C Dixon

New York University, New York City, NY, United States

Are you C Dixon?

Claim your profile

Publications (7)14.66 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Although transitional cell carcinoma of the bladder (TCC) metastasizes frequently with devastating consequences, no marker has been available to monitor this process. Uroplakins are a group of specific markers for normal urothelium and are continuously expressed by the majority of TCCs. Detection of uroplakin-positive cells in the circulation would be a strong indication of hematogenous dissemination of tumor cells in patients with TCC. Total RNAs were extracted from peripheral blood of 60 patients with TCC (50 non-metastatic and 10 metastatic) and 10 healthy controls, reverse-transcribed and subjected to polymerase chain reaction amplification (RT-PCR) using oligonucleotide primers of human uroplakin II gene. A uroplakin-expressing human bladder cancer cell line (RT4) was used as a positive control to establish the sensitivity of the RT-PCR assay. We showed that the PCR-amplification of the mRNA encoding uroplakin II (UPII), a 15-kDa urothelium-specific marker, constitutes a highly sensitive and specific assay for detecting 100% of transitional cell carcinoma tissue, and that this assay can detect a single bladder cancer cell in a 5-ml. blood sample. UPII mRNA was detected in the blood samples of 2 patients with metastatic bladder cancer without chemotherapy and 1 out of 8 such patients with chemotherapy, but not in those of 50 non-metastatic patients or normal controls. Uroplakin II is a highly specific marker for human TCC and the detection of uroplakin II in the peripheral blood is associated with metastatic spread of bladder cancer cells. The specific and sensitive detection of uroplakin II provides a useful adjunct for detecting bladder cancer metastasis, staging, and monitoring chemotherapeutic response.
    The Journal of Urology 10/1999; 162(3 Pt 1):931-5. · 3.70 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We determined if total prostate volume, transition zone volume or transition zone index is correlated with the severity of clinical benign prostatic hyperplasia (BPH). A total of 93 men 52 to 85 years old, who were referred to a urology outpatient facility for treatment of clinical BPH, elevated serum prostate specific antigen or abnormal digital rectal examination, underwent measurement of total prostate and transition zone volume at transrectal ultrasonography. All men were requested to undergo uroflowmetry and complete the American Urological Association (AUA) symptom score. The pairwise correlations between AUA symptom score, versus total prostate and transition zone volumes and transition zone index were not statistically or clinically significant. A weak pairwise relationship was observed between peak flow rate versus total prostate volume (r2 = 0.160), transition zone volume (r2 = 0.156) and transition zone index (r2 = 0.147). The pairwise relationships between AUA symptom scores versus all prostate volumes were not statistically significant for subjects with mild (score 8 or less) or moderate to severe (score more than 8) symptoms. Total prostate and transition zone volumes, and transition zone index are not directly related to AUA symptom score and only weakly related to peak flow rate. These findings provide further evidence that the total prostate, total BPH and relative BPH volumes are not useful determinants of the severity of clinical BPH.
    The Journal of Urology 08/1997; 158(1):85-8. · 3.70 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To determine if men with normal peak urinary flow rates (PFR) and prostatism respond to terazosin. Forty-one men over the age of 50 years with an American Urological Association (AUA) symptom score greater than 8, postvoid residual urine volume (PVR) less than 300 mL, and no clinical or biochemical evidence of prostate cancer were treated with terazosin independent of the baseline PFR. The effect of terazosin on the AUA symptom score and PFR were compared for subjects with a PFR of 15 mL/s or less (group I) and those with a PFR greater than 15 mL/s (group II). The baseline age, AUA symptom score, prostate volume, and PVR were not significantly different between the two groups. The mean changes in AUA symptom score were -45.0% and -49.5% for groups I and II, respectively. The mean changes in PFR were 7.0% and -26.6% for groups I and II, respectively. The effect of terazosin on AUA symptom score is independent of baseline PFR, indicating that the mechanism of action of terazosin is not exclusively mediated by reduction of bladder outlet obstruction. Randomized controlled studies are required to confirm this provocative observation.
