Paclitaxel-coated stents to prevent hyperplastic proliferation of ureteral tissue: from in vitro to in vivo.

Ureteric stents have become an indispensable tool in the armamentarium of every urologist. However, they carry their own morbidity resulting mostly from infectious or abacterial fouling and biofilm formation, and/or urothelial hyperplastic reaction. All of these may interact and lead to clinical complications. Many different stent designs and coatings have been proposed. In this study, we focused on the effect of paclitaxel-coated stents on hyperplastic proliferation of ureteral tissue, using as example anastomotic strictures after ureteroureterostomy in a rat model. Human urothelial cells (SV-HUC-1) were used to determine paclitaxel dosages in vitro. Polyurethane stents were coated with a paclitaxel containing biodegradable polymer and studied in a ureteroureterostomy rat model. 48 male 9-week-old Sprague-Dawley rats underwent either sham surgery (n = 16) or ureteroureterostomy with sutured anastomosis, and consecutive stenting with either a paclitaxel-coated or an uncoated stent (16 per group), respectively. The animals received daily intraperitoneal injections of 5-bromo-2-deoxyuridine (20 mg/ml, 100 mg/kg body weight) during the first eight postoperative days, and were sacrificed on day 28. Healing of the ureteral anastomosis and proliferation of urothelial cells was examined histologically and immunohistochemically. In vitro, a concentration of 10 ng/mm2 paclitaxel can be considered as non-toxic, while still exerting an anti-proliferative effect on urothelial cells. Histologically, typical wound healing processes were seen at the site of the ureteral anastomosis in vivo. Proliferation of urothelial cells was significantly lower in animals with paclitaxel-coated stents compared to those with uncoated stents (LI 41.27 vs. 51.58, p < 0.001). Our results indicate that stenting of ureteral anastomoses with paclitaxel-coated stents can reduce hyperplastic proliferation of ureteral tissue. Paclitaxel-coated stents thus might be able to prevent not only scar-induced postoperative stenosis after reconstructive surgery, but also hyperplastic urothelial reaction in non-anastomotic stent patients as part of their inflammatory response to the foreign material.

Development of a very large array for retinal stimulation.

Retina degeneration is one of the leading causes of blindness nowadays and cannot be cured in most cases. It has been shown that electrical stimulation of retinal ganglion cells can generate visual perceptions and therefore implantable electrode arrays can be possible treatment for these patients. Most implants developed for that purpose use electrode arrays with a size of a few millimeters squared and therefore could restore only a very small field of vision and hardly improve orientation in an unknown environment. In this paper we present results of the development of an implantable electrode array covering about 100 mm(2) of retinal tissue.

Implantation and explantation of an active epiretinal visual prosthesis: 2-year follow-up data from the EPIRET3 prospective clinical trial.

PURPOSE: The EPIRET3 retinal prosthesis was implanted in six volunteers legally blind from retinitis pigmentosa (RP) and removed after 4 weeks. Two years later, these subjects were re-examined to investigate ocular side effects and potential changes to quality of life. METHODS: Vision-related quality of life was recorded using the NEI-VFQ-25 questionnaire. Clinical data including interval history, visual acuity, and intraocular pressure were obtained. Anterior and posterior segments of the study eyes were examined and photographed; this included fluorescein angiography and optical coherence tomography (OCT). RESULTS: Data from five patients could be analysed. Life-quality score was consistent with results obtained at baseline. No unexpected structural alteration could be found in the study eyes. A moderate epiretinal gliosis was present in areas where the epiretinal stimulator had been fixated using retinal tacks. Angiography revealed no leakage or neovascularisation; OCT showed no generalised increase of central retinal thickness. CONCLUSIONS: Vision-related quality of life is low in patients suffering from end-stage RP. No further deterioration of life quality could however be detected within our monitoring period. Surgery was well tolerated by both patients and their eyes, without adverse events occurring during the follow-up period. Epiretinal gliosis is known to occur with retinal tacks, but seems of no major concern to the integrity of the study eyes. However, it may potentially interfere with functional aspects of active implants. Hence, alternative, possibly biochemical, fixation methods merit further research.

Magneto immunosensor for gliadin detection in gluten-free foodstuff: towards food safety for celiac patients.

