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Patógenos Transmitidos por la Sangre/aislamiento & purificación , Tamizaje Masivo/métodos , Servicios de Salud para Estudiantes/organización & administración , Universidades , Adolescente , Adulto , Femenino , VIH/aislamiento & purificación , Hepacivirus/aislamiento & purificación , Virus de la Hepatitis B/aislamiento & purificación , Humanos , Masculino , Aceptación de la Atención de Salud/estadística & datos numéricos , Proyectos Piloto , Escocia , Estudiantes/psicología , Estudiantes/estadística & datos numéricos , Adulto JovenRESUMEN
A DASH (dietary approaches to stop hypertension) dietary pattern rich in fruits and vegetables and low-fat dairy products with increased dietary protein provided primarily from plant protein sources decreases blood pressure. No studies, however, have evaluated the effects of a DASH-like diet with increased dietary protein from lean beef on blood pressure and vascular health. The aim of this study was to study the effect of DASH-like diets that provided different amounts of protein from lean beef (DASH 28 g beef per day; beef in an optimal lean diet (BOLD) 113 g beef per day; beef in an optimal lean diet plus additional protein (BOLD+) 153 g beef per day) on blood pressure, endothelial function and vascular reactivity versus a healthy American diet (HAD). Using a randomized, crossover study design, 36 normotensive participants (systolic blood pressure (SBP), 116 ± 3.6 mm Hg) were fed four isocaloric diets,: HAD (33% total fat, 12% saturated fatty acids (SFA), 17% protein (PRO), 20 g beef per day), DASH (27% total fat, 6% SFA, 18% PRO, 28 g beef per day), BOLD (28% total fat, 6% SFA, 19% PRO, 113 g beef per day) and BOLD+ (28% total fat, 6% SFA, 27% PRO, 153 g beef per day), for 5 weeks. SBP decreased (P<0.05) in subjects on the BOLD+ diet (111.4 ± 1.9 mm Hg) versus HAD (115.7 ± 1.9). There were no significant effects of the DASH and BOLD diets on SBP. Augmentation index (AI) was significantly reduced in participants on the BOLD diet (-4.1%). There were no significant effects of the dietary treatments on diastolic blood pressure or endothelial function (as measured by peripheral arterial tonometry). A moderate protein DASH-like diet including lean beef decreased SBP in normotensive individuals. The inclusion of lean beef in a heart healthy diet also reduced peripheral vascular constriction.
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Hipertensión/dietoterapia , Carne , Adulto , Anciano , Anciano de 80 o más Años , Animales , Bovinos , Estudios Cruzados , Endotelio Vascular/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Rigidez VascularRESUMEN
Quantification of MRS spectra is a challenging problem when a large baseline is present along with a low signal to noise ratio. This work investigates a robust fitting technique that yields accurate peak areas under these conditions. Using simulated long echo time (1)H MRS spectra with low signal to noise ratio and a large baseline component, both the accuracy and reliability of the fit in the frequency domain were greatly improved by reducing the number of fitted parameters and making full use of all the known information concerning the Voigt lineshape. Using an appropriate first order approximation to a popular approximation of the Voigt lineshape, a significant improvement in the estimate of the area of a known spectral peak was obtained with a corresponding reduction in the residual. Furthermore, this improved parameter choice resulted in a large reduction in the number of iterations of the least-squares fitting routine. On the other hand, making use of the known centre frequency differences of the component resonances gave negligible improvement. A wavelet filter was used to remove the baseline component. In addition to performing a Monte Carlo study, these fitting techniques were also applied to a set of 10 spectra acquired from healthy human volunteers. Again, the same reduced parameter model gave the lowest value for chi(2) in each case.
