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Bale TA, Jordan JT, Rapalino O, Ramamurthy N, Jessop N, DeWitt JC, Nardi V, Alvarez MML, Frosch M, Batchelor TT, Louis DN, Iafrate AJ, Cahill DP, Lennerz JK. Financially effective test algorithm to identify an aggressive, EGFR-amplified variant of IDH-wildtype, lower-grade diffuse glioma. Neuro Oncol 2020; 21:596-605. [PMID: 30496526 DOI: 10.1093/neuonc/noy201] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [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: 12/21/2022] Open
Abstract
BACKGROUND Update 3 of the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy (cIMPACT-NOW) recognizes amplification of epidermal growth factor receptor (EGFR) as one important aberration in diffuse gliomas (World Health Organization [WHO] grade II/III). While these recommendations endorse testing, a cost-effective, clinically relevant testing paradigm is currently lacking. Here, we use real-world clinical data to propose a financially effective diagnostic test algorithm in the context of new guidelines. METHODS To determine the prevalence, distribution, neuroradiographic features (Visually Accessible REMBRANDT Images [VASARI]), and prognostic relevance of EGFR amplification in lower-grade gliomas, we assembled a consecutive series of diffuse gliomas. For validation we included publicly available data from The Cancer Genome Atlas. For a cost-utility analysis we compared combined EGFR and isocitrate dehydrogenase (IDH) testing, EGFR testing based on IDH results, and no EGFR testing. RESULTS In n = 71 WHO grade II/III gliomas, we identified EGFR amplification in 28.2%. With one exception, all EGFR amplifications occurred in IDH-wildtype gliomas. Comparison of overall survival showed that EGFR amplification denotes a significantly more aggressive subset of tumors (P < 0.0001, log-rank). The radiologic phenotype in the EGFR-amplified tumors includes diffusion restriction (15%, P = 0.02), >5% tumor contrast enhancement (75%, P = 0.016), and mild (not avid) enhancement (P = 0.016). The proposed testing algorithm reserves EGFR fluorescence in situ hybridization (FISH) testing for IDH-wildtype cases. Implementation would result in ~37.9% cost reduction at our institution, or about $1.3-4 million nationally. CONCLUSION EGFR-amplified diffuse gliomas are "glioblastoma-like" in their behavior and may represent undersampled glioblastomas, or subsets of IDH-wildtype diffuse gliomas with inherently aggressive biology. EGFR FISH after IDH testing is a financially effective and clinically relevant test algorithm for routine clinical practice.
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Affiliation(s)
- Tejus A Bale
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts.,Memorial Sloan Kettering Cancer Center, New York, New York
| | - Justin T Jordan
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts.,Department of Neurology, Boston, Massachusetts.,Division of Hematology/Oncology, Boston, Massachusetts
| | - Otto Rapalino
- Department of Radiology, Division of Neuroradiology, Boston, Massachusetts
| | - Nisha Ramamurthy
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts
| | - Nicholas Jessop
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts
| | - John C DeWitt
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts
| | - Valentina Nardi
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts
| | | | - Matthew Frosch
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts
| | - Tracy T Batchelor
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts.,Department of Neurology, Boston, Massachusetts.,Division of Hematology/Oncology, Boston, Massachusetts
| | - David N Louis
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts
| | - A John Iafrate
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts
| | - Daniel P Cahill
- Department of Neurosurgery, Boston, Massachusetts.,Massachusetts General Hospital, Boston, Massachusetts
| | - Jochen K Lennerz
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts
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2
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Wempe MM, Stewart MD, Glass D, Lasiter L, Vega DM, Ramamurthy N, Allen J, Sigal EV. A National Assessment of Diagnostic Test Use for Patients with Advanced NSCLC and Factors Influencing Physician Decision-Making. Am Health Drug Benefits 2020; 13:110-119. [PMID: 32699571 PMCID: PMC7370822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 04/22/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Diagnostic tests, including US Food and Drug Administration (FDA)-approved tests and laboratory-developed tests, are frequently used to guide care for patients with cancer, and, recently, have been the subject of several policy discussions and insurance coverage determinations. As the use of diagnostic testing has evolved, stakeholders have raised questions about the lack of standardized test performance metrics and the risk this poses to patients. OBJECTIVES To describe the use of diagnostic testing for patients with advanced non-small-cell lung cancer (NSCLC), to analyze the utilization of FDA-approved versus laboratory-developed diagnostic tests, and to evaluate the impact of existing regulatory and coverage frameworks on diagnostic test ordering and physician treatment decision-making for patients with advanced NSCLC. METHODS We conducted a 2-part study consisting of an online survey and patient chart review from March 1, 2019, to March 25, 2019, of physicians managing patients with advanced NSCLC. Respondents qualified for this study if they managed at least 5 patients with advanced NSCLC per month and had diagnosed at least 1 patient with advanced NSCLC in the 12 months before the survey. A total of 150 physicians completed the survey; before completing the survey, they were instructed to review between 4 and 8 charts of patients with stage IV NSCLC from their list of active patients. RESULTS A total of 150 practicing oncologists who manage patients with advanced NSCLC responded to the survey and reviewed a total of 815 patient charts. Of these 815 patients, 812 (99.6%) were tested for at least 1 biomarker, including 73% of patients who were tested for EGFR, 70% tested for ALK, 58% tested for BRAF V600E, and 38% of patients tested for ROS1, by FDA-approved diagnostic tests. In all, 185 (83%) patients who tested positive for EGFR and 60 (83%) patients who tested positive for ALK received an FDA-approved targeted therapy for their biomarker. A total of 98 (65%) physicians responded that the patient's insurance coverage factored into their decision to order diagnostic tests and 69 (45%) physicians responded that cost or the patient's insurance coverage could influence them not to prescribe an indicated targeted therapy. CONCLUSION The survey results indicate that diagnostic testing has become routine in the treatment of patients with advanced NSCLC, the use of FDA-approved diagnostic tests has increased, and insurance coverage and cost influence patient access to diagnostic testing as well as to targeted treatment options.