Gliadin is a constituent of the cereal protein gluten, responsible for the intolerance generated in celiac disease. Its detection is of high interest for food safety of celiac patients, since the only treatment known until now is a lifelong avoidance of this protein in the diet. Therefore, it is essential to have an easy and reliable method of analysis to control the contents in gluten-free foods. An electrochemical magneto immunosensor for the quantification of gliadin or small gliadin fragments in natural or pretreated food samples is described for the first time and compared to a novel magneto-ELISA system based on optical detection. The immunological reaction was performed on magnetic beads as solid support by the oriented covalent immobilization, of the protein gliadin on tosyl-activated beads. Direct, as well as indirect competitive immunoassays were optimized, achieving the best analytical performance with the direct competitive format. Excellent detection limits (in the order of µg L(-1)) were achieved, according to the legislation for gluten-free products. The matrix effect, as well as the performance of the assays was successfully evaluated using spiked gluten-free foodstuffs (skimmed milk and beer), obtaining excellent recovery values in the results.

Magneto immunoassays for Plasmodium falciparum histidine-rich protein 2 related to malaria based on magnetic nanoparticles.

Magneto immunoassay-based strategies for the detection of Plasmodium falciparum histidine-rich protein 2 (HRP2) related to malaria are described for the first time by using magnetic micro- and nanoparticles. The covalent immobilization of a commercial monoclonal antibody toward the HRP2 protein in magnetic beads and nanoparticles was evaluated and compared. The immunological reaction for the protein HRP2 was successfully performed in a sandwich assay on magnetic micro- and nanoparticles by using a second monoclonal antibody labeled with the enzyme, horseradish peroxidase (HRP). Then, the modified magnetic particles were easily captured by a magneto sensor made of graphite-epoxy composite (m-GEC) which was also used as the transducer for the electrochemical detection. The performance of the immunoassay-based strategy with the electrochemical magneto immunosensors was successfully evaluated and compared with a novel magneto-ELISA based on optical detection using spiked serum samples. Improved sensitivity was obtained when using 300 nm magnetic nanoparticles in both cases. The electrochemical magneto immunosensor coupled with magnetic nanoparticles have shown better analytical performance in terms of limit of detection (0.36 ng mL(-1)), which is much lower than the LOD reported by other methods. Moreover, at a low level of HRP2 concentration of 31.0 ng mL(-1), a signal of 15.30 µA was reached with a cutoff value of 0.34 µA, giving a clear positive result with a non-specific adsorption ratio of 51. Due to the high sensitivity, this novel strategy offers great promise for rapid, simple, cost-effective, and on-site detection of falciparum malaria disease in patients, but also to screen out at-risk blood samples for prevention of transfusion-transmitted malaria.

Neuromonitoring in a porcine model of acute hepatic failure.

Cerebral oedema has been noted to occur frequently in patients dying of fulminant hepatic failure. Therefore, in the present study, multimodal neuromonitoring was evaluated in an animal model of hepatectomy. Acute liver failure was surgically induced in swine by complete hepatectomy (n = 8). Intracranial pressure monitoring via a ventricular drainage system, electroencephalogram and recording of visually evoked potentials were used to establish a continuous neuromonitoring system. Measurements of liquor and serum ammonia (NH(3)) levels were taken at later stages of the trial in an approach to widen monitoring. Serial monitoring of the electroencephalogram revealed progressive slowing of the frequency with decreasing amplitude. Monitoring of the intracranial pressure with a subdural pressure transducer demonstrated a progressive and reproducible elevation. Increase in blood NH(3) was observed. Anaesthesia was terminal. In all cases death was caused by cardiocirculatory insufficiency, confirmed by autopsy. At autopsy, brain tissue of the animals was found to be swollen showing flattened cortical gyri. In conclusion, the technique of extended neuromonitoring offers an advanced option for monitoring animal models of fulminant hepatic failure for further developments and investigations.

[Surgical treatment of esophageal cancer].

Prospective study, included 117 patients with esophageal cancer, all received resection of the esophagus through laparatomy and and right-side thoracotomy without neoadjuvant chemotherapy. 70,0% of patients demonstrated stage higher then IIb UICC. R0 resection was possible in 101 patients (86,3%). Hospital lethality was 5,1%. Overall lethality among the operated patients was 21,4%. Long-term follow-up results were obtained in 96,6%. Surgical treatment alone does not provide satisfactory results for the patients with cancer of esophagus. Further therapy individualization and combination of surgery with modern neoadjuvant chemotherapy can provide better prognosis for these patients.

