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1.
CJEM ; 25(7): 598-607, 2023 07.
Article in English | MEDLINE | ID: mdl-37245202

ABSTRACT

OBJECTIVES: Opioid use disorder is a major public health concern that accounts for a high number of potential years of life lost. Buprenorphine/naloxone is a recommended treatment for opioid use disorder that can be started in the emergency department (ED). We developed an ED-based program to initiate buprenorphine/naloxone for eligible patients who live with opioid use disorder, and to provide unscheduled, next-day follow-up referrals to an opioid use disorder treatment clinic (in person or virtual) for continuing patient care throughout Alberta. METHODS: In this quality improvement initiative, we supported local ED teams to offer buprenorphine/naloxone to eligible patients presenting to the ED with suspected opioid use disorder and refer these patients for follow-up care. Process, outcome, and balancing measures were evaluated over the first 2 years of the initiative (May 15, 2018-May 15, 2020). RESULTS: The program was implemented at 107 sites across Alberta during our evaluation period. Buprenorphine/naloxone initiations in the ED increased post-intervention at most sites with baseline data available (11 of 13), and most patients (67%) continued to fill an opioid agonist prescription at 180 days post-ED visit. Of the 572 referrals recorded at clinics, 271 (47%) attended their first follow-up visit. Safety events were reported in ten initiations and were all categorized as no harm to minimal harm. CONCLUSIONS: A standardized provincial approach to initiating buprenorphine/naloxone in the ED for patients living with opioid use disorder was spread to 107 sites with dedicated program support staff and adjustment to local contexts. Similar quality improvement approaches may benefit other jurisdictions.


ABSTRAIT: OBJECTIFS: Le trouble lié à la consommation d'opioïdes est une préoccupation majeure en santé publique qui explique le nombre élevé d'années potentielles de vie perdues. La buprénorphine/naloxone est un traitement recommandé pour le trouble lié à l'utilisation d'opioïdes qui peut être commencé au service des urgences (SU). Nous avons mis au point un programme axé sur les urgences pour commencer la buprénorphine/naloxone pour les patients éligibles qui vivent avec un trouble lié à l'utilisation d'opioïdes, et pour fournir suivis des cas référés le jour suivant vers une clinique de soins des troubles liés à l'utilisation d'opioïdes (sur place ou virtuelle) pour les soins continus aux patients partout en Alberta. MéTHODES: Dans le cadre de cette initiative d'amélioration de la qualité, nous avons aidé les équipes locales de SU à offrir la buprénorphine/naloxone aux patients admissibles qui se présentent à la SU avec un trouble présumé de consommation d'opioïdes et à les diriger vers des soins de suivi. Le processus, les résultats et les mesures d'équilibre ont été évalués au cours des deux premières années de l'initiative (du 15 mai 2018 au 15 mai 2020). RéSULTATS: Le programme a été mis en œuvre dans 107 sites en Alberta pendant notre période d'évaluation. Les initiations à la buprénorphine/naloxone à l'urgence ont augmenté après l'intervention dans la plus grande partie de sites pour lesquels des données de référence étaient disponibles (11 sur 13), et la plupart des patients (67 %) ont continué de remplir une ordonnance d'agonistes opioïdes 180 jours après la visite à l'urgence. Sur les 572 renvois enregistrés aux cliniques, 271 (47 %) ont assisté à leur première visite de suivi. Des événements liés à la sécurité ont été signalés dans 10 initiatives et ont tous été classés comme n'ayant causé aucun conséquences à des conséquences minimes. CONCLUSIONS: Une approche provinciale standardisé de lancement de la buprénorphine/naloxone à l'urgence pour les patients atteints d'un trouble lié à la consommation d'opioïdes a été diffusée à 107 sites à l'aide de soutien aux programmes spécialisé et des ajustements aux contextes locaux. Des approches semblables d'amélioration de la qualité pourraient profiter à d'autres juridictions.


