Posttranslational Processing of Carboxypeptidase E, a Neuropeptide-Processing Enzyme, in AtT-20 Cells and Bovine Pituitary Secretory Granules

Abstract: Carboxypeptidase E (CPE) functions in the posttranslational processing of peptide hormones and neurotransmitters. Like other peptide processing enzymes, CPE is present in secretory granules in soluble and membrane-associated forms that arise from posttranslational processing of a single precursor, “proCPE.” To identify the intracellular site of proCPE processing, the biosynthesis and posttranslational processing were investigated in the mouse anterior pituitary-derived cell line, AtT-20. Following a 15-min pulse with [³⁵S]Met, both soluble and membrane-bound forms of CPE were identified, indicating that the posttranslational processing event that generates these forms of CPE occurs in the endoplasmic reticulum or early Golgi apparatus. The relative proportion of soluble and membrane-bound forms of CPE changed when cells were chased for 2 h at 37°C but was unaffected when cells were chased at either 20 or 15°C, suggesting that further processing of membrane forms to the soluble form occurs in a post-Golgi compartment. Treatment of the cells with chloroquine did not alter the relative distribution of soluble and membrane forms, suggesting that an acidic compartment is not required for this processing event. Overexpression of CPE did not influence the distribution of soluble and membrane forms of CPE, indicating that the CPE-processing enzymes are not rate-limiting. To examine directly CPE-processing enzymes, bovine anterior pituitary secretory vesicles were isolated. An enzyme activity that releases the membrane-bound form of CPE was detected in the purified secretory vesicle membranes. This enzyme, which removes the C-terminal region of CPE, is partially inhibited by EDTA and phenylmethylsulfonyl fluoride and is activated by CaCI₂. Together, the data indicate that posttranslational processing of CPE occurs in secretory granules and that this activity may be mediated by a prohormone convertase-like enzyme.     

Vegetation boundary detection: A comparison of two approaches applied to field data

We examined and compared two approaches to vegetation boundarydetermination by applying them to field data collected from Betsch Fen, analkaline wetland in Ohio, USA. Two boundary detection methods were used to testhypothesized boundary locations determined through field observations: gradientanalysis by detrended correspondence analysis (DCA) and the moving split-window(MSW) technique. These two methods represent approaches suggested by vegetationanalysis and landscape ecological literature, respectively. DCA was moresuccessful in detecting vegetation changes at the community level, but it wasoften difficult to extrapolate this information to a landscape context. Incontrast, MSW detected changes at a landscape level which overestimated minorshifts in species composition at the community level. Although results from MSWwere more easily interpretable, neither method completely confirmedhypothesizedboundary locations derived from field reconnaissance and aerial photo analysis.While DCA and MSW can be used in conjunction to provide maximum information onboundary location and ecological significance, this would be unrealistic inpractical applications because of the time and effort required to do bothsimultaneously. We suggest an approach using primarily MSW principles, whichtake into consideration community-level information and optimum sampling plotplacement and spacing.     

Synthesis and characterisation of bis(2 methyl-8-hydroxyquinoline) zinc nanoparticles for organic light emitting diode applications

In this paper, bis(2 methyl-8-hydroxyquinoline) zinc (Zn(mq)₂) nanoparticles were synthesised at room temperature by a simple chemical precipitation method. The Zn(mq)₂ nanoparticles were characterised by powder X-ray diffraction (PXRD) analysis to confirm the crystalline nature of the Zn(mq)₂ nanoparticles. The morphology and the elemental composition of Zn (mq)₂ nanoparticles were analysed by high-resolution scanning electron microscopy (HR-SEM) and energy dispersive X-ray analysis (EDAX). The functional groups of the compound were studied with the help of Fourier transform infrared spectroscopy (FTIR) and FT Raman spectroscopy. Further, Zn (mq)₂ nanoparticles were characterised by C-13 NMR spectroscopy, mass spectroscopy and CHN analysis. The thermal stability of the particles was studied using TG-DSC curve. The optical properties of the particles were studied by means of UV–Visible spectroscopy. The luminescence property of the synthesised particles was observed from the photoluminescence spectrum to confirm the possible application in organic light emitting diode.     

Extended fuzzy c-means: an analyzing data clustering problems

In recent years the use of fuzzy clustering techniques in medical diagnosis is increasing steadily, because of the effectiveness of fuzzy clustering techniques in recognizing the systems in the medical database to help medical experts in diagnosing diseases. This study focuses on clustering lung cancer dataset into three types of cancers which are leading cause of cancer death in the world. This paper invents effective fuzzy clustering techniques by incorporating hyper tangent kernel function, and entropy methods for analyzing the Lung Cancer database to assist physician in diagnosing lung cancer. Further this paper proposes an algorithm to initialize the cluster centers to speed up the process of the algorithms. The effectiveness of the proposed methods has been proved through the experimental works on synthetic dataset, Wine dataset and IRIS dataset in terms of running time, number of iterations, visual segmentation effects and clustering accuracy. And then this paper proposes the proposed method on Lung cancer database to divide it into three types of lung cancers. In addition this paper proves the superiority of the proposed methods by comparing the obtained classes with reference classes through Error Matrix.     

