Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 27
Filter
Add more filters










Publication year range
1.
J Public Health Policy ; 44(1): 102-109, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36624270

ABSTRACT

Abuse of physician prescribed opioids contributes to health and economic burdens associated with dependency, overdose, and death. Since the 1900s, the United States (U.S.) Congress has legislated use and misuse of controlled substances. Under the U.S. Constitution, states developed prescription drug monitoring programs (PDMPs) that determine how the program is managed, what data to track, and what information to share with other states. Lack of a standard data set that allows providers to see prescribing data for designated controlled substances across state lines, limits benefits of state PDMPs. A federal PDMP with a standard minimal set of variables shared across states could enhance patient care. States would exercise their police powers while sharing standard data to decrease adverse consequences of the opioid epidemic.


Subject(s)
Prescription Drug Misuse , Prescription Drug Monitoring Programs , Humans , United States , Prescription Drug Misuse/prevention & control , Controlled Substances , Analgesics, Opioid/adverse effects , Information Dissemination
2.
Immunity ; 55(12): 2271-2284.e7, 2022 12 13.
Article in English | MEDLINE | ID: mdl-36384135

ABSTRACT

The NLRP3 inflammasome plays a central role in antimicrobial defense as well as in the context of sterile inflammatory conditions. NLRP3 activity is governed by two independent signals: the first signal primes NLRP3, rendering it responsive to the second signal, which then triggers inflammasome formation. Our understanding of how NLRP3 priming contributes to inflammasome activation remains limited. Here, we show that IKKß, a kinase activated during priming, induces recruitment of NLRP3 to phosphatidylinositol-4-phosphate (PI4P), a phospholipid enriched on the trans-Golgi network. NEK7, a mitotic spindle kinase that had previously been thought to be indispensable for NLRP3 activation, was redundant for inflammasome formation when IKKß recruited NLRP3 to PI4P. Studying iPSC-derived human macrophages revealed that the IKKß-mediated NEK7-independent pathway constitutes the predominant NLRP3 priming mechanism in human myeloid cells. Our results suggest that PI4P binding represents a primed state into which NLRP3 is brought by IKKß activity.


Subject(s)
Inflammasomes , NLR Family, Pyrin Domain-Containing 3 Protein , Humans , I-kappa B Kinase , Inflammasomes/metabolism , Mice, Inbred C57BL , NIMA-Related Kinases/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Protein Serine-Threonine Kinases/metabolism , trans-Golgi Network/metabolism
3.
Pain Manag ; 12(7): 821-827, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36017724

ABSTRACT

Aim: At our institution, reductions to hydromorphone and fentanyl unit dose quantities provided us with a unique opportunity to study opioid utilization. Materials & methods: A retrospective study examining effects of changes in opioid unit dose on intra-operative and postoperative opioid utilization in patients who underwent laparoscopic cholecystectomy. The study included three arms: the predosage change (n = 254), fentanyl only change group (n = 102) and the postdosage change arm (n = 254). Results: Decreasing opioid unit dosing decreased intraoperative opioid administration and total perioperative utilization. Decreased postanesthesia care unit morphine milligram equivalent (MME) requirements were observed in all, but one group comparison. Conclusion: Our data suggests that opioid unit dosing and administration are directly proportional and that decreased intraoperative MME utilization leads to decreased total perioperative MME use.


This study suggests that by supplying anesthesia providers with smaller quantities of opioid pain medication for use during surgery less pain medication is used both during and after surgery without a resultant increase in a patient's pain score or the amount of time they need to stay in the postoperative recovery area. As a result, some of the negative side effects associated with opioid pain medications may be diminished.


Subject(s)
Analgesics, Opioid , Cholecystectomy, Laparoscopic , Analgesics, Opioid/therapeutic use , Endrin/analogs & derivatives , Fentanyl , Humans , Hydromorphone , Pain, Postoperative/drug therapy , Pain, Postoperative/prevention & control , Retrospective Studies
4.
Nature ; 609(7927): 590-596, 2022 09.
Article in English | MEDLINE | ID: mdl-36002575

