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: Abstract Objectives : Approximately one third to one half of the penis is embedded in the pelvis and can be felt through the scrotum and in the perineum . The main arteries and nerves enter the penis through this perineal part of the penis , which seems to represent a highly sensitive area . We investigated the hypothesis that percutaneous perineal stimulation evokes erection in patients with neurogenic erectile dysfunction . Methods : Percutaneous electrostimulation of the perineum ( PESP ) with synchronous intracorporeal pressure ( ICP ) recording was performed in 28 healthy volunteers ( age 36.3 ± 7.4 y ) and 18 patients ( age 36.6 ± 6.8 y ) with complete neurogenic erectile dysfunction ( NED ) . Current was delivered in a sine wave summation fashion . Average maximal voltages and number of stimulations delivered per session were 15 to 18 volts and 15 to 25 stimulations , respectively . Results : PESP of healthy volunteers effected an ICP increase ( P < 0.0001 ) , which returned to the basal value upon stimulation cessation . The latent period recorded was 2.5 ± 0.2 seconds . Results were reproducible on repeated PESP in the same subject but with an increase of the latent period . Patients with NED recorded an ICP increase that was lower ( P < 0.05 ) and a latent period that was longer ( P < 0.0001 ) than those of healthy volunteers . Conclusion : PESP effected ICP increase in the healthy volunteers and patients with NED .  The ICP was significantly higher and latent period shorter in the healthy volunteers than in the NED patients . PESP may be of value in the treatment of patients with NED , provided that further studies are performed to reproduce these results Our experience with intracavernous injection of prostagl and in E1 in spinal cord injured patients with neurogenic erectile dysfunction included 15 men . They received testing dosage starting from 5 µg with increasing dosage ( maximum 20 µg ) to achieve a rigid erection of Schramek 's grade 5 and lasting for at least 20 min . All of them had achieved functional erection adequate for coitus after treatment except one patient who had been proved to have venogenic impotence . We found that intracavernous injection of prostagl and in E1 had significantly improved the erectile condition . No systemic side effect or any other complication was noted except that pain at the injection site was complained of in two patients with incomplete lesion Abstract Background / objective : To show the efficacy , safety , and tolerability of sildenafil in men with erectile dysfunction ( ED ) associated with complete or incomplete spinal cord injury ( SCI ) and to assess its effects on quality of life ( Qol ) using the Life-Satisfaction Check List . Methods : This was a placebo-controlled , multicenter , r and omized , double-blind , flexible-dose , 2-way crossover study with a 2-week washout period between each phase . Patients with ED attributable to SCI(Sexual Health Inventory-Male score ≤21 ) received 50 to 100 mg sildenafil ( n = 24 ) or placebo ( n = 26 ) . Results : Compared with placebo , sildenafil produced higher levels of successful sexual stimulation , intercourse success , satisfaction with sexual life and sexual relationship , erectile function , overall sexual satisfaction , and an improved Erectile Dysfunction Inventory of Treatment Satisfaction score , with no clinical ly relevant effects onvital signs . Sildenafil seemed more effective in patients with incomplete SCI than in those with complete SCI , producing significant improvements , compared with placebo , in a number of measures only in patients with incomplete SCI . All patients who expressed a preference selected sildenafil over placebo , although the drug had no effect on patient Qol .  Sildenafil was well tolerated , with a profile comparable to that of placebo . Conclusions : Compared with placebo , treatment with oral sildenafil safely and effectively improved erectile function in patients with ED attributable to SCI , especially in those with incomplete injury , and was theagent of choice in those who expressed a preference AIM Vardenafil is a highly selective phosphodiesterase type-5 inhibitor for the treatment of erectile dysfunction ( ED ) . Efficacy of vardenafil has been demonstrated in various ED population s , but that in Japanese patients with spinal cord injury ( SCI ) has not been assessed . METHODS This was an open-label , multicenter , flexible dose , 12-week study in patients with ED due to SCI . Following a 4-week observation period , patients received vardenafil 10 