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Verma R, Mupparaju V, Nair SP. Intrahepatic Splenosis: Benign but Can Be Misdiagnosed. Clin Gastroenterol Hepatol 2023; 21:A14. [PMID: 35934290 DOI: 10.1016/j.cgh.2022.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 07/08/2022] [Accepted: 07/12/2022] [Indexed: 02/07/2023]
Affiliation(s)
- Rajanshu Verma
- Department of Gastroenterology, University of Tennessee Health Sciences Center, Memphis, Tennessee
| | - Vamsee Mupparaju
- Department of Transplant Hepatology, University of Tennessee Health Sciences Center, Memphis, Tennessee
| | - Satheesh P Nair
- Division of Transplant Surgery, Department of Surgery, University of Tennessee Health Sciences Center, Memphis, Tennessee
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2
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Kreitman KR, Kothadia JP, Nair SP, Maliakkal BJ. Unexpected hepatitis B virus transmission after liver transplant from nucleic acid testing- and serology-negative liver donors who are hepatitis C viremic. Hepatol Res 2021; 51:1242-1246. [PMID: 34114715 DOI: 10.1111/hepr.13680] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 06/02/2021] [Accepted: 06/06/2021] [Indexed: 01/15/2023]
Abstract
The opioid epidemic has led to increased availability of organs for liver transplantation. The success of direct-acting antiviral therapy for hepatitis C (HCV) has led to the acceptance of HCV viremic donor organs. Nucleic acid testing (NAT) has led to increased detection of HCV and hepatitis B (HBV) in potential donors. A total of 36 patients underwent liver transplantation from donation after brain death donors who were HCV NAT-positive, and three of them were diagnosed with HBV several months after. All three recipients received livers from HCV viremic donors who were negative for HBV by serology and NAT. Soon after liver transplantation, HCV was treated, and all achieved sustained virologic response. They became HBV DNA-positive shortly thereafter. To date, there have been no reported cases of unexpected HBV transmission since universal donor NAT was implemented in 2013. We postulate that the inhibitory effect of HCV viremia on HBV may have prolonged the "NAT window period" in these donors beyond the 20-22 days quoted for solitary HBV infection. These cases highlight the need for more intensive and prolonged screening for HBV in recipients of livers from HCV viremic donors.
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Affiliation(s)
- Kyle R Kreitman
- MUH James D. Eason Transplant Institute, University of Tennessee Health Sciences Center, Memphis, Tennessee, USA
| | - Jiten P Kothadia
- MUH James D. Eason Transplant Institute, University of Tennessee Health Sciences Center, Memphis, Tennessee, USA
| | - Satheesh P Nair
- MUH James D. Eason Transplant Institute, University of Tennessee Health Sciences Center, Memphis, Tennessee, USA
| | - Benedict J Maliakkal
- MUH James D. Eason Transplant Institute, University of Tennessee Health Sciences Center, Memphis, Tennessee, USA
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3
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Nair SP, Marella HK, Maliakkal B, Snyder H, Handley C, Kothadia JP, Ali B, Satapathy SK, Molnar MZ, Clark I, Jain R, Helmick R, Eymard C, Eason JD. Transplantation of liver from hepatitis C-infected donors to hepatitis C RNA-negative recipients: Histological and virologic outcome. Clin Transplant 2021; 35:e14281. [PMID: 33690929 DOI: 10.1111/ctr.14281] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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: 07/26/2020] [Revised: 02/20/2021] [Accepted: 02/27/2021] [Indexed: 01/02/2023]
Abstract
BACKGROUND The virologic and histologic outcomes of a hepatitis C virus (HCV)-infected liver graft into an HCV-negative recipient are not well understood. We aimed to evaluate the sustained virologic response (SVR) rate and the liver histology at 1 year post-Orthotopic liver transplantation (OLT) with an HCV-infected graft. METHODS A total of 33 patients received the HCV antibody (Ab)+/nucleic acid amplification test (NAT)+ graft. Of these patients, 23 were HCV-negative recipients and 10 were HCV-positive recipients. The 1-year biopsy data were available for 24 patients: 15 patients in HCV-negative group who received an HCV Ab+/NAT+graft and 9 patients in HCV-positive group who received an HCV Ab+/NAT+ graft. Patients with (+) HCV ribonucleic acid (RNA) were started on direct-acting antiviral (DAA) treatment approximately 107 days after OLT using either a Glecaprevir-Pibrentasvir or Sofosbuvir-Velpatasvir or Sofosbuvir-Ledipasvir. RESULTS All patients (n = 33) were treated with DAA and achieved SVR. The 1-year post-OLT liver biopsies were available in 24 patients: 9 patients had F1 and F2 fibrosis and 17 patients had minimal to moderate inflammation. There was no statistical difference in fibrosis and inflammation between the HCV-negative vs. HCV-positive recipients. All patients who received the NAT+ graft developed viremia and subsequently achieved SVR with treatment. CONCLUSION At 1 year protocol liver biopsy, patients had inflammation consistent with viral hepatitis despite the successful eradication of HCV.
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Affiliation(s)
- Satheesh P Nair
- James D. Eason Transplant Institute, University of Tennessee Health Science Center', Methodist University Hospital, Memphis, TN, USA.,Department of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Hemnishil K Marella
- James D. Eason Transplant Institute, University of Tennessee Health Science Center', Methodist University Hospital, Memphis, TN, USA.,Department of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Benedict Maliakkal
- James D. Eason Transplant Institute, University of Tennessee Health Science Center', Methodist University Hospital, Memphis, TN, USA.,Department of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Heather Snyder
- James D. Eason Transplant Institute, University of Tennessee Health Science Center', Methodist University Hospital, Memphis, TN, USA
| | - Charlotte Handley
- James D. Eason Transplant Institute, University of Tennessee Health Science Center', Methodist University Hospital, Memphis, TN, USA
| | - Jiten P Kothadia
- James D. Eason Transplant Institute, University of Tennessee Health Science Center', Methodist University Hospital, Memphis, TN, USA.,Department of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Bilal Ali
- James D. Eason Transplant Institute, University of Tennessee Health Science Center', Methodist University Hospital, Memphis, TN, USA
| | - Sanjaya K Satapathy
- Department of Medicine, Zucker School of Medicine at Hofstra, Sandra Atlas Bass Center for Liver Diseases & Transplantation, Northshore University Hospital/Northwell Health, Manhasset, NY, USA
| | - Miklos Z Molnar
- James D. Eason Transplant Institute, University of Tennessee Health Science Center', Methodist University Hospital, Memphis, TN, USA
| | - Ian Clark
- Department of Pathology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Richa Jain
- Department of Pathology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Ryan Helmick
- James D. Eason Transplant Institute, University of Tennessee Health Science Center', Methodist University Hospital, Memphis, TN, USA
| | - Corey Eymard
- James D. Eason Transplant Institute, University of Tennessee Health Science Center', Methodist University Hospital, Memphis, TN, USA
| | - James D Eason
- James D. Eason Transplant Institute, University of Tennessee Health Science Center', Methodist University Hospital, Memphis, TN, USA
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4
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Muppidi V, Meegada S, Eaton JD, Nair SP, Verma R. Recurrent Cholangiocarcinoma Presenting as Sister Mary Joseph Nodule After Liver Transplantation. Cureus 2020; 12:e11673. [PMID: 33262920 PMCID: PMC7689875 DOI: 10.7759/cureus.11673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Hilar cholangiocarcinoma, also known as Klatskin tumor, is the most common type of cholangiocarcinoma. It usually has a lymphatic spread and is rarely associated with an umbilical nodule, also known as Sister Mary Joseph nodule. We report a case of a 53-year-old Caucasian man with hilar cholangiocarcinoma. The patient had an inoperable tumor and was referred to our center for liver transplantation. Post liver transplantation, the patient presented with a recurrence of the carcinoma in the umbilical region. The patient was found to have Sister Mary Joseph nodule. It carries a poor prognosis, and our patient succumbed to the illness in four months. Cholangiocarcinoma carries a poor prognosis. Surgical resection and liver transplantation with neoadjuvant chemoradiation are the preferred treatment strategies. Association of cholangiocarcinoma with umbilical metastasis is rare, and our patient had an even rarer presentation in the form of recurrence with umbilical nodule post-liver transplantation. We want to increase the awareness of the rare presentation, association, and recurrence of hilar cholangiocarcinoma in the form of umbilical nodule post-liver transplantation.
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5
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Satapathy SK, Thornburgh C, Heda R, Jiang Y, Kedia SK, Nair SP, Eason JD, Maluf D. Predicting harmful alcohol relapse after liver transplant: The HALT score. Clin Transplant 2020; 34:e14003. [PMID: 32506677 DOI: 10.1111/ctr.14003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [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: 12/11/2019] [Revised: 05/18/2020] [Accepted: 05/29/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND Alcohol-associated liver disease (AALD) is a rapidly growing indication for liver transplantation (LT). We aimed to examine various clinical, demographic, and behavioral factors to predict post-LT alcohol relapse and graft survival. METHODS Retrospective analysis was performed on 241 LT recipients with AALD as either a primary or secondary indication for LT (2006-2015). RESULTS Patients with <6 months of alcohol abstinence had significantly increased cumulative incidence for alcohol relapse compared to those with >6 months of abstinence (P = .0041, Log-Rank). We identified four variables to predict harmful alcohol relapse post-LT: age at LT, non-alcohol-related criminal history, pre-LT abstinence period (Ref >6 months of alcohol abstinence), and drinks per day (Ref <10 drinks/day). Area under the curve (AUC) for the final model was 0.79 (95% CI: 0.68-0.91). Our multivariable model was evaluated with internal cross-validation; random sampling of the study subjects 100 times yielded a median C statistic of 75 (±SD 0.097) and accuracy of 91 (±SD 0.026). The four-variable model served to form the harmful alcohol use post-LT (HALT) score. Graft survival remained significantly lower in patients with <6 months of pre-LT alcohol abstinence and those with blue-collar jobs. CONCLUSION The HALT score identifies LT candidates with AALD at significant risk for alcohol relapse, potentially guiding transplant centers for pre- and post-LT interventions for improved patient outcomes.
