Improvement in organophosphorus hydrolase activity of cell surface-engineered yeast strain using Flo1p anchor system

Organophosphorus hydrolase (OPH) hydrolyzes organophosphorus esters. We constructed the yeast-displayed OPH using Flo1p anchor system. In this system, the N-terminal region of the protein was fused to Flo1p and the fusion protein was displayed on the cell surface. Hydrolytic reactions with paraoxon were carried out during 24 h of incubation of OPH-displaying cells at 30 degrees C. p-Nitrophenol produced in the reaction mixture was detected by HPLC. The strain with highest activity showed 8-fold greater OPH activity compared with cells engineered using glycosylphosphatidylinositol anchor system, and showed 20-fold greater activity than Escherichia coli using the ice nucleation protein anchor system. These results indicate that Flo1p anchor system is suitable for display of OPH in the cell surface-expression systems.

Development of shock wave assisted therapeutic devices and establishment of shock wave therapy

In order to exploit systems for shock wave therapy, we are working for the development of clinical devices that are based on the concept of shock waves or related phenomena. The paper describes these new therapeutic devices designed for the minimally invasive approach to vascular thromboloysis, selective dissection of tissues, and drug or DNA delivery. To investigate the response of cells to shock loading, a precise method of shock waves generation in space and time has been developed. This method has been studied for application in cardiovascular therapy, cancer treatment, and cranioplasty in close vicinity of the brain. A laser ablation shock wave assisted particle acceleration device has been developed for delivering drug and DNA into soft targets in the human body. The penetration depth of microparticles observed in the experimental targets is believed to be sufficient for pharmacological treatments. In order to achieve an efficient method for rapid revascularization of cerebral thrombosis, a laser induced liquid jet (LILJ) system has been developed. The LILJ has been successfully applied for selective dissection of soft tissue preserving nerve and blood vessels. The system has been further improved by using piezoelectric actuators to drive the liquid jets, as an alternative to pulse laser.

Safety and efficacy of gefitinib monotherapy for patients (pts) ≥80 years (yrs) with advanced non-small cell lung cancer (NSCLC): A phase II subset analysis

e19059

Background: Lung cancer is a disease of the elderly with median age at diagnosis of 70 yrs. The very elderly pts (age ≥80 yrs) with advanced NSCLC have not been well studied, even though this proportion is increasing over coming years. There are no data to evaluate the safety and efficacy of gefitinib treatment for pts ≥80 yrs with advanced NSCLC. Methods: We reported the phase II trial of gefitinib monotherapy in chemotherapy-naïve pts of 75 yrs or older with advanced NSCLC (J Thorac Oncol. 2008;3: 1166–1171). We analyzed data for pts ≥80 yrs, comparing with those <80 yrs in our trial. Results: A total of 28 pts were 80 yrs old and over in our trial. Patient characteristics: male/female = 12/16, median age = 82 (range 80–90), ECOG PS 0/1/2=7/13/8, stage IB/IIIA/IV=1/3/24, and adenocarcinoma (Ad)/non-Ad= 22/6. Five pts achieved partial response. The response rate was 18% (CI 95%, 6–39). The disease control rate was 50%. Median survival time was 9 months and 1-year survival rate was 39%. The most frequent adverse events were skin disorders (86%). Nine pts (32%) experienced toxicities ≥grade 3. There were two pts with possible interstitial lung disease including one treatment-related death. Tumor samples from 10 pts were analyzed for EGFR mutation status. EGFR mutations were detected in tumor tissues from 5 pts, of which 3 had partial responses (60%). Table shows the difference between the pts ≥80 yrs and those <80 yrs. Conclusions: Gefitinib monotherapy is effective and relatively well tolerated for pts ≥80 yrs with advanced NSCLC. Gefitinib has potential as a first-line therapeutic option even if elderly pts are more than 80 yrs old.

[Table: see text]

No significant financial relationships to disclose.

Prediction of permeability of FD-4 through porous poly (2-hydroxyethyl methacrylate) membrane by multiple linear regression and artificial neural network

The aim of this study was to predict the permeability through porous poly (2-hydroxyethyl methacrylate) (pHEMA) membranes of fluorescein isothiocyanate-labeled dextran molecular weight 4400 (FD-4) as a model of peptide and protein drug movement. Homogeneous standard membranes were prepared by redox polymerization. Permeability data were predicted by an artificial neural network (ANN) as a function of polymerization factors, and the accuracy was compared with that of conventional multiple linear regression (MLR). Good linearity was observed with each model, with the correlation coefficient of a leave-one-out cross-validation (Rcross) being 0.857 for the MLR model and 0.876 for the ANN model. The mean bias and mean accuracy for the ANN were somewhat smaller than those of the MLR. The ANN method provides an accurate quantitative approximation of the permeability coefficient of FD-4, as judged by conventional MLR, and could be applied to prediction of the non-linear relation between polymerization factors and the permeability of FD-4.

A laser-induced liquid jet catheter system: a novel endovascular device for rapid and reliable fibrinolysis in acute cerebral embolism

OBJECTIVE

Mechanical removal of intravascular clots in addition to administration of tissue plasminogen activator are both desirable for improved outcome in acute embolic stroke. We have developed a novel endovascular catheter system for rapid and reliable mechanical recanalization of cerebral embolisms with little or no requirement for fibrinolytic agents. Here, we describe the evaluation of this device in vitro.

MATERIALS

Pulsed liquid jets were generated and ejected from the catheter exit by accelerating cold physiological saline (4 degrees C, 40 mL/h) using the energy of a pulsed holmium:yttrium-aluminum-garnet (YAG) laser (3 Hz, 1.2 W). Accessibility beyond the tortuous cavernous portion of the internal carotid artery to the M1 and A1 regions was confirmed using a transparent model of the human cerebral artery. Mechanical characteristics of the liquid jets were evaluated with a high-speed camera. Liquid jets of physiological saline or urokinase solution (1,200 IU/mL) were exposed to artificial thrombi made of human blood under temperature monitoring. Remnants of thrombi were collected and incubated at 37 degrees C for 10 min for estimation of fibrinolysis rates.

RESULTS

The jet velocity (maximum: 5 m/s) was controlled by changing the laser energy. The fibrinolysis rates (mean+/-SD) after exposure to jets of saline or urokinase solution for 45 s were 62.2+/-16.4 and 94.0+/-3.4%, respectively, and were significantly better than the rate of 8.1+/-2.0% with administration of urokinase alone. The local temperature rise was less than 8 degrees C.

CONCLUSIONS

The results show that the laser-induced liquid jet catheter system may be a powerful tool for mechanical destruction of emboli and augmentation of the effect of fibrinolytic agents beyond the tortuous part of the internal carotid artery.

Comparative Study of Pharmacokinetic Parameters Between Clarithromycin and Erythromycin Stearate in Relation to Their Physicochemical Properties

Pharmacokinetic parameters for clarithromycin (CAM) and erythromycin stearate (EMS) were obtained from a model including decomposition in the gastrointestinal tract. To confirm the accuracy of the parameters, various physicochemical properties of both drugs were examined. The ratio of the in vivo dissolution rate, the in vivo decomposition rate and the absorption rate between CAM and EMS were well correlated to the ratio of the in vitro intrinsic dissolution rate, the decomposition rate in the acidic solution, and partition coefficient, respectively. One of the reasons for the excellent absorption of CAM compared with that of EMS was the higher stability in the acidic solution and the higher partition coefficient of CAM. These findings indicate that the ratio of the partition coefficient to the decomposition rate constant in acidic solution plays an important role in determining drug bioavailability for macrolide antibiotics.