scholarly journals Development of a gel dedicated to gel immersion endoscopy

2021 ◽  
Vol 09 (06) ◽  
pp. E918-E924
Author(s):  
Tomonori Yano ◽  
Atsushi Ohata ◽  
Yuji Hiraki ◽  
Makoto Tanaka ◽  
Satoshi Shinozaki ◽  
...  

Abstract Backgrounds and study aims Gel immersion endoscopy is a novel technique to secure the visual field during endoscopy. The aim of this study was to develop a dedicated gel for this technique. Methods To identify appropriate viscoelasticity and electrical conductivity, various gels were examined. Based on these results, the dedicated gel “OPF-203” was developed. Efficacy and safety of OPF-203 were evaluated in a porcine model. Results  In vitro experiments showed that a viscosity of 230 to 1900 mPa·s, loss tangent (tanδ) ≤ 0.6, and hardness of 240 to 540 N/cm2 were suitable. Ex vivo experiments showed electrical conductivity ≤ 220 μS/cm is appropriate. In vivo experiments using gastrointestinal bleeding showed that OPF-203 provided clear visualization compared to water. After electrocoagulation of gastric mucosa in OPF-203, severe coagulative necrosis was not observed in the muscularis but limited to the mucosa. Conclusions OPF-203 is useful for gel immersion endoscopy.

2017 ◽  
Vol 11 (10) ◽  
pp. E396-404 ◽  
Author(s):  
Xavier Biardeau ◽  
Sami Hached ◽  
Oleg Loutochin ◽  
Lysanne Campeau ◽  
Mohamad Sawan ◽  
...  

Introduction: We aimed to present three novel remotely controlled hydromechanical artificial urinary sphincters (AUSs) and report their in-vitro and ex-vivo results.Methods: We successively developed three distinct hydromechanical AUSs on the basis of the existing AMS800™ device by incorporating an electronic pump. No changes were made to the cuff and balloon. The AUS#1 was designed as an electromagnetically controlled device. The AUS#2 and AUS#3 were conceived as Bluetooth 2.1 remotely controlled and Bluetooth 4.0 remotelycontrolled, adaptive devices, respectively. In-vitro experiments profiled occlusive cuff pressure (OCP) during a complete device cycle, with different predetermined OCP. Ex-vivo experiments were performed on a fresh pig bladder with 4 cm cuff placed around the urethra. Leak point pressure with different predetermined OCP values was successively measured during cystometry via a catheter at the bladder dome.Results: Our in-vitro and ex-vivo experiments demonstrated that these three novel AUSs provided stable and predetermined OCP — within the physiological range — and completely deflated the cuff, when required, in a limited time compatible with physiological voiding cycles.Conclusions: Our three novel, remotely controlled AUSs showed promising results that should be confirmed by in-vivo experiments focusing on efficacy and safety.


2021 ◽  
Vol 11 (3) ◽  
pp. 1165
Author(s):  
Wen-Tien Hsiao ◽  
Yi-Hong Chou ◽  
Jhong-Wei Tu ◽  
Ai-Yih Wang ◽  
Lu-Han Lai

The purpose of this study is to establish the minimal injection doses of magnetic resonance imaging (MRI) contrast agents that can achieve optimized images while improving the safety of injectable MRI drugs. Gadolinium-diethylenetriamine penta-acetic acid (Gd-DTPA) and ferucarbotran, commonly used in clinical practice, were selected and evaluated with in vitro and in vivo experiments. MRI was acquired using T1-weighted (T1W) and T2-weighted (T2W) sequences, and the results were quantitatively analyzed. For in vitro experiments, results showed that T1W and T2W images were optimal when Gd-DTPA-bisamide (2-oxoethyl) (Gd-DTPA-BMEA) and ferucarbotran were diluted to a volume percentage of 0.6% and 0.05%; all comparisons were significant differences in grayscale statistics using one-way analysis of variance (ANOVA). For in vivo experiments, the contrast agent with optimal concentration percentages determined from in vitro experiments were injected into mice with an injection volume of 100 μL, and the images of brain, heart, liver, and mesentery before and after injection were compared. The statistical results showed that the p values of both T1W and T2W were less than 0.001, which were statistically significant. Under safety considerations for MRI contrast agent injection, optimized MRI images could still be obtained after reducing the injection concentration, which can provide a reference for the safety concentrations of MRI contrast agent injection in the future.


2020 ◽  
Vol 22 (6) ◽  
pp. 819-829 ◽  
Author(s):  
Holger Fischer ◽  
Mohammed Ullah ◽  
Cecile C de la Cruz ◽  
Thomas Hunsaker ◽  
Claudia Senn ◽  
...  

