Sangsoo Park

Safety evaluation of self-expanding metallic biliary stents eluting gemcitabine in a porcine model

Background and Aim:  Palliative biliary decompression by metal stent is the treatment of choice for unresectable malignant biliary obstruction; however, conventional stents provide only mechanical palliation and exert no anti‐tumor effects. Gemcitabine (GEM) has been reported to be more effective in unresectable pancreatic cancer and biliary cancer compared with other chemotherapeutic drugs. We evaluated the safety of a GEM‐eluting stent by analyzing histologic responses of the porcine bile duct.

Lacrimal Canalicular Obstructions: Safety and Effectiveness of Balloon Dilation☆

PURPOSE Balloon dilation of the lacrimal canaliculi has been considered contraindicated because of possible damage to the canaliculi. The purpose of this study was to assess the safety and effectiveness of balloon dilation in treatment of obstruction of the lacrimal canaliculus. MATERIALS AND METHODS Fluoroscopically guided balloon dilation was performed in 26 eyes of 21 consecutive patients with epiphora due to lacrimal canalicular obstruction confirmed at dacryocystography. Nine of 26 eyes had complete obstruction and 17 eyes had incomplete obstruction. RESULTS Technical failure occurred in one eye. Only one acute complication (punctal slitting) and no late complications occurred. At 7 days after balloon dilation, 14 of 17 eyes (82%) with incomplete obstruction and five of nine eyes (56%) with complete obstruction showed complete or partial resolution of epiphora with patency of the lacrimal drainage system. At 6-month follow-up, that improvement was maintained in seven of 17 eyes (41%) with incomplete obstruction and three of nine eyes (33%) with complete obstruction. CONCLUSIONS Although the 6-month recurrence rate is rather high, balloon dilation seems to be safe and valuable as an initial therapy for patients with obstruction of the lacrimal canaliculus.

Penetration Difference of n-Butyl2-Cyanoacrylate into the Nidus in the Embolisation of Brain Arteriovenous Malformation.

Prediction of nidal penetration of the glue is difficult in the embolisation of brain arteriovenous malformations (AVM). We evaluated penetration differences of glue-lipiodol mixtures with and without tungsten powder for embolisation of brain AVM. Fifty eight injections during embolisation of brain AVM in 15 patients were evaluated. Glue contained lipiodol only (N=25), or lipiodol and tungsten powder (N=33). Glue concentration ranged from 20 to 80%. Injection was done at the pedicle (N=41) or nidus (N=17). Degree of penetration was rated as good, fair, or poor according to penetrated glue amount in the nidus. Penetration difference was compared in each injection at the pedicle or nidus. When the glue mixtures were injected at the pedicle, the glue-lipiodol mixture (GLM) penetrated into the nidus in eight of 16 injections (50%) and the glue-lipiodol-tungsten mixtures (GLTM) in 23 of 25 (92%). When glue was injected at the nidus, GLM was confined to the nidus in nine of nine injections (100%) and GLTM in seven of eight (88%). Penetration into the vein was noted in two of 25 injections (8%) in GLM and six of 33 (18%) in GLTM. Penetration difference into the nidus between GLM and GLTM was statistically significant (p < 0.05) when the glue mixtures were injected at the pedicle. GLM and GLTM can be used effectively at the nidus. In contrast to GLM, GLTM can be used effectively at the pedicle. However, the risk of venous penetration seemed to be higher with GLTM than in GLM.

Renal artery embolization using a new liquid embolic material obtained by partial hydrolysis of polyvinyl acetate (Embol): initial experience in six patients.

