human
***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: PURPOSE Now that individuals with spina bifida live well into adulthood erectile dysfunction has become a recognized associated medical disorder . To our knowledge no study has dealt specifically with treatment of  erectile dysfunction in men with spina bifida . Therefore , we conducted a prospect i ve , blinded , r and omized , placebo controlled , dose escalation , crossover study to determine the ability to treat erectile dysfunction in men with spina bifida with sildenafil citrate . MATERIAL S AND METHODS Erectile dysfunction was diagnosed in 15 men 19 to 35 years old with spina bifida who were assigned to take 4 sets of tablets , 5 tablets per set , in a r and om order . All patients took 25 and 50 mg . sildenafil and 2 identical looking sets of corresponding placebos 1 hour before planned sexual activity . Efficacy was assessed by the effect of treatment compared to baseline , that is before treatment , on rating of erections ( scored from 0 to 10 ) , duration of erections , frequency of erections based on response to question 1 ( scored from 0 to 5 ) of the International Index of Erectile Function and confidence to obtain an erection based on response to question 15 ( scored from 1 to 5 ) of the International Index of Erectile Function . RESULTS Improved erectile function was reported while on sildenafil by 12 ( 80 % ) men compared to baseline and placebos . There was a significant dose dependent improvement of erectile function with both 25 and 50 mg . sildenafil compared to baseline ( p < 0.05 ) , as mean erectile score increased by 50 % and 88 % , mean duration of erections increased by 192 % and 266 % , mean frequency of erections increased by 61 % and 96 % , and mean level of confidence increased by 33 % and 63 % , respectively . Furthermore , 50 mg . sildenafil provided greater improvement in all 4 parameters compared to 25 mg . The placebo results were not significantly different compared to baseline for any of the parameters . CONCLUSIONS Erectile dysfunction in patients with spina bifida is a medically treatable condition . Sildenafil is effective in this patient population and improves level of sexual confidence Study design : This was a two-part pilot study in men with erectile dysfunction ( ED ) due to spinal cord injury ( SCI : cord level range T6-L5 ) . Part I was a r and omised , double-blind , two-way cross-over study comparing a single dose of sildenafil 50 mg or placebo . Part II was a r and omised , double-blind , parallel-group evaluation of sildenafil 50 mg or placebo , taken as required ( not more than once daily ) approximately 1 h prior to sexual activity , over a period of 28 days . Objectives : To assay the efficacy and safety of sildenafil 50 mg and placebo . Setting : Clinic- and home-based assessment s in the United Kingdom . Methods : A total of 27 subjects who were able to achieve at least a grade 2 erection ( hard , but not hard enough for penetration ) in response to penile vibratory stimulation ( PVS ) were recruited . In Part I , the reflexogenic response of the penis to PVS was evaluated in the clinic while in Part II , the response to treatment was assessed in the home ( global efficacy , question niare , diary ) . Results : In Part I , 17/26 ( 65 % ) subjects had erections of > 60 % rigidity at the penile base ( median duration 3.5 min ) after sildenafil compared with 2/26 ( 8 % ) ( median duration 0 min ) after placebo ( P=0.0003 ) . In Part II , 9/12 ( 75 % ) subjects on sildenafil and 1/14 ( 7 % ) subjects on placebo reported that the treatment had improved their erections ( P<0.005 ) , and 8/12 ( 67 % ) and 2/13 ( 15 % ) men , respectively , indicated that they wished to continue treatment ( P<0.02 ) . An analysis of diary data showed no difference between the groups with respect to the mean number of erections hard enough for penetration ( P=0.08 ) . The mean proportion of attempts at sexual intercourse that were successful was 30 and 15 % , respectively ( P=0.21 ) . Similarly , responses to the end-of-treatment question naire indicated that there were no significant differences between the groups with respect to the frequency of erections hard enough for sexual intercourse ( P=0.47 ) or that lasted as long as the subject would have liked ( P=0.11 ) . No subject discontinued sildenafil due to adverse events . Conclusion : Sildenafil is an effective , well-tolerated oral treatment for ED in SCI subjects . Sponsorship : This study was funded by Pfizer The efficacy and safety of oral sildenafil , a