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Biomedical subjects

R D McClure

Publications and source records attributed to R D McClure.

At least 19 recordsLinked to original sources

Simultaneous resection of renal carcinoma and abdominal aortic aneurysm.

A 62-year-old man with a 6.5 cm abdominal aortic aneurysm and coexistent left renal cell carcinoma was treated by simultaneous radical left nephrectomy and abdominal aortic aneurysm repair. Care was taken to avoid potential infection of the bypass graft by inadvertent contamination with urine. Pathologic examination of the left kidney revealed a renal cell carcinoma, clear cell type, with no evidence of invasion into the renal vein or lymph node metastases. The patient had an uncomplicated recovery and is well and free of disease four years after operation. In cases of equivalently life threatening surgical diseases, simultaneous resection is warranted.

Aorta, Abdominal

Hypogonadal impotence treated by transdermal testosterone.

The transdermal therapeutic system for testosterone (TTS-T) (ALZA Corp.), applied to the scrotal skin for twenty-two hours daily, was tested for twelve weeks on 4 men with hypogonadal impotence; 2 of these men wore TTS-T for as long as twenty-six months. The 40 cm2 system delivered a daily dose of 2.8 +/- 0.16 (S.E.) mg (nominal dose 2.4 mg) and the 60 cm2 system delivered a dose of 3.99 +/- 0.24 mg (nominal dose 3.6 mg). Both systems promptly increased serum testosterone and dihydrotestosterone (DHT) to physiologic levels, restoring normal erectile activity with an increased frequency of ejaculation and a positive effect on both mood and energy. There were no changes in serum sex binding globulin and estradiol, prostate or breast size, hematologic or liver function measures, or urinary flow and frequency. There were no significant changes in serum cholesterol or low-density lipoproteins, but high-density lipoproteins tended to decline slightly. There were no dermatologic problems associated with the system. The tenfold increase in DHT over baseline levels was attributed to 5-alpha reduction of testosterone in the scrotal skin. The TTS-T is convenient, reliable, and mimics normal physiologic testosterone secretion and levels more closely than conventional methods of testosterone replacement.

Administration, Cutaneous

Vacuum tumescence devices: the role of papaverine in the selection of patients.

We conducted a prospective study to determine the positive predictive value of papaverine testing to select patients in whom a vacuum constriction device would be a successful alternative to operative management of impotence. A total of 30 men presenting to an impotence clinic was evaluated with a series of papaverine dosages up to 60 mg. These patients then received a physician-administered trial of a vacuum constriction device, followed by 3 months of home use and a repeat objective evaluation. Initial responses to the device were poor, with 46% of the patients (14) achieving a rigid erection. However, after 3 months of home use 83% of the patients (25) achieved a rigid erection. The positive predictive value of a good response to the papaverine trial was 94%.

Equipment Design

Subclinical varicocele: the effectiveness of varicocelectomy.

To investigate the controversial concept that subclinical varicoceles are detrimental to spermatogenesis, we undertook a prospective study of the effectiveness of surgery in 56 infertile men with clinical and subclinical varicoceles. Our statistical approach specifies improvement as a change from individual baseline level. The over-all variability in sperm counts precluded the demonstration of significant changes in sperm density consequent to surgery. Improvement in sperm motility was seen in both groups, being slightly greater in the subclinical group. The changes were inversely related to baseline levels and increased with time from surgery. Therefore, it appears that the detection of subclinical varicoceles may be warranted in infertile men with abnormal semen parameters.

Humans

Screening assays for immunologic infertility: a comparison study.

Because the immunobead antisperm antibody test (IBT) is difficult to learn and results are heavily operator-dependent, we compared findings on IBT with those of SpermMAR and SpermCheck in 58 patients to determine whether the latter two tests could demonstrate improved screening ability. Assays performed on both sperm and serum (i.e., direct and indirect) yielded 100% positive predictive values when IBT was used as the standard. Both SpermCheck and SpermMAR are easier to perform, and, as the former has a slightly greater sensitivity, we recommend SpermCheck for the detection of immunologic infertility.

Autoantibodies

MR imaging of the seminal vesicles.

MR imaging (0.35 and 1.50 T) was used to assess the appearance of the seminal vesicles. The size and signal intensity of normal seminal vesicles vary with the age of the subject. In general, on T2-weighted images, the signal intensity of normal seminal vesicles is lower than that of fat in prepubertal children, similar to or higher than that of fat in adults, and similar to or lower than that of fat in patients older than 70 years of age. Endocrine and radiation therapy will influence the size and signal intensity of the seminal vesicles. The purpose of the essay is to illustrate the spectrum of seminal vesicle disease, including congenital anomalies, inflammation, and neoplastic disease. Although MR imaging is helpful in depicting seminal vesicle abnormalities, it does not allow differentiation of benign from malignant disease, distinction of hemorrhage due to tumor invasion from postbiopsy changes, or distinguishing between glandular obstruction due to tumor infiltration and mechanical compression.

Genital Diseases, Male

Varicoceles. Radiologic diagnosis and treatment.

