Minimally invasive therapies for the treatment of symptomatic benign prostatic hyperplasia: the University of Florida experience

OBJECTIVE

To describe the University of Florida experience with minimally invasive therapies in the surgical treatment of benign prostatic hyperplasia (BPH).

BACKGROUND DATA

Typically, the standard surgical treatment for symptomatic benign prostatic hyperplasia (BPH) has been transurethral resection of the prostate (TURP). Due to the morbidity associated with TURP, several minimally invasive therapies, such as laser, microwaves, high intensity focused ultrasound, and radiofrequency needle ablation, have been utilized to treat BPH.

METHODS

The authors review their experience, along with that of others, with various forms of heat therapy in the treatment of BPH.

RESULTS AND CONCLUSIONS

Although high intensity focused ultrasound (HIFU), interstitial laser, and microwaves procedures have been shown to be effective in the treatment of BPH, our experience has been with laser, VaporTrode, and TUNA. We found that VaporTrode and TUNA currently offer several advantages over many of the other modalities.

Identification of endothelin receptor subtypes in sheep choroid plexus

Endothelin (ET) and its G-protein-coupled receptors are distributed in a wide variety of tissues, including the brain. In this study, we have identified and characterized the endothelin receptor subtypes in sheep choroid plexus. Competitive binding experiments using [125I]ET-1 and the receptor subtype-selective ligands, ET-1, ET-3, BQ-123, Sarafotoxin 6c, and [Ala1,3,11,15] ET-1 demonstrated the presence of both ETA and ETB receptor subtypes in the ratio of 30:70. In addition, a small fraction of the total binding sites exhibited affinities for ET-1 in the subpicomolar range. Chemical crosslinking of [125I]ET-1 with bis(sulfosuccinimidyl)-suberate (BS3) to choroid plexus membranes revealed the presence of two bands, with apparent molecular masses of 89 and 45 kDa, corresponding to the ETA receptor, and three bands, with apparent molecular masses of 75, 58, and 33 kDa, corresponding to the ETB receptor. Of considerable interest was the finding that dimers of the [125I]ET-1-occupied ETA receptor could be identified by crosslinking, as could apparent dimers and tetramers of [125I]ET-1, but only when bound to receptor. In addition to mapping the distribution of ET receptors in sheep choroid plexus, our results strongly suggest that ET-1 binding to the ETA receptor leads to dimer formation.

Hydrochlorothiazide is superior to isradipine for reduction of left ventricular mass: results of a multicenter trial. The Isradipine Study Group

OBJECTIVES

We sought to determine the efficacy of isradipine in reducing left ventricular (LV) mass and wall thickness in hypertensive patients.

BACKGROUND

LV hypertrophy on the echocardiogram is a strong predictor of cardiovascular events. Reduction of LV mass may be a desirable goal of drug therapy for hypertension. However, although thiazide diuretic drugs have been advocated as first-line therapy for hypertension, their efficacy in reducing LV mass has been questioned.

METHODS

Patients with mild to moderate diastolic hypertension and LV mass in excess of 1 SD of normal values were randomized to isradipine (n = 89) or hydrochlorothiazide therapy (n = 45). Evaluations were obtained at baseline, after 3 and 6 months of treatment and 2 weeks after treatment was stopped.

RESULTS

At 6 months, LV mass decreased by 43 +/- 45 g (mean +/- SD) with hydrochlorothiazide (p < 0.001) but only by 11 +/- 48 g with isradipine (p = NS; between-group comparison, p < 0.001). Two weeks after drug therapy was stopped, LV mass remained 24 +/- 41 g lower than that at baseline in the hydrochlorothiazide group (p = 0.003) but only 7 +/- 50 g lower in the isradipine group (p = NS). Septal and posterior wall thicknesses were significantly and equally reduced with both isradipine and hydrochlorothiazide. Greater LV mass reduction with hydrochlorothiazide was related to a 2.8 +/- 3.3-mm reduction of LV cavity size with hydrochlorothiazide but no reduction with isradipine. At 6 months of treatment, diastolic blood pressure (BP) by design was equally reduced in both treatment groups. At 3 months, systolic BP was reduced by 17 +/- 15 mm Hg with isradipine and by 26 +/- 15 and 25 +/- 17 mm Hg at 3 and 6 months, respectively, with hydrochlorothiazide (p = 0.003, between-group comparison). However, on stepwise multivariable regression analysis, treatment selection (partial r2 = 0.082, p = 0.001), change in average 24-h systolic BP (partial r2 = 0.032, p = 0.029) and change in average sitting systolic BP (partial r2 = 0.017, p = 0.096) were predictive of LV mass reduction.

CONCLUSIONS

Despite an equivalent reduction of diastolic BP, 6 months of therapy with hydrochlorothiazide is associated with a substantial reduction of LV mass, greater than that with isradipine. The superior efficacy of hydrochlorothiazide for LV mass reduction is associated with a greater reduction of systolic BP as well as drug selection itself. These data may have important therapeutic implications.

Effect of retinoic acid on prostatic development

BACKGROUND AND METHODS

To assess the effect of retinoids on prostatic ductal branching morphogenesis, anterior prostates from newborn rats were cultured under serum-free conditions for 6 days in the presence of testosterone (10(-8) mM) plus 13-cis-retinoic acid (13-cis-RA), all-trans-retinoic acid (at-RA), or N-4-hydroxyphenyl-retinamide (4-HPR). Measures of morphologic complexity were computed and compared between specimens of different treatment groups.

RESULTS

Prostatic ductal growth and branching were inhibited in a dose-dependent fashion by both 13-cis-RA and at-RA, but not by 4-HPR. This inhibitory effect of 13-cis-RA was reversible, as the prostatic ducts resumed branching and growth after removal of retinoic acid from the culture medium. Using reverse transcription polymerase chain reaction, we then investigated the expression of nuclear receptor genes for retinoic acid.

CONCLUSIONS

This showed the presence of RAR-beta and RAR-gamma in the 0-day prostate, suggesting that the effects of these retinoids on ductal morphogenesis may be via these receptors.

Effects of aerobic training on exaggerated blood pressure response to exercise in African-Americans with severe systemic hypertension treated with indapamide +/- verapamil +/- enalapril

Hypertensive patients are likely to have an exaggerated blood pressure (BP) response during physical exertion. When moderate aerobic exercise was added to medical antihypertensive therapy in patients with severe hypertension, excessive elevations in BP during physical exertion were attenuated even with a modest reduction in BP at rest.

Transurethral evaporation of the prostate for treatment of benign prostatic hyperplasia: results in 168 patients with up to 12 months of followup

PURPOSE

We assessed the safety and efficacy of transurethral evaporation of the prostate for the treatment of symptomatic benign prostatic hyperplasia (BPH).

MATERIALS AND METHODS

A total of 168 patients with symptomatic BPH underwent transurethral evaporation of the prostate. Peak flow rate, American Urological Association symptom index and post-void residual were assessed at baseline, and at 3, 6 and 12 months of followup.

RESULTS

We found a statistically significant decrease in mean American Urological Association symptom index from 20.6 at baseline to 7.2 at 12 months (mean difference 13.4, 65% reduction, p < 0.0001). We also found a statistically significant improvement in mean peak flow rate from 8.2 to 18.2 cc per second, respectively (mean difference 10, 122% increase, p < 0.0001). The most frequent complications were irritative voiding symptoms in 22.6% of patients and urinary tract infections in 4.8%. There were no additional major complications.

