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Sundy JS, Otipoby KL, Higginson-Scott N, Visweswaraiah J, Sampson E, Kis-Toth K, Monsef A, Petaipimol P, Essayan D, Cosenza ME, Kakkar R, Viney J. AB0282 SAFETY, TOLERABILITY AND SELECTIVE EXPANSION OF REGULATORY T CELLS BY A SINGLE DOSE OF THE NOVEL IL-2 MUTEIN PT101 IN A PHASE 1 STUDY IN HEALTHY VOLUNTEERS. Ann Rheum Dis 2021. [DOI: 10.1136/annrheumdis-2021-eular.1200] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Background:Activation and expansion of regulatory T cells (Tregs) has been proposed as a strategy to treat autoimmunity. When administered in low doses, IL-2 expands and activates Tregs leading to clinical response in several autoimmune diseases. However, the narrow therapeutic window of IL-2 results in loss of selectivity for Tregs and concurrent activation of conventional T cells (Tconv) and NK cells, limiting its clinical utility. This loss of selectivity may negate the clinical benefit of Treg activation and lead to dose-limiting side effects. PT101 is a novel engineered variant of IL-2 fused to an Fc protein backbone which in preclinical studies selectively activates Tregs without expanding Tconv or NK cells. PT101 is in clinical development for the treatment of patients with autoimmune diseases.Objectives:To assess the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of PT101 after a single dose in healthy human volunteers.Methods:We conducted a randomized, double-blind, single-ascending dose trial of PT101 or placebo (3:1 allocation). Five dose levels from 1 mg to 10 mg were administered by subcutaneous injection. Adverse events, physical examination findings, and clinical laboratory results were assessed for 29 days. Serum PT101 levels and antidrug antibody were assessed. Changes in mononuclear cell populations were measured in peripheral blood by flow cytometry.Results:56 subjects were administered PT101 or placebo. All subjects completed the study. There were no deaths, serious adverse events, dose limiting toxicities, or clinically significant changes in vital sign, ECG, or laboratory results. All adverse events were Grade 1 or 2 and self-limited. Injection site reactions were the most common adverse event. Transient increases in eosinophil counts were observed in some subjects, consistent with the known class effect of IL-2. Peak levels of PT101 occurred 11.0 to 14.6 hours after administration, and declined with a mean half-life of 20.4 to 28.3 hours, demonstrating linear exposure through the dose range. No anti-drug antibodies were induced. PT101 caused dose-related expansion of Tregs that plateaued at doses between 3.5 and 10 mg. Mean maximum expansion above baseline was 3.6-fold for total Tregs and 72.5-fold for the CD25bright subset of Tregs. Maximal expansion was observed by Day 8-10 with a return toward baseline by Day 29. Over 80% of subjects achieved a 2-fold or greater expansion of total Tregs (Table 1). No significant expansion of Tconv or NK cells was observed at any dose level.Table 1.Percent Total Treg RespondersFold Change Total TregsPlacebo(n=14)1 mg(n=6)3.5 mg(n=12)5 mg(n=12)7.5 mg(n=6)10 mg(n=6)≥ 2X7%33%83%83%100%100%≥ 3X0%0%58%75%33%50%≥ 4X0%0%24%42%33%17%Conclusion:PT101 was safe and well tolerated after a single dose in healthy volunteers. Marked expansion of both total Treg and CD25bright Treg cells was observed. High selectivity for Tregs was observed with no significant expansion of pro-inflammatory Tconv and NK cells even at the highest dose studied. These results support the therapeutic potential of PT101 in planned multiple dose studies in systemic lupus erythematosus, ulcerative colitis, and other autoimmune diseases.References:[1]Klatzmann, D., Abbas, A. The promise of low-dose interleukin-2 therapy for autoimmune and inflammatory diseases. Nat Rev Immunol 15, 283–294 (2015)Acknowledgements:Pandion Therapeutics acknowledges the participants and research staff who contributed to this clinical trialDisclosure of Interests:John S Sundy Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Kevin L. Otipoby Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Nathan Higginson-Scott Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Jyothsna Visweswaraiah Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Erik Sampson Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Katalin Kis-Toth Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Adrianne Monsef Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Parika Petaipimol Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, David Essayan Consultant of: Pandion Therapeutics, Mary Ellen Cosenza Consultant of: Pandion Therapeutics, Rahul Kakkar Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Jo Viney Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics
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Kakkar M, Kakkar R, Lal AK, Singla SK. Effect of Age, Sex and Pregnancy on Levels of Urinary Inhibitors of mineralization in Human Beings. Nepal J Epidemiol 2014. [DOI: 10.3126/nje.v4i4.11360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Background: Based upon the differences observed in the level of urinary inhibitors between adult normal subjects of both sexes and kidney stone patients of identical sex, it has been postulated that urinary inhibitors play an important role in the control of pathological mineralization. Review of literature revealed that corresponding studies on the level of urinary inhibitors in children of both sexes and during various stages of pregnancy are not available. These studies, so important to investigate the role of inhibitors in physiological mineralization, formed the objective of the present study. Materials and Methods: Homogenous system of In vitro mineralization was employed to study not only the extend of mineralization and the effect of various urine samples obtained from normal subjects of both sexes and pregnant females at various trimesters of pregnancy on extend of mineralization but also to quantify the level of the inhibitors. Results: Using in vitro system of mineralization (precipitation of Ca2+ or HPO4 2- ions as mineral phase), it has been shown that in contrast to the adult human beings, in children of less than 13 years of age no significant differences exists in the level of the urinary inhibitors between males and females children provided experimental support to the epidemiological studies on the occurrence of the renal calculosis problem in both sexes of children and adult human beings. The findings that the level of the urinary inhibitors of mineralization in both sexes of children is as high as present in adult females and that a highly significant decrease in their levels occurs during the 3rd trimester of pregnancy strongly suggests that hormones may be playing an important role in regulating their levels. Conclusion: Inhibitors of mineralization excreted in urine of normal healthy subjects of both sexes of Children (<13 years), adults (>20 years), kidney stone patients at these ages, non pregnant and pregnant females (during various trimesters of pregnancy) have been postulated to play an important role in the control of both physiological and pathological mineralization.DOI: http://dx.doi.org/10.3126/nje.v4i4.11360 Nepal Journal of Epidemiology 2014; 4(4):399-404
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Kakkar R, Hei H, Dobner S, Reichenspurner H, Lee R. Interleukin 33 as a mechanically responsive cytokine secreted by living cells. Thorac Cardiovasc Surg 2014. [DOI: 10.1055/s-0034-1367392] [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: 10/25/2022]
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Kaushik R, Kaushik RM, Kakkar R, Sharma A, Chandra H. Plasmodium vivax malaria complicated by acute kidney injury: experience at a referral hospital in Uttarakhand, India. Trans R Soc Trop Med Hyg 2013; 107:188-94. [DOI: 10.1093/trstmh/trs092] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Kakkar R, Scott M. Lateral Epicondylitis of The Elbow-Are Platelets the Answer? Int J Surg 2010. [DOI: 10.1016/j.ijsu.2010.07.269] [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: 11/28/2022]
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Abstract
BACKGROUND Injury to the spinal accessory nerve in the posterior cervical triangle leads to paralysis of the trapezius muscle. The aim of this study was to determine the indications for nerve repair or reconstructive surgery according to the etiology, the duration of the preoperative delay, and specific patient characteristics. METHODS Of twenty-seven patients with a trapezius palsy, twenty were treated with neurolysis or surgical repair (direct or with a graft) of the spinal accessory nerve and seven were treated with the Eden-Lange muscle transfer procedure. Lymph node biopsy was the main cause of the nerve injury. The nerve repairs were performed at an average of seven months after the injury, and the reconstructive procedures were done at an average of twenty-eight months. Nerve repair was performed for iatrogenic injuries of the spinal accessory nerve, within twenty months after the onset of symptoms, and in one patient with spontaneous palsy. Reconstructive surgery was performed for cases of trapezius palsy secondary to radical neck dissection, for spontaneous palsies, and after failure of nerve repair or neurolysis. The mean follow-up period was thirty-five months. The functional outcome was assessed clinically on the basis of active shoulder abduction, pain, strength of the trapezius on manual muscle-testing, and level of subjective patient satisfaction. RESULTS The results were good or excellent in sixteen of the twenty patients treated with nerve repair and in four of the seven patients treated with the Eden-Lange procedure. Poor results were seen in older patients and in patients with a previous radical neck dissection. CONCLUSIONS Good results can be expected from a repair of the spinal accessory nerve if it is performed within twenty months after the injury, as the nerve is basically a purely motor nerve and the distance from the injury to the motor end plates is short. Muscle transfer should be performed in patients with spontaneous trapezius palsy, when previous nerve surgery has failed, or when the time from the injury to treatment is over twenty months. Treatment is less likely to succeed when the patient is older than fifty years of age or the palsy was due to a radical neck dissection, penetrating injury, or spontaneous palsy.
