Monitoring sessile droplet evaporation on a micromechanical device.

A bulk acoustic mode micro-electro-mechanical dual resonator platform is utilised to study the evaporation of sub-microliter water droplets from the surface of the resonator. An analytical formulation for the observed frequency shift and the measure dependence of resonant frequency on the modes of evaporation which is consistent with the optically derived data. The resonators access only a thin layer of the liquid through shear contact and, hence, the response is not affected by the bulk mass of the droplet to first order. A relationship between the droplet contact area and the elapsed time was established for the evaporation process and is used to derive a value of the diffusion coefficient of water in air that is found to be in reasonable agreement with literature values. This work introduces a new tool for the electro-mechanical monitoring of droplet evaporation with relevance to applications such as biosensing in liquid samples of sub-microliter volumes.

The correlation between pretreatment serum hormone levels and treatment outcome for patients with prostatic cancer and bony metastasis.

OBJECTIVE: To evaluate whether pretreatment serum hormone levels are a prognostic factor for prostatic cancer with bony metastasis under hormonal treatment. PATIENTS AND METHODS: Between 1980 and 1994, 96 patients with prostate cancer and bony metastasis were included for an evaluation by a retrospective review of their charts. All 96 had received hormonal treatment after a diagnosis of metastatic prostatic carcinoma. Serum testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin were assessed before treatment. The patients were divided into two groups according to their response during the follow-up. Group 1 (good response) had no change or resolution of metastatic lesion(s) on the bone scan and a declining prostate-specific antigen (PSA) level. Group 2 had increased PSA or progression of metastatic lesion(s) on the bone scan. Tumours were graded as low (2-4), intermediate (5-7) and high (8-10) using the Gleason score. RESULTS: There were 43 patients in group 1 and 53 in group 2; the overall mean (sd) age was 72.5 (6.8) years and the follow-up 29.5 (0.5) months. The respective mean (sd) levels of testosterone, LH, FSH and prolactin before treatment were 4.6 (1.6) ng/mL, 20.2 (13.3) mIU/mL, 19.6 (18.6) mIU/mL and 20.7 (12.1) ng/mL in group 1, and 2.6 (1.0) ng/mL, 27.3 (11.0) mIU/mL, 27.1 (9.8) mIU/mL and 41.3 (28.4) ng/mL in group 2. The level of testosterone was significantly higher in group 1 than in group 2, while LH, FSH and prolactin were significantly lower in group 1 than in group 2. When stratified by tumour grade, patients in group 1 still had significantly higher pretreatment testosterone and lower LH, FSH and prolactin than those in group 2. CONCLUSION: Higher testosterone and lower LH, FSH and prolactin levels were good prognostic factors for patients with metastatic prostatic cancer under hormonal treatment, irrespective of tumour grading.

High failure rate using allograft fascia lata in pubovaginal sling surgery for female stress urinary incontinence.

OBJECTIVES: To present our unfavorable experiences using allograft fascia lata. Allograft fascia lata is an attractive sling material providing less pain, a shorter operation time, and a reported effectiveness equal to autologous fascia. METHODS: A total of 18 women (mean age 51.7 years, range 37 to 76) underwent pubovaginal sling surgery for stress urinary incontinence between March 1999 and July 1999 and were enrolled in this study. Solvent dehydrated gamma-irradiated human fascia lata with a size of 7 x 2 cm was used as the sling. The results were collected with a questionnaire survey. RESULTS: All patients were followed up for a mean of 9.2 months (range 6.9 to 11.6). Thirteen patients considered the surgery successful or to have provided improvement, with a mean of 82.5% (range 50% to 100%) subjective improvement. Five patients (27.8%) had significant failure with full recurrence of incontinence within 3 to 6 months. CONCLUSIONS: Solvent dehydrated gamma-irradiated allograft fascia is not reliable in pubovaginal sling surgery. The high failure rates within a short period prohibit its use in the operative management of stress urinary incontinence.

Treatment guideline of enuresis in Taiwan.

