A comparison of different surfactants on foam stability in foam sclerotherapy in vitro

Objective

This article compares the effect of different surfactants on foam stability and determines the foam decay relationship, so that the suitability of surfactants in a clinical setting can be evaluated.

Effect of poloxamer on the dissolution of felodipine and preparation of controlled release matrix tablets containing felodipine

The effects of poloxamer and HPMC on the dissolution rate of felodipine were investigated and a felodipine controlled release tablet was developed by increasing the water solubility of felodipine and using swelling polymer to control release rate. Milling of felodipine slightly increased the dissolution rate of felodipine when compared with physical mixture. XRD results indicated that felodipine remained in the crystalline form even after co-milling with poloxamer. Improved dissolution rates after co-milling with HPMC and poloxamer were due to both solubilization effect of polymer and milling. The effect of poloxamer on dissolution rate was more significant than that of HPMC. Based on increased solubility of felodipine in the presence of poloxamer, it was concluded that the improved dissolution rate of felodipine was mainly due to a high local concentration of poloxamer around felodipine. Controlled release felodipine tablets were prepared using poloxamer as a solubilizing agent and Carbopol as a controlled release matrix.     

In vivo retention of poloxamer-based in situ hydrogels for vaginal application in mouse and rat models

The purpose of this study is to evaluate the in vivo retention capabilities of poloxamer-based in situ hydrogels for vaginal application with nonoxinol-9 as the model drug. Two in situ hydrogel formulations, which contained 18% poloxamer 407 plus 1% poloxamer 188 (GEL1, relative hydrophobic) or 6% poloxamer 188 (GEL2, relative hydrophilic), were compared with respect to the rheological properties, in vitro hydrogel erosion and drug release. The vaginal retention capabilities of these hydrogel formulations were further determined in two small animal models, including drug quantitation of vaginal rinsing fluid in mice and isotope tracing with ^99mTc in rats. The two formulations exhibited similar phase transition temperatures ranging from 27 to 32 °C. Increasing the content of poloxamer 188 resulted in higher rheological moduli under body temperature, but slightly accelerated hydrogel erosion and drug release. When compared in vivo, GEL1 was eliminated significantly slower in rat vagina than GEL2, while the vaginal retention of these two hydrogel formulations behaved similarly in mice. In conclusion, increases in the hydrophilic content of formulations led to faster hydrogel erosion, drug release and intravaginal elimination. Rats appear to be a better animal model than mice to evaluate the in situ hydrogel for vaginal application.     

Alpha-2-antiplasmin Arg407Lys polymorphism and cryptogenic ischemic cerebrovascular events: Association with neurological deficit

Objective

Genetic background of cryptogenic ischemic stroke (IS) and transient ischemic attack (TIA) remains uncertain. Alpha-2-antiplasmin (α2AP) Arg407Lys polymorphism has been shown to be less common in patients with abdominal aortic aneurysm (AAA) compared with healthy controls. We investigated associations of α2AP Arg407Lys polymorphism with cryptogenic IS and TIA.

Novel Application of Internal-External Drainage Catheter as Biliary Stent for Percutaneous Transhepatic Treatment of Biliary Strictures in Living Donor Liver Transplantation Recipient Patients

ObjectivesAlthough endoscopic management is considered as the first-line treatment for biliary strictures, it may be challenging in living donor liver transplant recipients due to the complex nature of duct-to-duct reconstruction. In this study we present the use of a pigtail drainage catheter as a biliary stent to treat biliary strictures after a living donor liver transplant.MethodsTwenty-seven patients with biliary strictures were treated with our novel technique. In this technique, a pigtail catheter was trimmed into 3 parts (proximal, middle, and distal portions). A suture string was passed through the distal hole of the middle portion, which was then reversed and used as a stent while the proximal portion was used as a pusher. Following balloon dilation of the stenotic segment, the distal, reversed middle, and proximal portions were loaded over the guidewire. After proper placement of the stent, the retractor suture string, pusher, and guidewire were removed. The stent was removed during the third or fourth month of placement through endoscopic retrograde cholangiopancreatography (ERCP) in all patients.ResultsNo significant complications developed during the procedure or follow-up period. Ten patients required re-stenting by ERCP during the same session. The mean follow-up period was 2 years. Cholestase enzymes and bilirubin levels were within normal limits in all patients during follow-up.ConclusionStents derived from drainage catheter facilitate treatment of biliary strictures in patients not eligible for the retrograde approach. This stent is cheap, easy to implement, can be easily removed by ERCP, and re-stenting can be applicable in retrograde if needed.     

Poloxamer 188 failed to prevent exercise-induced membrane breakdown in mdx skeletal muscle fibers

We sought to determine the effectiveness of poloxamer 188 (P188) in protecting dystrophin-deficient, mdx skeletal muscle fiber membrane against exercise-induced breaches. mdx mice were treated with either P188 or placebo via intraperitoneal injections and run on a treadmill for 60–90 min. Membrane breakdown was quantified in cross-sections of rectus femoris muscle pretreated with Evans blue dye (in vivo). The mean % dye-penetrated muscle in the P188 and placebo groups was not significantly different in each of three trials. These results contrast with a recent report of P188 being highly effective in protecting the stretch- and dobutamine-stressed mdx heart muscle. The most likely explanations for the disparity are: (1) the exercise stress we used was beyond the protective range of P188, (2) P188 delivery and serum concentration were sub-optimal, or (3) the mdx skeletal myopathy and cardiomyopathy have fundamentally different responses to treatment.     

Endocrine Disruption of Cadmium in Rats Using the OECD Enhanced TG 407 Test System

Objective To evaluate the endocrine disrupting effects of cadmium(Cd) using OECD enhanced TG407 test guideline. Methods Sprague-Dawley(SD) rats were randomly divided into six groups and accordingly administered with 0, 1, 2.5, 5, 10, 20 mg/kg·BW/day of Cd by gavage for 28 days. Body weight, food consumption, hematology, biochemistry, sex hormone levels, urinary β2-microglobulin, organ weights and histopathology and estrous cycle were detected. Results Cd could significantly decrease animals' body weight(P0.05). Serum luteinizing hormone(LH) at 10-20 mg/kg·BW groups and testosterone(T) at 2.5 and 10 mg/kg·BW groups decreased significantly(P0.05). However, no statistically significant change was found in urinary β2-microglobulin among Cd-treatment groups(P0.05). Endpoints related to female reproduction including uterus weight and histopathological change at 10-20 mg/kg·BW groups showed significant increase(P0.05). While among male rats in 2.5, 10, 20 mg/kg·BW groups, weight of prostate, thyroids, and seminal vesicle glands significantly decreased(P0.05). Moreover, no histopathological change was observed in kidney. Conclusion Results suggested that Cd can cause endocrine disrupting effects in SD rats. Comparing with possible renal toxicity of Cd, its toxicity on endocrine system was more sensitive.