DIABETIC MEDICINE, Issue 10 2001
Y. P. Samarasinghe
Abstract Background, A case of avascular necrosis (AN) of the navicular bone, in a 24-year-old woman with Type 1 diabetes with peripheral neuropathy, in the absence of any history of direct trauma is presented. The clinical and radiological features at presentation suggested an evolving Charcot arthropathy (CA), but subsequent serial X-rays clearly confirmed AN. Conclusions Swelling and foot deformity in association with long-standing diabetic peripheral neuropathy is suggestive of CA, although AN, a less common condition, may show the same clinical features. It is therefore important to undertake further confirmatory radiological investigations if there is any doubt about the diagnosis. Diabet. Med. 18, 846,848 (2001) [source]

Molecular Design of Superabsorbent Polymers for Organic Solvents by Crosslinked Lipophilic Polyelectrolytes,

ADVANCED FUNCTIONAL MATERIALS, Issue 24 2008
Toshikazu Ono
Abstract Molecular design of lipophilic polyelectrolyte gels as superabsorbent polymers that exhibit a high degree of swelling in less-polar and nonpolar organic solvents is demonstrated. A small amount of tetraalkylammonium tetraphenylborate with long alkyl chains as a lipopholic ion pair is incorporated into crosslinked polyacrylates with variable alkyl chain lengths to provide novel lipophilic polyelectrolyte gels. Their swelling degree becomes more than 100 times as much as their dried weights in various organic solvents. The high effectiveness of the swellable solvents shifts to the polar ones by decreasing the length of the alkyl chain. Swelling or collapsing of the lipophilic polyelectrolyte gels originates from both incompatibility of the polymer chains in the media and dissociation of ionic groups. Thus, a unique superabsorbency is observed when the polymer chains have good compatibility with the solvents and the solvents have relatively high polarities enough to dissociate the ionic groups. By varying the polarity of the neutral monomer in these polyelectrolyte gels, the design of gels that can absorb solvents of nearly any polarity is demonstrated. [source]

Solvent-Assisted Decal Transfer Lithography by Oxygen-Plasma Bonding and Anisotropic Swelling

ADVANCED MATERIALS, Issue 22 2010
Pilnam Kim
Solvent-assisted decal transfer lithography (DTL) enables the formation of well-defined micro-/nanostructures over a large area (,4 in. wafer) by combining irreversible oxygen bonding and anisotropic swelling of poly(dimethoxylsiloxane) (PDMS). Such swelling-induced stress gradient allows for cohesion failure of the skin layer upon removal of the stamp, leaving behind a highly uniform layer (,100,nm). [source]

An upscaling method and a numerical analysis of swelling/shrinking processes in a compacted bentonite/sand mixture

INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 15 2004
M. Xie
Abstract This paper presents an upscaling concept of swelling/shrinking processes of a compacted bentonite/sand mixture, which also applies to swelling of porous media in general. A constitutive approach for highly compacted bentonite/sand mixture is developed accordingly. The concept is based on the diffuse double layer theory and connects microstructural properties of the bentonite as well as chemical properties of the pore fluid with swelling potential. Main factors influencing the swelling potential of bentonite, i.e. variation of water content, dry density, chemical composition of pore fluid, as well as the microstructures and the amount of swelling minerals are taken into account. According to the proposed model, porosity is divided into interparticle and interlayer porosity. Swelling is the potential of interlayer porosity increase, which reveals itself as volume change in the case of free expansion, or turns to be swelling pressure in the case of constrained swelling. The constitutive equations for swelling/shrinking are implemented in the software GeoSys/RockFlow as a new chemo-hydro-mechanical model, which is able to simulate isothermal multiphase flow in bentonite. Details of the mathematical and numerical multiphase flow formulations, as well as the code implementation are described. The proposed model is verified using experimental data of tests on a highly compacted bentonite/sand mixture. Comparison of the 1D modelling results with the experimental data evidences the capability of the proposed model to satisfactorily predict free swelling of the material under investigation. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Synthesis of poly(N,N -diethylacrylamide- co -acrylic acid) hydrogels with fast response rate in NaCl medium

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008
Hongliang Liu
Abstract A series of thermo- and pH-sensitive poly (N,N -diethylacrylamide- co -acrylic acid) (P(DEA- co -AA)) hydrogels were prepared in NaCl aqueous solutions with different concentrations. Swelling and deswelling studies showed that in comparison with conventional P(DEA- co -AA) hydrogels (prepared in distilled water), the P(DEA- co -AA) hydrogels thus prepared had almost the same volume phase transition temperature (VPTT), but exhibited much faster response rates as the temperature was raised above their VPTT. Besides, the hydrogels prepared by this method had faster response rates in low pH buffer solutions, and the response rates increased with the increased concentration of the NaCl solutions used during the polymerization. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]

Discovery of the Porosome: revealing the molecular mechanism of secretion and membrane fusion in cells

JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 1 2004
B. P. Jena
Abstract Secretion and membrane fusion are fundamental cellular processes involved in the physiology of health and disease. Studies within the past decade reveal the molecular mechanism of secretion and membrane fusion in cells. Studies reveal that membrane-bound secretory vesicles dock and fuse at porosomes, which are specialized plasma membrane structures. Swelling of secretory vesicles result in a build-up of intravesicular pressure, which allows expulsion of vesicular contents. The discovery of the porosome, its isolation, its structure and dynamics at nm resolution and in real time, its biochemical composition and functional reconstitution, are discussed. The molecular mechanism of secretory vesicle fusion at the base of porosomes, and vesicle swelling, have been resolved. With these findings a new understanding of cell secretion has emerged and confirmed by a number of laboratories. [source]

Acid Phosphatase Activity May Affect the Tuber Swelling by Partially Regulating Sucrose-mediated Sugar Resorption in Potato

JOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 6 2008
Da-Yong Wang
Abstract APase activity is involved in regulating many physiological and developmental events by affecting the resorption process. In this study, we investigate the role of APase activity in tuber development in potato. APase activities were mainly localized in cytoplasm, gaps among cells and stroma of amyloplasts of parenchyma cells at the stage of tuber swelling. AP1, encoding a putative APase, was also highly expressed in swelling tubers and a low level of expression was observed in elongated stolons and matured tubers. Inhibition of APase activity by applying Brefeldin A, an inhibitor of APase production and secretion, significantly suppressed the tuber swelling and moderately affected the stolon elongation and the tuberization frequency. During tuber development, sucrose serves as the main soluble sugar for long-distance transportation and resorption. Moreover, inhibition of APase activity by Brefeldin A markedly reduced the sucrose content in tubers and further decreased the starch accumulation, suggesting that the function of APase in regulating the tuber swelling might be at least partially mediated by the sugar resorption. Exogenous sucrose treatments further indicate the important role of sucrose-mediated sugar resorption in tuber swelling. These results suggest that the APase activity might affect the tuber swelling by partially regulating the sucrose-mediated sugar resorption. [source]

Role of mitogen-activated protein kinases in the mechanism of oxidant-induced cell swelling in cultured astrocytes

JOURNAL OF NEUROSCIENCE RESEARCH, Issue 11 2010
M. Moriyama
Abstract Cytotoxic brain edema, usually a consequence of astrocyte swelling, is an important complication of stroke, traumatic brain injury, hepatic encephalopathy, and other neurological disorders. Although mechanisms underlying astrocyte swelling are not fully understood, oxidative stress (OS) has generally been considered an important factor in its pathogenesis. To better understand the mechanism(s) by which OS causes cell swelling, we examined the potential involvement of mitogen-activated protein kinases (MAPKs) in this process. Cultures exposed to theoxidant H2O2 (10, 25, 50 ,M) for different time periods (1,24 hr) significantly increased cell swelling in a triphasic manner. Swelling was initially observed at 10 min (peaking at 30 min), which was followed by cell shrinkage at 1 hr. A subsequent increase in cell volume occurred at approximately 6 hr, and the rise lasted for at least 24 hr. Cultures exposed to H2O2 caused the activation of MAPKs (ERK1/2, JNK and p38-MAPK), whereas inhibition of MAPKs diminished cell swelling induced by 10 and 25 ,M H2O2. These findings suggest that activation of MAPKs is an important factor in the mediation of astrocyte swelling following oxidative stress. © 2010 Wiley-Liss, Inc. [source]

Swelling and polymer erosion for poly(ethylene oxide) tablets of different molecular weights polydispersities

JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 3 2010
Anna Körner
Abstract The aim of the study was to determine and compare the degree of swelling and the swelling kinetics of poly(ethylene oxide) (PEO) hydrophilic matrix tablets without any additives for matrixes with different molecular weight polydispersities. A wide range of "mixed" polydisperse PEO tablets were obtained by mixing two PEO batches with average molecular weights of 105 and 2,×,106, respectively. These were compared with "single-batch" tablets with narrower mono-modal molecular weight distributions. A texture analyzer (TA) was used to determine, during the entire dissolution process, the thickness of the "gel" layer, the height of the dry tablet core and the total height of the tablet. The release of polymer from the tablet was also measured using a chromatographic method. Both the swelling histories and the polymer release rates varied strongly with molecular weight and agitation rate, whereas the rate of dissolution of the solid core varied much less with molecular weight. For single-batch and mixed tablets, tuned to give the same release rate, the swelling process was found to be very similar, regardless of the molecular polydispersity (between 1.2 and 8.8). These results support a previously proposed dissolution model with the key assumption of a constant critical viscosity, independent of time or polymer molecular weight, at the surface of the gel layer of a dissolving tablet. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99: 1225,1238, 2010 [source]