The treatment guideline of enuresis suggested by the study group of enuresis in Taiwan is reported. Medical consultation and treatment of enuresis are recommended at the age of 5 and 6 years respectively. Evaluation of the enuretic children includes history taking, physical examination and laboratory investigations. A checklist is provided for quick evaluation in busy clinics. Urinalysis, urine specific gravity and office ultrasonography are essential tests. An algorithm of treatment of monosymptomatic enuresis is constructed. The two main options of treatment are behavioral modification with alarm system and pharmacotherapy with desmopressin or imipramine. Imipramine is recommended as one of the treatment options because of its relative safety in Taiwan. However the potential toxicity and mortality of imipramine is highlighted and warned. The responses to treatment are evaluated after a period of treatment for 1 to 3 months. Further evaluation and individualized treatment is suggested for poor responders.

Mannitol facilitates rabbit urinary bladder recovery from overdistension injury.

OBJECTIVES: To investigate the existence and functional significance of the enhanced lipid peroxidation in bladder overdistension injury and to explore the effect of mannitol, a free radical scavenger. METHODS: Overdistension of rabbit bladders was induced and maintained for 3 hours by infusing normal saline into the bladder while keeping the intravesical pressure at 30 cm H(2)O. The bladders were then emptied and decompressed. Intravenous 20% mannitol was initiated 5 minutes before decompressing the overdistension. Detrusor tissue was obtained from the following groups: control, at the end of the overdistension period, and 30 minutes, 2 hours, and 7 days after decompressing the bladder. The tissue level of adenosine triphosphate (ATP) and phosphocreatine (PCr) and the lipid peroxidation product malondialdehyde (MDA) was assayed. Detrusor contractility was assessed by the response of the detrusor strips to KCl and bethanechol. RESULTS: Decompressing the overdistended bladder led to a period of enhanced lipid peroxidation with an increase of MDA content from 225 to 384 pmol/mg protein 30 minutes after the decompression. Two hours later, the MDA content had recovered to the normal level. Mannitol abolished this period of enhanced lipid peroxidation. Overdistension impaired detrusor contractility and reduced the content of PCr (from 24.1 to 10.8 nmol/mg protein) and ATP (from 9.6 to 4.6 nmol/mg protein). Both detrusor contractility and the content of PCr and ATP further decreased 30 minutes after the decompression (PCr 5.4 nmol/mg, ATP 2.8 nmol/mg). They had recovered, but not fully, 7 days later. Mannitol prevented the further decrease in detrusor contractility and in the content of PCr and ATP during the initial decompression period (30 minutes after the decompression). In addition, the mannitol-treated group had quicker recovery in PCr and ATP levels, which returned to normal 7 days later. CONCLUSIONS: Decompressing an overdistended bladder leads to enhanced lipid peroxidation, which is associated with an additionally decreased energetic metabolism and a more impaired contractile function. Mannitol effectively prevents enhanced lipid peroxidation and facilitates functional recovery. These results show that reactive oxygen species play a significant role in bladder overdistension injury.

Effects of aging on mitochondrial enzyme activity of rat urinary bladder.

OBJECTIVES: Our previous study showed that aged rat bladders became fatigued faster than young bladders following repeated contraction induced by electrostimulation. One factor might be a lower energy-producing capability secondary to a decreased mitochondrial enzyme activity of the aged bladder. This study examined this possibility. MATERIALS AND METHODS: Mitochondria from 3- (n = 11) and 24-month-old (n = 10) Sprague-Dawley rats were isolated. Activities of the following enzymes were assayed: two key enzymes in the citric acid cycle, citrate synthase and malate dehydrogenase, and three enzymes in the respiratory chain reaction, NADH-cytochrome c reductase, succinate-cytochrome c reductase and cytochrome c oxidase. The concentration of phosphocreatine and ATP in the aged rat bladders and a separate group of young bladders (n = 12) was determined using high-performance liquid chromatography. RESULTS: (1) The aged bladders have a significantly lower level of phosphocreatine and ATP content than those of young bladders. (2) The activities of all five enzymes assayed were significantly lower in the aged bladders than in young bladders, especially for citrate synthase, which had only 46.8% of the activity of young bladders. CONCLUSIONS: Aging reduces the mitochondrial enzyme activity of the rat bladder resulting in a lower energy-production capability, which might explain some of the voiding dysfunctions found in the elderly.

Mitochondrial DNA deletion of the human detrusor after partial bladder outlet obstruction-correlation with urodynamic analysis.

