Glutathione S-transferase-mu (GSTM1) and -theta (GSTT1) genotypes in the etiology of prostate cancer

The glutathione S-transferases (GSTs) are involved in the metabolism of numerous potential prostate carcinogens. Common homozygous germ-line deletions exist in the genes that encode GST-mu (GSTM1) and GST-theta (GSTT1) and preclude enzyme expression. To evaluate whether GSTM1 and/or GSTT1 contribute to prostate cancer (CaP) etiology, we studied 237 incident CaP cases and 239 age- and race-matched controls. The probability of having CaP was increased in men who had nondeleted (functional) genotypes at GSTT1 (odds ratio, 1.83; 95% confidence interval, 1.19-2.80) but not GSTM1 (odds ratio, 1.07; 95% confidence interval, 0.74-1.55). No interaction of these genes in CaP etiology was observed. GST-theta is highly expressed in the prostate and can produce genotoxic effects upon exposure to specific carcinogens. These results suggest that GSTT1 is associated with CaP risk.

The overactive bladder: an overview for primary care health providers

The overactive bladder, with symptoms of frequency, urgency and urge incontinence, substantially affects the life styles of millions of people throughout the world. The symptoms are associated with significant social, psychological, occupational, domestic, physical, and sexual problems. Despite the considerable impact of the condition on quality of life, sufferers are often reluctant to discuss their problem with family members or health care professionals. This state of affairs is unfortunate, for much can be done to alleviate the symptoms of this distressing condition. It is therefore of utmost importance that medical education about symptoms of the overactive bladder and other related problems be improved, to help health care professionals identify and treat patients who will benefit from therapy. This article reviews current thinking regarding definition, epidemiology, quality of life effects, evaluation and management. Emphasis is placed on knowledge particularly useful in primary care, especially, noninvasive modalities of therapy.

Expression of myosin isoforms in smooth muscle cells in the corpus cavernosum penis

Corpus cavernosum smooth muscle (CCSM) in the penis is unique in that it exhibits a high resting tone and, on stimulation, the muscle cells relax, allowing cavernous spaces to fill with blood, which results in an erection (tumescence). During detumescence, the muscle cells contract and return to the state of high resting tone. This study was undertaken to determine whether CCSM with these unique properties contains myosin isoforms typical of aorta or bladder smooth muscles, muscles that exhibit tonic and phasic characteristics, respectively. RT-PCR revealed that normal CCSM contains an SM2/SM1 mRNA ratio of 1.2:1 (similar to the rabbit aorta). Approximately 31% of the myosin heavy chain transcripts possess a 21-nt insert (predominant in bladder smooth muscle but not expressed in aorta) that encodes the seven-amino acid insert near the NH2-terminal ATP binding region in the head portion of the myosin molecule found in SMB, with the remaining mRNA being noninserted (SMA). Quantitative competitive RT-PCR revealed that the CCSM possesses approximately 4.5-fold less SMB than the bladder smooth muscle. Western blot analysis using an antibody specific for the seven-amino acid insert reveals that both SM1 and SM2 in the CCSM contain the seven-amino acid insert. Furthermore, SMB containing the seven-amino acid insert was localized in the CCSM by immunofluorescence microscopy using this highly specific antibody. The analysis of the expression of LC17 isoforms a and b in the CCSM revealed that it is similar to that of bladder smooth muscle. Thus the CCSM possesses an overall myosin isoform composition intermediate between aorta and bladder smooth muscles, which generally express tonic- and phasiclike characteristics, respectively. Two-dimensional gel electrophoresis showed a relatively low level (approximately 10%) of Ca2+-dependent light-chain (LC20) phosphorylation at the basal tone, which reaches approximately 23% in response to maximal stimulation. The presence of noninserted and inserted myosin isoforms with low and high levels of actin-activated ATPase activities, respectively, in the CCSM may contribute to the ability of the CCSM to remain in a state of high resting tone and to relax rapidly for normal penile function.

Modification of clinical presentation of prostate tumors by a novel genetic variant in CYP3A4

BACKGROUND

Pathways involved in androgen metabolism have been implicated in the etiology of prostate cancer. The goal of this study was to evaluate the effect of CYP3A4, a gene associated with the oxidative deactivation of testosterone, on the clinical presentation of prostate cancers.

METHODS

A polymerase chain reaction-based approach was used to identify sequence variants of the human CYP3A4 gene. To ascertain whether allelic variants of the CYP3A4 gene were associated with tumor stage and grade and age of the patient at diagnosis, we determined CYP3A4 genotypes in 230 Caucasian men with incident prostate cancer.

RESULTS

We identified a novel genetic variant (CYP3A4-V) that has an altered 5' regulatory element, containing an A to G mutation, upstream of the CYP3A4 gene. We then compared clinical characteristics of prostate cancers in men who did and did not carry this variant. The presence of the CYP3A4-V allele was associated with a higher tumor-lymph node-metastasis (TNM) stage and Gleason grade. The association between CYP3A4 genotype and tumor stage was most pronounced in men diagnosed at a relatively old age who reported no family history of prostate cancer. In this group, 46% of men with stage T3/T4 tumors carried CYP3A4-V, whereas only 5% of individuals with stage T1 tumors carried CYP3A4-V (adjusted odds ratio = 9.45; 95% confidence interval = 2.54-35.17; chi2(1) = 12.28; two-sided P<.001).

CONCLUSIONS

We determined that a single base change in the 5' flanking region of the CYP3A4 gene was associated with higher clinical stage and grade in men with prostate tumors. Our results suggest that mutations in the CYP3A4 gene may influence prostate carcinogenesis.

Preemptive epidural analgesia and recovery from radical prostatectomy: a randomized controlled trial

CONTEXT

Preemptive analgesia can decrease the sensitization of the central nervous system that would ordinarily amplify subsequent nociceptive input, but a clear demonstration of its clinical efficacy is necessary for it to become a routine component of acute pain therapy.

OBJECTIVE

To determine the impact of preemptive epidural analgesia on postoperative pain and other clinically important outcome variables after radical retropubic prostatectomy.

DESIGN AND SETTING

A block randomized double-blind clinical trial lasting 20 months at a single academic medical center.

PATIENTS

A total of 100 generally healthy and neurologically intact patients scheduled for radical retropubic prostatectomy for the treatment of prostate cancer in whom an epidural catheter for treating postoperative pain was to be placed prior to the induction of general anesthesia.

INTERVENTIONS

Epidural bupivacaine, epidural fentanyl, or no epidural drug was administered prior to induction of anesthesia and throughout the entire operation, followed by aggressive postoperative epidural analgesia for all patients.

MAIN OUTCOME MEASURES

Daily pain scores during hospitalization and pain scores obtained 3.5, 5.5, and 9.5 weeks after hospital discharge.

RESULTS

The patients who received epidural fentanyl or bupivacaine prior to surgical incision (preemptive analgesia) experienced 33% less pain while hospitalized (P=.007). Pain scores in those receiving preemptive analgesia were significantly lower at 9.5 weeks (P=.02), but were not significantly different at 3.5 or 5.5 weeks. At 9.5 weeks, 32 (86%) of 37 patients receiving preemptive analgesia were pain-free compared with 9 (47%) of 19 control patients (P=.004). Patients receiving preemptive analgesia were more active 3.5 weeks after surgery (P=.01), but not at 5.5 or 9.5 weeks.

