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Tran VT, Perrodeau E, Saldanha J, Pane I, Ravaud P. Efficacy of first dose of covid-19 vaccine versus no vaccination on symptoms of patients with long covid: target trial emulation based on ComPaRe e-cohort. BMJ Med 2023; 2:e000229. [PMID: 36910458 PMCID: PMC9978748 DOI: 10.1136/bmjmed-2022-000229] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 11/25/2022] [Indexed: 03/04/2023]
Abstract
Objective To evaluate the effect of covid-19 vaccination on the severity of symptoms in patients with long covid. Design Target trial emulation based on ComPaRe e-cohort. Data source ComPaRe long covid cohort, a nationwide e-cohort (ie, a cohort where recruitment and follow-up are performed online) of patients with long covid, in France. Methods Adult patients (aged ≥18 years) enrolled in the ComPaRe cohort before 1 May 2021 were included in the study if they reported a confirmed or suspected SARS-CoV-2 infection, symptoms persistent for >3 weeks after onset, and at least one symptom attributable to long covid at baseline. Patients who received a first covid-19 vaccine injection were matched with an unvaccinated control group in a 1:1 ratio according to their propensity scores. Number of long covid symptoms, rate of complete remission of long covid, and proportion of patients reporting an unacceptable symptom state at 120 days were recorded. Results 910 patients were included in the analyses (455 in the vaccinated group and 455 in the control group). By 120 days, vaccination had reduced the number of long covid symptoms (mean 13.0 (standard deviation 9.4) in the vaccinated group v 14.8 (9.8) in the control group; mean difference -1.8, 95% confidence interval -3.0 to -0.5) and doubled the rate of patients in remission (16.6% v 7.5%, hazard ratio 1.93, 95% confidence interval 1.18 to 3.14). Vaccination reduced the effect of long covid on patients' lives (mean score on the impact tool 24.3 (standard deviation 16.7) v 27.6 (16.7); mean difference -3.3, 95% confidence interval -5.7 to -1.0) and the proportion of patients with an unacceptable symptom state (38.9% v 46.4%, risk difference -7.4%, 95% confidence interval -14.5% to -0.3%). In the vaccinated group, two (0.4%) patients reported serious adverse events requiring admission to hospital. Conclusion In this study, covid-19 vaccination reduced the severity of symptoms and the effect of long covid on patients' social, professional, and family lives at 120 days in those with persistent symptoms of infection.
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Affiliation(s)
- Viet-Thi Tran
- Université Paris Cité and Université Sorbonne Paris Nord, Inserm, INRAE, Center for Research in Epidemiology and StatisticS (CRESS), F-75004 Paris, France.,Centre d'Epidémiologie Clinique, AP-HP, Hôpital Hôtel Dieu, F-75004 Paris, France
| | - Elodie Perrodeau
- Centre d'Epidémiologie Clinique, AP-HP, Hôpital Hôtel Dieu, F-75004 Paris, France
| | | | - Isabelle Pane
- Centre d'Epidémiologie Clinique, AP-HP, Hôpital Hôtel Dieu, F-75004 Paris, France
| | - Philippe Ravaud
- Centre d'Epidémiologie Clinique, AP-HP, Hôpital Hôtel Dieu, F-75004 Paris, France.,Université Paris Cité, Paris, France.,Department of Epidemiology, Columbia University Mailman School of Public Health, New York, New York, USA
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Hughes R, Massie E, Saldanha J, Komolafe S, Chapman R, Kirk A, Vella M, Moug S, MacArthur C, Mackie H. 294 Implementation of Colorectal Robotic Assisted Surgical Programme During a Global Pandemic: Collaboration Between Territorial and National Waiting Times Centre. Br J Surg 2022. [DOI: 10.1093/bjs/znac039.194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
Introduction
Golden Jubilee National Hospital (GJNH) established a thoracic Robotic Assisted Surgical (RAS) programme in 2018. In March 2021, GJNH invested in a new elective colorectal service and in response to the Scottish Government robotic investment established a collaboration with a territorial health board to host their robot and start a RAS colorectal programme. We provide an overview of barriers and facilitators leading to establishing this new collaboration.
Method
An observational review of RAS training timeline. Demographics, surgical operations, and hospital length of stay were documented. Surgeons, perioperative team, management, and industry (Intuitive) were interviewed to provide insights into implementation and training.
Results
Boards approved RAS business case in April 2021, robot on-site with GJNH governance approval in May. First cohort of colorectal surgeons completed proctored training July 2021. To date, 17 RAS resections performed (mean age 64, 9 males: 8 female). Mean length of stay 4.65 days. No anastomotic leaks and no mortality reported. Interviews revealed key facilitators: advantage of having an established RAS perioperative team and building on pre-existing industry links; developing and strengthening collaborative working between different health boards and surgeons. Barriers included: education of all team members to ensure patient safety for new specialty; multisite collaborative working.
Conclusions
This work provides a template model for future RAS collaborations between different sites and health boards. Collaborative working in a green-hospital setting may improve equity of access for patients whilst future-proofing surgery against further waves of the pandemic.
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Affiliation(s)
- R. Hughes
- Golden Jubilee National Hospital, Glasgow, United Kingdom
| | - E. Massie
- Golden Jubilee National Hospital, Glasgow, United Kingdom
| | | | | | - R. Chapman
- Golden Jubilee National Hospital, Glasgow, United Kingdom
| | - A. Kirk
- Golden Jubilee National Hospital, Glasgow, United Kingdom
| | - M. Vella
- Golden Jubilee National Hospital, Glasgow, United Kingdom
| | - S. Moug
- Golden Jubilee National Hospital, Glasgow, United Kingdom
| | - C. MacArthur
- Golden Jubilee National Hospital, Glasgow, United Kingdom
| | - H. Mackie
- Golden Jubilee National Hospital, Glasgow, United Kingdom
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Khan KS, Reed-Embleton H, Lewis J, Saldanha J, Mahmud S. Does nosocomial COVID-19 result in increased 30-day mortality? A multi-centre observational study to identify risk factors for worse outcomes in patients with COVID-19. J Hosp Infect 2021; 107:91-94. [PMID: 32950587 PMCID: PMC7495174 DOI: 10.1016/j.jhin.2020.09.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 09/14/2020] [Indexed: 01/10/2023]
Abstract
This study aimed to determine whether nosocomial coronavirus disease 2019 (COVID-19) has a worse outcome compared with community-acquired COVID-19. This was a prospective cohort study of all hospitalized patients with confirmed COVID-19 in three acute hospitals on 9th April 2020. Patients were followed-up for at least 30 days. Nosocomial infection was defined as a positive swab after 7 days of admission. In total, one hundred and seventy-three patients were identified, and 19 (11.0%) had nosocomial infection. Thirty-two (18.5%) patients died within 30 days (all cause) of a positive swab test; there were no significant differences in 30-day all-cause mortality rates between the three groups (i.e. patients admitted with suspected COVID-19, patients with incidental COVID-19 and patients with nosocomial COVID-19): 21.1% vs 17.6% vs 21.6% (P=0.755). Nosocomial COVID-19 is not associated with increased mortality compared with community-acquired COVID-19.
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Affiliation(s)
- K S Khan
- Department of General Surgery, University Hospital Hairmyres, East Kilbride, UK.
