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Sushanth VH, Krishna M, Suresh Babu AM, Prashant GM, Chandu GN. A peer group approach model of oral health promotion among orphans at Puduchery, South India. J Int Soc Prev Community Dent 2011; 1:71-5. [PMID: 24478958 PMCID: PMC3894071 DOI: 10.4103/2231-0762.97710] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND Interactions between oral and systemic health are bi-directional and complex, involving many pathways. The orphans have been sympathized with, ignored, vitrified or even hidden away in the community. Hence, providing health care services for orphans remains a challenge. Oral health education has a positive impact in lowering plaque and gingivitis scores in health educational programs. OBJECTIVE The objective of this study is to assess the effectiveness of peer group health promotion model among 11 to 16 year old orphans at Puduchery, South India. MATERIALS AND METHODS A clinical trial of 6 months duration was carried out among 72 orphans with age ranging from 11 to 16 years residing in Cluny Padmini Sneha Illam, at Puduchery, India. The baseline data regarding oral health and oral hygiene practices were obtained using a pre-tested close-ended questionnaire. Oral health education was provided to 4 randomly picked children who in turn provided the same to their peer group orphans, supervised by the investigator. Tooth brushes and fluoridated tooth pastes were provided to all the participants throughout the study period. Oral hygiene of the participants was assessed using Modified Plaque Index by Loe H and Gingival Index by Loe H and Silness at baseline, 3(rd) and 6(th) month interval. Paired Student t test was used to analyze the categorical data. RESULTS Majority of the respondents felt consuming sugar was not harmful for dental health, while 15 respondents were not sure about the outcome. When asked if oral hygiene was important for general health, 45.8% were not aware of its association. Although all the participants brushed their teeth daily, none of them reported the use of dental floss. The findings of this study indicated a statisticallysignificant lower mean plaque score of 0.54 ± 0.20 at 6(th) month when compared to the baseline score of 1.76 ± 0.24. Similarly, statistically significant lower gingival index score of 0.65 ± 0.11 at 6(th) month was observed when compared to the baseline score of 1.76 ± 0.24. CONCLUSIONS The results of this study indicate that oral hygiene of orphans was improved using a peer group approach model of oral health promotion.
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Achem SR, Almansa C, Krishna M, Heckman MG, Wolfsen HC, Talley NJ, DeVault KR. Oesophageal eosinophilic infiltration in patients with noncardiac chest pain. Aliment Pharmacol Ther 2011; 33:1194-201. [PMID: 21466568 DOI: 10.1111/j.1365-2036.2011.04652.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
BACKGROUND Eosinophilic oesophagitis clinically presents with recurrent episodes of dysphagia and food impaction. Recently, we observed patients with noncardiac chest pain and eosinophilic oesophagitis. AIMS To estimate the prevalence of abnormal eosinophilic infiltration in noncardiac chest pain patients and examine diagnostic utility of demographic, clinical and endoscopic variables to predict eosinophilic oesophagitis. METHODS Retrospective study of 171 consecutive patients referred for EGD evaluation of noncardiac chest pain. Endoscopic signs consistent with eosinophilic oesophagitis were recorded. The histological findings were grouped as normal: 0-5 eosinophils/high power field (e/hpf), indeterminate: 6-20 e/hpf, and eosinophilic oesophagitis: ≥21 e/hpf. Abnormal eosinophilic infiltration was defined as ≥6 e/hpf. RESULTS Abnormal eosinophilic infiltrate was noted in 24 patients (14%). Thirteen (8%) had indeterminate counts, while 11 (6%) had eosinophilic oesophagitis. Compared with normal, those with abnormal oesophageal eosinophilic infiltration were more likely to be male (71% vs. 34%, P=0.001), have allergies (29% vs. 12%, P=0.050), have current GER symptoms (42% vs. 18%, P=0.013), rings (54% vs. 22%, P=0.002), furrows (21% vs. 1%, P<0.001) and abnormal eosinophilic oesophagitis findings on endoscopy (67% vs. 32%, P=0.001). Of the 24 abnormal patients, 23 (96%) were either male or had rings, furrows, or white specks. Conversely, 68 of 69 patients (99%) who were female did not have rings, furrows, or white specks, and endoscopy was normal. Eight patients (33%) with abnormal eosinophilic infiltration had a normal endoscopy. CONCLUSIONS Eosinophilic oesophagitis should be considered in the evaluation of noncardiac chest pain. Our findings suggest that oesophageal biopsies should be obtained particularly in males with recurrent unexplained chest pain, whether endoscopy is normal or abnormal.