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Affiliation(s)
- F Teboul
- 10 rue d'Alsace, 92300, Levallois-Perret, France.
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Abstract
BACKGROUND Injury to the spinal accessory nerve in the posterior cervical triangle leads to paralysis of the trapezius muscle. The aim of this study was to determine the indications for nerve repair or reconstructive surgery according to the etiology, the duration of the preoperative delay, and specific patient characteristics. METHODS Of twenty-seven patients with a trapezius palsy, twenty were treated with neurolysis or surgical repair (direct or with a graft) of the spinal accessory nerve and seven were treated with the Eden-Lange muscle transfer procedure. Lymph node biopsy was the main cause of the nerve injury. The nerve repairs were performed at an average of seven months after the injury, and the reconstructive procedures were done at an average of twenty-eight months. Nerve repair was performed for iatrogenic injuries of the spinal accessory nerve, within twenty months after the onset of symptoms, and in one patient with spontaneous palsy. Reconstructive surgery was performed for cases of trapezius palsy secondary to radical neck dissection, for spontaneous palsies, and after failure of nerve repair or neurolysis. The mean follow-up period was thirty-five months. The functional outcome was assessed clinically on the basis of active shoulder abduction, pain, strength of the trapezius on manual muscle-testing, and level of subjective patient satisfaction. RESULTS The results were good or excellent in sixteen of the twenty patients treated with nerve repair and in four of the seven patients treated with the Eden-Lange procedure. Poor results were seen in older patients and in patients with a previous radical neck dissection. CONCLUSIONS Good results can be expected from a repair of the spinal accessory nerve if it is performed within twenty months after the injury, as the nerve is basically a purely motor nerve and the distance from the injury to the motor end plates is short. Muscle transfer should be performed in patients with spontaneous trapezius palsy, when previous nerve surgery has failed, or when the time from the injury to treatment is over twenty months. Treatment is less likely to succeed when the patient is older than fifty years of age or the palsy was due to a radical neck dissection, penetrating injury, or spontaneous palsy.
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Affiliation(s)
- F Teboul
- Department of Orthopaedics, Hôpital Lariboisière, Paris, France.
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Kakkar R, Wang X, Radhi JM, Rajala RV, Wang R, Sharma RK. Decreased expression of high-molecular-weight calmodulin-binding protein and its correlation with apoptosis in ischemia-reperfused rat heart. Cell Calcium 2001; 29:59-71. [PMID: 11133356 DOI: 10.1054/ceca.2000.0157] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A cardiac high-molecular-weight calmodulin-binding protein (HMWCaMBP) was previously identified as a homologue of the calpain inhibitor, calpastatin. In the present study, we investigated the expression of HMWCaMBP and calpains in rat heart after ischemia and reperfusion. Western blot analysis of normal rat heart extract with a polyclonal antibody raised against bovine HMWCaMBP indicated a prominent immunoreactive band of 140kDa. Both the expression and the activity of HMWCaMBP were decreased by ischemia reperfusion. Immunohistochemical studies showed strong-to-moderate HMWCaMBP immunoreactivity in normal heart and poor immunoreactivity in ischemia-reperfused heart muscle. However, the expression of micro-calpain and m-calpain in ischemia-reperfused heart was increased as compared to normal heart. The calpain inhibitory activity of ischemia-reperfused heart tissues was significantly lower as compared to normal heart tissues. The pre-ischemic and post-ischemic perfusion of hearts with a cell-permeable calpain inhibitor suppressed the increase in calpain expression but increased the HMWCaMBP expression. In-vitro HMWCaMBP was proteolyzed by micro-calpain and m-calpain. We also measured apoptosis in normal and ischemia-reperfused tissues. An increase in the number of apoptotic bodies was observed with increased duration of ischemia and reperfusion. Bcl-2 expression did not change in any of the groups, whereas Bax expression increased with ischemia-reperfusion and correlated well with the degree of apoptosis. Our findings suggest that HMWCaMBP may sequester calpains from its substrates in the normal myocardium, but it is susceptible to proteolysis by calpains during ischemia-reperfusion. Thus, decreased expression of HMWCaMBP may play an important role in myocardial injury.
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Affiliation(s)
- R Kakkar
- Department of Pathology, College of Medicine, University of Saskatchewan, Saskatoon, Canada
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Sharma A, Kharb S, Chugh SN, Kakkar R, Singh GP. Effect of glycemic control and vitamin E supplementation on total glutathione content in non-insulin-dependent diabetes mellitus. Ann Nutr Metab 2000; 44:11-3. [PMID: 10838461 DOI: 10.1159/000012815] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Thirty patients with non-insulin-dependent diabetes mellitus were selected for the study. 15 age-matched healthy volunteers served as controls. Serum malonaldehyde, total glutathione, and vitamin E levels were estimated before and after glycemic control and after 4 weeks of vitamin E supplementation. Both total glutathione and vitamin E levels increased after glycemic control and showed an increase after vitamin E supplementation. Malonaldehyde levels lowered after glycemic control, but remained higher than controls. Since vitamin E supplementation significantly decreased oxidative stress in the present study, it may play a role in reducing free-radical-induced oxidant injury in diabetes mellitus.
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Affiliation(s)
- A Sharma
- Department of Biochemistry, Postgraduate Institute of Medical Sciences, Rohtak, India
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Abstract
A high-molecular-weight calmodulin-binding protein (HMWCaMBP) was previously identified and purified from the cytosolic fraction of bovine heart. Based on the sequence homology, amino acid analysis, antibody reactivity, and calpain inhibition, HMWCaMBP has been identified as a homologue of the calpain inhibitor calpastatin. In the present study the expression of HMWCaMBP was investigated in normal and ischaemic human myocardium. Western blot analysis of normal human cardiac muscle extract with the polyclonal antibody raised against bovine HMWCaMBP indicated a prominent immunoreactive band with a molecular mass of 140 kD. HMWCaMBP was localized in the cytoplasm and myofilaments of cardiac myocytes. Furthermore, Western blot analysis of normal and ischaemic cardiac tissues indicated a decrease in the expression of HMWCaMBP in ischaemic tissues. These studies were further substantiated by immunohistochemical studies, indicating strong to moderate HMWCaMBP immunoreactivity in normal cardiac muscle and poor to negative immunoreactivity in ischaemic muscle. The results obtained from the rat ischaemic model suggested that the expression of cardiac HMWCaMBP was significantly decreased during ischaemia/reperfusion. In addition, micro-calpain and m-calpain expression was higher in ischaemic cardiac tissue samples than in normal controls. The calpain inhibitory activity of ischaemic cardiac tissues was significantly lower than normal cardiac tissue samples. In some cases of cardiac ischaemia, HMWCaMBP highlighted the contraction band necrosis seen at the margins of a myocardial infarct. In vitro, HMWCaMBP was proteolysed by micro-calpain and m-calpain. These results indicate that HMWCaMBP could be susceptible to proteolysis by calpains during ischaemia or reperfusion and may play a contributory role in myocardial injury.
