A target repurposing approach identifies N-myristoyltransferase as a new candidate drug target in filarial nematodes

Myristoylation is a lipid modification involving the addition of a 14-carbon unsaturated fatty acid, myristic acid, to the N-terminal glycine of a subset of proteins, a modification that promotes their binding to cell membranes for varied biological functions. The process is catalyzed by myristoyl-CoA:protein N-myristoyltransferase (NMT), an enzyme which has been validated as a drug target in human cancers, and for infectious diseases caused by fungi, viruses and protozoan parasites. We purified Caenorhabditis elegans and Brugia malayi NMTs as active recombinant proteins and carried out kinetic analyses with their essential fatty acid donor, myristoyl-CoA and peptide substrates. Biochemical and structural analyses both revealed that the nematode enzymes are canonical NMTs, sharing a high degree of conservation with protozoan NMT enzymes. Inhibitory compounds that target NMT in protozoan species inhibited the nematode NMTs with IC50 values of 2.5-10 nM, and were active against B. malayi microfilariae and adult worms at 12.5 µM and 50 µM respectively, and C. elegans (25 µM) in culture. RNA interference and gene deletion in C. elegans further showed that NMT is essential for nematode viability. The effects observed are likely due to disruption of the function of several downstream target proteins. Potential substrates of NMT in B. malayi are predicted using bioinformatic analysis. Our genetic and chemical studies highlight the importance of myristoylation in the synthesis of functional proteins in nematodes and have shown for the first time that NMT is required for viability in parasitic nematodes. These results suggest that targeting NMT could be a valid approach for the development of chemotherapeutic agents against nematode diseases including filariasis

Factors Affecting Perceived Stigma in Leprosy Affected Persons in Western Nepal

Background There are various factors which construct the perception of stigma in both leprosy affected persons and unaffected persons. The main purpose of this study was to determine the level of perceived stigma and the risk factors contributing to it among leprosy affected person attending the Green Pastures Hospital, Pokhara municipality of western Nepal. Methods A cross-sectional study was conducted among 135 people affected by leprosy at Green Pastures Hospital and Rehabilitation Centre. Persons above the age of 18 were interviewed using a set of questionnaire form and Explanatory Model Interview Catalogue (EMIC). In addition, two sets of focused group discussions each containing 10 participants from the ward were conducted with the objectives of answering the frequently affected EMIC items. Results Among 135 leprosy affected persons, the median score of perceived stigma was 10 while it ranged from 0–34. Higher perceived stigma score was found in illiterate persons (p = 0.008), participants whose incomes were self-described as inadequate (p = 0.014) and who had changed their occupation due to leprosy (p = 0.018). Patients who lacked information on leprosy (p = 0.025), knowledge about the causes (p = 0.02) and transmission of leprosy (p = 0.046) and those who had perception that leprosy is a severe disease (p<0.001) and is difficult to treat (p<0.001) had higher perceived stigma score. Participants with disfigurement or deformities (p = 0.014), ulcers (p = 0.022) and odorous ulcers (p = 0.043) had higher perceived stigma score. Conclusion The factors associated with higher stigma were illiteracy, perceived economical inadequacy, change of occupation due to leprosy, lack of knowledge about leprosy, perception of leprosy as a severe disease and difficult to treat. Similarly, visible deformities and ulcers were associated with higher stigma. There is an urgent need of stigma reduction strategies focused on health education and health awareness programs in addition to the necessary rehabilitation support

Clinical significance of BRAF mutations in metastatic melanoma

Forty to eighty percent of melanoma tumors have activating mutations in BRAF although the clinical importance of these mutations is not clear. We previously reported an analysis of BRAF mutations in metastatic melanoma samples from 68 patients. In this study, we correlated patient baseline characteristics, prognostic factors, and/or clinical outcomes with the presence of BRAF mutations. No significant differences were observed in age, gender, location of primary melanoma, stage at the diagnosis, and depth of primary tumor between patients with and without BRAF mutations. Melanomas harboring BRAF mutations were more likely to metastasize to liver (P = 0.02) and to metastasize to multiple organs (P = 0.048). Neither time to progression to stage IV nor overall survival were associated with BRAF mutations. In conclusion, we observed no significant differences in clinical characteristics or outcomes between melanomas with or without BRAF mutations. Although there was an increased frequency of liver metastasis and tendency to metastasize to multiple organs in tumors with BRAF mutations, there was no detectable effect on survival. Future prospective studies should include analysis of whether BRAF mutations in melanoma tumors correlate with an increased tendency to metastasize to liver or to multiple organs

Cross-presentation of Disialoganglioside GD3 to Natural Killer T Cells

GD3, a ganglioside expressed on human melanoma, can be recognized by the humoral immune system. In this paper, we demonstrate that immunizing mice with the human melanoma cell line SK-MEL-28 (GD3+ GM2− CD1−) or with syngeneic APCs loaded with GD3 can induce a GD3-reactive natural killer T (NKT) cell response. GD3-reactive NKT cells were detected among splenocytes of immunized mice at frequencies of ∼1:2,000 both by ELISPOT and GD3-loaded mouse CD1d tetramer analysis. GD3-reactive NKT cells did not react with GM2, a closely related ganglioside, and were not detectable in unimmunized mice. GD3-reactive NKT cells initially produced IL-4 and IFN-γ followed by IL-10. They were CD1d restricted in that reactivity was abrogated when APCs were blocked with anti-CD1d monoclonal antibody before being loaded with GD3 or when APCs from CD1d knockout mice were used. Because SK-MEL-28 does not express any isoform of human CD1, GD3 must be cross-presented by murine APCs in vivo. This is the first analysis of a natural ligand for mouse NKT cells and the first definitive paper of cross-presentation to NKT cells. This could be a mechanism for NKT cell recognition of tumor gangliosides in CD1− tumors