| | - H Reed-Embleton
- Department of Medicine, University Hospital Hairmyres, East Kilbride, UK
| | - J Lewis
- Medical Statistics/Design, Trials and Statistics, School of Health and Related Research, University of Sheffield, Sheffield, UK
| | - J Saldanha
- Department of General Surgery, University Hospital Hairmyres, East Kilbride, UK
| | - S Mahmud
- Department of General Surgery, University Hospital Hairmyres, East Kilbride, UK
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Barnes J, Saldanha J, Lucera E. Preclinical pilot study results of 24-h apomorphine subcutaneous infusion delivered via the h-Patch wearable device. J Neurol Sci 2019. [DOI: 10.1016/j.jns.2019.10.1447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Iddles E, Macleod A, Wood C, Alex V, Saldanha J. WhatsAppTM with surgical training? Int J Surg 2018. [DOI: 10.1016/j.ijsu.2018.05.513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Rogers P, Saldanha J, Allain J. Report of EPFA/NIBSC Workshop 'Nucleic Acid Amplification Tests (NAT) for the Detection of Blood-Borne Viruses' Held on 31 October 1996 in Amsterdam, The Netherlands. Vox Sang 2017. [DOI: 10.1159/000461994] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Saldanha J, Minor P. Collaborative Study to Assess the Suitability of an HCV RNA Reference Sample for Detection of an HCV RNA in Plasma Pools by PCR. Vox Sang 2017. [DOI: 10.1159/000462102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Saldanha J, Minor P. Collaborative Study to Assess the
Suitability of a Proposed Working
Reagent for Human Parvovirus B19
DNA Detection in Plasma Pools by
Gene Amplification Techniques. Vox Sang 2017. [DOI: 10.1159/000461935] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Yu Y, Ma C, Sun X, Guan X, Zhang X, Saldanha J, Chen L, Wang D. Frequencies of red blood cell major blood group antigens and phenotypes in the Chinese Han population from Mainland China. Int J Immunogenet 2016; 43:226-35. [PMID: 27320061 DOI: 10.1111/iji.12277] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 05/09/2016] [Accepted: 05/19/2016] [Indexed: 11/30/2022]
Abstract
Alloantibodies directed to red blood cell (RBC) antigens play an important role in alloimmune-mediated haemolytic transfusion reactions and haemolytic disease of the foetus and newborn. The frequencies and phenotypes of RBC antigens are different in populations from different geographic areas and races. However, the data on major blood group antigens in the Chinese Han population from Mainland China are still very limited; thus, we aimed to investigate them in this study. A total of 1412 unrelated voluntary Chinese Han blood donors were randomly recruited. All donors were typed for blood group antigens: D, C, c, E, e, C(w) , Jk(a) , Jk(b) ,M, N, S, s, Le(a) , Le(b) , K, k. Kp(a) , Kp(b) , Fy(a) , Fy(b) , Lu(a) , Lu(b) , P1 and Di(a) using serological technology. Calculations of antigen and phenotype frequencies were expressed as percentages and for allele frequencies under the standard assumption of Hardy-Weinberg equilibrium. Amongst the Rh antigens, D was the most common (98.94%) followed by e (92.28%), C (88.81%), c (58.43%), E (50.78%) and C(w) (0.07%) with DCe/DCe (R1 R1 , 40.72%) being the most common phenotype. In the Kell blood group system, k was present in 100% of the donors and a rare phenotype, Kp (a+b+), was found in 0.28% of the donors. For the Kidd and Duffy blood group systems, Jk (a+b+) and Fy (a+b-) were the most common phenotypes (44.05% and 84.35%, respectively). In the MNS blood group system, M+N+S-s+ (45.54%) was the most common, whereas M+N-S-s- and M-N+S-s- were not found. The rare Lu (a-b-) and Lu (a+b+) phenotypes were identified in 0.43% and 1.13% of the donors, respectively. Le(a) and Le(b) were seen in 17.92% and 63.03% of donors, respectively. The frequency of Di(a) was 4.75%, which was higher than in the Chinese population in Taiwan region or the Caucasian and Black populations (P < 0.0001). This study systematically describes the frequencies of 24 blood group antigens in the Chinese Han population from Mainland China. The data can be helpful in creating a donor database for preparation of indigenous cell panels and providing antigen-negative blood to patients with multiple alloantibodies.
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Affiliation(s)
- Y Yu
- Department of Blood Transfusion, Chinese PLA General Hospital, Beijing, China
| | - C Ma
- Department of Blood Transfusion, Chinese PLA General Hospital, Beijing, China
| | - X Sun
- Department of Blood Transfusion, Chinese PLA General Hospital, Beijing, China
| | - X Guan
- Department of Blood Transfusion, Chinese PLA General Hospital, Beijing, China
| | - X Zhang
- Department of Blood Transfusion, Chinese PLA General Hospital, Beijing, China
| | - J Saldanha
- The Worldwide, Clinical Affairs of the Immucor Inc., Norcross, GA, USA
| | - L Chen
- Department of Blood Transfusion, Chinese PLA General Hospital, Beijing, China
| | - D Wang
- Department of Blood Transfusion, Chinese PLA General Hospital, Beijing, China
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Chamni N, Louisirirotchanakul S, Oota S, Sakuldamrongpanish T, Saldanha J, Chongkolwatana V, Phikulsod S. Genetic characterization and genotyping of hepatitis B virus (HBV) isolates from donors with an occult HBV infection. Vox Sang 2014; 107:324-32. [PMID: 25040474 DOI: 10.1111/vox.12178] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 05/29/2014] [Accepted: 06/12/2014] [Indexed: 12/20/2022]
Abstract
BACKGROUND AND OBJECTIVES Screening of Thai blood donors has resulted in the detection of donors with an occult HBV infection (OBI), where HBsAg is undetectable, but hepatitis B virus (HBV) DNA is present in serum in low concentrations. This study was designed to determine whether the occurrence of OBI in donors was linked to the HBV genotype and possibly to mutations in the surface (S) and core (C) gene regions. MATERIALS AND METHODS Mutations in the S and C gene regions in 48 Thai donors with OBI were mapped by sequencing. Genotyping was determined with the INNO-LiPA test and by phylogenetic analysis of sequences from the S and C genes. RESULTS The majority of OBI samples were genotype C (81·3%) with 6·3% of samples being genotype B. In addition, two genotype I isolates were identified. Mutations in the S region (100%) were found especially in loop 1 of the major hydrophilic loop (MHL) at positions I110L, T114S, T126I and S113T, whereas mutations in the C region (65%) were within the basal core promoter region (position A1762T/G1764A) and precore region (position G1896A). CONCLUSION The majority of OBI samples were HBV genotype C, although genotype I, which is newly emerging in Thailand, was also detected. The study demonstrated that OBI was probably not associated with a particular HBV genotype or with certain mutations in the S and C gene regions. However, mutations in the C gene region which could potentially impair viral replication and HBsAg production and potentially lead to OBI were identified.
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Affiliation(s)
- N Chamni
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
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11
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12
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Lin KT, Chang CL, Tsai MH, Lin KS, Saldanha J, Hung CM. Detection and identification of occult HBV in blood donors in Taiwan using a commercial, multiplex, multi-dye nucleic acid amplification technology screening test. Vox Sang 2013; 106:103-10. [PMID: 23909571 DOI: 10.1111/vox.12075] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 07/09/2013] [Accepted: 07/10/2013] [Indexed: 12/13/2022]
Abstract
BACKGROUND The ability of a new generation commercial, multiplex, multi-dye test from Roche, the cobas TaqScreen MPX test, version 2.0, to detect and identify occult HBV infections was evaluated using routine donor samples from Kaohsiung Blood Bank, Taiwan. STUDY DESIGN AND METHODS A total of 5973 samples were tested by nucleic acid amplification technology (NAT); 5898 in pools of six, 66 in pools of less than six and nine samples individually. NAT-reactive samples were retested with alternative NAT tests, and follow-up samples from the donors were tested individually by NAT and for all the HBV serological markers. RESULTS Eight NAT-only-reactive donors were identified, and follow-up samples were obtained from six of the donors. The results indicated that all eight donors had an occult HBV infection with viral loads <12 IU/ml. CONCLUSION The cobas(®) TaqScreen MPX test, version 2.0, has an advantage over the current Roche blood screening test, the cobas TaqScreen MPX test, for screening donations in countries with a high prevalence of occult HBV infections since the uncertainty associated with identifying samples with very low viremia is removed by the ability of the test to identify the viral target in samples that are reactive with the cobas TaqScreen MPX test, version 2.0.
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Affiliation(s)
- K T Lin
- Kaohsiung Blood Center, Taiwan Blood Services Foundation, Kaohsiung, Taiwan
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Müller MM, Fraile MIG, Hourfar MK, Peris LB, Sireis W, Rubin MG, López EM, Rodriguez GT, Seifried E, Saldanha J, Schmidt M. Evaluation of two, commercial, multi-dye, nucleic acid amplification technology tests, for HBV/HCV/HIV-1/HIV-2 and B19V/HAV, for screening blood and plasma for further manufacture. Vox Sang 2012; 104:19-29. [DOI: 10.1111/j.1423-0410.2012.01635.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Abstract
OBJECTIVE Current British Society of Gastroenterology guidelines use adenomatous polyp size as one of the key factors in determining polyp follow-up. This study aimed to compare polyp size assessment by colonoscopists and pathologists before and after fixation to determine the optimal method for measurement. METHOD Thirty-five colorectal polyps were found during pre-arranged colonoscopies in one centre. Polyp size was measured to the nearest 1 mm by three different methods: 1. by the endoscopist at colonoscopy; 2. by the pathologist fresh, following removal; 3. by the pathologist fixed, following fixation. The endoscopist and the pathologist were blinded to each other's measurements. RESULTS Seventeen men, eighteen women with mean age of 66.2 years (SD: 9.4, range: 38.7-85.5) underwent polypectomy/s with all polyps removed intact. Polypectomies were performed by consultants (43%), nurse specialists (34%) and specialist registrars (23%). The median size (mm) of polyps measured were endoscopically, 6.5 (2-25 mm); fresh specimen 7.0 (4-28 mm) and fixed 7.0 (4-28 mm). Endoscopic measurements were significantly lower than that of fresh and fixed sizes (P < 0.001 and P = 0.003 respectively), with poor correlation [correlation of variance (CV): 21.0% and intraclass correlation coefficient (ICCC): 0.841 for endoscopic and fresh measurements; CV: 21.1% and ICCC: 0.838 for endoscopic and fixed measurements]. There was no statistical difference between fresh and fixed specimen measurements (P > 0.05; CV: 4.2%, ICCC: 0.974). In three patients, the endoscopic measurement was < 1 cm in polyps that were found to be >or= 1 cm on pathological measurement. CONCLUSIONS Endoscopists consistently underestimated polyp size. Fixation had no effect on polyp size. Pathologists' measurement of polyp size on fixed specimens should determine the need for further colonoscopic follow-up.
