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1.
Frontline Gastroenterol ; 14(3): 201-221, 2023.
Article in English | MEDLINE | ID: mdl-37056319

ABSTRACT

Introduction: In the UK, endoscopy certification is awarded when trainees attain minimum competency standards for independent practice. A national evidence-based review was undertaken to update and develop standards and recommendations for colonoscopy training and certification. Methods: Under the oversight of the Joint Advisory Group (JAG), a modified Delphi process was conducted between 2019 and 2020 with multisociety expert representation. Following literature review and Grading of Recommendations, Assessment, Development and Evaluations appraisal, recommendation statements on colonoscopy training and certification were formulated and subjected to anonymous voting to obtain consensus. Accepted statements were peer reviewed by JAG and relevant stakeholders for incorporation into the updated colonoscopy certification pathway. Results: In total, 45 recommendation statements were generated under the domains of: definition of competence (13), acquisition of competence (20), assessment of competence (8) and postcertification support (4). The consensus process led to revised criteria for colonoscopy certification, comprising: (1) achieving key performance indicators defined within British Society of Gastroenterology standards (ie, unassisted caecal intubation rate >90%, rectal retroversion >90%, polyp detection rate >15%+, polyp retrieval rate >90%, patient comfort <10% with moderate-severe discomfort); (2) minimum procedure count 280+; (3) performing 15+ procedures over the preceding 3 months; (4) attendance of the JAG Basic Skills in Colonoscopy course; (5) terminal ileal intubation rates of 60%+ in inflammatory bowel disease; (6) satisfying requirements for formative direct observation of procedure skills (DOPS) and direct observation of polypectomy skills (Size, Morphology, Site, Access (SMSA) level 2); (7) evidence of reflective practice as documented on the JAG Endoscopy Training System reflection tool; (8) successful performance in summative DOPS. Conclusion: The UK standards for training and certification in colonoscopy have been updated, culminating in a single-stage certification process with emphasis on polypectomy competency (SMSA Level 2+). These standards are intended to support training, improve standards of colonoscopy and polypectomy, and provide support to the newly independent practitioner.

2.
Frontline Gastroenterol ; 14(3): 181-200, 2023.
Article in English | MEDLINE | ID: mdl-37056324

ABSTRACT

Introduction: Joint Advisory Group (JAG) certification in endoscopy is awarded when trainees attain minimum competency standards for independent practice. A national evidence-based review was undertaken to update standards for training and certification in flexible sigmoidoscopy (FS). Methods: A modified Delphi process was conducted between 2019 and 2020 with multisociety representation from experts and trainees. Following literature review and Grading of Recommendations, Assessment, Development and Evaluations appraisal, recommendation statements on FS training and certification were formulated and subjected to anonymous voting to obtain consensus. Accepted statements were peer-reviewed by national stakeholders for incorporation into the JAG FS certification pathway. Results: In total, 41 recommendation statements were generated under the domains of: definition of competence (13), acquisition of competence (17), assessment of competence (7) and postcertification support (4). The consensus process led to revised criteria for colonoscopy certification, comprising: (A) achieving key performance indicators defined within British Society of Gastroenterology standards (ie, rectal retroversion >90%, polyp retrieval rate >90%, patient comfort <10% with moderate-severe discomfort); (B) minimum procedure count ≥175; (C) performing 15+ procedures over the preceding 3 months; (D) attendance of the JAG Basic Skills in Lower gastrointestinal Endoscopy course; (E) satisfying requirements for formative direct observation of procedural skill (DOPS) and direct observation of polypectomy skill (SMSA level 1); (F) evidence of reflective practice as documented on the JAG Endoscopy Training System reflection tool and (G) successful performance in summative DOPS. Conclusion: The UK standards for training and certification in FS have been updated to support training, uphold standards in FS and polypectomy, and provide support to the newly independent practitioner.

