Effects of local anaesthetics on short-term desensitization of guinea-pig taenia caecum to histamine.

PubMed Central

Hishinuma, S.; Uchida, M. K.

1987-01-01

1 Short-term desensitization to histamine was induced by incubating guinea-pig taenia caecum with 10(-4)M histamine for 30 min (desensitizing incubation) in normal Locke-Ringer solution or Ca-free Locke-Ringer solution containing 0.2 mM EGTA. This desensitization was measured as a reduction of the maximal contractile response. 2 The effects of the presence of local anaesthetics during the desensitizing incubation were examined. Results showed that tetracaine, procaine, procainamide, oxybuprocaine and lignocaine inhibited the desensitization, whereas dibucaine, benzocaine and mepivacaine did not. 3 The inhibitory effects of these drugs on the desensitization were not correlated with their lipid solubility nor with the potency of their known effects, such as membrane stabilization, Ca channel blockade, calmodulin antagonism, or inhibition of C-kinase. 4 It is concluded that the inhibitory effects of local anaesthetics on the desensitization are not due to their non-specific membrane-stabilizing effects per se, but to some other action. PMID:3427278

Reduction of rewarming injury of the hepatic graft by a heat insulator.

PubMed

Wakiyama, S; Yanaga, K; Soejima, Y; Nishizaki, T; Sugimachi, K

1997-04-01

The deleterious effect of rewarming in orthotopic liver transplantation is recognized. This study examined the significance of rewarming the hepatic allograft, and the possibility of using a heat insulator to reduce rewarming injury. After total hepatectomy in rats with in situ perfusion by chilled (4 degrees C) lactated Ringer's solution, the livers were divided into four groups of ten each: group 1, 4-h preservation in chilled Ringer's solution and 15 min of rewarming; group 2, 6-h preservation in chilled Ringer's solution; group 3, 6-h preservation in chilled Ringer's solution and 15 min of rewarming; group 4, 6-h preservation in chilled Ringer's solution and 15 min of rewarming with a heat insulator. Glutamic-pyruvic transaminase (GPT) and N-acetyl-beta-glucosaminidase (NAG) concentrations in the final graft effluent, and the amount of adenosine 5'-triphosphate (ATP) in liver tissue after preservation, were measured. GPT and NAG concentrations in the final graft effluent of group 3 were higher than those of group 2 (P < 0.01), whereas values in group 4 were lower than those of group 3 (P < 0.05). The final ATP concentration in group 3 was significantly lower than that in group 2 (P < 0.01), whereas the value in group 4 was significantly higher than that of group 3 (P < 0.01). Rewarming diminishes the viability of a liver graft with degradation of ATP, and a heat insulator reduces rewarming injury.

Effects of ruthenium ions on the sensory terminal discharges of the frog muscle spindle.

PubMed

Ito, F; Fujitsuka, N; Komatsu, Y

1983-10-16

The presence of a mixed Na+-Ca2+ spike along the sensory terminal of the frog muscle spindle was verified. When the terminal was perfused with Ringer's solution containing 0.1-0.5 mM ruthenium red (RuR), the amplitude and duration of the spike were increased, occurring as a prolonged or a long-lasting depolarization of up to 20-30 s duration following individual afferent spikes evoked spontaneously or antidromically by electrical stimulation. In an isotonic TEA solution, the amplitude and duration of the afferent spikes were increased; however, no prolonged depolarization occurred. Adding 0.2 mM RuR to the TEA solution produced the prolonged and long-lasting depolarization. All responses disappeared in the presence of 3 microM TTX or Na+-free Ringer's solution. An impedance decrease along the terminal was observed during the prolonged or long-lasting depolarization. The prolonged depolarization was blocked by the addition of Ca2+-blockers; the afferent spikes remained. In preparations preincubated with 0.1 mM RuR, increasing CaCl2 in Ringer's solution from 0.2 mM, resulted in shortening of the duration of individual spikes with prolonged depolarization and in increase in the maximum rate of rise (MRR) of the spikes. Preincubation with higher concentrations of RuR produced higher sensitivities in the modifications of the duration and MRR to the change in [Ca2+]O. The responses were retained by adding RuR or RuCl3 to Ca2+-free Ringer's solution containing 0.1-5 mM EGTA, although all responses disappeared in Ca2+-free EGTA Ringer's solution. It is concluded that the RuR-induced prolonged response is produced by an influx of Na+.

Flow distribution during infusion of UW and HTK solution in anaesthetised rats.

PubMed

Jansson, Leif; Carlsson, Per-Ola; Bodin, Birgitta; Källskog, Orjan

2011-06-01

Organ transplantation necessitates the use of preservation solutions to maintain the integrity of the organs during retrieval. The aim of this study was to investigate the flow distribution in abdominal organs in rats during acute infusion of preservation solution. Microspheres were used to estimate the distribution of flow in the pancreas, duodenum, ileum, colon, liver, kidneys and lungs in untreated Wistar-Furth rats and in animals with an opened abdominal cavity and catheterised aorta. Some animals were infused by free flow of 5 ml of UW, HTK or Ringer solution containing microspheres at a pressure of 100 cm H(2)O through an intra-aortic catheter. Opening of the abdominal cavity did not affect any of the organ blood flow values. However, the fraction of total pancreatic blood flow diverted through the islets increased. During infusion of microsphere-containing UW, HTK or Ringer solution, splanchnic and renal organ flow values, represented by microsphere contents, were similar. The fraction of microspheres found in the islets was lower in UW-infused rats. The number of microspheres present in the lungs or liver was very low, suggesting that shunting was negligible. Infusion of HTK and UW solution into anaesthetised rats results in a flow distribution which is similar to that in normal animals in most abdominal organs, but there is a reduction in islet blood perfusion by UW but not HTK solution.

Albumin extravasation and tissue washout of hyaluronan after plasma volume expansion with crystalloid or hypooncotic colloid solutions.

PubMed

Berg, S; Golster, M; Lisander, B

2002-02-01

Intravascular volume expansion is followed by loss of fluid from the circulation. The extravasation of albumin in this readjustment is insufficiently known. Twelve male volunteers participated, each in three separate sessions, in a controlled, randomised, open fashion. They received one of the following: albumin 40 g/L,(7.1 mL/kg, i.e. 500 mL per 70 kg); Ringer's acetate (21.4 mL/kg), or dextran 30 g/L (7.1 mL/kg). The fluids were infused during 30 min and the subjects were followed for 180 min. ECG, arterial oxygen saturation and non-invasive arterial pressure were recorded. Haemoglobin, haematocrit, serum albumin and osmolality, plasma colloid osmotic pressure and hyaluronan concentration were determined in venous samples. The serum albumin concentration decreased (P < 0.05, anova) following Ringer's acetate or dextran, whereas serum osmolality was unchanged in all groups. The colloid osmotic pressure decreased (P < 0.05) after the Ringer solution. The blood volume increase was estimated from the decrease in haemoglobin concentration and did not differ between the three fluids. The cumulated extravasation of albumin was largest following albumin (10.4 +/- 5.4 g, mean +/- SD), less following dextran (5.6 +/- 5.0 g) and negligible in the Ringer group (0.5 +/- 10.0 g; P < 0.05 against albumin). However, the Ringer solution increased the plasma concentration of hyaluronan drastically. Infusion of hypotonic colloidal solutions entails net loss of albumin from the vascular space. This is not the case after Ringer's acetate. Increased interstitial hydration from the latter fluid is followed by lymphatic wash out of hyaluronan.

[Resistance of the functional systems of the smooth muscle cells of isolated myometrium to long-term incubation in Ringer-Locke solution at 4 degrees C].

PubMed

Peshikov, V L; Tsirkin, V I; Burmistrova, T D; Bordunovskaia, V P

1977-09-01

Contractile effects of adrenaline, acethylcholine and hyperpotassium solution on the isolated myometrium strips (non-pregnent rats, and women; pregnant rabbits, cats, and women) are studied. The amplitudes of these contractile effects were seen decreasing if the strips were previously immersed in the Ringer-Lokk solution at 4 degrees C 5--9 days prior to observation.

New recommendations for measuring collagen solubility.

PubMed

Latorre, María E; Lifschitz, Adrian L; Purslow, Peter P

2016-08-01

The heat-solubility of intramuscular collagen is usually conducted in 1/4 Ringer's solution at pH7.4, despite this ionic strength and pH being inappropriate for post-rigor meat. The current work studied the percentage of soluble collagen and hydrothermal isometric tension characteristics of perimysial strips on bovine semitendinosus muscles in either 1/4 Ringer's solution, distilled water, PBS, or a solution of the same salt concentration as 1/4 Ringer's but at pH5.6. Values of % soluble collagen were lower at pH7.4 than 5.6. Increasing ionic strength reduced % soluble collagen. The maximum perimysial isometric tension was independent of the bathing medium, but the percent relaxation was higher at pH7.4 than at pH5.6, and increased with ionic strength of the media. It is recommended that future measurements of collagen solubility and tests on connective tissue components of post-rigor meat should be carried out in a solution of concentrations NaCl and KCl equivalent to those in 1/4 Ringer's, but at pH5.6, a pH relevant to post-rigor meat. Copyright © 2016 Elsevier Ltd. All rights reserved.

Induction of therapeutic hypothermia after cardiac arrest in prehospital patients using ice-cold Ringer's solution: a pilot study.

PubMed

Virkkunen, Ilkka; Yli-Hankala, Arvi; Silfvast, Tom

2004-09-01

The cooling and haemodynamic effects of prehospital infusion of ice-cold Ringer's solution were studied in 13 adult patients after successful resuscitation from non-traumatic cardiac arrest. After haemodynamics stabilisation, 30 ml/kg of Ringer's solution was infused at a rate of 100ml/min into the antecubital vein. Arterial blood pressure and blood gases, pulse rate, end-tidal CO(2) and oesophageal temperature were monitored closely. The mean core temperature decreased from 35.8 +/- 0.9 degrees C at the start of infusion to 34.0 +/- 1.2 degrees C on arrival at hospital (P < 0.0001). No serious adverse haemodynamic effects occurred. It is concluded that the induction of therapeutic hypothermia using this technique in the prehospital setting is feasible.

Structure, function, and long-term maintenance of the isolated turtle colon

DOE Office of Scientific and Technical Information (OSTI.GOV)

LeFevre, M.E.; Reisman, L.

1978-01-01

We describe the 5-day maintenance of sacs of turtle colonic mucosa in enriched bathing solutions. The mean maximum transepithelial potential difference (PD) developed by the sacs in Ringer solution enriched with tissue-culture medium and gassed with 95% air-5% CO/sub 2/ was 126 mV at 24 hours. Lower values were observed in other solutions. The PD of 24-hour sacs was partially or totally inhibited by ouabain, replacement of Na by choline in mucosal bathing fluids, or removal of Ca from serosal bathing fluids. The sacs transported Na in excess of H/sub 2/O forming a dilute mucosal solution. The responses of fourmore » different sac preparations (normally oriented or everted, and stripped normally oriented or everted) to long incubation were compared. Stripped normally oriented tissue developed the highest PD and maintained the lowest water content. The morphology of fresh and long-incubated tissue was examined. This investigation demonstrates that the turtle colon can be maintained in vitro for long periods, and it provides information on the morphology and physiology of this tissue.« less

Induced Pacemaker Activity on Toad Skin

PubMed Central

Bueno, Enrique J.; Corchs, Lelio

1968-01-01

The electrical transients produced on the isolated abdominal skin obtained from Bufo arenarum Hensel, under the influence of inward current pulses of constant intensity have been studied. When both faces of the skin are bathed with Ringer's solution, short pulses of inward current give rise to transient variations of the potential difference between both faces of the skin with "all-or-nothing" characteristics (action potentials, AP). When the outer face is bathed with a modified Ringer solution with low sodium content (2.4 mM), the transients are longer and they are only evident when the pulse is several hundred milliseconds long. With even longer pulses (several seconds) a repetitive activity can be elicited, with the electrical characteristics of a "pacemaker" activity. In all these "excitability" phenomena Na+ may be replaced by Li+ in the outer solution. The logarithm of the duration of AP's is inversely related to the logarithm of the increase in concentration of Na+ or Li+ in the solution bathing the external face of the skin. The duration of AP's is increased when the Ca++ concentration in the outer solution is raised. This effect is more evident with low sodium concentration on the outside. The evolution of the slope conductance during repetitive activity has been determined. The site and mechanisms of the "excitable" behavior of the skin and the induced repetitive activity are discussed. Under the experimental conditions employed the behavior of the skin is compared with that of normally excitable plasma membranes. PMID:5692095

[The corrosion of pure iron in five different mediums].

PubMed

Xu, Li; Zhu, Shengfa; Huang, Nan; Li, Xinchang; Zhang, Yu

2009-08-01

The sectional test was adopted in this study to investigate the corrosion of pure iron in 0.15 mol/L NaCl solution, Ringer solution, PBS(-) solution, SBF solution and M199 cell culture medium at three different times. The result shows that different mediums have different corrosion effects on pure iron. The arrangement according to the medium's corrosion ability from the strongest to weakest is 0.15 mol/L NaCl solution (Ringer solution), PBS(-) solution, SBF solution and M199 cell culture medium. The results of scanning electron microscopy and energy dispersive X-ray spectrum analyses show that the addition of HPO4(2-), H2POC4-, Ca2+, Mg2+, SO4(2-) and the organic component can inhibit the corrosion to some degree.

Structure and corrosion behaviour of electrodeposited Co-Mo/TiO2 nano-composite coatings

NASA Astrophysics Data System (ADS)

Krawiec, H.; Vignal, V.; Latkiewicz, M.; Herbst, F.

2018-01-01

The structure and the corrosion behaviour in the Ringer's solution of Co-Mo/TiO2 nano-composite coatings have been investigated. They consist of aggregates of TiO2 nanoparticles uniformly distributed in a Co-Mo alloy matrix (crystallite size of about 2 nm). Both nodular (thickness less than 20 μm) and globular structures (thickness greater than 20 μm) have been observed using field-emission scanning electron microscopy. Under potentiostatic control (in Ringer's solution), oxidation of the coating first occurs followed by (with increasing applied potential) both oxidation and selective dissolution of Co. At the OCP value, Co is oxidized in the form of Co2+-based compounds (CoO, Co(OH)2 or α-CoMoO4) in the coating. This process only occurs in the outermost part of the coating. Therefore, the bulk properties of the coating are not affected after long-term ageing in the Ringer's solution at OCP.

Cerebral effects of resuscitation with hypertonic saline and a new low-sodium hypertonic fluid in hemorrhagic shock and head injury.

PubMed

Sheikh, A A; Matsuoka, T; Wisner, D H

1996-07-01

A 2400-mOsm/L hypertonic solution (isosal) with a lower sodium content, compared with conventional 7.5% hypertonic saline, was formulated using a mixture of sodium chloride, glucose, and mixed amino acids. This solution was developed to minimize hypernatremia during resuscitation. We assessed the effects of isosal on hemodynamics, brain edema, and plasma sodium concentration after head injury associated with hemorrhagic shock. DESIGN. Prospective, randomized laboratory study. University research laboratory. Twenty-one adult female Suffolk sheep, weighing 39 to 49 kg. Animals were subjected to a 2-hr period of hemorrhagic shock to a mean arterial pressure (MAP) of 40 to 45 mm Hg in the presence of a freeze injury to the cerebral cortex. The hemorrhagic shock/head injury phase was followed by 2 hrs of resuscitation with isosal, a new 2400-mosm/L low-sodium hypertonic fluid, 2400 mosm/L of 7.5% hypertonic saline, or lactated Ringer's solution. Initial resuscitation was with a bolus injection of 8 mL/kg of the study solution; subsequent resuscitation in all three groups was with lactated Ringer's solution as needed to maintain baseline cardiac output. Serial hemodynamics, intracranial pressure, electrolytes, and osmolarity were measured. AT the end of resuscitation, the animals were killed and brain water content (mL H2O/g dry weight) of the injured and uninjured areas was determined. Resuscitation volumes were significantly lower in the isosal (19 +/- 5 mL/kg) and 7.5% hypertonic saline (14 +/- 2 mL/mg) groups compared with the lactated Ringer's solution (35 +/- 5 mL/kg) group. Intracranial pressure after 2 hrs of resuscitation was significantly lower in the isosal (7 +/- 1 mm Hg) and hypertonic saline groups (4 +/- 1 mm Hg). Water content in all areas of the brain was significantly lower in the hypertonic saline group compared with the lactated Ringer's solution group. Brain water content in the isosal group was lower than in the lactated Ringer's solution group only in the cerebellum. Plasma sodium content was lower in the isosal group than in the hypertonic saline group. After combined head injury and shock, isosal and 7.5% hypertonic saline have similar effects on hemodynamics and intracranial pressure. Hypertonic saline induces a greater degree of brain dehydration; isosal resuscitation results in smaller increases in plasma sodium.

Analysis of three variables in sampling solutions used to assay bacteria of hands: type of solution, use of antiseptic neutralizers, and solution temperature.

PubMed Central

Larson, E L; Strom, M S; Evans, C A

1980-01-01

Tests were performed using the sterile bag technique to determine the effects of type of sampling solution, use of antiseptic neutralizers, and solution temperature on the detection and quantitation of bacteria on hands. Using paired hand cultures, three sampling solutions were compared: quarter-strength Ringer solution, a phosphate buffer containing Triton X-100, and the same buffer containing antiseptic neutralizers. The phosphate buffer containing Triton X-100 was significantly better than quarter-strength Ringer solution in mean bacterial yield; the neutralizer-containing sampling solution was slightly better than Triton X-100-containing solution, although differences were not significant at the P = 0.05 level. Temperature (6 or 23 degrees C) of the sampling solution showed no consistent effect on bacterial yield from hands tested with the fluid containing neutralizers. PMID:7012171

Local cerebral hypothermia induced by selective infusion of cold lactated ringer's: a feasibility study in rhesus monkeys.

PubMed

Wang, Bincheng; Wu, Di; Dornbos Iii, David; Shi, Jingfei; Ma, Yanhui; Zhang, Mo; Liu, Yumei; Chen, Jian; Ding, Yuchuan; Luo, Yinghao; Ji, Xunming

2016-06-01

Hypothermia has shown promise as a neuroprotective strategy for stroke. The use of whole body hypothermia has limited clinical utility due to many severe side effects. Selective brain cooling, or local brain hypothermia, has been previously proposed as an alternative treatment strategy. This study investigated the safety, feasibility, and efficacy of selective brain hypothermia induced by local infusion of ice-cold lactated Ringer's solution in rhesus monkeys. Eight male rhesus monkeys were used in this study. Brain temperature in the territory supplied by middle cerebral artery (MCA) was reduced by infusing 100 mL of ice-cold (0 °C) lactated Ringer's solution over 20 min via a micro-catheter placed in the proximal MCA (n = 4). Vital signs and the temperature of the brain and rectum were monitored before and after infusion. Transcranial Doppler, Magnetic resonance imaging (MRI), and digital subtraction angiography (DSA) were used to evaluate cerebral blood flow, cerebrovascular reactivity (CVR), cerebral edema, and vasospasm. Another cohort of rhesus monkeys (n = 4) were used as systemic cooling controls. Oxygen saturation, blood pressure, heart rate, and hematologic analysis of the two groups remained within the normal range after infusion. Mild cerebral hypothermia (<35 °C) was achieved in 10 min (0.3 °C/min) and was maintained for 20 min in local cortex and striatum following local infusion. The average lowest cerebral temperature in the locally cooled animals was 33.9 ± 0.3 °C in the striatum following 20-min infusion. This was not observed in animals cooled by systemic infusion. The decreases in the rectal temperature for local and systemic infusion were 0.5 ± 0.2 °C and 0.5 ± 0.3 °C, respectively. Selective brain cooling did not cause any cerebral edema as determined by MRI or vasospasm in the perfused vessel based on DSA. Selective cerebral hypothermia did not significantly alter CVR. Local infusion of ice-cold lactated Ringer's solution via micro-catheter is a safe and effective method for selective cerebral hypothermia. This cooling method could potentially be developed as a new treatment in acute ischemic stroke.

Lactated Ringer-based storage solutions are equally well suited for the storage of fresh osteochondral allografts as cell culture medium-based storage solutions.

PubMed

Harb, Afif; von Horn, Alexander; Gocalek, Kornelia; Schäck, Luisa Marilena; Clausen, Jan; Krettek, Christian; Noack, Sandra; Neunaber, Claudia

2017-07-01

Due to the rising interest in Europe to treat large cartilage defects with osteochondrale allografts, research aims to find a suitable solution for long-term storage of osteochondral allografts. This is further encouraged by the fact that legal restrictions currently limit the use of the ingredients from animal or human sources that are being used in other regions of the world (e.g. in the USA). Therefore, the aim of this study was A) to analyze if a Lactated Ringer (LR) based solution is as efficient as a Dulbecco modified Eagle's minimal essential medium (DMEM) in maintaining chondrocyte viability and B) at which storage temperature (4°C vs. 37°C) chondrocyte survival of the osteochondral allograft is optimally sustained. 300 cartilage grafts were collected from knees of ten one year-old Black Head German Sheep. The grafts were stored in four different storage solutions (one of them DMEM-based, the other three based on Lactated Ringer Solution), at two different temperatures (4 and 37°C) for 14 and 56days. At both points in time, chondrocyte survival as well as death rate, Glycosaminoglycan (GAG) content, and Hydroxyproline (HP) concentration were measured and compared between the grafts stored in the different solutions and at the different temperatures. Independent of the storage solutions tested, chondrocyte survival rates were higher when stored at 4°C compared to storage at 37°C both after short-term (14days) and long-term storage (56days). At no point in time did the DMEM-based solution show a superior chondrocyte survival compared to lactated Ringer based solution. GAG and HP content were comparable across all time points, temperatures and solutions. LR based solutions that contain only substances that are approved in Germany may be just as efficient for storing grafts as the USA DMEM-based solution gold standard. Moreover, in the present experiment storage of osteochondral allografts at 4°C was superior to storage at 37°C. Copyright © 2017 Elsevier Ltd. All rights reserved.

Electrochemical Impedance Analysis of β-TITANIUM Alloys as Implants in Ringers Lactate Solution

NASA Astrophysics Data System (ADS)

Bhola, Rahul; Bhola, Shaily M.; Mishra, Brajendra; Olson, David L.

2010-02-01

Commercially pure titanium and two β-titanium alloys, TNZT and TMZF, have been characterized using various electrochemical techniques for their corrosion behavior in Ringers lactate solution. The variation of corrosion potential and solution pH with time has been discussed. Electrochemical Impedance Spectroscopy has been used to fit the results into a circuit model. The stability of the oxides formed on the surface of these alloys has been correlated with impedance phase angles. Cyclic Potentiodynamic Polarization has been used to compute the corrosion parameters for the alloys. TMZF is found to be a better β-alloy as compared to TNZT.

Colloid osmotic pressure and extravasation of plasma proteins following infusion of Ringer's acetate and hydroxyethyl starch 130/0.4.

PubMed

Zdolsek, J H; Bergek, C; Lindahl, T L; Hahn, R G

2015-11-01

During fluid infusion therapy, plasma proteins are diluted and leak from the intravascular space, which alters the colloid osmotic pressure (COP) and potentially affects coagulation. We hypothesised that acetated Ringer's and starch solution, alone or in combination, influence these mechanisms differently. On different occasions, 10 male volunteers were infused with 20 ml/kg acetated Ringer's and 10 ml/kg 6% hyroxyethyl starch 130/0.4 (Voluven(®) ) alone or in combination (first with starch solution followed by Ringer's solution). Blood samples were collected every 30-min for measurements of COP, blood haemoglobin, platelets, and plasma concentrations of albumin, immunoglobulins (IgG and IgM), coagulation factor VII (FVII), fibrinogen, cystatin C, activated partial thromboplastin time (APTT) and prothrombin international normalised ratio (PT-INR). Changes were compared with the haemoglobin-derived plasma dilution. The COP increased by 8.4% (SD 3) with starch and decreased by 26.2% (7.9) with Ringer's. These infusions diluted the plasma by 23.4% (5.3) and 18.7% (4.9) respectively. The COP changes in the combined experiment followed the same pattern as the individual infusions. Albumin and IgG changes in excess of the plasma dilution were very subtle. The intravascular contents of the IgM and platelets decreased, whereas FVII, fibrinogen and cystatin C increased. PT-INR increased by 1/3 of the plasma dilution, whereas changes in APTT did not correlate with the plasma dilution. The starch increased COP and only minor capillary leak occurred in healthy volunteers. The fluid-induced plasma dilution correlated with mild impairment of the extrinsic coagulation pathway but not of the intrinsic pathway. © 2015 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

In vitro fatigue behaviour of vacuum plasma and detonation gun sprayed hydroxyapatite coatings.

PubMed

Gledhill, H C; Turner, I G; Doyle, C

2001-06-01

The fatigue behaviour of vacuum plasma sprayed (VPS) and detonation gun sprayed (DGUN) hydroxyapatite coatings on titanium substrates has been compared in air and in buffered Ringer's solution. There was an increase in the surface microcracking and bulk porosity of both types of coating tested in air. After 1 million cycles in Ringer's solution the VPS coatings had completely delaminated from their substrates. In contrast the DGUN coatings retained their integrity when tested up to 10 million cycles but were beginning to show signs of delamination at the interface.

Electrophysiological and Ultrastructural Characterization of Neuromuscular Junctions in Diaphragm Muscle of Acetylcholinesterase Knockout Mice

DTIC Science & Technology

2008-04-01

conditioned fresh air. The mice were on a 12-hr light/dark full-spectrum lighting cycle . AChE +/+ and AChE -/- mice were 58.7 ± 2.9 and 51.6 ± 3.2 days old...diaphragms were excised and pinned at resting length in Sylgard (Dow Chemical Co., Midland, MI) coated dishes containing oxygenated Krebs -Ringer solution of...measurements Hemidiaphragms with attached phrenic nerves were mounted in tissue baths at 37o C and immersed in an oxygenated Krebs -Ringer solution. To

A hyperosmolar-colloidal additive to the CPB-priming solution reduces fluid load and fluid extravasation during tepid CPB.

PubMed

Kvalheim, V; Farstad, M; Haugen, O; Brekke, H; Mongstad, A; Nygreen, E; Husby, P

2008-01-01

Cardiopulmonary bypass(CPB) is associated with fluid overload. We hypothesized that fluid gain during CPB could be reduced by substituting parts of a crystalloid prime with 7.2% hypertonic saline and 6% poly (O-2-hydroxyethyl) starch solution (HyperHaes). 14 animals were randomized to a control group (Group C) or to Group H. CPB-prime in Group C was Ringer's solution. In group H, 4 ml/kg of Ringer's solution was replaced by the hypertonic saline/hydroxyethyl starch solution. After 60 min stabilization, CPB was initiated and continued for 120 min. All animals were allowed drifting of normal temperature (39.0 degrees C) to about 35.0 degrees C. Fluid was added to the CPB circuit as needed to maintain a 300-ml level in the venous reservoir. Blood chemistry, hemodynamic parameters, fluid balance, plasma volume, fluid extravasation rate (FER), tissue water content and acid-base parameters were measured/calculated. Total fluid need during 120 min CPB was reduced by 60% when hypertonic saline/hydroxyethyl starch solution was added to the CPB prime (p < 0.01). The reduction was related to a lowered FER. The effect was most pronounced during the first 30 min on CPB, with 0.6 (0.43) (Group H) compared with 1.5 (0.40) ml/kg/min (Group C) (p < 0.01). Hemodynamics and laboratory parameters were similar in both groups. Serum concentrations of sodium and chloride increased to maximum levels of 148 (1.5) and 112 (1.6) mmol/l in Group H. To conclude: addition of 7.2% hypertonic saline and 6% poly (O-2-hydroxyethyl) starch solution to crystalloid CPB prime reduces fluid needs and FER during tepid CPB.

[Anesthesia for cesarean section in a patient with transient diabetes insipidus].

PubMed

Amano, Asako; Mitsuse, Tetsuro; Hashiguchi, Akira; Masuda, Kazuyuki; Jo, Yoshitaka; Akasaka, Takefumi; Ogata, Shinya; Sato, Toshihide

2003-02-01

A 32-year-old pregnant female was admitted to our hospital at 32 week gestation and was scheduled for emergent cesarean section because of fetal distress. She had been suffering hydrodipsia and dry mouth, and had lost 4 kg in 2 weeks. Hypernatremia, hyperchloremia, and lower urinary specific gravity were preoperatively noted. Her electrolyte imbalance was partially corrected by the infusion of 1400 ml of 5% glucose solution and 500 ml of acetated Ringer's solution, but unexpected hyperglycemia; 440 mg.dl-1, appeared before surgery. Cesarean section was successfully performed with spinal anesthesia. A 1566 g male infant was delivered with 1 and 5 min Apgar scores of 2 and 1. Hyperglycemia and secondary hypoglycemia occurred in the infant in the neonatal ICU. The mother's fluid loss, including blood and amniotic fluid, was estimated at 784 ml. Five hundred milliliters of acetated Ringer's solution and 1000 ml of half saline solution with 2.5% glucose were infused before delivery, followed by the glucose solution containing a low concentration of sodium after delivery. After surgery, high serum osmotic pressure and paradoxically low urinary osmotic pressure were found. The plasma antidiuretic hormone level was normal against the high serum osmotic pressure. The electrolyte imbalance and urinary osmotic pressure were improved by using I-deamino-8-d-arginine vasopressin, and DI was finally diagnosed. Hormonal therapy was discontinued on day 20, and the patient was discharged on day 21. Some pregnancies are complicated by transient DI. Anesthesiologists have to consider DI when a pregnant female has symptoms of dehydration and a significant electrolyte imbalance.

Effects of pH and elevated glucose levels on the electrochemical behavior of dental implants.

PubMed

Tamam, Evsen; Turkyilmaz, Ilser

2014-04-01

Implant failure is more likely to occur in persons with medically compromising systemic conditions, such as diabetes related to high blood glucose levels and inflammatory diseases related to pH levels lower than those in healthy people. The aim of this study was to investigate the effects of lower pH level and simulated- hyperglycemia on implant corrosion as these effects are critical to biocompatibility and osseointegration. The electrochemical corrosion properties of titanium implants were studied in four different solutions: Ringer's physiological solution at pH = 7.0 and pH = 5.5 and Ringer's physiological solution containing 15 mM dextrose at pH = 7 and pH = 5.5. Corrosion behaviors of dental implants were determined by cyclic polarization test and electrochemical impedance spectroscopy. Surface alterations were studied using a scanning electron microscope. All test electrolytes led to apparent differences in corrosion behavior of the implants. The implants under conditions of test exhibited statistically significant increases in I(corr) from 0.2372 to 1.007 μAcm(-2), corrosion rates from 1.904 to 8.085 mpy, and a decrease in polarization resistances from 304 to 74 Ω. Implants in dextrose-containing solutions were more prone to corrosion than those in Ringer's solutions alone. Increasing the acidity also yielded greater corrosion rates for the dextrose-containing solutions and the solutions without dextrose.

Plasma Electrolytic Oxidation Coatings on Pure Ti Substrate: Effects of Na3PO4 Concentration on Morphology and Corrosion Behavior of Coatings in Ringer's Physiological Solution

NASA Astrophysics Data System (ADS)

Roknian, Masoud; Fattah-alhosseini, Arash; Gashti, Seyed Omid

2018-03-01

Plasma electrolytic oxidation has been used as a relatively new method for applying ceramic coatings having different features. In the present study, commercially pure titanium is used as substrate, and effects of trisodium phosphate electrolyte concentration on the microstructure, as well as corrosion behavior of the coating in Ringer's physiological solution are investigated. The morphology and phase compositions of coatings were analyzed by using scanning electron microscopy (SEM) and x-ray diffraction patterns. The study on the corrosion behavior of samples in a Ringer's physiological solution was carried out using open-circuit potential potentiodynamic polarization and electrochemical impedance spectroscopy. The results of electrochemical analysis proved that higher concentration of phosphate electrolyte leads to increase in the corrosion resistance of applied coatings. Accordingly, obtained results revealed that the optimum electrolyte concentration for the best corrosion behavior was 20 g L-1. Furthermore, SEM images and reduction in the dielectric breakdown potential indicated that increase in the electrolyte concentration leads to morphological improvement and smoothening of the surface.

Effect of a zinc L-carnosine compound on acid-induced injury in canine gastric mucosa ex vivo.

PubMed

Hill, Tracy L; Blikslager, Anthony T

2012-05-01

To examine whether a zinc L-carnosine compound used for treatment of suspected gastric ulcers in dogs ameliorates acid-induced injury in canine gastric mucosa. Gastric mucosa from 6 healthy dogs. Mucosa from the gastric antrum was harvested from 6 unadoptable shelter dogs immediately after euthanasia and mounted on Ussing chambers. The tissues were equilibrated for 30 minutes in neutral Ringer's solution prior to incubation with acidic Ringer's solution (HCl plus Ringer's solution [final pH, 1.5 to 2.5]), acidic Ringer's solution plus zinc L-carnosine compound, or zinc L-carnosine compound alone. Tissues were maintained for 180 minutes in Ussing chambers, during which permeability was assessed by measurement of transepithelial electrical resistance. After the 180-minute treatment period, tissues were removed from Ussing chambers and labeled with immunofluorescent anti-active caspase-3 antibody as an indicator of apoptosis. Permeability of the gastric mucosa was significantly increased in a time-dependent manner by addition of HCl, whereas control tissues maintained viability for the study period. Change in permeability was detected within the first 15 minutes after acid application and progressed over the subsequent 150 minutes. The zinc L-carnosine compound had no significant effect on this increase in permeability. Apoptosis was evident in acid-treated tissues but not in control tissues. The zinc L-carnosine compound did not protect against development of apoptosis. Addition of HCl caused a dose-dependent increase in gastric permeability over time and apparent induction of apoptosis as determined on the basis of immunofluorescence. However, there was no significant protective effect of a zinc L-carnosine compound. Nonetheless, results suggested the utility of this method for further studies of canine gastric injury.

Gastric washing by distilled water can reduce free gastric cancer cells exfoliated into the stomach lumen.

PubMed

Ohki, Atsuko; Abe, Nobutsugu; Yoshimoto, Eri; Hashimoto, Yoshikazu; Takeuchi, Hirohisa; Nagao, Gen; Masaki, Tadahiko; Mori, Toshiyuki; Ohkura, Yasuo; Sugiyama, Masanori

2018-04-25

Intragastric free cancer cells in patients with gastric cancer have rarely been studied. The purpose of this study was to investigate the detection rate of intragastric free cancer cells in gastric washes using two types of solutions during endoscopic examination. We further clarified risk factors affecting the presence of exfoliated free cancer cells. A total of 175 patients with gastric cancer were enrolled. Lactated Ringer's solution (N = 89) or distilled water (DW; N = 86) via endoscopic working channel was sprayed onto the tumor surface, and the resultant fluid was collected for cytological examination. We compared the cancer-cell positivity rate between the two (Ringer and DW) groups. We also tested the correlation between cancer-cell positivity and clinicopathological factors in the Ringer group to identify risk factors for the presence of exfoliated cancer cells. The cancer-cell positivity rate was significantly higher in the Ringer group than that in the DW group (58 vs 6%). Cytomorphology in the Ringer group was well maintained, but not in the DW group. The larger tumor size (≥ 20 mm) and positive lymphatic involvement were significant risk factors of exfoliated free cancer cells. Cancer cells can be highly exfoliated from the tumor surface into the gastric lumen by endoscopic irrigation in large gastric cancer with lymphatic involvement. Gastric washing by DW can lead to cytoclasis of free cancer cells; therefore, it may minimize the possibility of cancer-cell seeding in procedures carrying potential risks of tumor-cell seeding upon transluminal communication, such as endoscopic full-thickness resection and laparoscopy-endoscopy cooperative surgery.

The effect of type and volume of fluid hydration on labor duration of nulliparous women: a randomized controlled trial.

PubMed

Garmi, Gali; Zuarez-Easton, Sivan; Zafran, Noah; Ohel, Iris; Berkovich, Ilanit; Salim, Raed

2017-06-01

Type and volume of fluid administered for intrapartum maintenance had been reported to differently affect labor length, delivery mode, and cord artery pH and glucose level. We aimed to compare the effect of three different fluid regimens on labor duration. In a randomized trial, healthy nulliparous in labor were randomized into one of three intravenous fluid regimens: group 1, the reference group, lactated Ringer's solution infused at a rate of 125 mL/h; group 2, lactated Ringer's solution infused at a rate of 250 mL/h; group 3, 0.9% saline solution boosted with 5% glucose, infused at a rate of 125 mL/h. The primary outcome was labor length from enrollment until delivery. Between December 2010 and July 2015, 300 women were randomized to one of the three groups. Demographic and baseline obstetric characteristics were comparable between the groups. There was no significant difference in the time from enrollment to delivery (p = 0.62). Furthermore, there were no significant differences in second stage duration (p = 0.73), mode of delivery (p = 0.21), cord artery pH and glucose level between the groups. Increasing the intravenous volume of lactated Ringer's solution or substituting to fluid containing 5% glucose solution does not affect labor length. ClinicalTrials.gov, http://www.clinicaltrials.gov , NCT01242293.

Chromium oxide coatings with the potential for eliminating the risk of chromium ion release in orthopaedic implants

PubMed Central

Oje, A. M.

2017-01-01

Chromium oxide coatings prepared by radiofrequency reactive magnetron sputtering on stainless steel substrates were exposed to Ringer's physiological solution and tested for their electrochemical corrosion stability using an open circuit potential measurement, potentiodynamic polarization, electrochemical impedance spectroscopy and Mott–Schottky analysis. The coatings were found to be predominantly Cr2O3, based on the observation of the dominance of A1g and Eg symmetric modes in our Raman spectroscopic investigation and the Eu vibrational modes in our Fourier transform infrared spectroscopic measurements on the coatings. We investigated for the presence of chromium ions in Ringer's solution after all of the above electrochemical tests using atomic absorption spectroscopy, without finding a trace of chromium ions at the ppm level for coatings tested under open circuit and at the lower potentials implants are likely to experience in the human body. The coatings were further exposed to Ringer's solution for one month and tested for adhesion strength changes, and we found that they retained substantial adhesion to the substrates. We expect this finding to be significant for future orthopaedic implants where chromium ion release is still a major challenge. PMID:28791150

DsRNA as a stimulator of cell pacemaker activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Airapetyan, S.N.; Zakharyan, R.A.; Rychkov, G.E.

1986-03-01

The authors study the action of double-stranded RNAs (dsRNA) on the characteristics of neuron pacemaker activity which permits prediction of the character of action of dsRNA on the pacemaker activity of cells and organs, and takes the investigators closer to an understanding of the membrane mechanisms underlying the action of dsRNA on the cell. The methods for isolating and fractionating dsRNA from yeasts and the intracellular recording of the electrical activity of the snail giant neuron have been described by the authors earlier. The authors determined the dependence of Ca/sup 2 +/ entry upon dsRNA concentration using the isotope /supmore » 45/Ca. Preweighed ganglia were incubated five each for an hour in 2 ml Ringer's solution containing dsRNA and 5 microliters /sup 45/CaCl/sub 2/ of 12.5 mCi activity. After incubation, the ganglia were rinsed three times for 8 min each time in normal Ringers solution. The washed ganglia were dissolved for one day in KOH. The amount of isotope entering was counted using Brav's scintillator and an RGT counter tuned to the /sup 45/Ca isotope. The physiological saline used for the isolated ganglion contained 85 mmole NaCl, 4 mmole KCl, 8 mmole CaCl/sub 2/, 10 mmole MgCl/sub 2/, 10 mmole Tris-HCl, and 5 mmole glucose.« less

[Optimization of ventricular function during anesthesia induction by administering crystalloids and colloids to heart surgery patients].

PubMed

Ballesteros, M; Boldt, J; Zickmann, B; Knothe, C; Hempelmann, G

1995-01-01

To describe the changes in cardiac function after administration of three different solutions infused after anesthetic induction. Thirty-six patients scheduled for elective aortocoronary bypass surgery were randomly distributed into three groups. Over a period of 25 min after anesthetic induction, 12 received 10 ml/kg of Ringer solution (low dose crystalloid group), 12 received 20 ml/kg of Ringer solution (high dose crystalloid group), and 12 received 10 ml/kg of Ringer solution with 10 ml/kg of hydroxi-ethyl-almidon solution 450,000 D, 0.7 substitution grade (group C-HEA). Minute volume, systemic and pulmonary pressures, osmolality of blood and urine, and plasma and urine sodium concentrations were measured before and after infusion of the assigned liquid. In spite of the volume infused, low dose crystalloid group showed a high incidence of oliguria, increased urinary osmolality and decreased sodium in urine. Cardiac and systolic indices and left ventricular work load remained stable after infusion of the assigned liquid in low and high dose crystalloid groups, whereas they increased significantly ion group C-HEA (+23%, +16% and +20%). Administration of restricted doses of crystalloids after anesthetic induction favors the retention of water and sodium. Higher doses of crystalloids weaken this effect. However, neither of these two regimens leads to a more effective cardiac work load. A combination of crystalloids and colloids administered immediately after anesthetic induction temporarily improves cardiac performance during surgery.

Hydrodynamics based transfection in normal and fibrotic rats

PubMed Central

Yeikilis, Rita; Gal, Shunit; Kopeiko, Natalia; Paizi, Melia; Pines, Mark; Braet, Filip; Spira, Gadi

2006-01-01

AIM: Hydrodynamics based transfection (HBT), the injection of a large volume of naked plasmid DNA in a short time is a relatively simple, efficient and safe method for in vivo transfection of liver cells. Though used for quite some time, the mechanism of gene transfection has not yet been elucidated. METHODS: A luciferase encoding plasmid was injected using the hydrodynamics based procedure into normal and thioacetamide-induced fibrotic Sprague Dawley rats. Scanning and transmission electron microscopy images were taken. The consequence of a dual injection of Ringer solution and luciferase pDNA was followed. Halofuginone, an anti collagen type I inhibitor was used to reduce ECM load in fibrotic rats prior to the hydrodynamic injection. RESULTS: Large endothelial gaps formed as soon as 10’ following hydrodynamic injection; these gradually returned to normal 10 d post injection. Hydrodynamic administration of Ringer 10 or 30 m prior to moderate injection of plasmid did not result in efficient transfection suggesting that endothelial gaps by themselves are not sufficient for gene expression. Gene transfection following hydrodynamic injection in thioacetamide induced fibrotic rats was diminished coinciding with the level of fibrosis. Halofuginone, a specific collagen typeIinhibitor, alleviated this effect. CONCLUSION: The hydrodynamic pressure formed following HBT results in the formation of large endothelial gaps. These gaps, though important in the transfer of DNA molecules from the blood to the space of Disse are not enough to provide the appropriate conditions for hepatocyte transfection. Hydrodynamics based injection is applicable in fibrotic rats provided that ECM load is reduced. PMID:17036386

In vitro corrosion resistance of plasma source ion nitrided austenitic stainless steels.

PubMed

Le, M K; Zhu, X M

2001-04-01

Plasma source ion nitriding has emerged as a low-temperature, low-pressure nitriding approach for low-energy implanting nitrogen ions and then diffusing them into steel and alloy. In this work, a single high nitrogen face-centered-cubic (f.c.c.) phase (gammaN) formed on the 1Cr18Ni9Ti and AISI 316L austenitic stainless steels with a high nitrogen concentration of about 32 at % was characterized using Auger electron spectroscopy, electron probe microanalysis, glancing angle X-ray diffraction, and transmission electron microscopy. The corrosion resistance of the gammaN-phase layer was studied by the electrochemical cyclic polarization measurement in Ringer's solutions buffered to pH from 3.5 to 7.2 at a temperature of 37 degrees C. No pitting corrosion in the Ringer's solutions with pH = 7.2 and 5.5 was detected for the gammaN-phase layers on the two stainless steels. The high pitting potential for the gammaN-phase layers is higher, about 500 and 600 mV, above that of the two original stainless steels, respectively, in the Ringer's solution with pH = 3.5. The corroded surface morphologies of the gammaN-phase layers observed by scanning electron microscopy are consistent with the results of the electrochemical polarization measurement.

Electrochemical studies on zirconium and its biocompatible alloys Ti-50Zr at.% and Zr-2.5Nb wt.% in simulated physiologic media.

PubMed

Oliveira, Nilson T C; Biaggio, Sonia R; Rocha-Filho, Romeu C; Bocchi, Nerilso

2005-09-01

Different electrochemical studies were carried out for Zr and its biocompatible alloys Ti-50Zr at.% and Zr-2.5Nb wt.% in solutions simulating physiologic media, Ringer and PBS (phosphate buffered saline) solutions. The results from rest-potential measurements showed that the three materials are spontaneously passivated in both solutions and that the Ti-50Zr alloy has the greatest tendency for spontaneous oxide formation. Some corrosion parameters (such as the pitting and repassivation potentials) were obtained via cyclic voltammetry in both solutions, revealing that the Ti-50Zr has the best corrosion protection while Zr has the worst. On the other hand, the pre-anodization (up to 8 V vs. SCE) of the alloys in a 0.15 mol/L Na2SO4 solution led to a significant improvement in their protection against pitting corrosion when exposed to the Ringer solution. Elemental analyses by EDX showed that during pitting corrosion, there is no preferential corrosion of any of the alloying elements (Zr, Ti, Nb). Copyright (c) 2005 Wiley Periodicals, Inc.