Abstract Background Studies evaluating the CNS penetration of a novel tyrosine kinase inhibitor, entrectinib, proved challenging, particularly due to discrepancies across earlier experiments regarding P-glycoprotein (P-gp) interaction and brain distribution. To address this question, we used a novel “apical efflux ratio” (AP-ER) model to assess P-gp interaction with entrectinib, crizotinib, and larotrectinib, and compared their brain-penetration properties. Methods AP-ER was designed to calculate P-gp interaction with the 3 drugs in vitro using P-gp–overexpressing cells. Brain penetration was studied in rat plasma, brain, and cerebrospinal fluid (CSF) samples after intravenous drug infusion. Unbound brain concentrations were estimated through kinetic lipid membrane binding assays and ex vivo experiments, while the antitumor activity of entrectinib was evaluated in a clinically relevant setting using an intracranial tumor mouse model. Results Entrectinib showed lower AP-ER (1.1–1.15) than crizotinib and larotrectinib (≥2.8). Despite not reaching steady-state brain exposures in rats after 6 hours, entrectinib presented a more favorable CSF-to-unbound concentration in plasma (CSF/Cu,p) ratio (>0.2) than crizotinib and larotrectinib at steady state (both: CSF/Cu,p ~0.03). In vivo experiments validated the AP-ER approach. Entrectinib treatment resulted in strong tumor inhibition and full survival benefit in the intracranial tumor model at clinically relevant systemic exposures. Conclusions Entrectinib, unlike crizotinib and larotrectinib, is a weak P-gp substrate that can sustain CNS exposure based on our novel in vitro and in vivo experiments. This is consistent with the observed preclinical and clinical efficacy of entrectinib in neurotrophic tropomyosin receptor kinase (NTRK) and ROS1 fusion-positive CNS tumors and secondary CNS metastases.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3938-3938
Author(s):  
Eli I. Lev ◽  
Jing-fei Dong ◽  
Marcin Bujak ◽  
Khatira Aboulfatova ◽  
Neal S. Kleiman ◽  
...  

Abstract We and others have found that platelets play an important role in the recruitment of endothelial progenitor cells to sights of vascular injury. However, it is not clear whether the EPCs mature and differentiate to endothelial cells following recruitment to the vascular injury sites. In addition, there is limited in vivo data to support the role of EPCs in re-endothlialization following vascular injury. We conducted in vitro experiments to investigate the maturation of EPCs on platelet based-media and in vivo experiments to evaluate the recruitment of EPCs following vascular injury. In in vitro experiments human EPCs were isolated from donated buffy coats by magnetic microbeads and flow cytometry cell sorting using CD133 and VEGFR-2, respectively, as cell markers. Isolated viable EPCs (CD133+, VEGFR-2+ cells) were plated on human fibronectin or a monolayer of washed human platelets. Cell colonies were counted 7 days after plating and stained for the endothelial cell markers CD31 (PECAM-1) and CD144 (VE-cadherin). The mean number of colony-forming cells was 35±2.6 colonies/106 cells on platelets, which was significantly higher than 18±4.2 colonies/106 cells on fibronectin (n = 4, P<0.01). Apart from the difference in colony numbers, the EPC colonies grew faster on the platelet substrate, were larger, and had more spindle-shaped cells (Figure 1 - staining of EPC colonies for CD31 and CD144). In the in vivo experiments a model of transluminal injury to mouse femoral arteries was used. Femoral artery denudation was performed by 0.25-mm-diameter angioplasty guidewire. Injured femoral arteries were compared to the contra-lateral controls (uninjured), and were harvested 1.5 hours following the injury and immunostaining performed with an anti-VEGFR-2 antibody. Four experiments showed a markedly higher number of VEGFR-2+ cells in the artery that has undergone denudation. These experiments indicate that a media composed of platelets promotes the maturation and differentiation of EPCs. Furthermore, in vivo, EPCs are recruited early following vascular injury. Thus, homing, maturation, and differentiation of EPCs are mediated by platelets.


