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Traupe T, Barton M. Protease-activated receptors and EDHF: the icing on the cake? Cardiovasc Res 2004; 61:645-7. [PMID: 14985059 DOI: 10.1016/j.cardiores.2004.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2003] [Accepted: 01/07/2004] [Indexed: 11/22/2022] Open
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O'Brien P, Roos D, Pratt G, Liew K, Barton M, Poulsen M, Olver I, Trotter G. 712 Improved survival at the cost of neurotoxicity in primary CNS lymphoma (PCNSL). Long-term follow-up of a Phase 2 multicentre combined modality study (Trans-Tasman Radiation Oncology Group-TROG). EJC Suppl 2003. [DOI: 10.1016/s1359-6349(03)90743-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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203
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Barton M, Thame M, Melbourne-Chambers R, Gabay L, Gray R. Recent upsurge of tuberculosis in paediatric admissions at the University Hospital of the West Indies. W INDIAN MED J 2003; 52:244-8. [PMID: 14649110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
These case reports describe the clinical course of eight children who were admitted to the University Hospital of the West Indies, Kingston, Jamaica, between July 2000 and November 2001 because of a diagnosis of tuberculosis. This represented an increase in the incidence of the disease in children at this institution. The purpose of this report is to make healthcare workers aware of the resurgence of tuberculosis. The diagnosis of paediatric tuberculosis is challenging and requires a high index of suspicion in the presence of suggestive clinical and laboratory findings. The diagnosis should not be limited to the immunocompromised patient, as in this report the majority of the patients were HIV negative.
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Barton M, Carmona R, Ortmann J, Krieger JE, Traupe T. Obesity-associated activation of angiotensin and endothelin in the cardiovascular system. Int J Biochem Cell Biol 2003; 35:826-37. [PMID: 12676169 DOI: 10.1016/s1357-2725(02)00307-2] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The renin-angiotensin system (RAS) and the endothelin system have been implicated in the pathogenesis of human cardiovascular and renal diseases, and inhibition of the RAS markedly improves morbidity and survival. Obesity in humans is associated with an increased risk for the development of hypertension, atherosclerosis and focal-segmental glomerulosclerosis, however the exact mechanisms underlying these pathologies in obese individuals are not known. This article discusses the clinical importance of obesity and the current evidence for local activation of the renin-angiotensin system and its interactions with the endothelin system in obesity and the cardiovascular pathologies associated with it.
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Traupe T, Ortmann J, Münter K, Barton M. Endothelial Therapy of Atherosclerosis and its Risk Factors. Curr Vasc Pharmacol 2003; 1:111-21. [PMID: 15320838 DOI: 10.2174/1570161033476763] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Atherosclerosis is a chronic systemic disease of the vasculature with an inflammatory component. It accounts for the majority of cardiovascular morbidity and mortality in industrialized countries and its incidence is increasing in developing countries. The impairment of vascular endothelial cell function in atherosclerosis and in conditions associated with increased cardiovascular risk is an important determinant of disease progression. The reduction of endothelium-dependent relaxation in the coronary and systemic circulation in atherosclerosis is in part due to decreased bioavailability of nitric oxide and increased release of oxygen-derived free radicals. Atherosclerosis also increases the formation of vasoconstrictors and growth factors, adhesion of leukocytes, thrombosis, inflammation, cell proliferation, as well as increases in vascular tone. Here we review mechanisms and therapeutic approaches to improve endothelial pathways in atherosclerosis. Restoration of NO bioactivity through pharmacological inhibition of the renin-angiotensin system, statin therapy, or endothelin receptor blockade, ameliorates vascular function in experimental hypercholesterolemia, hypertension and heart failure. These treatments also have therapeutic benefit for patients at risk or with overt atherosclerosis, to reduce vascular and myocardial complications of this disease.