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Affiliation(s)
- Sanjaya K Satapathy
- Division of Hepatology and Sandra Atlas Bass Center for Liver Diseases & Transplantation, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Northwell Health, Manhasset, United States, USA
| | - Cody Thornburgh
- College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Rajiv Heda
- College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Yu Jiang
- School of Public Health, University of Memphis, Memphis, TN, USA
| | - Satish K Kedia
- School of Public Health, University of Memphis, Memphis, TN, USA
| | - Satheesh P Nair
- James D Eason Transplant Institute, Methodist University Hospital, University of Tennessee Health Science Center, Memphis, TN, USA
| | - James D Eason
- James D Eason Transplant Institute, Methodist University Hospital, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Daniel Maluf
- James D Eason Transplant Institute, Methodist University Hospital, University of Tennessee Health Science Center, Memphis, TN, USA
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6
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Ali B, Jiang Y, Agbim U, Kedia SK, Satapathy SK, Barnes M, Maliakkal B, Nair SP, Eason JD, Gonzalez HC. Effect of opioid treatment on clinical outcomes among cirrhotic patients in the United States. Clin Transplant 2020; 34:e13845. [DOI: 10.1111/ctr.13845] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 01/30/2020] [Accepted: 02/22/2020] [Indexed: 12/23/2022]
Affiliation(s)
- Bilal Ali
- Division of Gastroenterology Department of Medicine University of Tennessee Health Science Center Memphis TN USA
| | - Yu Jiang
- School of Public Health University of Memphis Memphis TN USA
| | - Uchenna Agbim
- Division of Gastroenterology Department of Medicine University of Tennessee Health Science Center Memphis TN USA
| | - Satish K. Kedia
- School of Public Health University of Memphis Memphis TN USA
| | - Sanjaya K. Satapathy
- Division of Hepatology at Sandra Atlas Bass Center for Liver Disease and Transplantation Donald and Barbara Zucker School of Medicine Northwell Health Long Island NY USA
| | - Matthew Barnes
- Division of Gastroenterology Department of Medicine University of Tennessee Health Science Center Memphis TN USA
| | - Benedict Maliakkal
- Division of Transplant Surgery Department of Surgery Methodist University Hospital University of Tennessee Health Science Center Memphis TN USA
| | - Satheesh P. Nair
- Division of Transplant Surgery Department of Surgery Methodist University Hospital University of Tennessee Health Science Center Memphis TN USA
| | - James D. Eason
- Division of Transplant Surgery Department of Surgery Methodist University Hospital University of Tennessee Health Science Center Memphis TN USA
| | - Humberto C. Gonzalez
- Department of Gastroenterology and Hepatology Henry Ford Health System Detroit MI USA
- Department of Internal Medicine Wayne State University School of Medicine Detroit MI USA
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7
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Heda RP, Savage Y, Nair SP, Verma R. Enterococcus casseliflavus, Streptococcus equinus and Klebsiella oxytoca septicaemia associated with perinephric haematoma in a post-liver transplant patient with allograft cirrhosis. BMJ Case Rep 2019; 12:12/8/e230096. [PMID: 31466981 DOI: 10.1136/bcr-2019-230096] [Citation(s) in RCA: 3] [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] [Indexed: 11/03/2022] Open
Abstract
Liver transplant recipients are immunocompromised by the virtue of being on immunosuppressive agents which put them at risk of having infections from unusual and even multiple concomitant pathogens. We present a case of a 39-year-old man who developed septicaemia with Enterococcus casseliflavus, Streptococcus equinus and Klebsiella oxytoca in the setting of perinephric haematoma which resulted following a kidney biopsy performed to evaluate his nephrotic range proteinuria. E. casseliflavus has been known to cause infections in patients with liver disease/cirrhosis; however, simultaneous infection with S. equinus and K. oxytoca along with E. casseliflavus has never been reported earlier in post-transplant state.
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Affiliation(s)
| | - Yolanda Savage
- Microbiology, Methodist University Hospital, Memphis, Tennessee, USA
| | - Satheesh P Nair
- Transplant Hepatology, Methodist University Hospital, UTHSC College of Medicine Memphis, Memphis, Tennessee, USA
| | - Rajanshu Verma
- Transplant Hepatology, Methodist University Hospital, UTHSC College of Medicine Memphis, Memphis, Tennessee, USA
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8
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Satapathy SK, Joglekar K, Molnar MZ, Ali B, Gonzalez HC, Vanatta JM, Eason JD, Nair SP. Achieving Sustained Virological Response in Liver Transplant Recipients With Hepatitis C Decreases Risk of Decline in Renal Function. Liver Transpl 2018; 24:1040-1049. [PMID: 29573131 DOI: 10.1002/lt.25059] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Revised: 02/28/2018] [Accepted: 03/10/2018] [Indexed: 12/15/2022]
Abstract
The effect of antiviral therapy (AVT) on kidney function in liver transplantation (LT) recipients has not been well described despite known association of hepatitis C virus (HCV) infection with chronic kidney disease (CKD). We compared the incidence of CKD and end-stage renal disease (ESRD) in 204 LT recipients with HCV based on treatment response to AVT. The mean estimated glomerular filtration rate (eGFR) at baseline (3 months after LT) was similar in the sustained virological response (SVR; n = 145) and non-SVR group (n = 59; 69 ± 21 versus 65 ± 33 mL/minute/1.73 m2 ; P = 0.27). In the unadjusted Cox proportional regression analysis, the presence of SVR was associated with an 88% lower risk of CKD (hazard ratio, 0.12; 95% confidence interval [CI], 0.05-0.31) and 86% lower risk of ESRD (odds ratio, 0.14; 95% CI, 0.05-0.35). Similar results were found after adjusting for propensity score and time-dependent Cox regression analyses. The estimated slopes of eGFR based on a 2-stage mixed model of eGFR were calculated. Patients with SVR had a less steep slope in eGFR (-0.60 mL/minute/1.73 m2 /year; 95% CI, -1.50 to 0.30; P = 0.190) than recipients without SVR (-2.53 mL/minute/1.73 m2 /year; 95% CI, -3.99 to -1.07; P = 0.001), and the differences in the slopes were statistically significant (P = 0.026). In conclusion, in LT recipients with chronic HCV infection, achieving SVR significantly lowers the risk of decline in renal function and progression to ESRD independent of the AVT therapy used.
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Affiliation(s)
- Sanjaya K Satapathy
- Division of Transplant Surgery, Methodist University Hospital Transplant Institute, Memphis, TN.,Departments of Surgery, University of Tennessee Health Science Center, Memphis, TN
| | - Kiran Joglekar
- Departments of Medicine, University of Tennessee Health Science Center, Memphis, TN
| | - Miklos Z Molnar
- Division of Transplant Surgery, Methodist University Hospital Transplant Institute, Memphis, TN.,Departments of Surgery, University of Tennessee Health Science Center, Memphis, TN.,Departments of Medicine, University of Tennessee Health Science Center, Memphis, TN.,Department of Transplantation and Surgery, Semmelweis University, Budapest, Hungary
| | - Bilal Ali
- Division of Transplant Surgery, Methodist University Hospital Transplant Institute, Memphis, TN.,Departments of Gastroenterology, University of Tennessee Health Science Center, Memphis, TN
| | - Humberto C Gonzalez
- Division of Transplant Surgery, Methodist University Hospital Transplant Institute, Memphis, TN.,Departments of Surgery, University of Tennessee Health Science Center, Memphis, TN
| | - Jason M Vanatta
- Division of Transplant Surgery, Methodist University Hospital Transplant Institute, Memphis, TN.,Departments of Surgery, University of Tennessee Health Science Center, Memphis, TN
| | - James D Eason
- Division of Transplant Surgery, Methodist University Hospital Transplant Institute, Memphis, TN.,Departments of Surgery, University of Tennessee Health Science Center, Memphis, TN
| | - Satheesh P Nair
- Division of Transplant Surgery, Methodist University Hospital Transplant Institute, Memphis, TN.,Departments of Surgery, University of Tennessee Health Science Center, Memphis, TN
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9
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Akbar A, Tran QT, Nair SP, Parikh S, Bilal M, Ismail M, Vanatta JM, Eason JD, Satapathy SK. Role of MRCP in Diagnosing Biliary Anastomotic Strictures After Liver Transplantation: A Single Tertiary Care Center Experience. Transplant Direct 2018; 4:e347. [PMID: 29796418 PMCID: PMC5959342 DOI: 10.1097/txd.0000000000000789] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 03/11/2018] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Biliary strictures (BS) are common complication after liver transplantation. We aimed to determine the accuracy of magnetic resonance cholagiopancreatography (MRCP) in diagnosing BS in liver transplant recipients (LTRs) when compared to direct cholangiographic methods (endoscopic resonance cholagiopancreatography [ERCP] and/or percutaneous transhepatic cholangiography [PTC]). METHODS Retrospective chart review of 910 LTRs (July 2008 to April 2015) was performed, and a total of 39 patients with duct-to-duct anastomosis (22 males; 56.4%; mean age, 52.8 ± 8.3 years) were included who had an MRCP followed by either ERCP and/or PTC within 4 weeks. A cholangiographic narrowing (on ERCP and/or PTC) that required balloon dilation and/or stent placement was considered a BS and was considered clinically significant if the intervention resulted in at least 30% improvement of bilirubin within 2 weeks. Sensitivity, specificity, accuracy, positive predictive values and negative predictive values of MRCP in diagnosing BS were calculated. RESULTS Magnetic resonance cholagiopancreatography showed anastomotic BS in 17 of 39 patients, and subsequent ERCP and/or PTC revealed a total of 25 BS (positive predictive value of 0.94). Nine BS on cholangiography (ERCP, 8; PTC, 1) were not detected on earlier MRCP (sensitivity, 0.64; 95% CI, 0.45-0.82); 2 were clinically significant BS and 6 of the remaining 7 had no improvement in their liver function test with biliary intervention. Thirteen LTRs had no BS on either modality (specificity, 0.93; 95% CI, 0.66-0.99). The negative predictive value of MRCP was 0.59 for cholangiographic BS. The overall accuracy of MRCP is 0.74 (exact 95% CI, 0.58-0.87). Inclusion of age, race, and alanine aminotransferase level improved the predictive value of MRCP (area under the curve = 0.94, 95% CI: 0.86-1.00). CONCLUSIONS Magnetic resonance cholagiopancreatography has high specificity but low sensitivity in diagnosing cholangiographic BS in LTRs, although the predictive value further improved with inclusion of age, race, and alanine aminotransferase. Clinical significance of BS in LTRs not identified on MRCP is questionable because ERCP with intervention did not improve their liver function tests in the vast majority.