ABSTRACT

Bacterial cell wall components provide various unique molecular structures that are detected by pattern recognition receptors (PRRs) of the innate immune system as non-self. Most bacterial species form a cell wall that consists of peptidoglycan (PGN), a polymeric structure comprising alternating amino sugars that form strands cross-linked by short peptides. Muramyl dipeptide (MDP) has been well documented as a minimal immunogenic component of peptidoglycan1-3. MDP is sensed by the cytosolic nucleotide-binding oligomerization domain-containing protein 24 (NOD2). Upon engagement, it triggers pro-inflammatory gene expression, and this functionality is of critical importance in maintaining a healthy intestinal barrier function5. Here, using a forward genetic screen to identify factors required for MDP detection, we identified N-acetylglucosamine kinase (NAGK) as being essential for the immunostimulatory activity of MDP. NAGK is broadly expressed in immune cells and has previously been described to contribute to the hexosamine biosynthetic salvage pathway6. Mechanistically, NAGK functions upstream of NOD2 by directly phosphorylating the N-acetylmuramic acid moiety of MDP at the hydroxyl group of its C6 position, yielding 6-O-phospho-MDP. NAGK-phosphorylated MDP-but not unmodified MDP-constitutes an agonist for NOD2. Macrophages from mice deficient in NAGK are completely deficient in MDP sensing. These results reveal a link between amino sugar metabolism and innate immunity to bacterial cell walls.


Subject(s)
Acetylmuramyl-Alanyl-Isoglutamine , Nod2 Signaling Adaptor Protein , Phosphotransferases (Alcohol Group Acceptor) , Acetylmuramyl-Alanyl-Isoglutamine/chemistry , Acetylmuramyl-Alanyl-Isoglutamine/immunology , Acetylmuramyl-Alanyl-Isoglutamine/metabolism , Acetylmuramyl-Alanyl-Isoglutamine/pharmacology , Animals , Bacteria/chemistry , Bacteria/immunology , Cell Wall/chemistry , Hexosamines/biosynthesis , Immunity, Innate , Macrophages/enzymology , Macrophages/immunology , Mice , Nod2 Signaling Adaptor Protein/agonists , Nod2 Signaling Adaptor Protein/metabolism , Peptidoglycan/chemistry , Peptidoglycan/immunology , Phosphorylation , Phosphotransferases (Alcohol Group Acceptor)/deficiency , Phosphotransferases (Alcohol Group Acceptor)/genetics , Phosphotransferases (Alcohol Group Acceptor)/metabolism
5.
Nat Commun ; 12(1): 6053, 2021 10 18.
Article in English | MEDLINE | ID: mdl-34663829

ABSTRACT

Tumor necrosis factor (TNF) is one of the few cytokines successfully targeted by therapies against inflammatory diseases. However, blocking this well studied and pleiotropic ligand can cause dramatic side-effects. Here, we reason that a systems-level proteomic analysis of TNF signaling could dissect its diverse functions and offer a base for developing more targeted therapies. Therefore, we combine phosphoproteomics time course experiments with subcellular localization and kinase inhibitor analysis to identify functional modules of protein phosphorylation. The majority of regulated phosphorylation events can be assigned to an upstream kinase by inhibiting master kinases. Spatial proteomics reveals phosphorylation-dependent translocations of hundreds of proteins upon TNF stimulation. Phosphoproteome analysis of TNF-induced apoptosis and necroptosis uncovers a key role for transcriptional cyclin-dependent kinase activity to promote cytokine production and prevent excessive cell death downstream of the TNF signaling receptor. This resource of TNF-induced pathways and sites can be explored at http://tnfviewer.biochem.mpg.de/ .


Subject(s)
Cyclin-Dependent Kinases/metabolism , Proteome/metabolism , Signal Transduction , A549 Cells , Apoptosis , Cell Death , Cell Line , Cytokines/metabolism , Humans , Necroptosis , Phosphorylation , Tumor Necrosis Factor-alpha/metabolism , U937 Cells
6.
EMBO J ; 40(23): e103718, 2021 12 01.
Article in English | MEDLINE | ID: mdl-34698396

ABSTRACT

Mixed lineage kinase domain-like (MLKL) is the executioner in the caspase-independent form of programmed cell death called necroptosis. Receptor-interacting serine/threonine protein kinase 3 (RIPK3) phosphorylates MLKL, triggering MLKL oligomerization, membrane translocation and membrane disruption. MLKL also undergoes ubiquitylation during necroptosis, yet neither the mechanism nor the significance of this event has been demonstrated. Here, we show that necroptosis-specific multi-mono-ubiquitylation of MLKL occurs following its activation and oligomerization. Ubiquitylated MLKL accumulates in a digitonin-insoluble cell fraction comprising organellar and plasma membranes and protein aggregates. Appearance of this ubiquitylated MLKL form can be reduced by expression of a plasma membrane-located deubiquitylating enzyme. Oligomerization-induced MLKL ubiquitylation occurs on at least four separate lysine residues and correlates with its proteasome- and lysosome-dependent turnover. Using a MLKL-DUB fusion strategy, we show that constitutive removal of ubiquitin from MLKL licences MLKL auto-activation independent of necroptosis signalling in mouse and human cells. Therefore, in addition to the role of ubiquitylation in the kinetic regulation of MLKL-induced death following an exogenous necroptotic stimulus, it also contributes to restraining basal levels of activated MLKL to avoid unwanted cell death.