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Affiliation(s)
- S J Moug
- Department of General Surgery, Crosshouse Hospital, Kilmarnock, Scotland.
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15
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Schmidt M, Pichl L, Jork C, Hourfar MK, Schottstedt V, Wagner FF, Seifried E, Müller TH, Bux J, Saldanha J. Blood donor screening with cobas s 201/cobas TaqScreen MPX under routine conditions at German Red Cross institutes. Vox Sang 2009; 98:37-46. [PMID: 19682348 DOI: 10.1111/j.1423-0410.2009.01219.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND In 1997 the German Red Cross (GRC) blood donor services introduced mini-pool nucleic acid testing (NAT) for human immunodeficiency virus (HIV)-1, hepatitis C virus (HCV) and hepatitis B virus (HBV) to increase blood safety. With the new cobas s 201/cobas TaqScreen MPX, a fully automated extraction method and a multiplex amplification system specifically adapted to the needs of blood donation services is available. METHODS The cobas s 201 system was evaluated at the GRC BTS locations Hagen, Springe and Frankfurt. In phase A, the analytical sensitivity for the detection of HBV, HCV and HIV-1 was investigated and in phase B, at least 60,000 samples at each test site were screened in parallel with the MPX test on s 201 system and the existing routine mini-pool NAT system to compare the diagnostic specificity and the diagnostic sensitivity. RESULTS Comparable analytical sensitivities in a range of 1.6-3.6 IU/ml, 4.9-10.9 IU/ml and 14.7-26.6 IU/ml for HBV, HCV HIV, respectively, for the MPX test on s 201 system (95% probability based on probit analysis) were determined at all test sites. The diagnostic sensitivity was 99.8% and the diagnostic specificity was 99.85%. CONCLUSIONS The MPX test on s 201 system is a fully automated NAT system suitable for routine blood donor screening. The analytical sensitivity as well as the diagnostic sensitivity fulfilled all requirements of the Paul Ehrlich Institute for blood donor screening in mini-pools up to 96 donations per pool. A major benefit of the automated NAT system is the reduced personnel time and the extensive complete barcode-controlled process documentation.
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Affiliation(s)
- M Schmidt
- Institute of Transfusion Medicine and Immunohematology, German Red Cross, Johann Wolfgang Goethe University, Frankfurt, Germany.
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Sá-Leão R, Nunes S, Brito-Avô A, Frazão N, Simões AS, Crisóstomo MI, Paulo ACS, Saldanha J, Santos-Sanches I, de Lencastre H. Changes in pneumococcal serotypes and antibiotypes carried by vaccinated and unvaccinated day-care centre attendees in Portugal, a country with widespread use of the seven-valent pneumococcal conjugate vaccine. Clin Microbiol Infect 2009; 15:1002-7. [PMID: 19392883 DOI: 10.1111/j.1469-0691.2009.02775.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The seven-valent pneumococcal conjugate vaccine (PCV7) has been available in Portugal since June 2001, but is not included in the National Vaccination Plan. Its impact on colonization is unknown. A point-prevalence study to evaluate PCV7 usage was carried out in 2006 among day-care centre attendees from the Lisbon area. Pneumococcal carriage rates, serotypes, and antibiotypes were determined and compared with results from a similar study conducted in 2001 before vaccine approval. In 2001 and 2006, 717 and 571 children, respectively, were enrolled. In 2006, 45.9% of the participants were appropriately vaccinated and 11.5% were incompletely vaccinated. Carriage of pneumococci remained stable (64.9% in 2001; 68.7% in 2006). Vaccine types (VT) decreased from 53.1% of all pneumococci to 11.2% (p <0.001). Serotype replacement was observed among vaccinated and unvaccinated children. Non-vaccine types (NVT) 1, 6C, 7F, 15A, 16F, 21, 23A, 29, and non-typeable (NT) strains increased significantly; serotype 19A increased, but not significantly. Rates of resistance to penicillin, erythromycin, clindamycin and tetracycline remained stable (p >0.05) due to significant increases in intermediate resistance to penicillin (from 5.5% to 17.8%), erythromycin (from 9.2% to 21.8%), clindamycin (from 6.4% to 19.3%) and tetracycline (from 8.3% to 15.8%) among NVT. Whereas in 2001 resistance among NVT was mostly associated with serotype 19A and NT strains, in 2006 resistance was also found among serotypes 6C, 15A, 24F and 33F. In conclusion, dramatic shifts in serotypes of colonizing pneumococci were observed among vaccinated and unvaccinated children. Rates of antibiotic resistance remained unchanged due to a balance between reduction in VT and an increase in antimicrobial-resistant NVT.
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Affiliation(s)
- R Sá-Leão
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal.
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Mahadevan D, Garewal H, Riley C, Zhu Y, Engelhardt K, Cooke L, Nagle R, Saldanha J, Von Hoff D. Humanized anti-CEACAM6 PEGylated scFv: A promising novel therapy for pancreatic cancer. J Clin Oncol 2007. [DOI: 10.1200/jco.2007.25.18_suppl.3042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
3042 Background: Novel Therapies for pancreatic cancer (PC) based on biological insight are urgently needed. CEACAM6, a member of the carcinoembryonic antigen (CEA) family, is a cell surface oncogene on PC cells. It is a glycoprotein composed of 3 Ig-like domains (Mr ∼35.2kD) and is linked to the plasma membrane via a glycophospholipid linked anchor. It is over-expressed on ≥95% PC patients’ found irrespective of stage of disease and represents a target for antibody therapy. Methods: Murine anti-CEACAM6 monoclonal antibody (Mab) 13–1 was humanized by a structure-based approach and single chain variable fragments (scFv) designed consisting of a Gly/Ser-linker which includes a cysteine residue for PEGylation. Murine scFv and 4 humanized scFv fragments (Version.1, 2, 7, 8) were bacterially expressed, purified, PEGylated and evaluated for activity alone or in combination with gemcitabine in human PC cell lines and mouse xenograft tumors. Cell viability, apoptosis and in-cell Westerns were done for efficacy and binding. Mouse xenograft tumors were treated with scFv or PEGylated scFv or combination with gemcitabine. Tumors (treated Vs untreated) were analyzed by immunohistochemistry for Ki-67, CD31, CEACAM6 and Caspase 3 Results: Mab 13–1, murine and 4 humanized scFvs’ were cytotoxic to CEACAM6 expressing PC cells (BxPC-3, HPAF-2) and not to PC cells that lack CEACAM6 (CaPan-2) with increased PARP-cleavage that was dose dependent (IC50=10μg/mL). Western blotting of culture media and serum from xenograft mice showed that CEACAM6 is not shed. In-cell Western confirmed humanized V.7 to be the best binder (KD=1–10μg/mL) confirming protein-protein interaction studies performed in silico with homology models of murine and humanized scFvs’ and CEACAM6. The murine scFv alone or the humanized scFV (V.8) in combination with gemcitabine delayed tumor growth by >50%. This tumor reduction correlated well with the immunohistochemical markers of response. Conclusions: We have demonstrated that CEACAM6 is a clinically relevant target in PC and that a PEGylated humanized scFv is a novel effective therapy alone and/or in combination with gemcitabine. Humanized scFv V.7 is undergoing mouse xenograft evaluation and expect will be the most effective agent to take forward into clinical development. No significant financial relationships to disclose.
