Mapping the Sinorhizobium meliloti 1021 solute-binding protein-dependent transportome.

The number of solute-binding protein-dependent transporters in rhizobia is dramatically increased compared with the majority of other bacteria so far sequenced. This increase may be due to the high affinity of solute-binding proteins for solutes, permitting the acquisition of a broad range of growth-limiting nutrients from soil and the rhizosphere. The transcriptional induction of these transporters was studied by creating a suite of plasmid and integrated fusions to nearly all ATP-binding cassette (ABC) and tripartite ATP-independent periplasmic (TRAP) transporters of Sinorhizobium meliloti. In total, specific inducers were identified for 76 transport systems, amounting to approximately 47% of the ABC uptake systems and 53% of the TRAP transporters in S. meliloti. Of these transport systems, 64 are previously uncharacterized in Rhizobia and 24 were induced by solutes not known to be transported by ABC- or TRAP-uptake systems in any organism. This study provides a global expression map of one of the largest transporter families (transportome) and an invaluable tool to both understand their solute specificity and the relationships between members of large paralogous families.

Maize ROP2 GTPase provides a competitive advantage to the male gametophyte.

Rop GTPases have been implicated in the regulation of plant signal transduction and cell morphogenesis. To explore ROP2 function in maize, we isolated five Mutator transposon insertions (rop2::Mu alleles). Transmission frequency through the male gametophyte, but not the female, was lower than expected in three of the rop2::Mu mutants. These three alleles formed an allelic series on the basis of the relative transmission rate of each when crossed as trans-heterozygotes. A dramatic reduction in the level of ROP2-mRNA in pollen was associated with the three alleles causing a transmission defect, whereas a rop2::Mu allele that did not result in a defect had wild-type transcript levels, thus confirming that mutation of rop2 causes the mutant phenotype. These data strongly support a role for rop2 in male gametophyte function, perhaps surprisingly, given the expression in pollen of the nearly identical duplicate gene rop9. However, the transmission defect was apparent only when a rop2::Mu heterozygote was used as the pollen donor or when a mixture of wild-type and homozygous mutant pollen was used. Thus, mutant pollen is at a competitive disadvantage compared to wild-type pollen, although mutant pollen grains lacked an obvious cellular defect. Our data demonstrate the importance in vivo of a specific Rop, rop2, in the male gametophyte.

Patient-reported experience with the Viadur 12-month leuprolide implant for prostate cancer.

OBJECTIVES: To assess patient-reported general satisfaction, effect on daily activities, and effect on health-related quality of life of a 12-month leuprolide implant for prostate cancer. METHODS: A total of 80 men with prostate cancer participated in an open-label Phase III study of the Viadur leuprolide implant. One implant was inserted in each patient at enrollment and was removed after 52 weeks. At 24 and 52 weeks after implantation, patients were asked to complete a questionnaire about their experience with the implant, and at 0, 12, 24, 36, and 52 weeks after implantation, the patients were asked to complete the Medical Outcome Study Short Form-36 health-related quality-of-life instrument. RESULTS: The surveys about the patients' experience with the implant were completed by 70 subjects, and two or more SF-36 questionnaires were completed by 72 patients. At weeks 24 and 52 after implantation, greater than 90% of patients were extremely satisfied or satisfied with the overall treatment, found the implant convenient, forgot about the implant most of the time or were occasionally aware of the implant, and found the implant very comfortable or somewhat comfortable. No meaningful change was found in the summary scores of the mental and physical aspects of the SF-36 assessments during treatment. Of 73 men who were eligible for reimplantation after the 12-month study period, 70 (96%) elected to undergo reimplantation. CONCLUSIONS: In this study, patients found the Viadur 12-month leuprolide implant convenient, and the implant did not affect their health-related quality of life.

Prospective study of correlations between biopsy-detected high grade prostatic intraepithelial neoplasia, serum prostate specific antigen concentration, and race.