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Affiliation(s)
- Ali Akbar
- Division of Gastroenterology and Hepatology, University of Tennessee Health Science Center, Memphis, TN
| | - Quynh T. Tran
- Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis, TN
| | - Satheesh P. Nair
- Division of Transplant Surgery, Methodist University Hospital Transplant Institute, University of Tennessee Health Science Center, Memphis, TN
| | - Salil Parikh
- Department of Radiology, Methodist University Hospital, University of Tennessee Health Sciences Center, Memphis, TN
| | - Muhammad Bilal
- Division of Gastroenterology and Hepatology, University of Tennessee Health Science Center, Memphis, TN
| | - Mohammed Ismail
- Division of Gastroenterology and Hepatology, University of Tennessee Health Science Center, Memphis, TN
| | - Jason M. Vanatta
- Division of Transplant Surgery, Methodist University Hospital Transplant Institute, University of Tennessee Health Science Center, Memphis, TN
| | - James D. Eason
- Division of Transplant Surgery, Methodist University Hospital Transplant Institute, University of Tennessee Health Science Center, Memphis, TN
| | - Sanjaya K. Satapathy
- Division of Transplant Surgery, Methodist University Hospital Transplant Institute, University of Tennessee Health Science Center, Memphis, TN
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10
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Satapathy SK, Das K, Kocak M, Helmick RA, Eason JD, Nair SP, Vanatta JM. No apparent benefit of preemptive sorafenib therapy in liver transplant recipients with advanced hepatocellular carcinoma on explant. Clin Transplant 2018; 32:e13246. [PMID: 29577449 DOI: 10.1111/ctr.13246] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/17/2018] [Indexed: 12/13/2022]
Abstract
BACKGROUND Sorafenib has shown survival benefits in patients with advanced HCC; however, limited data are available on its role in OLT recipients with advanced HCC in the explant. AIM Evaluate the role of preemptive sorafenib therapy on HCC recurrence and survival after OLT with advanced HCC on explant pathology. METHODS We retrospectively reviewed the outcome after OLT of all HCC recipients with advanced HCC in the explant pathology from 04/2006 to 12/2012 based on preemptive treatment with sorafenib. RESULTS During the observation period, 217 HCC recipients underwent OLT; 50 explants revealed advanced HCC. After exclusion of 5 patients who were lost to follow-up, 45 LT recipients were finally included for analysis. Recipients were grouped as sorafenib Gr (N = 25) and nonsorafenib Gr (N = 20). Both recurrence-free survival (RFS) (P = .67) and overall survival were similar between groups (P = .53) on Kaplan-Meier analysis. Additionally, sorafenib use was neither associated with HCC recurrence-free survival (HR 0.74, 95% CI [0.32-1.70]; P = .48) nor overall survival (HR 0.92, 95% CI [0.39-2.15], P = .84) on multivariate Cox proportional hazard model with sorafenib use as time-varying covariates. CONCLUSION Preemptive treatment with sorafenib in OLT recipients with high-risk features in explant does not improve HCC recurrence-free or overall survival.
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Affiliation(s)
- Sanjaya K Satapathy
- Transplantation, Methodist University Hospital Transplant Institute/University of Tennessee Health Sciences Center, Memphis, TN, USA
| | - Kanak Das
- Division of Gastroenterology, University of Tennessee Health Sciences Center, Memphis, TN, USA
| | - Mehmet Kocak
- Department of Preventive Medicine, University of Tennessee Health Sciences Center, Memphis, TN, USA
| | - Ryan A Helmick
- Transplantation, Methodist University Hospital Transplant Institute/University of Tennessee Health Sciences Center, Memphis, TN, USA
| | - James D Eason
- Transplantation, Methodist University Hospital Transplant Institute/University of Tennessee Health Sciences Center, Memphis, TN, USA
| | - Satheesh P Nair
- Transplantation, Methodist University Hospital Transplant Institute/University of Tennessee Health Sciences Center, Memphis, TN, USA
| | - Jason M Vanatta
- Transplantation, Methodist University Hospital Transplant Institute/University of Tennessee Health Sciences Center, Memphis, TN, USA
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11
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Satapathy SK, Sheikh I, Ali B, Yahya F, Kocak M, Parsa LB, Eason JD, Vanatta JM, Nair SP. Long-term outcomes of early compared to late onset choledochocholedochal anastomotic strictures after orthotopic liver transplantation. Clin Transplant 2017; 31. [DOI: 10.1111/ctr.13003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/03/2017] [Indexed: 12/27/2022]
Affiliation(s)
- Sanjaya K. Satapathy
- Division of Transplantation; Methodist University Hospital Transplant Institute; University of Tennessee Health Science Center; Memphis TN USA
| | - Imran Sheikh
- Department of Gastroenterology and Hepatology; University of Tennessee Health Science Center; Memphis TN USA
| | - Bilal Ali
- Division of Transplantation; Methodist University Hospital Transplant Institute; University of Tennessee Health Science Center; Memphis TN USA
| | - Fazal Yahya
- Department of Medicine; University of Tennessee Health Science Center; Memphis TN USA
| | - Mehmet Kocak
- Department of Biostatistics and Epidemiology; University of Tennessee Health Sciences Center; Memphis TN USA
| | - Laxmi Babu Parsa
- Division of Transplantation; Methodist University Hospital Transplant Institute; University of Tennessee Health Science Center; Memphis TN USA
| | - James D. Eason
- Division of Transplantation; Methodist University Hospital Transplant Institute; University of Tennessee Health Science Center; Memphis TN USA
| | - Jason M. Vanatta
- Division of Transplantation; Methodist University Hospital Transplant Institute; University of Tennessee Health Science Center; Memphis TN USA
| | - Satheesh P. Nair
- Division of Transplantation; Methodist University Hospital Transplant Institute; University of Tennessee Health Science Center; Memphis TN USA
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12
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Twilla JD, Nair SP, Talwar M, Kovalic A, Satapathy SK. Severity of Systemic Inflammatory Response Syndrome Affects Outcomes in Decompensated Cirrhotics with Spontaneous Bacterial Peritonitis. Am J Gastroenterol 2016; 111:1043-5. [PMID: 27356838 DOI: 10.1038/ajg.2016.146] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Jennifer D Twilla
- Methodist University Hospital, Memphis, Tennessee, USA.,University of Tennessee Health Science Center, College of Pharmacy, Memphis, Tennessee, USA
| | - Satheesh P Nair
- Methodist University Hospital, Memphis, Tennessee, USA.,Methodist University Hospital Transplant Institute, Memphis, Tennessee, USA.,University of Tennessee Health Science Center, College of Medicine, Memphis, Tennessee, USA
| | - Manish Talwar
- Methodist University Hospital, Memphis, Tennessee, USA.,Methodist University Hospital Transplant Institute, Memphis, Tennessee, USA.,University of Tennessee Health Science Center, College of Medicine, Memphis, Tennessee, USA
| | - Alexander Kovalic
- University of Tennessee Health Science Center, College of Medicine, Memphis, Tennessee, USA
| | - Sanjaya K Satapathy
- Methodist University Hospital, Memphis, Tennessee, USA.,Methodist University Hospital Transplant Institute, Memphis, Tennessee, USA.,University of Tennessee Health Science Center, College of Medicine, Memphis, Tennessee, USA
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13
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Nair SP, Kumar GN, Mathew R. Histoid Leprosy Presenting with Keloid Like Lesions. Indian J Lepr 2016; 88:117-121. [PMID: 29757544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A 42 year old male presented with multiple, discrete, hyperpigmented, firm, non elastic, non tender papules and plaques on the posterior trunk of 5 months duration, resembling keloid. The patient had also a few skin colored papules on the anterior trunk and face. The sensations over the skin lesions were intact. The patient had glove and stocking type of anesthesia and bilaterally thickened, non tender peripheral nerve trunks. The slit skin smear for acid fast bacilli from the ear lobes, skin lesions and normal skin were highly positive for Mycobacterium leprae. A skin biopsy showed a well defined collection of spindle shaped histiocytes in the dermis packed with acid fast bacilli. We are presenting here a case of histoid leprosy presenting with keloid like lesions, probably the rarest presentation of histoid leprosy.
