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Biomedical subjects

Y Vardi

Publications and source records attributed to Y Vardi.

At least 19 recordsLinked to original sources
PubMed2005

Effect of tadalafil on sexual timing behavior patterns in men with erectile dysfunction: integrated analysis of randomized, placebo controlled trials.

PURPOSE: Tadalafil, a new phosphodiesterase type 5 inhibitor, has an extended period of responsiveness compared with other agents in this class. The distinct pharmacological profile of tadalafil may allow more flexibility for men to establish individual sexual timing behavior patterns. We determined if patients took advantage of the pharmacological profile of tadalafil by assessing the frequency, timing and success of intercourse attempts in men with erectile dysfunction. MATERIALS AND METHODS: Data on Eastern European countries were combined from 2 identically designed, randomized, double-blind, placebo controlled, parallel group studies. Patients self-administered 20 mg tadalafil (406) or placebo (108) as needed for 12 weeks. RESULTS: Of the men 63% made at least a quarter of their attempts and 42% made at least half of their attempts more than 4 hours after dose. At least 1 attempt was made after 8, 12 or 24 hours after dose by 87%, 75% and 52% of the men, respectively. Throughout a 36-hour post-dose period tadalafil was associated with significantly higher intercourse success rates than placebo (p <0.001) with 61% to 69% of tadalafil treated patients reporting success rates of greater than 75% compared with 19% to 30% of those on placebo (p <0.001). Tadalafil was well tolerated. CONCLUSIONS: In this study various use patterns of the tadalafil period of effectiveness were apparent, reflecting differences in the sexual timing behavior of patients. Tadalafil may provide men with erectile dysfunction more flexibility in deciding when to attempt intercourse in accordance with their sexual habits and attitudes.

Adult↗
PubMed2004

Evaluation of penile revascularization for erectile dysfunction: a 10-year follow-up.

The objective of this study was to report long-term success rates for penile revascularization (PR) and investigate factors responsible for failures. During the past 10 y, data were obtained on 52 patients who underwent PR. Surgical technique was selected according to preoperative arteriographic findings. The mean age was 28.5 y and the mean follow-up was 70.8 months. Success was defined as satisfactory intercourse without additional therapy. Overall success was 48%. Patients under 28 y showed a 73% success rate vs 23% in the older ones (P=0.0003). Nonsmokers had a 57% success compared to 29% in smokers (P=0.05). The presence of venous leak and type of procedure had an insignificant impact on success (P=0.33 and 0.23 respectively). To conclude, this curative treatment option is limited to a selective population with vasculogenic erectile dysfunction. We found that the cure rate of this procedure is maintained and long-term follow-up shows good results, especially in the young nonsmokers.

Adult↗
PubMed2001

Intracavernous injections: still the gold standard for treatment of erectile dysfunction in elderly men.

The objective of this work was to determine the effectiveness of intracavernous injections (ICI) of vasoactive drugs in elderly men with erectile dysfunction and to compare the results obtained with the injection of two different drug combinations. It was a case control study. The sample consisted of 300 men, 63-85 y of age (mean 67.1) with erectile dysfunction of organic origin. Among the patients 180 underwent first trial with injection of prostaglandin E1 (PE). Further on these 180 patients and another 120 (in total 300 patients) were treated with a triple combination of papaverine hydrochlorate, phentolamine messylate and prostaglandin E1 (PPR). The number of responders to the injection of either PE alone or the drug combination was recorded. The quality of the erections was evaluated in the outpatient clinic by the medical staff and through patient's report after home trial. The average volume of either PE or PPR necessary to obtain a functional erection was measured. We observed a statistically significant association between the results obtained after the injection of PPR as compared to PE (chi2 with 2 d.f.: 34.666; P= < 0.001). A functional erection was obtained in 224/300 (74.7%) after the injection of PPR as compared to 87/180 men (48.3%) treated with PE. The average volume of PPR necessary to obtain a functional erection was 0.35+/-0.14 ml whereas that of PE was 1.3+/-0.3 ml. intracavernous injection of vasoactive drugs is still one of the most successful therapies for patients suffering from organic impotence. It is less effective in the older age group as compared to younger. However, if this form of therapy is chosen for aged men the triple combination therapy (PPR) yields a higher response rate than that obtained with prostaglandin alone.

