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Interventional magnetic resonance imaging (MRI) could allow for diagnosis and immediate treatment of ischemic stroke; however, such endovascular catheter-based procedures under MRI guidance are inherently difficult. One major challenge is tracking the tip of the catheter, as standard fabrication methods for building inductively coupled coil markers are rigid and bulky. Here, we report a new approach that uses aerosol jet deposition to three-dimensional (3-D) print an inductively coupled RF coil marker on a polymer catheter. Our approach enables lightweight conforming markers on polymer catheters and these low-profile markers allow the catheter to be more safely navigated in small caliber vessels. Prototype markers with an inductor with the geometry of a double helix are incorporated on catheters for in vitro studies, and we show that these markers exhibit good signal amplification. We report temperature measurements and, finally, demonstrate feasibility in a preliminary in vivo experiment. We provide material properties and electromagnetic simulation performance analysis. This paper presents fully aerosol jet-deposited and functional wireless resonant markers on polymer catheters for use in 3T clinical scanners.
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Catéteres , Imagen por Resonancia Magnética Intervencional/instrumentación , Imagen por Resonancia Magnética Intervencional/métodos , Tecnología Inalámbrica/instrumentación , Animales , Diseño de Equipo , Femenino , Porcinos , TemperaturaRESUMEN
Purpose To assess the feasibility of a magnetically assisted remote-controlled (MARC) catheter system under magnetic resonance (MR) imaging guidance for performing a simple endovascular procedure (ie, renal artery embolization) in vivo and to compare with x-ray guidance to determine the value of MR imaging guidance and the specific areas where the MARC system can be improved. Materials and Methods In concordance with the Institutional Animal Care and Use Committee protocol, in vivo renal artery navigation and embolization were tested in three farm pigs (mean weight 43 kg ± 2 [standard deviation]) under real-time MR imaging at 1.5 T. The MARC catheter device was constructed by using an intramural copper-braided catheter connected to a laser-lithographed saddle coil at the distal tip. Interventionalists controlled an in-room cart that delivered electrical current to deflect the catheter in the MR imager. Contralateral kidneys were similarly embolized under x-ray guidance by using standard clinical catheters and guidewires. Changes in renal artery flow and perfusion were measured before and after embolization by using velocity-encoded and perfusion MR imaging. Catheter navigation times, renal parenchymal perfusion, and renal artery flow rates were measured for MR-guided and x-ray-guided embolization procedures and are presented as means ± standard deviation in this pilot study. Results Embolization was successful in all six kidneys under both x-ray and MR imaging guidance. Mean catheterization time with MR guidance was 93 seconds ± 56, compared with 60 seconds ± 22 for x-ray guidance. Mean changes in perfusion rates were 4.9 au/sec ± 0.8 versus 4.6 au/sec ± 0.6, and mean changes in renal flow rate were 2.1 mL/min/g ± 0.2 versus 1.9 mL/min/g ± 0.2 with MR imaging and x-ray guidance, respectively. Conclusion The MARC catheter system is feasible for renal artery catheterization and embolization under real-time MR imaging in vivo, and quantitative physiologic measures under MR imaging guidance were similar to those measured under x-ray guidance, suggesting that the MARC catheter system could be used for endovascular procedures with interventional MR imaging. (©) RSNA, 2016.
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Cateterismo Periférico/instrumentación , Embolización Terapéutica/instrumentación , Procedimientos Endovasculares/instrumentación , Imagen por Resonancia Magnética Intervencional , Magnetismo , Arteria Renal , Animales , Modelos Animales , Proyectos Piloto , Radiografía Intervencional , PorcinosRESUMEN
PURPOSE: To assess the feasibility of multiplanar vascular navigation with a new magnetically assisted remote-controlled (MARC) catheter with real-time magnetic resonance (MR) imaging at 1.5 T and 3 T and to compare it with standard x-ray guidance in simulated endovascular catheterization procedures. MATERIALS AND METHODS: A 1.6-mm-diameter custom clinical-grade microcatheter prototype with lithographed double-saddle coils at the distal tip was deflected with real-time MR imaging. Two inexperienced operators and two experienced operators catheterized anteroposterior (celiac, superior mesenteric, and inferior mesenteric arteries) and mediolateral (renal arteries) branch vessels in a cryogel abdominal aortic phantom. This was repeated with conventional x-ray fluoroscopy by using clinical catheters and guidewires. Mean procedure times and percentage success data were analyzed with linear mixed-effects regression. RESULTS: The MARC catheter tip was visible at 1.5 T and 3 T. Among inexperienced operators, MARC MR imaging guidance was not statistically different from x-ray guidance at 1.5 T (67% successful vessel selection turns with MR imaging vs 76% with x-ray guidance, P = .157) and at 3 T (75% successful turns with MR imaging vs 76% with x-ray guidance, P = .869). Experienced operators were more successful in catheterizing vessels with x-ray guidance (98% success within 60 seconds) than with 1.5-T (65%, P < .001) or 3-T (75%) MR imaging. Among inexperienced operators, mean procedure time was nearly equivalent by using MR imaging (31 seconds) and x-ray guidance (34 seconds, P = .436). Among experienced operators, catheterization was faster with x-ray guidance (20 seconds) compared with 1.5-T MR imaging (42 seconds, P < .001), but MARC guidance improved at 3 T (31 seconds). MARC MR imaging guidance at 3 T was not significantly different from x-ray guidance for the celiac (P = .755), superior mesenteric (P = .358), and inferior mesenteric (P = .065) arteries. CONCLUSION: Multiplanar navigation with a new MARC catheter with real-time MR imaging at 1.5 T and 3 T is feasible and comparable to x-ray guidance for anteroposterior vessels at 3 T in a vascular phantom.
