Simultaneous pharmacokinetic and pharmacodynamic analysis of 5α-reductase inhibitors and androgens by liquid chromatography tandem mass spectrometry.

Benign prostatic hyperplasia and prostate cancer can be treated with the 5α-reductase inhibitors, finasteride and dutasteride, when pharmacodynamic biomarkers are useful in assessing response. A novel method was developed to measure the substrates and products of 5α-reductases (testosterone, 5α-dihydrotestosterone (DHT), androstenedione) and finasteride and dutasteride simultaneously by liquid chromatography tandem mass spectrometry, using an ABSciex QTRAP(®) 5500, with a Waters Acquity™ UPLC. Analytes were extracted from serum (500 µL) via solid-phase extraction (Oasis(®) HLB), with (13)C3-labelled androgens and d9-finasteride included as internal standards.

Is there seasonal variation in symptom severity, uroflowmetry and frequency-volume chart parameters in men with lower urinary tract symptoms?

Purpose: There is a widely held perception that lower urinary tract symptoms may be exacerbated by cold weather. In this study, we examine the effect of seasonal variation in ambient temperatures on frequency-volume chart derivatives, symptom severity scores and uroflowmetry parameters in men with lower urinary tract symptom.

Methods: Between January 2000 and April 2004, men presenting with lower urinary tract symptom were prospectively recruited and assessed in Edinburgh, UK (55°52'N) with maritime temperate climates (Köppen classification Cfb).

5α-reductase type 1 modulates insulin sensitivity in men.

Context: 5α-Reductase (5αR) types 1 and 2 catalyze the A-ring reduction of steroids, including androgens and glucocorticoids. 5α-R inhibitors lower dihydrotestosterone in benign prostatic hyperplasia; finasteride inhibits 5αR2, and dutasteride inhibits both 5αR2 and 5αR1. In rodents, loss of 5αR1 promotes fatty liver.

Measurement of tamsulosin in human serum by liquid chromatography-tandem mass spectrometry.

A simple, sensitive and robust method to extract tamsulosin from human serum, and quantify by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed and validated and is applicable as a measure of compliance in clinical research. Tamsulosin was extracted from human serum (100μL) via liquid-liquid extraction with methyl tert-butyl ether (2mL) following dilution with 0.1M ammonium hydroxide (100μL), achieving 99.

Volume-induced responses in the isolated bladder: evidence for excitatory and inhibitory elements.

Objective: To quantify changes in autonomous activity in response to alterations in intravesical volume, to explore the possible underlying regulatory mechanisms.

Materials And Methods: Experiments were conducted using whole isolated bladders from six female guinea pigs (280-400 g). A cannula was inserted into the urethra to monitor intravesical pressure and the bladder was suspended in a heated chamber containing carboxygenated physiological solution at 33-36 degrees C.

Cholinergic activation of phasic activity in the isolated bladder: possible evidence for M3- and M2-dependent components of a motor/sensory system.

Objectives: To analyse pressure changes induced by muscarinic agonists on the isolated bladder in order to examine whether there are different responses representing different components of a motor/sensory system within the bladder wall.

Materials And Methods: Whole isolated bladders from 19 female guinea-pigs (280-400 g) were used. A cannula was inserted into the urethra to monitor intravesical pressure and the bladder was suspended in a heated chamber containing carboxygenated physiological solution at 33-36 degrees C.

Nocturia, nocturia indices and variables from frequency-volume charts are significantly different in Asian and Caucasian men with lower urinary tract symptoms: a prospective comparison study.

Objective: To describe and compare the patterns of nocturia in Asian and Caucasian men presenting with lower urinary tract symptoms (LUTS), and to identify associations or correlations between LUTS and variables from a frequency-volume chart (FVC), as nocturia is common among men with LUTS, and analysis of FVCs shows nocturnal polyuria and reduced nocturnal bladder capacity (NBC) as the predominant causes in Western patients, but there are few comparisons with other ethnic groups.

Patients And Methods: Consecutive men aged > or = 40 years, presenting with LUTS and nocturia to an Asian and a Caucasian tertiary centre, were recruited prospectively. The men completed the International Prostate Symptom Score and a 3-day FVC.

Antimuscarinic drugs in detrusor overactivity and the overactive bladder syndrome: motor or sensory actions?

Antimuscarinic drugs are generally thought to exert their therapeutic action on detrusor overactivity by reducing the ability of the detrusor muscle to contract. We review currently available published data to establish whether there is any evidence to support this contention. Using a PubMed data search, only 14 original articles (including two abstracts) were found that contained cystometric data for both filling and voiding phases and where the actions of antimuscarinic drugs have been reported in detail.

How do you stretch a bladder? A survey of UK practice, a literature review, and a recommendation of a standard approach.

Aims: To assess how and why hydrodistension of the bladder is performed by UK urologists and to compare this practise with the published literature on distension. To suggest a standardised technique for hydrodistension to allow comparison of diagnostic and therapeutic studies.

Methods: A questionnaire was sent to all UK consultant urologists.

Oral complications after buccal mucosal graft harvest for urethroplasty.

Objective: To report long-term oral complications after buccal mucosal graft (BMG) harvesting for urethroplasty.

Patients And Methods: In a retrospective study of all patients who had BMG harvesting for urethroplasty from April 1996 to September 2002, telephone interviews were conducted using a standard proforma.

Results: Thirty-five patients were identified but only 30 (mean age 48.

Magnetic resonance imaging for urinary incontinence.

Magnetic resonance imaging provides the most accurate, versatile and safe imaging of the pelvic floor. Images can be produced to show sections in any plane and even in three dimensions. The resolution is such that detail as good as that seen in histological sections is possible.