Cavoatrial Extension of Renal Cell Cancer: Results of Operative Treatment in Helsinki University Hospital between 1990 and 2000

Background and Aims:

To evaluate the technical procedures and the post-operative survival of patients having been operated for renal cell cancer with cavoatrial tumour thrombus (RCC-T).

Material and Methods:

Between 1990 and 2000 the cardiac unit at Helsinki University Central Hospital operated on seven patients for RCC-T. A cardiac surgeon along with a urologist, performed all seven operations using sternolaparotomy (either midline or Chevron incision) with cardiopulmonary bypass.

Results:

The average duration of the operations was eight hours (range 6–11 hours) and the average perfusion time was 118 minutes (range 35–206). Hypothermic circulatory arrest was used for one patient with an arrest time of 31 minutes. Only with one patient could the cavotomy be closed directly. In four patients a cava resection was performed and closed either with a pericardium patch or a Gore-Tex prosthesis. In two patients the cava was ligated below the renal veins. During the post-operative intensive care, there were two deaths. Of the remaining patients, five were alive after six months, four after 12 months, three after six years and one patient is still alive after 12 years of follow-up.

Conclusions:

In agreement with previously published results, although peri-operative mortality is relatively high with RCC-T patients, long-term post-operative survival is possible.

A phase I/II trial of gefitinib given concurrently with radiotherapy in patients with nonmetastatic prostate cancer

e16079

Background: We estimated the safety and tolerability of 250 mg gefitinib q.d. given concurrently with three- dimensional conformal radiotherapy (3D-CRT) in patients with non-metastatic prostate cancer (PC). Methods: 42 patients with T2/T3N0M0 PC were treated in a single centre, non-randomized study (study code ZD1839/IL0118). PSA<20 and good performance status (WHO 0–1) were required. Adjuvant or neo-adjuvant hormonal treatments were not allowed. 250 mg gefitinib q.d. was started one week before and lasted for the duration of radiation therapy. 50.4 Gy (1.8 Gy/day) of 3D-CRT was administered to the tumor, prostate and seminal vesicles, followed by a 22 Gy booster (2 Gy/day) for a 72.4 Gy total dose. EGFR expression, presence of EGFRvIII and activated pEGFR were studied. Levels of serum TNF, IL-1 α and IL-6 were also evaluated. Results: Maximum tolerated dose was not reached in phase I (12 patients) and 30 additional patients were treated in phase II. Thirty (71.4%) patients completed trial medication and 12 (28.6%) prematurely discontinued because of adverse events. Dose-limiting toxicities were recorded in 16 (38.1%) patients, the most common of which was grade 3–4 transaminase increase (6 patients). After median follow-up of 38 months nobody had died of PC. The estimated PSA-free survival rate at 4 years (Kaplan-Meier) was 97%, hormone-free survival 91% and overall survival 87%. These figures compared favourably with matched, non-randomized patients treated with radiation only. Data on biochemical analyses will be presented. Conclusions: The combination of gefitinib and radiation is reasonably well tolerated and has promising activity in non-metastatic PC. A randomized study is being discussed for evaluating the efficacy of the approach.

[Table: see text]

The use of bone markers in a 6-week study to assess the efficacy of oral clodronate in patients with metastatic bone disease

Biochemical markers of bone metabolism are strongly associated with skeletal complications in metastatic bone disease. The bisphosphonate clodronate reduces skeletal morbidity by inhibiting bone resorption. This study investigated the use of bone markers to assess the efficacy of oral clodronate across a range of clinically relevant doses. There were 125 patients with metastatic bone disease randomized to daily oral clodronate (800, 1,600, 2,400 and 3,200 mg) or placebo in a double-blind, multicenter study. Urinary N-terminal telopeptide of type I collagen (U-NTX), serum C-terminal telopeptide of type I collagen (S-CTX), urinary calcium (U-Ca), and bone alkaline phosphatase were measured weekly for a 6-week treatment period. Doses of >or=1,600 mg clodronate produced mean reductions of >40% in U-NTX, S-CTX and U-Ca, all significantly different from placebo (P=0.0015, 0.001, 0.0036, respectively), after 6 weeks. Evaluation of least significant changes in markers suggested that the commonly used 1,600 mg dose was most appropriate for breast cancer patients. However, this dose was suboptimal for other (mainly prostate cancer) patients, who showed better response to 2,400 mg. The number of adverse events in the treatment arms was not significantly different from that in placebo, but a higher number of patients had diarrhea in the 3,200 mg arm and withdrew from the study. This trial is the first to explore the dose-response relationship of clodronate in oncology using specific markers of bone turnover. It has confirmed that the 1,600 mg dose is safe and effective for breast cancer patients but may be suboptimal for the other tumors studied.

Effects of 17beta-estradiol and progesterone on transcription of human papillomavirus 16 E6/E7 oncogenes in CaSki and SiHa cell lines

Several in vitro studies have addressed the interactions between estrogen/progesterone and human papillomavirus (HPV), but the results are controversial. We evaluated the effects of estrogen and progesterone and their antagonists on messenger RNA expression of HPV16 E6/E7 in HPV16-positive cell lines CaSki and SiHa with real-time reverse-transciptase polymerase chain reaction method. Colorimetric assay with tetrazolium salt (WST-1) and flow cytometry were used for testing proliferation and apoptosis. No statistically significant changes were found after hormone treatment in the expression of HPV16 E6/E7 or hormone receptors in CaSki and SiHa cell lines. Progesterone increased cell proliferation in both the cells, while estrogen increased proliferation of SiHa cells only. Estrogen seemed to protect the CaSki cells from apoptosis, and tamoxifen did not abrogate this effect. Progesterone slightly increased apoptosis of CaSki cells, and this effect was neutralized with RU486. In this study, estrogen and progesterone did not change either the transcription levels of HPV16 E6/E7 or estrogen receptor or progesterone receptor levels. Hormone receptor antagonists had no effect on transcription. Both hormones might have a permissive effect for the growth of cervical cancer, by promoting cell proliferation and making the cells vulnerable to mutations. In addition, estrogen acts as an antiapoptotic agent allowing growth advance of the cells infected with oncogenic HPV.

