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Christopher W Johnson

Publications and source records attributed to Christopher W Johnson.

7 recordsLinked to original sources
PubMed2005

Transurethral resection of the ejaculatory ducts for treating ejaculatory symptoms.

OBJECTIVES: To report our experience with transurethral resection of the ejaculatory ducts (TURED) in infertile men with symptomatic ejaculatory duct obstruction (EDO). PATIENTS AND METHODS: Before surgery, all patients complained of a decrease in the volume of their ejaculate, 14 of 15 had a non-projectile ejaculation, nine had a genitourinary infection necessitating antibiotic treatment, and five had pain with orgasm. The mean ejaculate volume and total motile sperm count was 1.1 mL and 8.1 million sperm per ejaculate. After surgery, at a mean follow-up of 2 months, 10 men reported having projectile ejaculation, and eight reported a marked improvement in their sensation of orgasm. Overall, 14 men reported a subjective improvement in their ejaculation. The average postoperative ejaculate volume was 2.3 mL and the total motile sperm count was 38.1 million per ejaculate. CONCLUSIONS: Men with symptomatic EDO who underwent TURED showed improvements in their ejaculation, sensation of orgasm, semen analysis values and fertility.

Constriction, Pathologic↗
PubMed2003

Urologic anomalies and two-vessel umbilical cords: what are the implications?

A two-vessel umbilical cord (or single umbilical artery) is a perinatal finding that may be detected in infants with congenital or chromosomal abnormalities. Its presence has been associated with an increased risk of genitourinary defects. The urologic anomalies that typically are associated with a two-vessel cord often are minor and self-limiting. These defects usually can be detected perinatally in routine prenatal screening ultrasonographic examinations. The neonatal physical examination, an additional postnatal ultrasonography, and possibly a voiding cystourethrogram will be sufficient to complete the screening for genitourinary abnormalities in children with a single umbilical artery. Infants with two-vessel umbilical cords do not require additional screening for genitourinary defects, unless the imaging or amniocentesis detects a genitourinary abnormality. This review details the history of two-vessel cords and the associated genitourinary anomalies.

Animals↗
PubMed2003

Seminal vesicle involvement after radical prostatectomy: predicting risk factors for progression.

OBJECTIVES: To evaluate and study the factors for progression after radical prostatectomy with seminal vesicle invasion in a cohort of European and American patients. METHODS: The data of 137 patients with isolated seminal vesicle invasion who underwent radical retropubic prostatectomy between 1988 and 2001 were analyzed. The Gleason score of the specimen, presence of capsular invasion, and surgical margin status were noted. Follow-up data were obtained through routine serum prostate-specific antigen (PSA) assays and digital rectal examinations. A defining criterion for progression was a postoperative serum PSA level greater than 0.2 ng/mL or any postoperative radiotherapy or hormonal treatment. Kaplan-Meier analysis was used to determine the actuarial biochemical recurrence-free likelihood, and the log-rank test was used to compare these results. Differences were considered statistically significant when the P value was less than 0.05. RESULTS: After a mean follow-up of 4.9 years (range 0.9 to 13.4), 70 patients (51.9%) had progression. The biochemical 5-year progression-free survival rate was 33.8%. In univariate and multivariate analyses, only preoperative PSA level (P = 0.001) and Gleason score of the specimen (P = 0.01) were independent predictors of progression. Neither capsular invasion nor positive surgical margins predicted progression. When an analysis was performed according to the major Gleason grade of the radical prostatectomy specimen, Gleason grade 5 was associated with a worse prognosis compared with Gleason grade 3 and 4 (P = 0.01). The mean time to progression was 20.5, 17.1, and 10.1 months for Gleason grade 3, 4, and 5, respectively. CONCLUSIONS: Seminal vesicle invasion after radical prostatectomy has historically been associated with a poor prognosis. However, in the present study, seminal vesicle invasion was associated with a 34% rate of freedom from progression at 5 years after surgery alone. Preoperative PSA and Gleason score of the radical prostatectomy specimen were independent factors for progression in the present study, which described the largest patient group to date. The Gleason grade of the radical prostatectomy specimen distinguished among different times to progression.

