Influence of Precocene II on the estimated changes within the haemocyte population of parasitized spodoptera littoralis larvae by microplitis rufiventris

Series of experiments were undertaken to investigate whether application of Precocene II (PII) to parasitized S. littoralis larvae can influence their THCs and DHCs. PII was applied in single dose treatments (70μg/5 μl/dose). Haemolymph samples were taken at daily intervals from day 3 to day 8 post‐treatments. Two distinct alterations were noted; first, PII‐treatments caused significant decrease in THCs. Once the parasitoid larvae emerge from either treated or untreated hosts, a sharp decline in THCs was observed. The second effect was changes in DHCs of S. littoralis larvae. In controls, haemocyte types could be arranged in descending order due to their relative occurrence into plasmatocytes (PLs), prohaemocytes (PRs), spherule cells (SPs), granular cells (GRs) and oenocytoids (OEs). This order changed in treated hosts to PLs, GRs, PRs, SPs and OEs, i.e., GRs that were less prevalent in the haemolymph of control larvae increased significantly in PII‐treated hosts. In the latters, sharp rise in GRs levels followed parasitoid emergence. OEs cells were scarce in both treated and untreated hosts. No significant difference was observed between the overall means of PLs in both types of host larvae. But GRs‐PRs was markedly altered in treated larvae.     

Oral Administration of Polymyxin B Modulates the Activity of Lipooligosaccharide E. coli B against Lung Metastases in Murine Tumor Models

Introduction

Polymyxin B (PmB) belongs to the group of cyclic peptide antibiotics, which neutralize the activity of LPS by binding to lipid A. The aim of this study was to analyze the effect of PmB on the biological activity of lipooligosaccharide (LOS E. coli B,rough form of LPS) in vitro and in experimental metastasis models.

Results

Cultures of murine macrophage J774A.1 cells and murine bone marrow-derived dendritic cells (BM-DC) stimulated in vitro with LOS and supplemented with PmB demonstrated a decrease in inflammatory cytokine production (IL-6, IL-10, TNF-α) and down-regulation of CD40, CD80, CD86 and MHC class II molecule expression. Additionally, PmB suspended in drinking water was given to the C57BL/6 mice seven or five days prior to the intravenous injection of B16 or LLC cells and intraperitoneal application of LOS. This strategy of PmB administration was continued throughout the duration of the experiments (29 or 21 days). In B16 model, statistically significant decrease in the number of metastases in mice treated with PmB and LOS (p<0.01) was found on the 14th day of the experiments, whereas the most intensive changes in surface-antigen expression and ex vivo production of IL-6, IL-1β and TNF-α by peritoneal cells were observed 7 days earlier. By contrast, antigen expression and ex vivo production of IL-6, IL-10, IFN-γ by splenocytes remained relatively high and stable. Statistically significant decrease in LLC metastases number was observed after the application of LOS (p<0.01) and in the group of mice preconditioned by PmB and subsequently treated with LOS (LOS + PmB, p<0.01).

Conclusions

In conclusion, prolonged in vivo application of PmB was not able to neutralize the LOS-induced immune cell activity but its presence in the organism of treated mice was important in modulation of the LOS-mediated response against the development of metastases.     

Trapping Elusive Cats: Using Intensive Camera Trapping to Estimate the Density of a Rare African Felid

Camera trapping studies have become increasingly popular to produce population estimates of individually recognisable mammals. Yet, monitoring techniques for rare species which occur at extremely low densities are lacking. Additionally, species which have unpredictable movements may make obtaining reliable population estimates challenging due to low detectability. Our study explores the effectiveness of intensive camera trapping for estimating cheetah (Acinonyx jubatus) numbers. Using both a more traditional, systematic grid approach and pre-determined, targeted sites for camera placement, the cheetah population of the Northern Tuli Game Reserve, Botswana was sampled between December 2012 and October 2013. Placement of cameras in a regular grid pattern yielded very few (n = 9) cheetah images and these were insufficient to estimate cheetah density. However, pre-selected cheetah scent-marking posts provided 53 images of seven adult cheetahs (0.61 ± 0.18 cheetahs/100km²). While increasing the length of the camera trapping survey from 90 to 130 days increased the total number of cheetah images obtained (from 53 to 200), no new individuals were recorded and the estimated population density remained stable. Thus, our study demonstrates that targeted camera placement (irrespective of survey duration) is necessary for reliably assessing cheetah densities where populations are naturally very low or dominated by transient individuals. Significantly our approach can easily be applied to other rare predator species.     