Objective To evaluate the therapeutic efficacy of a new liquid embolic material, Embol, in embolization of the renal artery. Materials and Methods Embol is a new embolic material obtained by partial hydrolysis of polyvinyl acetate mixed in absolute ethanol and Iopromide 370 and manufactured by Schering Korea, Kyonggido, Korea. Six patients who underwent embolization of the renal artery using Embol were evaluated. Four were male and two were female and their ages ranged from 11 to 70 (mean, 53) years. Clinical and radiologic diagnoses referred for renal artery embolization were renal cell carcinoma (n = 3), renal angiomyolipoma (n = 2) and pseudoaneurysm of the renal artery (n = 1). After selective renal angiography, Embol was injected through various catheters, either with or without a balloon occlusion catheter. Changes in symptoms and blood chemistry which may have been related to renal artery embolization with Embol were analyzed. Results The six patients showed immediate total occlusion of their renal vascular lesions. One of the three in whom renal cell carcinoma was embolized with Embol underwent radical nephrectomy, and the specimen thus obtained revealed 40% tumor necrosis. In the two patients with angiomyolipomas, the tumors decreased in size and abdominal pain subsided. Bleeding from pseudoaneurysm of the renal artery was successfully controlled. Four patients showed symptoms of post-embolization syndrome, and one of these also showed increased levels of blood urea nitrogen and creatinine. One patient experienced transient hypertension. Conclusion Embol is easy to use, its radiopacity is adequate and it is a safe and effective embolic material which provides immediate and total occlusion of renal vascular lesions.

Comparative Study of a CsI and a ZnSe(Te/O) Scintillation Detector’s Properties for a Gamma-ray Measurement

A ZnSe crystal based on a II -VI compound semiconductor has various physical properties: electroluminescent, photoelectric, luminescent and scintillation. Activated ZnSe crystals are highly-efficient scintillators, and they are already being applied to the detecting units of a X-ray introscopy and a dosimetric system. ZnSe-based scintillators have a high absolute light output, and their radiation spectra matches well with the Si-photodiode spectral sensitivity. The present study was performed by using a polished ZnSe and CsI(Tl). ZnSe is a low-density crystal(5.42 g/cm3). The emission wavelength of ZnSe(Te) is 610 nm and ZnSe(O) is 592 nm. We have fabricated 10×10×1 mm and 10×10×2 mm ZnSe crystals in which the activators were doped with tellurium and oxygen. ZnSe and CsI crystals were mounted on a S3590-08 HAMAMATSU PIN photodiode and an R3479 HAMAMATSU PMT. Teflon tape as a reflector for the PIN photodiode and PMT. Gamma-ray spectrum measurements were performed by using 241Am, 57Co, 133Ba and 137Cs radio isotopes. We have compared the measured spectra of ZnSe and CsI under the same conditions.

Review of urinary continence care products using sensor technology to improve effectiveness

There have been many treatment and management modalities for urinary incontinence including absorbent products and urine collecting devices, but these modalities are manual in nature, requiring significant time and effort from caregivers. Recently, the application of sensor technology for urine detection in absorbent products and urine collection devices has helped to create new modalities for urinary incontinence and to automate some of the incontinence care processes. In this article, we review the new products and devices for incontinence care which make use of urine detection sensors.

Antitumor effect of the paclitaxel‑eluting membrane in a mouse model

Local treatment of primary bile duct cancer, which grows locally at the primary lesion and seldom metastasizes to distant sites, is challenging. The present study evaluated the antitumor effect, systemic toxicity, biodistribution and survival benefit of the paclitaxel-eluting polyurethane membrane in a tumor model. Membranes containing various amounts of paclitaxel (0, 100, 300, 600 and 1,200 µg/disc) were inserted beneath the tumor mass in mouse models. Tumor size and body weight of the tumor models were monitored for 26 days after insertion of the membrane. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay was performed in the tumor tissues. High-performance liquid chromatography was performed for evaluation of paclitaxel concentration in peripheral tissues. Tumor volumes on day 26 of membrane treatment were decreased in a dose-dependent manner. No significant difference in body weight was observed in the groups. A greater number of apoptotic cells were counted per high power field in tumor tissues following an increase of paclitaxel concentration. In the 1,200 µg-group, concentrations of paclitaxel were significantly higher in tumors compared with those of other tissues and serum. The paclitaxel-eluting membrane demonstrated a significant and dose-dependent antitumor activity, and did not exert systemic toxicity in the tumor model.