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1.
Int J Audiol ; 62(5): 400-409, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-35436167

RESUMO

OBJECTIVE: To assess the benefits of the Ida Institute's Why improve my hearing? Telecare Tool used before the initial hearing assessment appointment. DESIGN: A prospective, single-blind randomised clinical trial with two arms: (i) Why improve my hearing? Telecare Tool intervention, and (ii) standard care control. STUDY SAMPLE: Adults with hearing loss were recruited from two Audiology Services within the United Kingdom's publicly-funded National Health Service. Of 461 individuals assessed for eligibility, 57 were eligible to participate. RESULTS: Measure of Audiologic Rehabilitation Self-efficacy for Hearing Aids (primary outcome) scores did not differ between groups from baseline to post-assessment (Mean change [Δ]= -2.28; 95% confidence interval [CI]= -6.70, 2.15, p= .307) and 10-weeks follow-up (Mean Δ= -2.69; 95% CI= -9.52, 4.15, p = .434). However, Short Form Patient Activation Measure scores significantly improved in the intervention group compared to the control group from baseline to post-assessment (Mean Δ= -6.06, 95% CI= -11.31, -0.82, p = .024, ES= .61) and 10-weeks follow-up (Mean Δ= -9.87, 95% CI= -15.34, -4.40, p = .001, ES= -.97). CONCLUSIONS: This study demonstrates that while a patient-centred telecare intervention completed before management decisions may not improve an individual's self-efficacy to manage their hearing loss, it can lead to improvements in readiness.


Assuntos
Surdez , Perda Auditiva , Adulto , Humanos , Estudos Prospectivos , Método Simples-Cego , Medicina Estatal , Perda Auditiva/reabilitação , Audição , Qualidade de Vida , Análise Custo-Benefício
2.
Ir Med J ; 113(7): 125, 2020 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-35575605

RESUMO

Identifying citation classics is a valuable metric of research performance. Ireland has a distinguished history of medical research, although Ireland's top-cited articles are unknown. The SCOPUS database identified all medical and surgical articles published by journals in the Republic of Ireland or Northern Ireland. The 100 top-cited articles were analysed. The most cited article received 240 citations. There is an observed trend of increasing number of authors over time (p<0.05). General medicine and public health are the most common topics. The majority of works originate from Irish institutions. Collaborative research and non-Irish research are poorly represented among the citation classics. The Irish medical literature contains multiple highly cited and influential articles.

4.
Ir Med J ; 111(1): 669, 2018 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-29869850

RESUMO

In recent years there has been increased utilisation of computed tomography (CT) imaging in developed countries, however there is a paucity of data regarding the utilisation of CT in the emergency overnight setting. We retrospectively analysed trends in 'overnight' (midnight to 8am) CT utilisation over a ten-year period at a single Irish tertiary referral hospital. Over the study period, we observed a significant increase in the proportion of CT imaging that was carried out overnight. There was no significant variation in the yield of pathological findings over the study period, which remained low (64% of CT studies were normal or had non-critical findings). The multiple factors which have contributed to the increased utilization of overnight emergency CT in recent years, the potential for reporting errors overnight and the implications therein for patient safety warrant consideration.


Assuntos
Plantão Médico/estatística & dados numéricos , Serviço Hospitalar de Emergência/estatística & dados numéricos , Tomografia Computadorizada por Raios X/estatística & dados numéricos , Plantão Médico/tendências , Emergências/epidemiologia , Serviço Hospitalar de Emergência/tendências , Humanos , Irlanda , Estudos Retrospectivos , Centros de Atenção Terciária/estatística & dados numéricos , Centros de Atenção Terciária/tendências , Tomografia Computadorizada por Raios X/tendências
5.
Ir Med J ; 111(9): 820, 2018 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-30556668