OBJECTIVES: To investigate mitochondrial DNA (mtDNA) mutations in human detrusor after partial bladder outlet obstruction (BOO) and correlate the findings with the results of urodynamic studies. METHODS: Sixty-two male patients with and without BOO were recruited and assessed by the International Prostate Symptom Score, a quality-of-life assessment index, and sonography. The severity of partial BOO was determined by pressure-flow study with an International Continence Society (ICS) nomogram. Random detrusor biopsies obtained cystoscopically were analyzed by polymerase chain reaction (PCR) techniques to detect possible mtDNA deletions. Primer-shift PCR and DNA sequencing were then performed to characterize specific mtDNA deletions. A semiquantitative PCR method was used to determine the proportion of the deleted mtDNA in detrusor. Finally, the mtDNA deletion and the urodynamic results were compared statistically. RESULTS: A 4977-bp mtDNA deletion was identified in the human detrusor. Its incidence and proportion were found to increase after partial BOO (P = 0.005 and 0.012, respectively). The incidence of the mtDNA deletion was 4.2% (1 of 24) in the unobstructed group, 27.8% (5 of 18) in the equivocal group, and 40% (8 of 20) in the obstructed group. The mean proportion of the 4977-bp deleted mtDNA was 23.7 and 12.7 times higher in the obstructed and equivocal groups, respectively, compared with that of the unobstructed group. CONCLUSIONS: We found mtDNA with the 4977-bp deletion in human detrusor and an increase of this deletion after partial BOO. This molecular change might account for the previous observations of mitochondrial functional impairment and voiding dysfunction after partial BOO.

Single agent paclitaxel as a first-line therapy in advanced urothelial carcinoma: its efficacy and safety in patients even with pretreatment renal insufficiency.

BACKGROUND: Cisplatin-based chemotherapy is the mainstay of the treatment for advanced urothelial cancer, but patients with renal insufficiency before therapy are usually contraindicated to receiving platinum-based chemotherapy. Paclitaxel is one of the most promising agents against advanced urothelial carcinoma in recent trials and it can be easily tolerated even in patients with compromised renal function. We conducted a study in order to evaluate the efficacy and safety of paclitaxel as a first-line therapy in advanced urothelial carcinoma patients. METHODS: Thirteen advanced chemo-naive urothelial carcinoma patients with a median age of 71 years were studied, seven of them demonstrating renal insufficiency (pretreatment serum creatinine > or = 1.5 mg/dl). All 13 patients received a minimum of two cycles of paclitaxel 175 mg/m2, delivered by intravenous infusion for 3 h every 3 weeks. RESULTS: Four of the 13 patients responded to treatment, a response rate of 30.8%, with two of these achieving complete remission and two showing partial responses. The median overall survival period of all 13 patients was nine months (95% Cl: 6.51-11.49) and our study revealed a statistical tendency in the difference of median overall survival time between responders and non-responders (13 months versus 7.5 months, log-rank p = 0.038), although the number of cases was limited. The differences in response rate and median overall survival time, comparing patients with renal insufficiency and those with normal renal function, were not significant. Treatment-related toxicity was mild, with only two (15.4%) patients suffering from grade 3-4 leukopenia. No treatment-related mortality was noted. CONCLUSIONS: Single-agent paclitaxel can be used as a first-line therapy in advanced urothelial carcinoma patients, and is especially suitable for those with pretreatment renal insufficiency, since the antitumor activity is significant while toxicity is well tolerated.

Morphological and morphometric analysis of human detrusor mitochondria with urodynamic correlation after partial bladder outlet obstruction.

PURPOSE: We correlated ultrastructural changes in mitochondria in the human detrusor with the severity of partial bladder outlet obstruction on urodynamics. MATERIALS AND METHODS: We recruited into the study 52 men with and without bladder outlet obstruction symptoms. The severity of partial bladder outlet obstruction was determined by pressure flow study. Random detrusor biopsy specimens obtained by cystoscopy were fixed immediately and processed for transmission electron microscopic observation. Random areas were photographed for further morphological and morphometric analysis using mitochondrial damage score and stereological principles. RESULTS: Mitochondrial damage score and mean mitochondrial volume strongly correlated with the urodynamic severity of partial bladder outlet obstruction, while mitochondrial volume density, surface density of the mitochondrial outer membrane and number of mitochondria per unit of cytoplasm area did not significantly correlate with severity. CONCLUSIONS: Detrusor mitochondrial swelling and structural destruction increased with the severity of partial bladder outlet obstruction. These changes may be associated with impaired mitochondrial function and oxidative metabolism after partial bladder outlet obstruction. Detrusor mitochondrial damage may explain voiding dysfunction after partial bladder outlet obstruction develops.