mg for 4 weeks , and based on efficacy , tolerability and patient preference , doses for the remaining 8 weeks were decided by investigators . The primary efficacy parameter was erectile function domain score of the International Index of Erectile Function . RESULTS Ten patients took 10 mg all through the study , while 22 patients took 20 mg after completing 4 weeks ' treatment with 10 mg . The erectile function domain score increased from 12.2 at baseline to 25.0 at Last Observation Carried Forward ( LOCF ) in the former group and from 10.3 to 22.5 in the latter group , respectively . Importantly , there was a 5.0 point increase in erectile function domain score after up-titration in the latter group . Drug-related adverse events were observed in 22 % of patients including hot flushes ( 9 % ) and headache ( 6 % ) , but these were transient and mild in intensity . Serious adverse events and adverse events leading to discontinuation of the study drug were not reported . CONCLUSIONS Vardenafil 10 and 20 mg was well tolerated and improved erectile function in patients with SCI . Of interest , erectile function was further improved by 20 mg in patients who were not sufficiently treated with 10 mg Sildenafil ( Viagra , UK-92,480 ) is a novel oral agent under development for the treatment of  penile erectile dysfunction .  Erection is dependent on nitric oxide and its second messenger , cyclic guanosine monophosphate ( cGMP ) . However , the relative importance of phosphodiesterase ( PDE ) isozymes is not clear . We have identified both cGMP- and cyclic adenosine monophosphate-specific phosphodiesterases ( PDEs ) in human corpora cavernosa in vitro . The main PDE activity in this tissue was due to PDE5 , with PDE2 and 3 also identified . Sildenafil is a selective inhibitor of PDE5 with a mean IC50 of 0.0039 microM. In human volunteers , we have shown sildenafil to have suitable pharmacokinetic and pharmacodynamic properties ( rapid absorption , relatively short half-life , no significant effect on heart rate and blood pressure ) for an oral agent to be taken , as required , prior to sexual activity . Moreover , in a clinical study of 12 patients with erectile dysfunction without an established organic cause , we have shown sildenafil to enhance the erectile response ( duration and rigidity of erection ) to visual sexual stimulation , thus highlighting the important role of PDE5 in human penile erection . Sildenafil holds promise as a new effective oral treatment for penile erectile dysfunction OBJECTIVES To assess the efficacy of intraurethral prostagl and in E1 ( alprostadil , MUSE ) in treating  erectile dysfunction in patients with spinal cord injury ( SCI ) . METHODS Intraurethral alprostadil was tested in 15 patients with SCI to evaluate its effectiveness in treating SCI-associated erectile dysfunction . All patients were at least 1 year after injury , and all had previously used intracavernosal injections successfully ( Schramek 's grade 5 erection ) . The intraurethral drug was administered in the office , in the presence of a physician , with monitoring of blood pressure . If effective , the patient was then able to use MUSE at home . The first 3 patients underwent gradual dose escalation starting with 125 microg , without the use of a constriction ring . Because of hypotension , the remaining 12 patients all used a penile constriction ring prior to intraurethral drug administration using 1000 microg . The quality of the erection was compared with that achieved with intracavernosal injections using Schramek 's grading . RESULTS The dose escalation ( titration ) in the first 3 patients demonstrated that the 1000-microg dose was the most effective in creating an erectile response . Transient hypotension was noted in these first 3 patients in whom the constricting b and was not used . The highest dose of MUSE ( 1000 microg ) was , therefore , used in the remaining 12 patients , with the constriction b and . The quality of the erection varied and appeared to be less rigid in all patients ( 12 patients with grade 1 to 3 ; 3 patients with grade 4 ) than that noted with intracavernosal injection therapy ( 1 5 patients with grade 5 ) . There was no incidence of priapism . The 3 patients with grade 4 erections tried the MUSE at home . All 3 patients were dissatisfied with the quality of the erection and did not continue to use the MUSE at home and returned to intracavernosal injection therapy . CONCLUSIONS MUSE appears to be somewhat effective in creating erections ; however , these were less rigid erections than those obtained with intracavernosal therapy and