BACKGROUND: High grade prostatic intraepithelial neoplasia (HGPIN), a premalignant lesion of the prostate gland, is more common in black men than in white men. The influence of HGPIN on the serum prostate specific antigen (PSA) concentration is controversial, and correlations between HGPIN and PSA in black men and white men have not been investigated. METHODS: Between January 1992 and December 1998, 411 black men and 639 white men with suspected prostate carcinoma underwent an initial benign prostate biopsy at a single medical center. The presence or absence of HGPIN in the biopsy specimens was determined by one uropathologist. RESULTS: HGPIN was identified in 8.9% of the specimens. When stratified by PSA concentration (< 4.0 ng/mL, 4.0-9.9 ng/mL, and > or = 10.0 ng/mL), HGPIN was associated with an increased PSA concentration only among men with PSA concentrations < 4.0 ng/mL (P = 0.01). The prevalence of HGPIN in the black and white patients was 13.4% and 5.9%, respectively (P < 0.0001), and was significantly greater in black men than in white men with PSA concentrations < 4.0 ng/mL (P = 0.002). Among the patients with PSA concentrations < 4.0 ng/mL, black race was an independent predictor of an increased PSA concentration when adjusted for patient age, prostate volume, and the presence or absence of HGPIN (P = 0.03). CONCLUSIONS: HGPIN is more common in black men than in white men and may produce an increase in the PSA concentration. However, racial differences in the prevalence of HGPIN may not contribute to racial differences in PSA concentrations among men with no clinical or histologic evidence of carcinoma.

Information Technology Measurement and Testing Activities at NIST.

Our high technology society continues to rely more and more upon sophisticated measurements, technical standards, and associated testing activities. This was true for the industrial society of the 20th century and remains true for the information society of the 21st century. Over the last half of the 20th century, information technology (IT) has been a powerful agent of change in almost every sector of the economy. The complexity and rapidly changing nature of IT have presented unique technical challenges to the National Institute of Standards and Technology (NIST) and to the scientific measurement community in developing a sound measurement and testing infrastructure for IT. This measurement and testing infrastructure for the important non-physical and non-chemical properties associated with complex IT systems is still in an early stage of development. This paper explains key terms and concepts of IT metrology, briefly reviews the history of the National Bureau of Standards/National Institute of Standards and Technology (NBS/NIST) in the field of IT, and reviews NIST's current capabilities and work in measurement and testing for IT. It concludes with a look at what is likely to occur in the field of IT over the next ten years and what metrology roles NIST is likely to play.

Maize ROP7 GTPase contains a unique, CaaX box-independent plasma membrane targeting signal.

Signals in the carboxy-terminal hypervariable region (HVR) of Rho and Ras GTPases target these proteins to specific membrane compartments, where they function in signal transduction. ROP6 and ROP7 are closely related maize Rops (a plant-specific Rho subgroup) that share HVR sequences divergent from other Rho HVRs. Both ROPs terminate in CAA, instead of the consensus C-terminal CaaX motif required for membrane association of all characterized Ras and Rho GTPases. The ROP6/7 HVR contains two additional cysteines, potential sites for post-translational modification that leads to membrane association; one is in an internal CaaX motif, which would be at the C-terminus if the final intron in both genes were not removed. Transient expression of a GFP-ROP7 fusion revealed its near-total association with the plasma membrane (PM). Furthermore, the ROP7 HVR is sufficient to target GFP to the PM. Surprisingly, the cysteine in the terminal CAA is not required for PM targeting of GFP-ROP7. In contrast, an internal HVR cysteine is essential for proper targeting of the fusion, and the cysteine in the internal CaaX is required for complete membrane association. Interestingly, this CaaX motif can also direct PM association when placed at the fusion C-terminus by addition of an internal stop codon. Fractionation experiments confirm that maize ROPs associate with membranes in maize seedlings. Our analysis suggests that the ROP7 HVR directs PM localization by a mechanism independent of a C-terminal CaaX motif; this mechanism may have evolved through addition of 3' intron/exon sequences to a rop progenitor.

Safety and efficacy of an implantable leuprolide delivery system in patients with advanced prostate cancer.