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Affiliation(s)
| | - H. Garewal
- University of Arizona Cancer Center, Tucson, AZ
| | - C. Riley
- University of Arizona Cancer Center, Tucson, AZ
| | - Y. Zhu
- University of Arizona Cancer Center, Tucson, AZ
| | | | - L. Cooke
- University of Arizona Cancer Center, Tucson, AZ
| | - R. Nagle
- University of Arizona Cancer Center, Tucson, AZ
| | - J. Saldanha
- University of Arizona Cancer Center, Tucson, AZ
| | - D. Von Hoff
- University of Arizona Cancer Center, Tucson, AZ
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Saldanha J, Silvy M, Beaufils N, Arlinghaus R, Barbany G, Branford S, Cayuela JM, Cazzaniga G, Gonzalez M, Grimwade D, Kairisto V, Miyamura K, Lawler M, Lion T, Macintyre E, Mahon FX, Muller MC, Ostergaard M, Pfeifer H, Saglio G, Sawyers C, Spinelli O, van der Velden VHJ, Wang JQ, Zoi K, Patel V, Phillips P, Matejtschuk P, Gabert J. Characterization of a reference material for BCR-ABL (M-BCR) mRNA quantitation by real-time amplification assays: towards new standards for gene expression measurements. Leukemia 2007; 21:1481-7. [PMID: 17476280 DOI: 10.1038/sj.leu.2404716] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Monitoring of BCR-ABL transcripts has become established practice in the management of chronic myeloid leukemia. However, nucleic acid amplification techniques are prone to variations which limit the reliability of real-time quantitative PCR (RQ-PCR) for clinical decision making, highlighting the need for standardization of assays and reporting of minimal residual disease (MRD) data. We evaluated a lyophilized preparation of a leukemic cell line (K562) as a potential quality control reagent. This was found to be relatively stable, yielding comparable respective levels of ABL, GUS and BCR-ABL transcripts as determined by RQ-PCR before and after accelerated degradation experiments as well as following 5 years storage at -20 degrees C. Vials of freeze-dried cells were sent at ambient temperature to 22 laboratories on four continents, with RQ-PCR analyses detecting BCR-ABL transcripts at levels comparable to those observed in primary patient samples. Our results suggest that freeze-dried cells can be used as quality control reagents with a range of analytical instrumentations and could enable the development of urgently needed international standards simulating clinically relevant levels of MRD.
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Affiliation(s)
- J Saldanha
- 1National Institute of Biological Standards and Controls, South Mimms, UK
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Mato R, Sanches IS, Simas C, Nunes S, Carriço JA, Sousa NG, Frazão N, Saldanha J, Brito-Avô A, Almeida JS, de Lencastre H. Natural history of drug-resistant clones of Streptococcus pneumoniae colonizing healthy children in Portugal. Microb Drug Resist 2006; 11:309-22. [PMID: 16359190 DOI: 10.1089/mdr.2005.11.309] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A total of 3,539 Streptococcus pneumoniae (Pn) were recovered from 4,969 nasopharyngeal samples of children attending 13 day-care centers (DCCs) located in Lisbon, Portugal, during a surveillance study from January, 2001, through March, 2003, integrated in the European intervention project (EURIS, European Resistance Intervention Study). All Pn isolates were tested for anti-biotyping and drug-resistant pneumococci (DRPn) were further tested by serotyping and pulsed-field gel electrophoresis (PFGE). Overall carriage of Pn was very high (71.2%) and 39.9% of the isolates were resistant to antimicrobials (22.5% with decreased susceptibility to penicillin and 17.4% susceptible to penicillin and resistant to other antimicrobials). Serotypes 6B, 14, 23 F, 19F, and 19 A were prevalent among the 1,287 DRPn and 5.8% of the isolates were non-typeable. Eighty PFGE patterns were identified among 1,285 DRPn, and 93.1% of the DRPn belonged to 26 major clonal types that comprised: Pneumococcal Molecular Epidemiology Network (PMEN) clones (76.3%), Portuguese (PT)-DCC clones, previously detected in 1996-1999 (14.3%), and EURIS PT-DCC new clones, identified for the first time in the EURIS study, during 2001-2003 (9.4%). Comparing with previous Portuguese surveillance studies carried out since 1996, we observed that carriage increased from 47% to 71%, but no major changes were detected on the prevalence of pneumococcal serotypes. Moreover, although PMEN clones were predominant in all DCCs, in the present study the majority of them were gradually decreasing in time whereas several PT-DCC and new clones seemed to be increasing.
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Affiliation(s)
- R Mato
- Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa (ITQB/UNL), 2780-156 Oeiras, Portugal
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20
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Saldanha J, Garret R, Longmuir M, Watt C, George D, Wilson C, Doughty J, Smith D, Stallard S, Davidson R. A multidisciplinary team approach to family history risk assessment reduced clinic attendance by half. EJC Suppl 2006. [DOI: 10.1016/s1359-6349(06)80059-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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21
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Saldanha J, Heath A, Lelie N, Pisani G, Yu MY. A World Health Organization International Standard for hepatitis A virus RNA nucleic acid amplification technology assays. Vox Sang 2005; 89:52-8. [PMID: 15938741 DOI: 10.1111/j.1423-0410.2005.00633.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND AND OBJECTIVES Sixteen laboratories from 10 different countries participated in an international collaborative study to evaluate candidate materials as the first World Health Organization (WHO) International Standard for hepatitis A virus (HAV) RNA nucleic acid amplification technology (NAT) assays. MATERIALS AND METHODS Five candidate materials were analysed in this study: materials AA and BB were lyophilized, while materials CC, DD and EE were liquid preparations. Samples were diluted in pooled plasma or in pooled cryo-poor plasma (sample EE). Serial dilutions of the candidate materials were tested by each laboratory in four independent assays and the results were analysed statistically. RESULTS The mean log(10)'equivalents' per ml were 5.29 for sample AA, 5.07 for sample BB, 4.99 for sample CC, 5.40 for sample DD and 4.08 for sample EE. CONCLUSIONS Based on the results of this study, sample AA was established as the first International Standard for HAV RNA NAT assays at the WHO Expert Committee on Biological Standardizaton (ECBS) meeting held in February 2003. The code number of this preparation is 00/560 and the potency, based on the study, is 100 000 International Units (IU)/ml.
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Affiliation(s)
- J Saldanha
- Roche Molecular Systems Inc., Pleasanton, CA 94588, USA.
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Saldanha J, Heath A, Aberham C, Albrecht J, Gentili G, Gessner M, Pisani G. World Health Organization collaborative study to establish a replacement WHO international standard for hepatitis C virus RNA nucleic acid amplification technology assays. Vox Sang 2005; 88:202-4. [PMID: 15787732 DOI: 10.1111/j.1423-0410.2005.00606.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND OBJECTIVES A collaborative study was undertaken to establish a replacement for the current (1st) World Health Organization (WHO) hepatitis C virus (HCV) International Standard, 96/790. MATERIALS AND METHODS Both the 1(st) International Standard and the replacement standard were prepared from the same starting material by diluting a high titre genotype 1a HCV isolate in pooled, human plasma. The only difference was that each standard was lyophilized in two, separate lyophilisation runs but under the same conditions. RESULTS In the study to establish the 1st International Standard, no significant difference in potency was found between the material eventually designated as the 1st International Standard and that now selected as the 2nd International Standard. The present study also showed no significant differences between the materials stored at -20 degrees C and no evidence of degradation over 5 years. CONCLUSIONS Material 96/798 was established as the 2nd HCV International Standard and assigned the same unitage as the 1st International Standard, i.e. 10(5) IU/ml (50,000 IU/vial).
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Affiliation(s)
- J Saldanha
- Roche Molecular Systems Inc., Pleasanton, CA 94588, USA.