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Affiliation(s)
- R Kakkar
- Department of Pathology and Saskatoon Cancer Centre, College of Medicine, Royal University Hospital, University of Saskatchewan, Canada
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Rajala RV, Radhi JM, Kakkar R, Datla RS, Sharma RK. Increased expression of N-myristoyltransferase in gallbladder carcinomas. Cancer 2000; 88:1992-9. [PMID: 10813869] [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: 02/16/2023]
Abstract
BACKGROUND Activated Src, which has intrinsic protein tyrosine kinase activity, has been found in human solid tumors such as colorectal and breast carcinomas. The Src gene encodes a cytoplasmic tyrosine kinase p60src, which attaches to the inner surface of the membrane after N-terminal myristoylation and is implicated in transduction of signals to the nucleus. N-myristoyltransferase (NMT) catalyzes the biochemical modification process called N-myristoylation. To investigate whether, through Src, NMT contributes to the pathogenesis of gallbladder carcinoma, the authors investigated expression of NMT and p53 in in situ and invasive carcinomas. METHODS One hundred cases of documented gallbladder carcinoma were reviewed, and 30 cases were selected randomly to evaluate expression of NMT and p53 by immunohistochemistry in both in situ and in invasive tumor components. RESULTS Eighteen cases (60%) of gallbladder carcinoma showed moderate to strong cytoplasmic positivity for NMT with increased intensity in the invasive component, and 12 cases (40%) were negative. The in situ component revealed mild to moderate cytoplasmic staining in 20 cases (67%), whereas the normal gallbladder mucosa showed weak to negative cytoplasmic staining. Moderate to strong p53 staining was observed in 17 in situ cases (63%) and 24 invasive cases (80%). The in situ staining patterns of p53 were unrelated to the clinical outcome of the tumor. However, moderate to strong staining of the invasive component as observed in 15 cases (50%) was associated with a mean survival of 8.8 months. Amplification of intron-8 in normal gallbladder mucosa and invasive carcinoma were similar in intensity, suggesting the absence of NMT gene amplification in these tumors. CONCLUSIONS The increased expression of NMT in these tumors could be due to transcriptional activation. Tumors with increased expression of NMT and p53 were associated with poor clinical outcomes as evidenced by their mean survival times. NMT is likely to play a pathogenic role in gallbladder carcinoma.
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Affiliation(s)
- R V Rajala
- Department of Pathology, Saskatoon Cancer Centre, College of Medicine, Royal University Hospital, University of Saskatchewan, Canada
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Sharma A, Kharb S, Chugh SN, Kakkar R, Singh GP. Evaluation of oxidative stress before and after control of glycemia and after vitamin E supplementation in diabetic patients. Metabolism 2000; 49:160-2. [PMID: 10690938 DOI: 10.1016/s0026-0495(00)91117-x] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The present study evaluates the presence of oxidative stress in the uncontrolled diabetic state. Glycemic control reduced the oxidative stress, but total normalization of the parameters of oxidative stress was not achieved, indicating continued oxidant injury despite optimal control of the diabetes. Vitamin E supplementation for 4 weeks in these patients further reduced the oxidative stress, suggesting that vitamin E supplementation might be helpful in reducing free-radical-induced oxidant injury.
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Affiliation(s)
- A Sharma
- Postgraduate Institute of Medical Sciences, Rohtak, Haryana, India
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Abstract
Myristoylation refers to the co-translational addition of a myristoyl group to an amino-terminal glycine residue of a protein by an ubiquitously distributed enzyme myristoyl-CoA:protein N-myristoyltransferase (NMT, EC 2.3.1.97). This review describes the basic enzymology, molecular cloning and regulation of NMT activity in various pathophysiological processes such as colon cancer and diabetes.
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Affiliation(s)
- R V Rajala
- Department of Pathology and Saskatoon Cancer Centre, College of Medicine, Royal University Hospital, University of Saskatchewan, Canada
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Abstract
Ca2+/calmodulin-dependent cyclic nucleotide phosphodiesterase (PDE1) is one of the key enzymes involved in the complex interactions between the cyclic nucleotide and Ca2+ second messenger systems. Currently, three genes encode PDE1, and alternate splicing of these genes gives rise to functionally different isozymes which exhibit distinct catalytic and regulatory properties. Some isozymes have similar kinetic and immunological properties but are differentially regulated by Ca2+ and calmodulin. These isozymes also differ in their mechanism of regulation by phosphorylation. Analysis of various regulatory reactions involving Ca2+ and cyclic adenosine monophosphate (cAMP) has revealed the importance of the time dependence of these reactions during cell activation; however, no measurement is available for the time of occurrence of specific regulatory reactions. cAMP-signalling systems provide a pivotal centre for achieving crosstalk regulation by various signalling pathways. It has been proposed that polypeptide sequences enriched in proline (P), glutamate (E), serine (S) and threonine (T), known as PEST motifs, serve as putative intramolecular signals for rapid proteolytic degradation by calpains. Calpains are Ca(2+)-dependent cysteine proteases that regulate various enzymes, transcription factors and structural proteins through limited proteolysis. Isozyme PDE1A2 has a PEST motif and acts as a substrate for m-calpain. In this paper, we have described PDE1A2 regulation by calpains and its physiological implications. cAMP is an important component of the signal transduction pathway and plays an integral role in various physiological processes such as gene transcription, various neuronal functions, cardiac muscle contraction, vascular relaxation, cell proliferation and a host of other functions. It is important to identify the cellular processes where PDE isoform(s) and cAMP response are altered. This will lead to better understanding of the pathology of disease states and development of novel therapeutics. The different PDE1 isozymes, although similar in kinetic properties, can be distinguished by various pharmacological agents. Our recent understanding of the role of PDE1 inhibitors such as ginseng, dihydropy-ridine antagonists and antiparkinsonian agents are described in this review. The exact function of PDE1 isozymes in various pathophysiological processes is not clear because most of the studies have been carried out in vitro; therefore, it is essential that further research be directed to in vivo studies.