Subject(s)
Buprenorphine , Opioid-Related Disorders , Humans , Narcotic Antagonists/therapeutic use , Buprenorphine/therapeutic use , Alberta/epidemiology , Quality Improvement , Buprenorphine, Naloxone Drug Combination/therapeutic use , Opioid-Related Disorders/drug therapy , Opioid-Related Disorders/epidemiology , Emergency Service, Hospital , Referral and Consultation , Analgesics, Opioid/therapeutic use
2.
CJEM ; 22(6): 784-792, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32924911

ABSTRACT

BACKGROUND: Opioid use disorder is a major public health crisis, and evidence suggests ways of better serving patients who live with opioid use disorder in the emergency department (ED). A multi-disciplinary team developed a quality improvement project to implement this evidence. METHODS: The intervention was developed by an expert working group consisting of specialists and stakeholders. The group set goals of increasing prescribing of buprenorphine/naloxone and providing next day walk-in referrals to opioid use disorder treatment clinics. From May to September 2018, three Alberta ED sites and three opioid use disorder treatment clinics worked together to trial the intervention. We used administrative data to track the number of ED visits where patients were given buprenorphine/naloxone. Monthly ED prescribing rates before and after the intervention were considered and compared with eight nonintervention sites. We considered whether patients continued to fill opioid agonist treatment prescriptions at 30, 60, and 90 days after their index ED visit to measure continuity in treatment. RESULTS: The intervention sites increased their prescribing of buprenorphine/naloxone during the intervention period and prescribed more buprenorphine/naloxone than the controls. Thirty-five of 47 patients (74.4%) discharged from the ED with buprenorphine/naloxone continued to fill opioid agonist treatment prescriptions 30 days and 60 days after their index ED visit. Thirty-four patients (72.3%) filled prescriptions at 90 days. CONCLUSIONS: Emergency clinicians can effectively initiate patients on buprenorphine/naloxone when supports for this standardized evidence-based care are in place within their practice setting and timely follow-up in community is available.


Subject(s)
Buprenorphine , Opioid-Related Disorders , Buprenorphine/therapeutic use , Buprenorphine, Naloxone Drug Combination/therapeutic use , Emergency Service, Hospital , Humans , Narcotic Antagonists/therapeutic use , Opioid-Related Disorders/drug therapy , Opioid-Related Disorders/epidemiology
3.
Am Heart J ; 226: 75-84, 2020 08.
Article in English | MEDLINE | ID: mdl-32526532

ABSTRACT

BACKGROUND: The objective was to describe the design of a population-level electronic health record (EHR) and insurance claims-based surveillance system of adolescents and adults with congenital heart defects (CHDs) in Colorado and to evaluate the bias introduced by duplicate cases across data sources. METHODS: The Colorado CHD Surveillance System ascertained individuals aged 11-64 years with a CHD based on International Classification of Diseases, Ninth Revision, Clinical Modification diagnostic coding between 2011 and 2013 from a diverse network of health care systems and an All Payer Claims Database (APCD). A probability-based identity reconciliation algorithm identified duplicate cases. Logistic regression was conducted to investigate bias introduced by duplicate cases on the relationship between CHD severity (severe compared to moderate/mild) and adverse outcomes including all-cause mortality, inpatient hospitalization, and major adverse cardiac events (myocardial infarction, congestive heart failure, or cerebrovascular event). Sensitivity analyses were conducted to investigate bias introduced by the sole use or exclusion of APCD data. RESULTS: A total of 12,293 unique cases were identified, of which 3,476 had a within or between data source duplicate. Duplicate cases were more likely to be in the youngest age group and have private health insurance, a severe heart defect, a CHD comorbidity, and higher health care utilization. We found that failure to resolve duplicate cases between data sources would inflate the relationship between CHD severity and both morbidity and mortality outcomes by ~15%. Sensitivity analyses indicate that scenarios in which APCD was excluded from case finding or relied upon as the sole source of case finding would also result in an overestimation of the relationship between a CHD severity and major adverse outcomes. DISCUSSION: Aggregated EHR- and claims-based surveillance systems of adolescents and adults with CHD that fail to account for duplicate records will introduce considerable bias into research findings. CONCLUSION: Population-level surveillance systems for rare chronic conditions, such as congenital heart disease, based on aggregation of EHR and claims data require sophisticated identity reconciliation methods to prevent bias introduced by duplicate cases.