Specificity of serum prostate-specific antigen determination in the Finnish prostate cancer screening trial

Specificity constitutes a component of validity for a screening test. The number of false-positive (FP) results has been regarded as one of major shortcomings in prostate cancer screening. We estimated the specificity of serum prostate-specific antigen (PSA) determination in prostate cancer screening using data from a randomised, controlled screening trial conducted in Finland with 32 000 men in the screening arm. We calculated the specificity as the proportion of men with negative findings (screen negatives, SN) relative to those with negative and FP results (SN/(SN+FP)). A SN finding was defined as either PSA</=4 ng ml(-1) or PSA 3.0-3.9 ng ml(-1) combined with a negative ancillary test (digital rectal examination, DRE or free/total, F/T PSA ratio). False positives were those with positive screening test followed by a negative diagnostic examination. Of the 30 194 eligible men, 20 794 (69%) attended the first screening round and 1968 (9.5%) had a screen-positive finding. A total of 508 prostate cancers were detected at screening (2.4%). Hence, the number of SN findings was 18 825 and the number of FP results 1358. Specificity was estimated as 0.933 (18 825 out of 20 183) with 95% confidence interval (CI) 0.929-0.936. Specificity decreased with age. Digital rectal examination as ancillary examination had similar or higher specificity than F/T PSA. In the second screening round, specificity was slightly lower (0.912, 95% CI 0.908-0.916). The specificity of PSA screening in the Finnish screening trial is acceptable. Further improvement in specificity could, however, improve acceptability of screening and decrease screening costs.

Upregulation of telomerase (hTERT) is related to the grade of cervical intraepithelial neoplasia, but is not an independent predictor of high-risk human papillomavirus, virus persistence, or disease outcome in cervical cancer

Telomerase activation and telomere maintenance are essential for cell immortalization and represent a rate-limiting step in cancer progression. The E6 oncoprotein of high-risk human papillomavirus (HPV) is known to activate telomerase, but its expression in CIN lesions and its prognostic value in cervical cancer (CC) are still incompletely understood. As part of our HPV-PathogenISS study, a series of 150 CCs and 152 CIN lesions were examined using immunohistochemical (IHC) staining for hTERT (telomerase reverse transcriptase), and tested for HPV using PCR with three primer sets (MY09/11, GP5(+)/GP6(+), SPF). Follow-up data were available from all SCC patients, and 67 CIN lesions had been monitored with serial PCR for HPV after cone treatment. Expression of hTERT was increased in parallel with the grade of CIN, with major up-regulation upon transition to CIN3 (OR 18.81; 95% CI 8.48-41.69; P = 0.0001). Positive hTERT expression was 90% specific indicator of CIN, with 98.7% PPV, but suffers from low sensitivity (57.5%) and NPV (14.3%). hTERT expression was also significantly associated to HR-HPV with OR 3.38 (95% CI 1.90-6.02; P = 0.0001), but this association was confounded by the histological grade (Mantel-Haenszel common OR = 1.83; 95% CI 0.92-3.79; P = 0.086). Expression of hTERT did not predict clearance/persistence of HR-HPV after treatment of CIN, and it was not a prognostic predictor in cervical cancer in univariate or multivariate survival analysis. It was concluded that up-regulation of hTERT was closely associated with HR-HPV, due to activation by the E6 oncoprotein. hTERT is a late marker of cervical carcinogenesis, significantly associated with progression to CIN3. Theoretically, a combination of hTERT assay (showing high SP and PPV) with another test showing high SE and high NPV (e.g. Hybrid Capture 2 for HPV), should provide an ideal screening tool capable of high-performance detection of CIN lesions.

Upregulation of nuclear factor-kappaB (NF-kappaB) is related to the grade of cervical intraepithelial neoplasia, but is not an independent predictor of high-risk human papillomavirus or disease outcome in cervical cancer

Nuclear factor-kappaB (NF-kappaB) has a pivotal function in controlling a wide variety of gene functions, and has shown to be constitutively activated in many human cancers. The molecular links of NF-kappaB to oncogenic human papillomavirus (HPV) in cervical intraepithelial neoplasia (CIN) lesions and its prognostic value in cervical cancer (CC) are incompletely understood. As part of our HPV-PathogenISS study, a series of 150 squamous-cell carcinomas (SCCs) and 152 CIN lesions were examined using immunohistochemical staining for NF-kappaB, and tested for HPV using PCR with three primer sets (MY09/11, GP5+/GP6+, and SPF). Follow-up data were available from all SCC patients, and 67 CIN lesions had been monitored with serial PCR for HPV clearance/persistence after cone treatment. Cytoplasmic NF-kappaB expression was associated with CIN3/cancer at OR 3.55 (95% CI, 1.79-7.05), while nuclear NF-kappaB expression had an OR of 21.90 (95% CI, 2.96-161.74) (P = 0.0001). Strong nuclear expression was a rare event (8.8%) also in CC, but it was related to high-risk human papillomavirus (HR-HPV) detection, with OR 2.15 (95% CI, 1.08-4.30) (P = 0.022). This association was confounded, however, by the histological grade (Mantel-Haenszel common OR = 1.46; 95% CI, 0.70-3.03) (P = 0.308). Cytoplasmic or nuclear NF-kappaB expression did not predict clearance/persistence of HR-HPV after treatment of CIN, and neither one proved to be a prognostic predictor in CC. Overexpression of cytoplasmic NF-kappaB is significantly associated with progression to CIN3 and cancer. This is paralleled by only a slight increase in nuclear expression of NF-kappaB, which could be explained by the mechanisms whereby HR-HPVs escape from the transcriptional control of NF-kappaB, i.e., E7-mediated impaired nuclear translocation of cytoplasmic NF-kappaB, and E6-conditioned attenuated NF-kappaB (p65)-dependent transcriptional activity.

Down-regulated nucleoside diphosphate kinase nm23-H1 expression is unrelated to high-risk human papillomavirus but associated with progression of cervical intraepithelial neoplasia and unfavourable prognosis in cervical cancer

OBJECTIVE

One of the factors leading to an invasive phenotype is the nm23 family of metastases-associated genes. Of the six known members, nm23-H1 is the most frequently studied potential anti-metastatic gene in cervical cancer. However, the possible molecular links to oncogenic human papillomavirus (HPV) are completely unexplored as yet.

MATERIALS AND METHODS

As a part of the HPV-Pathogen Istituto Superiore di Sanità study, a series of 150 squamous cell carcinomas (SCCs) and 152 cervical intraepithelial neoplasia (CIN) lesions were examined by immunohistochemical staining for nm23-H1, and tested for HPV by polymerase chain reaction (PCR) with three sets of primers (MY09/11, GP5(+)/GP6(+) and short PCR fragment). Follow-up data were available on all patients with SCC, and 67 CIN lesions were monitored by serial PCR for clearance or persistence of HPV after cone treatment.

