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Earnshaw SR, Klok RM, Iyer S, McDade C. Methylnaltrexone bromide for the treatment of opioid-induced constipation in patients with advanced illness--a cost-effectiveness analysis. Aliment Pharmacol Ther 2010; 31:911-21. [PMID: 20096019 DOI: 10.1111/j.1365-2036.2010.04244.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
BACKGROUND Opioid-induced constipation is a common adverse event in patients with advanced illness and has a significant negative impact on patients' quality of life and costs. AIM To examine the cost-effectiveness of treating opioid-induced constipation with methylnaltrexone bromide (MNTX) plus standard care compared with standard care alone in patients with advanced illness who receive long-term opioid therapy from a third-party payer perspective in the Netherlands. METHODS A decision-analytical model was created in which advanced-illness patients with constipation were treated with MNTX plus standard care or standard care alone. Clinical efficacy in terms of percentage of patients with rescue-free laxation and time to rescue-free laxation were obtained from a randomized, controlled clinical study. Resource use, costs, utilities and mortality were obtained from published literature and supplemented with data from clinical experts. RESULTS Treatment with MNTX plus standard care results in more days without constipation symptoms. Cost of MNTX was mostly offset by reduction in other constipation-related costs. Thus, treating with MNTX plus standard care is cost-effective, with an incremental cost per QALY of 40,865 euro. Results were robust to changes in all parameters. CONCLUSIONS Although using MNTX may increase total costs, MNTX plus standard care is cost-effective in treating advanced-illness patients with opioid-induced constipation.
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Lota AS, Altaf F, Shetty R, Courtney S, Mckenna P, Iyer S. A case of necrotising fasciitis caused by Pseudomonas aeruginosa. ACTA ACUST UNITED AC 2010; 92:284-5. [DOI: 10.1302/0301-620x.92b2.22688] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Necrotising fasciitis is a rare but severe infection of soft-tissue associated with rapid progression, systemic toxicity and high mortality. Monomicrobial necrotising fasciitis caused by Pseudomonas aeruginosa is exceptionally uncommon with only 12 cases reported in the literature. We describe a fatal case with an atypical presentation in a patient following spinal decompression for a metastasis from prostate cancer.
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Sharma M, Iyer S, Kuriakose M, Vijayaraghavan S, Arun P, Sudhir V, Chatni S, Sharan R. Functional reconstruction of near total glossectomy defects using composite gastro omental-dynamic gracilis flaps. J Plast Reconstr Aesthet Surg 2009; 62:1277-80. [DOI: 10.1016/j.bjps.2007.10.092] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2006] [Revised: 08/22/2007] [Accepted: 10/30/2007] [Indexed: 10/21/2022]
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Meadows KN, Iyer S, Stevens MV, Wang D, Shechter S, Perruzzi C, Camenisch TD, Benjamin LE. Akt promotes endocardial-mesenchyme transition. JOURNAL OF ANGIOGENESIS RESEARCH 2009; 1:2. [PMID: 19946410 PMCID: PMC2776235 DOI: 10.1186/2040-2384-1-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2009] [Accepted: 09/21/2009] [Indexed: 01/30/2023]
Abstract
Endothelial to mesenchyme transition (EndMT) can be observed during the formation of endocardial cushions from the endocardium, the endothelial lining of the atrioventricular canal (AVC), of the developing heart at embryonic day 9.5 (E9.5). Many regulators of the process have been identified; however, the mechanisms driving the initial commitment decision of endothelial cells to EndMT have been difficult to separate from processes required for mesenchymal proliferation and migration. We have several lines of evidence that suggest a central role for Akt signaling in committing endothelial cells to enter EndMT. Akt1 mRNA was restricted to the endocardium of endocardial cushions while they were forming. The PI3K/Akt signaling pathway is necessary for mesenchyme outgrowth, as sprouting was inhibited in AVC explant cultures treated with the PI3K inhibitor LY294002. Furthermore, endothelial marker, VE-cadherin, was downregulated and mesenchyme markers, N-cadherin and Snail, were induced in response to expression of a constitutively active form of Akt1 (myrAkt1) in endothelial cells. Finally, we isolated the function of Akt1 signaling in the commitment to the transition using a transgenic model where myrAkt1 was pulsed only in endocardial cells and turned off after EndMT initiation. In this way, we determined that increased Akt signaling in the endocardium drives EndMT and discounted its other functions in cushion mesenchymal cells.
