Introducing an lsoprenaline Eluting Guidewire: Report on its Design and the Results of the Dose-Determining Pilot Study

Introduction: Retrograde intrarenal surgery (RIRS) is associated with complications, many of which are related to the intrarenal pressure (IRP). We aim to describe the design of a novel isoprenaline-eluting guidewire ("IsoWire") and present the results from the first in vitro release studies and the first animal studies showing its effect on IRP. Materials and Methods: The IsoWire comprises a Nitinol core surrounded by a stainless-steel wire wound into a tight coil. The grooves created by this coil provided a reservoir for adding a hydrogel coating into which isoprenaline, a beta-agonist, was loaded. Animal studies were performed using a porcine model. For the control, IRP, heart rate (HR), and mean arterial pressure (MAP) were measured continuously for 6 minutes with a standard guidewire in place. For the experiment, the standard hydrophilic guidewire was removed, the IsoWire was inserted into the renal pelvis, and the same parameters were measured. Results: In vitro analysis of the isoprenaline release profile showed that most (63.9 ± 5.9%) of the loaded drug mass was released in the 1st minute, and almost all of the drug was released in the first 4 minutes exponentially. Porcine studies showed a 25.1% reduction in IRP in the IsoWire that released 10 μg in the 1st minute; however, there was a marked increase in HR. The average percentage reduction in IRP was 8.95% and 21.3% in the IsoWire that released 5 and 7.5 μg of isoprenaline, respectively, with no changes in HR or MAP. Conclusions: The IsoWire, which releases 5 and 7.5 μg of isoprenaline in the 1st minute, appears to be safe and effective in reducing the IRP. Further studies are needed to establish whether the isoprenaline-induced ureteral relaxation will render easier insertion of a ureteral access sheath, reduce IRP during sheathless RIRS, or even promote the practice of sheathless RIRS.

Microfluidic-Assisted Formulation of ε-Polycaprolactone Nanoparticles and Evaluation of Their Properties and In Vitro Cell Uptake

The nanoprecipitation method was used to formulate ε-polycaprolactone (PCL) into fluorescent nanoparticles. Two methods of mixing the phases were evaluated: introducing the organic phase into the aqueous phase dropwise and via a specially designed microfluidic device. As a result of the nanoprecipitation process, fluorescein-loaded nanoparticles (NPs) with a mean diameter of 127 ± 3 nm and polydispersity index (PDI) of 0.180 ± 0.009 were obtained. The profiles of dye release were determined in vitro using dialysis membrane tubing, and the results showed a controlled release of the dye from NPs. In addition, the cytotoxicity of the NPs was assessed using an MTT assay. The PCL NPs were shown to be safe and non-toxic to L929 and MG63 cells. The results of the present study have revealed that PCL NPs represent a promising system for developing new drug delivery systems.

[Stickler's syndrome]

Stickler's syndrome or congenital, progressive arthro-ophthalmopathy refers to disturbances of the connective tissue of the organism but mainly the osteoarticular and visual systems. In the visual system one discovers a congenital high myopia, pathological changes in the vitreous in the form of membranes and proliferative bands as well as retinal detachment. A metabolic defect concerning the hyaluronic acid and the collagen of the 2-d type is assumed to be the cause of this syndrome.

[Errors in the diagnosis of chronic intrahepatic cholestasis]

In nine out of ten patients referred in the years 1982-1987 to the Infectious Diseases Department of the Medical Academy in Bydgoszcz with the diagnosis of chronic (sometimes lasting several years) intrahepatic cholestasis an extrahepatic etiology of cholestasis was recognised. The main causes of the made errors were, it seems, an excessive confidence in the results of laboratory examinations carried out by modern diagnostic methods and a not very careful analysis of the disease. Exploratory laparotomy should be the examination of decisive importance in cholestasis of unclear etiology.

[Our results of laser trabeculoplasty in simple glaucoma]

In 24 patients with simple glaucoma in whom the IOP did not normalize under the conservative treatment the authors checked--between others--the Po, the outflow coefficient (C) and calculated Po/C. Laser trabeculoplasty was performed subsequently. The enumerated indexes were examined the day after surgery, then after the 1-st and 2-nd week, after a month and 2 months. In the majority of cases the coefficient C showed an improvement and normalization of the IOP distinctly seen till the 1-st month after operation. In subsequent observations 5 persons showed a renewed deterioration of the hydrodynamic conditions and the intervention was repeated leading to an improvement in 3 cases. In consideration of the lack of normalization of the IOP in 2 persons it was necessary to subject them to a surgical procedure.

[Disorders of color vision in employees of the Masovian Refining and Petrochemical Industries in Płock]

Attention is drawn to the problem of the influence of the petrol derivates on the frequency of acquired dyschromatopsia. It has been observed--on the basis of performed examinations of the color vision by means of the Farnsworth-Munsell's 100-Hue test--that the general numerical index of the faults is increasing proportionally to the period of employment, i.s. the period of the contact of the workers with the derivates of petrol.