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Kader MA, Namburi P, Ramugade S, Ramakrishnan R, Krishnadas SR, Roos BR, Periasamy S, Robin AL, Fingert JH. Clinical and genetic characterization of a large primary open angle glaucoma pedigree. Ophthalmic Genet 2016; 38:222-225. [PMID: 27355837 DOI: 10.1080/13816810.2016.1193883] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
PURPOSE To both characterize the clinical features of large primary open angle glaucoma (POAG) pedigree from a village in southern India and to investigate the genetic basis of their disease. MATERIALS AND METHODS Eighty-four members of a large pedigree received complete eye examinations including slit lamp examination, tonometry, gonioscopy, and ophthalmoscopy. Some were further studied with perimetry. Those diagnosed with POAG were tested for disease-causing mutations in the myocilin and optineurin genes with Sanger sequencing. RESULTS Fourteen of 84 family members were diagnosed with POAG, while eight were clinically judged to be POAG-suspects. The family structure and the pattern of glaucoma in the pedigree are complex. Features of glaucoma in this pedigree include relatively early age at diagnosis (mean 50 ± 14 years) and maximum intraocular pressures ranging from 14 to 36 mm Hg with a mean of 23 mm Hg ± 6.5 mm Hg. Patients had an average central corneal thickness (mean 529 ± 37.8 microns) and moderate cup-to-disc ratios (0.74 ± 0.14). No mutations were detected in myocilin, optineurin, or TANK binding kinase 1 (TBK1). CONCLUSIONS We report a five-generation pedigree with a complex pattern of POAG inheritance that includes 22 POAG patients and glaucoma suspects. Although the familial clustering of POAG in this pedigree is consistent with dominant inheritance of a glaucoma-causing gene, mutations were not detected in genes previously associated with autosomal dominant glaucoma, suggesting the involvement of a novel disease-causing gene in this pedigree.
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Ramakrishnan R, Nazer MY, Suthanthirarajan N, Namasivayam A. An Experimental Analysis of the Catecholamines in Hyperglycemia and Acidosis-Induced Rat Brain. Int J Immunopathol Pharmacol 2016; 16:233-9. [PMID: 14611726 DOI: 10.1177/039463200301600308] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Hyperglycemia and acidosis are the hallmarks of diabetes. Since these factors play an important role in diabetic complications, we have studied the brain catecholamine levels in hyperglycemic and acidotic conditions per se. Experimentally induced hyperglycemia and acidosis are accompanied by significant alterations in the catecholamine levels in discrete areas of the brain. We and others have shown that chronic or acute diabetes in animals, as well as in humans results in altered neurotransmitter levels. In the present study, hyperglycemia maintained by daily external administration of glucose for thirty days showed increased level of dopamine in striatum and hippocampus, elevation of norepinephrine in hippocampus, and increased level of epinephrine in hypothalamus, midbrain and pons medulla. The ammonium chloride induced acidosis demonstrated significant elevation of dopamine in midbrain and significant increase of norepinephrine in hypothalamus and midbrain, and increased level of epinephrine in hypothalamus, pons medulla and cerebral cortex. On the other hand, sodium acetoacetate induced acidosis did not show any significant change in the level of catecholamines in any of the areas studied. In conclusion, the changes in catecholamine levels observed in experimentally induced hyperglycemic as well as in acidotic conditions are closely related to the changes observed in spontaneous or alloxan or streptozotocin diabetic animals, thereby suggesting that these conditions may be responsible for the changes observed in diabetic animals.
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Stockwell MS, Natarajan K, Ramakrishnan R, Holleran S, Forney K, Aponte A, Vawdrey DK. Immunization Data Exchange With Electronic Health Records. Pediatrics 2016; 137:peds.2015-4335. [PMID: 27244856 DOI: 10.1542/peds.2015-4335] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/28/2016] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE To assess the impact of exchange of immunization information between an immunization information system (IIS) and an electronic health record on up-to-date rates, overimmunization, and immunization record completeness for low-income, urban children and adolescents. METHODS The New York City Department of Health maintains a population-based IIS, the Citywide Immunization Registry (CIR). Five community clinics in New York City implemented direct linkage of immunization data from the CIR to their local electronic health record. We compared immunization status and overimmunization in children and adolescents 19 to 35 month, 7 to 10 year, and 13 to 17 year-olds with provider visits in the 6-month period before data exchange implementation (2009; n = 6452) versus 6-months post-implementation (2010; n = 6124). We also assessed immunization record completeness with and without addition of CIR data for 8548 children and adolescents with visits in 2012-2013. RESULTS Up-to-date status increased from before to after implementation from 75.0% to 81.6% (absolute difference, 6.6%; 95% confidence interval [CI], 5.2% to 8.1%) and was significant for all age groups. The percentage overimmunized decreased from 8.8% to 4.7% (absolute difference, -4.1%; 95% CI, -7.8% to -0.3%) and was significant for adolescents (16.4% vs 1.2%; absolute difference, -15.2%; 95% CI, -26.7 to -3.6). Up-to-date status for those seen in 2012 to 2013 was higher when IIS data were added (74.6% vs 59.5%). CONCLUSIONS This study demonstrates that data exchange can improve child and adolescent immunization status. Development of the technology to support such exchange and continued focus on local, state, and federal policies to support such exchanges are needed.