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Cateterismo Periférico/instrumentación , Imagen por Resonancia Magnética Intervencional/instrumentación , Imagen por Resonancia Magnética Intervencional/métodos , Cateterismo Periférico/métodos , Difusión , Estudios de Factibilidad , Fluoroscopía , Humanos , Magnetismo , Perfusión , Fantasmas de ImagenRESUMEN
Peripheral artery disease (PAD) is a broad disorder encompassing multiple forms of arterial disease outside of the heart. As such, PAD development is a multifactorial process with a variety of manifestations. For example, aneurysms are pathological expansions of an artery that can lead to rupture, while ischemic atherosclerosis reduces blood flow, increasing the risk of claudication, poor wound healing, limb amputation, and stroke. Current PAD treatment is often ineffective or associated with serious risks, largely because these disorders are commonly undiagnosed or misdiagnosed. Active areas of research are focused on detecting and characterizing deleterious arterial changes at early stages using non-invasive imaging strategies, such as ultrasound, as well as emerging technologies like photoacoustic imaging. Earlier disease detection and characterization could improve interventional strategies, leading to better prognosis in PAD patients. While rodents are being used to investigate PAD pathophysiology, imaging of these animal models has been underutilized. This review focuses on structural and molecular information and disease progression revealed by recent imaging efforts of aortic, cerebral, and peripheral vascular disease models in mice, rats, and rabbits. Effective translation to humans involves better understanding of underlying PAD pathophysiology to develop novel therapeutics and apply non-invasive imaging techniques in the clinic.
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Enfermedad Arterial Periférica/patología , Animales , Enfermedades de la Aorta/diagnóstico , Enfermedades de la Aorta/patología , Trastornos Cerebrovasculares/diagnóstico , Trastornos Cerebrovasculares/patología , Modelos Animales de Enfermedad , Humanos , Imagen por Resonancia Magnética , Imagen Óptica , Enfermedad Arterial Periférica/diagnóstico , Enfermedad Arterial Periférica/diagnóstico por imagen , Trombosis/diagnóstico , Trombosis/patología , Tomografía Computarizada por Rayos X , UltrasonografíaRESUMEN
PURPOSE: To compare in vitro navigation of a magnetically assisted remote-controlled (MARC) catheter under real-time magnetic resonance (MR) imaging with manual navigation under MR imaging and standard x-ray guidance in endovascular catheterization procedures in an abdominal aortic phantom. MATERIALS AND METHODS: The 2-mm-diameter custom clinical-grade microcatheter prototype with a solenoid coil at the distal tip was deflected with a foot pedal actuator used to deliver 300 mA of positive or negative current. Investigators navigated the catheter into branch vessels in a custom cryogel abdominal aortic phantom. This was repeated under MR imaging guidance without magnetic assistance and under conventional x-ray fluoroscopy. MR experiments were performed at 1.5 T by using a balanced steady-state free precession sequence. The mean procedure times and percentage success data were determined and analyzed with a linear mixed-effects regression analysis. RESULTS: The catheter was clearly visible under real-time MR imaging. One hundred ninety-two (80%) of 240 turns were successfully completed with magnetically assisted guidance versus 144 (60%) of 240 turns with nonassisted guidance (P < .001) and 119 (74%) of 160 turns with standard x-ray guidance (P = .028). Overall mean procedure time was shorter with magnetically assisted than with nonassisted guidance under MR imaging (37 seconds ± 6 [standard error of the mean] vs 55 seconds ± 3, P < .001), and time was comparable between magnetically assisted and standard x-ray guidance (37 seconds ± 6 vs 44 seconds ± 3, P = .045). When stratified by angle of branch vessel, magnetic assistance was faster than nonassisted MR guidance at turns of 45°, 60°, and 75°. CONCLUSION: In this study, a MARC catheter for endovascular navigation under real-time MR imaging guidance was developed and tested. For catheterization of branch vessels arising at large angles, magnetically assisted catheterization was faster than manual catheterization under MR imaging guidance and was comparable to standard x-ray guidance.
