78 research outputs found

    Detrusor overactivity induced by intravesical application of adenosine 5 '-triphosphate under different delivery conditions in rats

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    Objectives. We investigate the effects of intravesical application of adenosine 5'-triphosphate (ATP) on bladder activity to elucidate the role of urothelial barrier function and ecto-ATPase activity in the ATP-mediated mechanism inducing detrusor overactivity. Methods. Continuous cystometry by an intravesical catheter inserted from the bladder dome was performed in conscious female rats. Results. ATP solutions adjusted to pH 6.0 did not elicit significant detrusor overactivity at a concentration of 60 mM. However, in bladders pretreated with protamine sulfate (10 mg/mL) to increase urothelial permeability, ATP solution (pH 6.0) induced detrusor overactivity by decreasing the intercontraction intervals. These irritant effects of ATIP after protamine treatment were antagonized by P2X receptor antagonists, such as pyridoxal-5-phosphate-6-azophenyl-2',4-disulfonic acid (70 mu mol/kg) and 2',3'-O-(2,4,6, trinitrophenyl) ATP (30 mu mol/kg). These were also suppressed in rats pretreated with systemic capsaicin (125 mg/kg subcutaneously). Alpha,beta-methylene ATP (5 mM, pH 6.0) or ATP (60 mM, pH6) after intravesical infusion of 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (5 mM, pH 6.0), an ecto-ATPase inhibitor, induced detrusor overactivity without protamine pretreatment, but the reduction in intercontraction intervals was smaller compared with that with ATP after protamine treatment. Conclusions. Low permeability of bladder epithelium and ecto-ATPase activity can prevent ATP activation of subepithelial P2X receptors to induce bladder overactivity. Thus, enhanced penetration of endogenous ATIP owing to urothelial damage may contribute to urinary frequency and bladder pain in hypersensitive bladder disorders such as interstitial cystitis.</p

    A Novel Intravital Method to Evaluate Cerebral Vasospasm in Rat Models of Subarachnoid Hemorrhage: A Study with Synchrotron Radiation Angiography

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    Precise in vivo evaluation of cerebral vasospasm caused by subarachnoid hemorrhage has remained a critical but unsolved issue in experimental small animal models. In this study, we used synchrotron radiation angiography to study the vasospasm of anterior circulation arteries in two subarachnoid hemorrhage models in rats. Synchrotron radiation angiography, laser Doppler flowmetry-cerebral blood flow measurement, [125I]N-isopropyl-p-iodoamphetamine cerebral blood flow measurement and terminal examinations were applied to evaluate the changes of anterior circulation arteries in two subarachnoid hemorrhage models made by blood injection into cisterna magna and prechiasmatic cistern. Using synchrotron radiation angiography technique, we detected cerebral vasospasm in subarachnoid hemorrhage rats compared to the controls (p<0.05). We also identified two interesting findings: 1) both middle cerebral artery and anterior cerebral artery shrunk the most at day 3 after subarachnoid hemorrhage; 2) the diameter of anterior cerebral artery in the prechiasmatic cistern injection group was smaller than that in the cisterna magna injection group (p<0.05), but not for middle cerebral artery. We concluded that synchrotron radiation angiography provided a novel technique, which could directly evaluate cerebral vasospasm in small animal experimental subarachnoid hemorrhage models. The courses of vasospasm in these two injection models are similar; however, the model produced by prechiasmatic cistern injection is more suitable for study of anterior circulation vasospasm

    The IPIN 2019 Indoor Localisation Competition—Description and Results

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    IPIN 2019 Competition, sixth in a series of IPIN competitions, was held at the CNR Research Area of Pisa (IT), integrated into the program of the IPIN 2019 Conference. It included two on-site real-time Tracks and three off-site Tracks. The four Tracks presented in this paper were set in the same environment, made of two buildings close together for a total usable area of 1000 m 2 outdoors and and 6000 m 2 indoors over three floors, with a total path length exceeding 500 m. IPIN competitions, based on the EvAAL framework, have aimed at comparing the accuracy performance of personal positioning systems in fair and realistic conditions: past editions of the competition were carried in big conference settings, university campuses and a shopping mall. Positioning accuracy is computed while the person carrying the system under test walks at normal walking speed, uses lifts and goes up and down stairs or briefly stops at given points. Results presented here are a showcase of state-of-the-art systems tested side by side in real-world settings as part of the on-site real-time competition Tracks. Results for off-site Tracks allow a detailed and reproducible comparison of the most recent positioning and tracking algorithms in the same environment as the on-site Tracks