RESULTS

A linear decrease (p = 0.001) was observed in nm23-H1 expression, starting from CIN1 (85% with normal expression), with the most dramatic down regulation on transition from CIN2 (70% normal) to CIN3 (39%) and further to SCC (25%). Reduced expression was associated with CIN3 or cancer at an odds ratio 8.72 (95% confidence interval 4.13 to 18.41). Nm23-H1 was of no use as a marker of the high-risk human papillomavirus (HR-HPV) type, and it did not predict clearance or persistence of HR-HPV after treatment of CIN. Importantly, nm23-H1 expression was a significant prognostic factor in cervical cancer, reduced expression being associated with lower survival (p = 0.022) in univariate analysis. In the multivariate (Cox) regression model, however, only the International Federation of Gynecology and Obstetrics stage (p = 0.001) and age (p = 0.011) remained independent prognostic predictors.

CONCLUSIONS

Down-regulated nm23-H1 expression is markedly associated with progression from CIN2 to CIN3, and predicts poor prognosis in cervical cancer. Nm23-H1 down regulation is probably orchestrated by mechanisms independent of HR-HPV oncoproteins and is possibly related to the emergence of a proteolytic phenotype.

Effects of 17β-estradiol and progesterone on transcription of human papillomavirus 16 E6/E7 oncogenes in CaSki and SiHa cell lines

Several in vitro studies have addressed the interactions between estrogen/progesterone and human papillomavirus (HPV), but the results are controversial. We evaluated the effects of estrogen and progesterone and their antagonists on messenger RNA expression of HPV16 E6/E7 in HPV16-positive cell lines CaSki and SiHa with real-time reverse-transciptase polymerase chain reaction method. Colorimetric assay with tetrazolium salt (WST-1) and flow cytometry were used for testing proliferation and apoptosis. No statistically significant changes were found after hormone treatment in the expression of HPV16 E6/E7 or hormone receptors in CaSki and SiHa cell lines. Progesterone increased cell proliferation in both the cells, while estrogen increased proliferation of SiHa cells only. Estrogen seemed to protect the CaSki cells from apoptosis, and tamoxifen did not abrogate this effect. Progesterone slightly increased apoptosis of CaSki cells, and this effect was neutralized with RU486. In this study, estrogen and progesterone did not change either the transcription levels of HPV16 E6/E7 or estrogen receptor or progesterone receptor levels. Hormone receptor antagonists had no effect on transcription. Both hormones might have a permissive effect for the growth of cervical cancer, by promoting cell proliferation and making the cells vulnerable to mutations. In addition, estrogen acts as an antiapoptotic agent allowing growth advance of the cells infected with oncogenic HPV.

Bacterial adhesion to urethral catheters: role of coating materials and immersion in antibiotic solution

OBJECTIVE

To determine whether new coating materials (silver and hydrogel) or immersion in antibiotic solution may reduce or prevent bacterial adhesion to urethral catheters.

METHODS

Precut segment of Teflon-, silver- and hydrogel-coated urethral catheters were incubated with two uropathogenic bacterial strains with and without previous immersion in antibiotic solution. Tobramycin, ceftriaxone and ciprofloxacin solutions were used as these antibiotics are commonly administered for the prophylaxis and treatment of urinary tract infection (UTI), especially in hospitals.

RESULTS

Microbiological analysis showed that the new coating materials (silver and hydrogel) did not reduce bacterial adhesion to urethral catheters, whereas immersion in antibiotic solution yielded a statistically significant (p<0.05) reduction in bacterial adhesion to the test items. Among the antibiotic solutions tested, ciprofloxacin performed significantly better (p<0.005) than ceftriaxone and tobramycin.

CONCLUSIONS

Immersion in a suitable antibiotic solution may significantly reduce bacterial adhesion to urethral catheters and consequently reduce the risk of UTI in connection with these devices. Although experimental, these findings may be of clinical relevance and provide grounds for further studies in vivo.

Prospective randomized trial of interferon alfa-2a plus vinblastine versus vinblastine alone in patients with advanced renal cell cancer

PURPOSE

The combination of interferon alfa-2a (IFNalpha2a) plus vinblastine (VLB) induces objective tumor responses in patients with advanced renal cell cancer. However, no prospective randomized trial has shown that this treatment prolongs overall survival. We compared overall survival after treatment with IFNalpha2a plus VLB versus VLB alone in patients with advanced renal cell cancer.

PATIENTS AND METHODS

We prospectively randomized 160 patients with locally advanced or metastatic renal cell cancer to receive either VLB alone or IFNalpha2a plus VLB for 12 months or until progression of disease. In both groups, VLB was administered intravenously at 0.1 mg/kg every 3 weeks, and in the combination group IFNalpha2a was administered subcutaneously at 3 million units three times a week for 1 week, and 18 million units three times a week thereafter for the second and subsequent weeks. For patients unable totolerate IFNalpha2a at 18 million units per injection, the dose was reduced to 9 million units.

RESULTS

Median survival was 67.6 weeks for the 79 patients receiving IFNalpha2a plus VLB and 37.8 weeks for the 81 patients treated with VLB (P =.0049). Overall response rates were 16. 5% for patients treated with IFNalpha2a plus VLB and 2.5% for patients treated with VLB alone (P =.0025). Treatment with the combination was associated with constitutional symptoms and abnormalities in laboratory parameters, but no toxic deaths were reported.

CONCLUSION

The combination of IFNalpha2a plus VLB is superior to VLB alone in the treatment of patients with locally advanced or metastatic renal cell carcinoma. This is the first study to demonstrate that survival can be prolonged by using IFNalpha2a for these patients.