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Millar JS, Reyes-Soffer G, Jumes P, Dunbar RL, deGoma EM, Baer AL, Karmally W, Donovan DS, Rafeek H, Pollan L, Tohyama J, Johnson-Levonas AO, Wagner JA, Holleran S, Obunike J, Liu Y, Ramakrishnan R, Lassman ME, Gutstein DE, Ginsberg HN, Rader DJ. Anacetrapib lowers LDL by increasing ApoB clearance in mildly hypercholesterolemic subjects. J Clin Invest 2016; 126:1603-4. [PMID: 27035815 DOI: 10.1172/jci87364] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Reyes-Soffer G, Millar JS, Ngai C, Jumes P, Coromilas E, Asztalos B, Johnson-Levonas AO, Wagner JA, Donovan DS, Karmally W, Ramakrishnan R, Holleran S, Thomas T, Dunbar RL, deGoma EM, Rafeek H, Baer AL, Liu Y, Lassman ME, Gutstein DE, Rader DJ, Ginsberg HN. Cholesteryl Ester Transfer Protein Inhibition With Anacetrapib Decreases Fractional Clearance Rates of High-Density Lipoprotein Apolipoprotein A-I and Plasma Cholesteryl Ester Transfer Protein. Arterioscler Thromb Vasc Biol 2016; 36:994-1002. [PMID: 26966279 DOI: 10.1161/atvbaha.115.306680] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 02/22/2016] [Indexed: 01/14/2023]
Abstract
OBJECTIVE Anacetrapib (ANA), an inhibitor of cholesteryl ester transfer protein (CETP) activity, increases plasma concentrations of high-density lipoprotein cholesterol (HDL-C), apolipoprotein A-I (apoA)-I, apoA-II, and CETP. The mechanisms responsible for these treatment-related increases in apolipoproteins and plasma CETP are unknown. We performed a randomized, placebo (PBO)-controlled, double-blind, fixed-sequence study to examine the effects of ANA on the metabolism of HDL apoA-I and apoA-II and plasma CETP. APPROACH AND RESULTS Twenty-nine participants received atorvastatin (ATV) 20 mg/d plus PBO for 4 weeks, followed by ATV plus ANA 100 mg/d for 8 weeks (ATV-ANA). Ten participants received double PBO for 4 weeks followed by PBO plus ANA for 8 weeks (PBO-ANA). At the end of each treatment, we examined the kinetics of HDL apoA-I, HDL apoA-II, and plasma CETP after D3-leucine administration as well as 2D gel analysis of HDL subspecies. In the combined ATV-ANA and PBO-ANA groups, ANA treatment increased plasma HDL-C (63.0%; P<0.001) and apoA-I levels (29.5%; P<0.001). These increases were associated with reductions in HDL apoA-I fractional clearance rate (18.2%; P=0.002) without changes in production rate. Although the apoA-II levels increased by 12.6% (P<0.001), we could not discern significant changes in either apoA-II fractional clearance rate or production rate. CETP levels increased 102% (P<0.001) on ANA because of a significant reduction in the fractional clearance rate of CETP (57.6%, P<0.001) with no change in CETP production rate. CONCLUSIONS ANA treatment increases HDL apoA-I and CETP levels by decreasing the fractional clearance rate of each protein.
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St John ER, Al-Khudairi R, Balog J, Rossi M, Gildea L, Speller A, Ramakrishnan R, Shousha S, Takats Z, Leff DR, Darzi A. Abstract P2-12-20: Rapid evaporative ionisation mass spectrometry towards real time intraoperative oncological margin status determination in breast conserving surgery. Cancer Res 2016. [DOI: 10.1158/1538-7445.sabcs15-p2-12-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Introduction: Positive tumour margins following attempted breast conserving surgery (BCS) is an important risk factor for local recurrence. Nationally in the United Kingdom on average approximately 25% of patients undergoing BCS require additional surgery for positive margins. Traditional techniques such as specimen xray, frozen section & imprint cytology to optimise margin clearance have significant limitations. Various research methods under investigation include optical spectroscopy, high resolution imaging and radiofrequency spectroscopy. Rapid Evaporative Ionisation Mass Spectrometry (REIMS) is a new method that uses mass spectrometric analysis of the tissue specific ionic content of the surgical diathermy smoke plume for the rapid identification of dissected breast tissues as an intelligent knife (iKnife). We investigate the ability of the "iKnife" to analyze heterogeneous breast tissue intraoperatively using mass spectrometric techniques.