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Cateterismo/instrumentación , Procedimientos Endovasculares/instrumentación , Imagen por Resonancia Magnética Intervencional/instrumentación , Fantasmas de Imagen , Catéteres , Diseño de Equipo , Fluoroscopía/instrumentación , MagnetismoRESUMEN
A paucity of substantive data from clinical drug trials is available specifically evaluating the effects of therapy for hypercholesterolemia in African-Americans, even though a substantial number are candidates for medical advice and intervention for high blood cholesterol. The efficacy and safety of lovastatin in 459 African-Americans with hypercholesterolemia were studied in the Expanded Clinical Evaluation of Lovastatin study, a multicenter, double-blind, diet- and placebo-controlled trial. This trial involved 8,245 patients who were randomly assigned, regardless of race, to receive placebo or lovastatin at doses of 20 mg once daily, 40 mg once daily, 20 mg twice daily, or 40 mg twice daily for 48 weeks. Among African-Americans, lovastatin produced sustained, dose-related (p <0.001) decreases in low-density lipoprotein cholesterol (20% to 38%), total cholesterol (14% to 28%), and triglycerides (8% to 15%). From 75% to 96% of African-Americans treated with lovastatin achieved the National Cholesterol Education Program goal of low-density lipoprotien cholesterol <160 mg/di, and from 33% to 71% achieved the goal <130 mg/di. The safety profile of lovastotin in African-Americans was generally favorable. A relatively high incidence of creatine kinase levels greater than the upper limit of normal was observed in African-Americans during the study, i.e., 63% in the placebo group and similar levels in lovastatin treatment groups. Lovastatin is highly effective and generally well tolerated as therapy for primary hypercholesterolemia in African-Americans.
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Anticolesterolemiantes/uso terapéutico , Población Negra , Hipercolesterolemia/tratamiento farmacológico , Lovastatina/uso terapéutico , Negro o Afroamericano , Anticolesterolemiantes/administración & dosificación , Anticolesterolemiantes/efectos adversos , Colesterol/sangre , LDL-Colesterol/sangre , Creatina Quinasa/sangre , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Tolerancia a Medicamentos , Femenino , Humanos , Hipercolesterolemia/dietoterapia , Incidencia , Lovastatina/administración & dosificación , Lovastatina/efectos adversos , Masculino , Persona de Mediana Edad , Placebos , Seguridad , Triglicéridos/sangreRESUMEN
The Expanded Clinical Evaluation of Lovastatin study, a randomized, double-blind, placebo- and diet-controlled multicenter trial, evaluated the efficacy and tolerability of lovastatin over 48 weeks in 8,245 patients with moderately severe hypercholesterolemia. During year 1 of follow-up of the full cohort, lovastatin at 20 or 40 mg/day, or 20 or 40 mg twice daily, produced dose-dependent decreases in low-density lipoprotein (LDL) cholesterol (24% to 40%) and triglyceride levels (10% to 19%), and increases in high-density lipoprotein (HDL) cholesterol (6.6% to 9.5%). In all, 977 patients continued their original blinded treatment for an additional year. In year 2, the LDL cholesterol response to lovastatin was maintained, the triglyceride reductions were somewhat less, and the increases in HDL cholesterol were moderately greater than in year 1. Successive transaminase elevations > 3 times the upper limit of normal were observed in only 1 patient in year 2, yielding a cumulative 2-year incidence of from 0.1% (placebo or lovastatin 20 mg/day) to 1.9% (lovastatin 80 mg/day). Myopathy occurred in only 1 patient during year 2, and over the 2-year study was observed rarely and only at lovastatin dosages of 40 and 80 mg/day. This study indicates that lovastatin maintains its efficacy over long-term follow-up, particularly in effectively lowering LDL cholesterol, is generally well tolerated, and has a favorable safety profile.
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Hipercolesterolemia/tratamiento farmacológico , Lovastatina/uso terapéutico , Alanina Transaminasa/sangre , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Estudios de Cohortes , Creatina Quinasa/sangre , Método Doble Ciego , Femenino , Estudios de Seguimiento , Humanos , Hipercolesterolemia/sangre , Tablas de Vida , Hígado/efectos de los fármacos , Hígado/enzimología , Lovastatina/efectos adversos , Masculino , Persona de Mediana Edad , Enfermedades Musculares/inducido químicamente , Enfermedades Musculares/enzimología , Triglicéridos/sangre , Estados UnidosRESUMEN
PURPOSE: To compare fundus photography with ophthalmoscopy in the detection of diabetic retinopathy. METHODS: Ophthalmoscopy and fundus photographs with a nonmydriatic camera, both performed through dilated pupils, were compared to diagnose retinopathy in a cohort of 410 Oklahoma Indians with noninsulin-dependent diabetes mellitus. A total of 795 eyes were examined using both methods. The mean age of participants was 60.3 years, with a mean duration of diabetes of 17.3 years. RESULTS: An overall agreement of 86.3% with a kappa statistic kappa of 0.74 was found between ophthalmoscopy and fundus photography with a nonmydriatic camera. For the diagnosis of proliferative diabetic retinopathy, kappa = 0.84 with an agreement of 98.1%. With a total of 61 cases of proliferative retinopathy diagnosed by either method in our study, ophthalmoscopy alone detected 88.5% and fundus photography, 78.7%. When compared on a lesion-by-lesion basis, agreement between the two diagnostic methods was highest for nonproliferative retinopathy, as well as fibrous proliferation. CONCLUSION: The fundus photography with a nonmydriatic camera, performed with mydriasis, is comparable to ophthalmoscopy for the detection of retinopathy. It may prove to be a suitable, cost-effective method for routine screening in diabetes clinics, provided ophthalmologic referral is ensured for those with a diagnosis of any form of retinopathy, questionable retinopathy, nondiabetic retinopathy, those with poor quality photographs, as well as those with acute changes in visual acuity.