3.
Lancet Infect Dis ; 22(11): e327-e335, 2022 11.
Article in English | MEDLINE | ID: mdl-35594896

ABSTRACT

Schistosomiasis is a helminthiasis infecting approximately 250 million people worldwide. In 2001, the World Health Assembly (WHA) 54.19 resolution defined a new global strategy for control of schistosomiasis through preventive chemotherapy programmes. This resolution culminated in the 2006 WHO guidelines that recommended empirical treatment by mass drug administration with praziquantel, predominately to school-aged children in endemic settings at regular intervals. Since then, school-based and community-based preventive chemotherapy programmes have been scaled-up, reducing schistosomiasis-associated morbidity. Over the past 15 years, new scientific evidence-combined with a more ambitious goal of eliminating schistosomiasis and an increase in the global donated supply of praziquantel-has highlighted the need to update public health guidance worldwide. In February, 2022, WHO published new guidelines with six recommendations to update the global public health strategy against schistosomiasis, including expansion of preventive chemotherapy eligibility from the predominant group of school-aged children to all age groups (2 years and older), lowering the prevalence threshold for annual preventive chemotherapy, and increasing the frequency of treatment. This Review, written by the 2018-2022 Schistosomiasis Guidelines Development Group and its international partners, presents a summary of the new WHO guideline recommendations for schistosomiasis along with their historical context, supporting evidence, implications for public health implementation, and future research needs.


Subject(s)
Anthelmintics , Helminthiasis , Schistosomiasis , Child , Humans , Child, Preschool , Praziquantel/therapeutic use , Schistosomiasis/drug therapy , Schistosomiasis/epidemiology , Schistosomiasis/prevention & control , Helminthiasis/drug therapy , Mass Drug Administration , Prevalence , World Health Organization , Anthelmintics/therapeutic use
4.
World J Gastroenterol ; 26(23): 3283-3292, 2020 Jun 21.
Article in English | MEDLINE | ID: mdl-32684742

ABSTRACT

BACKGROUND: The Joint Advisory Group on Gastrointestinal Endoscopy basic skills in colonoscopy (BSC) course was introduced in 2009 to improve colonoscopy training within the United Kingdom, but its impact on trainee performance is unknown. AIM: To assess whether attendance of the BSC could improve colonoscopy performance. METHODS: Trainees awarded colonoscopy certification between 2011-2016 were stratified into 3 groups according to pre-course procedure count (< 70, 70-140 and > 140). Study outcomes, comprising the unassisted caecal intubation rate (CIR) and the performance indicator of colonic intubation (PICI), were studied over the 50 procedures pre and post- course. Interrupted time series analyses were performed to detect step-change changes attributable to the course. RESULTS: A total of 369 trainees with pre-course procedure counts of < 70 (n = 118), 70-140 (n = 121) and > 140 (n = 130) were included. Over the 50 pre-course procedures, significant linear improvements in CIR were found, with average increases of 4.2, 3.6 and 1.7 percentage points (pp) per 10 procedures performed in the < 70, 70-140 and > 140 groups respectively (all P < 0.001). The < 70 procedures group saw a significant step-change improvement in CIR, increasing from 46% in the last pre-course procedure, to 51% in the first procedure post-course (P = 0.005). The CIR step-change was not significant in the 70-140 (68% to 71%; P = 0.239) or > 140 (86% to 87%; P = 0.354) groups. For PICI, significant step-change improvements were seen in all three groups, with average increases of 5.6 pp (P < 0.001), 5.4 pp (P = 0.003) and 3.9 pp (P = 0.014) respectively. CONCLUSION: Attendance of the BSC was associated with a significant step-change improvement in PICI, regardless of prior procedural experience. However, CIR data suggest that the optimal timing of course attendance appears to be at earlier stages of training (< 70 procedures).