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Emmanuele L, Ortmann J, Doerflinger T, Traupe T, Barton M. Lovastatin stimulates human vascular smooth muscle cell expression of bone morphogenetic protein-2, a potent inhibitor of low-density lipoprotein-stimulated cell growth. Biochem Biophys Res Commun 2003; 302:67-72. [PMID: 12593849 DOI: 10.1016/s0006-291x(03)00109-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Bone morphogenetic proteins (BMPs) stimulate ectopic bone formation in skeletal muscle. Here we show that human vascular smooth muscle cells (VSMC) abundantly express mRNA encoding for BMP receptor type II, BMP-2, and BMP-7 proteins. Treatment with the 3-hydroxy-3-methylglutaryl coenzyme A inhibitor lovastatin (34 microM) increased BMP-2 gene transcription >14-fold as measured by real-time PCR analysis (P<0.05 vs. solvent control). Moreover, VSMC proliferation stimulated with native low-density lipoprotein (100 microg of protein/mL) was prevented by either human recombinant BMP-2 or BMP-7 at concentrations of 100 ng/mL (P<0.05). Both BMPs also inhibited basal cell proliferation (P<0.05). Induction of BMPs and subsequent inhibition of VSMC growth and/or induction of vascular bone formation could contribute to the mechanisms by which statins increase plaque stability in patients with coronary atherosclerosis.
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Traupe T, Lang M, Goettsch W, Münter K, Morawietz H, Vetter W, Barton M. Obesity increases prostanoid-mediated vasoconstriction and vascular thromboxane receptor gene expression. J Hypertens 2002; 20:2239-45. [PMID: 12409963 DOI: 10.1097/00004872-200211000-00024] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Vasoconstrictor prostanoids have been implicated in abnormal vasomotion in atherosclerosis and hypertension. METHOD Using lean and diet-induced obese mice, we investigated whether obesity affects vascular function or expression of genes involved in prostanoid action. RESULTS In lean C57BL/6J mice, at high concentrations acetylcholine caused endothelium-dependent contractions in the carotid artery but not in the aorta. Endothelium-dependent contractions to acetylcholine were blocked by the non-selective cyclooxygenase (COX) inhibitors indomethacin and meclofenamate, or a prostaglandin H2/thromboxane A2 receptor antagonist, but not by inhibitors of COX-2, thromboxane synthase or cytochrome P450 monooxygenase. Obesity increased endothelium-dependent contractions to acetylcholine in the carotid artery, and prostanoid-mediated vasoconstriction was now present in the aorta. Similarly, contractions to endothelin-1 were largely blocked by meclofenamate and were increased in the aorta of obese mice. Real-time quantitative polymerase chain reaction analysis of the thromboxane receptor gene in the carotid artery revealed a robust upregulation in obese animals (18-fold, 0.05); in comparison, obesity had a less pronounced effect on thromboxane synthase (2.1-fold increase, 0.05), or preproendothelin-1 gene expression (4.2-fold increase, 0.05). CONCLUSIONS These data demonstrate that obesity augments prostanoid-dependent vasoconstriction and markedly increases vascular thromboxane receptor gene expression. These changes are likely to promote the development of vascular disease, hypertension and thrombosis associated with obesity.
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Morawietz H, Goettsch W, Szibor M, Barton M, Shaw S, Hakim K, Zerkowski HR, Holtz J. Angiotensin-converting enzyme inhibitor therapy prevents upregulation of endothelin-converting enzyme-1 in failing human myocardium. Biochem Biophys Res Commun 2002; 295:1057-61. [PMID: 12135601 DOI: 10.1016/s0006-291x(02)00799-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In this study, we investigated the role of the renin-angiotensin system in expression of the endothelin system in atrial myocardium of patients with congestive heart failure. Atrial myocardium of control patients without angiotensin-converting enzyme (ACE) inhibitor therapy and heart failure patients without or with ACE inhibitor therapy undergoing aorto-coronary bypass surgery was studied. Endothelin-converting enzyme-1 (ECE-1) expression and endothelin-1 peptide level was upregulated in myocardium of heart failure patients without ACE inhibition. ACE inhibitor therapy prevented upregulation of ECE-1 and endothelin-1 in failing myocardium. Prepro-endothelin-1 and endothelin receptor A expression were not affected by heart failure. Endothelin receptor B was downregulated in heart failure patients. Our data demonstrate an upregulation of ECE-1 mRNA expression in failing human myocardium. Inhibition of the renin-angiotensin system by ACE inhibitor treatment prevents upregulation of ECE-1, suggesting that angiotensin II regulates ECE-1 expression in vivo.