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Retinopatía Diabética/diagnóstico , Retinopatía Diabética/etnología , Fondo de Ojo , Indígenas Norteamericanos , Oftalmoscopía , Diabetes Mellitus Tipo 2/diagnóstico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Oklahoma , Fotograbar , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
OBJECTIVE: To evaluate the efficacy and safety of lovastatin in women with moderate hypercholesterolemia. DESIGN: The Expanded Clinical Evaluation of Lovastatin (EXCEL) Study, a multicenter, double-blind, diet- and placebo-controlled trial, in which participants were randomly assigned to receive placebo or lovastatin at doses of 20 or 40 mg once daily, or 20 or 40 mg twice daily for 48 weeks. SETTING: Ambulatory patients recruited by 362 participating centers throughout the United States. PATIENTS: Women (n = 3390) from the total cohort of 8245 volunteers. MEASUREMENTS: Plasma total, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) cholesterol, and triglycerides; and laboratory and clinical evidence of adverse events monitored periodically throughout the study. RESULTS: Among women, lovastatin (20 to 80 mg/d) produced sustained (12- to 48-week), dose-related changes (P < 0.001): decreases in LDL cholesterol (24% to 40%) and triglycerides (9% to 18%), and increases in HDL cholesterol (6.7% to 8.6%). Depending on the dose, from 82% to 95% of lovastatin-treated women achieved the National Cholesterol Education Program goal of LDL cholesterol levels less than 4.14 mmol/L (160 mg/dL), and 40% to 87% achieved the goal of 3.36 mmol/L (130 mg/dL). Successive transaminase elevations greater than three times the upper limit of normal occurred in 0.1% of women and were dose dependent above the 20-mg dose. Myopathy, defined as muscle symptoms with creatine kinase elevations greater than 10 times the upper limit of normal, was rare and associated with the highest recommended daily dose of lovastatin (80 mg). Estrogen-replacement therapy appeared to have no effect on either the efficacy or safety profile of lovastatin. CONCLUSION: Lovastatin is highly effective and generally well tolerated as therapy for primary hypercholesterolemia in women.
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Hipercolesterolemia/tratamiento farmacológico , Lovastatina/uso terapéutico , Anciano , HDL-Colesterol/efectos de los fármacos , LDL-Colesterol/efectos de los fármacos , Creatina Quinasa/efectos de los fármacos , Método Doble Ciego , Terapia de Reemplazo de Estrógeno , Femenino , Humanos , Lovastatina/efectos adversos , Persona de Mediana Edad , Enfermedades Musculares/inducido químicamente , Factores Sexuales , Transaminasas/efectos de los fármacosRESUMEN
OBJECTIVE: To determine the incidence rates and risk factors for development of diabetic retinopathy in Oklahoma Indians. RESEARCH DESIGN AND METHODS: Cohort follow-up study with baseline examination between 1972 and 1980 and follow-up examination between 1987 and 1991. Mean +/- SD follow-up time was 12.8 +/- 1.7 yr. Eleven Indian Health Service facilities (clinics and hospitals) in Oklahoma participated in the study. Study participants were a quasirandom sample of 1012 American Indians (379 men, 633 women) in Oklahoma with NIDDM, 927 of whom received a detailed eye examination at baseline. The mean age of participants was 52 yr with a duration of diabetes of 6.9 yr at baseline. The average quantum of Indian blood was 92% (77% full blood). At follow-up, 515 (55.6%) were alive, 408 (44.0%) were deceased, and 4 (0.4%) could not be traced. Of the living participants, 380 (73.8%) underwent an ophthalmoscopic examination. RESULTS: The incidence of retinopathy among the participants who were free of disease at baseline and who survived the follow-up interval was 72.3%. By multivariate analysis, significant independent predictors of retinopathy recorded at baseline were FPG level, therapeutic regimen, systolic blood pressure, and duration of diabetes. FPG levels > or = 11.1 mM (200 mg/dl) increased the risk of retinopathy 1.7 times that for levels < 7.8 mM (140 mg/dl). Insulin use was associated with a 20% greater incidence. Hypertension was a particularly significant risk factor for those with lower FPG levels. CONCLUSIONS: Given that NIDDM is reaching epidemic proportions in Oklahoma Indians and that most may be afflicted with retinopathy, frequent ophthalmological examinations are clearly indicated for this high-risk population. The role of intervention, namely glycemic and hypertensive control, deserves further study.
