***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: OBJECTIVE To determine the effect of oral carnitine supplementation on the semen parameters of men with idiopathic asthenospermia . DESIGN Prospect i ve , r and omized , double-blind placebo-controlled study . SETTING Academic tertiary referral centers . PATIENT(S ) Male patients presenting with infertility and with sperm motility of 10%-50 % were selected . INTERVENTION(S ) Patients were r and omized to 24-week treatment arms of oral carnitine ( 2,000 mg L-carnitine and 1,000 mg L-acetyl-carnitine per day ) or placebo . MAIN OUTCOME MEASURE(S ) Sperm motility and total motile sperm counts at baseline , 12 weeks , and 24 weeks . Seminal plasma and sperm free , acetyl , and total L-carnitine levels at baseline and at week 24 . RESULT ( S ) Twenty-one patients entered the study , with 12 patients in the carnitine arm and 9 in the placebo arm . There were no significant differences in baseline semen parameters between the carnitine and placebo arms . There was no statistically significant or clinical ly significant increase in motility or total motile sperm counts between baseline , 12 week , or 24 weeks in the carnitine or placebo arms . CONCLUSION ( S ) Carnitine supplementation demonstrated no clinical ly or statistically significant effect on sperm motility or total motile sperm counts in men with idiopathic asthenospermia OBJECTIVE To investigate whether there is an impact of different sources of reactive oxygen species ( ROS ) on sperm functions . DESIGN Prospect i ve study . SETTING Patients at the Center for Dermatology and And rology , Giessen , Germany . PATIENT(S ) Semen collected from 63 r and omly collected patients attending the IVF unit of the University of Giessen , Germany . INTERVENTION(S ) Only patients with nonleukocytospermia were included in this study . MAIN OUTCOME MEASURE(S ) Sperm count and motility before and after sperm separation by swim-up , morphology , DNA fragmentation , and extrinsic ( by leukocytes ) and intrinsic ROS production ( by spermatozoa ) were evaluated . RESULT ( S ) Leukocytes correlated significantly with extrinsic ROS production ( r = 0.576 ) , but markedly less with intrinsic ROS production ( r = 0.296 ) . Sperm count , morphology , and motility in the ejaculate were markedly more affected by extrinsic than by intrinsic ROS . The DNA fragmentation was strongly positively correlated with intrinsic ROS production , whereas this correlation was weaker for extrinsic ROS production . No correlation was found between DNA fragmentation and the number of leukocytes , whereas the correlations with motility in the ejaculate and the motile sperm count after swim-up were highly significant . Moreover , significant differences were observed for extrinsic and intrinsic ROS production between groups of patients having a high ( > or = 1 x 10(6)/mL ) and a low number ( < 1 x 10(6)/mL ) of leukocytes in the ejaculate . CONCLUSION ( S ) The origin of ROS seems to have an influence on the site of the damage . Because leukocyte counts < 1 x 10(6)/mL caused a significant decrease of motility and DNA integrity , the threshold given by the World Health Organization ( WHO ) should be re-evaluated BACKGROUND Most studies examining the use of ICSI for cases of elevated sperm DNA fragmentation report poor pregnancy and implantation rates .  ICSI with testicular sperm sample s has recently been suggested for these cases . Here we test a less invasive approach based on oral antioxidant treatment prior to ICSI with ejaculated spermatozoa . METHODS Thirty-eight men with an elevated ( > or = 15 % ) percentage of DNA-fragmented spermatozoa in the ejaculate were treated with antioxidants ( 1 g vitamin C and 1 g vitamin E daily ) for 2 months after one failed ICSI attempt . In 29 ( 76 % ) of these cases this treatment led to a decrease in the percentage of DNA-fragmented spermatozoa , and a second ICSI attempt was performed . Outcomes of the two attempts were compared . RESULTS No differences in fertilization and cleavage rates or in embryo morphology were found between the ICSI attempts performed before and after the antioxidant treatment . However , a marked improvement of clinical pregnancy ( 48.2 % versus 6.9 % ) and implantation ( 19.6 % versus 2.2 % ) rates was observed after the antioxidant treatment as compared with the pretreatment ICSI outcomes . CONCLUSIONS Oral antioxidant treatment appears to improve ICSI outcomes in those patiens with sperm DNA damage , in whom this treatment reduces the percentage of damaged spermatozoa OBJECTIVE To determine the effectiveness of the in vivo administration of vitamin E as treatment for reactive oxygen species-associated male infertility .  