200 research outputs found

    NOViSE: a virtual natural orifice transluminal endoscopic surgery simulator

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    Purpose: Natural Orifice Transluminal Endoscopic Surgery (NOTES) is a novel technique in minimally invasive surgery whereby a flexible endoscope is inserted via a natural orifice to gain access to the abdominal cavity, leaving no external scars. This innovative use of flexible endoscopy creates many new challenges and is associated with a steep learning curve for clinicians. Methods: We developed NOViSE - the first force-feedback enabled virtual reality simulator for NOTES training supporting a flexible endoscope. The haptic device is custom built and the behaviour of the virtual flexible endoscope is based on an established theoretical framework – the Cosserat Theory of Elastic Rods. Results: We present the application of NOViSE to the simulation of a hybrid trans-gastric cholecystectomy procedure. Preliminary results of face, content and construct validation have previously shown that NOViSE delivers the required level of realism for training of endoscopic manipulation skills specific to NOTES Conclusions: VR simulation of NOTES procedures can contribute to surgical training and improve the educational experience without putting patients at risk, raising ethical issues or requiring expensive animal or cadaver facilities. In the context of an experimental technique, NOViSE could potentially facilitate NOTES development and contribute to its wider use by keeping practitioners up to date with this novel surgical technique. NOViSE is a first prototype and the initial results indicate that it provides promising foundations for further development

    94/Międzybłoniak opłucnej – diagnostyka i leczenie w materiale Centrum

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    Celem pracyjest prezentacja wyników leczenia chorych na międzybłoniaka opłucnej [MO] leczonych w latach 1965–2001 oraz ocena roli radioterapii w zapobieganiu niepowodzeniom miejscowym.Materiał i metodyW latach 1965–2001 w Centrum Onkologii w Krakowie leczono 75 chorych z powodu [MO]. Analizą objęto grupę 34 chorych leczonych od 1991 roku, u których postępowanie diagnostyczne i terapeutyczne było jednolite. U wszystkich chorych zastosowano leczenie operacyjne, które u 7 chorych miało charakter radykalny (pleuro-pericardio-diaphra-gmo-pneumonectomia). Pooperacyjna radioterapia zastosowana była u 23 chorych, z czego 14 chorych (61%) napromienianych było wiązką mieszaną fotonowo-elektronową. Zakres dawki podanej na teren jamy opłucnej wynosił od 45 do 55 Gy. W oszacowaniu odsetków przeżyć 1, 2 i 3-letnich zastosowano metodę Kaplana-Meiera. Wyniki uzyskane w grupie leczonej od 1991 roku porównano z wynikami leczenia grupy chorych leczonych w latach 1965–1990.Wyniki i wnioskiW analizowej grupie uzyskano nastęujące odsetki przeżyć: 1-rocznych 52.9%, 2-letnich 26.5%, 3-letnich 6.6%. Tolerancja leczenia była dobra. Stwierdzono, że wyniki te są lepsze w stosunku do grupy chorych leczonych do 1991 r. Różnice te dotyczą okresu 2 lat po zakończeniu leczenia. Zastosowanie u chorych na [MO] mieszanej wiązki fotonowoelektronowej pozwala na uzyskanie stosunkowo dobrych wyników leczenia przy dobrej tolerancji leczenia przez tych chorych

    Intermittent or Continuous Therapy of Experimental Meningitis Due to Streptococcus pneumoniae in Rabbits: Preliminary Observations on the Postantibiotic Effect in Vivo

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    The relative effectiveness of bolus vs. constant intravenous administration of equivalent doses of penicillin G in killing bacteria in vivo was studied in a rabbit model of meningitis due to Streptococcus pneumoniae. Samples of cerebrospinal fluid (CSF) and serum were obtained from 30 rabbits at intervals of ⩽8 hr after treatment for determination of antibiotic concentrations and titers of viable bacteria in the CSF. When penicillin G was given by continuous infusion (105 units/hr after an initial l05-unit loading dose), concentrations of drug in serum and CSF reached a steady state in 1 hr. With intermittent bolus administration of 4 × 105 units every 4 hr, higher peak and lower trough concentrations were achieved, and these concentrations paralleled those in the CSF. Although an initial acceleration in bactericidal rate was observed with the bolus infusion between the first and second hour of therapy, after the second hour the rate of bacterial killing was identical for the two methods of administration. The duration of therapy required for sterilization of the CSF was dependent only on the bacterial count before treatment and not on the mode of drug administration. The effect of single bolus intravenous administration of ampicillin was examined in experimental pneumococcal meningitis. Ampicillin was given at various dosages (3.25-62.5 mg/kg), and frequent samples of CSF were obtained for determination of concentrations of pneumococci and ampicillin. A long postantibiotic effect was observed in the CSF of all animals, and this effect consistently was longer than that observed in vitr