Method: The study involved three stages that comprised: method development, tissue specific ex-vivo database construction and intraoperative analysis. Smoke aerosol produced as a result of electrosurgical diathermy from a variety of frozen, fresh and in-vivo breast samples were aspirated into a mass spectrometer via a modified surgical handpiece. Tissue diagnosis was confirmed by subsequent histopathological validation. The data underwent computational analysis using multivariate statistics –predominantly Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA), along with leave one patient out cross-validation. A total of 128 patients (n=40 method development, n=66 ex-vivo database, n=22 intraoperative analysis) undergoing breast surgery were enrolled in this study. Ethical approval was obtained from the Research Ethics Committee.
Results: 40 patients contributed breast samples (normal and cancerous) for method optimisation to enable analysis of high intensity spectra from heterogeneous breast tissue. Following optimisation an ex-vivo database was constructed from 89 excised fresh breast tissue samples from 66 patients using 330 spectra (246 Normal, 60 Tumour – IDC, ILC, IMC and 24 Benign - fibroadenoma). Multivariate statistical analysis of data revealed classification of tumour compared to normal tissue with sensitivities of 93.0% and specificity of 91.9%. The iKnife was used intraoperatively during the entire operation of 25 surgeries. Spectral data was obtained within 1-2 seconds. Specific margin analysis correctly identified negative margins in 10 cases.
Conclusions: The iKnife has been successfully developed for analysis of intraoperative heterogeneous breast tissue. Preliminary data suggests that this technique is suitable with high accuracy for the separation of normal, benign (fibroadenoma) and cancerous (invasive ductal and invasive lobular carcinoma) breast tissues. In comparison to the normal breast, cancerous tissues exhibit statistically different spectral profiles. Further work is aimed at the development of a real time algorithm able to match intraoperative data with the pre-existing database for the rapid interpretation and real time feedback of intraoperative data towards detecting positive margins intraoperatively.
Citation Format: St John ER, Al-Khudairi R, Balog J, Rossi M, Gildea L, Speller A, Ramakrishnan R, Shousha S, Takats Z, Leff DR, Darzi A. Rapid evaporative ionisation mass spectrometry towards real time intraoperative oncological margin status determination in breast conserving surgery. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-12-20.
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Vaitheeswaran K, Subbiah M, Ramakrishnan R, Kannan T. A comparison of ordinal logistic regression models using Classical and Bayesian approaches in an analysis of factors associated with diabetic retinopathy. J Appl Stat 2016. [DOI: 10.1080/02664763.2016.1140725] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Millar JS, Reyes-Soffer G, Jumes P, Dunbar RL, deGoma EM, Baer AL, Karmally W, Donovan DS, Rafeek H, Pollan L, Tohyama J, Johnson-Levonas AO, Wagner JA, Holleran S, Obunike J, Liu Y, Ramakrishnan R, Lassman ME, Gutstein DE, Ginsberg HN, Rader DJ. Anacetrapib lowers LDL by increasing ApoB clearance in mildly hypercholesterolemic subjects. J Clin Invest 2015; 125:2510-22. [PMID: 25961461 DOI: 10.1172/jci80025] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 04/13/2015] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Individuals treated with the cholesteryl ester transfer protein (CETP) inhibitor anacetrapib exhibit a reduction in both LDL cholesterol and apolipoprotein B (ApoB) in response to monotherapy or combination therapy with a statin. It is not clear how anacetrapib exerts these effects; therefore, the goal of this study was to determine the kinetic mechanism responsible for the reduction in LDL and ApoB in response to anacetrapib. METHODS We performed a trial of the effects of anacetrapib on ApoB kinetics. Mildly hypercholesterolemic subjects were randomized to background treatment of either placebo (n = 10) or 20 mg atorvastatin (ATV) (n = 29) for 4 weeks. All subjects then added 100 mg anacetrapib to background treatment for 8 weeks. Following each study period, subjects underwent a metabolic study to determine the LDL-ApoB-100 and proprotein convertase subtilisin/kexin type 9 (PCSK9) production rate (PR) and fractional catabolic rate (FCR). RESULTS Anacetrapib markedly reduced the LDL-ApoB-100 pool size (PS) in both the placebo and ATV groups. These changes in PS resulted from substantial increases in LDL-ApoB-100 FCRs in both groups. Anacetrapib had no effect on LDL-ApoB-100 PRs in either treatment group. Moreover, there were no changes in the PCSK9 PS, FCR, or PR in either group. Anacetrapib treatment was associated with considerable increases in the LDL triglyceride/cholesterol ratio and LDL size by NMR. CONCLUSION These data indicate that anacetrapib, given alone or in combination with a statin, reduces LDL-ApoB-100 levels by increasing the rate of ApoB-100 fractional clearance. TRIAL REGISTRATION ClinicalTrials.gov NCT00990808. FUNDING Merck & Co. Inc., Kenilworth, New Jersey, USA. Additional support for instrumentation was obtained from the National Center for Advancing Translational Sciences (UL1TR000003 and UL1TR000040).