potent inhibitor of phosphodiesterase type 5 , were evaluated in men with diabetes mellitus and erectile dysfunction ( ED ) . Twenty-one men ( aged 42 - 65 years ) were enrolled in a double-blind , placebo-controlled , three-way crossover study conducted in two parts . In part I , the effect of a single dose ( 25 mg or 50 mg ) of sildenafil or placebo on penile rigidity was assessed by penile plethysmography during visual sexual stimulation . In part II , daily diary records of erectile activity and a global efficacy question were used to evaluate once-daily dosing with 25 mg or 50 mg of sildenafil or placebo for 10 days . After a single 50 mg dose of sildenafil , the adjusted geometric mean duration ( min ) of penile rigidity > 60 % at the base of the penis during visual sexual stimulation was significantly increased ( 10.1 min ) compared with placebo ( 2.8 min ; p = 0.0053 ) . In part II , sildenafil significantly increased the number of erections considered sufficiently hard for vaginal penetration compared with placebo ( p = 0.0005 ) . Improved erections were reported by 50 % and 52 % of patients treated with 25 mg and 50 mg of sildenafil , respectively , compared with 10 % of those receiving placebo ( p values < 0.05 ) . Adverse events were mostly mild or moderate in nature and included muscular pains , headache , and dyspepsia .  Sildenafil is a well-tolerated and potentially efficacious oral treatment for ED in men with diabetes mellitus PURPOSE We assessed patient preference , satisfaction and overall outcome of goal directed management of  erectile dysfunction . MATERIAL S AND METHODS The results of goal directed therapy of impotence were assessed by an independent telephone survey of 377 consecutive men who had not received prior therapy and who were followed for a minimum of 2 years . RESULTS Patients preferred medical to surgical therapies despite significantly higher satisfaction rates achieved with surgery . Average number of treatment modalities chosen by each patient was 2 ( range 0 to 5 ) . Ultimately , only 40 % of the patients achieved a long-term satisfactory result with goal directed therapy . The remainder were not satisfied with the last treatment but chose no further therapy , were lost to followup or refused therapy from the outset . CONCLUSIONS Our results clearly demonstrate a patient preference for the least invasive forms of therapy . Patients avoid significantly more effective but also more invasive treatment options despite unsatisfactory results with less invasive methods . Future research efforts should be concentrated on the development of new medical therapies to enhance overall patient satisfaction PURPOSE Goal oriented therapy for erectile dysfunction , based on a complete education of the couple , was offered to 460 patients . The short-term and long-term results of the first and second treatments selected were compared . MATERIAL S AND METHODS From September 1991 to March 1995 , 460 patients with erectile dysfunction were evaluated and treated prospect ively . The success of treatment , selected by the patient or couple , was defined as the ability to achieve and maintain good erections for successful coitus for at least 1 year after the start of therapy . Sexual satisfaction of the couple was required to confirm a successful outcome . RESULTS The preferred first line of treatment by 322 patients was pharmacotherapy , with intracavernous injections being the second most selected therapy ( 80 % success rate ) . However , there was a high long-term dropout rate for intracavernous injections . Approximately 70 % of the patients were lost to followup or refused further treatment . CONCLUSIONS Overall , this prospect i ve study showed that goal oriented therapy is initially highly successful . However , the long-term high dropout rate and dissatisfaction of the couple cast doubt about the efficacy of the present treatment options OBJECTIVES To evaluate the efficacy , safety , and tolerability of oral sildenafil in Asian men with erectile dysfunction of various causes ( organic , psychogenic , or mixed ) and of more than 6 months ' duration . METHODS In this double-blind , parallel-group trial conducted at eight centers in Malaysia , the Philippines , and Singapore , 254 men , 26 to 78 years old , were r and omized to 12 weeks of sildenafil or placebo taken as needed 1 hour before anticipated sexual activity . Initially , the sildenafil ( n = 127 ) or matching placebo ( n = 127 ) dose was 50 mg but could be increased to 100 mg or decreased to 25 mg because of a lack of efficacy