Journal articles: 'Hyperosmotic agent'

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Constable, P. D., W. W. Muir, and P. F. Binkley. "Hypertonic saline is a negative inotropic agent in normovolumic dogs." American Journal of Physiology-Heart and Circulatory Physiology 267, no. 2 (1994): H667—H677. http://dx.doi.org/10.1152/ajpheart.1994.267.2.h667.

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The inotropic effects of hypertonic saline (HS) and hyperosmotic dextrose (HD; 2,400 mosmol/l, 4 ml/kg) were determined in normovolumic, chloralose-anesthetized, intact (n = 14) and autonomically blocked (n = 8) dogs. Solutions were infused intravenously over 3 min. HS and HD rapidly increased preload in both intact and autonomically blocked dogs, as assessed by significant (P < 0.05) increases in plasma volume, end-diastolic volume, and end-diastolic pressure. In intact dogs, HS produced a nonsignificant decrease in end-systolic elastance (Ees) and a nonsignificant increase in the maximal rate of change of left ventricular pressure (dP/dtmax) and cardiac output, whereas HD produced a significant increase in Ees, dP/dtmax, and cardiac output. In autonomically blocked dogs, HS significantly decreased Ees and significantly increased dP/dtmax but did not alter cardiac output, whereas HD significantly increased Ees, dP/dtmax, and cardiac output. We conclude that in normovolumic animals, HS is a negative inotropic agent, HD is a positive inotropic agent, and the in vivo effect of an ionic hyperosmotic agent (HS) differs from that of a nonionic hyperosmotic agent (HD).

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Ghosn, Mohamad G., Esteban F. Carbajal, Natasha A. Befrui, Armando Tellez, Juan F. Granada, and Kirill V. Larin. "Permeability of hyperosmotic agent in normal and atherosclerotic vascular tissues." Journal of Biomedical Optics 13, no. 1 (2008): 010505. http://dx.doi.org/10.1117/1.2870153.

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Linville, Raleigh M., Jackson G. DeStefano, Matt B. Sklar, Chengyan Chu, Piotr Walczak, and Peter C. Searson. "Modeling hyperosmotic blood–brain barrier opening within human tissue-engineered in vitro brain microvessels." Journal of Cerebral Blood Flow & Metabolism 40, no. 7 (2019): 1517–32. http://dx.doi.org/10.1177/0271678x19867980.

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As the majority of therapeutic agents do not cross the blood–brain barrier (BBB), transient BBB opening (BBBO) is one strategy to enable delivery into the brain for effective treatment of CNS disease. Intra-arterial infusion of the hyperosmotic agent mannitol reversibly opens the BBB; however, widespread clinical use has been limited due to the variability in outcomes. The current model for mannitol-induced BBBO assumes a transient but homogeneous increase in permeability; however, the details are poorly understood. To elucidate the mechanism of hyperosmotic opening at the cellular level, we developed a tissue-engineered microvessel model using stem cell-derived human brain microvascular endothelial cells (BMECs) perturbed with clinically relevant mannitol doses. This model recapitulates physiological shear stress, barrier function, microvessel geometry, and cell-matrix interactions. Using live-cell imaging, we show that mannitol results in dose-dependent and spatially heterogeneous increases in paracellular permeability through the formation of transient focal leaks. Additionally, we find that the degree of BBB opening and subsequent recovery is modulated by treatment with basic fibroblast growth factor. These results show that tissue-engineered BBB models can provide insight into the mechanisms of BBBO and hence improve the reproducibility of hyperosmotic therapies for treatment of CNS disease.

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Holzman, Andrew, and Lorena LoVerde. "Effect of a hyperosmotic agent on epithelial disruptions during laser in situ keratomileusis." Journal of Cataract & Refractive Surgery 41, no. 5 (2015): 1044–49. http://dx.doi.org/10.1016/j.jcrs.2014.07.042.

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Tuchina, Daria K., Alexey N. Bashkatov, Elina A. Genina, and Valery V. Tuchin. "Quantification of glucose and glycerol diffusion in myocardium." Journal of Innovative Optical Health Sciences 08, no. 03 (2015): 1541006. http://dx.doi.org/10.1142/s1793545815410060.

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The results on determination of glucose and glycerol diffusion coefficients in myocardium tissue are presented. The method is based on the measurement and analysis of temporal dependence of tissue optical collimated transmittance under action of a hyperosmotic agent. This temporal tissue response is related to the rate of the agent and water diffusion in a tissue. The diffusion coefficients for tissue fluid fluxes at glucose and glycerol application to the myocardium at 20°C have been estimated as (4.75 ± 3.40) × 10-7 and (7.71 ± 4.63) × 10-7 cm2/s, respectively.

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Zeiler, F. A., L. M. Gillman, J. Teitelbaum, and M. West. "Early Implementation of THAM for ICP Control: Therapeutic Hypothermia Avoidance and Reduction in Hypertonics/Hyperosmotics." Case Reports in Critical Care 2014 (2014): 1–4. http://dx.doi.org/10.1155/2014/139342.

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Background. Tromethamine (THAM) has been demonstrated to reduce intracranial pressure (ICP). Early consideration for THAM may reduce the need for other measures for ICP control.Objective. To describe 4 cases of early THAM therapy for ICP control and highlight the potential to avoid TH and paralytics and achieve reduction in sedation and hypertonic/hyperosmotic agent requirements.Methods. We reviewed the charts of 4 patients treated with early THAM for ICP control.Results. We identified 2 patients with aneurysmal subarachnoid hemorrhage (SAH) and 2 with traumatic brain injury (TBI) receiving early THAM for ICP control. The mean time to initiation of THAM therapy was 1.8 days, with a mean duration of 5.3 days. In all patients, after 6 to 12 hours of THAM administration, ICP stability was achieved, with reduction in requirements for hypertonic saline and hyperosmotic agents. There was a relative reduction in mean hourly hypertonic saline requirements of 89.1%, 96.1%, 82.4%, and 97.0% for cases 1, 2, 3, and 4, respectively, comparing pre- to post-THAM administration. Mannitol, therapeutic hypothermia, and paralytics were avoided in all patients.Conclusions. Early administration of THAM for ICP control could potentially lead to the avoidance of other ICP directed therapies. Prospective studies of early THAM administration are warranted.

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Vargas, Gracie, Jennifer K. Barton, and Ashley J. Welch. "Use of hyperosmotic chemical agent to improve the laser treatment of cutaneous vascular lesions." Journal of Biomedical Optics 13, no. 2 (2008): 021114. http://dx.doi.org/10.1117/1.2907327.

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Ikeda, N. "Unilateral Symptomatic Elevation of Intraocular Pressure and Prevention Using a Hyperosmotic Agent During Hemodialysis." Japanese Journal of Ophthalmology 45, no. 6 (2001): 659–61. http://dx.doi.org/10.1016/s0021-5155(01)00408-7.

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Santi, P. A., B. N. Lakhani, L. B. Edwards, and T. Morizono. "Cell volume density alterations within the stria vascularis after administration of a hyperosmotic agent." Hearing Research 18, no. 3 (1985): 283–90. http://dx.doi.org/10.1016/0378-5955(85)90045-0.

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Zaman, Raiyan T., Narasimhan Rajaram, Brandon S. Nichols, et al. "Changes in morphology and optical properties of sclera and choroidal layers due to hyperosmotic agent." Journal of Biomedical Optics 16, no. 7 (2011): 077008. http://dx.doi.org/10.1117/1.3599985.

