Clinical and Experimental Pharmacology and Physiology最新文献

{"title":"Effect of cross-fostering on blood pressure and renal function in the New Zealand genetically hypertensive rat.","authors":"Nick Ashton,&nbsp;Philip Kelly,&nbsp;Janet M Ledingham","doi":"10.1046/j.1440-1681.2003.03918.x","DOIUrl":"https://doi.org/10.1046/j.1440-1681.2003.03918.x","url":null,"abstract":"<p><p>1. The severity of hypertension displayed by adult spontaneously hypertensive rats (SHR) and Dahl (SS/Jr) rats can be reduced by 20-30 mmHg if the hypertensive pup is cross-fostered to a normotensive mother within the first 2 weeks of birth. In the SHR, at least, this blood pressure-lowering effect arises through programming of the neonatal kidney to excrete sodium more effectively. Thus, cross-fostering may only be effective in lowering pressure in salt-sensitive hypertensive strains. Accordingly, the aim of the present study was to determine whether cross-fostering is effective in lowering adult blood pressure in the salt-resistant New Zealand genetically hypertensive (GH) rat. 2. Genetically hypertensive and control normotensive (N) rat pups were reared by either their natural mothers or a foster mother of the opposite strain (NX and GHX). Blood pressure was tracked from the age of 6-18 weeks, at which time renal function was assessed using standard clearance techniques in anaesthetized rats. Renal function was also assessed in a separate group of young rats at 5-6 weeks of age. 3. Cross-fostered GHX rats had lower blood pressure than GH rats, but this difference was only apparent until 9 weeks. The NX rats had higher blood pressures than N rats, but again pressure converged at 10 weeks. Basal renal function did not differ between GH and GHX rats or between N and NX rats at either age. However, young GH rats had lower renal blood flow, glomerular filtration rate, urine output and sodium excretion than N rats. 4. These data show that cross-fostering is effective in lowering blood pressure in GH rats, albeit transiently. The kidneys do not appear to play a role, because renal function did not differ under the current experimental conditions between GH and GHX rats. However, the kidney may play a greater role in the onset of hypertension in the GH rat than previously thought.</p>","PeriodicalId":10259,"journal":{"name":"Clinical and Experimental Pharmacology and Physiology","volume":"30 11","pages":"820-6"},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1046/j.1440-1681.2003.03918.x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24126098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Science and physicianly practice: are they compatible?","authors":"J Paul Seale","doi":"10.1046/j.1440-1681.2003.03924.x","DOIUrl":"https://doi.org/10.1046/j.1440-1681.2003.03924.x","url":null,"abstract":"<p><p>1. Science, in the present paper, is defined as the systematic study of humans, based on deduction and inferences from reproducible observation and measurement. Physicianly practice is the art of healing through accurate diagnosis and treatment. 2. The science that is conducted by clinical pharmacologists involves both clinical studies, which is working with patients or normal volunteers, and a variety of in vitro techniques. 3. Studies of patients with exercise-induced asthma (EIA) suggest that inhaled beta-adrenoceptor agonists may afford protection against EIA by inhibiting mast cell mediator release. In vitro experiments with human lung tissue demonstrate dose-dependent inhibition of histamine and leukotriene release by fenoterol, a beta-adrenoceptor agonist. 4. Studies in normal volunteers following the inhalation of corticosteroids (fluticasone and budesonide), which are used for the treatment of asthma, detected the presence of the administered drugs in the plasma. The potency ratio of fluticasone : budesonide for inhibition of the hypothalamic-pituitary-adrenal (HPA) axis in these normal volunteers was similar to the potency ratio determined in animal models of inflammation. 5. Studies in vitro showed that fluticasone and budesonide have effects on alkaline phosphatase release from human osteoblasts, with a potency ratio of similar rank order to that observed in vivo on the HPA axis. 6. These studies have shown that in vivo and in vitro techniques can be used in a complementary fashion to address questions of clinical relevance.</p>","PeriodicalId":10259,"journal":{"name":"Clinical and Experimental Pharmacology and Physiology","volume":"30 11","pages":"833-5"},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1046/j.1440-1681.2003.03924.x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24126100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel isoforms of NADPH oxidase in vascular physiology and pathophysiology.","authors":"Sara H M Bengtsson,&nbsp;Lerna M Gulluyan,&nbsp;Gregory J Dusting,&nbsp;Grant R Drummond","doi":"10.1046/j.1440-1681.2003.03929.x","DOIUrl":"https://doi.org/10.1046/j.1440-1681.2003.03929.x","url":null,"abstract":"<p><p>1. Vascular cells have evolved to use reactive oxygen species (ROS), such as superoxide and hydrogen peroxide, as signalling molecules. Under physiological conditions, ROS are important regulators of cell cycle, protein kinase activity and gene expression. However, in vascular disease states, such as hypertension and hypercholesterolaemia, excessive production of ROS may overwhelm the anti-oxidant defence mechanisms of cells, resulting in 'oxidative stress', damage to the artery wall and, ultimately, development of atherosclerotic plaques. 