or intolerance , respectively . Efficacy was assessed by the 15- question International Index of Erectile Function , patients ' event logs of sexual activity , and a global efficacy question about erections . RESULTS The two primary efficacy variables relating to achievement and maintenance of an erection sufficient for sexual intercourse , as assessed by the mean scores for International Index of Erectile Function question 3 ( 4.22 versus 2.59 ) and question 4 ( 4.15 versus 2.41 ) , were both significantly higher with sildenafil than with placebo ( P < 0.0001 ) . In addition , the five separate International Index of Erectile Function domains of sexual function , the percentage of successful intercourse attempts , and the global efficacy assessment of erections revealed significantly greater treatment effects in favor of sildenafil ( P < 0.0001 versus placebo for all variables ) . Treatment-related adverse events occurred in 22.8 % of patients who received sildenafil and in 10.2 % of those who received placebo . CONCLUSIONS Sildenafil is an effective and well-tolerated treatment for Asian men with erectile dysfunction of broad-spectrum etiology BACKGROUND Sildenafil is a potent inhibitor of cyclic guanosine monophosphate hydrolysis [ corrected ] in the corpus cavernosum and therefore increases the penile response to sexual stimulation . We evaluated the efficacy and safety of sildenafil , administered as needed in two sequential double-blind studies of men with erectile dysfunction of organic , psychogenic , and mixed causes . METHODS In a 24-week dose-response study , 532 men were treated with oral sildenafil  ( 25 , 50 , or 100 mg ) or placebo . In a 12-week , flexible dose-escalation study , 329 different men were treated with sildenafil or placebo , with dose escalation to 100 mg based on efficacy and tolerance . After this dose-escalation study , 225 of the 329 men entered a 32-week , open-label extension study . We assessed efficacy according to the International Index of Erectile Function , a patient log , and a global-efficacy question . RESULTS In the dose-response study , increasing doses of sildenafil were associated with improved erectile function ( P values for increases in scores for questions about achieving and maintaining erections were < 0.001 ) . For the men receiving 100 mg of sildenafil , the mean score for the question about achieving erections was 100 percent higher after treatment than at base line ( 4.0 vs. 2.0 of a possible score of 5 ) . In the last four weeks of treatment in the dose-escalation study , 69 percent of all attempts at sexual intercourse were successful for the men receiving sildenafil , as compared with 22 percent for those receiving placebo ( P<0.001 ) . The mean numbers of successful attempts per month were 5.9 for the men receiving sildenafil and 1.5 for those receiving placebo ( P<0.001 ) . Headache , flushing , and dyspepsia were the most common adverse effects in the dose-escalation study , occurring in 6 percent to 18 percent of the men . Ninety-two percent of the men completed the 32-week extension study . CONCLUSIONS Oral sildenafil is an effective , well-tolerated treatment for men with erectile dysfunction OBJECTIVES To evaluate the efficacy , safety , and tolerability of sildenafil in men with broad-spectrum erectile dysfunction ( ED ) , with reference to age-matched healthy control subjects . METHODS One hundred eleven patients were enrolled in a r and omized , double-blind , placebo-controlled , parallel-group , 12-week , flexible-dose study . Efficacy assessment s included the International Index of Erectile Function ( IIEF ) , a global assessment question , and patient event log data . In a separate , nontreatment study , 109 control subjects also completed the IIEF . RESULTS Mean IIEF scores at baseline were significantly lower for patients with ED than for control subjects without a history of ED . After treatment , mean IIEF scores for patients receiving sildenafil approached values observed in 
    Output:
    
agent
In data pooled from 6 parallel-group , fixed-dose trials , efficacy appeared slightly greater at higher doses .
Treatment response appeared to vary between patient subgroups , although relative to placebo , sildenafil significantly improved erectile function in all evaluated subgroups .
In trials with parallel-group design and flexible dosing , men r and omized to receive sildenafil were less likely than those receiving placebo to drop out for any reason and no more likely to drop out due to an adverse event or laboratory abnormality .