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Busch MP, Tobler LH, Saldanha J, Caglioti S, Shyamala V, Linnen JM, Gallarda J, Phelps B, Smith RIF, Drebot M, Kleinman SH. Analytical and clinical sensitivity of West Nile virus RNA screening and supplemental assays available in 2003. Transfusion 2005; 45:492-9. [PMID: 15819668 DOI: 10.1111/j.0041-1132.2005.04382.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Transfusion-transmitted West Nile virus (WNV) infections were first reported in 2002, which led to rapid development of investigational nucleic acid amplification tests (NAT). A study was conducted to evaluate sensitivities of WNV screening and supplemental NAT assays first employed in 2003. STUDY DESIGN AND METHODS Twenty-five member-coded panels were distributed to NAT assay manufacturers. Panels included five pedigreed WNV standards (1, 3, 10, 30, and 100 copies/mL), 15 or 16 donor units with very-low-level viremia identified through 2003 screening, and four or five negative control samples. Samples were tested neat in 10 replicates by all assays; for NAT screening assays, 10 replicates were also performed on dilutions consistent with minipool (MP)-NAT. The viral load distribution for 142 MP-NAT yield donations was characterized, relative to the analytical sensitivity of MP-NAT systems. RESULTS Analytical sensitivities (50% limits of detection [LoD] based on Poisson model of detection of WNV standards) for screening NAT assays ranged from 3.4 to 29 copies per mL; when diluted consistent with MP pool sizes, the 50 percent LoD of screening NAT assays was reduced to 43 to 309 copies per mL. Analytical sensitivity of supplemental assays ranged from 1.5 to 7.7 copies per mL (50% LoD). Detection of RNA in donor units varied consistent with analytical LoD of assays. Detection of low-level viremia after MP dilutions was particularly compromised for seropositive units, probably reflecting lower viral loads in the postseroconversion phase. Based on the viral load distribution of MP-NAT yield donations (median, 3519 copies/mL; range, < 50-690,000), 13 to 24 percent of units had viral loads below the 50 percent LoD of screening NAT assays run in MP-NAT format. CONCLUSION WNV screening and supplemental assays had generally excellent analytical sensitivity, comparable to human immunodeficiency virus-1 and hepatitis C virus NAT assays. The presence of low-level viremic units during epidemic periods and the impact of MP dilutions on sensitivity, however, suggest the need for further improvements in sensitivity as well as a role for targeted individual-donation NAT in epidemic regions.
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Affiliation(s)
- M P Busch
- Blood Systems Research Institute, San Francisco, California, USA.
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Nunes S, Sá-Leão R, Carriço J, Alves CR, Mato R, Avô AB, Saldanha J, Almeida JS, Sanches IS, de Lencastre H. Trends in drug resistance, serotypes, and molecular types of Streptococcus pneumoniae colonizing preschool-age children attending day care centers in Lisbon, Portugal: a summary of 4 years of annual surveillance. J Clin Microbiol 2005; 43:1285-93. [PMID: 15750097 PMCID: PMC1081291 DOI: 10.1128/jcm.43.3.1285-1293.2005] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2004] [Revised: 10/18/2004] [Accepted: 11/05/2004] [Indexed: 11/20/2022] Open
Abstract
Of the nasopharyngeal cultures recovered from 942 day care center (DCC) attendees in Lisbon, Portugal, 591 (62%) yielded Streptococcus pneumoniae during a surveillance performed in February and March of 1999. Forty percent of the isolates were resistant to one or more antimicrobial agents. In particular, 2% were penicillin resistant and 20% had intermediate penicillin resistance. Multidrug resistance to macrolides, lincosamides, and tetracycline was the most frequent antibiotype (17% of all isolates). Serotyping and molecular typing by pulsed-field gel electrophoresis were performed for 202 out of 237 drug-resistant pneumococci (DRPn). The most frequent serotypes were 6B (26%), 14 (22%), 19F (16%), 23F (10%), and nontypeable (12%). The majority (67%) of the DRPn strains were representatives of nine international clones included in the Pneumococcal Molecular Epidemiology Network; eight of them had been detected in previous studies. Fourteen novel clones were identified, corresponding to 26% of the DRPn strains. The remaining 7% of the strains were local clones detected in our previous studies. Comparison with studies conducted since 1996 in Portuguese DCCs identified several trends: (i) the rate of DRPn frequency has fluctuated between 40 and 50%; (ii) the serotypes most frequently recovered have remained the same; (iii) nontypeable strains appear to be increasing in frequency; and (iv) a clone of serotype 33F emerged in 1999. Together, our observations highlight that the nasopharynxes of children in DCCs are a melting pot of successful DRPn clones that are important to study and monitor if we aim to gain a better understanding on the epidemiology of this pathogen.
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Affiliation(s)
- S Nunes
- The Rockefeller University, 1230 York Ave., New York, NY 10021, USA
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25
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Pisani G, Cristiano K, Saldanha J, Wirz M, Bisso GM, Mele C, Gentili G. External quality assessment for the detection of blood-borne viruses in plasma by nucleic acid amplification technology: the first human immunodeficiency virus and hepatitis B virus studies (HIV EQA/1 and HBV EQA/1) and the fifth hepatitis C virus study (HCV EQA/5). Vox Sang 2004; 87:91-5. [PMID: 15355499 DOI: 10.1111/j.1423-0410.2004.00544.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND AND OBJECTIVES This External Quality Assessment (EQA) study was aimed at assessing the proficiency of blood centres and blood product manufacturers in detecting, by nucleic acid amplification technology (NAT), the possible contamination of plasma with hepatitis C virus (HCV), human immunodeficiency virus (HIV) and hepatitis B virus (HBV). MATERIALS AND METHODS Three independent panels, one for each virus, were prepared at the Istituto Superiore di Sanità (ISS) by diluting the respective reference preparations. NAT methods used by the EQA participants included polymerase chain reaction (PCR) assays by Roche, transcription-mediated amplification (TMA) assays by Chiron and in-house PCR assays. RESULTS Forty-three of the 45 participants (95.6%) in the HCV EQA/5 who used a validated method were consistently able to detect a nominal concentration of 100 IU/ml for all six major genotypes. In the case of the HIV EQA/1, all 35 participants detected the samples containing 1000 IU/ml HIV, while five (14.3%) did not identify the samples containing 100 IU/ml HIV. With respect to the HBV EQA/1, all 16 participants correctly identified the positive samples containing either 1000 IU/ml or 100 IU/ml HBV. No false-positive results were observed with any of the three panels. CONCLUSIONS The HCV EQA/5 showed an improved proficiency of laboratories as compared with the HCV EQA/4. In fact, HCV genotypes 1, 2, 3 and 5 were correctly identified in 100% of the assays and genotypes 4 and 6 in 97.8% of the assays. While most of the participants in the HIV EQA/1 showed a good level of proficiency, an excellent performance was shown by all participants in the HBV EQA/1.
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Affiliation(s)
- G Pisani
- Department of Infectious, Parasitic and Immune-mediated Diseases, Istituto Superiore di Sanità, Rome, Italy
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26
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Alexander G, Saldanha J, Ebrahim MK, Ghoneim I. Late secondary spontaneous pneumothorax occurring in a major burn patient with inhalation injury following MRSA pneumonia. Burns 2004; 30:488-90. [PMID: 15225918 DOI: 10.1016/j.burns.2004.01.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/22/2004] [Indexed: 11/30/2022]
Affiliation(s)
- G Alexander
- Al-Babtain Center for Burns and Plastic Surgery, Ibn-Sina Hospital, Post Box No. 25427, Safat 13115, Kuwait.
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Saldanha J, Cameron C. West Nile virus NAT testing. Dev Biol (Basel) 2004; 118:65-70. [PMID: 15645674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Affiliation(s)
- J Saldanha
- Canadian Blood Services, Ottawa, ON, Canada.
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Gentili G, Pisani G, Saldanha J, Cristiano K, Wirz M, Bisso GM, Mele C. High proficiency in detecting the six major hepatitis C virus genotypes of laboratories involved in testing plasma by nucleic acid amplification technology. Vox Sang 2003; 85:114-6. [PMID: 12925164 DOI: 10.1046/j.1423-0410.2003.00341.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Since the introduction of mandatory HCV RNA testing of plasma pools for fractionation by nucleic acid amplification technology, we have organised External Quality Assessment studies (EQAs) addressed to blood products manufacturers and blood centres. Here we report the results of a new EQA, the first one to include all six major HCV genotypes. The results, reported by laboratories worldwide, showed that genotypes 1, 2 and 3 were correctly identified in 100% of the tests, genotype 4 in 96.7% and genotypes 5 and 6 in 98.3% of the assays. As detection of all HCV genotypes is critical for laboratories involved in testing plasma for HCV, all six genotypes should continue to be included in the next EQA studies.
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Affiliation(s)
- G Gentili
- Laboratory of Immunology, Istituto Superiore di Sanità, Rome, Italy.
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29
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Alexander G, Saldanha J, Ebrahim MK, Ghoneim I. Is routine admission chest radiograph of any clinical value in non-intensive care burn patients without inhalation injury? Burns 2003; 29:499-500. [PMID: 12880735 DOI: 10.1016/s0305-4179(03)00054-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- G Alexander
- Al-Babtain Center for Plastic, Reconstructive Surgery and Burns, Ibn-Sina Hospital, P.O. Box 25427, Safat 13115, Kuwait.
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Padley D, Moody AH, Chiodini PL, Saldanha J. Use of a rapid, single-round, multiplex PCR to detect malarial parasites and identify the species present. Ann Trop Med Parasitol 2003; 97:131-7. [PMID: 12803868 DOI: 10.1179/000349803125002977] [Citation(s) in RCA: 160] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
A new, rapid assay, based on a single-round, multiplex PCR, can be used to detect Plasmodium falciparum, P. vivax, P. malariae or P. ovale in human blood. The PCR, which targets the conserved 18S small-subunit RNA genes of the parasites, not only permits a malarial infection to be detected but also allows each Plasmodium species present to be identified, even in cases of mixed infection.