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MESH Headings
- 3',5'-Cyclic-AMP Phosphodiesterases/antagonists & inhibitors
- 3',5'-Cyclic-AMP Phosphodiesterases/chemistry
- 3',5'-Cyclic-AMP Phosphodiesterases/genetics
- 3',5'-Cyclic-AMP Phosphodiesterases/physiology
- 3',5'-Cyclic-GMP Phosphodiesterases/antagonists & inhibitors
- 3',5'-Cyclic-GMP Phosphodiesterases/chemistry
- 3',5'-Cyclic-GMP Phosphodiesterases/genetics
- 3',5'-Cyclic-GMP Phosphodiesterases/physiology
- Animals
- Brain/enzymology
- Calcium Signaling/physiology
- Calcium-Calmodulin-Dependent Protein Kinase Type 2
- Calcium-Calmodulin-Dependent Protein Kinases/physiology
- Calmodulin/physiology
- Calpain/physiology
- Cattle
- Cyclic AMP/physiology
- Cyclic Nucleotide Phosphodiesterases, Type 1
- Enzyme Activation
- Humans
- Isoenzymes/antagonists & inhibitors
- Isoenzymes/chemistry
- Isoenzymes/genetics
- Isoenzymes/physiology
- Male
- Neoplasm Proteins/physiology
- Neoplasms/enzymology
- Nerve Tissue Proteins/physiology
- Organ Specificity
- Parkinson Disease/enzymology
- Phosphoric Diester Hydrolases
- Phosphorylation
- Protein Processing, Post-Translational
- Protein Structure, Tertiary
- RNA Splicing
- Rats
- Second Messenger Systems/physiology
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Affiliation(s)
- R Kakkar
- Department of Pathology, College of Medicine, University of Saskatchewan, Saskatoon, Canada
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Chugh SN, Kakkar R, Kalra S, Sharma A. An evaluation of oxidative stress in diabetes mellitus during uncontrolled and controlled state and after vitamin E supplementation. J Assoc Physicians India 1999; 47:380-3. [PMID: 10778519] [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: 02/16/2023]
Abstract
OBJECTIVE The study was conducted on 50 patients (10 insulin dependent diabetes mellitus (IDDM) and 40 non-insulin dependent diabetes mellitus (NIDDM) of recently diagnosed diabetes mellitus. The main objectives of the study were: 1. To evaluate oxidative stress at uncontrolled stage. 2. To evaluate the effect of optimal control on oxidative stress irrespective of type of drug therapy used. 3. To further evaluate the effect of vitamin E supplementation on oxidative stress after achieving optimal control. This was done in order to explore anti-oxidant effect of vitamin E. METHODS Fifty patients of uncontrolled diabetes of less than 1 year duration and without any overt complications were studied. The parameters of oxidative stress included malonyl-di-aldehyde (MDA), reduced glutathione and vitamin E levels in the blood. They were done at three stages i.e. (a) In uncontrolled stage, (b) At controlled stage and (c) After 4 weeks of vitamin E supplementation in dosage of 400 mg daily. The parameters of control included fasting blood sugar < or = 140 mg%, post prandial < or = 200 mg and HbA1c < or = 7% (analysed by prepared kit). RESULTS The significantly raised levels of MDA and decreased levels of reduced glutathione and vitamin E during uncontrolled stage of diabetes indicated free radical stress inducing lipid peroxidation. The significant fall of MDA and rise in reduced glutathione and vitamin E levels in blood after optimal control revealed its beneficial effect on oxidative stress. The levels were not normalised but still stayed higher than controls. After 4 weeks of vitamin E supplementation, further fall in MDA and rise in reduced glutathione suggested beneficial effect of vitamin E over and above the optimal control. Vitamin E estimation in blood at this stage did not constitute parameter of oxidative stress as it was provided from outside but was done to know the compliance of patients. Normalisation or near normalisation was not achieved with vitamin E therapy indicating persistence of oxidative stress. CONCLUSION There was an evidence of oxidative stress in diabetes which decreased with optimal control and further declined after vitamin E supplementation indicating anti-oxidant effect of vitamin E alone. Normalisation of oxidative stress was not achieved. A further study is desired to study the effect of vitamin E for longer period at least 3-6 months before a definite conclusion is drawn.
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Kakkar R, Sharma RK. Assay and purification of calmodulin-dependent protein kinase. Methods Mol Biol 1999; 114:325-41. [PMID: 10081028 DOI: 10.1385/1-59259-250-3:325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- R Kakkar
- Department of Pathology, Saskatoon Cancer Centre, College of Medicine, University of Saskatchewan, Canada
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Abstract
Myristoyl-CoA:protein N-myristoyltransferase (NMT) is an essential eukaryotic enzyme that catalyzes the co-translational transfer of myristate to the NH2-terminal glycine residue of a number of important proteins of diverse function. Recently, we have isolated full length cDNA encoding bovine spleen NMT [27] the full length cDNA was cloned and expressed in E. coli, resulting in the expression of functionally active 50 kDa NMT. Using the combination of SP-Sepharose fast flow and Mono S fast protein liquid chromatography, the enzyme was purified 20-fold with a high yield. The spleen NMT (sNMT) fusion protein exhibited an apparent molecular weight of 53 kDa on SDS-PAGE. Upon cleavage by the Enterokinase the sNMT exhibited an apparent molecular weight of 50 kDa without loss of catalytic activity. The two synthetic peptide substrates based on the N-terminal sequence of pp60src (GSSKSKMR) and cAMP dependent protein kinase (GNAAAKKRR) have different kinetic parameters of Km values of 40 and 200 microM. Recombinant sNMT was also potently inhibited by Ni2+ (histidine binder) in a concentration dependent manner with a half maximal inhibition of 280 microM. The E. coli expressed sNMT was homogenous and showed enzyme activity.
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Affiliation(s)
- R V Raju
- Department of Pathology and Saskatoon Cancer Centre, College of Medicine, University of Saskatchewan, Canada
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Kakkar R, Raju RV, Sharma RK. In vitro generation of an active calmodulin-independent phosphodiesterase from brain calmodulin-dependent phosphodiesterase (PDE1A2) by m-calpain. Arch Biochem Biophys 1998; 358:320-8. [PMID: 9784246 DOI: 10.1006/abbi.1998.0858] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In the present study we have shown that bovine brain 60-kDa calmodulin-dependent cyclic nucleotide phosphodiesterase isozyme (CaMPDE - PDE1A2) is proteolyzed by a Ca2+-dependent cysteine protease, m-calpain. The proteolysis of PDE1A2 by m-calpain results in its conversion to a totally calmodulin (CaM)-independent form accompanied by degradation of PDE1A2 into a 45-kDa catalytic fragment and a 15-kDa fragment. The activity of PDE1A2 is unaffected by the presence or absence of CaM during cleavage, suggesting that the interaction between CaM and PDE1A2 does not alter substrate recognition by calpain. Furthermore, we provide evidence, based on the studies of CaM overlay and phosphorylation, that the cleavage site is not present either in the CaM-binding domain or phosphorylation site. N-terminal sequence analysis of the 45-kDa fragment indicated that cleavage occurs between residues 126Gln and 127Ala, and eliminates the CaM-dependent activity of carboxy termini PDE1A2. The present findings suggest that limited proteolysis in the brain through calpains could be an alternate mechanism for activating CaMPDE(s) and for regulating intracellular levels of cAMP.
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Affiliation(s)
- R Kakkar
- College of Medicine, University of Saskatchewan, Saskatoon, S7N 4H4, Canada
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Kakkar R, Mantha SV, Radhi J, Prasad K, Kalra J. Increased oxidative stress in rat liver and pancreas during progression of streptozotocin-induced diabetes. Clin Sci (Lond) 1998; 94:623-32. [PMID: 9854460 DOI: 10.1042/cs0940623] [Citation(s) in RCA: 176] [Impact Index Per Article: 6.8] [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: 11/17/2022]
Abstract
1. Oxygen free radicals have been suggested to be a contributory factor in complications of diabetes mellitus. There are many reports indicating the changes in parameters of oxidative stress in diabetes mellitus. In this study we aimed to identify whether oxidative stress occurs in the liver and pancreas in the initial stages of development of diabetes. 2. We therefore investigated the lipid peroxide level (thiobarbituric acid-reactive substances, TBARS) and activities of antioxidant enzymes [superoxide dismutase (SOD), catalase and glutathione peroxidase] in liver and pancreas of control and streptozotocin-induced diabetic rats at various stages of development of diabetes. 3. Male Sprague-Dawley rats were divided into two groups: group I, control (n = 42) and group II, diabetic (n = 42). Each group was further subdivided into seven groups consisting of six rats each. Rats in these subgroups were studied at weekly intervals (0 to 6 weeks). Plasma glucose levels, TBARS levels and activities of antioxidant enzymes were measured in liver and pancreas at various time intervals. 4. There was a significant (P < 0.05) and progressive increase in TBARS levels of liver and pancreas in the diabetic group. Total SOD and Cu-Zn-SOD activity increased (P < 0.05) with progression of diabetes while Mn-SOD activity showed no significant change in either tissue. Catalase and glutathione peroxidase activities increased significantly (P < 0.05) in liver and pancreas. 5. Immunohistochemical study of pancreatic islet revealed a decrease in the expression of insulin with progression of diabetes. However, glucagon and somatostatin showed an increase in immunoreactivity and a difference in their distribution pattern. 6. The findings of the present study suggest that oxidative stress starts at early onset of diabetes mellitus and increases progressively. In conclusion, the structural damage to these tissues or complications of diabetes mellitus may be due to oxidative stress.