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Iyer S, Gaikwad RM, Subba-Rao V, Woodworth CD, Sokolov I. Atomic force microscopy detects differences in the surface brush of normal and cancerous cells. NATURE NANOTECHNOLOGY 2009; 4:389-93. [PMID: 19498402 PMCID: PMC3079421 DOI: 10.1038/nnano.2009.77] [Citation(s) in RCA: 233] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Accepted: 03/10/2009] [Indexed: 05/17/2023]
Abstract
The atomic force microscope is broadly used to study the morphology of cells, but it can also probe the mechanics of cells. It is now known that cancerous cells may have different mechanical properties to those of normal cells, but the reasons for these differences are poorly understood. Here, we report quantitatively the differences between normal and cancerous human cervical epithelial cells by considering the brush layer on the cell surface. These brush layers, which consist mainly of microvilli, microridges and cilia, are important for interactions with the environment. Deformation force curves obtained from cells in vitro were processed according to the 'brush on soft cell model'. We found that normal cells have brushes of one length, whereas cancerous cells have mostly two brush lengths of significantly different densities. The observed differences suggest that brush layers should be taken into account when characterizing the cell surface by mechanical means.
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Shaji J, Poddar A, Iyer S. Brain-Targeted Nasal Clonazepam Microspheres. Indian J Pharm Sci 2009; 71. [PMCID: PMC2846487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Gelatin-chitosan mucoadhesive microspheres of clonazepam were prepared using the emulsion cross linking method. Mirospheres were evaluated using the in vitro and ex vivo drug release patterns. In vivo CNS drug distribution studies were carried out in rats by administering the clonazepam microspheres intra-nasally and clonazepam solution intravenously. From the drug levels in plasma and CSF, drug targeting index and drug targeting efficiency were calculated. Results obtained indicated that intranasally administered clonazepam microspheres resulted in higher brain levels with a drug targeting index of 2.12. Gelatin-chitosan cross linked mucoadhesive microspheres have the potential to be developed as a brain-targeted drug delivery system for clonazepam.
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Kuriakose MA, Trivedi NP, Patel D, Thankappan K, Iyer S. Stomaplasty-anterior advancement flap and lateral splaying of trachea, a simple and effective technique. J Postgrad Med 2008; 54:21-4. [DOI: 10.4103/0022-3859.39185] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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133
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Fitzpatrick R, Bernstein E, Iyer S, Brown D, Andrews P, Penny K. A histopathologic evaluation of the plasma skin regeneration system (PSR) versus a standard carbon dioxide resurfacing laser in an animal model. Lasers Surg Med 2008; 40:93-9. [DOI: 10.1002/lsm.20547] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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134
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Rao L, Ushas P, Ravi V, Abraham Kuriakose M, Iyer S, Panicker D. Facial translocation approaches to skull base: indications, methods and morbidity profile. Int J Oral Maxillofac Surg 2007. [DOI: 10.1016/j.ijom.2007.09.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Israel R, Thomas J, Iyer S, Wang W, Stambler N. 1121 POSTER The effect of methylnaltrexone on global clinical impression of change (GCIC) in the bowel status of cancer patients with opioid-induced constipation. EJC Suppl 2007. [DOI: 10.1016/s1359-6349(07)70640-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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136
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Iyer S, Candrilli S, Davis K. 1158 POSTER Opioid use patterns, health care utilization and costs in metastatic cancer patients on chronic opioid therapy with constipation compared to patients without constipation. EJC Suppl 2007. [DOI: 10.1016/s1359-6349(07)70677-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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137
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Thankappan K, Rugmini SV, Cohen RF, Sunil B, Samuel J, Padmanabhan TK, Pavithran K, Sundaram KR, Iyer S, Kuriakose MA. Prognostic factors of concurrent chemo-radiotherapy in head and neck cancers. J Clin Oncol 2007. [DOI: 10.1200/jco.2007.25.18_suppl.16527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