    The mechanisms by which polyamines accelerate tumor spread

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    Increased polyamine concentrations in the blood and urine of cancer patients reflect the enhanced levels of polyamine synthesis in cancer tissues arising from increased activity of enzymes responsible for polyamine synthesis. In addition to their de novo polyamine synthesis, cells can take up polyamines from extracellular sources, such as cancer tissues, food, and intestinal microbiota. Because polyamines are indispensable for cell growth, increased polyamine availability enhances cell growth. However, the malignant potential of cancer is determined by its capability to invade to surrounding tissues and metastasize to distant organs. The mechanisms by which increased polyamine levels enhance the malignant potential of cancer cells and decrease anti-tumor immunity are reviewed. Cancer cells with a greater capability to synthesize polyamines are associated with increased production of proteinases, such as serine proteinase, matrix metalloproteinases, cathepsins, and plasminogen activator, which can degrade surrounding tissues. Although cancer tissues produce vascular growth factors, their deregulated growth induces hypoxia, which in turn enhances polyamine uptake by cancer cells to further augment cell migration and suppress CD44 expression. Increased polyamine uptake by immune cells also results in reduced cytokine production needed for anti-tumor activities and decreases expression of adhesion molecules involved in anti-tumor immunity, such as CD11a and CD56. Immune cells in an environment with increased polyamine levels lose anti-tumor immune functions, such as lymphokine activated killer activities. Recent investigations revealed that increased polyamine availability enhances the capability of cancer cells to invade and metastasize to new tissues while diminishing immune cells' anti-tumor immune functions

    Inducer-free recombinant protein production in Trichoderma reesei: secretory production of endogenous enzymes and heterologous nanobodies using glucose as the sole carbon source

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    Abstract Background The filamentous fungus Trichoderma reesei has been used as a host organism for the production of lignocellulosic biomass-degrading enzymes. Although this microorganism has high potential for protein production, it has not yet been widely used for heterologous recombinant protein production. Transcriptional induction of the cellulase genes is essential for high-level protein production in T. reesei; however, glucose represses this transcriptional induction. Therefore, cellulose is commonly used as a carbon source for providing its degraded sugars such as cellobiose, which act as inducers to activate the strong promoters of the major cellulase (cellobiohydrolase 1 and 2 (cbh1 and cbh2) genes. However, replacement of cbh1 and/or cbh2 with a gene encoding the protein of interest (POI) for high productivity and occupancy of recombinant proteins remarkably impairs the ability to release soluble inducers from cellulose, consequently reducing the production of POI. To overcome this challenge, we first used an inducer-free biomass-degrading enzyme expression system, previously developed to produce cellulases and hemicellulases using glucose as the sole carbon source, for recombinant protein production using T. reesei. Results We chose endogenous secretory enzymes and heterologous camelid small antibodies (nanobody) as model proteins. By using the inducer-free strain as a parent, replacement of cbh1 with genes encoding two intrinsic enzymes (aspartic protease and glucoamylase) and three different nanobodies (1ZVH, caplacizumab, and ozoralizumab) resulted in their high secretory productions using glucose medium without inducers such as cellulose. Based on signal sequences (carrier polypeptides) and protease inhibitors, additional replacement of cbh2 with the nanobody gene increased the percentage of POI to about 20% of total secreted proteins in T. reesei. This allowed the production of caplacizumab, a bivalent nanobody, to be increased to 9.49-fold (508 mg/L) compared to the initial inducer-free strain. Conclusions In general, whereas the replacement of major cellulase genes leads to extreme decrease in the degradation capacity of cellulose, our inducer-free system enabled it and achieved high secretory production of POI with increased occupancy in glucose medium. This system would be a novel platform for heterologous recombinant protein production in T. reesei
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