Low Water Swelling and High Proton Conducting Sulfonated Poly(arylene ether) with Pendant Sulfoalkyl Groups for Proton Exchange Membranes

MACROMOLECULAR RAPID COMMUNICATIONS, Issue 24 2007
Jinhui Pang
Abstract Novel side-chain-type sulfonated poly(arylene ether) with pendant sulfoalkyl group copolymers (PSA-SPAE-6F) have been synthesized by direct copolymerization from a new sulfonated monomer, sodium 3-(4-(2,6-difluorobenzoyl)phenyl)propane-1-sulfonate. The sulfonate content could be easily controlled by adjusting the sulfonated and the unsulfonated monomer feed ratio. The obtained copolymers all show good thermal and mechanical properties. It should be noted that the most highly sulfonated copolymer, PSA-SPAE-6F90 with an ion exchange capacity of 1.30 mequiv,·,g,1, shows a proton conductivity of 0.11 S,·,cm,1 and a water swelling ratio of only 12.9% at 100,°C, which indicates its high proton conductivity and excellent dimensional stability in hot water. [source]

Sorption and Swelling of Poly(D,L-lactic acid) and Poly(lactic-co-glycolic acid) in Supercritical CO2

MACROMOLECULAR SYMPOSIA, Issue 1 2007
Ronny Pini
Abstract Summary: The equilibrium sorption and swelling behavior in supercritical CO2 of poly(D,L-lactic acid) and poly(lactic-co-glycolic acid) has been studied at a temperature of 35,°C and at pressures up to 200 bar. Sorption was measured through a gravimetric technique and swelling by visualization. From these data, the behavior of the different polymers can be compared. In terms of partial molar volume of CO2 in the polymer matrix, all the polymers exhibit a behavior typical of rubbery systems. The experimental results have been modeled using the Sanchez-Lacombe equation of state, which is able to represent the actual behavior of the polymer-CO2 systems with reasonable accuracy. [source]

Effect of streptozotocin on the ultrastructure of rat pancreatic islets

MICROSCOPY RESEARCH AND TECHNIQUE, Issue 5 2004
M. Daisy Mythili
Abstract Our objective was to study the effects of three (30, 40, and 50 mg/kg) doses of Streptozotocin (STZ) on fasting plasma glucose level (FPG) and observe its effects at the cellular level in rat pancreas by electron microscopy. FPG was measured in rats before induction of diabetes and then on 3, 7, and 14 days after induction of diabetes with STZ. Keto diastix urine strips were used to check urine glucose and ketone bodies. Two weeks after the induction of diabetes, the rat pancreas was removed and fixed for light and electron microscopic studies. Three days after induction, the mean FPG level was 112 mg/dl in Group I (30 mg/kg STZ), 217 mg/dl in Group II (40 mg/kg STZ), and 376 mg/dl in Group III (50 mg/kg STZ). Histology was normal in Group I but revealed altered islet structure in Groups II and III. Ultrastructure revealed intact D cells in all three groups. The focal mitochondria and Golgi complex swelling found in A and B cells was occasional in Group I and frequent in Groups II and III. Swelling of other organelles and reduction in the size and number of granules was further observed in Group III. It is our conclusion that the 30-mg/kg body weight STZ produces mild changes while 50 mg/kg proves to be fatal. STZ at 40 mg/kg has a moderate effect on plasma glucose as well as on the islets of Langerhans at a cellular level. Microsc. Res. Tech. 63:274,281, 2004. © 2004 Wiley-Liss, Inc. [source]

A new composite sorbent for water and dye uptake: Highly swollen acrylamide/2-acrylamido-2-methyl-1-propanesulfonic acid/clay hydrogels crosslinked by 1,4-butanediol dimethacrylate

POLYMER COMPOSITES, Issue 1 2009
Semiha Kundakci
A novel type of highly swollen hydrogels based on acrylamide (AAm) with 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) and clay such as bentonite (Bent) crosslinked by 1,4-butanediol dimethacrylate (BDMA) was prepared by free radical solution polymerization in aqueous media. Water uptake and dye sorption properties of polyelectrolyte AAm/AMPS hydrogels and AAm/AMPS/Bent composite hydrogels were investigated as a function of composition to find materials with swelling and sorption properties. FTIR analyses were made. Swelling experiments were performed in water and dye solution at 25°C, gravimetrically. Highly swollen AAm/AMPS and AAm/AMPS/Bent hydrogels were used in experiments on sorption of water-soluble monovalent cationic dye such as Lauths violet "LV, (Thionin)." Swelling of AAm/AMPS hydrogels was increased up to 1,920,9,222% in water and 867,4,644% in LV solutions, while AAm hydrogels swelled 905% in water and swelling of AAm/AMPS/Bent hydrogels was increased up to 2,756,10,422% in water and 1,200,3,332% in LV solutions, while AAm/Bent hydrogels swelled 849% in water. Some swelling kinetic and diffusional parameters were found. Water and LV diffusion into hydrogels was found to be non-Fickian in character. For sorption of cationic dye, LV into AAm/AMPS and AAm/AMPS/Bent hydrogel was studied by batch sorption technique at 25°C. The amount of the dye sorbed per unit mass removal effiency and partition coefficient of the hydrogels was investigated. The influence of AMPS content in the hydrogels to sorption was examined. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers [source]