Sildenafil was not significantly associated with serious cardiovascular events or death .
CONCLUSIONS Sildenafil improves erectile function and is generally well tolerated .
Treatment response seems to vary between patient subgroups , although sildenafil has greater efficacy than placebo in all evaluated subgroups
***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: PURPOSE Now that individuals with spina bifida live well into adulthood erectile dysfunction has become a recognized associated medical disorder . To our knowledge no study has dealt specifically with treatment of  erectile dysfunction in men with spina bifida . Therefore , we conducted a prospect i ve , blinded , r and omized , placebo controlled , dose escalation , crossover study to determine the ability to treat erectile dysfunction in men with spina bifida with sildenafil citrate . MATERIAL S AND METHODS Erectile dysfunction was diagnosed in 15 men 19 to 35 years old with spina bifida who were assigned to take 4 sets of tablets , 5 tablets per set , in a r and om order . All patients took 25 and 50 mg . sildenafil and 2 identical looking sets of corresponding placebos 1 hour before planned sexual activity . Efficacy was assessed by the effect of treatment compared to baseline , that is before treatment , on rating of erections ( scored from 0 to 10 ) , duration of erections , frequency of erections based on response to question 1 ( scored from 0 to 5 ) of the International Index of Erectile Function and confidence to obtain an erection based on response to question 15 ( scored from 1 to 5 ) of the International Index of Erectile Function . RESULTS Improved erectile function was reported while on sildenafil by 12 ( 80 % ) men compared to baseline and placebos . There was a significant dose dependent improvement of erectile function with both 25 and 50 mg . sildenafil compared to baseline ( p < 0.05 ) , as mean erectile score increased by 50 % and 88 % , mean duration of erections increased by 192 % and 266 % , mean frequency of erections increased by 61 % and 96 % , and mean level of confidence increased by 33 % and 63 % , respectively . Furthermore , 50 mg . sildenafil provided greater improvement in all 4 parameters compared to 25 mg . The placebo results were not significantly different compared to baseline for any of the parameters . CONCLUSIONS Erectile dysfunction in patients with spina bifida is a medically treatable condition . Sildenafil is effective in this patient population and improves level of sexual confidence Study design : This was a two-part pilot study in men with erectile dysfunction ( ED ) due to spinal cord injury ( SCI : cord level range T6-L5 ) . Part I was a r and omised , double-blind , two-way cross-over study comparing a single dose of sildenafil 50 mg or placebo . Part II was a r and omised , double-blind , parallel-group evaluation of sildenafil 50 mg or placebo , taken as required ( not more than once daily ) approximately 1 h prior to sexual activity , over a period of 28 days . Objectives : To assay the efficacy and safety of sildenafil 50 mg and placebo . Setting : Clinic- and home-based assessment s in the United Kingdom . Methods : A total of 27 subjects who were able to achieve at least a grade 2 erection ( hard , but not hard enough for penetration ) in response to penile vibratory stimulation ( PVS ) were recruited . In Part I , the reflexogenic response of the penis to PVS was evaluated in the clinic while in Part II , the response to treatment was assessed in the home ( global efficacy , question niare , diary ) . Results : In Part I , 17/26 ( 65 % ) subjects had erections of > 60 % rigidity at the penile base ( median duration 3.5 min ) after sildenafil compared with 2/26 ( 8 % ) ( median duration 0 min ) after placebo ( P=0.0003 ) . In Part II , 9/12 ( 75 % ) subjects on sildenafil and 1/14 ( 7 % ) subjects on placebo reported that the treatment had improved their erections ( P<0.005 ) , and 8/12 ( 67 % ) and 2/13 ( 15 % ) men , respectively , indicated that they wished to continue treatment ( P<0.02 ) . An analysis of diary data showed no difference between the groups with respect to the mean number of erections hard enough for penetration ( P=0.08 ) . The mean proportion of attempts at sexual intercourse that were successful was 30 and 15 % , respectively ( P=0.21 ) . Similarly , responses to the end-of-treatment question naire indicated that there were no significant differences between the groups with respect to the