Subject(s)
Clinical Competence , Colonoscopy , Cecum , Interrupted Time Series Analysis , United Kingdom
5.
Parasitology ; 136(12): 1611-9, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19691867

ABSTRACT

The expansion in the volume of research activity over the last 100 years and the acceleration of technological change that underpins the nature and, to a lesser extent, the quality of the science we do, means that those in science today have little time, or indeed opportunity, for reflection on some of the pioneering efforts within their fields. From the first discovery of schistosome parasites in Egypt in 1851 by Theodor Bilharz, research on schistosomiasis has provided valuable insights into many wider aspects of biology and medicine and has attracted an array of colourful and dynamic scientists who have made major advances through elegant experimentation.


Subject(s)
Biomedical Research , Schistosoma , Schistosomiasis , Animals , Cattle , Female , Humans , Male , Schistosoma/classification , Schistosoma/growth & development , Schistosoma/immunology , Schistosoma/physiology , Schistosomiasis/immunology , Schistosomiasis/parasitology , Schistosomiasis/pathology , Schistosomiasis/prevention & control , Vaccines
6.
Parasitology ; 136(11): 1243-50, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19646303

ABSTRACT

An attenuated line of Leishmania major (L. major H-line) has been established by culturing promastigotes in vitro under gentamicin pressure. A modification of the previously described method for the generation of attenuated L. major is described, giving rise to attenuated parasites after 8 rather than 12 subpassages. No lesions developed in BALB/c mice infected with L. major H-line, whereas L. major wild-type (WT) induced a Th2 like response with progressive lesions. Analysis of splenocyte IFN-gamma and IL-4 production following stimulation with promastigotes shows that the L. major H-line preferentially induces Th1-like responses and possibly down-regulates Th2 responses in BALB/c mice. L. major H-line parasites remained localized in the skin and draining lymph node, whereas L. major WT parasites disseminated into the visceral organs of BALB/c mice. Mice infected with L. major H-line acquired some resistance against L. major WT. These results show that the attenuated cell line of L. major is not only avirulent but that it may also modulate the host immune response.


Subject(s)
Leishmania major/immunology , Leishmania major/pathogenicity , Leishmaniasis, Cutaneous/immunology , Th1 Cells/immunology , Animals , Antibodies, Protozoan/blood , CD4-Positive T-Lymphocytes/immunology , Cells, Cultured , Female , Gentamicins/pharmacology , Humans , Interferon-gamma/immunology , Interleukin-4/immunology , Leishmania major/drug effects , Leishmania major/growth & development , Leishmaniasis, Cutaneous/parasitology , Leishmaniasis, Cutaneous/pathology , Macrophages, Peritoneal/immunology , Macrophages, Peritoneal/parasitology , Mice , Mice, Inbred BALB C , Vaccination , Virulence
7.
Vet Immunol Immunopathol ; 129(1-2): 28-35, 2009 May 15.
Article in English | MEDLINE | ID: mdl-19147233

ABSTRACT

The clinicopathological changes following infection with an attenuated line of Leishmania infantum (L. infantum H-line) were evaluated in mixed breed dogs. Two groups of dogs were infected intravenously (i.v.) or intradermally (i.d.) with L. infantum H-line and two control groups were infected i.v. or i.d. with L. infantum wild-type (L. infantum WT). None of the dogs, which were infected i.v. or i.d. with L. infantum H-line, showed any abnormalities during the observation period. In contrast, two out of three dogs, which were infected i.v. with L. infantum WT, developed clinical signs of disease. In addition, no histopathological changes were seen in the liver and spleen of the dogs infected with the attenuated line of parasite, whereas the histopathological changes in the two dogs infected i.v. with L. infantum WT were severe in form and manifested by infiltration of high numbers of inflammatory cells. No promastigotes were found in cultures set up from spleens and livers of dogs infected with L. infantum H-line at 12 months post-infection, whereas promastigotes were seen in the spleen and liver cultures from 2 dogs infected i.v. with L. infantum WT. Serum levels of total IgG anti-Leishmania antibody were raised in all dogs. The antibody level in the serum of dogs infected i.v. with L. infantum WT was higher than that in dogs infected with L. infantum H-line. These results show no clinicopathological abnormalities in the dogs infected with gentamicin-attenuated L. infantum H-line. Moreover, L. infantum H-line induced IgG anti-Leishmania antibody in the dogs.