Role of Vascular Reflex in Nasal Mucosal Swelling in Nasal Allergy

THE LARYNGOSCOPE, Issue 2 2000
Tsutomu Numata MD
Abstract Objective: In patients with nasal allergy, antigen challenge on the unilateral nasal mucosa results in nasal secretion not only in the ipsilateral but also in the contralateral nasal cavities that can be inhibited almost completely by premedication with atropine sulfate. The present study was performed to elucidate if centrally mediated vascular reflex induced by antigen challenge plays a role in nasal mucosal swelling in subjects with nasal allergy. Methods: Variations of mucosal swelling and mucosal blood flow in the ipsilateral and the contralateral nasal cavities after unilateral antigen challenge were evaluated by acoustic rhinometry and laser Doppler flowmetry in 20 patients with perennial nasal allergy. Results: Unilateral antigen challenge caused ipsilateral and contralateral nasal mucosal swelling in 17 and 13 patients, respectively. Incidence of contralateral nasal mucosal swelling after unilateral antigen challenge was significantly higher compared with that after control disc challenge (P < .001). In 10 patients in whom unilateral antigen challenge caused bilateral nasal mucosal swelling, significant swelling of the nasal mucosa lasted for more than 30 minutes in the ipsilateral nasal cavity after antigen challenge compared with only 15 minutes in the contralateral nasal cavity. Peak values of contralateral mucosal swelling were 45.3% of those of ipsilateral nasal mucosa. Conclusions: Centrally mediated vascular reflex is partially involved in the onset of nasal mucosal swelling observed after antigen challenge in subjects with nasal allergy. However, nasal mucosal swelling that persists and proceeds even 20 minutes after antigen challenge is caused by the direct effects of chemical mediators on the nasal vasculature. [source]

Methotrexate catabolism to 7-hydroxymethotrexate in rheumatoid arthritis alters drug efficacy and retention and is reduced by folic acid supplementation

ARTHRITIS & RHEUMATISM, Issue 8 2009
Joseph E. Baggott
Objective To assess the catabolism of methotrexate (MTX) to 7-hydroxy-MTX (7-OH-MTX) in patients with rheumatoid arthritis as well as the effect of folic acid and folinic acid on this catabolism. Methods Urinary excretion of MTX and its catabolite, 7-OH-MTX, was measured in 2 24-hour urine specimens collected after MTX therapy. Urine samples were collected from patients after the sixth and seventh weekly doses of MTX. MTX and 7-OH-MTX concentrations were determined by high-performance liquid chromatography mass spectrometry. Swelling and pain/tenderness indices were used to measure symptoms before and at 6 and 7 weeks of therapy. Patients received either folic acid or folinic acid supplements (1 mg/day) from week 6 to week 7. Results Folic acid inhibited aldehyde oxidase (AO), the enzyme that produces 7-OH-MTX, but folinic acid did not. Excretion of 7-OH-MTX (determined as a percentage of the dose of MTX or as mg 7-OH-MTX/gm creatinine) was not normally distributed (n = 39). Patients with marked improvement in swelling and pain/tenderness indices had a lower mean 7-OH-MTX excretion level (P < 0.05). Patients who received folic acid supplements had decreased 7-OH-MTX excretion (P = 0.03). Relatively high 7-OH-MTX excretion was correlated with relatively high MTX excretion and with relatively low MTX retention in vivo (P < 0.05) (n = 35). Conclusion Our findings of a non-normal distribution of 7-OH-MTX excretion suggest that there are at least 2 phenotypes for this catabolism. Decreased 7-OH-MTX formation suggests folic acid inhibition of AO and a better clinical response, while increased 7-OH-MTX formation may interfere with MTX polyglutamylation and binding to enzymes and, therefore, may increase MTX excretion and decrease MTX retention and efficacy in vivo. [source]

Collagen-induced arthritis as a model of hyperalgesia: Functional and cellular analysis of the analgesic actions of tumor necrosis factor blockade