Distribution of crystalloid fluid changes with the rate of infusion: a population-based study.

PubMed

Hahn, R G; Drobin, D; Zdolsek, J

2016-05-01

Crystalloid fluid requires 30 min for complete distribution throughout the extracellular fluid space and tends to cause long-standing peripheral edema. A kinetic analysis of the distribution of Ringer's acetate with increasing infusion rates was performed to obtain a better understanding of these characteristics of crystalloids. Data were retrieved from six studies in which 76 volunteers and preoperative patients had received between 300 ml and 2375 ml of Ringer's acetate solution at a rate of 20-80 ml/min (0.33-0.83 ml/min/kg). Serial measurements of the blood hemoglobin concentration were used as inputs in a kinetic analysis based on a two-volume model with micro-constants, using software for nonlinear mixed effects. The micro-constants describing distribution (k12) and elimination (k10) were unchanged when the rate of infusion increased, with half-times of 16 and 26 min, respectively. In contrast, the micro-constant describing how rapidly the already distributed fluid left the peripheral space (k21) decreased by 90% when the fluid was infused more rapidly, corresponding to an increase in the half-time from 3 to 30 min. The central volume of distribution (V(c)) doubled. The return of Ringer's acetate from the peripheral fluid compartment to the plasma was slower with high than with low infusion rates. Edema is a normal consequence of plasma volume expansion with this fluid, even in healthy volunteers. The results are consistent with the view that the viscoelastic properties of the interstitial matrix are responsible for the distribution and redistribution characteristics of crystalloid fluid. © 2016 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Influences of red blood cell and platelet counts on the distribution and elimination of crystalloid fluid.

PubMed

Hahn, Robert G

2017-01-01

A high number of blood cells increases the viscosity of the blood. The present study explored whether variations in blood cell counts are relevant to the distribution and elimination of infused crystalloid fluid. On three different occasions, 10 healthy male volunteers received an intravenous infusion of 25mL/kg of Ringer's acetate, Ringer's lactate, and isotonic saline over 30min. Blood hemoglobin and urinary excretion were monitored for 4h and used as input in a two-volume kinetic model, using nonlinear mixed effects software. The covariates used in the kinetic model were red blood cell and platelet counts, the total leukocyte count, the use of isotonic saline, and the arterial pressure. Red blood cell and platelet counts in the upper end of the normal range were associated with a decreased rate of distribution and redistribution of crystalloid fluid. Simulations showed that high counts were correlated with volume expansion of the peripheral (interstitial) fluid space, while the plasma volume was less affected. In contrast, the total leukocyte count had no influence on the distribution, redistribution, or elimination. The use of isotonic saline caused a transient reduction in the systolic arterial pressure (P<0.05) and doubled the half-life of infused fluid in the body when compared to the two Ringer solutions. Isotonic saline did not decrease the serum potassium concentration, despite the fact that saline is potassium-free. High red blood cell and platelet counts are associated with peripheral accumulation of infused crystalloid fluid. Copyright © 2017 The Lithuanian University of Health Sciences. Production and hosting by Elsevier Sp. z o.o. All rights reserved.

Sodium-dependent calcium extrusion and sensitivity regulation in retinal cones of the salamander.

PubMed Central

Nakatani, K; Yau, K W

1989-01-01

1. Membrane current was recorded from an isolated, dark-adapted salamander cone by sucking its inner segment into a tight-fitting glass pipette containing Ringer solution. The outer segment of the cell was exposed to a bath solution that could be changed rapidly. 2. After removing Na+ from the bath Ringer solution for a short period of time in darkness (the 'loading period'), a transient inward current was observed upon restoring it in bright light. A similar but longer-lasting current was observed when Na+ was restored in the light after a large Ca2+ influx was induced through the light-sensitive conductance in darkness. 3. The above transient current was not observed if Li+ or guanidinium was substituted for Na+ in the light, or if Ba2+ was substituted for Ca2+ during the dark loading period. However, a current was observed if Sr2+ was the substituting ion for Ca2+ during loading. These observations suggested that the current was associated with an electrogenic Na+-dependent Ca2+ efflux at the cone outer segment. 4. The saturated amplitude of the exchange current was 12-25 pA with a mean around 16 pA. This is very comparable to that measured in the outer segment of a salamander rod under similar conditions. 5. By comparing a known Ca2+ load in a cone outer segment to the subsequent charge transfer through the exchange, we estimated that the stoichiometry of the exchange was near 3Na+:1Ca2+. 6. With a small Ca2+ load, or in the presence of Cs+ around the inner segment, the final temporal decline of the Na+-Ca2+ exchange current was roughly exponential, with a mean time constant of about 100 ms. This decline is about four times faster than that measured in rods. We interpret the shorter time constant in cones to reflect a faster rate of decline of intracellular free Ca2+ in their outer segments resulting from the exchange activity. 7. In the absence of external Na+, and hence any Na+-dependent Ca2+ efflux, the absolute sensitivity of a cone to a dim flash was several times higher than in normal Ringer solution. 8. A roughly similar increase in light sensitivity was observed for a rod under the same conditions. 9. We conclude that the Na+-dependent Ca2+ efflux, through lowering intracellular free Ca2+ in the light, has a role in regulating the absolute light sensitivity in cones as it does in rods.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:2479741

The effect of intravenous lactated Ringer's solution versus 0.9% sodium chloride solution on serum osmolality in human volunteers.

PubMed

Williams, E L; Hildebrand, K L; McCormick, S A; Bedel, M J

1999-05-01

Animal studies have shown that large volumes of IV lactated Ringer's solution (LR) decrease serum osmolality, thereby increasing cerebral water. These studies have led to recommendations to limit LR to avoid cerebral edema in neurosurgical patients. Eighteen healthy human volunteers aged 20-48 yr received 50 mL/kg LR over 1 h on one occasion and 0.9% sodium chloride (NS) on another. Venous samples were taken at baseline (T1), at infusion end (T2), and 1 h after T2 (T3). Time until first urination was noted. With LR, serum osmolality decreased by 4+/-3 mOsm/kg from T1 to T2 and increased insignificantly with NS. At T3, osmolality returned almost to baseline in the LR group. Blood pH increased from T1 to T2 with LR by 0.04+/-0.04 and decreased with NS by 0.04+/-0.04. These pH changes persisted at T3. Subjective mental changes occurred only with NS. Abdominal discomfort was more common with NS. Time until first urination was longer with NS (106+/-11 min) than with LR (75+/-10 min) (P < 0.001). In healthy humans, an infusion of large volumes of LR, but not NS, transiently decreased serum osmolality, whereas acidosis associated with NS persisted and urinary output was slower with NS. Large volumes of lactated Ringer's solution administered to healthy humans produced small transient changes in serum osmolality. Large volumes of sodium chloride did not change osmolality but resulted in lower pH.

In vitro bioactivity of novel tricalcium silicate ceramics.

PubMed

Zhao, Wenyuan; Chang, Jiang; Wang, Junying; Zhai, Wanyin; Wang, Zheng

2007-05-01

In this study, bone-like apatite-formation ability of tricalcium silicate (Ca(3)SiO(5)) ceramics in simulated body fluid (SBF) was evaluated and the in vitro degradability was investigated by soaking in Ringer's solution. The effect of ionic products from Ca(3)SiO(5) dissolution on osteobalsts proliferation was investigated. The result indicated that hydroxyapatite (HA) was formed on the surface of the Ca(3)SiO(5) ceramics after soaking in SBF for 1 day, and Ca(3)SiO(5) ceramics could degraded in Ringer's solution. The Si ions from Ca(3)SiO(5) dissolution at certain concentration range significantly stimulated osteoblasts proliferation. Our results show that Ca(3)SiO(5) ceramics possess bone-like apatite-formation ability and degradability, and can release soluble ionic products to stimulate cell proliferation.

Minimally invasive monitoring of skeletal muscle hypermetabolism induced by the phosphodiesterase-III-inhibitor milrinone and sodium fluoride.

PubMed

Schuster, Frank; Johannsen, Stephan; Roewer, Norbert; Anetseder, Martin

2013-04-01

We hypothesized that the phosphodiesterase-III-inhibitor milrinone and the non-specific G-protein activator sodium fluoride increase the skeletal muscular lactate levels as a sign of a hypermetabolic response. With approval of the local animal care committee Sprague-Dawley rats were killed and artificially perfused either with Ringer's solution or sodium fluoride 110 mM, while milrinone 1.32 mM or Ringer's solution at 1 μl/min was applied via microdialysis probes in both hind limbs. Lactate was measured spectrophotometrically in the dialysate. Baseline lactate levels before drug application did not differ between hind limbs. Local infusion of milrinone via microdialysis did not significantly increase intramuscular lactate concentrations compared with the Ringer control group. Muscular perfusion with sodium fluoride resulted in a significant increase of lactate and was potentiated by combination with local milrinone. Phosphodiesterase-III-inhibition alone does not significantly influence the lactate levels in skeletal muscle of sacrificed rats. Sodium fluoride infusion leads to an intramuscular lactate increase, which was further potentiated by local inhibition of phosphodiesterase-III. The fluoride-mediated hypermetabolic response following sodium fluoride could be a possible explanation for the observed myotoxic adverse effects in individuals treated by fluoride-containing agents. © 2012 The Authors. JPP © 2012. Royal Pharmaceutical Society.

Preoperative bowel preparation with meglumine and sodium diatrizoate (Gastrografin): a prospective randomised comparison.

PubMed

Koussidis, G A; Koussidis, A

2001-12-01

To test the use of meglumine and sodium diatrizoate (Gastrografin) as an agent for preoperative mechanical bowel preparation. Prospective randomised comparison. County general hospital, Greece. 58 patients listed for elective colorectal operations were randomly divided into 2 groups. The first (n = 30) was given Gastrografin 200 ml orally for 2 consecutive days before operation, and the second (n = 28) was given Ringer's solution through a nasogastric tube. Tolerability, acceptability, quality of cleansing, and complications. There were no disturbances in electrolyte concentrations, and other laboratory variables also remained unchanged. Two patients treated with Ringer's solution had appreciable increases in arterial blood pressure, but there were no significant overall changes. About half the patients given Ringer's felt nauseated and a third vomited. Such symptoms were uncommon in patients treated with Gastrografin (p < 0.01). 28/30 and 26/28 (93%) had a clean colonic lumen at operation, whereas in the reminder the lumen was evaluated as containing "slight residue". There were no operation-related complications. Gastrografin can be used successfully as an agent for mechanical bowel preparation before elective colorectal surgery, as it gives equally good cleansing results compared with the established method of whole gut irrigation. It also seems to be better tolerated and accepted by patients.

Structural evidence that botulinum toxin blocks neuromuscular transmission by impairing the calcium influx that normally accompanies nerve depolarization

PubMed Central

1981-01-01

Taking advantage of the fact that nerve terminal mitochondria swell and sequester calcium during repetitive nerve stimulation, we here confirm that this change is caused by calcium influx into the nerve and use this fact to show that botulinum toxin abolishes such calcium influx. The optimal paradigm for producing the mitochondrial changes in normal nerves worked out to be 5 min of stimulation at 25 Hz in frog Ringer's solution containing five time more calcium than normal. Applying this same stimulation paradigm to botulinum-intoxicated nerves produced no mitochondrial changes at all. Only when intoxicated nerves were stimulated in 4-aminopyridine (which grossly exaggerates calcium currents in normal nerves) or when they were soaked in black widow spider venom (which is a nerve-specific calcium ionophore) could nerve mitochondria be induced to swell and accumulate calcium. These results indicate that nerve mitochondria are not damaged directly by the toxin and point instead to a primary inhibition of the normal depolarization- evoked calcium currents that accompany nerve activity. Because these currents normally provide the calcium that triggers transmitter secretion from the nerve, this demonstration of their inhibition helps to explain how botulinum toxin paralyzes. PMID:6259176

Electrochemical behavior and corrosion resistance of Ti-15Mo alloy in naturally-aerated solutions, containing chloride and fluoride ions.

PubMed

Rodrigues, A V; Oliveira, N T C; dos Santos, M L; Guastaldi, A C

2015-01-01

The electrochemical behavior and corrosion resistance of Ti-15Mo alloy to applications as biomaterials in solutions 0.15 mol L(-1) Ringer, 0.15 mol L(-1) Ringer plus 0.036 mol L(-1) NaF and 0.036 mol L(-1) NaF (containing 1,500 ppm of fluoride ions, F(-)) were investigated using open-circuit potential, cyclic voltammetry, and electrochemical impedance spectroscopy techniques, X-ray photoelectron spectroscopy and scanning electron microscope. Corrosion resistance and electrochemical stability of the Ti-15Mo alloy decreased in solutions containing F(-) ions. In all cases, there were formation and growth of TiO2 and MoO3 (a protector film), not being observed pitting corrosion, which might enable Ti-15Mo alloys to be used as biomedical implant, at least in the studied conditions, since the electrochemical stability and corrosion resistance of the passive films formed are necessary conditions for osseointegration.

Regulation of intramembranous absorption and amniotic fluid volume by constituents in fetal sheep urine

PubMed Central

Jonker, Sonnet S.; Louey, Samantha; Cheung, Cecilia Y.; Brace, Robert A.

2013-01-01

Our objective was to test the hypothesis that fetal urine contains a substance(s) that regulates amniotic fluid volume by altering the rate of intramembranous absorption of amniotic fluid. In late gestation ovine fetuses, amniotic fluid volumes, urine, and lung liquid production rates, swallowed volumes and intramembranous volume and solute absorption rates were measured over 2-day periods under control conditions and when urine was removed and continuously replaced at an equal rate with exogenous fluid. Intramembranous volume absorption rate decreased by 40% when urine was replaced with lactated Ringer solution or lactated Ringer solution diluted 50% with water. Amniotic fluid volume doubled under both conditions. Analysis of the intramembranous sodium and chloride fluxes suggests that the active but not passive component of intramembranous volume absorption was altered by urine replacement, whereas both active and passive components of solute fluxes were altered. We conclude that fetal urine contains an unidentified substance(s) that stimulates active intramembranous transport of amniotic fluid across the amnion into the underlying fetal vasculature and thereby functions as a regulator of amniotic fluid volume. PMID:23824958

Effect of alpha/gamma phase ratio on corrosion behavior of dual-phase stainless steels.

PubMed

Lim, Y J; Reyes, M; Thongthammachat, S; Sukchit, K; Panich, M; Oshida, Y

1999-01-01

Dual-phase stainless steels have been developed in order to reduce the nickel content, which is potentially responsible to an allergic reaction when these steels are used as medical or dental applications. In this study, two different dual-phase stainless steels (2205 and Z100) were electrochemically tested to evaluate their corrosion resistance in three corrosive solutions (i.e., synthetic saliva, 0.9% NaCl solution, and Ringer solution). Particularly, an attempt was made to correlate the corrosion resistance to a metallographic parameter, which is, in this study, the alpha/gamma phase ratio. It was concluded that (1) type 2205 stainless steel exhibited excellent corrosion resistance in all three corrosion media; however 2205 stainless steel decreases its corrosion resistance by increasing chloride concentration in tested electrolytes from synthetic saliva through 0.9% NaCl solution to Ringer solution. (2) X-ray diffraction analysis indicated that the alpha/gamma phase ratio of 2205 (1.735) was higher than that of Z100 (0.905). As a result, it is suggested that by increasing the alpha/gamma phase ratio the material shows more corrosion-prone behavior when being subjected to a hostile environment containing higher chloride ion concentration.

Effect of corneal wetting solutions on corneal thickness during ophthalmic surgery.

PubMed

Emre, Sinan; Akkin, Cezmi; Afrashi, Filiz; Yağci, Ayşe

2002-01-01

To measure the changes in corneal thickness with wetting solutions used in ophthalmic surgery. Ege University, School of Medicine, Department of Ophthalmology, Izmir, Turkey. Thirty-one adult pigmented rabbits that weighed about 2.5 kg each were anesthetized with pentobarbital sodium. The rabbits were randomly divided into 3 groups to receive 3 wetting solutions: Group 1, Ringer's lactate; Group 2, balanced salt solution (BSS); and Group 3, BSS with glutation (BSS Plus). The solutions were dropped on the right cornea of the rabbits at a rate of 6.0 cc in 12 minutes using an intravenous infusion pump. Corneal thickness was measured by ultrasonic pachymetry before and after the procedure, and the between-group changes in corneal thickness were compared. The corneal thickness before and after the procedure was 361.27 microm +/- 19.3 (SD) and 380.00 +/- 25.0 microm, respectively, in Group 1 (P =.000); 372.10 +/- 18.8 microm and 388.60 +/- 24.1 microm, respectively, in Group 2 (P =.003); and 358.10 +/- 26.5 microm and 360.10 +/- 24.1 microm, respectively, in Group 3 (P =.316). As a corneal wetting solution, BSS Plus resulted in significantly fewer changes in corneal thickness than Ringer's lactate or BSS. This should be considered in cases involving long intraocular surgery.

Laser surface modification of Ti--6Al--4V: wear and corrosion characterization in simulated biofluid.

PubMed

Singh, Raghuvir; Kurella, A; Dahotre, Narendra B

2006-07-01

Laser surface melting (LSM) of Ti-6Al-4V is performed in argon to improve its properties, such as microstructure, corrosion, and wear for biomedical applications. Corrosion behavior is investigated by conducting electrochemical polarization experiments in simulated body fluid (Ringer's solution) at 37 C. Wear properties are evaluated in Ringer's solution using pin-on-disc apparatus at a slow speed. Untreated Ti-6Al-4V contains alpha+beta phase. After laser surface melting, it transforms to acicular alpha embedded in the prior beta matrix. Grain growth in the range of 65-89 microm with increase in laser power from 800 to 1500 W due to increase in associated temperature is observed. The hardness of as-laserprocessed Ti-6Al-4V alloy is more (275-297 HV) than that of the untreated alloy (254 HV). Passivation currents are significantly reduced to < 4.3 microA/cm2 after laser treatment compared to untreated Ti-6Al-4V (approximately 12 microA/cm2). The wear resistance of laser-treated Ti-6Al-4V in simulated body fluid is enhanced compared to that of the untreated one. It is the highest for the one that is processed at a laser power of 800 W. Typical micro-cutting features of abrasive wear is the prominent mechanism of wear in both untreated and as-laser-treated Ti-6Al-4V. Fragmentation of wear debris assisted by microcracking was responsible for mass loss during the wear of untreated Ti-6Al-4V in Ringer's solution.

Electrochemical characteristics of bioresorbable binary MgCa alloys in Ringer's solution: Revealing the impact of local pH distributions during in-vitro dissolution.

PubMed

Mareci, D; Bolat, G; Izquierdo, J; Crimu, C; Munteanu, C; Antoniac, I; Souto, R M

2016-03-01

Biodegradable magnesium-calcium (MgCa) alloy is a very attractive biomaterial. Two MgCa alloys below the solid solubility of Ca were considered, as to solely investigate the effect of Ca content on the behavior of magnesium and the pH changes associated to metal dissolution. X-ray diffraction analysis and optical microscopy showed that both Mg-0.63Ca and Mg-0.89Ca alloys were solely composed of α(Mg) phase. Degradation characteristics and electrochemical characterization of MgCa alloys were investigated during exposure to Ringer's solution at 37 °C by electrochemical impedance spectroscopy and scanning electrochemical microscopy. The impedance behavior showed both capacitive and inductive features that are related to the alloy charge transfer reaction and the relaxation of the absorbed corrosion compounds, and can be described in terms of an equivalent circuit. Scanning electron microscopy (SEM) was employed to view the surface morphology of the MgCa samples after 1 week immersion in Ringer's solution showing extensive precipitation of corrosion products, whereas the substrate shows evidence of a non-uniform corrosion process. Energy dispersive analysis showed that the precipitates contained oxygen, calcium, magnesium and chlorine, and the Mg:Ca ratios were smaller than in the alloys. Scanning electrochemical microscopy (SECM) was used to visualize local pH changes associated to these physicochemical processes with high spatial resolution. The occurrence of pH variations in excess of 3 units between anodic and cathodic half-cell reactions was monitored in situ. Copyright © 2015 Elsevier B.V. All rights reserved.

Effectiveness and tissue compatibility of a 12-week treatment of chronic venous leg ulcers with an octenidine based antiseptic--a randomized, double-blind controlled study.

PubMed

Vanscheidt, Wolfgang; Harding, Keith; Téot, Luc; Siebert, Jörg

2012-06-01

The aim of this study was to evaluate the cytotoxic effect of octenidine dihydrochloride/phenoxyethanol (OHP) found in vitro by conducting a randomized, double-blind controlled clinical study focusing on its safe and effective use in chronic venous leg ulcers. In total, 126 male and female patients were treated with either OHP (n = 60) or Ringer solution (n = 66). The treatment lasted over a period of maximum 12 weeks. For the assessment of the wound-healing process, clinical outcome parameters were employed, that is, time span until 100% epithelization, wound status and the wound surface area were analysed. Side effects were recorded during the study period. The median time to complete ulcer healing was comparable between the OHP and Ringer solution groups (92 versus 87 days; P = 0·952), without being influenced by wound size or duration of the target ulcer (P-values: 0·947/0·978). In patients treated with OHP, fewer adverse events (AEs) were observed compared with the Ringer group (17% versus 29% of patients reported 20 versus 38 AEs). OHP is well suitable for the treatment of chronic wounds without cytotoxic effects. Furthermore, OHP does not impair the wound healing in chronic venous ulcers. © 2011 The Authors. © 2011 Blackwell Publishing Ltd and Medicalhelplines.com Inc.

New insights into the passive force enhancement in skeletal muscles.

PubMed

Lee, Eun-Jeong; Joumaa, Venus; Herzog, Walter

2007-01-01

The steady-state isometric force following active stretching of a muscle is always greater than the steady-state isometric force obtained in a purely isometric contraction at the same length. This phenomenon has been termed "residual force enhancement" and it is associated with an active and a passive component. The origin of these components remains a matter of scientific debate. The purpose of this work was to test the hypothesis that the passive component of the residual force enhancement is caused by a passive structural element. In order to achieve this purpose, single fibers (n=6) from the lumbrical muscles of frog (Rana pipiens) were isolated and attached to a force transducer and a motor that could produce computer-controlled length changes. The passive force enhancement was assessed for three experimental conditions: in a normal Ringer's solution, and after the addition of 5 and 15mM 2,3-butanedione monoxime (BDM) which inhibits force production in a dose-dependent manner. If our hypothesis was correct, one would expect the passive force enhancement to be unaffected following BDM application. However, we found that increasing concentrations of BDM decreased the isometric forces, increased the normalized residual force enhancement, and most importantly for this study, increased the passive force enhancement. Furthermore, BDM decreased the rate of force relaxation after deactivation following active stretching of fibers, passive stretching in the Ringer's and BDM conditions produced the same passive force-sarcomere length relationship, and passive force enhancement required activation and force production. These results led to the conclusion that the passive force enhancement cannot be caused by a structural component exclusively as had been assumed up to date, but must be associated, directly or indirectly, with cross-bridge attachments upon activation and the associated active force.

Far Forward Treatment of Hemorrhagic Shock

DTIC Science & Technology

2007-02-01

Ringer’s solutions on human leukocytes. J Trauma 52(5):872-878, 2002 6. Alam HB, Punzalan CM, Koustova E, Bowyer MW, Rhee P. Hypertonic Saline: Intraosseous ...Fluid Resuscitation. 17. February 2006- Anesthesia Grand Rounds. Massachusetts General Hospital, Boston, MA. Topic: Trauma Resuscitation: New

Detection of dehydration by using volume kinetics.

PubMed

Zdolsek, Joachim; Li, Yuhong; Hahn, Robert G

2012-10-01

Patients admitted to surgery may be dehydrated, which is difficult to diagnose except when it is severe (>5% Gl116 of the body weight). We hypothesized that modest dehydration can be detected by kinetic analysis of the blood hemoglobin concentration after a bolus infusion of crystalloid fluid. Four series of experiments were performed on 10 conscious, healthy male volunteers. Separated by at least 2 days, they received 5 or 10 mL/kg acetated Ringer's solution over 15 minutes. Before starting half of the IV infusions, volume depletion amounting to 1.5 to 2.0 L (approximately 2% of body weight) was induced with furosemide. The elimination clearance and the half-life of the infused fluid were calculated based on blood hemoglobin over 120 minutes. The perfusion index and the pleth variability index were monitored by pulse oximetry after a change of body position. Dehydration decreased the elimination clearance of acetated Ringer's solution [median (25th-75th percentile)] from 1.84 (1.23-2.57) to 0.53 (0.41-0.79) mL/kg/min (Wilcoxon matched-pair test P < 0.001) and increased the half-life from 23 (12-37) to 76 (57-101) minutes (P < 0.001). The smaller infusion, 5 mL/kg, fully discriminated between experiments performed in the euhydrated and dehydrated states, whereas the urinary excretion provided a less-reliable indication of hydration status. Dehydration decreased the perfusion index but did not affect the pleth variability index. Dehydration amounting to 2% of the body weight could be detected from the elimination clearance and the half-life of an infusion of 5 mL/kg Ringer's solution.

Microstructure, Surface Characterization, and Electrochemical Behavior of New Ti-Zr-Ta-Ag Alloy in Simulated Human Electrolyte

NASA Astrophysics Data System (ADS)

Vasilescu, Cora; Drob, Silviu Iulian; Osiceanu, Petre; Moreno, Jose Maria Calderon; Prodana, Mariana; Ionita, Daniela; Demetrescu, Ioana; Marcu, Maria; Popovici, Ion Alexandru; Vasilescu, Ecaterina

2017-01-01

A new Ti-20Zr-5Ta-2Ag alloy was elaborated and characterized regarding its microstructure, its native passive film composition and thickness, its surface wettability, its electrochemical behavior in Ringer solution of different pH values, and its ion release. The new alloy has a bi-phase, α + β, acicular, homogeneous microstructure (scanning electron microscopy (SEM)). Its native passive film (12-nm thicknesses) consists of the protective TiO2, ZrO2, and Ta2O5 oxides, Ti and Ta suboxides, and metallic Ag (X-ray photoelectron spectroscopy (XPS) data). The alloy possesses high hydrophilic properties. The main electrochemical parameters of the new alloy are superior to those of Ti as a result of the beneficial influence of Zr, Ta, and Ag alloying elements, which reinforce its native passive film. Electrochemical impedance spectroscopy (EIS) spectra in Ringer solutions for the new alloy displayed better values of impedances and phase angles, proving a more insulate passive film than that on the Ti surface. The main corrosion parameters for the new Ti-20Zr-5Ta-2Ag alloy are more favorable by about 25 to 38 times than those of Ti, confirming extremely resistant passive film. The new Ti-20Zr-5Ta-2Ag alloy releases into Ringer solution low quantities of Ti4+, Zr4+ metallic ions (inductively coupled plasma-mass spectroscopy (ICP-MS)). The Ag+ ions are released in low quantity, conferring to this alloy's low antibacterial activity. All experimental results show that the new Ti-20Zr-5Ta-2Ag alloy fulfills the requirements for biocompatibility, corrosion resistance, and antibacterial protection.

Development of wear resistant NFSS-HA novel biocomposites and study of their tribological properties for orthopaedic applications.

PubMed

Younesi, M; Bahrololoom, M E; Fooladfar, H

2010-02-01

Implants made of nickel free austenitic stainless steel can reduce the toxic effect of released nickel ion and compounds from the conventional stainless steels. On the other hand, hydroxyapatite is a ceramic which has been used in orthopaedic applications due to its good osteoconductivity, biocompatibility and bioactivity. However, there is no evidence in the literature up to now on producing composites based on nickel free stainless steel and hydroxyapatite and study of their tribology. The aim of this work was to produce novel biocomposites made up of nickel free stainless steel with hydroxyapatite (prepared by heat treating bone ash) and studying their tribology under various loads in air and in Ringer's physiological solution. Different amounts of hydroxyapatite powder (10, 20, 30 and 40% Vol.) were added to this nickel free stainless steel powder to get the biocomposites. Variation of their density, hardness, wear resistance and friction with the ceramic (hydroxyapatite) content and wear load were investigated in air and in Ringer's solution. The density of the composites was decreased by increasing the volume percentage of the hydroxyapatite, while wear resistance of the composites was increased. The wear mechanism of these composites was changed by increasing the wear load and consequently the volume loss was enhanced dramatically. Furthermore, by increasing the sliding distance, the rate of volume loss was decreased slightly. The friction coefficient of the composites was also decreased by increasing the weight percentage of hydroxyapatite. Effect of the physiological Ringer's solution on wear resistance and friction coefficient of the composites was nearly negligible. The wear mechanisms of the samples were identified by studying the SEM images of the worn surfaces of the tested samples in different wear loads and HA contents. Copyright 2009 Elsevier Ltd. All rights reserved.

Intravenous infusion of amino acids in dogs attenuates hypothermia during anaesthesia and stimulates insulin secretion.

PubMed

Takashima, Satoshi; Shibata, Sanae; Yamada, Kazuto; Ogawa, Mizuho; Nishii, Naohito; Kitagawa, Hitoshi

2016-07-01

To evaluate the effect of intravenous infusion of amino acids on the prevention of hypothermia during anaesthesia in dogs. Randomized experimental trial. Seven healthy Beagle dogs. Four concentrations of amino acids were prepared with a 10% amino acid solution and an acetated Ringer's solution, and dogs were infused with each of the solutions at 1 week intervals. Dogs were infused with amino acid solution at 12 mL kg(-1)  hour(-1) for 60 minutes before and for 60 minutes after induction of anaesthesia. Acetated Ringer's solution was infused at the same rate for the remaining 60 minutes of anaesthesia. The infusion treatments were: 1) A0, nutrient-free acetated Ringer's solution; 2) A6, 0.6 g kg(-1)  hour(-1) ; 3) A9, 0.9 g kg(-1)  hour(-1) ; and 4) A12, 1.2 g kg(-1) hour(-1) . Rectal temperature (RT), heart rate (HR), mean arterial pressure (MAP), blood insulin, glucose, urea nitrogen (BUN) and creatinine concentrations, and time to extubation were measured. Before anaesthesia, RT was not affected by amino acid infusion. RT decreased progressively during anaesthesia and the absolute values of RT from 30 to 120 minutes were significantly higher in A12 than in A0 (p < 0.05). Reductions in HR and MAP during anaesthesia were attenuated by amino acid infusion in a dose-dependent manner. Plasma insulin concentration was significantly higher in A12 than in A0 during amino acid infusion and the increase in insulin concentration was greater during than before anaesthesia. BUN increased during amino acid infusion in a dose- and time-dependent fashion. Time until extubation was shorter in A12 than in A0. Amino acids infused at 1.2 g kg(-1)  hour(-1) in dogs attenuated the decrease in RT, HR, and MAP during anaesthesia, and induced a significant increase in plasma insulin concentration. © 2015 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.

Tribological Properties of Ti-Based Alloys in a Simulated Bone-Implant Interface with Ringer's Solution at Fretting Contacts

PubMed Central

Ramos-Saenz, C.R.; Sundaram, P.A.; Diffoot-Carlo, N.

2010-01-01

The wear properties of oxidized and non-oxidized gamma-TiAl (a potential biomaterial) as well as Ti-6Al-4V and CP-Ti disks were studied and characterized by means of standard wear tests using a custom made bone pin arrangement. The Ti-base disks were oxidized in air at 500°C and 800°C for one hour. The tribological properties of the oxides formed over the disks were studied using a linear reciprocating wear testing machine under both dry and simulated biological conditions using Ringer's solution. Loss of metal oxide and coefficient of friction values were determined from the wear testing. From the results, abrasion and adhesion were the primary wear mechanisms in each of the three alloy-bone pairs. Specifically, the oxide formed on gamma-TiAl possessed the highest COF and wear resistance of the three materials which were studied. Also, as expected, bone wears down faster than the Ti-base metal oxide. PMID:20826360

Preliminary study of coconut water for graft tissues preservation in transplantation.

PubMed

César, Jorge Miguel Schettino; Petroianu, Andy; Vasconcelos, Leonardo de Souza; Cardoso, Valbert Nascimento; Mota, Luciene das Graças; Barbosa, Alfredo José Afonso; Soares, Cristina Duarte Vianna; de Oliveira, Amanda Lima

2015-01-01

to verify the effectiveness of coconut water in preserving tissues for transplant. Fifty male Wistar rats were randomly distributed in five groups, according to the following preservation solutions for tissue grafts: Group 1: Lactated Ringer; Group 2: Belzer solution; Group 3: mature coconut water; Group 4: green coconut water; Group 5: modified coconut water. In Group 5, the green coconut water has been modified like the Belzer solution. From each animal we harvested the spleen, ovaries and skin of the back segment. These tissues were preserved for six hours in one of the solutions. Then, the grafts were reimplanted. The recovery of the function of the implanted tissues was assessed 90 days after surgery, by splenic scintigraphy and blood exam. The implanted tissues were collected for histopathological examination. The serum levels did not differ among groups, except for the animals in Group 5, which showed higher levels of IgG than Group 1, and differences in relation to FSH between groups 1 and 2 (p <0.001), 4 and 2 (p = 0.03) and 5 and 2 (p = 0.01). The splenic scintigraphy was not different between groups. The ovarian tissue was better preserved in mature coconut water (p <0.007). the coconut water-based solutions preserves spleen, ovary, and rat skin for six hours, maintaining their normal function.

Electrochemical and biological characterization of coatings formed on Ti-15Mo alloy by plasma electrolytic oxidation.

PubMed

Kazek-Kęsik, Alicja; Krok-Borkowicz, Małgorzata; Pamuła, Elżbieta; Simka, Wojciech

2014-10-01

β-Type titanium alloys are considered the future materials for bone implants. To improve the bioactivity of Ti-15Mo, the surface was modified using the plasma electrolytic oxidation (PEO) process. Tricalcium phosphate (TCP, Ca3PO4), wollastonite (CaSiO3) and silica (SiO2) were selected as additives in the anodizing bath to enhance the bioactivity of the coatings formed during the PEO process. Electrochemical analysis of the samples was performed in Ringer's solution at 37°C. The open-circuit potential (EOCP) as a function of time, corrosion potential (ECORR), corrosion current density (jCORR) and polarization resistance (Rp) of the samples were determined. Surface modification improved the corrosion resistance of Ti-15Mo in Ringer's solution. In vitro studies with MG-63 osteoblast-like cells were performed for 1, 3 and 7 days. After 24h, the cells were well adhered on the entire surfaces, and their number increased with increasing culture time. The coatings formed in basic solution with wollastonite exhibited better biological performance compared with the as-ground sample. Copyright © 2014 Elsevier B.V. All rights reserved.

Infusion of solutions of pre-irradiated components in rats.

PubMed

Pappas, Georgina; Arnaud, Francoise; Haque, Ashraful; Kino, Tomoyuki; Facemire, Paul; Carroll, Erica; Auker, Charles; McCarron, Richard; Scultetus, Anke

2016-06-01

The objective of this study was to conduct a 14-day toxicology assessment for intravenous solutions prepared from irradiated resuscitation fluid components and sterile water. Healthy Sprague Dawley rats (7-10/group) were instrumented and randomized to receive one of the following Field IntraVenous Resuscitation (FIVR) or commercial fluids; Normal Saline (NS), Lactated Ringer's, 5% Dextrose in NS. Daily clinical observation, chemistry and hematology on days 1,7,14, and urinalysis on day 14 were evaluated for equivalence using a two sample t-test (p<0.05). A board-certified pathologist evaluated organ histopathology on day 14. Equivalence was established for all observation parameters, lactate, sodium, liver enzymes, creatinine, WBC and differential, and urinalysis values. Lack of equivalence for hemoglobin (p=0.055), pH (p=0.0955), glucose (p=0.0889), Alanine-Aminotransferase (p=0.1938), albumin (p=0.1311), and weight (p=0.0555, p=0.1896), was deemed not clinically relevant due to means within physiologically normal ranges. Common microscopic findings randomly distributed among animals of all groups were endocarditis/myocarditis and pulmonary lesions. These findings are consistent with complications due to long-term catheter use and suggest no clinically relevant differences in end-organ toxicity between animals infused with FIVR versus commercial fluids. Copyright © 2016 Elsevier GmbH. All rights reserved.

21 CFR 522.1125 - Hemoglobin glutamer-200 (bovine).

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Hemoglobin glutamer-200 (bovine). 522.1125 Section... § 522.1125 Hemoglobin glutamer-200 (bovine). (a) Specifications. Each 125 milliliter bag contains 13 grams per deciliter of polymerized hemoglobin of bovine origin in modified Lactated Ringer's Solution...

Ringer tablet-based ionic liquid phase microextraction: Application in extraction and preconcentration of neonicotinoid insecticides from fruit juice and vegetable samples.

PubMed

Farajzadeh, Mir Ali; Bamorowat, Mahdi; Mogaddam, Mohammad Reza Afshar

2016-11-01

An efficient, reliable, sensitive, rapid, and green analytical method for the extraction and determination of neonicotinoid insecticides in aqueous samples has been developed using ionic liquid phase microextraction coupled with high performance liquid chromatography-diode array detector. In this method, a few microliters of 1-hexyl-3-methylimidazolium hexafluorophosphate (as an extractant) is added onto a ringer tablet and it is transferred into a conical test tube containing aqueous phase of the analytes. By manually shaking, the ringer tablet is dissolved and the extractant is released into the aqueous phase as very tiny droplets to provide a cloudy solution. After centrifuging the extracted analytes into ionic liquid are collected at the bottom of a conical test tube. Under the optimum extraction conditions, the method showed low limits of detection and quantification between 0.12 and 0.33 and 0.41 and 1.11ngmL(-1), respectively. Extraction recoveries and enrichment factors were from 66% to 84% and 655% to 843%, respectively. Finally different aqueous samples were successfully analyzed using the proposed method. Copyright © 2016 Elsevier B.V. All rights reserved.

Hyperoxygenated hydrogen-rich solution suppresses shock- and resuscitation-induced liver injury.

PubMed

Dang, Yangjie; Liu, Ting; Mei, Xiaopeng; Meng, Xiangzhong; Gou, Xingchun; Deng, Bin; Xu, Hao; Xu, Lixian

2017-12-01

It is not known whether simultaneous delivery of hydrogen and oxygen can reduce injury caused by hemorrhagic shock and resuscitation (HSR). This study investigated the therapeutic potential of hyperoxygenated hydrogen-rich solution (HHOS), a combined hydrogen/oxygen carrier, in a rat model of HSR-induced liver injury. Rats (n = 60) were randomly divided into 5 groups (n = 6 per group at each time point). One group underwent sham operation, and the others were subjected to severe hemorrhagic shock and then treated with lactated Ringer's solution (LRS), hydrogen-rich solution, hyperoxygenated solution, or HHOS. At 2 and 6 h after resuscitation, blood samples (n = 6) were collected from the femoral artery and serum concentrations of alanine aminotransferase and aspartate aminotransferase (AST) were measured. Rats were then sacrificed, and histopathological changes in the liver were evaluated by quantifying the percentage of apoptotic cells by caspase-3 immunohistochemistry and terminal deoxynucleotidyl transferase dUTP nick-end labeling. Inflammation was assessed by assessing malondialdehyde content and tumor necrosis factor-α, and interleukin (IL)-6 expression. Compared to lactated Ringer's solution, hydrogen-rich solution, or hyperoxygenated solution groups, serum AST and alanine aminotransferase levels and IL-6, tumor necrosis factor-α, and malondialdehyde expression in liver tissue were decreased by HHOS treatment. The number of caspase-3- and terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells was decreased (P < 0.05) by HHOS treatment, 2 and 6 h after resuscitation. HHOS has protective effects against liver injury in a rat model of HSR. Copyright © 2017 Elsevier Inc. All rights reserved.

Cortical gluing and Ringer lactate solution inflation to avoid cortical mantle collapse and subdural fluid collections in pediatric neurosurgery: safety and feasibility.

PubMed

Mirone, Giuseppe; Ruggiero, Claudio; Spennato, Pietro; Aliberti, Ferdinando; Trischitta, Vincenzo; Cinalli, Giuseppe

2015-06-01

Subdural fluid collections following intraventricular and/or paraventricular procedures in pediatric neurosurgery are common and can be hard to treat. We describe our technique to close cortical defects by the aid of a fibrin adhesive and subsequent Ringer inflation with the aim to avoid cortical mantle collapse and to prevent the development of subdural fluid collections. We report the preliminary results of a prospective study on a consecutive series of 29 children who underwent 37 transcortical or transcallosal surgical procedures since 2008 in our department. In 17 procedures, we performed a transcortical approach on lesions, and in other 19 operations, we operated by a transcallosal. In 5/17 transcortical approaches (29%) and in 3/20 transcallosal approaches (15%), we observed a 5-mm-thick subdural fluid collection of the 5 patients with subdural fluid collections in the transcortical group, 3 patients (17%) underwent surgery for symptomatic or progressive subdural fluid collections. Of the 3 patients in the transcallosal group, a subduro-peritoneal shunt was necessary only for 1 patient (5%). At the very end of the treatment (including chemotherapy and radiotherapy), it was possible to remove the subduro-peritoneal shunt in all these patients because of disappearance of the subdural fluid collections. In pediatric patients after transcortical or transcallosal procedures, the use of a fibrin adhesive to seal surgical opening and subsequent inflation of the residual cavity with Ringer lactate solution to avoid cortical mantle collapse seems safe and appears to prevent the development of subdural fluid collections.

Acidification of rabbit corneal endothelium during contact lens wear in vitro.

PubMed

Giasson, C; Bonanno, J A

1995-04-01

Contact lens wear causes significant epithelial and stromal acidosis. In this study, we tested whether lens wear can cause endothelial acidosis as well. Rabbit corneas were isolated and perfused in vitro. The endothelial intracellular pH (pHi) was measured with a pH sensitive fluorescent probe (BCECF). Three conditions were examined: 1) Polymethylmethacrylate (PMMA) and rigid gas-permeable (RGP) contact lens wear using a range of oxygen transmissibility (Dk/L) from 0 to 121, 2) epithelial hypoxia produced by exposure to oligomycin/sodium azide solution or epithelial perfusion with 100% N2 equilibrated Ringer's solution, and 3) epithelial exposure to Ringer's equilibrated with 5% CO2, balance air. PMMA and RGP contact lens wear acidified endothelial cells by 0.23 +/- 0.01 (n = 23) and 0.11 +/- 0.01 pH units (n = 23), respectively, within twenty min of lens insertion. Epithelial hypoxia, induced by sodium azide and oligomycin, reversibly acidified the endothelium by 0.04 +/- 0.01 pH units (n = 4). However, epithelial hypoxia induced by perfusion with 100% N2 equilibrated Ringer's did not have a significant effect on endothelial pHi. Introduction of 5% CO2 to the epithelium, acidified the endothelium by 0.15 +/- 0.02 pH units (n = 7) within 10 min. We conclude that contact lens wear can significantly acidify corneal endothelial cells. The endothelial pHi change is caused almost exclusively by a build up of CO2 behind the lens; hypoxia having very little contribution. As expected, RGP contact lenses induced less endothelial acidosis than PMMA controls.

Effects of microdialyzed oxotremorine, carbachol, epibatidine, and scopolamine on intraspinal release of acetylcholine in the rat.

PubMed

Höglund, A U; Hamilton, C; Lindblom, L

2000-10-01

Intrathecally administered cholinergic agonists such as oxotremorine (muscarinic), carbachol (mixed nicotinic and muscarinic agonist), and epibatidine (nicotinic) have all been shown to reduce nociception in behavioral studies. Thus, there is substantial evidence for a role of acetylcholine (ACh) in the control of nociception in the spinal cord, but the mechanisms regulating ACh release are not known. The present study was initiated to establish a rat model to study which mechanisms are involved in the control of ACh release. Spinal microdialysis probes were inserted intraspinally at the C1-C5 spinal level in isoflurane-anesthetized rats. The probes were perfused with Ringer's solution containing 10 microM neostigmine to prevent degradation of ACh. Oxotremorine, carbachol, epibatidine, and scopolamine, dissolved in Ringer's solution, were administered intraspinally via dialysis and 30 microliter/10-min samples of dialysate were collected for HPLC analysis of ACh content. The release of ACh was found to be constant in the control (Ringer's only) situation during the experimental period of 150 min. Oxotremorine (100-1000 microM), carbachol (1 mM), and epibatidine (50-5000 microM) enhanced but scopolamine (50-200 nM) decreased the intraspinal release of ACh. Oxotremorine (ED(50) = 118 microM) and epibatidine (ED(50) = 175 microM) were found to produce a dose-dependent increase of ACh release. Cholinergic agonists caused an increase of intraspinal ACh and the antagonist scopolamine caused a decreased release of ACh. The data do not support an autoreceptor function of either nicotinic or muscarinic receptors in the spinal cord, contrary to what has been observed in the brain.