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Sathyamurthy R, Manney S, Wood A, Perkins G, Webster C, Krishna M, Mansur A. P14 Does Vitamin D Axis have an effect on the severity of Asthma? Thorax 2010. [DOI: 10.1136/thx.2010.150961.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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kumar PR, Rao CSP, Reddy PC, Krishna M, Moiz M. A precision athletic track marking system. Br J Sports Med 2010. [DOI: 10.1136/bjsm.2010.078725.160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Al-Haddad M, Gill KR, Raimondo M, Woodward TA, Krishna M, Crook JE, Skarvinko LN, Jamil LH, Hasan M, Wallace MB. Safety and efficacy of cytology brushings versus standard fine-needle aspiration in evaluating cystic pancreatic lesions: a controlled study. Endoscopy 2010; 42:127-32. [PMID: 19998218 DOI: 10.1055/s-0029-1215351] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND AND STUDY AIMS Cystic pancreatic lesions (CPLs) are increasingly detected by various imaging studies. Mucinous CPLs carry a risk of malignant transformation but this is often difficult to diagnose preoperatively. In a previous report of 10 suspected mucinous CPLs, the cellular yield of endoscopic ultrasonography (EUS)-guided cytology brushings was found to be superior to the yield from standard fine-needle aspiration (FNA). The aim of this prospective and blinded study was to compare the cytology yield of mucinous epithelium from brushing with FNA in suspected mucinous CPLs. PATIENTS AND METHODS In total, 37 patients with 39 CPLs measuring at least 20 mm were enrolled between June 2006 and July 2008 for EUS-cytobrushing and EUS-FNA of CPLs. Demographic, clinical, EUS, cytopathologic, and surgical data were recorded whenever available. Yield of cytology brushings was compared with that of FNA. Procedure morbidity was evaluated after 30 days. The main outcome assessed was yield of intracellular mucin (ICM) on cytobrushing specimens compared with EUS-FNA for the diagnosis of suspected mucinous CPL. RESULTS Cytobrushings were more likely to detect ICM than the EUS-FNA method ( P = 0.001). In three patients with hypocellular FNA, dysplasia was found on cytology brushing and later confirmed by surgical pathology. Significant complications occurred in three patients (8 %): one postbrushing bleeding and two acute pancreatitis. CONCLUSIONS Cytology brushings are more likely to provide an adequate mucinous epithelium specimen than standard FNA and could aid the diagnosis of CPLs in a selective group of patients.
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Seddon SV, Krishna M, Davies HA, Borriello SP. Effect of Nutrition on the Expression of Known and Putative Virulence Factors ofClostridium difficile. MICROBIAL ECOLOGY IN HEALTH AND DISEASE 2009. [DOI: 10.3109/08910609109140280] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Abstract
The mitogen-activated protein kinase (MAPK) pathways are known to be involved in various processes of growth, differentiation and cell death. In spite of their ubiquitous presence and seemingly enormous cross-talk with each other, their action is very specific. This review deals with various aspects of the three different MAPK pathways (ERK, p38 and JNK) and how their specificity is brought about.
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Kunwar A, Narang H, Priyadarsini KI, Krishna M, Pandey R, Sainis KB. Delayed activation of PKCdelta and NFkappaB and higher radioprotection in splenic lymphocytes by copper (II)-Curcumin (1:1) complex as compared to curcumin. J Cell Biochem 2008; 102:1214-24. [PMID: 17471506 DOI: 10.1002/jcb.21348] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A mononuclear 1:1 copper complex of curcumin had been found to be superior to curcumin in its anti-oxidant properties. This paper describes the radio-protective effects of the complex in splenic lymphocytes from swiss mice. The complex was found to be very effective in protecting the cells against radiation-induced suppression of glutathione peroxidase, catalase and superoxide dismutase (SOD) activities. Both curcumin and the complex protected radiation-induced protein carbonylation and lipid peroxidation in lymphocytes with the complex showing better protection than curcumin. It also showed better overall protection by decreasing the radiation-induced apoptosis. The kinetics of activation of PKCdelta and NFkappaB after irradiation in presence or absence of these compounds was looked at to identify the molecular mechanism involved. The modulation of irradiation-induced activation of PKCdelta and NFkappaB by curcumin and the complex was found different at later time periods although the initial response was similar. The early responses could be mere stress responses and the activation of crucial signaling factors at later time periods may be the determinants of the fate of the cell. In this study this delayed effect was observed in case of complex but not in case of curcumin. The delayed effect of the complex along with the fact that it is a better free radical scavenger must be the reason for its better efficacy. The complex was also found to be less cytotoxic then curcumin at similar concentration.
