Determination of compound aminopyrine phenacetin tablets by using artificial neural networks combined with principal components analysis

A method for simultaneous, nondestructive analysis of aminopyrine and phenacetin in compound aminopyrine phenacetin tablets with different concentrations has been developed by principal component artificial neural networks (PC-ANNs) on near-infrared (NIR) spectroscopy. In PC-ANN models, the spectral data were initially analyzed by principal component analysis. Then the scores of the principal components were chosen as input nodes for the input layer instead of the spectral data. The artificial neural network models using the spectral data as input nodes were also established and compared with the PC-ANN models. Four different preprocessing methods (first-derivative, second-derivative, standard normal variate (SNV), and multiplicative scatter correction) were applied to three sets of NIR spectra of compound aminopyrine phenacetin tablets. The PC-ANNs approach with SNV preprocessing spectra was found to provide the best results. The degree of approximation was performed as the selective criterion of the optimum network parameters.     

Laparoscope resection of ectopic corticosteroid-secreting adrenal adenoma

Tumors originating from ectopic adrenal tissue are relatively rare. In this article, we describe a case with Cushing's syndrome caused by an ectopic adrenal adenoma. A 38 year-old male patient presenting with cushingoid appearance for 2 years was diagnosed to have ACTH-independent Cushing's syndrome based on endocrinological evaluation. Mutiple radiological examinations detected bilateral adrenal atrophy. When the images were investigated in a more expanded scope, a 3.0×3.5×5.3?cm mass was detected in the anterior of left renal hilum and left renal vein. The mass was successfully resected with intraoperative endoscopy and pathological evaluation revealed an ectopic adrenal tumor. It is suggested that when the endocrinlogically confirmed adrenal neoplasm could not be well and definitely localized, the possibility of ectopic adrenal should be presumed and further radiography examinations should extend to the field where ectopic adrenal usually presents.     

Two-level parallelization of Ehrenfest force calculations in ab initio molecular dynamics simulation

A two-level parallel code for Ehrenfest force calculations in ab initio molecular dynamics simulations was developed for a shared memory multiprocessor cluster. Coarse-grain parallelism was implemented by atomic decomposition and a fine-grained parallelism was exploited to perform matrix multiplications. This two-level parallelism efficiently enhances the speed of computations.     

Effects of vanadium-containing compounds on membrane lipids and on microdomains used in receptor-mediated signaling

There is increasing evidence for the involvement of plasma membrane microdomains in insulin receptor function. Moreover, disruption of these structures, which are typically enriched in sphingomyelin and cholesterol, results in insulin resistance. Treatment strategies for insulin resistance include the use of vanadium (V) compounds which have been shown in animal models to enhance insulin responsiveness. One possible mechanism for insulin-enhancing effects might involve direct effects of V compounds on membrane lipid organization. These changes in lipid organization promote the partitioning of insulin receptors and other receptors into membrane microdomains where receptors are optimally functional. To explore this possibility, we have used several strategies involving V complexes such as [VO(2)(dipic)](-) (pyridin-2,6-dicarboxylatodioxovanadium(V)), decavanadate (V(10)O(28)(6-), V(10)), BMOV (bis(maltolato)oxovanadium(IV)), and [VO(saltris)](2) (2-salicylideniminato-2-(hydroxymethyl)-1,3-dihydroxypropane-oxovanadium(V)). Our strategies include an evaluation of interactions between V-containing compounds and model lipid systems, an evaluation of the effects of V compounds on lipid fluidity in erythrocyte membranes, and studies of the effects of V-containing compounds on signaling events initiated by receptors known to use membrane microdomains as signaling platforms.     

Halothiobacillus neapolitanus carboxysomes sequester heterologous and chimeric RubisCO species

Background

The carboxysome is a bacterial microcompartment that consists of a polyhedral protein shell filled with ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO), the enzyme that catalyzes the first step of CO₂ fixation via the Calvin-Benson-Bassham cycle.

Methodology/Principal Findings

To analyze the role of RubisCO in carboxysome biogenesis in vivo we have created a series of Halothiobacillus neapolitanus RubisCO mutants. We identified the large subunit of the enzyme as an important determinant for its sequestration into α-carboxysomes and found that the carboxysomes of H. neapolitanus readily incorporate chimeric and heterologous RubisCO species. Intriguingly, a mutant lacking carboxysomal RubisCO assembles empty carboxysome shells of apparently normal shape and composition.