Aged↗
PubMed2000

Normative values for female genital sensation.

OBJECTIVES: Neurologic disorders might be responsible for many cases of female sexual dysfunction. Yet, they are currently undiagnosed because of the lack of measurement tools to assess genital neural function. Therefore, our objective is to provide norms for sensory thresholds in the vagina and clitoris, for a wide range of patient ages. METHODS: Vaginal and clitoral warm, cold, and vibratory sensory thresholds were measured in 89 healthy paid volunteers by the method of limits. Normograms were derived from this group of healthy volunteers. An additional 61 patients were also tested, for a total of 150 individuals. Sixty-two individuals (42 healthy volunteers and 20 patients) from the total group were tested twice to provide test-to-test repeatability data across the range of clinical (normal and abnormal) responses. RESULTS: Normograms are presented, providing age-corrected upper and lower normal values, expressed as 95% confidence limits for warm, cold, and vibratory thresholds. Intertest repeatability is also reported. CONCLUSIONS: Thermal and vibratory thresholds of both the vaginal and clitoral region are clinically feasible, valid, and repeatable. These can be applied as a valuable diagnostic tool to assess neural dysfunction through sensory assessment of the female genitalia.

Adolescent↗
PubMed2000

The multivariate L1-median and associated data depth.

This paper gives three related results: (i) a new, simple, fast, monotonically converging algorithm for deriving the L1-median of a data cloud in Rd, a problem that can be traced to Fermat and has fascinated applied mathematicians for over three centuries; (ii) a new general definition for depth functions, as functions of multivariate medians, so that different definitions of medians will, correspondingly, give rise to different dept functions; and (iii) a simple closed-form formula of the L1-depth function for a given data cloud in Rd.

Journal Article↗
PubMed2000

The role of corpus cavernosum electromyography.

Although corpus cavernosum electromyography presents great theoretical appeal as a possible direct clinical measure of penile neurogenic function, it has still not been adopted as a routine diagnostic test in the evaluation of patients with erectile dysfunction. This is because of the considerable technical and interpretative problems associated with the method. This review covers some of the more important research and clinical papers published since its first description in 1989, with a special focus on recent advances in this field.

Animals↗
PubMed2000

Cardiovascular effects of oral pharmacotherapy in erectile dysfunction.

Several drugs have been developed to treat patients with erectile dysfunction (ED). In general, patients prefer orally administered drugs. The use of these drugs (e.g. sildenafil and apomorphine) is reviewed. Because ED is a common problem in men with vascular disease it is important to assess the effect of these drugs on the cardiovascular system. The safe use of these drugs in patients with vascular disease needs to be clearly established in appropriately designed trials.

Arginine↗
PubMed2000

Psychological empowerment as a criterion for adjustment to a new job.

Interview data from 120 professionals and managers, collected by telephone after they experienced a job change, were matched with personality test scores from an employment testing center. Four dimensions of psychological empowerment (self-determination, meaning, competence, and impact) were tested as criteria, and four personality traits (achievement, endurance, locus of control, and self-esteem), measured prior to the job change, were used as predictors. In a multiple regression analysis the personality traits accounted for 26% of the variance in overall empowerment, and locus of control emerged as an important antecedent. Additional analyses pointed to perceived managerial support, sex, and rank as possible moderators. Ideas for further research and theoretical extension are discussed.

Adaptation, Psychological↗
PubMed2000

Logistic regression and survival analysis of 450 impotent patients treated with injection therapy: long-term dropout parameters.