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Ghabril M, Gross S, Krishna M, Raimondo M. Hyperplastic Polyposis following Treatment of Gastric Vascular Ectasia: A Case Report and Review of Clinical Correlates. Case Rep Gastroenterol 2007; 1:48-52. [PMID: 21487471 PMCID: PMC3073787 DOI: 10.1159/000105560] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The etiology of gastric antral vascular ectasia (GAVE) and hyperplastic polyps (HP) is not fully understood, but there is no known overlap. We report a case of gastroduodenal HP arising in a patient treated for GAVE.
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Krishna M, Keaveny AP, Genco PV, Rosser BG, Dickson RC, Nguyen JH, Steers JL, Nakhleh RE. Clinicopathological review of 18 cases of liver allografts lost due to bile duct necrosis. Transplant Proc 2005; 37:2221-3. [PMID: 15964383 DOI: 10.1016/j.transproceed.2005.03.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2004] [Indexed: 11/27/2022]
Abstract
Clinical, radiographic, and pathological features of 18 patients with biliary necrosis in their explanted liver allografts were reviewed. Twelve patients were men and ages ranged from 27 to 72 years. Indications for initial liver transplant (LT) were viral hepatitis (n = 7), steatohepatitic cirrhosis (n = 3), cryptogenic cirrhosis (n = 3), secondary sclerosing cholangitis (n = 2), primary sclerosing cholangitis (n = 1), biliary atresia (n = 1), and nodular regenerative hyperplasia (n = 1). Donor age ranged from 16 to 75 years. Duct-to-duct biliary anastomoses were fashioned in 13 cases; warm and cold ischemia times were not significantly different from general LT population. Seventeen allograft biopsies after recirculation had no significant findings. Post-LT, clinical and radiographic evaluation indicated biliary strictures (n = 7), bile leak (n = 7), intrahepatic abscess (n = 1), and duodenal perforation (n = 1). Radiographic vascular studies suggested hepatic arterial thrombosis or stenosis in 11 cases. Biopsies prior to retransplantation were performed on 17 patients and showed acute rejection (n = 10), biliary outflow impairment (n = 4), normal histology (n = 2), and centrilobular necrosis (n = 1). Retransplantation was performed 14 to 334 days after initial LT. Pathological examination of explants revealed perihilar duct necrosis in all cases, with bacterial colonies (n = 10) and fungal organisms (n = 2). Arterial thrombi were seen in 10 cases, and two had prominent arteriosclerosis. Infarction and centrilobular necrosis were seen in 9 and 13 cases, respectively. Four explants showed features of biliary outflow impairment. Twelve patients were alive 6 to 18 months following retransplantation. We conclude that post-LT biliary necrosis is associated with ischemia, and such a complication is rarely evident in allograft biopsies. Biliary and vascular imaging studies are essential in evaluating patients for this complication.
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Tun HW, Krishna M, Menke DM. Hepatitis C-related posttransplant plasma cell proliferative disorder with hepatitis C virus in neoplastic plasma cells: a new posttransplant disease entity? Transplant Proc 2005; 36:2692-6. [PMID: 15621126 DOI: 10.1016/j.transproceed.2004.09.058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Plasma cell proliferative disorder (PCPD) developed in two patients with actively replicating hepatitis C virus (HCV) in neoplastic plasma cells after orthotopic liver transplantation for HCV-related end-stage liver disease. PCPD was confined to the transplanted liver and was associated with monoclonal proteins in blood. Bone marrow biopsy did not show any evidence of PCPD. Epstein-Barr virus was not detected by in situ hybridization in either case. In situ hybridization for HCV RNA with sense and antisense probes in liver biopsy specimens showed signals in neoplastic plasma cells as well as in hepatocytes. We suggest that our patients had posttransplant PCPD resulting from HCV. It may represent a new posttransplant disease entity different from previously described posttransplant lymphoproliferative disorder. The findings raise intriguing questions about the role of HCV in PCPDs in patients with chronic HCV infection.