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Affiliation(s)
- Madison M Wempe
- Research Associate, Friends of Cancer Research, Washington, DC
| | - Mark D Stewart
- Vice President, Science Policy, Friends of Cancer Research, Washington, DC
| | - Daniel Glass
- Managing Director, Global Market Research, Deerfield Management, New York, NY
| | - Laura Lasiter
- Director, Health Policy, Friends of Cancer Research, Washington, DC
| | - Diana Merino Vega
- Director, Research Partnerships, Friends of Cancer Research, Washington, DC
| | | | - Jeff Allen
- President and CEO, Friends of Cancer Research, Washington, DC
| | - Ellen V Sigal
- Chairperson and Founder, Friends of Cancer Research, Washington, DC
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Thierauf J, Ramamurthy N, Jo VY, Robinson H, Frazier RP, Gonzalez J, Pacula M, Dominguez Meneses E, Nose V, Nardi V, Dias-Santagata D, Le LP, Lin DT, Faquin WC, Wirth LJ, Hess J, Iafrate AJ, Lennerz JK. Clinically Integrated Molecular Diagnostics in Adenoid Cystic Carcinoma. Oncologist 2019; 24:1356-1367. [PMID: 30926674 PMCID: PMC6795155 DOI: 10.1634/theoncologist.2018-0515] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 02/27/2019] [Indexed: 01/29/2023] Open
Abstract
Adenoid cystic carcinoma is a rare but aggressive type of salivary gland malignancy. This article addresses the need for more effective, biomarker‐informed therapies in rare cancers, focusing on clinical utility and financial sustainability of integrated next‐generation sequencing in routine practice. Background. Adenoid cystic carcinoma (ACC) is an aggressive salivary gland malignancy without effective systemic therapies. Delineation of molecular profiles in ACC has led to an increased number of biomarker‐stratified clinical trials; however, the clinical utility and U.S.‐centric financial sustainability of integrated next‐generation sequencing (NGS) in routine practice has, to our knowledge, not been assessed. Materials and Methods. In our practice, NGS genotyping was implemented at the discretion of the primary clinician. We combined NGS‐based mutation and fusion detection, with MYB break‐apart fluorescent in situ hybridization (FISH) and MYB immunohistochemistry. Utility was defined as the fraction of patients with tumors harboring alterations that are potentially amenable to targeted therapies. Financial sustainability was assessed using the fraction of global reimbursement. Results. Among 181 consecutive ACC cases (2011–2018), prospective genotyping was performed in 11% (n = 20/181; n = 8 nonresectable). Testing identified 5/20 (25%) NOTCH1 aberrations, 6/20 (30%) MYB‐NFIB fusions (all confirmed by FISH), and 2/20 (10%) MYBL1‐NFIB fusions. Overall, these three alterations (MYB/MYBL1/NOTCH1) made up 65% of patients, and this subset had a more aggressive course with significantly shorter progression‐free survival. In 75% (n = 6/8) of nonresectable patients, we detected potentially actionable alterations. Financial analysis of the global charges, including NGS codes, indicated 63% reimbursement, which is in line with national (U.S.‐based) and international levels of reimbursement. Conclusion. Prospective routine clinical genotyping in ACC can identify clinically relevant subsets of patients and is approaching financial sustainability. Demonstrating clinical utility and financial sustainability in an orphan disease (ACC) requires a multiyear and multidimensional program. Implications for Practice. Delineation of molecular profiles in adenoid cystic carcinoma (ACC) has been accomplished in the research setting; however, the ability to identify relevant patient subsets in clinical practice has not been assessed. This work presents an approach to perform integrated molecular genotyping of patients with ACC with nonresectable, recurrent, or systemic disease. It was determined that 75% of nonresectable patients harbor potentially actionable alterations and that 63% of charges are reimbursed. This report outlines that orphan diseases such as ACC require a multiyear, multidimensional program to demonstrate utility in clinical practice.
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Affiliation(s)
- Julia Thierauf
- Department of Pathology, Center for Integrated Diagnostics, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts, USA
- Department of Otorhinolaryngology, Head and Neck Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Nisha Ramamurthy
- Department of Pathology, Center for Integrated Diagnostics, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts, USA
| | - Vickie Y Jo
- Department of Pathology, Brigham and Women's Hospital/Harvard Medical School, Boston, Massachusetts, USA
| | - Hayley Robinson
- Department of Pathology, Center for Integrated Diagnostics, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts, USA
| | - Ryan P Frazier
- Department of Pathology, Center for Integrated Diagnostics, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts, USA
| | - Jonathan Gonzalez
- Department of Pathology, Center for Integrated Diagnostics, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts, USA
| | - Maciej Pacula
- Department of Pathology, Computational Pathology, Boston, Massachusetts, USA
| | | | - Vania Nose
- Department of Pathology, Head and Neck Pathology, Boston, Massachusetts, USA
- Department of Pathology, Surgical Pathology, Boston, Massachusetts, USA
| | - Valentina Nardi
- Department of Pathology, Center for Integrated Diagnostics, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts, USA
| | - Dora Dias-Santagata
- Department of Pathology, Center for Integrated Diagnostics, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts, USA
| | - Long P Le
- Department of Pathology, Center for Integrated Diagnostics, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts, USA
- Department of Pathology, Computational Pathology, Boston, Massachusetts, USA
| | - Derrick T Lin
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA
| | - William C Faquin
- Department of Pathology, Surgical Pathology, Boston, Massachusetts, USA
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA
| | - Lori J Wirth
- Cancer Center, Massachusetts General Hospital, Boston, Massachusetts, USA
- Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA
| | - Jochen Hess
- Department of Otorhinolaryngology, Head and Neck Surgery, Heidelberg University Hospital, Heidelberg, Germany
- Research Group Molecular Mechanisms of Head and Neck Tumors, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - A John Iafrate
- Department of Pathology, Center for Integrated Diagnostics, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts, USA
| | - Jochen K Lennerz
- Department of Pathology, Center for Integrated Diagnostics, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts, USA
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Garnon J, Ramamurthy N, Caudrelier J J, Erceg G, Breton E, Tsoumakidou G, Rao P, Gangi A. MRI-Guided Percutaneous Biopsy of Mediastinal Masses Using a Large Bore Magnet: Technical Feasibility. Cardiovasc Intervent Radiol 2015; 39:761-767. [PMID: 26604114 DOI: 10.1007/s00270-015-1246-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [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: 03/21/2015] [Accepted: 09/11/2015] [Indexed: 01/20/2023]
Abstract
OBJECTIVE To evaluate the diagnostic accuracy and safety of magnetic resonance imaging (MRI)-guided percutaneous biopsy of mediastinal masses performed using a wide-bore high-field scanner. MATERIALS AND METHODS This is a retrospective study of 16 consecutive patients (8 male, 8 female; mean age 74 years) who underwent MRI-guided core needle biopsy of a mediastinal mass between February 2010 and January 2014. Size and location of lesion, approach taken, time for needle placement, overall duration of procedure, and post-procedural complications were evaluated. Technical success rates and correlation with surgical pathology (where available) were assessed. RESULTS Target lesions were located in the anterior (n = 13), middle (n = 2), and posterior mediastinum (n = 1), respectively. Mean size was 7.2 cm (range 3.6-11 cm). Average time for needle placement was 9.4 min (range 3-18 min); average duration of entire procedure was 42 min (range 27-62 min). 2-5 core samples were obtained from each lesion (mean 2.6). Technical success rate was 100%, with specimens successfully obtained in all 16 patients. There were no immediate complications. Histopathology revealed malignancy in 12 cases (4 of which were surgically confirmed), benign lesions in 3 cases (1 of which was false negative following surgical resection), and one inconclusive specimen (treated as inaccurate since repeat CT-guided biopsy demonstrated thymic hyperplasia). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in our study were 92.3, 100, 100, 66.7, and 87.5%, respectively. CONCLUSION MRI-guided mediastinal biopsy is a safe procedure with high diagnostic accuracy, which may offer a non-ionizing alternative to CT guidance.
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Affiliation(s)
- J Garnon
- Department of Interventional Radiology, Nouvel Hôpital Civil, Strasbourg, France.
