Chemotaxonomic Studies on Centella asiatica (L.) Urb. from Varied Phytogeographical Conditions of India for Its Industrial Prospection

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - Centella asiatica (L.) Urb. (Apiaceae) with high commercial value is an important herb in traditional Indian...     

A sibship with hypokalemic alkalosis and renal proximal tubulopathy

A new syndrome, characterized by hypokalemic alkalosis, hyperreninemia, aldosterone, high urinary prostaglandin E2 excretion, normal BP, and resistance of BP to angiotensin II is described in three of four siblings. Histologic examination of tissue obtained by biopsy from the kidneys showed an intense staining of the proximal tubular cells, as well as an extreme hypertrophy of the proximal tubular basement membranes, features that previously have not been observed. On electron microscopic examination, the characteristic changes of the tubular cells consisted of very dense cytoplasm, compact mitochondria, and pyknotic nuclei. In contrast to Bartter's syndrome, the juxtaglomerular apparatus were of normal appearance. Glomerular filtration rate and renal plasma flow were within normal limits. Fractional distal delivery of proximal tubular solute and fractional chloride reabsorption in the thick ascending limb of the loop of Henle were normal. The findings of a genetic linkage between the syndrome and the major histocompatibility system suggests that this familial tubulopathy is an inherited disorder.     

Microscopic Visualization of Metabotropic Glutamate Receptors on the Surface of Living Cells Using Bifunctional Magnetic Resonance Imaging Probes

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Pharmacogenetics and outcome with antipsychotic drugs

Antipsychotic medications are the gold-standard treatment for schizophrenia, and are often prescribed for other mental conditions. However, the efficacy and side-effect profiles of these drugs are heterogeneous, with large interindividual variability. As a result, treatment selection remains a largely trial-and-error process, with many failed treatment regimens endured before finding a tolerable balance between symptom management and side effects. Much of the interindividual variability in response and side effects is due to genetic factors (heritability, h²~ 0.60-0.80). Pharmacogenetics is an emerging field that holds the potential to facilitate the selection of the best medication for a particular patient, based on his or her genetic information. In this review we discuss the most promising genetic markers of antipsychotic treatment outcomes, and present current translational research efforts that aim to bring these pharmacogenetic findings to the clinic in the near future.     

Formulation and Evaluation of Sustained Release Extrudes Prepared via Novel Hot Melt Extrusion Technique

The purpose of the present investigation is to emphasize the application of hot-melt extrusion technique (HMET) for the preparation of sustained release matrix formulation of highly dosed, freely soluble drugs. In this study, sustained release multiple unit dosage of venlafaxine hydrochloride (VH) was prepared by HMET. Custom design was used to screen the effect of four factors-type of polymer (ethylcellulose and eudragit RSPO) (X ₁), amount of polymer (X ₂), type of plasticizer (DBS, ATBC, TEC, and PEG) (X ₃), and plasticizer concentration (X ₄), on the drug release at 8 h (Y1) and machine torque (Y2). The experiments were carried out according to a four-factor 16-run statistical model and subjected to 12-h dissolution study in purified water. The significance of the model was indicated by ANOVA. Results of in vitro release study indicate that formulations prepared with higher amount of ethylcellulose and DBC show significant retardation at 8 h. The result shows that increase in concentration of polymer with the combination of water insoluble plasticizer (DBS and ATBC) has better sustained release while increasing concentration of TEC and PEG results faster in vitro release. Besides that increase in plasticizer concentration helps in reducing the melt temperature and machine torque. The in vivo study was performed, and formulations were compared using area under the plasma concentration-time curve (AUC_0-∞), time to reach peak plasma concentration (T_max), and peak plasma concentration (C_max). The drug release profiles of extrudes were found to fit both diffusion and surface erosion models. Further to this, scanning electron microscopy, differential scanning calorimetry, and X-ray diffraction analysis of the hot-melt extrudates demonstrated that VH remained crystalline and was homogeneously dispersed throughout the polymer matrix.