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Diabetes Mellitus Tipo 2/fisiopatología , Retinopatía Diabética/epidemiología , Hipertensión/epidemiología , Indígenas Norteamericanos , Glucemia/análisis , Presión Sanguínea , Colesterol/sangre , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/epidemiología , Angiopatías Diabéticas/epidemiología , Nefropatías Diabéticas/epidemiología , Retinopatía Diabética/sangre , Retinopatía Diabética/fisiopatología , Femenino , Estudios de Seguimiento , Humanos , Hipertensión/fisiopatología , Incidencia , Masculino , Persona de Mediana Edad , Oklahoma/epidemiología , Factores de Riesgo , Factores de Tiempo , Triglicéridos/sangreRESUMEN
BACKGROUND: Lovastatin produces consistent dose-related reductions in plasma levels of low density lipoprotein (LDL) cholesterol along with variable decreases in triglycerides and increases in high density lipoprotein (HDL) cholesterol. Patient characteristics from the Expanded Clinical Evaluation of Lovastatin (EXCEL) study were examined to determine their association with the magnitude of lovastatin-induced changes in these lipids and lipoproteins. METHODS AND RESULTS: After a baseline period consisting of dietary therapy, 8,245 patients with moderate hypercholesterolemia were randomized to five groups that received 48 weeks of treatment with either placebo or daily doses of lovastatin ranging from 20 to 80 mg. By use of linear statistical models, 20 different patient characteristics were examined for modification of the dose-dependent responses observed. For LDL cholesterol, the following were associated with enhanced lowering (p less than 0.05; percent changes are placebo-corrected, adjusted mean changes from baseline for the 80-mg/day lovastatin group): full drug compliance (-41.9%) versus 80% compliance (-20.3%); an age of 65 (-43.4%) versus 45 years (-38.1%) for women; white race (-40.9%) versus black race (-38.0%); and 4.5-kg weight gain (-42.6%) versus 4.5-kg weight loss (-37.9%). Similar relations for enhanced triglyceride lowering were found with older age and weight gain. Patients with initially low HDL cholesterol (less than 0.91 mmol/l) and high triglycerides (greater than 2.26 mmol/l) had enhanced responses for these parameters: placebo-corrected percent changes at 80 mg/day were -27.4% for triglycerides and +12.3% for HDL cholesterol. CONCLUSIONS: Overall, patient characteristics had very little impact of clinical importance on the dose-dependent LDL cholesterol lowering found with lovastatin. In patients with initially high levels of triglycerides and low levels of HDL cholesterol, the elevation of HDL cholesterol produced by lovastatin appears to be enhanced.
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HDL-Colesterol/efectos de los fármacos , LDL-Colesterol/efectos de los fármacos , Hipercolesterolemia/tratamiento farmacológico , Lovastatina/uso terapéutico , Triglicéridos/sangre , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Femenino , Humanos , Hipercolesterolemia/sangre , Hipercolesterolemia/epidemiología , Modelos Lineales , Masculino , Persona de Mediana EdadRESUMEN
Hypertension and hypercholesterolemia frequently coexist and may require concomitant drug treatments. The efficacy and safety profile of lovastatin given in the presence of antihypertensive medication was evaluated using patient subgroups identified in the Expanded Clinical Evaluation of Lovastatin (EXCEL) Study. The EXCEL study examined 8,245 patients with moderate hypercholesterolemia randomly assigned either to a group treated with lovastatin (20-80 mg daily) or to a group given placebo for 48 weeks. After adjustment for patient characteristics, pairwise comparisons were made between patients taking no antihypertensive agents (n = 3,772) and those taking either calcium antagonists (n = 446), selective beta 1-adrenergic receptor blockers (n = 326), nonselective beta-adrenergic receptor blockers (n = 219), potassium-sparing diuretics (n = 187), thiazide diuretics (n = 126), or angiotensin converting enzyme inhibitors (n = 171). The placebo-corrected dose-dependent effect of lovastatin on the percent change from baseline in low-density lipoprotein cholesterol was not attenuated in any subgroup and was slightly enhanced in the calcium antagonist subgroup (-29% to -44%, p = 0.06) when compared with patients taking no antihypertensive agents (-24% to -40%); this difference, however, was only of borderline significance. Patterns of lovastatin-induced increase in high-density lipoprotein cholesterol and decrease in triglycerides were not consistently different among the subgroups. Examination of mean changes in serum transaminases, mean changes in creatine kinase, and the proportion of patients discontinuing therapy for clinical adverse experiences did not indicate the presence of an interaction.(ABSTRACT TRUNCATED AT 250 WORDS)