provided less overall satisfaction . It should always be used in the patient with SCI after placement of a constriction ring to prevent hypotension . Its ultimate use depends on the patient 's level of satisfaction with the quality of the erection compared with intracavernosal injections A total of 66 spinal cord injury patients with erectile dysfunction entered a protocol of penile intracavernous pharmacotherapy with papaverine hydrochloride ( 30 mg . per ml . ) or a combination of papaverine ( 25 mg . per ml . ) and phentolamine mesylate ( 0.83 mg . per ml . ) in an attempt to restore erectile function . Of the patients 52 completed the protocol and all achieved transient functional penile erections after administration of the drug . Of the 52 responders 71 per cent currently practice self-injection as a method to restore erectile function . Sustained erections that required irrigation of the cavernous bodies with alpha-adrenergic agents developed in 4 patients and 1 suffered localized intracorporeal in duration . If the long-term followup shows that complications remain relatively minor , undoubtedly vasoactive intracavernous pharmacotherapy will have a major role in the restoration of erectile function in the motivated man with spinal cord injury . However , in view of the unknown long-term effects and potential dangers of this approach it is important that patients adhere to a strict drug injection protocol under the supervision of qualified urologists who are familiar with the potential risks and complications 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 To evaluate the efficacy of sildenafil in the treatment of neurogenic erectile dysfunction ( ED ) secondary to upper motor neuron ( UMN ) and lower motor neuron ( LMN ) spinal cord injury ( SCI ) . After taking consents 105 patients suffering from ED were enrolled in this prospect i ve study . Seventy-two patients had signs and symptoms of UMN and 33 patients had signs and symptoms of LMN or mixed ( UMN and LMN ) spinal cord injuries . The patients took 50 - 100 mg sildenafil or placebo tablet at least 45 min before sexual 
    Output:
    
agent
Conclusions : This systematic review and meta- analysis indicate that PDE5 inhibitors are effective and well tolerated to treat ED secondary to SCI compared with placebo , as measured by response to GEQ , SEP2 , SEP3 and incidence of adverse events .
PDE5 inhibitors could be considered as the first choice in the treatment of ED patients with SCI
***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: Abstract Objectives : Approximately one third to one half of the penis is embedded in the pelvis and can be felt through the scrotum and in the perineum . The main arteries and nerves enter the penis through this perineal part of the penis , which seems to represent a highly sensitive area . We investigated the hypothesis that percutaneous perineal stimulation evokes erection in patients with neurogenic erectile dysfunction . Methods : Percutaneous electrostimulation of the perineum ( PESP ) with synchronous intracorporeal pressure ( ICP ) recording was performed in 28 healthy volunteers ( age 36.3 ± 7.4 y ) and 18 patients ( age 36.6 ± 6.8 y ) with complete neurogenic erectile dysfunction ( NED ) . Current was delivered in a sine wave summation fashion . Average maximal voltages and number of stimulations delivered per session were 15 to 18 volts and 15 to 25 stimulations , respectively . Results : PESP of healthy volunteers effected an ICP increase ( P < 0.0001 ) , which returned to the basal value upon stimulation cessation . The latent period recorded was 2.5 ± 0.2 seconds . Results were reproducible on repeated PESP in the same subject but with an increase of the latent period . Patients with NED recorded an ICP increase that was lower ( P < 0.05 ) and a latent period that was longer ( P < 0.0001 ) than those of healthy volunteers . Conclusion : PESP effected ICP increase in the healthy volunteers and patients with NED .  