Subject(s)
Cell Membrane/metabolism , Necroptosis , Protein Kinases/metabolism , Protein Kinases/physiology , Protein Multimerization , Ubiquitin Thiolesterase/metabolism , Ubiquitination , Animals , Mice , Mice, Inbred C57BL , Mice, Knockout , Phosphorylation , Proteasome Endopeptidase Complex , Protein Kinases/chemistry , Protein Kinases/genetics , Ubiquitin Thiolesterase/genetics
7.
Nature ; 587(7835): 678-682, 2020 11.
Article in English | MEDLINE | ID: mdl-32911480

ABSTRACT

Cyclic GMP-AMP synthase (cGAS) is an innate immune sensor for cytosolic microbial DNA1. After binding DNA, cGAS synthesizes the messenger 2'3'-cyclic GMP-AMP (cGAMP)2-4, which triggers cell-autonomous defence and the production of type I interferons and pro-inflammatory cytokines via the activation of STING5. In addition to responding to cytosolic microbial DNA, cGAS also recognizes mislocalized cytosolic self-DNA and has been implicated in autoimmunity and sterile inflammation6,7. Specificity towards pathogen- or damage-associated DNA was thought to be caused by cytosolic confinement. However, recent findings place cGAS robustly in the nucleus8-10, where tight tethering of chromatin is important to prevent autoreactivity to self-DNA8. Here we show how cGAS is sequestered and inhibited by chromatin. We provide a cryo-electron microscopy structure of the cGAS catalytic domain bound to a nucleosome, which shows that cGAS does not interact with the nucleosomal DNA, but instead interacts with histone 2A-histone 2B, and is tightly anchored to the 'acidic patch'. The interaction buries the cGAS DNA-binding site B, and blocks the formation of active cGAS dimers. The acidic patch robustly outcompetes agonistic DNA for binding to cGAS, which suggests that nucleosome sequestration can efficiently inhibit cGAS, even when accessible DNA is nearby, such as in actively transcribed genomic regions. Our results show how nuclear cGAS is sequestered by chromatin and provides a mechanism for preventing autoreactivity to nuclear self-DNA.


Subject(s)
Catalytic Domain , Chromatin/chemistry , Chromatin/metabolism , Nucleotidyltransferases/antagonists & inhibitors , Nucleotidyltransferases/chemistry , Amino Acid Sequence , Animals , Autoantigens/chemistry , Autoantigens/immunology , Autoantigens/metabolism , Autoantigens/ultrastructure , Binding Sites , Binding, Competitive , Chromatin/genetics , Chromatin/ultrastructure , Cryoelectron Microscopy , DNA/chemistry , DNA/immunology , DNA/metabolism , DNA/ultrastructure , Enzyme Activation , Histones/chemistry , Histones/metabolism , Histones/ultrastructure , Humans , Hydrophobic and Hydrophilic Interactions , Immunity, Innate , Mice , Models, Molecular , Nucleosomes/chemistry , Nucleosomes/genetics , Nucleosomes/metabolism , Nucleosomes/ultrastructure , Nucleotidyltransferases/metabolism , Nucleotidyltransferases/ultrastructure , Protein Multimerization , THP-1 Cells
8.
EMBO Rep ; 21(11): e50400, 2020 11 05.
Article in English | MEDLINE | ID: mdl-32954645

ABSTRACT

Signaling via the intracellular pathogen receptors nucleotide-binding oligomerization domain-containing proteins NOD1 and NOD2 requires receptor interacting kinase 2 (RIPK2), an adaptor kinase that can be targeted for the treatment of various inflammatory diseases. However, the molecular mechanisms of how RIPK2 contributes to NOD signaling are not completely understood. We generated FLAG-tagged RIPK2 knock-in mice using CRISPR/Cas9 technology to study NOD signaling mechanisms at the endogenous level. Using cells from these mice, we were able to generate a detailed map of post-translational modifications on RIPK2. Similar to other reports, we did not detect ubiquitination of RIPK2 lysine 209 during NOD2 signaling. However, using site-directed mutagenesis we identified a new regulatory region on RIPK2, which dictates the crucial interaction with the E3 ligase XIAP and downstream signaling outcomes.


