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Biomedical subjects

P F Keane

Publications and source records attributed to P F Keane.

At least 19 recordsLinked to original sources
PubMed2004

Efficacy and safety peri-prostatic local anaesthetic injection in trans-rectal biopsy of the prostrate: a prospective randomised study.

OBJECTIVE: To assess the efficacy and safety of periprostatic lignocaine injection in trans-rectal ultrasound (TRUS) -guided biopsy of the prostate gland. METHODS: Ninety-six men (mean age 65 years, range 47-74) undergoing TRUS biopsy were randomised into the local anaesthetic (LA) or placebo group. Six to twelve biopsy cores were taken, the majority being 10 cores. Patients were asked to fill in the expected pain score on a visual analogue scale (VAS) prior to the procedure. They also completed the actual pain experienced on VAS after the biopsy. The incidence of complications was documented. RESULTS: The age, mean prostate specific antigen (PSA) were comparable in both groups. The expected pain score was also comparable (5.2 +/- 1.6 in LA, 5.0 +/- 1.4 in Placebo). In the LA group, the mean actual pain score was 3.0 +/- 1.8 and in the placebo group it was 6.5 +/- 2.2 (P = 0.0001). When patients were asked whether they would undergo the procedure again in the same way, 100% of the LA group and only 64% of the placebo group responded 'yes' (P = 0.002 using Fisher's test). The complication rates were not significantly different between the two groups. CONCLUSION: Peri-prostatic injection of local anaesthetic is safe and reduces discomfort significantly, and should be routinely offered to patients.

Aged↗
PubMed2004

Evidence of prostate cancer screening in a UK region.

OBJECTIVE: To examine the pattern of use of prostate-specific antigen (PSA) testing in a UK region, where National Health Service policy does not recommend screening for prostate cancer. SUBJECTS AND METHODS: Data were collected on all PSA tests in Northern Ireland between 1990 and 1999. Annual rates of PSA testing were calculated by age, GP Practice and year. RESULTS: In all, 165 862 PSA tests were performed on 84 669 men, and over a third of men aged > or = 50 years had at least one PSA test. Men aged < 50 years accounted for 12.9% of first tests. The proportion of tests from primary care increased from 47.2% in 1993 to 67.0% in 1999. The mean age of men tested once decreased from 65.6 to 61.9 years (P trend < 0.001) and the proportion with an elevated PSA level also declined during the period. Repeat testing increased with PSA level (P < 0.001) but 29.4% of men with a PSA level of < or = 4 ng/mL also had repeat testing. Raised PSA values were more common from hospital than primary care (32.4% vs 20.6%, P < 0.001) and in older men. Test rates varied 100-fold across general practices, a finding not explained by sociodemographic factors, but one which reflects differential adherence to national guidelines, suggesting that general practitioners are key targets for attempting to rationalise the use of the PSA test. CONCLUSION: These findings suggest that PSA screening is taking place against evidence-based advice and has resulted in over 20 000 men being designated as having a raised PSA level, creating a need for further assessment.

Adult↗
PubMed2003

T- and L-type Ca2+ currents in freshly dispersed smooth muscle cells from the human proximal urethra.

The purpose of the present study was to characterise Ca2+ currents in smooth muscle cells isolated from biopsy samples taken from the proximal urethra of patients undergoing surgery for bladder or prostate cancer. Cells were studied at 37 degrees C using the amphotericin B perforated-patch configuration of the patch-clamp technique. Currents were recorded using Cs+-rich pipette solutions to block K+ currents. Two components of current, with electrophysiological and pharmacological properties typical of T- and L-type Ca2+ currents, were present in these cells. When steady-state inactivation curves for the L current were fitted with a Boltzmann equation, this yielded a V1/2 of -45+/-5 mV. In contrast, the T current inactivated with a V1/2 of -80+/-3 mV. The L currents were reduced in a concentration-dependent manner by nifedipine (ED50=159+/-54 nM) and Ni2+ (ED50=65+/-16 microM) but were enhanced when external Ca2+ was substituted with Ba2+. The T current was little affected by TTX, reduction in external Na+, application of nifedipine at concentrations below 300 nM or substitution of external Ca2+ with Ba2+, but was reduced by Ni2+ with an ED50 of 6+/-1 microM. When cells were stepped from -100 to -30 mV in Ca2+-free conditions, small inward currents could be detected. These were enhanced 40-fold in divalent-cation-free solution and blocked in a concentration-dependent manner by Mg2+ with an ED50 of 32+/-16 microM. These data support the idea that human urethral myocytes possess currents with electrophysiological and pharmacological properties typical of T- and L-type Ca2+ currents.