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Affiliation(s)
- R Kakkar
- Department of Pathology, College of Medicine, University of Saskatchewan, Saskatoon, Canada
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Raju RV, Kakkar R, Datla RS, Radhi J, Sharma RK. Myristoyl-coA:protein N-myristoyltransferase from bovine cardiac muscle: molecular cloning, kinetic analysis, and in vitro proteolytic cleavage by m-calpain. Exp Cell Res 1998; 241:23-35. [PMID: 9633510 DOI: 10.1006/excr.1998.4021] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [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
Myristoyl-CoA:protein N-myristoyltransferase (NMT) catalyzes the attachment of myristate onto the amino terminal glycine residue of select polypeptides. Cardiac tissue expresses high levels of cAMP-dependent protein kinase whose catalytic subunit is myristoylated; however, cardiac muscle extracts were found to contain low NMT activities. Northern blot analysis of bovine heart poly(A)+ RNA probed with bovine spleen NMT cDNA revealed a 1.7-kb mRNA. Western blot analysis of cardiac muscle extracts with human NMT antibody indicated a prominent immunoreactive band with a molecular mass of 50 kDa. The expression of mRNA and protein levels in cardiac muscle is not correlated with NMT activities, suggesting the presence of regulators of the enzyme activity. We have isolated the cDNA encoding bovine cardiac muscle NMT (cNMT) by reverse transcription polymerase chain reaction. The single long open reading frame of 1248 bp of bovine cNMT specifies a protein of 416 amino acids with a predicted mass of 46,686 Da. The cDNA clone expressed in Escherichia coli resulted in the production of functionally active 50-kDa NMT. Ultrastructural and immunolocalization of NMT utilizing the immunogold labeling technique demonstrated cytoplasmic distribution with occasional mitochondrial and myofilaments localization of the NMT antibody. Cardiac muscle NMT has a higher affinity for myristoyl-CoA than toward palmitoyl-CoA. Substrate specificity indicated that cNMT has a higher affinity toward pp60src and M2 gene segment of reovirus type 3-derived peptide substrates than toward cAMP-dependent protein kinase-derived peptide. Primary translational product of cNMT sequence contained several regions rich in proline, glutamic acid, serine, and threonine, which are known as "PEST" regions. PEST-FIND analysis of the amino acid sequences indicated eight PEST regions were present in the cNMT. These PEST regions are suggested to be recognized by specific proteases, particularly Ca(2+)-dependent neutral proteases, calpains, which are responsible for the degradation of PEST-containing proteins. We have demonstrated the abolishment of NMT activity and NMT protein degradation in vitro by m-calpain. The proteolysis of cNMT by m-calpain and the abolishment of NMT activity was prevented by the calpain inhibitor, calpastatin. These observations indicate that calpains may regulate NMT activity.
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Affiliation(s)
- R V Raju
- Department of Pathology, College of Medicine, Royal University Hospital, University of Saskatchewan, Saskatoon, Canada
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Kakkar R, Taketa S, Raju RV, Proudlove S, Colquhoun P, Grymaloski K, Sharma RK. In vitro phosphorylation of bovine cardiac muscle high molecular weight calmodulin binding protein by cyclic AMP-dependent protein kinase and dephosphorylation by calmodulin-dependent phosphatase. Mol Cell Biochem 1997; 177:215-9. [PMID: 9450665 DOI: 10.1023/a:1006886111569] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
High molecular weight calmodulin binding protein (HMWCaMBP) is one of the major proteins expressed in bovine cardiac muscle. In this study, we report the phosphorylation and dephosphorylation of HMWCaMBP in vitro with a view to understand the function of this protein. The HMWCaMBP was phosphorylated by cAMP-dependent protein kinase with the incorporation of 2.30 mol of phosphate/mol of protein in the presence of EGTA. When phosphorylation was carried out in the presence of Ca2+/calmodulin (CaM), the incorporation of phosphate was reduced to 1.40 mol of phosphate/mol of protein. The decrease in the stoichometry of phosphorylation by Ca2+/CaM appears to be substrate directed i.e. due to the interaction of Ca2+/CaM with HMWCaMBP. The phosphorylated HMWCaMBP was unable to compete for free CaM in a CaM-dependent cyclic nucleotide phosphodiesterase (CaMPDE) assay. These results suggest that the phosphorylation sites may reside in or in proximity to the CaM-binding domain on HMWCaMBP since phosphorylated HMWCaMBP did not inhibit CaMPDE activity. HMWCaMBP was dephosphorylated by CaM-dependent phosphatase, calcineurin.
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Affiliation(s)
- R Kakkar
- Department of Pathology and Saskatoon Cancer Centre, College of Medicine, University of Saskatchewan, Canada
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Raju RV, Kakkar R, Radhi JM, Sharma RK. Biological significance of phosphorylation and myristoylation in the regulation of cardiac muscle proteins. Mol Cell Biochem 1997; 176:135-43. [PMID: 9406155] [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: 02/05/2023]
Abstract
Post-translational modification has long been recognized as a way in which the properties of proteins may be subtly altered after synthesis of the polypeptide chain is complete. Amongst the moieties most commonly encountered covalently attached to proteins are oligosaccharides, phosphate, acetyl, formyl and nucleosides. Protein phosphorylation and dephosphorylation is one of the most prevalent and best understood modifications employed in cellular regulation. The bovine heart calmodulin-dependent cyclic nucleotide phosphodiesterase (CaMPEDE) can be phosphorylated by cAMP-dependent protein kinase, resulting in a decrease in the enzyme's affinity for Ca2+ and calmodulin (CaM). The phosphorylation of CaMPDE is blocked by Ca2+ and CaM and reversed by the CaM-dependent phosphatase (calcineurin). The dephosphorylation is accompanied by an increase in the affinity of the phosphodiesterase for CaM. Analysis of the complex regulatory properties of CaMPDE has led to the suggestion that fluxes of cAMP and Ca2+ during cell activations are closely coupled and that the CaMPDE play a key role in the signal coupling phenomenon. The high molecular weight calmodulin binding protein (HMWCaMBP) was phosphorylated by cAMP-dependent protein kinase. Phosphorylation of HMWCBP was higher in the absence of Ca2+/CaM then in the presence of Ca2+/CaM and reversed by the CaM-dependent phosphatase. Recently, it has become apparent that the binding of myristate to proteins is also widespread in eukaryotic cells and viruses and certainly is of great importance to the correct functioning of an organism. Myristoyl CoA:protein N-myristoyltransferase (NMT) catalyses the attachment of myristate to the amino-terminal glycine residue of various signal transduction proteins. Cardiac tissue express high levels of cAMP-dependent protein kinase whose catalytic subunit is myristoylated. The subcellular localization of bovine cardiac muscle NMT indicated a majority of the activity was localized in cytoplasm. Under native conditions the enzyme exhibited an apparent molecular mass of 50 kDa. Recovery of NMT activity, from both cytosol and particulate fractions, was found to be higher than the total activity in crude homogenates, suggesting that particulate fraction may contain an inhibitory activity towards NMT. Research in our laboratory has been focusing on the covalent modification of proteins and regulation of various signal transduction proteins. This special review is designed to summarize some aspects of the current work on co- and post-translational modification of proteins in cardiac muscle.