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Krishna M, Theodore S, Varma PK, Neelakandhan KS. Spontaneous iliac arteriovenous fistula: recognition and management. THE JOURNAL OF CARDIOVASCULAR SURGERY 2005; 46:181-2. [PMID: 15793499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
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Nakhleh RE, Krishna M, Keaveny AP, Dickson RC, Rosser B, Nguyen JH, Steers JL. Review of 31 Cases of Morphologic Hepatitis in Liver Transplant Patients Not Related to Disease Recurrence. Transplant Proc 2005; 37:1240-2. [PMID: 15848682 DOI: 10.1016/j.transproceed.2004.12.113] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
AIMS We examined the clinical and pathologic features of morphologic hepatitis occurring after liver transplantation (LT) that is unrelated to disease recurrence. METHODS Between February 1998 and December 2003, 704 primary LTs were performed at our center. Patients transplanted for diagnoses with low risk of disease recurrence were considered for our study (n = 282). Those with hepatitis C (HCV), hepatitis B (HBV), primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC), and autoimmune hepatitis (AIH) were excluded. Those with morphologic hepatitis comprised our case series and had medical records reviewed for clinical associations, duration, and outcome. RESULTS Thirty-one cases were identified. They were transplanted for cryptogenic cirrhosis (n = 13), steatohepatitis (n = 12), alpha-1-antitrypsin deficiency (n = 3), tumor (n = 2), and acetaminophen toxicity (n = 1); 22 cases (67%) presented within the first 8 months post-LT (range, 0.5-72 months). Histological activity was mild in 19 and moderate in 12. Associated conditions were identified in 19 patients (57%) with 3 categories being identified: probable drug toxicity (n = 7), systemic infection (n = 4), and mechanical or hemodynamic abnormalities (n = 8). Of the 25 cases that underwent follow-up biopsy 2 to 32 months (mean, 15.5 months) after the index biopsy, 10 cases had resolution and 15 cases had persistence of the infiltrate. One patient had evidence of de novo HBV infection. CONCLUSIONS Morphologic hepatitis occurred in 11% of patients at low risk for disease recurrence. Associated conditions could be grouped into three categories: drug toxicity, systemic infection, and mechanical or hemodynamic factors. Most cases did not appear to progress or improved over time, with no allograft loss occurring as a result of chronic hepatitis.
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Wolfsen HC, Hemminger LL, Geiger XJ, Krishna M, Woodward TA. Photodynamic therapy and endoscopic metal stent placement for esophageal papillomatosis associated with squamous cell carcinoma. Dis Esophagus 2004; 17:187-90. [PMID: 15230738 DOI: 10.1111/j.1442-2050.2004.00400.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Esophageal squamous papillomatosis is a rare condition associated with human papilloma virus infection and has been complicated by the development of squamous cell carcinoma. Photodynamic therapy using porfimer sodium has been used for the treatment of esophageal cancer but has not been utilized in the treatment of esophageal squamous papillomatosis. We report here the first case of papillomatosis and obstructing squamous cell carcinoma of the esophagus palliated with porfimer sodium photodynamic therapy indicating successful photosensitizer uptake in papilloma-laden tissue. Extensive debulking of papilloma and tumor allowed esophageal recanalization and placement of a self-expanding metal stent for long-term dysphagia palliation. This unique case highlights the combined use of endoscopic techniques for optimal treatment results.
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Narang H, Krishna M. Mitogen-activated protein kinases: specificity of response to dose of ionizing radiation in liver. JOURNAL OF RADIATION RESEARCH 2004; 45:213-220. [PMID: 15304963 DOI: 10.1269/jrr.45.213] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Ionizing radiation is known to activate both the cytotoxic stress-activated kinases (SAPK/JNK, p38) and the cytoprotective mitogen-activated protein kinases (MAPKs, ERKs), which send divergent signals to the nucleus. However, all these kinases could not be activated simultaneously and at all the doses. An attempt has been made in this study to establish the dose and temporal response of these kinases with a view to establish the identity of the transcription factors that remain activated because only these will be translated into an effect. The study indicates that the stress-activated kinases (SAPK/JNK and p38) are activated by very low doses (0.1 Gy) of ionizing radiation. An induction of expression of MKK4, precursor to SAPK and p38, was found at lower doses (0.1-0.5 Gy). However, the cytoprotective ERK2 showed a progressive increase in expression with dose, except at 3 Gy where it shows a marginal decline. The stress-activated kinases show an increased expression or activation at early periods, unlike ERK2, which shows a prolonged response to stimuli. This study reveals that in the in vivo condition there is a chronological order of activation of the kinases and a dose-dependent activation. The activations of the cytoplasmic kinases and the transcription factors, Elk-1 and c-Jun, both show prolonged activation and maximum response at high doses.