Conclusions/Significance

These results indicate that carboxysome shell architecture is not determined by the enzyme they normally sequester. Our study provides, for the first time, clear evidence that carboxysome contents can be manipulated and suggests future nanotechnological applications that are based upon engineered protein microcompartments.     

Gold complexes as prospective metal-based anticancer drugs

Medical and therapeutic value of gold has been recognized thousands of years ago, but its rational use in medicine has not begun until the early 1920s. Cisplatin is one of the first metal-containing compounds with anti-cancer activity discovered in the 1960s. Despite the fact that cisplatin treatment is efficient for several types of solid tumors, its effectiveness is limited by toxic side effects and tumor resistance that often leads to the occurrence of secondary malignancies. Since gold(III) is isoelectronic with platinum(II) and tetracoordinate gold(III) complexes have the same square-planar geometries as cisplatin, the anticancer activity of gold(III) compounds has been investigated. Previous studies suggested that, in contrast to cisplatin, gold complexes target proteins but not DNA. Recently, we have investigated gold(III) dithiocarbamates for their anticancer activity and showed that their primary target is the proteasome. Treatment of human breast tumor-bearing nude mice with a gold(III) dithiocarbamate complex resulted in significant inhibition of tumor growth, associated with proteasome inhibition and massive apoptosis induction in vivo. Better understanding of physiological processing of gold compounds will provide a rational basis for their further development into novel anticancer drugs.     

Tea polyphenols, their biological effects and potential molecular targets

Tea is the most popular beverage in the world, second only to water. Tea contains an infusion of the leaves from the Camellia sinensis plant rich in polyphenolic compounds known as catechins, the most abundant of which is (-)-EGCG. Although tea has been consumed for centuries, it has only recently been studied extensively as a health-promoting beverage that may act to prevent a number of chronic diseases and cancers. The results of several investigations indicate that green tea consumption may be of modest benefit in reducing the plasma concentration of cholesterol and preventing atherosclerosis. Additionally, the cancer-preventive effects of green tea are widely supported by results from epidemiological, cell culture, animal and clinical studies. In vitro cell culture studies show that tea polyphenols potently induce apoptotic cell death and cell cycle arrest in tumor cells but not in their normal cell counterparts. Green tea polyphenols were shown to affect several biological pathways, including growth factor-mediated pathway, the mitogen-activated protein (MAP) kinase-dependent pathway, and ubiquitin/proteasome degradation pathways. Various animal studies have revealed that treatment with green tea inhibits tumor incidence and multiplicity in different organ sites such as skin, lung, liver, stomach, mammary gland and colon. Recently, phase I and II clinical trials have been conducted to explore the anticancer effects of green tea in humans. A major challenge of cancer prevention is to integrate new molecular findings into clinical practice. Therefore, identification of more molecular targets and biomarkers for tea polyphenols is essential for improving the design of green tea trials and will greatly assist in a better understanding of the mechanisms underlying its anti-cancer activity.     

Effects of simulated acid rain on the physiology of carmine spider mite, Tetranychus cinnabarinus (Boisduvals) (Acari: Tetranychidae)

Abstract:  The physiological effect of simulated acid rain sprayed on carmine spider mite Tetranychus cinnabarinus (Boisduvals) and host plant, were measured in a series of laboratory trials. We examined potential changes in three kinds of protective enzymes [peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT)] and three hydrolases [acid phosphatase (ACP), alkaline phosphatase (ALP) and carboxylesterase (CarE)] in response to changes in pH values of simulated acid rain at different time of exposure. POD, SOD and CAT activities increased significantly with the increase in the acidity of the acid rain, reaching the highest levels at pH 4.0 or 3.0, and then declined. Changes in ACP activity were similar to those observed in the protective enzymes. The increasing extent of the activities of these four enzymes after 30 and 45 days treatment became smaller than that after 15 days treatment . ALP activities decreased as pH value declined. There were no significant changes in CarE activities after 15 and 45 days, but that in pH 4.0 and 3.0 decreased after 30 days. The enhanced anti-oxidation enzyme levels (POD, SOD and CAT) and ACP activities in pH 4.0 and 3.0 reduced the effects of these toxic products on mites, resulting in the strengthening of the defensive power, and increase in survival and reproductive power of the mites, thus leading to an increase in the density of mites on host plant. From these results, we inferred that POD, SOD, CAT and ACP might be relevant to population changes of mites under acid rain pressure.