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Antagonistas Adrenérgicos beta/administración & dosificación , Antihipertensivos/administración & dosificación , Bloqueadores de los Canales de Calcio/administración & dosificación , LDL-Colesterol/efectos de los fármacos , Quimioterapia Combinada , Lovastatina/administración & dosificación , Inhibidores de la Enzima Convertidora de Angiotensina/administración & dosificación , LDL-Colesterol/sangre , Diuréticos/administración & dosificación , Método Doble Ciego , Evaluación de Medicamentos , Interacciones Farmacológicas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Triglicéridos/sangreRESUMEN
The efficacy and safety of bezafibrate were evaluated in 83 patients with type IIa, IIb, or IV hyperlipoproteinemia. Following a 12- to 14-week placebo period on a coronary-prudent diet (Period 1), patients were assigned randomly to receive either bezafibrate 600 mg/day or placebo, plus diet in a double-blind, 12-week treatment period (Period 2). The return of lipid and lipoprotein levels toward baseline was evaluated in a subsequent 8-week period on placebo plus diet (Period 3). In patients with type IIa hyperlipoproteinemia, bezafibrate significantly lowered total (14.6%, P less than 0.001) and LDL-cholesterol (16.4%, P less than 0.001) and total (29.9%, P less than 0.001) and VLDL-triglyceride (44.0%, P less than 0.001) and significantly increased HDL cholesterol (9.5%, P less than 0.001). In patients with type IIb, bezafibrate had a qualitatively similar effect to that seen in type IIa on each of these lipoproteins, but the sample size was too small for statistical evaluation. In patients with type IV, bezafibrate lowered total (48.3%, P less than 0.01) and VLDL-triglyceride (57.7%, P less than 0.001) and VLDL-cholesterol (56.8%, P less than 0.001) and increased HDL-cholesterol (16.6%, P less than 0.05). All values returned toward baseline during Period 3. Only two bezafibrate patients experienced adverse events that were considered definitely treatment related; one was dropped from the study because of elevations in SGOT and SGPT, 1.5- and 4-times the upper limit of normal, respectively. For other laboratory parameters, trends upward or downward were small and of doubtful clinical significance. Bezafibrate appears to be effective and safe for modifying lipid and lipoprotein levels in patients with types IIa, IIb and IV hyperlipoproteinemia.
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Bezafibrato/uso terapéutico , Hiperlipoproteinemias/tratamiento farmacológico , Adolescente , Adulto , Anciano , Bezafibrato/efectos adversos , Método Doble Ciego , Humanos , Hiperlipoproteinemia Tipo II/sangre , Hiperlipoproteinemia Tipo II/tratamiento farmacológico , Hiperlipoproteinemia Tipo IV/sangre , Hiperlipoproteinemia Tipo IV/tratamiento farmacológico , Hiperlipoproteinemias/sangre , Lípidos/sangre , Lipoproteínas/sangre , Masculino , Persona de Mediana EdadRESUMEN
We modified a Penlon Nuffield 200 for use in a monoplace hyperbaric oxygen chamber by feeding back the chamber pressure to the reducing valve of the Nuffield 200. This provides a compensating mechanism, allowing the ventilator to deliver adequate tidal volumes at pressures of up to 3 atmospheres. We report the laboratory testing of the ventilator and our experience of ventilating two patients with carbon monoxide poisoning. Although compensation is not complete the modification is adequate for short-term clinical use in patients in whom the airway is compromised but who need hyperbaric oxygen therapy.
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Intoxicación por Monóxido de Carbono/terapia , Oxigenoterapia Hiperbárica/instrumentación , Ventiladores Mecánicos , Adulto , Humanos , Masculino , Modelos Estructurales , Respiración/fisiología , Volumen de Ventilación Pulmonar/fisiologíaRESUMEN
In the multicenter, double-blind EXCEL (Expanded Clinical Evaluation of Lovastatin) study the efficacy of lovastatin in modifying plasma lipids and lipoproteins in 8,245 participants with moderate primary hypercholesterolemia was evaluated. Patients were randomly assigned to 48 weeks of treatment with diet and placebo or diet and lovastatin 20 or 40 mg once a day, or 20 or 40 mg twice a day. At all of these dosages, lovastatin produced substantial dose-dependent reductions in low-density-lipoprotein (LDL)-cholesterol levels, averaging 24% (20 mg/day) to 40% (80 mg/day). The magnitude of the effect of this lipoprotein was further reflected by the percentage of patients who achieved National Cholesterol Education Program (NCEP) goals. In the absence of coronary artery disease (CAD) or two other CAD risk factors, the LDL-cholesterol goal of 4.14 mmol/L (160 mg/dL) was attained by 22% of patients in the placebo group and between 81% (20 mg/day) and 96% (80 mg/day) of those treated with lovastatin. For those with CAD or at least two other CAD risk factors, the LDL-cholesterol goal of 3.36 mmol/L (130 mg/dL) was attained by 4% of placebo patients and between 38% (20 mg/day) and 83% (80 mg/day) of those treated with lovastatin. Lovastatin also increased high-density-lipoprotein cholesterol (7-10%) and decreased triglycerides (10-19%) in a dose-dependent manner. Thus, when used as an adjunct to a prudent diet, lovastatin produces favorable changes in the entire lipoprotein profile and is a highly effective agent for managing patients with primary hypercholesterolemia.