The role of parenteral polyestradiol phosphate in the treatment of advanced prostatic cancer on the threshold of the new millennium

Orchiectomy and estrogens have been used for over 50 years in the treatment of advanced prostatic cancer. Although orchiectomy is a simple procedure, it may cause psychological stress. Oral estrogen therapy is as effective as orchiectomy in terms of cancer inhibitory effect, but its acceptance as primary hormonal treatment is overshadowed by an increased risk of cardiovascular complications. Parenteral estrogen, polyestradiol phosphate (PEP), is effective, but also associated with cardiovascular complications, although to a lesser extent. During the last 20 years, well tolerated luteinizing hormone releasing hormone (LHRH) analogues have been replacing orchiectomy and estrogens. Efforts have been made to increase the efficacy of the treatment by adding antiandrogens to LHRH analogues and also to orchiectomy (combined androgen blockade, CAB). However, the efficacy of LHRH analogues and CAB has not proved to be superior to that of simple orchiectomy and, moreover, they are expensive treatment modalities. Orchiectomy and LHRH analogues are associated with negative effects on bone mass and may cause osteoporosis, whereas PEP treatment has an opposite effect. Parenteral polyestradiol phosphate is still a cheap potential treatment for advanced prostatic cancer, but further studies should be conducted to establish its future role, e.g. combining acetylsalicylic acid to prevent cardiovascular complications.

Evaluation and follow-up of patients with N1-3 M0 or NXM1 prostate cancer in phase III trials

OBJECTIVES

The aim of this discussion is to review the design and conduct of phase III trials in metastatic prostate cancer, to seek ways of improving their study design, accuracy, relevance to clinical practice, acceptability to patients, and ease of participation by clinicians. We also aim to try to set uniform definitions for the evaluation of the different endpoints used in clinical trials on metastasized prostate cancer.

METHODS

The work was started by correspondence between the participants in the group for the year before the consensus meeting. Two comprehensive questionnaires were circulated and the answers were distributed to all the members of the group. The statements were finalized during the consensus meeting.

RESULTS

There were some differing opinions concerning the methods of evaluation of endpoints for follow-up, such as time to tumor progression and time to treatment failure. After the consensus conference, there were no major disagreements within the group.

CONCLUSIONS

The aim of phase III trials is to influence clinical management. To obtain a credible result they require a sound statistical basis with appropriate power and encompassing patients from small urologic practices as well as large or academic institutions. However, deviation from routine practice may affect the accrual rate, and the trial procedure should therefore be as similar as possible to routine management. Trials inevitably involve extra work and cost. Both should be kept to a minimum to encourage participation and hasten a timely conclusion. It is mandatory to create uniform ways of designing and evaluating clinical trials in prostate cancer.

Immersion in antibiotic solution prevents bacterial adhesion onto biodegradable prostatic stents

OBJECTIVE

To determine whether immersion in antibiotic solution reduces or prevents bacterial adhesion onto biodegradable prostatic stents.

MATERIALS AND METHODS

Pre-cut segments of polyglycolic acid (PGA) and polylactic acid (PLA) prostatic stents were incubated with two common uropathogenic bacterial strains (Enterococcus faecalis and Escherichia coli) with and without previous immersion in antibiotic solution. Tobramycin, ceftriaxone and ciprofloxacin solutions were used, as these antibiotics are commonly administered for the prophylaxis and treatment of urinary tract infection (UTI).

RESULTS

Immersion in ciprofloxacin solution prevented the adherence of both bacterial strains. Immersion in ceftriaxone solution prevented only the adherence of the E. coli strain. Immersion in tobramycin solution had no effect on either of the strains. The stent materials per se did not influence bacterial adhesion. After immersion in ciprofloxacin, the stent segments retained significant antibacterial activity even after one day's incubation in saline.

CONCLUSION

Immersion in a suitable antibiotic solution may significantly reduce and even prevent bacterial adhesion onto biodegradable prostatic stents. Preventing bacterial adhesion may reduce the risk of UTI during the use of these devices.

Is it possible to prevent bacterial adhesion onto ureteric stents?

The aim of this study was to determine whether the use of bactericidal coatings or immersion in antibiotic solution reduces or prevents bacterial adhesion onto ureteric stents. Precut segments of full silicone, silver-coated and hydrogel-coated ureteric stents were incubated with two uropathogenic bacterial strains with and without previous immersion in antibiotic solution. Tobramycin, ceftriaxone and ciprofloxacin solutions were used, as these antibiotics are commonly administered for the prophylaxis and treatment of urinary tract infection (UTI). Microbiological analysis showed that immersion of ureteric stents in ceftriaxone and ciprofloxacin yielded a significant reduction of bacterial adhesion, whereas immersion in tobramycin did not. The surface material of the stents had no direct influence on bacterial adhesion. In this experimental study, neither the silver nor the hydrogel coat reduced bacterial adhesion onto ureteric stents whereas immersion in a suitable antibiotic solution significantly reduced and even prevented this phenomenon, probably due to the adhesion of the antibiotic onto the stent surface. Prevention of bacterial adhesion onto ureteric stents is essential to reduce the risk of UTI in connection with these devices.

Biocompatibility of latex and silicone T tubes in the porcine common bile duct: an experimental study

Toxicity of materials used in indwelling drains or catheters has the potential to damage surrounding tissues. The biocompatibility of biliary T-tubes was investigated using in groups of piglets (total 30 animals). In group 1 (n=16) a choledochotomy was performed with insertion of a latex T-tube (n=6) or a silicone T-tube (n=8), or without a T-tube (n=2). In group 2 (n=14) the common bile duct (CBD) was 3/4-transected, and the lesion was sutured over a latex T-tube (n=4) or a silicone T-tube (n=5), or without a T-tube (n=5). The groups were reoperated upon after 2 and 6 weeks respectively, and the CBD was harvested for scanning electron microscopy and light microscopy. The T-tubes were examined for cell culture toxicity with a DNA synthesis inhibition test. According to the cell culture tests, latex T-tubes were toxic and silicone T-tubes nontoxic. T-tubes induced moderate to pronounced fibrosis and epithelial damage in the CBD wall, but did not induce excessive fibrosis or scarring at the site of CBD suture. In the 6-week study period, however, the grade of tissue reactions in the CBD did not correlate with the toxicity of the T-tube materials, but rather reflected a foreign body reaction and mechanical pressure. Although gross anatomical changes did not occur, neither material seemed to be completely harmless for porcine CBD wall.

A positive pharmacological erection test does not rule out arteriogenic erectile dysfunction

PURPOSE

We tested the assumption that a positive pharmacological erection test implies normal penile vascular status.

MATERIALS AND METHODS

From March 1991 to February 1995, 372 patients with erectile dysfunction were referred to our institutions. Penile hemodynamics were studied in 205 patients with color coded Doppler ultrasonography after intracavernous injection of 40 micrograms. prostaglandin E1.