2. The primary source of ROS in the vasculature is NADPH oxidase. There appear to be at least three isoforms of NADPH oxidase expressed in the vascular wall, each differing with respect to the flavin-containing catalytic subunit it uses to transfer electrons from NADPH to molecular oxygen. Thus, although endothelial cells and adventitial fibroblasts express a gp91phox-containing NADPH oxidase similar to that originally identified in phagocytes, vascular smooth muscle cells may rely on novel homologues of gp91phox, namely Nox1 and Nox4, to produce superoxide. 3. Controversy remains over which isoform(s) of NADPH oxidase is responsible for the oxidative stress associated with vascular diseases. We and others have shown that although gp91phox mRNA expression is upregulated during atherogenesis in human and animal models, expression of the Nox4 subunit remains unchanged. Nox1 expression is also likely to be increased in diseased arteries; however, its relative level of expression, at least at the mRNA level, appears to be markedly lower than that of the other gp91phox homologues, even after upregulation. 4. Whether these findings suggest that a gp91phox-containing NADPH oxidase is more important than either Nox4 or Nox1 in vascular disease awaits studies examining relative protein expression and enzyme kinetics of each subunit, as well as the effects of targeted gene deletion of each of these gp91phox homologues on atherogenesis.</p>","PeriodicalId":10259,"journal":{"name":"Clinical and Experimental Pharmacology and Physiology","volume":"30 11","pages":"849-54"},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1046/j.1440-1681.2003.03929.x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24127262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Redox-dependent signalling by angiotensin II and vascular remodelling in hypertension.","authors":"Rhian M Touyz,&nbsp;Fatiha Tabet,&nbsp;Ernesto L Schiffrin","doi":"10.1046/j.1440-1681.2003.03930.x","DOIUrl":"https://doi.org/10.1046/j.1440-1681.2003.03930.x","url":null,"abstract":"<p><p>1. Hypertension is associated with structural alterations of resistance arteries, a process known as remodelling (increased media-to-lumen ratio). 2. At the cellular level, vascular remodelling involves changes in vascular smooth muscle cell (VSMC) growth, cell migration, inflammation and fibrosis. These processes are mediated via multiple factors, of which angiotensin (Ang) II appears to be one of the most important in hypertension. 3. Angiotensin II signalling, via AT1 receptors, is upregulated in VSMC from resistance arteries of hypertensive patients and rats. This is associated with hyperactivation of vascular NADPH oxidase, leading to increased generation of reactive oxygen species (ROS), particularly O2- and H2O2. 4. Reactive oxygen species function as important intracellular second messengers to activate many downstream signalling molecules, such as mitogen-activated protein kinase, protein tyrosine phosphatases, protein tyrosine kinases and transcription factors. Activation of these signalling cascades leads to VSMC growth and migration, modulation of endothelial function, expression of pro-inflammatory mediators and modification of extracellular matrix. 5. Furthermore, ROS increase intracellular free Ca2+ concentration ([Ca2+]i), a major determinant of vascular reactivity. 6. All these processes play major roles in vascular injury associated with hypertension. Accordingly, ROS and the signalling pathways that they modulate provide new targets to regress vascular remodelling, reduce peripheral resistance and prevent hypertensive end-organ damage. 7. In the present review, we discuss the role of ROS as second messengers in AngII signalling and focus on the implications of these events in the processes underlying vascular remodelling in hypertension.</p>","PeriodicalId":10259,"journal":{"name":"Clinical and Experimental Pharmacology and Physiology","volume":"30 11","pages":"860-6"},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1046/j.1440-1681.2003.03930.x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24127264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of calcitriol on the immune system: new possibilities in the treatment of glomerulonephritis.","authors":"Vincenzo Panichi,&nbsp;Massimiliano Migliori,&nbsp;Daniele Taccola,&nbsp;Cristina Consani,&nbsp;Luca Giovannini","doi":"10.1046/j.1440-1681.2003.03919.x","DOIUrl":"https://doi.org/10.1046/j.1440-1681.2003.03919.x","url":null,"abstract":"<p><p>1. 1,25-Dihydroxyvitamin D3 (1,25(OH)2D3), the hormonal form of vitamin D, is widely appreciated to play a central role in calcium and phosphate homeostasis. However, it is becoming increasingly clear that the sterol also play an important role in the regulation of cellular growth, haematopoietic tissues and the immune system, as well as in the modulation of hormone secretion by several endocrine glands. 2. In the present review, some of the mechanisms by which 1,25(OH)2D3 regulates immune function are highlighted. Moreover, a number of studies on the effects of calcitriol in several experimental animal models of renal disease are reported, suggesting new possibilities in the therapy of glomerulonephritis.