| | - N Ramamurthy
- Department of Radiology, Norfolk and Norwich University Hospital, Colney Lane, Norwich, NR4 7UY, UK
| | - J Caudrelier J
- Department of Interventional Radiology, Nouvel Hôpital Civil, Strasbourg, France
| | - G Erceg
- ICube, University of Strasbourg, CNRS, Strasbourg, France
| | - E Breton
- ICube, University of Strasbourg, CNRS, Strasbourg, France
| | - G Tsoumakidou
- Department of Interventional Radiology, Nouvel Hôpital Civil, Strasbourg, France
| | - P Rao
- Department of Interventional Radiology, Nouvel Hôpital Civil, Strasbourg, France.,ICube, University of Strasbourg, CNRS, Strasbourg, France
| | - A Gangi
- Department of Interventional Radiology, Nouvel Hôpital Civil, Strasbourg, France.,ICube, University of Strasbourg, CNRS, Strasbourg, France
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5
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Kolluri G, Ramamurthy N, Churchil RR, Dhinakar Raj G, Kannaki TR. Influence of age, sex and rearing systems on Toll-like receptor 7 (TLR7) expression pattern in gut, lung and lymphoid tissues of indigenous ducks. Br Poult Sci 2014; 55:59-67. [DOI: 10.1080/00071668.2013.867926] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Gautham K, Ramamurthy N, Churchil RR, Kannaki TR. Differential expression of duck Toll-like receptor 7 (dTLR7) in various organs of indigenous ducks. Vet World 2013. [DOI: 10.14202/vetworld.2013.931-935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Devipriya S, Vani G, Ramamurthy N, Shyamaladevi CS. Regulation of Intracellular Calcium Levels and Urokinase Activity in MDA MB 231 Cells by Quercetin. Chemotherapy 2006; 52:60-5. [PMID: 16462139 DOI: 10.1159/000091306] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2004] [Accepted: 05/02/2005] [Indexed: 11/19/2022]
Abstract
BACKGROUND The common plant bioflavonoid, quercetin, is cytotoxic to various tumor cell lines, particularly breast cancer, by affecting the protein-kinase-C-dependent signal pathways and by cell cycle regulation. However, its role in breast cancer metastasis has not been studied so far. Increased uPA activity is evident in highly metastatic breast cancer, which is calcium dependent. METHODS MDA MB 231 cells were treated with various concentrations of quercetin (15-45 microg/ml). The cytotoxic effect of quercetin was assessed by MTT assay and DNA fragmentation analysis. Intracellular calcium levels were measured using Fura-2, a specific Ca2+ fluorescence indicator. Calcium uptake and release in cells treated with quercetin were measured using radioactive 45Ca2+. Urokinase enzyme activity was assayed by a casein zymogram. RESULTS Quercetin elicited dose- and time-dependent cytotoxicity as evidenced by the MTT assay. The maximum effect was observed at 48 h with a quercetin concentration of (45 microg/ml). DNA agarose gel electrophoresis showed dose-dependent DNA fragmentation on quercetin treatment. Quercetin caused significant depletion of cytosolic calcium levels and decreased calcium uptake from the intracellular stores. Casein zymogram showed a marked reduction of urokinase activity as evident by clear lysis bands on a dark background on treatment with quercetin. CONCLUSION Quercetin was found to exhibit cytotoxicity in the highly invasive breast cancer cell line MDA MB 231 in a dose- and time-dependent manner. Quercetin inhibited calcium dependent urokinase activity and hence may prove to be an effective antimetastatic agent.
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Affiliation(s)
- S Devipriya
- Department of Biochemistry, University of Madras, Guindy Campus, Chennai, India
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Ramamurthy N, Subashini J, Muniraju N. Fourier transform-infrared analysis of vegetative parts of weed plant Parthenium hysterophorus Linn. J Environ Sci Eng 2005; 47:182-7. [PMID: 16841456] [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: 05/10/2023]
Abstract
Infrared spectra of vegetative parts (leaf, stem and flower) of the weed plant Parthenium hysterophorus Linn. was recorded. The observed frequencies in the region 4000-400 cm(-1) have been recorded along with vibrational assignments and intensities. Probable assignments of the bands were made with respect to the components present in the samples.
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Affiliation(s)
- N Ramamurthy
- Department of Physics, Annamalai University, Annamalainagar- 608 002, India
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Ramamurthy N, Thillaivelavan K. Determination of trace elements in dairy milk collected from the environment of coal-fired power plant. J Environ Sci Eng 2005; 47:53-8. [PMID: 16669336] [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: 05/09/2023]
Abstract
In the present study the environmental effects on herbivores mammals in and around Coal-fired power plant were studied by collecting the various milk samples of Cow and Buffalo in clean polyethylene bottles. Milk samples collected at five different locations along the banks of the Paravanaru river in and around Neyveli area. These samples were prepared for trace metal determination. The concentration of trace metals (Cu, Zn, Ni, Cd, Cr, Mn, Co and Hg) were determined by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) and Cold Vapour Atomic Absorption Spectrometry (CVAAS). It is observed that the samples contain greater amounts of trace metals than that in the unexposed areas. Obviously the milk samples are contaminated with these metals due to fly ash released in such environment.
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Affiliation(s)
- N Ramamurthy
- Department of Physics, Annamalai University, Annamalai Nagar-608 002, Tamil Nadu, India
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10
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Swamy PM, Usha R, Kiranmayee P, Ramamurthy N. Changes in polyamine contents and arginine decarboxylase activity associated with elongation growth of hypocotyls in Rhizophora apiculata Bl. ACTA ACUST UNITED AC 2004. [DOI: 10.1139/b04-126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Changes in polyamine (putrescine, spermidine, spermine) contents and arginine decarboxylase activity in three different regions of developing hypocotyls of Rhizophora apiculata Bl. were analyzed. Among the three polyamines, spermidine was present in higher quantities than either putrescine or spermine. Spermine occurred in the lowest quantities. Spermidine declined rapidly with the age of the hypocotyl. In contrast, a marked increase in putrescine was observed with the age of the hypocotyl. Arginine decarboxylase activity increased during the various developmental stages of hypocotyl growth, particularly in the final stage. The results suggest that putrescine plays a major role in the growth of the hypocotyl as evidenced by simultaneous increase in the content of putrescine and arginine decarboxylase activity.Key words: arginine decarboxylase, elongation, hypocotyls, polyamines, Rhizophora apiculata.
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Ramamurthy N, Thirumarran M. Automobile exhaust level of CO: study in Chidambaram town. Indian J Environ Health 2002; 44:37-40. [PMID: 12968723] [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: 03/04/2023]
Abstract
The exhaust gases from automobiles constitute about 75% of air pollution. Among the various pollutants emitted from vehicles, CO is the primary pollutant and very toxic one. The CO monitor method was used to predict the CO level in Chidambaram town. From the study it is evident that the pollution level is closely related to the density of motor vehicles on the roads. With increase in number of motor vehicles pollution level also increases which pollutes the roadside environment severely in future.
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Affiliation(s)
- N Ramamurthy
- Department of Physics, Annamalai University, Annamalai Nagar
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Ramamurthy N, Thirumarran M. The carbon monoxide levels in automobile exhaust. A case study in Chidambaram town. Indian J Environ Health 2001; 43:144-7. [PMID: 12395517] [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: 02/27/2023]
Abstract
The exhaust gases from automobiles constitute about 75% of air pollution. Among the various pollutants emitted from vehicles, CO is the primary pollutant and very toxic one. The CO monitor method was used to measure the CO level in Chidambaram town. From the study, it is evident that the CO level is closely related to the density of motor vehicles plying on the roads. With increase in number of motor vehicles CO level also increases, which pollutes the roadside environment severely in future.
