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Biomedical subjects

R B Meacham

Publications and source records attributed to R B Meacham.

18 recordsLinked to original sources
PubMed1998

Effect of storage temperature on sperm cryopreservation.

OBJECTIVE: To evaluate the influence of cryopreservation temperature on human sperm motility and morphology. DESIGN: Controlled study, investigator was blinded to the type of cryopreservation. SETTING: University-based andrology laboratory. PATIENT(S): Sixteen semen samples with normal motility and sperm count from men after a fertility work up. INTERVENTION(S): Semen aliquots were either stored in a mechanical freezer at -70 degrees C or in liquid nitrogen at -196 degrees C for 7 days or 3 months. Test yolk buffer was used as a cryoprotectant. With use of a programmable freezing unit, all samples were cooled at a controlled rate. MAIN OUTCOME MEASURE(S): Sperm motility and morphology. RESULT(S): After 7 days of cryopreservation, there was a greater decrease in sperm motility among specimens maintained at -70 degrees C than among those maintained at -196 degrees C (47% versus 39% decrease). The difference in sperm motility was even greater after 3 months of cryopreservation (72% versus 39% decrease). No difference in postthaw sperm morphology was detected among sperm preserved at -70 degrees C versus -196 degrees C. CONCLUSION(S): Sperm cryopreservation at -196 degrees C is superior to cryopreservation at -70 degrees C. Sperm can be stored at -70 degrees C for a short period of time with a relatively modest loss of motility.

Cryopreservation↗
PubMed1997

Use of electroejaculation in the treatment of ejaculatory failure secondary to diabetes mellitus.

OBJECTIVES: To describe the experience of two male fertility programs using electroejaculation (EEJ) in the management of men with ejaculatory failure secondary to diabetes mellitus. METHODS: Twenty-nine EEJ procedures were performed in 7 diabetic men with ejaculatory failure. Results were reviewed with attention paid to sperm characteristics in both antegrade and retrograde specimens as well as pregnancy rates. RESULTS: Retrograde semen specimens retrieved from the bladder following EEJ contained a mean of 3444.5 million sperm (range 269.2 to 4996 million). Antegrade specimens contained a mean of 698.8 million sperm (range 226.8 to 1961 million). Mean sperm motility was 4% for retrograde specimens (range 0% to 11%) and 7% for antegrade specimens (1% to 15%). In all but 1 case, semen specimens were used for intrauterine insemination. The total number of motile sperm contained in the processed, inseminated specimens ranged from 1 to 87.2 million. In 1 case, the sperm obtained through EEJ was used in an in vitro fertilization procedure. CONCLUSIONS: EEJ can be successfully used to obtain sperm from men with ejaculatory failure due to diabetes mellitus. The procedure requires general anesthesia, and pregnancy rates after intrauterine insemination with the processed sperm are low. Advanced reproductive technologies may offer a feasible alternative, providing higher success rates with fewer procedures.

Diabetes Complications↗
PubMed1996

Use of a moderated international Internet information exchange in the study of male reproduction.

It is clear that modern information technology is having a profound impact on the way researchers and clinicians exchange information. Use of the Internet is one example of how such change can be translated into scientific progress and improved patient care. Androlog, a moderated international information exchange, has proven to be very useful in the transfer of information pertaining to the study and treatment of male reproductive disorders. Allowing instantaneous dispersal of messages to members in 27 countries, this system has become a valuable source of scientific information, as well as an excellent forum for the discussion of a broad range of clinical and laboratory topics. Moderated-user groups such as Androlog are highly applicable to many other areas of urology. Establishment of such an information exchange requires only a modest investment in computer hardware and software and moderators who are willing to perform the necessary tasks of system administration and message review. Given the unique advantages provided by this method of communication, there is little doubt that systems such as Androlog will flourish in the future, providing a valuable tool in the advance of medical science.

Computer Communication Networks↗
PubMed1995

Ejaculatory duct obstruction: diagnosis and treatment with transrectal sonography.

Ejaculatory duct obstruction is thought to be a relatively uncommon but readily treatable cause of male infertility. Obstruction is frequently caused by cysts originating from or impinging on the ejaculatory ducts. The use of transrectal sonography has facilitated identification of patients with ejaculatory duct obstruction and has led to the realization that this abnormality is more common than was previously recognized. Transrectal sonography now plays a critical role in both the diagnosis and the treatment of this condition. The purpose of this pictorial essay is to illustrate the use of transrectal sonography in the diagnosis and treatment of ejaculatory duct obstruction.

Adult↗
PubMed1994

The incidence of varicoceles in the general population when evaluated by physical examination, gray scale sonography and color Doppler sonography.