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Stockwell MS, Catallozzi M, Camargo S, Ramakrishnan R, Holleran S, Findley SE, Kukafka R, Hofstetter AM, Fernandez N, Vawdrey DK. Registry-linked electronic influenza vaccine provider reminders: a cluster-crossover trial. Pediatrics 2015; 135:e75-82. [PMID: 25548331 DOI: 10.1542/peds.2014-2616] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE To determine the impact of a vaccination reminder in an electronic health record supplemented with data from an immunization information system (IIS). METHODS A noninterruptive influenza vaccination reminder, based on a real-time query of hospital and city IIS, was used at 4 urban, academically affiliated clinics serving a low-income population. Using a randomized cluster-crossover design, each study site had "on" and "off" period during the fall and winter of 2011-2012. Influenza vaccination during a clinic visit was assessed for 6-month to 17-year-old patients. To assess sustainability, the reminder was active at all sites during the 2012-2013 season. RESULTS In the 2011-2012 season, 8481 unique non-up-to-date children had visits. Slightly more non-up-to-date children seen when the reminder was 'on' were vaccinated than when 'off' (76.2% vs 73.8%; P = .027). Effects were seen in the winter (67.9% vs 62.2%; P = .005), not fall (76.8% vs 76.5%). The reminder also increased documentation of the reason for vaccine non-administration (68.1% vs 41.5%; P < .0001). During the 2011-2012 season, the reminder displayed for 8630 unique visits, and clinicians interacted with it in 83.1% of cases where patients required vaccination. During the 2012-2013 season, it displayed for 22 248 unique visits; clinicians interacted with it in 84.8% of cases. CONCLUSIONS An IIS-linked influenza vaccination reminder increased vaccination later in the winter when fewer vaccine doses are usually given. Although the reminder did not require clinicians to interact with it, they frequently did; utilization did not wane over time.
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Mitra A, Ramakrishnan R, Kader MA. Open angle glaucoma in a case of Type IV Ehler Danlos syndrome: a rarely reported association. Indian J Ophthalmol 2014; 62:880-4. [PMID: 25230966 PMCID: PMC4185169 DOI: 10.4103/0301-4738.141060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A 26-year-old male presented to us with defective vision in the left eye. He had best corrected visual acuity (BCVA) of hand movement (HM) in right eye and 6/9 in left eye. He had ptosis with ectropion in both eyes and relative afferent pupillary defect (RAPD) in right eye. Intraocular pressure (IOP) was 46 and 44 mmHg in right and left eye, respectively. Fundus showed glaucomatous optic atrophy (GOA) in right eye and cup disc ratio (CDR) of 0.75 with bipolar rim thinning in left eye. Systemic examination showed hyperextensible skin and joints, acrogeria, hypodontia, high arched palate, and varicose veins. He gave history of easy bruising and tendency to fall and history of intestinal rupture 5 years ago for which he had undergone surgery. He was diagnosed as a case of Type IV Ehler-Danlos syndrome (EDS) with open angle glaucoma. He underwent trabeculectomy in both eyes. This is a rare case that shows glaucoma in a patient of EDS Type IV. Very few such cases have been reported in literature.