Studies on Poly(propylene fumarate-co-caprolactone diol) Thermoset Composites towards the Development of Biodegradable Bone Fixation Devices

PubMed Central

Jayabalan, M.

2009-01-01

The effect of reinforcement in the cross-linked poly(propylene fumarate-co-caprolactone diol) thermoset composites based on Kevlar fibres and hydroxyapatite was studied. Cross-linked poly(propylene fumarate-co-caprolactone diol) was also studied without any reinforcement for comparison. The reinforcing fibre acts as a barrier for the curing reaction leading to longer setting time and lesser cross-link density. The fibre and HA reinforced composites have almost the same compressive strength. Nonreinforced material undergoes greater degree of swelling. Among the reinforced materials, the hydroxyapatite reinforced composite has a much higher swelling percentage than the fibre reinforced one. The studies on in vitro degradation of the cured materials reveal hydrolytic degradation in Ringer's solution and PBS medium during aging. All the three materials are found to swell initially in Ringer's solution and PBS medium during aging and then undergo gradual degradation. Compression properties of these cross-linked composites increase with aging; HA reinforced composite has the highest compressive strength and compressive modulus, whereas the aged fibre-reinforced composite has the least compressive strength and modulus. PMID:20126578

Studies on Poly(propylene fumarate-co-caprolactone diol) Thermoset Composites towards the Development of Biodegradable Bone Fixation Devices.

PubMed

Jayabalan, M

2009-01-01

The effect of reinforcement in the cross-linked poly(propylene fumarate-co-caprolactone diol) thermoset composites based on Kevlar fibres and hydroxyapatite was studied. Cross-linked poly(propylene fumarate-co-caprolactone diol) was also studied without any reinforcement for comparison. The reinforcing fibre acts as a barrier for the curing reaction leading to longer setting time and lesser cross-link density. The fibre and HA reinforced composites have almost the same compressive strength. Nonreinforced material undergoes greater degree of swelling. Among the reinforced materials, the hydroxyapatite reinforced composite has a much higher swelling percentage than the fibre reinforced one. The studies on in vitro degradation of the cured materials reveal hydrolytic degradation in Ringer's solution and PBS medium during aging. All the three materials are found to swell initially in Ringer's solution and PBS medium during aging and then undergo gradual degradation. Compression properties of these cross-linked composites increase with aging; HA reinforced composite has the highest compressive strength and compressive modulus, whereas the aged fibre-reinforced composite has the least compressive strength and modulus.

Hypothermic in situ perfusion of the porcine liver using Celsior or Ringer-lactate solution.

PubMed

Dinant, S; Roseboom, H J; Levi, M; van Vliet, A K; van Gulik, T M

2009-01-01

Hypothermic perfusion (HP) of the liver is applied during total vascular exclusion (TVE) to reduce ischemic injury during liver resection. No studies have been performed comparing different perfusion solutions for HP. The aim of this experimental study was to compare Ringer-lactate solution (RL) with Celsior solution (Cs) for HP in a pig model of 60-min TVE. Twenty pigs underwent 60-min TVE of the liver. Groups were TVE without HP (no-HP, n = 9), TVE with HP using RL (n = 6), and TVE with HP using Cs (n = 5). Blood and liver tissue samples were taken before TVE and during 24-h reperfusion. In the no-HP group, plasma aspartate aminotransferase values were significantly increased during reperfusion (p < 0.05), while liver tissue pO(2) levels (p < 0.01) were decreased when compared to the HP groups. After 24-h reperfusion, bile production and liver tissue glutathione content were significantly higher (p < 0.05) in the Cs group (42.0 +/- 1.7 mL/h and 44.9 +/- 2.2 nmol/mg, respectively) as compared to the RL group (31.5 +/- 3.5 mL/h and 19.6 +/- 1.8 nmol/mg, respectively). The protective effect of HP during TVE was confirmed in this study. HP with Cs was more effective in reducing ischemic injury as compared to HP with RL.

The Impact of Pre-Hospital Administration of Lactated Ringer's Solution versus Normal Saline in Patients with Traumatic Brain Injury

PubMed Central

Rowell, Susan E.; Barbosa, Ronald R.; Watters, Jennifer M.; Bulger, Eileen M.; Holcomb, John B.; Cohen, Mitchell J.; Rahbar, Mohammad H.; Fox, Erin E.; Schreiber, Martin A.

2016-01-01

Abstract Lactated Ringer's (LR) and normal saline (NS) are both used for resuscitation of injured patients. NS has been associated with increased resuscitation volume, blood loss, acidosis, and coagulopathy compared with LR. We sought to determine if pre-hospital LR is associated with improved outcome compared with NS in patients with and without traumatic brain injury (TBI). We included patients receiving pre-hospital LR or NS from the PRospective Observational Multicenter Major Trauma Transfusion (PROMMTT) study. Patients with TBI (Abbreviated Injury Scale [AIS] head ≥3) and without TBI (AIS head ≤2) were compared. Cox proportional hazards models including Injury Severity Score (ISS), AIS head, AIS extremity, age, fluids, intubation status, and hospital site were generated for prediction of mortality. Linear regression models were generated for prediction of red blood cell (RBC) and crystalloid requirement, and admission biochemical/physiological parameters. Seven hundred ninety-one patients received either LR (n = 117) or NS (n = 674). Median ISS, AIS head, AIS extremity, and pre-hospital fluid volume were higher in TBI and non-TBI patients receiving LR compared with NS (p < 0.01). In patients with TBI (n = 308), LR was associated with higher adjusted mortality compared with NS (hazard rate [HR] = 1.78, confidence interval [CI] 1.04–3.04, p = 0.035). In patients without TBI (n = 483), no difference in mortality was demonstrated (HR = 1.49, CI 0.757–2.95, p = 0.247). Fluid type had no effect on admission biochemical or physiological parameters, 6-hour RBC, or crystalloid requirement in either group. LR was associated with increased mortality compared with NS in patients with TBI. These results underscore the need for a prospective randomized trial comparing pre-hospital LR with NS in patients with TBI. PMID:26914721

Lactated ringer's solution and hetastarch but not plasma resuscitation after rat hemorrhagic shock is associated with immediate lung apoptosis by the up-regulation of the Bax protein.

PubMed

Deb, S; Sun, L; Martin, B; Talens, E; Burris, D; Kaufmann, C; Rich, N; Rhee, P

2000-07-01

We previously demonstrated that the type of resuscitation fluid used in hemorrhagic shock affects apoptosis. Unlike crystalloid, whole blood seems to attenuate programmed cell death. The purpose of this study was to determine whether the acellular components of whole blood (plasma, albumin) attenuated apoptosis and to determine whether this process involved the Bax protein pathway. Rats were hemorrhaged 27.5 mL/kg, kept in hypovolemic shock for 75 minutes, then resuscitated over 1 hour (n = 44). Control animals underwent anesthesia only (sham, n = 7). Treatment animals were bled then randomly assigned to the following resuscitation groups: no resuscitation (n = 6), whole blood (n = 6), plasma (n = 6), 5% human albumin (n = 6), 6% hetastarch (n = 7), and lactated Ringer's solution (LR, n = 6). Hetastarch was used to control for any colloid effect. LR was used as positive control. Immediately after resuscitation, the lung was collected and evaluated for apoptosis by using two methods. TUNEL stain was used to determine general DNA damage, and Bax protein was used to specifically determine intrinsic pathway involvement. LR and hetastarch treatment resulted in significantly increased apoptosis in the lung as determined by both TUNEL and Bax expression (p < 0.05). Plasma infusion resulted in significantly less apoptosis than LR and hetastarch resuscitation. Multiple cell types (epithelium, endothelium, smooth muscle, monocytes) underwent apoptosis in the lung as demonstrated by the TUNEL stain, whereas Bax expression was limited to cells residing in the perivascular and peribronchial spaces. Apoptosis after volume resuscitation of hemorrhagic shock can be affected by the type of resuscitation fluid used. Manufactured fluids such as lactated Ringer's solution and 6% hetastarch resuscitation resulted in the highest degree of lung apoptosis. The plasma component of whole blood resulted in the least apoptosis. The process of apoptosis after hemorrhagic shock resuscitation involves the Bax protein.

Small-volume fluid resuscitation with hypertonic saline prevents inflammation but not mortality in a rat model of hemorrhagic shock.

PubMed

Bahrami, Soheyl; Zimmermann, Klaus; Szelényi, Zoltán; Hamar, János; Scheiflinger, Friedrich; Redl, Heinz; Junger, Wolfgang G

2006-03-01

Hemorrhage remains a primary cause of death in civilian and military trauma. Permissive hypotensive resuscitation is a possible approach to reduce bleeding in patients until they can be stabilized in an appropriate hospital setting. Small-volume resuscitation with hypertonic saline (HS) is of particular interest because it allows one to modulate the inflammatory response to hemorrhage and trauma. Here, we tested the utility of permissive hypotensive resuscitation with hypertonic fluids in a rat model of hemorrhagic shock. Animals were subjected to massive hemorrhage [mean arterial pressure (MAP) = 30 - 35 mmHg for 2 h until decompensation] and partially resuscitated with a bolus dose of 4 mL/kg of 7.5% NaCl (HS), hypertonic hydroxyl ethyl starch (HHES; hydroxyl ethyl starch + 7.5% NaCl), or normal saline (NS) followed by additional infusion of Ringer solution to maintain MAP at 40 to 45 mmHg for 40 min (hypotensive state). Finally, animals were fully resuscitated with Ringer solution and the heparinized shed blood. Hypotensive resuscitation with NS caused a significant increase in plasma interleukin (IL)-1beta, IL-6, IL-2, interferon gamma (IFNgamma), IL-10, and granulocyte-macrophage colony stimulating factor (GM-CSF). This increase was blocked by treatment with HS. HHES treatment significantly reduced the increase of IL-1beta and IL-2 but not that of the other cytokines studied. Despite the strong effects of HS and HHES on cytokine production, both treatments had little effect on plasma lactate, base excess (BE), white blood cell (WBC) count, myeloperoxidase (MPO) content, and the wet/dry weight ratio of the lungs. Moreover, on day 7 after shock, the survival rate in rats treated with HS was markedly, but not significantly, lower than that of NS-treated animals (47% vs. 63%, respectively). In summary, hypotensive resuscitation with hypertonic fluids reduces the inflammatory response but not lung tissue damage or mortality after severe hemorrhagic shock.

Coconut water solutions for the preservation of spleen, ovary, and skin autotransplants in rats.

PubMed

Schettino César, J M; Petroianu, A; de Souza Vasconcelos, L; Cardoso, V N; das Graças Mota, L; Barbosa, A J A; Vianna Soares, C D; Lima de Oliveira, A

2015-03-01

The purpose of this study was to evaluate the efficacy of coconut water in the preservation of spleen, ovary, and skin autotransplantations in rats. Fifty female Wistar rats were divided randomly into 5 groups on the basis of the following tissue graft preservation solutions: group 1, lactated Ringer's; group 2, Belzer's solution; group 3, mature coconut water; group 4, green coconut water; and group 5, modified green coconut water. In group 5, the green coconut water solution was modified to obtain the same electrolyte composition as Belzer's solution. The spleen, ovaries, and a skin fragment were removed from each animal, stored for 6 hours in one of the solutions, and then re-implanted. The recoveries of tissue functions were assessed 90 days after surgery by means of spleen scintigraphy and blood tests. The implanted tissues were collected for histological analyses. Higher immunoglobulin G levels were observed in the animals of group 5 than in the animals of group 1. Differences in follicle-stimulating hormone levels were observed between groups 1 and 2 (P < .001), between groups 4 and 2 (P = .03), and between groups 5 and 2 (P = .01). The spleen scintigraphy results did not differ among the groups. The ovarian tissue was better preserved in the mature coconut water group (P < .007). Solutions containing coconut water allowed for the preservation of the spleen, ovaries, and skin for 6 hours, and the normal functions of these tissues were maintained in rats. Copyright © 2015 Elsevier Inc. All rights reserved.

Eliminating Preventable Death on the Battlefield

DTIC Science & Technology

2011-08-15

Phases of Tactical Combat Casualty Care Between October 1, 2001, and March 31, 2010 Intervention IVF Dose, mL Casualties, No. Saline lock only NA 35...Saline lock and IVF NA 55 Normal saline 250 1 500 25a 1000 6 1500 1 Hextendb 250 2 500 12a,c 1000 1 Normal salineHextendb 500500 3 1000250 1 500100...1a Lactated ringers 500 2a Abbreviations: IVF , intravenous fluid; NA, not applicable. aFour casualties received 2 saline locks and IVF . bHextend is

The physostigmine depolarization potentiating effect of salicylate in frog skeletal muscle.

PubMed

Varga, E; Kovács, L; Szücs, G; Illés, B

1975-01-01

1) The frog's sartorius muscle was depolarized depending on the degree of concentration 2--4 times more intensely by physostigmine salicylate than by physostigmine sulphate. 2) In normal Ringer's solution, 1 mM physostigmine salicylate decreased the sensitivity of the membrane to potassium depolarization by about 90%. Under similar experimental conditions, physostigmine sulphate and Na salicylate, respectively, decrease the sensitivity of the membrane to potassium depolarization by about 30%. 3) The difference manifested in the depolarizing effect of salicylate and other physostigmine salts (chloride, sulphate, phosphate, formiate, acetate, monochloracetate, benzoate and para-oxy-benzoate) is expressed already at 1 mM concentration (about 10-fold), if the muscle had been equilibrated in chloride-free glucuronate or sulphate milieu. 4) The depolarization develops slowly. It takes 30--60 minutes for the new steady state to develop even in the superficial sartorius fibres. If depolarization has reached its maximum on an average 100 mV, the membrane potential remains unchanged for hours. 5) Depolarization ensues at an unchanged degree in the presence of Na-free (choline) Ringer as well as in the presence of 2X10(-8) g/ml tetrodotoxin; therefore, it is not a Na-dependent process. 6) Under the influence of 1 mM physostigmine salicylate the membrane's resistance to the inward potassium current increased about twofold, while the increase was only 15% to the outward potassium current. It is assumed that the salicylate anion is characteristically capable of potentiating the decreasing effect of physostigmine on potassium permeability, though the role of the metabolic effect of salicylate cannot be excluded.

Effective Treatment of Traumatic Brain Injury in Rowett Nude Rats with Stromal Vascular Fraction Transplantation.

PubMed

Berman, Sean; Uhlendorf, Toni L; Berman, Mark; Lander, Elliot B

2018-06-18

Traumatic brain injury (TBI) affects 1.9 million Americans, including blast TBI that is the signature injury of the Iraq and Afghanistan wars. Our project investigated whether stromal vascular fraction (SVF) can assist in post-TBI recovery. We utilized strong acoustic waves (5.0 bar) to induce TBI in the cortex of adult Rowett Nude (RNU) rats. One hour post-TBI, harvested human SVF (500,000 cells suspended in 0.5 mL lactated Ringers) was incubated with Q-Tracker cell label and administered into tail veins of RNU rats. For comparison, we utilized rats that received SVF 72 h post-TBI, and a control group that received lactated Ringers solution. Rotarod and water maze assays were used to monitor motor coordination and spatial memories. Rats treated immediately after TBI showed no signs of motor skills and memory regression. SVF treatment 72 h post-TBI enabled the rats maintain their motor skills, while controls treated with lactated Ringers were 25% worse statistically in both assays. Histological analysis showed the presence of Q-dot labeled human cells near the infarct in both SVF treatment groups; however, labeled cells were twice as numerous in the one hour group. Our study suggests that immediate treatment with SVF would serve as potential therapeutic agents in TBI.

Friction and lubrication of pleural tissues.

PubMed

D'Angelo, Edgardo; Loring, Stephen H; Gioia, Magda E; Pecchiari, Matteo; Moscheni, Claudia

2004-08-20

The frictional behaviour of rabbit's visceral pleura sliding against parietal pleura was assessed in vitro while oscillating at physiological velocities and amplitudes under physiological normal forces. For sliding velocities up to 3 cm s(-1) and normal compressive loads up to 12 cm H2O, the average value of the coefficient of kinetic friction (mu) was constant at 0.019 +/- 0.002 (S.E.) with pleural liquid as lubricant. With Ringer-bicarbonate solution, mu was still constant, but significantly increased (Deltamu = 0.008 +/- 0.001; P < 0.001). Under these conditions, no damage of the sliding pleural surfaces was found on light and electron microscopy. Additional measurements, performed also on peritoneum, showed that changes in nominal contact area or strain of the mesothelia, temperature in the range 19-39 degrees C, and prolonged sliding did not affect mu. Gentle application of filter paper increased mu approximately 10-fold and irreversibly, suggesting alteration of the mesothelia. With packed the red blood cells (RBC) between the sliding mesothelia, mu increased appreciably but reversibly on removal of RBC suspension, whilst no ruptures of RBC occurred. In conclusion, the results indicate a low value of sliding friction in pleural tissues, partly related to the characteristics of the pleural liquid, and show that friction is independent of velocity, normal load, and nominal contact area, consistent with boundary lubrication.

β2-Adrenergic receptors and G-protein-coupled receptor kinase 2 in rabbit pleural mesothelium.

PubMed

Sironi, Chiara; Bodega, Francesca; Armilli, Marta; Porta, Cristina; Zocchi, Luciano; Agostoni, Emilio

2010-09-30

Former studies on net rate of liquid absorption from small Ringer or 1% albumin-Ringer hydrothoraces in rabbits indicated that Na+ transport and solute-coupled liquid absorption by mesothelium is increased by pleural liquid dilution, and stimulation of β2-adrenoreceptors (β2AR). In this research we tried to provide molecular evidence for β2AR in visceral and parietal mesothelium of rabbit pleura. Moreover, because prolonged stimulation of β2AR may lead to desensitization mediated by G-protein-coupled receptor kinase 2 (GRK2), we also checked whether GRK2 is expressed in pleural mesothelium. To this end we performed immunoblot assays on total protein extracts from scraped visceral and parietal mesothelium, and from cultured pleural mesothelial cells of rabbits. All three samples showed β2AR and GRK2 specific bands. Copyright 2010 Elsevier B.V. All rights reserved.

Monitoring of interstitial buffer systems using micro-dialysis and infrared spectrometry

NASA Astrophysics Data System (ADS)

Heise, H. M.; Cocchieri, L.; Vahlsing, T.; Ihrig, D.; Elm, J.

2017-02-01

Nowadays, continuous sensing systems are important point-of-care devices for the hospital and personalized patient technology. FTIR-spectrometers have been successfully employed for the development of bed-side systems. In-vivo applications for critically ill patients can be envisaged for analytes and parameters, which are of interest for intensive care such as lactate, urea, pCO2 and pH. The human body maintains the blood pH around 7.4, but for severe pH level changes acidosis or alkalosis can lead to serious health problems. Three different buffer systems exist based on bicarbonate, phosphate and proteins; for the most important bicarbonate and phosphate systems infrared transmission spectra were recorded. By using the CO2 and HCO3 - bands of the bicarbonate spectra, the pH of the harvested biofluid can be predicted using the Henderson-Hasselbalch equation. Furthermore, we studied the solubility of CO2 in aqueous solutions using gas mixtures of N2 and CO2 with known composition within partial pressures of CO2 as relevant for invivo conditions. Thus, values of pCO2 up to 150 mm Hg (200 hPa) with distilled water and a Ringer solution, which is an isotonic electrolyte solution used for medical infusion, were measured at 25 °C and 37 °C (normal body temperature).

Physical and chemical stability of palonosetron HCl in 4 infusion solutions.

PubMed

Trissel, Lawrence A; Xu, Quanyun A

2004-10-01

Palonosetron HCl is a selective 5-HT(3) receptor antagonist used for the prevention of chemotherapy-induced nausea and vomiting. Palonosetron HCl may be diluted in an infusion solution for administraton. Consequently, stability information is needed for palonosetron HCl admixed in common infusion solutions. To evaluate the physical and chemical stability of palonosetron HCl in concentrations of 5 and 30 microg/mL in dextrose 5% injection, NaCl 0.9% injection, dextrose 5% in NaCl 0.45% injection, and dextrose 5% in lactated Ringer's injection. Triplicate test samples of palonosetron HCl at each concentration in each diluent were tested. Samples were stored and evaluated at appropriate intervals for up to 48 hours at room temperature ( approximately 23 degrees C) and 14 days under refrigeration (4 degrees C). Physical stability was assessed using turbidimetric and particulate measurement, as well as visual inspection. Chemical stability was assessed by HPLC. All of the admixtures were initially clear and colorless when viewed in normal fluorescent room light and with a Tyndall beam. Measured turbidity and particulate content were low initially and remained low throughout the study. The drug concentration was unchanged in any of the samples at either temperature throughout the study. Palonosetron HCl is physically and chemically stable in all 4 common infusion solutions for at least 48 hours at room temperature and 14 days under refrigeration.

Ringer's lactate, but not hydroxyethyl starch, prolongs the food intolerance time after major abdominal surgery; an open-labelled clinical trial.

PubMed

Li, Yuhong; He, Rui; Ying, Xiaojiang; Hahn, Robert G

2015-05-06

The infusion of large amounts of Ringer's lactate prolongs the functional gastrointestinal recovery time and increases the number of complications after open abdominal surgery. We performed an open-labelled clinical trial to determine whether hydroxyethyl starch or Ringer's lactate exerts these adverse effects when the surgery is performed by laparoscopy. Eighty-eight patients scheduled for major abdominal cancer surgery (83% by laparoscopy) received a first-line fluid treatment with 9 ml/kg of either 6% hydroxyethyl starch 130/0.4 (Voluven) or Ringer's lactate, just after induction of anaesthesia; this was followed by a second-line infusion with 12 ml/kg of either starch or Ringer's lactate over 1 hour. Further therapy was managed at the discretion of the attending anaesthetist. Outcome data consisted of postoperative gastrointestinal recovery time, complications and length of hospital stay. The order of the infusions had no impact on the outcome. Both the administration of ≥ 2 L of Ringer's lactate and the development of a surgical complication were associated with a longer time period of paralytic ileus and food intolerance (two-way ANOVA, P < 0.02), but only surgical complications prolonged the length of hospital stay (P < 0.001). The independent effect of Ringer's lactate and complications of food intolerance time amounted to 2 days each. The infusion of ≥ 1 L of hydroxyethyl starch did not adversely affect gastrointestinal recovery. Ringer's lactate, but not hydroxyethyl starch, prolonged the gastrointestinal recovery time in patients undergoing laparoscopic cancer surgery. Surgical complications prolonged the hospital stay.

Antagonism of soluble guanylyl cyclase attenuates cutaneous vasodilation during whole body heat stress and local warming in humans

PubMed Central

Zhao, Joan L.; Wu, Yubo; Johnson, John M.

2011-01-01

We hypothesized that nitric oxide activation of soluble guanylyl cyclase (sGC) participates in cutaneous vasodilation during whole body heat stress and local skin warming. We examined the effects of the sGC inhibitor, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), on reflex skin blood flow responses to whole body heat stress and on nonreflex responses to increased local skin temperature. Blood flow was monitored by laser-Doppler flowmetry, and blood pressure by Finapres to calculate cutaneous vascular conductance (CVC). Intradermal microdialysis was used to treat one site with 1 mM ODQ in 2% DMSO and Ringer, a second site with 2% DMSO in Ringer, and a third site received Ringer. In protocol 1, after a period of normothermia, whole body heat stress was induced. In protocol 2, local heating units warmed local skin temperature from 34 to 41°C to cause local vasodilation. In protocol 1, in normothermia, CVC did not differ among sites [ODQ, 15 ± 3% maximum CVC (CVCmax); DMSO, 14 ± 3% CVCmax; Ringer, 17 ± 6% CVCmax; P > 0.05]. During heat stress, ODQ attenuated CVC increases (ODQ, 54 ± 4% CVCmax; DMSO, 64 ± 4% CVCmax; Ringer, 63 ± 4% CVCmax; P < 0.05, ODQ vs. DMSO or Ringer). In protocol 2, at 34°C local temperature, CVC did not differ among sites (ODQ, 17 ± 2% CVCmax; DMSO, 18 ± 4% CVCmax; Ringer, 18 ± 3% CVCmax; P > 0.05). ODQ attenuated CVC increases at 41°C local temperature (ODQ, 54 ± 5% CVCmax; DMSO, 86 ± 4% CVCmax; Ringer, 90 ± 2% CVCmax; P < 0.05 ODQ vs. DMSO or Ringer). sGC participates in neurogenic active vasodilation during heat stress and in the local response to direct skin warming. PMID:21292837

On the distribution of Na+ pump sites in the frog skin

PubMed Central

Mills, JW; DiBona, DR

1977-01-01

Exposure of the outside of the isolated frog skin to a Ringer's solution, made hypertonic by the addition of mannitol, causes a rapid and sustained increase in transepithelial permeability through a structural distortion-a focal blistering-of the "tight" junctions of the outermost living cell layer. [(3)H]ouabain, used as an autoradiographic marker for the Na+-pump (Na+-K+-adenosine triphosphatase), is usually unable to penetrate the frog skin from the outside solution, but when added to a hypertonic mannitol- Ringer's solution in the outside bath it readily penetrates the epithelium, presumably through the opened shunt pathway. Radioautographic analysis of [(3)H]ouabain binding sites revealed that most of ouabain enters from the outside solution binds to the sites on the cell membranes of the stratum spinosum, as was the case when it was applied from the inside bath in an earlier study. The outer living cell layer, the first to be exposed to ouabain, does not appear to be the major site for the Na+-pump, and therefore, is not likely to be responsible for most of the active pumping of Na+. This result demonstrates that previous failure to show a high density of Na+-pump sites on the cells of the outermost layer, when [(3)H]ouabain was applied from the inside solution, was not due to the inability of the marker to reach these cells at a sufficient concentration to reveal all pump sites. These results provide further support for a model of Na+-transport across the frog skin which distributes the active pump step on the inward facing membranes of all living cells. PMID:144738

Calcium and magnesium fluxes across the plasma membrane of the toad rod outer segment.

PubMed Central

Nakatani, K; Yau, K W

1988-01-01

1. Membrane current was recorded from an isolated, dark-adapted toad rod by sucking either its inner segment or outer segment into a tight-fitting glass pipette containing Ringer solution. The remainder of the cell was exposed to bath solution which could be changed rapidly. 2. In normal Ringer solution the current response of a cell to a saturating flash or step of light showed a small secondary rise at its initial peak. The profile of this secondary rise (i.e. amplitude and time course) was independent of both the intensity and the duration of illumination once the light response had reached a plateau level. 3. This secondary rise disappeared when external Na+ around the outer segment was replaced by Li+ or guanidinium, suggesting that it represented an electrogenic Na+-dependent Ca2+ efflux which was declining after the onset of light. 4. This Na+-Ca2+ exchange activity showed a roughly exponential decline, with a time constant of about 0.5 s. Exponential extrapolation of the exchange current to the time at half-height of the light response gave an initial amplitude of about 2 pA. Using La3+ as a blocker, we did not detect any steady exchange current after the initial exponential decline. 5. An intense flash superposed on a just-saturating steady background light failed to produce any incremental exchange current transient. 6. Our interpretation of the above results is that in darkness there are counterbalancing levels of Ca2+ influx (through the light-sensitive conductance) and efflux (through the Na+-Ca2+ exchange) across the plasma membrane of the rod outer segment. The exchange current transient at the onset of light merely represents the unidirectional Ca2+ efflux which becomes revealed as a result of the stoppage of the Ca2+ influx, rather than a de novo Ca2+ efflux triggered by light. 7. Consistent with this interpretation, a test light delivered soon after a saturating, conditioning light elicited little exchange current, which then gradually recovered to control value with a time course parallel to the restoration of the dark current. Conversely, when the dark current was increased above its physiological level by IBMX (isobutylmethylxanthine) the exchange current transient became larger than control.(ABSTRACT TRUNCATED AT 400 WORDS) Images Fig. 8 PMID:2457685

Effect of surface nanostructuring on corrosion behavior of Ti–6Al–4V alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Sanjeev, E-mail: sanjeevphy85@gmail.com; Ch

Surface nanostructure was induced in Ti–6Al–4V alloy by ultrasonic shot peening (USSP) for different durations, from 15 s to 30 min, and the modified surface was characterized by optical, scanning, atomic force and transmission electron microscopy. Nano size grains were observed to form on surface of the USSPed samples and surface roughness was increased with duration of USSP. Polarization study was carried out in Ringer's solution to examine the effect of surface nanostructuring on corrosion resistance of this alloy. Electrochemical corrosion was carried out for all the USSPed specimens as well as the non-USSPed sample in Ringer's solution. Surface morphologymore » of the corroded samples was examined by SEM. In general, corrosion resistance was improved by USSP up to the duration of 15 min and there was maximum improvement in the specimen USSPed for 1 min. However, corrosion resistance was drastically reduced due to USSP for long duration of 30 min. - Highlights: •Nanostructure was induced by USSP on alloy Ti–6Al–4V of about 28 nm. •Grain refinement was confirmed by XRD and TEM. •USSP is an effective technique for the improvement in corrosion resistance. •Nanostructured surface promotes formation of protective surface layer of TiO{sub 2}.« less

Effect of amiloride and bumetanide on transepithelial ion transport in isolated rabbit cecal and colonic wall.

PubMed

Kosik-Bogacka, Danuta; Młodzik-Danielewicz, Natalia; Banach, Bolesław; Tyrakowski, Tomasz

2005-06-03

The aim of the study was to compare the effects of amiloride and bumetanide on the baseline transepithelial electrical potential difference (PD) and changes in PD during mechanical stimulation (dPD) in isolated cecal and colonic wall of rabbits. The experiments were performed with a modified Ussing chamber system. Isolated tissue specimens were incubated in Ringer's solution, in amiloride and/or bumetanide, or in dimethyl sulfoxide (DMSO). Under control conditions, i.e. when all the experimental fluids were Ringer's solution, the PD and R values of the rabbit cecum and colon were similar, while during mechanical stimulation, dPD of the colon was twice as high as that of the cecum. Addition of amiloride and/or bumetanide to all experimental fluids diminished the electrophysiological parameters of both tissues. DMSO added to all experimental fluids significantly diminished the values of the electrophysiological parameters of the cecum. Addition of amiloride to the stimulation fluid only diminished the PD and dPD values in the colon, whereas addition of bumetanide to the stimulation fluid only diminished the PD and dPD values in the cecum. It was found that the PD and dPD values of the rabbit cecum depend primarily on chloride ion transport, while those of the colon depend on sodium ion transport.

Effect of cyclic aromatics on sodium active transport in frog skin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blankemeyer, J.T.; Bowerman, M.C.

1993-01-01

A modified glass Ussing-chamber was used to mount the skin. The electrical potential difference (PD) was measured by two 3% agar-frog Ringer's bridges. Current (i.e. short-circuit current, or ISC) was passed by Ag-AgCl electrodes placed so that current density was uniform across the skin. Ringer's solution, bathing each side of the frog skin, was stirred and aerated by gas-lift pumps. The effect of toxicants on the ISC was determined by using the 15 min prior to toxicant administration as a control period, then calculating the change in ISC during the toxicant period as a percent of the control ISC. Phenolmore » and benzene are components of crude oil and crude oil waste. These hydrocarbons and phenanthrene were tested for their effect on frog skin. The results show that the effect of organics on sodium active transport of an epithelium is to alter the active transport of sodium ions. 5 refs., 3 figs., 1 tab.« less

[A study on alpha-tricalcium phosphate bone cement carbon fiber-reinforced].

PubMed

Wu, Wenjin; Yang, Weizhong; Zhou, Dali; Ma, Jiang; Xiao, Bin

2006-06-01

In order to improve the mechanical properties of alpha-tricalcium phosphate (alpha-TCP), we prepared surface-modified carbon fibers (CF) reinforced alpha-TCP composite bone cement. Bone cement was soaked in Ringer's body solution to test its capacity of fast formation of hydroxyapatite crystals and self-solidification. Scan electronic microscope (SEM) observation and compressive strength measurement were taken to analyze the mechanical properties and the micro- morphological structure of CF reinforced alpha-TCP bone cement. The results showed that the bone cement was transferred into hydroxyapatite plates after being soaked in Ringer's simulated body fluid for 5 days. Suitable amount of carbon fibers could well spread in and bond with the matrix of the bone cement. The mechanical properties of the bone cement have been improved by CF reinforcing; the compressive strength reaches 46.7 MPa when the amount of carbon fibers is 0.5% in weight percent, which is 22% higher than that of the non-reinforced alpha-TCP bone cement.

Metallurgical and electrochemical characterization of contemporary silver-based soldering alloys.

PubMed

Ntasi, Argyro; Al Jabbari, Youssef; Mueller, Wolf Dieter; Eliades, George; Zinelis, Spiros

2014-05-01

To investigate the microstructure, hardness, and electrochemical behavior of four contemporary Ag-based soldering alloys used for manufacturing orthodontic appliances. The Ag-based alloys tested were Dentaurum Universal Silver Solder (DEN), Orthodontic Solders (LEO), Ortho Dental Universal Solder (NOB), and Silver Solder (ORT). Five disk-shaped specimens were produced for each alloy, and after metallographic preparation their microstructural features, elemental composition, and hardness were determined by scanning electron microscopy with energy-dispersive X-ray (EDX) microanalysis, X-ray diffraction (XRD) analysis, and Vickers hardness testing. The electrochemical properties were evaluated by anodic potentiodynamic scanning in 0.9% NaCl and Ringer's solutions. Hardness, corrosion current (Icorr), and corrosion potential (Ecorr) were statistically analyzed by one-way analysis of variance and Tukey test (α=.05). EDX analysis showed that all materials belong to the Ag-Zn-Cu ternary system. Three different mean atomic contrast phases were identified for LEO and ORT and two for DEN and NOB. According to XRD analysis, all materials consisted of Ag-rich and Cu-rich face-centered cubic phases. Hardness testing classified the materials in descending order as follows: DEN, 155±3; NOB, 149±3; ORT, 141±4; and LEO, 136±8. Significant differences were found for Icorr of NOB in Ringer's solution and Ecorr of DEN in 0.9% NaCl solution. Ag-based soldering alloys demonstrate great diversity in their elemental composition, phase size and distribution, hardness, and electrochemical properties. These differences may anticipate variations in their clinical performance.

Improved arterial blood oxygenation following intravenous infusion of cold supersaturated dissolved oxygen solution.

PubMed

Grady, Daniel J; Gentile, Michael A; Riggs, John H; Cheifetz, Ira M

2014-01-01

One of the primary goals of critical care medicine is to support adequate gas exchange without iatrogenic sequelae. An emerging method of delivering supplemental oxygen is intravenously rather than via the traditional inhalation route. The objective of this study was to evaluate the gas-exchange effects of infusing cold intravenous (IV) fluids containing very high partial pressures of dissolved oxygen (>760 mm Hg) in a porcine model. Juvenile swines were anesthetized and mechanically ventilated. Each animal received an infusion of cold (13 °C) Ringer's lactate solution (30 mL/kg/hour), which had been supersaturated with dissolved oxygen gas (39.7 mg/L dissolved oxygen, 992 mm Hg, 30.5 mL/L). Arterial blood gases and physiologic measurements were repeated at 15-minute intervals during a 60-minute IV infusion of the supersaturated dissolved oxygen solution. Each animal served as its own control. Five swines (12.9 ± 0.9 kg) were studied. Following the 60-minute infusion, there were significant increases in PaO2 and SaO2 (P < 0.05) and a significant decrease in PaCO2 (P < 0.05), with a corresponding normalization in arterial blood pH. Additionally, there was a significant decrease in core body temperature (P < 0.05) when compared to the baseline preinfusion state. A cold, supersaturated dissolved oxygen solution may be intravenously administered to improve arterial blood oxygenation and ventilation parameters and induce a mild therapeutic hypothermia in a porcine model.

Chalk in the prime.

PubMed Central

Yeo, H; Doyle, T; Saynor, R; Smith, G H

1986-01-01

After observations of cloudiness in the perfusion circuit at open intracardiac operations, laboratory experiments showed a precipitate in a Hartmann's solution (compound sodium lactate solution, Ringer-lactate) and sodium bicarbonate based priming fluid used for cardiopulmonary bypass. The precipitate was found to consist of calcium carbonate crystals. The crystals were not dissolved by adding plasma proteins, nor were they sufficiently cleared from the extracorporeal circuit by a 40 microns filter in the arterial line. The crystals may embolise in microvascular beds and thus be a cause of postoperative morbidity. The practice of adding sodium bicarbonate to the pump prime may be unnecessary. Images PMID:3010485

A novel nanobiotherapeutic poly-[hemoglobin-superoxide dismutase-catalase-carbonic anhydrase] with no cardiac toxicity for the resuscitation of a rat model with 90 minutes of sustained severe hemorrhagic shock with loss of 2/3 blood volume

PubMed Central

Bian, Yuzhu; Chang, Thomas Ming Swi

2015-01-01

Abstract We crosslink hemoglobin (Hb), superoxide dismutase (SOD), catalase (CAT), and carbonic anhydrase (CA) to form a soluble polyHb-SOD-CAT-CA nanobiotechnological complex. The obtained product is a soluble complex with three enhanced red blood cell (RBC) functions and without blood group antigens. In the present study, 2/3 of blood volume was removed to result in 90-min hemorrhagic shock at mean arterial blood pressure (MAP) of 30 mmHg. This was followed by the reinfusion of different resuscitation fluids, then followed for another 60 min. PolyHb-SOD-CAT-CA maintained the MAP at 87.5 ± 5 mmHg as compared with 3 volumes of lactated Ringer's solution, 43.3 ± 2.8 mmHg; blood, 91.3 ± 3.6 mmHg; polyHb-SOD-CAT, 86.0 ± 4.6 mmHg; poly stroma-free hemolysate (polySFHb), 85.0 ± 2.5 mmHg; and polyHb, 82.6 ± 3.5 mmHg. PolyHb-SOD-CAT-CA was superior to the blood and other fluids based on the following criteria. PolyHb-SOD-CAT-CA reduced tissue pCO2 from 98 ± 4.5 mmHg to 68.6 ± 3 mmHg. This was significantly (p < 0.05) more effective than lactated Ringer's solution (98 ± 4.5 mmHg), polyHb (90.1 ± 4.0 mmHg), polyHb-SOD-CAT (90.9 ± 1.4 mmHg), blood (79.1 ± 4.7 mmHg), and polySFHb (77 ± 5 mmHg). PolyHb-SOD-CAT-CA reduced the elevated ST level to 21.7 ± 6.7% and is significantly (< 0.05) better than polyHb (57.7 ± 8.7%), blood (39.1 ± 1.5%), polySFHb (38.3% ± 2.1%), polyHb-SOD-CAT (27.8 ± 5.6%), and lactated Ringer's solution (106 ± 3.1%). The plasma cardiac troponin T (cTnT) level of polyHb-SOD-CAT-CA group was significantly (P < 0.05) lower than that of all the other groups. PolyHb-SOD-CAT-CA reduced plasma lactate level from 18 ± 2.3 mM/L to 6.9 ± 0.3 mM/L. It was significantly more effective (P < 0.05) than lactated Ringer's solution (12.4 ± 0.6 mM/L), polyHb (9.6 ± 0.7 mM/L), blood (8.1 ± 0.2 mM/L), polySFHb (8.4 ± 0.1 mM/L), and polyHb-SOD-CAT (7.6 ± 0.3 mM/L). PolyHb-SOD-CAT-CA can be stored for 320 days at room temperature. Lyophilized poly-Hb-SOD-CAT-CA can be heat pasteurized at 68F for 2 h. This can be important if there is a need to inactivate human immunodeficiency virus, Ebola virus, and other infectious organisms. PMID:25297052

[Intravenous rehydration for diarrheal dehydration of eutrophic children: survey of protocols provided at Colombian medical schools].

PubMed

Flórez, Iván Darío; Ramos, Esteban; Bernal, Carlos; Cuéllar, Olga Juliana; Cornejo, José William

2011-01-01

In all cases of severe dehydration from diarrhea, WHO recommends rapid rehydration. If oral rehydration in children is contraindicated, intravenous rehydration is recommended for immediate administration. However, methods of intravenous rehydration appear to be inadequately addressed in the medical schools of Colombia. Current approaches to oral rehydration were summarized, and instructors were informed concerning current WHO recommendations. A survey was designed for pediatric instructors in Colombian medical schools. Direct questions about rehydration methods were included as well as presentation of theoretical clinical situations with dehydrated children. The survey also asked for the conditions necessary for intravenous rehydration and method of administration (volume, solution, concentration and speed of infusion). Forty-one surveys were included (82% of medical schools in Colombia). Inadequate contraindications for oral rehydration therapy were made in 41%. Rapid and slow intravenous rehydration was recommended in 71% and 29%, respectively; 57% recommended fluid bolus to rehydrate. Adequate volumes were recommended by less than half of the respondents and adequate sodium concentration was recommended by 85%. In 56% of medical schools, glucose was not included in solutions and 66% use Ringer lactate. Normal saline solution, dextrose solution with electrolytes and polyelectrolytes solutions are also used. Misconceptions are common concerning the contraindications to oral rehydration therapy. One-third of medical schools promote a slow therapy despite the superiority of the rapid therapy. Uniformity for rapid therapy schemes is lacking. Bolus rehydration is commonly advocated despite the fact that this method is unsupported by the literature. Concepts about rehydration must be updated in medical schools and a national guide for intravenous rehydration is recommended.

Comparisons of Normal Saline and Lactated Ringer’s Resuscitation on Hemodynamics, Metabolic Responses, and Coagulation in Pigs after Severe Hemorrhagic Shock

DTIC Science & Technology

2013-12-11

vasodilator effects and the risks of metabolic acidosis and hyperkalemia . Keywords: Hemorrhagic shock, Oxygen metabolism, Coagulation, Pre-hospital...www.sjtrem.com/content/21/1/86 of hyperchloremic acidosis from NS resuscitation [37]. Consistent with our current results, clinically significant hyperkalemia ...risks of meta- bolic acidosis and hyperkalemia . Currently, military first responders have NS, LR and Hextend available [20]. How- ever, the results from

Sequential assessment of pulmonary epithelial diethylene triamine penta-acetate clearance and intrapulmonary transferrin accumulation during Escherichia coli peritonitis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ishizaka, A.; Stephens, K.E.; Segall, G.M.

1990-03-01

The individual roles of pulmonary capillary endothelial and alveolar epithelial permeability in the pathogenesis of the adult respiratory distress syndrome (ARDS) are unclear. We developed a method for the sequential assessment of pulmonary macromolecule accumulation and small solute clearance in vivo using a gamma camera. We measured the exponential clearance coefficient of 111In-labeled diethylene triamine penta-acetate (111In-DTPA) to assess airway clearance of small solutes. We also calculated the exponential equilibration coefficient of 111In-labeled transferrin (111In-TF) to assess intrapulmonary accumulation of transferrin. We determined these parameters in guinea pigs with Escherichia coli peritonitis and compared them with a saline-treated control group,more » oleic-acid-treated groups, and a group treated with low molecular weight dextran Ringer solution. The pulmonary DTPA clearance and the intrapulmonary transferrin accumulation were significantly increased in the peritonitis group (29.4 +/- 8.2 x 10(-3) min-1, p less than 0.02, and 15.1 +/- 3.1 x 10(-3) min-1, p less than 0.02) when compared with the control group (3.1 +/- 0.8 x 10(-3) min-1 and 4.5 +/- 0.5 x 10(-3) min-1). These changes developed within 5.5 h of the initial insult. Neither increased extravascular lung water nor elevated pulmonary artery and left atrial pressures were detected in the peritonitis group. The low molecular weight dextran Ringer group did not show a significant increase in the pulmonary DTPA clearance and the intrapulmonary transferrin accumulation.« less

Performance of Plasma Sprayed Al2O3 Coating in Bio-Simulated Environment

NASA Astrophysics Data System (ADS)

Yıldız, F.; Yetim, A. F.; Alsaran, A.; Çelik, A.

2014-01-01

Alumina coatings deposited on the surface of stainless steel 316L by the method of plasma spraying are studied. Tests for wear and corrosion are preformed in Ringer's solution simulating a human body environment. The structure, microhardness, wear resistance and corrosion resistance of the steel are determined with and without a coating. Deposition of a coating onto the stainless steel is shown to be an effective means for protecting implants from corrosion and wear.

On the passive and semiconducting behavior of severely deformed pure titanium in Ringer's physiological solution at 37°C: A trial of the point defect model.

PubMed

Ansari, Ghazaleh; Fattah-Alhosseini, Arash

2017-06-01

The effects of sever plastic deformation through multi-pass accumulative roll bonding on the passive and semiconducting behavior of pure titanium is evaluated in Ringer's physiological solution at 37°C in the present paper. Produced results by polarization plots and electrochemical impedance spectroscopy measurements revealed a significant advance in the passive response of the nano-grained sample compared to that of the annealed pure titanium. Also, Mott-Schottky test results of the nano-grained pure titanium represented a lower donor density and reduced flat-band potential in the formed passive film in comparison with the annealed sample. Moreover, based on the Mott-Schottky analysis in conjunction with the point defect model, it was suggested that with increase in formation potential, the calculated donor density of both annealed and nano-grained samples decreases exponentially and the thickness of the passive film linearly increases. These observations were consistent with the point defect model predictions, considering that the point defects within the passive film are metal interstitials, oxygen vacancies, or both. From the viewpoint of passive and semiconducting behavior, nano-grained pure titanium appeared to be more suitable for implant applications in simulate human body environment compared to annealed pure titanium. Copyright © 2017 Elsevier B.V. All rights reserved.