Subject(s)
Nod2 Signaling Adaptor Protein , Receptor-Interacting Protein Serine-Threonine Kinase 2 , Animals , Mice , Nod2 Signaling Adaptor Protein/genetics , Nod2 Signaling Adaptor Protein/metabolism , Receptor-Interacting Protein Serine-Threonine Kinase 2/genetics , Receptor-Interacting Protein Serine-Threonine Kinase 2/metabolism , Regulatory Sequences, Nucleic Acid , Signal Transduction , Ubiquitination
9.
Cell Rep ; 30(4): 1260-1270.e5, 2020 01 28.
Article in English | MEDLINE | ID: mdl-31995763

ABSTRACT

The inflammatory functions of the cytokine tumor necrosis factor (TNF) rely on its ability to induce cytokine production and to induce cell death. Caspase-dependent and caspase-independent pathways-apoptosis and necroptosis, respectively-regulate immunogenicity by the release of distinct sets of cellular proteins. To obtain an unbiased, systems-level understanding of this important process, we here applied mass spectrometry-based proteomics to dissect protein release during apoptosis and necroptosis. We report hundreds of proteins released from human myeloid cells in time course experiments. Both cell death types induce receptor shedding, but only apoptotic cells released nucleosome components. Conversely, necroptotic cells release lysosomal components by activating lysosomal exocytosis at early stages of necroptosis-induced membrane permeabilization and show reduced release of conventionally secreted cytokines.


Subject(s)
Apoptosis , Caspase 8/metabolism , Cytokines/metabolism , Necroptosis , Pentanoic Acids/pharmacology , Proteome/metabolism , Tumor Necrosis Factor-alpha/pharmacology , Apoptosis/drug effects , Caspase Inhibitors/pharmacology , Cell Membrane/drug effects , Cell Membrane/metabolism , Chemokine CCL2/metabolism , Chemokine CCL24/metabolism , Dipeptides/pharmacology , Exocytosis/drug effects , Extracellular Vesicles/drug effects , Extracellular Vesicles/metabolism , HEK293 Cells , Histones/metabolism , Humans , Indoles/pharmacology , Interleukin-8/metabolism , Lysosomes/drug effects , Lysosomes/metabolism , Mass Spectrometry , Necroptosis/drug effects
10.
Front Cell Dev Biol ; 7: 208, 2019.
Article in English | MEDLINE | ID: mdl-31632962

ABSTRACT

Innate immune signaling and programmed cell death are intimately linked, and many signaling pathways can regulate and induce both, transcription of inflammatory mediators or autonomous cell death. The best-characterized examples for these dual outcomes are members of the TNF superfamily, the inflammasome receptors, and the toll-like receptors. Signaling via the intracellular peptidoglycan receptors NOD1 and NOD2, however, does not appear to follow this trend, despite involving signaling proteins, or proteins with domains that are linked to programmed cell death, such as RIP kinases, inhibitors of apoptosis (IAP) proteins or the CARD domains on NOD1/2. To better understand the connections between NOD signaling and cell death induction, we here review the latest findings on the molecular regulation of signaling downstream of the NOD receptors and explore the links between this immune signaling pathway and the regulation of cell death.

11.
EMBO J ; 38(2)2019 01 15.
Article in English | MEDLINE | ID: mdl-30573668

ABSTRACT

The E3 ubiquitin ligase Parkin is a key effector of the removal of damaged mitochondria by mitophagy. Parkin determines cell fate in response to mitochondrial damage, with its loss promoting early onset Parkinson's disease and potentially also cancer progression. Controlling a cell's apoptotic response is essential to co-ordinate the removal of damaged mitochondria. We report that following mitochondrial damage-induced mitophagy, Parkin directly ubiquitinates the apoptotic effector protein BAK at a conserved lysine in its hydrophobic groove, a region that is crucial for BAK activation by BH3-only proteins and its homo-dimerisation during apoptosis. Ubiquitination inhibited BAK activity by impairing its activation and the formation of lethal BAK oligomers. Parkin also suppresses BAX-mediated apoptosis, but in the absence of BAX ubiquitination suggesting an indirect mechanism. In addition, we find that BAK-dependent mitochondrial outer membrane permeabilisation during apoptosis promotes PINK1-dependent Parkin activation. Hence, we propose that Parkin directly inhibits BAK to suppress errant apoptosis, thereby allowing the effective clearance of damaged mitochondria, but also promotes clearance of apoptotic mitochondria to limit their potential pro-inflammatory effect.