RESUMO

Aim Recent studies have suggested gender-specific differences with respect to both baseline disease activity and severity in ankylosing spondylitis (AS). Tumour necrosis factor inhibitors (TNFi) have shown significant benefit in AS but there may be gender-specific differences regarding responses to TNFi therapy. Methods AS patients with active disease despite adequate trials of NSAIDs were commenced on TNFi and followed in a biologic clinic between 2004 and 2011. Response to treatment was measured based on clinical and serological outcomes. Baseline radiographic data were also collected where available. Results 147 AS patients commenced TNFi therapy and were followed in a biologic clinic between 2004 and 2011. One-hundred and six (72%) of the patients were male and 90 (61%) were current or ex-smokers. The specific TNFi prescribed included etanercept (74 patients, 50.3%), adalimumab (51 patients, 34.7%), infliximab (21 patients, 14.2%) and golimumab (1 patient, 0.7%). The median mSASSS score was 11 (interquartile range 5-35). At baseline, the metrology indices (BASMI) were significantly lower in women (2.6 v 4; p=0.01) but all other clinical indices were similar. At 3 months, female patients had significantly worse median disease activity and functional indices (BASDAI: 4 v 2; p<0.01; BASFI: 3 v 2; p=0.03) than male patients. In addition, females had higher median ESR (19 v 6; p<0.01) which correlated with their disease activity indices (r=0.42, p=0.02). Discussion Despite similar disease activity at baseline, post-TNFi therapy women had significantly higher disease activity. Furthermore, ESR levels in women during therapy correlated with their clinical disease activity scores. Further exploration of these gender-specific differences is crucial for a greater understanding of the pathogenesis of AS as well as development of targeted therapies.


Assuntos
Adalimumab/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Etanercepte/uso terapêutico , Infliximab/uso terapêutico , Caracteres Sexuais , Espondilite Anquilosante/tratamento farmacológico , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Adalimumab/farmacologia , Adulto , Anticorpos Monoclonais/farmacologia , Estudos de Coortes , Etanercepte/farmacologia , Feminino , Humanos , Infliximab/farmacologia , Masculino , Pessoa de Meia-Idade , Espondilite Anquilosante/etiologia , Fatores de Tempo , Resultado do Tratamento
6.
Clin Radiol ; 72(7): 611.e1-611.e8, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28214478

RESUMO

AIM: To evaluate the accuracy of non-arthrographic 64-section multidetector computed tomography (CT) in the assessment of cruciate ligament tears. A secondary goal was to determine its accuracy in the diagnosis of additional soft-tissue injuries around the knee. MATERIALS AND METHODS: Forty consecutive outpatients underwent same-day magnetic resonance imaging (MRI) and 64-slice multidetector CT (MDCT) of the knee in this prospective study. MDCT images were independently evaluated for integrity of the anterior (ACL) and posterior cruciate ligaments (PCL), medial and lateral menisci, and medial and lateral collateral ligaments. Recognised secondary signs of ACL tears were also documented. MRI images were subsequently assessed by two radiologists and a consensus reached. RESULTS: The sensitivity of MDCT for ACL tears was 87.5-100%, with a specificity of 100%. The presence of one or more secondary signs of ACL tears on MDCT had a sensitivity of 50-87.5% with a specificity of 100%. The sensitivity of MDCT for PCL tears was 0-25% with a specificity of 100%. The sensitivity for meniscal tears was 9.1-23.1% with a specificity of 96.3-100%. CONCLUSION: 64-section MDCT has very high sensitivity and specificity for ACL tears and, as on MRI, secondary signs, such as buckling of the PCL, are also useful in their diagnosis. MDCT has a low sensitivity for other soft-tissue injuries at the knee; however, its high specificity indicates that apparent PCL, meniscal, and collateral ligament tears can reliably be treated as true-positive findings.


Assuntos
Lesões do Ligamento Cruzado Anterior/diagnóstico por imagem , Tomografia Computadorizada Multidetectores , Ligamento Cruzado Posterior/diagnóstico por imagem , Ligamento Cruzado Posterior/lesões , Adolescente , Adulto , Idoso , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada Multidetectores/métodos , Estudos Prospectivos , Reprodutibilidade dos Testes , Adulto Jovem
7.
Ir Med J ; 110(4): 544, 2017 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-28665083

RESUMO

The aim of this study was to identify and analyse all articles published by Irish radiology departments in the medical literature since the year 2000. The PubMed database was searched to identify and review all articles published by radiologists based in the Republic of Ireland or Northern Ireland. Citation counts were then obtained and the top ten most cited articles were identified. There were 781 articles published during the study period. Of these, 558 (71%) were published in radiology journals and the remaining 223 (29%) were published in general medical journals. Abdominal radiology was the most represented sub-specialty (33% of all articles). There was a general trend of increased publications per year. Only 75 (9.6%) of articles were collaborative efforts by more than one radiology department. Irish radiology departments have a considerable research output and this has increased since the year 2000. More collaborative research between Irish radiology departments is encouraged.