Observations after orchiectomy in clinical stage I nonseminomatous germ cell tumors of the testis.

BACKGROUND: The optimal management of clinical stage I nonseminomatous germ cell tumor (NSGCT) of the testis remains controversial. For years, retroperitoneal lymph node dissection in combination with orchiectomy, has been the standard treatment in patients with clinical stage I NSGCT. Recently, with advancement of effective cisplatin-based chemotherapy and clinical staging procedures, a new approach of observation after orchiectomy is being evaluated. We reviewed cases of orchiectomy and observation for clinical stage I NSGCT of the testis in order to evaluate the treatment outcome. METHODS: We retrospectively reviewed the records of 13 patients with clinical stage I NSGCT of the testis treated at our hospital from February, 1981 to August, 1996. The patient age at diagnosis ranged from 0.6 to 44 years. Nine patients had yolk sac tumors, and four had mixed germ cell tumors. Median follow-up was 42 months (range, 20-132 months). RESULTS: Prior to orchiectomy, serum beta-human chorionic gonadotropin and alpha-fetoprotein (AFP) were raised to abnormal concentrations in four and in 13 patients, respectively. With a median follow-up of 42 months, three of 13 patients relapsed at a median of three months after orchiectomy. Two patients showed elevated AFP and radiographically identifiable tumors simultaneously, and one patient showed elevated AFP as the only evidence of relapse. Following treatment with cisplatin-based chemotherapy, the three patients who relapsed responded successfully and the elevated AFP returned to normal. The patients are currently alive and disease free. CONCLUSIONS: Observation after orchiectomy is a reasonable approach for patients with clinical stage I NSGCT of the testis.

Effects of outlet obstruction and its reversal on mitochondrial enzyme activity in rabbit urinary bladders.

PURPOSE: This study investigated the effects of outlet obstruction and its reversal on mitochondrial enzyme activity in the rabbit urinary bladder. MATERIALS AND METHODS: We induced mild bladder outlet obstruction in male New Zealand White rabbits. Following two weeks of obstruction, one group of animals (n = 6) was sacrificed, while outlet obstruction was relieved in three additional groups of animals, which were sacrificed one (n = 5), two (n = 5) and four (n = 5) weeks after relieving the obstruction. Seven sham operated rabbits served as controls. We extracted mitochondria from fresh detrusor and assayed activities of key mitochondrial enzymes in the citric acid cycle, citrate synthase and malate dehydrogenase, as well as those in the electron transport chain, succinate cytochrome c reductase, NADH-cytochrome c reductase and cytochrome c oxidase. With high performance liquid chromatography (HPLC) we determined the tissue content of phosphocreatine and the adenine nucleotides (ATP, ADP and AMP), which was used for calculating energy charge. Responses of detrusor strips to 500 microM bethanechol and 120 mM KCl provided the assessment of detrusor contractility. RESULTS: Contractile response of the detrusor strips to bethanechol stimulation was significantly reduced by outlet obstruction, nevertheless, it recovered gradually toward the control level after the relief of outlet obstruction. Outlet obstruction reduced the detrusor content of phosphocreatine, ATP and energy charge. After relieving the obstruction, however, these recovered gradually, reaching control levels 4 weeks later. The activities of all assayed enzymes were reduced by two weeks of outlet obstruction. Relieving the obstruction restored enzyme activity gradually but at different rates for different enzymes. Activities of the citric acid cycle enzymes citrate synthase and malate dehydrogenase recovered and were similar to control levels four weeks after relief of the obstruction. Of the enzymes in the electron transport chain, NADH cytochrome reductase activity recovered most quickly by one week after relief of the obstruction. The activity of cytochrome c oxidase improved more slowly, but 4 weeks after relieving the obstruction it, also, was restored and was similar to the control level. Succinate cytochrome reductase activity remained lower than the control over the entire four weeks of recovery. CONCLUSIONS: The close association between mitochondrial enzyme activity, energy metabolism and contractility of the detrusor indicates the important role of mitochondrial enzyme damage in decreasing energy production and impairing contractile function of the urinary bladders following outlet obstruction. Our findings also show that various mitochondrial enzymes exhibit different susceptibilities and reversibilities to pathological stress.