The association of clinically apparent varicoceles with male subfertility and infertility has been noted in the urology literature since the late nineteenth century, and surgical ligation of varicoceles has been considered appropriate therapy in an attempt to improve semen quality and increase fertility for the past 40 years. It has been established by several authors cited herein that varicocele size does not predict prognosis after ligation reliably. Because subclinical varicoceles may affect testicular function and histologic characteristics adversely and because age at time of therapy may affect probability of successful enhancement of fertility, the interest of radiologists and urologists has been directed toward diagnosis and treatment of both clinically obvious and clinically occult varicoceles, particularly in young adult men or adolescent boys. Testicular growth after varicocele ligation in adolescent boys also suggests a benefit from early intervention. Sonographic evidence of a varicocele must be correlated with analysis of semen for sperm density, motility, and morphology, as not all patients with varicoceles are infertile. Although surgical therapy is standard for varicocele occlusion, fairly extensive evidence exists to show that percutaneous transvenous occlusion of varicoceles is feasible, safe, and effective, particularly in the setting of varicocele recurrence after conventional surgical treatment.

Embolization, Therapeutic

Platelet-activating factor in sperm from fertile and subfertile men.

STUDY OBJECTIVE: To examine the proposed role of platelet-activating factor (PAF) as a mediator of sperm function first by quantitating the concentration of PAF in sperm and second by incubating sperm with PAF and assessing the change in sperm motion parameters with a computerized motion analysis system. DESIGN: Retrospective, case-control study. SETTING: University hospital urology clinic. PATIENTS: Concentrations of PAF were measured in sperm from 6 randomly chosen normal donors and 8 asthenozoospermic patients. The change in sperm motion parameters was assessed in sperm from 10 randomly chosen normal donors and 7 asthenozoospermic patients. RESULTS: Platelet-activating factor concentrations were significantly higher (P less than 0.05) in spermatozoa from asthenozoospermic patients (149 +/- 18.0 fmol/10(6) sperm) than in sperm from normal donors (91.9 +/- 13.0 fmol/10(6) sperm). Exogenous PAF did not enhance the percent motility of precapacitated or capacitated sperm from either patients or donors, and computerized semen analysis revealed no enhancement of sperm motion parameters in asthenozoospermic patients after addition of PAF to either precapacitated or capacitated sperm. CONCLUSION: Platelet-activating factor does not appear to have therapeutic value as a means of enhancing sperm motility.

Case-Control Studies

Optimizing the sperm penetration assay with human follicular fluid.

Major limitations of the conventional sperm penetration assay are the inability to assess several aspects of sperm function (zona binding and penetration) and the absence of human ovulatory products known to influence fertilization. We therefore modified the sperm penetration assay by the addition of human follicular fluid (FF) to induce the acrosome reaction in an attempt to improve the false-negative rate of the conventional technique. In 26 patients with negative results, results became positive in 20 with human FF and the acrosome reaction increased fourfold. In 19 different men, we compared the results of the conventional and modified assays with outcome of in vitro fertilization. The false-positive rate was the same, but the false-negative rate was reduced from 40% to 7% with the addition of human FF.

Acrosome

In vivo human testicular function assessed with P-31 MR spectroscopy.

The clinical feasibility of assessing testicular metabolic integrity with phosphorus-31 magnetic resonance (MR) spectroscopy was investigated in six healthy volunteers and 23 patients with azoospermia. MR spectroscopic findings were compared with sperm count and motility in all patients and with findings at testicular biopsy in 23 patients. Significant differences (P less than .05) were found between the P-31 spectra of normal and azoospermic testicles in the following peak area ratios: phosphomonoester (PM)/beta-adenosine triphosphate, PM/phosphodiester, and inorganic phosphate/PM. In the patients with azoospermia, there were significant differences in these same peak area ratios between patients with primary testicular failure and those with chronic tubular obstruction. Although the differences between these two groups were statistically significant, there was a large overlap in numbers, and therefore a study with a larger patient population will be required. P-31 MR spectroscopy is a sensitive tool for assessment of testicular metabolic integrity and differentiation of normal testicles from those with markedly decreased spermatogenesis.

Humans

Assessment of male infertility: correlation between results of semen analysis and phosphorus-31 magnetic resonance spectroscopy.

To evaluate the usefulness of phosphorus-31 magnetic resonance spectroscopy (31P-MRS) in assessing male infertility, we compared it with conventional semen analysis. Specimens were obtained from otherwise healthy patient groups as follows: group A, 7 fertile control subjects; group B, 12 azoospermic men after vasectomy; and group C, 11 patients presenting for infertility evaluation. Correlations between established semen analysis parameters and the 31P-MRS-derived ratio of glycerylphosphorylcholine to total phosphate (GPC/TP) were investigated. Group A controls had a mean GPC/TC ratio of 0.10 +/- 0.05, which was the same as that of group C. With the exception of significantly lowered motility and normal morphology in group C (p less than 0.001 and 0.05, respectively) semen analysis parameters in these two groups were similar. In contrast, the GPC/TP ratio in group B (0.05 +/- 0.04) was significantly different from the control (p less than 0.05), which appropriately reflected complete vasal occlusion. The results suggest that a significant portion of seminal GPC is derived from epididymal secretion and that 31P-MRS is useful for monitoring the GPC/TP levels when assessing epididymal function and male infertility.