PURPOSE: We evaluated the pharmacokinetics, safety and efficacy of the implantable Viadur++ leuprolide delivery system during 12 months in patients with advanced prostate cancer. MATERIALS AND METHODS: Our open label, multicenter, dose ranging study was done in 2 phases. The treatment phase was a stratified, randomized, parallel evaluation of the safety and efficacy of 1 or 2 implants. The safety extension phase assessed the long-term safety and efficacy of 1 implant. Implant insertion and removal, pharmacokinetic profile and patient satisfaction were also evaluated. The primary efficacy parameter was testosterone suppression for 12 months but luteinizing hormone and prostate specific antigen were also evaluated. RESULTS: Of the 51 patients 27 received 1 and 24 received 2 implants, of whom 49 completed the 12-month treatment phase. Steady serum leuprolide concentration was maintained from day 3 through the remainder of the 12-month treatment phase and for 2 months after reimplantation. Implantation and reimplantation were well tolerated and acceptable to physicians and patients. Testosterone suppression to the castrate range was 100% in each group. At 12 months mean prostate specific antigen decreased from a baseline of approximately 84% and 91% in groups 1 and 2, respectively. Serious adverse events during the study period in 15 patients were not attributable to treatment. CONCLUSIONS: The implantable leuprolide delivery system provides effective suppression of testosterone in patients with advanced prostate cancer.

Evaluation of an implant that delivers leuprolide for 1 year for the palliative treatment of prostate cancer.

OBJECTIVES: To evaluate the Viadur implant, which delivers leuprolide acetate for the palliative treatment of advanced prostate cancer. METHODS: Inserted subcutaneously, the 4 x 45-mm implant uses osmotic pressure to deliver leuprolide continuously at a controlled rate for 1 year. This 19-center open-label study enrolled patients with prostate cancer who had had no prior therapy or showed biochemical evidence of treatment failure after prostatectomy or radiotherapy. Each patient received one implant. After 1 year, that implant was removed, another was inserted, and patients were followed up for 2 additional months. The primary efficacy measure was suppression of testosterone to less than the castrate threshold (50 ng/dL). RESULTS: Eighty patients were enrolled. The implant effectively suppressed testosterone in 79 patients (99%) within 2 to 4 weeks and maintained that suppression through the study period. In 1 patient, the testosterone was suppressed to less than 100 ng/dL within 4 weeks but was not less than 50 ng/dL until week 24. Prostate-specific antigen levels normalized (4 ng/mL or less) or a clinically significant decrease occurred in all patients. Leuprolide was rapidly absorbed, resulting in mean serum concentrations of 16.8 ng/mL 4 hours after implant insertion and 2.4 ng/mL at 24 hours; steady mean serum leuprolide concentrations were then maintained throughout the year, at approximately 0.9 ng/mL. Investigators were satisfied with the insertion and removal procedures. All patients reported satisfaction after 1 year of treatment. The safety profile of the implant was consistent with androgen ablation therapy. Most adverse events were mild, and the most common event was hot flashes. CONCLUSIONS: The leuprolide implant effectively suppressed testosterone concentrations to less than the castrate threshold and maintained that suppression throughout the study period.

Predictors of first repeat biopsy cancer detection with suspected local stage prostate cancer.

