***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: In a r and omised , double-blind placebo-controlled trial , the effects of the administration of oral L-carnitine ( 2 g/day ) for 28 days were compared in the management of 51 ( carnitine group ) and 50 ( placebo group ) patients with suspected acute myocardial infa rct ion . At study entry , the extent of cardiac disease , cardiac enzymes and lipid peroxides were comparable between the groups , although both groups showed an increase in cardiac enzymes and lipid peroxides . At the end of the 28-day treatment period , the mean infa rct size assessed by cardiac enzymes showed a significant reduction in the carnitine group compared to placebo . Electrocardiographic assessment of infa rct size revealed that the QRS-score was significantly less in the carnitine group compared to placebo ( 7.4 + /- 1.2 vs 10.7 + /- 2.0 ) , while serum aspartate transaminase and lipid peroxides showed significant reduction in the carnitine group . Lactate dehydrogenase measured on the sixth or seventh day following infa rct ion showed a smaller rise in the carnitine group compared to placebo . Angina pectoris ( 17.6 vs 36.0 % ) , New York Heart Association class III and IV heart failure plus left ventricular enlargement ( 23.4 vs 36.0 % ) and total arrhythmias ( 13.7 vs 28.0 % ) were significantly less in the carnitine group compared to placebo . Total cardiac events including cardiac deaths and nonfatal infa rct ion were 15.6 % in the carnitine group vs 26.0 % in the placebo group . It is possible that L-carnitine supplementation in patients with suspected acute myocardial infa rct ion may be protective against cardiac necrosis and complications during the first 28 days Objectives To evaluate the effects of l-carnitine as an adjunct therapy to percutanenous coronary intervention ( PCI ) for non-ST elevation acute coronary syndrome ( NSTEMI ) . Material s and methods Ninety-six consecutive patients with NSTEMI were r and omized into treatment group ( l-carnitine 5 g IV bolus followed by 10 g/day IV infusion for 3 days ) , and control group .  All patients also underwent PCI  within 24 h from the onset of chest pain . The peak values of creatine kinase-MB and troponin-I before and after PCI were observed . Results In the treatment group , the peak values of creatine kinase-MB were significantly lower than the control group at 12 h and 24 h after PCI ( P < 0.01 ) . The peak values of troponin-I in the treatment group were also lower than the control group at 8 h after PCI ( P < 0.01 ) . Multivariate regression analysis showed that l-carnitine therapy was an independent predictor for the reduction of creatine kinase-MB ( r = 0.596 , P < 0.001 ) or troponin-I ( r = 0.633 , P < 0.001 ) . Conclusion l-carnitine adjunct therapy appears to be associated with a reduced level of cardiac markers in patients with NSTEMI . These results support a larger clinical trial to investigate the effect of l-carnitine on cardiac events following PCI A controlled study was carried out on 160 patients of both sexes ( age between 39 and 86 years ) discharged from the Cardiology Department of the Santa Chiara Hospital , Pisa , with a diagnosis of recent myocardial infa rct ion .  L-carnitine was r and omly administered to 81 patients  at an oral dose of g 4/die for 12 months , in addition to the pharmacological treatment generally used . For the whole period of 12 months , these patients showed , in comparison with the controls , an improvement in heart rate ( p < 0.005 ) , systolic arterial pressure ( p < 0.005 ) and diastolic arterial pressure ( NS ) ; a decrease of anginal attacks ( p < 0.005 ) , of rhythm disorders ( NS ) and of clinical signs of impaired myocardial contractility ( NS ) , and a clear improvement in the lipid pattern ( p < 0.005 ) . The above changes were accompanied by a lower mortality in the treated group ( 1.2 % , p < 0.005 ) , while in the control group there was a mortality of 12.5 % . Furthermore , in the control group there was a definite prevalence of deaths caused by reinfa rct ion and sudden death . On the basis of these results , it is concluded that L-carnitine represents an effective treatment