Glycerylphosphorylcholine

Semen manipulation: improved sperm recovery and function with a two-layer Percoll gradient.

The authors compared a simple, two-layer Percoll density gradient technique with the swim-up technique for semen preparation in 128 men. In samples from normospermic (n = 55), oligospermic (n = 26), and asthenospermic (n = 29) men, the Percoll technique significantly improved yield, percent motility, and absolute number of motile sperm recovered, but in samples from oligoasthenospermic men (n = 18), only percent motility was improved. The Percoll density gradient also selected sperm with markedly improved function as assessed by both the sperm penetration assay and the fertility index. In 37 samples negative on the sperm penetration assay when processed with the swim-up technique, 19 (51%) became positive when processed with the Percoll technique. The Percoll density gradient is an improved method for semen manipulation as it allows greater recovery of sperm with higher motility and improved sperm function.

Adult

SpermCheck: a simplified screening assay for immunological infertility.

SpermCheck (Bio-Rad Laboratories, Hercules, CA), a new screening test for regional surface antibodies on motile sperm, uses monodispersed latex microspheres of uniform size as a vehicle to link rabbit antihuman immunoglobulins (IgA, IgG, IgM) and provides both negative and positive control sera, as well as sufficient buffer for sperm preparation in ambient CO2 atmosphere. When compared with reference data available for the immunobead test (IBT), the direct protocol (semen) for SpermCheck yielded 94.4% sensitivity with 100% specificity; the indirect protocol (serum) provided a sensitivity of 100% with 94.7% specificity. The microspheres of SpermCheck maintain a nearly uniform concentration per volume, with none to negligible clumping. The greater difference between the optical densities of latex and cytoplasm allows use of a light microscope for the rapid assessment of the percent of regional binding rather than the phase-contrast microscope required for the IBT. SpermCheck eliminates many difficulties encountered with the IBT, making SpermCheck a convenient screening assay for use in the physician's office.

Antibodies

Immunological status of patients before and after vasovasostomy as determined by the immunobead antisperm antibody test.

With the immunobead antisperm antibody test a prospective study was conducted to evaluate the immune status of 55 men before and after vasectomy reversal. A third of the vasectomy patients (19 of 55) had significant serum-sperm antibodies (20 per cent binding or more) detected by the indirect immunobead antisperm antibody test. Of 31 vasovasostomy patients 12 (38 per cent) had significant sperm-surface antibodies (20 per cent binding or more) by the direct immunobead antisperm antibody test. Preoperative serum assays correctly classified the antibody status of 69 per cent of the vasectomy patients. The immunological impact of spermatic granuloma formation, duration of vasal obstruction, patient age and presence of sperm in the vasal fluid at operation also were assessed. An inverse relationship between the proportion of antibody-bound sperm and the percentage of motile sperm in the ejaculate of vas reversal patients was found with videomicrographic semen analysis. The percentage motility was significantly lower among patients with greater quantities of sperm-surface antibodies. No other parameter of semen analysis showed this difference when compared for positive or negative immunobead antisperm antibody test results.

Adult

Localization of abscess in adult polycystic kidney by indium-111 leukocyte scan.

In patients with adult polycystic kidney disease (APKD) infected cysts are difficult to localize with current radiographic techniques, especially those dependent on renal function. Indium-111 leukocyte (In-WBC) imaging is both highly sensitive and effective in detecting and localizing abscesses in patients with renal failure. We report on a patient with APKD and sepsis in whom computed tomography, ultrasound, and physical examination failed to locate the renal abscess, which was found by In-WBC scanning.

Abscess

Endocrine evaluation and therapy of erectile dysfunction.

Recent innovative laboratory and clinical investigations have implicated an organic cause for as many as 30 to 50 per cent of cases of impotence. Understanding the clinical subtleties of hypogonadism and the reproductive hormonal axis in the male is critical to the evaluation and treatment of impotence of endocrinologic origin. Gonadotropin assays are essential for detecting elevations of FSH and LH, which will help to distinguish primary from secondary testicular failure. The goal of androgen replacement is the maintenance of physiologic testosterone levels without the potential hepatotoxic effects.

Aging

Is there a role for Chlamydia trachomatis and genital mycoplasma in male infertility?

We believe that, without evidence of inflammation (greater than 5 WBC on VB1), there is no indication for routine culture or antibiotic treatment of infertile men. In the presence of active inflammation and positive cultures for chlamydia, treatment with antibiotics is appropriate. However, active inflammation and positive chlamydial cultures were rare findings in our population (2 of 52 and 1 of 52, respectively). Thus, we find no evidence for a role of current asymptomatic mycoplasma or chlamydial infection in male infertility.

Adult