PURPOSE: We determine demographic and tumor related predictors of repeat biopsy cancer detection in men with suspected stage T1c-2 prostate cancer. MATERIALS AND METHODS: The study population included 298 consecutive men with suspected stage T1c-2 prostate cancer who had a benign prostate biopsy at 1 institution between January 1, 1992 and April 1, 1999 and underwent 1 repeat biopsy. Mean age plus or minus standard deviation was 66.8+/-6.7 years for 133 black (55%) and 165 white (45%) patients. Clinical measures included determination of high grade prostatic intraepithelial neoplasia in benign biopsy specimens, Gleason score of malignant biopsy specimens, prostate specific antigen (PSA), PSA density, annualized interbiopsy PSA change, percent free PSA (201 cases) and PSA velocity (171). RESULTS: Cancer was detected on repeat biopsy in 80 cases (27%). Significant differences between patients with benign and malignant repeat biopsies included age (p = 0.001), PSA density (p = 0.0001), percent free PSA (p = 0.0001) and PSA velocity (p = 0.009). High grade prostatic intraepithelial neoplasia in an initial benign biopsy was not predictive of cancer in repeat biopsy (p = 0.12). Multiple logistic regression analysis of all cases showed that age (p = 0.002) and PSA density (p = 0.0002) were independent predictors of cancer. Subset multiple logistic regression analysis modeled with age, PSA density and percent free PSA demonstrated that age (p = 0.002) and percent free PSA (p = 0.0001) were significant independent predictors of malignancy. Subset multiple logistic regression analysis modeled with age, PSA density, percent free PSA and PSA velocity revealed that age (p = 0.02) and percent free PSA (p = 0.0003) were significant independent predictors of cancer. There were no significant differences between the Gleason scores of cancers detected on repeat biopsy compared to 587 stage T1c-2 cancers detected on initial biopsy during the study period (p = 0.09). PSA, PSA density, percent free PSA and PSA velocity were not significantly different among men without a cancer diagnosis who had high grade neoplasia in 1 or 2 benign biopsies. CONCLUSIONS: Greater than 25% of this population of select patients with suspected stage T1c-2 prostate cancer had malignancy detected on repeat biopsy. Percent free PSA was the most powerful predictor of cancer. High grade prostatic intraepithelial neoplasia was not a predictor of repeat biopsy cancer detection and PSA functions were similar among men without cancer who did and did not have high grade neoplasia in 1 or more benign biopsies. This finding suggests that high grade prostatic intraepithelial neoplasia may not be a reliable indicator of clinically significant existing prostate cancer.

Percent free prostate specific antigen and cancer detection in black and white men with total prostate specific antigen 2.5 to 9.9 ng./ml.

PURPOSE: The ratio of free-to-total prostate specific antigen (PSA), or percent free PSA, is a useful adjunct to total PSA for estimating the risk of prostate cancer when total PSA is 2.5 to 9.9 ng./ml. Relationships between cancer detection and total PSA are influenced by race but to our knowledge relationships between cancer detection and percent free PSA have not been studied. MATERIALS AND METHODS: A total of 222 black and 298 white consecutive and evaluable men with total PSA 2.5 to 9.9 ng./ml. underwent prostate biopsy for suspected cancer at a Veterans Affairs Medical Center. Clinical measurements included digital rectal examination, total and free serum PSA, prostate volume, PSA density and Gleason score of malignant biopsy specimens. RESULTS: Median percent free PSA was 14.1 (range 3.6 to 49.2) in 201 men with prostate cancer and 21.9 (range 5.7 to 83.3) in 319 without detectable cancer (p <0.0001). Significant racial differences in demographic characteristics and clinical measurements were limited to total PSA, which was higher in black men (p = 0.03). Cancer was detected in 156 black (47%) and 206 white (33%) men (p = 0.001). Areas under receiver operating characteristics curves for percent free PSA and total PSA were 0.66 and 0.58, respectively, for black men (p = 0.15), and 0.76 and 0.58, respectively, for white men (p <0.00001). Percent free PSA was 35.2 in black men and 29.2 in white men, and specificity was 9.1% and 28.7%, respectively, when sensitivity for percent free PSA was set at 95%. Of 156 black and 206 white men with percent free PSA less than 25, 83 (53%) and 85 (41%), respectively, had detectable cancer (p = 0.03). Of 66 black and 92 white men with percent free PSA 25 or greater 21 (32%) and 12 (13%), respectively, had detectable cancer (p = 0.005). CONCLUSIONS: Our study demonstrates racial differences in relationships between percent free PSA and cancer detection in men with suspected prostatic carcinoma and total PSA 2.5 to 9.9 ng./ml. Clinical application of the commonly used percent free PSA cutoff of less than 25 to determine the advisability of prostate biopsy may lead to under diagnosis of early stage prostate cancer in black men, who are at greater risk of morbidity and mortality from disease than white men.

Race and cause specific survival with prostate cancer: influence of clinical stage, Gleason score, age and treatment.