BIOPOTENCY OF SERINE PROTEASE INHIBITORS FROM COWPEA (Vigna unguiculata) SEEDS ON DIGESTIVE PROTEASES AND THE DEVELOPMENT OF Spodoptera littoralis (BOISDUVAL)

Serine protease inhibitors (PIs) have been described in many plant species and are universal throughout the plant kingdom, where trypsin inhibitors is the most common type. In the present study, trypsin and chymotrypsin inhibitory activity was detected in the seed flour extracts of 13 selected cultivars/accessions of cowpea. Two cowpea cultivars, Cream7 and Buff, were found to have higher trypsin and chymotrypsin inhibitory potential compared to other tested cultivars for which they have been selected for further purification studies using ammonium sulfate fractionation and DEAE‐Sephadex A‐25 column. Cream7‐purified proteins showed two bands on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) corresponding to molecular mass of 17.10 and 14.90 kDa, while the purified protein from Buff cultivar showed a single band corresponding mass of 16.50 kDa. The purified inhibitors were stable at temperature below 60°C and were active at wide range of pH from 2 to 12. The kinetic analysis revealed noncompetitive type of inhibition for both inhibitors against both enzymes. The inhibitor constant (K_i) values suggested high affinity between inhibitors and enzymes. Purified inhibitors were found to have deep and negative effects on the mean larval weight, larval mortality, pupation, and mean pupal weight of Spodoptera littoralis, where Buff PI was more effective than Cream7 PI. It may be concluded that cowpea PI gene(s) could be potential insect control protein for future studies in developing insect‐resistant transgenic plants.     

Differential responses of oat cultivars to phosphate deprivation: plant growth and acid phosphatase activities

The effect of phosphate starvation on growth and acid phosphatases (APases) localization and activity in oat tissues was investigated. Oat cultivars (Avena sativa L.??Arab, Polar, Szakal) were grown for 1?C3?weeks in complete nutrient medium (+P) and without phosphate (?P). Pi concentration in plant tissues decreased strongly after culturing on ?P medium. Pi deficit reduced shoot growth, stimulated root elongation and increased ratio of root/shoot in all oat cultivars. Pi deficit had a greater impact on growth of oat cv. Polar than other varieties. A decrease in the internal Pi status led to an increase of acid phosphatase activities in extracts from shoots and roots, and in root exudates. The highest activity of secreted APases was observed for oat cv. Arab, during the third week of growth under Pi-deficient conditions. The activity of extracellular APase was high in young, growing zones of roots of ?P plants. Histochemical visualization indicated high activity of APases in the epidermis and vascular tissues of ?P plants. Pi deficiency increased intracellular APase activity in shoot mainly in oat cv. Polar, whereas APase activity in roots was the highest in oat cv. Szakal. Protein extracts from roots and shoots were run on native discontinuous PAGE to determine which isoform(s) may be affected by Pi deficiency. Three major APase isoforms were detected in all oat plants; one was strongly induced by Pi deficit. The studied oat cultivars differed in terms of acclimation to deficiency of phosphate??used various pools of APases to acquire Pi from external or internal sources.     