Subject(s)
Heart Defects, Congenital/epidemiology , Information Storage and Retrieval/statistics & numerical data , Medical Record Linkage , Population Surveillance/methods , Adolescent , Adult , Bias , Child , Colorado/epidemiology , Electronic Health Records , Female , Humans , Insurance Claim Reporting , Male , Middle Aged , Young Adult
4.
Toxicol Rep ; 6: 1155-1163, 2019.
Article in English | MEDLINE | ID: mdl-31737489

ABSTRACT

The in vitro mutagenic and genotoxic potential of Heated Tobacco Products (HTPs) has already been studied with the particulate phase and reported previously. This study has been designed to complement the in vitro assessment of the HTP and to determine whether the inclusion of potential flavourings would alter the in vitro response by testing the other phase of the aerosol, the gas-vapour phase (GVP). Both flavoured and unflavoured Neostik GVP samples did not show any sign of mutagenic activity in the Ames test but induced a mutagenic response in the mouse lymphoma assay (MLA), however, these responses were significantly less than those of the reference cigarette, 3R4F. The results demonstrated that GVP emissions of this HTP did not induce either new qualitative or quantitative mutagenic hazards compared to 3R4F, as assessed by the Ames test (no new responsive strains) and MLA (a lower mutagenic response), respectively. A statistical comparative analysis of the responses showed that the addition of flavourings that may thermally decompose under the conditions of use did not add to the in vitro baseline responses of the unflavoured Neostik.

5.
Food Chem Toxicol ; 118: 940-952, 2018 Aug.
Article in English | MEDLINE | ID: mdl-29879435

ABSTRACT

We designed a novel tobacco-heating product (THP) that heats tobacco to release nicotine and aerosolised components, such as glycerol and tobacco volatiles from a tobacco rod (Neostik). Heating tobacco significantly reduces levels of combustion-derived toxicants in the aerosol compared to cigarette smoke. This study was conducted to determine whether the inclusion of potential flavourings in the THP would add to the levels of toxicants in the emissions or alter in vitro responses. Levels of measured toxicants were similar in the flavoured and unflavoured Neostik emissions and significantly less than emissions from the reference cigarette, 3R4F. No mutagenicity was observed with the Neostiks in the Ames test or in the mouse lymphoma assay. There was evidence of a weak genotoxic response in the in vitro micronucleus test using V79 cells from both Neostiks and these responses were less than 3R4F. They did not show tumour-promoting potential in the Bhas 42 cell transformation assay and were not cytotoxic in the Neutral Red uptake assay. 3R4F elicited toxic responses in all assays at significantly lower concentrations. The addition of flavourings to the Neostik tested did not alter the chemical profile of THP emissions or change in vitro responses relative to the unflavoured Neostik.


Subject(s)
Flavoring Agents/toxicity , Nicotiana/chemistry , Animals , Carcinogenicity Tests , Carcinogens/toxicity , Cell Line, Transformed , Cell Survival/drug effects , Cricetinae , Cricetulus , Hot Temperature , Mice , Mice, Inbred BALB C , Mutagenicity Tests , Rats
6.
Food Res Int ; 109: 380-386, 2018 07.
Article in English | MEDLINE | ID: mdl-29803463

ABSTRACT

The characterisation of a serine protease isolated from tamarillo (Solanum betaceum) fruit and its milk casein hydrolysis activity were investigated. Compared with calf rennet, a crude extract from tamarillo exhibited wider caseinolytic activity on sodium caseinate. The purified protease was named "tamarillin" and revealed proteolytic activity toward purified α-, ß- and κ-casein. Similar to calf rennet, tamarillin preferably hydrolysed κ-casein, but, unlike calf rennet, it also displayed high proteolytic activity toward both α- and ß-casein. The major peptide generated from κ-casein by tamarillin was analysed by gel electrophoresis and liquid chromatography mass spectrometry to confirm its molecular mass as 14,290 Da. The cleavage site was confirmed by in-gel tryptic digestion and time-of-flight mass spectrometry analysis to be at Asn123-Thr124. This was in contrast to the Phe105-Met106 cleavage site of rennet hydrolysis.


Subject(s)
Caseins/metabolism , Food Analysis/methods , Food Handling/methods , Fruit/enzymology , Plant Extracts/metabolism , Plant Proteins/metabolism , Serine Proteases/metabolism , Solanum/enzymology , Chromatography, Reverse-Phase , Chymosin/metabolism , Electrophoresis, Polyacrylamide Gel , Hydrolysis , Molecular Weight , Peptide Fragments/metabolism , Plant Extracts/isolation & purification , Plant Proteins/isolation & purification , Serine Proteases/isolation & purification , Spectrometry, Mass, Electrospray Ionization , Substrate Specificity
7.
Food Chem ; 256: 228-234, 2018 Aug 01.
Article in English | MEDLINE | ID: mdl-29606442