CONCLUSIONS

Even in the presence of aggressive postoperative pain management, preemptive epidural analgesia significantly decreases postoperative pain during hospitalization and long after discharge, and is associated with increased activity levels after discharge.

Pharmacologic options for the overactive bladder

OBJECTIVES

To review the current pharmacologic options for treatment of the overactive bladder and to describe potential therapies on the horizon.

METHODS

The literature on the clinical efficacy and safety of the currently available agents is described.

RESULTS

According to the guidelines issued by the Agency for Health Care Policy and Research (AHCPR), anticholinergic agents should be the first-line pharmacologic therapy for patients with detrusor instability. Oxybutynin is the anticholinergic of choice for this indication, whereas propantheline is the second-line therapy. Although calcium antagonists have been investigated, the one such drug introduced for the treatment of overactive bladder (terodiline) was withdrawn from the market because of a risk of cardiac arrhythmia. Studies of potassium channel openers have found either a lack of clinical efficacy or an unacceptable level of side effects. Alpha-adrenergic antagonists may be useful for decreasing bladder overactivity in patients who have autonomous bladders as the result of conditions such as spinal cord injury. Tricyclic antidepressants (particularly imipramine) may be effective in decreasing bladder contractility, although the AHCPR guidelines caution that these drugs should be reserved for use in carefully evaluated patients. Future developments in the treatment of detrusor overactivity are likely to occur in 3 categories: drugs that affect peripheral excitatory mechanisms, drugs that inhibit afferent mechanisms, and drugs that affect more central actions at either the ganglionic, spinal cord, or supraspinal level.

CONCLUSIONS

Although pharmacologic management of the overactive bladder has progressed little in the past 10 years, the future may hold the promise of more effective therapies.

Collagen injection therapy for post-radical retropubic prostatectomy incontinence: role of Valsalva leak point pressure

PURPOSE

We retrospectively evaluated the role of Valsalva leak point pressure as a predictor of successful management of post-radical retropubic prostatectomy incontinence with collagen injection.

MATERIALS AND METHODS

Urodynamic studies and Valsalva leak point pressures of 31 men who received retrograde collagen injection for post-radical retropubic prostatectomy incontinence were reviewed. Patients were interviewed before and after treatment to assess pad use and the American Urological Association quality of life index (scale 0 to 6). Parameters for success were postoperative quality of life score 3 or less or 50% or greater decrease in pad use and that the patient would recommend collagen therapy to someone else.

RESULTS

Of 31 patients 11 (35%) met the criteria for success, 2 (6%) were completely dry and 9 (29%) were improved. Successfully treated patients had a mean Valsalva leak point pressure of 64.0 cm. water compared to 42.2 cm. water in the failure group (p <0.01). Of patients with Valsalva leak point pressure of 60 cm. water or greater, 70% responded favorably to collagen injection (positive predictive value), while 81% with Valsalva leak point pressure less than 60 cm. water had treatment failure (negative predictive value) (p <0.02). There were no other statistically significant differences between those successfully treated with collagen injection and those in whom treatment failed, including mean age (62.7 to 68.1 years), mean volume of collagen (26.1 to 28.9 ml.), mean number of treatment sessions (2.45 to 2.65), mean followup (14.9 to 15.1 months), preoperative quality of life score (5.1 to 4.9), and preoperative pads per day (4.0 to 3.37).

CONCLUSIONS

Our data suggest that collagen injection improves 35% but cures a minority of patients (less than 10%) with post-radical retropubic prostatectomy incontinence. A pretreatment Valsalva leak point pressure of 60 cm. water or greater has high predictive value for a beneficial outcome after collagen injection. We propose a role for Valsalva leak point pressure to select men cost-effectively with post-radical retropubic prostatectomy incontinence for therapy with collagen injection.

Progressive angiomyolipoma with inferior vena cava tumor thrombus

A 45-year-old man presented with an incidentally discovered benign renal angiomyolipoma. This lesion initially demonstrated renal vein involvement. On referral to our institution 3 years later, there was interval progression of tumor thrombus to the intrahepatic inferior vena cava. Intravascular extension of benign angiomyolipoma, though rare, has been reported. We present a new example and review the literature concerning this unusual complication of a common renal neoplasm.

The use of combined radiation therapy and hormonal therapy in the management of lymph node-positive prostate cancer

PURPOSE

To determine the rate of tumor response and patterns of relapse following combined hormonal-radiation therapy of adenocarcinoma of the prostate and to measure the survival in a group of men with tumor metastatic to pelvic lymph nodes.

METHODS AND MATERIALS

66 patients with adenocarcinoma of the prostate with pathologically confirmed pelvic lymph node involvement were treated with combined radiation therapy and hormonal therapy. An additional five patients declined hormonal therapy. The patients treated with combined therapy represented a group with locally advanced disease including 44 patients (67%) with T3 or T4 tumors and 51 patients (80%) had N2 or N3 lymph node metastases. The pelvic lymph nodes were treated to a dose of 45 Gy and the prostate was boosted to a dose of 65 to 71 Gy. Hormonal therapy began up to 2 months before radiation and continued indefinitely. Patients were allowed to select their hormonal therapy and could choose DES (2 patients), orchiectomy (21 patients), LHRH agonist (7 patients) or combined androgen blockade (34 patients).

RESULTS

Median follow-up is 49 months (range 12 to 131 months) and 21 patients have been followed for longer than 5 years. There have been 15 recurrences the entire group including three local recurrences in the prostate, seven patients with distant metastases, four patients with biochemical recurrences without clinical evidence of disease, and one patient where the location was unknown. Two of the PSA recurrences occurred in patients who elected to discontinue hormones after less than 3 years of therapy. The overall survival at 5 and 8 years is 94 and 84%, the clinical disease free survival is 85 and 67%, and the biochemical disease-free survival is 78 and 47%. There was no increased toxicity of the combined modality regimen compared to the expected effects of radiation and hormonal therapy.

CONCLUSION

Combined hormonal and radiation therapy represents an effective treatment option for patients with adenocarcinoma of the prostate metastatic to pelvic lymph nodes. Combined modality therapy appears to extend the disease-free survival and allow patients to maintain their independent function.

Prostate imaging may not be necessary in nonpalpable carcinoma of the prostate

OBJECTIVES

Stage T1c carcinoma of the prostate is defined as a nonpalpable carcinoma (NPC-P) that is not visible by imaging and is identified by needle biopsy performed because of elevated prostate-specific antigen (PSA) concentrations. The purpose of this study was to define the incidence of normal findings on transrectal ultrasound (TRUS) and/or endorectal coil magnetic resonance imaging (EMRI) among patients with NPC-P, as well as to investigate the value of differentiating patients with Stage T1c disease from all other patients with NPC-P.

METHODS

The records of 2211 patients diagnosed with prostate carcinoma between 1988 and 1995 were reviewed to identify 291 men with NPC-P. TRUS and EMRI reports were analyzed with regard to the presence and laterality of hypoechoic nodules or low-signal areas reported on T2-weighted images, respectively. Ninety percent of patients (n = 262) had at least six prostate biopsies, 185 patients (64%) underwent both TRUS and EMRI, 224 (77%) had TRUS, and 251 (86%) had an EMRI study.