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Xiong, Honglian, Zhouyi Guo, Changchun Zeng, Like Wang, Yonghong He, and Songhao Liu. "Application of hyperosmotic agent to determine gastric cancer with optical coherence tomography ex vivo in mice." Journal of Biomedical Optics 14, no. 2 (2009): 024029. http://dx.doi.org/10.1117/1.3103341.

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Benavent, Carlos, Carlos Torrado-Salmerón, and Santiago Torrado-Santiago. "Development of a Solid Dispersion of Nystatin with Maltodextrin as a Carrier Agent: Improvements in Antifungal Efficacy against Candida spp. Biofilm Infections." Pharmaceuticals 14, no. 5 (2021): 397. http://dx.doi.org/10.3390/ph14050397.

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The aim of this study was to improve the treatment of Candida albicans biofilms through the use of nystatin solid dispersions developed using maltodextrins as a hyperosmotic carrier. Characterization studies by differential scanning calorimetry, X-ray diffraction, dissolution studies, and particle size analysis were performed to evaluate changes in nystatin crystallinity. Antifungal activity and anti-biofilm efficacy were assessed by microbiological techniques. The results for nystatin solid dispersions showed that the enhancement of antifungal activity may be related to the high proportions of maltodextrins. Anti-biofilm assays showed a significant reduction (more than 80%) on biofilm formation with SD-N:MD [1:6] compared to the nystatin reference suspension. The elaboration process and physicochemical properties of SD-N:MD [1:6] could be a promising strategy for treatment of Candida biofilms.

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Singh, Pranisha, A. P. Rijal, A. Rizyal, and S. Karmacharya. "A Case of Bilateral Acute Angle Closure Attack with Some Unusual Clinical Features." Nepal Medical College Journal 21, no. 3 (2019): 240–43. http://dx.doi.org/10.3126/nmcj.v21i3.26471.

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Bilateral acute angle closure attack is a rare ocular emergency. Early diagnosis and immediate intervention can have a profound effect on patient’s visual outcome and ocular morbidity. A 70 year old female presented with vomiting about 7 to 8 episodes along with sudden diminution of vision in both eyes for last 3 days. Initially she was examined by physician where all the routine blood tests and upper GI endoscopy was advised which failed to reveal the cause. She was then referred to our department for ophthalmic evaluation. On ocular examination she was diagnosed as a case of bilateral acute angle closure attack with some unusual clinical features. After treatment with hyperosmotic agent, anti glaucoma drugs and Nd: Yag peripheral laser iridotomy, intraocular pressure came down to normal limits and the patient regained good vision.

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Postic, Ivana, and Heather Sheardown. "Poly(ethylene glycol) induces cell toxicity in melanoma cells by producing a hyperosmotic extracellular medium." Journal of Biomaterials Applications 33, no. 5 (2018): 693–706. http://dx.doi.org/10.1177/0885328218807675.

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Poly(ethylene glycol) is a polymer that is widely used as a biomaterial and has been approved in a host of applications. While generally viewed as inert, recent studies with poly(ethylene glycol) suggest that it may have some effects on cells and tissues, making it potentially attractive as a therapeutic agent. In this study, the effect of poly(ethylene glycol) on the cell viability, membrane transport and apoptotic markers of metastatic melanoma cells was examined. The data were combined with observed effects of the polymer on the cell media, including osmolality and viscosity, in order to elucidate any structure-function relationship between the polymer and cells. It was observed that poly(ethylene glycol) reduced the cellular viability of A375 cells, and that the effect was dependent on poly(ethylene glycol) molecular weight and concentration. The mechanism was highly correlated with changes in the osmolality of the cell medium, which is determined by the inherent structure of poly(ethylene glycol), and in particular the ethylene oxide units. This mechanism was specific to poly(ethylene glycol) and was not observed with the similar linear, hydrophilic polymer poly(vinyl pyrrolidone). Overall, the data suggest that poly(ethylene glycol) and poly(ethylene glycol)-like compounds have a distinct effect on cellular activity, presumably mediated in part by their osmotic effects, supporting the further investigation of these polymers as pharmaceutically active compounds.

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KATAYAMA, YASUO, FUMIHIKO KASHIWAGI, HAJIME MEMEZAWA, and AKIRO TERASHI. "Effect of a prostacyclin derivative (OP-41483) and a hyperosmotic agent (glycerol) on brain edema and metabolism in cerebral ischemia." Japanese Circulation Journal 56, no. 12 (1992): 1239–47. http://dx.doi.org/10.1253/jcj.56.1239.

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Zhang, Yongjun, Jianhua Zhao, Weiguo Fang, et al. "Mitogen-Activated Protein Kinase hog1 in the Entomopathogenic Fungus Beauveria bassiana Regulates Environmental Stress Responses and Virulence to Insects." Applied and Environmental Microbiology 75, no. 11 (2009): 3787–95. http://dx.doi.org/10.1128/aem.01913-08.

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ABSTRACT Beauveria bassiana is an economically important insect-pathogenic fungus which is widely used as a biocontrol agent to control a variety of insect pests. However, its insecticide efficacy in the field is often influenced by adverse environmental factors. Thus, understanding the genetic regulatory processes involved in the response to environmental stress would facilitate engineering and production of a more efficient biocontrol agent. Here, a mitogen-activated protein kinase (MAPK)-encoding gene, Bbhog1, was isolated from B. bassiana and shown to encode a functional homolog of yeast HIGH-OSMOLARITY GLYCEROL 1 (HOG1). A Bbhog1 null mutation was generated in B. bassiana by targeted gene replacement, and the resulting mutants were more sensitive to hyperosmotic stress, high temperature, and oxidative stress than the wild-type controls. These results demonstrate the conserved function of HOG1 MAPKs in the regulation of abiotic stress responses. Interestingly, ΔBbhog1 mutants exhibited greatly reduced pathogenicity, most likely due to a decrease in spore viability, a reduced ability to attach to insect cuticle, and a reduction in appressorium formation. The transcript levels of two hydrophobin-encoding genes, hyd1 and hyd2, were dramatically decreased in a ΔBbhog1 mutant, suggesting that Bbhog1 may regulate the expression of the gene associated with hydrophobicity or adherence.

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Probst, Stephanie, Bettina Scharner, Ruairi McErlean, Wing-Kee Lee, and Frank Thévenod. "Inverse Regulation of Lipocalin-2/24p3 Receptor/SLC22A17 and Lipocalin-2 Expression by Tonicity, NFAT5/TonEBP and Arginine Vasopressin in Mouse Cortical Collecting Duct Cells mCCD(cl.1): Implications for Osmotolerance." International Journal of Molecular Sciences 20, no. 21 (2019): 5398. http://dx.doi.org/10.3390/ijms20215398.