Sexual dysfunction in men with lower urinary tract symptoms.

The conventional view that sexual function is not adversely affected by lower urinary tract symptoms (LUTS), assumed to be caused by enlargement secondary to benign prostatic hyperplasia (BPH), was investigated in this study of 423 men aged 40 years and over in a community population in the UK and 1271 urology clinic attenders aged 45 years and over in 12 countries, using the ICSmale and ICSsex questionnaires. Sexual dysfunction was found to be common: in the community, age standardized prevalences of reduced rigidity of erections were 53%, reduced ejaculation 47%, and pain on ejaculation 5%; in clinic men, age standardized prevalences of reduced rigidity of erections were 60%, reduced ejaculation 62%, and pain on ejaculation 17%. Sex lives were reported to be spoiled by LUTS in 8% of community men and 46% in the clinic. There were negative trends for age in the extent to which clinic men were bothered by these symptoms, although older men were still very concerned. Significantly raised odds ratios of sexual dysfunction were found in those with LUTS, especially storage symptoms associated with incontinence. Urinary flow rates were not associated with sexual symptoms. Sexual dysfunction is, therefore, strongly associated with LUTS, is a matter of concern to the men affected, and should be taken into account when managing patients with LUTS.

Formalin treatment of refractory hemorrhagic cystitis in systemic lupus erythematosus.

Hemorrhagic cystitis is a potentially life-threatening complication in systemic lupus erythematosus (SLE). No safe, effective and conservative treatment exists for patients who fail to respond to standard therapy. We report a 17-year-old girl with SLE who suffered from severe hemorrhagic cystitis. Initially, she received frequent red blood cell and platelet transfusions, continuous bladder irrigation, and blood clots were evacuated. Numerous kinds of treatment were tried, including electrocoagulation of bleeding foci, prostaglandin E1 bladder instillation, and hyperbaric oxygen. However, she remained severely anemic and thrombocytopenic necessitating daily transfusions of blood products. After intravesical formalin instillation was performed twice, the hematuria ceased completely.

Complicated urinary tract infection: analysis of 179 patients.

BACKGROUND: The aim of our study was to investigate the incidence, bacteriology, management and outcome of complicated urinary tract infections (UTIs) at the Veterans General Hospital-Taipei. METHODS: Between June, 1993, and July, 1994, medical records of 2,566 patients admitted to the Division of Urology, Veterans General Hospital-Taipei, were retrospectively reviewed. Of these patient, 1,322 had a diagnosis of benign prostatic hyperplasia (BPH), 607 were admitted for renal stones, 496 for ureteral stones, 75 for transitional cell carcinoma (TCC) of the urinary bladder, 47 for renal tumors and 19 for TCC of the ureter. Among all patients studied, 179 (6.98%) acquired a complicated UTI. Of these, 81 were admitted for BPH, 46 for renal stones, 42 for ureteral stones, five for TCC of the urinary bladder, three for renal tumors and two for TCC of the ureter. RESULTS: Of the 179 patients with complicated UTIs, 155 were men and 24 were women. The urine culture positive rate was 76.0% (136/179) and the most common bacteria were Escherichia coli, Proteus mirabilis and Pseudomonas aeruginosa. The principle mode of treatment included parenteral antibiotics and urinary diversion (percutaneous nephrostomy and Foley catheterization), when necessary. The infection control rate for these complicated UTIs was 96.3% for BPH, 95.5% for renal stone, 97.6% for ureteral stone, 80% for TCC of the urinary bladder, 100% for renal tumor and 100% for TCC of the ureter. Mortality due to complicated UTI was 3.9% (7/179). CONCLUSIONS: We concluded that the prognosis of complicated UTI is good if diagnosis and appropriate treatment are given promptly. Early drainage to relieve obstruction and intravenous antibiotics are initially necessary. Surgical intervention is required to resolve functional or structural abnormalities after the UTI has been controlled.