PURPOSE: We report the dropout rate associated with intracavernosal self-injection for erectile dysfunction at long-term followup, and determine parameters related to dropout. MATERIALS AND METHODS: Of 2,252 impotent patients evaluated during 9 years 450 (20%) enrolled in our self-injection program. Papaverine and phentolamine were given in 53% (initial treatment), prostaglandin E1 in 21%, and papaverine, phentolamine and prostaglandin E1 (triple mixture) in 26% of cases. Average injection volume for the 3 injection types was 0.52 cc. Data were retrospectively reviewed for patient dropout versus nondropout, specifically for type of drug, volume injected, changing treatment (from 1 drug and/or dosage to another), patient age, marital status, ethnic group, impotence duration and diabetes. RESULTS: Patient age ranged from 23 to 79 years (mean age 55). Of the patients treated at least 4 months 155 (35%) dropped out of the study. Mean treatment duration was 3.5 years. Logistic regression suggested that type of drug, changing treatment during the course of therapy and dosage (volume injected) were the only significant (p <0.05) parameters influencing dropout. Papaverine and phentolamine were twice as likely to lead to dropout as triple mixture or prostaglandin E1, and injection greater than 0.5 cc was more than twice as likely to lead to dropout. Demographic, ethnic, age and etiological factors had no significant effect on the overall dropout rate. CONCLUSIONS: The effectiveness of injection therapy was an underlying factor determining the long-term dropout rate for patients with erectile dysfunction. Other parameters or combinations of parameters that may influence patient dropout remain to be explored.

Erectile Dysfunction↗
PubMed1999

Nitric oxide and penile erection in streptozotocin-diabetic rats.

The purpose of this investigation was to study the time course, response to insulin and characteristics of erectile dysfunction in streptozotocin (STZ)-diabetic Sprague-Dawley rats, and the function of the NO-generating system in these animals. Copulation-induced and reflex erection were quantified in conscious Sprague-Dawley rats at different times after injection of STZ. The corporal vasodilatation response to nerve stimulation was studied by measuring the rise in corporal pressure in pithed rats following electrical stimulation of sacral spinal nerve roots. The activity of NO synthase was determined in corporal tissue by measuring the generation of [3H]citrulline from [3H]arginine. Copulation-induced erection was inhibited at 1 and 2 months after STZ treatment, but this could be prevented by a short (2-week) pretreatment with insulin. Reflex erection was inhibited at 1, 4, 6 and 9 months after STZ; at 6 months, this inhibition was also reversible by insulin pretreatment. Following pithing, the basal corporal pressure was elevated in diabetic rats. At 4 months after STZ, this increase was normalized by a 2-week, but not by a 1-week, pretreatment with insulin; however, at 9 months after STZ, insulin pretreatment did not normalize corporal pressure. The increase in corporal pressure caused by stimulation of sacral nerve roots in pithed rats was enhanced in diabetic animals. This enhancement was also normalized at 4 months, but not at 9 months, by 2 weeks of insulin treatment. The inhibition of the stimulation-induced increase in corporal pressure by NG-nitro-L-arginine methyl ester (5 mg/kg) was less following 9 months of diabetes, although NO synthase activity was normal in cavernosal tissue following 6-8 months of diabetes. In conclusion, STZ-induced diabetes caused changes in the erectile system that were initially reversible by a short insulin treatment, but which with time (more than 6 months) became irreversible. NO synthase activity in cavernosal tissue was normal, but the response to NG-nitro-L-arginine methyl ester was inhibited in long-term diabetes (9 months).

Animals↗
PubMed1998

Electrical activity from rat corpora is affected by pharmacological but not mechanical intracorporal manipulation.

Smooth muscle electromyographic (EMG) recording from the corpora cavernosa is a potentially useful clinical tool for the diagnosis of impotence. Controversy still exists regarding the nature of this signal, which could be resolved using animal models. The signal recorded from denuded rat corporal surface was Fourier transformed, and power at 0.01-1 Hz was calculated. Measurements were taken in the flaccid state and during erection induced by intracorporal injection of smooth muscle relaxants [the phosphodiesterase inhibitors papaverin and isobutylmethylxanthine (IBMX)]. Recorded activity decreased significantly during the pharmacologically evoked erection: the mean square root power of 250.7+/-137.1 microV decreased to 49.8+/-14.1 microV (P<0.0001) after papaverin, and IBMX caused it to decrease from 222.8+/-132.0 microV to 58.1+/-40.8 microV (P<0.0001) (mean +/- SD). Intracorporal injection of adrenaline partially reversed the response, increasing activity to 135.3+/-72.3 microV (P=0.01) and 137.5+/-122.6 microV (P=0.015), respectively, in parallel with detumescence. In order to rule out a mechanical artefactual explanation for these results, recording was also performed before and during artificial erection induced by the intracorporal infusion of saline. This manipulation did not cause any change in corporal activity, despite corporal engorgement and increased pressure. In conclusion, the signal indeed reflects changes in the tone of corporal smooth muscle, and therefore should be regarded as a genuine EMG recording.