CONCLUSIONS

From these results transurethral evaporation of the prostate appears to be safe and effective for treatment of BPH at 12 months of followup.

hCG-receptor binding and transmembrane signaling

The technique of site-directed mutagenesis has proven to be quite powerful in elucidating contact sites involved in the interaction of the heterodimeric glycoprotein hormones and their respective seven transmembrane (TM) G protein-coupled receptors. Our laboratory has focused on identification of the minimum core sequences of the alpha and beta subunits required for bioactivity, the minimum length of a conjoined (yoked) single-chain hCG, the amino acid residues on hCG and the LH/CG-receptor (LH/CG-R) responsible for high-affinity binding, and the regions of the receptor that are involved in TM signaling. A number of amino acid residues have been mapped on the alpha and beta subunits of hCG that appear important in receptor binding. When projected onto the crystal structure of HF-treated hCG, these residues, by and large, cluster on one side of the molecule and cover a sizeable surface area, indicating that the hormone-receptor binding interface is rather extensive. Based on mutagenesis studies of several conserved ionizable amino acid residues in the extracellular domain (ECD) of LH/CG-R and a model that we, in collaboration with Drs Lapthorn and Isaacs, have developed for this region based on the crystal structure of porcine ribonuclease inhibitor, a charged region that appears to play an important role in hormone-receptor recognition has been identified. We have also delineated several regions of LH/CG-R that do not appear to participate in hCG binding but are involved in hCG-mediated signaling. These regions are located in the ECD and extracellular loop III just prior to entry into the membrane via TM helices I and VII, respectively, and in TM helices VI and VII. Similarly, a homologous region in the ECD of the FSH receptor, located with ten residues of TM helix I, is important in signaling but not hormone binding. These results suggest that ligand binding and ligand-mediated receptor activation are quasi-distinct, albeit sequential phenomena. Collectively, our mutagenesis and modeling studies, coupled with results from other laboratories, argue for a ligand-induced conformational change of the receptor that may involve a relative reorientation of the TM helices.

Protein engineering of a novel constitutively active hormone-receptor complex

Human chorionic gonadotropin (hCG) is a heterodimeric glycoprotein hormone consisting of an alpha and a beta subunit that stimulates intracellular levels of cAMP via a G protein-coupled receptor. Herein we report the engineering and characterization of a novel molecule in which the receptor and its heterodimeric ligand were covalently linked in a single polypeptide chain. The hormone-receptor complex was expressed in cells transfected with this construct, but the cells were unable to bind significant amounts of exogenous hCG. However, cleavage of the hormone with a site-specific protease rendered the receptor accessible to exogenously added hormone. Cells transfected with the hCG-receptor construct contained elevated basal levels of cAMP; moreover, addition of hormone had no significant effect. These results are consistent with a strong and stable interaction between the single-chain hormone and its covalently linked receptor that results in a constitutively active complex.

Endothelin binding to NG108-15 cells: evidence for conventional ETA and ETB receptor subtypes and super-high affinity binding components

The endothelin (ET) peptides have been identified in the CNS, but there is a paucity of information on their physiological roles. NG108-15 cells, a clonal strain of a neuroblastoma x glioma hybrid cell line, have been widely used in neurobiological research since they retain certain differentiated properties of the non-transformed parental cells. It is known that NG108-15 cells respond to the ET peptides, but only limited information is available on the characterization of the ET receptors that mediate these effects. The present study was designed to identify the type(s) of ET receptors on NG108-15 cells in a proliferative state by competitive binding assays using [125I]ET-1 as the radiolabelled ligand and the receptor-selective ligands. ET-1, ET-3, BQ-123, sarafatoxin-6-c and [Ala1,3,11,15]ET-1. The results suggested the presence of conventional ETA and ETB receptor subtypes, with ETA in excess over ETB. These findings were consistent with the results of Northern analysis in that mRNAs encoding the ETA and ETB receptor subtypes were identified in NG108-15 cells, with a preponderance of ETA to ETB. Of considerable interest was the observation of other ET-binding components with much higher affinities than the conventional receptors. It remains to be demonstrated if these particular binding components are functional and represent differ gene products or arise from association of the conventional ETA and ETB receptor subtypes with themselves or other structures, e.g. proteins or lipids, of CNS origin.

Mutations of Arg68 of the human chorionic gonadotrophin beta subunit lead to reduced secretion

The Arg68-Leu69 sequence is invariant in the beta subunits of chorionic gonadotrophin and luteinizing hormone from a variety of species. Using site-directed mutagenesis of the human chorionic gonadotrophin (hCG)-beta cDNA, several replacements of Arg68, an Ala replacement of Leu69, and a multiple replacement with Ala-Ala-Ala-Ala of the tetrapeptide sequence, Arg68-Leu69-Pro70-Gly71, were prepared and characterized. The wild-type and mutant cDNAs were subcloned into a pRSV expression vector and transiently transfected into CHO cells containing a stably integrated gene for bovine a. Concentrations of secreted wild-type and mutant hCG-beta subunit and holoprotein were determined using radioimmunoassays; potencies, i.e. the ratio of biologic to immunologic activity, of several of the mutant heterodimers were measured in vitro via gonadotrophin-mediated steroidogenesis in transformed murine Leydig cells (MA-10). The Leu69-->Ala mutant formed a mutant holoprotein that was essentially equipotent with wild-type hormone in the steroidogenesis assay. The Arg68 replacements with Lys, Ala, and Leu were poorly secreted by the cells, e.g. < 10% that of wild-type hCG; however, sufficient quantities of mutant holoproteins containing Lys68 and Ala68 were obtained for biological assays, and both exhibited greater apparent potencies than wild-type hormone. Likewise, a mutant holoprotein containing the Arg68-Leu69-Pro70-Gly71-->Ala-Ala-Ala-Ala multiple replacement was apparently more potent than wild-type hormone, but it too was secreted at lower levels than wild-type. These results establish that replacements of Arg68 in hCG-beta diminish secretion, but the small amount of holoprotein that is formed and secreted appears to be of somewhat greater potency than wild-type hormone.

Effect of hydrochlorothiazide therapy on cardiac arrhythmias in African-American men with systemic hypertension and moderate to severe left ventricular hypertrophy

The effect of hydrochlorothiazide therapy on ventricular arrhythmias was studied in 45 hypertensive African-American men with moderate to severe left ventricular (LV) hypertrophy. After medication washout, patients were treated with placebo followed by hydrochlorothiazide. Clinical, biochemical, and 48-hour ambulatory electrocardiographic data was collected after each treatment phase. Signal-averaged electrocardiograms were recorded in a subgroup of 24 patients. Average LV posterior wall thickness was 15 +/- 1.1 mm, septum 16 +/- 2 mm, LV mass 420 +/- 90 g, and LV mass index 212 = 51 g/m2. Systolic blood pressure (BP) was 168 +/- 18 mm Hg after the placebo phase and 146 +/- 15 mm Hg after hydrochlorothiazide; diastolic BP was 103 +/- 6 mm Hg and 89 +/- 9 mm Hg, respectively. Serum potassium decreased significantly from 4.2 +/- 0.4 mmol/L to 3.7 +/- 0.6 mmol/L after hydrochlorothiazide therapy. The average hourly incidence of ventricular premature contractions was 22 with placebo and 25 with hydrochlorothiazide. There were 3 and 1 couplets and 0.2 and 0.2 runs of ventricular tachycardia per patient per hour, respectively. Variables of signal-averaged electrocardiography did not differ between the 2 treatments. Thus, in hypertensive African-American men with moderate to severe LV hypertrophy, hydrochlorothiazide does not worsen ventricular arrhythmias or signal-averaged electrocardiographic variables.

The proportional decrease in prostate specific antigen level best predicts the duration of survival after hormonal therapy in patients with metastatic carcinoma of the prostate

OBJECTIVE

To examine the usefulness of a test for prostate specific antigen (PSA) to predict survival in hormonally treated patients with metastatic prostate cancer.