ABSTRACT

A protease from tamarillo fruit (Cyphomandra betacea Cav.) was purified by ammonium sulphate precipitation and diethylaminoethyl-Sepharose chromatography. Protease activity was determined on selected peak fractions using a casein substrate. Sodium dodecyl sulphate polyacrylamide gel electrophoresis analysis showed that the peak with the highest protease activity consisted of one protein of molecular mass ca. 70 kDa. The protease showed optimal activity at pH 11 and 60 °C. It was sensitive to phenylmethylsulphonyl fluoride while ethylenediaminetetraacetic acid and p-chloromercuribenzoic acid had little effect on its activity, indicating that this enzyme was a serine protease. Hg2+ strongly inhibited enzyme activity, possibly due to formation of mercaptide bonds with the thiol groups of the protease, suggesting that some cysteine residues may be located close to the active site. De novo sequencing strongly indicated that the protease was a subtilisin-like alkaline serine protease. The protease from tamarillo has been named 'tamarillin'.


Subject(s)
Fruit/enzymology , Serine Proteases/isolation & purification , Solanum/enzymology , Electrophoresis, Polyacrylamide Gel , Enzyme Stability , Fruit/genetics , Hydrogen-Ion Concentration , Molecular Weight , Proteolysis , Sequence Analysis, Protein , Serine Proteases/genetics , Serine Proteases/metabolism , Solanum/genetics , Subtilisin , Temperature
8.
Food Chem Toxicol ; 106(Pt A): 522-532, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28576286

ABSTRACT

Vapour products have demonstrated potential to be a lower-risk alternative to cigarettes. The present study describes a novel hybrid tobacco product that combines a warm aerosol stream generated by an electronic vaporisation mechanism with tobacco top flavour from cut tobacco. During operation, the aerosol stream released from the vapour cartomiser is passed through a bed of blended cut tobacco by the puffing flow, elevating the tobacco temperature and eluting volatile tobacco flavour components. A preliminary but comprehensive analysis of the aerosol composition of the hybrid tobacco product found that emissions were dominated by the control vapour formulation. In non-targeted chemical screening, no detectable difference in GC scans was observed between the hybrid tobacco product and the control vapour product. However, a sensorially elevated tobacco flavour was confirmed by a consumer sensory panel (P < 0.05). In a targeted analysis of 113 compounds, either identified by regulatory bodies as potential toxicants in cigarette smoke or formed from electronic vapour products, only 26 were quantified. The novel action of tobacco heating and liquid aerosolisation produced classes and levels of toxicants that were similar to those of the control vapour product, but much lower than those of a Kentucky 3R4F reference cigarette. For nine toxicants mandated by the WHO Study Group on Tobacco Product Regulation for reduction in cigarette emissions, the levels were 91%-99% lower per puff in the hybrid tobacco product aerosol than in 3R4F smoke. Overall, the novel hybrid tobacco product provides a sensorially enhanced tobacco flavour, but maintains a toxicant profile similar to its parent vapour product with relatively low levels of known cigarette smoke toxicants.


Subject(s)
Aerosols/chemistry , Electronic Nicotine Delivery Systems/instrumentation , Flavoring Agents/chemistry , Nicotiana/chemistry , Adult , Consumer Product Safety , Electronic Nicotine Delivery Systems/methods , Electronic Nicotine Delivery Systems/standards , Humans , Smoking
9.
Regul Toxicol Pharmacol ; 71(3): 507-14, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25584437

ABSTRACT

Tobacco smoke from a combustible cigarette contains more than 6000 constituents; approximately 150 of these are identified as toxicants. Technologies that modify the tobacco blend to reduce toxicant emissions have been developed. These include tobacco sheet substitute to dilute toxicants in smoke and blend treated tobacco to reduce the levels of nitrogenous precursors and some polyphenols. Filter additives to reduce gas (vapour) phase constituents have also been developed. In this study, both tobacco blend and filter technologies were combined into an experimental cigarette and smoked to International Organisation on Standardisation and Health Canada puffing parameters. The resulting particulate matter was subjected to a battery of in vitro genotoxicity and cytotoxicity assays - the Ames test, mouse lymphoma assay, the in vitro micronucleus test and the Neutral Red Uptake assay. The results indicate that cigarettes containing toxicant reducing technologies may be developed without observing new additional genotoxic hazards as assessed by the assays specified. In addition, reductions in bacterial mutagenicity and mammalian genotoxicity of the experimental cigarette were observed relative to the control cigarettes. There were no significant differences in cytotoxicity relative to the control cigarettes.