Subject(s)
Mitochondria/physiology , Ubiquitin-Protein Ligases/metabolism , bcl-2 Homologous Antagonist-Killer Protein/metabolism , bcl-2-Associated X Protein/metabolism , Animals , Apoptosis , Cell Line , HEK293 Cells , HeLa Cells , Humans , Lysine/metabolism , Mice , Mitophagy , Ubiquitination , bcl-2 Homologous Antagonist-Killer Protein/chemistry
12.
Cell Rep ; 22(6): 1496-1508, 2018 02 06.
Article in English | MEDLINE | ID: mdl-29425505

ABSTRACT

Inhibitors of apoptosis (IAPs) proteins are critical regulators of innate immune signaling pathways and therefore have potential as drug targets. X-linked IAP (XIAP) and cellular IAP1 and IAP2 (cIAP1 and cIAP2) are E3 ligases that have been shown to be required for signaling downstream of NOD2, an intracellular receptor for bacterial peptidoglycan. We used genetic and biochemical approaches to compare the responses of IAP-deficient mice and cells to NOD2 stimulation. In all cell types tested, XIAP is the only IAP required for signaling immediately downstream of NOD2, while cIAP1 and cIAP2 are dispensable for NOD2-induced nuclear factor κB (NF-κB) and mitogen-activated protein kinase (MAPK) activation. However, mice lacking cIAP1 or TNFR1 have a blunted cytokine response to NOD2 stimulation. We conclude that cIAPs regulate NOD2-dependent autocrine TNF signaling in vivo and highlight the importance of physiological context in the interplay of innate immune signaling pathways.


Subject(s)
Bacterial Infections/immunology , Immunity, Innate/immunology , Inhibitor of Apoptosis Proteins/immunology , Signal Transduction/immunology , Animals , Bacterial Proteins/immunology , Gene Knockout Techniques , Mice , Nod2 Signaling Adaptor Protein , Peptidoglycan/immunology
13.
Mol Psychiatry ; 22(8): 1096-1109, 2017 08.
Article in English | MEDLINE | ID: mdl-28584287

ABSTRACT

CACNA1C, encoding the Cav1.2 subunit of L-type Ca2+ channels, has emerged as one of the most prominent and highly replicable susceptibility genes for several neuropsychiatric disorders. Cav1.2 channels play a crucial role in calcium-mediated processes involved in brain development and neuronal function. Within the CACNA1C gene, disease-associated single-nucleotide polymorphisms have been associated with impaired social and cognitive processing and altered prefrontal cortical (PFC) structure and activity. These findings suggest that aberrant Cav1.2 signaling may contribute to neuropsychiatric-related disease symptoms via impaired PFC function. Here, we show that mice harboring loss of cacna1c in excitatory glutamatergic neurons of the forebrain (fbKO) that we have previously reported to exhibit anxiety-like behavior, displayed a social behavioral deficit and impaired learning and memory. Furthermore, focal knockdown of cacna1c in the adult PFC recapitulated the social deficit and elevated anxiety-like behavior, but not the deficits in learning and memory. Electrophysiological and molecular studies in the PFC of cacna1c fbKO mice revealed higher E/I ratio in layer 5 pyramidal neurons and lower general protein synthesis. This was concurrent with reduced activity of mTORC1 and its downstream mRNA translation initiation factors eIF4B and 4EBP1, as well as elevated phosphorylation of eIF2α, an inhibitor of mRNA translation. Remarkably, systemic treatment with ISRIB, a small molecule inhibitor that suppresses the effects of phosphorylated eIF2α on mRNA translation, was sufficient to reverse the social deficit and elevated anxiety-like behavior in adult cacna1c fbKO mice. ISRIB additionally normalized the lower protein synthesis and higher E/I ratio in the PFC. Thus this study identifies a novel Cav1.2 mechanism in neuropsychiatric-related endophenotypes and a potential future therapeutic target to explore.