Assuntos
Bibliometria , Radiologia/estatística & dados numéricos , Pesquisa Biomédica , Humanos , Irlanda , Irlanda do Norte , Publicações Periódicas como Assunto/estatística & dados numéricos , PubMed
8.
Psychol Med ; 46(3): 611-21, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26549475

RESUMO

BACKGROUND: Understanding individual-level changes in mental health status after prison release is crucial to providing targeted and effective mental health care to ex-prisoners. We aimed to describe trajectories of psychological distress following prison discharge and compare these trajectories with mental health service use in the community. METHOD: The Kessler Psychological Distress Scale (K10) was administered to 1216 sentenced adult prisoners in Queensland, Australia, before prison release and approximately 1, 3 and 6 months after release. We used group-based trajectory modeling to identify K10 trajectories after release. Contact with community mental health services in the year following release was assessed via data linkage. RESULTS: We identified five trajectory groups, representing consistently low (51.1% of the cohort), consistently moderate (29.8%), high increasing (11.6%), high declining (5.5%) and consistently very high (1.9%) psychological distress. Mood disorder, anxiety disorder, history of self-harm and risky drug use were risk factors for the high increasing, very high and high declining trajectory groups. Women were over-represented in the high increasing and high declining groups, but men were at higher risk of very high psychological distress. Within the high increasing and very high groups, 25% of participants accessed community mental health services in the first year post-release, for a median of 4.4 contact hours. CONCLUSIONS: For the majority of prisoners with high to very high psychological distress, distress persists after release. However, contact with mental health services in the community appears low. Further research is required to understand barriers to mental health service access among ex-prisoners.


Assuntos
Prisioneiros/psicologia , Estresse Psicológico/diagnóstico , Estresse Psicológico/epidemiologia , Adulto , Feminino , Acessibilidade aos Serviços de Saúde , Humanos , Masculino , Serviços de Saúde Mental , Prisões , Estudos Prospectivos , Escalas de Graduação Psiquiátrica , Queensland , Fatores de Risco
9.
Clin Radiol ; 71(9): 863-8, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27345612

RESUMO

AIM: To assess if diffusion-weighted imaging (DWI) alone could be used for follow-up of neuroendocrine hepatic metastases. MATERIAL AND METHODS: This was a retrospective study, approved by the institutional review board. Twenty-two patients with neuroendocrine liver metastases who had undergone more than one liver magnetic resonance imaging (MRI) examination, (including DWI and using hepatocyte-specific contrast medium) were evaluated. Up to five metastases were measured at baseline and at each subsequent examination. The reference standard measurement was performed on the hepatocyte phase by one reader. Three independent readers separately measured the same lesions on DWI sequences alone, blinded to other sequences, and recorded the presence of any new lesions. RESULTS: The longest diameters of 317 liver metastases (91 on 22 baseline examinations and a further 226 measurements on follow-up) were measured on the reference standard by one reader and on three b-values by three other readers. The mean difference between DWI measurements and the reference standard measurement was between 0.01-0.08 cm over the nine reader/b-value combinations. Based on the width of the Bland and Altman interval containing approximately 95% of the differences between the reader observation and the mean of reference standard and DWI measurement, the narrowest interval over the nine reader/b-value combinations was -0.6 to +0.7 cm and the widest was -0.9 to 1 cm. In the evaluation of overall response using Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria, the weighted kappa statistic was between 0.49 and 0.86, indicating moderate-to-good agreement between the reference standard and DWI. CONCLUSION: The visualisation and measurement of hepatic metastases using DWI alone are within acceptable limits for clinical use, allowing the use of this rapid technique to restage hepatic disease in patients with neuroendocrine metastases.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Interpretação de Imagem Assistida por Computador/métodos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/secundário , Tumores Neuroendócrinos/diagnóstico por imagem , Tumores Neuroendócrinos/secundário , Adulto , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
10.
Ir Med J ; 108(10): 316-7, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26817293

