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BACKGROUND: ß-Hydroxy-ß-methylbutyrate (HMB) supplementation has been demonstrated to enhance muscle protein synthesis and attenuate loss of muscle mass by multiple pathways. The beneficial effects of HMB have been studied by using either the calcium salt, monohydrate, of HMB (CaHMB) or the free acid form (FAHMB). OBJECTIVE: The present study was designed to compare the pharmacokinetics and relative bioavailability of the 2 forms of HMB administered as a liquid suspension in male Sprague-Dawley rats. METHODS: CaHMB at 30, 100, and 300 mg/kg and equivalent doses of FAHMB at 24.2, 80.8, and 242 mg/kg were administered orally as a liquid suspension to male Sprague-Dawley rats. A single i.v. dose of 5 mg/kg CaHMB, corresponding to an equivalent dose of 4.04 mg/kg FAHMB, was also administered. Plasma concentrations of HMB were analyzed by liquid chromatography tandem mass spectrometry, and pharmacokinetic variables and relative bioavailability of the 2 forms of HMB were determined. RESULTS: After oral administration, the area under the plasma concentration time curve (AUC) from time 0 to time t (0-t) and from time 0 to infinity (0-∞) and the maximum (peak) plasma concentration (Cmax) for CaHMB were significantly greater than for FAHMB, whereas the time to reach Cmax did not differ from that of FAHMB. The relative bioavailability of CaHMB was 49%, 54%, and 27% greater than that of FAHMB for the 3 respective oral doses tested. After i.v. administration, the AUCs 0-t and 0-∞ of the calcium salt were significantly greater than those of FAHMB. The relative bioavailability of CaHMB was 80% greater than that of FAHMB. The higher relative bioavailability of CaHMB may be attributable to its low systemic clearance compared with FAHMB. CONCLUSIONS: This study demonstrates the enhanced relative bioavailability of CaHMB compared with FAHMB. Further studies are warranted to understand the physiologic mechanisms contributing to the differences in systemic clearance.
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Calcio/farmacocinética , Ácidos Grasos no Esterificados/farmacocinética , Valeratos/farmacocinética , Administración Oral , Animales , Área Bajo la Curva , Disponibilidad Biológica , Calcio/administración & dosificación , Calcio/sangre , Suplementos Dietéticos , Ácidos Grasos no Esterificados/administración & dosificación , Ácidos Grasos no Esterificados/sangre , Masculino , Microsomas/efectos de los fármacos , Microsomas/metabolismo , Unión Proteica/fisiología , Ratas , Ratas Sprague-Dawley , Espectrometría de Masas en Tándem , Valeratos/administración & dosificación , Valeratos/sangreRESUMEN
Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are an increasingly common chronic liver disease closely associated with diabetes and obesity that have reached epidemic proportions. Reports on the prevalence of NAFLD have suggested that 27-34% of the general population in the USA and 40-90% of the obese population worldwide have this disease. Increasing urbanisation rate and associated inappropriate lifestyle changes are not only the risk factors of diabetes, but also unmask genetic predisposition in various populations for the metabolic syndrome and its manifestations including NAFLD and NASH. Lifestyle modifications and balanced nutrition are among the foremost management strategies along with ursodeoxycholic acid, metformin, vitamin E and pentoxifylline. Although weight reduction associated with current therapeutic strategies has shown some promise, maintaining it in the long run is largely unsuccessful. With the safety of pharmacotherapy still being uncertain and can be started only after confirmation, other reasonable interventions such as nutrition hold promise in preventing disease progression. The role of dietary components including branched-chain amino acids, methionine, choline and folic acid is currently being evaluated in various clinical trials. Nutritional approaches sought to overcome the limitations of pharmacotherapy also include evaluating the effects of natural ingredients, such as silymarin and spirulina, on liver disease. Understanding the specific interaction between nutrients and dietary needs in NAFLD and maintaining this balance through either a diet or a nutritional product thus becomes extremely important in providing a more realistic and feasible alternative to treat NAFLD. A planned complete nutritional combination addressing specific needs and helping to prevent the progression of NAFLD is the need of the hour to avert people from ending up with complications.
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Enfermedad del Hígado Graso no Alcohólico/dietoterapia , Progresión de la Enfermedad , Humanos , Síndrome Metabólico/complicaciones , Síndrome Metabólico/metabolismo , Modelos Biológicos , Enfermedad del Hígado Graso no Alcohólico/etiología , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Fenómenos Fisiológicos de la Nutrición , Obesidad/complicaciones , Obesidad/metabolismo , Factores de RiesgoRESUMEN
Despite its ancient roots and prominence in India as an accepted alternative to modern medicine, Ayurveda's growth has been hampered by an inability to carry out clinical studies of its effectiveness and safety using modern scientific methods - while preserving the core of Ayurveda, which is personalised medicine. In this comment, we propose that the N-of-1 trial be used as a practical method to evaluate Ayurvedic treatments, which is simultaneously consistent with the canons of modern medicine and of Ayurveda. We emphasise the importance of doing this as a practical alternative that will benefit patients. We need not wait to resolve the epistemic inconsistency between Ayurveda and modern medicine to take steps in this direction.
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Medicina Ayurvédica , Humanos , IndiaRESUMEN
The objective of this study was to characterize the maximum tolerated dose (MTD), dose-limiting toxicities (DLT), pharmacokinetics, and antitumor effects of DRF-1042, a novel camptothecin analog, in refractory solid tumor patients. DRF-1042 was given for 5 consecutive days for 2 weeks, repeated every 3 weeks at 1.5 to 270 mg/m(2). Adverse events were monitored following NCI-CTC. Pharmacokinetics of lactone and total forms were determined using validated high-performance liquid chromatography (HPLC) and noncompartmental methods. Efficacy was evaluated applying World Health Organization (WHO) criteria. The 1st course was used to determine DLT and MTD. Twenty-five patients received 73 courses of therapy. Myelosuppression and diarrhea were DLTs. MTD was 120 mg/m(2)/day. AUC increased approximately linearly with dose. The t(1/2) for lactone and total forms was 9.9 and 29 hours, respectively. AUCs correlated significantly with nadir leucopenia and grade 4 diarrhea. Two complete responses (CRs) and 2 partial responses (PRs) were observed. In addition, 4 stable diseases were observed. The recommended phase II dose is 80 mg/m(2)/day.
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Antineoplásicos/farmacología , Camptotecina/farmacología , Neoplasias/tratamiento farmacológico , Adulto , Anciano , Antineoplásicos/efectos adversos , Antineoplásicos/farmacocinética , Área Bajo la Curva , Camptotecina/efectos adversos , Camptotecina/análogos & derivados , Camptotecina/farmacocinética , Relación Dosis-Respuesta a Droga , Femenino , Semivida , Humanos , Masculino , Dosis Máxima Tolerada , Persona de Mediana EdadRESUMEN
Global pharmaceutical companies face an increasingly harsh environment for their primary business of selling medicines. They have to contend with a spiraling decline in the productivity of their R&D programs that is guaranteed to severely diminish their growth prospects. Outsourcing of drug discovery activities to low-cost locations is a growing response to this crisis. However, the upsides to outsourcing are capped by the failure of global pharmaceutical companies to take advantage of the full range of possibilities that this model provides. Companies that radically rethink and transform the way they conduct R&D, such as seeking the benefits of low-cost locations in India and China will be the ones that thrive in this environment. In this article we present our views on how the outsourcing model in drug discovery should go beyond increasing the efficiency of existing drug discovery processes to a fundamental rethink and re-engineering of these processes.