Effects of Piper hispidinervum on spermatogenesis and histochemistry of ovarioles of Spodoptera frugiperda

The fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), not only damages crops, but controlling its population also requires synthetic insecticides, which leads to selection of resistant populations and environmental contamination. Essential oils are an alternative for controlling this insect. There are few studies of the effects of these oils on the insect's reproductive system. We evaluated the effects of the long pepper, Piper hispidinervum, essential oil on the gonads of the armyworm and tested its possible influence on the fertility of this insect. Dosages of 30 and 50 mg/ml were tested in 3^rd instar caterpillars using the leaf immersion method. Testes and ovarioles were collected, fixed with 10% formalin and embedded in Historesin. The sections were stained with toluidine blue and Mallory trichrome to detect connective tissue, periodic acid-Schiff to detect neutral carbohydrates, and bromophenol blue to detect proteins. We found that the long pepper essential oil affected negatively the spermatogenesis and altered the histochemistry of the ovarioles of S. frugiperda. The effects of long pepper oil suggest that it is a promising tool for controlling the armyworm pest.     

Propagation of cytotoxic effectors from chronic myeloid leukemia patients and cloning of cytotoxic T cells

Summary Cytotoxic cells (CTCs) generated from peripheral blood lymphocytes of 5 chronic myeloid leukemia (CML) patients in remission on stimulation with autologous leukemic cells and allogeneic lymphocytes (3-cell assay), were propagated in vitro in interleukin-2 (IL-2)-containing medium and periodic stimulation with autologous leukemic cells, for a period of 4 to 6 months. During this period, the cells were assessed for phenotype and for cytotoxic responses in a 4-h ⁵¹Cr release microcytotoxicity assay. The CTCs continued to show specific lysis of autologous leukemic cells and bone marrow (BM) cells. However, the nonspecific lysis of natural killer (NK) targets and the proportion of cells showing NK phenotype (HNK-1 antigen) increased progressively on cultivation in IL-2-containing medium. Therefore cells showing CD8 phenotype and specific cytotoxic function were segregated by cloning CTCs under the condition of limiting dilution in the presence of allogeneic feeder cells and IL-2-containing medium. Three cytotoxic T cell (CTL) clones expressing CD3+, CD8+, and HLA DR+ phenotypes were obtained from CTCs of 2 CML patients. These clonoid populations, maintained in IL-2-containing medium and periodic antigenic stimulation with autologous leukemic cells, showed specific lysis of autologous leukemic cells and BM cells even at lower (10:1) effector:target ratios. They did not kill K562 (erythroblastoid leukemic NK target cell line) cells and autologous phytohemagglutinin-induced blasts. These clones apparently functioned in an MHC-restricted manner as they did not lyse allogeneic CML cells which would also express a similar set of maturation antigens if sensitization was, as it appeared, against these antigens. Finally, interaction of autologous BM cells with CTL clones reduced the colony forming potential of BM cells only to the extent of 18%–30%. The results therefore indicate that such CTL clones can possibly be used in adoptive immunotherapy as they showed minimal BM toxicity.     

Production of interleukin-1 and tumour necrosis factor in non-Hodgkin's lymphoma patients

Summary Peripheral blood monocytes from non-Hodgkin's lymphoma (NHL) patients were assessed for the monocyte functions with respect to their ability to secrete interleukin-1 and tumour necrosis factor (TNF) and their cytotoxic potential to tumour target WEHI 164 clone 13. Our results indicate comparable levels of interleukin-1 and TNF production by NHL patients. The cytotoxic potential by monocytes was also not depressed in these patients. The data obtained suggest normal monocyte functions in NHL patients.     

A network map of thrombopoietin signaling

Thrombopoietin (THPO), also known as megakaryocyte growth and development factor (MGDF), is a cytokine involved in the production of platelets. THPO is a glycoprotein produced by liver and kidney. It regulates the production of platelets by stimulating the differentiation and maturation of megakaryocyte progenitors. It acts as a ligand for MPL receptor, a member of the hematopoietic cytokine receptor superfamily and is essential for megakaryocyte maturation. THPO binding induces homodimerization of the receptor which results in activation of JAKSTAT and MAPK signaling cascades that subsequently control cellular proliferation, differentiation and other signaling events. Despite the importance of THPO signaling in various diseases and biological processes, a detailed signaling network of THPO is not available in any publicly available database. Therefore, in this study, we present a resource of signaling events induced by THPO that was manually curated from published literature on THPO. Our manual curation of thrombopoietin pathway resulted in identification of 48 molecular associations, 66 catalytic reactions, 100 gene regulation events, 19 protein translocation events and 43 activation/inhibition reactions that occur upon activation of thrombopoietin receptor by THPO. THPO signaling pathway is made available on NetPath, a freely available human signaling pathway resource developed previously by our group. We believe this resource will provide a platform for scientific community to accelerate further research in this area on potential therapeutic interventions.     

Pulsed-field gel electrophoresis analysis of Bordetella pertussis populations in various European countries with different vaccine policies

The increasing incidence of pertussis in a number of countries, despite good vaccination coverage, is a cause for concern. We used pulsed-field gel electrophoresis (PFGE) typing to examine the genetic diversity of 101 clinical isolates of Bordetella pertussis, recovered during 1999-2001, and circulating in five different European countries to evaluate temporal and geographical distribution. This DNA fingerprinting approach seems to be a more discriminative epidemiological tool than sequencing of individual genes. Despite differences in vaccination policies in the five countries, these European isolates were found to be very similar and fell into the same major PFGE profile groups, with a predominance of one profile group. There was no evidence of geographic clustering, except that one new profile subgroup was predominantly found in one country. This study provides a baseline for continued surveillance of the B. pertussis population in Europe.     