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Heigl A, Lachat M, Lattmann T, Lüscher T, Barton M. Acute effects of 17 beta-oestradiol on functional activity of endothelin-converting enzymes in human arteries and veins. Clin Sci (Lond) 2002; 103 Suppl 48:438S-441S. [PMID: 12193140 DOI: 10.1042/cs103s438s] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In this study, we investigated the short-term effect of 17 beta-oestradiol on functional enzyme activity (FEA) of endothelin-converting enzymes in vitro using human internal mammary arteries (n=7-8) and human saphenous veins (n=16-17) obtained from patients undergoing coronary artery bypass graft surgery. Vascular rings were preincubated with either solvent control (0.2% ethanol) or 17 beta-oestradiol (1 microM) for 30 min and concentration-response curves to big ET-1 (0.1-100 nM) or ET-1 (0.1-100 nM) were performed. FEA for each concentration was calculated as the percentage activity [(contraction to big ET-1/contraction to ET-1)x100] normalized to KCl (100 mM). In control experiments, at low concentrations FEA was lower in internal mammary arteries than in saphenous veins (P<0.05). While FEA was suppressed in saphenous veins by 10 nM (4+/-1 versus 22+/-5%, P<0.01) and 30 nM (26+/-4 versus 48+/-7%, P<0.05) 17 beta-oestradiol, FEA was markedly enhanced in internal mammary arteries by 10 nM (33+/-12 versus 1+/-1%, P<0.001) and 30 nM (44+/-12 versus 8+/-3%, P<0.01) 17 beta-oestradiol. FEA was not affected by 100 nM 17 beta-oestradiol. These results demonstrate for the first time that short-term exposure to 17 beta-oestradiol affects FEA in vitro. Human internal mammary arteries have lower FEA than the saphenous veins, but FEA is differentially affected by acute exposure to 17 beta-oestradiol in human arteries and veins. Whether changes in FEA play a role in the vascular effects of 17 beta-oestradiol in vivo remains to be determined.
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Morawietz H, Goettsch W, Szibor M, Barton M, Shaw S, Hakim K, Zerkowski HR, Holtz J. Increased expression of endothelin-converting enzyme-1 in failing human myocardium. Clin Sci (Lond) 2002; 103 Suppl 48:237S-240S. [PMID: 12193094 DOI: 10.1042/cs103s237s] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Endothelin-1 (ET-1) is considered to be involved in the development and progression of heart failure. Therefore, we analysed the expression of endothelin-converting enzyme-1 (ECE-1), endothelin receptors A (ET(A)) and B (ET(B)) mRNAs by standard-calibrated, competitive reverse transcriptase-PCR using an internal-deleted in vitro-transcribed cRNA standard. ET-1 peptide levels were measured using isoform-specific rabbit antibodies against synthetic ET-1. mRNA and protein expression was determined in the right atrial myocardium of New York Heart Association class I patients and class IV patients undergoing aorto-coronary bypass surgery. ECE-1 mRNA was upregulated in failing atrial myocardium. Furthermore, ET-1 peptide levels were increased in failing atrial myocardium. Atrial ET(A) mRNA expression was not changed, while ET(B) mRNA was downregulated in the failing atrial myocardium. Our results support an upregulation of ET-1 synthesis by induction of ECE-1 in failing atrial myocardium. Pharmacological inhibition of augmented ECE-1 expression might provide a new therapeutic perspective in the treatment of heart failure.