PURPOSE: We assess the influence of race on stage stratified cause specific survival of men with prostate cancer, and Gleason score, age at diagnosis and treatment on potential racial differences in survival. MATERIALS AND METHODS: A total of 524 black and 396 white men were diagnosed with prostate cancer at a Veterans Affairs Medical Center between January 1982 and December 1992. Clinical stage was determined by retrospective review of the medical records and Gleason score of biopsy material as assigned by a single uropathologist. Of 611 patients who died the cause of death was determined by retrospective or prospective review of hospital records in 493 and by review of the death certificates in 102. In 16 cases the cause of death was indeterminate. Median potential followup was 112 months (range 60 to 182) and median period of observation was 61 months (range 1 to 182). RESULTS: Cause specific survival with stage T1b-2 cancer was lower in 231 black than in 264 white men of all ages (p = 0.02) and lower in 110 black than in 170 white men younger than in 70 years at diagnosis (p = 0.04). Gleason 7 to 10 cancer, which was associated with a less favorable cause specific survival compared to Gleason 2 to 6 cancer (p <0.0001), was more common in black than in white men with stage T1b-2 cancer of all ages (p = 0.01) and younger than 70 years at diagnosis (p = 0.04). No or unknown treatment status, which was associated with a less favorable cause specific survival compared to treatment (p = 0.05), was more common in black than in white men with stage T1b-2 cancer of all ages (p = 0.0005) but not significantly different when stratified by age. In men of all ages racial differences in cause specific survival were not significant when adjusted for age and Gleason score (p = 0.14) or age, Gleason score and treatment status (p = 0.17). In men younger than 70 years racial differences in cause specific survival were not significant when adjusted for age and Gleason score (p = 0.22). There were no significant racial differences in overall or age stratified all cause survival of men with stage T1b-2 cancer. There were no significant differences in overall or age stratified cause specific or all cause survival of 112 black and 58 white men with stage T3-4 cancer, or 181 and 74, respectively, with metastatic cancer. CONCLUSIONS: Our data indicate that local stage prostate cancer is more lethal in black than in white men and the difference is most pronounced in men younger than 70 years. The survival disadvantage of black men with local stage cancer is due in part to a propensity for development of less differentiated and more aggressive malignancies.

Prostate specific antigen measurements after minimally invasive surgery of the prostate in men with benign prostatic hypertrophy.

There is a trend of minimally invasive surgery in the treatment of benign prostatic hypertrophy (BPH). Studies have examined levels of prostate specific antigen (PSA) in patients after open prostatectomy or transurethral resection of prostate (TURP) and noted reset of PSA to lower values after surgery. We reviewed PSA levels in patients after minimally invasive procedures to determine if levels were reset. There were 120 patients (age 45-70) enrolled in the study. Fifty patients underwent laser ablation, 20 patients had electrovaporization (TVP) and 50 patients underwent TURP. PSA measurements were obtained prior to and after surgical procedures in a three-year follow-up. Mean pre-operative PSA was 2.8 (+/-0.34) ng/ml for laser cohort, 3.2 (+/-0.31) ng/ml for the TURP group and 2.3 (+/-0.42) ng/ml for TVP patients (P=0.33). At 1 y follow-up, mean PSA decreased 32% for laser patients, 46% for the TURP cohort and 8% for TVP group. The largest mean decrease in PSA velocity was-1.5 (+/-0.31) ng/ml per y for TURP followed by 0.9 (+/-0.29) ng/ml per y for laser patients and-0.1 (s.d.+/-1.2) ng/ml per y for TVP group in y 1. The TURP group maintained the largest decrease in PSA velocity in y 2,-0.6 (+/-0.26) ng/ml per y. Three patients (2-TURP, 1-TVP) were diagnosed with prostate cancer during follow-up. In conclusion, serum PSA levels were reset at lower levels following different surgical interventions. This lower level of PSA remained decreased for 2 y post-procedure. Urologists should be cognizant of this reset level and monitor PSA levels for possible increases to screen for prostate cancer in this patient population. Prostate Cancer and Prostatic Diseases (2000) 3, 200-202

A randomized prospective study of laser ablation of the prostate versus transurethral resection of the prostate in men with benign prostatic hyperplasia.