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Affiliation(s)
- R V Raju
- Department of Pathology, College of Medicine, Royal University Hospital, University of Saskatchewan, Saskatoon, Canada
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Abstract
A high molecular weight calmodulin binding protein (HMWCaMBP) was previously identified and purified from bovine heart cytosolic fraction [Sharma, R.K. (1990) J. Biol. Chem. 265, 1152-1157]. In this study, we report the biological function of this protein. HMWCaMBP was subjected to peptide mapping and three peptides were sequenced. Two of the three peptide sequences were shown to be highly homologous to the calpain inhibitor, calpastatin. However, the third peptide did not show homology to any known proteins. The Western blot analysis of HMWCaMBP and purified calpastatin from bovine cardiac muscle showed immunoreactivity with polyclonal antibody raised against HMWCaMBP. Furthermore, HMWCaMBP inhibited calpain II and calpain I activities in a dose dependent fashion. Our data based on sequence homology, amino acid analysis, antibody reactivity and calpain inhibition suggests that HMWCaMBP is homologous to calpastatin and may be a CaM-binding form of calpastatin.
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Affiliation(s)
- R Kakkar
- Department of Pathology, College of Medicine, University of Saskatchewan, Royal University Hospital, Saskatoon, SK, S7N 0W0, Canada
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Chugh SN, Kolley T, Kakkar R, Chugh K, Sharma A. A critical evaluation of anti-peroxidant effect of intravenous magnesium in acute aluminium phosphide poisoning. Magnes Res 1997; 10:225-30. [PMID: 9483483] [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: 02/06/2023]
Abstract
The anti-peroxidant effect of intravenous magnesium was evaluated in 50 patients with acute aluminium phosphide poisoning. The patients were divided into two groups, one who received magnesium sulphate therapy (Group I) and the other who did not (Group II). The clinical and biochemical parameters in both groups were comparable. Finding of increased mean malonyl-di-aldehyde (MDA) levels in group I (3.18 +/- 0.93 micromol/L) and group II (3.15 +/- 0.78 mmol/L) combined with low blood levels of reduced glutathione (18.5 +/- 1.6 mg/dl in group I) and (17.8 +/- 1.4 mg/dl in group II) indicated oxidative stress leading to accelerated lipid peroxidation in the early phase (0-6 h) of AlP poisoning. A significant fall in MDA levels was observed after 2 h in the magnesium treated group (group I) compared to the non-treated group (group II) and levels became normal between 48-72 h. Similarly reduced glutathione started recovering between 12-24 h which became significant after 24 h and full recovery took place between 48-72 h in the magnesium treated group (group I). Both these parameters suggested an anti-peroxidant effect of magnesium. There was also a slight fall in MDA levels and a rise in reduced glutathione in the non-treated group II patients. This could be due to elimination of phosphine (PH3). We hypothesize that oxidative stress in AlP poisoning buffered the magnesium leading to a transient fall in magnesium and magnesium dependent GSH, resulting in increased susceptibility of oxygen free radical injury and accelerated lipid peroxidation. The fall in MDA and slower rise in GSH in group I than in group II suggested magnesium combated free radical stress slowly and independent of elimination of phosphine. This hypothesis was further strengthened by similar observations when both these parameters were compared in survivors in both groups. Mortality was higher in group II than in group I (44 per cent vs 20 per cent) and was probably related directly to oxidative stress.
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Affiliation(s)
- S N Chugh
- Department of Medicine and Biochemistry, Postgraduate Institute of Medical Sciences, Rohtak, Haryana, India
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Hirano I, Kakkar R, Saha JK, Szymanski PT, Goyal RK. Tyrosine phosphorylation in contraction of opossum esophageal longitudinal muscle in response to SNP. Am J Physiol 1997; 273:G247-52. [PMID: 9252532 DOI: 10.1152/ajpgi.1997.273.1.g247] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Sodium nitroprusside (SNP) has been shown to elicit a guanosine 3',5'-cyclic monophosphate (cGMP)-mediated, indomethacin-sensitive contraction of the opossum esophageal longitudinal muscle. We examined the role of tyrosine phosphorylation in the signal transduction pathway of contractions induced by SNP and cGMP in longitudinal muscle strips in vitro. Force of isometric contractions was expressed as the percentage of responses to KCl (73 mM). SNP (100 microM)-induced contractions were 75 +/- 5% before and 3 +/- 2% after 50 microM genistein (P < 0.005) and 86 +/- 16% before and 0 +/- 0% after 50 microM tyrphostin B46. Contractions in response to 8-bromo-cGMP (8-BrcGMP; 1 mM) were 74 +/- 15% before and 3 +/- 2% after genistein (P < 0.01) and 63 +/- 15% before and 18 +/- 4% after tyrphostin B46 (P < 0.05). In contrast, KCl-induced contractions were 82 +/- 8% and 96 +/- 9% of the control value after genistein and tyrphostin B46 treatments, respectively (P > 0.05 for both). Carbachol contractions were partially suppressed by genistein (106 +/- 8% vs. 79 +/- 8%; P < 0.05) but unaffected by tyrphostin B46 (114 +/- 10% vs. 107 +/- 12%; P > 0.05). Western blot analysis revealed a 116-kDa phosphotyrosine protein in the control muscle strips. The level of this protein was increased to 206 +/- 15% of control after SNP treatment. Both genistein and tyrphostin B46 blocked this increase. These studies show that contractions of the esophageal longitudinal muscle induced by SNP and cGMP utilize a signal transduction pathway different from that used by the depolarizing agent KCl and the muscarinic agonist carbachol. Contractions induced by SNP and cGMP involve tyrosine phosphorylation of a protein, possibly identified as a 116-kDa protein, as a key step in the signaling pathway.
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Affiliation(s)
- I Hirano
- Center for Swallowing and Motility Disorders, Brockton/West Roxbury Veterans Affairs Medical Center, West Roxbury, Massachusetts 02132, USA
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Bains JS, Kakkar R, Sharma SP. Increased longevity, reduced fecundity, and delayed development in fruitfly (Zaprionus paravittiger) fed on butylated hydroxy anisole. Proc Soc Exp Biol Med 1997; 215:237-42. [PMID: 9207858 DOI: 10.3181/00379727-215-44133] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Oxygen free radicals are generated as a by-product during normal metabolism, and they cause damage to proteins, lipids, and DNA in organisms. The defense system of the body counteracts these highly reactive chemical moieties and neutralizes them. However, a small fraction of free radicals escapes, which causes lipid peroxidation and hence aging of the organism. It has been hypothesized that, if the free radicals are arrested/reduced, then aging can be delayed or life span could be enhanced. To test the above hypothesis, we fed butylated hydroxy anisole (BHA) to a drosophilid insect, Zaprionus paravittiger, and observed its effect on life span, fecundity, and developmental period. The insects were reared and maintained on standard corn meal agar (CMA) medium at 26 degrees +/- 2 degrees C. Various concentrations (1, 5, 10, 25, 50, and 100 mM) of BHA were mixed with CMA medium, and the cultures were reared and maintained on these mixtures to study the life span of insects. Survivor curves showed that lower concentrations (5, 10, 25 mM) of BHA increased the life span, while higher concentrations (50, 100 mM), which were rather toxic, decreased life span. The most suitable concentration was 10 mM, which increased median (LT50) (27% and 15% in male and female) and maximum (LT100) (18% and 27% in male and female) life spans of insects maximally. Females exhibited longer life spans compared with males. The cultures were fed on the optimal concentration (10 mM) of BHA to study its effect on developmental period and egg-laying rate. The total developmental period was delayed by 7.2%, and egg-laying rate was reduced by 19.7% on BHA feeding. The extension in developmental period and reduction in egg-laying capacity could be the contributory factors to the favorable effect of BHA on life span.