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Camargos ERS, Machado CRS, Teixeira AL, Rocha LLV, Ferreira AJ, Almeida AP, Barton M, Teixeira MM. Role of endothelin during experimental Trypanosoma cruzi infection in rats. Clin Sci (Lond) 2002; 103 Suppl 48:64S-67S. [PMID: 12193056 DOI: 10.1042/cs103s064s] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Chagas' disease is caused by the intracellular protozoan Trypanosoma cruzi. Here we have investigated the role of endothelin-1 in T. cruzi acute infection in rats, using the orally active ET(A) receptor antagonist BSF-461314. Treatment with BSF-461314 markedly increased parasitaemia, but animals managed to control the infection by day 15. Histopathological analysis of heart tissue at the end of the acute phase showed greater numbers of parasite nests in BSF-461314-treated animals. The perfusion of isolated rat hearts from infected animals with bradykinin failed to induce an increase, and actually reduced, coronary blood flow. Pretreatment with BSF-461314 prevented changes in coronary flow induced by T. cruzi infection. Together these results demonstrate that endothelin-1, through ET(A) receptor activation, contributes to the protective immune response against acute T. cruzi infection. Moreover, these data suggest that endothelin-1 is a mediator of impaired endothelium-dependent vasomotion in the coronary microcirculation associated with acute T. cruzi infection.
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Traupe T, D'Uscio LV, Muenter K, Morawietz H, Vetter W, Barton M. Effects of obesity on endothelium-dependent reactivity during acute nitric oxide synthase inhibition: modulatory role of endothelin. Clin Sci (Lond) 2002; 103 Suppl 48:13S-15S. [PMID: 12193045 DOI: 10.1042/cs103s013s] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This study investigated vascular reactivity in response to acetylcholine, in the presence of acute inhibition of nitric oxide synthase, in the carotid artery and aorta of obese C57Bl6/J mice fed on a high-fat diet for 30 weeks, and of control mice. A subgroup of obese animals was also treated with the ET(A) receptor antagonist darusentan (50 mg x kg(-1) x day(-1)). In vascular rings from control animals, acetylcholine caused endothelium-dependent contractions in the carotid artery, but not in the aorta. In vascular rings from obese mice, contractility to acetylcholine was also evident in the aorta, and that in the carotid artery was increased compared with control mice. ET(A) receptor blockade by darusentan treatment of the obese mice prevented enhanced vasoconstriction to acetylcholine, resulting in mild vasodilatation. Thus obesity increases endothelium-dependent vasoconstriction in the absence of endothelial nitric oxide. This effect can be completely prevented by chronic ET(A) receptor blockade, suggesting that endothelin modulates increased endothelium-dependent vasoconstriction in obesity.
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Barton M, Dubey RK, Traupe T. Oral contraceptives and the risk of thrombosis and atherosclerosis. Expert Opin Investig Drugs 2002; 11:329-32. [PMID: 11866662 DOI: 10.1517/13543784.11.3.329] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Oral contraceptives containing synthetic oestrogens have been used successfully as birth control for > 40 years and are currently prescribed to > 100 million women worldwide. Several new progestins have been introduced and the third generation of progestins has now been available for two decades. Oral contraceptives are prescribed over a prolonged period of time and therefore substantially impact on hormonal, metabolic and plasmatic functions. Oral contraceptives increase the risk for venous thrombosis and pulmonary embolism, particularly if associated with confounding factors, such as genetic predisposition, smoking, hypertension or obesity. The risk of developing coronary artery disease is also increased in users with cardiovascular risk factors. This article discusses mechanistic and clinical issues and reviews the need for novel approaches targeting the considerable side effects in order to reduce cardiovascular morbidity in women using oral contraceptives.
