METHODS: Recombinant PPDK (rPPDK) was expressed, purified and evaluated by Western blot. In parallel, recombinant galactose-and-N-acetyl-D-galactosamine inhibitable lectin (Gal/GalNAc lectin) was produced and tested similarly. The protein identity was confirmed by analysis using MALDI-TOF/TOF. A lateral flow dipstick (LFD) test using rPPDK was subsequently developed (rPPDK-LFD) and evaluated for serodiagnosis of ALA.
RESULTS: rPPDK was expressed as soluble protein after 4 hours of induction with 1 mM isopropyl β-D-1-thiogalactopyranoside (IPTG) at 30°C. Purification using nickel-nitrilotriacetic acid (Ni-NTA) resin yielded 1.5 mg of rPPDK from 1 L of culture with estimated molecular mass of 98 kDa on SDS-PAGE. Western blots using sera from patients with ALA, healthy individuals and other diseases probed with anti-human IgG4-HRP showed the highest sensitivity (93.3%) and specificity (100%); as compared to blots using IgG and IgG1 as secondary antibodies. Moreover, rPPDK showed better specificity when compared to rGal/GalNAc lectin. In the development of the LFD test, the optimum amount of rPPDK was 0.625 μg per dipstick and the optimum working concentration of colloidal gold conjugated anti-human IgG4 was optical density (OD) 5 (1.7 μg of anti-human IgG4). Evaluation of rPPDK-LFD using ALA patients and controls serum samples showed 87% diagnostic sensitivity and 100% specificity.
CONCLUSION: The developed rPPDK-LFD showed good potential for rapid diagnosis of ALA, and merit further multicentre validation using larger number of serum samples.
METHODS: All members of the Penang Private Medical Practitioners' Society were asked to complete a self-administered survey. Nonresponders were contacted after 3 weeks and received a telephone request after 6 weeks.
RESULTS: Of the 786 practitioners contacted, 669 considered themselves to be PCPs, including 279 (42%) who responded to the survey. Adult males with prostatitis-like symptoms typically constitute <1% of the patients seen by PCPs. Most PCPs (72%) believe that prostatitis-like symptoms are caused by bacterial infection. 61% of PCPs base their diagnosis of prostatitis-like symptoms on clinical history, a physical examination and dipstick urinalysis. Standard management was to prescribe 1 or 2 courses of antimicrobials.
CONCLUSIONS: Despite the 8.7% prevalence found in a previous survey in this population, prostatitis remains underdiagnosed in Malaysia. In contrast to many other clinical settings, urologists in Malaysia see a large proportion of newly diagnosed and treatment-naive prostatitis patients, providing an opportunity for clinical diagnostic and treatment studies.