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Affiliation(s)
- D Padley
- Division of Virology, National Institute for Biological Standards and Control, Blanche Lane, South Mimms EN6 3QG, UK.
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31
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Abstract
BACKGROUND AND OBJECTIVES A major requirement of a hepatitis C virus (HCV) RNA nucleic acid amplification technology (NAT) assay validation is the ability of the assay to detect the six major genotypes of HCV with equivalent sensitivities. The aim of this study was to characterize and calibrate an HCV genotype panel for use in such studies. MATERIALS AND METHODS Panels consisting of the first International Standard (IS) for HCV RNA NAT assays (96/790; HCV genotype 1a) and isolates of genotypes 2-6 were sent to 17 laboratories worldwide which use a variety of NAT tests, both qualitative and quantitative. The HCV RNA content of each panel member was determined and the mean titre calculated in International Units/ml (IU/ml). RESULTS The calculated mean titres (calibrated against the HCV International Standard), in log10 IU/ml, of the genotype 2-6 samples were 3.99, 3.81, 4.14, 4.18 and 4.61, respectively. CONCLUSIONS An HCV genotype panel, calibrated in IU/ml, has been established and should be valuable for assay validation. All the genotypes were detected by all the assays used, but it was not possible to demonstrate that the genotypes were detected with equal efficiencies.
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Affiliation(s)
- J Saldanha
- Division of Virology, National Institute for Biological Standards and Control, South Mimms, Herts., UK
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Saldanha J, Lelie N, Yu MW, Heath A. Establishment of the first World Health Organization International Standard for human parvovirus B19 DNA nucleic acid amplification techniques. Vox Sang 2002; 82:24-31. [PMID: 11856464 DOI: 10.1046/j.1423-0410.2002.00132.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND OBJECTIVES A collaborative study, involving 26 laboratories from 14 countries, was carried out in order to establish a World Health Organization (WHO) International Standard for human parvovirus B19 (B19) DNA nucleic acid amplification techniques (NAT). MATERIALS AND METHODS Four samples: AA, BB (which were lyophilized), CC and DD (which were liquid preparations) were analysed using several different NAT assays. The mean B19 DNA content of each sample was determined for each laboratory using an end-point dilution method. RESULTS There was good agreement between the overall mean 'equivalents'/ml obtained by the different assays. The mean log(10) 'equivalents'/ml were 5.76 for sample AA, 5.73 for sample BB, 5.82 for sample CC and 7.70 for sample DD. The differences in titre among samples AA, BB and CC were not statistically significant, but the titre of DD was significantly higher. CONCLUSIONS Despite the range of NAT assays used in the study, it was possible to calculate the mean B19 DNA concentrations in the four preparations. Lyophilized preparation AA was established as the first International Standard for B19 DNA NAT assays and was assigned a concentration of 10(6) international units (IU)/ml.
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Affiliation(s)
- J Saldanha
- Division of Virology, National Institute for Biological Standards and Controls, South Mimms, Herts., UK.
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Abstract
Proteins and small molecules are capable of regulating the agonist binding and function of G-protein coupled receptors by multiple allosteric mechanisms. In the case of muscarinic receptors, there is the well-characterised allosteric site that binds, for example, gallamine and brucine. The protein kinase inhibitor, KT5720, has now been shown to bind to a second allosteric site and to regulate agonist and antagonist binding. The binding of brucine and gallamine does not affect KT5720 binding nor its effects on the dissociation of [3H]-N-methylscopolamine from M1 receptors. Therefore it is possible to have a muscarinic receptor with three small ligands bound simultaneously. A model of the M1 receptor, based on the recently determined structure of rhodopsin, has the residues that have been shown to be important for gallamine binding clustered within and to one side of a cleft in the extracellular face of the receptor. This cleft may represent the access route of acetylcholine to its binding site.
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Affiliation(s)
- N J Birdsall
- Division of Physical Biochemistry, National Institute for Medical Research, Mill Hill, London, UK.
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Abstract
The recently-determined structure of rhodopsin has provided a suitable basis for modeling the three-dimensional structure of the M1 muscarinic acetylcholine receptor. Using this as a framework for interpreting mutagenesis studies, we have been able to suggest most of the contacts which the receptor makes with acetylcholine and many of the intramolecular contacts which are important for the ground-state structure of the receptor. It is possible to outline a mechanism of G-protein interaction.
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Affiliation(s)
- E C Hulme
- National Institute for Medical Research, The Ridgeway, Mill Hill, London, UK.
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Buck V, Quinn J, Soto Pino T, Martin H, Saldanha J, Makino K, Morgan BA, Millar JB. Peroxide sensors for the fission yeast stress-activated mitogen-activated protein kinase pathway. Mol Biol Cell 2001; 12:407-19. [PMID: 11179424 PMCID: PMC30952 DOI: 10.1091/mbc.12.2.407] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The Schizosaccharomyces pombe stress-activated Sty1p/Spc1p mitogen-activated protein (MAP) kinase regulates gene expression through the Atf1p and Pap1p transcription factors, homologs of human ATF2 and c-Jun, respectively. Mcs4p, a response regulator protein, acts upstream of Sty1p by binding the Wak1p/Wis4p MAP kinase kinase kinase. We show that phosphorylation of Mcs4p on a conserved aspartic acid residue is required for activation of Sty1p only in response to peroxide stress. Mcs4p acts in a conserved phospho-relay system initiated by two PAS/PAC domain-containing histidine kinases, Mak2p and Mak3p. In the absence of Mak2p or Mak3p, Sty1p fails to phosphorylate the Atf1p transcription factor or induce Atf1p-dependent gene expression. As a consequence, cells lacking Mak2p and Mak3p are sensitive to peroxide attack in the absence of Prr1p, a distinct response regulator protein that functions in association with Pap1p. The Mak1p histidine kinase, which also contains PAS/PAC repeats, does not regulate Sty1p or Atf1p but is partially required for Pap1p- and Prr1p-dependent transcription. We conclude that the transcriptional response to free radical attack is initiated by at least two distinct phospho-relay pathways in fission yeast.
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Affiliation(s)
- V Buck
- Division of Yeast Genetics, National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA United Kingdom
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Saldanha J, Gerlich W, Lelie N, Dawson P, Heermann K, Heath A. An international collaborative study to establish a World Health Organization international standard for hepatitis B virus DNA nucleic acid amplification techniques. Vox Sang 2001; 80:63-71. [PMID: 11339072 DOI: 10.1046/j.1423-0410.2001.00003.x] [Citation(s) in RCA: 196] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
BACKGROUND AND OBJECTIVES Twenty-two laboratories from nine countries participated in an international collaborative study to establish a World Health Organization (WHO) international standard for hepatitis B virus (HBV) DNA nucleic acid amplification techniques (NAT). MATERIALS AND METHODS Three samples, AA, BB (both of which were lyophilized) and CC (which was a liquid preparation), were analysed using several different NAT assays. The mean HBV DNA content of each sample was determined from the study. RESULTS Despite the range of assays (commercial and in-house) used by participants, there was good agreement among the overall mean 'equivalents'/ml obtained by the different assays, except for one laboratory (laboratory 4). The variation in estimates of log10 'equivalents'/ml was 1.75-1.25 for the three samples if results from laboratory 4 were excluded. The mean log10 'equivalents'/ml for all laboratories were 6.42 for sample AA, 6.30 for sample BB and 5.03 for sample CC (exclusion of results from laboratory 4 made little difference). The difference in titres between the two lyophilized samples (AA and BB) was not statistically significant but the titre of the frozen sample (CC) was significantly lower. Material AA (code 97/746) was accepted as the first WHO international standard for HBV DNA NAT assays and assigned a potency of 10(6) international units (IU)/ml. CONCLUSIONS The titres (genome equivalents/ml) of three HBV preparations were determined by several laboratories using different NAT assays. This study enabled the establishment of an international standard, 97/746, for HBV DNA NAT assays.
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Affiliation(s)
- J Saldanha
- Division of Virology, National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Herts EN6 3QG, UK.