Subject(s)
Calcium Channels, L-Type/drug effects , Calcium Channels, L-Type/metabolism , Animals , Anxiety , Behavior, Animal/drug effects , Calcium/metabolism , Calcium Channels, L-Type/genetics , Disease Models, Animal , Eukaryotic Initiation Factor-2/genetics , Eukaryotic Initiation Factor-2/metabolism , Eukaryotic Initiation Factors/genetics , Eukaryotic Initiation Factors/metabolism , Genetic Predisposition to Disease/genetics , Hippocampus/metabolism , Humans , Mice , Mice, Knockout , Neurons/metabolism , Prosencephalon/metabolism , Pyramidal Cells/metabolism , Social Behavior
14.
Curr Radiopharm ; 9(2): 128-36, 2016.
Article in English | MEDLINE | ID: mdl-26013570

ABSTRACT

BACKGROUND AND OBJECTIVE: Prostate cancer continues to be the most prevalent cancer in men in Malaysia. As time progresses, the prospect of PET imaging modality in diagnosis of prostate cancer is promising, with on-going improvement on novel tracers. Among all tracers, 18F-Fluorocholine is reported to be a reputable tracer and reliable diagnostic technique for prostate imaging. Nonetheless, only 18F-Fluorodeoxyglucose (18F-FDG) is available and used in most oncology cases in Malaysia. With a small scale GMP-based radiopharmaceuticals laboratory set-up, initial efforts have been taken to put Malaysia on 18F-Fluorocholine map. This article presents a convenient, efficient and reliable method for quality control analysis of 18F-Fluorocholine. Besides, the aim of this research work is to assist local GMP radiopharmaceuticals laboratories and local authority in Malaysia for quality control analysis of 18F-Fluorocholine guideline. METHODS: In this study, prior to synthesis, quality control analysis method for 18F-Fluorocholine was developed and validated, by adapting the equipment set-up used in 18F-Fluorodeoxyglucose (18FFDG) routine production. Quality control on the 18F-Fluorocholine was performed by means of pH, radionuclidic identity, radio-high performance liquid chromatography equipped with ultraviolet, radio- thin layer chromatography, gas chromatography and filter integrity test. RESULTS: Post-synthesis; the pH of 18F-Fluorocholine was 6.42 ± 0.04, with half-life of 109.5 minutes (n = 12). The radiochemical purity was consistently higher than 99%, both in radio-high performance liquid chromatography equipped with ultraviolet (r-HPLC; SCX column, 0.25 M NaH2PO4: acetonitrile) and radio-thin layer chromatography method (r-TLC). The calculated relative retention time (RRT) in r-HPLC was 1.02, whereas the retention factor (Rf) in r-TLC was 0.64. Potential impurities from 18F-Fluorocholine synthesis such as ethanol, acetonitrile, dimethylethanolamine and dibromomethane were determined in gas chromatography. Using our parameters, (capillary column: DB-200, 30 m x 0.53 mm x 1 um) and oven temperature of 35°C (isothermal), all compounds were well resolved and eluted within 3 minutes. Level of ethanol and acetonitrile in 18F-Fluorocholine were detected below threshold limit; less than 5 mg/ml and 0.41 mg/ml respectively. Meanwhile, dimethylethanolamine and dibromomethane were undetectable. CONCLUSION: A convenient, efficient and reliable quality control analysis work-up procedure for 18FFluorocholine has been established and validated to comply all the release criteria. The convenient method of quality control analysis may provide a guideline to local GMP radiopharmaceutical laboratories to start producing 18F-Fluorocholine as a tracer for prostate cancer imaging.


Subject(s)
Choline/analogs & derivatives , Radiopharmaceuticals/chemical synthesis , Choline/chemical synthesis , Choline/chemistry , Half-Life , Laboratories , Malaysia , Quality Control , Radiopharmaceuticals/chemistry
15.
Curr Radiopharm ; 9(2): 121-7, 2016.
Article in English | MEDLINE | ID: mdl-26239237