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Nair SP, Righetti R. Resimulation of noise: a precision estimator for least square error curve-fitting tested for axial strain time constant imaging. Phys Med Biol 2015; 60:3515-29. [DOI: 10.1088/0031-9155/60/9/3515] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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15
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Nair SP. Protease inhibitor therapy post-liver transplantation in the treatment of hepatitis C virus infection. Gastroenterol Hepatol (N Y) 2013; 9:388-390. [PMID: 23935546 PMCID: PMC3736796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Affiliation(s)
- Satheesh P Nair
- Professor of Medicine Director of Transplant Hepatology University of Tennessee Health Science Center Memphis, Tennessee
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16
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Nair SP. Management of hepatitis C virus infection in liver transplant recipients. Gastroenterol Hepatol (N Y) 2012; 8:56-59. [PMID: 22347835 PMCID: PMC3277201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Affiliation(s)
- Satheesh P Nair
- Transplant Hepatology Methodist University Hospital, University of Tennessee Health Science Center Memphis, Tennessee, USA
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17
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Xanthopoulos P, Liu CC, Zhang J, Miller ER, Nair SP, Uthman BM, Kelly K, Pardalos PM. A robust spike and wave algorithm for detecting seizures in a genetic absence seizure model. Annu Int Conf IEEE Eng Med Biol Soc 2009; 2009:2184-7. [PMID: 19965148 DOI: 10.1109/iembs.2009.5334941] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Animal Models are used extensively in basic epilepsy research. In many studies, there is a need to accurately score and quantify all epileptic spike and wave discharges (SWDs) as captured by electroencephalographic (EEG) recordings. Manual scoring of long term EEG recordings is a time-consuming and tedious task that requires inordinate amount of time of laboratory personnel and an experienced electroencephalographer. In this paper, we adapt a SWD detection algorithm, originally proposed by the authors for absence (petit mal) seizure detection in humans, to detect SWDs appearing in EEG recordings of Fischer 334 rats. The algorithm is robust with respect to the threshold parameters. Results are compared to manual scoring and the effect of different threshold parameters is discussed.
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Affiliation(s)
- Petros Xanthopoulos
- Industrial and Systems Engineering Department at University of Florida, Gainesville, FL 32611, USA.
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18
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Narband N, Mubarak M, Ready D, Parkin IP, Nair SP, Green MA, Beeby A, Wilson M. Quantum dots as enhancers of the efficacy of bacterial lethal photosensitization. Nanotechnology 2008; 19:445102. [PMID: 21832719 DOI: 10.1088/0957-4484/19/44/445102] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Because of the increasing resistance of bacteria to antibiotics there is considerable interest in light-activated antimicrobial agents (LAAAs) as alternatives to antibiotics for treating localized infections. The purpose of this study was to determine whether CdSe/ZnS quantum dots (QD) could enhance the antibacterial activity of the LAAA, toluidine blue O (TBO). Suspensions of Staphylococcus aureus and Streptococcus pyogenes were exposed to white light (3600 lux) and TBO (absorbance maximum = 630 nm) in the presence and absence of 25 nm diameter QD (emission maximum = 627 nm). When the TBO:QD ratio was 2667:1, killing of Staph. aureus was enhanced by 1.72log(10) units. In the case of Strep. pyogenes, an enhanced kill of 1.55log(10) units was achieved using TBO and QD in the ratio 267:1. Singlet oxygen and fluorescence measurements showed that QD suppress the formation of singlet oxygen from TBO and that QD fluorescence is significantly quenched in the presence of TBO (70-90%). Enhanced killing appears to be attributable to a non-Förster resonance energy transfer mechanism, whereby the QD converts part of the incident light to the absorption maximum for TBO; hence more light energy is harvested, resulting in increased concentrations of bactericidal radicals. QD may, therefore, be useful in improving the efficacy of antimicrobial photodynamic therapy.
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Affiliation(s)
- N Narband
- Materials Chemistry Research Centre, Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK
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19
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Abstract
Staphylococcus aureus produce a family of exotoxins (staphylococcal superantigen like proteins, SSLs) with structural, but not functional, homology to superantigens. These proteins have previously been shown to interact selectively with antigen presenting cells, including dendritic cells. The functional consequences of this interaction are now explored. SSL7 and 9 had no effect on viability or morphology of dendritic cells. The proteins did not induce dendritic cell maturation, as measured by cell surface phenotype. Exposure to SSL did not alter the ability of dendritic cells to take up FITC-dextran. Finally, exposure to SSLs did not impair the ability of the dendritic cells to stimulate allogeneic or antigen specific T cell responses. However, dendritic cells loaded with SSL7 or 9 were able to stimulate a T cell proliferative response in 3/8 healthy individuals tested. Sera from nine out of 10 individuals tested contained antibodies against both SSL7 and SSL9, and the response to each SSL was specific and not cross-reactive. The results demonstrate that SSLs are immunogenic in humans at both the B and T cell level, but it remains unclear whether this response is to the benefit of the bacterium or the host.
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20
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Balamurugan V, Renji R, Venkatesh G, Reddy GR, Nair SP, Ganesh K, Suryanarayana VVS. Protective immune response against foot-and-mouth disease virus challenge in guinea pigs vaccinated with recombinant P1 polyprotein expressed in Pichia pastoris. Arch Virol 2005; 150:967-79. [PMID: 15662485 DOI: 10.1007/s00705-004-0460-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [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: 01/20/2004] [Accepted: 10/29/2004] [Indexed: 11/24/2022]
Abstract
Vaccination of the susceptible livestock with potent, safe and cost effective vaccine is the primary requirement to control foot-and-mouth disease (FMD) in an endemic country. In this study, an alternative approach was used in which structural protein genes of all the four serotypes of FMDV (O, Asia 1, A22 and C) were expressed separately in methylotrophic yeast Pichia pastoris. The recombinant polyproteins (P1) were characterized by SDS-PAGE and in Western Blot analysis. Partially purified protein was used for immunization in guinea pigs with different adjuvant formulations and immune response studied. Ninety micrograms of the recombinant protein per monovalent dose was used for immunization. A single injection of a monovalent or polyvalent vaccine was given to guinea pigs with various adjuvant combinations viz., Monovalent recombinant protein either adjuvanted with Montanide-ISA50V or Indigenous oil, Monovalent recombinant protein mixed with 1/10th dose of inactivated oil-adjuvanted virus vaccine and Polyvalent recombinant protein with Montanide ISA50V. FMDV specific humoral immune response was observed at about 28th day post vaccination. The immune response as assessed by indirect ELISA and Serum neutralization test titres was found to be 320-640 and 16-32, respectively. When challenged with virulent homologous type 'O' virus, the guinea pigs showed protective C index of 2.01,1.81, 2.56 and 2.48, respectively, with above said adjuvant combinations. The study has shown that yeast-expressed FMDV P1 polyprotein in a single dose could elicit a protective immune response in guinea pigs, and this could be a possible future vaccine candidate in homologous host.
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Affiliation(s)
- V Balamurugan
- Indian Veterinary Research Institute, Hebbal, Bangalore, India
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21
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Nair SP, Moorty KP, Suprakasan S. Clinico-epidemiological study of HIV patients in Trivandrum. Indian J Dermatol Venereol Leprol 2003; 69:100-3. [PMID: 17642847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
A retrospective descriptive study of 121 HIV patients in the Department was carried out. The male/female ratio was 2.3:1. The maximum number of patients were seen in age group 21-40 (77.68%). Skilled workers constituted the maximum (13.2%). Sexual route was the commonest mode of transmission (78.5%). Cutaneous manifestations were present in 57% of patients, oral condidiasis being the commonest (16.5%). Pulmonary tuberculosis was the commonest systemic manifestation (13.2%). 37 patients (30.57%) had other STD's, syphilis being the commonest (12.39%). 22 patients had AIDS defining conditions.
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Affiliation(s)
- S P Nair
- Dept. of Dermatology & Venereology, Medical College Hospitals, Trivandrum
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Patil PK, Bayry J, Nair SP, Gopalakrishna S, Sajjanar CM, Misra LD, Natarajan C. Early antibody responses of cattle for foot-and-mouth disease quadrivalent double oil emulsion vaccine. Vet Microbiol 2002; 87:103-9. [PMID: 12034538 DOI: 10.1016/s0378-1135(02)00046-9] [Citation(s) in RCA: 11] [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: 11/18/2022]
Abstract
Foot-and-mouth disease (FMD) is an economically important disease of cloven-hoofed animals. The multiplicity of FMDV serotypes in animals poses a central problem in the policy of vaccination and is of much concern to health authorities. Hence it is the practice of vaccination with polyvalent vaccine for prophylactic measure. In the present report, we analysed the early antibody responses elicited by FMDV quadrivalent (FMDV O, A, C and Asia 1 serotypes) double emulsion (Montanide ISA 206) vaccines in cattle. We observed variations between various viral serotypes in eliciting early antibody response although neutralizing antibody response against all the four serotypes were detected as early as fourth day following vaccination. The duration of immunity also appeared to maintain for long period. The neutralizing antibody titres were maintained well above 2log(10) even after 6 months of vaccination irrespective of serotypes. Thus, allows the possibilities of two vaccinations per year for the maintenance of herd immunity.
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Affiliation(s)
- P K Patil
- Indian Veterinary Research Institute, Hebbal, Bangalore 560 024, India
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23
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Williams RJ, Nair SP, Henderson B, Holland KT, Ward JM. Expression of the S. aureus hysA gene in S. carnosus from a modified E. coli-staphylococcal shuttle vector. Plasmid 2002; 47:241-5. [PMID: 12151240 DOI: 10.1016/s0147-619x(02)00004-5] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We have modified an E. coli-staphylococcal shuttle vector for use in the general cloning and expression of genes from pathogenic staphylococci in Staphylococcus carnosus. As S. carnosus is non-pathogenic, this expression system will facilitate the study of the roles of individual gene products in the disease process. To evaluate the use of this expression system, a DNA fragment containing the Staphylococcus aureus hyaluronate lyase (hysA) gene was cloned into the modified vector, pNW21, and introduced into S. carnosus. Hyaluronate lyase was both produced and secreted by S. carnosus. In addition, the secreted HysA protein was enzymatically active, as determined using a zymographic assay.