frequency of erections hard enough for sexual intercourse ( P=0.47 ) or that lasted as long as the subject would have liked ( P=0.11 ) . No subject discontinued sildenafil due to adverse events . Conclusion : Sildenafil is an effective , well-tolerated oral treatment for ED in SCI subjects . Sponsorship : This study was funded by Pfizer The efficacy and safety of oral sildenafil , a potent inhibitor of phosphodiesterase type 5 , were evaluated in men with diabetes mellitus and erectile dysfunction ( ED ) . Twenty-one men ( aged 42 - 65 years ) were enrolled in a double-blind , placebo-controlled , three-way crossover study conducted in two parts . In part I , the effect of a single dose ( 25 mg or 50 mg ) of sildenafil or placebo on penile rigidity was assessed by penile plethysmography during visual sexual stimulation . In part II , daily diary records of erectile activity and a global efficacy question were used to evaluate once-daily dosing with 25 mg or 50 mg of sildenafil or placebo for 10 days . After a single 50 mg dose of sildenafil , the adjusted geometric mean duration ( min ) of penile rigidity > 60 % at the base of the penis during visual sexual stimulation was significantly increased ( 10.1 min ) compared with placebo ( 2.8 min ; p = 0.0053 ) . In part II , sildenafil significantly increased the number of erections considered sufficiently hard for vaginal penetration compared with placebo ( p = 0.0005 ) . Improved erections were reported by 50 % and 52 % of patients treated with 25 mg and 50 mg of sildenafil , respectively , compared with 10 % of those receiving placebo ( p values < 0.05 ) . Adverse events were mostly mild or moderate in nature and included muscular pains , headache , and dyspepsia .  Sildenafil is a well-tolerated and potentially efficacious oral treatment for ED in men with diabetes mellitus PURPOSE We assessed patient preference , satisfaction and overall outcome of goal directed management of  erectile dysfunction . MATERIAL S AND METHODS The results of goal directed therapy of impotence were assessed by an independent telephone survey of 377 consecutive men who had not received prior therapy and who were followed for a minimum of 2 years . RESULTS Patients preferred medical to surgical therapies despite significantly higher satisfaction rates achieved with surgery . Average number of treatment modalities chosen by each patient was 2 ( range 0 to 5 ) . Ultimately , only 40 % of the patients achieved a long-term satisfactory result with goal directed therapy . The remainder were not satisfied with the last treatment but chose no further therapy , were lost to followup or refused therapy from the outset . CONCLUSIONS Our results clearly demonstrate a patient preference for the least invasive forms of therapy . Patients avoid significantly more effective but also more invasive treatment options despite unsatisfactory results with less invasive methods . Future research efforts should be concentrated on the development of new medical therapies to enhance overall patient satisfaction PURPOSE Goal oriented therapy for erectile dysfunction , based on a complete education of the couple , was offered to 460 patients . The short-term and long-term results of the first and second treatments selected were compared . MATERIAL S AND METHODS From September 1991 to March 1995 , 460 patients with erectile dysfunction were evaluated and treated prospect ively . The success of treatment , selected by the patient or couple , was defined as the ability to achieve and maintain good erections for successful coitus for at least 1 year after the start of therapy . Sexual satisfaction of the couple was required to confirm a successful outcome . RESULTS The preferred first line of treatment by 322 patients was pharmacotherapy , with intracavernous injections being the second most selected therapy ( 80 % success rate ) . However , there was a high long-term dropout rate for intracavernous injections . Approximately 70 % of the patients were lost to followup or refused further treatment . CONCLUSIONS Overall , this prospect i ve study showed that goal oriented therapy is initially highly successful . However , the long-term high dropout rate and dissatisfaction of the couple cast doubt about the efficacy of the present treatment options OBJECTIVES To evaluate the efficacy , safety , and tolerability of oral sildenafil in Asian men with erectile dysfunction of various causes ( organic , psychogenic , or mixed ) and of more than 