PATIENTS AND METHODS

The study comprised 49 patients (mean age 72 years, SD 6) who underwent orchidectomy for metastatic prostate cancer. PSA was measured before orchidectomy and after 6 months, and the absolute, differential and proportional decreases calculated. A Cox proportional hazards regression model, which controlled for patient age, tumour (Gleason) grade and the number of skeletal metastases, was then used to evaluate these estimates of PSA as predictors of survival.

RESULTS

The 6-month proportional decrease in PSA from the pre-operative level was the most accurate predictor of patient survival (P = 0.006) after hormonal therapy for metastatic prostate cancer.

CONCLUSION

This information may help to direct appropriate patients to new and experimental therapies for metastatic disease.

The efficacy of terazosin, finasteride, or both in benign prostatic hyperplasia. Veterans Affairs Cooperative Studies Benign Prostatic Hyperplasia Study Group

BACKGROUND

Men with benign prostatic hyperplasia can be treated with alpha 1-adrenergic-antagonist drugs that relax prostatic smooth muscle or with drugs that inhibit 5 alpha-reductase and therefore reduce tissue androgen concentrations. However, the effects of the two types of drugs have not been compared.

METHODS

We compared the safety and efficacy of placebo, terazosin (10 mg daily), finasteride (5 mg daily), and the combination of both drugs in 1229 men with benign prostatic hyperplasia. American Urological Association symptom scores and peak urinary-flow rates were determined at base line and periodically for one year.

RESULTS

The mean changes from base line in the symptom scores in the placebo, finasteride, terazosin, and combination-therapy groups at one year were decreases of 2.6, 3.2, 6.1, and 6.2 points, respectively (P<0.001 for the comparisons of both terazosin and combination therapy with finasteride and with placebo). The mean changes at one year in the peak urinary-flow rates were increases of 1.4, 1.6, 2.7, and 3.2 ml per second, respectively (P<0.001 for the comparisons of both terazosin and combination therapy with finasteride and with placebo). Finasteride had no more effect on either measure than placebo. In the placebo group, 1.6 percent of the men discontinued the study because of adverse effects, as did 4.8 to 7.8 percent of the men in the other three groups.

CONCLUSIONS

In men with benign prostatic hyperplasia, terazosin was effective therapy, whereas finasteride was not, and the combination of terazosin and finasteride was no more effective than terazosin alone.

P53 tumour-suppressor gene mutations are mainly localised on exon 7 in human primary and metastatic prostate cancer

Mutations in the p53 tumour-suppressor gene are among the most common genetic alterations in human cancers. In the present study we analysed the mutations in the p53 tumor-suppressor gene in 25 primary and 20 metastatic human prostate cancer specimens. DNA extracted from the paraffin-embedded sections was amplified by hot-start polymerase chain reaction, and p53 gene mutations in the conserved mid-region (exons 4-9) were examined using single-strand conformation polymorphism (SSCP) analysis and immunohistochemistry. In the present study, we used a novel hot-start PCR-SSCP technique using DNA Taq polymerase antibody, which eliminates primer-dimers and non-specific products. Because of this new technique, the results of PCR-SSCP showed very high resolution. Polymerase chain reaction products were sequenced directly for point mutations for the p53 gene. Mutations were found in 2 out of 25 primary prostate cancers (8%) and 4 out of 20 metastatic cancers (20%). Mutations were observed exclusively in exon 7 and not in exons 4, 5, 6, 8 or 9. Nuclear accumulation of p53 protein, determined by immunohistochemistry, correlated with the degree of metastasis in prostatic cancer.

Identification of conventional and novel endothelin receptors in sheep choroid plexus cells

Previous studies have demonstrated the presence of super-high affinity endothelin receptors with apparent Kd's on the order of pM in different brain tissues. This study was designed to characterize, in detail, the receptors present in SCP cells, a non-transformed sheep choroid plexus cell line. Competitive binding assays with receptor-selective ligands indicated the presence of at least three classes of binding sites: a conventional receptor of the ETA subtype with a Kd = 0.4 nM that mediates an increase in intracellular levels of inositol 1,4,5-trisphosphate (IP3)in response to ET-1 and two additional sites with much higher binding affinities. The latter two sites are not coupled to the common signal transduction pathways of IP3, cAMP and cGMP. Northern blot analysis confirmed the presence of only the ETA subtype mRNA in SCP cells. It remains to determined if the multiple binding sites are distinct gene products, multiple affinity states of a single receptor molecule or a result of cooperative association of one site with either the ligand or with other proteins.

Comparison of transrectal ultrasound prostatic volume estimation with magnetic resonance imaging volume estimation and surgical specimen weight in patients with benign prostatic hyperplasia

There are relatively few reports in the literature comparing transrectal ultrasound (TRUS) to magnetic resonance imaging (MRI) in estimating the volume of the prostate in the management of benign prostatic hyperplasia (BPH). In this study, we compared volumes determined by TRUS with MRI and TRUS-estimated weights with surgical specimen weights. The main findings of this study were (a) TRUS and MRI measurement of prostate volumes are quite similar; and (b) TRUS underestimates (by 10%) the prostatic weight as determined from the surgical specimens. A better volume estimate can thus be obtained by multiplying the TRUS measurement by a factor of 1.10. We conclude that because TRUS is cheap, user-friendly, noninvasive, and equally as accurate as MRI, it should be the preferred modality in the follow-up of BPH patients.

Factors affecting size and configuration of electrovaporization lesions in the prostate

OBJECTIVES

Transurethral electrovaporization of the prostate is a new, minimally invasive technique being used by urologists for surgical ablation of prostatic tissue. There are insufficient data concerning factors affecting the vaporization and coagulation lesions produced by this technique. The aim of this study was to determine the role of various parameters for adequate tissue evaporation.

METHODS

This study compared bovine liver and human prostatic lesions made by the Vaportrode instrument with those produced by standard electrocautery loops, roller balls, and laser fibers. Additionally, two electrosurgical instruments with differing technical capabilities were compared for their ability to cause vaporization of tissue.

RESULTS

Results revealed that the Vaportrode lesions were maximal with a new electrode when used with a Force 40S electrosurgical generator set at 300 W and a drag speed of 25 to 30 seconds per 10 mm of tissue. The lesions produced by this technique had a 74% greater coagulation volume compared to a standard cautery loop. The evaporation defect was comparable to a laser lesion produced in contact at 60 W.

CONCLUSIONS

We conclude that electrovaporization under optimal conditions causes a vaporization lesion comparable to that produced by high power density laser prostatectomy. Additionally, the coagulation volume of a vaportrode lesion is considerably greater than that produced by standard electrocautery resection.

Transurethral vaportrode electrovaporization of the prostate: physical principles, technique, and results

OBJECTIVES

This is a study to evaluate technique, efficacy, and safety of a new electrosurgical instrument (Vaportrode) in management of benign prostatic hyperplasia (BPH).

METHODS

Forty-two symptomatic BPH patients form the subject of this study. Preoperative and postoperative International Prostate Symptom Score (IPSS), peak flow rates (PFR), postvoid residual urine (PVR), operative details, and complications were recorded in each patient. Baseline, 1, 3, and 6 months follow-up data were used for analyses.

RESULTS

Results reveal that transurethral electrovaporization of the prostate (TUEVP) is a reasonable procedure to treat symptomatic BPH, and at 6 months, this procedure results in 68% reduction in IPSS, 128% improvement in PFR, and 58% reduction in PVR. Even in patients who are in retention prior to TUEVP, at 6 months the IPSS is 7.7, PFR is 20.4 cc/s, and PVR reduces to 130 cc. The procedure is well tolerated without any significant short-term complications.