Subject(s)
Dog Diseases/parasitology , Gentamicins/pharmacology , Immunization/veterinary , Leishmania infantum/drug effects , Leishmaniasis, Visceral/veterinary , Protozoan Vaccines/immunology , Animals , Antibodies, Protozoan/blood , Dog Diseases/pathology , Dog Diseases/prevention & control , Dogs , Double-Blind Method , Female , Histocytochemistry/veterinary , Immunization/methods , Immunoglobulin G/blood , Leishmania infantum/immunology , Leishmania infantum/pathogenicity , Leishmaniasis, Visceral/parasitology , Leishmaniasis, Visceral/pathology , Leishmaniasis, Visceral/prevention & control , Liver/parasitology , Male , Mice , Mice, Inbred BALB C , Random Allocation , Spleen/parasitology , Vaccines, Attenuated/immunology
8.
Astrobiology ; 17(5): 413-430, 2017 May.
Article in English | MEDLINE | ID: mdl-28520472

ABSTRACT

Thrombolites are buildups of carbonate that exhibit a clotted internal structure formed through the interactions of microbial mats and their environment. Despite recent advances, we are only beginning to understand the microbial and molecular processes associated with their formation. In this study, a spatial profile of the microbial and metabolic diversity of thrombolite-forming mats of Highborne Cay, The Bahamas, was generated by using 16S rRNA gene sequencing and predictive metagenomic analyses. These molecular-based approaches were complemented with microelectrode profiling and in situ stable isotope analysis to examine the dominant taxa and metabolic activities within the thrombolite-forming communities. Analyses revealed three distinctive zones within the thrombolite-forming mats that exhibited stratified populations of bacteria and archaea. Predictive metagenomics also revealed vertical profiles of metabolic capabilities, such as photosynthesis and carboxylic and fatty acid synthesis within the mats that had not been previously observed. The carbonate precipitates within the thrombolite-forming mats exhibited isotopic geochemical signatures suggesting that the precipitation within the Bahamian thrombolites is photosynthetically induced. Together, this study provides the first look at the spatial organization of the microbial populations within Bahamian thrombolites and enables the distribution of microbes to be correlated with their activities within modern thrombolite systems. Key Words: Thrombolites-Microbial diversity-Metagenome-Stable isotopes-Microbialites. Astrobiology 17, 413-430.


Subject(s)
Bacteria , Metagenomics , Bahamas , Geologic Sediments , Isotopes , Phylogeny , RNA, Ribosomal, 16S
9.
BMC Public Health ; 6: 225, 2006 Sep 06.
Article in English | MEDLINE | ID: mdl-16956417