Paraneoplastic elevation of serum alkaline phosphatase in renal cell carcinoma: incidence and implication on prognosis.

PURPOSE: We investigated the incidence and prognostic significance of paraneoplastic elevation of serum alkaline phosphatase in patients with renal cell carcinoma. MATERIALS AND METHODS: Clinical data of 365 pathologically proved renal cell carcinoma cases were reviewed. Serum alkaline phosphatase level greater than 100 units per 1., but without obvious conditions that may cause phosphatase elevation, including metastasis to or disease of liver or bone and pregnancy, was regarded as paraneoplastic serum alkaline phosphatase elevation. Survival was evaluated using the Kaplan-Meier method. RESULTS: Of 365 patients 77 (21.1%) had paraneoplastic serum alkaline phosphatase elevation. The respective incidence from stage I to IV cases was 9.9% (16 of 161), 31.9% (15 of 47), 34.3% (23 of 67) and 25.6% (23 of 90). Patients with stage I disease had the lowest incidence but there were no statistically significant differences among stages II, III and IV disease. Of 77 patients with elevated serum alkaline phosphatase 48 had additional paraneoplastic manifestations. The disease specific 5-year survival rate in patients with normal serum alkaline phosphatase was significantly better than in patients with isolated phosphatase elevation, which in turn was better than in patients with multiple paraneoplastic syndromes (70.7 versus 50.5 versus 30.8%). Patients with persistent or recurrent elevation of serum alkaline phosphatase after radical nephrectomy had metastatic lesion or local recurrence. In some patients serum alkaline phosphatase returned to normal after nephrectomy but metastasis developed later without recurrent phosphatase elevation. CONCLUSIONS: Paraneoplastic serum alkaline phosphatase elevation in renal cell carcinoma patients implies an unfavorable prognosis, and additional paraneoplastic syndromes further worsen the prognosis. Recurrent or persistent serum alkaline phosphatase elevation after radical nephrectomy suggests distant metastasis or residual tumor. However, the return of serum alkaline phosphatase to normal does not guarantee cure of the disease. Identification of paraneoplastic serum alkaline phosphatase elevation is valuable in the prediction of outcome and postoperative followup of renal cell carcinoma patients.

Clinical outcome at 3 months after transurethral vaporization of prostate for benign prostatic hyperplasia.

OBJECTIVES: To evaluate the clinical outcome of transurethral vaporization of the prostate (TUVP) for the management of benign prostatic hyperplasia (BPH). METHODS: Between March and June 1995, 30 patients with symptomatic BPH treated by TUVP were enrolled in this study. Transrectal ultrasonography (TRUS) was done preoperatively. American Urological Association (AUA) symptom score determination, pressure flow study, and questionnaire (for evaluating potency) were done preoperatively and 3 months postoperatively. RESULTS: The average age was 70.5 years (range 60 to 83) and estimated prostate size by TRUS before surgery was 33.8 +/- 14.0 g. The average AUA symptom score decreased significantly 3 months after TUVP (6.2 +/- 7.8 versus 18.2 +/- 9.0; P < 0.01). The maximum urine flow rate (Qmax) was 11.1 +/- 3.7 mL/min before TUVP (mean +/- SD) and 17.0 +/- 6.5 mL/min 3 months after TUVP, whereas the detrusor pressure at maximum urine flow (Pdes at Qmax) was 61.0 +/- 23.9 and 41.2 +/- 15.2 cm H2O, respectively. Qmax increased and Pdes at Qmax decreased significantly 3 months after TUVP. Of the 30 patients, 3 (10%) developed bladder neck contracture. Of the 24 patients who were potent sexually before operation, 3 (12.5%) developed impotence 3 months after surgery. CONCLUSIONS: TUVP is an effective alternative surgical procedure to relieve obstruction for patients with symptomatic BPH. However, cautious attitude on its usage is advocated based on our preliminary results indicating the occurrence of late complication such as impotence and bladder neck contracture.

Impact of aging on rat urinary bladder fatigue.