CONCLUSIONS

The results of this modality in improving the symptoms and PFR in symptomatic BPH patients in the short term appear promising. Advantages over transurethral resection (TUR) of the prostate and laser prostatectomy include familiarity of the transurethral route, lack of need for high-cost laser equipment and fibers, excellent intraoperative hemostasis, lack of bleeding or fluid absorption, and ability to cause a predictable TUR-like prostate defect at the end of the procedure. Further studies involving larger numbers of patients and longer follow-up are warranted to assess further the utility of this procedure.

A dose-response study of the effect of flutamide on benign prostatic hyperplasia: results of a multicenter study

OBJECTIVES

The objective of this study was to evaluate efficacy, safety, and dose-response profiles of four dosing schemes of flutamide over 24 weeks.

METHODS

Patients were randomized to receive one of the following five treatment regimens for a period of 24 weeks: placebo capsule, flutamide capsules 125 mg twice daily, 250 mg once daily, 250 mg twice daily, and 250 mg three times daily. Patients were then evaluated at baseline (0 weeks) and at 4, 6, 12, 18, and 24 weeks after the start of treatment, and 8 weeks after the end of treatment (32 weeks). Evaluation of efficacy was performed by noting changes in urine flow rate, residual urine volume, symptom score, prostate volume, and prostate-specific antigen level. A total of 372 patients were enrolled into the study at 32 centers (14 centers in the United States and 18 international centers).

RESULTS

Baseline peak urinary flow rate and percent change from baseline in maximum flow rate showed a dose-related increase at 4 and 6 weeks; this increase was significant in the 250 mg three times daily group. At later time points, no significant differences between the flutamide and placebo groups were observed, largely because of the decreasing number of evaluable patients. At 4 and 6 weeks, 25% of patients in the 250 mg three times daily group had more than 3 cc/s increase in uroflow compared to about 10% of placebo patients (P < 0.05). All flutamide-treated groups had a significant decrease in prostate volume from baseline to the last treatment visit compared to placebo and this reduction was dose related (in comparison to placebo: P < 0.05 for 125 mg twice daily and P < 0.001 for all other treatment arms). Median decrease for the flutamide-treated groups ranged from 6% to 23% at 12 weeks and from 14% to 29% at 24 weeks. All treatment groups showed a subsequent increase in prostate volume after treatment was stopped. Furthermore, there was a significant reduction in residual urine volume at 24 weeks only in the 250 mg three times daily group. It increased following cessation of therapy. Urinary symptoms at 6, 12, 18, and 24 weeks did not show any significant difference between placebo and any flutamide dose group. The most common adverse events were nipple and breast tenderness (42% to 52%), diarrhea (29% to 34%), and gynecomastia (14% to 19%). Each of these adverse events had a significantly higher incidence in all flutamide dose groups compared with placebo, but none appeared to occur in a dose-related fashion. Sixteen percent of patients in the placebo group and 25% to 39% of patients in flutamide groups were discontinued due to diarrhea (12% to 17%) or nipple and breast tenderness (4% to 8%). A total of 1% to 3% of patients in various treatment arms discontinued due to deranged liver enzymes (1% for placebo); and 1% to 4% due to impotence (1% for placebo).

CONCLUSIONS

Flutamide reduced the prostate volume in a dose-related fashion and resulted in an increase in peak flow rate at 4 weeks (3% for 250 mg three times daily, P value < 0.05), but the early positive effects did not maintain statistical significance due to an increasing number of dropouts due to adverse events. Effect on postvoid residual volume was observed only at the highest dose and at 24 weeks (median reduction, 23 mL, P < 0.05). Despite volume reduction and early improvement in peak flow rate, there were no significant differences in urinary symptoms among the placebo and flutamide groups. Higher incidences of diarrhea, breast tenderness, and gynecomastia, however, were the main limiting factors in this study and until these problems are overcome, the role of flutamide in the management of benign prostatic hyperplasia remains investigational.

Expression of functional lutropin/choriogonadotropin receptor in the baculovirus system

The LH/CG receptor (LH/CG-R) is a G protein-coupled receptor with a relatively large glycosylated extracellular domain. The complete 674 amino acid residue rat receptor was expressed in Sf9 insect cells using the baculovirus expression system. Optimal expression under the control of the polyhedrin promoter was obtained at 72 h post-infection and a multiplicity of infection of 0.1. The recombinant LH/CG-R was expressed on the cell surface (ca. 4500 receptors/cell) and exhibited saturable, high affinity binding of human CG (hCG) with a Kd of 0.4 nM. There was no evidence of intracellular trapping of the receptor. The intracellular concentration of cAMP was increased in response to hCG binding. In contrast, baculovirus-expressed recombinant hCG only weakly stimulated intracellular cAMP levels at relatively high doses. Two forms of the receptor (approximately 75 and approximately 200 kDa) were detected by Western blot analysis. These results demonstrate that the full length LH/CG-R expressed in insect cells is functional in that it binds hormone with high affinity and is able to couple to adenylate cylase.

Three-dimensional H-1 MR spectroscopic imaging of the in situ human prostate with high (0.24-0.7-cm3) spatial resolution

PURPOSE

To evaluate if three-dimensional hydrogen-1 magnetic resonance spectroscopic imaging (3D MRSI) when combined with a clinical MR imaging examination could discriminate prostatic adenocarcinoma from normal prostatic zonal anatomy and benign prostatic hyperplasia (BPH) on the basis of observable metabolite levels.

MATERIALS AND METHODS

Combined phased-array, endorectal MR imaging and 3D MRSI was performed in nine young healthy volunteers, five patients with BPH, and 85 patients with prostate cancer and BPH. Volume MR imaging and 3D MRSI data were analytically corrected for the reception profile of the endorectal and pelvic phased-array coils, aligned with the MR imaging data, and compared with postoperative pathologic histology findings.

RESULTS

Statistically significant variations in metabolite levels with prostatic zonal anatomy, age, and pathologic condition were detected with a 3D MRSI examination added to a clinical MR imaging examination. Significantly higher choline levels and significantly lower citrate levels were observed in regions of cancer compared with BPH and normal peripheral zone tissues. The ratio (choline + creatine/citrate) in regions of cancer (2.1 +/- 1.3 [standard deviation]) had no overlap with normal peripheral zone values and minimal overlap with BPH values (0.61 +/- 0.21). An estimate of the spatial extent of prostate cancer was determined by generating metabolite images in which this metabolite ratio significantly exceeded normal peripheral zone values in multiple contiguous sections.

CONCLUSION

These results suggest that a 3D MRSI examination added to a clinical MR imaging examination may help define the presence and spatial extent of prostate cancer.

Nd:YAG laser transurethral evaporation of the prostate (TUEP) for urinary retention

BACKGROUND AND OBJECTIVE

Little information is available regarding the effectiveness of laser prostatectomy in patients with urinary retention from benign prostatic hyperplasia since there is no paper specifically dealing with laser prostatectomy in patients in urinary retention.

STUDY DESIGN/MATERIALS AND METHODS

Twenty two unselected consecutive patients presenting with urinary retention due to benign prostatic hypertrophy underwent transurethral evaporation of the prostate (TUEP) using a neodymium:YAG laser and total internally reflecting side-firing free beam quartz fiber. All patients failed at least one voiding trial and averaged > 30 days of urinary catheter drainage preoperatively. A contact evaporation technique was used to evaporate a "TURP-like" channel in the prostatic fossa by means of a series of parallel evaporation troughs.

RESULTS

Eighteen of 22 patients completed 6 months of follow up. Two patients were lost to follow up and two failed TUEP. The average AUA score dropped from 26 to 9 at 1 month and to 3.4 by 6 months postoperatively. All patients who successfully underwent TUEP were urinating spontaneously by 10 days. Average time to catheter removal was 3.5 days. Maximal uroflow was 15.7 ml/sec at 1 month and 20.3 ml/sec by 6 months. Postvoid residual preoperatively averaged 784 ml and decreased to 76 ml by 1 month. Pre- and postoperative hematocrit and serum sodium values did not vary by more than 5%.