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Espectroscopía de Resonancia Magnética/métodos , Modelos Teóricos , Procesamiento de Señales Asistido por Computador , Simulación por Computador , Humanos , Aumento de la Imagen , Matemática , Método de MontecarloRESUMEN
AIM: To investigate the expression of p63 and cytokeratins throughout the course of producing a cultivated autograft of limbal epithelial cells. METHODS: A 75 year old male with a severe alkali burn to his right eye received two cultivated autografts of limbal epithelial cells on amniotic membrane followed by a corneal allograft. Immunostaining for p63 and cytokeratins was performed during ex vivo expansion with 3T3 fibroblasts, following subcultivation on amniotic membrane, and on the excised corneal button. RESULTS: Cultures grown in the presence of 3T3 fibroblasts or on amniotic membrane displayed positive staining for keratins 14 and 19, and p63, but poor staining for keratin 3 (K3). The excised corneal button possessed a stratified epithelium of K3 positive cells residing on amniotic membrane. CONCLUSIONS: Our results document for the first time the co-expression of cytokeratins 14 and 19 with p63 in a cultivated limbal graft. These data support the conclusion that cultivated grafts of limbal epithelium contain predominantly undifferentiated cells with the potential to regenerate a normal corneal epithelium.
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Quemaduras Químicas/cirugía , Células Epiteliales/química , Epitelio Corneal/química , Quemaduras Oculares/cirugía , Queratinas/análisis , Limbo de la Córnea/patología , Fosfoproteínas/análisis , Transactivadores/análisis , Anciano , Quemaduras Químicas/metabolismo , Células Cultivadas , Trasplante de Córnea/métodos , Proteínas de Unión al ADN , Células Epiteliales/trasplante , Epitelio Corneal/trasplante , Quemaduras Oculares/metabolismo , Genes Supresores de Tumor , Humanos , Queratina-14 , Queratina-3 , Masculino , Fenotipo , Trasplante de Células Madre/métodos , Factores de Transcripción , Trasplante Autólogo , Proteínas Supresoras de TumorRESUMEN
Levosimendan, a pyridazinone-dinitrile derivative, is a calcium sensitiser with additional action on adenosine triphosphate (ATP)-sensitive potassium channels. It is used intravenously (IV) for the treatment of decompensated cardiac failure. At therapeutic doses, levosimendan exhibits enhanced contractility with no increase in oxygen demands. It also produces antistunning effects without increasing myocardial intracellular calcium concentrations or prolonging myocardial relaxation. Levosimendan also causes coronary and systemic vasodilation. In patients with decompensated congestive heart failure (CHF), IV levosimendan significantly reduced the incidence of worsening CHF or death. IV levosimendan significantly increased cardiac output or cardiac index and decreased filling pressure in the acute treatment of stable or decompensated CHF in large, double-blind, randomised trials and after cardiac surgery in smaller trials. Levosimendan is well tolerated, with the most common adverse events (headache, hypotension, nausea) being secondary to vasodilation. It has not been shown to be arrhythmogenic. Levosimendan has shown no clinically important pharmacokinetic interactions with captopril, felodipine, beta-blockers, digoxin, warfarin, isosorbide-5-mononitrate, carvedilol, alcohol (ethanol) or itraconazole.