Blood autotransfusion outcomes compared with Ringer lactate infusion in dogs with hemorrhagic shock induced by controlled bleeding.

PubMed

Safaei, Mansour; Takami, Hassan Mousavi

2011-10-01

The most common cause of shock in the surgical or trauma patient is hemorrhage. Crystalloid solutions and blood transfusion are the mainstays of treatment of hemorrhagic shock. Considering the disadvantages of allogeneic blood transfusion, such as risk of transmission of infectious diseases, and access and maintenance limitations, treatment of shock with autologous blood seems to be a decent solution. Autologous blood accumulated in body cavities in traumatic bleeding (such hemothorax), and bloodshed in operation field during open heart or vascular surgeries, and similar situations, can be utilized again. In this study, autotransfusion effects compared with crystalloid fluid in the treatment of hemorrhagic shock was investigated. After induction of hemorrhagic shock in dogs by Wiggers type controlled bleeding, treating them in a group with autologous blood and another group with Ringer lactate were performed, and the results of treatment were studied. There was no mortality in both treatment approaches. Immediately after treatment, crystalloid positive effects such as renormalized vital signs and appropriate consciousness were more noticeable than autotransfusion, while twenty-four hours after, the desired effects of autologous blood were more pronounced like decreased metabolic acidosis and improvement of diuresis. Crystalloid during the first hours after treatment of hemorrhagic shock may be better than autologous blood as preferred treatment, while autotransfusion showed its benefits some hours after. This finding can be used to develop better strategies for treatment of hemorrhagic shock.

A multiple reader scoring system for Nasal Potential Difference parameters.

PubMed

Solomon, George M; Liu, Bo; Sermet-Gaudelus, Isabelle; Fajac, Isabelle; Wilschanski, Michael; Vermeulen, Francois; Rowe, Steven M

2017-09-01

Nasal Potential Difference (NPD) is a biomarker of CFTR activity used to diagnose CF and monitor experimental therapies. Limited studies have been performed to assess agreement between expert readers of NPD interpretation using a scoring algorithm. We developed a standardized scoring algorithm for "interpretability" and "confidence" for PD (potential difference) measures, and sought to determine the degree of agreement on NPD parameters between trained readers. There was excellent agreement for interpretability between NPD readers for CF and fair agreement for normal tracings but slight agreement of interpretability in indeterminate tracings. Amongst interpretable tracings, excellent correlation of mean scores for Ringer's Baseline PD, Δ amiloride , and Δ Cl-free+Isoproterenol was observed. There was slight agreement regarding confidence of the interpretable PD tracings, resulting in divergence of the Ringers and Δ amiloride , and ΔCl -free+Isoproterenol PDs between "high" and "low" confidence CF tracings. A multi-reader process with adjudication is important for scoring NPDs for diagnosis and in monitoring of CF clinical trials. Copyright © 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Intravenous lipid emulsion only minimally influences bupivacaine and mepivacaine distribution in plasma and does not enhance recovery from intoxication in pigs.

PubMed

Litonius, Erik S; Niiya, Tomohisa; Neuvonen, Pertti J; Rosenberg, Per H

2012-04-01

The reported successful use of IV lipid emulsions in local anesthetic intoxications is thought to be due to lipid sequestration of local anesthetics. However, controlled efficacy studies were lacking, and other mechanisms of action have also been suggested. We investigated the effect of lipid infusion on plasma concentrations and cardiovascular effects of 2 local anesthetics differing in lipophilicity, bupivacaine, and mepivacaine. Bupivacaine (n = 20) or mepivacaine (n = 20) was infused into a central vein of anesthetized (isoflurane 1%, Fio(2) 0.21) pigs until mean arterial blood pressure decreased to 50% from baseline. Isoflurane was discontinued and Fio(2) was increased to 1.0. Ten pigs in each local anesthetic group were treated with 20% lipid emulsion (ClinOleic®), and 10 pigs with Ringer's solution: 1.5 mL/kg in 1 minute followed by an infusion of 0.25 mL · kg(-1) · min(-1) for 29 minutes. Five additional pigs were infused bupivacaine and Intralipid®. Total and nonlipid-bound local anesthetic concentrations were determined from repeated blood samples. There were no overall differences in total or nonlipid-bound plasma local anesthetic concentrations between the lipid and Ringer's groups. However, plasma median total bupivacaine concentration was 21% and 23% higher at 20 and 30 minutes, respectively, in the lipid group (P = 0.016 without Holm-Bonferroni correction). There was also no overall difference between lipid and Ringer's groups in the rate of recovery of hemodynamic and electrocardiographic variables. Median mean arterial blood pressure in the lipid group with bupivacaine intoxication was 16 mm Hg and 15 mm Hg higher than in the corresponding Ringer's group at 10 and 15 minutes, respectively (P = 0.016 and P = 0.021, respectively, without Holm-Bonferroni correction). Intralipid® also caused no difference between total plasma and nonlipid-bound concentrations of bupivacaine with no apparent enhancement of recovery. Lipid emulsion neither had any measurable effect on the disposition of the studied local anesthetics in plasma, nor did it improve the rate of recovery from intoxication by either local anesthetic as measured by hemodynamic variables.

A comparative study of 28 culture media for Trichomonas gallinae

USGS Publications Warehouse

Diamond, L.S.

1954-01-01

1. 1. A study was made of the ability of 28 different culture media to support growth of 5 strains of Trichomonas gallinae with their normally associated bacteria. A standard inoculum of 50 protozoa was used, and the cultures were incubated at 35 ?C. Based upon the number of positive cultures obtained, abundance of growth, and number of strains which grew in a given medium, the most satisfactory were Ringer-Loeffler serum, saline-Loeffler serum, and saline-serum. 2. 2. Pigeon serum used alone in a simple saline solution produced abundant growth and when added to other nutrients greatly enhanced the medium. Autoclaving of the serum appeared to have no effect on its growth promoting qualities. 3. 3. Neither egg yolk nor egg albumin alone appeared capable of supporting appreciable growth of T. gallinae. 4. 4. In general, the heavier the bacterial population supported by a medium the poorer the growth of T. gallinae. 5. 5. Strains of T. gallinae differ in their culturability. One strain grew in 82% of the media tested, another only in 43%.

Hog-ringer speeds seed trap construction

Treesearch

D.O. Hall

1964-01-01

An upholsterer's hog-ringer, with Hill's No. 1 pig rings, increased production of one-foot-square wire seed traps by 25 percent. A design modification allowed two bottom sections to be cut from a 36-inch roll of wire.

Comparison of the effects of a balanced crystalloid-based and a saline-based tetrastarch solution on canine whole blood coagulation and platelet function.

PubMed

Reuteler, Annina; Axiak-Flammer, Shannon; Howard, Judith; Adamik, Katja-Nicole

2017-01-01

To evaluate the effects of a 6% hydroxyethyl starch (130/0.42) solution in either a buffered, electrolyte-balanced (HES-BAL), or a saline (HES-SAL) carrier solution on canine platelet function and whole blood coagulation. Prospective, randomized study. University teaching hospital. Thirty-seven client-owned dogs undergoing general anesthesia for arthroscopy or imaging studies. Dogs received a 15 mL/kg intravenous bolus of HES-SAL (n = 13), HES-BAL (n = 14), or a modified Ringer's solution (n = 10) over 30-40 minutes. Coagulation was analyzed using a Platelet Function Analyzer-100 (closure time [Ct PFA ]), and whole blood thromboelastometry (ROTEM) with extrinsically (ex-tem and fib-tem) and intrinsically (in-tem) activated assays, which assessed clotting time (CT), clot formation time (CFT), maximal clot firmness (MCF), and lysis index (LI). Coagulation samples were assayed prior to fluid administration (T0), and 5 minutes (T1), and 3 hours (T2) following fluid bolus administration, respectively. Both HES solutions resulted in impaired platelet function as indicated by a significant prolongation of Ct PFA at T1 as compared to T0, but which resolved by T2. An IV bolus of Ringer's solution did not alter platelet function. In both HES groups, whole blood coagulation was significantly impaired at T1 as indicated by a significant increase in in-tem CFT, and a significant decrease in ex-tem, in-tem, and fib-tem MCF compared to T0. Furthermore, a significant increase in ex-tem CFT at T1 compared to T0 was found in the HES-SAL group. With the exception of in-tem MCF after HES-BAL, these effects were not present at T2. No significant differences were found in Ct PFA or any ROTEM variable at any time point between HES-SAL and HES-BAL. Administration of a single bolus of 15 mL/kg 6% HES 130/0.42 results in significant but short-lived impairment of canine platelet function and whole blood coagulation, regardless of carrier solution. © Veterinary Emergency and Critical Care Society 2016.

Hepatic Metabolism of Perfluorinated Carboxylic Acids and Polychlorotrifluoroethylene: A Nuclear Magnetic Resonance Investigation in Vivo

DTIC Science & Technology

1994-01-05

1 v/v) followed by perfusion with warm, oxygenated Krebs-Ringer solution (10 mil/min). The thorax was opened to expose the heart and the inferior vena ... cava was cannulated (PE 240-1.7 mm ID) via an incision in the right atrium . Livers were excised, washed with warm saline, transferred to the...AFOSR grant. Marjorie Artz was a Ph.D. graduate student who worked in this laboratory briefly in 1992 and then left in January 1993. She was supported

Investigating the Functional Role of Prostate-Specific Membrane Antigen and Its Enzymatic Activity in Prostate Cancer Metastasis

DTIC Science & Technology

2009-11-01

24-well plates and grown for 2-3 days prior to initiating the experiments. Cells were rinsed in Krebs -Ringer buffer, and incubated with mAbs J591...J415, 7E11 at 10µg/ml in Krebs - Ringer buffer at 370C for 30 min. 3H-NAAG were co-incubated along with the respective antibody at 0.8 µci/ml for 60 min...at 370C. Cells were washed in Krebs -Ringer buffer, and lysed in 1N of NaOH. Cell lysates were counted in liquid scintillation counter. PSMA negative

Final Inspection of Lactated Ringer’s Resuscitation Fluid, Intravenous Sodium Chloride Solution, and Sodium Chloride-Glucose Solution Used in the Deglycerolization of Human Red Cells Frozen With 40% W/V Glycerol, Produced by the Sterimatics EDM Reflups System and Stored for 8 Months to 2.3 Years.

DTIC Science & Technology

1994-09-08

SHIP LR500 000218201816 07/28/94 P N N 25 8237 SHIP LR500 000218201905 07/30/94 P N N 26 8301 SHIP LR500 000218201910 07/30/94 P N N 27 7395 SHIP...24 25 8237 SHIP LR500 000218201905 07/30/94 P 561 512 PASS 537 500 PASS 24 26 8301 SHIP LR500 000218201910 07/30/94 P 562 513 PASS 538 501 PASS 24

μPIXE for a μBrain: The vinegar fly's brain, antenna, sensilla hairs and eye ion concentrations

NASA Astrophysics Data System (ADS)

Reinert, Anja; Barapatre, Nirav; Sachse, Silke; Reinert, Tilo

2011-10-01

The vinegar fly Drosophila melanogaster is used as model organism to study a variety of different scientific purposes. Thus, our laboratory studies the olfactory system by neurobiological experiments. These techniques are often disruptive and need to compensate or exchange the body fluid, the lymph, with an artificial Ringer's solution in defined compartments of the fly. The solution mainly contains Na, Cl, K and Ca and is to keep physiological conditions. Therefore, the knowledge about the ion concentrations in the respective Drosophila lymph is required for a correct mixture of the ions. This paper presents the spatially resolved concentrations of P, S, Cl, K, Ca, Fe, Cu and Zn in lyophilised head cryosections of Drosophila by using quantitative μPIXE at the ion beam facility LIPSION in Leipzig. The PIXE maps enable a detailed analysis of particular regions of interest down to a spatial resolution of 0.5 μm. We quantified the ion concentrations especially in the brain, the antenna and its sensilla hairs acting as the olfactory organ of the fly, in the compound eye and in the mouthparts. The averaged element concentrations of these main compartments are (in descending order): P: 90 mM, K: 81 mM, S: 38 mM, Cl: 18 mM, Ca: 4.9 mM, Fe: 1.4 mM, Zn: 1.2 mM, Cu: 0.06 mM. Certain structures or cavities possess a remarkably high concentration of particular elements and might reflect the different functions of the compartments. An example presented in more detail is the composition of the compound eye. Conclusively, our findings on the ion concentrations might be useful for the mixture of the Drosophila Ringer's solution to ensure physiological conditions in experiments.

Ion transport across an isolated preparation of sheep rumen epithelium

PubMed Central

Ferreira, H. G.; Harrison, F. A.; Keynes, R. D.; Zurich, L.

1972-01-01

1. The fluxes of isotopically labelled sodium, potassium and chloride passing in each direction across isolated sheets of rumen epithelium from the sheep have been measured under short-circuit conditions. 2. With both sides of the epithelium bathed in chloride Ringer the mean sodium fluxes were 2·85 μmole/cm2.hr from rumen to blood and 1·28 μmole/cm2.hr in the reverse direction. In sulphate Ringer the sodium fluxes were 1·64 μmole/cm2.hr from rumen to blood and 0·54 μmole/cm2.hr from blood to rumen. 3. In chloride Ringer the mean potassium fluxes were 0·18 μmole/cm2.hr from rumen to blood and 0·54 μmole/cm2.hr from blood to rumen. In sulphate Ringer the potassium fluxes were 0·07 μmole/cm2.hr from rumen to blood and 0·35 μmole/cm2.hr from blood to rumen. 4. In chloride Ringer the mean chloride fluxes were 4·89 μmole/cm2.hr from rumen to blood and 3·78 μmole/cm2.hr from blood to rumen. 5. In chloride Ringer the mean value of the short-circuit current was 13 μA/cm2, corresponding to a flux of 0·49 μequiv/cm2.hr. When sulphate was substituted for chloride, the short-circuit current was increased by about 40%, and the net flux of sodium from rumen to blood fell by 30%. 6. Neither the sodium nor the chloride fluxes changed significantly when the epithelium was temporarily open-circuited. PMID:5037110

Effect of hydroxylamine on photon-like events during dark adaptation in toad rod photoreceptors.

PubMed Central

Leibrock, C S; Lamb, T D

1997-01-01

1. The suction pipette technique was used to investigate the recovery of toad rod photoreceptors following small bleaches of 0.2-3% of the rhodopsin. 2. The reduction in sensitivity and the increase in noise elicited by bleaches were measured, and from these measurements the underlying rate of occurrence of photon-like events was calculated as a function of time after the bleach. 3. Exposure to hydroxylamine solution was used to hasten the decomposition of the metarhodopsin photoproducts. The outer segment was exposed to 110 mM hydroxylamine in a low-Ca2+ Ringer solution for a period of 10-50 s beginning 10-17 min after the bleaching exposure. 4. By the time of the hydroxylamine exposure, the flash sensitivity and response kinetics had returned almost to normal, and were not significantly altered by the exposure. 5. Following hydroxylamine exposure, the rate of spontaneous photon-like events in the rods declined rapidly to near pre-bleach levels. 6. We conclude that hydroxylamine reduces the rate of occurrence of photon-like events induced by a bleach, and we postulate that this reduction results from the removal of metarhodopsin (most likely metarhodopsin II) from the outer segment. 7. Our results are consistent with a model in which photon-like events result from reversal of the reactions (phosphorylation and capping by arrestin) that lead to inactivation of the activated form of rhodopsin, Rh*. PMID:9174997

Comparison of Postoperative Pain and Residual Gas Between Restrictive and Liberal Fluid Therapy in Patients Undergoing Laparoscopic Cholecystectomy.

PubMed

Yao, Lei; Wang, Yulan; Du, Boxiang; Song, Jie; Ji, Fuhai

2017-10-01

Different fluid regimens are used in the clinical management of perioperative fluid therapy, but there still is the argument about which fluid regimen is better for patients. This study was mainly designed to compare different fluid regimens on postoperative pain and residual gas in patients undergoing laparoscopic cholecystectomy. A total of 100 patients were equally randomized to receive restrictive fluid infusion (n=50) with lactated Ringer (LR) solution 5 mL/kg/h or liberal fluid infusion (n=50), with 30 mL/kg/h lactated Ringer solution. Postoperative pain was evaluated at 1, 6, and 24 hours after surgery using a visual analog scale (VAS). Postoperative subdiaphragmatic residual gas was monitored by x-ray at 24 hours after surgery. Patients in the restrictive group had significantly higher VAS pain scores at 6 hours after surgery than those in the liberal group (P=0.009). The incidence of subdiaphragmatic residual gas in the restrictive group was higher than in the liberal group (P=0.045). Patients who had residual gas had higher VAS pain scores than those with no residual gas in the restrictive group at 6 hours after surgery (P=0.02). Patients undergoing laparoscopic cholecystectomy with restrictive fluid therapy may suffer more severe postoperative pain than those receiving liberal fluid therapy. It suggests that the higher incidence of subdiaphragmatic residual gas may have occurred with restrictive fluid therapy.

Blood autotransfusion outcomes compared with Ringer lactate infusion in dogs with hemorrhagic shock induced by controlled bleeding*

PubMed Central

Safaei, Mansour; Takami, Hassan Mousavi

2011-01-01

BACKGROUND: The most common cause of shock in the surgical or trauma patient is hemorrhage. Crystalloid solutions and blood transfusion are the mainstays of treatment of hemorrhagic shock. Considering the disadvantages of allogeneic blood transfusion, such as risk of transmission of infectious diseases, and access and maintenance limitations, treatment of shock with autologous blood seems to be a decent solution. Autologous blood accumulated in body cavities in traumatic bleeding (such hemothorax), and bloodshed in operation field during open heart or vascular surgeries, and similar situations, can be utilized again. In this study, autotransfusion effects compared with crystalloid fluid in the treatment of hemorrhagic shock was investigated. METHODS: After induction of hemorrhagic shock in dogs by Wiggers type controlled bleeding, treating them in a group with autologous blood and another group with Ringer lactate were performed, and the results of treatment were studied. RESULTS: There was no mortality in both treatment approaches. Immediately after treatment, crystalloid positive effects such as renormalized vital signs and appropriate consciousness were more noticeable than autotransfusion, while twenty-four hours after, the desired effects of autologous blood were more pronounced like decreased metabolic acidosis and improvement of diuresis. CONCLUSIONS: Crystalloid during the first hours after treatment of hemorrhagic shock may be better than autologous blood as preferred treatment, while autotransfusion showed its benefits some hours after. This finding can be used to develop better strategies for treatment of hemorrhagic shock. PMID:22973328

On the mechanical characteristics of a self-setting calcium phosphate cement.

PubMed

Bimis, A; Canal, L P; Karalekas, D; Botsis, J

2017-04-01

To perform a mechanical characterization of a self-setting calcium phosphate cement in function of the immersion time in Ringer solution. Specimens of self-setting calcium phosphate cement were prepared from pure α-TCP powder. The residual strains developed during hardening stage were monitored using an embedded fiber Bragg grating sensor. Additionally, the evolution of the elastic modulus was obtained for the same time period by conducting low-load indentation tests. Micro-computed tomography as well as microscope-assisted inspections were employed to evaluate the porosity in the specimens. Moreover, diametral compression tests were conducted in wet and dried specimens to characterize the material strength. The volume of the estimated porosity and absorbed fluid mass, during the first few minutes of the material's exposure in a wet environment, coincide. The immersion in Ringer solution lead to a noticeable increase in the moduli values. The critical value of stresses obtained from the diametral compression tests were combined with the data from uniaxial compression tests, to suggest a Mohr-Coulomb failure criterion. This study presents different techniques to characterize a self-setting calcium phosphate cement and provides experimental data on porosity, mechanical properties and failure. The investigated material possessed an open porosity at its dried state with negligible residual strains and its Young's modulus, obtained from micro-indentation tests, increased with hardening time. The failure loci may be described by a Mohr-Coulomb criterion, characteristic of soil and rock materials. Copyright © 2017 Elsevier Ltd. All rights reserved.

Influence of the antiseptic agents polyhexanide and octenidine on FL cells and on healing of experimental superficial aseptic wounds in piglets. A double-blind, randomised, stratified, controlled, parallel-group study.

PubMed

Kramer, A; Roth, B; Müller, G; Rudolph, P; Klöcker, N

2004-01-01

The main target of the combination of octenidine with phenoxyethanol (Octenisept) is the antisepsis of acute wounds, whereas polyhexanide combined with polyethylene glycol in Ringer solution (Lavasept) is the agent of choice for antisepsis of chronic wounds and burns. Because comparative data for both agents on the effects on wound healing are lacking, we investigated the influence of preparations based on polyhexanide and octenidine versus placebo (Ringer solution) in experimental superficial aseptic skin wounds (n = 108) of 20 mm diameter, using a double-blind, randomised, stratified, controlled, parallel-group design in piglets. Computerised planimetry and histopathological methods were used for the assessment of wound healing. Histologically, no significant differences could be verified at any time between the 3 groups. However, in the early phase (day 9 after wounding), the octenidine-based product retarded wound contraction to a significantly greater extent than placebo and polyhexanide, whereas in the later phase (days 18 and 28), polyhexanide promoted contraction significantly more than did placebo and octenidine. The consequence is complete wound closure after 22.9 days using polyhexanide, in comparison to the placebo after 24.1 days (p < 0.05) and octenidine after 28.3 days (no statistical difference to placebo). This may be explained by the better tolerance of polyhexanide in vitro, which was demonstrated with dose and time dependence in cytotoxicity tests on human amnion cells. Copyright 2004 S. Karger AG, Basel

Effect of temperature on the survival of Alaria alata mesocercariae.

PubMed

González-Fuentes, Hiromi; Hamedy, Ahmad; Koethe, Martin; von Borell, Eberhard; Luecker, Ernst; Riehn, Katharina

2015-03-01

Recent findings of Alaria alata mesocercariae in wild boars and other animals in Europe reinforced the concern about the public health risk posed by this parasite especially if the game meat is insufficiently heated during preparation. Cooking and freezing are effective methods for the inactivation of parasites in meat whereas refrigeration is considered as an essential part of the Good Hygiene Practice. Additionally, microwave dielectric heating may represent an equally effective tool for parasite inactivation. Therefore, isolated vital mesocercariae were examined with respect to their resilience against heating, refrigeration, freezing, and microwave heating. A. alata mesocercariae stored in Ringer's solution do not survive heating temperatures that exceed 60.0 °C. Similarly, exposure to microwave heating ensured an inactivation of all parasite developmental stages after 90 s of treatment. In contrast, the parasites' tolerance towards cold is far higher as the mesocercariae survived refrigeration temperatures (4.0 ± 2 °C) in Ringer's solution for up to 13 days. An effective inactivation by cold is therefore only guaranteed if the infested game meat is frozen to a core temperature of -13.7 °C for a minimum of 2 h at least. Game meat should be handled with the same or even higher caution than meat of husbandry animals since wild animals may be infected with parasites or other zoonotic agents that are not common in livestock. It is therefore of crucial importance that appropriate temperature time protocols are used for the reliable inactivation of these zoonotic agents.

Comparison of histamine and hyperosmotic arabinose infusion on brain capillary permeability to hydrophilic solutes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lucchesi, K.J.

1986-03-01

The effect of bilateral intracarotid infusion of histamine (HA) on capillary permeability-surface area products (PS) of two metabolically inert tracers was determined and compared to that of L(+)arabinose (ARAB) in rat brain. Ringer's solution alone, or with 1 mg/kg HA diphosphate or 1.6M ARAB added, was infused (0.9 ml over 0.5 min) into each external carotid artery (CA). Five minutes later, a bolus of /sup 14/C-sucrose and /sup 3/H-L-glucose was injected i.v. Estimates of PS for both tracers were computed by the method of Ohno et al after brain concentration was corrected for tracer within cerebral blood vessels. Brain bloodmore » volume, based on the /sup 14/C-dextran space, was the same (.016 ml/g) in discrete cortical and midbrain regions of all rats except those treated with ARAB. The latter yielded .033 ml/g, presumably due to dextran extravasation. Infusion of ARAB, HA and Ringer's increased the PS's of sucrose and L-glucose by 10x, 8x, and 3x in brain regions perfused by the internal CA's. The ratio, PS-sucrose/PS-L-glucose was unchanged by any treatment. Both ARAB and HA caused transient falls in arterial pressure, but only ARAB caused deaths (3 of 9 rats). While as effective as ARAB in opening the blood-brain barrier, HA may be safer than hyperosmotic shock to enhance delivery of chemotherapeutic agents to brain tumors.« less

Protective effects of ethyl pyruvate in cisplatin-induced nephrotoxicity

PubMed Central

Kelle, Ilker; Akkoc, Hasan; Tunik, Selcuk; Nergiz, Yusuf; Erdinc, Meral; Erdinc, Levent

2014-01-01

This study was performed to investigate the effect of ethyl pyruvate on changes in renal functions and oxidative stress related renal injury caused by cisplatin (cis-dichlorodiammine platinum-II; CDDP). Male Wistar albino rats were divided into four groups (n = 8): (1) control group (1 ml Ringer's lactate solution i.p.); (2) ethyl pyruvate (EP) group (50 mg/kg Ringer's EP solution (REPS) i.p.); (3) cisplatin group (a single dose of cisplatin (5 mg/kg, i.p.); and (4) cisplatin + EP group (a single dose of cisplatin (5 mg/kg, i.p.) + REPS 50 mg/kg/day, i.p.) for five days. At the sixth day, kidneys of rats were mounted to a Langendorff apparatus. Renal perfusion pressures were recorded. Blood samples were taken for serum urea, creatinine, total oxidant status (TOS), total antioxidant status (TAS) and oxidative stres index (OSI) evaluations. Kidney tissues were obtained for malondialdehyde (MDA) analyses and histopathological examination. Perfusion pressures, serum urea, creatinine, TOS, OSI and tissue MDA levels were found significantly higher, whereas TAS was notably lower in cisplatin group. Histopathological examination showed apparent renal paranchymal injury in cisplatin group. In cisplatin + REPS group, perfusion pressures, serum urea, creatinine and tissue MDA levels were decreased. Moreover, EP co-administration provided less inflammatory cell infiltration, tubular dilatation, whereas TOS, TAS and OSI improved significantly versus cisplatin group. These findings show that EP has protective effects against cisplatin nephrotoxicity. PMID:26019553

Tension in Skinned Frog Muscle Fibers in Solutions of Varying Ionic Strength and Neutral Salt Composition

PubMed Central

Gordon, A. M.; Godt, R. E.; Donaldson, S. K. B.; Harris, C. E.

1973-01-01

The maximal calcium-activated isometric tension produced by a skinned frog single muscle fiber falls off as the ionic strength of the solution bathing this fiber is elevated declining to zero near 0.5 M as the ionic strength is varied using KCl. When other neutral salts are used, the tension always declines at high ionic strength, but there is some difference between the various neutral salts used. The anions and cations can be ordered in terms of their ability to inhibit the maximal calcium-activated tension. The order of increasing inhibition of tension (decreasing tension) at high ionic strength for anions is propionate- ≃ SO4 -- < Cl- < Br-. The order of increasing inhibition of calcium-activated tension for cations is K+ ≃ Na+ ≃ TMA+ < TEA+ < TPrA+ < TBuA+. The decline of maximal calcium-activated isometric tension with elevated salt concentration (ionic strength) can quantitatively explain the decline of isometric tetanic tension of a frog muscle fiber bathed in a hypertonic solution if one assumes that the internal ionic strength of a muscle fiber in normal Ringer's solution is 0.14–0.17 M. There is an increase in the base-line tension of a skinned muscle fiber bathed in a relaxing solution (no added calcium and 3 mM EGTA) of low ionic strength. This tension, which has no correlate in the intact fiber in hypotonic solutions, appears to be a noncalcium-activated tension and correlates more with a declining ionic strength than with small changes in [MgATP], [Mg], pH buffer, or [EGTA]. It is dependent upon the specific neutral salts used with cations being ordered in increasing inhibition of this noncalcium-activated tension (decreasing tension) as TPrA+ < TMA+ < K+ ≃ Na+. Measurements of potentials inside these skinned muscle fibers bathed in relaxing solutions produced occasional small positive values (<6 mV) which were not significantly different from zero. PMID:4543066

The kinetics of inactivation of the rod phototransduction cascade with constant Ca2+i

PubMed Central

1996-01-01

A rich variety of mechanisms govern the inactivation of the rod phototransduction cascade. These include rhodopsin phosphorylation and subsequent binding of arrestin; modulation of rhodopsin kinase by S- modulin (recoverin); regulation of G-protein and phosphodiesterase inactivation by GTPase-activating factors; and modulation of guanylyl cyclase by a high-affinity Ca(2+)-binding protein. The dependence of several of the inactivation mechanisms on Ca2+i makes it difficult to assess the contributions of these mechanisms to the recovery kinetics in situ, where Ca2+i is dynamically modulated during the photoresponse. We recorded the circulating currents of salamander rods, the inner segments of which are held in suction electrodes in Ringer's solution. We characterized the response kinetics to flashes under two conditions: when the outer segments are in Ringer's solution, and when they are in low-Ca2+ choline solutions, which we show clamp Ca2+i very near its resting level. At T = 20-22 degrees C, the recovery phases of responses to saturating flashes producing 10(2.5)-10(4.5) photoisomerizations under both conditions are characterized by a dominant time constant, tau c = 2.4 +/- 0.4 s, the value of which is not dependent on the solution bathing the outer segment and therefore not dependent on Ca2+i. We extended a successful model of activation by incorporating into it a first-order inactivation of R*, and a first-order, simultaneous inactivation of G-protein (G*) and phosphodiesterase (PDE*). We demonstrated that the inactivation kinetics of families of responses obtained with Ca2+i clamped to rest are well characterized by this model, having one of the two inactivation time constants (tau r* or tau PDE*) equal to tau c, and the other time constant equal to 0.4 +/- 0.06 s. PMID:8741728

Effects of cell volume changes on membrane ionic permeabilities and sodium transport in frog skin (Rana ridibunda).

PubMed

Costa, P M; Fernandes, P L; Ferreira, H G; Ferreira, K T; Giraldez, F

1987-12-01

1. Membrane potential and conductances and short-circuit current were continuously measured with microelectrodes and conventional electrophysiological techniques in a stripped preparation of frog skin epithelium. The effects of the removal of chloride or sodium ions and the concentration or dilution of the serosal (inner) bathing solution were studied. 2. Chloride- or sodium-free solutions produced a cell depolarization of about 30 mV in parallel with a fall in the short-circuit current. Mucosal and serosal membrane conductances both decreased and the sodium permeability of the mucosal barrier was calculated to fall to about one-half its value in standard Ringer solution. The observed decrease in the short-circuit current is probably related to the combined effect of the decrease in sodium permeability and the decrease in the driving force across the mucosal membrane. 3. The removal of chloride or sodium ions reduced the depolarization caused by serosal perfusion with high-potassium solutions (50 mM-KCl). The ratio of the change in cell membrane potential under short-circuit conditions to the change in the potassium equilibrium potential (delta Ec(s.c.)/delta EK), was 0.59 in standard Ringer solution and 0.26 and 0.24 after the removal of chloride or sodium respectively. The depolarizing effect of barium-containing solutions (2 mM-BaCl2) was also markedly reduced in chloride- or sodium-free solutions, suggesting a decrease of the potassium selectivity of the serosal membrane in these conditions. 4. Increasing the osmolality of the serosal bathing solution produced similar effects, i.e. cell depolarization, fall in the short-circuit current and membrane conductances and reduction of the depolarizing effect of high-potassium and barium solutions. On the contrary, dilution of the serosal bath produced the opposite effects, consistent with an increase in the serosal permeability to potassium. 5. The effects of chloride- or sodium-free solutions were reversed by the dilution of the serosal bath. Cells repolarized when exposed to low-osmolality solutions after being in the absence of serosal chloride or sodium. The repolarization ran in parallel with the restoration of the short-circuit current and the potassium selectivity of the serosal membrane. 6. The results show that the effects produced by the removal of sodium or chloride ions from the serosal bathing solution are most probably mediated by a reduction in cell volume. Cell volume changes would lead to changes in the serosal membrane selectivity to potassium and thus to changes in cell membrane potential and sodium transport.(ABSTRACT TRUNCATED AT 400 WORDS)

A Low Frequency Electromagnetic Sensor for Indirect Measurement of Glucose Concentration: In Vitro Experiments in Different Conductive Solutions

PubMed Central

Tura, Andrea; Sbrignadello, Stefano; Cianciavicchia, Domenico; Pacini, Giovanni; Ravazzani, Paolo

2010-01-01

In recent years there has been considerable interest in the study of glucose-induced dielectric property variations of human tissues as a possible approach for non-invasive glycaemia monitoring. We have developed an electromagnetic sensor, and we tested in vitro its ability to estimate variations in glucose concentration of different solutions with similarities to blood (sodium chloride and Ringer-lactate solutions), differing though in the lack of any cellular components. The sensor was able to detect the effect of glucose variations over a wide range of concentrations (∼78–5,000 mg/dL), with a sensitivity of ∼0.22 mV/(mg/dL). Our proposed system may thus be useful in a new approach for non-invasive and non-contact glucose monitoring. PMID:22219665

An Alternative Health Care Facility: Concept of Operations for the Off-site Triage, Treatment, and Transportation Center (OST3C). Mass Casualty Care Strategy for a Chemical Terrorism Incident

DTIC Science & Technology

2001-03-01

destruction incident. These exercises identified the need for jurisdictions to formulate response plans that optimize their existing resources by... formulated with state licensing and public health agencies and approved prior to use. Jurisdictions should consider developing guidelines pertaining to...Phenergan), 50mg/ suppository Ea Ringers Lactate, 1000cc Case/6 Saline Solution IV (0.9% 500ml) Case/24 Sodium Bicarbonate (4.2% Injection) (Pkg/10) Pkg/10

Online particle detection with Neural Networks based on topological calorimetry information

NASA Astrophysics Data System (ADS)

Ciodaro, T.; Deva, D.; de Seixas, J. M.; Damazio, D.

2012-06-01

This paper presents the latest results from the Ringer algorithm, which is based on artificial neural networks for the electron identification at the online filtering system of the ATLAS particle detector, in the context of the LHC experiment at CERN. The algorithm performs topological feature extraction using the ATLAS calorimetry information (energy measurements). The extracted information is presented to a neural network classifier. Studies showed that the Ringer algorithm achieves high detection efficiency, while keeping the false alarm rate low. Optimizations, guided by detailed analysis, reduced the algorithm execution time by 59%. Also, the total memory necessary to store the Ringer algorithm information represents less than 6.2 percent of the total filtering system amount.

Effects of pH on the electrochemical behaviour of titanium alloys for implant applications.

PubMed

Souza, Maria E P; Lima, Lonetá; Lima, Carmo R P; Zavaglia, Cecília A C; Freire, Célia M A

2009-02-01

The electrochemical behaviour of two commercial titanium alloys Ti-6Al-4 V (ASTM F136) and Ti-13Nb-13Zr (ASTM F1713) was investigated in Ringer physiological solution at two pH values (5.5 and 7.0). The corrosion properties were examined by using electrochemical techniques: Potentiodynamic anodic polarization, cyclic polarization and electrochemical impedance spectroscopy (EIS). The electrochemical corrosion properties of both alloys at different conditions were measured in terms of corrosion potential (E (corr)), corrosion current density (i (corr)) and passivation current density (i (pass)). Equivalent electrical circuits were used to modulate EIS data, in order to characterize alloys surface and better understanding the pH effect on the interface alloy/solution.

Anti-apoptotic and myocardial protective effects of ethyl pyruvate after regional ischaemia/reperfusion myocardial damage in an in vivo rat model.

PubMed

Shim, Haeng Seon; Lee, Wang Gyu; Kim, Yeon A; Han, Jeong Yeol; Park, Miyeong; Song, Yun Gyu; Kim, Joon Soo; Shin, Il-Woo

2017-09-01

The integration of reactive oxygen species is strongly associated with important pathophysiological mechanisms that mediate myocardial ischaemia/reperfusion (I/R) damage. Pyruvate is an efficacious scavenger of reactive oxygen species and a previous study has shown that ethyl pyruvate (EP) has a myocardial protective effect against regional I/R damage in an in vivo rat model. The purpose of this study was to determine whether the myocardial protective effect of EP is associated with anti-apoptosis. Rats were allocated to receive EP dissolved in lactated Ringer's solution or lactated Ringer's solution alone, via intraperitoneal infusion one hour before ischaemia. They were exposed to 30 minutes of ischaemia followed by reperfusion of the left coronary artery territory over two hours. Anti-apoptotic effects were checked using several biochemical parameters after two hours of reperfusion. Apoptosis was analysed using measured caspase-3 activity, Western blotting of B-cell lymphoma 2 (Bcl-2) family protein cleaved by caspase-3, and assessment of DNA laddering patterns and the terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) staining test. In ischaemic myocardium, EP increased Bcl-2 expression, but reduced Bcl-2-associated X protein and cleaved caspase-3 expressions. EP reduced the expression of DNA laddering and the number of myocardial I/R-damaged TUNEL-positive cells. This study demonstrated that EP has an anti-apoptotic effect after regional I/R damage in an in vivo rat heart model. The myocardial protective effect of EP may be related to its anti-apoptotic effect. Copyright: © Singapore Medical Association

[A new two-chamber model for examination and demonstration of transdural fluid leakage after spinal anesthesia].

PubMed

Enk, D; Enk, E

1995-11-01

Various in vitro models have been introduced for comparative examinations of post-dural-puncture trauma and measurement of liquor leakage through puncture sites. These models allow simulation of subarachnoid, but not of peridural, pressure. A new two-chamber-model realizes the simulation of both subarachnoid and peridural pressure and allows observation of in vitro punctures with video-documentation. Frame grabbing and (computer-aided) image analysis show new aspects of spinal puncture effects. Therefore, post-dural-puncture trauma and retraction can be objectively visualized by this method, which has not previously been demonstrated. Two-chamber-model consists of two short aluminium cylinders. Native human dura patches (8X8 mm) from fresh cadavers are put (correctly oriented) between two special polyamide seals. Mounted between the upper and lower cylinder, these seals stretch the dura patch, which remains flexible and even in all directions. After filling of the lower (subarachnoid) and upper (peridural) chamber with Ringer lactate solution, positive or negative physiological pressure can be adjusted by way of two (Ringer lactate solution filled) infusion lines in each chamber. Puncturing is performed at an angle of 57 degrees to the dura. The model allows examination with epi-illumination and transmitted (polarized) light. In vitro punctures are observed through an inverted camera lens with an CCD-Hi8 video camera (Canon UC1HI) looking into the peridural chamber and documented by means of an S-VHS video recorder (Panasonic NV-FS200EG). After true-colour frame grabbing by a video digitizer (Fast Screen Machine II), single video frames can be optimized and analysed with a 486-66 MHz computer and conventional software (Corel Draw 3.0, Photostyler 1.1a, DDL Aequitas 1.00b). Punctures demonstrated in this paper have been done under simulation of a transdural gradient of 20 cm water similar to the situation of a recumbent patient (15 cm water in the subarachnoid and -5 cm water in the peridural chamber). The punctures were followed by short-time observation for up to 10 minutes. By making it possible to obtains a picture of the puncture site at 20-ms intervals (because of the PAL norm of 50 half-frames/s), video-documentation has become accepted as superior to conventional photography. When the Ringer lactate solution in the subarachnoid chamber is stained with methylene blue, transdural leakage can easily be observed. The result of this documentation technique demonstrate that not dural puncture can be atraumatic, when a 29-G Quincke needle is used. Calculation on the difference between a digitized video frame before and after the puncture clearly illustrates the dural trauma. Owing to their non-cutting tip, as expected, pencil-point needles leave diffuse changes across the dura patch, whereas a more local trauma was observed after puncturing with cutting-tip needles. The same computer calculation between two video frames allows examination of post-puncture-dural retraction of the puncture site. In this connection, we found that relevant dural retraction is a phenomenon limited to the first minute after puncture. Thin spinal needles with so-called modern tips (e.g. Whitacre, Atraucan) can minimize the post-dural-puncture trauma, whereas thicker, conventional, spinal needles (Quincke) leave considerable dural defects. The two-chamber-model presented allows easy simulation of physiological subarachnoid and peridural pressure. The Ringer lactate solution in the subarachnoid chamber corresponds to the liquor, whereas that in the peridural chamber corresponds to the intercellular (peridural) space. The tension of the dural patch between the polyamide seals is similar to the situation in an anotomical model observed by spinaloscopy (in an earlier study). With the video documentation and computer-aided analysis technique introduced, dural trauma and retraction of the puncture site can be examined and demo

Effect of melatonin on kidney cold ischemic preservation injury

PubMed Central

Aslaner, Arif; Gunal, Omer; Turgut, Hamdi Taner; Celik, Erdal; Yildirim, Umran; Demirci, Rojbin Karakoyun; Gunduz, Umut Riza; Calis, Hasan; Dogan, Sami

2013-01-01

Melatonin is a potent free radical scavenger of reactive oxygen species, nitric oxide synthase inhibitor and a well-known antioxidant secreted from pineal gland. This hormone has been reported to protect tissue from oxidative damage. In this study, we aim to investigate the effect of melatonin on kidney cold ischemia time when added to preservation solution. Thirty male Wistar albino rats were divided equally into three groups; Ringer Lactate (RL) solution, University of Wisconsin (UW) solution with and without melatonin. The serum Lactate Dehydrogenase (LDH) activities of the preservation solutions at 2nd, 24th, 36th, and 48th hours were determined. Tissue malondialdehyde (MDA) levels were also measured and a histological examination was performed at 48th hour. Melatonin that added to preservation solution prevented enzyme elevation and decreased lipid peroxidation in preservation solution when compared to the control group (p<0.05). The histological examination revealed that UW solution containing melatonin significantly prevented the kidney from pathological injury (p<0.05). Melatonin added to preservation solutions such as UW solution seemed to protect the tissue preserved effectively from cold ischemic injury for up to 48 hour. PMID:24179573

Occurance of apoptosis during ischemia in porcine pancreas islet cells.

PubMed

Stadlbauer, V; Schaffellner, S; Iberer, F; Lackner, C; Liegl, B; Zink, B; Kniepeiss, D; Tscheliessnigg, K H

2003-03-01

Pancreas islet transplantation is a potential treatment of diabetes mellitus and porcine organs provide an easily available source of cells. Unfortunately quality and quantity of isolated islets are still not satisfactory. Apoptosis occurs in freshly isolated islets and plays a significant role in early graft loss. We evaluated the influence of four storage solutions on porcine pancreas islets. After warm ischemia of 15-20 minutes 12 organs were stored in 4 cold preservation solutions: Histidine-Tryptophan-Ketoglutarate solution (HTK), Hank's buffered saline solution (HBSS), University of Wisconsin (UW) solution and Ringer-Lactate (R). After cold ischemia for 100 minutes, organs were fixed in 3% formalin. Apoptotic cells were counted on hematocylin-eosin stainings. Most apoptotic cells were found in organs stored in R. Low numbers were found in the other groups. The difference between organs stored in R and organs stored in UW, HTK, or HBSS was highly significant. No significant difference could be found between UW, HTK and HBSS. Cold and warm ischemia of the pancreas seems to induce apoptosis in islet cells. Preservation solutions cause less apoptosis than electrolyte solution. No significant differences could be found among the preservation solutions.

Dietary sodium loading impairs microvascular function independent of blood pressure in humans: role of oxidative stress

PubMed Central

Greaney, Jody L; DuPont, Jennifer J; Lennon-Edwards, Shannon L; Sanders, Paul W; Edwards, David G; Farquhar, William B

2012-01-01

Animal studies have reported dietary salt-induced reductions in vascular function independent of increases in blood pressure (BP). The purpose of this study was to determine if short-term dietary sodium loading impairs cutaneous microvascular function in normotensive adults with salt resistance. Following a control run-in diet, 12 normotensive adults (31 ± 2 years) were randomized to a 7 day low-sodium (LS; 20 mmol day−1) and 7 day high-sodium (HS; 350 mmol day−1) diet (controlled feeding study). Salt resistance, defined as a ≤5 mmHg change in 24 h mean BP determined while on the LS and HS diets, was confirmed in all subjects undergoing study (LS: 84 ± 1 mmHg vs. HS: 85 ± 2 mmHg; P > 0.05). On the last day of each diet, subjects were instrumented with two microdialysis fibres for the local delivery of Ringer solution and 20 mm ascorbic acid (AA). Laser Doppler flowmetry was used to measure red blood cell flux during local heating-induced vasodilatation (42°C). After the established plateau, 10 mm l-NAME was perfused to quantify NO-dependent vasodilatation. All data were expressed as a percentage of maximal cutaneous vascular conductance (CVC) at each site (28 mm sodium nitroprusside; 43°C). Sodium excretion increased during the HS diet (P < 0.05). The plateau % CVCmax was reduced during HS (LS: 93 ± 1 % CVCmax vs. HS: 80 ± 2 % CVCmax; P < 0.05). During the HS diet, AA improved the plateau % CVCmax (Ringer: 80 ± 2 % CVCmax vs. AA: 89 ± 3 % CVCmax; P < 0.05) and restored the NO contribution (Ringer: 44 ± 3 % CVCmax vs. AA: 59 ± 6 % CVCmax; P < 0.05). These data demonstrate that dietary sodium loading impairs cutaneous microvascular function independent of BP in normotensive adults and suggest a role for oxidative stress. PMID:22907057

A comparison of two different 2400 mOsm solutions for resuscitation of major burns.