ABSTRACT

BACKGROUND: Intestinal parasitic infections are a public health problem in developing countries such as Mexico. As a result, two governmental programmes have been implemented: a) "National Deworming Campaign" and b) "Opportunities" aimed at maternal care. However, both programmes are developed separately and their impact is still unknown. We independently investigated whether a variety of socio-economic factors, including maternal education and employment levels, were associated with intestinal parasite infection in rural school children. METHODS: This cross-sectional study was conducted in 12 rural communities in two Mexican states. The study sites and populations were selected on the basis of the following traits: a) presence of activities by the national administration of albendazole, b) high rates of intestinal parasitism, c) little access to medical examination, and d) a population having less than 2,500 inhabitants. A total of 507 schoolchildren (mean age 8.2 years) were recruited and 1,521 stool samples collected (3 per child). Socio-economic information was obtained by an oral questionnaire. Regression modelling was used to determine the association of socio-economic indicators and intestinal parasitism. RESULTS: More than half of the schoolchildren showed poliparasitism (52%) and protozoan infections (65%). The prevalence of helminth infections was higher in children from Oaxaca (53%) than in those from Sinaloa (33%) (p < 0.0001). Giardia duodenalis and Hymenolepis nana showed a high prevalence in both states. Ascaris lumbricoides, Trichuris trichiura and Entamoeba hystolitica/dispar showed low prevalence. Children from lower-income families and with unemployed and less educated mothers showed higher risk of intestinal parasitism (odds ratio (OR) 6.0, 95% confidence interval (CI) 1.6-22.6; OR 4.5, 95% CI 2.5-8.2; OR 3.3, 95% CI 1.5-7.4 respectively). Defecation in open areas was also a high risk factor for infection (OR 2.4, 95% CI 2.0-3.0). CONCLUSION: Intestinal parasitism remains an important public health problem in Sinaloa (north-western Mexico) and Oaxaca (south-eastern Mexico). Lower income, defecation in open areas, employment status and a lower education level of mothers were the significant factors related to these infections. We conclude that mothers should be involved in health initiatives to control intestinal parasitism in Mexico.


Subject(s)
Employment/statistics & numerical data , Intestinal Diseases, Parasitic/epidemiology , Mothers/education , Rural Health/statistics & numerical data , Analysis of Variance , Animals , Ascariasis/epidemiology , Body Height , Body Weight , Child , Child Nutritional Physiological Phenomena , Employment/economics , Female , Giardiasis/epidemiology , Helminthiasis/epidemiology , Humans , Hygiene/education , Hymenolepiasis/epidemiology , Intestinal Diseases, Parasitic/parasitology , Male , Mexico/epidemiology , Parasite Egg Count , Prevalence , Schools
10.
BJPsych Open ; 2(3): 204-209, 2016 May.
Article in English | MEDLINE | ID: mdl-27703777

ABSTRACT

BACKGROUND: The widespread use of smartphones makes effective therapies such as cognitive-behavioural therapy (CBT) potentially accessible to large numbers of people. AIMS: This paper reports the usage data of the first trial of Catch It, a new CBT smartphone app. METHOD: Uptake and usage rates, fidelity of user responses to CBT principles, and impact on reported negative and positive moods were assessed. RESULTS: A relatively modest proportion of people chose to download the app. Once used, the app tended to be used more than once, and 84% of the user-generated content was consistent with the basic concepts of CBT. There were statistically significant reductions in negative mood intensity and increases in positive mood intensity. CONCLUSIONS: Smartphone apps have potential beneficial effects in mental health through the application of basic CBT principles. More research with randomised controlled trial designs should be conducted. DECLARATION OF INTEREST: None. COPYRIGHT AND USAGE: Ā© The Royal College of Psychiatrists 2016. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) licence.

11.
PLoS One ; 11(8): e0159256, 2016.
Article in English | MEDLINE | ID: mdl-27486857

ABSTRACT

BACKGROUND: Reducing health inequalities is an important policy objective but there is limited quantitative information about the impact of specific interventions. OBJECTIVES: To provide estimates of the impact of a range of interventions on health and health inequalities. MATERIALS AND METHODS: Literature reviews were conducted to identify the best evidence linking interventions to mortality and hospital admissions. We examined interventions across the determinants of health: a 'living wage'; changes to benefits, taxation and employment; active travel; tobacco taxation; smoking cessation, alcohol brief interventions, and weight management services. A model was developed to estimate mortality and years of life lost (YLL) in intervention and comparison populations over a 20-year time period following interventions delivered only in the first year. We estimated changes in inequalities using the relative index of inequality (RII). RESULTS: Introduction of a 'living wage' generated the largest beneficial health impact, with modest reductions in health inequalities. Benefits increases had modest positive impacts on health and health inequalities. Income tax increases had negative impacts on population health but reduced inequalities, while council tax increases worsened both health and health inequalities. Active travel increases had minimally positive effects on population health but widened health inequalities. Increases in employment reduced inequalities only when targeted to the most deprived groups. Tobacco taxation had modestly positive impacts on health but little impact on health inequalities. Alcohol brief interventions had modestly positive impacts on health and health inequalities only when strongly socially targeted, while smoking cessation and weight-reduction programmes had minimal impacts on health and health inequalities even when socially targeted. CONCLUSIONS: Interventions have markedly different effects on mortality, hospitalisations and inequalities. The most effective (and likely cost-effective) interventions for reducing inequalities were regulatory and tax options. Interventions focused on individual agency were much less likely to impact on inequalities, even when targeted at the most deprived communities.