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The rodent collecting duct (CD) expresses a 24p3/NGAL/lipocalin-2 (LCN2) receptor (SLC22A17) apically, possibly to mediate high-affinity reabsorption of filtered proteins by endocytosis, although its functions remain uncertain. Recently, we showed that hyperosmolarity/-tonicity upregulates SLC22A17 in cultured mouse inner-medullary CD cells, whereas activation of toll-like receptor 4 (TLR4), via bacterial lipopolysaccharides (LPS), downregulates SLC22A17. This is similar to the upregulation of Aqp2 by hyperosmolarity/-tonicity and arginine vasopressin (AVP), and downregulation by TLR4 signaling, which occur via the transcription factors NFAT5 (TonEBP or OREBP), cAMP-responsive element binding protein (CREB), and nuclear factor-kappa B, respectively. The aim of the study was to determine the effects of osmolarity/tonicity and AVP, and their associated signaling pathways, on the expression of SLC22A17 and its ligand, LCN2, in the mouse (m) cortical collecting duct cell line mCCD(cl.1). Normosmolarity/-tonicity corresponded to 300 mosmol/L, whereas the addition of 50–100 mmol/L NaCl for up to 72 h induced hyperosmolarity/-tonicity (400–500 mosmol/L). RT-PCR, qPCR, immunoblotting and immunofluorescence microscopy detected Slc22a17/SLC22A17 and Lcn2/LCN2 expression. RNAi silenced Nfat5, and the pharmacological agent 666-15 blocked CREB. Activation of TLR4 was induced with LPS. Similar to Aqp2, hyperosmotic/-tonic media and AVP upregulated Slc22a17/SLC22A17, via activation of NFAT5 and CREB, respectively, and LPS/TLR4 signaling downregulated Slc22a17/SLC22A17. Conversely, though NFAT5 mediated the hyperosmolarity/-tonicity induced downregulation of Lcn2/LCN2 expression, AVP reduced Lcn2/LCN2 expression and predominantly apical LCN2 secretion, evoked by LPS, through a posttranslational mode of action that was independent of CREB signaling. In conclusion, the hyperosmotic/-tonic upregulation of SLC22A17 in mCCD(cl.1) cells, via NFAT5, and by AVP, via CREB, suggests that SLC22A17 contributes to adaptive osmotolerance, whereas LCN2 downregulation could counteract increased proliferation and permanent damage of osmotically stressed cells.

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Gouffi, Kamila, Vianney Pichereau, Jean-Paul Rolland, Daniel Thomas, Théophile Bernard, and Carlos Blanco. "Sucrose Is a Nonaccumulated Osmoprotectant inSinorhizobium meliloti." Journal of Bacteriology 180, no. 19 (1998): 5044–51. http://dx.doi.org/10.1128/jb.180.19.5044-5051.1998.

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ABSTRACT Intracellular accumulation of sucrose in response to lowered water activity seems to occur only in photosynthetic organisms. Here we demonstrate, for the first time, the potent ability of this common sugar, supplied exogenously, to reduce growth inhibition ofSinorhizobium meliloti cells in media of inhibitory osmolarity. Independently of the nature of the growth substrates and the osmotic agent, sucrose appears particularly efficient in promoting the recovery of cytoplasmic volume after plasmolysis. Surprisingly, sucrose is not accumulated by the bacteria at an osmotically efficient level. Instead, it strongly stimulates the accumulation of the main endogenous osmolytes glutamate andN-acetylglutaminylglutamine amide (NAGGN). Examining cell volume changes during the hyperosmotic treatment, we found a close correlation between the enhancement of the osmotically active solute pool and the increase in cell volume. Sucrose shares several features with ectoine, another nonaccumulated osmoprotectant for S. meliloti. Overall, osmoregulation in S. melilotiappears to be strongly divergent from that in most bacteria.

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Böhmer, Isabella, Anja Spadinger, and Frank Ebel. "Functional comparison of the group III hybrid histidine kinases TcsC of Aspergillus fumigatus and NikA of Aspergillus nidulans." Medical Mycology 58, no. 3 (2019): 362–71. http://dx.doi.org/10.1093/mmy/myz069.

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Abstract In filamentous fungi, group III hybrid histidine kinases (HHKs) are major and nonredundant sensing proteins of the high osmolarity glycerol pathway. In this study, we have compared the biological functions of the two homologous group III HHKs TcsC of Aspergillus fumigatus and NikA of A. nidulans. As expected from previous studies, the corresponding mutants are severely impaired in their ability to adapt to hyperosmotic stress and are both resistant to the antifungal agent fludioxonil. However, our data also reveal novel phenotypes and differences between these mutants. Both TcsC and NikA are required for wild-type-like growth on Czapek-Dox medium and a normal resistance to certain oxidative stressors, whereas an increased resistance to the cell wall disturbing agents Congo red and Calcofluor white was found for the ΔtcsC but not for the ΔnikA mutant. With respect to the cell wall reorganizations that are triggered by fludioxonil in a TcsC/NikA-dependent manner, we observed similarities but also striking differences. Strains from seven Aspergillus species, including A. fumigatus and A. nidulans incorporated more chitin into their cell walls in response to fludioxonil. In contrast, fludioxonil treatment resulted in a shedding of surface accessible galactomannan and β-1,3-glucan in all Aspergillus strains tested except A. nidulans. Hence, the fludioxonil-induced activation of NikA results in a distinct and apparently A. nidulans-specific pattern of cell wall reorganizations that is not due to NikA itself, but its integration into the A. nidulans signaling network.

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Liedtke, C. M. "Bumetanide-sensitive NaCl uptake in rabbit tracheal epithelial cells is stimulated by neurohormones and hypertonicity." American Journal of Physiology-Lung Cellular and Molecular Physiology 262, no. 5 (1992): L621—L627. http://dx.doi.org/10.1152/ajplung.1992.262.5.l621.

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Loop diuretic-sensitive NaCl(K) cotransport plays a fundamental role in absorption and secretion of electrolytes in epithelial tissues. Cotransport activity was measured as uptake of 22Na, 36Cl, or 86Rb at 27 degrees C in isolated rabbit tracheal epithelial cells. Uptake of radiotracer was linear from 1 to 2 min after initiation of radiotracer transport. Bumetanide at 10 microM final concentration did not affect tracer uptake. The endogenous catecholamine l-epinephrine and alpha 2-adrenergic agent clonidine increased sodium and chloride uptake at least 5.5-fold. Bumetanide blocked sodium uptake by 85% and chloride uptake by 72%. 86Rb uptake was not affected by l-epinephrine, clonidine, or bumetanide. The alpha 2-adrenergic antagonist yohimbine blocked the effects of l-epinephrine and clonidine on 22Na and 36Cl uptake. In Ca(2+)-depleted transport medium, baseline levels of sodium and chloride uptake increased 3.8- and 2.4-fold, respectively, in a bumetanide-independent manner. Nevertheless, l-epinephrine and clonidine induced a net stimulation of sodium and chloride uptake similar to that found in Ca(2+)-replete medium. This response was reduced by bumetanide and yohimbine. The Ca(2+)-elevating agent ionomycin increased bumetanide-sensitive sodium and chloride uptake 7.2- and 6.2-fold, respectively. Replacement of chloride with gluconate or sodium with N-methyl-D-glucamine in the extracellular medium inhibited l-epinephrine and clonidine-stimulated bumetanide-sensitive sodium and chloride uptake, respectively. Osmotic shrinkage in hyperosmotic (500 mM NaCl with all other electrolytes at normal concentration) transport medium markedly increased bumetanide-inhibitable sodium and chloride uptake.(ABSTRACT TRUNCATED AT 250 WORDS)

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Beese-Sims, Sara E., Shih-Jung Pan, Jongmin Lee, Elizabeth Hwang-Wong, Brendan P. Cormack, and David E. Levin. "Mutants in the Candida glabrata Glycerol Channels Are Sensitized to Cell Wall Stress." Eukaryotic Cell 11, no. 12 (2012): 1512–19. http://dx.doi.org/10.1128/ec.00231-12.