PURPOSE: Little is known about the fatigability of the urinary bladder. In these experiments, we characterized contractile and bioenergetic changes in bladder fatigue and investigated the impact of aging on these changes. MATERIALS AND METHODS: Whole urinary bladders from 3-month-old (n = 17) and 24-month-old (n = 12) SD rats were isolated and individually mounted in organ baths. The bladders were electrostimulated repeatedly (50 volts, 32 Hz, 1 MS; every 2.5 minutes). The pressure generation, rate of pressure generation and the emptying ability (% volume emptied) of the isolated bladders were measured with each stimulation. After the 20th electrostimulation, the bladders were immediately stimulated with 500 microM bethanechol. Upon completion of their series of stimulations, some of the bladders were quickly frozen in liquid nitrogen. Tissue phosphocreatine and ATP content of the frozen bladders and a group (six 3-month-old and six 24-month-old rats) of fresh bladder tissues was determined using high performance liquid chromatography (HPLC). RESULTS: The results can be summarized as follows: (1) Pressure generation, rate of pressure generation and emptying ability were gradually reduced in both young and aged bladders as repeated stimulation proceeded. (2) The final bethanechol stimulation emptied the same intravesical volume as the 20th electrostimulation emptied (in both groups), indicating that bladder fatigue is due to a post-synaptic mechanism. (3) As compared to their own first responses, aged rats exhibited significantly greater rates of reduction in both pressure generation and emptying ability than did young rats. (4) Analysing fresh bladder tissues, the phosphocreatine and ATP concentration of the aged bladders were significantly less than those of the young bladders-13.2 +/- 2.0 and 1.2 +/- 0.3 nmol/mg. protein respectively in the aged bladders vs. 21.2 +/- 1.8 and 7.5 +/- 1.0 nmol/mg. protein respectively in the young bladders. After repeated stimulation, phosphocreatine and ATP concentration were reduced in both groups (1.4 +/- 0.3 and 0.43 +/- 0.1 nmol./mg. protein in the aged bladders, 7.5 +/- 1.4 and 4.1 +/- 0.5 nmol./mg. protein in the young bladders), with a greater degree of reduction in the aged bladders. CONCLUSION: These observations indicate that, in response to repeated electrostimulation, aged rat bladders became fatigued faster than young bladders. Decreased capability in energy production might be one contributing factor for faster fatiguability of the aged urinary bladders.

The significance of serum alkaline phosphatase bone isoenzyme in prostatic carcinoma with bony metastasis.

OBJECTIVE: To evaluate the clinical significance of serum alkaline phosphatase (ALP). ALP bone isoenzyme (ALPb) and prostate specific antigen (PSA) levels in predicting bony metastasis in prostatic carcinoma. PATIENTS AND METHODS: The levels of serum ALP, ALPb and PSA were assessed in 32 patients with prostatic carcinoma and bony metastasis (group 1), 31 with prostatic carcinoma without bony metastasis (group 2), and 31 with benign prostatic hyperplasia (group 3). Bony metastases were detected using whole-body bone scintigraphy and ALPb was estimated electrophoretically before surgical or medical treatment. The levels of the three markers were compared for their ability to predict bony metastasis. RESULTS: In groups 1, 2 and 3, respectively, the mean (SD) serum levels of ALP were 304 (322.2), 76.6 (47.5) and 63.8 (14.7) IU/L, of ALPb were 79.9 (76.9), 23.6 (9.9) and 25.3 (9.0) IU/L and of PSA were 478.1 (352.2), 46.9 (32.1) and 8.1 (1.8) ng/mL. The differences in serum ALP and ALPb between groups 1 and 2, and between groups 1 and 3 were significant (P < 0.05), but not those between groups 2 and 3. The positive predictive value (PPV) for bony metastasis in patients with prostatic carcinoma was 91.3% (21/23) and 100% (18/18) and the negative predictive value (NPV) was 71.8% (28/39) and 68.9% (31/45) for ALP and ALPb, respectively. CONCLUSION: Both serum ALP and ALPb were increased significantly in patients with prostatic carcinoma with bony metastasis. The level of ALPb had a higher PPV and specificity for bony metastasis than had the level of ALP, but a lower NPV and sensitivity than ALP or PSA (at PSA levels > 20 ng/mL).