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Cardiotónicos , Insuficiencia Cardíaca/tratamiento farmacológico , Hidrazonas , Piridazinas , Disponibilidad Biológica , Cardiotónicos/efectos adversos , Cardiotónicos/metabolismo , Cardiotónicos/farmacocinética , Cardiotónicos/farmacología , Cardiotónicos/uso terapéutico , Circulación Coronaria/efectos de los fármacos , Semivida , Humanos , Hidrazonas/efectos adversos , Hidrazonas/metabolismo , Hidrazonas/farmacocinética , Hidrazonas/farmacología , Hidrazonas/uso terapéutico , Unión Proteica , Piridazinas/efectos adversos , Piridazinas/metabolismo , Piridazinas/farmacocinética , Piridazinas/farmacología , Piridazinas/uso terapéutico , Ensayos Clínicos Controlados Aleatorios como Asunto , SimendánRESUMEN
Pioglitazone is an orally administered insulin sensitising thiazolidinedione agent that has been developed for the treatment of type 2 diabetes mellitus. Pioglitazone activates the nuclear peroxisome proliferator activated receptor-gamma (PPAR-gamma), which leads to the increased transcription of various proteins regulating glucose and lipid metabolism. These proteins amplify the post-receptor actions of insulin in the liver and peripheral tissues, which leads to improved glycaemic control with no increase in the endogenous secretion of insulin. In placebo-controlled clinical trials, monotherapy with pioglitazone 15 to 45 mg/day has been shown to decrease blood glycosylated haemoglobin (HbA1c) levels in patients with type 2 diabetes mellitus. The addition of pioglitazone 30 mg/day to preexisting therapy with metformin, or of pioglitazone 15 or 30 mg/day to sulphonylurea, insulin or voglibose therapy, has been shown to decrease HbA1c and fasting blood glucose levels significantly in patients with poorly controlled type 2 diabetes mellitus. Pioglitazone has also been associated with improvements in serum lipid profiles in randomised placebo-controlled clinical studies. The drug has been well tolerated by adult patients of all ages in clinical studies. Oedema has been reported with monotherapy, and pooled data have shown hypoglycaemia in 2 to 15% of patients after the addition of pioglitazone to sulphonylurea or insulin treatment. There have been no reports of hepatotoxicity.
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Hipoglucemiantes/uso terapéutico , Tiazoles/uso terapéutico , Tiazolidinedionas , Animales , Ensayos Clínicos como Asunto , Quimioterapia Combinada , Glucosa/metabolismo , Humanos , Metabolismo de los Lípidos , Pioglitazona , Tiazoles/efectos adversos , Tiazoles/farmacologíaRESUMEN
Insulin glargine is an extended-action biosynthetic human insulin. It precipitates in the neutral environment of subcutaneous tissue and is thus gradually absorbed into the bloodstream. The addition of small amounts of zinc to the formulation further delays absorption. In small euglycaemic clamp studies, the onset of action of insulin glargine was shown to be later, the duration of action longer and the time-action profile flatter than that of Neutral Protamine Hagedorn (NPH) insulin in patients with type 1 diabetes mellitus and healthy volunteers. Four large clinical trials of up to 28 weeks' duration have shown that a single bedtime dose of insulin glargine, in combination with preprandial short-acting insulin, is as effective or more effective than once or twice daily NPH plus short-acting insulin in improving glycaemic control in patients with type 1 diabetes mellitus. In 3 large comparative trials, insulin glargine decreased glycosylated haemoglobin and/or fasting blood glucose levels to a similar extent to that seen with NPH insulin in patients with insulin-dependent or non-insulin-dependent type 2 diabetes mellitus, either as monotherapy or in combination with oral hypoglycaemic agents. Insulin glargine appears to be well tolerated. A lower incidence of hypoglycaemia, especially at night, was reported in most trials with insulin glargine when compared with NPH insulin.
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Diabetes Mellitus Tipo 1/tratamiento farmacológico , Hipoglucemiantes/farmacocinética , Insulina/análogos & derivados , Glucemia/efectos de los fármacos , Ritmo Circadiano , Preparaciones de Acción Retardada , Esquema de Medicación , Hemoglobina Glucada/análisis , Semivida , Humanos , Hipoglucemia/inducido químicamente , Hipoglucemiantes/farmacología , Hipoglucemiantes/uso terapéutico , Insulina/farmacocinética , Insulina/farmacología , Insulina/uso terapéutico , Insulina Glargina , Insulina de Acción Prolongada , Proteínas Recombinantes/farmacocinética , Proteínas Recombinantes/farmacología , Proteínas Recombinantes/uso terapéuticoRESUMEN
Ganirelix is a synthetic third generation gonadotropin-releasing hormone (GnRH) antagonist that is administered via the subcutaneous route. The drug competitively blocks GnRH receptors in the anterior pituitary gland, preventing endogenous GnRH from inducing luteinising hormone (LH) and follicle stimulating hormone release. Ganirelix effectively inhibited LH surges during controlled ovarian stimulation in a large, multicentre clinical trial in women undergoing in vitro fertilisation. A vital pregnancy rate per embryo transfer of 40.3% was achieved at weeks 5 to 6 after treatment with the 0.25 mg/day dosage. Subcutaneous ganirelix has been generally well tolerated in clinical trials. The most common adverse events were local injection site events, asthenia, nausea, malaise, headache and fatigue.