Neuroprotective role of taurine during aging

Aging of the brain is characterized by several neurochemical modifications involving structural proteins, neurotransmitters, neuropeptides and related receptors. Alterations of neurochemical indices of synaptic function are indicators of age-related impairment of central functions, such as locomotion, memory and sensory performances. Several studies demonstrate that ionotropic GABA receptors, glutamate decarboxylase (GAD), and somatostatinergic subpopulations of GABAergic neurons are markedly decreased in experimental animal brains during aging. Additionally, levels of several neuropeptides co-expressed with GAD decrease during aging. Thus, the age-related decline in cognitive functions could be attributable, at least in part, to decrements in GABA inhibitory neurotransmission. In this study, we showed that chronic supplementation of taurine to aged mice significantly ameliorated the age-dependent decline in spatial memory acquisition and retention. We also demonstrated that concomitant with the amelioration in cognitive function, taurine caused significant alterations in the GABAergic and somatostatinergic system. These changes included (1) increased levels of the neurotransmitters GABA and glutamate, (2) increased expression of both isoforms of GAD (65 and 67) and the neuropeptide somatostatin, (3) decreased hippocampal expression of the β3 subunits of the GABA_A receptor, (4) increased expression in the number of somatostatin-positive neurons, (5) increased amplitude and duration of population spikes recorded from CA1 in response to Schaefer collateral stimulation and (6) enhanced paired pulse facilitation in the hippocampus. These specific alterations of the inhibitory system caused by taurine treatment oppose those naturally occurring in the aging brain, suggesting a protective role of taurine in this process. An increased understanding of age-related neurochemical changes in the GABAergic system will be important in elucidating the underpinnings of the functional changes of aging. Taurine supplementation might help forestall the age-related decline in cognitive functions through interaction with the GABAergic system.     

Piericidin A Aggravates Tau Pathology in P301S Transgenic Mice

ObjectiveThe P301S mutation in exon 10 of the tau gene causes a hereditary tauopathy. While mitochondrial complex I inhibition has been linked to sporadic tauopathies. Piericidin A is a prototypical member of the group of the piericidins, a class of biologically active natural complex I inhibitors, isolated from streptomyces spp. with global distribution in marine and agricultural habitats. The aim of this study was to determine whether there is a pathogenic interaction of the environmental toxin piericidin A and the P301S mutation.MethodsTransgenic mice expressing human tau with the P301S-mutation (P301S^+/+) and wild-type mice at 12 weeks of age were treated subcutaneously with vehicle (N = 10 P301S^+/+, N = 7 wild-type) or piericidin A (N = 9 P301S^+/+, N = 9 wild-type mice) at a dose of 0.5 mg/kg/d for a period of 28 days via osmotic minipumps. Tau pathology was measured by stereological counts of cells immunoreative with antibodies against phosphorylated tau (AD2, AT8, AT180, and AT100) and corresponding Western blot analysis.ResultsPiericidin A significantly increased the number of phospho-tau immunoreactive cells in the cerebral cortex in P301S^+/+ mice, but only to a variable and mild extent in wild-type mice. Furthermore, piericidin A led to increased levels of pathologically phosphorylated tau only in P301S^+/+ mice. While we observed no apparent cell loss in the frontal cortex, the synaptic density was reduced by piericidin A treatment in P301S^+/+ mice.DiscussionThis study shows that exposure to piericidin A aggravates the course of genetically determined tau pathology, providing experimental support for the concept of gene-environment interaction in the etiology of tauopathies.     

Antiviral Activities of β-Enantiomers of 3′-Substituted-3′-deoxythymidine Analogs

Abstract

Several β-L-3′-substituted-3′-deoxythymidine were stereospecifically synthesized. None of these analogs inhibited HIV-1 nor HBV replication in vitro suggesting that these β-L-pyrimidine derivatives may not be efficiently phosphorylated inside the cells.     

Curcumin ameliorates diclofenac sodium‐induced nephrotoxicity in male albino rats

Exposure to drugs often results in toxicity in the kidney which represents the major control system maintaining homeostasis of the body and thus is especially susceptible to xenobiotics. Nephrotoxicity is a life‐threatening side‐effect of nonsteroidal anti‐inflammatory drugs (NSAIDs). Diclofenac is one of the most frequently prescribed NSAIDs and have been reported to cause multiple organs damage. Curcumin (CUR) exhibits nephroprotective properties. Therefore, rats were divided into four groups; rats of groups 3 and 4 received diclofenac (100 mg/kg, i.m.), whereas rats of groups 2 and 4 received CUR (100 mg/kg, p.o.) for 3 days. Diclofenac revealed a significant increase in urea and creatinine levels and malondialdehyde concentration and marked reduction in catalase activity and reduced glutathione concentration. Histopathologically, diclofenac produced fatty changes and eosinophilic casts were detected in the renal tubules, those were attenuated by administration of CUR prior diclofenac.