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Affiliation(s)
- N Ramamurthy
- Department of Physics, Annamalai University, Annamalainagar-608 002
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Ramamurthy N, Bain S, Liang CT, Barnes J, Llavaneras A, Liu Y, Puerner D, Strachan MJ, Golub LM. A combination of subtherapeutic doses of chemically modified doxycycline (CMT-8) and a bisphosphonate (clodronate) inhibits bone loss in the ovariectomized rat: a dynamic histomorphometric and gene expression study. Curr Med Chem 2001; 8:295-303. [PMID: 11172684 DOI: 10.2174/0929867013373534] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recent studies have demonstrated that tetracyclines can reduce bone loss in the ovariectomized (OVX) rat model of osteoporosis. In the current study, a non-antimicrobial, chemically modified doxycycline (CMT-8), alone or in combination with a bisphosphonate (Clodronate), was evaluated in this model. Forty-two, 6month old, female rats were randomly assigned to the following groups, (6/ group): a) sham/vehicle, b) OVX/vehicle; c) OVX/1 mg/day CMT-8; d) OVX/2 mg/day CMT-8, e) OVX/1 mg/week Clodronate; and f) OVX/1 mg/day CMT-8 + 1 mg/week Clodronate, CMT-8 was administered by oral gavage, Clodronate injected S/C. Following sham surgery or OVX, the rats were treated for 90 days with CMT-8 or vehicle alone, injected at three different times with fluorochrome labels, the rats were sacrificed, and the tibiae excised for analysis by dynamic bone histomorphometry. Femurs were aseptically removed and analyzed for collagen, collagenase and osteopontin mRNAs by Northern and dot blot analysis. As expected, OVX decreased trabecular bone volume (BV/TV by 73.8% vs. sham p<.01), and also reduced trabecular thickness, numbers, and increased spacing. Bone loss in the OVX animals was partially prevented with either 2 mg/day CMT-8 or 1 mg/wk Clodronate (p<.01), while the 1 mg/day CMT-8 had no effect. Interestingly, the efficacy of the combination therapy of CMT-8 and Clodronate was significantly better than either treatment by itself, maintaining bone mass and structural indices at levels identical to sham values. OVX rats mRNA for collagen, collagenase and osteopontin were elevated indicating high-turnover bone loss. Only COMBO therapy significantly reduced the collagenase and osteopontin mRNA. In summary, CMT-8 mono-therapy (2 mg) alone partially inhibited bone loss in this animal model of osteoporosis. However, 1 mg/day (CMT-8) monotherapy had no effect on bone loss or bone mRNA levels and when combined with Clodronate, interacted to increase efficacy. Thus, a combination of a suboptimal dose of CMT-8 and a bisphosphonate appears to increase the amount of bone by suppressing resorption in a model of osteoporosis.
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Affiliation(s)
- N Ramamurthy
- School of Dental Medicine, SUNY at Stony Brook, Stony Brook, NY 11794-8702, USA
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Pirilä E, Ramamurthy N, Maisi P, McClain S, Kucine A, Wahlgren J, Golub L, Salo T, Sorsa T. Wound healing in ovariectomized rats: effects of chemically modified tetracycline (CMT-8) and estrogen on matrix metalloproteinases -8, -13 and type I collagen expression. Curr Med Chem 2001; 8:281-94. [PMID: 11172683 DOI: 10.2174/0929867013373552] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [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: 11/22/2022]
Abstract
Cutaneous wound healing is a complex process involving interactions of various cell types. Skin, in addition to certain other organs, is dependent on estrogen; and estrogen-deficiency is associated with impaired wound healing. Wound healing involves the action of collagenolytic matrix metalloproteinases (MMPs). We investigated the expression and localization of collagenolytic MMPs -8 and -13 by collagenase activity assay, Western immunoblot analysis, in situ hybridization and immunohistochemical staining as well as type I collagen by hydroxyproline content analysis and immunohistochemical staining in cutaneous wounds from aged Sham and ovarioectomized (OVX) rats. After wounding, OVX rats were treated with either placebo, chemically modified tetracycline-8 (CMT-8) or estrogen. We found that MMP-8 and MMP-13 mRNA were expressed in wound epithelium of all samples examined as evidenced by in situ hybridization. Type I collagen, which was abundant in all groups examined, was decreased in OVX rats, but was increased by both CMT-8 and estrogen treatments to the level of Sham group. Hydroxyproline analysis revealed similar results. Western blot data showed that all forms of MMP-8 and MMP-13 were clearly reduced in the CMT-8 treated group compared to OVX. Analysis of collagenolytic activity confirmed the decreased collagenolysis in skin wound extracts from CMT-treated rats when compared with skin wound extracts from OVX rats. Our results show for the first time that MMP-8 mRNA and protein are expressed in rat wound epithelium. We further show that CMT-8 and estrogen have a beneficial effect on skin wound healing in OVX rats by increasing the collagen content and reducing the MMP-mediated collagenolysis.
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Affiliation(s)
- E Pirilä
- Department of Clinical Veterinary Sciences, University of Helsinki, Helsinki, Finland.
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15
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Liu Y, Ramamurthy N, Marecek J, Lee HM, Chen JL, Ryan ME, Rifkin BR, Golub LM. The lipophilicity, pharmacokinetics, and cellular uptake of different chemically-modified tetracyclines (CMTs). Curr Med Chem 2001; 8:243-52. [PMID: 11172678 DOI: 10.2174/0929867013373525] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
CMTs are analogs of tetracyclines, which are chemically modified to eliminate their antimicrobial efficacy but which retain their inhibitory activity against matrix metalloproteinases. These compounds have been found to inhibit connective tissue breakdown in animal models of diseases such as periodontitis, arthritis and cancer. Because CMTs exhibit different in vivo efficacy in these various models of disease, the current study compared their pharmacokinetics and other properties as follows: Adult male Sprague-Dawley rats were administered by oral gavage a single dose of 5mg of different CMTs suspended in 1 ml 2% carboxymethyl-cellulose, and blood samples were collected from 1-48 hours after dosing. The sera were extracted, then analyzed by HPLC using a C-18 reverse-phase column. The results showed that the peak concentrations (C(max)) in rat sera 1-12 hours after oral administration of CMTs -1, -2,-3, -4,-5,-6,-7,-8 and doxycycline were 5.5, 0.7, 4.6, 6.2, 0.8, 0.7, 9.0 (note: the 3 peaks detected for CMT-7 were combined), 15.0 and 0.9 microg/ml, respectively. Their in vivo half-lives (t(1/2)) were 11, 5, 22, 11, 32, 15, 37, 38, and 17 hours, respectively. Of the anticollagenase CMTs tested, CMT-8 showed the greatest C(max) and t(1/2)values, followed by CMTs-3, -1, -4, and perhaps -7; CMTs-2, -5, and -6 exhibited much lower levels in serum. The relative lipophilicities of the 8 CMTs and doxycycline were tested by examining their extractability in octanol. The results showed that CMT-2, -5, and -6 had the lowest partition coefficients using this organic solvent, while CMT-3 was the most lipophilic. The lipophilicity of the different CMTs was also positively correlated (r(2)=0.767, P<0.05) to peak serum concentrations (C(max)), but not to their serum half-lives (r(2)=0.25,P=0.49). This property of the different CMTs was also found to be positively correlated to their ability to enter into human whole blood cells in vitro (r2=0.95, P<0.001). Since CMT-8, as well as CMTs-3 and -1, consistently exhibited the greatest in vivo efficacy in animal models of tissue breakdown, this may reflect, at least in part, their favorable pharmacokinetics and tissue uptake.
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Affiliation(s)
- Y Liu
- Department of Oral Biology and Pathology, School of Dental Medicine, State University of New York, at Stony Brook, New York, NY 11794, USA
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16
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Abstract
1. The hatchability of checked Leghorn and broiler parent hatching eggs was significantly improved by shell treatment: smearing with synthetic adhesive resin (Fevicol), or pasting cellophane tape or insulation tape over the checked portion of the shell. 2. Shell damage reduced hatchability by increasing evaporative loss, leading to embryonic dehydration. 3. Relative chick weight, expressed as a percentage of egg weight was lower in untreated checked eggs but comparable between intact and shell-treated hatching eggs. 4. The cost of chick production can be reduced by shell treatment of checked hatching eggs, especially in broiler parent eggs.
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Affiliation(s)
- D Narahari
- Department of Poultry Science, Madras Veterinary College, Tamil Nadu Veterinary and Animal Sciences University, Chennai, India.