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PubMed2002

The Coprinus cinereus adherin Rad9 functions in Mre11-dependent DNA repair, meiotic sister-chromatid cohesion, and meiotic homolog pairing.

Mitotic sister-chromatid cohesion (SCC) is known to depend in part on conserved proteins called adherins, which although necessary for SCC are not themselves localized between sister chromatids. We have examined mitotic DNA-repair and meiotic chromosome behavior in the Coprinus cinereus adherin mutant rad9-1. Genetic pathway analysis established that Rad9 functions in an Mre11-dependent pathway of DNA repair. Using fluorescence in situ hybridization, we found that the rad9-1 mutant is defective in the establishment of meiotic homolog pairing at both interstitial and subtelomeric sites but in the maintenance of pairing at only interstitial loci. To determine the role of Rad9 in meiotic SCC, we hybridized nuclear spreads simultaneously with a homolog-specific probe and a probe that recognizes both members of a homologous pair. We found that Rad9 is required for wild-type levels of meiotic SCC, and that nuclei showing loss of cohesion were twice as likely also to fail at homolog pairing. To ask whether the contribution of Rad9 to homolog pairing is solely in the establishment of SCC, we examined a rad9-1;msh5-22 double mutant, in which premeiotic DNA replication is inhibited. The msh5-22 mutation partially suppressed the deleterious effects of the rad9-1 mutation on homolog pairing; however, pairing in the double mutant still was significantly lower than in the msh5-22 single mutant control. Because the role of Rad9 in homolog pairing is not obviated by the absence of a sister chromatid, we conclude that adherins have one or more early meiotic functions distinct from the establishment of cohesion.

Cell Cycle Proteins↗
PubMed2002

Ejaculatory duct obstruction.

PURPOSE OF REVIEW: We surveyed the growing literature on ejaculatory duct obstruction and provide suggestions regarding its diagnosis and management. RECENT FINDINGS: Ejaculatory duct obstruction is a rare cause of male infertility. With the advent of the high resolution transurethral ultrasound (TRUS) technology, there has been an increase in diagnosis of this disorder. As for the treatment, it appears that central cystic lesions and partial obstructions respond best to transurethral resection of the ejaculatory ducts (TURED). SUMMARY: Ejaculatory duct obstruction is a rare but surgically correctable cause of male infertility. Although there are no pathognomonic findings associated with ejaculatory duct obstruction, the diagnosis should be suspected in an infertile male with oligospermia or azoospermia with low ejaculate volume, normal secondary sex characteristics, testes, and hormonal profile, and dilated seminal vesicles, midline cyst, or calcifications on TRUS. In select cases, TURED has resulted in marked improvement in semen parameters, and pregnancies have been achieved. More studies are needed in the areas of diagnosis and long-term surgical outcome.

Constriction, Pathologic↗
PubMedDate not supplied

Prognostic indicators for long term outcome following radical retropubic prostatectomy for prostate cancer involving the seminal vesicles.

Seminal vesicle involvement at the time of radical prostatectomy (RP) for prostate cancer has been equated with metastatic disease. We review our biochemical freedom from disease results following RP in patients with seminal vesicle involvement with particular attention to identifying variables that may be predictive of disease recurrence. We retrospectively reviewed our surgical database and identified patients with pT3b (2002 AJCC) prostate cancer at RP [corrected]. There were 70 cases without lymph node involvement and with available clinical follow-up identified. Any patient receiving androgen deprivation therapy, radiation therapy, or with a sustained PSA elevation greater than 0.2 ng/mL was considered a biochemical failure. Results were calculated using the Kaplan-Meier method. Mean age was 63.4 (range 45.7-79.5) years, mean preoperative PSA was 11.3 ng/mL (range 2-60), mean biopsy Gleason score was 7.2 (range 4-9), mean RP Gleason score was 7.5 (range 5-9), and median follow-up time was 61.5 months (range 2.3-160.6). Overall, 33/70 (47%) patients were without evidence of disease without further therapy. For patients with pT3bN0Mx prostate cancer, margin status, capsular invasion, and PSA were not statistically significant risk factors for disease progression. Gleason score and major Gleason grade were the only statistically significant variables that predicted disease progression. A specimen Gleason score of greater than 7 and major Gleason grades greater than 3 were associated with an increased rate of disease progression in this patient group.

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