6 months ' duration . METHODS In this double-blind , parallel-group trial conducted at eight centers in Malaysia , the Philippines , and Singapore , 254 men , 26 to 78 years old , were r and omized to 12 weeks of sildenafil or placebo taken as needed 1 hour before anticipated sexual activity . Initially , the sildenafil ( n = 127 ) or matching placebo ( n = 127 ) dose was 50 mg but could be increased to 100 mg or decreased to 25 mg because of a lack of efficacy or intolerance , respectively . Efficacy was assessed by the 15- question International Index of Erectile Function , patients ' event logs of sexual activity , and a global efficacy question about erections . RESULTS The two primary efficacy variables relating to achievement and maintenance of an erection sufficient for sexual intercourse , as assessed by the mean scores for International Index of Erectile Function question 3 ( 4.22 versus 2.59 ) and question 4 ( 4.15 versus 2.41 ) , were both significantly higher with sildenafil than with placebo ( P < 0.0001 ) . In addition , the five separate International Index of Erectile Function domains of sexual function , the percentage of successful intercourse attempts , and the global efficacy assessment of erections revealed significantly greater treatment effects in favor of sildenafil ( P < 0.0001 versus placebo for all variables ) . Treatment-related adverse events occurred in 22.8 % of patients who received sildenafil and in 10.2 % of those who received placebo . CONCLUSIONS Sildenafil is an effective and well-tolerated treatment for Asian men with erectile dysfunction of broad-spectrum etiology BACKGROUND Sildenafil is a potent inhibitor of cyclic guanosine monophosphate hydrolysis [ corrected ] in the corpus cavernosum and therefore increases the penile response to sexual stimulation . We evaluated the efficacy and safety of sildenafil , administered as needed in two sequential double-blind studies of men with erectile dysfunction of organic , psychogenic , and mixed causes . METHODS In a 24-week dose-response study , 532 men were treated with oral sildenafil  ( 25 , 50 , or 100 mg ) or placebo . In a 12-week , flexible dose-escalation study , 329 different men were treated with sildenafil or placebo , with dose escalation to 100 mg based on efficacy and tolerance . After this dose-escalation study , 225 of the 329 men entered a 32-week , open-label extension study . We assessed efficacy according to the International Index of Erectile Function , a patient log , and a global-efficacy question . RESULTS In the dose-response study , increasing doses of sildenafil were associated with improved erectile function ( P values for increases in scores for questions about achieving and maintaining erections were < 0.001 ) . For the men receiving 100 mg of sildenafil , the mean score for the question about achieving erections was 100 percent higher after treatment than at base line ( 4.0 vs. 2.0 of a possible score of 5 ) . In the last four weeks of treatment in the dose-escalation study , 69 percent of all attempts at sexual intercourse were successful for the men receiving sildenafil , as compared with 22 percent for those receiving placebo ( P<0.001 ) . The mean numbers of successful attempts per month were 5.9 for the men receiving sildenafil and 1.5 for those receiving placebo ( P<0.001 ) . Headache , flushing , and dyspepsia were the most common adverse effects in the dose-escalation study , occurring in 6 percent to 18 percent of the men . Ninety-two percent of the men completed the 32-week extension study . CONCLUSIONS Oral sildenafil is an effective , well-tolerated treatment for men with erectile dysfunction OBJECTIVES To evaluate the efficacy , safety , and tolerability of sildenafil in men with broad-spectrum erectile dysfunction ( ED ) , with reference to age-matched healthy control subjects . METHODS One hundred eleven patients were enrolled in a r and omized , double-blind , placebo-controlled , parallel-group , 12-week , flexible-dose study . Efficacy assessment s included the International Index of Erectile Function ( IIEF ) , a global assessment question , and patient event log data . In a separate , nontreatment study , 109 control subjects also completed the IIEF . RESULTS Mean IIEF scores at baseline were significantly lower for patients with ED than for control subjects without a history of ED . After treatment , mean IIEF scores for patients receiving sildenafil approached values observed in 
    Output:
    