Asunto(s)
Hipercolesterolemia/tratamiento farmacológico , Lovastatina/uso terapéutico , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Terapia Combinada , Grasas de la Dieta/administración & dosificación , Método Doble Ciego , Femenino , Humanos , Hipercolesterolemia/sangre , Hipercolesterolemia/dietoterapia , Lipoproteínas/sangre , Lovastatina/administración & dosificación , Lovastatina/farmacología , Masculino , Persona de Mediana Edad , Triglicéridos/sangreRESUMEN
This randomized, double-blind, multicenter, diet-and-placebo-controlled study was designed to clarify the dose-response relationship of lovastatin therapy to lipid-modifying efficacy and drug-related adverse events. Exclusion criteria were minimized so that study patients were representative of the majority of patients with moderate hypercholesterolemia seen in medical practice. After 6 weeks on the American Heart Association Step 1 Diet, a total of 8,245 patients were randomly assigned to 48 weeks of treatment with diet and placebo or lovastatin at dosages of 20 or 40 mg once a day or 20 or 40 mg twice a day. All adverse events were monitored, with particular attention to evaluation of liver and muscle. Liver transaminase elevations suggestive of possible hepatotoxicity, defined as successive elevations in either aspartate transaminase or alanine aminotransferase greater than 3 times the upper limit of normal, occurred in equal numbers of placebo and lovastatin 20 mg/day treated patients (0.1%). The frequencies were higher in lovastatin 40 mg/day and 80 mg/day patient groups (0.9 and 1.5%, respectively). No patient was diagnosed as having clinically symptomatic hepatic dysfunction. Creatinine kinase (CK) elevations above the upper limit of normal occurred frequently in placebo- (29%), as well as lovastatin-treated patients (29-35%), and muscle symptoms were reported with similar frequency in all groups (7-9%). The combination of muscle symptoms with marked CK elevations (greater than 10 times the upper limit of normal) was seen in only five patients: one in a 40 mg/day dose group and four in the 80 mg/day dose group. No patient developed rhabdomyolysis. The incidence of clinical and laboratory adverse events requiring discontinuation was 6% for the placebo group and from 7% (20 mg/day) to 9% (80 mg/day) for lovastatin treatment groups. No new types of adverse experiences related to lovastatin treatment were reported. Lovastatin, as an adjunct to diet for the reduction of elevated LDL cholesterol, was generally very well tolerated.
Asunto(s)
Hipercolesterolemia/tratamiento farmacológico , Lovastatina/efectos adversos , Alanina Transaminasa/sangre , Aspartato Aminotransferasas/sangre , Terapia Combinada , Creatina Quinasa/sangre , Grasas de la Dieta/administración & dosificación , Método Doble Ciego , Erupciones por Medicamentos/epidemiología , Erupciones por Medicamentos/etiología , Femenino , Enfermedades Gastrointestinales/inducido químicamente , Enfermedades Gastrointestinales/epidemiología , Humanos , Hipercolesterolemia/sangre , Hipercolesterolemia/dietoterapia , Incidencia , Lovastatina/administración & dosificación , Lovastatina/uso terapéutico , Masculino , Persona de Mediana Edad , Enfermedades Musculares/sangre , Enfermedades Musculares/inducido químicamente , Enfermedades Musculares/epidemiología , Enfermedades del Sistema Nervioso/inducido químicamente , Enfermedades del Sistema Nervioso/epidemiologíaRESUMEN
In the Expanded Clinical Evaluation of Lovastatin (EXCEL) Study, a multicenter, double-blind, diet- and placebo-controlled trial, we evaluated the efficacy and safety of lovastatin in 8245 patients with moderate hypercholesterolemia. Patients were randomly assigned to receive placebo or lovastatin at a dosage of 20 mg once daily, 40 mg once daily, 20 mg twice daily, or 40 mg twice daily for 48 weeks. Lovastatin produced sustained, dose-related (P less than .001) changes as follows (for dosages of 20 to 80 mg/d): decreased low-density lipoprotein-cholesterol level (24% to 40%), increased high-density lipoprotein-cholesterol level (6.6% to 9.5%), decreased total cholesterol level (17% to 29%), and decreased triglyceride level (10% to 19%). The National Cholesterol Education Program's low-density lipoprotein-cholesterol level goal of less than 4.14 mmol/L (160 mg/dL) was achieved by 80% to 96% of patients, while the less than 3.36 mmol/L (130 mg/dL) goal was achieved by 38% to 83% of patients. The difference between lovastatin and placebo in the incidence of clinical adverse experiences requiring discontinuation was small, ranging from 1.2% at 20 mg twice daily to 1.9% at 80 mg/d. Successive transaminase level elevations greater than three times the upper limit of normal were observed in 0.1% of patients receiving placebo and 20 mg/d of lovastatin, increasing to 0.9% in those receiving 40 mg/d and 1.5% in those receiving 80 mg/d of lovastatin (P less than .001 for trend). Myopathy, defined as muscle symptoms with a creatine kinase elevation greater than 10 times the upper limit of normal, was found in only one patient (0.1%) receiving 40 mg once daily and four patients (0.2%) receiving 80 mg/d of lovastatin. Thus, lovastatin, when added after an adequate trial of a prudent diet, is a highly effective and generally well-tolerated treatment for patients with moderate hypercholesterolemia.