ARTHRITIS & RHEUMATISM, Issue 12 2007
Julia J. Inglis
Objective There is a disparity in the animal models used to study pain in rheumatoid arthritis (RA), which tends to be acute in nature, and models used to assess the pathogenesis of RA. The latter models, like human RA, are lymphocyte-driven and polyarthritic. We assessed pain behavior and mechanisms in collagen-induced arthritis (CIA), the model of preclinical arthritis used most commonly in the field of immunology. We then validated the model using anti,tumor necrosis factor (anti-TNF) therapy, which has analgesic effects in models of inflammation as well as in human RA. Methods CIA was induced in DBA/1 mice by immunization with type II collagen at the base of the tail. Swelling and mechanical and thermal hyperalgesia were assessed before and for 28 days after the onset of arthritis. Spontaneous behavior was assessed using an automated activity monitor. Glial activity was assessed by glial fibrillary acidic protein expression, and nerve damage was evaluated by activating transcription factor 3 expression. The actions of anti-TNF therapy on nociception were then evaluated. Results Arthritis resulted in a decrease in the threshold for thermal and mechanical stimuli, beginning on the day of onset. Decreased spontaneous activity was also observed. A significant increase in the number of hyperplasic spinal cord astrocytes was observed beginning 10 days after the onset of arthritis. Anti-TNF therapy was profoundly analgesic, with an efficacy similar to that of cyclooxygenase 2 inhibition, and reduced astrocyte activity in CIA. Conclusion This study shows that the CIA model is suitable for testing not only antiinflammatory but also analgesic drugs for potential use in RA, and highlights the importance of using appropriate disease models to assess relevant pain pathways. [source]

Swelling Induced Detachment of Chondrocytes Using RGD-Modified Poly(N -isopropylacrylamide) Hydrogel Beads

BIOTECHNOLOGY PROGRESS, Issue 3 2002
Mee Ryang Kim
Thermally sensitive poly( N -isopropylacrylamide, NIPAAm) hydrogel beads conjugated with a cell adhesive motif, GRGDY, were prepared and utilized as cell culture substrate for chondrocytes. They were produced to be uniform in size and distribution by using calcium alginate as a temporal mold. The RGD moieties were introduced, in a spatially selective manner, to the surface of the beads by conjugating GRGDY under the precollapsed state at a higher temperature above the lower critical solution temperature (LCST). These RGD-conjugated polyNIPAAm beads demonstrated a reversible swelling and deswelling behavior around the LCST, which enabled the chondrocytes attached on the surface of collapsed beads at 37 °C to readily detach when the temperature was shifted below 37 °C. The cell detachment percentage was largely affected by the temperature-dependent reswelling extent of the collapsed RGD-modified beads. [source]

Enhanced Biomacromolecule Encapsulation by Swelling and Shrinking Procedures

CHEMPHYSCHEM, Issue 1 2004
Changyou Gao Prof. Dr.
Reversible growth: Microcapsules were fabricated by layer-by-layer assembly of poly(diallyldimethyl ammonium chloride)/poly(styrene sulfonate) onto removable melamine formaldehyde particles. The capsules with swelling and shrinking features (see graphic) provide a novel route for microencapsulation. Loading of biomacromolecules such as dextran with ultrahigh molecular weight is achieved by spontaneously opening the capsule during core removal procedure, followed by closing the capsule in salt solution. [source]

Vascular endothelial growth factor in edematous mouse embryos induced by retinoic acid in utero

CONGENITAL ANOMALIES, Issue 2 2001
Yoshiko Yasuda
ABSTRACT, Vascular endothelial growth factor (VEGF) is induced by hypoxic environment and contributes to vascular formation in both developing embryos and adults. Exogenous retinoic acid (RA) induces avascular yolk sacs with anemic stunted embryos of day 9 and 10 of gestation when RA is given to pregnant mice on day 6, 6.5 or 7 of pregnancy (Yasuda et al., 1996). We undertook the present studies to find out whether VEGF is activated and plays any role in those RA-exposed embryos. Embryos were obtained from dams given 60 mg/kg of RA on day 6 or 7 of pregnancy and sacrificed three days later. Most RA-exposed embryos showed edematous swelling without prominent vascular nets, but had beating heart tubes on day 9 and day 10 of gestation. Microscopic examination of developing tissue components showed various degrees of degeneration, and distension of the dorsal aorta when the body cavity was dosed. Northern blot analysis revealed expression of VEGF mRNA in the RA-exposed and control embryos. The highest expression of VEGF mRNA was seen in the embryos of day 10 exposed to RA on day 7, and these embryos had a significantly lower ATP content than did the controls (p < 0.01). Immunoreactive VEGF was detectable in both experimental and control embryos; in the former it was especially visible in the distended neuroepithelium, endothelium and membranes. These VEGF-immunoreactive regions also expressed another permeability factor, bradykinin. These findings suggest that VEGF upregulated by hypoxic conditions in edematous embryos induced by RA exposure in utero acts as hyperpermeability. [source]

A role for the volume regulated anion channel in volume regulation in the murine CNS cell line, CAD