Subject(s)
Health Promotion/methods , Health Status Disparities , Taxes/classification , Humans , Investments , Models, Theoretical , Mortality , Patient Admission/statistics & numerical data , Policy , United Kingdom
12.
Trends Microbiol ; 10(10 Suppl): S38-46, 2002.
Article in English | MEDLINE | ID: mdl-12377567

ABSTRACT

Models currently occupy the crucial first step in the research flow for the development of new drugs and vaccines. Some animal models are better at reflecting the host-pathogen interaction in humans than others; this depends on the pathogen and its host specificity. Data gathered from what are often poorly adapted models provide a mosaic of sometimes contradictory information, yet there is little incentive to better delineate the relevance of models or to exploit recent advances to develop improved ones. This review reports on three particularly intractable human pathogens - Mycobacterium, Plasmodium and Schistosoma - and reflects that the extent to which these model systems mimic infection and protection processes in humans might not be sufficiently well defined.


Subject(s)
Communicable Diseases/etiology , Disease Models, Animal , Animals , Communicable Disease Control/methods , Drug Design , Genomics/trends , Immunity, Innate , Mice , Mycobacterium tuberculosis/immunology , Proteomics/trends , Vaccines
13.
Trends Parasitol ; 20(2): 92-7, 2004 Feb.
Article in English | MEDLINE | ID: mdl-14747023

ABSTRACT

Despite the limited reports of praziquantel resistance, the relative success of chemotherapy-based control programmes for schistosomiasis has prompted overdue efforts to expand the use of cheap, generic, praziquantel in sub-Saharan Africa. The likely impact of such programmes on the development and spread of praziquantel resistance is uncertain, but this possibility reinforces the need for monitoring the spectrum of praziquantel sensitivity of schistosome populations and for an improved knowledge of the precise targets for the action of the drug. The search for alternatives to praziquantel and other tools for control of schistosomiasis must continue.


Subject(s)
Praziquantel/pharmacology , Schistosoma/drug effects , Schistosomiasis/prevention & control , Schistosomicides/pharmacology , Administration, Oral , Animals , Drug Resistance , Humans , Parasitic Sensitivity Tests , Praziquantel/therapeutic use , Schistosomiasis/drug therapy , Schistosomicides/therapeutic use , Tablets
14.
Expert Opin Biol Ther ; 3(8): 1271-8, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14640953

ABSTRACT

While there are many challenges in vaccine development, none is greater than that of developing vaccines against large metazoan parasites such as schistosomes, the parasitic worms that are responsible for schistosomiasis. Initial optimism stemming from the identification of the first vaccine candidate antigens that gave protection in animals has been dashed by the failure, as yet, of any of the vaccine candidate antigens to enter Phase III clinical trials. Now, despite an improved understanding of the biology of the parasites and of the immune responses they stimulate in naturally exposed populations, the vaccine effort is stalled. The control effort has switched heavily in favour of the wider use of conventional chemotherapy with praziquantel, which is now affordable by all but the poorest countries. Disagreements among researchers in the schistosome field as to whether or not a vaccine is needed have not helped convince funding agencies that schistosomiasis vaccines, rather than drugs, should be a priority. With the schistosome genome projects at an advanced stage plus the power of the proteomics, perhaps it is still too early to call time on schistosome vaccine development.