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Affiliation(s)
- J S Bains
- Department of Pathology, University of Calgary, Alberta, Canada
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Kakkar R, Raju RV, Rajput AH, Sharma RK. Amantadine: an antiparkinsonian agent inhibits bovine brain 60 kDa calmodulin-dependent cyclic nucleotide phosphodiesterase isozyme. Brain Res 1997; 749:290-4. [PMID: 9138729 DOI: 10.1016/s0006-8993(96)01318-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The effect of amantadine (an antiparkinsonian agent) on calmodulin-dependent cyclic nucleotide phosphodiesterase isozymes was investigated. Amantadine inhibited bovine brain 60 kDa calmodulin-dependent cyclic nucleotide phosphodiesterase but not the bovine brain 63 kDa, heart and lung calmodulin-dependent cyclic nucleotide phosphodiesterase isozymes. The inhibition of bovine brain 60 kDa calmodulin-dependent cyclic nucleotide phosphodiesterase was overcome by increasing the concentration of calmodulin. This suggests that amantadine may be an antagonist of calmodulin or act specifically and reversibly on the action of calmodulin. The bovine brain 60 kDa calmodulin-dependent cyclic nucleotide phosphodiesterase isozyme is predominantly expressed in the brain and its inhibition may result in increased intracellular levels of cyclic AMP (cAMP). The increased intracellular levels of cAMP have a protective role for dopaminergic neurons. The present findings suggest that amantadine may be a valuable tool to investigate the physiological role of 60 kDa calmodulin-dependent cyclic nucleotide phosphodiesterase isozyme in the progression of Parkinson's disease and gives a new insight into the action of this drug.
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Affiliation(s)
- R Kakkar
- Department of Pathology, Saskatoon Cancer Centre, University of Saskatchewan, Canada
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Abstract
Oxygen free radicals (OFRs) have been suggested to be a contributory factor in complications of diabetes mellitus. In the present study, we investigated the lipid peroxide level measured as thiobarbituric acid reactive substances (TBARS) and activities of antioxidant enzymes viz., [superoxide dismutase (SOD), catalase (CAT) and glutathione-peroxidase (GSH-Px)] in the kidney of streptozotocin induced diabetic rats at various stages of development of diabetes. Sprague Dawley rats were divided into two groups: group I, control (n = 42) and group II, diabetic (n = 42). Each group was further subdivided into seven groups each consisting of six rats. Rats in subgroups were studied at weekly intervals (0 to 6 weeks). Blood glucose levels were estimated at the time of sacrifice. TBARS levels and activity of antioxidant enzymes were measured in kidney. The levels of TBARS in the diabetic group increased initially, dropped to baseline level after 2 weeks and then progressively increased at 5th and 6th week (p < 0.05). There was an increase in catalase activity at first week after that it decreased as compared to control group. However, GSH-Px activity in the diabetic group increased after 1 week and then remained at the same level except a small drop in the 2nd week. Total SOD and CuZn-SOD activity increased significantly in diabetic kidney as compared to controls at all time intervals, while Mn-SOD activity showed no change. The present findings suggest that oxidative stress accompanies at early onset of diabetes mellitus and the susceptibility of the kidney to oxidative stress during the early stages may be an important factor in the development of diabetic nephropathy.
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Affiliation(s)
- R Kakkar
- Department of Pathology and Physiology, College of Medicine, University of Saskatchewan, Saskatoon, Canada
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Bains JS, Kakkar R, Sharma SP. Gender specific alterations in antioxidant status of aging Zaprionus paravittiger fed on propyl gallate. Biochem Mol Biol Int 1996; 40:731-40. [PMID: 8950031 DOI: 10.1080/15216549600201333] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Zaprionus paravittiger fed on propyl gallate (PG) supplemented diet (2.5, 25 and 250 micrograms/ml) showed an increase in life span. Further increase in concentration (2500, 5000 and 7500 micrograms/ml) accelerated the mortality rate. Females exhibited longer life span as compared to males. Antioxidant enzymes (catalase, peroxidase and glutathione reductase) were measured in control and optimum concentration of PG (25 micrograms/ml) fed flies at various age intervals. Antioxidant enzyme activities showed an increase during reproductive phase. Catalase and glutathione reductase activities decreased with age however no significant change was observed in peroxidase activity. The females exhibited higher enzyme activities as compared to males in control and PG fed group at most of the age intervals. PG feeding caused a significant increase in catalase and glutathione reductase activities in both the sexes. These findings suggest the PG has dose dependent and sex specific influence on longevity of Z. paravittiger and support the view that longevity and activity of antioxidant enzymes are positively linked.
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Affiliation(s)
- J S Bains
- Department of Pathology, University of Calgary, AB, Canada
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31
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Abstract
1. Oxygen free radicals have been suggested to be a contributory factor in complications of diabetes mellitus. In the present study, we investigated the lipid peroxide level [thiobarbituric acid-reactive substances (TBARS)] and activities of antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase) in aorta, heart and blood of control and streptozotocin-induced diabetic rats at various stages of development of diabetes (0 to 6 weeks). 2. There was no change in the TBARS levels of aorta, heart and blood in the control group. A significant (P < 0.05) increase in TBARS levels of aorta, heart and blood was observed in the diabetic group. 3. There were no significant changes in the activities of superoxide dismutase, catalase and glutathione peroxidase in the aorta, heart and blood of control rats at all time intervals. In the diabetic group, there was a significant (P < 0.05) increase in the activity of superoxide dismutase and glutathione peroxidase in aorta from the fourth week onwards while the activity of catalase increased at all time intervals. In the heart of diabetic rats, the activity of total superoxide dismutase and Cu-Zn-superoxide dismutase increased significantly (P < 0.05) from the second week onwards while activity of Mn-superoxide dismutase decreased at the fourth week and increased at the sixth week. The activity of catalase and glutathione peroxidase increased significantly (P < 0.05) at all time intervals. In the blood, the activity of superoxide dismutase and glutathione peroxidase increased from the third week while catalase activity increased from the fourth week. 4. The present findings suggest that oxidative stress starts at early onset of diabetes mellitus and increases progressively.
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Affiliation(s)
- R Kakkar
- Department of Pathology and Physiology, University of Saskatchewan and Royal University Hospital, Saskatoon, Canada
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Abstract
Intracellular concentrations of cyclic nucleotides is regulated by cyclic nucleotide phosphodiesterases and calmodulin-dependent cyclic nucleotide phosphodiesterases (CaMPDE), one of the most intensively studied and best characterized phosphodiesterases. In the present study, the effect of an antiparkinsonian agent, deprenyl (selegeline hydrochloride) which is believed to be a selective inhibitor of monoamine oxidase-B, on bovine brain calmodulin-dependent cyclic nucleotide phosphodiesterase (CaMPDE) isozymes have been investigated. The findings indicated that deprenyl inhibited brain 60 kDa isozyme, however the inhibition for brain 63 kDa CaMPDE was observed to a lesser extent. The inhibition of brain 60 kDa CaMPDE was overcome by increasing the concentration of calmodulin suggesting that deprenyl may be calmodulin antagonist or act specifically and reversibly on the action of calmodulin. The 60 kDa CaMPDE isozyme is predominantly expressed in brain and its inhibition can result in increased intracellular levels of cAMP. The increased intracellular levels of cAMP have a protective role for dopaminergic neurons. Therefore, deprenyl may be a valuable tool to investigate the physiological roles of brain CaMPDE isozymes in progression of Parkinson's disease and gives a new insight into the action of this drug.