SETTING University-based center for reproductive medicine . DESIGN Double-blind r and omized placebo cross-over controlled trial . PATIENTS , PARTICIPANTS Thirty healthy men with high levels of reactive oxygen species generation in semen and a normal female partner . INTERVENTIONS Patients were allocated to two groups according to the blinded r and omization . Each patient received either 600 mg/d of vitamin E ( Ephynal , 300 mg tablets ; F. Hoffman-La Roche Ltd. , Basle , Switzerl and ) ( order A ) or identical placebo tablets ( order B ) for 3 months . Then after a 1-month wash-out period the patients were crossed-over to the other treatment . MAIN OUTCOME MEASURES Improvement in the in vitro function of the spermatozoa measured by conventional semen analysis , computerized motility assessment , determination of reactive oxygen species generation , binding to the zona pellucida of the unfertilized human oocyte in a competitive zona binding assay , development of hyperactivated motility ( both spontaneous and in the presence of 20 % of the natural agonist , human follicular fluid ) and pregnancy . RESULTS Rise in the blood serum vitamin E levels after treatment accompanied by improvement in one of the sperm function tests : the zona binding assay . The zona binding ratio for order A improved from 0.2 ( range 0 to 0.5 ) before treatment to 0.5 ( range 0.1 to 1.0 ) after treatment , the corresponding values for order B were 0.2 ( range 0 to 1.0 ) before treatment and 0.3 ( range 0.1 to 0.7 ) after treatment . CONCLUSION Oral administration of vitamin E significantly improves the in vitro function of human spermatozoa as assessed by the zona binding test To investigate the role of increased seminal leukocytes in enhancing reactive oxygen species ( ROS ) production by human spermatozoa . A prospect i ve study . Male infertility clinic . Forty-eight infertile men .  St and ard semen analysis . Assessment of sperm nuclear DNA damage by sperm chromatin structure assay . Incubation of spermatozoa from nonleukocytospermic sample s with blood neutrophils . Spontaneous and phorbol 12-myristate 13-acetate (PMA)-induced ROS production in pure-sperm suspensions ( after removal of leukocytes ) as measured by a chemiluminescence assay . Levels of spontaneous and PMA-induced ROS production in pure-sperm suspensions from the infertile men with a diagnosis of leukocytospermia ( n = 16 ) were significantly higher compared with the case of infertile men without leukocytospermia ( n = 32 ) and with the case of a control group of healthy volunteers ( n = 13 ) . A similar pattern of increased ROS was observed when spermatozoa were incubated with blood neutrophils . Leukocytospermia was associated with a significant decrease in sperm motility and increase in DNA damage . Increased seminal leukocytes may play a role in stimulating ROS production by human spermatozoa . Such stimulation may be mediated via direct cell-cell contact or by soluble products released by leukocytes . Poor sperm quality in leukocytospermic sample s may be due to leukocyte-mediated oxidative stress OBJECTIVE To determine the effect of ascorbic acid supplementation on the sperm quality of heavy smokers . DESIGN Microscopic examination of semen for 1 month during supplementation with placebo or ascorbic acid at dose levels of 200 or 1,000 mg/d . SETTING Department of Obstetrics and Gynecology , The University of Texas Medical Branch . PARTICIPANTS Seventy-five men ( 20 to 35 years old ) r and omly divided into one of three supplementation groups : placebo , 200 mg and 1,000 mg of ascorbic