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ABSTRACT Many fungal species use glycerol as a compatible solute with which to maintain osmotic homeostasis in response to changes in external osmolarity. In Saccharomyces cerevisiae , intracellular glycerol concentrations are regulated largely by the h igh o smolarity g lycerol (HOG) response pathway, both through induction of glycerol biosynthesis and control of its flux through the plasma membrane Fps1 glycerol channel. The channel activity of Fps1 is also controlled by a pair of positive regulators, Rgc1 and Rgc2. In this study, we demonstrate that Candida glabrata , a fungal pathogen that possesses two Fps1 orthologs and two Rgc1/-2 orthologs, accumulates glycerol in response to hyperosmotic stress. We present an initial characterization of mutants with deletions in the C. glabrata FPS1 (CAGL0C03267 [ www.candidagenome.org ]) and FPS2 (CAGL0E03894) genes and find that a double mutant accumulates glycerol, experiences constitutive cell wall stress, and is hypersensitive to treatment by caspofungin, an antifungal agent that targets the cell wall. This mutant is cleared more efficiently in mouse infections than is wild-type C. glabrata by caspofungin treatment. Finally, we demonstrate that one of the C. glabrata RGC orthologs complements an S. cerevisiae rgc1 rgc2 null mutant, supporting the conclusion that this regulatory assembly is conserved between these species.

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Chao, Shih-Chun, Chan-Wei Nien, Codrin Iacob, Dan-Ning Hu, Sheng-Chieh Huang, and Hung-Yu Lin. "Effects of Lutein on Hyperosmoticity-Induced Upregulation of IL-6 in Cultured Corneal Epithelial Cells and Its Relevant Signal Pathways." Journal of Ophthalmology 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/8341439.

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Dry eye is a common disorder characterized by deficiency of tear. Hyperosmoticity of tear stimulates inflammation and damage of ocular surface tissues and plays an essential role in the pathogenesis of dry eye. Cultured human corneal epithelial (CE) cells were used for the study of effects of lutein and hyperosmoticity on the secretion of IL-6 by CE cells. Cell viability of CE cells was not affected by lutein at 1–10 μM as determined by MTT assay. Hyperosmoticity significantly elevated the secretion of IL-6 by CE cells as measured by ELISA analysis. The constitutive secretion of IL-6 was not affected by lutein. Lutein significantly and dose-dependently inhibited hyperosmoticity-induced secretion of IL-6. Phosphorylated- (p)- p38 MAPK, p-JNK levels in cell lysates and NF-κB levels in cell nuclear extracts were increased by being exposed to hyperosmotic medium. JNK, p38, and NF-κB inhibitors decreased hyperosmoticity-induced secretion of IL-6. Lutein significantly inhibited hyperosmoticity-induced elevation of NF-κB, p38, and p-JNK levels. We demonstrated that lutein inhibited hyperosmoticity-induced secretion of IL-6 in CE cells through the deactivation of p38, JNK, and NF-κB pathways. Lutein may be a promising agent to be explored for the treatment of dry eye.

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KASHIWAGI, FUMIHIKO, YASUO KATAYAMA, JUN SHIMIZU, TATSUSHI KAMIYA, and AKIRO TERASHI. "Effect of a new hyperosmotic agent, NIK-242 injection, on brain water content, metabolites and cerebral blood flow in cerebral ischemia in the spontaneously hypertensive rat." Japanese Circulation Journal 55, no. 12 (1991): 1246–51. http://dx.doi.org/10.1253/jcj.55.1246.

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Fodorpataki, Laszlo. "Exogenous S-Methylmethionine Alleviates Salinity Stress by Modulation of Physiological Processes in Canola (Brassica napus)." International Journal of Agriculture and Biology 25, no. 01 (2021): 11–19. http://dx.doi.org/10.17957/ijab/15.1632.

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Canola is a moderately salt tolerant plant, high salinity inhibits germination of seeds, vegetative growth of young plantlets, and reduces biomass production. This study investigated the effects of priming with 1 mM S-methylmethionine (SMM) on germination, leaf gas exchange, induced chlorophyll fluorescence, photosynthetic pigment content and membrane damage through lipid peroxidation by exposing canola (Brassica napus L. cv. Cindi) plants to moderate and severe salt stress (induced by 60 mM and 120 mM NaCl) for different periods. Priming with SMM alleviated the reduction of net photosynthetic rate, the effective quantum efficiency and efficiency of excitation energy capture by open photosystem II reaction centers, chlorophylls to carotenoids ratio, enhanced water use efficiency and contributed to reduction of oxidative membrane damage in fully developed young leaves. Delay and inhibition of seed germination by salt stress were significantly reduced by SMM, as well as the non-photochemical quenching of the singlet excited state of chlorophyll a, suggesting a more efficient protection against hyperosmotic stress, ionic toxicity and associated oxidative stress in primed plants exposed to high salinity. This first assay of SMM as a priming agent for canola plants under high salinity contributes to a better understanding of the mode of action of this natural, plant-derived bioactive compound and the optimization of canola cultivation under the adverse growth conditions caused by salt stress. © 2021 Friends Science Publishers

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Gokal, Ram, Chandra D. Mistry, Elizabeth Peers, et al. "A United Kingdom Multicenter Study of Icodextrin in Continuous Ambulatory Peritoneal Dialysis." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 14, no. 2_suppl (1994): 22–27. http://dx.doi.org/10.1177/089686089401402s03.

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While glucose remains the only osmotic agent used universally for peritoneal dialysis, its various shortcomings for the long dwell equilibration continuous ambulatory peritoneal dialysis (CAPD) has led to a search for alternative agents. The large molecular weight group has been of interest, because these agents theoretically would lead to greater ultrafiltration and a better metabolic profile. Mostsubstances (dextrans, charged macromolecules) have been found unsuitable for reasons of insolubility, allergenicity, and peritoneal toxicity. Short-chain polypeptides have been studied in humans, but the experience is limited, and there is the potential for allergenicity with long-term use. The only large molecular weight agent that has been studied in some detail but hitherto in one center only and in a limited number of patients is glucose polymer (generic name, icodextrin). Because of the promise shown by these initial studies, a randomized controlled multicenter investigation of icodextrin in CAPD (MIDAS Study Group) was undertaken to evaluate the long-term safety and efficacy by comparing daily overnight (8 12 hours) use of a slightly hypo-osmolar solution (282 mOsm/ kg) with 1.36% (346 mOsm/kg) and 3.86% (484 mOsm/kg) glucose exchanges. Over a 6-month period 209 patients from 11 centers in the United Kingdom were randomized, with 106 allocated to receive icodextrin (study group) and 103 to remain on glucose (control group). One hundred and thirty-eight patients completed the 6-month study (71 control, 67 study). The mean net ultrafiltration overnight with icodextrin was 3.5 times greater than 1.36% at 8 hours and 5.5 times greater at 12 hours (p<0.0001), but no different from that of 3.86% glucose at 8 and 12 hours (although for the latter dwell the net mean ultrafiltration volume was greater by about 140 mL). Biochemical profiles were no different except for a small fall in serum sodium and chloride in the icodextrin group. The mean serum maltose rose to a steady-state level of 1.2 g/L within 2 weeks and remained stable. The mean carbohydrate absorbed for icodextrin (29±5 g) was lower than with 3.86% glucose (62±5 g). The use of icodextrin did not increase the incidence of peritonitis, nor did it alter its outcome, affect uptake of icodextrin from the peritoneum, alter serum osmolality or sodium levels. There were no adverse effects associated with the use of icodextrin, and the overall CAPD-related symptom score was significantly better for icodextrin than control subjects. This study and subsequent extensive use and clinical experience has demonstrated that the daily use of an iso-osmolar icodextrin solution is generally well tolerated, effective, and could replace the overnight use of hyperosmotic glucose solution. Its use was of equal efficacy in peritonitis and in diabetic patients. The elevated levels of maltose did not appear to have any clinical side effects.