RESULTS

Of the 205 patients undergoing color coded Doppler utrasonography 92 had a rigid erection, that is a positive pharmacological erection test. Doppler wave analysis showed that 76 of the 92 patients (82%) had normal and 7 (8%) had borderline arterial function (peak systolic velocity greater than 35 and 25 to 35 cm. per second, respectively), while 9 (10%) had arterial insufficiency (peak systolic velocity less than 25 cm. per second). All 92 patients had a normal veno-occlusive mechanism (resistance index greater than 0.90). Of the 9 patients with pure arteriogenic erectile dysfunction 8 had risk factors for arterial insufficiency, such as aortoiliac occlusive disease (5), diabetes mellitus (3), longer than 20-year smoking history (8) and hypertension (7).

CONCLUSIONS

Our study shows hemodynamically that a positive pharmacological erection test does not rule out arteriogenic erectile dysfunction.

cDNA cloning and characterization of a novel nucleolar protein

In an initial study of anti-nuclear antibodies in the chronic inflammatory bladder disease interstitial cystitis, we reported that 7% of interstitial cystitis patients studied had autoantibodies to the nucleolus. We now report that, using an autoimmune serum from a patient with interstitial cystitis, we have identified and partially characterized a novel protein with an M(r) of approximately 55 kDa (hereafter referred to as No55) localized to the granular component of the nucleolus. No55 was initially characterized by diffuse nucleolar immunofluorescence staining in interphase cells and by Western blotting as a 55-kDa doublet on whole-cell extracts. During mitosis, No55 was associated with chromosomes and appeared in prenucleolar bodies during telophase, but it did not colocalize with p80-coilin in coiled bodies. Immunoelectron microscopy revealed that No55 was localized uniformly throughout the granular component of the nucleolus compared with a more peripheral localization of nucleolar granular component protein B23. On segregation of the nucleolus with actinomycin D, No55 remained with the granular component of the segregated nucleolus, whereas protein B23 was found predominantly in the nucleoplasm. Finally, a cDNA expression library was screened with the human autoantibody against No55, and a 2.4-kb insert was isolated, subcloned to homogeneity, and then sequenced. Analysis of this sequence showed an open reading frame of approximately 1.3 kb coding for 437 amino acids with a predicted molecular weight of 50 kDa. A search of the gene sequence database indicated homology with SC65, a rat synaptonemal complex protein. Therefore, on the basis of molecular weight, nucleolar sublocalization, response to actinomycin D, and cDNA sequence determination, No55 is a novel protein of the interphase nucleolus.

Cyclosporine in severe interstitial cystitis

PURPOSE

Cyclosporine is a widely used immunosuppressive drug in organ transplantation and recently it has been used in several autoimmune disorders with good results. Because interstitial cystitis may have an autoimmune etiology, we wished to determine whether cyclosporine has any effect on symptoms in patients with severe interstitial cystitis.

MATERIALS AND METHODS

A total of 11 patients, who fulfilled the criteria for interstitial cystitis according to an international accrual form, received cyclosporine for 3 to 6 months at an initial dose of 2.5 to 5 mg./kg. daily and a maintenance dose of 1.5 to 3 mg./kg. daily. Blood pressure, serum creatinine and cyclosporine concentrations were monitored regularly. The patients completed frequency-volume charts at 2-week intervals.

RESULTS

The frequency-volume charts showed favorable effects. Micturition frequency decreased (p<0.01), and mean and maximum voided volumes increased significantly (p<0.001 and p<0.01, respectively). Bladder pain decreased or disappeared in 10 patients, allowing for storage of large urine volumes. Serum creatinine did not change with the dosages used. Mild hypertension occurred in 2 patients and resolved after the cyclosporine dose was lowered. After cessation of treatment symptoms recurred in the majority of patients.

CONCLUSIONS

The findings revive the concept of interstitial cystitis as an autoimmune disease.

Aortofemoral surgery and sexual function

OBJECTIVES

To determine the incidence and pathophysiology of erectile dysfunction (ED) in patients with aortoiliac occlusive disease (AIOD) and the effects of aortofemoral surgery, including endarterectomy (E) and reconstruction (R), on erectile function (EF).

DESIGN

Evaluation of EF before and 3 months after surgery.

METHODS

31 out of 40 male patients scheduled for aortofemoral surgery were given multiple choice questionnaires and penile dynamic Colour Doppler Ultrasonography.

RESULTS

Of the 31 who agreed to enter the study five (16%) were found to be potent and 26 (84%) to suffer from ED. This was purely arteriogenic in 8% of the cases, purely venogenic in 23%, combined arteriogenic and venogenic in 53%, and neurogenic in 16%. Twenty patients returned for postoperative evaluation of EF, nine who had undergone E and 11 who had undergone R. Improvement of EF, in terms of increased penile arterial inflow, occurred in seven patients, six who had undergone E and one who had undergone R. EF remained unchanged in nine patients, three who had undergone E and six who had undergone R. Deterioration of EF occurred in four patients, all who had undergone R, and was attributable to decreased arterial inflow in two cases and to neurogenic surgical injury in the other two.

CONCLUSIONS

The majority of patients with AIOD suffers from ED. Reduced penile arterial inflow and cavernovenous leakage are equally important in the pathophysiology of ED in patients with AIOD, suggesting that atherosclerosis may also compromise the penile veno-occlusive mechanism. Endarterectomy seems more likely than reconstruction to improve or maintain EF.

Simple methods of quantifying oxidation products and antioxidant potential of low density lipoproteins

OBJECTIVES

The present study describes new methods for the measurement of oxidation products and antioxidant potential of low density lipoproteins (LDL).

DESIGN AND METHODS

LDL is isolated by precipitation with buffered heparin. The assay for LDL oxidation products (LDL-BDC) is based on determination of baseline levels of conjugated dienes (BDC) in lipids extracted from LDL. The assay for antioxidant potential of LDL (LDL-TRAP) is based on the ability of LDL to trap peroxyl radicals.

RESULTS

LDL-BDC was found to increase linearly over a range from 100 to 1750 microL, LDL-TRAP from 250 to 1750 microL of serum taken for precipitation. For LDL-BDC, the CV was 4.4% and 4.5% for within- and between-assay precision, respectively. For the LDL-TRAP, the CV was 8.1% and 8.7% for within- and between-assay precisions, respectively. Freezing of the serum (2 weeks at -70 degrees C) did not affect LDL-BDC or LDL-TRAP levels. A negative correlation was found to exist between the LDL-BDC and LDL-TRAP values. LDL-BDC and LDL-TRAP values were at the same level in both sexes. The LDL-BDC was found to increase with age. Short-term intervention with antioxidants increased LDL-TRAP substantially, but did not affect the LDL-BDC level.