</p>","PeriodicalId":10259,"journal":{"name":"Clinical and Experimental Pharmacology and Physiology","volume":"30 11","pages":"807-11"},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1046/j.1440-1681.2003.03919.x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24126096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stem cell-derived angiogenic/vasculogenic cells: possible therapies for tissue repair and tissue engineering.","authors":"J J Zwaginga,&nbsp;P Doevendans","doi":"10.1046/j.1440-1681.2003.03931.x","DOIUrl":"https://doi.org/10.1046/j.1440-1681.2003.03931.x","url":null,"abstract":"<p><p>1. The recent ability to isolate stem cells and study their specific capacity of self-renewal with the formation of different cell types has opened up exciting vistas to help the repair of damaged tissue and even the formation of new tissue. In the present review, we deal with the characteristics and sources that stem cells can be derived and cultured from. 2. We focus on the role that stem cell-derived vascular cells or endothelial progenitor cells (EPC) may play in (re)vascularization of ischaemic and engineered tissues. This so-called vasculogenesis resembles the embryological process in which 'haemangioblasts' differentiate in blood cells, as well as in primitive vessels. Although also derived from the blood-forming bone marrow, in adult life vasculogenic stem cells contribute only little to the regular vascular repair mechanisms: namely (i) angiogenesis (outgrowth of vessels from existing vessels); and (ii) arteriogenesis (monocyte-aided increase in the calibre of existing arteriolar collaterals). 3. Most attempts to increase vascular repair by stem cells involve the use of growth factors, which mobilize stem cells from bone marrow into the blood, sometimes combined with isolation and reinfusion of these cells after ex vivo expansion and differentiation into EPC. 4. Clear improved perfusion of ischaemic sites and new vasculature has been observed in vivo mostly in animal models. Specific homing or administration of these cells and regulated and quantitative expansion and (final) differentiation at these vascular (repair) sites are less studied, but are paramount for efficacy and safety. 5. In conclusion, the use of embryonic stem cells will still encounter ethical objections. Moreover, special attention and measures are needed to cope with the allogeneic barriers that these cells usually encounter. In general, the long and complicated ex vivo cultures to obtain sufficient offspring from the very small numbers of stem cells that can be obtained as starting material will be costly and cumbersome. Both basic research on conceptual matters and cost-effective development of the product itself will have to go a long way before the clinical use of some volume can be expected.</p>","PeriodicalId":10259,"journal":{"name":"Clinical and Experimental Pharmacology and Physiology","volume":"30 11","pages":"900-8"},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1046/j.1440-1681.2003.03931.x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24127707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mouse isolated perfused heart: characteristics and cautions.","authors":"Fiona J Sutherland,&nbsp;Michael J Shattock,&nbsp;Kathryn E Baker,&nbsp;David J Hearse","doi":"10.1046/j.1440-1681.2003.03925.x","DOIUrl":"https://doi.org/10.1046/j.1440-1681.2003.03925.x","url":null,"abstract":"<p><p>1. Owing to the considerable potential for manipulating the murine genome and, as a consequence, the increasing availability of genetically modified models of cardiovascular diseases, the mouse is fast becoming a cornerstone of animal research. However, progress in the use of various murine preparations is hampered by the lack of facilities and skills for the adequate physiological assessment of genetically modified mice. 2. We have attempted to address this problem by refining and characterizing a mouse isolated heart preparation that was originally developed for use with larger hearts. 3. We used the isolated buffer-perfused Langendorff preparation (perfused at constant flow or constant pressure) to characterize: (i) the frequency-response characteristics; (ii) heart isolation conditions; (iii) perfusion chamber conditions; (iv) temperature-function relationships; (v) stability over extended periods of perfusion; (vi) perfusate calcium-function relationships; (vii) pressure-volume relationships; (viii) pressure-rate relationships; and (ix) flow-function relationships.</p>","PeriodicalId":10259,"journal":{"name":"Clinical and Experimental Pharmacology and Physiology","volume":"30 11","pages":"867-78"},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1046/j.1440-1681.2003.03925.x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24127265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of losartan on pressure overload-induced cardiac gene expression profiling in rats.","authors":"Jinliang Li,&nbsp;Ping Li,&nbsp;Xinheng Feng,&nbsp;Zhaoping Li,&nbsp;Rong Hou,&nbsp;Chide Han,&nbsp;Youyi Zhang","doi":"10.1046/j.1440-1681.2003.03917.x","DOIUrl":"https://doi.org/10.1046/j.1440-1681.2003.03917.x","url":null,"abstract":"<p><p>1. In the present study, the effects of losartan on myocardial gene expression changes following cardiac hypertrophy were investigated. 