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Hormona Liberadora de Gonadotropina/análogos & derivados , Antagonistas de Hormonas/uso terapéutico , Infertilidad Femenina/tratamiento farmacológico , Animales , Ensayos Clínicos como Asunto , Femenino , Hormona Liberadora de Gonadotropina/efectos adversos , Hormona Liberadora de Gonadotropina/farmacocinética , Hormona Liberadora de Gonadotropina/uso terapéutico , Humanos , Hormona Luteinizante/antagonistas & inhibidores , EmbarazoRESUMEN
Smoking among partners of non-smoking pregnant women has been linked to adverse pregnancy outcome, including low birthweight. Paternal smoking also increases the risk of infant respiratory infections and sudden infant death syndrome, irrespective of maternal smoking status. Furthermore, men's smoking habits are probably one of the strongest influences on the extent to which women are able to quit smoking in pregnancy and maintain cessation post birth. In four focus group discussions, male smokers whose partners were pregnant discussed their beliefs about passive smoking in pregnancy, the barriers they perceived to quitting in pregnancy and their preparedness to support maternal cessation. Men were largely unaware that their own smoking could pose a specific risk to the fetus, but when pregnant women are smokers, men believed their own smoking habits were unimportant. For men, barriers to quitting during their partners' pregnancy were: lack of understanding as to how passive smoking can affect the fetus, including a belief that the fetus is "protected" inside its mother; lack of motivation to quit early in pregnancy due to the baby not being "real"; and concern about stress-induced marital discord associated with cigarette withdrawal. These findings are discussed with regard to messages and strategies which may influence men to quit during their partners' pregnancy.
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Embarazo , Cese del Hábito de Fumar/psicología , Fumar/psicología , Esposos , Femenino , Grupos Focales , Humanos , Estilo de Vida , Masculino , Motivación , Contaminación por Humo de TabacoRESUMEN
OBJECTIVE: To evaluate outcomes of a sexual health promotion intervention to prevent transmission of sexually transmitted diseases (STD) including HIV among genitourinary medicine clinic attenders. DESIGN: A randomized controlled trial using pre-test and post-test measurements after 4 months, with clinical follow-up at 18 months. SETTING: A genitourinary medicine clinic in Nottingham, UK. PATIENTS: A total of 492 patients were randomly assigned either to an individually focused counselling and skills training intervention, including written materials (n = 148), to receive written materials only (n = 162), or to usual clinic procedure (n = 182). INTERVENTION: Social learning theory provided the theoretical framework for the intervention, which was informed by previous research in this setting, and aimed to alter perception of risk for HIV infection, increase knowledge and attitudes to condoms, and increase condom use. MAIN OUTCOME MEASURES: The main outcomes of interest were self-reported condom use and behaviour change. Other outcomes of interest were knowledge and attitudes to condoms, and re-attendance at the clinic with a diagnosis of STD. RESULTS: Intervention subjects were significantly more likely than controls to report carrying condoms when anticipating sexual intercourse with a new sexual partner (P < or = 0.05), and were more likely to perceive themselves at risk of HIV infection (P < or = 0.001). There were no significant effects of the intervention on levels of knowledge about correct condom use, attitudes to condoms, self-reported condom use or incidence of STD. CONCLUSIONS: The limited effectiveness of the intervention suggests that condom promotion should continue, but that additional investment in clinic-based health promotion is unlikely to result in consequent health gain.