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Affiliation(s)
- R J Williams
- Cellular Microbiology Research Group, Division of Surgical Sciences, Eastman Dental Institute, UK
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Williams RJ, Henderson B, Nair SP. Staphylococcus aureus fibronectin binding proteins A and B possess a second fibronectin binding region that may have biological relevance to bone tissues. Calcif Tissue Int 2002; 70:416-21. [PMID: 12055657 DOI: 10.1007/s00223-001-2073-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2001] [Accepted: 10/25/2001] [Indexed: 10/26/2022]
Abstract
Staphylococcus aureus is a major human pathogen that has a propensity for targeting to bone tissues and thereby causing bone disease. A plausible hypothesis is that S. aureus targets to bone using the MSCRAMM family of surface proteins possessed by this organism. Two such proteins that have recently been shown to be important in bone infections are the S. aureus fibronectin binding proteins (FnBP) A and B. To identify fibronectin-binding domains from S. aureus that have biological relevance to bone, a phage display library of S. aureus genomic DNA was constructed and panned sequentially against immobilized fibronectin and cultured osteoblasts. Using this system, phage displaying a second fibronectin-binding region within the N-terminal part of FnBPA and FnBPB, which is distinct from the primary fibronectin-binding domain located within the D repeat region of these proteins, was isolated. Phage displaying this second region bound to both immobilized fibronectin and to osteoblasts and/or the extracellular matrix synthesized by these cells, thereby suggesting a biological relevance for these regions in S. aureus binding to bone tissues. Analysis of these binding regions for their ability to bind to other extracellular matrix proteins revealed a preference for fibronectin, with slight binding to fibrinogen and no binding to collagen or laminin.
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Affiliation(s)
- R J Williams
- Cellular Microbiology Research Group, Division of Surgical Sciences, Eastman Dental Institute for Oral Health Care Sciences, University College London, London, UK
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Akifusa S, Poole S, Lewthwaite J, Henderson B, Nair SP. Recombinant Actinobacillus actinomycetemcomitans cytolethal distending toxin proteins are required to interact to inhibit human cell cycle progression and to stimulate human leukocyte cytokine synthesis. Infect Immun 2001; 69:5925-30. [PMID: 11500475 PMCID: PMC98715 DOI: 10.1128/iai.69.9.5925-5930.2001] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [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: 11/20/2022] Open
Abstract
It has recently been discovered that Actinobacillus actinomycetemcomitans, an oral bacterium causing periodontitis, produces cytolethal distending toxin (CDT), a cell cycle-modulating toxin that has three protein subunits: CdtA, CdtB, and CdtC. In this study, we have cloned and expressed each toxin gene from A. actinomycetemcomitans in Escherichia coli and purified the recombinant Cdt proteins to homogeneity. Individual Cdt proteins failed to induce cell cycle arrest of the human epithelial cell line HEp-2. The only combinations of toxin proteins causing cell cycle arrest were the presence of all three Cdt proteins and the combination of CdtB and CdtC. A similar experimental protocol was used to determine if recombinant Cdt proteins were able to induce human peripheral blood mononuclear cells (PBMCs) to produce cytokines. The individual Cdt proteins were able to induce the synthesis by PBMCs of interleukin-1beta (IL-1beta), IL-6, and IL-8 but not of tumor necrosis factor alpha, IL-12, or granulocyte-macrophage colony-stimulating factor, with CdtC being the most potent and CdtB being the least potent cytokine inducer. There was evidence of synergism between these Cdt proteins in the stimulation of cytokine production, most markedly with gamma interferon, which required the minimum interaction of CdtB and -C to stimulate production.
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Affiliation(s)
- S Akifusa
- Cellular Microbiology Research Group, Eastman Dental Institute, University College London, London WC1X 8LD, United Kingdom
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26
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Bhatti M, Nair SP, Macrobert AJ, Henderson B, Shepherd P, Cridland J, Wilson M. Identification of photolabile outer membrane proteins of Porphyromonas gingivalis. Curr Microbiol 2001; 43:96-9. [PMID: 11391471 DOI: 10.1007/s002840010268] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [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: 08/30/2000] [Accepted: 01/01/2001] [Indexed: 10/26/2022]
Abstract
As the prevalence of antibiotic-resistant strains of bacteria increases, novel ways of treating infections need to be developed. This is particularly pertinent with respect to the periodontal diseases--the most common chronic bacterial infections of man. The use of a photosensitizer in combination with red light has been demonstrated to be effective in killing several human pathogens, including the oral bacterium, Porphyromonas gingivalis, a major pathogen in periodontitis. Killing was associated with alterations in the molecular masses of several outer membrane and plasma membrane proteins and these may be therapeutic targets for photodynamic therapy and other antimicrobial approaches. To identify these photolabile proteins, we have used a panel of monoclonal antibodies raised to whole P. gingivalis. A number of the antibodies recognized various photolabile proteins. Using a combination of Western blotting and protein sequencing the predominant photolabile proteins in P. gingivalis have been identified as the major secreted/cell surface proteases--Lys and Arg gingipain.
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Affiliation(s)
- M Bhatti
- Department of Microbiology, Eastman Dental Institute for Oral Health Care Sciences, University College London, 256 Grays Inn Road, London WC1X 8LD, UK
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Abstract
Many of the genes encoding the virulence factors for Staphylococcus aureus are controlled by the accessory gene regulator (agr) and staphylococcal accessory regulator (sar). This regulation may be affected by the environment in which the organisms are grown. In the majority of ecosystems, bacteria grow attached to surfaces and form biofilms. We used S. aureus strains containing mutations inactivating agr and sar to determine whether the presence of these genes influences the attachment of the bacterium to a surface. We also used strains harbouring reporter constructs of the agr and sar operons to determine their expression in biofilms. The attachment study results showed that the sarA mutant strain adhered better to glass than did the agrA mutant or the wild type. There was an increased adherence to fibronectin-coated glass for all three strains compared to glass. Thus, these adhesion studies demonstrate that agr and sar have pleiotrophic effects on the surface expression of molecules responsible for binding to different substrata. In the biofilms higher numbers of bacteria and the greatest expression were observed at the base, but there were no observable differences between the reporter constructs. Expression of the agr and sar reporter fusions was significantly higher in the deepest layers of the biofilms where the greatest numbers of bacteria were also observed, perhaps as one might expect for genes that are regulated in a cell density dependent fashion.
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Affiliation(s)
- J Pratten
- Department of Microbiology, Eastman Dental Institute for Oral Health Care Sciences, University College London, University of London, 256 Gray's Inn Road, WC1X 8LD, London, UK.
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Fletcher JM, Nair SP, Ward JM, Henderson B, Wilson M. Analysis of the effect of changing environmental conditions on the expression patterns of exported surface-associated proteins of the oral pathogen Actinobacillus actinomycetemcomitans. Microb Pathog 2001; 30:359-68. [PMID: 11399142 DOI: 10.1006/mpat.2000.0439] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [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: 11/22/2022]
Abstract
Actinobacillus actinomycetemcomitans has been specifically implicated in the aetiology of one or more of the periodontal diseases, conditions in which inflammation of the gums is associated with destruction of the alveolar bone supporting the teeth. In these diseases there is loss of attachment of the gums (gingivae) to the teeth forming a periodontal pocket. The microenvironment of this pocket is extremely complex and it is likely that there will be substantial variation in the environmental conditions operating in this habitat. The aim of the current investigation was to study the effect of disease-relevant environmental factors on the production and release of secreted surface- associated proteins of A. actinomycetemcomitans. These secreted proteins contain many of the virulence determinants of this organism. A range of environmental conditions were investigated: growth in a CO(2)-enriched aerobic atmosphere vs anaerobic growth, presence of serum or blood, biofilm vs planktonic mode of growth and iron depletion. Differential expression of a number of the secreted surface-associated proteins was observed under different growth conditions and these included the glycolytic enzyme triose phosphate isomerase. An ability to adapt to prevailing environmental conditions may facilitate the survival of the organism in the changing microIenvironment of the periodontal pocket.
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Affiliation(s)
- J M Fletcher
- Department of Microbiology, Eastman Dental Institute, University College London, 256 Grays Inn Road, London WC1X 8LD, UK
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Ahmed S, Meghji S, Williams RJ, Henderson B, Brock JH, Nair SP. Staphylococcus aureus fibronectin binding proteins are essential for internalization by osteoblasts but do not account for differences in intracellular levels of bacteria. Infect Immun 2001; 69:2872-7. [PMID: 11292701 PMCID: PMC98237 DOI: 10.1128/iai.69.5.2872-2877.2001] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.0] [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
Staphylococcus aureus is a major pathogen of bone that has been shown to be internalized by osteoblasts via a receptor-mediated pathway. Here we report that there are strain-dependent differences in the uptake of S. aureus by osteoblasts. An S. aureus septic arthritis isolate, LS-1, was internalized some 10-fold more than the laboratory strain 8325-4. Disruption of the genes for the fibronectin binding proteins in these two strains of S. aureus blocked their ability to be internalized by osteoblasts, thereby demonstrating the essentiality of these genes in this process. However, there were no differences in the capacity of these two strains to bind to fibronectin or osteoblasts. Analysis of the kinetics of internalization of the two strains by osteoblasts revealed that strain 8325-4 was internalized only over a short period of time (2 h) and to low numbers, while LS-1 was taken up by osteoblasts in large numbers for over 3 h. These differences in the kinetics of uptake explain the fact that the two strains of S. aureus are internalized by osteoblasts to different extents and suggest that in addition to the fibronectin binding proteins there are other, as yet undetermined virulence factors that play a role in the internalization process.