1-Methyl-3-isobutylxanthine↗
PubMed1997

Radioimmunotherapy of experimental pancreatic cancer with 131I-labeled monoclonal antibody PAM4.

We examined the therapeutic efficacy of 131I-labeled murine monoclonal antibody (MAb) PAM4 against human pancreatic cancers carried as xenografts in athymic nude mice. Animals bearing the CaPan1 tumor (0.2 cm3) were either untreated or were given, 131I-labeled nonspecific Ag8 antibody. By week 7 mean tumor size had grown 16.5 +/- 8.4-fold and 4.2 +/- 2.5-fold for the untreated and 131I-Ag8-treated animals, respectively. In contrast, animals administered 131I-PAM4 exhibited marked regression of tumors to an average of 15% of initial tumor volume. Since most pancreatic cancer patients present with large tumor burdens, the limitation of 131I-PAM4 treatment with respect to initial tumor size was investigated in animals bearing tumors of approximately 0.5 cm3, 1.0 cm3 and 2.0 cm3. Significant extension of survival time (>3-fold increase) was noted for both the 0.5 cm3 and 1.0 cm3 131I-PAM4-treated groups, compared to their respective untreated controls. Even in the group bearing large 2.0-cm3 tumors, survival was increased 2-fold over the control group. To further improve anti-tumor effects in large tumors, 2 injections of 131I-PAM4 were administered at a 4-week interval to animals bearing tumors of approximately 1.0 cm3. Significant extended survival was noted for the group receiving 2 doses when compared to the group receiving only 1 dose.

Adenocarcinoma↗
PubMed1997

Smooth muscle electromyography from rat urethra.

Electrical signals recorded from the penis have been suggested as reflecting electromyographic activity in the underlying smooth muscles. In order to verify this assertion, we manipulated the signal recorded from rat urethra surface. Stimulation of the pelvic nerve brought about a reduction of activity (965 +/- 826 to 166 +/- 143 microV, root mean square of the power at range 0.005-1 Hz, P = 0.008), with a significant frequency-response relationship (P = 0.0002). This effect was not altered by temporary closure of the aorta (P = 0.89), thus ruling out hemodynamic artifact as a possible cause of signal change during stimulation. Our findings support the assertion that the signal indeed reflects activity in smooth muscle.

Animals↗
PubMed1997

Functional and radiologic evidence of vascular communication between the spongiosal and cavernosal compartments of the penis.

OBJECTIVES: To investigate the possible communication of the glans penis and corpus spongiosum with the corpora cavernosa. METHODS: We performed a functional and anatomic study in men with erectile dysfunction. The functional study consisted of the injection of alprostadil (10 to 20 micrograms) into the glans in 17 men while recording intracavernosal pressure (ICP). Once the ICP response had stabilized, patients received a second injection of alprostadil by direct intracavernosal (IC) administration. For the anatomic study, a spongiogram was performed in 5 patients by the injection of radiologic contrast into the glans. RESULTS: Injection of alprostadil into the glans caused tumescence of the glans and corpus spongiosum, followed by tumescence of the corpora cavernosa with an increase in ICP from 9 +/- 2 mm Hg (mean +/- SD) at baseline to a peak response of 50 +/- 25 mm Hg. Subsequent IC injection of alprostadil, on average, increased ICP by only 5 mm Hg (a 15% increase) above the response to injection in the glans. The spongiogram demonstrated drainage of the glans into the deep dorsal vein, as well as drainage of the spongiosum into the circumflex veins, which in turn drained into the deep dorsal vein. Filling of the corpora was also visualized, suggesting that it occurred in a retrograde manner, through the draining venules. CONCLUSIONS: Our study demonstrates that injection of alprostadil into the spongy tissue of the glans can provoke erection of the corpora cavernosa, and that common channels for the drainage of the glans, corpus spongiosum, and corpora cavernosa are most likely the route for drug transfer from the spongiosal to the cavernosal compartment.

Humans↗
PubMed1997

Phase I/II clinical radioimmunotherapy with an iodine-131-labeled anti-carcinoembryonic antigen murine monoclonal antibody IgG.