CONCLUSIONS

These methods are fast and simple to perform, and can, therefore, be applied to clinical purposes.

Bacterial adherence and biofilm formation on latex and silicone T-tubes in relation to bacterial contamination of bile

BACKGROUND

T-tube-related bacteriobilia causes infectious complications and obstruction. To prevent these, the choice of T-tube material may be of importance.

METHODS

Transected common bile ducts (CBDs) of 17 piglets were sutured over latex or silicone T-tubes, or without a T-tube.

RESULTS

After 6 weeks bacteriobilia was found in all of 12 CBDs with and in 1 of 5 CBDs without a T-tube (p < 0.05). By scanning electron microscopy (SEM) four of five latex and none of five silicone T-tubes had bacterial biofilms (p < 0.05). All tubes remained patent. Segments of T-tubes were incubated with five different bacterial strains. Sonication and SEM showed that 0.1-1.1% of 10(7) colony-forming units of inoculum adhered to T-tubes. Two to six times more bacteria adhered to latex than to silicone (p < 0.05).

CONCLUSIONS

Silicone offers better long-term patency than latex. Less infectious complications occur if T-tubes are omitted.

Bacterial adhesion and biofilm formation on various double-J stents in vivo and in vitro

The aim of this study was to determine whether bacterial adhesion and biofilm formation occur on various ureteric stent materials in vivo and in vitro and whether there is any correlation between biofilm formation and urinary tract infection. Using an open surgical procedure, 23 double-J stents of 8 different types were inserted in the ureters of 13 piglets. After 6 weeks intubation, 2 (9%) of the 23 stented renal units yielded positive urine culture. Scanning Electron Microscopy (SEM) showed sporadic bacteria on 7 (30%) of the 23 indwelling ureteric stents and bacterial biofilms on only 2 (9%), those indwelling the renal units which yielded positive urine cultures. Precut segments of the 8 double-J stent brands were incubated with 5 different bacterial strains. Microbiological and SEM analysis of the stents revealed that only 0.1-0.01% of the bacterial inoculum adhered to the stents. There was no statistically significant difference in bacterial adherence to the various stent materials. Interestingly, the two Escherichia coli strains with P-fimbriae adhered significantly more than the two without P-fimbriae. Sporadic bacterial adhesion to ureteric stents seemed to have little clinical significance whereas biofilm formation seemed to result in urinary tract infection. None of the tested stents proved to be superior to the others in this respect, and adhesion appeared to depend on the virulence of the bacteria rather than the properties of the biomaterials.

Alternating mitomycin C and bacillus Calmette-Guerin instillation therapy for carcinoma in situ of the bladder. The Finnbladder Group

PURPOSE

Our aim was to prove if alternating chemotherapeutic and immunotherapeutic instillations improved efficacy and reduced toxicity in patients with carcinoma in situ of the bladder.

MATERIALS AND METHODS

Of 68 carcinoma in situ patients randomly treated with instillations 40 received mitomycin C and 28 received mitomycin C and Pasteur bacillus Calmette-Guerin (BCG) in alternating courses. Mean followup was 33 months.

RESULTS

The complete response rates with mitomycin C and mitomycin C/BCG were 45% and 71% at 3 months, 59% and 82% at 12 months, and 47% and 74% at 24 months, respectively (p = 0.041). The disease-free interval showed the superiority of alternating therapy (p = 0.043). Recurrence rates during the instillation period were 1.834 with mitomycin C and 0.922 with mitomycin C/BCG (p = 0.013). No remarkable side effects developed in the alternating group.

CONCLUSIONS

Therapy of carcinoma in situ with alternating mitomycin C and BCG is more effective than mitomycin C alone. Compared to BCG monotherapy only few side effects occur.

Pregnancy results from a vibrator application, electroejaculation, and a vas aspiration programme in spinal-cord injured men

In an infertility treatment programme for spinal-cord injured men, vibrator application was primarily used in cases of upper motor neurone lesion and electroejaculation in men with lower lesions, or when vibrator application failed to induce ejaculation. Spermatozoa were obtained by these methods from 29 out of 35 men who desired infertility treatment. No ejaculate was obtained from six men. Three of these men plus two others with very poor sperm quality with electroejaculation underwent micro-surgical sperm aspiration from the vas deferens for invitro fertilization (IVF), and spermatozoa were obtained from all of them. Thus it was possible to obtain spermatozoa from almost every spinal-cord injured man who had ongoing spermatogenesis using these three methods. Insemination was the primary infertility treatment used with all the couples where there was successful ejaculation. In all, 12 pregnancies resulted from home vaginal inseminations, eight from intrauterine inseminations, two from IVF with ejaculated spermatozoa, and two from IVF with spermatozoa aspirated from the vas. Three couples had children from donor inseminations (not counted in the results); 12 are still in the programme. From 24 pregnancies, 22 children have now been born to 18 couples out of the original 35 (51%), and there were four abortions. Hence, overall, infertility treatment of spinal-cord injured men has given good results.

Biocompatibility of various indwelling double-J stents

The biocompatibility of 8 double-J stent brands was evaluated both in vivo, by scanning electron microscopy and histological analysis of pig ureters intubated for 6 weeks, and in vitro, by cell culture methods. In vivo findings showed that superficial epithelial destruction was milder in the ureters intubated with hydrogel-coated stents than in those intubated with other stents. Inflammatory reactive changes were milder in the ureters intubated with silicone stents than in those intubated with other stents, while encrustation was more severe on silicone and Grey stents than the others. In vitro, the 3 stent brands made of "modified polyurethane" were found to be cytotoxic while the others were not. Overall, silicone and hydrogel-coated stents seemed to be more biocompatible than the others, and hydrogel-coated stents to be more suitable than silicone stents for long-term ureteral stenting, being less prone to encrustation. Although they are of an experimental nature, these findings may be of relevance to clinical practice.

The effects of various indwelling JJ stents on renal pelvic pressure and renal parenchymal thickness in the pig

OBJECTIVE

To determine whether indwelling JJ stents significantly alter renal pelvic pressure and consequently have deleterious effects on renal function.