1981 ◽  
Author(s):  
J W D McDonald ◽  
M Ali ◽  
J D Cooper ◽  
E R Townsend

The infusion of plasma containing Zymosan-activated complement (ZAC) into sheep produces leukopenia with pulmonary leukostasis and transient pulmonary arterial hypertension (PAH). Previous work has related PAH to elevations of plasma thromboxane B2 (TXB2) rather than to mechanical obstruction by sequestered leukocytes (WBC). We have investigated the source of the TXB2 formation in this model. Incubation of platelet-poor WBC preparations with arachi- donate resulted in negligible TXB2 formation. WBC-poor platelet preparations on the other hand formed significant amounts of TXB2 (approximately 6-18 ng/108 platelets). Incubation of whole sheep blood or plasma with ZAC failed to generate significant amounts of TXB2. Thus, WBC agglutination in vitro did not induce platelet TXB2 formation.Pretreatment of sheep with aspirin (ASA)(10 mg/kg IV) completely blocked TXB2 formation and PAH in response to infusion of plasma containing ZAC. The infusion of 10-50% nonnal platelets into sheep 4 hours after ASA pretreatment failed to restore TXB2 formation and pulmonary vascular response to subsequent challenge with ZAC. TXB2 formation during blood clotting ex vivo was restored by the platelet infusions. These experiments make it appear unlikely that platelets are the source of the TXB2. It is possible that the transfused platelets respond to thrombin but are unable to interact with sequestered leukocytes. Sheep lung and pulmonary artery were incubated in vitro with arachidonate. Lung formed 630 ng TXB2 and 39 ng 6-keto-PGF1α/g of wet tissue. Pulmonary artery formed 9 ng TXB2 and 180 ng 6-keto-PGF1α/g of wet tissue. The relative proportions of TXB2 and 6-keto-PGF1α formed by lung parenchyma but not pulmonary artery resemble the proportions observed in previous in vivo experiments with ZAC. It appears that lung tissue is the most likely source of TXB2 formation causing PAH in response to ZAC-mediated pulmonary leukostasis.


RSBO ◽  
2019 ◽  
Vol 16 (2) ◽  
pp. 109
Author(s):  
Carina Do Nascimento Menezes ◽  
Verydianna Frota Carneiro ◽  
Mônica Sampaio do Vale

Introduction: Removal of filling material from the root canal system is required when a previous endodontic treatment fails, what may result in the permanence of an unfavorable periapical condition. The intent is to completely remove the filling material inside of the root canal to achieve sufficient cleaning and shaping for successful retreatment. Objective: The aims of this article were to provide asystematic review of the different techniques of endodontic filling material associated or not with organic solvents and to analyze them critically in terms of advantages and disadvantages of each technique. Literature review: The descriptors used were “guttapercha”, “obturation,” and “retreatment” in the following databases: PubMed, MEDLINE, Latin American and Caribbean Center on Health Sciences Information (Bireme), Latin-American and CaribbeanHealth Sciences (Lilacs), Brazilian Dentistry Bibliography (BBO), and Scientific Electronic Library Online (SciELO). Publications of in vitro/ ex vivo and in vivo experiments without language restriction between the years 2010 and 2018 were selected. Conclusion: None of the techniques were capable of performing complete root canal cleaning, and the manual method was so effective as the automated method, although it requires longer working time. Furthermore, although this review confirmed that the solvent action did not allow a significantimprovement in the removal of the filling material, ultrasoundactivated irrigation proved to be an efficient adjunctive device as it could significantly reduce the volume of intracanal residuals.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Weijie Liang ◽  
Jie Wu ◽  
Xinguang Qiu

Abstract Background Colorectal cancer (CRC) is a common malignant tumor globally. Meanwhile, LINC01116 has been proposed as risk factor for various tumors, including CRC. But the regulation of LINC01116 in CRC required more validated data. This study aimed to elucidate the potential function of LINC01116 in regulating cell proliferation and angiogenesis of CRC. Methods LINC01116 expression in 80 pairs of CRC tumor and adjacent non-tumor tissues was determined by qRT-PCR. After transfection of pcDNA3.1-LINC01116, sh-LINC01116, sh-TPM1, pcDNA3.1-EZH2 or sh-EZH2 in SW480 and HCT116 cells, the levels of LINC01116, TPM1 and EZH2 were measured by qRT-PCR or Western blot. The cell biological function of CRC cell lines was determined by CCK-8, colony formation assays, tube formation and scratch assays. RNA pull-down and RIP assays were applied to detect the binding of LINC01116 with EZH2 and H3K27me3. Binding of EZH2 to the TPM1 promoter was assessed by ChIP assay. Finally, xenograft models in nude mice were established to validate the results of in vitro experiments. Results LINC01116 was overexpressed in CRC tissues and high expression of LINC01116 was negatively correlated with postoperative survival. In vitro study showed LINC01116 expression could significantly enhance CRC progression, including increasing cell proliferation, migration and angiogenesis. Besides, investigations into the mechanism disclosed that LINC01116 could regulate EZH2 to inactivate TPM1 promoter, thus promoting CRC cell proliferation and angiogenesis. Moreover, consistent results of in vivo experiments were conformed in vitro experiments. Conclusion LINC01116 promotes the proliferation and angiogenesis of CRC cells by recruiting EZH2 to potentiate methylation in the TPM1 promoter region to inhibit the transcription of TPM1.