Subject(s)
Antigens, Helminth , Protozoan Vaccines , Schistosomiasis/prevention & control , Animals , Anthelmintics , Clinical Trials as Topic , Combined Modality Therapy , Humans , Praziquantel/therapeutic use , Schistosomiasis/epidemiology
15.
Acta Trop ; 83(2): 183-7, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12088860

ABSTRACT

The Kato-Katz technique is the method routinely used for diagnosing human schistosomiasis mansoni by estimating faecal egg burdens. To improve the sensitivity of faecal diagnosis, we established and validated a novel separation technique based upon the greater density of viable schistosome eggs relative to faecal material. Subsequently, it was used for faecal examination of 27 schistosomiasis patients in El-Sharkia, Egypt, with Kato-Katz smears as criterion standard. Low intensity infections (<100 eggs/g) were only detected by our technique. Moreover, triple Kato-Katz analysis on consecutive samples still missed 7.4% of all human patients, whereas the new method diagnosed 100% of samples correctly on second analysis. We conclude that in endemic areas many patients are being systematically missed by routine diagnosis. Moreover, the sensitivity of our method allows its use in proposed pre-clinical and clinical vaccine trials in non-human primates and humans, where reliable estimates of faecal egg counts are essential.


Subject(s)
Feces/parasitology , Parasite Egg Count/methods , Schistosoma mansoni/isolation & purification , Schistosomiasis/diagnosis , Animals , Humans , Reproducibility of Results
16.
J Proteomics ; 75(5): 1463-71, 2012 Feb 16.
Article in English | MEDLINE | ID: mdl-22154982

ABSTRACT

We have previously described an attenuated line of Leishmania infantum (H-line), selected by culturing promastigotes in vitro in the presence of gentamicin. To elucidate the molecular basis for this attenuation, we undertook a comparative proteomic analysis using multiplex 2-dimensional (2D) difference gel electrophoresis. Eighteen proteins that showed significant and reproducible changes in expression were identified. Many of these were components of the thiol-redox control system in Leishmania and this observation, validated by Western blot, prompted us to investigate the sensitivity of the attenuated line to oxidative stress. The attenuated line was found to be significantly more susceptible to hydrogen peroxide, a change which may explain the loss of virulence. In a direct assay of trypanothione-dependent peroxidase activity, hydrogen peroxide metabolism in the H-line was significantly lower than in wild type. Furthermore, trypanothione reductase activity was significantly lower in the H-line, suggesting that gentamicin selection may result in pleiotropic affects on thiol metabolism in Leishmania. A putative RNA-binding protein was very strongly up-regulated in the attenuated line, suggesting a possible target for gentamicin in Leishmania.


Subject(s)
Gene Expression Regulation/drug effects , Gentamicins/pharmacology , Leishmania infantum/metabolism , Protein Synthesis Inhibitors/pharmacology , Proteomics , Protozoan Proteins/biosynthesis , Hydrogen Peroxide/metabolism , Hydrogen Peroxide/pharmacology , Leishmania infantum/genetics , Oxidants/metabolism , Oxidants/pharmacology , Protozoan Proteins/genetics
18.
J Egypt Soc Parasitol ; 39(3): 769-87, 2009 Dec.
Article in English | MEDLINE | ID: mdl-20120744

ABSTRACT

Although Egypt has very high rates of HCV, not much is known about genotype 4a which is the most predominant genotype in Egypt. In the present study, core (C_ED43) gene of the Egyptian strain ED43 of HCV genotype 4a was first analyzed using PC/GENE program. Computer analysis of Core region of the isolate ED43 revealed that the Egyptian genotype 4a is different from those isolated from Europe and Central Africa and that it is closely related to genotype 1b. The DNA region coding for the Core was amplified from HCV_ED43/PUC19 plasmid. The PCR product was then cloned and expressed in E. coli M15 using pQE-30 vector. The expression and antigenicity of the core (Core_4a) protein in E. coli was confirmed by SDS-PAGE and western blotting, which will make it useful for developing assay systems for detecting anti-HCV antibodies and HCV antigen, respectively and which might help in the design of a vaccine against the Egyptian genotype 4a.