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Saldanha J. Validation and standardisation of nucleic acid amplification technology (NAT) assays for the detection of viral contamination of blood and blood products. J Clin Virol 2001; 20:7-13. [PMID: 11163577 DOI: 10.1016/s1386-6532(00)00149-9] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Standardisation of NAT assays is necessary before the introduction of such assays for routine screening of blood and blood products for viral contaminants such as HBV, HCV, and HIV-1. Standardisation can be achieved by the use of well-characterised reference materials (working reagents) to validate each assay run. Working reagents for HCV, HIV-1, HBV, HAV, and human parvovirus B19 have been established by the NIBSC. Such reagents and reference panels are also available from other official medicinal control laboratories and commercial organisations. However, the nucleic acid content of these reagents are expressed in many different units, e. g. genome equivalents/ml, copies/ml, PCR detectable units/ml, making comparisons of results from laboratories using different reagents difficult. The establishment of internationally accepted standards against which all working reagents could be calibrated, using a common standard unit of measurement, IU, would overcome this major problem. The first International Standard for HCV RNA assays was established in 1997. This reagent, 96/790, is a lyophilised preparation of a genotype 1 isolate and the concentration of the standard is 10(5) IU/ml. Two further International Standards have since been established; for HIV-1 and HBV, containing 10(5) IU/ml and 10(6) IU/ml respectively. The establishment of the HCV International Standard has been critical in the introduction of mandatory testing. Since 1st July 1999, all batches of blood products marketed in Europe have to be prepared from plasma pools tested and found non-reactive for HCV RNA using a validated assay which can detect a sample containing 100 IU/ml of HCV RNA. In Germany, screening of blood donations for HCV RNA by NAT has been mandatory since 1st April 1999. The minimum sensitivity of assays should be 5000 IU/ml for a single donation.
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Affiliation(s)
- J Saldanha
- Division of Virology, National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Hertshire, EN6 3QG, UK.
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Abstract
We report two cases of a peculiar leukoencephalopathy with temporal cysts. Both patients have a non-progressive neurological disorder with mental retardation, microcephaly and sensorineural deafness although clinical differences between them may reflect a different aetiology. The metabolic disorders with white matter involvement and the recently described leukoencephalopathies (Van Der Knaap disease, 'vanishing white matter disease') were excluded based on clinical, biologic and imaging findings. Cytomegalovirus infection is a likely possibility in the first case although the magnetic resonance imaging picture is only partially similar to previously reported cases. Our patients are strikingly similar to the patients reported by Deonna et al. and Olivier et al. We discuss the clinical and imaging findings in our patients and the differential diagnosis considering the known disorders of the white matter in childhood.
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Affiliation(s)
- A L Gomes
- Department of Pediatrics, Hospital de Santa Maria, Lisboa, Portugal
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Abstract
ycf24 is a well conserved gene found in all major groups of bacteria, as well as on red algal plastid genomes and the vestigal plastid genome of apicomplexan pathogens like the malaria parasite Plasmodium falciparum (ORF470). Some database annotations describe Ycf24 as an ABC transporter subunit, but we find the level of significance is low. To investigate ycf24's function we disrupted it in the cyanobacterium Synechocystis sp., strain PCC6803 which has a multi-copy genome. This showed ycf24 is essential, partial loss producing a terminal phenotype of chlorosis, reduced cell size, loss of DNA, and a striking arrest in cytokinesis. Attempts to disrupt the single copy of ycf24 in E. coli failed to give stable transformants. When Ycf24 was over-expressed in E. coli as a soluble fusion protein, it localized mostly as a band on either side of the nucleoid and nucleoid partitioning was aberrant. We propose the relict plastid organelle of apicomplexans retains its capacity for protein synthesis because Ycf24 is essential.
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Affiliation(s)
- A E Law
- National Institute for Medical Research, Mill Hill, London, UK
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Sá-Leão R, Tomasz A, Sanches IS, Nunes S, Alves CR, Avô AB, Saldanha J, Kristinsson KG, de Lencastre H. Genetic diversity and clonal patterns among antibiotic-susceptible and -resistant Streptococcus pneumoniae colonizing children: day care centers as autonomous epidemiological units. J Clin Microbiol 2000; 38:4137-44. [PMID: 11060081 PMCID: PMC87554 DOI: 10.1128/jcm.38.11.4137-4144.2000] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Characterization by antibiotype of the 1,096 Streptococcus pneumoniae recovered from 2,111 nasopharyngeal samples of children attending 16 day care centers (DCCs) in Lisbon, Portugal, and molecular typing of 413 drug-resistant pneumococci (DRPn) and 89 fully drug-susceptible pneumococci (DSPn) has allowed several conclusions. (i) There was an increase in the frequency of DRPn colonizing children in DCCs from 40% in 1996 to 45% in 1997 to 50% in 1998. (ii) Drug resistance spread by cross-transmission of DRPn clones. A few (8 out of 57) DRPn clones were repeatedly isolated from a large number of children in several DCCs and during each period of surveillance, suggesting the epidemic nature of these clones, which included lineages representing internationally spread S. pneumoniae clones. (iii) Dissemination of resistance determinants among pneumococci colonizing the nasopharynx occurred. Association of identical pulsed-field gel electrophoresis patterns with diverse antibiotypes among pneumococci colonizing children suggests that the high prevalence of DRPn involves not only cross-transmission of resistant strains but also dispersal of resistance genes through recombinational mechanisms. (iv) DCCs are autonomous epidemiological units. Among the 413 DRPn, 57 different lineages were detected; these lineages were dispersed among the 16 DCCs to produce unique microbiological profiles for each of the DCCs. Higher genetic diversity and less sharing of clonal types were observed among the DSPn.
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Affiliation(s)
- R Sá-Leão
- Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa, Oeiras, Lisbon, Portugal
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Saldanha J, Heath A, Lelie N, Pisani G, Nübling M, Yu M. Calibration of HCV working reagents for NAT assays against the HCV international standard. The Collaborative Study Group. Vox Sang 2000; 78:217-24. [PMID: 10895094 DOI: 10.1159/000031184] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND AND OBJECTIVES Five HCV RNA reference reagents, the Paul Ehrlich Institut (PEI) reference 75, the National Institute for Biological Standards and Control (NIBSC) reagent 96/586, the Central Laboratory of the Netherlands Red Cross Blood Transfusion Service (CLB) Pelispy HCV RNA run control S2001, the Istituto Superiore di Sanità (ISS) reagent 0498 and the CBER panel member No. 1, were calibrated against the WHO International Standard, 96/790. MATERIALS AND METHODS The reference materials were calibrated in a collaborative study organised by NIBSC. Nineteen laboratories, using a range of qualitative and quantitative assays returned results. RESULTS The concentrations of the reagents were: 25,000 IU/ml for the PEI material, 710 IU/ml for the NIBSC material 96/586, 1,000 IU/ml for the CLB material, 1,700 IU/ml for the ISS material 0498 and 250 IU/ml for the CBER panel member No. 1. CONCLUSIONS The calibration of these five reference reagents for HCV RNA nucleic acid amplification technology (NAT) assays enables them to be used for standardisation and validation of assays. Such calibrants are essential for meeting the requirements of the European Medicinal Evaluation Agency (EMEA) for the testing of plasma pools and donations for HCV RNA for the release of blood products and the PEI requirements for the release testing of erythrocyte and thrombocyte concentrates.
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Affiliation(s)
- J Saldanha
- Division of Virology, National Institute for Biological Standards and Control, South Mimms, UK.
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Saldanha J, Lelie N, Heath A. Establishment of the first international standard for nucleic acid amplification technology (NAT) assays for HCV RNA. WHO Collaborative Study Group. Vox Sang 2000; 76:149-58. [PMID: 10341329 DOI: 10.1159/000031040] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND AND OBJECTIVES The aims of this study were the establishment of a WHO International standard for HCV RNA for nucleic acid amplification technology (NAT) assays and the determination of the HCV RNA content of the candidate standard. MATERIALS AND METHODS Twenty-two laboratories evaluated three candidate materials (two lyophilised, AA and BB, which were derived from the same source and one a liquid preparation, CC). All samples were HCV genotype 1 with a concentration of approximately 10(5) genome equivalents/ml. The methods used included the Roche Amplicor assay (version 1), Chiron Quantiplex (bDNA) assay, Organon Teknika NASBA assay, Transcription Mediated assay and various in-house assays, using single or nested primers. RESULTS There was reasonable agreement between the overall mean NAT detectable units/ml obtained by the different assays except for some of the in-house assays using single primers which gave substantially lower estimates. These titres were 5.0 log10 for samples AA and BB and 4.6 log10 for sample CC. CONCLUSIONS Sample AA was accepted as the candidate standard and assigned a titre of 10(5) international units (IU)/ml. The International Standard consists of a batch of vials each containing 50,000 IU/vial. Preliminary studies indicated that the material is stable at +4 degrees C and +20 degrees C for up to 200 days.