PubMed

Milner, S M; Kinsky, M P; Guha, S C; Herndon, D N; Phillips, L G; Kramer, G C

1997-01-01

The reduction of burn edema is a common goal in the resuscitation of patients with thermal injury. Initial infusion of a 2400 mOsm hypertonic 7.5% NaCl 6% dextran (HSD) has been shown to reduce volume needs, but elevated serum sodium levels limit the dose that can be safely used. This study tested the hypothesis that a 2400 mOsm solution of NaCl, amino acids, glucose, and 6% dextran (Isosal-D) would reduce similar volume requirements while maintaining normal plasma sodium levels. Hemodynamics, plasma sodium, fluid balance, and tissue water content were measured after an initial baseline period and during resuscitation of a large scald injury in 21 anesthetized sheep. Resuscitation was begun 30 minutes after the scald with infusion of 10 ml/kg of either lactated Ringer's (LR), Isosal-D, or HSD and was continued with LR to restore and maintain baseline oxygen delivery throughout the 8-hour period. Oxygen delivery, cardiac output, and mean arterial pressure were rapidly reestablished by all three solutions, although a persistent tachycardia was noted with Isosal-D. Net fluid requirements of both HSD (35 +/- 13 ml/kg) and Isosal-D (72 +/- 13 ml/kg) were significantly lower than in the LR group (203 +/- 39 ml/kg). Mean serum sodium increased 11 mEq with HSD to a peak after 4 hours of 152 +/- 5 mEq, whereas with LR sodium fell 7 mEq to 132 +/- 4. Isosal-treated animals had minimal change in serum sodium. HSD significantly decreased tissue water content in colon, liver, pancreas, and nonburned skin compared with LR, whereas Isosal-D reduced edema only in the colon. It is concluded that in this protocol Isosal-D was not as effective as HSD at reducing volume needs and edema and had unexpected chronotropic effects.

How Large Is the "Public Domain"? A Comparative Analysis of Ringer's 1961 Copyright Renewal Study and HathiTrust CRMS Data

ERIC Educational Resources Information Center

Wilkin, John P.

2017-01-01

The 1961 Copyright Office study on renewals, authored by Barbara Ringer, has cast an outsized influence on discussions of the U.S. 1923-1963 public domain. As more concrete data emerge from initiatives such as the large-scale determination process in the Copyright Review Management System (CRMS) project, questions are raised about the reliability…

The Farrelly Brothers and Special Olympics Reach Out to Youth at a Favorite Venue--The Movies

ERIC Educational Resources Information Center

Exceptional Parent, 2005

2005-01-01

"The Ringer" is the new comedy produced by Bobby and Peter Farrelly, the writer-directors of such edgy fare as "Kingpin," "Stuck on You" and the blockbuster comedy "Something About Mary." "The Ringer" is a film about a guy named Stevie (played by Johnny Knoxville, the star of MTV's hit series "Jackass") who is pretending to have an intellectual…

Resuscitation with lactated ringer's does not increase inflammatory response in a Swine model of uncontrolled hemorrhagic shock.

PubMed

Watters, Jennifer M; Brundage, Susan I; Todd, S Rob; Zautke, Nathan A; Stefater, J A; Lam, J C; Muller, Patrick J; Malinoski, Darren; Schreiber, Martin A

2004-09-01

Lactated Ringer's (LR) and normal saline (NS) are widely and interchangeably used for resuscitation of trauma victims. Studies show LR to be superior to NS in the physiologic response to resuscitation. Recent in vitro studies demonstrate equivalent effects of LR and NS on leukocytes. We aimed to determine whether LR resuscitation would produce an equivalent inflammatory response compared with normal saline (NS) resuscitation in a clinically relevant swine model of uncontrolled hemorrhagic shock. Thirty-two swine were randomized. Control animals (n = 6) were sacrificed following induction of anesthesia for baseline data. Sham animals (n = 6) underwent laparotomy and 2 h of anesthesia. Uncontrolled hemorrhagic shock animals (n = 10/group) underwent laparotomy, grade V liver injury, and blinded resuscitation with LR or NS to maintain baseline blood pressure for 1.5 h before sacrifice. Lung was harvested, and tissue mRNA levels of interleukin-6 (IL-6), granulocyte colony-stimulating factor (G-CSF), and tumor necrosis factor-alpha (TNF-alpha) were determined using quantitative reverse transcriptase polymerase chain reaction (Q-RT-PCR). Sections of lung were processed and examined for neutrophils sequestered within the alveolar walls. Cytokine analysis showed no difference in IL-6 gene transcription in any group (P = 0.99). Resuscitated swine had elevated G-CSF and TNF-alpha gene transcription, but LR and NS groups were not different from each other (P= 0.96 and 0.10, respectively). Both resuscitation groups had significantly more alveolar neutrophils present than controls (P < 0.01) and shams (P < 0.05) but were not different from one another (P= 0.83). LR and NS resuscitation have equivalent effects on indices of inflammation in the lungs in our model of uncontrolled hemorrhagic shock.

Ringers lactate vs Normal saline for children with acute diarrhea and severe dehydration- a double blind randomized controlled trial.

PubMed

Mahajan, Vidushi; Sajan, Shiv Saini; Sharma, Amit; Kaur, Jasbinder

2012-12-01

WHO recommends Ringers lactate (RL) and Normal Saline (NS) for rapid intravenous rehydration in childhood diarrhea and severe dehydration. We compared these two fluids for improvement in pH over baseline during rapid intravenous rehydration in children with acute diarrhea. Double-blind randomized controlled trial Pediatric emergency facilities at a tertiary-care referral hospital. Children with acute diarrhea and severe dehydration received either RL (RL-group) or NS (NS-group), 100 mL/kg over three or six hours. Children were reassessed after three or six hours. Rapid rehydration was repeated if severe dehydration persisted. Blood gas was done at baseline and repeated after signs of severe dehydration disappeared. Primary outcome was change in pH from baseline. Secondary outcomes included changes in serum electrolytes, bicarbonate levels, and base-deficit from baseline; mortality, duration of hospital stay, and fluids requirement. Twenty two children, 11 each were randomized to the two study groups. At primary end point (disappearance of signs of severe dehydration), the improvement in pH from baseline was not significant in RL-group [from 7.17 (0.11) to 7.28 (0.09)] as compared to NS-group [7.09 (0.11) to 7.21 (0.09)], P=0.17 (after adjusting for baseline serum Na/ Cl). Among this limited sample size, children in RL group required less fluids [median 310 vs 530 mL/kg, P=0.01] and had shorter median hospital stay [38 vs 51 hours, P=0.03]. There was no difference in improvement in pH over baseline between RL and NS among children with acute diarrhea and severe dehydration.

Administration of platelet concentrates suspended in bicarbonated Ringer's solution in children who had platelet transfusion reactions.

PubMed

Kobayashi, J; Yanagisawa, R; Ono, T; Tatsuzawa, Y; Tokutake, Y; Kubota, N; Hidaka, E; Sakashita, K; Kojima, S; Shimodaira, S; Nakamura, T

2018-02-01

Adverse reactions to platelet transfusions are a problem. Children with primary haematological and malignant diseases may experience allergic transfusion reactions (ATRs) to platelet concentrates (PCs), which can be prevented by giving washed PCs. A new platelet additive solution, using bicarbonated Ringer's solution and acid-citrate-dextrose formula A (BRS-A), may be better for platelet washing and storage, but clinical data are scarce. A retrospective cohort study for consecutive cases was performed between 2013 and 2017. For 24 months, we transfused washed PCs containing BRS-A to children with primary haematological and malignant diseases and previous adverse reactions. Patients transfused with conventional PCs (containing residual plasma) were assigned as controls, and results were compared in terms of frequency of ATRs, corrected count increment (CCI) and occurrence of bleeding. We also studied children transfused with PCs washed by a different system as historical controls. Thirty-two patients received 377 conventional PC transfusions. ATRs occurred in 12 (37·5%) patients from transfused with 18 (4·8%) bags. Thirteen patients, who experienced reactions to regular PCs in plasma, then received 119 transfusion bags of washed PCs containing BRS-A, and none had ATRs to washed PCs containing BRS-A. Before study period, six patients transfused 137 classical washed PCs with different platelet additive solution, under same indication, ATRs occurred in one (16·7%) patient from transfused with one (0·7%) bags. CCIs (24 h) in were lower with classical washed PCs (1·26 ± 0·54) compared to regular PCs in plasma (2·07 ± 0·76) (P < 0·001), but there was no difference between washed PCs containing BRS-A (2·14 ± 0·77) and regular PCs (2·21 ± 0·79) (P = 0·769), and we saw no post-transfusion bleeding. Washed PCs containing BRS-A appear to prevent ATRs without loss of transfusion efficacy in children with primary haematological and malignant diseases. Their efficacy should be further evaluated through larger prospective clinical trials. © 2017 International Society of Blood Transfusion.

Biochemical composition of fluids for amnioinfusion during fetoscopy.

PubMed

Adama van Scheltema, P N; In't Anker, P S; Vereecken, A; Vandenbussche, F P H A; Deprest, J A; Devlieger, R

2008-01-01

To evaluate which of the commercially available solutions is best suited for amnioinfusion during fetoscopy, based on resemblance with the biochemical properties of amniotic fluid. Amniotic fluid samples from 10 pregnancies were studied. Specimens were obtained from 5 pathologic pregnancies (of which 3 were complicated by polyhydramnios) and 5 uncomplicated pregnancies. The concentrations of sodium, potassium, chloride, bicarbonate, calcium, glucose, osmolality, pH, total protein content and albumin were determined in each sample. A literature search (PubMed, Embase) was performed to identify commercially available fluids used for amnioinfusion in clinical practice. The composition of these infusion solutions was compared to the amniotic fluid samples mentioned above. We identified two different electrolyte solutions used in clinical practice for amnioinfusion. We identified four additional commercially available solutions that could potentially be used for amnioinfusion. Most of these infusion solutions differ considerably from midtrimester amniotic fluid samples both in electrolyte composition and pH, with the most striking difference in the latter. Lactated Ringer's solution approximates amniotic fluid the closest for both electrolyte composition and pH. This infusion solution seems to be the most suitable choice for amnioinfusion during fetoscopy. (c) 2008 S. Karger AG, Basel.

Comparison of the effects of albumin 5%, hydroxyethyl starch 130/0.4 6%, and Ringer's lactate on blood loss and coagulation after cardiac surgery.

PubMed

Skhirtladze, K; Base, E M; Lassnigg, A; Kaider, A; Linke, S; Dworschak, M; Hiesmayr, M J

2014-02-01

Infusion of 5% human albumin (HA) and 6% hydroxyethyl starch 130/0.4 (HES) during cardiac surgery expand circulating volume to a greater extent than crystalloids and would be suitable for a restrictive fluid therapy regimen. However, HA and HES may affect blood coagulation and could contribute to increased transfusion requirements. We randomly assigned 240 patients undergoing elective cardiac surgery to receive up to 50 ml kg(-1) day(-1) of either HA, HES, or Ringer's lactate (RL) as the main infusion fluid perioperatively. Study solutions were supplied in identical bottles dressed in opaque covers. The primary outcome was chest tube drainage over 24 h. Blood transfusions, thromboelastometry variables, perioperative fluid balance, renal function, mortality, intensive care unit, and hospital stay were also assessed. The median cumulative blood loss was not different between the groups (HA: 835, HES: 700, and RL: 670 ml). However, 35% of RL patients required blood products, compared with 62% (HA) and 64% (HES group; P=0.0003). Significantly, more study solution had to be administered in the RL group compared with the colloid groups. Total perioperative fluid balance was least positive in the HA group [6.2 (2.5) litre] compared with the HES [7.4 (3.0) litre] and RL [8.3 (2.8) litre] groups (P<0.0001). Both colloids affected clot formation and clot strength and caused slight increases in serum creatinine. Despite equal blood loss from chest drains, both colloids interfered with blood coagulation and produced greater haemodilution, which was associated with more transfusion of blood products compared with crystalloid use only.

Inhibition of glycogen synthase kinase (GSK)-3-β improves liver microcirculation and hepatocellular function after hemorrhagic shock.

PubMed

Jellestad, Lena; Fink, Tobias; Pradarutti, Sascha; Kubulus, Darius; Wolf, Beate; Bauer, Inge; Thiemermann, Chris; Rensing, Hauke

2014-02-05

Ischemia and reperfusion may cause liver injury and are characterized by hepatic microperfusion failure and a decreased hepatocellular function. Inhibition of glycogen synthase kinase (GSK)-3β, a serine-threonine kinase that has recently emerged as a key regulator in the modulation of the inflammatory response after stress events, may be protective in conditions like sepsis, inflammation and shock. Therefore, aim of the study was to assess the role of GSK-3β in liver microcirculation and hepatocellular function after hemorrhagic shock and resuscitation (H/R). Anesthetized male Sprague-Dawley rats underwent pretreatment with Ringer´s solution, vehicle (DMSO) or TDZD-8 (1 mg/kg), a selective GSK-3β inhibitor, 30 min before induction of hemorrhagic shock (mean arterial pressure 35±5 mmHg for 90 min) and were resuscitated with shed blood and Ringer´s solution (2h). 5h after resuscitation hepatic microcirculation was assessed by intravital microscopy. Propidium iodide (PI) positive cells, liver enzymes and alpha-GST were measured as indicators of hepatic injury. Liver function was estimated by assessment of indocyanine green plasma disappearance rate. H/R led to a significant decrease in sinusoidal diameters and impairment of liver function compared to sham operation. Furthermore, the number of PI positive cells in the liver as well as serum activities of liver enzymes and alpha-GST increased significantly after H/R. Pretreatment with TDZD-8 prevented the changes in liver microcirculation, hepatocellular injury and liver function after H/R. A significant rise in the plasma level of IL-10 was observed. Thus, inhibition of GSK-3β before hemorrhagic shock modulates the inflammatory response and improves hepatic microcirculation and hepatocellular function. Copyright © 2013 Elsevier B.V. All rights reserved.

Short-term effects of stored homologous red blood cell transfusion on cardiorespiratory function and inflammation: an experimental study in a hypovolemia model

PubMed Central

Biagini, S.; Dale, C.S.; Real, J.M.; Moreira, E.S.; Carvalho, C.R.R.; Schettino, G.P.P.; Wendel, S.; Azevedo, L.C.P.

2017-01-01

The pathophysiological mechanisms associated with the effects of red blood cell (RBC) transfusion on cardiopulmonary function and inflammation are unclear. We developed an experimental model of homologous 14-days stored RBC transfusion in hypovolemic swine to evaluate the short-term effects of transfusion on cardiopulmonary system and inflammation. Sixteen healthy male anesthetized swine (68±3.3 kg) were submitted to controlled hemorrhage (25% of blood volume). Two units of non-filtered RBC from each animal were stored under blood bank conditions for 14 days. After 30 min of hypovolemia, the control group (n=8) received an infusion of lactated Ringer's solution (three times the removed volume). The transfusion group (n=8) received two units of homologous 14-days stored RBC and lactated Ringer's solution in a volume that was three times the difference between blood removed and blood transfusion infused. Both groups were followed up for 6 h after resuscitation with collection of hemodynamic and respiratory data. Cytokines and RNA expression were measured in plasma and lung tissue. Stored RBC transfusion significantly increased mixed oxygen venous saturation and arterial oxygen content. Transfusion was not associated with alterations on pulmonary function. Pulmonary concentrations of cytokines were not different between groups. Gene expression for lung cytokines demonstrated a 2-fold increase in mRNA level for inducible nitric oxide synthase and a 0.5-fold decrease in mRNA content for IL-21 in the transfused group. Thus, stored homologous RBC transfusion in a hypovolemia model improved cardiovascular parameters but did not induce significant effects on microcirculation, pulmonary inflammation and respiratory function up to 6 h after transfusion. PMID:29185590

Primary effects of metals on osmoregulatory processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

DiBona, D.R.; Kendall, L.K.; Ferreria, H.G.

1995-12-31

Isolated skins of the bullfrog, Rana catesbiana, were chamber-mounted as sheets, bathed on the inside (serosa) with a Ringer`s solution but on the outside with simulations of freshwater to mimic environmental conditions. An automatic voltage-clamping protocol measured short-circuit current (I{sub sc}), an index of transepithelial Na{sup +} transport, and total tissue conductance (G{sub t}). Aluminum, cadmium, chromium, copper, lead, mercury and zinc were studied separately as additives to the outer bath and yielded qualitatively similar results. Al has been most thoroughly examined. At 200 ppB (7.4 {micro}M) or more, and at pH 5.0 or below, Al inhibits both I{sub sc}more » and G{sub t}. Effects are precluded by the addition of amiloride, a diuretic that blocks Na{sup +} transport at the level of the Na{sup +} channel. Kinetic analysis reveals that Al and amiloride compete for a single binding site on the channel protein. At levels of 10 ppM, Al addition results in amiloride-insensitive increases in G{sub t} (10-fold or more) and I{sub sc} (20+ {micro}A/cm{sup 2}). Isotopic flux measurements suggest that these effects are due to an ``opening`` of epithelial tight junctions with passive, downhill diffusion of salt from inside to outside; the polarity of the resulting current reflects enhanced paracellular permeability with specificity for Cl{sup {minus}} over Na{sup +}. Varying medium pH indicates that Al{sup 3+} is the dominant species in each of the two effects. Al addition to the inner bathing medium was without effect despite access to the Na{sup +}-K{sup +}-ATPase. Contaminant metals may interfere with osmoregulation by impairing salt accumulation and by enlarging leak pathways through which solutes are lost to the environment.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moraes, Paulo E.L., E-mail: pauloeduardo.leitedemoraes@gmail.com; Contieri, Rodrigo J., E-mail: contieri@fem.unicamp.br; Lopes, Eder S.N., E-mail: ederlopes@fem.unicamp.br

Ti and Ti alloys are widely used in restorative surgery because of their good biocompatibility, enhanced mechanical behavior and high corrosion resistance in physiological media. The corrosion resistance of Ti-based materials is due to the spontaneous formation of the TiO{sub 2} oxide film on their surface, which exhibits elevated stability in biological fluids. Ti–Nb alloys, depending on the composition and the processing routes to which the alloys are subjected, have high mechanical strength combined with low elastic modulus. The addition of Sn to Ti–Nb alloys allows the phase transformations to be controlled, particularly the precipitation of ω phase. The aimmore » of this study is to discuss the microstructure, mechanical properties and corrosion behavior of cast Ti–Nb alloys to which Sn has been added. Samples were centrifugally cast in a copper mold, and the microstructure was characterized using optical microscopy, scanning electron microscopy and X-ray diffractometry. Mechanical behavior evaluation was performed using Berkovich nanoindentation, Vickers hardness and compression tests. The corrosion behavior was evaluated in Ringer's solution at room temperature using electrochemical techniques. The results obtained suggested that the physical, mechanical and chemical behaviors of the Ti–Nb–Sn alloys are directly dependent on the Sn content. - Graphical abstract: Effects of Sn addition to the Ti–30Nb alloy on the elastic modulus. - Highlights: • Sn addition causes reduction of the ω phase precipitation. • Minimum Vickers hardness and elastic modulus occurred for 6 wt.% Sn content. • Addition of 6 wt.% Sn resulted in maximum ductility and minimum compression strength. • All Ti–30Nb–XSn (X = 0, 2, 4, 6, 8 and 10%) alloys are passive in Ringer's solution. • Highest corrosion resistance was observed for 6 wt.% Sn content.« less

Evaluation of methods for the microbiological control of natural corks for sparkling wine bottles.

PubMed

Centeno, S; Calvo, M A

2000-01-01

The various parameters proposed in Norm 0.20/95 of Catalunya (Spain) for the microbiological analysis of natural corks for sparkling wines were evaluated. The best results were obtained through the use of 1/4 Ringer's solution or saline for rinsing with an agitation time of 30 min, and an agitation speed of 150-200 rpm. Tryptone soya agar (TSA) and Sabouraud dextrose agar (SDA) were used as a culture medium for the bacteria and fungi, respectively, and a cultivation time of 48 h and incubation temperatures of 37 +/- 2 degrees C for bacteria and 28 degrees C for yeast and filamentous fungi.

Daily Profiles of Fibrinogen Metabolism for 5 Days Following Hemorrhage and Lactated Ringer’s Resuscitation in Pigs

DTIC Science & Technology

2012-01-01

Sterile stable isotope solutions of 1 13C phenylalanine (1 13C phe, 100 2mol/mL) and d5 phe (100 2mol/mL) were made in 0.45% saline and infused via the left...described by Stein et al. (15). The enrichments of phenylalanine from isolated fibrinogen were determined by gas chromatography mass spectrometry (GC MS...baseline of 5.5 T 0.3 to 4.3 T 0.3 g/ dL (P G 0.05) on day 1 but returned to baseline on day 2 and thereafter. Changes in plasma fibrinogen

Aortoiliac aneurysm with congenital right pelvic kidney.

PubMed

Date, Kazuma; Okada, Shuuichi; Ezure, Masahiko; Takihara, Hitomi; Okonogi, Shuuichi; Hasegawa, Yutaka; Sato, Yasushi; Kaneko, Tatsuo

2015-05-01

The association of congenital pelvic kidney with abdominal aortoiliac aneurysm is an extremely rare clinical finding. Previous reports have described various methods of aneurysm repair with successful preservation of the function of pelvic kidney. However, to our knowledge, reconstruction of more than two renal arteries has not been established. We report a case of abdominal aortic aneurysm complicated by congenital right pelvic kidney in a 72-year-old man. Computed tomography (CT) revealed an abdominal aortic aneurysm with a maximum diameter of 54 mm and a right common iliac aneurysm of 45 mm. In addition, he had a congenital right pelvic kidney and CT angiography identified three right pelvic renal arteries. The upper artery originated from the bifurcation of the terminal aorta and the lower two originated from the right common iliac artery. Three-dimensional CT was helpful for the accurate planning of the operation. Open surgical repair of the aortoiliac aneurysm with a Dacron bifurcated graft replacement was decided and reimplantation of all three right pelvic kidney arteries to the right limb of the graft was also performed. For renal preservation, the right pelvic kidney arteries were perfused with cold Ringer's lactate using a rapid infusion pump and coronary perfusion cannula. The patient's postoperative course was uneventful, and worsening of renal function was not observed. The perfusion of renal arteries with cold Ringer's solution was thought to be a simple and appropriate procedure for renal protection.

Measurement of drug and macromolecule diffusion across atherosclerotic rabbit aorta ex vivo by attenuated total reflection-Fourier transform infrared imaging

NASA Astrophysics Data System (ADS)

Palombo, Francesca; Danoux, Charlène B.; Weinberg, Peter D.; Kazarian, Sergei G.

2009-07-01

Diffusion of two model drugs-benzyl nicotinate and ibuprofen-and the plasma macromolecule albumin across atherosclerotic rabbit aorta was studied ex vivo by attenuated total reflection-Fourier transform infrared (ATR-FTIR) imaging. Solutions of these molecules were applied to the endothelial surface of histological sections of the aortic wall that were sandwiched between two impermeable surfaces. An array of spectra, each corresponding to a specific location in the section, was obtained at various times during solute diffusion into the wall and revealed the distribution of the solutes within the tissue. Benzyl nicotinate in Ringer's solution showed higher affinity for atherosclerotic plaque than for apparently healthy tissue. Transmural concentration profiles for albumin demonstrated its permeation across the section and were consistent with a relatively low distribution volume for the macromolecule in the middle of the wall. The ability of albumin to act as a drug carrier for ibuprofen, otherwise undetected within the tissue, was demonstrated by multivariate subtraction image analysis. In conclusion, ATR-FTIR imaging can be used to study transport processes in tissue samples with high spatial and temporal resolution and without the need to label the solutes under study.

Transport of fluid and solutes in the body II. Model validation and implications.

PubMed

Gyenge, C C; Bowen, B D; Reed, R K; Bert, J L

1999-09-01

A mathematical model of short-term whole body fluid, protein, and ion distribution and transport developed earlier [see companion paper: C. C. Gyenge, B. D. Bowen, R. K. Reed, and J. L. Bert. Am. J. Physiol. 277 (Heart Circ. Physiol. 46): H1215-H1227, 1999] is validated using experimental data available in the literature. The model was tested against data measured for the following three types of experimental infusions: 1) hyperosmolar saline solutions with an osmolarity in the range of 2,000-2,400 mosmol/l, 2) saline solutions with an osmolarity of approximately 270 mosmol/l and composition comparable with Ringer solution, and 3) an isosmotic NaCl solution with an osmolarity of approximately 300 mosmol/l. Good agreement between the model predictions and the experimental data was obtained with respect to the trends and magnitudes of fluid shifts between the intra- and extracellular compartments, extracellular ion and protein contents, and hematocrit values. The model is also able to yield information about inaccessible or difficult-to-measure system variables such as intracellular ion contents, cellular volumes, and fluid fluxes across the vascular capillary membrane, data that can be used to help interpret the behavior of the system.

Cardiotonic action of two tannins

PubMed Central

Broadbent, J. L.

1962-01-01

A tannin isolated from Paullinia pinnata Linn., and tannic acid, have cardiotonic actions on the isolated perfused frog heart. Paullinia tannin is more firmly “fixed” than tannic acid. Tannin solutions contain peroxide, but the cardiotonic action is not dependent on this, since drugs believed to prevent peroxide formation, and sodium pyruvate which destroys peroxides, do not prevent the cardiotonic action. Maximal stimulation by tannin greatly reduces subsequent stimulation by ouabain. If calcium is omitted from the Ringer solution tannins cannot stimulate the heart. In this respect they differ from ouabain. However, the ouabain stimulation can be prevented by prior perfusion with tannin. It is suggested that the antagonism between tannin and ouabain is due to the former preventing ouabain from reaching its receptor sites, and that tannin stimulation is dependent on the formation of a calcium-tannin complex at the heart surface. In the isolated perfused mammalian heart preparation tannins increase diastolic tonus and coronary flow. PMID:13873207

Self-Expanding, Tough Biodegradable Elastomers for Wound Stasis

DTIC Science & Technology

2015-08-06

laparotomy and small bowel was retracted to identify the abdominal aorta and vena cava. The peritoneumwas incised along a 3 cm length of the right external...Resuscitation protocol Duration Mortality Blood loss Sondeen et al. [7] Open 4.4 mm perforation of abdominal aorta 100% 300 mL/min IV lactated Ringer...g/kg Control 3. 50% 15 g/kg Kheirabadi et al. [6] Open 4.4 mm perforation of infrarenal aorta 100% Lactated Ringers, 3 pretreatment blood volume at

[Effect of priming solution and ultrafiltration on post-operative bleeding and blood transfusion in cardiac surgery. Randomized controlled trial].

PubMed

Olmos Rodríguez, M; Ballester Hernández, J A; Arteta Bárcenas, M T; Rodríguez Cerezo, A; Vidarte Ortiz de Artiñano, M A; Veiga Alameda, C

2015-02-01

Assess the effectiveness of priming the extracorporeal circulation system with albumin-mannitol combined with ultrafiltration during extracorporeal circulation to reduce post-operative bleeding and transfusion requirements in heart surgery, as well as its impact on the fluid balance, coagulation and hematocrit parameters, re-operation for bleeding, ICU, and hospital length of stay. A total of 134 patients scheduled for heart surgery were randomized to receive Ringer's lactate 1,500mL in the priming reservoir (group C), or mannitol 20% 250mL, albumin 20% 150mL and Ringer's lactate 1,100mL combined with ultrafiltration (group T). Bleeding volume, transfusions, fluid balance, coagulation, and hematology parameters were determined until 48h in the post-operative period. There was a reduction of postoperative bleeding in group T, 1,165±789mL vs 992±662mL (P=.17), and red blood cell concentrate transfusions, 694±843mL vs 413±605mL (P=.03). Intra-operative and post-operative fluid balance was significantly less positive in group T, with an overall balance of 2,292±2,152mL vs 5,388±2,834mL (P<.001). There were higher values of hemoglobin and hematocrit, intraoperative (P<.001), on admission to ICU (P=.001), and at 6h (P=.05) in group T, and lower INR at 6h (P=.01) and 24h (P=.02). Re-operation rate and length of stay in ICU were higher in group C, but not statiscally significant. The priming of extracorporeal reservoir with mannitol, albumin, and Ringer's lactate, combined with ultrafiltration, significantly improves intra- and post-operative fluid balance, resulting in a reduction in blood transfusions, with no significant decrease in post-operative bleeding, re-operation bleeding rate, and length of stay in the ICU. Copyright © 2014 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Ion Transport Function of SLC4A11 in Corneal Endothelium

PubMed Central

Jalimarada, Supriya S.; Ogando, Diego G.; Vithana, Eranga N.; Bonanno, Joseph A.

2013-01-01

Purpose. Mutations in SLC4A11, a member of the SLC4 superfamily of bicarbonate transporters, give rise to corneal endothelial cell dystrophies. SLC4A11 is a putative Na+ borate and Na+:OH− transporter. Therefore we ask whether SLC4A11 in corneal endothelium transports borate (B[OH]4−), bicarbonate (HCO3−), or hydroxyl (OH−) anions coupled to Na+. Methods. SLC4A11 expression in cultured primary bovine corneal endothelial cells (BCECs) was determined by semiquantitative PCR, SDS-PAGE/Western blotting, and immunofluorescence staining. Ion transport function was examined by measuring intracellular pH (pHi) or Na+ ([Na+]i) in response to Ringer solutions with/without B(OH)4− or HCO3− after overexpressing or small interfering RNA (siRNA) silencing of SLC4A11. Results. SLC4A11 is localized to the basolateral membrane in BCEC. B(OH)4− (2.5–10 mM) in bicarbonate-free Ringer induced a rapid small acidification (0.01 pH unit) followed by alkalinization (0.05–0.1 pH unit), consistent with diffusion of boric acid into the cell followed by B(OH)4−. However, the rate of B(OH)4−-induced pHi change was unaffected by overexpression of SLC4A11. B(OH)4− did not induce significant changes in resting [Na+i] or the amplitude and rate of acidification caused by Na+ removal. siRNA-mediated knockdown of SLC4A11 (∼70%) did not alter pHi responses to CO2/HCO3−-rich Ringer, Na+-free induced acidification, or the rate of Na+ influx in the presence of bicarbonate. However, in the absence of bicarbonate, siSLC4A11 knockdown significantly decreased the rate (43%) and amplitude (48%) of acidification due to Na+ removal and recovery (53%) upon add-back. Additionally, the rate of acid recovery following NH4+ prepulse was decreased significantly (27%) by SLC4A11 silencing. Conclusions. In corneal endothelium, SLC4A11 displays robust Na+-coupled OH− transport, but does not transport B(OH)4− or HCO3−. PMID:23745003

Gluconeogenesis in the amphibian retina. Lactate is preferred to glutamate as the gluconeogenic precursor.

PubMed Central

Goldman, S S

1988-01-01

The capacity for gluconeogenesis in the isolated amphibian retina was found to be approx. 70-fold greater with lactate than with glutamate as the gluconeogenic precursor, 1426 versus 21 pmol of glucose incorporated into glycogen/h per mg of protein. It was also found that 11-15% of the glucosyl units in glycogen are derived from C3 metabolites of the glycolytic pathway, suggesting that lactate is recycled within the retina. In concert with these metabolic observations, a full complement of the gluconeogenic enzymes was detected in retinal homogenates. These included: glucose-6-phosphatase, fructose-1,6-bisphosphatase, acetyl-CoA-dependent pyruvate carboxylase and phosphoenolpyruvate carboxykinase. Agents that regulate the rate of gluconeogenesis in hepatic tissue were tested on the retina. At concentrations of glutamate and lactate that are presumed to be relevant physiologically, it was found that vasoactive intestinal peptide, ionophore A23187 and elevated [K+] each enhanced the rate of gluconeogenesis in Ringer containing 50 microM-glutamate, whereas in Ringer containing 8.5 mM-lactate these agents inhibited the rate of gluconeogenesis. Further, it was found that the classic gluconeogenic hormone glucagon inhibited gluconeogenesis in both glutamate- and lactate-containing Ringer. Retinal energy metabolism was found to be altered in lactate-containing Ringer, in that lactate production was suppressed completely. In addition, glycogen metabolism appeared to be dependent on increased cytosolic Ca2+ and was insensitive to increased retinal cyclic AMP. PMID:2902849

Estimation of in-vivo neurotransmitter release by brain microdialysis: the issue of validity.

PubMed

Di Chiara, G.; Tanda, G.; Carboni, E.

1996-11-01

Although microdialysis is commonly understood as a method of sampling low molecular weight compounds in the extracellular compartment of tissues, this definition appears insufficient to specifically describe brain microdialysis of neurotransmitters. In fact, transmitter overflow from the brain into dialysates is critically dependent upon the composition of the perfusing Ringer. Therefore, the dialysing Ringer not only recovers the transmitter from the extracellular brain fluid but is a main determinant of its in-vivo release. Two types of brain microdialysis are distinguished: quantitative micro-dialysis and conventional microdialysis. Quantitative microdialysis provides an estimate of neurotransmitter concentrations in the extracellular fluid in contact with the probe. However, this information might poorly reflect the kinetics of neurotransmitter release in vivo. Conventional microdialysis involves perfusion at a constant rate with a transmitter-free Ringer, resulting in the formation of a steep neurotransmitter concentration gradient extending from the Ringer into the extracellular fluid. This artificial gradient might be critical for the ability of conventional microdialysis to detect and resolve phasic changes in neurotransmitter release taking place in the implanted area. On the basis of these characteristics, conventional microdialysis of neurotransmitters can be conceptualized as a model of the in-vivo release of neurotransmitters in the brain. As such, the criteria of face-validity, construct-validity and predictive-validity should be applied to select the most appropriate experimental conditions for estimating neurotransmitter release in specific brain areas in relation to behaviour.

Deformation Mechanisms and Biocompatibility of the Superelastic Ti-23Nb-0.7Ta-2Zr-0.5N Alloy

NASA Astrophysics Data System (ADS)

Castany, P.; Gordin, D. M.; Drob, S. I.; Vasilescu, C.; Mitran, V.; Cimpean, A.; Gloriant, T.

2016-03-01

In this study, we have synthesized a new Ti-23Nb-0.7Ta-2Zr-0.5N alloy composition with the aim to obtain useful mechanical properties to be used in medicine such as high strength, good superelastic property, low modulus, and large ductility. Thus, mechanical properties including superelasticity and plasticity were investigated in relation with the different deformation mechanisms observed (stress-induced martensitic transformation, twinning and dislocation slip). On the other hand, the corrosion resistance in simulated body fluid (Ringer solution) and the in vitro cell behavior (MG63 human osteoblasts) of such biomedical alloy were also evaluated in order to assess its biocompatibility.

[Analysis of inadvertent epidural injection of drugs].

PubMed

Kasaba, T; Uehara, K; Katsuki, H; Ono, Y; Takasaki, M

2000-12-01

We asked 31 anesthesiologists, who were on the Japanese Board of Anesthesiology, about inadvertent injection of drugs into the epidural space, and received answers from 28 (90%). Fifteen (54%) had an experience of inadvertent epidural injection, and five of them had two experiences. Injected drugs were ephedrine (6 times), a mixture of neostigmine and atropine (3), thiopental (2), etilefrine (2), vecuronium (1), suxamethonium (1), bicarbonate (1), midazolam (1), lactated Ringer's solution (1), nicardipine (1), and pentazocine (1). The inadvertent injection of thiopental or bicarbonate was noticed by back pain during injection. No treatment was added after the inadvertent injections, except a patient with an epidural steroid injection following thiopental. No neurological complications were found in any patients.

Comparison of Cross-Linked Hemoglobin Solution to Lactated Ringers and 5% Albumin in Resuscitation of a Rat Model of escherichia coli Septic Shock

DTIC Science & Technology

1993-08-01

and 0M. in BHI (0). 35 36 7 II I "I -. I 4I I .0 Z 2 L 0 1 2 3 4 5 6 7 Time (hours) Figure 10. Death Rate The Death Rates of 3 septic groups receiving...There were insufficient numbers of animals in each group to make statistical conclusions regarding death rates between groups. 37 38 7 _! 5 S o 2.0 Z 2...0 0 1 2 3 4 5 6 7 Time (hours) Figure 11. Death Rate Death rates of 3 septic groups receiving 40 cc/kg intravenous boluses of either 7

Enhanced corrosion resistance of strontium hydroxyapatite coating on electron beam treated surgical grade stainless steel

NASA Astrophysics Data System (ADS)

Gopi, D.; Rajeswari, D.; Ramya, S.; Sekar, M.; R, Pramod; Dwivedi, Jishnu; Kavitha, L.; Ramaseshan, R.

2013-12-01

The surface of 316L stainless steel (316L SS) is irradiated by high energy low current DC electron beam (HELCDEB) with energy of 500 keV and beam current of 1.5 mA followed by the electrodeposition of strontium hydroxyapatite (Sr-HAp) to enhance its corrosion resistance in physiological fluid. The coatings were characterised by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and High resolution scanning electron microscopy (HRSEM). The Sr-HAp coating on HELCDEB treated 316L SS exhibits micro-flower structure. Electrochemical results show that the Sr-HAp coating on HELCDEB treated 316L SS possesses maximum corrosion resistance in Ringer's solution.

Comparison of NaCl-induced response across the tongue epithelium to that across other epithelia in the frog.

PubMed

Soeda, H; Sakudo, F

1990-01-01

Electrical properties of the frog tongue epithelium were compared to those of skin and bladder, which have active sodium transport. During perfusion with Ringer solution, the potential difference across the tongue epithelium was negligible, unlike those of the skin and bladder. NaCl stimulation of the tongue epithelium produced a response with a polarity opposite to that of the skin and bladder. The response profile of the tongue epithelium except for the polarity resembled that of other tissues. In conclusion, the NaCl response of the tongue epithelium is independent of active sodium transport and instead occurs by passive transport, which may influence taste reception.

Characterization of the effect of high molecular weight hyaluronan on trans-synovial flow in rabbit knees.

PubMed

Coleman, P J; Scott, D; Mason, R M; Levick, J R

1999-01-01

1. The effect of a rooster comb hyaluronan (3.6-4.0 g l-1) of similar chain length to rabbit synovial fluid hyaluronan, on the trans-synovial escape of fluid from the joint cavity in the steady state ( 8d s) was studied in 29 rabbit knees at controlled intra-articular pressures (Pj). 2. Rooster hyaluronan caused the pressure-flow relation to flatten out as pressure was raised. At 10-20 cmH2O the slope of the quasi-plateau, 0.05 +/- 0.01 microliter min-1 cmH2O-1 (mean +/- s.e.m.), was 1/39th that for Ringer solution (1.94 +/- 0.01 microliter 2O-1 ). 3. Bovine synovial fluid had a similar effect to hyaluronan in Ringer solution. 4. The quasi-plateau was caused by increasing opposition to outflow; the pressure required to drive unit outflow increased 4.4-fold between 5 and 20 cmH2O. The increased opposition to outflow at 20 cmH2O was equivalent to an effective osmotic pressure of 13-17 cmH2O at the interface. Since the infusate's osmotic pressure was only 0.9 cmH2O, this implied concentration polarization to 15-18 g l-1 hyaluronan at the interface. 5. Mechanical perforation of the lining, or enzymatic degradation of the interstitial matrix by chymopapain, abolished the quasi-plateau. Hydrational expansion of the matrix by approximately 2-fold did not. The increased opposition to outflow was reversible by washing out the hyaluronan, or by reducing Pj. It was unaffected by interruption of tissue blood flow or synoviocyte oxidative metabolism. These properties are compatible with a concentration polarization mechanism, i.e. flow-induced concentration of hyaluronan at the synovial interface due to molecular reflection. 6. A concentration polarization theory was developed for a partially reflected solute. Numerical solutions supported the feasibility of this osmotic explanation of the quasi-plateau. Additional mechanisms may also be involved. 7. It is concluded that native-size hyaluronan helps to retain synovial fluid in the joint cavity when pressure is raised and acts, at least in part, by exerting osmotic pressure at the interface between synovial matrix and a concentration polarization layer.

Characterization of the effect of high molecular weight hyaluronan on trans-synovial flow in rabbit knees

PubMed Central

Coleman, P J; Scott, D; Mason, R M; Levick, J R

1999-01-01

The effect of a rooster comb hyaluronan (3.6–4.0 g l−1) of similar chain length to rabbit synovial fluid hyaluronan, on the trans-synovial escape of fluid from the joint cavity in the steady state (Q̇s) was studied in 29 rabbit knees at controlled intra-articular pressures (Pj).Rooster hyaluronan caused the pressure-flow relation to flatten out as pressure was raised. At 10–20 cmH2O the slope of the quasi-plateau, 0.05 ± 0.01 μl min−1 cmH2O−1 (mean ±s.e.m.), was 1/39th that for Ringer solution (1.94 ± 0.01 μl min−1 cmH2O−1).Bovine synovial fluid had a similar effect to hyaluronan in Ringer solution.The quasi-plateau was caused by increasing opposition to outflow; the pressure required to drive unit outflow increased 4.4-fold between 5 and 20 cmH2O. The increased opposition to outflow at 20 cmH2O was equivalent to an effective osmotic pressure of 13–17 cmH2O at the interface. Since the infusate's osmotic pressure was only 0.9 cmH2O, this implied concentration polarization to 15–18 g l−1 hyaluronan at the interface.Mechanical perforation of the lining, or enzymatic degradation of the interstitial matrix by chymopapain, abolished the quasi-plateau. Hydrational expansion of the matrix by /2-fold did not. The increased opposition to outflow was reversible by washing out the hyaluronan, or by reducing Pj. It was unaffected by interruption of tissue blood flow or synoviocyte oxidative metabolism. These properties are compatible with a concentration polarization mechanism, i.e. flow-induced concentration of hyaluronan at the synovial interface due to molecular reflection.A concentration polarization theory was developed for a partially reflected solute. Numerical solutions supported the feasibility of this osmotic explanation of the quasi-plateau. Additional mechanisms may also be involved.It is concluded that native-size hyaluronan helps to retain synovial fluid in the joint cavity when pressure is raised and acts, at least in part, by exerting osmotic pressure at the interface between synovial matrix and a concentration polarization layer. PMID:9831732

Saline versus balanced crystalloids for intravenous fluid therapy in the emergency department: study protocol for a cluster-randomized, multiple-crossover trial.

PubMed

Self, Wesley H; Semler, Matthew W; Wanderer, Jonathan P; Ehrenfeld, Jesse M; Byrne, Daniel W; Wang, Li; Atchison, Leanne; Felbinger, Matthew; Jones, Ian D; Russ, Stephan; Shaw, Andrew D; Bernard, Gordon R; Rice, Todd W

2017-04-13

Prior studies in critically ill patients suggest the supra-physiologic chloride concentration of 0.9% ("normal") saline may be associated with higher risk of renal failure and death compared to physiologically balanced crystalloids. However, the comparative effects of 0.9% saline and balanced fluids are largely unexamined among patients outside the intensive care unit, who represent the vast majority of patients treated with intravenous fluids. This study, entitled Saline Against Lactated Ringer's or Plasma-Lyte in the Emergency Department (SALT-ED), is a pragmatic, cluster, multiple-crossover trial at a single institution evaluating clinical outcomes of adults treated with 0.9% saline versus balanced crystalloids for intravenous fluid resuscitation in the emergency department. All adults treated in the study emergency department receiving at least 500 mL of isotonic crystalloid solution during usual clinical care and subsequently hospitalized outside the intensive care unit are included. Treatment allocation of 0.9% saline versus balanced crystalloids is assigned by calendar month, with study patients treated during the same month assigned to the same fluid type. The first month (January 2016) was randomly assigned to balanced crystalloids, with each subsequent month alternating between 0.9% saline and balanced crystalloids. For balanced crystalloid treatment, clinicians can choose either Lactated Ringer's or Plasma-Lyte A©. The study period is set at 16 months, which will result in an anticipated estimated sample size of 15,000 patients. The primary outcome is hospital-free days to day 28, defined as the number of days alive and out of the hospital from the index emergency department visit until 28 days later. Major secondary outcomes include proportion of patients who develop acute kidney injury by creatinine measurements; major adverse kidney events by hospital discharge or day 30 (MAKE30), which is a composite outcome of death, new renal replacement therapy, and persistent creatinine elevation >200% of baseline; and in-hospital mortality. This ongoing pragmatic trial will provide the most comprehensive evaluation to date of clinical outcomes associated with 0.9% saline compared to physiologically balanced fluids in patients outside the intensive care unit. ClinicalTrials.gov, NCT02614040 . Registered on 18 November 2015.

