Sensing Escherichia coli O157:H7 via frequency shift through a self-assembled monolayer based QCM immunosensor.

By means of the specific immuno-recognition and ultra-sensitive mass detection, a quartz crystal microbalance (QCM) biosensor for Escherichia coli O157:H7 detection was developed in this work. As a suitable surfactant, 16-mercaptohexadecanoic acid (MHDA) was introduced onto the Au surface of QCM, and then self-assembled with N-hydroxysuccinimide (NHS) raster as a reactive intermediate to provide an active interface for the specific antibody immobilization. The binding of target bacteria with the immobilized antibodies decreased the sensor's resonant frequency, and the frequency shift was correlated to the bacterial concentration. The stepwise assembly of the immunosensor was characterized by means of the electrochemical techniques. Using the immersion-dry-immersion procedure, this QCM biosensor could detect 2.0x10(2) colony forming units (CFU)/ml E. coli O157:H7. In order to reduce the fabrication time, a polyelectrolyte layer-by-layer self-assembly (LBL-SA) method was adopted for fast construction. Finally, the reproducibility of this biosensor was discussed.

[Transurethral holmium laser enucleation of the prostate for the treatment of benign prostatic hyperplasia].

OBJECTIVE: To evaluate the efficacy and safety of transurethral holmium laser enucleation of the prostate (HoLEP) for the treatment of benign prostatic hyperplasia (BPH). METHODS: A retrospective review was conducted of transurethral (HoLEP) performed on 68 patients, aged 65.7 (50 - 91) with benign prostatic hyperplasia. The efficacy and complications were all assessed. RESULTS: The mean procedure time was 87 mins (45 - 158 mins). The mean specimen weight was 61 g (31 - 128 g). The procedure allows a precise, bloodless field with no need for transfusion. No TUR syndrome and other major complications were encountered during the operation. The mean catheter time and hospital stay were 2.8 d (1 - 4 d) and 3.6 d (2 - 5 d), respectively. Follow-up of 7.6 months (1 - 13 months) revealed that the urination symptoms were markedly improved in all patients, and that the IPSS decreased from 25.7 +/- 6.9 to 7.7 +/- 4.3 (P < 0.01) and the maximum urine flow rate increased from 8.1 +/- 4.2 ml/s to 18.8 +/- 4.6 ml/s (P < 0.01). Postoperative complications occurred in 3 patients. 2 with transient incontinence were recovered within 3 months postoperatively. The other one with mild posterior urethral stricture was treated effectively with urethral sounding. CONCLUSIONS: Was associated with high effectiveness, safety, short hospital stay and less complications, HoLEP is a new minimally invasive surgical procedure for BPH.