16527 Background: Concurrent chemo-radiotherapy either as primary or adjuvant treatment is now the standard of care in high- risk head and neck squamous cell carcinomas. This has improved survival rates and chances of organ preservation. Advanced stage, extra- capsular extension, perineural and lympho-vascular invasion and positive surgical margins were considered as poor prognostic factors with radiotherapy alone. Herein we report the significance of these clinical and pathological factors, with concurrent chemo-radiotherapy regimens. Methods:A retrospective analysis of 54 patients with squamous cell carcinoma of head and neck who underwent either primary (21,39 %) or adjuvant (33,61%) concurrent chemoradiation at Amrita Institute of Medical Sciences, Kochi, India, during January 2004 to May 2005 and followed up to Dec 2006. 6 (11%) patients had stage III and 48 (89 %) had stage IV disease. Prognostic significance of clinical and pathological factors was evaluated. Kaplan-Meir curves for survival analysis, log rank test for univariate and Cox proportional method for multivariate analysis were employed. Results: The median follow up was 22 months. Two-year overall (OS) and disease free survival (DFS) rates were 66 % and 52 % respectively. Univariate and multivariate analysis of T stage, nodal stage, radiotherapy interruptions, completion of chemotherapy, schedule of chemotherapy (week 1,4,7 vs weekly), perineural invasion, extra-capsular extension and positive margins showed no significant difference in OS and DFS. However both univariate (p = 0.019 for OS and p = 0.012 for DFS) and multivariate analysis (p = 0.029, HR 0.16,95 %CI - 0.03 to 0.8 for OS and p = 0.017,HR 0.188,95% CI - 0.04 to 0.74 for DFS) revealed lympho-vascular invasion as a significant prognostic factor. Conclusions: Advanced stage, extra capsular invasion and positive margins were conventionally thought to be poor prognostic markers in head and neck cancer. However in our series of patients treated with concurrent chemo radiation lymphovascular invasion was the only significant poor prognostic factor. Other factors were found to be not significant. No significant financial relationships to disclose.
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Raj D, Iyer S, Fergusson CM. Methicillin-resistant Staphylococcus aureus infection following arthroscopy of the knee joint. Ann R Coll Surg Engl 2007; 88:675-6. [PMID: 17132321 PMCID: PMC1963815 DOI: 10.1308/003588406x149345] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Arthroscopic surgery of the knee is considered to be a safe procedure. We had a microbiologically confirmed infection of methicillin-resistant Staphylococcus aureus (MRSA). Although various rare infective cases are reported following arthroscopy of the knee joint, to the best of our knowledge there is no previous report of MRSA infection following arthroscopy of the knee joint.
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Attar KH, Imran D, Iyer S. Vacuum-assisted closure (VAC) therapy in the management of digital pulp defects. ACTA CHIRURGIAE PLASTICAE 2007; 49:75-76. [PMID: 18051587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Vacuum-assisted closure (VAC) therapy is a relatively new technique in the field of wound management. It has been increasingly used in treating various types of open wounds with effective results and minimal adverse effects. Digital injuries can occasionally be problematic. We report a new application of vacuum-assisted closure therapy in treating digital pulp defects.
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Yap YS, Karapetis C, Lerose S, Iyer S, Koczwara B. Reducing the risk of peripherally inserted central catheter line complications in the oncology setting. Eur J Cancer Care (Engl) 2006; 15:342-7. [PMID: 16968315 DOI: 10.1111/j.1365-2354.2006.00664.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
At our institution, a retrospective review of peripherally inserted central catheters (PICCs) in oncology patients had previously demonstrated a complication rate of 40.7%. Since then we have implemented strategies to reduce complications including staff and patient education, insertion technique modification and PICC maintenance utilizing a PICC nurse. The objectives of this study were to evaluate the recent PICC complication rate and to compare it with the previously reported findings. Prospectively collected PICC complication data and medical records from all patients with solid tumours who had PICCs inserted in 2003 were analysed. A historical cohort comparative analysis was performed using our PICC complication rate from 2000 to 2001. Eighty-eight PICC lines were inserted in 73 patients under radiological guidance. The median PICC dwell time was 44 days (1-524 days). The overall complication rate was 15.9% (14/88) or 2.0 complications per 1,000 PICC-days. Infections developed in 5.7% (5/88) and thrombotic events occurred in 4.5% (4 /88) of PICCs. The mean time to complication was 45 days. The complication rate for 2003 was significantly lower than the rate for 2001 (P = 0.006), especially of infective complications (P = 0.004). Strategies introduced to reduce PICC complications may have been the reason for this improvement.