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Drozdov, V. N., E. V. Shikh, A. A. Astapovskiy, S. Yu Serebrova, and I. A. Komissarenko. "Modern opportunities of pharmacological effect on gut microbiome and motor activity." Meditsinskiy sovet = Medical Council, no. 12 (September 19, 2021): 200–208. http://dx.doi.org/10.21518/2079-701x-2021-12-200-208.

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Currently, lactulose is known to most as a laxative that has a hyperosmotic effect, stimulating intestinal peristalsis. The drug has long established itself as a safe and effective medicine. Lactulose is one of the few drugs that is approved for use in pregnant women and children under 6 months of age with functional constipation. The prebiotic properties of lactulose were discovered in 1957. After research, it was found that it promotes the growth of beneficial bacteria, such as bifidobacteria and lactobacilli. In addition to being used as an effective weak and prebiotic agent, lactulose has been successfully used since 1966 for the treatment of hepatic encephalopathy. The mechanism of action of the drug is that it prevents the absorption of excess ammonia, which is formed in the large intestine, through the hydrolysis of protein and urea by the intestinal microflora. Lactulose, which has a wide range of effects on nitrogen metabolism by the intestinal microflora, affects not only ammonia, but also other bacterial toxins as a result of the studies that have demonstrated the reliable effectiveness of the drug, the world’s leading professional communities have included lactulose in their recommendations as the drug of choice for the treatment of patients with hepatic encephalopathy at any stage of the disease. The article presents current data on the effectiveness and safety of the use of lactulose in various diseases. In addition, attention is paid to such a concept as microbiota. Its functions and influence on the human body are described.

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Kornguth, Steven E., Patrick A. Turski, William H. Perman, et al. "Magnetic resonance imaging of gadolinium-labeled monoclonal antibody polymers directed at human T lymphocytes implanted in canine brain." Journal of Neurosurgery 66, no. 6 (1987): 898–906. http://dx.doi.org/10.3171/jns.1987.66.6.0898.

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✓ Two different murine monoclonal anti-human T cell antibodies, that were coupled to gadolinium (Gd), bind specifically to human T lymphocyte cells implanted in canine brain. This binding was at a concentration of Gd sufficient to detect the implanted cells and to distinguish them from the surrounding brain tissue with magnetic resonance imaging (MRI) at a field strength of 1.5 Tesla. These Gd-labeled immunoglobulin preparations did not bind bovine T cells at a concentration sufficient to be detected on MRI. A protein solution containing the immunoglobulins (100 µg), gelatin (2 mg), and bovine serum albumin (2.5 mg) was reacted with the dianhydride of diethylenetriaminepenta-acetic acid (DTPA); the DTPA serves as a metal chelator and as a protein crosslinking agent. The DTPA-protein complex was reacted with Gd chloride. There were approximately 10 DTPA residues per protein molecule in the modified protein mixture. Isolated human or bovine monocytes (approximately 12 million cells) were implanted in the brains of anesthetized dogs in a volume of 40 µl. The blood-brain barrier was then disrupted by the intra-arterial injection of hyperosmotic mannitol, and the Gd-labeled antibodies were injected through a catheter placed at the branch of the internal and external carotid arteries. The brains were imaged 48 to 72 hours later. The MRI scans revealed a markedly decreased T1 relaxation time with a high signal intensity (TE = 25 msec, TR = 200 msec) related to the human T cell implants. There was no evidence of decreased T1 at the site of the bovine T cells. Neither control murine gamma globulin coupled to Gd-DTPA nor anti-human T cell antibodies uncoupled to Gd modified the MRI contrast of the human T cells in the brain.

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Mangat, Halinder S., Xian Wu, Linda M. Gerber, et al. "Hypertonic Saline is Superior to Mannitol for the Combined Effect on Intracranial Pressure and Cerebral Perfusion Pressure Burdens in Patients With Severe Traumatic Brain Injury." Neurosurgery 86, no. 2 (2019): 221–30. http://dx.doi.org/10.1093/neuros/nyz046.

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Abstract BACKGROUND Hypertonic saline (HTS) and mannitol are effective in reducing intracranial pressure (ICP) after severe traumatic brain injury (TBI). However, their simultaneous effect on the cerebral perfusion pressure (CPP) and ICP has not been studied rigorously. OBJECTIVE To determine the difference in effects of HTS and mannitol on the combined burden of high ICP and low CPP in patients with severe TBI. METHODS We performed a case–control study using prospectively collected data from the New York State TBI-trac® database (Brain Trauma Foundation, New York, New York). Patients who received only 1 hyperosmotic agent, either mannitol or HTS for raised ICP, were included. Patients in the 2 groups were matched (1:1 and 1:2) for factors associated with 2-wk mortality: age, Glasgow Coma Scale score, pupillary reactivity, hypotension, abnormal computed tomography scans, and craniotomy. Primary endpoint was the combined burden of ICPhigh (&gt; 25 mm Hg) and CPPlow (&lt; 60 mm Hg). RESULTS There were 25 matched pairs for 1:1 comparison and 24 HTS patients matched to 48 mannitol patients in 1:2 comparisons. Cumulative median osmolar doses in the 2 groups were similar. In patients treated with HTS compared to mannitol, total number of days (0.6 ± 0.8 vs 2.4 ± 2.3 d, P &lt; .01), percentage of days with (8.8 ± 10.6 vs 28.1 ± 26.9%, P &lt; .01), and the total duration of ICPhigh + CPPlow (11.12 ± 14.11 vs 30.56 ± 31.89 h, P = .01) were significantly lower. These results were replicated in the 1:2 match comparisons. CONCLUSION HTS bolus therapy appears to be superior to mannitol in reduction of the combined burden of intracranial hypertension and associated hypoperfusion in severe TBI patients.

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Hein, Travis W., James C. Liao, and Lih Kuo. "oxLDL specifically impairs endothelium-dependent, NO-mediated dilation of coronary arterioles." American Journal of Physiology-Heart and Circulatory Physiology 278, no. 1 (2000): H175—H183. http://dx.doi.org/10.1152/ajpheart.2000.278.1.h175.

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Our previous studies implicated that oxidized low-density lipoprotein (oxLDL), a putative atherogenic agent, impairs endothelium-dependent, nitric oxide (NO)-mediated dilation of isolated coronary arterioles to pharmacological agonists. However, it is not known whether oxLDL specifically affects NO-mediated dilation or generally impairs endothelium-dependent function, including the release of hyperpolarizing factors. In this regard, we investigated the dilation of isolated porcine coronary arterioles (50- to 100-μm luminal diameter) in response to the activation of various endothelium-dependent pathways before and after intraluminal incubation of the vessels with oxLDL (0.5 mg protein/ml for 60 min). In the absence of oxLDL, all vessels developed basal tone and dilated in response to the activation of NO synthase (by flow and adenosine), cyclooxygenase (by arachidonic acid), cytochrome P-450 monooxygenase (by bradykinin), and endothelial membrane hyperpolarization (by sucrose-induced hyperosmolarity). Incubation of the vessels with oxLDL for 60 min did not alter basal tone but did inhibit the vasodilatory responses to increased flow and adenosine in a manner similar to that of the NO synthase inhibitor N G-nitro-l-arginine methyl ester. Vasodilations in response to flow and adenosine were not affected by intraluminal incubation of the vessels with either a vehicle solution or the native LDL (0.5 mg protein/ml, 60 min). In contrast with the NO-mediated response, hyperosmotic vasodilation mediated by endothelial hyperpolarization was not affected by oxLDL. Endothelium-dependent dilations to the cyclooxygenase activator arachidonic acid and to the cytochrome P-450 monooxygenase activator bradykinin and endothelium-independent vasodilation to sodium nitroprusside were also not altered by oxLDL. Collectively, these results indicate that oxLDL has a selective effect on endothelium-dependent dilation with specific impairment of the NO-mediated response, whereas cyclooxygenase and cytochrome P-450 monooxygenase-mediated dilations are spared from this inhibitory effect. In addition, oxLDL does not appear to affect vasodilation mediated by hyperpolarization of the endothelium.