RESULTS

Results were considered normal in 101 (47%) of 214 patients undergoing TRUS, in 58 (23%) of 249 undergoing EMRI, and in 22 (12%) of 185 undergoing both TRUS and EMRI. For the side of the prostate with positive biopsy results, correlation with imaging abnormalities was better for EMRI than for TRUS (39% versus 24%). There was no significant difference in mean PSA value, distribution of Gleason score, or unilateral versus bilateral positive biopsy results among patients with normal versus abnormal findings on both TRUS and EMRI.

CONCLUSIONS

(1) Only 12% of men with NPC-P have no TRUS or EMRI abnormalities, fulfilling the criteria for Stage T1c prostate carcinoma. (2) Those patients with Stage T1c disease do not differ from patients with NPC-P up-staged by TRUS or EMRI, with regard to pretreatment PSA levels, Gleason scores, and the probability of having bilateral rather than unilateral positive biopsy results. (3) The value of classifying patients with NPC-P into Stage T1c versus higher stages of prostate carcinoma on the basis of imaging should be questioned.

Transurethral biopsy of the prostate for persistently elevated or increasing prostate specific antigen following multiple negative transrectal biopsies

PURPOSE

Treatment of the patient with persistently elevated prostate specific antigen (PSA) levels after pathologically negative transrectal or manually directed prostate needle biopsy is unclear. We retrospectively evaluated the use of transurethral biopsy of the prostate as an adjunctive study for the diagnosis of prostate cancer in these patients.

MATERIALS AND METHODS

From January 1993 through February 1996, 71 patients underwent transurethral biopsy in conjunction with repeat prostatic needle biopsy for a persistently elevated PSA (greater than 4 ng./ml.) after previously negative needle biopsy. All patients had at least 1 previous ultrasound guided sextant prostatic needle biopsy (mean 1.85, range 1 to 7) with or without manually directed biopsies. Following negative prostatic needle biopsy these patients subsequently underwent a minimum of a 4-quadrant transurethral sampling of the prostatic fossa followed by repeat sextant prostatic needle biopsy. A subset of patients underwent sampling of the anterior prostatic tissue or transition zone using transrectal ultrasound guided prostatic needle biopsy at transurethral biopsy.

RESULTS

Of the 71 patients with elevated PSA (mean 16.2 ng./ml., range 4.2 to 171) 17 (24%) had prostate cancer on the repeat prostatic needle biopsy. Both patients who had prostate cancer on the transurethral biopsy specimens also had prostate cancer on the repeat prostatic needle biopsy specimens. A total of 68 patients had benign prostatic tissue and 1 had high grade prostatic intraepithelial neoplasia on transurethral biopsy specimens. Of 19 patients with high grade prostatic intraepithelial neoplasia on the initial prostatic needle biopsy, transurethral biopsy specimens revealed no prostate cancer or prostatic intraepithelial neoplasia. Repeat prostatic needle biopsy in these patients with high grade prostatic intraepithelial neoplasia revealed prostate cancer in 6 and high grade prostatic intraepithelial neoplasia in 4.

CONCLUSIONS

In patients with persistently elevated or increasing serum PSA after a previously negative prostatic needle biopsy, transurethral biopsy is not a useful adjunct in diagnosing prostate cancer. In this high risk group of patients transurethral biopsy adds little or no diagnostic value to prostatic needle biopsy even in those with high grade prostatic intraepithelial neoplasia.

Associations among cystoscopic and urodynamic findings for women enrolled in the Interstitial Cystitis Data Base (ICDB) Study

OBJECTIVES

Interstitial cystitis is a symptom complex characterized by pelvic pain, urinary urgency, urinary frequency, and nocturia. Patients with these symptoms, at the 5 clinical centers participating in the National Interstitial Cystitis Data Base (ICDB) Study, have been evaluated with history and physical exams, questionnaires, and urodynamic studies.

METHODS

Of the 388 female subjects entered in the study as of December 31, 1995, 150 women have undergone cystoscopy with hydrodistension. The data from the endoscopic procedures and the urodynamic studies were analyzed. The associations among cystoscopic and urodynamic findings were reviewed.

RESULTS

Patient demographics of this subgroup show a predominance of Caucasians 139/150 (92.7%), with the average age being 43 (+/-13.2) years. Of the total, 17 patients (11.3%) had a Hunner's patch (HP). The prevalence by center varied from a low of 2/38 (5.3%) to a high of 3/9 (33.3%). Bloody effluent following hydrodistension was present in 113/150 (75.3%). Glomerulations appeared in varying degrees (mild, moderate, severe) in 91.3% of the 150 patients. There was a strong inverse relationship (P < 0.001) between bladder capacity under anesthesia and the presence of a HP (mean of 845 cc with HP absent versus a mean of 531 cc when present). The incidence of HP varied from 67.6% among women with a bladder capacity at hydrodistension of < 400 cc to 3.8% for those with a bladder capacity of at least 800 cc. The presence and increasing severity of glomerulations was positively associated (P < 0.003) with the presence of HP, ranging from 0/13 (0%) when glomerulations were not present to 6/31 (19.4%) when glomerulations were graded as severe. Of the patients with HP, 17/17 (100%) had glomerulations after hydrodistension. HP is more closely associated with the moderate to severe range of glomerulations (P < 0.01). Nearly half of the patients with HP or 8/17 (47.1%) had "moderate" glomerulations, while 6/17 (35.3%) had "severe" glomerulations. The volume at first sensation to void on urodynamics (mean 87 cc without HP versus 34.7 cc with HP) was highly inversely associated (P = 0.002) with the presence of HP, but not with any of the other cystoscopic findings. Of patients with HP, 94% had a volume at first sensation to void of < or = 50 cc where only 36% of patients without HP had a volume at first sensation to void of < or = 50 cc. The volume at maximum capacity on urodynamics was positively associated with the volume at hydrodistension (P < 0.001).

CONCLUSIONS

Overall, patients with HP had lower bladder capacities, lower volumes at first sensation to void, and more severe glomerulations. Thus, the presence of HP would imply a more severe case of interstitial cystitis. Logically, a higher bladder capacity on cystometrogram is associated with a higher volume at the time of hydrodistension, and bloody effluent is associated with more severe glomerulations.

Logical and systematic approach to the evaluation and management of patients suspected of having interstitial cystitis

OBJECTIVES

To outline a systematic approach to the evaluation, diagnosis and treatment of interstitial cystitis (IC).

METHODS

A review of the literature as well as of our experience.

RESULTS

The exclusion criteria for the research definition of IC can be used as guides when obtaining the history, physical examination, laboratory workup, and finally urodynamics and cystoscopy/hydrodistension under anesthesia. Once the diagnosis is established, patients who are still symptomatic after hydrodistension are treated initially with oral medications. Those who do not respond to oral therapy are given intravesical therapy. Patients whose symptoms are refractory to both routes can be considered for a TENS unit, experimental oral therapies, chronic pain control with opioids, or, as a last resort, surgery to create a urinary diversion.

CONCLUSION

As IC is a diagnosis of exclusion, the evaluation remains one of ruling out other disorders that produce similar symptoms in patients whose history suggests IC. Until the etiology and pathogenesis of IC are identified, specific therapy is not possible. However, symptomatic treatments are helpful in the majority of patients.