Subject(s)
Nicotiana/toxicity , Smoke/adverse effects , Smoking/adverse effects , Tobacco Products/toxicity , Toxicity Tests , Animals , Cell Line , Cell Proliferation/drug effects , DNA, Bacterial/drug effects , DNA, Bacterial/genetics , Dose-Response Relationship, Drug , Fibroblasts/drug effects , Fibroblasts/metabolism , Fibroblasts/pathology , Humans , Mice, Inbred BALB C , Micronuclei, Chromosome-Defective/chemically induced , Micronucleus Tests , Mutation , Neutral Red/metabolism , Rats , Risk Assessment , Salmonella typhimurium/drug effects , Salmonella typhimurium/genetics , Toxicity Tests/methods
10.
FEMS Microbiol Lett ; 352(1): 54-61, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24372739

ABSTRACT

Phosphate signaling and acquisition are critical for the bacterial response to phosphate limitation, and bacteria express multiple factors to scavenge phosphate. We previously found that multidrug-resistant strains of Pseudomonas aeruginosa from critically ill patients can form unusual outer-surface appendages harboring PstS proteins. Here, we have expanded our investigation to DING proteins that like PstS belong to the family of high-affinity phosphate-binding proteins but have strong similarity with eukaryotic DING proteins. We demonstrate the localization of DING on PstS-containing outer-surface appendages in both multidrug-resistant strain MDR25 and the PA14 strain of P. aeruginosa. However, the number of cells producing appendages and the amount of appendages on each cell in PA14 were found to be negligible, unless overexpression of either PstS or DING was achieved by transformation with constructed plasmids. We further noticed that DING expression under low phosphate conditions was significantly higher in MDR25 compared to PA14 which may explain the greater abundance of appendages in MDR25. Our finding that DING proteins are localized on extracellular appendages provides an opportunity to study the interaction of bacterial DING with host proteins by mimicking the action of host DINGs.


Subject(s)
Bacterial Proteins/metabolism , Cell Surface Extensions/metabolism , Phosphate-Binding Proteins/metabolism , Pseudomonas Infections/microbiology , Pseudomonas aeruginosa/metabolism , Bacterial Proteins/genetics , Cell Surface Extensions/genetics , Humans , Phosphate-Binding Proteins/genetics , Protein Transport , Pseudomonas aeruginosa/genetics
11.
Article in English | MEDLINE | ID: mdl-24100568

ABSTRACT

In prokaryotes, phosphate starvation induces the expression of numerous phosphate-responsive genes, such as the pst operon including the high-affinity phosphate-binding protein (PBP or pstS) and alkaline phosphatases such as PhoA. This response increases the cellular inorganic phosphate import efficiency. Notably, some Pseudomonas species secrete, via a type-2 secretion system, a phosphate-binding protein dubbed LapA endowed with phosphatase activity. Here, the expression, purification, crystallization and X-ray data collection at 0.87 Šresolution of LapA are described. Combined with biochemical and enzymatic characterization, the structure of this intriguing phosphate-binding protein will help to elucidate the molecular origin of its phosphatase activity and to decipher its putative role in phosphate uptake.


Subject(s)
Bacterial Proteins/chemistry , Phosphate-Binding Proteins/chemistry , Phosphoric Monoester Hydrolases/chemistry , Pseudomonas aeruginosa/enzymology , X-Ray Diffraction , Amino Acid Sequence , Crystallization , Crystallography, X-Ray , Molecular Sequence Data , Phylogeny
12.
Chem Cent J ; 7(1): 146, 2013 Sep 03.
Article in English | MEDLINE | ID: mdl-24004496

ABSTRACT

BACKGROUND: The development of whole smoke exposure systems have been driven by the fact that traditional smoke exposure techniques are based on the particulate phase of tobacco smoke and not the complete smoke aerosol. To overcome these challenges in this study, we used a Vitrocell® VC 10 whole smoke exposure system. For characterisation purposes, we determined smoke deposition in relationship to airflow (L/min), regional smoke deposition within the linear exposure module, vapour phase dilution using a known smoke marker (carbon monoxide) and finally assessed biological responses using two independent biological systems, the Ames and Neutral Red uptake (NRU) assay. RESULTS: Smoke dilution correlates with particulate deposition (R2 = 0.97) and CO concentration (R2 = 0.98). Regional deposition analysis within the linear exposure chamber showed no statistical difference in deposited mass across the chamber at any airflows tested. Biological analysis showed consistent responses and positive correlations with deposited mass for both the Ames (R2 = 0.76) and NRU (R2 = 0.84) assays. CONCLUSIONS: We conclude that in our study, under the experimental conditions tested, the VC 10 can produce stable tobacco smoke dilutions, as demonstrated by particulate deposition, measured vapour phase smoke marker delivery and biological responses from two independent in vitro test systems.