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141
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Ramakrishnan N, Baronia AK, Divatia JV, Bhagwati A, Chawla R, Iyer S, Jani CK, Joad S, Kamat V, Kapadia F, Mehta Y, Myatra SN, Nagarkar S, Nayyar V, Padhy S, Rajagopalan R, Ray B, Sahu S, Sampath S, Todi S. Critical care delivery in intensive care units in India: Defining the functions, roles and responsibilities of a consultant intensivist. Indian J Crit Care Med 2006. [DOI: 10.5005/ijccm-10-1-53] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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142
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Padmanabhan TK, Samuel J, Pavithran K, Iyer S, Kuriakose MA, Geeta SN. Comparison of acute toxicities of two chemotherapy schedules for head and neck cancers. J Cancer Res Ther 2006; 2:100-4. [DOI: 10.4103/0973-1482.27584] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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143
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Green C, Foster W, Iyer S, Booth J. A married couple with streptococcal septicaemia. J R Soc Med 2005. [PMID: 16199816 DOI: 10.1258/jrsm.98.10.471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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144
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Green C, Foster W, Iyer S, Booth J. A Married Couple with Streptococcal Septicaemia. Med Chir Trans 2005; 98:471-2. [PMID: 16199816 PMCID: PMC1240104 DOI: 10.1177/014107680509801013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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145
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Rajagopalan R, Iyer S, Perez A. Comparison of pioglitazone with other antidiabetic drugs for associated incidence of liver failure: no evidence of increased risk of liver failure with pioglitazone. Diabetes Obes Metab 2005; 7:161-9. [PMID: 15715889 DOI: 10.1111/j.1463-1326.2004.00382.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
AIM The aim of this study was to assess the incidence of liver failure in association with antidiabetic treatment using pioglitazone vs. other oral antidiabetic medications. METHODS The study was a retrospective analysis of claim data from the PharMetrics Patient-Centric Database that had over 1.12 million enrollees with type 2 diabetes. All patients, > or =18 years of age with type 2 diabetes, who had initiated treatment either with a thiazolidinedione (pioglitazone and rosiglitazone), sulfonylurea or metformin were identified and matched on the basis of propensity scores, which served as a proxy for severity of disease. The primary measure of interest was the incidence of liver failure or hepatitis post-index date. In addition to unadjusted comparisons, Cox proportional hazard models were employed to estimate the risk of developing liver failure or hepatitis. RESULTS There was no significant difference in the 1- and 2-year incidence rates of liver failure or hepatitis (primary and secondary diagnoses) between the pioglitazone monotherapy group and the respective comparator groups. In Cox proportional hazard models controlling for age, pre-index total healthcare costs, Charlson comorbidity index, procedures and a hospitalization or Emergency room (ER) visit for pre-index hyperglycaemia, and pioglitazone were not associated with an increased risk of liver failure or hepatitis, compared to all other defined groups. Furthermore, no primary or secondary diagnosis of liver failure was reported in the pioglitazone group during the follow-up period. CONCLUSIONS Results of retrospective data analysis demonstrate no evidence of increased risk of liver failure or hepatitis for patients initiating therapy on pioglitazone, compared to other oral antidiabetic agents. Pioglitazone therapy was not associated with an increased risk of liver failure at 2 years relative to other oral antidiabetic therapies.