MATERIALS AND METHODS

Thirteen piglets were used totalling 26 renal units. Using an open, sterile surgical procedure, 23 renal units were stented with 6 F JJ catheters of eight different types: three renal units were not stented and served as controls. Intra-pelvic pressure values during diuretic stress were measured before and after 6 weeks of intubation. The kidneys were then removed and sent for pathological evaluation of renal parenchymal thickness.

RESULTS

A marked increase in intra-pelvic pressure values was found in two of the 19 stented renal units suitable for this measurement. A significant reduction (more than one third with respect to the control values) in renal parenchymal thickness was found in six of the 21 stented renal units suitable for this measurement, three of which had been intubated with a Cook polyurethane stent and three with an Angiomed Puroflex stent.

CONCLUSION

In the present experimental study some JJ stents seemed to cause long-lasting changes in renal pelvic pressure and consequently to have deleterious effects on renal function. Although experimental findings are not always fully related to clinical practice, a knowledge of the potential effects of these prostheses is essential to minimize complications related to their use.

Penile necrosis in a diabetic with renal disease and clean intermittent catheterization for recurrent urethral stricture. Case report

In a patient with diabetic microangiopathy and renal disease, penile necrosis occurred in connection with clean intermittent catheterization. Microangiopathy of the urethral and penile arteries presumably lowered the local defences, so that the catheterization initiated penile necrotic changes by introducing bacteria and traumatizing the poorly vascularized urethral epithelium.

Spontaneous Perforation of the Rectum by Carcinoma of the Prostate. Case Report

A case of spontaneous perforation of the rectum by a locally advanced prostatic carcinoma is described. The mechanisms of rectal involvement by prostatic carcinoma are discussed, focusing attention on the difficulties in differential diagnosis with primary carcinoma of the rectum.

Toxicity and immediate allergenicity of latex gloves

Surgical latex gloves and a natural rubber latex (NRL) catheter were evaluated for biocompatibility by cell culture methods and Type I allergic reactions in operating room personnel using latex gloves. The prevalence of relevant immediate allergy to NRL was 5.2% when using eluates made from different latex gloves as allergens and the skin-prick test methodology. The reliability of a questionnaire in detecting the sensitized persons was limited. Weak positive skin test reactions to surgical latex glove eluates were found to be unreliable as compared with challenging with the corresponding glove. Latex gloves exhibited more toxicity in cell culture than non latex gloves, but, inversely, the toxic catheter gave weak positive skin-prick test reaction in only one sensitized person, confirming that the allergenicity and toxicity of natural rubber products do not refer to the same properties of the products. Catheters exhibiting toxicity in cell culture have earlier been found to cause significant clinical symptoms in operated patients, but in the case of surgical gloves this relationship is not clear. One glove brand with a low content of known sensitizing rubber chemicals caused clear toxicity in cell culture but was well tolerated by the hospital personnel.

Zinc compounds in urethral catheters. A possible source of toxicity?

The cytotoxicity of latex urinary catheters has been earlier documented. During the manufacturing process tens of chemicals are added to the natural rubber base. Several of the accelerators and other chemicals used have carcinogenic and acute toxic effects. Some of the accelerators are zinc compounds. In the present study, the cytotoxicity and zinc concentration of 68 latex catheter extracts were analysed. The siliconized latex catheters were the most toxic, and a correlation was seen between the IC50 values and the zinc concentration. The good manufacturing practice (GMP) has to some extent resolved the cytotoxicity problem of latex urinary catheters. There is, however, still a need to reformulate the manufacturing process and to find new catheter materials to meet the new EN standards concerning the biological safety of urinary catheters.

Combined adrenal adenoma and myelolipoma in a patient with Conn syndrome. Case report

Adrenal myelolipoma is an uncommon benign tumor usually discovered by chance in patients with hypertension, obesity, arteriosclerosis or cancer. The association with adrenocortical endocrine dysfunctions is rare. We report herein an unusual case, the second in the literature to the best of our knowledge, of combined adrenal adenoma and myelolipoma in a patient with Conn syndrome.

Müllerian adenosarcomalike tumor of the seminal vesicle. A case report with immunohistochemical and ultrastructural observations

A müllerian adenosarcomalike tumor of the seminal vesicle is described in a 49-year-old man. The tumor occupied the entire right seminal vesicle and adhered to the right lobe of the prostate, in the area adjacent to the seminal vesicle. The tumor was also adherent to the rectum. Microscopically, the cells were seen to invade the prostatic tissue. The tumor consisted of a highly cellular stroma with spindle-shaped pleomorphic cells, suggesting the diagnosis of a low-grade sarcoma. In addition, dilated cystic spaces lined by columnar epithelium were seen. Immunohistochemically, most tumor cells showed positivity for vimentin, desmin, and muscle-specific actin, suggesting smooth-muscle cell differentiation. Furthermore, electron microscopy also demonstrated smooth-muscle differentiation of the tumor cells. The patient has been disease-free for 48 months since undergoing a cystoprostatetectomy.

Effect of oral clodronate on bone pain. A controlled study in patients with metastic prostatic cancer

Although osteosclerotic metastases are characteristic of prostatic carcinoma, bone resorption is also accelerated. Since clodronate inhibits bone resorption and relieves bone pain, we have given it to patients with painful bone disease from prostatic cancer after failure of hormonal therapy. All patients received estramustine phosphate orally. Simultaneously they were randomly allocated to clodronate (36) and placebo (39) groups. Clodronate was given by mouth. The dose was 3.2 g for the first month, thereafter 1.6 g. Pain relief was more distinct in the clodronate group where one third of patients were totally free of bone pain. The use of analgesics stopped in 38% of patients on clodronate and in 18% on placebo which effect probably belongs to estramustine phosphate. Serum calcium concentration decreased more markedly in the clodronate group. Clodronate dose of 3.2 g seemed to be more potent than that of 1.6 g. Side effects were uncommon and occurred equally in both groups. No significant differences were seen in median survival or survival rates between the groups.

Can fine needle aspiration biopsy detect incidental prostatic carcinoma (T1) prior to TUR?

The purpose of this study was to find out whether randomly taken fine needle aspiration biopsy (FNA) can detect incidental prostatic carcinoma prior to transurethral resection (TUR) and what are the effects of local tumor stage and grade on detection rate. Biopsies were taken from 344 patients, who came to hospitals for elective TUR without clinical evidence of prostatic carcinoma. Histologic examination of the TUR material showed prostatic carcinoma in 49 cases (14%). Sufficient material for cytologic examination was found in 343 cases. Of the 16 cases of T1a carcinoma in histologic examination, cytology found only 1, which was a G3 carcinoma. Of 33 T1b carcinoma in histologic examination, cytology found 6 and an additional 7 were suspect findings. Out of 6 G3 tumors in histologic examination, cytology showed 4. In our hands the proportion of false-negative cytologic findings in randomly taken FNA was so large that routine use of random FNA prior to TUR or as a screening procedure cannot be recommended, but positive FNA finding can be regarded as cancer.