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Affiliation(s)
- S Ahmed
- Cellular Microbiology Research Group, Eastman Dental Institute, University College London, United Kingdom
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Ward J, Fletcher J, Nair SP, Wilson M, Williams RJ, Poole S, Henderson B. Identification of the exported proteins of the oral opportunistic pathogen Actinobacillus actinomycetemcomitans by using alkaline phosphatase fusions. Infect Immun 2001; 69:2748-52. [PMID: 11254647 PMCID: PMC98219 DOI: 10.1128/iai.69.4.2748-2752.2001] [Citation(s) in RCA: 9] [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] Open
Abstract
A phoA fusion library of Actinobacillus actinomycetemcomitans genomic DNA has been screened to identify genes encoding exported and secreted proteins. A total of 8,000 colonies were screened, and 80 positive colonies were detected. From these, 48 genes were identified with (i) more than half having homology to known or hypothetical Haemophilus influenzae genes, (ii) 14 having no ascribed function, and (iii) 4 having very limited or no homology to known genes. The proteins encoded by these genes may, by virtue of their presence on the cell surface, be novel virulence determinants.
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Affiliation(s)
- J Ward
- Molecular Microbiology Group, Department of Biochemistry and Molecular Biology, University College London, London WC1E 6BT.
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31
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Nair SP, Krishnan M, Scheel P, Thuluvath PJ. Renal allograft survival in patients who had simultaneous liver and kidney transplantation compared with those who had renal transplantation alone. Transplant Proc 2001; 33:1139-40. [PMID: 11267226 DOI: 10.1016/s0041-1345(00)02462-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- S P Nair
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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32
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Henderson B, Tabona P, Poole S, Nair SP. Cloning and expression of the Actinobacillus actinomycetemcomitans thioredoxin (trx) gene and assessment of cytokine inhibitory activity. Infect Immun 2001; 69:154-8. [PMID: 11119501 PMCID: PMC97867 DOI: 10.1128/iai.69.1.154-158.2001] [Citation(s) in RCA: 9] [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] Open
Abstract
Thioredoxin is a ubiquitous redox control and cell stress protein. Unexpectedly, in recent years, thioredoxins have been found to exhibit both cytokine and chemokine activities, and there is increasing evidence that this class of protein plays a role in the pathogenesis of inflammatory diseases. In spite of this evidence, it has been reported that the oral bacterium and periodontopathogen Actinobacillus actinomycetemcomitans secretes an immunosuppressive factor (termed suppressive factor 1 [SF1] [T. Kurita-Ochiai and K. Ochiai, Infect. Immun. 64:50-54, 1996]) whose N-terminal sequence, we have determined, identifies it as thioredoxin. We have cloned and expressed the gene encoding the thioredoxin of A. actinomycetemcomitans and have purified the protein to homogeneity. The A. actinomycetemcomitans trx gene has 52 and 76% identities, respectively, to the trx genes of Escherichia coli and Haemophilus influenzae. Enzymatic analysis revealed that the recombinant protein had the expected redox activity. When the recombinant thioredoxin was tested for its capacity to inhibit the production of cytokines by human peripheral blood mononuclear cells, it showed no significant inhibitory capacity. We therefore conclude that the thioredoxin of A. actinomycetemcomitans does not act as an immunosuppressive factor, at least with human leukocytes in cultures, and that the identity of SF1 remains to be elucidated.
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Affiliation(s)
- B Henderson
- Cellular Microbiology Research Group, Eastman Dental Institute, University College London, London WC1X 8LD, United Kingdom.
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33
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Royan S, Sharp L, Nair SP, Crean S, Henderson B, Poole S, Scott GL, Evans AW. Identification of the secreted macromolecular immunogens of Staphylococcus aureus by analysis of serum. FEMS Immunol Med Microbiol 2000; 29:315-21. [PMID: 11118913 DOI: 10.1111/j.1574-695x.2000.tb01539.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The ability of sera to recognise secreted macromolecules of Staphylococcus aureus was examined by ELISA and Western immunoblotting. Individual secreted proteins were also studied using both human sera and sera from rabbits immunised with secreted macromolecules. Patients sera showed a wide range of IgG antibody titres to secreted macromolecules and whole bacteria. Controls showed a significantly lower IgG response. Western immunoblotting revealed that a significant number of secreted proteins were recognised by circulating IgG antibodies. Surprisingly, both the sera from controls and from patients recognised similar macromolecules including a number of potential virulence factors. The major difference was in the IgG binding to a 16-kDa component, which was recognised by the majority of the sera from infected individuals, but only by a small number of sera from healthy controls. The higher incidence of antibodies recognising the 16 kDa component may be related to our earlier finding that the major bone resorbing component of S. aureus is a heterodimeric protein containing a 16-kDa subunit, the activity of which could be blocked by sera.
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Affiliation(s)
- S Royan
- Cellular Microbiology Research Group, Division of Surgical Sciences, Eastman Dental Institute, University College London, UK
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Poonawala A, Nair SP, Thuluvath PJ. Prevalence of obesity and diabetes in patients with cryptogenic cirrhosis: a case-control study. Hepatology 2000. [PMID: 11003611 DOI: 10.1053/jhep.200.17894] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
It has recently been suggested that nonalcoholic steatohepatitis (NASH) is an under-recognized cause of cryptogenic cirrhosis (CC) on the basis of higher prevalence of obesity and type II diabetes among these patients. To test this hypothesis, we studied 65 consecutive patients with advanced cirrhosis (Child-Pugh Score >/= 7) of undetermined etiology (CC) from our active waiting list for liver transplantation in January 1993, 1996, and 1999. For each patient, we selected 2 age- and sex-matched controls from the corresponding lists. The prevalence of obesity (defined as body mass index [BMI] >/= 30) and diabetes were compared between the groups. Sixteen patients (and their 32 controls) with CC were excluded as further review of records suggested other possible etiologies. Thus, the final analysis included 49 patients and 98 controls. The etiology of cirrhosis in the control group was alcohol in 16.3%, chronic viral hepatitis in 30.6%, autoimmune hepatitis in 8.2%, and primary biliary cirrhosis (PBC) or primary sclerosing cholangitis in 35.7%. The prevalence of obesity (55% vs. 24%) and type II diabetes (47% vs. 22%) was significantly higher in patients with CC compared with controls. Twenty-three percent of patients with CC had both obesity and diabetes compared with 5% among controls (P =.002). There was no difference in the prevalence of hypercholesterolemia (serum cholesterol > 200 mg/dL) between the groups. In conclusion, patients with advanced CC are more likely to be obese and diabetic compared with age- and sex-matched patients with advanced cirrhosis. This supports the hypothesis that NASH may be an etiological factor in some of the patients with CC.
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Affiliation(s)
- A Poonawala
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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35
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Abstract
It has recently been suggested that nonalcoholic steatohepatitis (NASH) is an under-recognized cause of cryptogenic cirrhosis (CC) on the basis of higher prevalence of obesity and type II diabetes among these patients. To test this hypothesis, we studied 65 consecutive patients with advanced cirrhosis (Child-Pugh Score >/= 7) of undetermined etiology (CC) from our active waiting list for liver transplantation in January 1993, 1996, and 1999. For each patient, we selected 2 age- and sex-matched controls from the corresponding lists. The prevalence of obesity (defined as body mass index [BMI] >/= 30) and diabetes were compared between the groups. Sixteen patients (and their 32 controls) with CC were excluded as further review of records suggested other possible etiologies. Thus, the final analysis included 49 patients and 98 controls. The etiology of cirrhosis in the control group was alcohol in 16.3%, chronic viral hepatitis in 30.6%, autoimmune hepatitis in 8.2%, and primary biliary cirrhosis (PBC) or primary sclerosing cholangitis in 35.7%. The prevalence of obesity (55% vs. 24%) and type II diabetes (47% vs. 22%) was significantly higher in patients with CC compared with controls. Twenty-three percent of patients with CC had both obesity and diabetes compared with 5% among controls (P =.002). There was no difference in the prevalence of hypercholesterolemia (serum cholesterol > 200 mg/dL) between the groups. In conclusion, patients with advanced CC are more likely to be obese and diabetic compared with age- and sex-matched patients with advanced cirrhosis. This supports the hypothesis that NASH may be an etiological factor in some of the patients with CC.
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Affiliation(s)
- A Poonawala
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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36
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Williams RJ, Ward JM, Henderson B, Poole S, O'Hara BP, Wilson M, Nair SP. Identification of a novel gene cluster encoding staphylococcal exotoxin-like proteins: characterization of the prototypic gene and its protein product, SET1. Infect Immun 2000; 68:4407-15. [PMID: 10899837 PMCID: PMC98335 DOI: 10.1128/iai.68.8.4407-4415.2000] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.6] [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
We report the discovery of a novel genetic locus within Staphylococcus aureus that encodes a cluster of at least five exotoxin-like proteins. Designated the staphylococcal exotoxin-like genes 1 to 5 (set1 to set5), these open reading frames have between 38 and 53% homology to each other. All five proteins contain consensus sequences that are found in staphylococcal and streptococcal exotoxins and toxic shock syndrome toxin 1 (TSST-1). However, the SETs have only limited overall sequence homology to the enterotoxins and TSST-1 and thus represent a novel family of exotoxin-like proteins. The prototypic gene in this cluster, set1, has been cloned and expressed. Recombinant SET1 stimulated the production of interleukin-1beta, interleukin-6, and tumor necrosis factor alpha by human peripheral blood mononuclear cells. PCR analysis revealed that set1 was distributed among other strains of S. aureus but not in the other staphylococcal species examined. Sequence analysis of the set1 genes from different strains revealed at least three allelic variants. The protein products of these allelic variants displayed a 100-fold difference in their cytokine-inducing potency. The distribution of allelic variants of the set genes among strains of S. aureus may contribute to differences in the pathogenic potential of this bacterium.