OBJECTIVES: To compare the safety and efficacy of laser ablation of the prostate, one of the minimally invasive treatments available for men with benign prostatic hyperplasia, to transurethral resection of the prostate (TURP). METHODS: A prospective randomized study of 100 men with benign prostatic hyperplasia, with 50 patients in each treatment arm, was conducted. All patients met the entry criteria: age older than 45 years, no history of carcinoma of the prostate, a peak flow rate less than 15 mL/s, medical therapy failure, and the ability to undergo regional or general anesthesia. All patients underwent a preoperative evaluation consisting of the American Urological Association (AUA) symptom score, uroflowmetry, pressure-flow study, transrectal ultrasound for prostate volume, and serum prostate-specific antigen determination. Patients underwent either TURP or laser ablation of the prostate using the potassium titanyl phosphate (KTP)/neodymium: yttrium-aluminum-garnet laser. Patients were seen for follow-up at 1, 3, 6, and 12 months. RESULTS: The mean age was 68.2 years (range 45 to 90) for the laser group and 67.4 years (range 54 to 82) for the TURP group. The mean AUA symptom score was 22 for the laser group and 21 for the TURP group. The mean peak uroflow rate was 7.6 +/- 3.4 mL/s for the laser group and 6.5 +/- 4.0 mL/s for the TURP group. At 12 months of follow-up, the mean AUA symptom score had decreased to 7 (-69.5%) for the laser group and to 3 (-80.9%) for the TURP group. The mean peak uroflow rate increased to 15.4 mL/s (+ 107.8%) for the laser group and to 16.7 mL/s (+ 150.7%) for the TURP cohort. Seventy-five percent of the laser group had a 50% or greater decrease in their individual AUA symptom score compared with 93% of the TURP group. Sixty-five percent of the laser cohort had a 50% or greater increase in their peak uroflow rate compared with 75% of the TURP cohort. CONCLUSIONS: Laser prostatectomy produced improvements in the peak flow rate and symptom score similar to those produced by TURP. The patients who underwent laser treatment required a longer period to reach maximum improvement, which probably reflects the lack of tissue debulking at the time of surgery. Further improvement in laser technology will be required to produce more immediate results.

A prospective study of the serum prostate specific antigen concentrations and Gleason histologic scores of black and white men with prostate carcinoma.

BACKGROUND: The stage specific survival rates of black American men with prostate carcinoma are less favorable than those of white American men. The authors conducted a prospective study of the serum prostate specific antigen (PSA) concentrations and Gleason histologic scores of black and white men with newly diagnosed prostate carcinoma to determine whether there were racial differences in these prognostic variables. METHODS: At a Veterans Affairs Medical Center between January 1, 1992, and December 31, 1997, clinical stage, Gleason histologic score, serum PSA concentration, prostate volume, and PSA density were determined for 796 consecutive men (465 black and 331 white) who had biopsy-detected prostate carcinoma. RESULTS: The percentages, respectively, of black and white men with local, regional, and metastatic carcinoma were 58 and 72; 22 and 17; and 20 and 11 (P < 0.0001). Of 271 black and 329 white men with local stage cancer, 20% and 12%, respectively, had Gleason 8-10 tumors (P = 0.02), and the age-adjusted risk of Gleason 8-10 cancer was 1.39 times greater for black men (95% confidence interval [CI] = 1.09-2.93). Gleason 8-10 cancer was found in 12 of 68 black (18%) and 5 of 87 white (6%) men with local cancer who were age 65 years or younger (P = 0.02). Among black and white men with local stage cancer, the mean PSA was 12.9 (95% CI = 11.5-14.4) and 8.5 (95% CI = 7.6-9.4) ng/mL, respectively (P < 0.0001), and among black and white men with regional stage cancer the mean PSA was 53.3 (95% CI = 42.7-63.9) and 35.0 (95% CI = 27.3-42.6) ng/mL, respectively (P = 0.02). The mean PSA of black and white men with local cancer who were age 65 years or younger was 11.6 (95% CI = 8.8-14.4) and 6.9 (95% CI = 5.9-8.0) ng/mL, respectively (P = 0.0009). CONCLUSIONS: Disparities in the risk of Gleason score 8-10 cancer for black and white men with local stage disease and in the serum PSA concentrations of black and white men with local and regional stage disease help to explain racial differences in cancer survival. Racial differences in the risk of Gleason 8-10 cancer and in the serum PSA concentrations of men age 65 years or younger have implications regarding the potential benefits of screening for prostate carcinoma in the African American community.