Asunto(s)
Hipercolesterolemia/tratamiento farmacológico , Lipoproteínas/sangre , Lovastatina/uso terapéutico , Adulto , Anciano , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Creatina Quinasa/metabolismo , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Femenino , Humanos , Hipercolesterolemia/sangre , Pruebas de Función Hepática , Lovastatina/efectos adversos , Masculino , Persona de Mediana Edad , Enfermedades Musculares/inducido químicamente , Cooperación del Paciente , Triglicéridos/sangreRESUMEN
The randomized, double-blind, placebo-controlled trial described in this report was undertaken to clarify the dose-response relation of lovastatin therapy to lipid-modifying efficacy (lipid/lipoprotein modification) and drug-related adverse events in a population with moderately elevated fasting plasma total cholesterol (240 to 300 mg/dl) and low-density lipoprotein cholesterol (greater than or equal to 160 mg/dl). Men or women (postmenopausal or surgically sterile), aged 18 to 70 years, were entered into the trial with minimal exclusion criteria. After 4 to 6 weeks of an American Heart Association phase I diet or a more stringent diet, 8,245 patients from 362 sites were randomized to 1 of 5 parallel diet and drug treatment groups: placebo (n = 1,663) or lovastatin, 20 mg (n = 1,642) and 40 mg (n = 1,645) with the evening meal, and 20 mg (n = 1,646) or 40 mg twice daily (n = 1,649). The regimen of diet and lovastatin (or placebo) was followed for 48 weeks. The 5 treatment groups were similar at baseline. The total cohort had the following characteristics: 59% were men (mean age 56 years); 92% were white; 59% had completed at least 1 year of education beyond high school; 57% had a history of cardiovascular and associated disease; 40% had a history of hypertension; and 29% had coronary artery disease. Health habits were similar among groups, with 18% of patients reporting cigarette smoking, 14% reporting that they consume greater than 1 alcoholic beverage daily and 67% reporting no strenous exercise. Mean lipid/lipoprotein levels were also similar among groups, with the following average levels: total cholesterol (258 mg/dl), low-density lipoprotein cholesterol (180 mg/dl), high-density lipoprotein cholesterol (45 mg/dl) and triglycerides (median = 155 mg/dl). The large size of this trial, its placebo-controlled, double-blind design and the similarity of treatment groups at baseline should allow clear documentation of the long-term effects of lovastatin treatment and generalization of the results to a substantial portion of patients who may be candidates for lipid-modifying therapy.
Asunto(s)
Hipercolesterolemia/tratamiento farmacológico , Lovastatina/uso terapéutico , Adulto , Anciano , Colesterol/sangre , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Método Doble Ciego , Femenino , Humanos , Lovastatina/administración & dosificación , Lovastatina/efectos adversos , Masculino , Persona de Mediana Edad , Placebos , Ensayos Clínicos Controlados Aleatorios como Asunto , Triglicéridos/sangreRESUMEN
A multicenter study of blood cholesterol screening was performed in several typical environments, such as community sites (shopping malls and a supermarket), health care sites, work sites, a blood bank and a school. Cholesterol was measured with a portable, dry-chemistry analyzer using capillary blood obtained by fingerstick. Data are reported from a total of 13,824 participants, spanning the entire age spectrum. Overall, 25% of screened subjects had blood cholesterol levels above the age-specific cutpoints used in the current study. Although in the aggregate this screening experience very closely approximates the expected level of referrals, the proportion of referred screened subjects differed significantly among the 5 types of screening environments and by gender. Follow-up telephone interviews indicated that 53% of referrals had initiated a physician contact. More than 75% of those who had seen a physician reported that the diagnosis of hypercholesterolemia had been confirmed, and almost 72% had been prescribed a diet. A large proportion of referred screened subjects reported having modified their diet, particularly when recommended to do so by a physician. This study has yielded encouraging evidence that physicians gave referred screened subjects appropriate initial advice for managing hypercholesterolemia. The new technology for blood cholesterol measurement evaluated in the current study has proven to be a feasible and reliable means for measuring blood cholesterol in typical screening settings.