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17
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Yun JH, Han IS, Chang LC, Ramamurthy N, Meyerhoff ME, Yang VC. Electrochemical sensors for polyionic macromolecules: development and applications in pharmaceutical research. Pharm Sci Technol Today 1999; 2:102-110. [PMID: 10322363 DOI: 10.1016/s1461-5347(99)00121-2] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The first electrochemical sensors responsive towards polyionic heparin and protamine - two clinically important polymeric drugs - have been fully developed. The response mechanism of these sensors has been completely elucidated. As well as their significance in measuring blood heparin levels in clinically relevant concentration ranges, these polyion sensors could also find broad applications in pharmaceutical research, such as in the study of the binding events between heparin (or protamine) and other polycationic (or polyanionic) macromolecules. In addition, the sensors could be employed in the design of blood assays for a range of clinically important proteases and their inhibitors by utilizing either protamine or specially designed synthetic polypeptides as the substrates
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Affiliation(s)
- JH Yun
- aCollege of Pharmacy, The University of Michigan, 428 Church Street, Ann Arbor, MI 48109-1065 USA
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18
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Abstract
Recent developments in the design and bioanalytical applications of polyion-sensitive electrodes (PSEs) are reviewed. The general electrochemical principles governing the potentiometric response of such polymer membrane-based devices are summarized and new directions for the use of these novel sensors are detailed. These new directions include basic fundamental studies aimed at determining the thermodynamics of polyion extraction into ion exchanger-doped polymeric membranes, new methods to quantitate the anticoagulant drug heparin in whole blood via titrations with polycationic protamine, selective assays of protease activities (and inhibitors of such activities) using natural and synthetic polyionic peptides as substrates, and novel homogeneous immunoassay schemes based on potentiometric polyion detection.
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Affiliation(s)
- S Dai
- Department of Chemistry, The University of Michigan, Ann Arbor 48109-1055, USA
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19
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Ramamurthy N, Baliga N, Wakefield TW, Andrews PC, Yang VC, Meyerhoff ME. Determination of low-molecular-weight heparins and their binding to protamine and a protamine analog using polyion-sensitive membrane electrodes. Anal Biochem 1999; 266:116-24. [PMID: 9887220 DOI: 10.1006/abio.1998.2947] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A polycation-sensitive membrane electrode based on the ion-exchanger dinonylnaphthalene sulfonate has previously been developed and used as an end-point detector for the determination of unfractionated heparin in whole blood samples via simple potentiometric titration with protamine. Herein, we report the application of the same methodology for the quantitation of a commercial low-molecular-weight heparin (LMWH) preparation (Fragmin) in whole blood samples at concentrations up to 2 U/ml. Further, an analogous polyanion (heparin)-sensitive electrode is used to estimate the binding constants between protamine and various LMWH preparations. The equilibrium constants (Keq) and the number of binding sites per mole of heparin (n) are determined by recasting the data in the form of a Scatchard plot. Results show that the average molecular weight and molecular weight distribution of the LMWH preparation are important parameters affecting their binding with protamine. Comparable binding constants are obtained for the same LMWH preparations titrated with a synthetic protamine analog, [+18RGD] [acetyl-EA(R2A2R2A)4R2GRGDSPA-NH2].
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Affiliation(s)
- N Ramamurthy
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, 48109, USA
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20
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Pruzanski W, Stefanski E, Vadas P, McNamara TF, Ramamurthy N, Golub LM. Chemically modified non-antimicrobial tetracyclines inhibit activity of phospholipases A2. J Rheumatol 1998; 25:1807-12. [PMID: 9733464] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVE Tetracyclines have been recognized as useful agents for therapy of inflammatory arthritides. However, prolonged use of tetracyclines is limited by their detrimental antimicrobial properties. Recently, a group of chemically modified tetracyclines (CMT) devoid of antimicrobial properties has been synthesized. Some CMT were found to inhibit various matrix metalloproteinases (MMP). We reported previously that antimicrobial tetracyclines inhibit the activity of proinflammatory secretory group II phospholipase A2 (sPLA2). The objective of this study was to detect whether non-antimicrobial CMT also inhibit sPLA2 and other phospholipases A2. METHODS Ten synthetic CMT were tested for inhibition of sPLA2 human and porcine PLA2, and Naja naja PLA2. PLA2 activity was assessed by radiolabeled Escherichia coli assay using standard and high calcium concentrations. RESULTS Six of 10 CMT inhibited sPLA2 activity at concentrations close to or lower than 50 microg/ml. All 6 CMT had identical C1-3 and C10-12a positions in the 4-ringed nucleus of the tetracycline molecule. Calcium concentrations up to 20 mM did not eliminate the inhibitory activity of CMT. Inhibition of other PLA2 was induced by some CMT, all but one (CMT-9) belonging to the group of strong inhibitors of sPLA2. Thus, inhibition of PLA2 different from sPLA2 does not necessarily require identical C1-3/C10-12a residues. CONCLUSION Since CMT, which inhibit proinflammatory sPLA2, are also inhibitors of some MMP, they may be useful for therapy of inflammatory diseases in which both MMP and sPLA2 are overexpressed.
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Affiliation(s)
- W Pruzanski
- Inflammation Research Group, University of Toronto, ON, Canada
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21
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Craig RG, Yu Z, Xu L, Barr R, Ramamurthy N, Boland J, Schneir M, Golub LM. A chemically modified tetracycline inhibits streptozotocin-induced diabetic depression of skin collagen synthesis and steady-state type I procollagen mRNA. Biochim Biophys Acta 1998; 1402:250-60. [PMID: 9606983 DOI: 10.1016/s0167-4889(98)00008-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Wasting of connective tissues including skin, bone, and cartilage have been closely associated with elevated matrix metalloproteinase (MMP) activity and depressed collagen content in the streptozotocin (STZ)-induced diabetic rat, while tetracyclines have been reported to normalize total body weight, skin hydroxyproline and collagen content in this model, in part through inhibition of MMPs. In the present study, we report the effect of CMT-1, a chemically modified tetracycline that lacks antimicrobial properties but retains divalent cation binding and MMP inhibitory activity, on diabetic skin collagen synthesis and steady-state levels of procollagen alpha 1(I) mRNA. Male, 4-month old Sprague-Dawley rats received a single injection of 75 mg/kg STZ or citrate vehicle alone and diabetic status was confirmed by positive glucosuria. Some diabetic animals received 10 mg/day of CMT-1 by oral gavage and, 28 days after STZ treatment, body weight, blood glucose values and the in vivo rates of skin collagen production were measured using the pool-expansion technique. Steady-state levels of procollagen alpha 1(I) mRNA were analyzed 21 days after STZ treatment by hybridization of total RNA with a 32P labelled cDNA to rat type I procollagen alpha 1(I) mRNA in a dot-blot assay. STZ treatment was found to significantly depress body weight, skin collagen hydroxyproline content, the in vivo rate of collagen production, and hybridizable levels of type I procollagen alpha 1(I) mRNA. CMT-1 administered daily to STZ-treated rats inhibited the diabetic depression of these parameters but had little or no effect on non-diabetic controls or on STZ-induced hyperglycemia. Thus, in addition to the inhibition of MMP mediated extracellular collagen degradation, these results suggest CMT-1 also acts to inhibit diabetic connective tissue breakdown in STZ-induced diabetes by increasing both steady-state levels of type I procollagen mRNA and collagen synthesis through mechanism(s) that are independent of the antibacterial properties of tetracyclines.