UNLABELLED: The aim of this study was to determine, in a Phase I/II clinical trial, the pharmacokinetics, dosimetry and toxicity, as well as antitumor activity, of the 131I-labeled murine anti-carcinoembryonic antigen (CEA) monoclonal antibody, NP-4 (IgG1 subtype). METHODS: A total of 57 patients with CEA-expressing tumors (29 colorectal, 9 lung, 7 pancreas, 6 breast and 4 medullary thyroid cancer patients), mostly in very advanced stages, were treated. The patients underwent a diagnostic study (1-3 mg of IgG and 8-30 mCi of 131I) to assess tumor targeting and to estimate dosimetry, followed by the therapeutic dose (4-23 mg and 44-268 mCi), based on the radiation dose to the red marrow. Imaging was performed from 4-240 hr postinjection (planar and SPECT). Blood and whole-body clearance were determined; radiation doses were calculated by the Medical Internal Radiation Dose scheme. RESULTS: Red marrow doses ranged from 45 to 706 cGy, and whole-body doses ranged from 31 to 344 cGy. Differences in pharmacokinetics were found between different types of CEA-producing tumors: blood T 1/2 was significantly lower in colorectal cancer when compared to all other tumor types (21.4 +/- 11.1 hr versus 35.8 +/- 13.2 hr, p < 0.01), as was also whole-body t 1/2. Myelotoxicity was dose-limiting, and its severity was related to the types of prior therapy and extent of bone marrow involvement. In patients without prior radiation or chemotherapy, marrow doses as high as 600 cGy were tolerated without evidence of dose-limiting toxicity. No major toxicity to other organs was observed. Tumor doses were inversely related to the tumor mass and ranged between 2 and 218 cGy/mCi. Modest antitumor effects were seen in 12 of 35 assessable patients (1 partial remission, 4 minor/mixed responses and 7 with stabilization of previously rapidly progressing disease). CONCLUSION: These results suggest that prior chemotherapy or external beam radiation is an important risk factor for the development of hematological toxicity in radioimmunotherapy and that higher radiation doses may be delivered to tumors of patients without prior therapy compromising the bone marrow reserve. The different and, in the individual cases, unpredictable clearance rates suggest the necessity of dosimetry-based treatment planning rather than mCi/m2 dosing. Small tumors seem to be more suitable for radioimmunotherapy because of their favorable dosimetry, but to achieve better therapeutic results in patients with bulky disease, the application of higher, potentially myeloablative doses is indicated.

Aged↗
PubMed1997

Penile intracorporeal infusion--possible access to the systemic circulation. Pressure flow studies in dogs and humans.

OBJECTIVE: To assess penile intracorporeal infusion as a simple alternative method of intravenous access during the initial phase of fluid resuscitation in male patients. DESIGN: Laboratory pressure flow studies in dogs and in humans. SUBJECTS: 5 male mongrel dogs, and 10 male patients who were being investigated for psychogenic impotence (n = 5) or organic impotence (n = 5). INTERVENTIONS: Dogs- two 19G needles were inserted into the canine corpora cavernosa, one for fluid infusion, and the other for cavernosal pressure monitoring. Ringer's lactate solution was infused into the corpora cavernosa, through an infusion pump. The dogs were then bled until systolic blood pressure reached 60 mmHg, and resuscitated by transfusion of autologous blood into the corpora cavernosa. HUMANS: Ringer's lactate solution was infused into a corpus cavernosum through a 19G scalp vein needle. Pressure monitoring was done through another 19 G needle. MAIN OUTCOME MEASURE: Fluid flow rates and in humans time taken to insert an intracorporeal needle. RESULTS: Mean (SD) infusion rate through the canine corpora was 110 (22) ml/minute for Ringer's lactate solution and 109 (18) ml/minute for autologous blood. Mean infusion rate into the human corpora was 89.7 (12) ml/minute in the psychogenic impotent patients, and 88.2 (9) ml/minute in the organic impotent patients. Mean time taken to insert the needle was 15 (7) sec. CONCLUSIONS: An intracorporeal infusion line can be established in a short period of time and adequate quantities of fluids can be infused through the human and canine corpora cavernosa.

Animals↗