13.
PLoS One ; 8(8): e69623, 2013.
Article in English | MEDLINE | ID: mdl-23936341

ABSTRACT

Independent research groups reported that DING protein homologues isolated from bacterial, plant and human cells demonstrate the anti-HIV-1 activity. This might indicate that diverse organisms utilize a DING-mediated broad-range protective innate immunity response to pathogen invasion, and that this mechanism is effective also against HIV-1. We performed structural analyses and evaluated the anti-HIV-1 activity for four DING protein homologues isolated from different species. Our data show that bacterial PfluDING, plant p38SJ (pDING), human phosphate binding protein (HPBP) and human extracellular DING from CD4 T cells (X-DING-CD4) share high degrees of structure and sequence homology. According to earlier reports on the anti-HIV-1 activity of pDING and X-DING-CD4, other members of this protein family from bacteria and humans were able to block transcription of HIV-1 and replication of virus in cell based assays. The efficacy studies for DING-mediated HIV-1 LTR and HIV-1 replication blocking activity showed that the LTR transcription inhibitory concentration 50 (IC50) values ranged from 0.052-0.449 ng/ml; and the HIV-1 replication IC50 values ranged from 0.075-0.311 ng/ml. Treatment of cells with DING protein alters the interaction between p65-NF-κB and HIV-1 LTR. Our data suggest that DING proteins may be part of an innate immunity defense against pathogen invasion; the conserved structure and activity makes them appealing candidates for development of a novel therapeutics targeting HIV-1 transcription.


Subject(s)
HIV-1/genetics , Phylogeny , Polycomb Repressive Complex 1/pharmacology , Promoter Regions, Genetic/drug effects , Sequence Homology, Amino Acid , Terminal Repeat Sequences/genetics , Transcription, Genetic/drug effects , Amino Acid Sequence , Anti-HIV Agents/chemistry , Anti-HIV Agents/pharmacology , Cell Line, Tumor , Conserved Sequence , HIV-1/drug effects , HIV-1/physiology , Humans , Hypericum , Inhibitory Concentration 50 , Models, Molecular , Molecular Sequence Data , NF-kappa B p50 Subunit/chemistry , Polycomb Repressive Complex 1/chemistry , Promoter Regions, Genetic/genetics , Protein Multimerization/drug effects , Protein Structure, Quaternary , Pseudomonas fluorescens , Transcription Factor RelA/chemistry , Virus Replication/drug effects
14.
Virol J ; 10: 234, 2013 Jul 15.
Article in English | MEDLINE | ID: mdl-23855931

ABSTRACT

BACKGROUND: Anti-HIV-1 therapy depends upon multiple agents that target different phases of the viral replication cycle. Recent reports indicate that plant and human DING proteins are unique in targeting viral gene transcription as the basis of their anti-HIV-1 therapy. METHODS: Two cloned DING genes from Pseudomonas were transiently expressed in human cells, and effects on NFκB-mediated transcription, HIV-1 transcription, and HIV-1 production were measured. RESULTS: Both DING proteins elevated NFκB-mediated transcription. In microglial cells, one protein, from P. aeruginosa PA14, suppressed HIV-1 transcription; the other protein, from P. fluorescens SBW25, was inactive. The PA14DING protein also reduces HIV-1 production in microglial cells. CONCLUSIONS: Structural differences between the two DING proteins highlight regions of the PA14DING protein essential to the anti-HIV-1 activity, and may guide the design of therapeutic agents.