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Affiliation(s)
- R J Williams
- Cellular Microbiology Research Group, Division of Surgical Sciences, University College London, London, United Kingdom
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Nair SP, Williams RJ, Henderson B. Advances in our understanding of the bone and joint pathology caused by Staphylococcus aureus infection. Rheumatology (Oxford) 2000; 39:821-34. [PMID: 10952735 DOI: 10.1093/rheumatology/39.8.821] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- S P Nair
- Cellular Microbiology Research Group, Division of Surgical Sciences, Eastman Dental Institute, University College London, London, UK
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Williams RJ, Ward JM, Henderson B, Wilson M, Nair SP. Rapid screening for putative exported proteins from Staphylococcus aureus using alkaline phosphatase as a reporter molecule. Mol Biotechnol 2000; 15:11-20. [PMID: 10911618 DOI: 10.1385/mb:15:1:11] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [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: 11/11/2022]
Abstract
Staphylococcus aureus causes a wide range of infections in humans, ranging from superficial skin infections to the more serious toxin-mediated diseases such as toxic shock syndrome. Owing to the increasing resistance of this bacterium to a wide range of antibiotics, the need to determine the virulence factors involved in infection is becoming more important as these molecules are potential therapeutic targets. In this study, we have screened for putative exported proteins from S. aureus on the basis that these proteins are likely to be the first point of contact between the bacterium and host during infection. We have constructed gene fusions between S. aureus DNA and a truncated version of the Escherichia coli phoA gene, and we report on the characterization of the recombinants exhibiting alkaline phosphatase activity. As well as known S. aureus proteins, we have identified a number of putative open reading frames that encode proteins similar to those from nonstaphylococcal species and also unique proteins that do not have any homologues on the current databases.
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Affiliation(s)
- R J Williams
- Division of Surgical Sciences, University College London
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Nair SP, Vijayadharan M, Vincent M. Primaty cutaneous histoplasmosis. Indian J Dermatol Venereol Leprol 2000; 66:151-153. [PMID: 20877062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A 29-year old woman presented with diffuse swelling of the base of the right thumb along with ulceration. X-ray indicated bony damage. Histopathology showed PAS positive intracellular organisms suggestive of histoplasmosis. We are reporting a very rare case of primary cutaneous histoplasmosis from this part of the country.
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Affiliation(s)
- S P Nair
- Department of Dermatology and Venereology, Medical College Hospital, Trivandrum - 695 011, India
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Jevon M, Guo C, Ma B, Mordan N, Nair SP, Harris M, Henderson B, Bentley G, Meghji S. Mechanisms of internalization of Staphylococcus aureus by cultured human osteoblasts. Infect Immun 1999; 67:2677-81. [PMID: 10225942 PMCID: PMC116025 DOI: 10.1128/iai.67.5.2677-2681.1999] [Citation(s) in RCA: 134] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/1998] [Accepted: 02/05/1999] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus is an important bone pathogen, and evidence shows that this organism is internalized by chick osteoblasts. Here we report that S. aureus is internalized by human osteoblasts. Internalization was inhibited by monodansylcadaverine and cytochalasin D and to a lesser extent by ouabain, monensin, colchicine, and nocodazole. We propose that internalization occurs via a receptor-mediated pathway, requiring the participation of cytoskeletal elements, principally actin.
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Affiliation(s)
- M Jevon
- Maxillofacial Surgery Research Unit, Eastman Dental Institute, University College London, London, United Kingdom
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41
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Abstract
Molecular chaperones, also known as heat shock proteins (hsp), are intracellular proteins found in all cells that catalyze protein folding. We have discovered that one class of bacterial molecular chaperone, the chaperonins, are potent inducers of bone resorption. To address the question of whether the osteolytic activity of the chaperonins was unique to this protein class, or was a common attribute of molecular chaperones generally, we have examined a number of bacterial and mammalian molecular chaperones for activity in the murine calvarial bone resorption assay. All the Escherichia coli molecular chaperones (groEL, groES, and dnaK) were active. The osteolytic activity of groEL was inhibited by indomethacin and the natural antagonist of interleukin-1 receptor antagonist (IL-1ra) but was unaffected by neutralization of tumor necrosis factor (TNF) or inhibition of 5-lipoxygenase. Mammalian molecular chaperones of molecular mass 27, 47, 70, and 90 kDa were also tested and, with the exception of the 47 kDa protein, all showed activity in the murine calvarial assay. Molecular chaperones appear, therefore, to have the capacity to modulate the cellular processes in bone explant cultures, resulting in resorption of the calcified matrix. The possibility that these proteins could play a role in the normal or pathological remodeling of bone is discussed.
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Affiliation(s)
- S P Nair
- Maxillofacial Surgery Research Unit, Eastman Dental Institute, University College London, 256 Gray's Inn Road, London WC1X 8LD, United Kingdom
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Meghji S, Crean SJ, Hill PA, Sheikh M, Nair SP, Heron K, Henderson B, Mawer EB, Harris M. Surface-associated protein from Staphylococcus aureus stimulates osteoclastogenesis: possible role in S. aureus-induced bone pathology. Br J Rheumatol 1998; 37:1095-101. [PMID: 9825749 DOI: 10.1093/rheumatology/37.10.1095] [Citation(s) in RCA: 56] [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] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE Staphylococcus aureus is the cause of bone destruction in osteomyelitis, bacterial arthritis and orthopaedic implant failure. We have previously shown that gentle saline extraction of S. aureus has revealed the presence of an extremely potent stimulator of osteoclast activation in both the murine calvarial bone resorption assay and the isolated chick osteoclast resorption assay. In order to investigate the mechanism of action of this surface-associated material (SAM), we have investigated its capacity to recruit osteoclasts. METHODS The murine bone marrow osteoclast recruitment assay was used. The ability of the recruited cells to resorb dentine slices was also investigated. Results. The SAM from S. aureus dose dependently stimulated tartrate-resistant acid phosphatase (TRAP)-positive osteoclast formation and pit formation on dentine slices. Neutralization of the cytokines tumour necrosis factor alpha and interleukin (IL)-6 totally inhibited, but antagonism of IL-1 only partially blocked, the stimulated maturation of osteoclast-like cells. CONCLUSION These findings suggest that bone destruction associated with local infection by S. aureus is due to the stimulation of osteoclast formation induced by the action of the easily solubilized SAM, and could explain the large numbers of osteoclasts found in infarcted bone in osteomyelitis.
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Affiliation(s)
- S Meghji
- Department of Oral and Maxillofacial Surgery, Eastman Dental Institute for Oral Health Care Sciences, London
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43
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Reddi K, Meghji S, Nair SP, Arnett TR, Miller AD, Preuss M, Wilson M, Henderson B, Hill P. The Escherichia coli chaperonin 60 (groEL) is a potent stimulator of osteoclast formation. J Bone Miner Res 1998; 13:1260-6. [PMID: 9718194 DOI: 10.1359/jbmr.1998.13.8.1260] [Citation(s) in RCA: 40] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Chaperonins (cpns) are intracellular oligomeric protein complexes that fold and refold proteins in a catalytic manner and aid in the transmembrane transport of cellular proteins. We reported previously that the lipopolysaccharide-free recombinant cpn60 of Escherichia coli (groEL) is able to stimulate the breakdown of murine calvarial bone in culture and showed that such resorption is potently inhibited by an inhibitor of the enzyme cyclo-oxygenase and to a lesser extent by inhibitors of 5-lipoxygenase. In this study, we have investigated the effects of groEL on the resorptive activity and formation of osteoclasts in culture. In low density, osteoclast-containing cultures from neonatal rats incubated for 24 or 96 h on dentine discs, groEL (1-1000 ng/ml) stimulated resorption pit formation up to 4-fold, but this effect was essentially dependent on cell number. Using 12-day cultures of mouse bone marrow to assess osteoclast recruitment, groEL (1-1000 ng/ml) caused a dramatic dose-dependent stimulation of the formation of tartrate-resistant acid phosphatase-positive multinucleated cells and the resorption of the dentine on which bone marrow cells were cultured. Osteoclast formation elicited by groEL was almost completely abolished by indomethacin, an inhibitor of cyclo-oxygenase, but was unaffected by inhibitors of 5-lipoxygenase, suggesting that prostaglandins but not leukotrienes may mediate the action of groEL on osteoclastogenesis. It is possible that bacterial cpn60s such as groEL may play a role in the osteolysis associated with bone infections. Whether endogenous ("self") chaperonins have a role in other bone loss disorders, such as osteoporosis, is an intriguing possibility.
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Affiliation(s)
- K Reddi
- Maxillofacial Surgery Research Unit, Eastman Dental Institute, University College London, United Kingdom
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Tabona P, Reddi K, Khan S, Nair SP, Crean SJ, Meghji S, Wilson M, Preuss M, Miller AD, Poole S, Carne S, Henderson B. Homogeneous Escherichia coli chaperonin 60 induces IL-1 beta and IL-6 gene expression in human monocytes by a mechanism independent of protein conformation. J Immunol 1998; 161:1414-21. [PMID: 9686605] [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] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Escherichia coli chaperonin (cpn) 60 (groEL) is a protein-folding oligomer lacking tryptophan residues that copurifies with tryptophan-containing proteins and peptides. Cpn 60 is a major immunogen in infectious diseases, and evidence suggests that groEL and mycobacterial cpn 60s can induce cytokine synthesis, stimulate cytokine-dependent bone resorption, and up-regulate expression of vascular endothelial cell adhesion molecules. Whether such activities are due to the cpn 60 or to the copurifying/contaminating proteins/peptides has not been determined. Here we report a method for removing the protein contaminants of groEL and demonstrate that this, essentially homogeneous, groEL remains a potent inducer of human monocyte IL-1beta and IL-6 production. Contaminating peptides had no cytokine-inducing activity and did not synergize with purified groEL. The LPS inhibitor polymyxin B and the CD14-neutralizing Ab MY4 had no inhibitory action on groEL demonstrating that activity is not due to LPS contamination. Heating groEL had no effect on its capacity to stimulate human monocytes to secrete IL-6. Proteolysis of groEL with trypsin, sufficient to produce low molecular mass peptides, also had no inhibitory effect. Thus, we conclude that groEL is a potent inducer of monocyte proinflammatory cytokine production, which acts through the binding of nonconformational peptide domains that are conserved after proteolysis. These data suggest that if groEL was released from bacteria it could induce prolonged tissue pathology by virtue of its cytokine-inducing activity and its resistance to proteolytic inhibition of bioactivity.