Relationships between prostate-specific antigen and prostate volume in black and white men with benign prostate biopsies.

OBJECTIVES: To determine whether the higher age-adjusted serum prostate-specific antigen (PSA) levels in black compared with white men with no clinical evidence of prostate cancer reflect racial differences in relationships between PSA and prostate volume. METHODS: The age, PSA, findings on digital rectal examination (DRE), prostate volume, and PSA density were assessed prospectively in 810 consecutive, evaluable men who underwent prostate biopsy for suspected cancer but who had benign histologic findings. RESULTS: Among the black and white patients, there were significant differences in age (mean 67.2 +/- 8.1 and 65.9 +/- 7.7 years, respectively, P = 0.02), PSA (median 4.7 and 3.9 ng/mL, respectively, P <0.0001), prostate volume (median 41 and 36 mL, respectively, P = 0.004), and PSA density (median 0.11 and 0.08 ng/mL/mL, respectively, P = 0.005). Multiple linear regression analyses showed that black race was significantly associated with increased prostate volume when controlled for age (P = 0.02), with increased PSA when controlled for prostate volume and age (P = 0.002), and with increased PSA density when controlled for age (P = 0.007). When controlled for prostate volume, PSA was not significantly different in black and white men 50 to 59 years old but was significantly greater in black men 60 to 69 and 70 to 79 years old (P = 0.02 and 0.002, respectively). CONCLUSIONS: On a volume/volume basis, the benign prostatic tissue of black men appears to contribute more PSA to the circulating blood than does the benign prostatic tissue of white men, and the difference increases with advancing age. These phenomena provide a reasonable explanation for the age-adjusted racial differences in the PSA of men with no clinical evidence of cancer.

Low-power v high-power KTP laser: improved method of laser ablation of prostate.

BACKGROUND AND OBJECTIVE: Current treatment technique for laser prostatectomy involve Nd:YAG wavelength at 60 to 80 W. Use of the KTP wavelength in addition to Nd:YAG allows for vaporization of more tissue, decreasing the amount undergoing coagulation necrosis. In this study, we compared 20 W and 40 W of KTP laser energy in conjunction with the Nd:YAG wavelength for the treatment of benign prostatic hyperplasia (BPH). PATIENTS AND MATERIALS: A total of 50 consecutive patients underwent laser ablation of the prostate, with 38 patients (Group I) receiving treatment with 20 W of the KTP and 60 W of the Nd:YAG wavelengths. The other 12 patients (Group II) underwent treatment with 40 W of KTP and 60 W of Nd:YAG laser energy. The patients had an initial evaluation consisting of American Urological Association (AUA) Symptom Score, uroflowmetry, transrectal ultrasonography for prostate volume measurement, and assay of prostate specific antigen (PSA) serum level. The patients were seen in follow-up at 1, 3, and 6 months. RESULTS: The mean symptom score decreased from 23.4 to 8.9 from Group I and from 18.2 to 3.5 for Group II at the 6-month follow-up. The mean peak urinary flow rate increased from 8.4 to 15.4 mL/sec Group I and from 8.3 to 16.5 mL/sec in Group II at the 6-month follow-up. CONCLUSIONS: The patients treated with the 40 W of KTP laser energy experienced a more rapid and sustained improvement in symptom score than those treated at 20 W. The improvement in peak urinary flow rate was approximately the same in the two groups.

Results of transition zone biopsy in black and white men with suspected prostate cancer.