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Мусина, Г. Р., А. А. Гавдуш, Н. В. Черномырдин та ін. "Оптические свойства гиперосмотических агентов для иммерсионного просветления тканей в терагерцовом диапазоне". Журнал технической физики 129, № 7 (2020): 1020. http://dx.doi.org/10.21883/os.2020.07.49576.65-20.

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The transmission spectra of the most common hyperosmotic agents, such as pure glycerol, propylene glycol (PG), dimethyl sulfoxide (DMSO), polyethylene glycol (PEG) with 200, 300, 400 and 600 Da molecular weights, and their aqueous solutions, as well as aqueous solutions of sucrose, glucose, fructose, dextran 40 and 70 were measured. The experiments were carried out using a THz pulsed spectrometer with a vacuum measuring compartment to reduce the effect of water vapor on spectral measurements. The dielectric properties of hyperosmotic agents were restored in the spectral range from 0.1 to 2.5 THz and the dependence of the amplitude absorption coefficient on the concentration of considered agents at 0.5 THz frequency was constructed. The obtained results make it possible to choose the optimal agents for immersion optical clearing in the THz range.

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Baldwin, David L., Josef M. Miller, K. Agnetha Ohlsén, and Alfred L. Nuttall. "Cochlear Blood Flow and Microvascular Resistance Changes in Response to Hypertonic Glycerol, Urea, and Mannitol Infusions." Annals of Otology, Rhinology & Laryngology 101, no. 2 (1992): 168–75. http://dx.doi.org/10.1177/000348949210100212.

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The effect of hyperosmotic agents on cochlear blood flow (CBF) was tested in normal guinea pigs and in guinea pigs having prior unilateral operations to ablate the endolymphatic duct. Laser-Doppler-measured CBF was normalized to remove apparent changes related directly to systemic blood pressure. Hyperosmotic fluids were given via venous infusion: glycerol (20% and 40% solutions), urea (10%, 30%, and 40% solutions), and mannitol (40% solution). All agents were dissolved in 0.9% saline and the mixtures were given at a rate of 0.3 to 0.6 mL/min for 5 minutes. Control infusions were of 0.9% saline and isotonic dextran 70 (Pharmacia). All hyperosmotic infusions resulted in similar increases in normalized cochlear blood flow (nCBF) that extended to a maximum of 300 % of the baseline value in a dose-dependent way during the infusion time period. Within approximately 30 minutes following infusions, nCBF had returned to baseline levels. Saline infusion alone had little effect on nCBF, but isotonic dextran 70 gave a sustained increase to 122% of the baseline levels. There was no difference between the responses of nCBF in hydropic and normal cochleas for either control or hyperosmotic solutions. Measurements of systemic hematocrit at time intervals during and following the infusions showed that transient reductions of up to approximately 8% (for the maximum osmotic challenge) occurred during the infusion. It is concluded that the hyperosmotic treatments tested here are equally effective for short-term enhancements of nCBF in both normal and hydropic cochleas. The basis of the flow increase is partially rheologic and partially due to a local vasodilation.

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Siddiqui, Manzer, Saud Alamri, Mutahhar Al-Khaishany, et al. "Exogenous Melatonin Counteracts NaCl-Induced Damage by Regulating the Antioxidant System, Proline and Carbohydrates Metabolism in Tomato Seedlings." International Journal of Molecular Sciences 20, no. 2 (2019): 353. http://dx.doi.org/10.3390/ijms20020353.

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Melatonin, a natural agent, has multiple functions in animals as well as in plants. However, its possible roles in plants under abiotic stress are not clear. Nowadays, soil salinity is a major threat to global agriculture because a high soil salt content causes multiple stresses (hyperosmotic, ionic, and oxidative). Therefore, the aim of the present study was to explore: (1) the involvement of melatonin in biosynthesis of photosynthetic pigments and in regulation of photosynthetic enzymes, such as carbonic anhydrase (CA) and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco); (2) the role of melatonin in osmoregulation by proline and carbohydrate metabolism; and (3) the function of melatonin in the antioxidant defense system under salinity. Outcomes of the study reveal that under non-saline conditions, application of melatonin (20 and 50 µM) improved plant growth, viz. shoot length, root length, shoot fresh weight (FW), root FW, shoot dry weight (DW), root DW and leaf area and physio-biochemical parameters [chlorophyll (Chl) a and b, proline (Pro) and total soluble carbohydrates (TSC) content, and increased the activity of CA and Rubisco]. However, tomato seedlings treated with NaCl exhibited enhanced Chl degradation, electrolyte leakage (EL), malondialdehyde (MDA) and reactive oxygen species (ROS; superoxide and hydrogen peroxide). ROS were detected in leaf and root. Interestingly, application of melatonin improved plant growth and reduced EL, MDA and ROS levels through upregulation of photosynthesis enzymes (CA, Rubisco), antioxidant enzymes (superoxide dismutase, catalase, glutathione reductase and ascorbate reductase) and levels of non-enzymatic antioxidants [ascorbate (ASC) and reduced glutathione (GSH)], as well as by affecting the ASC—GSH cycle. Additionally, exogenous melatonin also improved osmoregulation by increasing the content of TSC, Pro and Δ1-pyrroline-5-carboxylate synthetase activity. These results suggest that melatonin has beneficial effects on tomato seedlings growth under both stress and non-stress conditions. Melatonin’s role in tolerance to salt stress may be associated with the regulation of enzymes involved in photosynthesis, the antioxidant system, metabolism of proline and carbohydrate, and the ASC—GSH cycle. Also, melatonin could be responsible for maintaining the high ratios of GSH/GSSG and ASC/DHA.

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Dabrowski, Wojciech, Dorota Siwicka-Gieroba, Chiara Robba, et al. "Potentially Detrimental Effects of Hyperosmolality in Patients Treated for Traumatic Brain Injury." Journal of Clinical Medicine 10, no. 18 (2021): 4141. http://dx.doi.org/10.3390/jcm10184141.

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Hyperosmotic therapy is commonly used to treat intracranial hypertension in traumatic brain injury patients. Unfortunately, hyperosmolality also affects other organs. An increase in plasma osmolality may impair kidney, cardiac, and immune function, and increase blood–brain barrier permeability. These effects are related not only to the type of hyperosmotic agents, but also to the level of hyperosmolality. The commonly recommended osmolality of 320 mOsm/kg H2O seems to be the maximum level, although an increase in plasma osmolality above 310 mOsm/kg H2O may already induce cardiac and immune system disorders. The present review focuses on the adverse effects of hyperosmolality on the function of various organs.

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Rojas Briones, Mónica Elizabeth, Ricardo Oliva Rodríguez, Omar González Ortega, et al. "Antibacterial effect of a hyperosmotic solution containing sorbate and ethanol on Enterococcus faecalis in planktonic form and as biofilm: an in vitro study." Investigación Clínica 61, no. 2 (2020): 105–16. http://dx.doi.org/10.22209/ic.v61n2a01.

