Biomedical subjects
Publications and source records attributed to A Melman.
The man who seeks treatment for impotence typically has a sense of inadequacy that extends beyond sexual satisfaction to his business and personal relationships. Although no magic potion is available, current medical technology allows the surgeon to accommodate each patient who seeks treatment, guaranteeing sufficient penile rigidity to effect coitus.
One to four years after penile prosthesis surgery, detailed medical and psychosocial interviews were conducted separately with 52 patients and 22 of their partners. Patients tended to be negative or disappointed about postoperative pain, penis size, postoperative sexual frequency, and prosthesis malfunctions. Positive comments emphasized the psychological benefits of renewed masculine self-esteem, repair of humiliation, and reduction of marital guilt. Most patients said they would have the surgery again. Partners corroborated patients' assessments of psychological benefits, but tended to rate the mechanical benefits of the prosthesis somewhat lower. Methodological difficulties in measuring satisfaction with the prosthesis and suggestions for future follow-up research are emphasized in the discussion.
Normal penile erection is a complex event dependent upon the proper sequential function of the endocrine, nervous, and vascular systems. Medical or surgical therapy can influence those systems and so cause erectile dysfunction. Physicians must understand these iatrogenic causes of erectile dysfunction in order to prevent or reverse them.
Men with erectile problems seen for a comprehensive urology-department-based medical and psychological evaluation were sent questionnaires 2 to 3 years later. A representative sample of 99 (52%) responded. The majority (51%) has taken no action and reported that their sexual function was no better. Patients were more likely to comply with a recommendation for sex therapy than with one for a penile prosthesis. This was related to their attitude towards mental health professionals. These findings suggest the need for more knowledge of patient psychology and expectations.
Explore the source record for details and available documents.
Previous studies in our laboratory have demonstrated that alpha-methyldopa, a potent inhibitor of catecholamine synthesis, reduced both libido and erectile function in sexually mature male rats as it does in humans. In this report, those studies were extended to identify the drug's effect upon catecholamine content in the brain, spinal cord and penile erectile tissue in mature male rats. Because many men report that the adverse effects of alpha-methyldopa upon their sexual performance continue after withdrawal from the drug, a 2nd group of animals was retested after the drug was stopped. Results of the group I study showed diminished copulatory and erectile activity as well as penile and brain norepinephrine content. In the group II rats there was a continued significant reduction in erectile and copulatory activity. At the same time, brain, spinal cord and penile tissue content of norepinephrine returned to normal levels. In another experiment an alpha 2-receptor antagonist was administered with alpha-methyldopa and no inhibition of the effects of alpha-methyldopa was observed. These findings imply that the effect of alpha-methyldopa on sexual function is mediated in the central nervous system as an abnormality of receptor function.
We evaluated 70 patients for male sexual dysfunction in our center during its first 6 months of operation. The results of the analysis demonstrated that 55 per cent had organic impairment. Several important findings should be emphasized. There was mild elevation of serum prolactin in 6 cases, none of which was the direct cause of the impotence. A total of 15 patients had a diagnosis of either impaired glucose tolerance or overt diabetes (7 with organic and 8 with psychogenic disease). Therefore, the diagnosis of diabetes or impaired glucose tolerance, whether known previously or not, should not be accepted as confirming the organicity of impotence. Also, nocturnal penile tumescence alone confirmed the diagnosis of psychogenic impotence only when a rigid erection 5 minutes in duration occurred. The absence of nocturnal erections cannot be interpreted as conclusive evidence of organic impotence. Finally, a definitive diagnosis of psychogenic impotence was made based only on visual sexual stimulation in 6 patients. Our results emphasize further that etiologic factors of organic or psychogenic impotence are complex and that a multidisciplinary approach should be used.
The noradrenergic sympathetic innervation of the penis of control and 4-month streptozotocin-diabetic rats was examined with the glyoxylic acid histofluorescence method. Noradrenergic varicosities were found in the corpora cavernosa in a dense subtunical plexus and in the perisinusoidal and trabecular regions of the erectile tissue, in the corpus spongiosum in perisinusoidal tissue, around large arteries and veins, and around small tortuous arterioles and small draining veins of the corpora cavernosa and spongiosum. Noradrenergic varicosities were diminished in number and fluorescent intensity in all regions of the penis of diabetic rats compared with controls. The subtunical plexus was absent, perisinusoidal and trabecular varicosities were sparse, and only occasional intermittent, discontinuous, dull fluorescent fibers or plexuses were found around the vessels. Quantitation with high-performance liquid chromatography revealed a significant reduction of norepinephrine in the penis of diabetic rats compared with controls. The present study suggests that long-term streptozotocin diabetes in the rat is accompanied by sympathetic autonomic neuropathy of the penis that seems to parallel changes in the noradrenergic content of penile corpora of men with diabetes and erectile impotence. The streptozotocin-diabetic rat merits further study to explore the relationship between noradrenergic innervation of the penis and erectile tissue.