CONCLUSION

From this preliminary series we conclude that aggressive evaporation of prostatic tissue is feasible endoscopically and provides a reliable method of near bloodless removal of tissue.

A randomized study comparing visual laser ablation and transurethral evaporation of prostate in the management of benign prostatic hyperplasia

PURPOSE

We evaluated the safety, efficacy, failure and complications of 2 techniques of laser prostatectomy for benign prostatic hyperplasia (BPH): transurethral evaporation of the prostate (evaporation) versus visual laser ablation of the prostate (coagulation) in a randomized trial.

MATERIALS AND METHODS

A total of 64 consecutive patients with symptomatic BPH was randomized to undergo evaporation (32) or coagulation (32). American Urological Association symptom score, peak urinary flow rate and post-void residual urine volume were measured at baseline, and at 1, 3, 6 and 12 months. Other parameters evaluated included prostate volume by transrectal ultrasound, total laser energy per patient and per cc volume of the prostate, number of laser fibers per prostate, duration of catheterization and hospitalization, need for re-catheterization, and failure and complication rates.

RESULTS

Our main findings were that patients undergoing laser prostatectomy using the coagulation technique (visual laser ablation of the prostate) had higher reoperation rates (16% versus 0%, p = 0.0199) and were 4 times more likely to have prolonged postoperative urinary retention (25% versus 6.3%, p = 0.0389), evaporation and coagulation were effective at relieving symptoms of prostatism with significant improvement in American Urological Association symptom scores and post-void residual urine volumes compared to baseline, improvement in peak flow rates was significantly greater in patients undergoing evaporation at 1, 3, 6 and 12 months (p < 0.001) compared to coagulation, and a significantly greater amount of laser energy was required to evaporate a unit volume of prostate tissue compared to coagulation (2,251 J./cc versus 1,036 J./cc, p < 0.03).

CONCLUSIONS

Between the 2 major techniques of laser prostatectomy, transurethral evaporation is associated with better results at up to 12 months of followup.

Functional expression of yoked human chorionic gonadotropin in baculovirus-infected insect cells

hCG is a glycoprotein hormone composed of an alpha-subunit, common to all gonadotropins and to TSH, and a hormone-specific beta-subunit. The non-covalent association of the two subunits is an obligatory step for the formation of biologically active hormones. The correct assembly of the heterodimer is also important for efficient secretion of the hormone, receptor binding, and signal transduction. Herein, we have demonstrated that expression of the two subunits from independent promoters present in a single recombinant baculovirus resulted in subunit association and secretion of biologically active holoprotein by the insect cells. To determine whether the active conformation of heterodimer could be achieved when the two subunits were synthesized in tandem on a single polypeptide chain, two single chain or yoked hCG1, the C-terminus of the complete beta-subunit (145 amino acid residues) was conjoined to the N-terminus of the alpha-subunit. Yoked hCG2 was similar, except that it contained the N-terminal 123 amino acid residues of the beta-subunit. Both yoked hCG molecules bound LH/CG receptor with high affinity and stimulated adenylate cyclase and progesterone levels in transformed mouse Leydig (MA-10) cells. Therefore, the alpha- and beta-subunits are able to fold into a biologically active conformation when covalently linked. Interestingly, when compared with urinary hCG, the hormone expressed in baculovirus-infected insect cells binds to the LH/CG receptor with higher affinity, but exhibits diminished signaling, thus providing another example of a partial dissociation between receptor binding and activation.

Effects of regular exercise on blood pressure and left ventricular hypertrophy in African-American men with severe hypertension

BACKGROUND

The prevalence of hypertension and its cardiovascular complications is higher in African Americans than in whites. Interventions to control blood pressure in this population are particularly important. Regular exercise lowers blood pressure in patients with mild-to-moderate hypertension, but its effects in patients with severe hypertension have not been studied. We examined the effects of moderately intense exercise on blood pressure and left ventricular hypertrophy in African-American men with severe hypertension.

METHODS

We randomly assigned 46 men 35 to 76 years of age to exercise plus antihypertensive medication (23 men) or antihypertensive medication alone (23 men). A total of 18 men in the exercise group completed 16 weeks of exercise, and 14 completed 32 weeks of exercise, which was performed three times per week at 60 to 80 percent of the maximal heart rate.

RESULTS

After 16 weeks, mean (+/- SD) diastolic blood pressure had decreased from 88 +/- 7 to 83 +/- 8 mm Hg in the patients who exercised, whereas it had increased slightly, from 88 +/- 6 to 90 +/- 7 mm Hg, in those who did not exercise (P = 0.002). Diastolic blood pressure remained significantly lower after 32 weeks of exercise, even with substantial reductions in the dose of antihypertensive medication. In addition, the thickness of the interventricular septum (P = 0.03), the left ventricular mass (P = 0.02), and the mass index (P = 0.04) had decreased significantly after 16 weeks in the patients who exercised, whereas there was no significant change in the nonexercisers.

CONCLUSIONS

Regular exercise reduced blood pressure and left ventricular hypertrophy in African-American men with severe hypertension.

The significance of prostatic intra-epithelial neoplasia

OBJECTIVE

To investigate the relationship between the detection of prostatic intra-epithelial neoplasia (PIN) on initial prostate biopsy and subsequent invasive prostatic adenocarcinoma.

PATIENTS AND METHODS

Thirty-six men (mean age 67 years, range 52-82) with PIN underwent digital rectal examination (DRE), serum prostate-specific antigen (PSA) measurement and transrectal ultrasonography (TRUS) before the initial biopsy and documentation of PIN. They were followed up with serial PSA, TRUS and a repeat biopsy every 6 months until either invasive carcinoma was identified or 2 years had elapsed.

RESULTS

The initial biopsy revealed Grade I PIN in 33%, Grade II in 22%, and Grade III in 45% of the men. The repeat biopsy showed evidence of invasive carcinoma in 21 patients (58%; Group I), while 15 (42%) showed persistence of PIN (Group II). In Group I, 19 had had high-grade PIN (Grade II/III) on initial biopsy compared with one in Group II. The findings on DRE, and age, were no significantly different between groups. TRUS revealed a hypoechoic lesion in 15/21 patients in Group I compared with 7/15 patients in Group II. There was an increase in PSA level in 18 patients in Group I (from 8.4 to 11.6 ng/mL).

CONCLUSIONS

PIN and invasive adenocarcinoma of the prostate were closely associated, and the likelihood for coexistence was higher in patients with high-grade PIN, increasing PSA level or positive findings on TRUS. We recommend that all patients who show high-grade PIN on prostate biopsy be followed very closely with serial PSA measurements and repeat biopsies from both the area of PIN and other areas of the prostate.

Cardiorespiratory fitness and coronary heart disease risk factor association in women

OBJECTIVES

The purpose of this study was to examine the association between cardiorespiratory fitness and coronary risk factors in healthy, nonsmoking adult women.

BACKGROUND

A sedentary life-style is recognized as an independent risk factor for coronary heart disease, and increasing physical activity is strongly recommended to reduce this risk. However, studies examining the effects of increased physical activity on coronary heart disease risk factors in women are relatively few, and the findings have been equivocal.

METHODS

Subjects provided written informed consent, completed a questionnaire on medical history and performed an exercise tolerance test. Blood chemistry and lipid levels were determined from fasting blood samples. Three fitness categories were established on the basis of treadmill time to exhaustion and were adjusted for age.