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The antibacterial effect of a hyperosmotic solution containing sorbate and ethanol on E. faecalis in planktonic state and in biofilm was evaluated. Three hyperosmotic solutions (HS-A, HS-B y HS-C) were obtained from different formulations of potassium sorbate and sodium chloride, which were tested as antimicrobials against planktonic forms of E. faecalis, in McFarland standards from 0.5 to 7, using the sedimentation technique and colony forming units (CFU) count. Afterwards an E. faecalis biofilm was produced in the palatal roots of upper first molars, by a static method in 21 days; subsequently they were prepared biomechanically by the Universal Protaper system, using the hyperosmotic solution B as an irrigant to evaluate the bacterial load reduction. One pre-instrumentation sample and one post-instrumentation sample were taken, and then were processed and cultivated to count CFU. Consecutively, roots were observed by scanning electron microscopy. The hyperosmotic solution had an important antibacterial effect when used against E. faecalis in planktonic state; solutions HS-A and HS-B were effective in eliminating E. faecalis up to 7 McFarland, while a statistical difference (p˂0.001) was observed in reducing the bacterial load in the biofilm, based on the log10 CFU count. The final solution tested seemed not to harm the dentinal structure and was capable of causing morphological changes to the bacterial cell consistent with a hyperosmotic shock. Thus, the solutions tested could be an option to be considered as irrigating agents; nonetheless further research is required regarding its biocompatibility.

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Wang, R. K., Xiangqun Xu, Yonghong He, and J. B. Elder. "Investigation of optical clearing of gastric tissue immersed with hyperosmotic agents." IEEE Journal of Selected Topics in Quantum Electronics 9, no. 2 (2003): 234–42. http://dx.doi.org/10.1109/jstqe.2003.813300.

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Kolesnikov, A. S., E. A. Kolesnikova, K. N. Kolesnikova, et al. "THz monitoring of the dehydration of biological tissues affected by hyperosmotic agents." Physics of Wave Phenomena 22, no. 3 (2014): 169–76. http://dx.doi.org/10.3103/s1541308x14030029.

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Hirsh, Andrew J. "Altering airway surface liquid volume: inhalation therapy with amiloride and hyperosmotic agents." Advanced Drug Delivery Reviews 54, no. 11 (2002): 1445–62. http://dx.doi.org/10.1016/s0169-409x(02)00161-8.

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Pickering, James D., Ed White, Adrian M. Duke, and Derek S. Steele. "DHPR activation underlies SR Ca2+ release induced by osmotic stress in isolated rat skeletal muscle fibers." Journal of General Physiology 133, no. 5 (2009): 511–24. http://dx.doi.org/10.1085/jgp.200910191.

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Changes in skeletal muscle volume induce localized sarcoplasmic reticulum (SR) Ca2+ release (LCR) events, which are sustained for many minutes, suggesting a possible signaling role in plasticity or pathology. However, the mechanism by which cell volume influences SR Ca2+ release is uncertain. In the present study, rat flexor digitorum brevis fibers were superfused with isoosmotic Tyrode's solution before exposure to either hyperosmotic (404 mOsm) or hypoosmotic (254 mOsm) solutions, and the effects on cell volume, membrane potential (Em), and intracellular Ca2+ ([Ca2+]i) were determined. To allow comparison with previous studies, solutions were made hyperosmotic by the addition of sugars or divalent cations, or they were made hypoosmotic by reducing [NaCl]o. All hyperosmotic solutions induced a sustained decrease in cell volume, which was accompanied by membrane depolarization (by 14–18 mV; n = 40) and SR Ca2+ release. However, sugar solutions caused a global increase in [Ca2+]i, whereas solutions made hyperosmotic by the addition of divalent cations only induced LCR. Decreasing osmolarity induced an increase in cell volume and a negative shift in Em (by 15.04 ± 1.85 mV; n = 8), whereas [Ca2+]i was unaffected. However, on return to the isoosmotic solution, restoration of cell volume and Em was associated with LCR. Both global and localized SR Ca2+ release were abolished by the dihydropyridine receptor inhibitor nifedipine by sustained depolarization of the sarcolemmal or by the addition of the ryanodine receptor 1 inhibitor tetracaine. Inhibitors of the Na-K-2Cl (NKCC) cotransporter markedly inhibited the depolarization associated with hyperosmotic shrinkage and the associated SR Ca2+ release. These findings suggest (1) that the depolarization that accompanies a decrease in cell volume is the primary event leading to SR Ca2+ release, and (2) that volume-dependent regulation of the NKCC cotransporter contributes to the observed changes in Em. The differing effects of the osmotic agents can be explained by the screening of fixed charges by divalent ions.

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Orlov, S. N., J. Tremblay, and P. Hamet. "Cell volume in vascular smooth muscle is regulated by bumetanide-sensitive ion transport." American Journal of Physiology-Cell Physiology 270, no. 5 (1996): C1388—C1397. http://dx.doi.org/10.1152/ajpcell.1996.270.5.c1388.

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Vascular smooth muscle cells (VSMC) exhibit shrinkage-induced bumetanide-inhibited 86Rb influx and ethylisopropylamiloride (EIPA)-inhibited 22Na influx. In this study, we examined the role of these transport pathways in volume adjustment of VSMC after isosmotic and hyperosmotic shrinkage. Cell volume was assessed by measurement of [14C]urea distribution. An initial 18-20% cell volume decrease in isosmotically shrunken VSMC was followed by a regulatory volume increase (RVI). RVI was completely abolished by bumetanide but not by EIPA. No RVI was noted in hyperosmotically shrunken VSMC. The initial rate of bumetanide-inhibited 86Rb influx was two- to threefold higher in isosmotically shrunken VSMC than with hyperosmotic shrinkage. Hyperosmotic shrinkage of VSMC was accompanied by a three- to fourfold increase in the rate of bumetanide-inhibited 86Rb efflux, whereas isosmotic shrinkage augmented this component by only 20-30%. In contrast to bumetanide-inhibited 86Rb influx, isosmotic shrinkage slightly increased the rate of EIPA-sensitive 22Na influx. Hyperosmotic shrinkage led to transient activation of EIPA-inhibited 22Na influx, which was completely abolished in 15 min. Activation of adenosine 3',5'-cyclic monophosphate (cAMP) signaling with isoproterenol arborized VSMC and decreased their volume by approximately 15%. A similar volume decrease was seen in VSMC treated with the microfilament-disrupting compound, cytochalasin B. The isoproterenol-induced cell volume decrease was prolonged by the addition of bumetanide. Unlike isoproterenol, agents that raise intracellular Ca2+ (A-23187 and angiotensin II) did not modify VSMC volume. Thus our data demonstrate involvement of cAMP signaling in the regulating of VSMC volume and a key role of bumetanide-inhibited ion transport in the RVI after isosmotically induced shrinkage.

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Traynelis, S. F., and R. Dingledine. "Role of extracellular space in hyperosmotic suppression of potassium-induced electrographic seizures." Journal of Neurophysiology 61, no. 5 (1989): 927–38. http://dx.doi.org/10.1152/jn.1989.61.5.927.