ACTA PHYSIOLOGICA, Issue 2 2010
V. L. Harvey
Abstract Aim:, The role of the volume regulated anion channel (VRAC) in a model CNS neuronal cell line, CAD, was investigated. Methods:, Changes in cell volume following hypotonic challenges were measured using a video-imaging technique. The effect of the Cl, channel antagonists tamoxifen (10 ,m) and 4,4,-diisothiocyanatostilbene-2,2,-disulphonic acid (DIDS; 100 ,m) on regulatory volume decrease (RVD) were measured. The whole-cell voltage-clamp technique was used to characterize IClswell, the current underlying the VRAC. Results:, Using the video-imaging technique, CAD cells were found to swell and subsequently exhibit RVD when subjected to a sustained hypotonic challenge from 300 mOsmol kg,1 H2O to 210 mOsmol kg,1 H2O. In the presence of tamoxifen (10 ,m) or DIDS (100 ,m) RVD was abolished, suggesting a role for the VRAC. A hypotonic solution (230 mOsmol kg,1 H2O) evoked IClswell, an outwardly rectifying current displaying time-independent activation, which reversed upon return to isotonic conditions. The reversal potential (Erev) for IClswell was ,14.7 ± 1.4 mV, similar to the theoretical Erev for a selective Cl, conductance. IClswell was inhibited in the presence of DIDS (100 ,m) and tamoxifen (10 ,m), the DIDS inhibition being voltage dependent. Conclusions:, Osmotic swelling elicits an outwardly rectifying Cl, conductance in CAD cells. The IClswell observed in these cells is similar to that observed in other cells, and is likely to provide a pathway for the loss of Cl, which leads to water loss and RVD. As ischaemia, brain trauma, hypoxia and other brain pathologies can cause cell swelling, CAD cells represent a model cell line for the study of neuronal cell volume regulation. [source]

Activation of PLA2 isoforms by cell swelling and ischaemia/hypoxia

ACTA PHYSIOLOGICA, Issue 1-2 2006
I. H. Lambert
Abstract Phospholipase A2 (PLA2) activity is increased in mammalian cells in response to numerous stimuli such as osmotic challenge, oxidative stress and exposure to allergens. The increased PLA2 activity is seen as an increased release of free, polyunsaturated fatty acids, e.g. arachidonic acid and membrane-bound lysophospholipids. Even though arachidonic acid acts as a second messenger in its own most mammalian cells seem to rely on oxidation of the fatty acid into highly potent second messengers via, e.g. cytochrome P450, the cyclo-oxygenase, or the lipoxygenase systems for downstream signalling. Here, we review data that illustrates that stress-induced PLA2 activity involves various PLA2 subtypes and that the PLA2 in question is determined by the cell type and the physiological stress condition. [source]

Evaluation of radiographs, clinical signs and symptoms associated with pulp canal obliteration: an aid to treatment decision

DENTAL TRAUMATOLOGY, Issue 6 2009
Adeleke O. Oginni
The dental clinician faced with this condition has to make a difficult decision. The aim of this study was to evaluate the clinical signs and symptoms associated with teeth with PCO and to assess the status of the periapical tissues using the periapical index (PAI) as an aid in making a treatment decision. The study included teeth diagnosed with PCO in patients with a history of traumatic injury to the involved teeth. Histories of associated signs and symptoms including pain, swelling and drainage from a sinus tract were elicited. Tooth color, sensibility to electric pulp testing, mobility and percussion tenderness were recorded. The periapical status was assessed using the PAI. Two hundred and seventy-six teeth were diagnosed with PCO. One hundred and fifty-seven (56.9%) and 119 (43.1%) demonstrated partial or total PCO, respectively. Yellow discoloration presented most frequently, occurring in 186 (67.4%) teeth. Sixty-two (33.3%) of these had developed periapical lesions and reacted negatively to sensibility testing. Fifty-seven (30.7%) of these teeth presented radiographically with a normal periapical appearance and reacted normally to sensibility testing, whereas 67 (36.0%) presented with small changes in the periapical bone pattern and reacted in the high normal range to sensibility testing. Teeth with PAI scores ,2 presented with occasional spontaneous pain. Teeth with PAI scores ,3 presented with clinical symptoms and signs ranging from pain on percussion to spontaneous pain, and slight swelling to sinus tract drainage. Based on the findings of this study, endodontic treatment should be initiated in teeth with tenderness to percussion, PAI scores ,3 and a negative response to sensibility testing. [source]

Dental emergencies presenting to a dental teaching hospital due to complications from traumatic dental injuries