The association between male subfertility and varicocele has long been recognized. Physical examination is the most widely used method for detecting varicoceles but other techniques may be more sensitive. Color Doppler sonography has the theoretical advantage of allowing direct demonstration of reversed flow in the testicular veins. The frequency of detection of reversed flow by color Doppler ultrasound in a normal population is, however, unknown. We evaluated 34 asymptomatic young men with physical examination, standard scrotal sonography and color Doppler evaluation of the scrotal veins. Findings were correlated with semen analysis. Of the subjects 15% had varicoceles by physical examination and 18% by scrotal sonography, while 35% had retrograde flow by color Doppler evaluation. The majority of men in this population did not exhibit retrograde flow within the gonadal veins when evaluated by color Doppler sonography. The physiological significance of retrograde flow, however, remains to be defined.

Adolescent↗
PubMed1994

Reproductive function in the aging male.

Although the association between advanced paternal age and serious birth defects has received less attention than the effect of maternal age on such defects, this association has been demonstrated. This, as well as the potential decline in fertility among older men, should be borne in mind by men electing to defer establishing a family.

Adult↗
PubMed1993

The effect of age on male reproductive function.

When couples elect to defer child bearing, the effects of age on reproductive potential must be considered. The impact of advancing age on female reproductive potential has been well documented. Relatively less attention, however, has been directed toward the effect of age on male reproductive function. Although less pronounced than its effect on female fertility, advancing age does have an impact on male reproduction. Among men, increasing age is associated with a decrease in sexual function as well as changes in testicular histology and a decline in basic fertility parameters. Additionally, there is an identifiable association between advanced paternal age and subsequent birth defects. These issues should be borne in mind when men are counseled regarding the age at which they elect to establish families.

Adult↗
PubMed1993

Evaluation and treatment of ejaculatory duct obstruction in the infertile male.

OBJECTIVE: To evaluate the role of ejaculatory duct obstruction as a cause for male factor infertility and review the treatment of this condition. DESIGN: A retrospective study was carried out involving male patients diagnosed as having ejaculatory duct obstruction as a contributing cause for their subfertility. SETTING: Patients were evaluated and treated through a university-based male infertility clinic. PATIENTS, PARTICIPANTS: Patients were evaluated for the presence of ejaculatory duct obstruction if they suffered from decreased ejaculate volume, sperm density, and sperm motility but had normal physical examinations and otherwise normal laboratory evaluations. INTERVENTIONS: Patients were treated by transurethral resection of the ejaculatory ducts. MAIN OUTCOME MEASURES: Results of semen analysis and pregnancy rates. RESULTS: An alteration in semen quality was achieved in 79% of patients after transurethral resection. An increase in sperm density or motility was achieved in 50%, whereas 29% showed an increase in ejaculate volume only. Pregnancy rate postoperatively was 29%. CONCLUSIONS: Ejaculatory duct obstruction as a cause of male infertility is more common than was previously recognized, especially among nonazoospermic patients. In properly selected patients, transurethral resection of the ejaculatory ducts can result in marked improvement in semen quality with subsequent pregnancy.

Constriction, Pathologic↗
PubMed1992

Transrectal ultrasound and partial ejaculatory duct obstruction in male infertility.

Partial ejaculatory duct obstruction, due to either a congenital or an acquired cyst or ejaculatory duct stenosis secondary to calcification, chronic inflammation, can produce a wide spectrum of seminal fluid abnormalities. Sperm density may range from azoospermia to normospermia while ejaculate volume can be low to normal. Sperm motility is consistently diminished (less than 30%). We have treated 2 patients with ejaculatory duct stenosis whose diagnosis was accurately made with transrectal ultrasonography (TRUS). We now suggest that TRUS be used when there is a low semen volume (less than 1.0 cc), or low motility (less than 30%), or oligospermia (less than 20 million sperm/mL), and normal findings on physical examination with normal serum gonadotropin values in the absence of any other explanation.

Adult↗
PubMed1991

Assisted reproductive technologies for male factor infertility.

Experience in the diagnosis and treatment of infertility has led to an increased understanding of the prominent role male factors play in many couples' inability to conceive. While many forms of male factor infertility are amenable to treatment, for some patients there is no corrective therapy available. For this reason, a great deal of attention has been focused on developing technologies for semen processing and sperm utilization in cases of decreased semen quality. One area of research is the development of more sophisticated methods of assessing sperm function, as well as methods of sperm preparation. Progress is also being made in the application of technologies such as intrauterine insemination and in vitro fertilization in the treatment of male factor infertility. Such developments have improved prospects for fertility among patients suffering from decreased semen quality, as well as those suffering from such disorders as ejaculatory failure and congenital vasal agenesis. Current research also offers promise for future applications such as gamete micromanipulation. This technology holds potential for improving fertility even among patients suffering from profound male factor disorders. The following is a summary of recent publications pertaining to the application of these assisted reproductive technologies in the management of male factor infertility.