Influence of perfusate temperature on nasal potential difference.

PubMed

Bronsveld, Inez; Vermeulen, François; Sands, Dorotha; Leal, Teresinha; Leonard, Anissa; Melotti, Paola; Yaakov, Yasmin; de Nooijer, Roel; De Boeck, Kris; Sermet, Isabelle; Wilschanski, Michael; Middleton, Peter G

2013-08-01

Nasal potential difference (NPD) quantifies abnormal ion transport in cystic fibrosis. It has gained acceptance as an outcome measure for the investigation of new therapies. To quantify the effect of solution temperature on NPD, we first examined the effect of switching from room temperature (20-25°C) to warmed (32-37°C) solutions and vice versa during each perfusion step. Secondly, standard protocols were repeated at both temperatures in the same subjects. Changing solution temperature did not alter NPD during perfusion with Ringer's solution (<1 mV) (p>0.1). During perfusion with zero chloride solution, changing from room temperature to warmed solutions tended to decrease absolute NPD (i.e. it became less negative) by 0.9 mV (p>0.1); changing from warmed to room temperature increased NPD by 2.1 mV (p<0.05). During isoprenaline perfusion, changing from room temperature to warmed solutions increased NPD by 1.5 mV (p<0.01) and from warmed to room temperature decreased NPD by 1.4 mV (p<0.05). For full protocols at room temperature or warmed in the same subjects, mean values were similar (n = 24). During warmed perfusion, group results for total chloride response had a larger standard deviation. As this increased variability will probably decrease the power of trials, this study suggests that solutions at room temperature should be recommended for the measurement of NPD.

Intracellular chloride regulation in amphibian dorsal root ganglion neurones studied with ion-selective microelectrodes.

PubMed Central

Alvarez-Leefmans, F J; Gamiño, S M; Giraldez, F; Noguerón, I

1988-01-01

1. Intracellular Cl- activity (aiCl) and membrane potential (Em) were measured in frog dorsal root ganglion neurones (DRG neurones) using double-barrelled Cl- -selective microelectrodes. In standard Ringer solution buffered with HEPES (5 mM), equilibrated with air or 100% O2, the resting membrane potential was -57.7 +/- 1.0 mV and aiCl was 23.6 +/- 1.0 mM (n = 53). The value of aiCl was 2.6 times the activity expected for an equilibrium distribution and the difference between Em and ECl was 25 mV. 2. Removal of external Cl- led to a reversible fall in aiCl. Initial rates of decay and recovery of aiCl were 4.1 and 3.3 mM min-1, respectively. During the recovery of aiCl following return to standard Ringer solution, most of the movement of Cl- occurred against the driving force for a passive distribution. Changes in aiCl were not associated with changes in Em. Chloride fluxes estimated from initial rates of change in aiCl when external Cl- was removed were too high to be accounted for by electrodiffusion. 3. The intracellular accumulation of Cl- was dependent on the extracellular Cl- activity (aoCl). The relationship between aiCl and aoCl had a sigmoidal shape with a half-maximal activation of about 50 mM-external Cl-. 4. The steady-state aiCl depended on the simultaneous presence of extracellular Na+ and K+. Similarly, the active reaccumulation of Cl- after intracellular Cl- depletion was abolished in the absence of either Na+ or K+ in the bathing solution. 5. The reaccumulation of Cl- was inhibited by furosemide (0.5-1 x 10(-3) M) or bumetanide (10(-5) M). The decrease in aiCl observed in Cl- -free solutions was also inhibited by bumetanide. 6. Cell volume changes were calculated from the observed changes in aiCl. Cells were estimated to shrink in Cl- -free solutions to about 75% their initial volume, at an initial rate of 6% min-1. 7. The present results provide direct evidence for the active accumulation of Cl- in DRG neurones. The mechanism of Cl- transport is electrically silent, dependent on the simultaneous presence of external Cl-, Na+ and K+ and inhibited by loop diuretics. It is suggested that a Na+:K+:Cl- co-transport system mediates the active transport of Cl- across the cell membrane of DRG neurones. PMID:3254412

Pediatric patients on ketogenic diet undergoing general anesthesia-a medical record review.

PubMed

Soysal, Elif; Gries, Heike; Wray, Carter

2016-12-01

To identify guidelines for anesthesia management and determine whether general anesthesia is safe for pediatric patients on ketogenic diet (KD). Retrospective medical record review. Postoperative recovery area. All pediatric patients who underwent general anesthesia while on KD between 2009 and 2014 were reviewed. We identified 24 patients who underwent a total of 33 procedures. All children were on KD due to intractable epilepsy. The age of patients ranged from 1 to 15 years. General anesthesia for the scheduled procedures. Patients' demographics, seizure history, type of procedure; perioperative blood chemistry, medications including the anesthesia administered, and postoperative complications. Twenty-four patients underwent a total of 33 procedures. The duration of KD treatment at the time of general anesthesia ranged from 4 days to 8 years. Among the 33 procedures, 3 patients had complications that could be attributable to KD and general anesthesia. A 9-year-old patient experienced increased seizures on postoperative day 0. An 8-year-old patient with hydropcephalus developed metabolic acidosis on postoperative day 1, and a 7-year-old patient's procedure was complicated by respiratory distress and increased seizure activity in the postanesthesia care unit. This study showed that it is relatively safe for children on KD to undergo general anesthesia. The 3 complications attributable to general anesthesia were mild, and the increased seizure frequencies in 2 patients returned back to baseline in 24 hours. Although normal saline is considered more beneficial than lactated Ringer's solution in patients on KD, normal saline should also be administered carefully because of the risk of exacerbating patients' metabolic acidosis. One should be aware of the potential change of the ketogenic status due to drugs given intraoperatively. Copyright © 2016 Elsevier Inc. All rights reserved.

Colloid normalizes resuscitation ratio in pediatric burns.

PubMed

Faraklas, Iris; Lam, Uyen; Cochran, Amalia; Stoddard, Gregory; Saffle, Jeffrey

2011-01-01

Fluid resuscitation of burned children is challenging because of their small size and intolerance to over- or underresuscitation. Our American Burn Association-verified regional burn center has used colloid "rescue" as part of our pediatric resuscitation protocol. With Institutional Review Board approval, the authors reviewed children with ≥15% TBSA burns admitted from January 1, 2004, to May 1, 2009. Resuscitation was based on the Parkland formula, which was adjusted to maintain urine output. Patients requiring progressive increases in crystalloid were placed on a colloid protocol. Results were expressed as an hourly resuscitation ratio (I/O ratio) of fluid infusion (ml/kg/%TBSA/hr) to urine output (ml/kg/hr). We reviewed 53 patients; 29 completed resuscitation using crystalloid alone (lactated Ringer's solution [LR]), and 24 received colloid supplementation albumin (ALB). Groups were comparable in age, gender, weight, and time from injury to admission. ALB patients had more inhalation injuries and larger total and full-thickness burns. LR patients maintained a median I/O of 0.17 (range, 0.08-0.31), whereas ALB patients demonstrated escalating ratios until the institution of albumin produced a precipitous return of I/O comparable with that of the LR group. Hospital stay was lower for LR patients than ALB patients (0.59 vs 1.06 days/%TBSA, P = .033). Twelve patients required extremity or torso escharotomy, but this did not differ between groups. There were no decompressive laparotomies. The median resuscitation volume for ALB group was greater than LR group (9.7 vs 6.2 ml/kg/%TBSA, P = .004). Measuring hourly I/O is a helpful means of evaluating fluid demands during burn shock resuscitation. The addition of colloid restores normal I/O in pediatric patients.

[General principles of wound management in emergency departments].

PubMed

Zacher, M T; Högele, A M; Hanschen, M; von Matthey, F; Beer, A-K; Gebhardt, F; Biberthaler, P; Kanz, K-G

2016-04-01

Wound management is one of the major tasks in emergency departments. The surrounding intact skin but not the wound itself should be disinfected before starting definitive wound treatment. Hair should first be removed by clipping to 1-2 mm above the skin with scissors or clippers as shaving the area with a razor damages the hair follicles and increases the risk of wound infections. Administration of local anesthetics should be performed directly through the exposed edges of the wound. After wound examination, irrigation is performed with Ringer's solution, normal saline or distilled water. The next step is débridement of contaminated and devitalized tissue. There are several wound closure techniques available, including adhesive tapes, staples, tissue adhesives and numerous forms of sutures. Management of specific wounds requires particular strategies. A bleeding control problem frequently occurs with scalp lacerations. Superficial scalp lacerations can be closed by alternative wound closure methods, for example by twisting and fixing hair and the use of tissue adhesives, i.e. hair apposition technique (HAT). For strongly bleeding lacerations of the scalp, the epicranial aponeurosis should be incorporated into the hemostasis. Aftercare varies depending on both the characteristics of the wound and those of the patient and includes adequate analgesia as well as minimizing the risk of infection. Sufficient wound aftercare starts with the treating physician informing the patient about the course of events, potential complications and providing relevant instructions.

Fractionation of Sodium Efflux in Frog Sartorius Muscles by Strophanthidin and Removal of External Sodium

PubMed Central

Horowicz, P.; Taylor, J. W.; Waggoner, D. M.

1970-01-01

The influence of strophanthidin, ouabain, and the removal of external sodium on the sodium efflux from frog sartorius muscle was measured. In freshly dissected muscles strophanthidin and ouabain in maximally effective concentrations reduced the efflux of sodium by about 50%. Of the sodium efflux which is strophanthidin-insensitive about 75% is inhibited after complete replacement of external sodium by lithium. In the absence of strophanthidin replacement of external sodium by lithium, calcium, or magnesium produces an initial rise in the sodium efflux, followed by a fall in the efflux as the exposure of the muscles to sodium-free media is continued. When the muscles are exposed for prolonged periods in sodium-free media, the fraction of internal sodium lost per minute is higher when returned to normal Ringer fluid than it was initially. The activation of sodium efflux by external sodium after long periods in sodium-free solutions is partly strophanthidin-sensitive and partly strophanthidin-insensitive. The internal sodium concentration is an important factor in these effects. The effects of temperature on the sodium efflux were also measured. Above 7°C the Q 10 of both the strophanthidin-sensitive and strophanthidin-insensitive sodium efflux is about 2.0. Below 7°C the strophanthidin-insensitive sodium efflux has a Q 10 of about 7.4. PMID:5315424

Transdiaphragmatic transport of tracer albumin from peritoneal to pleural liquid measured in rats.

PubMed

Lai-Fook, Stephen J; Houtz, Pamela K; Jones, Philip D

2005-12-01

In conscious Wistar-Kyoto rats, we studied the uptake of radioactive tracer (125)I-albumin into the pleural space and circulation after intraperitoneal (IP) injections with 1 or 5 ml of Ringer solution (3 g/dl albumin). Postmortem, we sampled pleural liquid, peritoneal liquid, and blood plasma 2-48 h after IP injection and measured their radioactivity and protein concentration. Tracer concentration was greater in pleural liquid than in plasma approximately 3 h after injection with both IP injection volumes. This behavior indicated transport of tracer through the diaphragm into the pleural space. A dynamic analysis of the tracer uptake with 5-ml IP injections showed that at least 50% of the total pleural flow was via the diaphragm. A similar estimate was derived from an analysis of total protein concentrations. Both estimates were based on restricted pleural capillary filtration and unrestricted transdiaphragmatic transport. The 5-ml IP injections did not change plasma protein concentration but increased pleural and peritoneal protein concentrations from control values by 22 and 30%, respectively. These changes were consistent with a small (approximately 8%) increase in capillary filtration and a small (approximately 20%) reduction in transdiaphragmatic flow from control values, consistent with the small (3%) decrease in hydration measured in diaphragm muscle. Thus the pleural uptake of tracer via the diaphragm with the IP injections occurred by the near-normal transport of liquid and protein.

Neurotransmitter modulation of extracellular H+ fluxes from isolated retinal horizontal cells of the skate

PubMed Central

Molina, Anthony J A; Verzi, Michael P; Birnbaum, Andrea D; Yamoah, Ebenezer N; Hammar, Katherine; Smith, Peter J S; Malchow, Robert Paul

2004-01-01

Self-referencing H+-selective microelectrodes were used to measure extracellular H+ fluxes from horizontal cells isolated from the skate retina. A standing H+ flux was detected from quiescent cells, indicating a higher concentration of free hydrogen ions near the extracellular surface of the cell as compared to the surrounding solution. The standing H+ flux was reduced by removal of extracellular sodium or application of 5-(N-ethyl-N-isopropyl) amiloride (EIPA), suggesting activity of a Na+–H+ exchanger. Glutamate decreased H+ flux, lowering the concentration of free hydrogen ions around the cell. AMPA/kainate receptor agonists mimicked the response, and the AMPA/kainate receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) eliminated the effects of glutamate and kainate. Metabotropic glutamate agonists were without effect. Glutamate-induced alterations in H+ flux required extracellular calcium, and were abolished when cells were bathed in an alkaline Ringer solution. Increasing intracellular calcium by photolysis of the caged calcium compound NP-EGTA also altered extracellular H+ flux. Immunocytochemical localization of the plasmalemma Ca2+–H+-ATPase (PMCA pump) revealed intense labelling within the outer plexiform layer and on isolated horizontal cells. Our results suggest that glutamate modulation of H+ flux arises from calcium entry into cells with subsequent activation of the plasmalemma Ca2+–H+-ATPase. These neurotransmitter-induced changes in extracellular pH have the potential to play a modulatory role in synaptic processing in the outer retina. However, our findings argue against the hypothesis that hydrogen ions released by horizontal cells normally act as the inhibitory feedback neurotransmitter onto photoreceptor synaptic terminals to create the surround portion of the centre-surround receptive fields of retinal neurones. PMID:15272044

Role of hyaluronan chain length in buffering interstitial flow across synovium in rabbits

PubMed Central

Coleman, P J; Scott, D; Mason, R M; Levick, J R

2000-01-01

Synovial fluid drains out of joints through an interstitial pathway. Hyaluronan, the major polysaccharide of synovial fluid, attenuates this fluid drainage; it creates a graded opposition to outflow that increases with pressure (outflow ‘buffering’). This has been attributed to size-related molecular reflection at the interstitium-fluid interface. Chain length is reduced in inflammatory arthritis. We therefore investigated the dependence of outflow buffering on hyaluronan chain length.Hyaluronan molecules of mean molecular mass ≈2200, 530, 300 and 90 kDa and concentration 3.6 mg ml−1 were infused into the knees of anaesthetized rabbits, with Ringer solution as control in the contralateral joint. Trans-synovial drainage rate was recorded at known joint pressures. Pressure was raised in steps every 30–60 min (range 2–24 cmH2O).With hyaluronan-90 and hyaluronan-300 the fluid drainage rate was reduced relative to Ringer solution (P < 0.001, ANOVA) but increased steeply with pressure. The opposition to outflow, defined as the pressure required to drive unit outflow, did not increase with pressure, i.e. there was no outflow buffering.With hyaluronan-530 and hyaluronan-2000 the fluid drainage rate became relatively insensitive to pressure, causing a near plateau of flow. Opposition to outflow increased markedly with pressure, by up to 3.3 times over the explored pressures.Hyaluronan concentration in the joint cavity increased over the drainage period, indicating partial reflection of hyaluronan by synovial interstitium. Reflected fractions were 0.12, 0.33, 0.25 and 0.79 for hyaluronan-90, -300, -530 and -2200, respectively.Thus the flow-buffering effect of hyaluronan depended on chain length, and shortening the chains reduced the degree of molecular reflection. The latter should reduce the concentration polarization at the tissue interface, and hence the local osmotic pressure opposing fluid drainage. In rheumatoid arthritis the reduced chain length will facilitate the escape of hyaluronan and fluid. PMID:10896731

Minocycline and Doxycycline, but not Tetracycline, Mitigate Liver and Kidney Injury after Hemorrhagic Shock/Resuscitation*

PubMed Central

Kholmukhamedov, Andaleb; Czerny, Christoph; Hu, Jiangting; Schwartz, Justin; Zhong, Zhi; Lemasters, John J.

2014-01-01

Background Despite recovery of hemodynamics by fluid resuscitation after hemorrhage, development of the systemic inflammatory response and multiple organ dysfunction syndromes can nonetheless lead to death. Minocycline and doxycycline are tetracycline derivatives that are protective in models of hypoxic, ischemic and oxidative stress. Our Aim was to determine whether minocycline and doxycycline protect liver and kidney and improve survival in a mouse model of hemorrhagic shock and resuscitation. Methods Mice were hemorrhaged to 30 mm Hg for 3 h and then resuscitated with shed blood followed by half the shed volume of lactated Ringer's solution containing tetracycline (10 mg/kg), minocycline (10 mg/kg), doxycycline (5 mg/kg) or vehicle. For pre-plus post-treatment, drugs were administered intraperitoneally prior to hemorrhage followed by second equal dose in Ringer's solution after blood resuscitation. Blood and tissue were harvested after 6 h. Results Serum alanine aminotransferase (ALT) increased to 1988 and 1878 U/L after post-treatment with vehicle and tetracycline, respectively, whereas minocycline and doxycycline post-treatment decreased ALT to 857 and 863 U/L. Pre-plus post-treatment with minocycline and doxycycline also decreased ALT to 849 and 834 U/L. After vehicle, blood creatinine increased to 279 μM, which minocycline and doxycycline post-treatment decreased to 118 and 112 μM. Minocycline and doxycycline pre- plus post-treatment decreased creatinine similarly. Minocycline and doxycycline also decreased necrosis and apoptosis in liver and apoptosis in both liver and kidney, the latter assessed by TUNEL and caspase-3 activation. Lastly after 4.5 h of hemorrhage followed by resuscitation, minocycline and doxycycline (but not tetracycline) post-treatment improved 1-week survival from 38%(vehicle) to 69% and 67%, respectively. Conclusion Minocycline and doxycycline were similarly protective when given before as after blood resuscitation and might therefore have clinical efficacy to mitigate liver and kidney injury after resuscitated hemorrhage. PMID:24978888

Studies on the effect of virtual crosslinking on the hydrolytic stability of novel aliphatic polyurethane ureas for blood contact applications.

PubMed

Thomas, V; Jayabalan, M

2001-07-01

The effect of virtual crosslinking on the hydrolytic stability of completely aliphatic novel poly(urethane ureas), HFL9-PU1 (hard-segment content 57.5%) and HFL13-PU2 (hard-segment content 67.9%) based on 4,4'-methylene bis(cyclohexyl isocyanate) (H(12)MDI)-hydroxy-terminated polybutadiene-1,6-hexamethylene diamine, was studied. Fourier transform infrared-attenuated total reflectance and wide-angle X-ray diffraction studies revealed hydrogen-bonding interaction and microphase separation and formation of crystallites by short- and long-range ordering in hard-segment domains. Three-dimensional networks from hydrogen bonding in the present polymers lead to virtually crosslinking and insolubility. These polymers were noncytotoxic to L929 fibroblast cells. The hemolytic potential is below the accepted limit. The studies on in vitro biostability in Ringer's solution, phosphate buffered saline, and papain enzyme revealed no weight loss. The infrared spectral studies revealed changes in the surface, especially on HFL9-PU1 aged in Ringer's solution and phosphate buffered saline, and no changes when aged in papain. The marginal changes noticed in tensile properties were attributed to the changes in degree of hydrogen bonding and associated rearrangement of molecular structure in the bulk. The results revealed that the lesser the crosslinking in virgin polymer, the higher the crosslinking in aged polymer and vice versa. Increased crosslinking during aging provided increased tensile properties in the aged polymer over the virgin polymer and vice versa. For comparison, an aliphatic polyetherurethane urea (HFL16-PU3) was also synthesized using poly(oxy tetra methylene glycol) in addition to the above reactants. Though both HFL9-PU1 and HFL16-PU3 contained the same hard-segment content, the aged sample of the latter showed decreased tensile properties with increased crosslinking during aging in contrast to the former. This was attributed to less microphase separation in the virgin HFL16-PU3 polymer.

The intravascular volume effect of Ringer's lactate is below 20%: a prospective study in humans.

PubMed

Jacob, Matthias; Chappell, Daniel; Hofmann-Kiefer, Klaus; Helfen, Tobias; Schuelke, Anna; Jacob, Barbara; Burges, Alexander; Conzen, Peter; Rehm, Markus

2012-05-16

Isotonic crystalloids play a central role in perioperative fluid management. Isooncotic preparations of colloids (for example, human albumin or hydroxyethyl starch) remain nearly completely intravascular when infused to compensate for acute blood losses. Recent data were interpreted to indicate a comparable intravascular volume effect for crystalloids, challenging the occasionally suggested advantage of using colloids to treat hypovolemia. General physiological knowledge and clinical experience, however, suggest otherwise. In a prospective study, double-tracer blood volume measurements were performed before and after intended normovolemic hemodilution in ten female adults, simultaneously substituting the three-fold amount of withdrawn blood with Ringer's lactate. Any originated deficits were substituted with half the volume of 20% human albumin, followed by a further assessment of blood volume. To assess significance between the measurements, repeated measures analysis of variance (ANOVA) according to Fisher were performed. If significant results were shown, paired t tests (according to Student) for the singular measurements were taken. P < 0.05 was considered to be significant. A total of 1,097 ± 285 ml of whole blood were withdrawn (641 ± 155 ml/m(2) body surface area) and simultaneously replaced by 3,430 ± 806 ml of Ringer's lactate. All patients showed a significant decrease in blood volume after hemodilution (-459 ± 185 ml; P < 0.05) that did not involve relevant hemodynamical changes, and a significant increase in interstitial water content (+2,157 ± 606 ml; P < 0.05). The volume effect of Ringer's lactate was 17 ± 10%. The infusion of 245 ± 64 ml of 20% human albumin in this situation restored blood volume back to baseline values, the volume effect being 184 ± 63%. Substitution of isolated intravascular deficits in cardiopulmonary healthy adults with the three-fold amount of Ringer's lactate impedes maintenance of intravascular normovolemia. The main side effect was an impressive interstitial fluid accumulation, which was partly restored by the intravenous infusion of 20% human albumin. We recommend to substitute the five-fold amount of crystalloids or to use an isooncotic preparation in the face of acute bleeding in patients where edema prevention might be advantageous.

Dehydration, hemodynamics and fluid volume optimization after induction of general anesthesia.

PubMed

Li, Yuhong; He, Rui; Ying, Xiaojiang; Hahn, Robert G

2014-01-01

Fluid volume optimization guided by stroke volume measurements reduces complications of colorectal and high-risk surgeries. We studied whether dehydration or a strong hemodynamic response to general anesthesia increases the probability of fluid responsiveness before surgery begins. Cardiac output, stroke volume, central venous pressure and arterial pressures were measured in 111 patients before general anesthesia (baseline), after induction and stepwise after three bolus infusions of 3 ml/kg of 6% hydroxyethyl starch 130/0.4 (n=86) or Ringer's lactate (n=25). A subgroup of 30 patients who received starch were preloaded with 500 ml of Ringer's lactate. Blood volume changes were estimated from the hemoglobin concentration and dehydration was estimated from evidence of renal water conservation in urine samples. Induction of anesthesia decreased the stroke volume to 62% of baseline (mean); administration of fluids restored this value to 84% (starch) and 68% (Ringer's). The optimized stroke volume index was clustered around 35-40 ml/m2/beat. Additional fluid boluses increased the stroke volume by ≥10% (a sign of fluid responsiveness) in patients with dehydration, as suggested by a low cardiac index and central venous pressure at baseline and by high urinary osmolality, creatinine concentration and specific gravity. Preloading and the hemodynamic response to induction did not correlate with fluid responsiveness. The blood volume expanded 2.3 (starch) and 1.8 (Ringer's) times over the infused volume. Fluid volume optimization did not induce a hyperkinetic state but ameliorated the decrease in stroke volume caused by anesthesia. Dehydration, but not the hemodynamic response to the induction, was correlated with fluid responsiveness.

Long-term Effects on the Histology and Function of Livers and Spleens in Rats after 33% Toploading of PEG-PLA-nano Artificial Red Blood Cells

PubMed Central

Liu, Zun Chang; Chang, Thomas M.S.

2012-01-01

This study is to investigate the long-term effects of nanodimension PEG-PLA artificial red blood cells containing hemoglobin and red blood cell enzymes on the liver and spleen after 1/3 blood volume top loading in rats. The experimental rats received one of the following infusions: Nano artificial red blood cells in Ringer lactate, Ringer lactate, stroma-free hemoglobin, polyhemoglobin, and autologous rat whole blood. Blood samples were taken before infusions and on days 1, 7, and 21 after infusions for analysis. Nano artificial red blood cells, polyhemoglobin, Ringer lactate and rat red blood cells did not have any significant adverse effects on alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, creatine kinase, amylase and creatine kinase. On the other hand, stroma-free hemoglobin induced significant adverse effects on liver as shown by elevation in alanine aminotransferase and aspartate aminotransferase throughout the 21 days. On day 21 after infusions rats were sacrificed and livers and spleens were excised for histological examination. Nano artificial red blood cells, polyhemoglobin, Ringer lactate and rat red blood cells did not cause any abnormalities in the microscopic histology of the livers and spleens. In the stroma-free hemoglobin group the livers showed accumulation of hemoglobin in central veins and sinusoids, and hepatic steatosis. In conclusion, injected nano artificial red blood cells can be efficiently metabolized and removed by the reticuloendothelial system, and do not have any biochemical or histological adverse effects on the livers or the spleens. PMID:19043818

Potassium Fluxes in Desheathed Frog Sciatic Nerve

PubMed Central

Hurlbut, William P.

1963-01-01

Desheathed frog (R. pipiens) sciatic nerves were soaked in Na-deficient solutions, and measurements were made of their Na and K contents and of the movements of K42. When a nerve is in Ringer's solution, the Na fluxes are equal to the K fluxes, and about 75 per cent of the K influx is due to active transport. The Na content and the Na efflux are linearly related to the Na concentration of the bathing solution, while the K content and the K fluxes are not so related. When a nerve is in a solution in which 75 per cent of the NaCl has been replaced by choline chloride or sucrose, the active K influx exceeds the active Na efflux, and the K content is maintained. When a nerve is soaked in a solution that contains Li, the K42 uptake is inhibited, and the nerve loses K and gains Li. When a Li-loaded nerve recovers in a Li-free solution, K is taken up in exchange for Li. This uptake of K requires Na in the external solution. It is concluded that the active transports of K and of Na may be due to different processes, that an accumulation of K occurs only in exchange for an intracellular cation, which need not be Na, and that Na plays a specific, but unknown, role in K transport. PMID:14043000

Successful snakebite treatment in three juvenile African wild dogs (Lycaon pictus) with polyvalent antivenom: a Namibian case report.

PubMed

Weise, Florian J; van Vuuren, Rudie J; Echement, Katherine E; Cleverley, Matthew P; van Vuuren, Marlice

2013-03-27

This article reports the first documented treatment of venomous snakebite with a polyvalent snake antivenom from the South African Institute for Medical Research in endangered African wild dogs (Lycaon pictus). Three juvenile male animals (6.5 months of age) showed clinical signs after being bitten by an unidentified venomous snake. The signs included loss of appetite, disorientation, impaired locomotion, excessive facial swelling, profuse salivation, reduced respiratory effort and an apparent depressed mental state. Intravenous treatment with isotonic Ringer lactate solution, hetastarch 6% and dexamethazone, subcutaneous administration of procaine benzylpenicillin and benzathine benzylpenicillin, and ultimately intravenous administration of the polyvalent snake antivenom resulted in the complete recovery of all three wild dogs.

No bacterial growth found in spiked intravenous fluids over an 8-hour period.

PubMed

Haas, Richard E; Beitz, Edwin; Reed, Amy; Burtnett, Howard; Lowe, Jason; Crist, Arthur E; Stierer, Kevin A; Birenberg, Allan M

2017-04-01

Protocol changes prompted by the Joint Commission mandating intravenous (IV) fluid bags to be used within 1 hour of spiking because of possible bacterial contamination have sparked clinical and economic concerns. This study investigated the degree of bacterial growth in which samples were obtained from spiked IV fluid bags at the time of spiking and 1, 2, 4, and 8 hours after spiking. No bacterial growth occurred in any of the 80 bags of Lactated Ringer's (LR) IV solutions sampled. This study demonstrated that LR IV bags do not support any bacterial growth for up to 8 hours after spiking. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Quantitative analysis of serotonin secreted by human embryonic stem cells-derived serotonergic neurons via pH-mediated online stacking-CE-ESI-MRM.

PubMed

Zhong, Xuefei; Hao, Ling; Lu, Jianfeng; Ye, Hui; Zhang, Su-Chun; Li, Lingjun

2016-04-01

A CE-ESI-MRM-based assay was developed for targeted analysis of serotonin released by human embryonic stem cells-derived serotonergic neurons in a chemically defined environment. A discontinuous electrolyte system was optimized for pH-mediated online stacking of serotonin. Combining with a liquid-liquid extraction procedure, LOD of serotonin in the Krebs'-Ringer's solution by CE-ESI-MS/MS on a 3D ion trap MS was0.15 ng/mL. The quantitative results confirmed the serotonergic identity of the in vitro developed neurons and the capacity of these neurons to release serotonin in response to stimulus. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Comparative effect of lidocaine and bupivacaine on glucose uptake and lactate production in the perfused working rat heart

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cronau, L.H. Jr.; Merin, R.G.; Aboulish, E.

1986-03-01

It has been suggested that at equivalent therapeutic concentrations, lidocaine and bupivacaine may have different cardiotoxic potency. In the isolated working rat heart preparation, the effect of a range of lidocaine and bupivacaine concentrations on glucose uptake and lactate production (LP) were observed. Insulin was added, 10 ..mu../L, to Ringer's solution containing /sup 3/H-labeled glucose to measure the glycolytic flux (GF). The effect of the local anesthetics on LP at the indicated concentrations were similar. Lidocaine appears to depress the glycolytic flux from exogenous glucose to a lesser degree. Bupivacaine, 10 mg/L, depresses VO/sub 2/ to a greater degree thanmore » does lidocaine, 40 mg/L.« less

The effects of intravenous lipid emulsion on hemodynamic recovery and myocardial cell mitochondrial function after bupivacaine toxicity in anesthetized pigs.

PubMed

Heinonen, J A; Schramko, A A; Skrifvars, M B; Litonius, E; Backman, J T; Mervaala, E; Rosenberg, P H

2017-04-01

Local anesthetic toxicity is thought to be mediated partly by inhibition of cardiac mitochondrial function. Intravenous (i.v.) lipid emulsion may overcome this energy depletion, but doses larger than currently recommended may be needed for rescue effect. In this randomized study with anesthetized pigs, we compared the effect of a large dose, 4 mL/kg, of i.v. 20% Intralipid ® ( n = 7) with Ringer's acetate ( n = 6) on cardiovascular recovery after a cardiotoxic dose of bupivacaine. We also examined mitochondrial respiratory function in myocardial cell homogenates analyzed promptly after needle biopsies from the animals. Bupivacaine plasma concentrations were quantified from plasma samples. Arterial blood pressure recovered faster and systemic vascular resistance rose more rapidly after Intralipid than Ringer's acetate administration ( p < 0.0001), but Intralipid did not increase cardiac index or left ventricular ejection fraction. The lipid-based mitochondrial respiration was stimulated by approximately 30% after Intralipid ( p < 0.05) but unaffected by Ringer's acetate. The mean (standard deviation) area under the concentration-time curve (AUC) of total bupivacaine was greater after Intralipid (105.2 (13.6) mg·min/L) than after Ringer's acetate (88.1 (7.1) mg·min/L) ( p = 0.019). After Intralipid, the AUC of the lipid-un-entrapped bupivacaine portion (97.0 (14.5) mg·min/L) was 8% lower than that of total bupivacaine ( p < 0.0001). To conclude, 4 mL/kg of Intralipid expedited cardiovascular recovery from bupivacaine cardiotoxicity mainly by increasing systemic vascular resistance. The increased myocardial mitochondrial respiration and bupivacaine entrapment after Intralipid did not improve cardiac function.

Mechanism of inhibition of net ion transport across frog corneal epithelium by calcium channel antagonists.

PubMed

Huff, J W; Reinach, P S

1985-01-01

In the isolated bullfrog cornea, three calcium channel antagonists had dose-dependent inhibitory effects on the Cl-originated short-circuit current (SCC). Their order of decreasing potency was bepridil, verapamil and diltiazem. One millimolar diltiazem inhibited the SCC by 98% and subsequent incubation with the calcium ionophore A23187 had no restorative effect. Increasing the bathing solution Ca concentration from 0.05 to 15 mM, however, decreased diltiazem's inhibitory efficacy. This antagonist depolarized the intracellular potential difference Vsc from -54 to -18 mV (tear:reference) and the voltage divider ratio FRo decreased from 0.58 to 0.30, suggesting an increase in basolateral membrane electrical resistance. Additional indication of a basolateral membrane effect by the drug was that preincubation with 10(-5) M amphotericin B in Cl-free Ringer's did not eliminate the inhibitory effect of the drug on the Na- and K-elicited SCC. In the absence of amphotericin B in Cl-free Ringer's (SCC = 0), 1 X 10(-3) M diltiazem depolarized the Vsc from -78 to -9 mV suggesting that the increase in basolateral membrane resistance was due to K channel blockade. Diltiazem (1 X 10(-3) M) significantly decreased cyclic AMP content; however, isoproterenol in the presence of the drug increased cyclic AMP fourfold without having any restorative effect on the inhibited SCC. Therefore, the inhibition of the Cl-originated SCC resulting from an increase in basolateral membrane K resistance is not caused by a decline in cyclic AMP content.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison between human and porcine thromboelastograph parameters in response to ex-vivo changes to platelets, plasma, and red blood cells.

PubMed

Sondeen, Jill L; de Guzman, Rodolfo; Amy Polykratis, Irene; Dale Prince, Malcolm; Hernandez, Orlando; Cap, Andrew P; Dubick, Michael A

2013-12-01

In the acute care setting, both the tracings and numeric outputs (R time, angle, and MA) of thrombelastography (TEG) may be used to inform treatment decisions. The objective was to determine the sensitivity of TEG to isolated changes in platelet count, hematocrit and fibrinogen concentration in human blood. As pigs have a similar coagulation system, we also compared the responses of the pig blood. Eight volunteers (>18 years of age, no anticoagulation or nonsteroidal anti-inflammatory therapy, not pregnant) were enrolled into this study. Four female anesthetized donor pigs were instrumented percutaneously with a catheter for blood collection. All blood was collected into sodium citrate. The concentration of each component (platelets, fibrinogen, and red blood cells) was changed while keeping the other components constant by use of centrifugation or preparation of each individual's plasma into platelet poor plasma, platelet rich plasma, cryoprecipitate, purified washed platelets, and packed red blood cells as appropriate. TEG (Haemoscope) analysis was performed and compared with the patients' whole blood diluted with lactated Ringer's solution. We demonstrated that the major factor affecting the MA and angle was the platelet count. In fact, reducing platelets alone resulted in TEG profiles and parameters that were similar to lactated Ringer's dilution profiles. Swine blood responses were parallel to that of human blood, although there were offsets especially of TEG-R and angle that confirmed that the swine are hypercoagulable compared with humans. Superficially similar TEG tracing patterns can be produced by divergent mechanisms associated with altered concentrations of blood components.

Hypertonic lactated saline resuscitation reduces the risk of abdominal compartment syndrome in severely burned patients.

PubMed

Oda, Jun; Ueyama, Masashi; Yamashita, Katsuyuki; Inoue, Takuya; Noborio, Mitsuhiro; Ode, Yasumasa; Aoki, Yoshiki; Sugimoto, Hisashi

2006-01-01

Secondary abdominal compartment syndrome is a lethal complication after resuscitation from burn shock. Hypertonic lactated saline (HLS) infusion reduces early fluid requirements in burn shock, but the effects of HLS on intraabdominal pressure have not been clarified. Patients admitted to our burn unit between 2002 and 2004 with burns > or =40% of the total body surface area without severe inhalation injury were entered into a fluid resuscitation protocol using HLS (n = 14) or lactated Ringer's solution (n = 22). Urine output was monitored hourly with a goal of 0.5 to 1.0 mL/kg per hour. Hemodynamic parameters, blood gas analysis, intrabladder pressure as an indicator of intraabdominal pressure (IAP), and the peak inspiratory pressure were recorded. Pulmonary compliance and the abdominal perfusion pressure were also calculated. In the HLS group, the amount of intravenous fluid volume needed to maintain adequate urine output was less at 3.1 +/- 0.9 versus 5.2 +/- 1.2 mL/24 h per kg per percentage of total body surface area, and the peak IAP and peak inspiratory pressure at 24 hours after injury were significantly lower than those in the lactated Ringer's group. Two of 14 patients (14%) in the HLS group and 11 of 22 patients (50%) developed IAH within 20.8 +/- 7.2 hours after injury. In patients with severe burn injury, a large intravenous fluid volume decreases abdominal perfusion during the resuscitative period because of increased IAP. Our data suggest that HLS resuscitation could reduce the risk of secondary abdominal compartment syndrome with lower fluid load in burn shock patients.

Effects of PEG-PLA-nano Artificial Cells Containing Hemoglobin on Kidney Function and Renal Histology in Rats

PubMed Central

Liu, Zun Chang; Chang, Thomas M.S.

2012-01-01

This study is to investigate the long-term effects of PEG-PLA nano artificial cells containing hemoglobin (NanoRBC) on renal function and renal histology after 1/3 blood volume top loading in rats. The experimental rats received one of the following infusions: NanoRBC in Ringer lactate, Ringer lactate, stroma-free hemoglobin (SFHB), polyhemoglobin (PolyHb), autologous rat whole blood (rat RBC). Blood samples were taken before infusions and on days 1, 7 and 21 after infusions for biochemistry analysis. Rats were sacrificed on day 21 after infusions and kidneys were excised for histology examination. Infusion of SFHB induced significant decrease in renal function damage evidenced by elevated serum urea, creatinine and uric acid throughout the 21 days. Kidney histology in SFHb infusion group revealed focal tubular necrosis and intraluminal cellular debris in the proximal tubules, whereas the glomeruli were not observed damaged. In all the other groups, NanoRBC, PolyHb, Ringer lactate and rat RBC, there were no abnormalities in renal biochemistry or histology. In conclusion, injection of NanoRBC did not have adverse effects on renal function nor renal histology. PMID:18979292

[The influence of lactate Ringer solution versus hydroxyethyl starch on coagulation and fibrinolytic system in patients with septic shock].

PubMed

Lv, Jie; Zhao, Hui-ying; Liu, Fang; An, You-zhong

2012-01-01

To investigate the influence of lactate Ringer solution (RL) versus hydroxyethyl starch 130/0.4 (HES130/0.4) solution on coagulation and fibrinolytic system in the patients with septic shock. Forty-two consecutive patients with septic shock diagnosed between September 2009 and June 2011 were randomized to two study groups: RL resuscitation group (RL group) with 20 patients, and HES130/0.4 resuscitation group (HES group) with 22 patients. In all of them peripheral blood was collected at four points of time: before resuscitation, 6, 12, 24 hours after resuscitation, and then prothrombin time (PT), activated partial thromboplastin time (APTT) and levels of plasma tissue plasminogen activator (t-PA), and plasminogen activator inhibitor (PAI) were determined. Meanwhile, the patients' outcome and the length of intensive care unit stay (ICU-LOS) were recorded. ICU-LOS (days) in HES group was significantly shorter than the RL group (12.5 ± 8.8 vs. 17.1 ± 16.6, P < 0.01). Meanwhile, the volume of fluid (L: 2.77 ± 0.59) as well as vasoactive drugs [μg×kg(-1)×min(-1): 0.56 ± 0.15] used in the HES group were significantly lower than RL group (3.46 ± 0.73, 0.81 ± 0.41, both P < 0.01). In RL group, 12 patients died and 8 patients survived, while in HES group, 7 patients died and 15 patients survived, showing no difference between two groups. PT, APTT and the levels of t-PA showed no significant differences between two groups at different time points, but the levels of plasma PAI (μg/L) of the HES group decreased gradually, and was significantly lower than that before resuscitation and RL group at 24 hours after resuscitation (41.76 ± 25.95 vs. 89.11 ± 14.27, 55.08 ± 35.43, both P < 0.05). Both RL and HES130/0.4 fluid resuscitation did not affect the outcome of the patients with septic shock, but the resuscitation efficiency of HES130/0.4 is much better than RL. Both type of fluids did not show the effect on coagulability of the septic patients, but colloid fluid resuscitation may protect the vascular endothelial cell, reduce the inhibition of fibrinolytic system, and alleviate hypercoagulability state of patients in early stage.

Relationship between frequency and impedance change in an infusion rate measurement system employing a capacitance sensor - biomed 2011.

PubMed

Amano, Hikaru; Ogawa, Hidekuni; Maki, Hiromichi; Tsukamoto, Sosuke; Yonezawa, Yoshiharu; Hahn, Allen W; Caldwell, W Morton

2011-01-01

We have been searching for a suitable frequency range for an electrical impedance measurement infusion solution drip monitoring system, which we have previously reported. This electrical impedance, which is formed between two electrodes wrapped around the infusion supply polyvinyl-chloride tube and around the drip chamber, is changed by the growth and fall of each drop of fluid. Thus, the drip rate can be detected by measuring this impedance. However, many different kinds of infusion solutions such as glucose, amino acid, soya oil, and lactated Ringer’s solution are used in hospitals and care facilities. Therefore, it was necessary to find a suitable frequency for driving the capacitance-change sensor with a wide range of infusion solutions. In this study, the sensor electrical impedance change of 16 infusion solutions was measured from 1 kHz up to 1 MHz. The drip impedance produced by 5% glucose solution, 10% glucose solution and soya oil indicated the maximum sensor output change at 10 kHz, 20 kHz, and 70 kHz, respectively. The other 13 infusion solutions increased up to 10 kHz, and were constant from 10 kHz to 1 MHz. However, the growth, fall, and drip rate of the drops of all the infusion solutions were monitored by measuring the impedance change from 10 kHz to 30 kHz. Our experimental results indicated that most suitable excitation range for the infusion monitoring system is from 10 kHz to 30 kHz. Thus, we can now “fine-tune” the system for optimal sensing.

Treatment of PPROM with anhydramnion in humans: first experience with different amniotic fluid substitutes for continuous amnioinfusion through a subcutaneously implanted port system.

PubMed

Tchirikov, Michael; Bapayeva, Gauri; Zhumadilov, Zhaxybay Sh; Dridi, Yasmina; Harnisch, Ralf; Herrmann, Angelika

2013-11-01

This study aims to treat patients with preterm premature rupture of the membranes (PPROM) and anhydramnion using continuous amnioinfusion through a subcutaneously implanted port system. An amniotic fluid replacement port system was implanted in seven patients with PPROM and anhydramnion starting at the 20th week of gestation (range, 14-26 weeks) for long-term amnioinfusion. Saline solutions (2 L/day; Jonosteril(®), Sterofundin(®), isotonic NaCl 0.9% solution, lactated Ringer's solution) and a hypotonic aqueous composition with reduced chloride content similar to the electrolyte concentration of human amniotic fluid were used for the continuous amnioinfusion. The mean duration of the PPROM delivery interval continued for 49 days (range, 9-69 days), with 3 weeks of amnioinfusion via the port system (range, 4-49). The newborns showed no signs of lung hypoplasia. Long-term lavage of the amniotic cavity via a subcutaneously implanted port system in patients with PPROM and anhydramnion may help prolong the pregnancy and avoid fetal lung hypoplasia. A hypotonic aqueous composition with reduced chloride content similar to human amniotic fluid can be safely used for amnioinfusion. Prospective randomized studies are ongoing.

In vitro evaluation of the electrochemical behaviour of stainless steel and Ni-Ti orthodontic archwires at different temperatures.

PubMed

Pakshir, M; Bagheri, T; Kazemi, M R

2013-08-01

The aim of this study was to compare the electrochemical corrosion behaviour of stainless steel (SS) and nickel-titanium (Ni-Ti) orthodontic archwires in Ringer's solution at temperatures ranging from 15 to 55°C by using linear sweep voltametry and electrochemical impedance spectroscopy. Polarization curves show that the corrosion current density of SS is greater than that of Ni-Ti alloy. Since the corrosion current density is directly proportional to the corrosion rate, a great corrosion current density shows a lower resistance against corrosion. Therefore, in comparison with SS, Ni-Ti alloys have a lower corrosion rate. Results show that the temperature of the solution affects the corrosion rates of the alloys. As the temperature increases, the corrosion resistance of both of the alloys decreases, although these variations were not so large. Impedance measurements show that the electrochemical behaviour of Ni-Ti exhibits higher polarization resistance and lower capacitance, which means that passive film formed on this alloy is more homogeneous and thicker in comparison with SS. Results also show that polarization resistance of both alloys decreases slowly with increases in the temperature of the solution.

Antihistamine effect on synaptosomal uptake of serotonin, norepinephrine and dopamine

NASA Technical Reports Server (NTRS)

Brown, P. A.; Vernikos, J.