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Rinninger F, Heine M, Singaraja R, Hayden M, Brundert M, Ramakrishnan R, Heeren J. High density lipoprotein metabolism in low density lipoprotein receptor-deficient mice. J Lipid Res 2014; 55:1914-24. [PMID: 24954421 DOI: 10.1194/jlr.m048819] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The LDL receptor (LDLR) and scavenger receptor class B type I (SR-BI) play physiological roles in LDL and HDL metabolism in vivo. In this study, we explored HDL metabolism in LDLR-deficient mice in comparison with WT littermates. Murine HDL was radiolabeled in the protein ((125)I) and in the cholesteryl ester (CE) moiety ([(3)H]). The metabolism of (125)I-/[(3)H]HDL was investigated in plasma and in tissues of mice and in murine hepatocytes. In WT mice, liver and adrenals selectively take up HDL-associated CE ([(3)H]). In contrast, in LDLR(-/-) mice, selective HDL CE uptake is significantly reduced in liver and adrenals. In hepatocytes isolated from LDLR(-/-) mice, selective HDL CE uptake is substantially diminished compared with WT liver cells. Hepatic and adrenal protein expression of lipoprotein receptors SR-BI, cluster of differentiation 36 (CD36), and LDL receptor-related protein 1 (LRP1) was analyzed by immunoblots. The respective protein levels were identical both in hepatic and adrenal membranes prepared from WT or from LDLR(-/-) mice. In summary, an LDLR deficiency substantially decreases selective HDL CE uptake by liver and adrenals. This decrease is independent from regulation of receptor proteins like SR-BI, CD36, and LRP1. Thus, LDLR expression has a substantial impact on both HDL and LDL metabolism in mice.
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Mitra A, Ramakrishnan R, Kader MA. Anterior segment optical coherence tomography documentation of a case of topiramate induced acute angle closure. Indian J Ophthalmol 2014; 62:619-22. [PMID: 24881612 PMCID: PMC4065517 DOI: 10.4103/0301-4738.129784] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
We present a case report of a 31-year-old female patient who presented to us with a 1 day history of acute bilateral eye pain, blurred vision and headache. She was found to have a myopic shift, raised intraocular pressure (IOP) and shallow anterior chambers in both eyes. She had been commenced on oral topiramate 1 week previously. A number of investigations, including anterior segment optical coherence tomography (AS-OCT) were done and a diagnosis of topiramate induced bilateral acute angle closure (TiAAC) was made. Topiramate was discontinued and she was managed with topical and oral antiglaucoma medications, topical steroids and cyclopegics. Her symptoms subsided dramatically at the next follow-up. The AS-OCT documentation revealed lucidly the improvement in her anterior chamber depth and anterior chamber angle parameters. Her IOP decreased, her myopic shift showed reversal and her AS-OCT findings revealed gross improvement in all the parameters angle opening distance, trabecular iris space area and scleral spur angle. This case report clearly shows with AS OCT documentation the changes which occur in the anterior segment in a case of TiAAC.
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Reyes-Soffer G, Dionizovik M, Jimenez J, Obunike J, Holleran S, Ramakrishnan R, Karmally W, Fontanez N, Thomas T, Donovan D, Morey R, Mittleman R, Chin W, Baker B, Ginsberg HN. Abstract 634: Treatment with Mipomersen Reduces Levels of ApoB-Containing Lipoproteins by Increasing Fractional Removal of VLDL and LDL-apoB Without Reducing VLDL-apob Secretion. Arterioscler Thromb Vasc Biol 2014. [DOI: 10.1161/atvb.34.suppl_1.634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objectives:
Mipomersen (MIPO), a second generation antisense oligonucleotide, targets apoB mRNA, thereby inhibiting apolipoprotein B (apoB) synthesis. In humans, MIPO reduces plasma levels of low density lipoprotein-cholesterol (LDL-C), and plasma triglycerides (TG). We hypothesized that these changes are due to reduced assembly and secretion of very low density lipoproteins (VLDL) and lower production of LDL.
Methods:
Healthy volunteers (HVs) (9M, 8F), mean age 43.5 ± 14.2 yr, completed a single-blind, fixed-sequence, phase I study. They received sc-placebo injections once weekly for 3-wks followed by 200mg sc-MIPO injections once weekly for 7-9 wks. Stable isotope turnover studies were performed after each treatment. Blood samples were collected over 48-hrs to determine fractional catabolic rates (FCRs) and production rates (PRs) of apoB in VLDL, IDL, and LDL, and of TG in VLDL. Rates of de novo lipogenesis (DNL) were also measured.
Results:
MIPO treatment resulted in significant reductions in plasma LDL-C (45%), TG (29%), and apoB (40%). VLDL, IDL, and LDL apoB levels fell by 29%, 25%, and 42%, respectively. These changes were associated with increases in FCRs of VLDL apoB (42%) and LDL apoB (30%), and by reductions in PRs of IDL apoB (15%) and LDL apoB (27%). The PR of VLDL apoB was unaffected. The FCR of VLDL-TG increased 46% without change in PR. DNL did not change.
Conclusion:
In summary, 7 wks of MIPO significantly reduced levels of all apoB-lipoproteins in HVs by increasing the FCRs of VLDL and LDL apoB. The absence of a reduction in VLDL apoB secretion is consistent with many studies in isolated hepatocytes demonstrating both intracellular degradation and secretion of newly synthesized apoB. Thus, if MIPO submaximally inhibited apoB synthesis in this study, the liver could have compensated by increasing the efficiency of VLDL assembly and secretion. The basis of increases in VLDL and LDL FCRs requires further investigation.