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Affiliation(s)
- R G Craig
- Division of Basic Sciences, New York University College of Dentistry, NY 10010, USA
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22
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Ramamurthy N, Baliga N, Wahr JA, Schaller U, Yang VC, Meyerhoff ME. Improved protamine-sensitive membrane electrode for monitoring heparin concentrations in whole blood via protamine titration. Clin Chem 1998; 44:606-13. [PMID: 9510869] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
An improved protamine-sensitive electrode based on a polymeric membrane doped with the charged ion exchanger dinonylnaphthalenesulfonate (DNNS) is used for monitoring heparin concentrations in whole blood. The electrode exhibits significant nonequilibrium potentiometric response to polycationic protamine over the concentration range of 0.5-20 mg/L in undiluted whole-blood samples. The sensor can serve as a simple end point detector for the determination of heparin via potentiometric titrations with protamine. Whole-blood heparin concentrations determined by the electrode method (n > or = 157) correlate well with other protamine titration-based methods, including the commercial Hepcon HMS assay (r = 0.934) and a previously reported potentiometric heparin sensor-based method (r = 0.973). Reasonable correlation was also found with a commercial chromogenic anti-Xa heparin assay (r = 0.891) with corresponding plasma samples and appropriate correction for whole-blood hematocrit levels. Whereas a significant positive bias (0.62 kU/L; P < 0.001) is observed between the anti-Xa assay and the protamine sensor methods, insignificant bias is observed between the protamine sensor and the Hepcon HMS tests (0.08 kU/L; P = 0.02). The possibility of fully automating these titrations offers a potentially simple, inexpensive, and accurate method for monitoring heparin concentrations in whole blood.
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Affiliation(s)
- N Ramamurthy
- Department of Chemistry, College of Pharmacy, University of Michigan, Ann Arbor 48109, USA
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23
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Badr IH, Ramamurthy N, Yang VC, Meyerhoff ME. Electrochemical assay of proteinase inhibitors using polycation-sensitive membrane electrode detection. Anal Biochem 1997; 250:74-81. [PMID: 9234901 DOI: 10.1006/abio.1997.2188] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A simple and sensitive electrochemical method suitable for real time detection of trypsin-like proteinase inhibitors is described. The method is based on utilizing a protamine (a polycationic substrate for trypsin-like proteinases)-sensitive membrane electrode to monitor, potentiometrically, the initial rate of protamine decomposition upon the addition of a proteinase-antiproteinase test solution. In the presence of proteinase inhibitors, the initial rate of change in electromotive force is dependent on the concentration of proteinase inhibitor in the sample solution. The feasibility of this new assay method is demonstrated by detecting four inhibitors of trypsin-like proteinases: alpha1-antiproteinase inhibitor, alpha2-macroglobulin, aprotinin, and soybean inhibitor, using trypsin as the indicator proteinase. The efficacy of inhibition by each species, as expressed by I50 values (concentration of the inhibitor that induces 50% of the maximum proteinase inhibition), is shown to correlate well with literature values for the association constant of the proteinase-antiproteinase complex (k[assoc]). The proposed electrochemical assay for aprotinin is examined further using trypsin, plasmin, and kallikrein as the proteinase indicator reagents. It is found that the trypsin-aprotinin system offers the highest sensitivity and lowest detection limit for aprotinin detection. Application of the proposed method for measuring aprotinin in pretreated plasma samples is also reported.
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Affiliation(s)
- I H Badr
- Department of Chemistry, The University of Michigan, Ann Arbor 48109, USA
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24
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Han IS, Ramamurthy N, Yun JH, Schaller U, Meyerhoff ME, Yang VC. Selective monitoring of peptidase activities with synthetic polypeptide substrates and polyion-sensitive membrane electrode detection. FASEB J 1996; 10:1621-6. [PMID: 9002554 DOI: 10.1096/fasebj.10.14.9002554] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A novel method to monitor specific peptidase activities in biological samples as complex as undiluted plasma/blood is described. The approach is based on the design of synthetic polypeptide substrates in which di- or triarginine sequences are linked to each other via one or more other amino acids recognized specifically by the peptidase to be determined. Detection of chymotrypsin and renin activities using synthetic substrates P4 (F-R-R-R-F-V-R-R-F-NH2) and P5 (R-R-R-L-L-R-R-L-L-R-R-R), respectively, serves to demonstrate the principles of this new assay system. A polyion-sensitive membrane electrode, prepared by doping polymer films with dinonylnaphthalene-sulfonate (DNNS), is shown to exhibit significant nonequilibrium electromotive force (EMF) responses toward these and other polycationic substrates at microgram/milliliter levels under physiological conditions. The same electrode, however, exhibits much smaller total EMF response toward the shorter fragments of the synthetic peptides generated by peptidase activity; hence, the addition of peptidase to a solution containing the synthetic substrate yields a change in electrode EMF response, the rate of which is proportional to the activity of peptidase present. Other synthetic polycationic peptides as well as natural polycationic peptides (e.g., protamine) that lack specific cleavage sites for chymotrypsin and renin, yet are detected by the DNNS-based membrane electrode, do not elicit any significant change in EMF response in the presence of the peptidases, confirming the feasibility and utility of the proposed bioanalytical method.
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Affiliation(s)
- I S Han
- College of Pharmacy, University of Michigan, Ann Arbor 48109-1065, USA
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25
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Ramamurthy N, Greenwald R, Moak S, Scuibba J, Goren A, Turner G, Rifkin B, Golub L. CMT/Tenidap treatment inhibits temporomandibular joint destruction in adjuvant arthritic rats. Ann N Y Acad Sci 1994; 732:427-30. [PMID: 7978829 DOI: 10.1111/j.1749-6632.1994.tb24775.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- N Ramamurthy
- State University of New York at Stony Brook 11794-8702
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26
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Affiliation(s)
- N Ramamurthy
- Department of Oral Biology & Pathology, School of Dental Medicine, SUNY, Stony Brook 11794-8702
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27
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Suomalainen K, Sorsa T, Golub LM, Ramamurthy N, Lee HM, Uitto VJ, Saari H, Konttinen YT. Specificity of the anticollagenase action of tetracyclines: relevance to their anti-inflammatory potential. Antimicrob Agents Chemother 1992; 36:227-9. [PMID: 1317148 PMCID: PMC189275 DOI: 10.1128/aac.36.1.227] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The concentrations of doxycycline and 4-de-dimethylaminotetracycline required to inhibit 50% of collagenase activity were found to be 15 to 30 microM for human neutrophil and gingival crevicular fluid collagenases. Fibroblast collagenase was relatively resistant to inhibition by tetracyclines; the 50% inhibitory concentrations of doxycycline and 4-de-dimethylaminotetracycline were 280 and 510 microM, respectively.
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Affiliation(s)
- K Suomalainen
- Department of Periodontology, University of Helsinki, Finland
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28
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Deivanayagam N, Ramamurthy N, Krishnamurthy PV, Shankar VJ, Ashok TP, Nedunchelian K, Mala N, Ahmed SS. Age for measles immunization seroconversion after measles vaccination at 6-8 months of age--a randomized controlled trial. Indian Pediatr 1990; 27:1171-6. [PMID: 2081639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The objective of the study was to compare the effectiveness of measles vaccine by seroconversion in vaccinated children with non-vaccinated children of 6 to 8 months age group in a city slum community so as to study the feasibility of advancing the age of immunization. Live attenuated lyophilized Schwartz strain of measles vaccine was used. Hemagglutination inhibition (HI) antibody was estimated. Seroconversion was defined as either the conversion of negative to positive or a two fold rise in titre. One hundred and thirty two children completed the study. There was no difference in the age, sex and nutritional status between vaccinated and non-vaccinated groups (p greater than 0.7). The seroconversion rate in the vaccinated group was 65% and in the non-vaccinated group was 26%. The age, sex and nutritional status did not significantly affect the seroconversion. Our data suggest that immunization with measles vaccine may be effective as early as 6 months of age. Immunization at 6 months may be needed at least for children in densely populated areas like cities and towns.