Erectile impotence is a commonly reported undesired side effect in patients treated for hypertension with alpha-methyldopa. However, the mechanism of that dysfunction has not been determined. In this study we report the effect of 12 days of daily intraperitoneal injections, 300 mg./kg., of alpha-methyldopa on adult male, Long-Evans rats and their age-matched saline controls. The effect of the drug upon copulation, penile reflexes and tissue catecholamines was measured. The results showed significant differences between control and experimental animals in all parameters studied. Tests of copulatory ability showed significant decreases in mounts from 5.8 +/- 1.6 (mean +/- standard error) to 3.1 +/- 1.3; penile intromissions from 27.0 +/- 3.8 to 4.8 +/- 1.9; and ejaculations from 2.1 +/- 0.3 to 1.1 +/- 0.6 per 30 minute test period. Penile reflexes measured as erection and cup formation showed similar significant reductions. The norepinephrine content of the penile corpora in the controls was 0.460 +/- 0.084 ng./mg. wet weight and 0.112 +/- 0.022 ng./mg. wet weight in the experimental group. There were similar significant reductions of norepinephrine content in the vas deferens of these animals 32.95 +/- 4.31 ng./mg. and 0.25 +/- 0.1 ng./mg. wet weight in the control and experimental groups respectively.
Inadvertent, ureteral ligation is a frequent occurrence with pelvic surgery. We determined the effect of the ureteral ligation of varying lengths of time in an animal model in order to provide a rational basis for the clinical management of such injuries in humans. In the rat, simple deligation of a ureter that has been ligated for as long as 24 hours results in complete resolution of the injury with no gross or microscopic evidence of the trauma. After 48 and 72 hours of ligation, hydroureter was apparent.
Male rats made diabetic by streptozotocin injection were tested intermittently for copulation and penile reflexes. Eight to nine months later their bodies, penises, and seminal vesicles weighed significantly less than those of control-injected males, although serum androgen as well as penile and vas deferens norepinephrine levels were not significantly depressed. None of the measures of sexual motivation, performance, or penile responsivity was depressed in the diabetic rats, suggesting that rats are not a fruitful animal model for diabetic impotence.
Explore the source record for details and available documents.
We report on a patient with persistent müllerian duct syndrome and normal external genitalia who had embryonal cancer of the testis 16 years after neonatal bilateral orchiopexy. In previous cases the testes of these patients have not been considered predisposed to form tumors. However, the occurrence of a testis tumor has been reported in 8 patients with this syndrome. The specific factors resulting in tumor formation in such patients are uncertain. Until they are clarified we suggest that these patients should be observed carefully for the possible development of testis tumor.
Past studies of the alteration of nerve morphology of penile erectile tissue in men with impotence using light and histofluorescent techniques have been inconclusive. We evaluated the ultrastructure of erectile tissue of five men; the content of the neurotransmitter norepinephrine in this tissue was also known. Our results show that in nerve fibers of men whose penile tissue samples displayed very low norepinephrine content, nerve fibers were extremely sparse. In two men with insulin dependent diabetes, alteration of the intracellular caveolae, glycogen, and microfilaments of smooth muscles were found. In addition, in these patients, there was an increased amount of cell surface coat material. In diabetic patients, these changes may translate into biomechanical alterations of the smooth muscle function within the erectile tissue.
Samples of erectile tissue taken from the corpora cavernosa of 16 male diabetic patients suffering from impotence were studied. The content of norepinephrine, which reflects sympathetic nerve activity of that tissue, was significantly lower in insulin-dependent patients 104.2 +/- 24.8 (SE) pg/mg wet weight (P less than .001) and diet-controlled patients 483.7 +/- 103.7 (P less than .01) than the normal men (881.7 +/- 62.0). Myelinated and unmyelinated nerve fibers were observed intact and unaltered in each group of patients. The results indicated that normally a dense adrenergic innervation of human erectile tissue is present, but that a reduction occurs in norepinephrine content in diabetic patients with impotence. It appears, however, that the anatomic integrity of the sympathetic nerves is intact. The presence of intact nerve fibers along with a diminished content of neurotransmitter suggests the possibility of pharmacologic treatment of impotence.
We measured the content of the two principal neurotransmitters of the autonomic nervous system from the erectile tissue of four men with normal erection and 38 men impotent as a result of injury or disease. In the former the norepinephrine content was 812 +/- 82.6 (SE) pg per mg of wet weight; In the latter, statistically significant reductions of norepinephrine were found with the greatest decrease occurring with insulin-dependent diabetes mellitus. Neither choline acetyltransferase activity nor morphologic alterations of the nerve fibers of erectile tissue were observed in either group. Our findings suggest that the sympathetic nervous system is an integral component of human erection and that a functional alteration of the corporal nerve fibers occurs with several diseases associated with impotence.
The object of this study was to determine the effect of mannitol upon lymph flow during acute unilateral renal obstruction in the dog--whether it would sustain, increase, or have an adverse effect upon renal hilar lymph flow. Two groups of dogs were used so that the efficacy of bolus injection could be compared with continuous infusion of mannitol. After ureteral obstruction renal hilar lymph flow increased significantly. Renal artery pressure, venous pressure, blood flow, and lymph flow were sustained by both bolus and continuous infusion. These results show that intravenous mannitol given during acute ureteral obstruction will sustain an increase in renal hilar lymph flow.
The etiology of impotence, which effects 50 per cent of the men with diabetes, is unknown. The neurotransmitter (norepinephrine) released from adrenergic neurons is thought to be the most direct regulator of vascular smooth muscle. We have measured the norepinephrine content of the erectile tissue of diabetic men. Our results indicate the presence of a dual neural regulator mechanism of the corpora that controls penile erection.