in post-infa rct ion ischaemic cardiopathy , since it can improve the clinical evolution of this pathological condition as well as the patient 's quality of life and life expectancy BACKGROUND Although most cardiovascular disease occurs in low-income and middle-income countries , little is known about the use of effective secondary prevention medications in these communities . We aim ed to assess use of proven effective secondary preventive drugs ( antiplatelet drugs , β blockers , angiotensin-converting-enzyme [ ACE ] inhibitors or angiotensin-receptor blockers [ ARBs ] , and statins ) in individuals with a history of coronary heart disease or stroke . METHODS In the Prospect i ve Urban Rural Epidemiological ( PURE ) study , we recruited individuals aged 35 - 70 years from rural and urban communities in countries at various stages of economic development . We assessed rates of previous cardiovascular disease ( coronary heart disease or stroke ) and use of proven effective  secondary preventive drugs  and blood-pressure-lowering drugs with st and ardised question naires , which were completed by telephone interviews , household visits , or on patient 's presentation to clinics . We report estimates of drug use at national , community , and individual levels . FINDINGS We enrolled 153,996 adults from 628 urban and rural communities in countries with incomes classified as high ( three countries ) , upper-middle ( seven ) , lower-middle ( three ) , or low ( four ) between January , 2003 , and December , 2009 . 5650 participants had a self-reported coronary heart disease event ( median 5·0 years previously [ IQR 2·0 - 10·0 ] ) and 2292 had stroke ( 4·0 years previously [ 2·0 - 8·0 ] ) . Overall , few individuals with cardiovascular disease took antiplatelet drugs  ( 25·3 % ) , β blockers ( 17·4 % ) , ACE inhibitors or ARBs ( 19·5 % ) , or statins ( 14·6 % ) . Use was highest in high-income countries ( antiplatelet drugs 62·0 % , β blockers 40·0 % , ACE inhibitors or ARBs 49·8 % , and statins 66·5 % ) , lowest in low-income countries ( 8·8 % , 9·7 % , 5·2 % , and 3·3 % , respectively ) , and decreased in line with reduction of country economic status ( p(trend)<0·0001 for every drug type ) . Fewest patients received no drugs in high-income countries ( 11·2 % ) , compared with 45·1 % in upper middle-income countries , 69·3 % in lower middle-income countries , and 80·2 % in low-income countries . Drug use was higher in urban than rural areas ( antiplatelet drugs 28·7 % urban vs 21·3 % rural , β blockers 23·5%vs 15·6 % , ACE inhibitors or ARBs 22·8%vs 15·5 % , and statins 19·9%vs 11·6 % ; all p<0·0001 ) , with greatest variation in poorest countries ( p(interaction)<0·0001 for urban vs rural differences by country economic status ) . Country-level factors ( eg , economic status ) affected rates of drug use more than did individual-level factors ( eg , age , sex , education , smoking status , body-mass index , and hypertension and diabetes statuses ) . INTERPRETATION Because use of secondary prevention medications is low worldwide-especially in low-income countries and rural areas - systematic approaches are needed to improve the long-term use of basic , inexpensive , and effective drugs . FUNDING Full funding sources listed at end of paper ( see Acknowledgments ) Increasing skeletal muscle carnitine content may alleviate the decline in muscle fat oxidation seen during intense exercise . Studies to date , however , have failed to increase muscle carnitine content , in healthy humans , by dietary or intravenous L-carnitine administration . We hypothesized that insulin could augment Na+-dependent skeletal muscle carnitine transport . On two r and omized visits , eight healthy men underwent 5 h of intravenous L-carnitine infusion with serum insulin maintained at fasting ( 7.4+/-0.4 mIU*l(-1 ) ) or physiologically high ( 149.2+/-6.9 mIU*l(-1 ) ) concentrations . The combination of hypercarnitinemia ( approximately 500 micromol*l(-1 ) ) and hyperinsulinemia increased muscle total carnitine ( TC ) content from 22.0 + /- 0.9 to 24.7 + /- 1.4 mmol*(kg dm)(-1 ) ( P<0.05 ) and was associated with a 2.3 + /- 0.3-fold increase in carnitine transporter