Microsporogenesis and pollen formation in Zingiber officinale Roscoe

Zingiber officinale Roscoe, the common ginger, is an invaluable horticultural crop cultivated majorly in China, India, Brazil, Jamaica and Nigeria. Its pungent aromatic rhizome is used all over the world as a spice, culinary herb, condiment, home remedy and medicinal agent. This species does not produce seeds and so is difficult to breed its new genotypes through sexual hybridization. Despite the economic and genetic value, ginger has not been subjected to detailed cytogenetic research, which could lead to a better understanding of its reproduction for future genetic improvement. Therefore, the present work is undertaken for the first time to study microsporogenesis and pollen formation in Z. officinale. Pre-meiotic stages were observed under light microscope using anther squashes and staining by either acetocarmine or carbol fuchsin, whereas, the post meiotic stages were visualized under fluorescence microscope using either isolated microspores or pollen grains stained by 4′, 6′-diamidino-2-phenylindole. The combination of these two different cytological techniques allowed the study of the complete microsporogenesis and pollen formation processes step by step starting from pollen mother cells (PMCs) stage to mature pollen grain. Assessment of meiotic behavior was also performed by evaluating all possible PMCs on each slide and at all stages of meiosis. Cytological analysis revealed that only anthers from flowers of small spikes presented appropriate PMCs to analyze meiotic irregularities. The present paper enriches the database of cytology and pollen viability estimations for supporting sexual hybridization. The present study demonstrated a good relationship between the development stage of microspore and the size of the spike. This basic information will hopefully allow the development of protocol for production of androgenic haploids to accelerate breeding and genetic improvement of ginger. Further, research is under progress for evaluation of several media and other cultural factors to achieve microspore embryogenesis and plant regeneration in this species.     

Analysis of maslinic acid and gallic acid compounds as xanthine oxidase inhibitors in isoprenaline administered myocardial necrotic rats

ObjectiveThis research designed to analyze the in vivo and in silico ameliorative action of maslinic acid (MA) and gallic acid (GA) on reactive oxygen species generating enzyme xanthine oxidase (XO) in isoprenaline or isoproterenol (ISO) induced myocardial infarcted rats.MethodsAlbino Wistar rats were categorized into four groups with eight rats in each group. A dose of 15 mg/kg of MA and GA were pretreated to each MA and GA groups for seven days. A dose of 85 mg/kg of ISO administered to the ISO group along with MA and GA groups except normal group on two consecutive days of pretreatment. All animals sacrificed and the heart tissues were collected for the analysis of XO. The in silico molecular docking analysis of the compounds MA and GA with XO was analyzed by using Gold 3.0.1 software.ResultsXO enzyme levels were significantly increased in the heart homogenate of ISO administered rats when compared to normal rats. Pretreatment of MA and GA to ISO treated rats significantly brought XO enzyme to the near normal levels which indicate the protective action of MA and GA against myocardial necrosis. The in vivo results were further supported by the in silico molecular docking study which revealed the inhibition of XO enzyme by the formation of enzyme and ligand complex with the compounds MA and GA.ConclusionMA and GA compounds manifested the ameliorative effect against ISO administrated myocardial necrosis by inhibiting the free radical generating enzyme XO which is evidenced by both in vivo and in silico studies.     

Processes driving male breeding colour and ecomorphological diversification in rainbow skinks: a phylogenetic comparative test

We used a phylogenetic comparative approach to investigate the importance of ecological shifts in the diversification of both signalling traits and ecomorphological traits in a diverse group of Australian skinks (Carlia). First, we tested whether divergence in male breeding coloration is associated with shifts in habitat openness. Second, we examined whether the type or location of male breeding coloration changes predictably with habitat openness. Third, we tested the ecomorphological predictions that body size should vary in relation to habitat openness and that limb length, toe length and head depth should vary with substrate use. Divergence in male breeding coloration was positively associated with shifts in habitat openness. Our results also indicate that species occupying more open habitats tend to use male sexual signals located on lateral body regions and not necessarily on body regions that are potentially more concealed from aerial predators (e.g. chest and throat). With regard to ecomorphological traits, habitat openness appears to have no predictable influence on body size at the inter-specific level, contrary to expectations based on intra-specific studies. However, consistent with functional predictions, we found that preference for rocky habitats is associated with relatively longer hind limb length, presumably due to selection for greater speed and jumping ability on these substrates. Overall, results of this study support the hypothesis that ecological shifts play a central role in promoting morphological diversification.     

Oxidative stress in erythrocytes: a study on the effect of antioxidant mixtures during intermittent exposures to high altitude

The aim of our study was to compare and assess the effectiveness of antioxidant mixtures on the erythrocytes (RBC) of adult male albino rats (Wister) subjected to simulated intermittent high altitudes—5,100 m (AL₁) and 6,700 m (AL₂)—to induce oxidative stress (OS). To achieve our objective, we pre-supplemented four sets of animals with different antioxidant mixtures [vitamin E (vit.E; 50 IU/kg BW), vitamin C (vit.C; 400 mg/kg) and l-carnitine (400 mg/kg)] in different combinations [M1 (vit.E+vit.C), M2 (vit.C+carnitine), M3 (vit.E+carnitine) and M4 (vit.C+vit.E+carnitine)] for 30 days prior to as well during exposure to intermittent hypobaric hypoxia (IHH). Membrane instability, in terms of osmotic fragility and hemolysis, decreased in RBCs of supplemented animals. There was a significant increase in the activity of glutathione peroxidase in the RBCs of supplemented animals. We confirmed OS imposed by IHH with assays relating to lipid [thiobarbituric acid reactive substances (TBARS) and lipofuscin (LF)] and protein (carbonyl, PrC) oxidation, and found a positive correlation between PrC and hemolysis, with a decrease in both upon supplementation with M3 and M4 mixtures. Fluorescence microscopic observation showed a maximum decrease in the LF content in rats administered M4 and M1 compared to those on M2 and M3 mixtures at both altitudes. We suggest that multiple antioxidant fortifications are effective in overcoming increased OS experienced by RBCs at high altitudes.