Adult↗
PubMed2001

Non-invasive antidromic neurostimulation: a simple effective method for improving bladder storage.

Patients with intractably diminished bladder storage function are encountered frequently by neurourologists, occasionally requiring reconstructive surgery for appropriate resolution. Although sacral neuromodulation is a recognized effective therapeutic modality, present techniques are technically demanding, invasive, and expensive. This study investigated the effect of non-invasive third sacral nerve (S3) stimulation on bladder activity during filling cystometry. One hundred forty-six patients underwent standard urodynamic filling cystometry that was then immediately repeated. Patients in the study group (n = 74) received antidromic transcutaneous sacral neurostimulation during the second fill and the control group (n = 72) underwent a second fill without neurostimulation. A statistically significant increase in bladder storage capacity without a corresponding rise in detrusor pressure was observed in the neurostimulated patients. This improvement in functional capacity is an encouraging finding that further supports the use of this non-invasive treatment modality in clinical practice.

Adolescent↗
PubMed2001

The BTA stat test: a tumor marker for the detection of upper tract transitional cell carcinoma.

OBJECTIVES: To conduct a prospective evaluation to determine the utility of the BTA stat test in the detection of upper tract transitional cell carcinoma (UTTCC). Monitoring for UTTCC currently relies on invasive procedures such as upper tract imaging, ureteral washing cytology (UWC) and/or ureteroscopy, or voided urine cytology (VUC). The BTA stat test is a sensitive qualitative immunoassay that detects human complement factor H-related protein in voided urine. METHODS: A total of 81 patients participated, 27 with histopathologically confirmed UTTCC, 26 with upper tract calculi, and 28 with microscopic hematuria but no evidence of urologic disease. Voided specimens collected before surgery or treatment were tested with the BTA stat test and VUC. UWC was performed in specimens collected by a ureteral catheter. RESULTS: The BTA stat test was significantly more sensitive and specific than VUC or UWC. The overall sensitivity for each was 82%, 11%, and 48%; the specificity was 89%, 54%, and 33%. The positive predictive value for the BTA stat test was 79% and the negative predictive value was 91%, both the highest of the three tests. CONCLUSIONS: The BTA stat test was superior to VUC and UWC in the detection of UTTCC. These results may support the adoption of a less aggressive follow-up policy when monitoring for UTTCC when the BTA stat result is negative. If cystoscopy is negative and the BTA stat test is positive, upper tract investigations should be expedited and, if the bladder is in place, bladder biopsies performed.

Adult↗
PubMed2001

Antisense Bcl-2 oligonucleotide uptake in human transitional cell carcinoma.

OBJECTIVES: Antisense oligonucleotides (AO) downregulate Bcl-2 protein expression in various tumours if good target cell uptake is achieved. In this study, uptake of FITC labelled AO (FITC-AO) directed at Bcl-2 was examined in: (1) the RT4 bladder tumour cell line; (2) normal pig urothelium, and (3) human superficial bladder tumours. METHODS: In the RT4 cell line, uptake of FITC-AO, FITC-scrambled and FITC-sense oligonucleotides were quantified by flow cytometry at 4-hour intervals over 24 h. Uptake of FITC-AO was assessed in normal pig urothelium by flow cytometry after FITC-AO was infused for 1 h. Uptake of FITC AO was assessed in samples from 14 human superficial bladder tumours which were maintained in an ex vivo model. In samples from 6 tumours, uptake at 4 h was assessed using fluorescence microscopy. In samples from 8 separate tumours uptake every 4 h within the first 24-hour incubation period was assessed by flow cytometry. RESULTS: In the RT4 cell line the FITC-AO, FITC-scrambled and FITC-sense oligonucleotide uptake was similar. Disaggregated cells from the normal urothelium of the 3 pigs exhibited 33, 46 and 51% of cells staining positively for FITC-AO as determined by flow cytometry. All 6 tumour samples had detectable intracellular FITC-AO by fluorescence microscopy at 4 h. In the 8 tumours examined over the 24-hour incubation period, there was a range of percentages of positively staining cells. However, most tumours had a monotonic increase in intracellular fluorescence intensity that plateaued 16 h post-infusion. CONCLUSION: Antisense Bcl-2 oligonucleotides were readily taken up by superficial bladder cancer cells but the heterogeneous uptake in tumour samples needs to be considered when assessing the bioavailability of these drugs.

Animals↗
PubMed2001

The effect of antisense Bcl-2 oligonucleotides on Bcl-2 protein expression and apoptosis in human bladder transitional cell carcinoma.