RESUMO

Paget's disease of bone is a focal disorder of bone remodelling leading to areas of enlarged weakened bone manifesting with chronic pain, bone deformity, and fracture. Predominantly a disease of older adults, its prevalence is strongly linked to European ancestry. Pre-disposing factors include exposure to viruses such as measles and mutations in the SQSTM1 gene. PDB is diagnosed on plain radiograph, the extent of disease is delineated by radionuclide bone imaging, the degree of activity is quantified biochemically, and it is treated with a nitrogen-containing bisphosphonate, most effectively by a single intravenous infusion of zoledronate 5mg. Lifelong specialist follow-up is advocated because some patients require repeated infusions. Current clinical research is focusing on genetic factors in order to identify patients suitable for prevention.


Assuntos
Osteíte Deformante/etiologia , Osteíte Deformante/terapia , Humanos , Osteíte Deformante/diagnóstico , Indução de Remissão
11.
Ir Med J ; 107(8): 244-5, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25282967

RESUMO

There has been an increase in gun-related crime in Ireland over the last decade to gangland violence, especially in west Dublin. This places a burden on hospital services not previously encountered. The aim of this study was to examine the demographics of gunshot: injuries presenting to a Dublin teaching hospital, and the impact on radiology over a ten year period. A total of 65 gunshot injuries were seen. Mortality for high velocity wounds was much higher (10/23, 43%) than for low-velocity shotgun injuries (2/34, 6%).


Assuntos
Ferimentos por Arma de Fogo/diagnóstico por imagem , Adolescente , Adulto , Feminino , Hospitais de Ensino , Humanos , Irlanda/epidemiologia , Masculino , Pessoa de Meia-Idade , Radiografia , Estudos Retrospectivos , Ultrassonografia , Ferimentos por Arma de Fogo/epidemiologia , Adulto Jovem
12.
Eur J Dent Educ ; 18(1): 44-50, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24423175

RESUMO

INTRODUCTION: Peer assessment is a widely recognised practice in higher education and is being increasingly utilised in healthcare education. It offers multiple advantages and may play a useful role in enhancing students' learning experience. This study was carried out to evaluate the utility of peer assessment in tooth extraction competency in simulated dental learning environment (SDLE). METHODS: Year 2 dental students were invited to participate in a formative, peer assessment exercise on forceps tooth extraction in SDLE. The ratings made by peers in the formative assessment were compared with the ratings made by academic supervisors in an equivalent summative assessment. RESULTS: One hundred and twenty-two students participated in both the formative and summative assessments. Descriptive statistics demonstrated that the majority of students were given the same rating in both assessments. However, there were a number of students who were rated as 'Competent' in one assessment and 'Not Competent' in the other assessment. Spearman's Rho correlations showed that there were weak relationships between the formative and summative assessments. There was also weak inter-rater reliability for the ratings of the peers and academic supervisors, as measured by the intraclass correlation coefficient. Feedback from the students and academic supervisors showed unanimously positive perceptions about the peer assessment experience, and they expressed the desire for incorporating peer assessment in other competencies. CONCLUSIONS: This study shows mixed results with regard to the value of the peer assessment. Given the potential utility of peer assessment as a tool to augment and enrich students' learning experience, further work needs to be done to evaluate the use of peer assessment in operative competencies in dentistry.


Assuntos
Competência Clínica , Educação em Odontologia , Avaliação Educacional/métodos , Revisão por Pares , Cirurgia Bucal/educação , Extração Dentária/normas , Adulto , Feminino , Humanos , Masculino
13.
Eur J Dent Educ ; 18(3): 135-41, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24266873