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Sarma AK, Krishna M, Jayakumar K, Neelakandhan KS. An unusual presentation of severe hypothyroidism following cardiopulmonary bypass. Indian J Thorac Cardiovasc Surg 2004. [DOI: 10.1007/s12055-004-0328-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Krishna M, Bhatia BD, Gupta J, Satya K. Predicting low birth weight delivery using maternal nutritional and uterine parameters. INDIAN JOURNAL OF MATERNAL AND CHILD HEALTH : OFFICIAL PUBLICATION OF INDIAN MATERNAL AND CHILD HEALTH ASSOCIATION 2002; 2:87-91. [PMID: 12346055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
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Varadkar P, Dubey P, Krishna M, Verma N. Modulation of radiation-induced protein kinase C activity by phenolics. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2001; 21:361-370. [PMID: 11787891 DOI: 10.1088/0952-4746/21/4/304] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Natural phenolic compounds were tested in vitro for their effect on the activity of protein kinase C (PKC) isolated from the liver cytosol and the particulate fraction of unirradiated mice and mice irradiated at 5 Gy. Following irradiation, the PKC activity was found to be increased in both cytosolic and particulate fractions. Curcumin, ellagic acid and quercetin were effective in inhibiting radiation-induced PKC activity. Curcumin and ellagic acid were found to be more inhibitory towards radiation-induced PKC activity, while quercetin was the least effective. Curcumin was found to inhibit the activated cytosolic and particulate PKC at very low concentrations. Activation of PKC is one of the means of conferring radioresistance on a tumour cell. Suppression of PKC activity by phenolics may be one of the means of preventing the development of radioresistance following radiotherapy.
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Mistry KJ, Krishna M, Bhattacharya RK. Effect of aflatoxin B1 on phosphoinositide signal transduction pathway during regeneration of liver cells following partial hepatectomy. INDIAN JOURNAL OF BIOCHEMISTRY & BIOPHYSICS 2001; 38:270-3. [PMID: 11811624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Aflatoxin B1 (AFB1) when administered to partially hepatectomised rats 4 hr prior to sacrifice, activated the signalling pathway in regenerating rat liver. The activity of phosphatidylinositol (PI) kinase was found decreased at 30 min but increased at 24 hr and returned to normal at 48 hr. At 30 min, inositol-1,4,5-triphosphate (IP3) level increased significantly whereas diacylglycerol (DAG) level dropped. However, at 24 hr and 48 hr, DAG and IP3 showed the same trend i.e. an increase in their levels. Phosphatidylinositol-4-phosphate levels were found to increase at 24 hr. Protein kinase C (PKC), activity from the particulate fraction was significantly inhibited at 30 min, followed by increase in activity at 24 hr and return to normal at 48 hr. Cytosolic PKC showed a decrease at 24 hr and a significant increase at 48 hr. At the peak of DNA synthesis (24 hr) following partial hepatectomy, all these signalling steps had earlier been found to be inhibited, but the present study shows that aflatoxin B1 administration 4 hr prior to sacrifice reverses the action. Activation of PKC by aflatoxin B1, during regeneration of liver cells when PKC in normally inhibited, may possibly create conditions conducive to carcinogenesis.
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Varadkar P, Krishna M, Verma NC. Alterations in hepatic kinase activity following whole body gamma-irradiation of mice. Antioxid Redox Signal 2001; 3:483-92. [PMID: 11491659 DOI: 10.1089/15230860152409112] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The chronological activation of the signaling molecules following whole body gamma-irradiation was investigated in mouse liver. The activity of two kinases, tyrosine kinase and protein kinase C (PKC), was found to respond differently to gamma-irradiation. Tyrosine kinase was found to respond to much lower doses of irradiation (10 cGy), whereas PKC was found to be activated at comparatively higher doses (3 Gy). Tyrosine kinase showed a sharp activation at 30 min and then a decline to normal values at 1 h. Activation of PKC was apparent at as early as 15 min of irradiation and showed a maximal increase at 30 min. This was followed by a decline to normal values at 1 h. The response of the whole organ was found to be different from that of reported effects on a single cell. These results suggest that the data obtained from the single-cell studies would have limited application in the experiments involving the whole animal. Interruption of these signals at various steps is currently being used to manipulate tumor response to radiotherapy. In such cases, the difference in response of a single cell and a whole animal must be considered.