PURPOSE: Bcl-2 is an important determinant of transitional cell carcinoma of the bladder recurrence and progression as well as a factor in patient response to chemotherapy or radiotherapy. We determined Bcl-2 down-regulation after antisense oligonucleotide therapy and synergism with mitomycin C in transitional cell carcinoma of the bladder. MATERIALS AND METHODS: Bcl-2 protein was quantified using flow cytometry and immunohistochemistry in 4 bladder cancer cell lines, in bladder washings from 6 patients with carcinoma in situ and in 16 patient tumor samples. The synergistic effects of antisense oligonucleotides G3139 and 2009, and mitomycin C were investigated in 4 cell lines, while 2009 down-regulation was examined in 20 tumor explants in an ex vivo model. RESULTS: Bcl-2 protein expression was found in all 4 cell lines and in 5 of the 6 cell populations derived from patients with carcinoma in situ. Of the 16 tumors 7 were classified positive by frozen section immunohistochemistry and quantitative flow cytometry. G3139 and 2009 down-regulated Bcl-2 protein expression in all 4 cell lines and 2009 down-regulated Bcl-2 protein expression in half of the Bcl-2 positive tumor specimens. There was only evidence in 1 cell line, T24/83, that Bcl-2 protein expression down-regulation enhanced mitomycin C induced apoptotic cell death. CONCLUSIONS: Bcl-2 was expressed in a significant proportion of bladder tumors and in carcinoma in situ. Therefore, antisense oligonucleotides represent a viable strategy for Bcl-2 protein down-regulation. However, it may not always translate into an increased level of mitomycin C induced apoptosis in transitional cell carcinoma of the bladder.

Apoptosis↗
PubMed2000

Contractile properties of human renal cell carcinoma recruited arteries and their response to nicotinamide.

BACKGROUND AND PURPOSE: The manipulation of tumour blood supply and thus oxygenation is a potentially important strategy for improving the treatment of solid tumours by radiation. Increased knowledge about the characteristics that distinguish the tumour vasculature from its normal counterparts may enable tumour blood flow to be more selectively modified. Nicotinamide (NA) causes relaxation of preconstricted normal and tumour-supply arteries in rats. It has also been shown to affect microregional blood flow in human tumours. Direct effects of NA on human tumour supply arteries have not previously been reported. This paper describes our evaluation of the effects of NA on two parameters: 'spontaneous', oscillatory contractile activity and agonist (phenylephrine)-induced constriction in the arteries supplying human renal cell carcinomas. MATERIALS AND METHODS: Isolated renal cell carcinoma feeder vessels were perfused in an organ bath with the alpha(1)-adrenoceptor agonist phenylephrine (PE). When the arteries had reached a plateau of constriction, nicotinamide (8.2 mM) was added to the perfusate and changes in perfusion pressure were measured. RESULTS: PE (10 microM) induced a sustained constriction in the majority of the renal cell carcinoma feeder vessels examined, demonstrating that they retain contractile characteristics, at least in response to this alpha(1)-adrenoceptor agonist. In combination with NA (8.2 mM) the constriction was significantly attenuated in half of the preparations. In addition, seven arteries exhibited spontaneous contractile activity which was significantly attenuated by NA in six of them. CONCLUSIONS: NA can significantly attenuate both 'spontaneous' and agonist-induced constrictions in tumour-recruited human arteries, though not all arteries are sensitive.

Adrenergic alpha-Agonists↗
PubMed2000

Induction of apoptosis by mitomycin-C in an ex vivo model of bladder cancer.

OBJECTIVE: To examine mitomycin-C (MMC)-induced apoptosis in an ex vivo model of superficial TCC, and relate it to the in vivo response to chemotherapy. Materials and methods Dose- and time-response curves were constructed to determine the optimal conditions for the induction of apoptosis by MMC in an ex vivo model of superficial bladder cancer. Subsequently, 41 individual tumours were exposed to MMC in the model and the effects assessed by measuring of apoptosis before and after chemotherapy. The relationships between tumour grade and stage and the intrinsic and induced apoptotic counts were determined. In tandem, in a clinical study, the relationship between in vivo response of a marker tumour to MMC and the ex vivo induction of apoptosis was determined. RESULTS: In the ex vivo model, apoptosis was induced at a MMC concentration of 0.5 mg/mL after an incubation time of 8 h. In 41 tumours the intrinsic apoptotic index (AI) was higher with increased grade and stage of tumour (P = 0.048). There was no correlation between the intrinsic AI and the AI after treatment with MMC (induced AI). In 21 tumours (51%) the induced AI did not increase above a predetermined response threshold and these tumours were considered resistant to MMC. Resistance to MMC was related to tumour grade (P = 0.037) with a trend for G3 pT1 tumours to be resistant to the therapy. There was a significant association between ex vivo sensitivity and in vivo marker tumour response (P = 0.02). CONCLUSIONS: Apoptosis is differentially induced in an ex vivo incubation model of superficial TCC by MMC and evidence suggests that this response matches that seen in vivo. The measurement of apoptosis before therapy does not predict the apoptotic response of a tumour to chemotherapy. The ability to undergo apoptosis correlates with clinical outcome.