RESULTS

The women in the lowest fitness category had less favorable lipid profiles, blood glucose levels, blood pressures and anthropometric indexes than those in the moderate and high fitness categories.

CONCLUSIONS

Moderate fitness (equivalent to 10 metabolic equivalents [METs]) is required to improve the coronary risk profile in women.

The role of transrectal ultrasound-guided biopsy-based staging, preoperative serum prostate-specific antigen, and biopsy Gleason score in prediction of final pathologic diagnosis in prostate cancer

OBJECTIVES

To evaluate the role of ultra sound-guided systematic and lesion-directed biopsies, biopsy gleason score, preoperative serum prostate-specific antigen (PSA) as three objective and reproducible variables to provide a reliable combination in preoperative identification of risk of extraprostatic extension in patients with clinically localized prostate cancer.

METHODS

The case records of 813 patients who underwent radical prostatectomy for clinically localized prostate cancer were analyzed. All had multiple systematic biopsies, two to three from each lobe, in addition to lesion-directed biopsies. Additionally, biopsies were done on seminal vesicles (SVs), if abnormal. Based on biopsy results, patients were classified as having stage B1 (T2a-T2b) or B2 (T2c) disease, depending on whether biopsies from one or both lobes were positive and stage C (T3) if there was evidence of SV involvement by biopsy of biopsies from areas of extracapsular extension as seen on transrectal ultrasound (TRUS) were positive. Logistic regression analyses with log likelihood chi-square test was used to define the correlation between individual as well as combination of preoperative variables and pathologic stage.

RESULTS

On final pathologic examination, 473 (58%) patients had organ-confined disease, 188 (23%) had extracapsular extension (ECE), with or without positive surgical margins, and 72 (9%) had SV involvement. Eighty (10%) patients had pelvic lymph node metastases. Biopsy-based staging was superior to clinical staging in predicting final pathologic diagnosis. Logistic regression analyses revealed that the combination of biopsy-based stage, preoperative serum PSA, and biopsy Gleason score provided the best prediction of final pathologic stage. Probability plots constructed with these data can provide significant information on risk of extraprostatic extension in individual patients.

CONCLUSIONS

This study demonstrates that TRUS-guided systematic biopsy in combination with preoperative serum PSA and biopsy Gleason score may provide a cost-effective approach for management decisions and prognostication in patients with prostate cancer.

Epididymo-orchitis after cryoablation of prostate for prostate cancer

We report two cases of acute epididymo-orchitis developing 4 to 6 weeks after cryoablation for prostate cancer. One patient required a simple orchiectomy for epididymal abscess; the other responded to treatment with antibiotics. Since the occurrence of these two cases, we routinely perform bilateral vasectomy prior to prostate cryoablation. We suggest that an extended course of prophylactic antibiotics may also be needed in order to avoid this complication.

Impact of prostate size on the outcome of transurethral laser evaporation of the prostate for benign prostatic hyperplasia

OBJECTIVES

The aim of this study was to evaluate efficacy and safety of transurethral evaporation of the prostate (TUEP) using neodymium:yttrium-aluminum-garnet (Nd:YAG) laser in prostate glands of various sizes.

METHODS

One hundred consecutive patients with benign prostatic hyperplasia (BPH) and prostate volumes less than 40 cc (group I, n = 41), 41 to 80 cc (group II, n = 39), and more than 80 cc (group III, n = 20), who had preoperative prostate volume estimation by transrectal ultrasound and had completed a minimum of 3 months' follow-up, underwent TUEP. At baseline, and at 3 and 6 months, American Urological Association (AUA) score, peak flow rate (PFR), postvoid residual urine (PVR), and complications, if any, were documented.

RESULTS

There were no significant differences in failure rates, complications, or ability to improve symptom score, PFR, and PVR between patients with prostate glands of various sizes. The mean improvement in PFR at 6 months was: group I, 9.9 cc/s (116%); group II, 7.4 cc/s (81%); and group III, 9.2 cc/s (107%). Reduction in AUA score was: group I, 14.6 (63%); group II, 17.7 (71%); and group III, 16.2 (70%). PVR was: group I, 62.5 cc (51%); group II, 31.4 cc (16%), and group III, 71 cc (83%) (differences not significant). The patients in urinary retention were separately analyzed (group I, 9, group II, 12, and group III, 5) and mean PFR at 6 months was: group I, 18.5 cc/s, group II, 15 cc/s, and group III, 17.1 cc/s. Mean AUA score at 6 months was: group I, 25.8; group II, 21; and group III, 23.6. Mean PVR score was: group I, 370 cc, group II, 439 cc; and group III, 400 cc (differences not significant). Mean postoperative catheterization time was higher in patients with glands larger than 80 cc (2.2 versus 2.9 versus 4.7 days in groups I, II, and III, respectively, P < 0.009 between groups II and III). Incidence of urinary tract infection (10 versus 0%) was greater in patients receiving only 48-hour as opposed to 10-day postoperative antibiotics.

CONCLUSIONS

TUEP appears to be a safe and effective treatment for relief of symptoms of BPH and improvement of PFR in patients with all sizes of prostate glands.

Prostate cancer: effect of postbiopsy hemorrhage on interpretation of MR images

PURPOSE

To assess the frequency of changes in signal intensity after prostatic biopsy and the effect of these changes on the magnetic resonance (MR) imaging staging of prostate cancer.

MATERIALS AND METHODS

Seventy-three patients with biopsy-proved prostate cancer were divided into two groups according to time between biopsy and imaging (less than and more than 21 days). The findings at MR imaging were compared with those at pathologic examination.

RESULTS

Postbiopsy hemorrhage was detected in 21 of 26 (81%) patients who underwent imaging less than 21 days after biopsy and in 23 of 47 (49%) patients who underwent imaging more than 21 days after biopsy (P < .01). Postbiopsy changes persisted for as long as 4 1/2 months. Less than 21 days after biopsy, there was a tendency to overestimate tumor presence and extracapsular extension. After 21 days, tumor presence was underestimated but the positive predictive value for extracapsular extension was improved. Staging accuracy less than 21 days after biopsy was 46%; this improved to 83% after 21 days (P < .01).

CONCLUSION

Staging accuracy is significantly improved when imaging is deferred for 21 days after biopsy.

c-myc copy number gains in bladder cancer detected by fluorescence in situ hybridization

Amplification and overexpression of c-myc have been suggested as prognostic markers in human cancer. To assess the role of c-myc gene copy number alterations in bladder cancer, 87 bladder tumors were examined for c-myc aberrations by fluorescence in situ hybridization. Dual labeling hybridization with a repetitive pericentromeric probe specific for chromosome 8 and a probe for the c-myc locus (at 8q24) was performed to analyze c-myc copy number in relation to chromosome 8 copy number on a cell by cell basis. A clear-cut c-myc amplification (up to 40 to 150 copies per cell) was found in 3 tumors. There was a low level c-myc copy number increase in 32 of the remaining 84 tumors. There was no association of low level c-myc copy number increase with c-myc protein overexpression. This suggests that a c-myc gene copy number gain as detected by fluorescence in situ hybridization does not necessarily reflect a disturbed c-myc gene function but may indicate a structural chromosome 8 abnormality including gain of distal 8q. The strong association of low level c-myc (8q) gains with tumor grade (P < 0.0001), stage (P < 0.0001), chromosome polysomy (P < 0.0001), p53 protein expression (P = 0.0019), p53 deletion (P = 0.0403), and tumor cell proliferation (Ki67 labeling index; P = 0.0021) is consistent with a role of chromosome 8 alterations in bladder cancer progression.