    Urology 04/1997; 49(3):476-80. · 2.42 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Transurethral resection of the prostate (TURP) represents the accepted standard of surgical therapy for the management of symptomatic bladder outlet obstruction due to benign prostatic hyperplasia (BPH). However, this is a major operative procedure associated with significant perioperative morbidity. Visual laser ablation of the prostate (VLAP) utilizing a neodymium:yttrium-aluminum-garnet laser represents a new technologic approach to the surgical management of BPH. We compared the relative safety and efficacy of these two surgical approaches in a prospective, randomized trial. At 6 investigational sites in the United States, 115 men with symptomatic BPH more than 50 years of age and not in retention, were randomly assigned to undergo either TURP (59 patients) of VLAP (56 patients). VLAP patients received a mean of 10,200 J of energy delivered in a mean of 5.5 intraprostate laser applications. At preoperative baseline, 3 months, 6 months, and 1 year postoperatively, all patients underwent clinical evaluations, including ultrasonic prostatic volume determination, standardized American Urological Association (AUA)-6 symptom score, peak urine flow, postvoid residual urine volume, and quality-of-life assessment. Compared to TURP, the VLAP procedure required less time (23.4 versus 45.2 minutes; P < 0.01) and shorter hospitalization (1.8 versus 3.1 days, P < 0.01). VLAP was associated with a significantly lower rate of serious treatment-related complications compared to TURP (10.7% versus 35.6%; P < 0.01). Only One (2.2%) patient undergoing VLAP experienced a greater than 2.2 g/dL decrease in hemoglobin compared to 40% of TURP patients (P = 0.01). No patient in the VLAP group required blood transfusion compared with 3.4% of those undergoing TURP. Of the 115 patients, clinical outcomes measured at 1 year showed a mean improvement in AUA-6 symptom scores of -9.0 for VLAP compared with -13.3 for TURP (P < 0.04), mean increase in peak urinary flow rate of 5.3 cc/s for VLAP compared with 7.0 cc/s for TURP (P = 0.27), and mean decrease in postvoid residual urine volume of -55.4 cc for VLAP compared with -138.8 cc for TURP (P < 0.01). At 1 year, 78.2% of patients undergoing VLAP indicated that their quality of life was improved compared with 93.0% of patients undergoing TURP (P = 0.03). When compared with TURP, treatment of BPH with VLAP is associated with less hemoglobin decrease, a lower likelihood of serious complication, and requires less procedure time and a shorter hospital stay. Through a 1-year follow-up, VLAP produced significant improvement over baseline in objective and subjective outcome measures. However, for 1-year improvement in AUA-6 symptom score, postvoid residual urine volume, and quality of life, VLAP was less effective than TURP. In this initial study in the United States, with relatively low-energy laser applications, VLAP did not result in as complete a removal of prostatic tissue as did TURP. Considering the lower morbidity, shorter procedure and hospitalization times, and the degree of effectiveness that was achieved even at the low-energy doses used in this study, VLAP appears to be a viable and safe alternative to standard TURP.
    Urology 09/1995; 46(2):155-60. · 2.42 Impact Factor
  • H Lepor, M Guerena, C M Dixon
    [Show abstract] [Hide abstract]
    ABSTRACT: The present study represents the first attempt to improve urinary continence following radical prostatectomy (RP) by perianastomotic injection of autologous fat at the time of the surgical procedure. A total of 15 consecutive men with clinically localized carcinoma of the prostate underwent nerve-sparing radical retropubic prostatectomy (RRP) with perianastomotic injection of autologous fat. The autologous fat was obtained using a liposuction cannula connected to a power aspirator. The fat was harvested from the adipose tissue immediately adjacent to the lower midline incision. After the pelvic floor musculature was perforated, a total of 30 mL of autologous fat was injected through a 12 gauge angiocatheter under cystoscopic guidance. There were no complications resulting from the harvesting or injection of the autologous fat. All of the patients were evaluated for 6 months. Of the 15 patients, 12 (80%) achieved total urinary control within 6 months. The average time required to achieve total urinary continence was 89 days. None of the patients experienced total or nocturnal incontinence. Of the 3 patients with stress urinary incontinence (SUI), 2 required 2 small pads per day and 1 required 3 pads per day. Only 1 patient reported that the level of bother resulting from the incontinence was severe. The preliminary experiences with the perianastomotic fat injection at the time of RRP are encouraging. Determining the ultimate safety and effectiveness of this technique requires longer follow-up in expanded series of patients.
    Urology 12/1994; 44(5):783-8. · 2.42 Impact Factor
  • C M Dixon, H Lepor
    Contemporary urology 11/1993; 5(10):44-62.
  • C M Dixon, H Lepor
    Seminars in urology 12/1992; 10(4):273-7.

Publication Stats

202 Citations
14.66 Total Impact Points

Institutions

  • 1997
    • New York University
      • Department of Urology
      New York City, NY, United States
  • 1992–1993
    • Medical College of Wisconsin
      • Department of Urology
      Milwaukee, WI, United States