovasc Genet ; 3(2): 169-78, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20124439

RESUMEN

BACKGROUND: Recent studies in mice have established that an endothelial cell protein, glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1), is essential for the lipolytic processing of triglyceride-rich lipoproteins. METHODS AND RESULTS: We report the discovery of a homozygous missense mutation in GPIHBP1 in a young boy with severe chylomicronemia. The mutation, p.C65Y, replaces a conserved cysteine in the GPIHBP1 lymphocyte antigen 6 domain with a tyrosine and is predicted to perturb protein structure by interfering with the formation of a disulfide bond. Studies with transfected Chinese hamster ovary cells showed that GPIHBP1-C65Y reaches the cell surface but has lost the ability to bind lipoprotein lipase (LPL). When the GPIHBP1-C65Y homozygote was given an intravenous bolus of heparin, only trace amounts of LPL entered the plasma. We also observed very low levels of LPL in the postheparin plasma of a subject with chylomicronemia who was homozygous for a different GPIHBP1 mutation (p.Q115P). When the GPIHBP1-Q115P homozygote was given a 6-hour infusion of heparin, a significant amount of LPL appeared in the plasma, resulting in a fall in the plasma triglyceride levels from 1780 to 120 mg/dL. CONCLUSIONS: We identified a novel GPIHBP1 missense mutation (p.C65Y) associated with defective LPL binding in a young boy with severe chylomicronemia. We also show that homozygosity for the C65Y or Q115P mutations is associated with low levels of LPL in the postheparin plasma, demonstrating that GPIHBP1 is important for plasma triglyceride metabolism in humans.


Asunto(s)
Proteínas Portadoras/genética , Quilomicrones/sangre , Lipoproteína Lipasa/sangre , Sustitución de Aminoácidos , Animales , Células CHO , Proteínas Portadoras/química , Preescolar , Cricetinae , Cricetulus , Exones , Heparina/farmacología , Homocigoto , Humanos , Lipoproteína Lipasa/metabolismo , Masculino , Mutación Missense , Receptores de Lipoproteína , Triglicéridos/sangre
15.
Atherosclerosis ; 207(2): 614-6, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19616211

RESUMEN

BACKGROUND: Fecal bile acid and neutral sterol excretion are the obligate endpoints of the reverse cholesterol transport pathway (RCT). In studies in mice, no evidence was found for a relation between HDL-cholesterol (HDL-c) levels and fecal sterol excretion. In this study, we have evaluated this relationship in patients with isolated low HDL-c versus controls. RESULTS: Fecal sterol excretion was studied in 12 subjects with familial hypoalphalipoproteinemia (FHA) and 11 healthy controls. Compared to the controls (8.9+/-6.3mg/kg/day), neutral sterol excretion was significantly lower in the FHA group (4.0+/-2.4mg/kg/day). Fecal bile acid excretion showed a similar pattern. Across the groups, a strong positive correlation between HDL-c and fecal neutral sterol excretion was found (r=0.53; p=0.01). CONCLUSIONS: Isolated low HDL-c levels in humans are associated with reduced fecal sterol excretion suggesting that in humans HDL regulates the final step in the RCT pathway at low HDL-c levels.


Asunto(s)
HDL-Colesterol/sangre , Heces/química , Hipoalfalipoproteinemias/metabolismo , Esteroles/metabolismo , Adulto , Ácidos y Sales Biliares/metabolismo , Estudios de Casos y Controles , Regulación hacia Abajo , Femenino , Humanos , Hipoalfalipoproteinemias/sangre , Masculino , Persona de Mediana Edad , Factores de Tiempo
16.
Curr Opin Lipidol ; 17(4): 426-30, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16832167

RESUMEN

PURPOSE OF REVIEW: The reputation of acyl coenzyme A:cholesterol acyltransferase (ACAT) inhibitors has changed profoundly from promising new drugs for cardiovascular prevention to drugs without clinical benefits or possibly even with adverse effects. RECENT FINDINGS: ACAT inhibitors decrease the intracellular conversion of free cholesterol into cholesteryl ester in a number of tissues, including intestine, liver and macrophages. In contrast to promising results in experimental animal models, all subsequent clinical studies in humans with ACAT inhibitors failed to show lipid profile changes as well as reductions in surrogate markers for coronary artery disease. In fact, there was even a tendency towards an increase in atheroma burden in the most recent and well executed clinical trials. In addition, the inhibition of this pivotal enzyme in cholesterol esterification may interfere with reverse cholesterol transport. SUMMARY: In our opinion, the consistent negative findings in recent clinical trials have virtually eliminated the chances for this class of drugs to be introduced for cardiovascular prevention. Possible strategies focused on selective ACAT 2 inhibition or the combination of ACAT inhibitors with compounds that stimulate reverse cholesterol transport may prove to have clinical benefit. This will have to await further clinical research in humans, however, as, obviously, rodent models cannot provide reliable data as to the efficacy of this class of drugs in humans.


Asunto(s)
Enfermedades Cardiovasculares/prevención & control , Inhibidores Enzimáticos/efectos adversos , Inhibidores Enzimáticos/farmacología , Esterol O-Aciltransferasa/antagonistas & inhibidores , Animales , Humanos
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