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Affiliation(s)
- P Tabona
- Cellular Microbiology Research Group, Eastman Dental Institute, University College London, United Kingdom
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45
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White PA, Nair SP, Kim MJ, Wilson M, Henderson B. Molecular characterization of an outer membrane protein of Actinobacillus actinomycetemcomitans belonging to the OmpA family. Infect Immun 1998; 66:369-72. [PMID: 9423883 PMCID: PMC107906 DOI: 10.1128/iai.66.1.369-372.1998] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [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: 02/05/2023] Open
Abstract
The major outer membrane protein (OMP) of Actinobacillus actinomycetemcomitans is an OmpA homolog that demonstrates electrophoretic heat modifiability. The gene encoding this protein was isolated from a genomic library of A. actinomycetemcomitans NCTC 9710 by immunoscreening with serum from a patient with localized juvenile periodontitis. Expression of the cloned gene in Escherichia coli and subsequent Western blot analysis revealed a protein with an approximate molecular mass of 34 kDa. The amino acid sequence predicted from the cloned gene demonstrated that the mature protein had a molecular mass of 34,911 Da and significant identity to members of the OmpA family of proteins. We have named the major OMP of A. actinomycetemcomitans Omp34, and its corresponding gene has been named omp34.
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Affiliation(s)
- P A White
- School of Biological Sciences, Macquarie University, Sydney, New South Wales, Australia.
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46
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Nair SP, Vijayadharan M, Gupta A. Werner's Syndrome. Indian J Dermatol Venereol Leprol 1998; 64:31-33. [PMID: 20921707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A 41-year old unmarried man presented with erosions, ulcers and keratosis of tendoachilles. He was short statured and had features of premature aging, sclerosis of the skin of the limbs and hypogonadism. The head was small with a beak-like nose. Investigations revealed diabetes mellitus, generalised osteoporosis, calcification of blood vessel walls and microsplanchia of kidneys. All the features suggested a diagnosis of Werners's syndrome.
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Affiliation(s)
- S P Nair
- From the Department of Dermatology and Venerology, Medical College Hospital, Thiruvananthapuram-655 011, India,
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47
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Meghji S, White PA, Nair SP, Reddi K, Heron K, Henderson B, Zaliani A, Fossati G, Mascagni P, Hunt JF, Roberts MM, Coates AR. Mycobacterium tuberculosis chaperonin 10 stimulates bone resorption: a potential contributory factor in Pott's disease. J Exp Med 1997; 186:1241-6. [PMID: 9334363 PMCID: PMC2199082 DOI: 10.1084/jem.186.8.1241] [Citation(s) in RCA: 71] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Pott's disease (spinal tuberculosis), a condition characterized by massive resorption of the spinal vertebrae, is one of the most striking pathologies resulting from local infection with Mycobacterium tuberculosis (Mt; Boachie-Adjei, O., and R.G. Squillante. 1996. Orthop. Clin. North Am. 27:95-103). The pathogenesis of Pott's disease is not established. Here we report for the first time that a protein, identified by a monoclonal antibody to be the Mt heat shock protein (Baird, P.N., L.M. Hall, and A.R.M. Coates. 1989. J. Gen. Microbiol. 135:931-939) chaperonin (cpn) 10, is responsible for the osteolytic activity of this bacterium. Recombinant Mt cpn10 is a potent stimulator of bone resorption in bone explant cultures and induces osteoclast recruitment, while inhibiting the proliferation of an osteoblast bone-forming cell line. Furthermore, we have found that synthetic peptides corresponding to sequences within the flexible loop and sequence 65-70 of Mt cpn10 may comprise a single conformational unit which encompasses its potent bone-resorbing activity. Our findings suggest that Mt cpn10 may be a valuable pharmacological target for the clinical therapy of vertebral tuberculosis and possibly other bone diseases.
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Affiliation(s)
- S Meghji
- Maxillofacial Surgery Research Unit, Eastman Dental Institute, University College London, United Kingdom
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Abstract
Porins are abundant outer membrane proteins of gram-negative bacteria involved in transport of low-molecular-mass molecules. During the past decade, porins from a number of bacteria have also been shown to have proinflammatory activities including inducing the synthesis of proinflammatory mediators (cytokines, platelet-activating factor, and nitric oxide) in cultured cells and inducing inflammation in vivo. With this range of actions, it was possible that porins could also interact with bone cells to cause aberrant bone remodeling and that this could contribute to the bone destruction seen in gram-negative bone infections. By using purified preparations of Salmonella typhimurium and Pseudomonas aeruginosa porins, in the presence of polymyxin B, it was possible to induce concentration-dependent loss of calcium from cultured murine calvaria at porin concentrations in the range of 1 to 10 nM. The mechanism of action of the porins was determined by the inclusion of inhibitors of cyclooxygenase or inflammatory cytokines in the culture media. The bone-resorbing activity of both porins was not inhibited by the cyclooxygenase inhibitor indomethacin or by neutralizing the activity of tumor necrosis factor. Indeed, relatively high concentrations of these agents produced an unexpected increase in the bone resorption induced by the porins. In contrast, porin-induced bone resorption could be inhibited by relatively high concentrations of the natural inhibitor of interleukin-1 (IL-1 receptor antagonist). It appears that these porins stimulate bone resorption by a mechanism distinct from that of lipopolysaccharide, and the possibility therefore exists that porins play a role in bone destruction in gram-negative bacterial infections of bone.
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Affiliation(s)
- S Meghji
- Division of Surgical Sciences, Eastman Dental Institute, University College London, United Kingdom.
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49
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Nair SP, Meghji S, Wilson M, Nugent I, Ross A, Ismael A, Bhudia NK, Harris M, Henderson B. Clinical isolates of Staphylococcus aureus have osteolytic surface proteins and a proportion of the population have antibodies that block this activity: is this of prognostic significance? Br J Rheumatol 1997; 36:328-32. [PMID: 9133964 DOI: 10.1093/rheumatology/36.3.328] [Citation(s) in RCA: 13] [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] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Staphylococcus aureus is directly implicated in the bone destruction associated with infected orthopaedic implants and bacterial arthritis. The Oxford (laboratory) strain of this organism has surface-associated proteins (SAPs) which have potent osteolytic activity. In this study, we have examined the osteolytic activity of SAPs from clinical isolates and also investigated the role of the humoral immune response to such proteins. Nine patients with infected orthopaedic prostheses or infective arthritis, and six volunteers not suffering from overt S. aureus infection, were examined. The sera from 5/9 patients and 4/6 volunteers were able to neutralize the osteolytic activity of the SAPs. The SAPs were extracted from four clinical isolates and were found to have osteolytic activity, but with a wide range of efficacies and potencies. All four patients from whom the clinical isolates were obtained had serum IgG antibodies to the surface proteins from their autologous isolates as determined by ELISA. In conclusion, clinical isolates of S. aureus contain osteolytic SAPs which may be responsible for bone destruction. Apparently disease-free individuals and patients have antibodies able to block this activity. However, since the capacity of patients' sera to neutralize the activity of the SAPs derived from their own S. aureus isolate was not investigated, it is unclear whether these findings are of prognostic value.
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Affiliation(s)
- S P Nair
- Maxillofacial Surgery Research Unit, Eastman Dental Institute for Oral Health Care Sciences, University College London
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50
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Abstract
Normal bone remodelling requires the coordinated regulation of the genesis and activity of osteoblast and osteoclast lineages. Any interference with these integrated cellular systems can result in dysregulation of remodelling with the consequent loss of bone matrix. Bacteria are important causes of bone pathology in common conditions such as periodontitis, dental cysts, bacterial arthritis, and osteomyelitis. It is now established that many of the bacteria implicated in bone diseases contain or produce molecules with potent effects on bone cells. Some of these molecules, such as components of the gram-positive cell walls (lipoteichoic acids), are weak stimulators of bone resorption in vitro, while others (PMT, cpn60) are as active as the most active mammalian osteolytic factors such as cytokines like IL-1 and TNF. The complexity of the integration of bone cell lineage development means that there are still question marks over the mechanism of action of many well-known bone-modulatory molecules such as parathyroid hormone. The key questions which must be asked of the now-recognized bacterial bone-modulatory molecules are as follows: (i) what cell population do they bind to, (ii) what is the nature of the receptor and postreceptor events, and (iii) is their action direct or dependent on the induction of secondary extracellular bone-modulating factors such as cytokines, eicosanoids, etc. In the case of LPS, this ubiquitous gram-negative polymer probably binds to osteoblasts or other cells in bone through the CD14 receptor and stimulates them to release cytokines and eicosanoids which then induce the recruitment and activation of osteoclasts. This explains the inhibitor effects of nonsteroidal and anticytokine agents on LPS-induced bone resorption. However, other bacterial factors such as the potent toxin PMT may act by blocking the normal maturation pathway of the osteoblast lineage, thus inducing dysregulation in the tightly regulated process of resorption and replacement of bone matrix. At the present time, it is not possible to define a general mechanism by which bacteria promote loss of bone matrix. Many bacteria are capable of stimulating bone matrix loss, and the information available would suggest that each organism possesses different factors which interact with bone in different ways. With the rapid increase in antibiotic resistance, particularly with Staphylococcus aureus and M. tuberculosis, organisms responsible for much bone pathology in developed countries only two generations ago, we would urge that much greater attention should be focused on the problem of bacterially induced bone remodelling in order to define pathogenetic mechanisms which could be therapeutic targets for the development of new treatment modalities.
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Affiliation(s)
- S P Nair
- Maxillofacial Surgery Research Unit, Eastman Dental Insitute, University College London, United Kingdom
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