Urethral blood circulation during cardiopulmonary bypass

The haemodynamic changes induced by extracorporeal circulation (ECC) are thought to be important in the induction of urethral strictures in open heart surgery when indwelling latex catheters are used. In the present study, 6 piglets were cannulated and connected to extracorporeal perfusion apparatus. Pump flows correlated with human ECC values with non-haemic prime were used. The mucosal and submucosal blood circulation in the urethra reduced by 66% during ECC (P less than 0.05). The brain and hepatic arterial flows increased. A significant reduction was seen in renal blood circulation. The changes in the urethral blood circulation during ECC correlated with previous findings. The reduced wash out levels of chemicals leaching from the indwelling latex catheters as a result of reduced local blood circulation are the main trigger for the induction of urethral strictures during ECC and in other shock-like circulatory disturbances in the human body.

Comparison of two different cell culture methods in evaluation of biocompatibility of latex urinary catheters

International biocompatibility standards for urinary catheters have not yet been set. The used in vivo animal tests earlier have been shown to be insensitive and expensive. The present study compared the sensitivity and other properties of two in vitro cell culture methods, the reference method of the British Standards Institution (BSI) and the thymidine incorporation method (DNA synthesis inhibition test. The cell culture toxicities of thirty-seven latex catheters were measured and 84.8% of the catheters tested passed the BSI reference test while 94.6% passed the thymidine incorporation test. The overall batch-to-batch correlation was poor (p greater than 0.05), but within brands the correlation was better. This is obviously to be explained by the differences the characteristics of the tests and/or the chemical composition of the catheters. The thymidine incorporation test is easier to perform, requires less manpower, and is therefore less liable to subjective interpretations than the BSI test. The biocompatibility toxicity limits for latex urinary catheters need to be tightened. Our experience in this study indicates that the thymidine incorporation test or tests similar to it, which can be highly automated can be recommended for biocompatibility screening in large series, and BSI reference test can be used additionally in unclear cases.

Orchiectomy versus oestrogen in the treatment of advanced prostatic cancer

The primary clinical efficacy of orchiectomy and the combination therapy of intramuscular polyoestradiol phosphate 80 mg monthly and oral ethinyl oestradiol 0.15 mg daily was evaluated by progression and cancer mortality rates in a series of 277 prostatic cancer patients representing part of the Finnprostate study. After a follow-up of 5 years there was a significant difference between the groups in terms of progression rate and prostatic cancer deaths. The oestrogen combination was more effective in delaying progression of the disease. The overall mortality rate was similar in both groups. About one-third of the patients were alive after 5 years.

Intralesional corticosteroid injections in combination with internal urethrotomy in the treatment of urethral strictures

In the treatment of 38 patients with urethral stricture, 21 received intralesional corticosteroid injections, combined in 17 cases with internal urethrotomy. The aetiology of the lesion is discussed, together with a review of the pertaining literature, and the results of the treatment are evaluated.

Maximal electrical stimulation in the treatment of unstable detrusor and urge incontinence

Ninety-one patients with unstable detrusor and urge incontinence were treated with maximal electrical stimulation. There were 17 dropouts. From the remaining 74 patients 51 were subjectively cured or significantly improved, this effect lasted for more than 6 weeks in 40. Objectively a significant decrease in frequency was found, also a significant increase in bladder volume. No effect on detrusor pressure at bladder contraction was noted.

Intracavernous self-injection for erectile failure

Thirty-three patients with erectile failure were taught to self-inject papaverine intracavernosally. The dose was from 15 to 80 mg. Phentolamine was added if 80 mg was not sufficient. The patients kept a diary on the effects of the regimen, and also filled out a questionnaire after a follow-up of 4-16 months. The results showed that 55% were satisfied with the method. However, technical difficulties were common. Sexual stimulation turned out to be very important resulting in varying erections on consecutive occasions with the same papaverine dose. Prolonged erection occurred once in 5 patients and was easily handled conservatively in all. Fibrous plaques developed in 2 patients. Twelve patients (36%) stopped the injections for various reasons. When failure occurred the disappointment was usually severe. Thus, the selection of patients for self-injection is important.

Treatment of ulcer and nonulcer interstitial cystitis with sodium pentosanpolysulfate: a multicenter trial

The effect of sodium pentosanpolysulfate (Elmiron) in the treatment of interstitial cystitis was observed in an open controlled multicenter trial. We studied 87 patients with symptoms for more than 2 years at 17 centers in Finland and Sweden. Patient selection was based on the typical chronic symptomatology but the material subsequently was stratified according to objective cystoscopic findings. The medication (400 mg. daily in 2 oral doses) was discontinued after 6 months. The response was evaluated every 4 weeks during treatment and every 3 months thereafter. Most patients responded favorably, many with diminution of pain within only 4 weeks from the start of treatment. The frequency of micturition decreased significantly and the mean volume per void per 24 hours increased in the patients without bladder ulceration but such changes were not found in the patients with ulcer. The bladder capacity was smaller in the ulcer group. In these patients the pre-treatment intensity of pain was somewhat greater than in those without bladder ulcer but the pain was alleviated in both groups and this effect was stable at the 3-month followup. The differences in responses in the 2 groups indicate a probable fundamental difference between ulcerative and nonulcerative interstitial cystitis. Side effects of the drug were few, slight and transient. Therefore, the study indicates that a significant number of patients with interstitial cystitis can be expected to benefit from treatment with sodium pentosanpolysulfate.

Blood circulation in the urethra during hypovolemia--an experimental study

The changes in urethral blood circulation caused by hypovolemia were studied in male piglets to simulate the hemodynamic changes during extracorporeal perfusion used in open-heart surgery. Changes caused by mild pancreatitis were studied which produced a similar reduction in urethral blood flow measured by microspheres comparable to a 34% hemorrhage of the circulating blood volume. According to this study the urethral mucosa is very sensitive to hemodynamic changes. It may be the case that catheter toxicity is more significant when the urethral blood flow is diminished.