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Sudha JD, Sivakala S, Chandrakanth CK, Neethu KS, Rohini KN, Ramakrishnan R. Percolated conductive polyaniline-clay nanocomposite in polyvinyl chloride through the combined approach porous template and self-assembly. EXPRESS POLYM LETT 2014. [DOI: 10.3144/expresspolymlett.2014.13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Padmavathi K, Ramakrishnan R. Tribological Behaviour of Aluminium Hybrid Metal Matrix Composite. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.proeng.2014.12.295] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Kim S, Ramakrishnan R, Gabrilovich D. Impact of Radiation-Induced Autophagy on the Efficacy of Combination Radiation Therapy and Immunotherapy. Int J Radiat Oncol Biol Phys 2013. [DOI: 10.1016/j.ijrobp.2013.06.1671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Sharma PK, Sen T, Ramakrishnan R, Hutin Y, Murhekar M. The shift from public to private health care providers and malaria deaths in Jalpaiguri district, West Bengal, India, 2006. Int Health 2013; 1:148-53. [PMID: 24036559 DOI: 10.1016/j.inhe.2009.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
We investigated an increase in malaria deaths in order to formulate control measures. A search of records in health care facilities for cases of death following fever, with a blood smear or rapid antigen test positive for Plasmodium falciparum, identified 77 fatalities. Of these, 72 (93%) occurred in hospitals (78% of which in the 24 hours following admission). Of 60 family members of the patients who died interviewed, 70% reported that the patient had received care from unqualified rural private practitioners available round the clock. Among 100 of these rural practitioners assessed, 21% knew anti-malarial dosage and 7% knew malaria severity criteria. There were 65% and 42% vacancies among 240 community health worker and 12 microscopist positions, respectively, in the public sector in the area. As a result, the mean interval between active case search rounds in the community was 35 days (standard: 14) and the median time between blood slide collection and radical treatment was 12 days (standard < 2 days). Deficiencies in the public health system may have led to a shift towards rural practitioners. Poor management of malaria may have contributed to deaths. We posted microscopists and community health workers in the area to restore appropriate malaria management in the public sector.
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Ravindran V, Balakrishnan K, Diwakaran M, Ramakrishnan R. AB0732 Pregnancy outcome in lupus patients with previous adverse outcomes: Experience with protocol based, multidisiplinary care. Ann Rheum Dis 2013. [DOI: 10.1136/annrheumdis-2012-eular.732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Reyes-Soffer G, Millar JS, Lassman ME, Jumes P, Wagner JA, Gutstein DE, Ramakrishnan R, Holleran S, Rader DJ. Abstract 120: Effects of Anacetrapib Treatment on CETP Metabolism. Arterioscler Thromb Vasc Biol 2013. [DOI: 10.1161/atvb.33.suppl_1.a120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background
Cholesteryl ester transfer protein (CETP) is required for the exchange of core lipids, cholesteryl esters and triglycerides (TG), between lipoproteins. This results in net exchanges of TG in very-low-density (VLDL) or low-density lipoproteins (LDL) for cholesteryl esters in high-density lipoproteins (HDL). Treatment with anacetrapib, a CETP inhibitor in phase 3 development, is associated with an increased HDL-C and apo AI, and reduced both LDL-C and triglycerides. There are no published data on the regulation of CETP levels in humans. CETP mass has been reported to increase following CETP inhibition which prompted us to examine CETP kinetics. We developed a novel method using stable isotopes and LC-MS analysis to study the effects of anacetrapib on CETP turnover.
Methods
Thirty-nine moderately hyperlipidemic participants were enrolled in a fixed-sequence study: 75% (N=29) were on atorvastatin (20mg/day) plus placebo for four weeks followed by atorvastatin plus anacetrapib (100 mg/day) for 8 weeks (S-ANA). Twenty-Five percent (N=10) of participants received double placebo for four weeks followed by placebo plus anacetrapib for 8 weeks (P-ANA). At the end of each period, we measured CETP mass, and kinetic studies were performed using D3 leucine to determine the fractional clearance and production rates of CETP.
Results
Eight weeks of anacetrapib treatment was associated with 129% increase in CETP plasma levels and an 18% decrease in CETP activity (RFU/sec) in both groups. The increase in CETP mass was associated with a significant reduction in the fractional clearance of CETP from plasma (0.48 vs. 0.23 pools/day) p <.001. The decrease in fractional clearance of CETP was similar in Panel A and Panel B (Panel A 57%, Panel B 55%). There were no significant changes in the production rate of CETP.