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Miranda KM, Espey MG, Yamada K, Krishna M, Ludwick N, Kim S, Jourd'heuil D, Grisham MB, Feelisch M, Fukuto JM, Wink DA. Unique oxidative mechanisms for the reactive nitrogen oxide species, nitroxyl anion. J Biol Chem 2001; 276:1720-7. [PMID: 11042174 DOI: 10.1074/jbc.m006174200] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The nitroxyl anion (NO-) is a highly reactive molecule that may be involved in pathophysiological actions associated with increased formation of reactive nitrogen oxide species. Angeli's salt (Na2N2O3; AS) is a NO- donor that has been shown to exert marked cytotoxicity. However, its decomposition intermediates have not been well characterized. In this study, the chemical reactivity of AS was examined and compared with that of peroxynitrite (ONOO-) and NO/N2O3. Under aerobic conditions, AS and ONOO- exhibited similar and considerably higher affinities for dihydrorhodamine (DHR) than NO/N2O3. Quenching of DHR oxidation by azide and nitrosation of diaminonaphthalene were exclusively observed with NO/N2O3. Additional comparison of ONOO- and AS chemistry demonstrated that ONOO- was a far more potent one-electron oxidant and nitrating agent of hydroxyphenylacetic acid than was AS. However, AS was more effective at hydroxylating benzoic acid than was ONOO-. Taken together, these data indicate that neither NO/N2O3 nor ONOO- is an intermediate of AS decomposition. Evaluation of the stoichiometry of AS decomposition and O2 consumption revealed a 1:1 molar ratio. Indeed, oxidation of DHR mediated by AS proved to be oxygen-dependent. Analysis of the end products of AS decomposition demonstrated formation of NO2- and NO3- in approximately stoichiometric ratios. Several mechanisms are proposed for O2 adduct formation followed by decomposition to NO3- or by oxidation of an HN2O3- molecule to form NO2-. Given that the cytotoxicity of AS is far greater than that of either NO/N2O3 or NO + O2, this study provides important new insights into the implications of the potential endogenous formation of NO- under inflammatory conditions in vivo.
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Jurgens S, Hennessy CH, Broadway P, Krishna M, Wadhwani S. Paediatric trauma in a district hospital: three cases of small bowel injury. Paediatr Anaesth 2000; 10:701-2. [PMID: 11119237 DOI: 10.1111/j.1460-9592.2000.ab01z.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Packard CJ, O'Reilly DS, Caslake MJ, McMahon AD, Ford I, Cooney J, Macphee CH, Suckling KE, Krishna M, Wilkinson FE, Rumley A, Lowe GD. Lipoprotein-associated phospholipase A2 as an independent predictor of coronary heart disease. West of Scotland Coronary Prevention Study Group. N Engl J Med 2000; 343:1148-55. [PMID: 11036120 DOI: 10.1056/nejm200010193431603] [Citation(s) in RCA: 600] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Chronic inflammation is believed to increase the risk of coronary events by making atherosclerotic plaques in coronary vessels prone to rupture. We examined blood constituents potentially affected by inflammation as predictors of risk in men with hypercholesterolemia who were enrolled in the West of Scotland Coronary Prevention Study, a trial that evaluated the value of pravastatin in the prevention of coronary events. METHODS A total of 580 men who had had a coronary event (nonfatal myocardial infarction, death from coronary heart disease, or a revascularization procedure) were each matched for age and smoking status with 2 control subjects (total, 1160) from the same cohort who had not had a coronary event. Lipoprotein-associated phospholipase A2, C-reactive protein, and fibrinogen levels, and the white-cell count were measured at base line, along with other traditional risk factors. The association of these variables with the risk of coronary events was tested in regression models and by dividing the range of values according to quintiles. RESULTS Levels of C-reactive protein, the white-cell count, and fibrinogen levels were strong predictors of the risk of coronary events; the risk in the highest quintile of the study cohort for each variable was approximately twice that in the lowest quintile. However, the association of these variables with risk was markedly attenuated when age, systolic blood pressure, and lipoprotein levels were included in multivariate models. Levels of lipoprotein-associated phospholipase A2 (platelet-activating factor acetylhydrolase), the expression of which is regulated by mediators of inflammation, had a strong, positive association with risk that was not confounded by other factors. It was associated with almost a doubling of the risk in the highest quintile as compared with the lowest quintile. CONCLUSIONS Inflammatory markers are predictors of the risk of coronary events, but their predictive ability is attenuated by associations with other coronary risk factors. Elevated levels of lipoprotein-associated phospholipase A2 appear to be a strong risk factor for coronary heart disease, a finding that has implications for atherogenesis and the assessment of risk.
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