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Locher R, Brandes RP, Vetter W, Barton M. Native LDL induces proliferation of human vascular smooth muscle cells via redox-mediated activation of ERK 1/2 mitogen-activated protein kinases. Hypertension 2002; 39:645-50. [PMID: 11882624 DOI: 10.1161/hy0202.103473] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study investigated mechanisms underlying native low-density lipoprotein (LDL)-stimulated proliferation of human vascular smooth muscle cells (VSMC). Experiments were performed to determine whether native LDL affects reactive oxygen species (ROS) formation and activity of extracellular signal-regulated kinase 1/2 (ERK1/2), and whether redox-sensitive pathways contribute to LDL-induced cell proliferation. Native LDL (100 microg/mL, 24 hours) increased cell proliferation (to 303 to 388% of control, P<0.0001) as determined by [methyl-(3)H] thymidine incorporation. This effect was completely blocked either by the antioxidants N-acetylcysteine, Tiron, or nordihydroguaiaretic acid; the flavin-inhibitor diphenylene iodonium; or superoxide dismutase (all P<0.0001), and partly blocked by ERK-inhibitor PD98059 or meclofenamate (P<0.01). Exposure of VSMC to native LDL for 20 minutes stimulated ROS formation, measured by dichlorodihydrofluorescein oxidation, and increased ERK1/2 activity by 3.1-fold (P<0.001). The latter effect was sensitive to MEK1/2 inhibitor PD98059 and Tiron (P<0.001), and in part to N-acetylcysteine or diphenylene iodonium (P<0.05). These results demonstrate that native LDL induces acute formation of ROS and subsequent activation of redox-sensitive ERK 1/2 mitogen-activated protein kinases, pathways that appear to be important for mitogenic signaling of native LDL in human vascular smooth muscle cells.
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d'Uscio LV, Barton M, Shaw S, Lüscher TF. Chronic ET(A) receptor blockade prevents endothelial dysfunction of small arteries in apolipoprotein E-deficient mice. Cardiovasc Res 2002; 53:487-95. [PMID: 11827700 DOI: 10.1016/s0008-6363(01)00469-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE This study investigated whether endothelial dysfunction occurs in mesenteric arteries of apoE-deficient mice and determined the role of endothelin (ET)-1, which is increased in human atherosclerosis, using an orally active endothelin ET(A) receptor antagonist. METHODS ApoE-deficient and C57BL/6J control mice were fed for 30 weeks with normal chow or high-fat Western-type diet alone or in combination with darusentan (LU135252; 50 mg/kg/day). Vasomotor reactivity of isolated small mesenteric arteries (I.D. 200-250 microm) was studied in vitro under perfused and pressurized conditions. RESULTS In both mouse strains, about one fourth of the endothelium-dependent relaxant response to acetylcholine was insensitive to inhibition by L-NAME and indomethacin. In mesenteric arteries of apoE-deficient mice on Western-type diet, increased intima-media thickness and levels of endothelin-1 protein were observed. In addition, NO-mediated endothelium-dependent relaxation to acetylcholine was reduced without affecting L-NAME/indomethacin insensitive relaxation and contractions to endothelin-1 and serotonin were enhanced. Treatment with darusentan normalized vascular structure, NO-mediated relaxation to acetylcholine and contractions to endothelin-1 and serotonin without affecting blood pressure or plasma cholesterol levels. CONCLUSIONS Severe hypercholesterolemia in apoE-deficient mice is associated with attenuation of NO-mediated relaxation to acetylcholine and increased vascular endothelin-1 content. Chronic ET(A) receptor blockade may provide a new therapeutic approach to improve NO-mediated endothelium-dependent vasomotion in small arteries.