    Prioritization of mycotoxins for risk management action based on both public health risk and mitigation efficacy

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    There is a large and progressively growing number of mycotoxins with new potential concerns and implications on consumer protection. The classical approach to risk management is to deal with each emerging hazard individually, leading to both overload and lack of coherence in terms of an overall riskbased approach. The development of mitigation strategies should prioritize mycotoxins that regularly occur at undesirable levels in commonly consumed commodities, wherein both the toxicological profiles and effectiveness of mitigation are understood with a reasonable degree of certainty. The ultimate goal of mycotoxin mitigation is to prevent adverse health effects caused by foodborne exposure to mycotoxins, while preserving nutritional and organoleptic quality of food. The International Life Sciences Institute Europe (ILSI Europe) Food Contaminants Task Force is firmly committed to contributing to the understanding of the issues of mycotoxins affecting the different points of the food chain. This presentation will illustrate a recent new activity that is devoted to establishing a framework for the prioritization of mycotoxins found in food following a risk-based approach (decision tree). Based on the evidence and scale of risk to consumers, and the potential for risk mitigation, the framework will enable the differentiation between mycotoxins where risk management action is both warranted and likely to be effective based on available evidence. Through case-studies, this framework will also highlight potential knowledge gaps. The proposed activity is therefore devoted to delineating the right path for scaling and prioritizing mycotoxins in terms of risk-ranking and consequent mitigation opportunities.info:eu-repo/semantics/publishedVersio

    Role of phosphoinositides in STIM1 dynamics and store-operated calcium entry

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    Ca2+ entry through store-operated Ca2+ channels involves the interaction at ER–PM (endoplasmic reticulum–plasma membrane) junctions of STIM (stromal interaction molecule) and Orai. STIM proteins are sensors of the luminal ER Ca2+ concentration and, following depletion of ER Ca2+, they oligomerize and translocate to ER–PM junctions where they form STIM puncta. Direct binding to Orai proteins activates their Ca2+ channel function. It has been suggested that an additional interaction of the C-terminal polybasic domain of STIM1 with PM phosphoinositides could contribute to STIM1 puncta formation prior to binding to Orai. In the present study, we investigated the role of phosphoinositides in the formation of STIM1 puncta and SOCE (store-operated Ca2+ entry) in response to store depletion. Treatment of HeLa cells with inhibitors of PI3K (phosphatidylinositol 3-kinase) and PI4K (phosphatidylinositol 4-kinase) (wortmannin and LY294002) partially inhibited formation of STIM1 puncta. Additional rapid depletion of PtdIns(4,5)P2 resulted in more substantial inhibition of the translocation of STIM1–EYFP (enhanced yellow fluorescent protein) into puncta. The inhibition was extensive at a concentration of LY294002 (50 μM) that should primarily inhibit PI3K, consistent with a major role for PtdIns(4,5)P2 and PtdIns(3,4,5)P3 in puncta formation. Depletion of phosphoinositides also inhibited SOCE based on measurement of the rise in intracellular Ca2+ concentration after store depletion. Overexpression of Orai1 resulted in a recovery of translocation of STMI1 into puncta following phosphoinositide depletion and, under these conditions, SOCE was increased to above control levels. These observations support the idea that phosphoinositides are not essential but contribute to STIM1 accumulation at ER–PM junctions with a second translocation mechanism involving direct STIM1–Orai interactions

    Pregnancy outcome following gestational exposure to azithromycin

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    BACKGROUND: Azithromycin is an azalide antibiotic with an extensive range of indications and has become a common treatment option due to its convenient dosing regimen and therapeutic advantages. Human studies addressing gestational use of azithromycin have primarily focused on antibiotic efficacy rather than fetal safety. Our primary objective was to evaluate the possibility of teratogenic risk following gestational exposure to azithromycin. METHODS: There were 3 groups of pregnant women enrolled in our study: 1) women who took azithromycin. 2) women exposed to non-teratogenic antibiotics for similar indications, and 3) women exposed to non-teratogenic agents. They were matched for gestational age at time of call, maternal age, cigarette and alcohol consumption. Rates of major malformations and other endpoints of interest were compared among the three groups. RESULTS: Pregnancy outcome of 123 women in each group was ascertained. There were no statistically significant differences among the three groups in the rates of major malformations; 3.4% (exposed) versus 2.3% (disease matched) and 3.4% (non teratogen) or any other endpoints that were examined. In the azithromycin group, 88 (71.6%) women took the drug during the first trimester CONCLUSION: Results suggest that gestational exposure to azithromycin is not associated with an increase in the rate of major malformations above the baseline of 1–3%. Our data adds to previous research showing that macrolide antibiotics, as a group, are generally safe in pregnancy and provides an evidence-based option for health professionals caring for populations with chlamydia
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