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Affiliation(s)
- R Kakkar
- Department of Pathology, Saskatoon Cancer Centre, Canada
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Abstract
Calmodulin-dependent protein kinase II was purified to apparent homogeneity with a high yield from the total calmodulin-binding protein fraction of bovine cardiac muscle in a single step by gel filtration column chromatography. This procedure is simple and suitable for adaptation to large scale preparations. The purified calmodulin-dependent protein kinase has a specific enzymic activity of 2.4 mumol/min/mg when mixed histone was used as a substrate. The preparation of enzyme appears to be homogeneous when examined by SDS-PAGE. The molecular weight of the enzyme was determined to be 570 kDa by gel filtration. SDS-PAGE of the enzyme subunit showed a single protein band with an apparent molecular weight of 56 kDa. These results suggest that the calmodulin-dependent protein kinase II from bovine heart is composed of 10 identical subunits. Anti-peptide antibody raised against multifunctional calmodulin-dependent protein kinase II from rat brain showed a single immunoreactive band of 56 kDa on Western blot. These results suggested that bovine cardiac muscle calmodulin-dependent protein kinase could resemble the brain isozyme. Calmodulin-dependent protein kinase II undergoes autophosphorylation with a maximal incorporation of 1 mol of phosphate per mol of the subunit of the enzyme and the autophosphorylated enzyme remains active in the absence of Ca2+ and calmodulin. The concentration of Ca2+ required for the activation of calmodulin-dependent protein kinase II depends on the level of calmodulin in the reaction.
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Affiliation(s)
- R Kakkar
- Department of Pathology, Saskatoon Cancer Centre, College of Medicine, University of Saskatchewan, Canada
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Kakkar R, Bains JS, Sharma SP. Effect of vitamin E on life span, malondialdehyde content and antioxidant enzymes in aging Zaprionus paravittiger. Gerontology 1996; 42:312-21. [PMID: 8930618 DOI: 10.1159/000213809] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Zaprionus paravittiger fed with vitamin E supplemented diet (1, 5 and 10 micrograms/ml) showed an increase in median and maximum life spans. Further increase in concentration accelerated the mortality rate. Females exhibited longer life span as compared to males. Malondialdehyde (MDA) content and antioxidant enzymes (catalase and peroxidase) were measured in control and optimum concentration of vitamin E (5 micrograms/ml)-fed flies at various age intervals. MDA content showed an increase with age in control and vitamin E-fed group whereas catalase and proxidase activities showed a decrease with age. The females exhibited lower MDA content and higher activities of catalase and peroxidase as compared to males in control and vitamin E group. Vitamin E feeding caused a significant decrease in MDA and increase in catalase and peroxidase activities. These findings suggest that vitamin E has dose-dependent and sex-specific influence on longevity of Z. paravittiger and support the view that longevity and activity of antioxidant enzymes are positively linked.
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Affiliation(s)
- R Kakkar
- Saskatoon Cancer Centre-Research Unit, University of Saskatchewan, Canada
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Abstract
We hypothesized that oxygen free radicals (OFRs) may be involved in pathogenesis of diabetic complications. We therefore investigated the levels of lipid peroxidation by measuring thiobarbituric acid reactive substances (TBARS) and activity of antioxidant enzymes [superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT)] in tissues and blood of streptozotocin (STZ)-induced diabetic rats. The animals were divided into two groups: control and diabetic. After 10 weeks (wks) of diabetes the animals were sacrificed and liver, heart, pancreas, kidney and blood were collected for measurement of various biochemical parameters. Diabetes was associated with a significant increase in TBARS in pancreas, heart and blood. The activity of CAT increased in liver, heart and blood but decreased in kidney. GSH-Px activity increased in pancreas and kidney while SOD activity increased in liver, heart and pancreas. Our findings suggest that oxidative stress occurs in diabetic state and that oxidative damage to tissues may be a contributory factor in complications associated with diabetes.
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Affiliation(s)
- R Kakkar
- Department of Pathology, College of Medicine, University of Saskatchewan, Saskatoon, Canada
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Kalra J, Kakkar R, Prasad K. Oxidative stress in the pancreas of experimentally induced diabetic rats. Clin Biochem 1995. [DOI: 10.1016/0009-9120(95)91403-p] [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: 11/28/2022]
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Sharma SP, Sharma M, Kakkar R. Methionine-induced alterations in the life span, antioxidant enzymes, and peroxide levels in aging Zaprionus paravittiger (Diptera). Gerontology 1995; 41:86-93. [PMID: 7744272 DOI: 10.1159/000213668] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The median and maximum life spans of both sexes of Zaprionus paravittiger increased with methionine (100 mM) feeding. It was accompanied by higher catalase and peroxidase enzyme activities. The lipid peroxide level as measured by malondialdehyde content and the inorganic peroxides showed an increase with age and a decrease in methionine-fed insects. The reduction was, however, more pronounced in females than in males. The findings indicate that a life-prolonging effect of methionine on Z. paravittiger may be by virtue of its free radical scavenging effect.
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Affiliation(s)
- S P Sharma
- Department of Zoology, Guru Nanak Dev University, Amritsar, India
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Kakkar R, Kalra J, Mantha S, Prasad K. Alterations in antioxidant enzymes and malondialdehyde content diabetic heart: A time course study. Clin Biochem 1994. [DOI: 10.1016/0009-9120(94)90076-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Uppal SS, Pande I, Kakkar R, Yechoor V, Kumar A, Saxena A, Wali JP, Malaviya AN. Infective endocarditis in a case of systemic lupus erythematosus. J Assoc Physicians India 1993; 41:470. [PMID: 8300503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- S S Uppal
- Dept. of Medicine, All India Institute of Medical Sciences, New Delhi
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Trivedi N, Kakkar R, Srivastava MK, Mithal A, Raizada RB. Effect of oral administration of fungicide-mancozeb on thyroid gland of rat. Indian J Exp Biol 1993; 31:564-6. [PMID: 8406605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- N Trivedi
- Pesticide Toxicology Laboratory, Industrial Toxicology Research Centre, Lucknow, India
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Narayanaswamy AS, Prakash MP, Kakkar R. Neurological manifestations of leukemia--clinical and pathological findings. J Assoc Physicians India 1992; 40:740-2. [PMID: 1307537] [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: 12/26/2022]
Abstract
Out of 70 cases of leukemia studied, 19 had neurological manifestations. All cases were autopsied. Leukemic infiltrates and intracranial hemorrhages produced various neurological manifestations. In autopsied cases 37.2% showed infiltrative changes. Intracranial hemorrhages contributed to 20%, the cause of which were due to thrombocytopenia and leukostasis. Leukemic nodules, demyelination and astrocytosis, gliosis were also seen on histopathology.
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Abstract
Survival in patients with systemic lupus erythematosus (SLE) in developed countries has improved considerably over the last 2 decades. In India, however, survival in patients with SLE reported 5 years ago from this tertiary referral centre was very poor. The present study was conducted to examine trends, if any, towards improvement in the survival of patients with SLE attending the same centre during the period 1981-1990. No statistically significant change in survival was noted. It appears that improvement in the survival of SLE patients would require an overall improvement in the standard of medical care in India.
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Affiliation(s)
- A Kumar
- Department of Medicine, All India Institute of Medical Sciences, New Delhi
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Bhalla IP, Chopra A, Kakkar R, Narayanan VA, Sinha KN, Krishnan NR. Current status of autoimmunity in endocrinopathies. J Assoc Physicians India 1988; 36:329-32. [PMID: 3053633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Lahiry S, Kakkar R. Magnetism of ferroelectric guanidinium vanadium(III) sulphate hexahydrate (GVSH) and its diluted salt V3+: GASH. Chem Phys Lett 1982. [DOI: 10.1016/0009-2614(82)83394-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Kakkar R, Ahuja IS. Myelofibrosis. J Indian Med Assoc 1970; 55:204-6. [PMID: 5501471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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