Subject(s)
Bacterial Proteins/metabolism , Gene Expression Regulation , HIV-1/physiology , Transcription Factors/metabolism , Virus Replication , Bacterial Proteins/chemistry , Bacterial Proteins/genetics , Cell Line , HIV-1/immunology , Humans , Immunologic Factors/chemistry , Immunologic Factors/metabolism , Models, Molecular , Neuroglia/virology , Protein Conformation , Pseudomonas aeruginosa/genetics , Pseudomonas fluorescens/genetics , Transcription Factors/chemistry , Transcription Factors/genetics
15.
Article in English | MEDLINE | ID: mdl-23545651

ABSTRACT

DING proteins form an emergent family of proteins consisting of an increasing number of homologues that have been identified in all kingdoms of life. They belong to the superfamily of phosphate-binding proteins and exhibit a high affinity for phosphate. In eukaryotes, DING proteins have been isolated by virtue of their implication in several diseases and biological processes. Some of them are potent inhibitors of HIV-1 replication/transcription, raising the question of their potential involvement in the human defence system. Recently, a protein from Pseudomonas aeruginosa strain PA14, named PA14DING or LapC, belonging to the DING family has been identified. The structure of PA14DING, combined with detailed biochemical characterization and comparative analysis with available DING protein structures, will be helpful in understanding the structural determinants implicated in the inhibition of HIV-1 by DING proteins. Here, the expression, purification and crystallization of PA14DING and the collection of X-ray data to 1.9 Šresolution are reported.


Subject(s)
Bacterial Proteins/chemistry , Phosphate-Binding Proteins/chemistry , Pseudomonas aeruginosa/chemistry , Amino Acid Sequence , Base Sequence , Crystallization , Crystallography, X-Ray , Molecular Sequence Data
16.
Acta Crystallogr Sect F Struct Biol Cryst Commun ; 66(Pt 12): 1647-51, 2010 Dec 01.
Article in English | MEDLINE | ID: mdl-21139216

ABSTRACT

Zebrafish (Danio rerio) are an important developmental and embryological model given the optical clarity of the embryos and larvae, which permits real-time viewing of developing pathologies. More recently, a broader scope for these vertebrates to model a range of human diseases, including some cancers, has been indicated. Zebrafish Drgal1-L2 has been identified as an orthologue of mammalian galectin-1, which is is a carbohydrate-binding protein that exhibits ß-galactoside-binding specificity and which is overexpressed by many aggressive human cancers. This study describes the cloning, expression in Escherichia coli, purification and crystallization of recombinant Drgal1-L2 protein in the presence of lactose (ligand). X-ray diffraction data from these novel crystals of zebrafish Drgal1-L2 were collected to a resolution of 1.5 Šusing a synchrotron-radiation source, enabling their characterization.


Subject(s)
Galectins/chemistry , Zebrafish Proteins/chemistry , Zebrafish/metabolism , Animals , Chromatography, Affinity , Chromatography, Gel , Crystallization , Crystallography, X-Ray , Electrophoresis, Polyacrylamide Gel , Humans , Lactose/chemistry
17.
J Popul Ther Clin Pharmacol ; 17(3): e358-62, 2010.
Article in English | MEDLINE | ID: mdl-21041869

ABSTRACT

The cornerstone of Canadian response to the pandemic H1N1 outbreak was the Canadian Pandemic Influenza Plan. The Plan was based on a moderate scenario, articulated around 7 pillars: surveillance, antiviral drugs, vaccines, public health measures, clinical care, communications, and research. This presentation provides an overview of Canada's response to pandemic H1N1. It presents the context (Who did what? How? …), what happened (focusing on pregnant women), addresses making decisions together, and includes some post-H1N1 reflections.


Subject(s)
Influenza A Virus, H1N1 Subtype , Influenza, Human/prevention & control , Pandemics , Antiviral Agents/therapeutic use , Canada/epidemiology , Decision Making , Female , Humans , Influenza Vaccines/administration & dosage , Influenza, Human/epidemiology , Population Surveillance/methods , Pregnancy , Public Health Practice
18.
J Am Chem Soc ; 131(22): 7879-86, 2009 Jun 10.
Article in English | MEDLINE | ID: mdl-19445459