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Affiliation(s)
- N Deivanayagam
- Department of Clinical Epidemiology and Pediatrics, Madras Medical College
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29
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Schneir M, Ramamurthy N, Golub L. Minocycline-treatment of diabetic rats normalizes skin collagen production and mass: possible causative mechanisms. Matrix 1990; 10:112-23. [PMID: 2374516 DOI: 10.1016/s0934-8832(11)80177-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Daily minocycline-treatment of streptozotocin-induced diabetic rats not only prevented a diabetes-caused atrophy of skin collagen mass (10-mos old rats), but also normalized skin collagen mass to match that of growing (ca. 1%/d) non-diabetic controls (4- and 5-mos old rats). The causative mechanism by which minocycline-treatment normalizes skin collagen mass must, in part, be related to a general anabolic effect on growth (body weight) because the effect on skin collagen mass correlates strongly to that on body weight. Consequently, a minocycline-stimulated increase of a systemic factor (such as insulin-like growth factor) is not unlikely. The anabolic effect of minocycline-treatment of diabetic rats is also expressed as a normalized cellular ribosome mass (an index of total protein synthetic capacity) and a normalized absolute rate of collagen production. (Calculation of an absolute rate was justified by an apparent maximum saturation of the prolyl-tRNA pool(s) of skin, maximum saturation obtained by the pool-flooding approach). The normalized skin ribosome amount does not, however, explain a selective effect of minocycline-treatment on collagen production as opposed to that for non-collagen protein, this selective effect measured as relative collagen production. To explain such selectivity, the inhibition of diabetes-induced excess skin collagenase activity seems unlikely. (This inference is based on results from a preliminary study indicating that recently [less than 2 h] synthesized collagen is not degraded by the excess collagenase in skin of diabetic rats). Thus, the principal collagen fraction acted on by pathologically excess collagenase might be collagen at a later stage (greater than 2 h after synthesis) in its life cycle. (Another possibility for the selective effect of minocycline on collagen production, as yet untested, is reduced intracellular procollagen degradation.) Overall, this is the first study aimed at discerning the mechanism(s) by which minocycline-treatment enhances the rate of collagen production in tissues of a diabetic rat. For future studies, the extent to which the positive effect on growth, ribosome mass, and rate of collagen production contributes to the change of collagen mass must, along with the known minocycline-inhibition of collagenase activity, be quantified. Such quantification is a prerequisite for evaluating the chemotherapeutic efficacy of minocycline-treatment on collagen-degradative diseases.
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Affiliation(s)
- M Schneir
- Department of Basic Science, School of Dentistry, University of Southern California, Los Angeles 90089
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30
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Spinucci C, Zucker S, Wieman JM, Lysik RM, Imhof B, Ramamurthy N, Liotta LA, Nagase H. Purification of a gelatin-degrading type IV collagenase secreted by ras oncogene-transformed fibroblasts. J Natl Cancer Inst 1988; 80:1416-20. [PMID: 2845110 DOI: 10.1093/jnci/80.17.1416] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Connective tissue matrix-degrading metalloproteinases play an important role in cancer invasion. In this report we describe the isolation of a metalloproteinase exhibiting both type IV collagenolytic and gelatinolytic activities from the conditioned medium of NIH-3T3 fibroblasts transformed with DNA containing an activated c-Harvey-ras oncogene from T24 bladder cancer cells. This tumor proteinase was purified by anion exchange chromatography, zinc-chelate Sepharose chromatography, and gel permeation chromatography. The final product was homogeneous on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (relative molecular mass = 67,000). Gelatin zymography revealed two bands of gelatinolytic activity, corresponding to molecular weights of 67,000 and 62,000. Upon immunoblotting with the use of an affinity-purified polyclonal rabbit antibody to a peptide region of type IV collagenase that lacks homology with interstitial collagenase or stromelysin, the purified tumor enzyme was identified as type IV collagenase.
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Affiliation(s)
- C Spinucci
- Department of Research, Veterans Administration Medical Center, Northport, NY 11768
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31
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Schneir M, Imberman M, Ramamurthy N, Golub L. Streptozotocin-induced diabetes and the rat periodontium: decreased relative collagen production. Coll Relat Res 1988; 8:221-32. [PMID: 3396306 DOI: 10.1016/s0174-173x(88)80042-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
This is the first study concerning the extent to which relative collagen production (RCP) in rat periodontal tissues is affected by diabetes. Determination of RCP, rather than individual production rates for collagen or for non-collagen protein, was deemed necessary because saturation of all proline pools in tissues of diabetics (and non-diabetic controls) was not achieved. Such non-saturation occurred despite the injection of a pool-expanding dose of proline (400-1150 mg/rat), non-saturation indicated by the lesser specific radioactivity (S.R.) of free-[3H]proline in tissues than that of the injected solution. RCP was decreased in five periodontal tissues (incisor and molar gingiva, incisor and molar periodontal ligament, antemolar palatal mucosa) and in skin. Diabetes-decreased RCP seems to result from decreased collagen synthesis and increased intracellular degradation, although some evidence is presented for increased extracellular degradation of recently secreted collagen.
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Affiliation(s)
- M Schneir
- Department of Basic Science, School of Dentistry, University of Southern California, Los Angeles 90089
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Narahari D, Abdul Mujeer K, Thangavel A, Ramamurthy N, Viswanathan S, Mohan B, Muruganandan B, Sundararasu V. Traits influencing the hatching performance of Japanese quail eggs. Br Poult Sci 1988. [DOI: 10.1080/00071668808417031] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Zucker S, Turpeenniemi-Hujanen T, Ramamurthy N, Wieman J, Lysik R, Gorevic P, Liotta LA, Simon SR, Golub LM. Purification and characterization of a connective-tissue-degrading metalloproteinase from the cytosol of metastatic melanoma cells. Biochem J 1987; 245:429-37. [PMID: 3663169 PMCID: PMC1148140 DOI: 10.1042/bj2450429] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A metalloproteinase with activity against type IV collagen, type I collagen and gelatin has been purified from the cytosol of a highly metastatic mouse melanoma by anion-exchange, zinc-chelated and lectin-affinity column chromatography. The purified enzyme has a molecular mass of approx. 59 kDa and on isoelectric focusing in two-dimensional gels produced three spots with apparent isoelectric points (pI) between 5.7 and 6.1. Enzymic activity with collagen, but not gelatin, substrates was latent, requiring activation by trypsin or organomercurials. Trypsin activation of this metalloproteinase was accompanied by a change in molecular mass, whereas autoactivation after 1 month's storage, was not. The degradation of types I and IV collagen by the melanoma enzyme yielded products of lower molecular masses than those yielded by mammalian collagenases, this characteristic thus differentiating this metalloproteinase from classical collagenases.