protein ( OCTN2 ) mRNA expression ( P<0.05 ) . Hypercarnitinemia in the presence of a fasting insulin concentration had no effect on either of these parameters . This study demonstrates that insulin can acutely increase muscle TC content in humans during hypercarnitinemia , which is associated with an increase in OCTN2 transcription . These novel findings may be of importance to the regulation of muscle fat oxidation during exercise , particularly in obesity and type 2 diabetes where it is known to be impaired A double blind r and omized placebo controlled clinical trial was carried out to assess the efficacy and safety of L-carnitine in patients suffering from acute anterior wall myocardial infa rct ion with respect to left ventricular function . Sixty patients ( 34 men , 26 women , mean age 56 + 11 yr . ) with acute anterior wall myocardial infa rct ion were r and omized to placebo and L-carnitine . All the patients were given intravenous L-carnitine / placebo in the dose of 6gm/day for the first seven days followed by oral L-carnitine / placebo 3 gm/day in three divided doses for a period of three months . Echocardiography was performed for regional wall motion abnormality , left ventricular end systolic volume ( ESV ) , end diastolic volume ( EDV ) and ejection fraction ( EF ) on admission , after seven days and after three months of the infa rct ion . Forty-four patients completed the study . There were three deaths , two in the placebo and one in the L-carnitine group ( p>0.05 ) . Thirteen patients were lost to follow up . Echo parameters in both groups were comparable ( p>0.05 ) . The duration of chest pain prior to initiation of the I.V. L-carnitine was 7.5 + 5.2 hrs in the L-carnitine group and 7 + 4 hrs in the placebo group ( p>0.05 ) . There was no statistical difference in the EF , ESV and EDV on admission , at discharge and after three months in the L-carnitine and the placebo groups ( p>0.05 ) . No significant adverse effects were noted . L-carnitine , though a safe drug , does not affect the left ventricular function in patients with myocardial infa rct ion Skeletal muscle CoA and carnitine metabolism were investigated in six human volunteers at rest and after exhaustive exercise under normoxic and hypoxic conditions .  In comparison to the values at rest , exhaustive exercise was associated with a three- to fourfold increase in the skeletal muscle lactate , and with a twofold increase in the acetyl-CoA content , both under normoxic and hypoxic conditions . Since exercise did not significantly affect the skeletal muscle CoA radical ( CoASH ) , total acid-soluble , or total CoA contents , the increase in the acetyl-CoA content was at the expense of short-chain acyl-CoAs different from acetyl-CoA. With exhaustive exercise , the skeletal muscle acetylcarnitine and short-chain acylcarnitine contents increased by a factor of three to four both under normoxic and hypoxic conditions . In contrast to the CoA pool , these increases were associated with a decrease in the free carnitine content , whereas the total acid-soluble and total carnitine contents were not affected by exercise . After exhaustive exercise , the skeletal muscle acetyl-CoA/CoASH ratio showed a linear correlation with the corresponding acetylcarnitine/free carnitine ratio . The plasma short-chain acylcarnitine concentration increased by a factor of two to three during exercise , and was not significantly different from the values at rest 40 min after completion of exercise . Thus , the current studies illustrate the close interaction between the CoA and carnitine pools in the exercising human skeletal muscle , and they underscore the important role of carnitine in maintaining the muscular CoASH content during exhaustive exercise The effects of L-carnitine on respiratory chain enzymes in muscle of long distance runners were studied in 14 athletes . These subjects received placebo 
    Output:
    
Conclusions There appears to be no significant marginal benefit in terms of all-cause mortality , heart failure , unstable angina , or myocardial reinfa rct ion in the setting of acute MI for oral L-carnitine maintenance doses of greater or less than 3 g per day