ABSTRACT

PfluDING is a bacterial protein isolated from Pseudomonas fluorescens that belongs to the DING protein family, which is ubiquitous in eukaryotes and extends to prokaryotes. DING proteins and PfluDING have very similar topologies to phosphate Solute Binding Proteins (SBPs). The three-dimensional structure of PfluDING was obtained at subangstrom resolution (0.88 and 0.98 A) at two different pH's (4.5 and 8.5), allowing us to discuss the hydrogen bond network that sequesters the phosphate ion in the binding site. From this high resolution data, we experimentally elucidated the molecular basis of phosphate binding in phosphate SBPs. The phosphate ion is tightly bound to the protein via 12 hydrogen bonds between phosphate oxygen atoms and OH and NH groups of the protein. The proton on one oxygen atom of the phosphate dianion forms a 2.5 A low barrier hydrogen bond with an aspartate, with the energy released by forming this strong bond ensuring the specificity for the dianion even at pH 4.5. In particular, contrary to previous theories on phosphate SBPs, accurate electrostatic potential calculations show that the binding cleft is positively charged. PfluDING structures reveal that only dibasic phosphate binds to the protein at both acidic and basic phosphate, suggesting that the protein binding site environment stabilizes the HPO(4)(2-) form of phosphate.


Subject(s)
Bacterial Proteins/chemistry , Phosphate-Binding Proteins/chemistry , Phosphates/chemistry , Bacterial Proteins/metabolism , Binding Sites , Crystallography, X-Ray , Models, Molecular , Phosphate-Binding Proteins/metabolism , Phosphates/metabolism , Protein Binding , Pseudomonas fluorescens/chemistry , Pseudomonas fluorescens/metabolism , Static Electricity
19.
Bioessays ; 31(5): 570-80, 2009 May.
Article in English | MEDLINE | ID: mdl-19360767

ABSTRACT

PstS and DING proteins are members of a superfamily of secreted, high-affinity phosphate-binding proteins. Whereas microbial PstS have a well-defined role in phosphate ABC transporters, the physiological function of DING proteins, named after their DINGGG N termini, still needs to be determined. PstS and DING proteins co-exist in some Pseudomonas strains, to which they confer a highly adhesive and virulent phenotype. More than 30 DING proteins have now been purified, mostly from eukaryotes. They are often associated with infections or with dysregulation of cell proliferation. Consequently, eukaryotic DING proteins could also be involved in cell-cell communication or adherence. The ubiquitous presence in eukaryotes of proteins structurally and functionally related to bacterial virulence factors is intriguing, as is the absence of eukaryotic genes encoding DING proteins in databases. DING proteins in eukaryotes could originate from unidentified commensal or symbiotic bacteria and could contribute to essential functions. Alternatively, DING proteins could be encoded by eukaryotic genes sharing special features that prevent their cloning. Both hypotheses are discussed.


Subject(s)
ATP-Binding Cassette Transporters/genetics , ATP-Binding Cassette Transporters/metabolism , Phosphate-Binding Proteins/genetics , Phosphate-Binding Proteins/metabolism , Animals , Eukaryotic Cells , Humans , Models, Theoretical , Pseudomonas/genetics , Pseudomonas/metabolism , Pseudomonas/pathogenicity
20.
Cell Mol Life Sci ; 66(14): 2205-18, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19290474

ABSTRACT

DING proteins, identified mainly by their eponymous N-terminal sequences, are ubiquitous in living organisms. Amongst bacteria, they are common in pseudomonads, and have been characterised with respect to genetics and structure. They form part of a wider family of phosphate-binding proteins, with emerging roles in phosphate acquisition and pathogenicity. Many DING proteins have been isolated in eukaryotes, in which they have been associated with very diverse biological activities, often in the context of possible signalling roles. Disease states in which DING proteins have been implicated include rheumatoid arthritis, lithiasis, atherosclerosis, some tumours and tumour-associated cachexia, and bacterial and viral adherence. Complete genetic and structural characterisation of eukaryotic DING genes and proteins is still lacking, though the phosphate-binding site seems to be conserved. Whether as bacterial proteins related to bacterial pathogenicity, or as eukaryotic components of biochemical signalling systems, DING proteins require further study.


Subject(s)
DNA-Binding Proteins , Disease , Escherichia coli Proteins , Health , Repressor Proteins , Ubiquitin-Protein Ligases , Animals , DNA-Binding Proteins/chemistry , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Escherichia coli Proteins/chemistry , Escherichia coli Proteins/genetics , Escherichia coli Proteins/metabolism , Forecasting , Humans , Models, Molecular , Polycomb Repressive Complex 1 , Protein Binding/genetics , Protein Structure, Tertiary/genetics , Repressor Proteins/chemistry , Repressor Proteins/genetics , Repressor Proteins/metabolism , Structure-Activity Relationship , Ubiquitin-Protein Ligases/chemistry , Ubiquitin-Protein Ligases/genetics , Ubiquitin-Protein Ligases/metabolism
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