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Affiliation(s)
- J Saldanha
- Division of Virology, National Institute for Biological Standards and Control, South Mimms, UK.
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Abstract
BACKGROUND AND OBJECTIVES A collaborative study was organised to establish a hepatitis A virus (HAV) RNA standard for genomic amplification assays (GAT). MATERIALS AND METHODS A panel of 10 samples consisting of a 10-fold serial dilution of wild-type HAV diluted in HAV-negative cryosupernatant and samples of the diluent were sent to 14 laboratories in duplicate for testing for HAV RNA by the polymerase chain reaction. RESULTS Data returned by 12 laboratories indicated that the sensitivities of the assays performed by different laboratories were fairly close: there was a 100-fold difference in sensitivity between the majority of laboratories. Only one laboratory reported false-positive results. CONCLUSION A 10-5 dilution of the virus in cryosupernatant could be an appropriate working reagent for GAT assays for HAV RNA in plasma pools.
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Affiliation(s)
- J Saldanha
- Division of Virology, National Institute for Biological Standards and Control, South Mimms, UK.
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Saldanha J, Heath A, Lelie N, Pisani G, Nubling M, Yu M. Calibration of HCV Working Reagents for NAT Assays against the HCV International Standard. Vox Sang 2000. [DOI: 10.1046/j.1423-0410.2000.7840217.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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De Lencastre H, Kristinsson KG, Brito-Avô A, Sanches IS, Sá-Leão R, Saldanha J, Sigvaldadottir E, Karlsson S, Oliveira D, Mato R, Aires de Sousa M, Tomasz A. Carriage of respiratory tract pathogens and molecular epidemiology of Streptococcus pneumoniae colonization in healthy children attending day care centers in Lisbon, Portugal. Microb Drug Resist 2000; 5:19-29. [PMID: 10332718 DOI: 10.1089/mdr.1999.5.19] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In an effort to establish the rate of carriage of antibiotic resistant respiratory pathogens in children attending urban day care centers (DCC) in Portugal, seven DCC in Lisbon were selected for determining the rate of nasopharyngeal colonization of children between the ages of 6 months to 6 years by Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Of the 586 children studied between January and March 1996, 47% carried S. pneumoniae, 72% H. influenzae, and 54% M. catarrhalis. Twenty-four percent of the pneumococci had reduced susceptibility to penicillin, and most of these belonged to serogroups 19, 23, 14, and 6. An additional 19% were fully susceptible to penicillin but showed decreased susceptibility to other antimicrobials. These isolates expressed serogroups 6, 11, 14, 18, 19, and 34. The majority (96%) of M. catarrhalis and 20% of H. influenzae were penicillin resistant due to the production of beta-lactamases. Recent antimicrobial use was associated with carriage of penicillin non-susceptible pneumococci and beta-lactamase producing H. influenzae (p < 0.05). Individual DCC differed substantially from one another in their rates of carriage of antibiotic resistant H. influenzae and S. pneumoniae. Characterization of antibiotic resistant S. pneumoniae isolates by molecular fingerprinting techniques showed that each DCC had a unique microbiological profile, suggesting little, if any, exchange of the resistant microbial flora among them. An exception to this was the presence of isolates belonging to two internationally spread epidemic clones: the multiresistant Spanish/USA clone expressing serotype 23F, and the penicillin and sulfamethoxazole-trimethoprim resistant French/Spanish clone (serotype 14) which were detected in four and three DCC, respectively.
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Affiliation(s)
- H De Lencastre
- Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa, Oerias, Portugal
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Abstract
The introduction of nucleic acid amplification technology (NAT) assays for the detection of viral contamination of blood and blood products requires the availability of well-characterized reference reagents. Working reagents for hepatitis C virus RNA, hepatitis B virus DNA, HIV-1 RNA and human parvovirus B19 DNA have been established at NIBSC and at many other laboratories (both official medicinal control laboratories and commercial laboratories). However, as these reagents have been characterised independently, it is difficult to compare results from assays using different working reagents. Recently, a WHO International Standard was established for HCV RNA NAT assays. This standard has been calibrated in International Units (IU) and provides a common standard against which all working reagents can be calibrated. Collaborative studies to characterise two further candidate International Standards for HBV DNA and HIV-1 RNA NAT assays have been completed.
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Affiliation(s)
- J Saldanha
- Division of Virology, National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Herts, EN6 3QG, U.K
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Saldanha J, Lelie N, Heath A. Establishment of the first international standard for nucleic acid amplification technology (NAT) assays for HCV RNA. WHO Collaborative Study Group. Vox Sang 1999. [PMID: 10341329 DOI: 10.1046/j.1423-0410.1999.7630149.x] [Citation(s) in RCA: 214] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND OBJECTIVES The aims of this study were the establishment of a WHO International standard for HCV RNA for nucleic acid amplification technology (NAT) assays and the determination of the HCV RNA content of the candidate standard. MATERIALS AND METHODS Twenty-two laboratories evaluated three candidate materials (two lyophilised, AA and BB, which were derived from the same source and one a liquid preparation, CC). All samples were HCV genotype 1 with a concentration of approximately 10(5) genome equivalents/ml. The methods used included the Roche Amplicor assay (version 1), Chiron Quantiplex (bDNA) assay, Organon Teknika NASBA assay, Transcription Mediated assay and various in-house assays, using single or nested primers. RESULTS There was reasonable agreement between the overall mean NAT detectable units/ml obtained by the different assays except for some of the in-house assays using single primers which gave substantially lower estimates. These titres were 5.0 log10 for samples AA and BB and 4.6 log10 for sample CC. CONCLUSIONS Sample AA was accepted as the candidate standard and assigned a titre of 10(5) international units (IU)/ml. The International Standard consists of a batch of vials each containing 50,000 IU/vial. Preliminary studies indicated that the material is stable at +4 degrees C and +20 degrees C for up to 200 days.
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Affiliation(s)
- J Saldanha
- Division of Virology, National Institute for Biological Standards and Control, South Mimms, UK.
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Saldanha J, Singh J, Mahadevan D. Identification of a Frizzled-like cysteine rich domain in the extracellular region of developmental receptor tyrosine kinases. Protein Sci 1998; 7:1632-5. [PMID: 10082384 PMCID: PMC2144082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
In Drosophila, members of the Frizzled family of tissue-polarity genes encode proteins that appear to function as cell-surface receptors for Wnts. The Frizzled genes belong to the seven transmembrane class of receptors (7TMR) and have on their extracellular region a cysteine-rich domain that has been implicated as the Wnt binding domain. This region has a characteristic spacing of ten cysteines, which has also been identified in FrzB (a secreted antagonist of Wnt signaling) and Smoothened (another 7TMR, which is involved in the hedgehog signalling pathway). We have identified, using BLAST, sequence similarity between the cysteine-rich domain of Frizzled and several receptor tyrosine kinases, which have roles in development. These include the muscle-specific receptor tyrosine kinase (MuSK), the neuronal specific kinase (NSK2), and ROR1 and ROR2. At present, the ligands for these developmental tyrosine kinases are unknown. Our results suggest that Wnt-like ligands may bind to these developmental tyrosine kinases
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Affiliation(s)
- J Saldanha
- Division of Mathematical Biology, National Institute for Medical Research, London, United Kingdom
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Saldanha J, Singh J, Mahadevan D. Identification of a Frizzled-like cysteine rich domain in the extracellular region of developmental receptor tyrosine kinases. Protein Sci 1998; 7:1632-5. [PMID: 9684897 PMCID: PMC2144063 DOI: 10.1002/pro.5560070718] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In Drosophila, members of the Frizzled family of tissue-polarity genes encode proteins that appear to function as cell-surface receptors for Wnts. The Frizzled genes belong to the seven transmembrane class of receptors (7TMR) and have on their extracellular region a cysteine-rich domain that has been implicated as the Wnt binding domain. This region has a characteristic spacing of ten cysteines, which has also been identified in FrzB (a secreted antagonist of Wnt signaling) and Smoothened (another 7TMR, which is involved in suppression of the hedgehog pathway). We have identified, using BLAST, sequence similarity between the cysteine-rich domain of Frizzled and several receptor tyrosine kinases, which have roles in development. These include the muscle-specific receptor tyrosine kinase (MuSK), the neuronal specific kinase (NSK2), and ROR1 and ROR2. At present, the ligands for these developmental tyrosine kinases are unknown. Our results suggest that Wnt-like ligands may bind to these developmental tyrosine kinases.
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Affiliation(s)
- J Saldanha
- Division of Mathematical Biology, National Institute for Medical Research, London, United Kingdom
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