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Iyer S, Korada M, Rainbow L, Kirk J, Brown RM, Shaw N, Barrett TG. Wolcott-Rallison syndrome: a clinical and genetic study of three children, novel mutation in EIF2AK3 and a review of the literature. Acta Paediatr 2004; 93:1195-201. [PMID: 15384883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
BACKGROUND Wolcott-Rallison syndrome is a rare autosomal recessive condition characterized by early infancy onset diabetes mellitus and multiple epiphyseal dysplasia. So far, 17 children have been described in the world literature. Recently, mutations in the gene encoding EIF2AK3 have been shown to segregate with the syndrome in three affected families. AIMS We aimed to describe the clinical characterization and mutation analysis of a further child, and full clinical and follow-up details on our first family including the longest surviving child. METHODS Retrospective case notes review of three children presenting to the diabetic unit at our institution; mutation analysis of the EIF2AK3 gene in our most recent patient; and review of the literature on Wolcott-Rallison syndrome. RESULTS Previously unreported phenotypic features in our patients included developmental regression after episodes of hepatic failure, and pachygyria on brain imaging. We have identified a novel 4-base pair deletion (nt 3021-3024 del GAGA) in exon 13, which results in a frameshift and premature stop codon (R908 F/S +22X), causing premature truncation of the protein and abolition of the carboxy-segment of the catalytic domain. CONCLUSIONS Wolcott-Rallison syndrome causes early-onset diabetes and acute hepatic failure, before epiphyseal dysplasia is manifest. We have identified a novel mutation in EIF2AK3, and prenatal diagnosis may now be offered to affected families.
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Iyer S, Monteiro MFG. THE RISK OF CHILD AND ADOLESCENT MORTALITY AMONG VULNERABLE POPULATIONS IN RIO DE JANEIRO, BRAZIL. J Biosoc Sci 2004; 36:523-46. [PMID: 15446350 DOI: 10.1017/s0021932003006436] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This study investigated the importance of socioeconomic factors such as education, income, religion, family structure and residence in explaining the increased risk of mortality among vulnerable populations aged less than 20 years in Rio de Janeiro, Brazil. Data used were from the 1991 Brazilian Demographic Census and comprised 121,060 women aged 15–49 residing in Rio de Janeiro. Two alternative statistical methods were used to calculate the risk of death: the widely used Brass method (an indirect estimate which assesses population risks) and a case-control study (which assesses individual risks). The study also focused on the importance of indicators of human and social capital, the lack of which may explain the higher risk of death among children and adolescents. Lack of education was found to be a major determinant of mortality at young ages. Residence in a favela (shantytown), families in which mothers were the head of the family, and a lower median level of income were found to be significant determinants of mortality among vulnerable populations in Brazil. However, religion was not found to be as important a predictor of high mortality.
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Braudeau C, Bouchet D, Tesson L, Iyer S, Rémy S, Buelow R, Anegon I, Chauveau C. Induction of long-term cardiac allograft survival by heme oxygenase-1 gene transfer. Gene Ther 2004; 11:701-10. [PMID: 14973545 DOI: 10.1038/sj.gt.3302208] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Elevated expression of heme oxygenase-1 (HO-1), an intracellular enzyme that degrades heme into carbon monoxide (CO), biliverdine and free iron, has anti-inflammatory and antiapoptotic effects in diverse models. Here, we analyzed the effects of specific overexpression of HO-1 following adenovirus-mediated (AdHO-1) gene transfer in an acute cardiac allograft rejection model. The intragraft (i.g.) injection of AdHO-1 into cardiac allografts, as well as intramuscular (i.m.) or intravenous (i.v.) administration, prolonged allograft survival with, respectively, 13.3, 62.5 and 80% of the grafts surviving long term (>100 days), whereas control grafts were rejected with acute kinetics. HO-1 overexpression was associated with inhibited allogeneic responses in MLRs using graft-infiltrating leukocytes and splenocytes, but not with lymph node cells. The inhibition of splenocyte proliferation was mediated by soluble factors and was dependent on the presence of APCs, since purified T cells proliferated normally. i.v. but not i.g. AdHO-1 administration decreased the number of graft-infiltrating leukocytes, cytokine mRNA accumulation and apoptosis in transplanted hearts, whereas i.v. and i.g. AdHO-1 did not modify normal immune responses against cognate antigens, indicating that there was no general immunosuppression. These results indicate that HO-1 overexpression prolongs the survival of vascularized allografts by promoting tolerogenic mechanisms acting on allogeneic cellular immune responses.