1980-01-01

A study on the effects of five H1 and H2 antihistamines on the synaptosomal uptake of serotonin (5HT), norepinephrine (NE), and dopamine (DA) is presented. Brain homogenates from female rats were incubated in Krebs-Ringer phosphate buffer solution in the presence of one of three radioactive neurotransmitters, and one of the five antihistamines. Low concentrations of pyrilamine competitively inhibited 5HT uptake, had little effect on NE uptake, and no effect on DA uptake. Promethazine, diphenhydramine, metiamide, and cimetidine had no effect on 5HT or DA uptake at the same concentration. Diphenhydramine had a small inhibitory effect on NE uptake. It is concluded that pyrilamine is a selective and potent competitive inhibitor of 5HT uptake at concentrations between .05 and .5 micromolars.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weeks, J.M.; Svendsen, C.

A simple subcellular histochemical staining technique employing the lysosomal probe neutral red has been developed for use with the epiendogeic earthworm Lumbricus rubellus Hoffmeister. Coelomocytes extracted from the coelomic cavity of earthworms into an isotonic earthworm Ringer solution were allowed to adhere to a microscope slide for 30 s before the application of a neutral red dye. This red dye was rapidly accumulated within the lysosomes. Observation of the loss of this dye from these lysosomes into the surrounding cytosol has enabled the quantification of the degree of lysosomal damage caused to earthworms with exposure to an increasing range ofmore » soil copper concentrations, in both laboratory and mesocosm studies. This simple in vitro biomarker has potential for the rapid assessment of the toxic effects to earthworms from soils contaminated with heavy metals and metalloids.« less

The Ionic Permeability Changes during Acetylcholine-Induced Responses of Aplysia Ganglion Cells

PubMed Central

Sato, Makoto; Austin, George; Yai, Hideko; Maruhashi, Juro

1968-01-01

ACh-induced depolarization (D response) in D cells markedly decreases as the external Na+ is reduced. However, when Na+ is completely replaced with Mg++, the D response remains unchanged. When Na+ is replaced with Tris(hydroxymethyl)aminomethane, the D response completely disappears, except for a slight decrease in membrane resistance. ACh-induced hyperpolarization (H response) in H cells is markedly depressed as the external Cl- is reduced. Frequently, the reversal of the H response; i.e., depolarization, is observed during perfusion with Cl--free media. In cells which show both D and H responses superimposed, it was possible to separate these responses from each other by perfusing the cells with either Na+-free or Cl--free Ringer's solution. High [K+]0 often caused a marked hyperpolarization in either D or H cells. This is due to the primary effect of high [K+]0 on the presynaptic inhibitory fibers. The removal of this inhibitory afferent interference by applying Nembutal readily disclosed the predicted K+ depolarization. In perfusates containing normal [Na+]0, the effects of Ca++ and Mg++ on the activities of postsynaptic membrane were minimal, supporting the current theory that the effects of these ions on the synaptic transmission are mainly presynaptic. The possible mechanism of the hyperpolarization produced by simultaneous perfusion with both high [K+]0 and ACh in certain H cells is explained quantitatively under the assumption that ACh induces exclusively an increase in Cl- permeability of the H membrane. PMID:5648831

Analysis of Variability in Intraoperative Fluid Administration for Colorectal Surgery: An Argument for Goal-Directed Fluid Therapy.

PubMed

Quinn, Timothy D; Brovman, Ethan Y; Urman, Richard D

2017-09-01

Fluid therapy in the perioperative period varies greatly between anesthesia providers and may have a negative impact on surgical outcomes. We conducted a retrospective analysis of 705 elective colorectal cases consisting of colectomies, ileocolic resections, and low anterior resections at an academic institution from January 1, 2010 to May 29, 2015, collected by our electronic medical record before implementation of Enhanced Recovery After Surgery (ERAS ® ) pathways. The mean for total crystalloid administration was 2578 mL with a standard deviation (SD) that was approximately 50% of the mean value. A combination of both normal saline and lactated Ringer's solution was used in almost all cases without a clear rationale for fluid choice. Fluid administered to patients was disproportional to measured intraoperative fluid losses (estimated blood loss and urine output) by a factor of 10. The average rate of fluid given was 1050 mL/h with an SD of nearly the same amount (951 mL). There was a variability of over 67% in total crystalloid administered based on both ideal body weight and total body weight. We found that a wide variability in the amount and type of fluid therapy administered existed at our institution before implementation of a colorectal ERAS pathway or routine use of goal-directed fluid therapy (GDFT). ERAS pathways with GDFT protocols could lead to more rational and consistent fluid therapy leading to improved outcomes.

Development of β Type Ti23Mo-45S5 Bioglass Nanocomposites for Dental Applications

PubMed Central

Jurczyk, Karolina; Miklaszewski, Andrzej; Jurczyk, Mieczyslawa U.; Jurczyk, Mieczyslaw

2015-01-01

Titanium β-type alloys attract attention as biomaterials for dental applications. The aim of this work was the synthesis of nanostructured β type Ti23Mo-x wt % 45S5 Bioglass (x = 0, 3 and 10) composites by mechanical alloying and powder metallurgy methods and their characterization. The crystallization of the amorphous material upon annealing led to the formation of a nanostructured β type Ti23Mo alloy with a grain size of approximately 40 nm. With the increase of the 45S5 Bioglass contents in Ti23Mo, nanocomposite increase of the α-phase is noticeable. The electrochemical treatment in phosphoric acid electrolyte resulted in a porous surface, followed by bioactive ceramic Ca-P deposition. Corrosion resistance potentiodynamic testing in Ringer solution at 37 °C showed a positive effect of porosity and Ca-P deposition on nanostructured Ti23Mo 3 wt % 45S5 Bioglass nanocomposite. The contact angles of glycerol on the nanostructured Ti23Mo alloy were determined and show visible decrease for bulk Ti23Mo 3 wt % 45S5 Bioglass and etched Ti23Mo 3 wt % 45S5 Bioglass nanocomposites. In vitro tests culture of normal human osteoblast cells showed very good cell proliferation, colonization, and multilayering. The present study demonstrated that porous Ti23Mo 3 wt % 45S5 Bioglass nanocomposite is a promising biomaterial for bone tissue engineering. PMID:28793695

Randomized Double-blind Trial of Ringer Lactate Versus Normal Saline in Pediatric Acute Severe Diarrheal Dehydration.

PubMed

Kartha, Gayathri Bhuvaneswaran; Rameshkumar, Ramachandran; Mahadevan, Subramanian

2017-12-01

The aim of this study was to compare the effectiveness of Ringer lactate (RL) versus normal saline (NS) in the correction of pediatric acute severe diarrheal dehydration, as measured by improvement in clinical status and pH (≥7.35). A total of 68 children ages 1 month to 12 years with acute severe diarrheal dehydration (World Health Organization [WHO] classification) were randomized into RL (n = 34) and NS groups (n = 34) and received 100 mL/kg of the assigned intravenous fluid according to WHO PLAN-C for the management of diarrheal dehydration. The primary outcome was an improvement in clinical status and pH (≥7.35) at the end of 6 hours. Secondary outcomes were changes in serum electrolytes, renal and blood gas parameters, the volume of fluid required for dehydration correction excluding the first cycle, time to start oral feeding, hospital stay, and cost-effectiveness analysis. Primary outcome was achieved in 38% versus 23% (relative risk = 1.63, 95% confidence interval 0.80-3.40) in RL and NS groups, respectively. No significant differences were observed in secondary outcomes in electrolytes, renal, and blood gas parameters. None required second cycle of dehydration correction. Median (interquartile range) time to start oral feeding (1.0 [0.19-2.0] vs 1.5 [0.5-2.0] hours) and hospital stay (2.0 [1.0-2.0] vs 2.0 [2.0-2.0] days) was similar. The median total cost was higher in RL than NS group ((Equation is included in full-text article.)120 [(Equation is included in full-text article.)120-(Equation is included in full-text article.)180] vs (Equation is included in full-text article.)55 [(Equation is included in full-text article.)55-(Equation is included in full-text article.)82], P ≤ 0.001). In pediatric acute severe diarrheal dehydration, resuscitation with RL and NS was associated with similar clinical improvement and biochemical resolution. Hence, NS is to be considered as the fluid of choice because of the clinical improvement, cost, and availability.

Action of polysaccharides of similar average mass but differing molecular volume and charge on fluid drainage through synovial interstitium in rabbit knees

PubMed Central

Scott, D; Coleman, P J; Mason, R M; Levick, J R

2000-01-01

Hyaluronan (HA), an anionic polysaccharide of synovial fluid, attenuates fluid loss from joints as joint pressure is raised (‘outflow buffering’). The buffering is thought to depend on the expanded molecular domain of the polymer, which causes reflection by synovial extracellular matrix, leading to flow-dependent concentration polarization. We therefore assessed the effects of polysaccharides of differing average molecular volume and charge. Trans-synovial fluid drainage(Q̇s) was measured at controlled joint fluid pressure (Pj) in knees of anaesthetized rabbits. The joints were infused with polydisperse HA of weight-average mass 2100 kDa (4 mg ml−1, n = 17), with polydisperse neutral dextran of similar average mass (2000 kDa; n = 7) or with Ringer solution vehicle (n = 2). The role of polymer charge was assessed by infusions of neutral or sulphated dextran of average molecular mass 500 kDa (n = 6). When HA was present, Q̇s increased little with pressure, forming a virtual plateau of ∼4 μl min−1 from 10 to 25 cmH2O. Neutral dextran 2000 failed to replicate this effect. Instead, Q̇s increased steeply with Pj, reaching eight times the HA value by 20 cmH2O (P = 0.0001, ANOVA). Dextran 2000 reduced flows in comparison with Ringer solution. Analysis of the aspirated joint fluid showed that 31 ± 0.07 % (s.e.m.) of dextran 2000 in the filtrand was reflected by synovium, compared with ≥ 79 % for HA. The viscometric molecular radius of the dextran, ∼31 nm, was smaller than that of HA (101–181 nm), as was its osmotic pressure. Anionic dextran 500 failed to buffer fluid drainage, but it reduced fluid escape and synovial conductance dQ̇s/dPj more than neutral dextran 500 (P < 0.0001, ANOVA). The anionic charge increased the molecular volume and viscosity of dextran 500. The results support the hypothesis that polymer molecular volume influences its reflection by interstitial matrix and outflow buffering. Polymer charge influences flow through an effect on viscosity and possibly electrostatic interactions with negatively charged interstitial matrix. PMID:11060134

Prevalence, Timing, Causes, and Outcomes of Hyponatremia in Hospitalized Orthopaedic Surgery Patients.

PubMed

Hennrikus, Eileen; Ou, George; Kinney, Bradley; Lehman, Erik; Grunfeld, Robert; Wieler, Jane; Damluji, Abdulla; Davis, Charles; Mets, Berend

2015-11-18

Hyponatremia is common among orthopaedic patients and is associated with adverse clinical outcomes. We examined the prevalence, timing, causes, and outcomes of hyponatremia in adult hospitalized orthopaedic surgery patients. We evaluated the medical records of 1067 consecutive orthopaedic surgery patients admitted to a tertiary academic institution. The medical records were reviewed to investigate hyponatremia (serum sodium <135 mEq/L) that (1) had been present on hospital admission or (2) had developed postoperatively. The primary outcomes were the prevalence and timing of, and risk factors for, presentation with or development of hyponatremia. Secondary outcomes were hospital length of stay, total hospital cost, and discharge disposition. Multivariable logistic regression models were used to assess the variables associated with hyponatremia and the effects of hyponatremia on clinical outcomes. Of the 1067 patients, seventy-one (7%) had preoperative hyponatremia and 319 (30%) developed hyponatremia postoperatively. Of the latter, 298 (93%) developed hyponatremia within forty-eight hours postoperatively. Compared with patients with normonatremia, those who presented with hyponatremia, on the average, were older (67.2 versus 60.5 years, p < 0.001), had longer hospital stays (4.6 versus 3.3 days, p < 0.001), incurred higher hospital costs ($19,200 versus $17,000, p = 0.006), and were more likely to be discharged to an extended-care facility (odds ratio [OR] = 2.87, p < 0.001). Developing hyponatremia postoperatively resulted, on average, in a longer hospital stay (3.7 versus 3.3 days, p = 0.002) and greater hospital cost ($18,800 versus $17,000, p < 0.001). Age (OR = 1.13 per decade, p = 0.012), spine surgery (OR = 2.76 versus knee, p < 0.001), hip surgery (OR = 1.76 versus knee, p < 0.001), and the amount of lactated Ringer solution used (OR = 1.16, p = 0.002) increased the risk of developing hyponatremia. Hyponatremia in orthopaedic patients is associated with longer, costlier hospitalizations. The factors that significantly increased the risk of developing postoperative hyponatremia were an older age, spine fusion, hip arthroplasty, and the amount of lactated Ringer solution used. Copyright © 2015 by The Journal of Bone and Joint Surgery, Incorporated.

In vitro corrosion behaviour of Ti-Nb-Sn shape memory alloys in Ringer's physiological solution.

PubMed

Rosalbino, F; Macciò, D; Scavino, G; Saccone, A

2012-04-01

The nearly equiatomic Ni-Ti alloy (Nitinol) has been widely employed in the medical and dental fields owing to its shape memory or superelastic properties. The main concern about the use of this alloy derives form the fact that it contains a large amount of nickel (55% by mass), which is suspected responsible for allergic, toxic and carcinogenic reactions. In this work, the in vitro corrosion behavior of two Ti-Nb-Sn shape memory alloys, Ti-16Nb-5Sn and Ti-18Nb-4Sn (mass%) has been investigated and compared with that of Nitinol. The in vitro corrosion resistance was assessed in naturally aerated Ringer's physiological solution at 37°C by corrosion potential and electrochemical impedance spectroscopy (EIS) measurements as a function of exposure time, and potentiodynamic polarization curves. Corrosion potential values indicated that both Ni-Ti and Ti-Nb-Sn alloys undergo spontaneous passivation due to spontaneously formed oxide film passivating the metallic surface, in the aggressive environment. It also indicated that the tendency for the formation of a spontaneous oxide is greater for the Ti-18Nb-5Sn alloy. Significantly low anodic current density values were obtained from the polarization curves, indicating a typical passive behaviour for all investigated alloys, but Nitinol exhibited breakdown of passivity at potentials above approximately 450 mV(SCE), suggesting lower corrosion protection characteristics of its oxide film compared to the Ti-Nb-Sn alloys. EIS studies showed high impedance values for all samples, increasing with exposure time, indicating an improvement in corrosion resistance of the spontaneous oxide film. The obtained EIS spectra were analyzed using an equivalent electrical circuit representing a duplex structure oxide film, composed by an outer and porous layer (low resistance), and an inner barrier layer (high resistance) mainly responsible for the alloys corrosion resistance. The resistance of passive film present on the metals' surface increases with exposure time displaying the highest values to Ti-18Nb-4Sn alloy. All these electrochemical results suggest that Ti-Nb-Sn alloys are promising materials for biomedical applications.

Resveratrol ameliorates mitochondrial dysfunction but increases the risk of hypoglycemia following hemorrhagic shock.

PubMed

Wang, Hao; Guan, Yuxia; Widlund, Anne Lykkegaard; Becker, Lance B; Baur, Joseph A; Reilly, Patrick M; Sims, Carrie A

2014-12-01

Hemorrhagic shock (HS) may contribute to organ failure, by profoundly altering mitochondrial function. Resveratrol (RSV), a naturally occurring polyphenol, has been shown to promote mitochondrial function and regulate glucose homeostasis in diabetes. We hypothesized that RSV during resuscitation would ameliorate HS-induced mitochondrial dysfunction and improve hyperglycemia following acute blood loss. With the use a decompensated HS model, male Long-Evans rats (n = 6 per group) were resuscitated with lactated Ringer's solution with or without RSV (30 mg/kg) and were killed before hemorrhage (sham), at severe shock, following resuscitation, and 18 hours after resuscitation. At each time point, the liver and kidney mitochondria were isolated to assess individual respiratory complexes (CI, CII, and CIV) and the production of reactive oxygen species (ROS). Blood samples were assayed for glucose, insulin, corticosterone, total glucagon-like peptide (GLP-1), glucagon, and serum cytokine levels. The Homeostatic Model Assessment-Insulin Resistance index was used to quantify insulin resistance. RSV supplementation following HS significantly improved mitochondrial function and decreased mitochondrial ROS production in both liver and kidney. RSV-treated animals had significantly lower blood glucose levels following resuscitation when compared with sham animals (116.0 ± 20.2 mg/dL vs. 227.7 ± 8.3 mg/dL, p < 0.05) or those resuscitated with lactated Ringer's solution (116.0 ± 20.2 mg/dL vs. 359.0 ± 79.5 mg/dL, p < 0.05). RSV supplementation was associated with significantly decreased plasma insulin levels (1.0 ± 0.4 ng/mL vs. 6.5 ± 3.7 ng/mL, p < 0.05), increased total GLP-1 levels (385.8 ± 56.6 ng/mL vs. 187.3 ± 11.1 ng/mL, p < 0.05), and a lower natural Log Homeostatic Model Assessment-Insulin Resistance index (1.30 ± 0.42 vs. 4.18 ± 0.68, p < 0.05) but had minimal effect on plasma corticosterone, glucagon, or cytokine levels. Resuscitation with RSV restores mitochondrial function and decreases insulin resistance but may be associated with increased hypoglycemia. The observed antiglycemic effects of RSV may be mediated by decreased mitochondrial ROS and increased GLP-1 secretion.

Complete human serum maintains viability and chondrogenic potential of human synovial stem cells: suitable conditions for transplantation.

PubMed

Mizuno, Mitsuru; Katano, Hisako; Otabe, Koji; Komori, Keiichiro; Kohno, Yuji; Fujii, Shizuka; Ozeki, Nobutake; Horie, Masafumi; Tsuji, Kunikazu; Koga, Hideyuki; Muneta, Takeshi; Sekiya, Ichiro

2017-06-13

In our clinical practice, we perform transplantations of autologous synovial mesenchymal stem cells (MSCs) for cartilage and meniscus regenerative medicine. One of the most important issues to ensuring clinical efficacy involves the transport of synovial MSCs from the processing facility to the clinic. Complete human serum (100% human serum) is an attractive candidate material in which to suspend synovial MSCs for their preservation during transport. The purpose of this study was to investigate whether complete human serum maintained MSC viability and chondrogenic potential and to examine the optimal temperature conditions for the preservation of human synovial MSCs. Human synovium was harvested from the knees of 14 donors with osteoarthritis during total knee arthroplasty. Passage 2 synovial MSCs were suspended at 2 million cells/100 μL in Ringer's solution or complete human serum at 4, 13, and 37 °C for 48 h. These cells were analyzed for live cell rates, cell surface marker expression, metabolic activity, proliferation, and adipogenic, calcification, and chondrogenic differentiation potentials before and after preservation. After preservation, synovial MSCs maintained higher live cell rates in human serum than in Ringer's solution at 4 and 13 °C. Synovial MSCs preserved in human serum at 4 and 13 °C also maintained high ratios of propidium iodide - and annexin V - cells. MSC surface marker expression was not altered in cells preserved at 4 and 13 °C. The metabolic activities of cells preserved in human serum at 4 and 13 °C was maintained, while significantly reduced in other conditions. Replated MSCs retained their proliferation ability when preserved in human serum at 4 and 13 °C. Adipogenesis and calcification potential could be observed in cells preserved in each condition, whereas chondrogenic potential was retained only in cells preserved in human serum at 4 and 13 °C. The viability and chondrogenic potential of synovial MSCs were maintained when the cells were suspended in human serum at 4 and 13 °C.

Hextend and 7.5% hypertonic saline with Dextran are equivalent to Lactated Ringer's in a swine model of initial resuscitation of uncontrolled hemorrhagic shock.

PubMed

Riha, Gordon M; Kunio, Nicholas R; Van, Philbert Y; Hamilton, Gregory J; Anderson, Ross; Differding, Jerome A; Schreiber, Martin A

2011-12-01

The optimal fluid strategy for the early treatment of trauma patients remains highly debated. Our objective was to determine the efficacy of an initial bolus of resuscitative fluids used in military and civilian settings on the physiologic response to uncontrolled hemorrhagic shock in a prospective, randomized, blinded animal study. Fifty anesthetized swine underwent central venous and arterial catheterization followed by celiotomy. Grade V liver injury was performed, followed by 30 minutes of uncontrolled hemorrhage. Then, liver packing was completed, and fluid resuscitation was initiated over 12 minutes with 2 L normal saline (NS), 2 L Lactated Ringer's (LR), 250 mL 7.5% hypertonic saline with 3% Dextran (HTS), 500 mL Hextend (HEX), or no fluid (NF). Animals were monitored for 2 hours postinjury. Blood loss after initial hemorrhage, mean arterial pressure (MAP), tissue oxygen saturation (StO2), hematocrit, pH, base excess, and lactate were measured at baseline, 1 hour, and 2 hours. NF group had less post-treatment blood loss compared with other groups. MAP and StO2 for HEX, HTS, and LR at 1 hour and 2 hours were similar and higher than NF. MAP and StO2 did not differ between NS and NF, but NS resulted in decreased pH and base excess. Withholding resuscitative fluid results in the least amount of posttreatment blood loss. In clinically used volumes, HEX and HTS are equivalent to LR with regard to physiologic outcomes and superior to NF. NS did not provide a measurable improvement in outcome compared with NF and resulted in increased acidosis.

Lubiprostone activates non-CFTR-dependent respiratory epithelial chloride secretion in cystic fibrosis mice

PubMed Central

MacDonald, Kelvin D.; McKenzie, Karen R.; Henderson, Mark J.; Hawkins, Charles E.; Vij, Neeraj; Zeitlin, Pamela L.

2008-01-01

Periciliary fluid balance is maintained by the coordination of sodium and chloride channels in the apical membranes of the airways. In the absence of the cystic fibrosis transmembrane regulator (CFTR), chloride secretion is diminished and sodium reabsorption exaggerated. ClC-2, a pH- and voltage-dependent chloride channel, is present on the apical membranes of airway epithelial cells. We hypothesized that ClC-2 agonists would provide a parallel pathway for chloride secretion. Using nasal potential difference (NPD) measurements, we quantified lubiprostone-mediated Cl− transport in sedated cystic fibrosis null (gut-corrected), C57Bl/6, and A/J mice during nasal perfusion of lubiprostone (a putative ClC-2 agonist). Baseline, amiloride-inhibited, chloride-free gluconate-substituted Ringer with amiloride and low-chloride Ringer plus lubiprostone (at increasing concentrations of lubiprostone) were perfused, and the NPD was continuously recorded. A clear dose-response relationship was detected in all murine strains. The magnitude of the NPD response to 20 μM lubiprostone was −5.8 ± 2.1 mV (CF, n = 12), −8.1 ± 2.6 mV (C57Bl/6 wild-type, n = 12), and −5.3 ± 1.2 mV (AJ wild-type, n = 8). A cohort of ClC-2 knockout mice did not respond to 20 μM lubiprostone (n = 6, P = 0.27). In C57Bl/6 mice, inhibition of CFTR with topical application of CFTR inhibitor-172 did not abolish the lubiprostone response, thus confirming the response seen is independent of CFTR regulation. RT-PCR confirmed expression of ClC-2 mRNA in murine lung homogenate. The direct application of lubiprostone in the CF murine nasal airway restores nearly normal levels of chloride secretion in nasal epithelia. PMID:18805957

Lubiprostone activates non-CFTR-dependent respiratory epithelial chloride secretion in cystic fibrosis mice.

PubMed

MacDonald, Kelvin D; McKenzie, Karen R; Henderson, Mark J; Hawkins, Charles E; Vij, Neeraj; Zeitlin, Pamela L

2008-11-01

Periciliary fluid balance is maintained by the coordination of sodium and chloride channels in the apical membranes of the airways. In the absence of the cystic fibrosis transmembrane regulator (CFTR), chloride secretion is diminished and sodium reabsorption exaggerated. ClC-2, a pH- and voltage-dependent chloride channel, is present on the apical membranes of airway epithelial cells. We hypothesized that ClC-2 agonists would provide a parallel pathway for chloride secretion. Using nasal potential difference (NPD) measurements, we quantified lubiprostone-mediated Cl(-) transport in sedated cystic fibrosis null (gut-corrected), C57Bl/6, and A/J mice during nasal perfusion of lubiprostone (a putative ClC-2 agonist). Baseline, amiloride-inhibited, chloride-free gluconate-substituted Ringer with amiloride and low-chloride Ringer plus lubiprostone (at increasing concentrations of lubiprostone) were perfused, and the NPD was continuously recorded. A clear dose-response relationship was detected in all murine strains. The magnitude of the NPD response to 20 muM lubiprostone was -5.8 +/- 2.1 mV (CF, n = 12), -8.1 +/- 2.6 mV (C57Bl/6 wild-type, n = 12), and -5.3 +/- 1.2 mV (AJ wild-type, n = 8). A cohort of ClC-2 knockout mice did not respond to 20 muM lubiprostone (n = 6, P = 0.27). In C57Bl/6 mice, inhibition of CFTR with topical application of CFTR inhibitor-172 did not abolish the lubiprostone response, thus confirming the response seen is independent of CFTR regulation. RT-PCR confirmed expression of ClC-2 mRNA in murine lung homogenate. The direct application of lubiprostone in the CF murine nasal airway restores nearly normal levels of chloride secretion in nasal epithelia.

Knowledge, attitude, and concussion-reporting behaviors among high school athletes: a preliminary study.

PubMed

Register-Mihalik, Johna K; Guskiewicz, Kevin M; McLeod, Tamara C Valovich; Linnan, Laura A; Mueller, Frederick O; Marshall, Stephen W

2013-01-01

Many athletes continue to participate in practices and games while experiencing concussion-related symptoms, potentially predisposing them to subsequent and more complicated brain injuries. Limited evidence exists about factors that may influence concussion-reporting behaviors. To examine the influence of knowledge and attitude on concussion-reporting behaviors in a sample of high school athletes. Cross-sectional study. Participants completed a validated survey instrument via mail. A total of 167 high school athletes (97 males, 55 females, 5 sex not indicated; age = 15.7 ± 1.4 years) participating in football, soccer, lacrosse, or cheerleading. Athlete knowledge and attitude scores served as separate predictor variables. We examined the proportion of athletes who reported continuing to participate in games and practices while symptomatic from possible concussion and the self-reported proportion of recalled concussion and bell-ringer events disclosed after possible concussive injury. Only 40% of concussion events and 13% of bell-ringer recalled events in the sample were disclosed after possible concussive injury. Increased athlete knowledge of concussion topics (increase of 1 standard deviation = 2.8 points) was associated with increased reporting prevalence of concussion and bell-ringer events occurring in practice (prevalence ratio [PR] = 2.27, 95% confidence interval [CI] = 1.60, 3.21) and the reporting prevalence of bell-ringer-only events overall (PR = 1.87, 95% CI = 1.38, 2.54). Athlete attitude scores (increase of 1 standard deviation = 11.5 points) were associated with decreases in the proportion of athletes stating they participated in games (PR = 0.74, 95% CI = 0.66, 0.82) and practices (PR = 0.67, 95% CI = 0.59, 0.77) while symptomatic from concussions. Most recalled concussion events in our study were not reported to a supervising adult. Clinicians should be aware that knowledge and attitude influence concussion reporting. Clinicians and administrators should make concussion education a priority and encourage an optimal reporting environment to better manage and prevent concussive injuries in young athletes.

Self-Propelled Dressings Containing Thrombin and Tranexamic Acid Improve Short-Term Survival in a Swine Model of Lethal Junctional Hemorrhage.

PubMed

Baylis, James R; St John, Alexander E; Wang, Xu; Lim, Esther B; Statz, Matthew L; Chien, Diana; Simonson, Eric; Stern, Susan A; Liggins, Richard T; White, Nathan J; Kastrup, Christian J

2016-09-01

Hemorrhage is the leading cause of preventable death in trauma, and hemorrhage from noncompressible junctional anatomic sites is particularly difficult to control. The current standard is QuikClot Combat Gauze packing, which requires 3 min of compression. We have created a novel dressing with calcium carbonate microparticles that can disperse and self-propel upstream against flowing blood. We loaded these microparticles with thrombin and tranexamic acid and tested their efficacy in a swine arterial bleeding model without wound compression. Anesthetized immature female swine received 5 mm femoral arteriotomies to induce severe junctional hemorrhage. Wounds were packed with kaolin-based QuikClot Combat Gauze (KG), propelled thrombin-microparticles with protonated tranexamic acid (PTG), or a non-propelling formulation of the same thrombin-microparticles with non-protonated tranexamic acid (NPTG). Wounds were not compressed after packing. Each animal then received one 15 mL/kg bolus of hydroxyethyl starch solution followed by Lactated Ringer as needed for hypotension (maximum: 100 mL/kg) for up to 3 h. Survival was improved with PTG (3-h survival: 8/8, 100%) compared with KG (3/8, 37.5%) and NPTG (2/8, 25%) (P <0.01). PTG animals maintained lower serum lactate and higher hemoglobin concentrations than NPTG (P <0.05) suggesting PTG decreased severity of subsequent hemorrhagic shock. However, total blood loss, Lactated Ringer infusion volumes, and mean arterial pressures of surviving animals were not different between groups (P >0.05). Thus, in this swine model of junctional arterial hemorrhage, gauze with self-propelled, prothrombotic microparticles improved survival and 2 indicators of hemorrhagic shock when applied without compression, suggesting this capability may enable better treatment of non-compressible junctional wounds.

Accuracy of noninvasive haemoglobin measurement by pulse oximetry depends on the type of infusion fluid.

PubMed

Bergek, Christian; Zdolsek, Joachim H; Hahn, Robert G

2012-12-01

Measurement of blood haemoglobin concentration by pulse oximetry could be of value in determining when erythrocytes should be transfused during surgery, but the effect of infusion fluids on the results is unclear. To study the effect of crystalloid and colloid fluid on the accuracy (bias) and precision of pulse oximetry haemoglobin estimation to indicate the venous haemoglobin concentration in volunteers. Open interventional crossover study. Single university hospital. Ten male volunteers aged 18-28 (mean 22) years. Each volunteer underwent three infusion experiments on separate days and in random order. The infusions were Ringer's acetate (20 ml kg), hydroxyethyl starch 130/0.4 (10 ml kg) and a combination of both. At the end of the infusions of Ringer's acetate, pulse oximetry haemoglobin concentration had decreased more than the true haemoglobin concentration (15 vs. 8%; P < 0.005; n = 10) whereas starch solution decreased pulse oximetry haemoglobin concentration less than true haemoglobin concentration (7 vs. 11%; P < 0.02; n = 20). The same differences were seen when the fluids were infused separately and when they were combined. The overall difference between all 956 pairs of pulse oximetry haemoglobin concentration and true haemoglobin concentrations (the bias) averaged only -0.7 g l whereas the 95% prediction interval was wide, ranging from -24.9 to 23.7 g l. In addition to the choice of infusion fluid, the bias was strongly dependent on the volunteer (each factor, P < 0.001). The bias of measuring haemoglobin concentration by pulse oximetry is dependent on whether a crystalloid or a colloid fluid is infused. Trial registration ClinicalTrials identifier: NCT01195025.

Prevention of altered hemodynamics after spinal anesthesia: A comparison of volume preloading with tetrastarch, succinylated gelatin and ringer lactate solution for the patients undergoing lower segment caesarean section

PubMed Central

Mitra, Tapobrata; Das, Anjan; Majumdar, Saikat; Bhattacharyya, Tapas; Mandal, Rahul Deb; Hajra, Bimal Kumar

2014-01-01

Background: Spinal anesthesia has replaced general anesthesia in obstetric practice. Hemodynamic instability is a common, but preventable complication of spinal anesthesia. Preloading the circulation with intravenous fluids is considered a safe and effective method of preventing hypotension following spinal anesthesia. We had conducted a study to compare the hemodynamic stability after volume preloading with either Ringer's lactate (RL) or tetrastarch hydroxyethyl starch (HES) or succinylated gelatin (SG) in the patients undergoing cesarean section under spinal anesthesia. Materials and Methods: It was a prospective, double-blinded and randomized controlled study. Ninety six ASA-I healthy, nonlaboring parturients were randomly divided in 3 groups HES, SG, RL (n = 32 each) and received 10 ml/kg HES 130/0.4; 10 ml/kg SG (4% modified fluid gelatin) and 20 ml/kg RL respectively prior to SA scheduled for cesarean section. Heart rate, blood pressure (BP), oxygen saturation was measured. Results: The fall in systolic blood pressure (SBP) (<100 mm Hg) noted among 5 (15.63%), 12 (37.5%) and 14 (43.75%) parturients in groups HES, SG, RL respectively. Vasopressor (phenylephrine) was used to treat hypotension when SBP <90 mm Hg. Both the results and APGAR scores were comparable in all the groups. Lower preloading volume and less intra-operative vasopressor requirement was noted in HES group for maintaining BP though it has no clinical significance. Conclusion: RL which is cheap, physiological and widely available crystalloid can preload effectively and maintain hemodynamic stability well in cesarean section and any remnant hypotension can easily be manageable with vasopressor. PMID:25422601

Nutritional support for treatment of hepatic lipidosis in a llama.

PubMed

Van Saun, R J; Callihan, B R; Tornquist, S J

2000-11-15

A 3-year-old female llama that was 3 months into her first lactation and 10 weeks pregnant was evaluated for anorexia of 24 hours' duration. On physical examination, the llama was in lateral recumbency, bradycardic, tachypneic, and hyperthermic. Palpation per rectum confirmed the presence of a possible dry fecal mass in the spiral colon. A tissue biopsy specimen of the liver was obtained, and histologic examination revealed moderate diffuse lipid accumulation within the hepatocytes. Lactated Ringer's solution was administered for rehydration, and partial parenteral nutrition was then initiated. Hepatic lipidosis is a disease characterized by abnormal accumulation of lipid in the liver and is associated with high mortality in camelids. Anorexia associated with hepatic lipidosis promotes further lipid mobilization and fatty infiltration of the liver. Partial parenteral nutrition with enteral supplementation may be used to maintain adequate energy intake and minimize further lipid mobilization. The distinctive metabolism of camelids may require higher amino acid supplementation relative to nonprotein calories in parenteral solutions than those traditionally provided to other species. Treatment with insulin may be effective

Analysis of friction between articular cartilage and polyvinyl alcohol hydrogel artificial cartilage.

PubMed

Li, Feng; Wang, Anmin; Wang, Chengtao

2016-05-01

Many biomaterials are being used to repair damaged articular cartilage. In particular, poly vinyl alcohol hydrogel has similar mechanical properties to natural cartilage under compressive and shearing loading. Here, three-factor and two-level friction experiments and long-term tests were conducted to better evaluate its tribological properties. The friction coefficient between articular cartilage and the poly vinyl alcohol hydrogel depended primarily on the three factors of load, speed, and lubrication. When the speed increased from 10 to 20 mm/s under a load of 10 N, the friction coefficient increased from 0.12 to 0.147. When the lubricant was changed from Ringer's solution to a hyaluronic acid solution, the friction coefficient decreased to 0.084 with loads as high as 22 N. The poly vinyl alcohol hydrogel was severely damaged and lost its top surface layers, which were transferred to the articular cartilage surface. Wear was observed in the surface morphologies, which indicated the occurrence of surface adhesion of bovine cartilage. Surface fatigue and adhesive wear was the dominant wear mechanism.

In vitro effects of some herbs used in Egyptian traditional medicine on viability of protoscolices of hydatid cysts.

PubMed

Yones, Doaa A; Taher, Gamal A; Ibraheim, Zedan Z

2011-09-01

The present work evaluated the effects of alcoholic extracts of salvia (Salvia officinalis), thyme (Thymus vulgaris), and 2 pure compounds (thymol and menthol) on the viability of Echinococcus granulosus protoscolices in vitro. Four different concentrations of each extract (2,500, 1,500, 1,000, and 500 µg/ml) and 3 different concentrations each of thymol and menthol (50, 10, and 1 µg/ml) were used. Concentration of 2,500 µg/ml of both extracts showed a significant protoscolicidal activity on the 6th day. Complete loss of viability of protoscolices occurred with 500 µg/ml concentration of both extracts at day 6 and day 7 post-treatment (PT), respectively. Pure compounds, i.e., menthol and thymol, showed potent effects with 50 µg/ml concentration at day 2 and day 5 PT, respectively. These effects were compared with those of albendazole sulfoxide (800 µg/ml), a commonly used treatment drug for hydatidosis. Krebs-Ringer solution and the hydatid cystic fluid at a ratio of 4:1 was a good preservative solution which kept the protoscolices viable for 15 days.

Microwave effects on isolated chick embryo hearts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caddemi, A.; Tamburello, C.C.; Zanforlin, L.

1986-01-01

This study was designed to examine the effects of microwaves on the electric activity of hearts as a means of elucidating interactive mechanisms of nonionizing radiation with cardiac tissue. Experiments were performed on isolated hearts of 9-12-day-old chick embryos placed in small petri dishes. Oxygenated isotonic Ringer's solution at 37 degrees C permitted heart survival. Samples were irradiated at 2.45 GHz with a power density of 3 mW/cm2. The heart signal was detected with a glass micropipet inserted into the sinoatrial node and examined by means of a Berg-Fourier analyzer. Pulsed microwaves caused the locking of the heartbeat to themore » modulation frequency, whereas continuous wave irradiation might have induced slight bradycardia. Pulsed fields induced stimulation or regularization of the heartbeat in arrhythmia, fibrillation, or arrest of the heart.« less

NaCl and water responses across the frog tongue epithelium in vitro.

PubMed

Soeda, H; Sakudo, F

1990-01-01

Isolated dorsal epithelium of the frog tongue elicited transepithelial NaCl and water responses across the tissue when NaCl was added to or removed from the adapting Ringer solution in the mucosal surface, respectively. The NaCl response which was a negative polarization in the mucosa with respect to the serosa was associated with a decrease in resistance across the tissue, whereas the water response which was a positive polarization was associated with an increase in the resistance. The decrease and increase in the tissue resistance remained unchanged by various polarizations of the transepithelial potential difference across the tissue. Characteristics of the NaCl and water responses were similar in many respects to those in the taste cells and nerves of frogs. Thus the NaCl and water responses may relate to taste reception.

An all-silicone zoom lens in an optical imaging system

NASA Astrophysics Data System (ADS)

Zhao, Cun-Hua

2013-09-01

An all-silicone zoom lens is fabricated. A tunable metal ringer is fettered around the side edge of the lens. A nylon rope linking a motor is tied, encircling the notch in the metal ringer. While the motor is operating, the rope can shrink or release to change the focal length of the lens. A calculation method is developed to obtain the focal length and the zoom ratio. The testing is carried out in succession. The testing values are compared with the calculated ones, and they tally with each other well. Finally, the imaging performance of the all-silicone lens is demonstrated. The all-silicone lens has potential uses in cellphone cameras, notebook cameras, micro monitor lenses, etc.

Fibrinolytic preflush upon liver retrieval from non-heart beating donors to enhance postpreservation viability and energetic recovery upon reperfusion.

PubMed

Minor, T; Hachenberg, A; Tolba, R; Pauleit, D; Akbar, S

2001-06-27

Our objective was to evaluate graft equilibration with high viscosity (University of Wisconsin solution [UW]) or low viscosity (Bretschneider's histidine-tryptophan-ketoglutarate [HTK]) during liver procurement from non-heart beating donors (NHBD) and the potential impact of a preceding fibrinolysis with streptokinase on postpreservation viability. After 60 min of cardiac arrest, rat livers were perfused by gravity (60 cm H2O) via the portal vein with either 60 ml of HTK, 20 ml of UW, or 20 ml of Ringer's solution (22 degrees C including 7500U of streptokinase) and, subsequently, 20 ml of UW. After 24 h of storage at 4 degrees C, viability of the livers was assessed upon isolated reperfusion in vitro. Magnetic resonance imaging revealed severe perfusion deficits, which were mildly attenuated with HTK, upon flush-out with UW. After preflush with streptokinase, a mostly homogenous distribution of the preservation solution was observed throughout the liver tissue. The choice of the flush-out solution (UW or HTK) had no influence on parenchymal enzyme leakage, hepatic bile production, or tissue levels of ATP after reperfusion of the livers. Fibrinolytic preflush, however, resulted in a relevant and significant improvement of structural integrity as well as functional and metabolic recovery. Compromised vascular tissue perfusion upon organ harvest in NHBD triggers graft dysfunction after cold storage and can easily be circumvented by temporary fibrinolysis before graft retrieval.

Effects of Ca2+ channel blockers on transmitter release and presynaptic currents at the frog neuromuscular junction.

PubMed Central

Katz, E; Ferro, P A; Cherksey, B D; Sugimori, M; Llinás, R; Uchitel, O D

1995-01-01

1. The effects of the calcium channel blockers, funnel-web spider toxin (FTX), omega-agatoxin IVA (omega-Aga IVA) and omega-conotoxin GVIA (omega-CgTX), were tested on transmitter release and presynaptic currents in frog motor nerve endings. 2. Evoked transmitter release was blocked by FTX (IC50 = 0.02 microliter ml-1) and omega-CgTX (1 microM) but was not affected by omega-Aga IVA (0.5 microM). When FTX (0.1 microliter ml-1) was assayed on spontaneous release either in normal Ringer solution or in low Ca(2+)-high Mg2+ solution, it was found not to affect miniature endplate potential (MEPP) amplitude but to increase MEPP frequency by approximately 2-fold in both conditions. 3. Presynaptic calcium currents (ICa), measured by the perineurial technique in the presence of 10 mM tetraethylammonium chloride (TEA) and 200 microM BaCl2 to block K+ currents, were blocked by omega-CgTX (5 microM), partially blocked by FTX (1 microliter ml-1) and not affected by omega-Aga IVA (0.5 microM). 4. The presynaptic calcium-activated potassium current (IK(Ca)) measured by the perineurial technique in the presence of 0.5 microM 3,4-aminopyridine (DAP) to block voltage-dependent K+ currents, was strongly affected by charybdotoxin (ChTX) (300 nM) and completely abolished by BaCl2 (200 microM). This current was also blocked by omega-CgTX (5 microM) and by CdCl2 (200 microM) but was not affected by FTX (1 microliter ml-1). The blockade by omega-CgTX could not be reversed by elevating [Ca]o to 10 mM. 5. The results suggest that in frog synaptic terminals two omega-CgTX-sensitive populations might coexist. The transmitter release process seems to be mediated by calcium influx through a omega-CgTX- and FTX-sensitive population. PMID:7473230

Effects of Ca2+ channel blockers on transmitter release and presynaptic currents at the frog neuromuscular junction.

PubMed

Katz, E; Ferro, P A; Cherksey, B D; Sugimori, M; Llinás, R; Uchitel, O D

1995-08-01

1. The effects of the calcium channel blockers, funnel-web spider toxin (FTX), omega-agatoxin IVA (omega-Aga IVA) and omega-conotoxin GVIA (omega-CgTX), were tested on transmitter release and presynaptic currents in frog motor nerve endings. 2. Evoked transmitter release was blocked by FTX (IC50 = 0.02 microliter ml-1) and omega-CgTX (1 microM) but was not affected by omega-Aga IVA (0.5 microM). When FTX (0.1 microliter ml-1) was assayed on spontaneous release either in normal Ringer solution or in low Ca(2+)-high Mg2+ solution, it was found not to affect miniature endplate potential (MEPP) amplitude but to increase MEPP frequency by approximately 2-fold in both conditions. 3. Presynaptic calcium currents (ICa), measured by the perineurial technique in the presence of 10 mM tetraethylammonium chloride (TEA) and 200 microM BaCl2 to block K+ currents, were blocked by omega-CgTX (5 microM), partially blocked by FTX (1 microliter ml-1) and not affected by omega-Aga IVA (0.5 microM). 4. The presynaptic calcium-activated potassium current (IK(Ca)) measured by the perineurial technique in the presence of 0.5 microM 3,4-aminopyridine (DAP) to block voltage-dependent K+ currents, was strongly affected by charybdotoxin (ChTX) (300 nM) and completely abolished by BaCl2 (200 microM). This current was also blocked by omega-CgTX (5 microM) and by CdCl2 (200 microM) but was not affected by FTX (1 microliter ml-1). The blockade by omega-CgTX could not be reversed by elevating [Ca]o to 10 mM. 5. The results suggest that in frog synaptic terminals two omega-CgTX-sensitive populations might coexist. The transmitter release process seems to be mediated by calcium influx through a omega-CgTX- and FTX-sensitive population.

Acetylcholine released from cholinergic nerves contributes to cutaneous vasodilation during heat stress

NASA Technical Reports Server (NTRS)

Shibasaki, Manabu; Wilson, Thad E.; Cui, Jian; Crandall, Craig G.