Contractile responses and calcium mobilization induced by muscarinic agonists in the rat urinary bladder: effects of age

In the current study, the contractile responses to muscarinic stimulation of urinary bladder strips from young rats and aged rats were compared. 1. The EC50 values of the two groups in response to bethanechol were similar. 2. The magnitude and the velocity of tension generation was significantly lower in strips from the aged group. 3. The magnitude as well as the velocity of tension generation in response to high K+ solution of the two models were similar. 4. The time to peak [Ca2+]i in response to bethanechol was prolonged in strips from the aged group as compared with the young group. 5. 45Ca2+ influx in response to bethanechol was significantly reduced in the aged group as compared with the young group. It is concluded that the reduced contractile response to muscarinic stimulation of isolated urinary bladder strips from aged rats is mediated at least in part by a decreased rate of Ca2+ entry.

Development of prostate cancer after pituitary dysfunction: a report of 8 patients

OBJECTIVES

Eight patients with a history of pituitary dysfunction were seen in the Department of Radiation Oncology at the Hospital of the University of Pennsylvania for evaluation of their prostate carcinoma. Because prostate cancer is a hormonally responsive cancer, hormonal abnormalities from pituitary dysfunction may have played a role in its development. In addition, many patients with pituitary dysfunction receive exogenous hormonal replacement. The histories of these 8 patients were reviewed to look for any common underlying factor in the development of their prostate cancer.

METHODS

The radiation oncology charts, hospital charts, and pathology reports were reviewed. The cause and treatment of the pituitary disorder were reviewed. Hormonal dysfunction, hormonal replacement, and treatment duration were recorded. The interval to the development of prostate cancer, stage at diagnosis, prostate-specific antigen level, Gleason score, treatment, and treatment outcome were also investigated.

RESULTS

We found a variety of pituitary disorders and treatments. However, all patients received testosterone replacement therapy prior to the development of their prostate cancer (median of 30 months). The time to the development of the cancer ranged from 26 to 250 months (median 98). Patients had Stage T2 or T3 tumors at diagnosis. Patients were treated either with radical prostatectomy or radiation therapy. Six of the 8 patients were alive and doing well at their last follow-up examination.

CONCLUSIONS

Prostate cancer has been shown to be androgen responsive. All the patients in this series were placed on physiologic testosterone replacement for pituitary dysfunction. The role of testosterone in the initiation of prostate cancer has been debated. However, at the present time, it seems appropriate to establish close monitoring for prostate cancer in patients receiving androgen therapy for pituitary dysfunction.

Calcium regulation of urinary bladder function

PURPOSE

To investigate the effect of independently inhibiting calcium influx from extracellular sources and calcium release from intracellular stores on the ability of the urinary bladder to generate pressure and empty.

MATERIALS AND METHODS

Rabbit bladders were mounted in an in vitro whole organ bath and filled with 15 ml. saline. Each bladder was incubated separately in Tyrode's solution, with diltiazem (10 microM), to block extracellular calcium influx, or with thapsigargin (40 microM) and ryanodine (80 microM), to block the uptake and release of calcium from the sarcoplasmic reticulum. The bladder was then stimulated isometrically with field stimulation (32 Hz), and to empty with field stimulation and with bethanechol (250 microM), independently. During stimulation, transmural pressure and volume emptied were measured. From these, flow rate, power, and external mechanical work were calculated.

RESULTS

In the presence of diltiazem, the time to maximal pressure decreased while the rate of pressure generation increased. This results from increased participation of intracellular calcium release, which occurs rapidly and near the smooth muscle filaments, decreasing the diffusion time. In the presence of thapsigargin and ryanodine the maximal rate of pressure generation was decreased, due to the increased diffusion time required for calcium to move to the muscle filaments from extracellular sites.

CONCLUSIONS

The current study demonstrates that bladder pressure generation and emptying are dependent upon both an influx of calcium through L-type calcium channels (inhibited by diltiazem) and the stimulated release of calcium from the SR (inhibited by thapsigargin and ryanodine).

Correlation of ischemia/reperfusion or partial outlet obstruction-induced spectrin proteolysis by calpain with contractile dysfunction in rabbit bladder

OBJECTIVES

In the rabbit, both experimental ischemia and partial outlet obstruction of the urinary bladder induce similar dysfunctions with regard to the contractile responses to both field (neuronal) stimulation and postsynaptic receptor stimulation. Circumstantial evidence indicates that the pathologic response to both conditions is related to two connected processes-tissue ischemia and reperfusion injury-that result in a marked increase in intracellular calcium ([Ca2+]i), followed by the activation of the Ca(2+)-dependent neutral protease calpain. Calpain activation results in the proteolysis of specific membrane proteins, including those of neuronal membranes (resulting in progressive denervation of the detrusor) and the sarcoplasmic reticulum Ca(2+)-ATPase (SERCA), resulting in the previously reported decrease in SERCA. The current study is designed to generate direct support for the theory that both ischemia and partial outlet obstruction result in the activation of calpain.

METHODS

Separate sets of rabbits were subjected to 1 or 2 hours of ischemia, followed by reperfusion for different lengths of time, or partial outlet obstruction for different lengths of time. We determined the state of calpain activation by quantitating tissue proteolysis of alpha-spectrin by Western blot analysis. Correlative organ bath studies were conducted to observe the contractile responses of bladder strips to field stimulation and bethanechol administration.

RESULTS

(1) Sixty minutes of ischemia followed by 30 minutes of reperfusion resulted in (a) a reduction in the contractile responses to field stimulation and bethanechol (89% and 57%, respectively), and (b) a 72% decrease in native alpha-spectrin, with a concomitant 300% increase in its breakdown products (BDPs). Neither alpha-spectrin nor its BDPs had returned to control levels after 72 hours of reperfusion. (2) Twenty-four hours after the creation of a partial obstruction, alpha-spectrin BDP levels were increased 330%, then gradually fell to 130% of control levels by 14 days after obstruction. Concomitantly, the native alpha-spectrin level was decreased 74% 24 hours after obstruction and remained low through 7 days after obstruction. At 14 days after obstruction, the alpha-spectrin levels had recovered to 75% of control levels.

CONCLUSIONS

These findings suggest that Ca(2+)-dependent proteolysis of the preferred calpain substrate alpha-spectrin in urinary bladder tissues is increased significantly by both ischemia/reperfusion and partial outlet obstruction. Temporally, proteolysis precedes the reduced muscle function resulting from these pathologic conditions.

Etiology of bladder dysfunction secondary to partial outlet obstruction. Calcium disregulation in bladder power generation and the ability to perform work

Similar to all smooth muscle, contraction of urinary bladder smooth muscle depends upon a rise in intracellular free calcium, which results from both calcium influx from extracellular spaces and calcium release from intracellular stores (calcium-induced calcium release [CICR]). Recent studies from our laboratory demonstrate that one of the major dysfunctions induced by partial outlet obstruction is a marked reduction in the participation of CICR (from IP3-sensitive and IP3-insensitive sites on the sarcoplasmic reticulum [SR]) during stimulation by both field stimulation (neurotransmitter release) and by direct muscarinic stimulation (bethanechol). Experimentally, rabbit urinary bladder function can be evaluated using an isolated whole bladder model. The current study utilizes the isolated whole bladder model to compare the effects of partial outlet obstruction on the responses to field stimulation and bethanechol with the responses of normal bladders following inhibition of CICR with the combination of thapsigargin+ryanodine. The parameters measured include the magnitude of pressure generation, rate of pressure generation, time to maximal pressure generation, percent volume emptied, rate of emptying, power generation, and work performed (both total work and work per ml emptied). Partial outlet obstruction resulted in virtually identical alterations in the responses of the bladder to stimulation (field stimulation and bethanechol) to that of inhibition of CICR by thapsigargin+ryanodine. Thus, these studies provide strong support for our hypothesis that the contractile dysfunctions secondary to partial outlet obstruction are directly related to a marked inhibition of the CICR component of the response to both field stimulation and bethanechol.