Fertilization in Vitro↗
PubMed1989

The risk of distant metastases after transurethral resection of the prostate versus needle biopsy in patients with localized prostate cancer.

Although transurethral resection of the prostate provides an effective treatment for obstructive voiding symptoms associated with prostate cancer, there is growing concern about the possible role of transurethral resection in the dissemination of this malignancy. To determine the effect of transurethral resection on the rate of development of distant metastasis, we analyzed a large series of patients (379) treated at our institution with definitive radiotherapy for localized prostate cancer that was diagnosed by either needle biopsy or transurethral prostatic resection. In our series the presence of lymph node metastasis was documented by pelvic lymph node dissection in all patients. An initial univariate analysis suggested that patients diagnosed by transurethral resection had distant metastases significantly more rapidly than patients diagnosed by needle biopsy. However, transurethral resection usually was performed because of the presence of obstructive voiding symptoms and such patients were much more likely to have positive lymph node dissections than patients without obstructive voiding symptoms. A proportional hazards regression analysis showed that nodal status and the degree of obstructive voiding symptoms at diagnosis were independent and powerful predictors of the interval to distant metastases, along with stage and grade. The type of initial biopsy (transurethral prostatic resection versus needle biopsy) had no independent prognostic significance in this analysis. Among patients who had substantial obstructive voiding symptoms there was no significant difference in interval to distant metastases between the transurethral prostatic resection and needle biopsy groups. We conclude that the apparent adverse effect of transurethral prostatic resection results from the poor prognosis of tumors causing obstructive voiding symptoms rather than as a direct result of the resection itself.

Actuarial Analysis↗
PubMed1988

Testicular metastasis as the first manifestation of colon carcinoma.

Metastatic carcinoma to the testes is uncommon, and it is most often found incidentally at autopsy or after orchiectomy for prostatic carcinoma. One of the rarest causes of testicular tumor is metastasis from another primary site. It is even more unusual when the metastasis to the testicle is the first manifestation of the tumor. We report a case of asymptomatic colon carcinoma presenting as metastases to the testis and epididymis, which was diagnosed after biopsy of testicular nodules. Although nonlymphomatous cancer presenting as an intrascrotal mass is extremely rare, seldom detected clinically and almost never the first sign of disease, it should be considered a possibility, even in the young adult who presents with a mass involving the testicle or epididymis.

Adenocarcinoma↗
PubMed1988

The role of silicone ureteral stents in extracorporeal shock wave lithotripsy of large renal calculi.

Between November 1984 and December 1985 extracorporeal shock wave lithotripsy was used to treat 1,645 kidneys at our institution. A total of 646 kidneys with stone burden greater than 14 mm. was evaluated with regard to the impact of silicone ureteral stents in post-extracorporeal shock wave lithotripsy morbidity. Our results indicate that small stones were pulverized and eliminated with minimum morbidity. Larger stones frequently were associated with post-treatment ureteral obstruction by sand and fragments. Of 283 kidneys with stone burden exceeding 25 mm. pretreatment placement of silicone ureteral stents reduced complications from 26 to 7 per cent and auxiliary procedure rates from 15 to 6 per cent. Silicone ureteral stents protect the kidney from ureteral obstruction, and allow for safe and effective extracorporeal shock wave lithotripsy of large renal calculi.

Catheters, Indwelling↗
PubMed1986

The prognostic significance of post-irradiation biopsy results in patients with prostatic cancer.

To evaluate the prognostic significance of post-irradiation biopsy results in patients with prostatic cancer, we reviewed the records of 803 patients who had been treated with pelvic lymph node dissection, radioactive gold seed implantation and external beam irradiation. Of the patients 124 had 1 or more biopsies within 6 to 36 months after completion of radiotherapy when there was no evidence of local or distant recurrence of tumor. Patients were followed for a mean of 64 months (range 14 to 175 months) and received no other therapy before relapse. Over-all, 43 of these patients (35 per cent) had a positive biopsy result. The incidence of positive biopsy results correlated directly with the initial stage of the tumor, ranging from 22 per cent of stage B1N to 50 per cent of stage C1 lesions. However, biopsy results did not correlate with the grade of the tumor. Local recurrence and distant metastases were much more common among patients with a positive biopsy result (p equals 0.0006). Local recurrence developed in 58 per cent of the patients with a positive biopsy by 5 years and in 82 per cent by 10 years. Of those in whom all biopsies were negative only 18 per cent had local recurrence by 5 years and 32 per cent by 10 years. Biopsy results retained their prognostic significance even among the more favorable subset of patients whose pelvic lymph nodes were negative initially and those with a normal prostatic examination at biopsy. These results indicate that a post-irradiation prostate biopsy 6 to 36 months after completion of treatment can be used to determine the efficacy of a particular radiotherapeutic regimen as well as the success or failure of radiotherapy in an individual patient.

Aged↗