Early exposure to haloperidol or olanzapine induces long‐term alterations of dendritic form

Exposure of the developing brain to a wide variety of drugs of abuse (e.g., stimulants, opioids, ethanol, etc.) can induce life‐long changes in behavior and neural circuitry. However, the long‐term effects of exposure to therapeutic, psychotropic drugs have only recently begun to be appreciated. Antipsychotic drugs are little studied in this regard. Here, we quantitatively analyzed dendritic architecture in adult mice treated with paradigmatic typical‐ (haloperidol) or atypical (olanzapine) antipsychotic drugs at developmental stages corresponding to fetal or fetal plus early childhood stages in humans. In layer 3 pyramidal cells of the medial and orbital prefrontal cortices and the parietal cortex and in spiny neurons of the core of the nucleus accumbens, both drugs induced significant changes (predominantly reductions) in the amount and complexity of dendritic arbor and the density of dendritic spines. The drug‐induced plasticity of dendritic architecture suggests changes in patterns of neuronal connectivity in multiple brain regions that are likely to be functionally significant. Synapse 64: 191–199, 2010. © 2009 Wiley‐Liss, Inc.     

The pulmonary circulation and exercise responses in the elderly

Aging is associated with a progressive deterioration in the structure and function of the pulmonary circulation. Remodeling of the pulmonary vasculature occurs from maturity to senescence that is characterized by an increase in pulmonary vascular stiffness, pulmonary vascular pressures, and pulmonary vascular resistance along with increased heterogeneity of alveolar ventilation and pulmonary perfusion and decreased pulmonary capillary blood volume and membrane diffusing capacity that is consistent with a reduction in alveolar-capillary surface area. In theory, the aforementioned age-related changes in the pulmonary circulation may conspire to make elderly individuals more susceptible to gas exchange abnormalities during exercise. However, despite the erosion in ventilatory reserve with aging, the healthy older adult appears able to maintain alveolar ventilation at a level that allows maintenance of arterial blood gases within normal limits, even during heavy exercise. This ability to maintain adequate gas exchange likely occurs because age-related reductions in the maximal metabolic demand of exercise occur at a rate equal to or greater than the rate of deterioration in ventilatory reserve. A more prominent aspect of aging is the loss of lung elastic recoil that is associated with a modest reduction in the expiratory boundary of the maximal flow-volume envelope. This in turn increases the severity of expiratory airflow limitation and induces dynamic lung hyperinflation during exercise. The consequences of this age-associated decrease in elastic recoil on the pulmonary circulation are speculative, but an age-associated decline in elastic recoil may influence pulmonary vascular resistance and cardiac output, in addition to its impact on the work and oxygen cost of breathing.     

Gene profiling of maternal hepatic adaptations to pregnancy

Background: Maternal metabolic demands change dramatically during the course of gestation and must be co‐ordinated with the needs of the developing placenta and fetus. The liver is critically involved in metabolism and other important functions. However, maternal hepatic adjustments to pregnancy are poorly understood. Aim: The aim of the study was to evaluate the influences of pregnancy on the maternal liver growth and gene expression profile. Methods: Holtzman Sprague–Dawley rats were mated and sacrificed at various stages of gestation and post‐partum. The maternal livers were analysed in gravimetric response, DNA content by PicoGreen dsDNA quantitation reagent, hepatocyte ploidy by flow cytometry and hepatocyte proliferation by ki‐67 immunostaining. Gene expression profiling of non‐pregnant and gestation d18.5 maternal hepatic tissue was analysed using a DNA microarray approach and partially verified by northern blot or quantitative real‐time PCR analysis. Results: During pregnancy, the liver exhibited approximately an 80% increase in size, proportional to the increase in body weight of the pregnant animals. The pregnancy‐induced hepatomegaly was a physiological event of liver growth manifested by increases in maternal hepatic DNA content and hepatocyte proliferation. Pregnancy did not affect hepatocyte polyploidization. Pregnancy‐dependent changes in hepatic expression were noted for a number of genes, including those associated with cell proliferation, cytokine signalling, liver regeneration and metabolism. Conclusions: The metabolic demands of pregnancy cause marked adjustments in maternal liver physiology. Central to these adjustments are an expansion in hepatic capacity and changes in hepatic gene expression. Our findings provide insights into pregnancy‐dependent hepatic adaptations.     

Paclitaxel/sirolimus combination coated drug-eluting stent: in vitro and in vivo drug release studies

Paclitaxel and sirolimus are the two major drugs for the treatment of coronary arterial disease in current drug-eluting stents. The two drugs can effectively inhibit the in-stent restenosis through their independent pathways and show synergistic effect in preventing tumor tissue growth. We hypothesize that the combination of the two drugs in a drug-eluting stent (DES) can also effectively suppress the neointima growth in the stented artery. The present work was focused on the investigation of paclitaxel/sirolimus combination release profiles from a novel biodegradable polymer (poly (D, L-lactide-co-glycolide)/amorphous calcium phosphate, PLGA/ACP) coated stent both in vitro and in vivo. For the in vitro, the drug releasing profiles were characterized by measuring the drug concentration in a drug release medium (Dulbecco's phosphate buffered saline, DPBS, pH 7.4) at predetermined time points. For the in vivo, a rat aorta stenting model was employed. The results showed that both paclitaxel and sirolimus had a two-phase release profile both in vitro and in vivo, which is similar to the drug release profile of their individual coated DESs, and there is no evident of interference between two drugs. The data suggest that paclitaxel and sirolimus can be combined pharmacokinetically in a DES for the treatment of coronary arterial diseases.     

A systematic approach to development of liquid chromatographic impurity methods for pharmaceutical analysis

A strategy for developing chromatographic methods designed to determine impurities and degradation products in active pharmaceutical ingredients and drug products is presented. Selectivity is achieved by evaluating a chromatographic space comprised of 12 stationary/mobile phase combinations. Stationary phases predicted to be orthogonal based on their hydrophobic subtraction model parameters used. The particle sizes, column dimensions, and gradient times chosen provide high peak capacities and allow operation at backpressures that can be achieved with standard instrumentation. The mobile phases utilized are compatible with MS detection and cover a wide range of pH, solvent strength, and solvent selectivity. Analyte detection is accomplished using a combination of diode array and mass spectroscopic detectors which allow mixtures of project compounds to be injected and selectively detected. Automation of data acquisition and processing is accomplished using AutoChrom software from ACD\Labs. The strategy is illustrated with detailed data from two case studies and summary data from nineteen pharmaceutical projects.