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1. Focal electrographic seizures arose in the CA1 region of rat hippocampal slices bathed in elevated (8.5 mM) external potassium [( K+]o). High [K+]o also induced spontaneous interictal bursts that originated in area CA3 and propagated to CA1. To examine the contribution to electrographic seizure initiation of excitatory mechanisms that are influenced by extracellular volume, we studied the effect of hyperosmotic expansion of interstitial volume on seizure occurrence, interictal bursts, and excitatory synaptic transmission. The tissue electrical resistance was also measured leading up to and during seizures. 2. Media made 5-30 mosmol/kg hyperosmotic by addition of agents restricted to the extracellular space (mannitol, sucrose, raffinose, L-glucose, dextran) rapidly and reversibly abolished [K+]o-induced spontaneous CA1 seizures in 86% of slices tested. However, similar increases in osmolality effected by agents that access the intracellular compartment (D-glucose, glycerol) did not influence electrographic seizure occurrence. Hyperosmotic changes with plasma membrane impermeable compounds, but not permeable compounds, produced significant concentration-dependent decreases (1-10%) in the electrical resistance of CA1 stratum pyramidale. Because tissue resistance is proportional to extracellular volume, these results suggest that hyperosmotic suppression of electrographic seizures is associated with expansion of the extracellular space in hippocampal slices. 3. Measurement of electrical resistance of the CA1 stratum pyramidale during spreading depression and electrographic seizure revealed an increase in tissue resistance to 122% and 108% of control, respectively. Furthermore, a slight (approximately 2%) but significant increase in electrical resistance gradually occurred over the 20 s immediately preceding seizure generation. The observed increase in tissue resistance suggests extracellular space is decreased during these events. 4. Hyperosmolality did not alter CA3 interictal burst frequency. However, burst intensity, estimated from the total length of the burst waveform, was significantly reduced in both the CA3 (83% control) and CA1 region (67% control) when osmotic changes were imposed by plasma membrane impermeant compounds. Additionally, media made hypoosmotic by removal of 7.5 mM NaCl reversibly increased burst intensity. 5. High [K+]o potentiated excitatory synaptic transmission and excitatory postsynaptic potential (EPSP) spike coupling.(ABSTRACT TRUNCATED AT 400 WORDS)

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Garg, Rakesh, Arindam Choudhary, Mridula Pawar, DeshDeepak Panwar, SR Goel, and MD Kaur. "Gangrene of hand due to faulty intravenous cannulation: Be cautious with hyperosmotic agents." Journal of Anaesthesiology Clinical Pharmacology 27, no. 3 (2011): 418. http://dx.doi.org/10.4103/0970-9185.83704.

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Musina, G. R., A. A. Gavdush, N. V. Chernomyrdin, et al. "Optical Properties of Hyperosmotic Agents for Immersion Clearing of Tissues in Terahertz Spectroscopy." Optics and Spectroscopy 128, no. 7 (2020): 1026–35. http://dx.doi.org/10.1134/s0030400x20070279.

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Schreiner, Thomas, Martina R. Mohrs, Rosemarie Blau-Wasser, et al. "Loss of the F-Actin Binding and Vesicle-Associated Protein Comitin Leads to a Phagocytosis Defect." Eukaryotic Cell 1, no. 6 (2002): 906–14. http://dx.doi.org/10.1128/ec.1.6.906-914.2002.

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ABSTRACT Comitin is an F-actin binding and membrane-associated protein from Dictyostelium discoideum, which is present on Golgi and vesicle membranes and changes its localization in response to agents affecting the cytoskeleton. To investigate its in vivo functions we have generated knockout mutants by gene replacement. Based on comitin's in vitro functions we examined properties related to vesicular transport and microfilament function. Whereas cell growth, pinocytosis, secretion, chemotaxis, motility, and development were unaltered, comitin-lacking cells were impaired in the early steps of phagocytosis of Saccharomyces cerevisiae particles and of Escherichia coli, whereas uptake of latex beads was unaffected. Furthermore, the lack of comitin positively affected survival of pathogenic bacteria. Mutant cells also showed an altered response to hyperosmotic shock in comparison to the wild type. The redistribution of comitin during hyperosmotic shock in wild-type cells and its presence on early phagosomes suggest a direct involvement of comitin in these processes.

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Gilmore, Wayne. "SAFELY UTILIZING ORAL HYPEROSMOTIC AGENTS IN THE INTIAL TREATMENT OF ACUTE ANGLE CLOSURE GLAUCOMA." Optometry and Vision Science 78, SUPPLEMENT (2001): 168. http://dx.doi.org/10.1097/00006324-200112001-00270.

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Kolesnikov, A. S., E. A. Kolesnikova, A. P. Popov, M. M. Nazarov, A. P. Shkurinov, and V. V. Tuchin. "In vitro terahertz monitoring of muscle tissue dehydration under the action of hyperosmotic agents." Quantum Electronics 44, no. 7 (2014): 633–40. http://dx.doi.org/10.1070/qe2014v044n07abeh015493.

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Wang, Ruikang K., Xiangqun Xu, Valery V. Tuchin, and James B. Elder. "Concurrent enhancement of imaging depth and contrast for optical coherence tomography by hyperosmotic agents." Journal of the Optical Society of America B 18, no. 7 (2001): 948. http://dx.doi.org/10.1364/josab.18.000948.

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Vargas, Gracie, Allison Readinger, Susan S. Dozier, and Ashley J. Welch. "Morphological Changes in Blood Vessels Produced by Hyperosmotic Agents and Measured by Optical Coherence Tomography ¶." Photochemistry and Photobiology 77, no. 5 (2007): 541–49. http://dx.doi.org/10.1562/0031-8655(2003)0770541mcibvp2.0.co2.

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Vargas, Gracie, Allison Readinger, Susan S. Dozier, and Ashley J. Welch. "Morphological Changes in Blood Vessels Produced by Hyperosmotic Agents and Measured by Optical Coherence Tomography¶." Photochemistry and Photobiology 77, no. 5 (2003): 541. http://dx.doi.org/10.1562/0031-8655(2003)077<0541:mcibvp>2.0.co;2.

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Kavanagh, Oisín, Fiona Hogan, Caoimhe Murphy, Denise Croker, and Gavin Walker. "Formulating a Stable Mannitol Infusion while Maintaining Hyperosmolarity." Pharmaceutics 12, no. 2 (2020): 187. http://dx.doi.org/10.3390/pharmaceutics12020187.

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Mannitol infusion is commonly used in the treatment of intracranial hypertension following traumatic brain injury. It has long been known to have stability issues, specifically, mannitol recrystallises from solutions greater than 10% w/v in ambient conditions. This can happen at any time, whether on the pharmacy shelf or during a medical procedure. This study describes the stability limits of 20% w/v mannitol infusion (the most common strength used clinically) and proposes a number of safer, stable and tuneable hyperosmotic formulations of mannitol in combination with clinically acceptable osmotic agents (NaCl, sorbitol and glycerol).

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Селифонов, А. А., та В. В. Тучин. "Определение коэффициента диффузии 40%-глюкозы в ткани десны человека оптическим методом". Журнал технической физики 128, № 6 (2020): 760. http://dx.doi.org/10.21883/os.2020.06.49408.29-20.

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Due to the significant development of optical technologies and methods used for both noninvasive diagnostics (optical biopsy, tomography, etc.) and improvement of therapeutic protocols (photodynamic therapy, photothermal destruction, etc.), the increasing of the penetration depth of light into tissues is an urgent problem, which is solved using immersion agents, including hyperosmotic, such as glucose. Moreover, the determination of the quantitative characteristics of the diffusion of immersion agents in tissues is important. In this work, we determined the effective diffusion coefficient of a 40%-glucose solution in human gingival mucosa tissue in vitro, which was (4.1 ± 0.8) • 10-6 cm2/s. The method is based on recording the kinetics of changes in the diffuse reflection spectra and applying the free diffusion model.

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Journal articles on the topic 'Hyperosmotic agent'

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