Conclusions
Using a novel method, we demonstrated significant effects of CETP inhibition with anacetrapib on the metabolism of CETP in plasma.
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Reyes-Soffer G, Ngai CI, Lovato L, Karmally W, Ramakrishnan R, Holleran S, Ginsberg HN. Effect of combination therapy with fenofibrate and simvastatin on postprandial lipemia in the ACCORD lipid trial. Diabetes Care 2013; 36:422-8. [PMID: 23033246 PMCID: PMC3554305 DOI: 10.2337/dc11-2556] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE The Action to Control Cardiovascular Risk in Diabetes lipid study (ACCORD Lipid), which compared the effects of simvastatin plus fenofibrate (FENO-S) versus simvastatin plus placebo (PL-S) on cardiovascular disease outcomes, measured only fasting triglyceride (TG) levels. We examined the effects of FENO-S on postprandial (PP) lipid and lipoprotein levels in a subgroup of ACCORD Lipid subjects. RESEARCH DESIGN AND METHODS We studied 139 subjects (mean age of 61 years, 40% female, and 76% Hispanic or black) in ACCORD Lipid, from a total 529 ACCORD Lipid subjects in the Northeast Clinical Network. PP plasma TG, apolipoprotein (apo)B48, and apoCIII were measured over 10 h after an oral fat load. RESULTS The PP TG incremental area under the curve (IAUC) above fasting (median and interquartile range [mg/dL/h]) was 572 (352-907) in the FENO-S group versus 770 (429-1,420) in the PL-S group (P = 0.008). The PP apoB48 IAUC (mean ± SD [μg/mL/h]) was also reduced in the FENO-S versus the PL-S group (23.2 ± 16.3 vs. 35.2 ± 28.6; P = 0.008). Fasting TG levels on the day of study were correlated with PP TG IAUC (r = 0.73 for FENO-S and r = 0.62 for PL-S; each P < 0.001). However, the fibrate effect on PP TG IAUC was a constant percentage across the entire range of fasting TG levels, whereas PP apoB48 IAUC was only reduced when fasting TG levels were increased. CONCLUSIONS FENO-S lowered PP TG similarly in all participants compared with PL-S. However, levels of atherogenic apoB48 particles were reduced only in individuals with increased fasting levels of TG. These results may have implications for interpretation of the overall ACCORD Lipid trial, which suggested benefit from FENO-S only in dyslipidemic individuals.
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Jayahar Bharathi M, Murugan N, Ramesh Kumar G, Ramakrishnan R, Anitha V, Ramesh S. Vittaforma corneae keratitis in southern India: role of a novel duplex PCR. J Med Microbiol 2013; 62:553-559. [PMID: 23319308 DOI: 10.1099/jmm.0.051722-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Microsporidia are obligate intracellular parasites that infect eukaryotic cells and have emerged as major opportunistic human pathogens. Due to the difficulties in definitive laboratory diagnosis and insufficient knowledge, ocular microsporidiosis is infrequently reported in India. To improve diagnostic facilities, we have developed a novel duplex PCR (dPCR) for the simultaneous identification of both genera and species of isolates with microsporidian aetiology that cause keratitis. The material scraped from the corneas of 12 clinically diagnosed microsporidial keratitis patients was subjected to routine microbiological examinations and molecular diagnosis using a novel dPCR that targeted the small-subunit rRNA gene (SSU-rRNA) of microsporidia and Vittaforma corneae using genus- and species-specific primers. Of the 12 corneal scrapes, 6 showed positive results in smears, while dPCR provided positive amplification with both pan-microsporidial and V. corneae species-specific primers for 9 corneal scrapes. The results were validated by sequencing and blast analysis. The sensitivity of this novel dPCR method was higher than that of conventional microscopy in the diagnosis of corneal microsporidial infection. dPCR with specific primers is potentially more sensitive, specific and depends less on more complicated methods for exact identification of the aetiology of microsporidial keratitis.