Reprogramming the genetic code: The emerging role of ribosomal frameshifting in regulating cellular gene expression

Reading frame maintenance is a critical property of ribosomes. However, a number of genetic elements have been described that can induce ribosomes to shift on mRNAs, the most well understood of which are a class that directs ribosomal slippage by one base in 5' (‐1) direction. This is referred to as programmed ‐1 ribosomal frameshifting (‐1 PRF). Recently, a new ‐1 PRF promoting element was serendipitously discovered in a study examining the effects of stretches of adenosines in the coding sequences of mRNAs. Here, we discuss this finding, recent studies describing how ‐1 PRF is used to control gene expression in eukaryotes, and how ‐1 PRF is itself regulated. The implications of dysregulation of ‐1 PRF on human health are examined, as are possible new areas in which novel ‐1 PRF promoting elements might be discovered. Also watch the Video Abstract .

     

In silico optimization of pharmacokinetic properties and receptor binding affinity simultaneously: a ‘parallel progression approach to drug design’ applied to β-blockers

The present work exploits the potential of in silico approaches for minimizing attrition of leads in the later stages of drug development. We propose a theoretical approach, wherein ‘parallel’ information is generated to simultaneously optimize the pharmacokinetics (PK) and pharmacodynamics (PD) of lead candidates. β-blockers, though in use for many years, have suboptimal PKs; hence are an ideal test series for the ‘parallel progression approach’. This approach utilizes molecular modeling tools viz. hologram quantitative structure activity relationships, homology modeling, docking, predictive metabolism, and toxicity models. Validated models have been developed for PK parameters such as volume of distribution (log V_d) and clearance (log Cl), which together influence the half-life (t_1/2) of a drug. Simultaneously, models for PD in terms of inhibition constant pK_i have been developed. Thus, PK and PD properties of β-blockers were concurrently analyzed and after iterative cycling, modifications were proposed that lead to compounds with optimized PK and PD. We report some of the resultant re-engineered β-blockers with improved half-lives and pK_i values comparable with marketed β-blockers. These were further analyzed by the docking studies to evaluate their binding poses. Finally, metabolic and toxicological assessment of these molecules was done through in silico methods. The strategy proposed herein has potential universal applicability, and can be used in any drug discovery scenario; provided that the data used is consistent in terms of experimental conditions, endpoints, and methods employed. Thus the ‘parallel progression approach’ helps to simultaneously fine-tune various properties of the drug and would be an invaluable tool during the drug development process.     

Blood viscosity parameter correlation with types of leukemia.

We investigated the hemorheological, hematological and biochemical parameters in 30 cases of acute lymphocytic leukemia (ALL), 21 cases of acute myelogenous leukemia (AML) and 30 cases of chronic myelogenous leukemia (CML). The parameters studied include whole blood viscosity, plasma viscosity, erythrocyte sedimentation rate (ESR), red cell filterability, hematocrit, platelet count and aggregation, fibrinogen, hemoglobin, leucocyte count, bleeding time and lactate dehydrogenase activity (LDH). In the cases of ALL we observed significant decrease in whole blood viscosity, hemoglobin, hematocrit and platelet count but an increase in plasma viscosity, fibrinogen, bleeding time and LDH activity. In the cases of AML, we observed increase in whole blood viscosity, plasma viscosity, ESR, fibrinogen, leucocyte count, bleeding time and LDH activity but decrease in the hemoglobin, hematocrit and platelet count. In the cases of CML, we observed an increase of whole blood viscosity, plasma viscosity, ESR, fibrinogen elevation but decreases in bleeding time. In all cases, red cell filterability was unaffected.     

An integrated signal transduction network of macrophage migration inhibitory factor

Macrophage migration inhibitory factor (MIF) is a glycosylated multi-functional protein that acts as an enzyme as well as a cytokine. MIF mediates its actions through a cell surface class II major histocompatibility chaperone, CD74 and co-receptors such as CD44, CXCR2, CXCR4 or CXCR7. MIF has been implicated in the pathogenesis of several acute and chronic inflammatory diseases. Although MIF is a molecule of biomedical importance, a public resource of MIF signaling pathway is currently lacking. In view of this, we carried out detailed data mining and documentation of the signaling events pertaining to MIF from published literature and developed an integrated reaction map of MIF signaling. This resulted in the cataloguing of 68 molecules belonging to MIF signaling pathway, which includes 24 protein-protein interactions, 44 post-translational modifications, 11 protein translocation events and 8 activation/inhibition events. In addition, 65 gene regulation events at the mRNA levels induced by MIF signaling have also been catalogued. This signaling pathway has been integrated into NetPath (http://www.netpath.org), a freely available human signaling pathway resource developed previously by our group. The MIF pathway data is freely available online in various community standard data exchange formats. We expect that data on signaling events and a detailed signaling map of MIF will provide the scientific community with an improved platform to facilitate further molecular as well as biomedical investigations on MIF.