Effects of tadenan pretreatment on bladder physiology and biochemistry following partial outlet obstruction

PURPOSE

Tadenan is a pharmaceutical agent used in the treatment of BPH. Prior studies demonstrated that pretreatment of rabbits with Tadenan significantly reduced the contractile dysfunction following two weeks of partial outlet obstruction. The specific aim of the present study was to determine the effect of Tadenan pretreatment on the time course of the response to partial outlet obstruction and correlate the effect of Tadenan on the contractile responses to field stimulation, bethanechol, and KCl with both mitochondrial enzyme activity (citrate synthase) and sarcoplasmic reticular function (calcium-ATP'ase activity).

MATERIALS AND METHODS

Sixty male New Zealands white rabbit (3 to 5 kg.) were separated into 12 groups of 5 rabbits each. Each rabbit in groups 1-6 received Tadenan orally at 100 mg./kg./day for three weeks; each rabbit in groups 7-12 received vehicle (peanut oil). Each rabbit in groups 2-6 and 8-12 received a partial outlet obstruction as described below. One group of Tadenan treated and one group of vehicle-treated rabbits were euthanized at 1, 3, 5, 7, and 14 days following partial outlet obstruction. The non-obstructed groups were studied after 4 weeks of drug or vehicle treatment. Each bladder was rapidly removed and weighed, and 3 longitudinal strips prepared and mounted in individual baths for contractile studies. The remainder of the bladder was frozen for biochemical analysis. The contractile responses to field stimulation, bethanechol, and KCl were determined; and the enzyme activities of citrate synthase (marker for mitochondrial function) and calcium-ATP'ase (marker for sarcoplasmic reticulum) were determined.

RESULTS

1) Tadenan did not reduce the effect of partial outlet obstruction on bladder mass. 2) Although the contractile responses to forms of stimulation were reduced at 1 day following partial outlet obstruction, Tadenan pretreatment resulted in a significant protective effect on the contractile responses to field stimulation, bethanechol, and KCl at 3, 5, 7, and 14 days of obstruction. 3) The activities of both citrate synthase and calcium ATP'ase were reduced significantly at 1 day following obstruction for both Tadenan treated and vehicle treated groups. The activities of both enzymes returned to near normal levels at 7 and 14 days for the Tadenan groups whereas the activities of both enzymes remained significantly reduced in the vehicle treated groups.

CONCLUSIONS

These results clearly demonstrate that Tadenan pretreatment protected the bladder from both the contractile and metabolic dysfunctions induced by partial outlet obstruction.

The decompensated detrusor II: evidence for loss of sarcoplasmic reticulum function after bladder outlet obstruction in the rabbit

PURPOSE

While it may lack the classic morphological pattern in striated muscle systems, there is ample evidence that smooth muscle also contains sarcoplasmic reticulum. These intracellular storage sites release calcium into the cytosol to generate contractile force in response to various stimuli. A major component of the sarcoplasmic reticulum is an adenosine triphosphate dependent ion pump, which serves to drive free calcium out of the cytosol back into this intracellular reservoir. This ion pump serves to maintain the intracellular calcium storage sites, and also as a marker of the sarcoplasmic reticulum.

MATERIALS AND METHODS

Muscle strip studies were performed to stratify the data into 3 major groups (controls, and compensated and decompensated obstructions) based on physiological performance. These were correlated with biochemical and molecular determinations of sarcoplasmic endoplasmic reticulum calcium, magnesium-adenosinetriphosphatase expression.

RESULTS

Our results demonstrate a remarkable loss of sarcoplasmic endoplasmic reticulum calcium-adenosinetriphosphatase activity in the decompensated group and a moderate loss in the compensated group.

CONCLUSIONS

These data provide molecular support for our previous physiological studies in which we demonstrated an important role for intracellular calcium storage and release with normal bladder smooth muscle function. These data strongly support our contention that contractile dysfunction in bladder smooth muscle following outlet obstruction is partially mediated by changes in the mechanisms of intracellular calcium homeostasis.

Erectile dysfunction following minimally invasive treatments for prostate cancer

OBJECTIVES

Cryosurgical ablation of the prostate (CSAP) and interstitial radiotherapy (IR) are relatively new procedures intended to be less invasive than radical prostatectomy for the treatment of prostate cancer. Despite absence of long-term or intermediate data of efficacy, many patients choose one of these therapies because they presume their potency will be maintained. We report our experience with CSAP, IR, and post-procedure erectile dysfunction.

METHODS

Global sexual assessments were made in 12 months after therapy in 28 CSAP patients, and at 18 months in 37 IR patients. Each patient was contacted by telephone following his procedure. The patients were asked several questions regarding their sexual function both preoperatively and postoperatively. The questionnaire was administered only to the patient.

RESULTS

Twenty-eight of 36 patients who underwent CSAP responded to the questionnaire (78%). Twenty patients were potent preoperatively (71%). The mean age of the potent group was 69 years (range 54 to 82). Following therapy, 2 of these patients (10%) reported potency at 12 months. Thirty-seven of 42 patients who underwent IR responded to the questionnaire (88%). Twenty-seven were potent preoperatively (73%). The mean age of the potent group was 70 years (range 56 to 83). The mean follow-up was 18 months (range 5 to 36). Following therapy, 15 patients reported potency (55%). All of the patients who reported potency felt that the quality of their erections had decreased following radiation.

CONCLUSIONS

Our short-term results with IR and CSAP suggest a significant adverse effect on erectile function. Our results suggest that enhanced preservation of potency should not be used as an enticement in the promotion of IR or CSAP.

Laparoscopic lymphadenectomy based on magnetic resonance imaging: is a unilateral dissection adequate for staging prostate cancer?

Laparoscopic pelvic lymphadenectomy is a satisfactory alternative to open lymphadenectomy for staging prostate cancer. Specific information obtained by endorectal coil magnetic resonance imaging may be used to predict the most likely side for lymph node metastases. These criteria may be used to define side selection for performing a unilateral laparoscopic lymphadenectomy without the risk of missing contralateral nodes that may be positive. A unilateral dissection when feasible reduces operative time and morbidity.

The role of the Sertoli cell in active immunosuppression in the human testis

OBJECTIVE

To define the involvement of Sertoli cells in immune suppression within the testis by identifying surface receptor molecules that describe or communicate with cells of the immune system.

MATERIALS AND METHODS

Ten pairs of human testes obtained from orchidectomy were stained immunohistochemically with established monoclonal antibodies that identify common cells of the immune system.

RESULTS

Patterns of staining were similar in all testes. Class I major histocompatibility complex (MHC) antigen, important for self/non-self recognition, was found on Sertoli cells. Class II MHC antigen, important for immune cell interaction and limited to immune cells, was absent. Leu M3, characteristically found on macrophages, was also seen on Sertoli cells but no receptor antigens defining basic T cell types (CD4, CD8), B cells (Leu 12) or natural killer cells (Leu 11) were seen on Sertoli cells.

CONCLUSIONS

The Sertoli cell membrane lacks lymphocyte-cell surface markers but harbours somatic cell and macrophage markers. This suggests that immunosuppression within the testis is not maintained through classic lymphocyte receptors. The presence of a macrophage marker is consistent with the known phagocytic activity of the Sertoli cell.