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Reena VL, Sudha JD, Ramakrishnan R. Development of electromagnetic interference shielding materials from the composite of nanostructured polyaniline-polyhydroxy iron-clay and polycarbonate. J Appl Polym Sci 2012. [DOI: 10.1002/app.38320] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Congdon NG, Krishnadas R, Friedman DS, Goggins W, Ramakrishnan R, Kader MA, Gilbert D, Tielsch J, Quigley HA. A study of initial therapy for glaucoma in southern India: India Glaucoma Outcomes and Treatment (INGOT) Study. Ophthalmic Epidemiol 2012; 19:149-58. [PMID: 22568428 DOI: 10.3109/09286586.2012.667493] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To compare initial glaucoma therapy with medications and trabeculectomy in southern India. METHODS Patients aged ≥ 30 years newly diagnosed with glaucoma were randomized to trabeculectomy with 5-fluorouracil or medical therapy. Subjects with best-corrected vision <6/18 due to cataract underwent phacoemulsification (phaco/intraocular lens, IOL). Intraocular pressure (IOP), vision and visual function were assessed at 12 months. RESULTS Patients assigned to medications and surgery received the expected therapy in 86% (172/199) and 64% (126/199) of cases, respectively. Forty patients (20%) assigned to surgery refused any treatment and 33 (17%) received medications. Among 199 patients randomized to medications, 52 (26.1%) underwent phaco/IOL, as did 89/199 (43.7%) of patients randomized to trabeculectomy. Baseline parameters of the two groups did not differ, nor did 1-year follow-up rates (medication 65%, trabeculectomy 58%, P = 0.15). Final IOP was lower with randomization to trabeculectomy (16.3 ± 5.1 mmHg) than medication (18.8 ± 6.7 mmHg, P < 0.0001). In regression models, randomization to trabeculectomy (P < 0.0001) was associated with lower IOP, and simultaneous trabeculectomy and cataract surgery was associated with higher IOP (P = 0.008) than trabeculectomy alone. Subjects receiving Phaco/IOL had significantly better final acuity (P < 0.0001) and visual function (P = 0.035), despite concurrent glaucoma treatment. Final visual acuity was worse in those receiving trabeculectomy in addition to cataract surgery, but this was of borderline significance (P = 0.06). CONCLUSIONS Trabeculectomy lowered IOP significantly more than medical treatment, but with slightly greater loss of visual acuity. Combined phaco/IOL and trabeculectomy improved visual acuity with substantial IOP lowering.
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Thomas TA, Zhou H, Roddy T, Previs S, Lassman M, Hubbard B, Jumes P, Wagner JA, Gutstein DE, Ramakrishnan R, Marcovina SM, Rader DJ, Ginsberg H, Millar J, Reyes-Soffer G. Abstract 329: Mechanism by Which Anacetrapib Lowers Plasma Lipoprotein (a) Concentration. Arterioscler Thromb Vasc Biol 2012. [DOI: 10.1161/atvb.32.suppl_1.a329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objective:
Anacetrapib, a CETP inhibitor, was previously shown to decrease plasma lipoprotein (a) [Lp(a)] levels by 35-40% in subjects also taking a statin. Thus, anacetrapib is an efficacious Lp(a)-lowering agent. The goal of this study was to define the mechanism by which anacetrapib lowers plasma Lp(a) levels.
Methods:
39 moderately hyperlipidemic volunteers were enrolled in a fixed-sequence study, in which 75% were on atorvastatin 20mg/day, plus placebo for four weeks (period 1), and then atorvastatin plus anacetrapib (100 mg/day) for 8 weeks (period 2). The other 25% of the subjects received double placebo for four weeks, and then placebo plus anacetrapib for 8 weeks. Turnover studies using D3-leucine were performed at the end of each period. The present analysis utilized samples from a subset of subjects (n=12) who had plasma Lp(a) levels greater than 10 nM at the end of period 1 and had a greater than 10% reduction in Lp(a) by the end of period 2. The fractional synthetic rate (FSR:equal to fractional catabolic rate at steady state) of mature Lp(a), isolated from a D:1.019-1.21 g/ml density interval, was determined from the enrichment of a leucine-containing peptide specific to apo(a). The production rate (PR) of mature Lp(a) was calculated from the FSR and the Lp(a) pool size. To date, we have calculated the FSR and PR in 4 participants.
Results:
Baseline Lp(a) mean levels were 45.7 ± 6.3nM in the entire group and 56.5 ± 33.6nM in the 12 qualifying subjects. Anacetrapib lowered Lp(a) by 43 ± 22% in the 12 subjects and 21 ±12% in the 4 subjects with turnover data. In these 4 subjects, the reduction in mature Lp(a) was associated with a 24% reduction in FSR and a 41% reduction in PR. Lp(a) kinetics analyses of the remaining 8 subjects are in progress.
Conclusion:
These preliminary results suggest that anacetrapib decreases Lp(a) levels by significantly decreasing the production of mature Lp(a). Additional analyses are planned to determine if the reduced production of Lp(a) results from decreased entry of Lp(a) into plasma or reduced conversion of a precursor form to the mature Lp(a).
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Krishnan A, Ramakrishnan R. Endoscopic management of a migrated biliary T-tube. Endoscopy 2012; 43 Suppl 2 UCTN:E325. [PMID: 22020708 DOI: 10.1055/s-0030-1256739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
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