2013 ◽  
Vol 683 ◽  
pp. 712-715
Author(s):  
Feng Zhou ◽  
Liang Liang Wu ◽  
Yuan Yuan Cui ◽  
Ying Chen ◽  
Jie Yang ◽  
...  

The experiments of artificial heart valves were divided into in vivo and in vitro experiments; in vivo experiments provide accurate experimental parameters serving in vitro research. Simulation experiment used in vitro usually goes like this, firstly design a similar model or prototype phenomenon, then analysis the model working out the regular parameters related to the process, ruled out the possibility of impact on the study of individual exist in vivo experiment. In vitro experiments are likely designed; performance can be simplified and prominently concerned about contents, even designed some extreme conditions to test. A number of means related to fluid experimental measurement are included, such as the Particle Image Velocimetry(PIV)[1], Dual Catheter Method [2],and ultrasonic method[3] and so on. However, these methods have different kinds of limitations, for example the Dual Catheter Method cannot be used as a routine determination for clinic due to its destructiveness, and PIV test requires expensive equipment. This study was designed by the image processing technology of high-speed photography aiming at the production of a reliable, simple, economic, injury-free and non-contact measurement method.


1980 ◽  
Vol 93 (1) ◽  
pp. 32-36 ◽  
Author(s):  
F. Monaco ◽  
C. Santolamazza ◽  
I. De Ros ◽  
A. Andreoli

Abstract. The effect of 6-propyl-2-thiouracil (PTU), and 1-methyl-2-mercaptoimidazole (MMI) on thyroglobulin (Tg) biosynthesis has been studied in vivo and in vitro. In vivo experiments were performed in rats treated for 20 days with PTU or MMI. analyzing soluble and particulate, cold and 125I-labelled, Tg. Thyroglobulin biosynthesis was also investigated by in vitro experiments, incubating thyroid tissue with labelled amino acid and carbohydrate in the presence of antithyroid compounds. It has been found that in vivo antithyroid agents decrease the amount of soluble Tg and increase the proportion of particulate Tg. Tg from treated animals is poorly iodinated being mainly represented by its 12S subunit. In vitro studies demonstrate that PTU and MMI inhibit Tg biosynthesis which is impaired in the polypeptide synthesis as wellas in carbohydrate chains addition. Thus the inhibition of the hormonogenetic processes induced by antithyroid treatment leading to a depressed iodinating activity also appears to be related to a significant impairment of the production of the Tg molecule, the specific iodine acceptor.


Blood ◽  
2011 ◽  
Vol 118 (18) ◽  
pp. 5040-5049 ◽  
Author(s):  
Thomas Helbing ◽  
René Rothweiler ◽  
Elena Ketterer ◽  
Lena Goetz ◽  
Jennifer Heinke ◽  
...  

Abstract The endothelium plays a pivotal role in vascular inflammation. Here we study bone morphogenetic protein (BMP) signaling in endothelial inflammation and in particular the role of BMPER, an extracellular BMP modulator that is important in vascular development and angiogenesis. Using the BMP antagonist dorsomorphin or BMP2 as an agonist we show that BMP signaling is essential for the inflammatory response of vascular endothelial cells as demonstrated by intravital microscopy. We found that BMPER is decreased in inflammation similar to vascular protective genes like KLF2 and eNOS. Using in vitro and in vivo models we show that BMPER is down-regulated through the TNFα-NFκB-KLF2 signaling pathway. Functionally, lack of BMPER induced by siRNA or in BMPER+/− mice confers a proinflammatory endothelial phenotype with reduced eNOS levels and enhanced expression of adhesion molecules leading to increased leukocyte adhesion and extravasation in ex vivo and in vivo experiments. Vice versa, addition of BMPER exerts endothelium protective functions and antagonizes TNFα induced inflammation. Mechanistically, we demonstrate that these effects of BMPER are dependent on BMP signaling because of enhanced NFκB activity. In conclusion, the BMP modulator BMPER is a new protective regulator of vascular inflammation that modulates leukocyte adhesion and migration in vitro and in vivo.


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