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Infecciones por VIH/prevención & control , Promoción de la Salud , Enfermedades de Transmisión Sexual/prevención & control , Adolescente , Adulto , Condones/estadística & datos numéricos , Consejo , Femenino , Enfermedades Urogenitales Femeninas/terapia , Conductas Relacionadas con la Salud , Conocimientos, Actitudes y Práctica en Salud , Humanos , Masculino , Enfermedades Urogenitales Masculinas , Evaluación de Resultado en la Atención de Salud , Servicio Ambulatorio en Hospital , Encuestas y Cuestionarios , Reino UnidoRESUMEN
Novel 4,4-bis(trifluoromethyl)imidazolines have been found to be the potent acyl-CoA cholesterol acyltransferase (ACAT) inhibitors. ACAT is responsible for cholesterol esterification in the intestine, liver, and the arterial wall. These novel imidazolines also inhibit cholesterol ester formation in the macrophage. Several compounds have shown potent serum cholesterol-lowering activity in several animal models. Para-substitution of the 2-phenyl is critical for in vitro and in vivo activity. The 4,4-bis(trifluoromethyl)imidazolines with a para-cyano group on 2-phenyl and a 4-alkylcyclohexyl amide as the side-chain at the 5-position possess the most potent inhibitory activity in this series. Based on biochemical studies, this series acts as a competitive inhibitor with respect to cholesterol binding at the enzyme, which distinguishes it from most of the ACAT inhibitors discovered to date. Preliminary biological studies supported by X-ray crystal structures, molecular modeling, and structure-activity relationship (SAR) studies suggest that this series may be a cholesterol mimic.
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Anticolesterolemiantes/síntesis química , Anticolesterolemiantes/farmacología , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Imidazoles/síntesis química , Imidazoles/farmacología , Esterol O-Aciltransferasa/antagonistas & inhibidores , Anticolesterolemiantes/química , Inhibidores Enzimáticos/química , Imidazoles/química , Conformación Molecular , Relación Estructura-ActividadRESUMEN
Acyl-CoA:cholesterol acyltransferase (ACAT) is the enzyme largely responsible for intracellular cholesterol esterification. A systemic inhibitor of ACAT is believed to be able to slow or even reverse the atherosclerotic process. Towards that goal, a series of cyclic sulfides, derived from the hetero-Diels-Alder reaction of thioaldehydes with 1,3-dienes, and bearing carboxamide substituents, were prepared and evaluated for in vitro (in several tissues and species) and ex vivo ACAT inhibition. Minor changes in subsequent structure were found to have a significant effect in optimization of the biological activity of this series of compounds.
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Aldehídos/química , Inhibidores Enzimáticos/química , Esterol O-Aciltransferasa/antagonistas & inhibidores , Compuestos de Sulfhidrilo/química , Animales , Fenómenos Químicos , Química , Cromatografía Líquida de Alta Presión , Masculino , Microsomas Hepáticos/enzimología , Ratas , Ratas Sprague-DawleyRESUMEN
This paper aims to begin to consider the evidence for AIDS as a disease of poverty. It seeks to describe the important influence of the social and economic context of HIV/AIDS and of those behaviours associated with HIV transmission, and argues for a shift in emphasis in the conceptualization of the 'problem of AIDS'. The relationship between poverty and AIDS is explored, particularly in relation to global economic development, urbanization, homelessness and the disintegration of neighbourhoods, migration and systems of labour and production. Examples of socially-driven community-based responses to the prevention and control of the HIV epidemic in diverse cultures are discussed and the need for new outcome measures for assessing community initiatives is proposed.