Protective effect of Tadenan on bladder function secondary to partial outlet obstruction

PURPOSE

Tadenan (DEBAT, Paris, France) is a pharmaceutical agent used in the treatment of benign prostatic hyperplasia (BPH). The specific aim of this study was to determine if pretreatment of rabbits with Tadenan reduced either the hypertrophic response of the bladder to partial outlet obstruction or the accompanying contractile dysfunction.

MATERIALS AND METHODS

Twenty-five male New Zealand rabbits (3 to 5 kg.) were separated into 5 groups of 5 rabbits each. Each rabbit in groups 1,2, and 3 received Tadenan orally at 1, 10 and 100 mg./kg./day for 3 weeks. Group 4 received vehicle only (peanut oil); Group 5 were controls. The bladders were evaluated (in vitro studies) after 2 weeks of obstruction.

RESULTS

1) Tadenan did not reduce the effect of partial outlet obstruction on bladder mass. 2) Tadenan pretreatment resulted in a significant protective effect on the contractile responses to field stimulation, bethanechol and KCl.

CONCLUSIONS

These results clearly demonstrate that Tadenan pretreatment protected the bladder from the contractile dysfunctions induced by partial outlet obstruction.

Effects of partial outlet obstruction on bladder-strip sensitivity to glucose deprivation: an in vitro study in the rat

Partial outlet obstruction has been shown to result in contractile and metabolic dysfunctions. Specifically, there is a greater reduction in the response to field stimulation (FS) in comparison with the responses to bethanechol and KCl, a greater reduction in the tonic response to stimulation in comparison with the phasic response, and a reduction in oxidative metabolism of glucose accompanied by an increase in the glycolytic metabolism of glucose. The specific aim of the current study was to correlate the effects of partial outlet obstruction on the contractile responses of isolated strips of bladder smooth muscle to repetitive stimulation in the presence and absence of glucose. Adult male Sprague-Dawley rats were subjected to partial outlet obstruction by the surgical placement of silk ligatures around the urethra. After 2 weeks, each rate was anesthetized, the bladder was excised, and isolated strip studies were performed. These studies demonstrated that the maximal phasic response to FS was significantly decreased in the obstructed strips as compared with controls, with no difference being noted for responses to bethanechol or KCl; the tonic responses to all forms of stimulation were significantly decreased after obstruction, with the tonic response to FS being decreased to a greater degree than were the tonic responses to bethanechol and KCl; and in the absence of glucose, the tonic responses of control strips to all forms of stimulation were reduced to a greater degree than were the phasic responses. These studies demonstrate that the tonic response to FS is extremely sensitive to fatigue induced by repetitive stimulation.

Effect of alteration in the extracellular potassium and calcium on field-stimulated relaxation of the rabbit corpus cavernosum

Changes in extracellular potassium or calcium concentration can alter the calcium equilibrium between intracellular and extracellular calcium pools in smooth muscle. The current study was designed to investigate the effect of alterations in the extracellular potassium and calcium concentrations, primarily on field-stimulated relaxation of the corpus cavernosum. The results can be summarized as follows: 1. Increasing extracellular calcium at constant potassium mediated a moderate increase in the contractile response to phenylephrine; 2. Increasing extracellular potassium at constant calcium did not affect the contractile response to phenylephrine; 3. Increasing the concentration of extracellular calcium at constant potassium resulted in an increase in field-stimulated relaxation only at low frequency stimulation; 4. Increasing the concentration of extracellular potassium at constant calcium resulted in a marked increase in field-stimulated relaxation, especially prominent at high-frequency stimulation; 5. Increasing the extracellular potassium concentration at constant calcium, or increasing the calcium at constant potassium, had no significant effects on the relaxant effects of ATP and bethanechol; 6. Our findings suggest that, within the corpus cavernosum, neuronal release or synthesis of nitric oxide depends, at least in part, on intracellular bioavailability of calcium.

Effect of thapsigargin on the contractile response of the normal and obstructed rabbit urinary bladder

Excitation-contraction coupling is achieved by translocation of calcium from the extracellular space as well as by the release of calcium from intracellular stores. Thapsigargin has been shown to selectively block the sarcoplasmic Ca-ATPase, thereby preventing the reuptake of calcium into intracellular stores and the participation of these calcium storage sites in the contractile response to stimulation. The current study determined the effect of thapsigargin on the contractile response to field stimulation, bethanechol, and KCl in control rabbit bladders and bladders obtained from rabbits subjected to partial outlet obstruction. Partial bladder outlet obstruction resulted in a marked increase in bladder mass and in significant decreases in the contractile response to field stimulation, bethanechol, and KCl. Thapsigargin (5-40 microM) had no effect on the contractile responses of bladder strips isolated from control rabbits to field stimulation, bethanechol, or KCl. However, bladder strips isolated from obstructed rabbits showed a significant concentration-dependent decrease in the contractile response to field stimulation in the presence of thapsigargin. Thapsigargin had no effect on the contractile responses of bladder strips isolated from obstructed rabbits to either bethanechol or KCl. In general, the data described in this study support our current hypothesis: as smooth muscle cells enlarge (hypertrophy) and the cell volume increases, there is an increased dependence on the release of intracellular calcium from the sarcoplasmic reticulum to mediate the contractile response to field stimulation.

Effect of ischemia of the rabbit bladder on Ca-Mg-activated ATP-ase activity

This investigation is concerned with the effect of ischemia on the activity of Ca-Mg-stimulated ATP-ase in rabbit bladder tissue. White New Zealand male rabbits were used for the experiments. Ischemia was produced by clamping of the vesical arteries. After 1 and 2 hours the clamps were removed, and the animals were sacrificed 2 days later. The bladders were removed, and the muscle and mucosal parts of the bladders were separated. In some experiments with 2-hour ischemia the animals were allowed to recover for 7 days. Homogenates were made of the muscle and mucosal tissue and separated by differential centrifugation into three parts: 1) an initial particulate fraction obtained by low-speed centrifugation; 2) a supernate fraction free of mitochondria; and 3) a mitochondrial-rich fraction. ATP-ase activity was determined in the different fractions in the presence of magnesium or calcium as the activating ion, and the results were expressed as nmols/mg protein/minute. The following results were obtained: with the supernates, ischemia was found to produce a marked inhibition of enzyme activity that was large and significant in muscle tissue after 1 hour and in mucosal tissue after 2 hours. Seven days after termination of 1 hour of ischemia, the ATP-ase activity of the muscle fraction had been partially restored towards normal. Activity of ATP-ase when measured in the particulate fraction was less sensitive to the effect of ischemia; a significant diminution of enzyme activity in preparations from muscle was seen only after 2 hours of ischemia, and no inhibition was observed with mucosal tissue. ATP-ase of muscle mitochondria was severely inhibited by ischemia, and the effect of 1 hour of ischemia was not reversed 7 days after the insult. Mitochondria from mucosal tissue were affected to only a small extent by ischemia. In all cases, results were similar whether magnesium or calcium was used for activation of the enzyme.

Strategy for repeat biopsy of patients with prostatic intraepithelial neoplasia detected by prostate needle biopsy

PURPOSE

We evaluated the strategy for repeat biopsy of patients with prostatic intraepithelial neoplasia without concurrent carcinoma detected on prostate needle biopsy.