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Barton M, Dubey RK. Postmenopausal hormone-replacement therapy. N Engl J Med 2002; 346:63-5. [PMID: 11799956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
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Locher R, Emmanuele L, Suter PM, Vetter W, Barton M. Green tea polyphenols inhibit human vascular smooth muscle cell proliferation stimulated by native low-density lipoprotein. Eur J Pharmacol 2002; 434:1-7. [PMID: 11755158 DOI: 10.1016/s0014-2999(01)01535-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This study investigated whether human vascular smooth muscle cell proliferation induced by native low-density lipoprotein (LDL) is affected by green tea catechins. Furthermore, the effects of native LDL on extracellular signal-regulated kinase (ERK) 1/2 activity were determined. Cell proliferation stimulated by native LDL was concentration-dependently inhibited by epigallocatechin, epigallocatechin-3-gallate, green tea polyphenon, and the nonspecific antioxidant N-acetylcysteine (P<0.05). Combined treatment of green tea polyphenon and N-acetylcysteine markedly potentiated the effect of each drug on vascular smooth muscle cell proliferation. ERK1/2 activity was only partly inhibited by green tea catechins alone or in combination with N-acetylcysteine (P<0.05). These data suggest that green tea constituents inhibit proliferation of human vascular smooth muscle cells exposed to high levels of native LDL. Green tea constituents and antioxidants may exert vascular protection by inhibiting human vascular smooth muscle cell growth associated with hypercholesterolemia.
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Brueck M, Barton M, Rauber K, Zikova A, Kramer W. [Ileus of the small intestine in intestinal marginal-zone B-cell lymphoma of mucoid-associated lymphoid tissue (MALT)]. Dtsch Med Wochenschr 2001; 126:1391-5. [PMID: 11740631 DOI: 10.1055/s-2001-18881] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
HISTORY AND ADMISSION FINDINGS A 67-year-old man had complained of diffuse abdominal pain and constipation for 4 days without indication of any underlying disease. On admission there was no evidence of weight loss, fever or nocturnal sweating. INVESTIGATIONS Physical examination revealed signs of an acute abdomen with high-pitched bowel sounds and diffuse abdominal guarding. The X-ray showed ileus of the small intestine which required emergency laparotomy. An obstructing conglomerate tumour was present in the area of the ileum, ca. 80 cm proximal to the caecum. It was removed by partial resection of the small intestine. DIAGNOSIS Ileus of the small intestine with a low-malignant marginal zone B-cell (non-Hodgkin) lymphoma of MALT type (mucoid-associated lymphoid tissue). TREATMENT AND COURSE Postoperative staging indicated no further manifestation of the lymphoma. As no radical operation in resecting the tumour had been performed, combined radio- and chemotherapy was undertaken. CONCLUSION Marginal B-cell lymphomas of the small intestine are only rarely seen in central Europe. Despite its usually slow growth this non-Hodgkin lymphoma of low malignancy can produce an acute mechanical ileus without prodromal symptoms. A multimodal therapeutic approach is often employed, but there are no established treatment strategies.
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Abstract
Atherosclerosis, a chronic systemic disease of the vasculature with an inflammatory component, is the primary cause of cardiovascular morbidity and mortality in industrialized countries. Impairment of vascular endothelial cell function in atherosclerosis and in conditions associated with increased cardiovascular risk are important determinants of disease progression. Reduced endothelium-dependent relaxation in the coronary and systemic circulation due to decreased bioavailability of nitric oxide (NO) and increased release of oxygen-derived free radicals promotes the adhesion of leukocytes, thrombosis, inflammation, cell proliferation, and increases in vascular tone. In addition to decreases in bioactive NO, enhanced production of the 21-amino acid peptide endothelin-1 contributes to the progression of atherosclerosis. This paper discusses mechanisms and therapeutic approaches to improving endothelial pathways in atherosclerosis. Restoration of endothelium-derived NO bioactivity through inhibition of the renin-angiotensin system, the endothelin system, or statin therapy improves vascular function in experimental hypercholesterolemia, hypertension and heart failure. These treatments may also have therapeutic benefit for patients at risk or with overt atherosclerosis, and are likely to reduce vascular and myocardial complications of this disease.