Antibiotics, Antineoplastic↗
PubMed1999

Transcutaneous sacral neurostimulation for irritative voiding dysfunction.

OBJECTIVE: Patients with irritative voiding dysfunction are often unresponsive to standard clinical treatment. We evaluated the response of such individuals to transcutaneous electrical stimulation of the third sacral nerve. METHODS: 32 patients with refractory irritative voiding dysfunction (31 female and 1 male; mean age 47 years) were recruited to the study. Ambulatory transcutaneous electrical neurostimulation was applied bilaterally to the third sacral dermatomes for 1 week. Symptoms of frequency, nocturia, urgency, and bladder pain were scored by each patient throughout and up to 6 months following treatment. RESULTS: The mean daytime frequency was reduced from 11.3 to 7.96 (p = 0.01). Nocturia episodes were reduced from a mean of 2.6 to 1.8 (p = 0.01). Urgency and bladder pain mean symptom scores were reduced from 5.97 to 4.89 and from 1.48 to 0.64, respectively. After stopping therapy, symptoms returned to pretreatment levels within 2 weeks in 40% of the patients and within 6 months in 100%. Three patients who continued with neurostimulation remained satisfied with this treatment modality at 6 months. CONCLUSIONS: Transcutaneous third sacral nerve stimulation may be an effective and noninvasive ambulatory technique for the treatment of patients with refractory irritative voiding dysfunction. Following an initial response, patients may successfully apply this treatment themselves to ensure long-term relief.

Female↗
PubMed1998

Characterization and assessment of a novel poly(ethylene oxide)/polyurethane composite hydrogel (Aquavene) as a ureteral stent biomaterial.

The effective long-term use of indwelling ureteral stents is often hindered by the formation of encrusting deposits which may cause obstruction and blockage of the stent. Development of improved ureteral stent biomaterials capable of preventing or reducing encrustation is therefore particularly desirable. In this study, the suitability as a ureteral stent biomaterial of Aquavene, a novel poly(ethylene oxide)/polyurethane composite hydrogel was compared with that of silicone and polyurethane, two materials widely employed in ureteral stent manufacture. Examination of Aquavene in dry and hydrated states by confocal laser scanning microscopy, scanning electron microscopy, and atomic force microscopy showed the presence of numerous channels within a cellular matrix structure. The channel size increased considerably to as much as 10 microm in diameter in the hydrated state. Aquavene provided superior resistance to encrustation and intraluminal blockage over a 24-week period in a simulated urine flow model. Unobstructed urine flow continued with Aquavene at 24 weeks, whereas silicone and polyurethane stents became blocked with encrustation at 8 and 10 weeks, respectively. Weight loss within Aquavene on the order of 9% (w/w) over the 24-week flow period indicates that extraction of the noncrosslinked poly(ethylene oxide) hydrogel may be responsible for the prevention of encrustation blockage of this biomaterial. In the dry state, Aquavene was significantly harder than either silicone or polyurethane, as shown by Young's modulus, and rapidly became soft on hydration. These additional properties of Aquavene would facilitate ease of stent insertion in the dry state past obstructions in the ureter and provide improved patient comfort on subsequent biomaterial hydration in situ. Aquavene is a promising candidate for use in the urinary tract, as it is probable that effective long-term urine drainage would be maintained in vivo. Further evaluation of this novel biomaterial is therefore warranted.

Biocompatible Materials↗
PubMed1998

Clinical response to an oral prostaglandin analogue in patients with interstitial cystitis.

OBJECTIVE: To assess the efficacy of the oral prostaglandin analogue misoprostol in controlling the symptoms of interstitial cystitis in patients with refractory disease. METHODS: Twenty-five patients were commenced on misoprostol 600 micrograms daily for 3 months. Patients who responded to therapy were offered treatment for a further 6 months. Assessment of the response was by a voiding log and an interstitial cystitis symptom score. RESULTS: At 3 months, 14 patients (56%) had significantly improved, and after a further 6 months, 12 patients (48%) had a sustained response. The incidence of adverse drug effects was 64%. Most side effects were minimal, and the response rate in patients who were able to tolerate the drug was 87% at 3 months and 75% at 9 months. CONCLUSIONS: The oral prostaglandin analogue misoprostol is effective in treating the symptoms of interstitial cystitis. It is possible that prostaglandins have a cytoprotective action in the urinary bladder.

Administration, Oral↗