Nursery pollination by a moth in Silene latifolia: the role of odours in eliciting antennal and behavioural responses.

Since the 1970s it has been known that the nursery pollinator Hadena bicruris is attracted to the flowers of its most important host plant, Silene latifolia, by their scent. Here we identified important compounds for attraction of this noctuid moth. Gas chromatographic and electroantennographic methods were used to detect compounds eliciting signals in the antennae of the moth. Electrophysiologically active compounds were tested in wind-tunnel bioassays to foraging naïve moths, and the attractivity of these compounds was compared with that to the natural scent of whole S. latifolia flowers. The antennae of moths detected substances of several classes. Phenylacetaldehyde elicited the strongest signals in the antennae, but lilac aldehydes were the most attractive compounds in wind-tunnel bioassays and attracted 90% of the moths tested, as did the scent of single flowers. Our results show that the most common and abundant floral scent compounds in S. latifolia, lilac aldehydes, attracted most of the moths tested, indicating a specific adaptation of H. bicruris to its host plant.

[Development of an epiretinal prosthesis for stimulation of the human retina]. / Entwicklung einer epiretinalen Prothese zur Stimulation der humanen Netzhaut.

Degenerations of the outer retina in retinal diseases such as retinitis pigmentosa lead to blindness due to photoreceptor loss. A therapeutic option for visual rehabilitation is presently not available. Over the last few years, a retinal prosthesis has been developed and its use has been tested in animal experiments as well as in humans. With the epiretinal implant images of the environment are taken by a camera, these data are transmitted to an intraocular encoder, and the retina is electrically stimulated by a retinal stimulator placed epiretinally. The stimulation electrodes are placed as flexible microcontact electrodes by pars plana vitrectomy in an epimacular position. The threshold is determined by stimulations of increasing amplitudes. Initial results of acute epiretinal stimulation using an epiretinal implant in legally blind patients demonstrate that acute epiretinal stimulation of the human retina is feasible and safe.

Determination of surgeon's absorbed dose in iodine 125 and ruthenium 106 ophthalmic plaque surgery.

OBJECTIVE: Validation of dosimetry and exposition time to an ophthalmic surgeon during radioactive plaque operations. DESIGN: Experimental study in which videotaped operations and dosimetric measurements were used to model dosimetry. METHODS: We used thermoluminescence detectors for high sensitivity readings in radiation fields. Typical intersurgical mobility was videotaped and distances to the plaque was evaluated. MAIN OUTCOME MEASURE: Estimated radiation received by surgeons. RESULTS: All simulated plaque operations have a maximum dose rate of 6 mGy per minute (value in the inner eyeball). Mean dose rate is 2 mGy per minute (average of approximately all measurements). The surgeon's fingers receive a dose from 2 to 6 mSv from plaque operation. CONCLUSIONS: Results suggest that radioactive plaque operations are safe for the surgeon but that the time for plaque handling should be minimized. A surgeon should not exceed 100 to 200 operations per year.

[Cholesterol in serum and vaginal content in healthy, non-pregnant women]. / Cholesterol in Serum und Scheideninhalt gesunder, nichtschwangerer Frauen.

We examined 97 healthy and non-pregnant women aged between 17 and 58 years, who especially did not show any symptoms of vulvitis or colpitis, for the contents of cholesterol in serum and vaginal smear. In the vaginal smear we found significantly lower concentrations of total cholesterol as in serum, whereas the part of free cholesterol on total cholesterol in vaginal smear was triple than in serum and its absolutely concentration was double than that in serum. Possible reasons are discussed.

[Primary and secondary extrauterine pregnancy in a cat]. / Primäre oder sekundäre Extrauteringravidität bei einer Katze.

The primary and secondary extrauterine gravidity is defined and the different types are explained. With reference to embryos found in the abdomen of a cat, four embryos in different developmental stages and mummification grades are discussed, emphasizing which of the extrauterine gravidity type is present in this clinical case. A primary abdominal pregnancy could not be proven histologically.