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Síndrome de Inmunodeficiencia Adquirida/etiología , Pobreza , Síndrome de Inmunodeficiencia Adquirida/prevención & control , Síndrome de Inmunodeficiencia Adquirida/transmisión , Anomia (Social) , Actitud Frente a la Salud , Participación de la Comunidad , Emigración e Inmigración , Femenino , Salud Global , Personas con Mala Vivienda , Humanos , Masculino , Factores Socioeconómicos , UrbanizaciónRESUMEN
The gene expression and enzyme kinetics of acyl coenzyme A:cholesterol acyltransferase (ACAT) were investigated in human monocytes, macrophages, and foam cells. Northern blot analysis using a 1.65-kb coding region of human ACAT cDNA as the probe showed that each of the cell types exhibited four mRNA transcripts. The levels of the 4.2- and 3.7-kb ACAT transcripts were three- and sixfold higher, respectively, in macrophages than monocytes. These transcripts were expressed at the same high levels after conversion of macrophages to foam cells. In contrast, the 6.3- and 4.4-kb transcripts for ACAT were expressed at a relatively constant level in all three cell types. The expression of mRNA for glyceraldehyde phosphate dehydrogenase, the control gene in this study, was also expressed at a constant level in each of the cell types. The increase in ACAT mRNA was accompanied by changes in the kinetic properties of the enzyme. Specifically, there was a 14-fold increase in Vmax and a 71% decrease in Km with respect to oleoyl coenzyme A. Although not definitive, the concomitant changes in mRNA and Vmax strongly suggest that the amount of ACAT protein increases upon conversion of monocytes to macrophages. The data show that ACAT in monocytes can be regulated by both substrate and gene expression.
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Células Espumosas/enzimología , Regulación Enzimológica de la Expresión Génica , Macrófagos/enzimología , Monocitos/enzimología , Esterol O-Aciltransferasa/genética , Secuencia de Bases , Diferenciación Celular , ADN Complementario/genética , Inducción Enzimática , Humanos , Cinética , Datos de Secuencia Molecular , Monocitos/patología , Reacción en Cadena de la Polimerasa , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Esterol O-Aciltransferasa/metabolismoRESUMEN
A cross-sectional interview survey of 103 HIV/AIDS and 100 oncology staff in nine treatment sites in London aimed to identify ways in which work stress affected domestic and social lives of such staff. In all staff one-third of those without long-term emotional relationships stated they felt their work formed a barrier to their being involved in that way. Most subjects reported spending a considerable amount of time discussing work with partners, and work-related subjects caused conflict for just under half of the total sample. Thirty-nine percent reported their partners complained regularly about their commitment to work, and one-quarter overall reported their relationship had suffered as a result of their work in HIV or oncology. Using tests of association comparing group responses to structured interview and standardized psychometric items, few differences were found overall between staff in HIV/AIDS and staff in oncology. HIV staff were more likely to be motivated to work through peer concern, and friends of HIV staff were more likely to be supportive of their working in such a field. On the other hand, families of oncology staff were more supportive of their work than were families of HIV staff HIV staff were more likely to have had a family member who had suffered from a chronic or life-threatening disease. HIV staff were less likely to avoid discussing their work socially. Suggestions for addressing the potentially corrosive impact of health care in these fields, based on these samples, are made.
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Agotamiento Profesional/psicología , Familia/psicología , Infecciones por VIH/terapia , Personal de Salud/psicología , Neoplasias/terapia , Adulto , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Motivación , Factores de Riesgo , Apoyo Social , Encuestas y CuestionariosRESUMEN
Several investigators have reported that feeding a semi-synthetic diet of casein and dextrose to New Zealand White (NZW) rabbits will increase total serum cholesterol concentration, principally through an increase in the beta-lipoprotein fractions, thereby creating a useful model for atherosclerosis research. Although there is evidence to suggest that the dextrose/casein diet alters low-density lipoprotein receptor and bile acid clearance of cholesterol, the underlying mechanism is not completely understood. The effects of the diet on the overall physiology of the rabbit have received little attention. In this study feeding a diet of casein and dextrose of male NZW rabbits for 4 weeks resulted in changes in the serum lipid concentrations. During that time the rabbits fed the dextrose/casein diet gained less weight than did control rabbits. In the test diet rabbits, liver aspartate and alanine transaminase activities were increased from baseline values of 27 +/- 2 U/L and 89 +/- 9 U/L respectively to 112 +/- 21 U/L and 281 +/- 34 U/L respectively, then returned to the high end of the reference range. Necropsy findings included hepatomegaly caused by vacuolar hepatopathy in 19 or 20 experimental rabbits; rabbits fed the control diet had no hepatic lesions. Ultrastructural analysis revealed that enlargement of the liver cells was due to glycogen deposition. Adrenal glands from animals fed the experimental diet had a minimal change in the size of the adrenocortical cells consisting of slight ballooning and rarefaction of the cytoplasm. In a second study the level of dietary fiber was doubled. This resulted in a three-fold increase in lipid concentrations, compared with the fivefold increase in the first study. The liver enzyme activities were increased to the same extent as in the first study. Histologic changes were comparable to those in the first study. The activity of hepatic cholesterol 7alpha-hydroxylase was 3.7 +/- 0.4 pmol/min/mg of protein, compared with the control value of 7.7 +/- 1.1 pmol/min/mg of protein (P < 0.05) in the second study. The improved rate of weight gain and the lesser increase in total serum cholesterol concentration in the second study with increased dietary fiber suggest that two separate activities may be involved. Although the level of dietary fiber may be related to weight gain and total serum cholesterol values, the relation to the decrease in liver transaminase activities in study 1 was probably coincidental. It appears that the dextrose/casein diet causes decreased activity of hepatic cholesterol 7alpha-hydroxylase, which could cause a decrease in the biliary excretion of cholesterol.