The Role of Language in Anatomy and Physiology Instruction

Research indicates that student learning of science, student attitudes toward science, and their motivation to learn science and pursue science-related careers is related to classroom instruction. This study examined anatomy and physiology (A&P) classes in a south Texas high school where 97 percent of students are Hispanic bilingual learners. Classes were assigned to control or treatment groups, with the treatment group receiving instruction designed to help students develop a deeper understanding of anatomy vocabulary related to brain structures by making connections to these words in everyday life as well as to their understanding of Spanish. Main effects between group and test scores were significant, with the control group reporting higher test scores than the treatment group. We attribute this finding to a bleed-over of the treatment group instructional design to the control group. In addition, significant differences in mean and median scores were observed with respect to intrinsic motivation and self-efficacy. The statistically significant increases in learning for both groups suggests the activity-, problem-, and project-based (APB) curriculum has the potential to be an effective type of instruction, especially for bilingual learners

An examination of business occupier relocation decision making : distinguishing small and large firm behaviour

This paper explores how business occupiers decide whether and where to relocate. It captures the experience and behaviour of a range of sizes and types of business occupier and subjects their decision-making processes to detailed scrutiny. A linear three-stage decision model is used to sequence and structure interviews with individuals who have intimate involvement with the relocation of 28 firms and organizations in Tyne and Wear, in the north-east of England. The 'constant comparative' method is used to analyse the interview data, from which emerges 18 key concepts, comprising 51 characteristic components. Using an axial approach, these are organized into 10 cross-cutting themes that represent the main areas of consideration or influence on the thinking of the people involved in determining whether a firm or organization should relocate and, if so, where to. The resulting analysis finds that organizations adopt varying degrees of sophistication when making relocation decisions; small firms are more inclined to make decisions based on constrained information; larger organizations adopt a more complex approach. Regardless of firm size, key individuals exert considerable influence over the decision-making process and its outcome

Collisional decoherence in trapped atom interferometers that use non-degenerate sources

The coherence time, and thus sensitivity, of trapped atom interferometers that use non-degenerate gasses are limited by the collisions between the atoms. An analytic model that describes the effects of collisions between atoms in an interferometer is developed. It is then applied to an interferometer using a harmonically trapped non-degenerate atomic gas that is manipulated with a single set of standing wave laser pulses. The model is used to find the optimal operating conditions of the interferometer and direct Monte-Carlo simulation of the interferometer is used to verify the analytic model.Comment: (23 pages, 5 figures

Tumour micro-environment elicits innate resistance to RAF inhibitors through HGF secretion.

Drug resistance presents a challenge to the treatment of cancer patients. Many studies have focused on cell-autonomous mechanisms of drug resistance. By contrast, we proposed that the tumour micro-environment confers innate resistance to therapy. Here we developed a co-culture system to systematically assay the ability of 23 stromal cell types to influence the innate resistance of 45 cancer cell lines to 35 anticancer drugs. We found that stroma-mediated resistance is common, particularly to targeted agents. We characterized further the stroma-mediated resistance of BRAF-mutant melanoma to RAF inhibitors because most patients with this type of cancer show some degree of innate resistance. Proteomic analysis showed that stromal cell secretion of hepatocyte growth factor (HGF) resulted in activation of the HGF receptor MET, reactivation of the mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3-OH kinase (PI(3)K)-AKT signalling pathways, and immediate resistance to RAF inhibition. Immunohistochemistry experiments confirmed stromal cell expression of HGF in patients with BRAF-mutant melanoma and showed a significant correlation between HGF expression by stromal cells and innate resistance to RAF inhibitor treatment. Dual inhibition of RAF and either HGF or MET resulted in reversal of drug resistance, suggesting RAF plus HGF or MET inhibitory combination therapy as a potential therapeutic strategy for BRAF-mutant melanoma. A similar resistance mechanism was uncovered in a subset of BRAF-mutant colorectal and glioblastoma cell lines. More generally, this study indicates that the systematic dissection of interactions between tumours and their micro-environment can uncover important mechanisms underlying drug resistance

The Spitzer Gould Belt Survey of Large Nearby Interstellar Clouds: Discovery of A Dense Embedded Cluster in the Serpens-Aquila Rift

We report the discovery of a nearby, embedded cluster of young stellar objects, associated filamentary infrared dark cloud, and 4.5 mu m shock emission knots from outflows detected in Spitzer IRAC mid-infrared imaging of the Serpens-Aquila Rift obtained as part of the Spitzer Gould Belt Legacy Survey. We also present radial velocity measurements of the region from molecular line observations obtained with the Submillimeter Array (SMA) that suggest the cluster is comoving with the Serpens Main embedded cluster to the north. We therefore assign it 3 degrees the same distance, 260 pc. The core of the new cluster, which we call Serpens South, is composed of an unusually large fraction of protostars (77%) at high mean surface density (> 430 pc(-2)) and short median nearest neighbor spacing (3700 AU). We perform basic cluster structure characterization using nearest neighbor surface density mapping of the YSOs and compare our findings to other known clusters with equivalent analyses available in the literature.Astronom