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149
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Iyer S, Robinett RSR, HogenEsch H, Hem SL. Mechanism of adsorption of hepatitis B surface antigen by aluminum hydroxide adjuvant. Vaccine 2004; 22:1475-9. [PMID: 15063571 DOI: 10.1016/j.vaccine.2003.10.023] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2003] [Revised: 10/16/2003] [Accepted: 10/17/2003] [Indexed: 10/26/2022]
Abstract
Hepatitis B surface antigen (HBsAg) differs from many antigens because of its associated lipid bilayer that is largely composed of phospholipids. In general, phosphate groups adsorb strongly to hydroxylated mineral surfaces by ligand exchange. The purpose of this study was to investigate the mechanism of adsorption of hepatitis B surface antigen to aluminum hydroxide adjuvant with emphasis on the role of phospholipids in this adsorption. The adsorption of HBsAg by aluminum hydroxide adjuvant exhibits a high affinity adsorption isotherm. The Langmuir equation was used to calculate the adsorptive capacity (1.7 microg/microg Al), which is the amount of HBsAg adsorbed at monolayer coverage and the adsorptive coefficient (6.0 ml/microg), which is a measure of the strength of the adsorption force. The relatively high value of the adsorptive coefficient indicates that adsorption is due to a strong attractive force. Ligand exchange between a phosphate of the antigen and a surface hydroxyl of the adjuvant provides the strongest adsorption mechanism. The adsorption capacity of HBsAg was not affected by increased ionic strength indicating that electrostatic attraction is not the predominant adsorption force. Adsorption was also not affected by the addition of ethylene glycol indicating that hydrophobic interactions were not the predominant adsorption force. The strength of the adsorption force was indicated by the resistance of HBsAg to elution when exposed to interstitial fluid. Less than 5% of the HBsAg adsorbed to aluminum hydroxide adjuvant in a model vaccine was eluted during a 12 h in vitro exposure to interstitial fluid at 37 degrees C. Less than 1% of the adsorbed HBsAg in two commercial vaccines was eluted by in vitro exposure to interstitial fluid for 48 h at 37 degrees C. Thus, it was concluded that adsorption of HBsAg by aluminum hydroxide adjuvant is predominantly due to ligand exchange between the phospholipids in HBsAg and surface hydroxyls in aluminum hydroxide adjuvant.
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Iyer S, Ferreri DM, DeCocco NC, Minnear FL, Vincent PA. VE-cadherin-p120 interaction is required for maintenance of endothelial barrier function. Am J Physiol Lung Cell Mol Physiol 2003; 286:L1143-53. [PMID: 14672921 DOI: 10.1152/ajplung.00305.2003] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Interaction of p120 with juxtamembrane domain (JMD) of VE-cadherin has been implicated in regulation of endothelial cell-cell adhesion. We used a number of approaches to alter the level of p120 available for binding to VE-cadherin as a means to investigate the role of p120-VE-cadherin interaction in regulation of barrier function in confluent endothelial monolayers. Expression of an epitope-tagged fragment corresponding to JMD of VE-cadherin resulted in a decrease in endothelial barrier function as assessed by changes in albumin clearance and electrical resistance. Binding of JMD-Flag to p120 resulted in a decreased level of p120. In addition to decreasing p120 level, expression of JMD also decreased level of VE-cadherin. Expression of JMD also caused an increase in MLC phosphorylation and rearrangement of actin cytoskeleton, which, coupled with decreased cadherin, can contribute to loss of barrier function. Reducing p120 by siRNA resulted in a decrease in VE-cadherin, whereas increasing the level of p120 increased the level of VE-cadherin, demonstrating that p120 regulates the level of VE-cadherin. Overexpression of p120 was, however, associated with decreased barrier function and rearrangement of the actin cytoskeleton. Interestingly, expression of p120 was able to inhibit thrombin-induced increases in MLC phosphorylation, suggesting that p120 inhibits activation of Rho/Rho kinase pathway in endothelial cells. Excess p120 also prevented JMD-induced increases in MLC phosphorylation, correlating this phosphorylation with Rho/Rho kinase pathway. These findings show p120 plays a major role in regulating endothelial barrier function, as either a decrease or increase of p120 resulted in disruption of permeability across cell monolayers.
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