acid . MAIN OUTCOME Improvement in sperm quality as compared with presupplementation levels and between the three treatment groups . RESULTS The placebo group showed no improvement in sperm quality . The groups receiving ascorbic acid showed improvement in sperm quality with most improvement in the 1,000-mg group . Pearson 's correlation showed statistically significant relationships between the weekly group means of serum and seminal plasma ascorbic acid levels and sperm qualities . CONCLUSIONS Ascorbic acid supplementation of heavy smokers in excess of 200 mg/d results in improved sperm quality OBJECTIVE To determine the efficacy of L-carnitine therapy in selected cases of male factor infertility . DESIGN Placebo-controlled , double-blind , crossover trial . SETTING University tertiary referral center . PATIENT(S ) One hundred infertile patients ( ages 20 - 40 years ) with the following baseline sperm selection criteria : concentration , 10 - 20 x 10(6)/mL ; total motility , 10%-30 % ; forward motility , < 15 % ; atypical forms , < 70 % ; velocity , 10 - 30 micro/s ; linearity , < 4 . Eighty-six patients completed the study . INTERVENTION(S ) Patients underwent L-carnitine therapy 2 g/day or placebo ; the study design was 2 months of washout , 2 months of therapy/placebo , 2 months of washout , and 2 months placebo/therapy . MAIN OUTCOME MEASURE(S ) Variation in sperm parameters used in the patients selection criteria , in particular , sperm motility . Excluding outliers , a statistically significant improvement in semen quality , greater than after the placebo cycle , was seen after the L-carnitine therapy for sperm concentration and total and forward sperm motility . The increase in forward sperm motility was more significant in those patients with lower initial values , i.e. , < 5 x 10(6 ) or < 2 x 10(6 ) of forward motile sperm/ejaculate or sperm/mL. CONCLUSION ( S ) Based on a controlled study of efficacy , L-carnitine therapy was effective in increasing semen quality , especially in groups with lower baseline levels . However , these results need to be confirmed by larger clinical trials and in vitro studies BACKGROUND Selenium is a central determinant of antioxidative glutathione peroxidase 1 ( GPx-1 ) expression and activity . The relevance of selenium supplementation on GPx-1 in coronary artery disease ( CAD ) needs to be established . We assessed the effect of selenium supplementation on GPx-1 in cell culture and on endothelial function in a prospect i ve clinical trial . METHODS Human coronary artery endothelial cells were incubated with 5.78 to 578 nmol/L sodium selenite , Se-methyl-selenocysteine hydrochloride , or seleno-l-methionine . Glutathione peroxidase 1 mRNA and protein expression and activity were measured . Coronary artery disease patients ( n = 465 ) with impaired endothelial function ( flow-mediated dilation [ FMD ] < 8 % ) were r and omly assigned to receive 200 or 500 microg sodium selenite daily or matching placebo during a 12-week period . We tested the effect on red blood cell GPx-1 activity and brachial artery FMD . Furthermore , differences in biomarkers of oxidative stress and inflammation were measured . RESULTS Sodium selenite and Se-methyl-selenocysteine hydrochloride increased GPx-1 protein and activity in a dose-dependent manner ( P < .0001 ) . The intention-to-treat groups comprised 433 CAD patients .  Glutathione peroxidase 1 activity increased from 37.0 U/gHb ( 31.3 - 41.7 ) to 41.1 U/gHb ( 35.2 - 48.4 ) ( P < .0001 ) in the 200 microg and from 38.1 U/gHb ( 33.2 - 43.8 ) to 42.6 U/gHb ( 35.0 - 49.1 ) ( P < .0001 ) in the 500 microg sodium selenite group treated for 12-weeks . No relevant changes were observed for FMD or biomarkers of oxidative stress and inflammation . CONCLUSIONS Sodium selenite supplementation increases GPx-1 activity in endothelial cells and in CAD patients . Future studies have to demonstrate whether long-term CAD outcome can be improved The objective of this study was to detect a therapy for idiopathic and varicoce 
    Output:
    
The use of  oral antioxidants in infertile men could improve sperm quality and pregnancy rates .