OBJECTIVES: To determine whether biopsy-detectable transition zone tumors are more common in black than in white men with suspected Stage T1c and T2 prostate cancer. METHODS: We performed a prospective study of transition zone prostate biopsy (TZ biopsy) in 1 78 black and 261 white men who had not undergone previous prostate biopsy and in 61 black and 65 white men who had undergone one benign sextant peripheral zone prostate biopsy (PZ biopsy). RESULTS: The mean age of the 239 black and 326 white study patients was 68.6+/-7.4 and 67.2+/-7.2 years, respectively (P = 0.02), the mean prostate-specific antigen (PSA) was 8.4+/-7.4 and 6.4+/-5.4 ng/mL, respectively (P = 0.003), and the mean PSA density was 0.20+/-0.23 and 0.16+/-0.16 ng/mL/mL, respectively (P = 0.006). Overall, cancer was diagnosed by TZ biopsy only in 7 black men (3%) and in no white men (0%) (P = 0.003). However, cancer detection with a TZ biopsy only was not significantly different in the black and white men when controlled for age, PSA, or PSA density (P>0.90). A TZ biopsy only detected cancer in 1% of patients who had not undergone prior PZ biopsy and in 2% of patients who had undergone prior PZ biopsy. Of the seven cancers detected with TZ biopsy, six (86%) had a Gleason score of 2 to 6. CONCLUSIONS: Prostate cancer detection with a TZ biopsy only is not common and when controlled for confounding variables is the same in black and white men. The preferential use of TZ biopsies in black men is not warranted, and the low diagnostic yield argues against routine use of the biopsy technique in men of either race.

Ectopic expression of the maize homeobox gene liguleless3 alters cell fates in the leaf.

The semidominant mutation Liguleless3-O (Lg3-O) causes a blade-to-sheath transformation at the midrib region of the maize (Zea mays L.) leaf. We isolated a full-length lg3 cDNA containing a knotted1-like family homeobox. Six Lg3-O partial revertant alleles caused by insertion of a Mutator (Mu) transposon and two deletion derivatives were isolated and used to verify that our knotted1-like cDNA corresponds to the LG3 message. In wild-type plants the LG3 mRNA is expressed in apical regions but is not expressed in leaves. In mutant plants harboring any of three dominant lg3 alleles (Lg3-O, -Mlg, and -347), LG3 mRNA is expressed in leaf sheath tissue, indicating that the Lg3 phenotype is due to ectopic expression of the gene. The Lg3-O revertant alleles represent two classes of Lg3 phenotypes that correlate well with the level of ectopic Lg3 expression. High levels of ectopic LG3 mRNA expression results in a severe Lg3 phenotype, whereas weak ectopic Lg3 expression results in a mild Lg3 phenotype. We propose that ectopic Lg3 expression early in leaf development causes the blade-to-sheath transformation, but the level of expression determines the extent of the transformation.

Prostate cancer detection in candidates for open prostatectomy.

PURPOSE: We determine the incidence of biopsy detectable prostate cancer in men with clinical benign prostatic hyperplasia (BPH) and prostate specific antigen (PSA) elevation who are candidates for open prostatectomy, and the histology of prostatic tissue of men who underwent surgery. MATERIALS AND METHODS: Sextant peripheral zone prostate biopsies were performed in 128 consecutive men with obstructive voiding symptoms who had digital rectal examination not suspicious for cancer, PSA greater than 4.0 ng./ml. and prostate volume 75 ml. or greater. Of the patients 59 also underwent transition zone biopsy. Median PSA was 9.9 ng./ml. (range 4.1 to 80.0), median prostate volume was 92 ml. (range 75 to 220), median PSA density was 0.10 ng./ml./ml. (range 0.03 to 0.80) and median percent free PSA in 43 patients was 23.6 (range 8.8 to 41.3). RESULTS: Of the 128 patients 16 (13%) had malignant biopsy including 1 who had cancer detected with transition zone biopsy only. Gleason score of tumors ranged from 4 to 8 (median 5). Of 57 patients who underwent prostatectomy 6 (11%) had stage T1a and 2 (4%) had stage T1b cancer. Among men without an indwelling urethral catheter due to acute urinary retention mean PSA, PSA density and percent free PSA were not significantly different in those with benign and malignant biopsies and/or prostatectomy specimens. CONCLUSIONS: Greater than 10% of men with PSA elevation who are potential candidates for open prostatectomy will have biopsy detectable prostate cancer. This diagnostic yield, while lower than that reported for unselect men with normal digital rectal examination and PSA elevation, may justify preoperative peripheral zone biopsy to avoid surgical misadventure during open enucleation. Among patients with benign peripheral zone biopsy there is a less than 5% prevalence of large volume tumors that may complicate open enucleation.