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Glándulas Suprarrenales/patología , Hiperlipidemias/patología , Hígado/patología , Animales , Encéfalo/patología , Caseínas , Colesterol/metabolismo , Colesterol 7-alfa-Hidroxilasa/metabolismo , Dieta , Modelos Animales de Enfermedad , Alimentos Formulados , Glucosa , Glucógeno/ultraestructura , Hidroximetilglutaril-CoA Reductasas/metabolismo , Hiperlipidemias/inducido químicamente , Lipoproteínas/química , Hígado/metabolismo , Masculino , Microscopía Electrónica , Tamaño de los Órganos , ConejosRESUMEN
This study was conducted to examine the interpatient variability in steady-state plasma concentrations of fluphenazine by repeat depot intramuscular administration, and to determine the relationship between these concentrations and clinical state. Steady-state pre-dose concentrations of fluphenazine in plasma were measured using a sensitive and specific gas chromatography/mass spectrometry (GC/MS) assay in 24 patients with schizophrenia who were receiving continuous treatment with depot intramuscular fluphenazine decanoate. Clinical response was measured using the Andreasen Scale for positive and negative symptoms. Steady-state plasma concentrations of fluphenazine ranged from undetectable (< 0.1 ng/ml) to 27.9 ng/ml, with a median of 0.5 ng/ml. No significant associations were found between plasma concentration and dosage, or age and sex of the patient. Steady-state plasma concentrations in patients taking anticholinergic agents were significantly higher than in patients not receiving such drugs (P < 0.05 by Mann-Whitney U-test). Poorer control, expressed as the sum of the negative symptom scores or the sum of the positive and negative symptom scores, was related to higher log transformed plasma concentration of fluphenazine and higher fluphenazine decanoate dosage. The log transformed plasma concentrations of fluphenazine and the fluphenazine decanoate dosages were weakly related. Patients receiving another antipsychotic drug in addition to fluphenazine decanoate tended to have poorer clinical control and higher dosages of fluphenazine decanoate. These results indicate the useful role that plasma level monitoring can fulfil in identifying patients who are therapy-resistant despite high plasma levels.
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Flufenazina/análogos & derivados , Flufenazina/sangre , Esquizofrenia/tratamiento farmacológico , Adulto , Anciano , Antipsicóticos/uso terapéutico , Preparaciones de Acción Retardada , Relación Dosis-Respuesta a Droga , Quimioterapia Combinada , Femenino , Flufenazina/administración & dosificación , Flufenazina/farmacocinética , Flufenazina/uso terapéutico , Cromatografía de Gases y Espectrometría de Masas , Humanos , Inyecciones Intramusculares , Pruebas de Función Renal , Pruebas de Función Hepática , Masculino , Persona de Mediana Edad , Cooperación del PacienteRESUMEN
Acyl-CoA:cholesterol acyltransferase (ACAT) is the primary enzyme involved in intracellular cholesterol esterification. Arterial wall infiltration by macrophages and subsequent uncontrolled esterification of cholesterol leading to foam cell formation is believed to be an important process which leads to the development of fatty streaks. Inhibitors of the ACAT enzyme may retard this atherogenic process. We have recently discovered a series of imidazoles which are potent in vitro ACAT inhibitors in the J774 macrophage cell culture assay. This paper will describe the design, synthesis, and structure--activity relationship for this very potent series of compounds.