ABSTRACT

BACKGROUND AND OBJECTIVE: 18F-Fluorocholine has been suggested as one of the reputable imaging tracers for diagnosis of prostate tumour in Positron Emission Tomography / Computed Tomography (PET/CT) modality. Nevertheless, it has never been synthesised in Malaysia. We acknowledged that the major problem with 18F-Fluorocholine is due to its relatively low radiochemical yield at the end of synthesis (EOS). Therefore, this article presents improved 18FFluorocholine radiochemical yields after carrying out optimisation on azeotropic drying of 18F-Fluorine. METHODS: In the previous study, the azeotropic drying of non-carrier-added (n.c.a) 18F-Fluorine in the reactor was conducted at atmospheric pressure (0 atm) and shorter duration time. In this study, however, the azeotropic drying of non-carried-added (n.c.a) 18FFluorine was made at a high vacuum pressure (- 0.65 to - 0.85 bar) with an additional time of 30 seconds. At the end of the synthesis, the mean radiochemical yield was statistically compared between the two azeotropic drying conditions so as to observe whether the improvement made was significant to the radiochemical yield. RESULTS: From the paired sample t-test analysis, the improvement done to the azeotropic drying of non-carrier-added (n.c.a) 18F-Fluorine was statistically significant (p < 0.05). With the improvement made, the 18F-Fluorcholine radiochemical yield was found to have increase by one fold. CONCLUSION: Improved 18F-Fluorocholine radiochemical yields were obtained after the improvement had been done to the azeotropic drying of non-carrier-added (n.c.a) 18F-Fluorine. It was also observed that improvement made to the azeotropic drying of non-carrier-added (n.c.a) 18F-Fluorine did not affect the 18F-Fluorocholine quality control analysis.


Subject(s)
Choline/analogs & derivatives , Fluorine Radioisotopes/chemistry , Radiopharmaceuticals/chemical synthesis , Chemistry Techniques, Synthetic/methods , Choline/chemical synthesis , Desiccation/methods
16.
J Labelled Comp Radiopharm ; 58(11-12): 458-9, 2015.
Article in English | MEDLINE | ID: mdl-26395258

ABSTRACT

(18)F-Fluoromethylcholine ((18)F-FCH) has been suggested as one of the reputable imaging tracers for diagnosis of prostate tumour in PET/CT examination. Nevertheless, it has never been synthesised in Malaysia. We acknowledged the major problem with (18)F-FCH is due to its relatively low radiochemical yield at the end of synthesis (EOS). Therefore, this technical note presents improved (18)F-FCH radiochemical yields after carrying out optimisation on azeotropic drying of non-carrier-added (18)F-Fluorine.


Subject(s)
Chemistry Techniques, Synthetic/methods , Choline/analogs & derivatives , Desiccation/methods , Radiopharmaceuticals/chemical synthesis , Chemistry Techniques, Synthetic/instrumentation , Choline/chemical synthesis , Desiccation/instrumentation , Fluorine Radioisotopes/chemistry
17.
Nat Commun ; 6: 6442, 2015 Mar 17.
Article in English | MEDLINE | ID: mdl-25778803

ABSTRACT

Intracellular nucleotide binding and oligomerization domain (NOD) receptors recognize antigens including bacterial peptidoglycans and initiate immune responses by triggering the production of pro-inflammatory cytokines through activating NF-κB and MAP kinases. Receptor interacting protein kinase 2 (RIPK2) is critical for NOD-mediated NF-κB activation and cytokine production. Here we develop and characterize a selective RIPK2 kinase inhibitor, WEHI-345, which delays RIPK2 ubiquitylation and NF-κB activation downstream of NOD engagement. Despite only delaying NF-κB activation on NOD stimulation, WEHI-345 prevents cytokine production in vitro and in vivo and ameliorates experimental autoimmune encephalomyelitis in mice. Our study highlights the importance of the kinase activity of RIPK2 for proper immune responses and demonstrates the therapeutic potential of inhibiting RIPK2 in NOD-driven inflammatory diseases.


Subject(s)
Cytokines/metabolism , Inflammation/metabolism , Receptor-Interacting Protein Serine-Threonine Kinases/metabolism , Adenosine Triphosphate/chemistry , Animals , Chromatography, Liquid , Encephalomyelitis, Autoimmune, Experimental/genetics , Female , Humans , Immune System , Inhibitory Concentration 50 , Interferon-gamma/metabolism , MAP Kinase Signaling System , Male , Mice , Mice, Inbred C57BL , Mice, Inbred NOD , NF-kappa B/metabolism , Protein Binding , Protein Conformation , Receptor-Interacting Protein Serine-Threonine Kinase 2/antagonists & inhibitors , Receptor-Interacting Protein Serine-Threonine Kinase 2/metabolism , Receptor-Interacting Protein Serine-Threonine Kinases/antagonists & inhibitors , Recombinant Proteins/metabolism , Signal Transduction , Tandem Mass Spectrometry , Ubiquitin/metabolism
18.
Genes Brain Behav ; 13(8): 802-11, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25130614