RESUMO

INTRODUCTION: Wisdom tooth removal is one of the most common oral surgical procedures performed across the world. The aim of this study was to gauge the teaching and training of impacted wisdom teeth in undergraduate dental programmes across the UK. The objectives were to identify consistencies and variations in theoretical instructions and clinical training as well as approaches to management of impacted wisdom teeth. METHODS: This was a cross-sectional survey utilising an online questionnaire. A purposefully designed pro forma with open- as well as closed-ended questions was used. The questionnaire was hosted online on the school's blackboard academic suite (Emily). Prior to conducting the study, approval was gained from the Research and Ethics Committee, and all the ethical principles pertaining to data protection were strictly followed. E-mail invitations were sent to oral surgery leads in all dental schools in the UK. The participants were provided with an information sheet, and an informed consent was obtained. The participants were invited by e-mail to complete the questionnaire online voluntarily. RESULTS: A total of 16 dental schools offering an undergraduate course in dentistry in the UK, 13 responded positively. (response rate = 81.25%). In majority of dental schools, this subject is taught in the 4th and 5th years. A pre-clinical competency on phantom heads is a requirement in six schools, whilst only one school requires the students to pass a clinical competency. The clinical exposure of students to wisdom tooth surgery is quite variable. Although the dental schools are fairly consistent in their teaching with regard to the indications for surgical intervention, diagnostic/treatment modalities as well as the post-operative care, interesting variations were also observed. CONCLUSIONS: This study, perhaps the first of its kind, provides useful insights into management of impacted wisdom teeth, as taught in the undergraduate dental programmes across the UK.


Assuntos
Competência Clínica , Currículo , Educação em Odontologia , Dente Serotino/cirurgia , Cirurgia Bucal/educação , Dente Impactado/cirurgia , Estudos Transversais , Humanos , Internet , Faculdades de Odontologia , Inquéritos e Questionários , Reino Unido
14.
Ir Med J ; 105(4): 115-6, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22708226

RESUMO

Tumours of the chest wall are uncommon and are usually malignant. A bone haemangioma is a rare benign vascular neoplasm, which more commonly occurs in middle-aged patients. We present the case of a scoliosis caused by a rib haemangioma in an adolescent male. Other causes of scoliosis secondary to rib lesions are discussed.


Assuntos
Neoplasias Ósseas/complicações , Hemangioma/complicações , Escoliose/etiologia , Adolescente , Neoplasias Ósseas/diagnóstico , Hemangioma/diagnóstico , Humanos , Masculino , Costelas/patologia , Tomografia Computadorizada por Raios X
15.
Eur J Dent Educ ; 16(2): 102-9, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22494309

RESUMO

INTRODUCTION: Established in 2007, Peninsula Dental School offers a highly innovative, enquiry-based, student-led, patient-centred curriculum. It is one of the first dental schools in UK to be based exclusively in a primary care setting. This study was carried out to evaluate the academic environment at Peninsula Dental School and to identify differences between expectations of new entrants and perceptions of senior cohorts. METHODS: This was a cross-sectional survey utilising an online questionnaire based on Dundee Ready Educational Environment Measure (DREEM). The subjects were 234 dental students from all years in this enquiry-based Bachelor of Dental Surgery programme. RESULTS: The response rate to the questionnaire was 56.42% with an equal gender distribution of the participants. The overall mean DREEM score of the four cohorts was 143.58 (SD ± 20.84), and the mean score for individual items was 2.87 (SD ± 0.41). The reliability of the DREEM data as a whole was strong (α = 0.93). The difference in questionnaire means for the new entrants and the senior cohorts was not significant (P > 0.05). The ANOVA results showed that there were no significant effects of age, gender or ethnicity on the mean DREEM scores. The MANOVA results showed a significant effect of ethnicity with regard to perceptions of teachers and atmosphere. CONCLUSIONS: An enquiry-based, student-centred curriculum at the Peninsula Dental School provides a positive academic environment for the students.