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Macrófagos/enzimología , Esterol O-Aciltransferasa/antagonistas & inhibidores , Animales , Línea Celular , Diseño de Fármacos , Imidazoles/síntesis química , Imidazoles/farmacología , Isoenzimas/antagonistas & inhibidores , Ratones , Microsomas Hepáticos/enzimología , Ratas , Relación Estructura-ActividadRESUMEN
A series of 4,5-diaryl-2-(substituted thio)-1H-imidazoles has been synthesized and demonstrated to be potent inhibitors of acyl-CoA:cholesterol acyltransferase (ACAT). The design, synthesis, and structure-activity relationships for this series are reported herein. One of the compounds from this series, N'-(2,4-difluorophenyl)-N-[5-[(4,5-diaryl-1H-imidazol-2- yl)thio]pentyl]-N-heptylurea (DuP 128), was selected for development as an intestinally active ACAT inhibitor. DuP 128 is a potent ACAT inhibitor in vitro and in vivo, inhibiting ACAT in rat hepatic microsomes with an IC50 = 10 nM and possessing potent antihypercholesterolemic activity in vivo.
Asunto(s)
Imidazoles/síntesis química , Esterol O-Aciltransferasa/antagonistas & inhibidores , Urea/análogos & derivados , Animales , Anticolesterolemiantes/síntesis química , Anticolesterolemiantes/farmacología , Colesterol/sangre , Cricetinae , Imidazoles/farmacología , Masculino , Mesocricetus , Microsomas Hepáticos/enzimología , Estructura Molecular , Ratas , Relación Estructura-Actividad , Urea/síntesis química , Urea/farmacologíaRESUMEN
To test the hypothesis that hepatic cholesteryl ester is involved in the regulation of apolipoprotein (apo) B secretion into plasma, apoB kinetic studies were performed in six control miniature pigs and in six pigs after a 21-day administration of the acyl coenzyme A:cholesterol acyltransferase (ACAT) inhibitor DuP 128 (2.2 mg.kg-1.d-1 i.v.). Pigs were fed low-fat, cholesterol-free diets. Total plasma cholesterol, triglyceride, very-low-density lipoprotein (VLDL) triglyceride, and low-density lipoprotein (LDL) cholesterol decreased 18%, 29%, 40%, and 26% respectively (P < .03). 131I-VLDL and 125I-LDL were injected simultaneously into each animal, and apoB kinetics were analyzed by using multi-compartmental analysis (SAAM30). VLDL apoB pool size decreased significantly by 60% (0.32 versus 0.84 mg/kg), which was due to a 65% reduction in the VLDL apoB production or secretion rate (1.03 versus 2.94 mg.kg-1.h-1). The fractional catabolic rate was unchanged. LDL apoB pool size decreased nonsignificantly by 18% (5.61 versus 6.90 mg/kg) due entirely to a 24% decrease in production rate (0.26 versus 0.34 mg.kg-1.h-1). At necropsy, hepatic microsomal ACAT activity decreased by 68% (0.28 versus 0.88 nmol.min-1.mg-1; P < .0002). Although an increase in hepatic free cholesterol leading to a decreased LDL receptor expression might be expected, this did not occur. The concentration of hepatic cholesterol and the LDL apoB fractional catabolic rate were unaffected by DuP 128. In addition, the concentration of hepatic triglyceride and the activity of diacylglycerol acyltransferase were not altered by DuP 128, indicating a lack of effect of DuP 128 on hepatic triglyceride metabolism. We conclude that inhibition of hepatic cholesteryl ester synthesis in vivo decreases apoB secretion into plasma.