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Affiliation(s)
- S Zucker
- Department of Medicine and Research, Veterans Administration Medical Center, Northport, NY 11768
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Zucker S, Wieman JM, Lysik RM, Wilkie DP, Ramamurthy N, Lane B. Metastatic mouse melanoma cells release collagen-gelatin degrading metalloproteinases as components of shed membrane vesicles. Biochim Biophys Acta 1987; 924:225-37. [PMID: 3030444 DOI: 10.1016/0304-4165(87)90091-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The purpose of this study has been to compare collagen-gelatin degrading enzymes isolated from cancer cell organelles and cytosol to the metalloproteinases released by cancer cells. To this end, metastatic mouse melanoma cell organelles were isolated by sucrose density gradient centrifugation and metalloproteinases were assayed using native and denatured [methyl-3H]collagen substrates. Solubilized proteinases were purified by ammonium sulfate precipitation, anion exchange, concanavalin A affinity and gel-filtration column chromatographic procedures and characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The conclusions were as follows: malignant melanoma cells have a metalloproteinase (Mr = 59,000) which is shed from cells into conditioned medium as a component of intact membrane vesicles rather than as a soluble enzyme; storage of tumor-conditioned medium leads to the generation of autoactivated soluble metalloproteinases of lower molecular weight; purification of these metalloproteinase species yielded variant collagenases that have considerable gelatinolytic activity and a cleavage preference site for the Gly-Ile bond in a collagen-like synthetic octapeptide substrate which is typical for collagenase-type metalloproteinases. It is proposed that localization of potent proteinases to the surface of cancer cells facilitates the local breakdown of connective tissues during the invasive process.
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Imberman M, Ramamurthy N, Golub L, Schneir M. A reassessment of collagen half-life in rat periodontal tissues: application of the pool-expansion approach. J Periodontal Res 1986; 21:396-402. [PMID: 2942667 DOI: 10.1111/j.1600-0765.1986.tb01473.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Schneir M, Imberman M, Ramamurthy N, Golub L. The in vivo fractional rate of gingival collagen production in non-diabetic and diabetic rats. Application of a novel approach for quantification-pool expansion. J Periodontal Res 1986; 21:56-63. [PMID: 2937895 DOI: 10.1111/j.1600-0765.1986.tb01438.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Schneir M, Ramamurthy N, Golub L. Dietary ascorbic acid normalizes diabetes-induced underhydroxylation of nascent type I collagen molecules. Coll Relat Res 1985; 5:415-22. [PMID: 4085195 DOI: 10.1016/s0174-173x(85)80029-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Nascent collagen alpha chains (types I and III) isolated from diabetic rat skin were shown to be underhydroxylated, an underhydroxylation normalized (type I) or partially corrected (Type III) by dietary ascorbic acid. Increased hydroxylation occurred concomitantly with reduced intracellular procollagen degradation and increased production of nascent collagen molecules, both contributing to an increased total skin collagen mass. Overall, by correcting a defect (underhydroxylation) in a posttranslational event and by increasing collagen production, dietary ascorbic acid improved the collagen status of a diabetes-perturbed connective tissue.
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Golub LM, Ramamurthy N, McNamara TF, Gomes B, Wolff M, Casino A, Kapoor A, Zambon J, Ciancio S, Schneir M. Tetracyclines inhibit tissue collagenase activity. A new mechanism in the treatment of periodontal disease. J Periodontal Res 1984; 19:651-5. [PMID: 6098638 DOI: 10.1111/j.1600-0765.1984.tb01334.x] [Citation(s) in RCA: 222] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Schneir M, Ramamurthy N, Golub L. Skin collagen metabolism in the streptozotocin-induced diabetic rat: free hydroxyproline, the principal in vivo degradation product of newly synthesized collagen--probably procollagen. Coll Relat Res 1984; 4:183-93. [PMID: 6467885 DOI: 10.1016/s0174-173x(84)80040-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
We characterized the degradation products of recently synthesized collagen present in skins of control and diabetic rats. Specifically, the TCA-soluble fractions of homogenized skins from control and diabetic rats (killed 1 and 4 hours after [3H]-proline injection) were fractionated by molecular sieve chromatography, and eluted fractions were analyzed for hydroxyproline and [3H]-hydroxyproline. Free [3H]-hydroxyproline was the principal (greater than 95%), low molecular weight (greater than 2000 daltons), [3H]-hydroxyproline-containing material eluted from the molecular sieve column, this amount representing approximately 80% (controls) and approximately 87% (diabetics) of [3H]-hydroxyproline-containing material in TCA-soluble fractions of skin homogenates. These observations are similar to those from the intracellular degradation of cellular and secretory proteins in that the principal--almost exclusive--degradation product was the free amino acid. The free hydroxyproline had a greater specific radioactivity than that in any other [3H]-hydroxyproline-containing fraction (soluble and insoluble, see below); furthermore, the total radioactivity of free [3H]-hydroxyproline was greater at 1 hour than 3 hours later. These two properties (identity with free amino acid; time-dependent decrease in amounts) are consistent with [3H]-hydroxyproline arising from the intracellular degradation of procollagen. The [3H]-hydroxyproline-containing material eluting before free hydroxyproline (designated peptidyl [3H]-hydroxyproline) was similar to free [3H]-hydroxyproline in terms of specific radioactivity and the time-dependent decreases of specific and total radioactivities, these similarities indicating that the peptidyl [3H]-hydroxyproline are intermediates in the degradative pathway of procollagen to free amino acids. Results for control and diabetic rats were qualitatively similar, with regard to the inter-fraction ratios of specific radioactivities and their time-dependent changes. However, the degradative process, as assessed by the release of free and peptidyl [3H]-hydroxyproline, was dramatically enhanced by the diabetic state, extending our previous results based on analyses of uncharacterized degradation products.
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Schneir M, Ramamurthy N, Golub L. Skin collagen metabolism in the streptozotocin-induced diabetic rat. Enhanced catabolism of collagen formed both before and during the diabetic state. Diabetes 1982; 31:426-31. [PMID: 6218001 DOI: 10.2337/diab.31.5.426] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Collagen catabolism has been measured in skins of streptozotocin-induced diabetic rats. For measuring catabolism of collagen synthesized de novo during the diabetic state, we measured the amounts of [3H]hydroxyproline-containing degradation products in skins of diabetic rats, killed 4 h after [3H]proline injection (protocol 1); degradation products were isolated in TCA-soluble fractions of skin homogenates. For measuring catabolism of collagen preexisting before the induction of the diabetic state, we measured the 21-day loss of [3H]hydroxyproline (and hydroxyproline) in entire skins of rats that were streptozotocin-treated after [3H]proline injection (protocol 2). A 2.5-fold increase in the relative amounts of [3H]hydroxyproline-containing degradation products was measured in the TCA-soluble fractions of skins from diabetic rats (protocol 1). These degradation products had a low molecular weight (as evident from their diffusibility), and they were derived from recently synthesized collagen, possibly procollagen (as evident from their high [3H]hydroxyproline specific activity). Furthermore, they were not derived from the degradation of [3H]hydroxyproline-labeled collagen present before induction of the diabetic state (protocol 2). Evidence for this conclusion is as follows: the amounts of [3H]hydroxyproline-containing degradation products in skins of diabetic rats were not greater than that in skins of control rats, despite a 50% resorption of collagen in skins of diabetic rats. Overall, the catabolism of collagen formed de novo during the diabetic state was distinguished from the catabolism of collagen formed before, and both catabolic processes were enhanced in rat skins of streptozotocin-induced diabetic rats.
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Golub LM, Iacono VJ, Nicoll G, Ramamurthy N, Kaslick RS. The response of human sulcular leucocytes to a chemotactic challenge. A new in vivo assay. J Periodontal Res 1981; 16:171-9. [PMID: 6453980 DOI: 10.1111/j.1600-0765.1981.tb00963.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Schneir M, Bowersox J, Ramamurthy N, Yavelow J, Murray J, Edlin-Folz E, Golub L. Response of rat connective tissues to streptozotocin-diabetes. Tissue-specific effects on collagen metabolism. Biochim Biophys Acta 1979; 583:95-102. [PMID: 420871 DOI: 10.1016/0304-4165(79)90313-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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