Assuntos
Educação em Odontologia/tendências , Percepção , Faculdades de Odontologia/organização & administração , Meio Social , Estudantes de Odontologia/psicologia , Adulto , Análise de Variância , Estudos Transversais , Feminino , Humanos , Masculino , Inquéritos e Questionários , Reino Unido
16.
Aust J Prim Health ; 28(3): 264-270, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35512815

RESUMO

BACKGROUND: People released from prison have poorer health than the general public, with a particularly high prevalence of mental illness and harmful substance use. High-frequency use of hospital-based services is costly, and greater investment in transitional support and primary care services to improve the health of people leaving prison may therefore be cost-effective. METHODS: A prospective cohort study of 1303 men and women released from prisons in Queensland, Australia, between 2008 and 2010, using linked data was performed. We calculated healthcare costs and the cost of re-incarceration. We compared healthcare costs to the general public, and assessed the impact of past mental illness, substance use disorder, and dual diagnosis on both healthcare and criminal justice costs. RESULTS: Healthcare costs among the cohort were 2.1-fold higher than expected based on costs among the public. Dual diagnosis was associated with 3.5-fold higher healthcare costs (95% CI 2.6-4.6) and 2.8-fold higher re-incarceration costs (95% CI 1.6-5.0), compared with no past diagnosis of either mental illness or substance use disorder. CONCLUSIONS: People released from prison incur high healthcare costs, primarily due to high rates of engagement with emergency health services and hospital admissions. Comorbid mental illness and substance use disorders are associated with high health and criminal justice costs among people recently released from prison.


Assuntos
Prisioneiros , Transtornos Relacionados ao Uso de Substâncias , Estudos de Coortes , Direito Penal , Diagnóstico Duplo (Psiquiatria) , Feminino , Custos de Cuidados de Saúde , Humanos , Masculino , Prisões , Estudos Prospectivos , Queensland/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/diagnóstico , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/terapia
18.
Ir Med J ; 101(6): 184-5, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18700514

RESUMO

Pseudoaneurysm of the subclavian artery is a rare but serious condition generally occurring as a result of penetrating injury to the shoulder region, often iatrogenic. As well as the potential for distal ischaemia, this condition can result in compression of adjacent structures. Untreated it can lead to rupture with life-threatening haemorrhage. We describe the unusual case of a patient with a background of metastatic breast carcinoma who presented with a pseudoaneurysm of the subclavian artery secondary to a pathological fracture of the clavicle. The patient was managed surgically due to the development of necrosis of the overlying skin. Less invasive management of subclavian pseudoaneurysms has recently been described, including endovascular stenting and percutaneous thrombin injection.


Assuntos
Falso Aneurisma/etiologia , Clavícula/lesões , Fraturas Ósseas/complicações , Artéria Subclávia/patologia , Idoso , Falso Aneurisma/diagnóstico , Clavícula/patologia , Feminino , Humanos
19.
J Clin Invest ; 90(3): 953-64, 1992 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1522243

RESUMO

We find that pADEO16, a recombinant cosmid carrying the rck gene of the Salmonella typhimurium virulence plasmid, when cloned into either rough or smooth Escherichia coli and Salmonella strains, confers high level resistance to the bactericidal activity of pooled normal human serum. The rck gene encodes a 17-kD outer membrane protein that is homologous to a family of virulence-associated outer membrane proteins, including pagC and Ail. Complement depletion, C3 and C5 binding, and membrane-bound C3 cleavage products are similar in strains with and without rck. Although a large difference in C9 binding was not seen, trypsin cleaved 55.7% of bound 125I-C9 counts from rough S. typhimurium with pADEO16, whereas only 26.4% were released from S. typhimurium with K2011, containing a mutation in rck. The majority of C9 extracted from rck strain membranes sediments at a lower molecular weight than in strains without rck, suggesting less C9 polymerization. Furthermore, SDS-PAGE analysis of gradient peak fractions indicated that the slower sedimenting C9-containing complexes in rck strains did not contain polymerized C9 typical of the tubular membrane attack complex. These results indicate that complement resistance mediated by Rck is associated with a failure to form fully polymerized tubular membrane attack complexes.


Assuntos
Proteínas da Membrana Bacteriana Externa/genética , Atividade Bactericida do Sangue , Proteínas do Sistema Complemento/fisiologia , Genes Bacterianos , Plasmídeos , Salmonella typhimurium/genética , Anticorpos Monoclonais/imunologia , Autorradiografia , Centrifugação com Gradiente de Concentração , Complemento C5/metabolismo , Complemento C9/metabolismo , Complexo de Ataque à Membrana do Sistema Complemento/metabolismo , Cosmídeos , Humanos , Salmonella typhimurium/patogenicidade , Virulência
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