Subject(s)
Hepacivirus/genetics , Hepatitis C/virology , Viral Core Proteins/genetics , Amino Acid Sequence , Antibodies, Viral , Antigens, Viral , Base Sequence , Cloning, Molecular , Escherichia coli/genetics , Genotype , Hepacivirus/chemistry , Humans , Molecular Sequence Data , Polymerase Chain Reaction , Recombinant Proteins/biosynthesis , Viral Core Proteins/immunology , Viral Core Proteins/metabolism
19.
J Egypt Soc Parasitol ; 39(3): 865-80, 2009 Dec.
Article in English | MEDLINE | ID: mdl-20120752

ABSTRACT

Clone and express NS3 gene of the Egyptian strain ED43 of HCV genotype 4a in E. coli was studied. Gene and protein sequences of NS3 gene of the ED43 strain were first analyzed using PC/GENE program. DNA homology was 89% the homologies and that of the protein was 78.8% indicating that NS3 gene of the genotype 4a is different from those isolated from other strains. DNA of NS3 region of genotype 4a was amplified from HCV_ED43/PUC19 plasmid. The PCR product was cloned and expressed in E. coli M15 using pQE-30 vector. Fusion protein containing the peptides coded by HCV NS3 (NS3_4a) was expressed by Escherichia coli. The specific HCV antigenicity of the NS3_4a fusion protein was identified by western blotting.


Subject(s)
Cloning, Molecular , Hepacivirus/genetics , Hepatitis C/virology , Viral Core Proteins/genetics , Viral Nonstructural Proteins/genetics , Amino Acid Sequence , Base Sequence , DNA, Viral/genetics , Escherichia coli/virology , Genotype , Humans , Polymerase Chain Reaction
20.
Parasite Immunol ; 25(11-12): 589-96, 2003.
Article in English | MEDLINE | ID: mdl-15053780

ABSTRACT

An attenuated line of Leishmania mexicana (the L. mexicana H-line) has been established by culturing in vitro under gentamicin pressure. BALB/c mice infected with the L. mexicana H-line developed a CD4(+)Th1-like response, indicated by the cytokine profile of their splenocytes stimulated by L. mexicana wild-type (WT) promastigotes. This profile is sustained after these mice are challenged with L. mexicana WT. Control mice infected with L. mexicana WT alone developed a CD4(+)Th2-like cytokine profile. In mice immunized with L. mexicana H-line and then challenged with WT-line, were eliminated when immunizing H-line parasites persisted in the skin and draining popliteal lymph nodes (PLNs). In experiments in which mice were inoculated with attenuated and WT parasites at the same time, either at the same site or on separate sides of the mouse, growth of the WT parasites was significantly contained and controlled, indicating a possible therapeutic role for the attenuated parasites.


Subject(s)
Gentamicins/pharmacology , Leishmania mexicana/drug effects , Leishmania mexicana/immunology , Leishmaniasis, Cutaneous/immunology , Leishmaniasis, Cutaneous/prevention & control , Th1 Cells/immunology , Animals , Antibodies, Protozoan/blood , Cytokines/biosynthesis , Female , Immunoglobulin G/blood , In Vitro Techniques , Leishmaniasis, Cutaneous/parasitology , Lymphocyte Activation , Mice , Mice, Inbred BALB C , Protozoan Vaccines/pharmacology , Vaccines, Attenuated/pharmacology
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