DENTAL TRAUMATOLOGY, Issue 4 2002
Suhad H. Al-JundiArticle first published online: 29 JUL 200
Abstract ,,,In Jordan, only two surveys of dental trauma have been carried out. The aim of this study was to determine the incidence and pattern of dental emergencies resulting from traumatic injuries, as well as treatment provided to children presenting with these dental emergencies. Over a 1-year period, 620 children presented to our pediatric dental clinics with dental emergencies; 195 (31%) of these emergencies were a consequence of dental trauma to 287 teeth and were included in the study. The average time between the trauma and the dental emergency was 5 months. Pain or sensitivity was the most frequent presenting symptom (31.3%) followed by swelling or sinus tract (17.4%). The age of these patients ranged from 15 months to 14 years, with an average age of 9.3 years. Males accounted for 75.4% of the children in the samples, whereas females accounted for only 24.6%. The main cause of dental trauma was falling during play (58.5%); the least common cause was motor vehicle accidents, accounting for only 1.5% of all injuries. Most of the dental injuries occurred at home (41.5%), around noon time. The most commonly involved teeth were permanent maxillary central incisors accounting for 79.5% of all teeth involved by dental trauma. The most frequently encountered type of trauma in this sample was crown fracture seen in 76.6% of the teeth . Soft tissue injuries were estimated to occur in 16.9% of the children. The treatment received by the children in the sample ranged from no active treatment (6.2%) to elaborate dental procedures such as pulp therapy (41.3%) and prosthetic replacement of missing teeth (5.1%). [source]

The lateral periodontal cyst: aetiology, clinical significance and diagnosis

DENTAL TRAUMATOLOGY, Issue 4 2000
N. P. Kerezoudis
Abstract , The lateral periodontal cyst (LPC) is a relatively uncommon but widely recognized odontogenic cyst of developmental origin. It is found mostly in adults and has no sex predilection. LPC is usually discovered during routine radiographic examination, is located mainly between the roots of vital mandibular canines and premolars, and seldom causes pain or other clinical symptoms. The defect appears on radiographs as a round or teardrop-shaped, well circumscribed radiolucency. Due to its location it can easily be misdiagnosed as a lesion of endodontic origin. In this paper, two cases of lateral periodontal cysts are presented. In the first case, the patient (woman, 62 years old) complained of an asymptomatic gingival swelling in the region between the right maxillary canine and premolar. The radiographic examination revealed a well circumscribed radiolucency with a radiopaque margin between the roots of the canine and premolar. The adjacent teeth had vital pulp. Surgical enucleation of the lesion was performed and the histological examination revealed that the lesion was a "lateral periodontal cyst of developmental origin". In the second case, the patient (woman, 44 years old) compained of a swelling in the area of tooth 32. During radiographic examination a well circumscribed radiolucency between the roots of the lateral incisor and the canine was discovered. Surgical enucleation of the lesion was performed and the histological examination revealed that the lesion was a "lateral periodontal cyst of developmental origin". [source]

Postoperative discomfort associated with surgical and nonsurgical endodontic retreatment

DENTAL TRAUMATOLOGY, Issue 2 2000
T. Kvist
Abstract , Endodontic retreatment decision-making must include an appraisal of the costs of the different strategies proposed. In addition to direct costs, postoperative discomfort may have other consequences in terms of time off work, unscheduled visits and suffering. To establish a foundation for the appraisal of such indirect and intangible costs the present study was set up in which patients' assessments of pain and swelling after surgical and nonsurgical retreatment procedures were recorded. Ninety-two patients with 95 root-filled incisors and canine teeth exhibiting apical periodontitis were included in the study. The mode of retreatment was randomly assigned. Each day during the first post-treatment week patients assessed their degree of swelling and pain on horizontal 100-mm visual analog scales (VAS). The scales ranged from "no swelling" to "very severe swelling" and "no pain" to "intolerable pain", respectively. Consumption of self-prescribed analgesics and time off work were also recorded. Significantly more patients reported discomfort after surgical retreatment than after nonsurgical procedures. High pain scores were most frequent on the operative day while swelling reached its maximum on the first postoperative day followed by progressive decrease both in frequency and magnitude. Postoperative symptoms associated with nonsurgical retreatment were less frequent but reached high VAS values in single cases. Analgesics were significantly more often consumed after periapical surgery. Patients reported absence from work mainly due to swelling and discoloration of the skin. This was found to occur only after surgical retreatment. Conclusively, surgical retreatment resulted in more discomfort and tended to bring about greater indirect costs than nonsurgical retreatment. [source]

Novel Pretrichial Browlift Technique and Review of Methods and Complications

DERMATOLOGIC SURGERY, Issue 9 2009
COURTNEY S. McGUIRE BS
BACKGROUND The upper third of the face is integral to our perception of youth and beauty. While the eyelids anchor this facial cosmetic unit, the eyebrows and forehead are intrinsically linked to the upper eyelids, and their position and texture play an important role in creating pleasing eyes as well as conveying mood and youth. The most common browlifts are performed with endoscopic visualization. Yet, this technique requires special equipment and a prolonged learning curve. OBJECTIVE To demonstrate a novel pretrichial technique and to review different browlift methods and their potential adverse effects. METHODS Case series and review of the literature. RESULTS The pretrichial browlift results in a mild to moderate browlift with secondary smoothing of the forehead topography. Aside from bruising and swelling, it results in minimal adverse effects. Other techniques are also effective but may create a larger scar such as a direct browlift, may be more difficult in terms of approach such as the browpexy, or require endoscopes. CONCLUSION Browlifts are an important procedure in rejuvenating the upper third of the face and improving the overall facial aesthetic appearance. The pretrichial browlift is a less invasive open technique that is safe and effective for the appropriate patient. [source]