Differential suppression of serum prostatic acid phosphatase and prostate-specific antigen by 5-alpha-reductase inhibitor

OBJECTIVE

To evaluate the effect of finasteride (Proscar) on the serum levels of prostatic acid phosphatase (PAP) and prostate-specific antigen (PSA) in patients with benign prostatic hyperplasia (BPH).

PATIENTS AND METHODS

Thirty patients on finasteride therapy for BPH formed the study group. Serum PSA and PAP levels were monitored for 2 years while the patients were receiving finasteride.

RESULTS

During 12 months of finasteride therapy the serum PSA was suppressed but serum PAP was unaffected. The baseline mean PAP value was 1.303 ng/mL prior to finasteride therapy; this changed to 1.510 ng/mL (P = 0.195) at 6 months and 1.166 ng/mL (P = 0.383) at 12 months. The serum PSA was 2.630 ng/mL at baseline, 1.757 ng/mL (P < 0.001) at 6 months and 1.545 ng/mL (P = 0.001) at 12 months.

CONCLUSIONS

Further studies are warranted to determine if PAP has a role as a tumour marker in patients whose PSA is suppressed as a result of finasteride therapy.

Laser effects on prostatic tissue: review of experimental data

Laser-tissue interaction is a highly dynamic event affected by many features of the laser, the tissue, and the operative procedure. The continuous-wave lasers used in urology produce lesions in three basic phases: initial heating, protein denaturation, and evaporation with charring. There are three components of these lesions: a central cavity, a zone of char, and a coagulation zone. The configuration of the lesion differs depending on the method of laser ablation (noncontact coagulation, contact tip incision, contact free-beam evaporation). Understanding of these differences will enable the endourologist to choose rationally among the various techniques of laser prostate ablation.

Regression of LNCaP human prostate tumor xenografts in athymic nude mice by 13-cis-retinoic acid and androgen ablation

The present study was designed to investigate the effects of 13-cis-retinoic acid (13-cis-RA) (100 micrograms/mouse/day) and androgen ablation (castration) alone and in combination on growth of a human prostatic carcinoma line (LNCaP) transplanted to athymic nude mice as an experimental model. The results of these studies suggest that; (1) androgen ablation (castration) significantly decreased the size of LNCaP xenograft as compared to untreated animals; (2) when 13-cis-RA was administered to nude mice carrying established tumors (0.51 +/- 0.04 cm3), the tumor size was significantly reduced as compared to untreated controls (0.65 +/- 0.06 cm3 versus 1.63 +/- 0.12 cm3). About 50% of the animals in this group showed xenografts necrosis followed by complete regression of tumors by five months; (3) the combination of androgen ablation and 13-cis-RA treatment to nude mice carrying tumors showed synergistic effect in decreasing the tumor size. These results indicate that combination therapies based on androgen ablation and retinoid administration may be a useful approach for the treatment of prostate cancer.

Citrate as an in vivo marker to discriminate prostate cancer from benign prostatic hyperplasia and normal prostate peripheral zone: detection via localized proton spectroscopy

OBJECTIVES

This study was designed to determine whether citrate levels detected by localized 1H spectroscopy could reliably discriminate regions of prostate adenocarcinoma from surrounding regions of normal peripheral zone and benign prostatic hyperplasia (BPH).

METHODS

In 28 patients and 5 volunteers stimulated echo proton spectroscopy was used in conjunction with endorectal surface coils to obtain water-suppressed 1H spectra from regions of normal prostate peripheral zone, BPH, and prostate cancer. 1H spectra from prostate cancer patients were correlated with pathologic areas identified on T2-weighted endorectal coil magnetic resonance (MR) images and histologic study of the step-sectioned gland after surgery.

RESULTS

The major finding of in vivo studies was consistently lower citrate levels in prostate cancer compared with BPH and normal prostate peripheral zone. This was reflected by significantly (P < 0.05) lower mean citrate/(creatine plus choline) peak area ratio observed for regions of cancer (0.67 +/- 0.17) compared with BPH (1.21 +/- 0.29) and normal peripheral zone (1.46 +/- 0.28). Moreover, there was no overlap of individual cancer and normal peripheral zone citrate ratios and no significant difference between citrate ratios in regions of normal peripheral zone in young volunteers (1.28 +/- 0.14) and age-matched patients (1.46 +/- 0.28). The observed alterations in vivo citrate levels were supported by citrate concentration data obtained from extracts of histologically proven samples of normal, benign, and malignant prostatic tissues removed at surgery. In vitro citrate levels in the normal peripheral zone (30.9 +/- 8.5 mumol/g wet weight) and BPH (46.3 +/- 5.4 mumol/g wet weight) were significantly higher than those for prostate cancer (3.74 +/- 0.54 mumol/g wet weight).

CONCLUSIONS

These studies further demonstrate the potential of citrate as an in vivo marker for discriminating prostate cancer from surrounding regions of normal peripheral zone and BPH.

Miles run per week and high-density lipoprotein cholesterol levels in healthy, middle-aged men. A dose-response relationship

OBJECTIVE

To examine the association between miles run per week and high-density lipoprotein cholesterol levels in healthy middle-aged men.

BACKGROUND

Regular exercise increases levels of high-density lipoprotein cholesterol. However, the exercise requirements for such increases are not well defined.

METHODS

Healthy, nonsmoking men (n = 2906; age, 43 +/- 4 years) completed a questionnaire on health habits and physical activities and a symptom-limited exercise test. They were then stratified on the basis of the number of miles run per week. Six groups, with mileages of 0, 5, 9, 12, 17, and 31 per week, were established.

RESULTS

A gradual increase in high-density lipoprotein cholesterol level was observed with increased miles (0.008-mmol/L [0.308-mg/dL] increase in high-density lipoprotein cholesterol level per mile). Most of the changes were associated with distances of 7 to 14 miles per week. Levels of low-density lipoprotein cholesterol, triglycerides, and the ratio of total cholesterol to high-density lipoprotein cholesterol also improved with weekly mileage. The high-density lipoprotein cholesterol level correlated significantly with all exercise components, anthropometric measures, and alcohol consumption. Group comparisons disclosed significant differences (P < .05) in exercise time to exhaustion, miles run per week, body fat, body weight, and body mass index. Age and alcohol consumption were similar across groups.

CONCLUSIONS

These results indicate a dose-response relationship between miles run per week, high-density lipoprotein cholesterol level, and other lipoprotein-lipid levels. Most changes were noted in those who ran 7 to 14 miles per week at mild to moderate intensities. A mile-age threshold for changes in high-density lipoprotein cholesterol level was not observed. However, when compared with those of the nonexercising group, high-density lipoprotein cholesterol levels attained statistical significance at 7 or more miles per week.

Neuroanatomy of the external urethral sphincter: implications for urinary continence preservation during radical prostate surgery

Post-prostatectomy urinary incontinence probably is multifactorial and sphincteric nerve injury could be a contributing cause. Controversy still exists regarding the innervation of the external sphincter, and currently pudendal nerve injury is not believed to be an etiological factor in post-prostatectomy urinary incontinence. To understand better the sphincter and its innervation, we undertook an anatomical and histological study of 18 adult male cadavers, which revealed that the external urethral sphincter receives part of its innervation through special branches originating from the dorsal nerve of the penis after it splits from the pudendal nerve. These nerve branches were located 0.3 to 1.3 cm. from the prostatic apex, and in 50% of the cadavers they were identified only unilaterally or had only 1 branch on each side. The proximity of these nerves to the prostatic apex may make them liable to injury during radical prostatectomy. These nerves are most likely sensory in nature although the presence of motor components cannot be completely ruled out. Injury to these nerves may explain several features of post-prostatectomy urinary incontinence.