2. Male Wistar rats were randomized to receive 5 or 30 mg/kg per day losartan (i.p.) 1 day after suprarenal abdominal aortic constriction. Two weeks later, cardiac morphology and function were recorded with echocardiography and mean arterial central pressure was measured using carotid catheters. Myocardial gene expression was assessed with cDNA microarrays. 3. The ratios of left ventricular weights to bodyweights, the posterior thickness of the left ventricle and mean arterial central pressure were significantly increased by aortic constriction and attenuated by losartan in a dose-related manner. Genes in different functional categories were regulated in pressure overload-induced cardiac hypertrophy and the majority of changes in gene expression were inhibited by losartan in a dose-dependent manner. 4. However, there were still some genes that were unaffected by losartan, even at a higher dose. In contrast, losartan, especially at a lower dose, was able to induce changes in the expression of several additional genes that were unregulated in simple aortic constriction. 5. In conclusion, losartan is able to inhibit pressure overload-induced cardiac hypertrophy, as well as the majority of pressure overload-related changes in gene expression. The genes that remained unaffected or those that were additionally induced by losartan are likely to be new targets for investigation or therapy.</p>","PeriodicalId":10259,"journal":{"name":"Clinical and Experimental Pharmacology and Physiology","volume":"30 11","pages":"827-32"},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1046/j.1440-1681.2003.03917.x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24126099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Neurocardiovascular regulation in mice: experimental approaches and novel findings.","authors":"Xiuying Ma,&nbsp;Francois M Abboud,&nbsp;Mark W Chapleau","doi":"10.1046/j.1440-1681.2003.03927.x","DOIUrl":"https://doi.org/10.1046/j.1440-1681.2003.03927.x","url":null,"abstract":"<p><p>1. Neural mechanisms are of major importance in the regulation of arterial blood pressure, blood volume and other aspects of cardiovascular function. The recent explosion in gene discovery and advances in molecular technologies now provide the opportunity to define the molecular and cellular mechanisms essential to integrative neurocardiovascular regulation. The unique susceptibility of mice to genetic manipulation makes this species an attractive model for such investigation. 2. We provide here a brief overview of: (i) experimental approaches used to assess autonomic and reflex control of the circulation in mice; (ii) novel mechanisms of neurocardiovascular regulation revealed using these approaches; and (iii) findings from recent studies involving mouse models of cardiovascular disease.</p>","PeriodicalId":10259,"journal":{"name":"Clinical and Experimental Pharmacology and Physiology","volume":"30 11","pages":"885-93"},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1046/j.1440-1681.2003.03927.x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24127705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental therapeutics of Parkinson's disease.","authors":"Jasmine M Henderson","doi":"10.1046/j.1440-1681.2003.03922.x","DOIUrl":"https://doi.org/10.1046/j.1440-1681.2003.03922.x","url":null,"abstract":"<p><p>1. The loss of central dopamine, which characterises Parkinson's disease, led to the main pharmacological strategy for treatment, namely levodopa, a dopamine-replacement therapy. Several years after treatment, the majority of patients experience dose-limiting side-effects and loss of symptom control. There is a resurgence of interest in neurosurgery for treating the Parkinson's disease, particularly in new techniques targeting the subthalamic nucleus (STN), which is overactive in Parkinson's disease and contributes to symptom development. 2. We performed unilateral subthalamotomy (lesioning the subthalamic nucleus via the toxin N-methyl-d-aspartate) in marmosets and rats with experimentally induced parkinsonism (induced using the toxin 6-hydroxydopamine). A range of similar behaviours common to both rodents and primates were evaluated before and after each type of surgery. Post-mortem histology was used to confirm the lesions. We also provide details of a case with Parkinson's disease who underwent high-frequency bilateral stimulation of the STN and in whom we analysed the STN post-mortem. 3. Unilateral subthalamotomy improved akinesia in parkinsonian primates. However, both monkeys and rodents showed postural abnormalities. The patient who underwent bilateral high-frequency stimulation showed improvement of akinesia and other disease symptoms and no postural abnormalities. Post-mortem analysis did not demonstrate substantial damage of the STN as a result of the electrodes. 4. Although unilateral subthalamotomy improves some aspects of parkinsonism, it causes postural abnormalities in animal models of Parkinson's disease. Because bilateral high-frequency STN stimulation improves disease symptoms, is reversible and is not reported to induce postural side-effects, it may be a better surgical therapy for Parkinson's disease than lesioning the STN.</p>","PeriodicalId":10259,"journal":{"name":"Clinical and Experimental Pharmacology and Physiology","volume":"30 11","pages":"841-4"},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1046/j.1440-1681.2003.03922.x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24127260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}