Effects of Botulinum Toxin Type A on Contouring of the Lower Face

DERMATOLOGIC SURGERY, Issue 5 2005
Seong Wook Choe MD
background. Masseteric muscle hypertrophy is an uncommon condition represented as a swelling of the masseter muscle. Recent reports have demonstrated the successful use of botulinum in the treatment of masseteric hypertrophy. objective. This study was a prospective trial to evaluate the effectiveness of botulinum toxin type A (Botox) in the treatment of masseteric muscle hypertrophy according to doses of 10, 20, and 30 U. materials and methods. Twenty-two patients were referred to the dermatologic clinic for the management of masseteric muscle hypertrophy. Ultrasonographic measurements of the thickness of the masseter muscle were performed, and clinical photographs were taken before treatment and 1, 2, 3, 4, 6, and 9 months after the treatment. results. The median values of percentage reduction of muscle mass were 10.3%, 16.5%, 23.7%, 24.7%, 21.6%, 16.5% in the 10 U group; 11.9%, 18.8%, 24.8%, 27.7%, 26.7%, and 21.8% in the 20 U group; and 12.0%, 19.4%, 25.0%, 27.8%, 37.8%, and 24.1% in the 30 U group. conclusion. The adequate dose of botulinum toxin type A for treatment of masseteric muscle hypertrophy should be above 20 U. The effect of botulinum toxin type A is maintained for at least 9 months as the treatment of masseteric muscle hypertrophy. [source]

Complications of Expanded Polytetrafluoroethylene (e-PTFE) Facial Implant

DERMATOLOGIC SURGERY, Issue 9 2001
Harold J. Brody MD
Implantation of the expanded polytetrafluoroethylene (e-PTFE) implant to achieve correction of nasolabial folds or thinning lip has been fraught with complications in spite of patient acceptance since its introduction in 1997. The four most frequent postoperative complications are extrusion, movement, infection, and swelling. In examination of 86 insertions of the 3.2 mm tubular implants, these sequelae are generally manageable for the physician and patient. If the patient understands possible courses of healing, both physician and patient satisfaction may be achieved. [source]

Complications of Nail Surgery: A Review of the Literature

DERMATOLOGIC SURGERY, Issue 3 2001
Meena Moossavi MD
Background. The realm of nail unit surgery encompasses the dermatologist as well as the hand surgeon. Nail surgery complications may include allergy to anesthetic, infection, hematoma, nail deformity, and persistent pain and swelling. Objective. To review the pertinent literature regarding nail unit surgery complications. Methods. A Medline literature search was performed for relevant publications. Results. Nail unit surgery complications appear to be relatively infrequent. The majority of postoperative nail deformity complications result from nail matrix damage. Conclusion. Complications may be reduced to a minimum by preventive measures, such as careful patient selection, sterile technique, and gentle treatment of the nail matrix. [source]

Cleansing without compromise: the impact of cleansers on the skin barrier and the technology of mild cleansing

DERMATOLOGIC THERAPY, Issue 2004
K. P. Ananthapadmanabhan
ABSTRACT:, Cleanser technology has come a long way from merely cleansing to providing mildness and moisturizing benefits as well. It is known that harsh surfactants in cleansers can cause damage to skin proteins and lipids, leading to after-wash tightness, dryness, barrier damage, irritation, and even itch. In order for cleansers to provide skin-care benefits, they first must minimize surfactant damage to skin proteins and lipids. Secondly, they must deposit and deliver beneficial agents such as occlusives, skin lipids, and humectants under wash conditions to improve skin hydration, as well as mechanical and visual properties. While all surfactants tend to interact to some degree with lipids, their interaction with proteins can vary significantly, depending upon the nature of their functional head group. In vitro, ex vivo, and in vivo studies have shown that surfactants that cause significant skin irritation interact strongly with skin proteins. Based on this understanding, several surfactants and surfactant mixtures have been identified as "less irritating" mild surfactants because of their diminished interactions with skin proteins. Surfactants that interact minimally with both skin lipids and proteins are especially mild. Another factor that can aggravate surfactant-induced dryness and irritation is the pH of the cleanser. The present authors' recent studies demonstrate that high pH (pH 10) solutions, even in the absence of surfactants, can increase stratum corneum (SC) swelling and alter lipid rigidity, thereby suggesting that cleansers with neutral or acidic pH, close to SC-normal pH 5.5, may be potentially less damaging to the skin. Mildness enhancers and moisturizing agents such as lipids, occlusives, and humectants minimize damaging interactions between surfactants, and skin proteins and lipids, and thereby, reduce skin damage. In addition, these agents play an ameliorative role, replenishing the skin lipids lost during the wash period. The present review discusses the benefits of such agents and their respective roles in improving the overall health of the skin barrier. [source]