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Barton M. The lonely crowd in Minnesota: a psychometric approach to the study of the modern American character. PROSPECTS 2001; 7:365-90. [PMID: 11617968 DOI: 10.1017/s0361233300003641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The Historical study of the American character has been hobbled for several reasons, many of which are summarized by David Stannard in “American Historians and the Idea of National Character: Some Problems and Prospects.” Stannard emphasizes that America has always been too complex a sociocultural system to have produced a uniform national character or a typical personality. He notes that cultural anthropologists have not found psychological uniformity even in small, preliterate communities. If scholars would study the variety of the nation's psychological characteristics instead—if they would search for the modal personality (most frequently occurring type) and the distribution of other personality types rather than only the basic personality type—then, at least in Stannard's opinion, they would avoid oversimplification, the most serious conceptual error. But even this more realistic approach retains methodological problems that are so serious that he suggests historians concentrate on understanding “deeds and events” and leave the study of national character and characteristics to the social and behavioral scientists. (Philosophers of history might deny that the study of deeds and events is less troublesome than the study of national character, but that is another matter.)
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Barton M. Good bodies: Horace Mann and the physiology of morals. THE PSYCHOHISTORY REVIEW 2001; 7:43-4. [PMID: 11615787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
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Barton M, Kiowski W. The therapeutic potential of endothelin receptor antagonists in cardiovascular disease. Curr Hypertens Rep 2001; 3:322-30. [PMID: 11470015 DOI: 10.1007/s11906-001-0095-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Endothelin (ET)-1, a 21-amino acid peptide, is the predominant isoform of the endothelin peptide family. ET-1 is ubiquitously expressed and stimulates vasoconstriction and cell proliferation. Enzymes such as endothelin converting enzymes (ECE), chymases, and non-ECE metalloproteinases contribute to the synthesis of ET-1, which is regulated in an autocrine fashion in vascular and nonvascular cells. Endothelin ET(A) receptors mediate vasoconstriction and cell proliferation, whereas ET(B) receptors are involved in the clearance of ET-1, inhibition of endothelial apoptosis, release of nitric oxide and prostacyclin, and inhibition of ECE-1 expression. Most cardiovascular diseases, such as arterial hypertension, atherosclerosis, restenosis, heart failure, idiopathic cardiomyopathy, pulmonary hypertension, and renal failure are associated with local activation of the endothelin system. Experimental studies and first clinical trials suggest that ET-1 is importantly involved in the functional and structural changes in the cardiovascular system, and that many of the actions of ET-1 are mediated through pressure-independent mechanisms. Endothelin antagonists promise to be successful as a new class of drugs for the treatment of cardiovascular diseases.
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Barton M. Postmenopausal oestrogen replacement therapy and atherosclerosis: can current compounds provide cardiovascular protection? Expert Opin Investig Drugs 2001; 10:789-809. [PMID: 11322858 DOI: 10.1517/13543784.10.5.789] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The natural oestrogen, 17 beta-oestradiol, has been implicated in protection from atherosclerosis, a chronic systemic vascular disease with an inflammatory component accounting for the majority of morbidity and mortality in Western countries. Despite the protective effects of 17 beta-oestradiol in premenopausal women and experimental evidence demonstrating inhibitory effects of oestrogen on atherosclerosis progression, it is currently unclear whether hormone replacement therapy can affect cardiovascular morbidity and mortality in postmenopausal women. The recent advances in understanding the mechanisms of oestrogen action demonstrated roles for different oestrogen receptors and oestrogen metabolites in the pathogenesis of vascular injury and endothelial cell dysfunction. However, their respective role in the process of atherogenesis remains yet to be elucidated. Moreover, the availability of novel drugs with tissue- and/or receptor-specific actions will help to understand the role of oestrogen in cardiovascular diseases. Several ongoing large-scale clinical trials using opposed or unopposed replacement therapy with natural or synthetic oestrogens, or selective oestrogen receptor modulators (SERMs) will resolve the question whether the drugs currently available have therapeutic potential to interfere with the progression of atherosclerosis and its complications.
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Delaney G, Jalaludin B, Gildea B, Moylan E, Barton M. The development of a model of outpatient chemotherapy throughout — chemotherapy basic treatment equivalent (CBTE). Eur J Cancer 2001. [DOI: 10.1016/s0959-8049(01)81340-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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