Transition zone volume and transition zone ratio: predictor of uroflow response to finasteride therapy in benign prostatic hyperplasia patients

OBJECTIVES

The aim of this study was to: (1) determine effects of finasteride on transition zone (TZ) volume, TZ ratio (TZ volume/total prostate volume), and total prostate volume; (2) analyze differences in TZ and total volume reduction among patients who improve peak urinary flow rates following finasteride therapy with those who do not; (3) investigate which parameters correlate with improvement in peak urinary flow rate and urinary symptom score; and (4) establish if there is any predictive value of these parameters for response to therapy.

METHODS

Twenty-three patients with symptomatic benign prostatic hyperplasia (BPH) were treated with finasteride (5 mg/d) for 12 months and underwent transrectal ultrasound (TRUS) evaluation of total and TZ volume of prostate and measurement of peak flow rate and modified Boyarsky symptom score at baseline and at 12 months. Statistical analysis was done by unpaired t, Mann-Whitney, and Spearman rank correlation tests among responders (more than 3 cc/s improvement in peak flow rate) and nonresponders (less than 3 cc/s improvement in peak flow rate) to therapy.

RESULTS

(1) Responders had substantial reduction in TZ volume (44.8% versus 16.05%; P < 0.03) and TZ ratio (25% versus 5% increase, P < 0.02) compared with nonresponders. (2) There was a significant correlation between reduction in TZ volume (r = 0.50; P < 0.03) and TZ ratio (r = 0.60; P < 0.006) with improvement in peak flow rates. No similar correlation was seen with total prostate volume changes. (3) Pretreatment TZ ratio helped in predicting peak flow improvement following finasteride therapy (r = 0.52; P < 0.01) and there was a 2.5-fold increased chance of improvement if baseline TZ ratio was more than 0.51. The modified Boyarsky symptom score decreased by 3.1 (mean), but there was no correlation with changes in peak urinary flow rate, total prostate volume, TZ volume, and TZ ratio. TZ ratio did not have significant predictive value for improvement in symptom score.

CONCLUSIONS

This study provides data that simple measurable parameters are available which may be used prior to therapy to predict uroflow response to finasteride and similar agents.

Mechanical alternans and the force-frequency relationship in failing rat hearts

We examined contractile performance in perfused ventricles from normal rats and from SHHF/Mccfacp rats with end-stage heart failure. Changes in pacing frequency from 3 to 5 Hz evoked a complex response in normal rat myocardium. The first beat after a switch to 5 Hz was extremely weak, but each successive beat was stronger until force exceeded the 3 Hz steady state value by approximately 30%. Force then gradually declined to a new steady state where developed pressure was depressed but rate-pressure product was slightly greater than that at 3 Hz. By contrast, in failing SHHF/Mcc-facp hearts, an increase in pacing frequency from 3 to 5 Hz did not increase force development. Instead, the isovolumic left ventricles exhibited mechanical alternans. This alternation between weak and strong beats was abolished by 1 mM caffeine but restored by its washout. Inhibition of SR Ca2+ accumulation by 50-500 nM thapsigargin in normal ventricles did not evoke alternans when pacing frequencies were increased. The results indicate that mechanical alternans in failing rat hearts is due to altered reactions of the sarcoplasmic reticulum, but a decreased rate of Ca2+ accumulation is not the primary cause.

Transurethral Nd:YAG laser prostatectomy with a laterally firing fiber: local effects on tissue associated with erectile dysfunction

BACKGROUND AND OBJECTIVES

Transurethral laser prostatectomy is anticipated to become a recognized alternative to conventional transurethral resection of the prostate. However, the effects of this procedure on the nerves of the pelvic plexus and erectile dysfunction remain unaddressed. The objective of this study was to evaluate the effects of laser energy on extent of prostatic damage as well as injury to periprostatic cavernosal nerves and erectile dysfunction in a canine model.

STUDY DESIGN/MATERIALS AND METHODS

Six adult male mongrel dogs underwent transurethral laser prostatectomy at 30 (n = 3) and 40 (n = 3) watt power settings. Total laser energy delivered varied between 6,000 and 13,800 joules. Erectile function was evaluated by pelvic nerve stimulation at 2, 4, and 8 weeks. Animals were then sacrificed to assess histopathology of the prostate at each time point.

RESULTS

Histopathologic changes were noted in the prostate in a dose-dependent manner and did not vary with different laser power settings. In dogs that received approximately 10,000 J, substantial prostate ablation confined within the capsule was achieved in every prostate gland. Adequate erectile responses were noted in five of six animals; all received < 10,000 J. In one animal that received a total dose of 13,800 J, an erectile response was not obtained, and histology revealed both prostatic capsule perforation in close proximity to the cavernous nerves and thermal neural damage.

CONCLUSIONS

We conclude that cavernous nerve damage may result from excessive doses of laser energy during transurethral laser treatment of the prostate gland. In canines, the upper limit for periprostatic injury is between 10 and 14,000 joules.

Establishment and characterization of an immortalized but non-transformed human prostate epithelial cell line: BPH-1

This report describes the development and characterization of an epithelial cell line (BPH-1) from human prostate tissue obtained by transurethral resection. Primary epithelial cell cultures were immortalized with SV40 large T antigen. One of the isolated clones was designated BPH-1. These cells have a cobblestone appearance in monolayer culture and are non-tumorigenic in nude mice following subcutaneous injection or subrenal capsule grafting. They express the SV40 large T antigen and exhibit increased levels of p53, as determined by immunocytochemistry. Cytogenetic analysis by G-banding demonstrated an aneuploid karyotype with a modal chromosome number of 76 (range 71 to 79, n = 28) and 6 to 8 marker chromosomes. Some structurally rearranged chromosomes were observed, but the Y chromosome was normal. The expressed cytokeratin profile was consistent with a prostatic luminal epithelial cell. This profile was the same as that of primary prostatic epithelial cultures from which the BPH-1 cells were derived. In serum-free culture in plastic dishes epidermal growth factor (EGF), transforming growth factor (TGF)-alpha, fibroblast growth factor (FGF) 1 (aFGF), and FGF 7 (KGF) induced increased proliferation in these cells whereas FGF 2 (bFGF), TGF-beta 1, and TGF-beta 2 inhibited proliferative activity. Testosterone had no direct effect on the proliferative rate of BPH-1 cells. 5 alpha-Reductase, 3 alpha-hydroxysteroid oxidoreductase, and 17 beta-hydroxy-steroid oxidoreductase activities were detected in BPH-1 cells. Expression of androgen receptors and the secretory markers, prostate specific antigen and prostatic acid phosphatase, were not detectable by immunocytochemistry, biochemical assay, or RT-PCR analysis.

Carcinoma of the prostate gland: MR imaging with pelvic phased-array coils versus integrated endorectal--pelvic phased-array coils

PURPOSE

To compare the performance of pelvic phased-array (PPA) coils and integrated endorectal PPA coils in evaluation of local extent of prostate cancer.

MATERIALS AND METHODS

Seventy-one men underwent magnetic resonance (MR) imaging within 3 weeks of radical prostatectomy. MR findings of tumor, extracapsular extension, seminal vesicle invasion, nodal involvement, and stage were compared with step-sectioned (3-4-mm intervals) whole-mounted pathologic specimens. Prospective consensus versus single-reader interpretation (kappa statistics) and PPA versus integrated endorectal PPA coils (McNemar test) were compared, and a rating scale of 1-6 was developed for analysis of receiver operating characteristics. Statistical significance was calculated at delta = .05.

RESULTS

Comparison between consensus and single-reader image interpretation showed positive but poor agreement (kappa = .38) and no statistical significance. Staging accuracy was better (difference approached significance) for integrated endorectal PPA coils (77%) than for PPA coils (68%).

CONCLUSION

The integrated endorectal PPA coil is better for evaluation of local prostatic cancer than is the PPA coil.