MATERIALS AND METHODS

Of 1,275 consecutive patients undergoing prostate needle biopsy 61 were identified with prostatic intraepithelial neoplasia but without concurrent prostate carcinoma. Of the 61 patients 53 had undergone repeat biopsy. The medical records, transrectal ultrasound, and operative and pathological reports of these patients were reviewed.

RESULTS

Repeat biopsy was done in 53 patients with prostatic intraepithelial neoplasia, yielding carcinoma in 15, prostatic intraepithelial neoplasia without carcinoma in 8 and benign tissue in 30. The yield of carcinoma from repeat biopsy of a prostatic intraepithelial neoplasia site was 8.3% (7 of 84 sites). A total of 18 sites of carcinoma was detected by repeat biopsy of a previous random biopsy site (8), a prostatic intraepithelial neoplasia site only (5), a transrectal ultrasound nodule (3), a palpable nodule and prostatic intraepithelial neoplasia site (1), and a transrectal ultrasound nodule and prostatic intraepithelial neoplasia site (1). Carcinoma was as frequently detected by repeat biopsy of a prostatic intraepithelial neoplasia site (6 patients) as by random repeat biopsy (6 patients).

CONCLUSIONS

Repeat prostate needle biopsy of patients with prostatic intraepithelial neoplasia should include random repeat biopsy and repeat biopsy of transrectal ultrasound abnormalities as well as previous sites of prostatic intraepithelial neoplasia.

Comparative response of rabbit bladder smooth muscle and mucosa to anoxia

Recent studies indicate that the mucosa of the urinary bladder plays a major role in the maintenance of normal bladder function. Previous studies have demonstrated that rabbit bladder mucosa has higher rates of basal glycolysis and oxidative phosphorylation than that of bladder smooth muscle. The current study compares the response of rabbit bladder mucosa and smooth muscle compartments to anoxia. The results demonstrate that the rate of high energy phosphate degradation of the mucosa is significantly greater than the rate of high energy phosphate degradation of the smooth muscle. The implication is that the mucosa would be significantly more sensitive to ischemia than the smooth muscle of the bladder. This hypothesis may be extremely relevant to conditions such as interstitial cystitis and recurrent urinary bladder infections, in which ischemia has been implicated in their etiology.

Effects of glucose deprivation on the contractile response of the rabbit bladder to repetitive stimulation

The urinary bladder requires an adequate energy supply to maintain contractile function. The primary metabolic fuel is glucose. Through glycolysis and oxidative phosphorylation, high energy phosphates are generated, which in turn supply the metabolic energy for the contractile activities of the urinary bladder. The aim of this study was to determine the effects of glucose deprivation and recovery from glucose deprivation on the phasic and tonic components of the contractile responses of rabbit bladder strips to field stimulation, bethanechol, and KCl. The results can be summarized as follow: In response to glucose deprivation, (1) the tonic responses to field stimulation, bethanechol, and KCl all decreased at a significantly greater rate than the phasic responses; (2) the phasic and tonic responses to field stimulation were both reduced to less than 10% of control within 70 minutes of initiating glucose deprivation; (3) the tonic responses to bethanechol and KCI were reduced to approximately 10% of control within 180 minutes whereas the phasic responses remained stable at 40 and 30%, respectively; and (4) glucose replacement stimulated a rapid and nearly complete recovery of the phasic and tonic components of the responses to field stimulation, bethanechol, and KCI. These results indicate that the tonic responses to all forms of stimulation are more sensitive to glucose deprivation than the phasic responses.

Age-related differential susceptibility to calcium channel blocker and low calcium medium in rat detrusor muscle: response to field stimulation

The influences of aging on the response of urinary bladder detrusor smooth muscle in response to neurogenic stimulation (electric field stimulation) were investigated in rats aged 3-4 months (young) and 18-20 months (old). In addition, age-associated changes in calcium homeostasis were evaluated by comparing the basal intracellular free calcium concentration ([Ca2+]i), the change of [Ca2+]i in response to field stimulation, the contractile response at different extracellular calcium concentrations (Ca2+ = 1.8, 0.6, and 0 mM), and the sensitivity to the L-type calcium channel blocker. In both groups, the frequency-response curve in response to field stimulation (1-32 Hz) was similar. The contractile response to field stimulation was biphasic (phasic and tonic). The phasic/tonic ratio at different frequencies was similar between the two groups. The contractile responses were equally inhibited by atropine (1 microM) and preincubation with alpha, beta-methylene ATP (50 microM). Tetrodotoxin (1 microM) virtually abolished the responses to field stimulation in both groups. The biphasic components showed different sensitivities to diltiazem and low calcium. The tonic component was more readily inhibited by diltiazem, whereas the phasic component was more sensitive to low calcium medium. In general, the response to lower frequency stimulations was more sensitive to both diltiazem and low calcium. The aged group was more sensitive to the inhibitory effects of both low calcium and diltiazem. In Ca2(+)-free medium, the contractile response to higher frequency (e.g., 32 Hz) was temporarily preserved in most of the preparations. This response disappeared after repeated stimulation. The magnitude of this Ca2(+)-free response to 32 Hz stimulation was significantly lower in the aged group than in the young group (18.1 +/- 1.4 vs.29.1 +/- 3.2% of the control response in normal Tyrode medium, P < 0.05). The basal [Ca2+]i levels were similar in the two groups (young: 131 +/- 12 nM, n = 5; old: 118 +/- 10 nM, n = 4, P > 0.05). The magnitude and time course of the [Ca2+]i response to field stimulation were also similar in the two groups. It is concluded that aging seems to have little effect on the neuromuscular activities of rat urinary bladder. However, the calcium homeostasis may be altered as evidenced by the increased sensitivity to diltiazem and low extracellular calcium.

Properties of Ca2(+)-Mg2+ ATP-ase in rabbit bladder muscle and mucosa: effect of urinary outlet obstruction

The contractile response of the smooth muscle of the urinary bladder is dependent upon both the entrance of extracellular calcium through receptor-operated calcium channels and the stimulated release of calcium from the sarcoplasmic reticulum. In addition, partial outlet obstruction induces marked alterations in the utilization of intracellular calcium. Although calcium ATP-ase provides the energy for the translocation of intracellular free calcium into storage sites within the sarcoplasmic reticulum, very little is known about the properties of this enzyme in bladder muscle and mucosa. As an initial study, divalent ion specific ATP-ase activity was measured in extracts of rabbit bladder muscle and mucosa from control animals and from rabbits following partial urinary outlet obstruction. In both normal bladder muscle and mucosa, magnesium and calcium ions were equally effective in activating the enzyme. Seven days following partial urinary outlet obstruction, the ATP-ase activity in both bladder muscle and mucosa was significantly depressed by over 70%. The degree of the decreased enzyme activities observed within the muscularis and mucosa would indicate that specific membrane functions supported by divalent-ion-ATP-ase are dysfunctional. This hypothesis is supported by marked alterations in the utilization of intracellular calcium following partial outlet obstruction and the marked dysfunctions in both mucosal permeability and bacterial adherence to mucosa observed following partial outlet obstruction.