The ICP was significantly higher and latent period shorter in the healthy volunteers than in the NED patients . PESP may be of value in the treatment of patients with NED , provided that further studies are performed to reproduce these results Our experience with intracavernous injection of prostagl and in E1 in spinal cord injured patients with neurogenic erectile dysfunction included 15 men . They received testing dosage starting from 5 µg with increasing dosage ( maximum 20 µg ) to achieve a rigid erection of Schramek 's grade 5 and lasting for at least 20 min . All of them had achieved functional erection adequate for coitus after treatment except one patient who had been proved to have venogenic impotence . We found that intracavernous injection of prostagl and in E1 had significantly improved the erectile condition . No systemic side effect or any other complication was noted except that pain at the injection site was complained of in two patients with incomplete lesion Abstract Background / objective : To show the efficacy , safety , and tolerability of sildenafil in men with erectile dysfunction ( ED ) associated with complete or incomplete spinal cord injury ( SCI ) and to assess its effects on quality of life ( Qol ) using the Life-Satisfaction Check List . Methods : This was a placebo-controlled , multicenter , r and omized , double-blind , flexible-dose , 2-way crossover study with a 2-week washout period between each phase . Patients with ED attributable to SCI(Sexual Health Inventory-Male score ≤21 ) received 50 to 100 mg sildenafil ( n = 24 ) or placebo ( n = 26 ) . Results : Compared with placebo , sildenafil produced higher levels of successful sexual stimulation , intercourse success , satisfaction with sexual life and sexual relationship , erectile function , overall sexual satisfaction , and an improved Erectile Dysfunction Inventory of Treatment Satisfaction score , with no clinical ly relevant effects onvital signs . Sildenafil seemed more effective in patients with incomplete SCI than in those with complete SCI , producing significant improvements , compared with placebo , in a number of measures only in patients with incomplete SCI . All patients who expressed a preference selected sildenafil over placebo , although the drug had no effect on patient Qol .  Sildenafil was well tolerated , with a profile comparable to that of placebo . Conclusions : Compared with placebo , treatment with oral sildenafil safely and effectively improved erectile function in patients with ED attributable to SCI , especially in those with incomplete injury , and was theagent of choice in those who expressed a preference AIM Vardenafil is a highly selective phosphodiesterase type-5 inhibitor for the treatment of erectile dysfunction ( ED ) . Efficacy of vardenafil has been demonstrated in various ED population s , but that in Japanese patients with spinal cord injury ( SCI ) has not been assessed . METHODS This was an open-label , multicenter , flexible dose , 12-week study in patients with ED due to SCI . Following a 4-week observation period , patients received vardenafil 10 mg for 4 weeks , and based on efficacy , tolerability and patient preference , doses for the remaining 8 weeks were decided by investigators . The primary efficacy parameter was erectile function domain score of the International Index of Erectile Function . RESULTS Ten patients took 10 mg all through the study , while 22 patients took 20 mg after completing 4 weeks ' treatment with 10 mg . The erectile function domain score increased from 12.2 at baseline to 25.0 at Last Observation Carried Forward ( LOCF ) in the former group and from 10.3 to 22.5 in the latter group , respectively . Importantly , there was a 5.0 point increase in erectile function domain score after up-titration in the latter group . Drug-related adverse events were observed in 22 % of patients including hot flushes ( 9 % ) and headache ( 6 % ) , but these were transient and mild in intensity . Serious adverse events and adverse events leading to discontinuation of the study drug were not reported . CONCLUSIONS Vardenafil 10 and 20 mg was well tolerated and improved erectile function in patients with SCI . Of interest , erectile function was further improved by 20 mg in patients who were not sufficiently treated with 10 mg Sildenafil ( Viagra , UK-92,480 ) is a novel oral agent under development for the treatment of  penile erectile dysfunction .  Erection is dependent on nitric oxide and its second messenger , cyclic guanosine monophosphate ( cGMP ) . However , the relative importance of phosphodiesterase ( PDE ) isozymes is not clear . We have identified both cGMP- and cyclic adenosine monophosphate-specific phosphodiesterases ( PDEs ) in human corpora cavernosa in vitro . The main PDE activity in this tissue was due to PDE5 , with PDE2 and 3 also identified . Sildenafil is a selective inhibitor of PDE5 with a mean IC50 of 0.0039 microM. In human volunteers , we have shown sildenafil to have suitable pharmacokinetic and pharmacodynamic properties ( rapid absorption , relatively short half-life , no significant effect on heart rate and blood pressure ) for an oral agent to be taken , as required , prior to sexual activity . Moreover , in a clinical study of 12 patients with erectile dysfunction without an established organic cause , we have shown sildenafil to enhance the erectile response ( duration and rigidity of erection ) to visual sexual stimulation , thus highlighting the important role of PDE5 in human penile erection . Sildenafil holds promise as a new effective oral treatment for penile erectile dysfunction OBJECTIVES To assess the efficacy of intraurethral prostagl and in E1 ( alprostadil , MUSE ) in treating  erectile dysfunction in patients with spinal cord injury ( SCI ) . METHODS Intraurethral alprostadil was tested in 15 patients with SCI to evaluate its effectiveness in treating SCI-associated erectile dysfunction . All patients were at least 1 year after injury , and all had previously used intracavernosal injections successfully ( Schramek 's grade 5 erection ) . The intraurethral drug was administered in the office , in the presence of a physician , with monitoring of blood pressure . If effective , the patient was then able to use MUSE at home . The first 3 patients underwent gradual dose escalation starting with 125 microg , without the use of a constriction ring . Because of hypotension , the remaining 12 patients all used a penile constriction ring prior to intraurethral drug administration using 1000 microg . The quality of the erection was compared with that achieved with intracavernosal injections using Schramek 's grading . RESULTS The dose escalation ( titration ) in the first 3 patients demonstrated that the 1000-microg dose was the most effective in creating an erectile response . Transient hypotension was noted in these first 3 patients in whom the constricting b and was not used . The highest dose of MUSE ( 1000 microg ) was , therefore , used in the remaining 12 patients , with the constriction b and . The quality of the erection varied and appeared to be less rigid in all patients ( 12 patients with grade 1 to 3 ; 3 patients with grade 4 ) than that noted with intracavernosal injection therapy ( 1 5 patients with grade 5 ) . There was no incidence of priapism . The 3 patients with grade 4 erections tried the MUSE at home . All 3 patients were dissatisfied with the quality of the erection and did not continue to use the MUSE at home and returned to intracavernosal injection therapy . CONCLUSIONS MUSE appears to be somewhat effective in creating erections ; however , these were less rigid erections than those obtained with intracavernosal therapy and provided less overall satisfaction . It should always be used in the patient with SCI after placement of a constriction ring to prevent hypotension . Its ultimate use depends on the patient 's level of satisfaction with the quality of the erection compared with intracavernosal injections A total of 66 spinal cord injury patients with erectile dysfunction entered a protocol of penile intracavernous pharmacotherapy with papaverine hydrochloride ( 30 mg . per ml . ) or a combination of papaverine ( 25 mg . per ml . ) and phentolamine mesylate ( 0.83 mg . per ml . ) in an attempt to restore erectile function . Of the patients 52 completed the protocol and all achieved transient functional penile erections after administration of the drug . Of the 52 responders 71 per cent currently practice self-injection as a method to restore erectile function . Sustained erections that required irrigation of the cavernous bodies with alpha-adrenergic agents developed in 4 patients and 1 suffered localized intracorporeal in duration . If the long-term followup shows that complications remain relatively minor , undoubtedly vasoactive intracavernous pharmacotherapy will have a major role in the restoration of erectile function in the motivated man with spinal cord injury . However , in view of the unknown long-term effects and potential dangers of this approach it is important that patients adhere to a strict drug injection protocol under the supervision of qualified urologists who are familiar with the potential risks and complications 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 To evaluate the efficacy of sildenafil in the treatment of neurogenic erectile dysfunction ( ED ) secondary to upper motor neuron ( UMN ) and lower motor neuron ( LMN ) spinal cord injury ( SCI ) . After taking consents 105 patients suffering from ED were enrolled in this prospect i ve study . Seventy-two patients had signs and symptoms of UMN and 33 patients had signs and symptoms of LMN or mixed ( UMN and LMN ) spinal cord injuries . The patients took 50 - 100 mg sildenafil or placebo tablet at least 45 min before sexual 
    Output:
    