Bayesian probability encoding in medical decision analysis

Ph.DDOCTOR OF PHILOSOPH

Cinnamomum iners as Mitogen-Activated Protein Kinase Kinase (MKK1) inhibitor

Novel inhibitors targeting signal transductions have emerged for cancer therapies. Cinnamomum species have been reported to inhibit the proliferation of various cell lines. In this study, the methanol and acetone extracts of Cinnamomum iner’s leaves demonstrated significant anti-kinase activity against MKK1 in the signal transduction pathway at quantity as low as 1 and 6 mg respectively. Both of the extracts were found to contain polyphenol and flavonoid with potent anti-oxidation activity against DPPH free radicals (IC50=0.2 and 0.3 mg/mL respectively). In conclusion, the extracts may serve as potential MKK1 inhibitors which can be developed into anti-cancer drug

Elucidating the specificity of binding of sulfonylurea herbicides to acetohydroxyacid synthase

ABSTRACT: Acetohydroxyacid synthase (AHAS, EC 2.2.1.6) is the target for the sulfonylurea herbicides, which act as potent inhibitors of the enzyme. Chlorsulfuron (marketed as Glean) and sulfometuron methyl (marketed as Oust) are two commercially important members of this family of herbicides. Here we report crystal structures of yeast AHAS in complex with chlorsulfuron (at a resolution of 2.19 Å), sulfometuron methyl (2.34 Å), and two other sulfonylureas, metsulfuron methyl (2.29 Å) and tribenuron methyl (2.58 Å). The structures observed suggest why these inhibitors have different potencies and provide clues about the differential effects of mutations in the active site tunnel on various inhibitors. In all of the structures, the thiamin diphosphate cofactor is fragmented, possibly as the result of inhibitor binding. In addition to thiamin diphosphate, AHAS requires FAD for activity. Recently, it has been reported that reduction of FAD can occur as a minor side reaction due to reaction with the carbanion/enamine of the hydroxyethylThDP intermediate that is formed midway through the catalytic cycle. Here we report that the isoalloxazine ring has a bent conformation that would account for its ability to accept electrons from the hydroxyethyl intermediate. Most sequence and mutation data suggest that yeast AHAS is a high-quality model for the plant enzyme

Emerging therapeutic roles of exosomes in HIV-1 infection

Exosomes are nanometer-sized vesicles derived from endosomes of a variety of cell types and could be found in various biological fluids. The contents of exosomes vary depending on the cellular origin and state of health. Exosomes are a form of vehicle to transmit information between cells, transport wastes out of cells, and in the case of Human Immunodeficiency Virus Type 1 (HIV-1), promote infection and pathogenesis. HIV-1 and exosomes share many similarities in terms of lipid profile and protein make-up and could be the reason why the exosomal pathway is an effective route for HIV-1 to exploit. While exosomes have been shown in many instances to promote viral pathogenesis, there are also evidences that exosomes from specific cell origins could inhibit HIV-1, to a certain extent. This review summarizes the roles of exosome in promoting or inhibiting HIV-1 pathogenesis, as diagnostic biomarkers, therapeutic tools, and the challenges faced for its successful implementation in clinical applications

PNMA family: Protein interaction network and cell signalling pathways implicated in cancer and apoptosis

Paraneoplastic Ma Family (PNMA) comprises a growing number of family members which share relatively conserved protein sequences encoded by the human genome and is localized to several human chromosomes, including the X-chromosome. Based on sequence analysis, PNMA family members share sequence homology to the Gag protein of LTR retrotransposon, and several family members with aberrant protein expressions have been reported to be closely associated with the human Paraneoplastic Disorder (PND). In addition, gene mutations of specific members of PNMA family are known to be associated with human mental retardation or 3-M syndrome consisting of restrictive post-natal growth or dwarfism, and development of skeletal abnormalities. Other than sequence homology, the physiological function of many members in this family remains unclear. However, several members of this family have been characterized, including cell signalling events mediated by these proteins that are associated with apoptosis, and cancer in different cell types. Furthermore, while certain PNMA family members show restricted gene expression in the human brain and testis, other PNMA family members exhibit broader gene expression or preferential and selective protein interaction profiles, suggesting functional divergence within the family. Functional analysis of some members of this family have identified protein domains that are required for subcellular localization, protein-protein interactions, and cell signalling events which are the focus of this review paper

Aquatic Exercise Compared to Contrast Therapy With Shallow Water Treadmill Running to Assist Recovery in Elite Australian Rules Footballers

The purpose of this pilot exploratory study was to determine any immediate effects of a session of aquatic exercise (AE) compared to contrast therapy shallow water treadmill running (CSWR). Twenty-nine elite footballers were allocated randomly to AE or CSWR, 48 hours after a practice match. Outcome measures included maximum vertical jump height; visual analogue scale (VAS) for pain; the squeeze test for adductor strength, sit and reach test, plus ankle and hip range of movement. A significant difference between groups was found for maximum vertical jump height with the AE group being able to jump higher after the intervention (95% CI [-8.63 to -1.28]). No other significant differences between groups were detected for any outcome. Significant within group effects were found for the CSWR group in improving sit and reach (p = 0.04), and reducing pain when performing the squeeze test (p = 0.02). Both interventions may have improved aspects of performance; however, more highly powered trials, incorporating a control group, need to be conducted

Cell-Based Assays for Evaluation of Autophagy in Cancers

Autophagy is a cellular mechanism that degrades damaged organelles and misfolded proteins to maintain cellular homeostasis. Autophagy in cancers is drawing increasing attentions due to its multifaceted roles in cancer development, progression, and treatment. There are several key autophagy effectors that are being extensively studied to understand the role of autophagy in cancer as well as their potential value as predictive and/or prognostic biomarkers and therapeutic target. These include ATG4A, ATG4B, Beclin-I, p62, LC3A, LC3B, LC3C, and LAMP. While having its own sophisticated pathway, autophagy has been reported to associate with multiple oncogenic pathways such as NF-kB, mTOR, and PI3K signaling. This chapter aims to provide a detailed protocol for researchers to investigate the role of autophagy using in vitro cell line as model. Here, we demonstrate several techniques including Western blot (WB), immunofluorescence (IF), and small-interfering RNA (siRNA) knockdown using colorectal cancer cell lines as samples. This chapter provides information to researchers especially those in their early- and mid-career to plan and design their experiments to study the autophagy events in their area of interests

Molecular basis of sulfonylurea herbicide inhibition of acetohydroxyacid synthase

Acetohydroxyacid synthase (AHAS) (acetolactate synthase, EC 4.1.3.18) catalyzes the first step in branchedchain amino acid biosynthesis and is the target for sulfonylurea and imidazolinone herbicides. These compounds are potent and selective inhibitors, but their binding site on AHAS has not been elucidated. Here we report the 2.8 Angstrom resolution crystal structure of yeast AHAS in complex with a sulfonylurea herbicide, chlorimuron ethyl. The inhibitor, which has a K-i of 3.3 nM blocks access to the active site and contacts multiple residues where mutation results in herbicide resistance. The structure provides a starting point for the rational design of further herbicidal compounds