Hyperplasia in the rabbit bladder urothelium following partial outlet obstruction. Autoradiographic evidence

Previous experiments have shown that adult male rabbits subjected to partial outlet obstruction or overdistension and acutely labeled, 24 h later, in vivo or in vitro with 3H-Thymidine(3H-TdR) show high levels of incorporated radioactivity in bladder epithelium when they are visualized with autoradiography. To test the hypothesis that such labeling represents the onset of a wave of proliferation (that is, true hyperplasia), we injected 3H-TdR subcutaneously in two normal and three partially obstructed New Zealand White male rabbits on each of days One, Two or Three following obstruction. Bladders were excised on the seventh day(D) following obstruction or the sixth day after injection of normals. Under these conditions, cells labeled with 3H-TdR had the opportunity to proliferate, after labelling, for 6(OneD and Normals), 5(TwoD) or 4(ThreeD) days respectively. After processing tissues for autoradiography, normal bladders showed only trace levels of labeling. Animals exposed to 3H-TdR one day after obstruction, when large numbers of basal cells of the urothelium are known to incorporate 3HTdR (i.e., synthesize DNA), showed labeling in most layers of the urothelium seven days after injection, but levels of labeling in bladders injected TwoD or ThreeD were lower than those injected OneD after obstruction. The smaller numbers of urothelial cells labeled by 3H-TdR in TwoD bladders were found in clusters where one or two alternate or adjacent layers of cells were labeled. Obstructed animals injected ThreeD after surgery showed even less labeling. This evidence clearly supports the hypothesis that DNA synthesis that occurs in the urothelium within 24 h after obstruction is followed by proliferation, because by the seventh day, labeling can be found at all levels of the urothelium. The decline of labeling in TwoD and ThreeD animals suggests that the proliferative stimulus probably operates only during the first 24 h after insult. The data suggest that a substantial fraction of the urothelium enters one or more rounds of proliferation following obstruction and support the contention that hyperplasia does occur.

Cell saver and radical retropubic prostatectomy: analysis of cost-effectiveness

OBJECTIVES

To determine the effectiveness of using cell saver suction during radical prostatectomy to decrease the risk of random donor transfusions in patients predonating blood, as well as to compare costs.

METHODS

From March 1992 to October 1993, two consecutive groups of 86 patients underwent radical retropubic prostatectomy. The first group utilized predonated blood alone, and the second group utilized cell saver suction and predonated blood. The two groups were compared with respect to their transfusion records, preoperative and discharge hemoglobins, and estimated blood losses to determine the usefulness of cell saver suction during radical retropubic prostatectomy.

RESULTS

There was no statistical difference in the rate of random donor blood transfusions between these two evenly matched groups of patients. The risk of receiving random donor transfusions was decreased to 5% by having 4 U of blood predonated by or for the patient prior to radical prostatectomy.

CONCLUSIONS

For patients who are able to predonate blood, cell saver suction is neither cost-effective nor useful in decreasing the risk of receiving random donor blood transfusions.

Effect of anoxia on the urethral response to phenylephrine

PURPOSE

Smooth muscle requires oxygen for proper contractile function. In addition, anoxia has been shown to inhibit the contractile response to various forms of stimulation. Continence, at least in part, depends upon active alpha-adrenergic tone, which provides intraurethral tension during bladder filling. The current study was designed to determine the effect of anoxia on the ability of the urethra to sustain tension.

MATERIALS AND METHODS

Standard isolated urethral strip preparations were used to determine the effect of anoxia on the contractile response to phenylephrine; isolated whole urethra preparations were used to determine the effect of anoxia on the intraurethral pressure--flow characteristics.

RESULTS

The peak tension responses of the female and male urethra to phenylephrine were significantly greater than the plateau tension. Anoxia induced an immediate decrease in phenylephrine-stimulated tonic tension to baseline tension. In the whole urethra preparation, phenylephrine increased opening pressure to a greater extent in the male urethra than in the female urethra. In both sexes, anoxia reduced the opening pressure and completely prevented phenylephrine stimulated increases in opening pressure.

CONCLUSION

The tonic response to phenylephrine is lost virtually immediately upon the initiation of hypoxia. This suggests that hypoxia decreases the ability of the urethra to maintain a tonic response to alpha-adrenergic stimulation during bladder filling and may be a factor in incontinence, especially in females.

Effects of the peptide leukotriene receptor antagonist ICI 198,615 on the in vivo and in vitro changes in guinea pig bladder function which occur after sensitization with ovalbumin

PURPOSE

The present studies were designed to determine the effects of in vivo and in vitro administration of ICI 198,615 (ICI), a leukotriene receptor antagonist, on the inflammatory changes that occur in the bladder after sensitization with ovalbumin.

MATERIALS AND METHODS

The effect of intravenous administration of ICI on urodynamic changes after instillation of ovalbumin to sensitized guinea pigs was evaluated by in vivo cystometry. Responses of in vitro bladder muscle strips to contractile stimuli and ovalbumin were also evaluated in the presence of ICI.

RESULTS

In sensitized guinea pigs, in vivo cystometry with ovalbumin induced a marked decrease in bladder capacity and increase in intravesical pressure. Pretreatment with ICI prior to cystometry prevented the ovalbumin-induced changes in capacity and intravesical pressure. There were no significant differences between control and sensitized animals in the responses of in vitro bladder muscle strips to field stimulation or bethanechol. However, maximal contractile responses to ovalbumin were significantly greater in the strips from sensitized animals than in controls. Preincubation with ICI, indomethacin, or pyrilamine alone was unable to inhibit the contractile responses to ovalbumin. However, combined administration of ICI, indomethacin and pyrilamine completely blocked the responses.

CONCLUSIONS

In vivo administration of the leukotriene receptor antagonist ICI 198,615 reversed the urodynamic changes induced by ovalbumin challenge in sensitized guinea pigs. These results indicate that leukotrienes are primarily responsible for the changes in in vivo bladder function associated with sensitization.

Effect of magnesium ions on rabbit detrusor contractility and intracellular free calcium

Magnesium (Mg2+) is one of the most abundant ions in the body. In the human body, Mg2+ plays important roles including cofactors in many crucial enzyme systems, especially those involving energy transfer, storage and utilization. Alteration of the concentration of Mg2+ may cause neuromuscular hyperactivity, psychiatric disturbances, calcium/potassium abnormalities, and overactivity of cardiac muscle. Most information on the effect of Mg2+ on muscle contraction has been obtained from studies on cardiac, skeletal, and vascular muscle; much less is known about the effect of Mg2+ in other smooth muscle systems. In the current study, we investigated the effect of Mg2+ on the contraction and intracellular free calcium of rabbit urinary bladder detrusor muscle in response to carbachol and transmural field stimulation (FS). The results can be summarized as follows: (1) Reduction of the concentration of magnesium [Mg2+] from normal Tyrode's solution enhanced the spontaneous basal activity, whereas addition of Mg2+ gradually abolished this spontaneous activity. (2) Muscle contraction induced by FS or carbachol was enhanced in Mg(2+)-free Tyrode's solution. Addition of Mg2+ inhibited the response to both forms of stimulation in a dose-dependent manner. (3) Inhibitory effects of Mg2+ were potentiated when the Ca2+ concentration in the Tyrode's solution was reduced to 0.6 mM, whereas increasing the extracellular concentration of Ca2+ (5.4 mM) reduced the inhibitory effects of Mg2+. (4) Using FURA-2 to monitor intracellular free calcium simultaneous with contractile tension, we demonstrated that the alterations in the contractile responses observed at different concentrations of extracellular Mg2+ correlated with similar changes in intracellular free calcium.(ABSTRACT TRUNCATED AT 250 WORDS)