ABSTRACT

Dyslexia is a complex neurodevelopmental disorder characterized by impaired reading ability despite normal intellect, and is associated with specific difficulties in phonological and rapid auditory processing (RAP), visual attention and working memory. Genetic variants in Doublecortin domain-containing protein 2 (DCDC2) have been associated with dyslexia, impairments in phonological processing and in short-term/working memory. The purpose of this study was to determine whether sensory and behavioral impairments can result directly from mutation of the Dcdc2 gene in mice. Several behavioral tasks, including a modified pre-pulse inhibition paradigm (to examine auditory processing), a 4/8 radial arm maze (to assess/dissociate working vs. reference memory) and rotarod (to examine sensorimotor ability and motor learning), were used to assess the effects of Dcdc2 mutation. Behavioral results revealed deficits in RAP, working memory and reference memory in Dcdc2(del2/del2) mice when compared with matched wild types. Current findings parallel clinical research linking genetic variants of DCDC2 with specific impairments of phonological processing and memory ability.


Subject(s)
Auditory Perception/genetics , Auditory Perceptual Disorders/genetics , Behavior, Animal/physiology , Maze Learning/physiology , Memory/physiology , Microtubule-Associated Proteins/genetics , Animals , Male , Mice , Mice, Knockout , Motor Skills/physiology , Rotarod Performance Test
19.
Biotechnol Bioeng ; 111(8): 1627-37, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24615218

ABSTRACT

Recent progress in the field of genetic engineering has opened up the door to novel synthetic biology applications. Microfluidic technology has been emphasized as a key technology to support the development of these applications. While several important synthetic biology protocols have been developed in microfluidic format, no study has yet demonstrated on-chip error control. In synthetic biology protocols, the purification phase is a critical error control process which enhances the reliability of the genome segment assembly by removing undesired oligos. In this context, we report the design and characterization of a fully integrated platform, demonstrating the purification of up to 4 genome segments in parallel, prior to their off-chip assembly. The key innovation of this platform is the decoupling control strategy which eliminates the need to integrate expensive components onto the microfluidic device, enabling lower cost, disposability and rapid operation. Unlike most microfluidic chips where fluid connector plugs are needed to connect external pumps, this approach is plug-less and the chips are simply connected to the control breadboard by clamping. Furthermore the passive chip is isolated from the active control layer thereby eliminating the risk of sample-to-sample contamination in the reusable parts. As a validation of this fully-integrated system, the parallel on-chip purification of genome segments was demonstrated with ratio of correct phenotypes after final assembly up to 20% superior to the bench controls, proving thereby the suitability of the platform for synthetic biology applications.


Subject(s)
DNA/chemical synthesis , Microfluidic Analytical Techniques/instrumentation , Combinatorial Chemistry Techniques/instrumentation , DNA/isolation & purification , Equipment Design , Genome , Reproducibility of Results
20.
Magn Reson Med ; 67(2): 531-40, 2012 Feb.
Article in English | MEDLINE | ID: mdl-21656561

ABSTRACT

The variation of the native T(1) (T(10)) of different tissues and B(1) transmission-field inhomogeneity at 3 T are major contributors of errors in the quantification of breast dynamic contrast-enhanced MRI. To address these issues, we have introduced new enhancement indices derived from saturation-recovery snapshot-FLASH (SRSF) images. The stability of the new indices, i.e., the SRSF enhancement factor (EF(SRSF)) and its simplified version (EF'(SRSF)) with respect to differences in T(10) and B(1) inhomogeneity was compared against a typical index used in breast dynamic contrast-enhanced MRI, i.e., the enhancement ratio (ER), by using computer simulations. Imaging experiments with Gd-DTPA-doped gel phantoms and a female volunteer were also performed. A lower error was observed in the new indices compared to enhancement ratio in the presence of typical T(10) variation and B(1) inhomogeneity. At changes of relaxation rate (ΔR(1)) of 8 s(-1), the differences between a T(10) of 1266 and 566 ms are <1, 12, and 58%, respectively, for EF(SRSF), EF'(SRSF), and ER, whereas differences of 20, 8, and 51%, respectively, result from a 50% B(1) field reduction at the same ΔR(1). These quantification techniques may be a solution to minimize the effect of T(10) variation and B(1) inhomogeneity on dynamic contrast-enhanced MRI of the breast at 3 T.


Subject(s)
Breast Neoplasms/diagnosis , Breast/pathology , Image Enhancement/methods , Image Processing, Computer-Assisted/methods , Mammography/methods , Computer Simulation , Female , Humans , Phantoms, Imaging , Sensitivity and Specificity
SELECTION OF CITATIONS
SEARCH DETAIL
...