2002-01-01

Nitric oxide (NO) contributes to active cutaneous vasodilation during a heat stress in humans. Given that acetylcholine is released from cholinergic nerves during whole body heating, coupled with evidence that acetylcholine causes vasodilation via NO mechanisms, it is possible that release of acetylcholine in the dermal space contributes to cutaneous vasodilation during a heat stress. To test this hypothesis, in seven subjects skin blood flow (SkBF) and sweat rate were simultaneously monitored over three microdialysis membranes placed in the dermal space of dorsal forearm skin. One membrane was perfused with the acetylcholinesterase inhibitor neostigmine (10 microM), the second membrane was perfused with the NO synthase inhibitor N(G)-nitro-l-arginine methyl ester (l-NAME; 10 mM) dissolved in the aforementioned neostigmine solution (l-NAME(Neo)), and the third membrane was perfused with Ringer solution as a control site. Each subject was exposed to approximately 20 min of whole body heating via a water-perfused suit, which increased mean body temperature from 36.4 +/- 0.1 to 37.5 +/- 0.1 degrees C (P < 0.05). After the heat stress, SkBF at each site was normalized to its maximum value, identified by administration of 28 mM sodium nitroprusside. Mean body temperature threshold for cutaneous vasodilation was significantly lower at the neostigmine-treated site relative to the other sites (neostigmine: 36.6 +/- 0.1 degrees C, l-NAME(Neo): 37.1 +/- 0.1 degrees C, control: 36.9 +/- 0.1 degrees C), whereas no significant threshold difference was observed between the l-NAME(Neo)-treated and control sites. At the end of the heat stress, SkBF was not different between the neostigmine-treated and control sites, whereas SkBF at the l-NAME(Neo)-treated site was significantly lower than the other sites. These results suggest that acetylcholine released from cholinergic nerves is capable of modulating cutaneous vasodilation via NO synthase mechanisms early in the heat stress but not after substantial cutaneous vasodilation.

[Adsorbent effect of activated carbon on small molecular uremic toxin and its influence factors].

PubMed

Yang, Bo; Jiang, Yun-sheng; Li, Jun

2003-06-01

To analyze the adsorbent effect of activated carbon on uremic toxin and its influence factors. Uremic toxins (urea, creatinine and uric acid) were dissolved in the distilled water to obtain uremic toxic solution. Activated carbon was added to the solution, and the concentrations of uremic toxins were measured at different time spots. To determine the influence factors, some possible related materials, such as bile, amino acid, Ringer's, solution of glucose, HCl or NaOH respectively were added simultaneously. The concentrations of toxins in uremic toxic solution decreased 5 min after adding the activated carbon. The concentration of urea was the lowest at 30 min, but it increased after 50 min; while the concentrations of creatinine and uric acid reached the lowest level from 10 to 30 min after adding the activated carbon, and maintained at the same level after that. The bile, amino acid, electrolyte, glucose and pH value did not influence the adsorption of uric acid significantly, but they influenced the adsorption of urea and creatinine. Bile and amino acid influenced the concentration of urea remarkably, following glucose, NaOH and HCl. The effect of pH 2.0 solution on the creatinine concentration was the most significant, following glucose. Activated carbon has adsorptive effect on uremic toxins, but its adsorptive effect decreases as time goes on. Bile, glucose, amino acid, NaOH and HCl can affect the adsorptive effect of activated carbon on uremic toxins to some extent.

Safe total corporal contouring with large-volume liposuction for the obese patient.

PubMed

Dhami, Lakshyajit D; Agarwal, Meenakshi

2006-01-01

The advent of the tumescent technique in 1987 allowed for safe total corporal contouring as an ambulatory, single-session megaliposuction with the patient under regional anesthesia supplemented by local anesthetic only in selected areas. Safety and aesthetic issues define large-volume liposuction as having a 5,000-ml aspirate, mega-volume liposuction as having an 8,000-ml aspirate, and giganto-volume liposuction as having an aspirate of 12,000 ml or more. Clinically, a total volume comprising 5,000 ml of fat and wetting solution aspirated during the procedure qualifies for megaliposuction/large-volume liposuction. Between September 2000 and August 2005, 470 cases of liposuction were managed. In 296 (63%) of the 470 cases, the total volume of aspirate exceeded 5 l (range, 5,000-22,000 ml). Concurrent limited or total-block lipectomy was performed in 70 of 296 cases (23.6%). Regional anesthesia with conscious sedation was preferred, except where liposuction targeted areas above the subcostal region (the upper trunk, lateral chest, gynecomastia, breast, arms, and face), or when the patient so desired. Tumescent infiltration was achieved with hypotonic lactated Ringer's solution, adrenalin, triamcinalone, and hyalase in all cases during the last one year of the series. This approach has clinically shown less tissue edema in the postoperative period than with conventional physiologic saline used in place of the Ringer's lactate solution. The amount injected varied from 1,000 to 8,000 ml depending on the size, site, and area. Local anesthetic was included only for the terminal portion of the tumescent mixture, wherever the subcostal regions were infiltrated. The aspirate was restricted to the unstained white/yellow fat, and the amount of fat aspirated did not have any bearing on the amount of solution infiltrated. There were no major complications, and no blood transfusions were administered. The hospital stay ranged from 8 to 24 h for both liposuction and liposuction with a lipectomy. Serous discharge from access sites and serosanguinous fluid accumulation requiring drainage were necessitated in 32 of 296 cases (10.8%). Minor recontouring touch-ups were requested in 17 of 296 cases (5.7%). Early ambulation was encouraged for mobilization of third-space fluid shifts to expedite recovery and to prevent deep vein thrombosis. Follow-up evaluation ranged from 6 to 52 months, with 38 (12.8%) of 296 patients requesting further sessions for other new areas. Average weight reduction observed was 7 to 11.6 kg (approx. 4 to 10% of pre-operative body weight). Meticulous perioperative monitoring of systemic functions ensures safety in tumescent megaliposuction for the obese, and rewarding results are achieved in a single sitting.

Determination of picomole quantities of acetylcholine and choline in physiologic salt solutions.

PubMed

Gilberstadt, M L; Russell, J A

1984-04-01

An assay capable of detecting tens-of-picomole quantities of choline and acetylcholine in milliliter volumes of a physiological salt solution has been developed. Silica column chromatography was used to bind and separate 10-3000 pmol [14C]choline and [14C]acetylcholine standards made up in 3 ml of a bicarbonate-buffered Krebs-Ringer solution. The silica columns bound 95-98% of both choline and acetylcholine. Of the bound choline 84-87% was eluted in 1.5 ml of 0.075 N HCl, whereas 95-98% of the bound acetylcholine was eluted in a subsequent wash with 1.5 ml of 0.030 N HCl in 10% 2-butanone. Vacuum centrifugation of the eluants yielded small white pellets with losses of choline and acetylcholine of only 1%. Dried pellets of unlabeled choline and acetylcholine standards were assayed radioenzymatically using [gamma-32P]ATP, choline kinase, and acetylcholinesterase. The net disintegrations per minute of choline[32P]phosphate product was proportional to both the acetylcholine (10-3000 pmol) and choline (30-3000 pmol) standards. The "limit sensitivity" was 8.5 pmol for acetylcholine and 11.4 pmol for choline. Cross-contamination of the choline assay by acetylcholine averaged 1.3%, whereas contamination of the acetylcholine assay by choline averaged 3.1%.

Comparison of microdialysis sampling perfusion fluid components on the foreign body reaction in rat subcutaneous tissue.

PubMed

Keeler, Geoffrey D; Durdik, Jeannine M; Stenken, Julie A

2014-06-16

Microdialysis sampling is a commonly used technique for collecting solutes from the extracellular space of tissues in laboratory animals and humans. Large molecular weight solutes can be collected using high molecular weight cutoff (MWCO) membranes (100kDa or greater). High MWCO membranes require addition of high molecular weight dextrans or albumin to the perfusion fluid to prevent fluid loss via ultrafiltration. While these perfusion fluid additives are commonly used during microdialysis sampling, the tissue response to the loss of these compounds across the membrane is poorly understood. Tissue reactions to implanted microdialysis sampling probes containing different microdialysis perfusion fluids were compared over a 7-day time period in rats. The base perfusion fluid was Ringer's solution supplemented with either bovine serum albumin (BSA), rat serum albumin (RSA), Dextran-70, or Dextran-500. A significant inflammatory response to Dextran-70 was observed. No differences in the tissue response between BSA and RSA were observed. Among these agents, the BSA, RSA, and Dextran-500 produced a significantly reduced inflammatory response compared to the Dextran-70. This work demonstrates that use of Dextran-70 in microdialysis sampling perfusion fluids should be eliminated and replaced with Dextran-500 or other alternatives. Copyright © 2013 Elsevier B.V. All rights reserved.

Effect of solution and post-mortem time on mechanical and histological properties of liver during cold preservation.

PubMed

Ayyildiz, Mehmet; Aktas, Ranan Gulhan; Basdogan, Cagatay

2014-01-01

In liver transplantation, the donor and recipient are in different locations most of the time, and longer preservation periods are inevitable. Hence, the choice of the preservation solution and the duration of the preservation period are critical for the success of the transplant surgery. In this study, we examine the mechanical and histological properties of the bovine liver tissue stored in Lactated Ringer's (control), HTK and UW solutions as a function of preservation period. The mechanical experiments are conducted with a shear rheometer on cylindrical tissue samples extracted from 3 bovine livers and the change in viscoelastic material properties of the bovine liver is characterized using the fractional derivative Kelvin-Voigt Model. Also, the histological examinations are performed on the same liver samples under a light microscope. The results show that the preservation solution and period have a significant effect on the mechanical and histological properties of the liver tissue. The storage and loss shear moduli, the number of the apoptotic cells, the collagen accumulation, and the sinusoidal dilatation increase, and the glycogen deposition decreases as the preservation period is longer. Based on the statistical analyses, we observe that the liver tissue is preserved well in all three solutions for up to 11 h. After then, UW solution provides a better preservation up to 29 h. However, for preservation periods longer than 29 h, HTK is a more effective preservation solution based on the least amount of change in mechanical properties. On the other hand, the highest correlation between the mechanical and histological properties is observed for the liver samples preserved in UW solution.

Cytoprotective Mechanisms in Fatty Liver Preservation against Cold Ischemia Injury: A Comparison between IGL-1 and HTK

PubMed Central

Panisello-Roselló, Arnau; Verde, Eva; Flores, Marta; Folch-Puy, Emma; Rolo, Anabela; Palmeira, Carlos; Hotter, Georgina; Adam, René; Roselló-Catafau, Joan

2018-01-01

Institute Goeorges Lopez 1 (IGL-1) and Histidine-Tryptophan-Ketoglutarate (HTK) preservation solutions are regularly used in clinical for liver transplantation besides University of Wisconsin (UW) solution and Celsior. Several clinical trials and experimental works have been carried out comparing all the solutions, however the comparative IGL-1 and HTK appraisals are poor; especially when they deal with the underlying protection mechanisms of the fatty liver graft during cold storage. Fatty livers from male obese Zücker rats were conserved for 24 h at 4 °C in IGL-1 or HTK preservation solutions. After organ recovery and rinsing of fatty liver grafts with Ringer Lactate solution, we measured the changes in mechanistic target of rapamycin (mTOR) signaling activation, liver autophagy markers (Beclin-1, Beclin-2, LC3B and ATG7) and apoptotic markers (caspase 3, caspase 9 and TUNEL). These determinations were correlated with the prevention of liver injury (aspartate and alanine aminostransferase (AST/ALT), histology) and mitochondrial damage (glutamate dehydrogenase (GLDH) and confocal microscopy findings). Liver grafts preserved in IGL-1 solution showed a marked reduction on p-TOR/mTOR ratio when compared to HTK. This was concomitant with significant increased cyto-protective autophagy and prevention of liver apoptosis, including inflammatory cytokines such as HMGB1. Together, our results revealed that IGL-1 preservation solution better protected fatty liver grafts against cold ischemia damage than HTK solution. IGL-1 protection was associated with a reduced liver damage, higher induced autophagy and decreased apoptosis. All these effects would contribute to limit the subsequent extension of reperfusion injury after graft revascularization in liver transplantation procedures. PMID:29364854

In vitro effects of hydrochloric acid and various concentrations of acetic, propionic, butyric, or valeric acids on bioelectric properties of equine gastric squamous mucosa.

PubMed

Andrews, Frank M; Buchanan, Benjamin R; Smith, Sionagh H; Elliott, Sarah B; Saxton, Arnold M

2006-11-01

To compare the effects of hydrochloric acid (HCl) and various concentrations of volatile fatty acids (VFAs) on tissue bioelectric properties of equine stomach nonglandular (NG) mucosa. Gastric tissues obtained from 48 adult horses. NG gastric mucosa was studied by use of Ussing chambers. Short-circuit current (Isc) and potential difference (PD) were measured and electrical resistance (R) and conductance calculated for tissues after addition of HCl and VFAs (5, 10, 20, and 40 mM) in normal Ringer's solution (NRS). Mucosa exposed to HCl in NRS (pH of 1.5 and, to a lesser extent, 4.0) had a significant decrease in Isc, PD, and R, whereas tissues exposed to acetic acid at a pH of < 4.0, propionic and butyric acids at a pH of

Increased cell membrane permeability to Na+ and K+ induced by thyroid hormone in rat skeletal muscle.

PubMed

Asano, Y

1978-01-01

Thyroid hormone (T3) increased Na+ dependent respiration accompanied by an increase in NaK-ATPase activity. Administration of T3 increased intracellular K+ concentration and Na/K ratio in thyroidectomized rats, and the Na+ efflux rate constant incubated in oxygenized Na+, K+-Ringers in euthyroid rats. However, the magnitude of the changes in intracellular K+ concentration was modest or invisible in comparison to the changes in QO2(t) and NaK-ATPase activity. The Na+ and K+ efflux rate constants in K+-free +ouabain Ringers were increased by T3 in both thyroidectomized and euthyroid rats. Thus, thyroid hormone stimulates not only Na pump but also the permeability of cell membrane to Na+ and K+. The both effects might contribute to the thyroid thermogenesis.

Whole-bowel irrigation for mechanical colon cleansing.

PubMed

Michael, K A; DiPiro, J T; Bowden, T A; Tedesco, F J

1985-01-01

The physiology, solution composition, indications, efficacy, and safety of whole-bowel irrigation (WBI) for mechanical bowel cleansing are reviewed. WBI with isotonic electrolyte solutions produces diarrhea when the infusion rate exceeds the capacity of the intestine to distend and absorb the solution. A number of solutions are used for WBI, including 0.9% sodium chloride, balanced electrolyte solutions, lactated Ringer's, mannitol, and electrolyte solutions containing polyethylene glycol 3350 (PEG). WBI solution administration rates vary from 15-90 mL/min, by oral ingestion or nasogastric tube, with total volumes ranging from 1 to 20 L. The onset of diarrhea occurs as soon as 20 minutes with clearing of the effluent as early as 90 minutes. Faster administration rates appear to shorten overall cleansing time. Two PEG-electrolyte lavage solutions (ELSs) have recently gained FDA approval. The recommended dosage rate is 1.2-1.8 L/hr orally or by nasogastric tube until rectal effluent is clear. In most patients, this requires a maximum of 4-6 L. Initial data indicate that PEG-ELSs are safe for elderly patients and for patients who have an increased risk of fluid overload, but these solutions have not been evaluated in children, pregnant women, or patients with inflammatory bowel disease. WBI is an effective alternative to other regimens for removing fecal material and reducing bowel lumen bacterial counts before colonoscopy and colorectal surgery. Retention of bacterial counts before colonoscopy and colorectal surgery. Retention of excess WBI solution may interfere with the quality of barium enema radiographs; this can be minimized by completing the irrigation the evening before the examination. Gastrointestinal side effects occur in about one third of the patients following WBI, but do not generally require discontinuing the irrigation. Solutions containing PEG with sodium sulfate as the primary electrolyte result in the least net water and electrolyte movement and are preferred over other solutions.

Comparison of 7.2% hypertonic saline - 6% hydroxyethyl starch solution and 6% hydroxyethyl starch solution after the induction of anesthesia in patients undergoing elective neurosurgical procedures.

PubMed

Shao, Liujiazi; Wang, Baoguo; Wang, Shuangyan; Mu, Feng; Gu, Ke

2013-01-01

The ideal solution for fluid management during neurosurgical procedures remains controversial. The aim of this study was to compare the effects of a 7.2% hypertonic saline - 6% hydroxyethyl starch (HS-HES) solution and a 6% hydroxyethyl starch (HES) solution on clinical, hemodynamic and laboratory variables during elective neurosurgical procedures. Forty patients scheduled for elective neurosurgical procedures were randomly assigned to the HS-HES group orthe HES group. Afterthe induction of anesthesia, patients in the HS-HES group received 250 mL of HS-HES (500 mL/h), whereas the patients in the HES group received 1,000 mL of HES (1000 mL/h). The monitored variables included clinical, hemodynamic and laboratory parameters. Chictr.org: ChiCTR-TRC-12002357 The patients who received the HS-HES solution had a significant decrease in the intraoperative total fluid input (p<0.01), the volume of Ringer's solution required (p<0.05), the fluid balance (p<0.01) and their dural tension scores (p<0.05). The total urine output, blood loss, bleeding severity scores, operation duration and hemodynamic variables were similar in both groups (p>0.05). Moreover, compared with the HES group, the HS-HES group had significantly higher plasma concentrations of sodium and chloride, increasing the osmolality (p<0.01). Our results suggest that HS-HES reduced the volume of intraoperative fluid required to maintain the patients undergoing surgery and led to a decrease in the intraoperative fluid balance. Moreover, HS-HES improved the dural tension scores and provided satisfactory brain relaxation. Our results indicate that HS-HES may represent a new avenue for volume therapy during elective neurosurgical procedures.

Comparison of 7.2% hypertonic saline - 6% hydroxyethyl starch solution and 6% hydroxyethyl starch solution after the induction of anesthesia in patients undergoing elective neurosurgical procedures

PubMed Central

Shao, Liujiazi; Wang, Baoguo; Wang, Shuangyan; Mu, Feng; Gu, Ke

2013-01-01

OBJECTIVE: The ideal solution for fluid management during neurosurgical procedures remains controversial. The aim of this study was to compare the effects of a 7.2% hypertonic saline - 6% hydroxyethyl starch (HS-HES) solution and a 6% hydroxyethyl starch (HES) solution on clinical, hemodynamic and laboratory variables during elective neurosurgical procedures. METHODS: Forty patients scheduled for elective neurosurgical procedures were randomly assigned to the HS-HES group or the HES group. After the induction of anesthesia, patients in the HS-HES group received 250 mL of HS-HES (500 mL/h), whereas the patients in the HES group received 1,000 mL of HES (1000 mL/h). The monitored variables included clinical, hemodynamic and laboratory parameters. Chictr.org: ChiCTR-TRC-12002357 RESULTS: The patients who received the HS-HES solution had a significant decrease in the intraoperative total fluid input (p<0.01), the volume of Ringer's solution required (p<0.05), the fluid balance (p<0.01) and their dural tension scores (p<0.05). The total urine output, blood loss, bleeding severity scores, operation duration and hemodynamic variables were similar in both groups (p>0.05). Moreover, compared with the HES group, the HS-HES group had significantly higher plasma concentrations of sodium and chloride, increasing the osmolality (p<0.01). CONCLUSION: Our results suggest that HS-HES reduced the volume of intraoperative fluid required to maintain the patients undergoing surgery and led to a decrease in the intraoperative fluid balance. Moreover, HS-HES improved the dural tension scores and provided satisfactory brain relaxation. Our results indicate that HS-HES may represent a new avenue for volume therapy during elective neurosurgical procedures. PMID:23644851

The Protective Effects of Trypsin Inhibitor on Hepatic Ischemia-Reperfusion Injury and Liver Graft Survival

PubMed Central

Guan, Lianyue; Liu, Hongyu; Fu, Peiyao; Li, Zhuonan; Li, Peidong; Xie, Lijuan; Xin, Mingang; Wang, Zhanpeng

2016-01-01

The aim of this study was to explore the protective effects of ulinastatin (urinary trypsin inhibitor, UTI) on liver ischemia-reperfusion injury (IRI) and graft survival. We employed mouse liver cold IRI and orthotopic liver transplantation (OLTx) models. UTI was added to lactated Ringer's (LR) solution for liver perfusion and preservation in vitro or combined with UTI injection intraperitoneally to the liver graft recipient. Our results indicated that UTI supplementation protected the liver from cold IRI in a dose-dependent manner and prolonged liver graft survival from extended cold preserved liver donors significantly. The underlying mechanism of UTI on liver IRI may be mediated by inhibition of proinflammatory cytokine release, increasing the expression of the antiapoptotic gene Bcl-2 and decreasing the expression of the proapoptosis genes of Caspase-3 and Bax, and further protects hepatocytes from apoptotic death and improves liver function. PMID:26783413

On the fractography of overload, stress corrosion, and cyclic fatigue failures in pyrolytic-carbon materials used in prosthetic heart-valve devices.

PubMed

Ritchie, R O; Dauskardt, R H; Pennisi, F J

1992-01-01

A scanning electron microscopy study is reported of the nature and morphology of fracture surfaces in pyrocarbons commonly used for the manufacture of mechanical heart-valve prostheses. Specifically, silicon-alloyed low-temperature-isotropic (LTI)-pyrolytic carbon is examined, both as a coating on graphite and as a monolithic material, following overload, stress corrosion (static fatigue), and cyclic fatigue failures in a simulated physiological environment of 37 degrees C Ringer's solution. It is found that, in contrast to most metallic materials yet in keeping with many ceramics, there are no distinct fracture morphologies in pyro-carbons which are characteristic of a specific mode of loading; fracture surfaces appear to be identical for both catastrophic and subcritical crack growth under either sustained or cyclic loading. We conclude that caution should be used in assigning the likely cause of failure of pyrolytic carbon heart-valve components using fractographic examination.

The Protective Effects of Trypsin Inhibitor on Hepatic Ischemia-Reperfusion Injury and Liver Graft Survival.

PubMed

Guan, Lianyue; Liu, Hongyu; Fu, Peiyao; Li, Zhuonan; Li, Peidong; Xie, Lijuan; Xin, Mingang; Wang, Zhanpeng; Li, Wei

2016-01-01

The aim of this study was to explore the protective effects of ulinastatin (urinary trypsin inhibitor, UTI) on liver ischemia-reperfusion injury (IRI) and graft survival. We employed mouse liver cold IRI and orthotopic liver transplantation (OLTx) models. UTI was added to lactated Ringer's (LR) solution for liver perfusion and preservation in vitro or combined with UTI injection intraperitoneally to the liver graft recipient. Our results indicated that UTI supplementation protected the liver from cold IRI in a dose-dependent manner and prolonged liver graft survival from extended cold preserved liver donors significantly. The underlying mechanism of UTI on liver IRI may be mediated by inhibition of proinflammatory cytokine release, increasing the expression of the antiapoptotic gene Bcl-2 and decreasing the expression of the proapoptosis genes of Caspase-3 and Bax, and further protects hepatocytes from apoptotic death and improves liver function.

Wound bed preparation: A novel approach using HydroTherapy.

PubMed

Atkin, Leanne; Ousey, Karen

2016-12-01

Wounds that fail to heal quickly are often encountered by community nursing staff. An important step in assisting these chronic or stalled wounds progress through healing is debridement to remove devitalised tissue, including slough and eschar, that can prevent the wound from healing. A unique wound treatment called HydroTherapy aims to provide an optimal healing environment. The first step of HydroTherapy involves HydroClean plus™, this dressing enables removal of devitalised tissue through autolytic debridement and absorption of wound fluid. Irrigation and cleansing provided by Ringer's solution from the dressing further removes any necrotic tissue or eschar. Once effective wound bed preparation has been achieved a second dressing, HydroTac™, provides an ongoing hydrated wound environment that enables re-epithelialisation to occur in an unrestricted fashion. This paper presents 3 case studies of slow healing wounds treated with HydroClean plus™ which demonstrates effective wound debridement.

Evaluating the effects of hydroxyapatite coating on the corrosion behavior of severely deformed 316Ti SS for surgical implants.

PubMed

Mhaede, Mansour; Ahmed, Aymen; Wollmann, Manfred; Wagner, Lothar

2015-05-01

The present work investigates the effects of severe plastic deformation by cold rolling on the microstructure, the mechanical properties and the corrosion behavior of austenitic stainless steel (SS) 316Ti. Hydroxyapatite coating (HA) was applied on the deformed material to improve their corrosion resistance. The martensitic transformation due to cold rolling was recorded by X-ray diffraction spectra. The effects of cold rolling on the corrosion behavior were studied using potentiodynamic polarization. The electrochemical tests were carried out in Ringer's solution at 37±1 °C. Cold rolling markedly enhanced the mechanical properties while the electrochemical tests referred to a lower corrosion resistance of the deformed material. The best combination of both high strength and good corrosion resistance was achieved after applying hydroxyapatite coating. Copyright © 2015 Elsevier B.V. All rights reserved.

Knowledge, Attitude, and Concussion-Reporting Behaviors Among High School Athletes: A Preliminary Study

PubMed Central

Register-Mihalik, Johna K.; Guskiewicz, Kevin M.; McLeod, Tamara C. Valovich; Linnan, Laura A.; Mueller, Frederick O.; Marshall, Stephen W.

2013-01-01

Context: Many athletes continue to participate in practices and games while experiencing concussion-related symptoms, potentially predisposing them to subsequent and more complicated brain injuries. Limited evidence exists about factors that may influence concussion-reporting behaviors. Objective: To examine the influence of knowledge and attitude on concussion-reporting behaviors in a sample of high school athletes. Design: Cross-sectional study. Setting: Participants completed a validated survey instrument via mail. Patients or Other Participants: A total of 167 high school athletes (97 males, 55 females, 5 sex not indicated; age = 15.7 ± 1.4 years) participating in football, soccer, lacrosse, or cheerleading. Intervention(s): Athlete knowledge and attitude scores served as separate predictor variables. Main Outcome Measure(s): We examined the proportion of athletes who reported continuing to participate in games and practices while symptomatic from possible concussion and the self-reported proportion of recalled concussion and bell-ringer events disclosed after possible concussive injury. Results: Only 40% of concussion events and 13% of bell-ringer recalled events in the sample were disclosed after possible concussive injury. Increased athlete knowledge of concussion topics (increase of 1 standard deviation = 2.8 points) was associated with increased reporting prevalence of concussion and bell-ringer events occurring in practice (prevalence ratio [PR] = 2.27, 95% confidence interval [CI] = 1.60, 3.21) and the reporting prevalence of bell-ringer-only events overall (PR = 1.87, 95% CI = 1.38, 2.54). Athlete attitude scores (increase of 1 standard deviation = 11.5 points) were associated with decreases in the proportion of athletes stating they participated in games (PR = 0.74, 95% CI = 0.66, 0.82) and practices (PR = 0.67, 95% CI = 0.59, 0.77) while symptomatic from concussions. Conclusions: Most recalled concussion events in our study were not reported to a supervising adult. Clinicians should be aware that knowledge and attitude influence concussion reporting. Clinicians and administrators should make concussion education a priority and encourage an optimal reporting environment to better manage and prevent concussive injuries in young athletes. PMID:23848520

Visualization of predentine matrix components and endocytic structures in rat incisor odontoblasts with tannic acid.

PubMed

Goldberg, M; Septier, D

1989-12-01

Rat incisor odontoblasts and predentine fixed with tannic acid-glutaraldehyde-osmium tetroxide (Tago) were compared with those obtained by prior incubation in tannic acid-Ringer before conventional fixation with glutaraldehyde-osmium-tetroxide (Tari) The Tago method allowed visualization of complex glycoconjugates along the plasma membrane, in the pericellular spaces and in the intercellular predentine matrix. The non-collagenous proteins, proteoglycans and lipids were seen as granules and thin filaments located between the collagen fibers and at their surface. The collagen fibers themselves were also stained. The Tari method which was used to visualize exocytosis, mainly revealed endocytosis in the form of large intracellular vacuoles containing tannic acid and stained proteoglycans. It is suggested that tannic acid-Ringer incubation prior to fixation increases the endocytosis of the matrix components, which acculumates in these large vesicles.

The Effects of Direct Oxygen Supply During Static Cold Preservation of Rat Livers: An Experimental Study.

PubMed

Zumrutdal, Emin; Karateke, Faruk; Eser, Pınar Eylem; Turan, Umit; Ozyazici, Sefa; Sozutek, Alper; Gulkaya, Mustafa; Kunt, Mevlut

2016-12-01

We aimed to determine the biochemical and histopathologic effects of direct oxygen supply to the preservation fluid of static cold storage system with a simple method on rat livers. Sixteen rats were randomly divided into 2 groups: the control group, which contained Ringer's lactate as preservation fluid; and the oxygen group, which contained oxygen and Ringer's lactate for preservation. Each liver was placed in a bag containing 50 mL Ringer's lactate and placed in ice-filled storage containers. One hundred percent oxygen supplies were given via a simple, inexpensive system created in our laboratory, to the livers in oxygen group. We obtained samples for histopathologic evaluation in the 12th hour. In addition, 3 mL of preservation fluid was subjected to biochemical analysis at 0, sixth, and twelfth hours. Aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and pH levels were measured from the preservation fluid. In oxygen-supplemented group, the acceleration speed of increase in alanine aminotransferase and lactate dehydrogenase levels at sixth hour and lactate dehydrogenase, alanine aminotransferase, and lactate dehydrogenase levels at 12th hour were statistically significantly reduced. In histopathologic examination, all parameters except ballooning were statistically significantly better in the oxygen-supplemented group. This simple system for oxygenation of liver tissues during static cold storage was shown to be effective with good results in biochemical and histopathologic assessments. Because this is a simple, inexpensive, and easily available method, larger studies are warranted to evaluate its effects (especially in humans).

Puerarin attenuates severe burn-induced acute myocardial injury in rats.

PubMed

Liu, Sheng; Ren, Hong-Bo; Chen, Xu-Lin; Wang, Fei; Wang, Ren-Su; Zhou, Bo; Wang, Chao; Sun, Ye-Xiang; Wang, Yong-Jie

2015-12-01

Puerarin, the main isoflavone glycoside extracted from the root of Pueraria lobata, is widely prescribed for patients with cardiovascular disorders in China. This study investigates the effect of puerarin on severe burn-induced acute myocardial injury in rats and its underlying mechanisms. Healthy adult Wistar rats were divided into three groups: (1) sham group, sham burn treatment; (2) burn group, third-degree burns over 30% of the total body surface area (TBSA) with lactated Ringer's solution for resuscitation; and (3) burn plus puerarin group, third-degree burns over 30% of TBSA with lactated Ringer's solution containing puerarin for resuscitation. The burned animals were sacrificed at 1, 3, 6, 12, and 24 h after burn injury. Myocardial injury was evaluated by analyzing serum creatine kinase MB fraction (CK-MB) activity and cardiac troponin T (cTNT) level. Changes in cardiomyocyte ultrastructure were also determined using a transmission electron microscope. Tumor necrosis factor (TNF)-α concentration in serum was measured by radioimmunoassay. Cardiac myeloperoxidase (MPO) activity and malondialdehyde (MDA) concentration were measured to determine neutrophil infiltration and oxidative stress in the heart, respectively. The expression of p38 mitogen-activated protein (MAP) kinase in the heart was determined by Western blot analysis. After the 30% TBSA full-thickness burn injury, serum CK-MB activities and cTnT levels increased markedly, both of which were significantly decreased by the puerarin treatment. The level of serum TNF-α concentration in burn group at each time-point was obviously higher than those in sham group (1.09±0.09 ng/ml), and it reached the peak value at 12 h post burn. Burn trauma also resulted in worsen ultrastructural condition, elevated MPO activity and MDA content in heart tissue, and a significant activation of cardiac p38 MAP kinase. Administration of puerarin improved the ultrastructural changes in cardiomyocytes, decreased TNF-α concentration in serum as well as suppressed cardiac MPO activity and reduced MDA content, and abolished the activation of p38 MAP kinase in heart tissue after severe burn. These results suggest that puerarin attenuates inflammatory responses, reduces neutrophil infiltration and oxidative stress in the heart, and protects against acute myocardial injury induced by severe burn. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

Effect of depletion of glycosaminoglycans and non-collagenous proteins on interstitial hydraulic permeability in rabbit synovium

PubMed Central

Scott, D; Coleman, P J; Abiona, A; Ashhurst, D E; Mason, R M; Levick, J R

1998-01-01

The hydraulic resistance of synovial interstitium helps to retain a lubricating fluid within the joint cavity. The contributions of sulphated glycosaminoglycans to resistance were assessed by selective depletion by chondroitinase ABC, keratanase and heparinases I, II and III in vivo. Also, since glycosaminoglycans do not account fully for the resistance, the contribution of non-collagenous, structural proteins in interstitium was assessed by treatment with chymopapain, a collagen-sparing protease. Ringer solution containing enzyme was injected into the synovial cavity of the knee in anaesthetized rabbits. After ≥ 30 min the intra-articular pressure was raised and the relation between pressure (Pj) and trans-synovial outflow (Q̇s) determined. The slope dQ̇s/dPj at low pressures, i.e. below yield pressure, represents the hydraulic conductance of the lining, i.e. 1/resistance. The contralateral joint received Ringer solution without enzyme as a control. Action of enzymes on the tissue was confirmed by histochemical and immunohistochemical studies. Treatment with chondroitinase ABC (5 joints) increased the hydraulic conductance of the lining by 2.3 times (control, 1.34 ± 0.22 μl min−1 cmH2O−1; post-enzyme, 3.11 ± 0.45 μl min−1 cmH2O−1). This was significantly less than the effects of leech, Streptomyces and testicular hyaluronidases, which caused an average 4.7 times increase (P < 0.001, ANOVA). Analogous findings were made above yield pressure. Treatment with keratanase (3 joints) or heparinases I, II and III (3 joints) caused no significant increase in trans-synovial flows or conductance, even though the concentration of heparan sulphate in synovium is higher than that of chondroitin sulphates or hyaluronan. Treatment with chymopapain (7 joints) caused the greatest increases in trans-synovial flow, which exceeded control flow by an order of magnitude in one case. After 0.1 U chymopapain the average conductance was 6.6 times the control conductance below yield pressure. Immunohistochemical studies confirmed that chymopapain treatment removed the synovial proteoglycans. It is concluded that, despite their similar resistivities in vitro, the different glycosaminoglycans do not contribute equally, weight for weight, to interstitial resistance in vivo. Hyaluronan is the dominant glycosaminoglycan governing synovial interstitial resistance. In addition, non-collagenous structural proteins contribute significantly to interstitial resistance. PMID:9706037

Metabolic alterations without metal accumulation in the ovary of adult Bufo arenarum females, observed after long-term exposure to Zn(2+), followed by toxicity to embryos.

PubMed

Naab, F; Volcomirsky, M; Burlón, A; Caraballo, M E; Debray, M; Kesque, J M; Kreiner, A J; Ozafrán, M J; Schuff, J A; Stoliar, P; Vázquez, M E; Davidson, J; Davidson, M; Fonovich de Schroeder, T M

2001-08-01

Long-term exposure of aquatic organisms to metals, even those considered micronutrients, may affect their metabolism and produce sublethal effects. We evaluated the effects of long-term exposure of adult amphibian (Bufo arenarum) females to 4 microg/L of Zn(2+) (ZnSO(4) x H(2)O) in Ringer solution on the concentration of Zn and Fe, the activity of the key enzyme of the pentose phosphate pathway glucose 6-phosphate dehydrogenase, and glutathione content, both in the liver and ovary of these animals. We also performed early embryonic development studies by in vitro insemination from control and treated females. Zn exposure rendered lower Zn concentrations in the ovaries than did exposure of animals to Ringer solution without metal addition (97 +/- 50 versus 149 +/- 46 Zn microg/wet tissue g). Zn and Fe concentration correlation was positive and linear in the ovary, but was negative and nonlinear in the liver of the studied females. The activity of the enzyme glucose 6-phosphate dehydrogenase decreased (0.0599 +/- 0.0109 versus 0.0776 +/- 0.0263 micromol of NADPH/min x mg of proteins) and the endogenous glutathione content increased (0.027 +/- 0.005 versus 0.018 +/- 0.007 mg/10 mg of proteins) in the ovary but remained unaltered in the liver as a consequence of Zn treatment. Our results suggest the existence of different mechanisms of regulation of Zn and Fe concentrations in the ovary and in the liver of adult B. arenarum females. Binding of Zn to low-molecular-weight proteins, as metallothioneins, may occur in the liver, thus protecting this organ from toxic effects. In the ovary high-molecular-weight proteins, like glucose-6-phosphate dehydrogenase, should be able to bind Zn, leading to oxidative stress responsible for the observed increase in endogenous glutathione content. Inhibition of the pentose phosphate pathway in the ovary by Zn can be responsible for the reproductive failure that we detected through embryos survival studies during early life stages: 81.3 +/- 6.3% of embryos from control females survived versus 63.1 +/- 13.8% of embryos from Zn-treated females at the branchial circulation stage of development.

[FEATURES OF FLUID THERAPY IN CHILDREN WITH SEVERE MAJOR TRAUMA].

PubMed

Pshenisnov, K V; Aleksandrovich, Yu S; Mironov, P I; Suhanov, Yu V; Kuzmin, O V; Blinov, S A; Kondin, A N

2016-01-01

Fluid and transfusion therapy is proved to be a required component of treating children with severe major trauma significantly influencing the case outcome. To analyze efficiency of fluid and transfusion therapy in children with severe major trauma and assess its correspondence with current recommendations. 150 children aged from 0 to 18 years getting treatment in intensive care units of children's city hospitals of Saint Petersburg, Archangelsk, Ufa, Samara, and Leningrad region were included in the research. The main course of severe major trauma were car injury and catatrauma. The coefficient according to Pediatric trauma score (PTS) was 6.4 points. The mean duration of hospitalization in emergencies units was 3 (2-7) days, the duration of artificial lung ventilation was 48 ± 99.9 hours, the duration of hospitalization in the department ward was 24 (15-32) days. Favorable outcome (transferring from emergencies units to department wards) was reported in 147 (98%) children, death cases were registered in 4 (2.6%) children. There was determined that the basic crystalloid solutions used for infusion therapy in children were the following: Ringer solution, Plasma-lit solution and 10% glucose solution. "Gelofisin" and "Voluven" had more frequent administration rate among colloidal solutions. Transfusion of blood was performed in 26% patients. The infusion therapy in the first three days did not exceed the necessary physiological requirements that provided stabilization of the patient's condition and did not produce a negative influence on the status of hemodynamics and gas exchange. Administration of current well-balanced crystalloid and colloidal solutions to children with severe combined trauma in an amount within the limits of required physiological indicators does not produce a negative influence on the status of gas exchange and the case outcome.

Effect of an amorphous titania nanotubes coating on the fatigue and corrosion behaviors of the biomedical Ti-6Al-4V and Ti-6Al-7Nb alloys.

PubMed

Campanelli, Leonardo Contri; Bortolan, Carolina Catanio; da Silva, Paulo Sergio Carvalho Pereira; Bolfarini, Claudemiro; Oliveira, Nilson Tadeu Camarinho

2017-01-01

An array of self-organized TiO 2 nanotubes with an amorphous structure was produced on the biomedical Ti-6Al-4V and Ti-6Al-7Nb alloys, and the resulting fatigue and corrosion behaviors were studied. The electrochemical response of the nanotubular oxide surfaces was investigated in Ringer physiological solution through potentiodynamic polarization and electrochemical impedance spectroscopy measurements. The absence of transpassivation in the chloride-containing solution, in addition to the micron-scale values of the passivation current density, indicated the excellent corrosion behavior of the coating and the satisfactory protection against the creation of potential stress concentrators in the surface. Axial fatigue tests were performed in physiological solution on polished and coated conditions, with characterization of the treated surfaces by scanning electron microscopy before and after the tests. The surface modification was not deleterious to the fatigue response of both alloys mainly due to the nano-scale dimension of the nanotubes layer. An estimation based on fracture mechanics revealed that a circumferential crack in the range of 5μm depth would be necessary to affect the fatigue performance, which is far from the thickness of the studied coating, although no cracks were actually observed in the oxide surfaces after the tests. Copyright © 2016 Elsevier Ltd. All rights reserved.

VIP/PACAP receptor mediation of cutaneous active vasodilation during heat stress in humans

PubMed Central

Zhao, Joan L.; Wu, Yubo; Johnson, John M.

2010-01-01

Vasoactive intestinal peptide (VIP) is implicated in cutaneous active vasodilation in humans. VIP and the closely related pituitary adenylate cyclase activating peptide (PACAP) act through several receptor types: VIP through VPAC1 and VPAC2 receptors and PACAP through VPAC1, VPAC2, and PAC1 receptors. We examined participation of VPAC2 and/or PAC1 receptors in cutaneous vasodilation during heat stress by testing the effects of their specific blockade with PACAP6–38. PACAP6–38 dissolved in Ringer's was administered by intradermal microdialysis at one forearm site while a control site received Ringer's solution. Skin blood flow was monitored by laser-Doppler flowmetry (LDF). Blood pressure was monitored noninvasively and cutaneous vascular conductance (CVC) calculated. A 5- to 10-min baseline period was followed by ∼70 min of PACAP6–38 (100 μM) perfusion at one site in normothermia and a 3-min period of body cooling. Whole body heating was then performed to engage cutaneous active vasodilation and was maintained until CVC had plateaued at an elevated level at all sites for 5–10 min. Finally, 58 mM sodium nitroprusside was perfused through both microdialysis sites to effect maximal vasodilation. No CVC differences were found between control and PACAP6–38-treated sites during normothermia (19 ± 3%max untreated vs. 20 ± 3%max, PACAP6–38 treated; P > 0.05 between sites) or cold stress (11 ± 2%max untreated vs. 10 ± 2%max, PACAP6–38 treated, P > 0.05 between sites). PACAP6–38 attenuated the increase in CVC during whole body heating when compared with untreated sites (59 ± 3%max untreated vs. 46 ± 3%max, PACAP6–38 treated, P < 0.05). We conclude that VPAC2 and/or PAC1 receptor activation is involved in cutaneous active vasodilation in humans. PMID:20395540

Carbonate precipitates and bicarbonate secretion in the intestine of sea bass, Dicentrarchus labrax.

PubMed

Faggio, Caterina; Torre, Agata; Lando, Gabriele; Sabatino, Giuseppe; Trischitta, Francesca

2011-05-01

The aim of this paper was to study the chemical composition of the precipitates found in the intestine of Dicentrarchus labrax and the source of HCO(3)(-) secreted into the intestinal lumen. The chemical analysis was performed by employing the potentiometric double titration method and by means of an electron microscope coupled with a spectrometer and X-ray powder diffraction. The results obtained suggest the presence of very insoluble intestinal precipitates, presumably formed by a mixture of CaCO(3) and MgCO(3), with a higher quantity of the former with respect to the latter. HCO(3)(-) secretion rate was investigated with the aid of the pH stat method in isolated tissues mounted in Ussing chamber, where the transepithelial electrical parameters were also measured. When the serosal surface of the intestinal mucosa was bathed in HCO(3)(-)-Ringer bubbled with 1% CO(2) in O(2) while the serosal surface was bathed in HCO(3)(-) free Ringer solution bubbled with pure O(2), bicarbonate secretion proceeded at an almost stable rate of 0.9 ± 0.05 μeq cm(-2) h(-1) for about 3 h while I(sc) maintained a constant value of 38 ± 1.5 μA cm(-2). The carbonic anhydrase inhibitor ethoxyzolamide elicited a progressive reduction of HCO(3)(-) secretion that was about 75% of the initial value after 80 min. When serosal HCO(3)(-)-CO(2) saline was substituted with Hepes-O(2) saline base secretion progressively declined reaching a value of about 20% of the initial value. It was also strongly inhibited when Na(+) was substituted with the impermeant cation choline and when either DIDS or ouabain were added to the basolateral side. These results suggest that most of the bicarbonate secreted is of extracellular source and is probably transported across the basolateral membrane by both Na(+) independent mechanism and Na(+) dependent transporter, presumably a NaHCO(3) cotransport.

Fluid resuscitation with isotonic or hypertonic saline solution avoids intraneural calcium influx after traumatic brain injury associated with hemorrhagic shock.

PubMed

Balbino, Marcos; Capone Neto, Antonio; Prist, Ricardo; Ferreira, Alice Teixeira; Poli-de-Figueiredo, Luiz F

2010-04-01

Calcium is one of the triggers involved in ischemic neuronal death. Because hypotension is a strong predictor of outcome in traumatic brain injury (TBI), we tested the hypothesis that early fluid resuscitation blunts calcium influx in hemorrhagic shock associated to TBI. Fifteen ketamine-halothane anesthetized mongrel dogs (18.7 kg +/- 1.4 kg) underwent unilateral cryogenic brain injury. Blood was shed in 5 minutes to a target mean arterial pressure of 40 mm Hg to 45 mm Hg and maintained at these levels for 20 minutes (shed blood volume = 26 mL/kg +/- 7 mL/kg). Animals were then randomized into three groups: CT (controls, no fluid resuscitation), HS (7.5% NaCl, 4 mL/kg, in 5 minutes), and LR (lactate Ringer's, 33 mL/kg, in 15 minutes). Twenty minutes later, a craniotomy was performed and cerebral biopsies were obtained next to the lesion ("clinical penumbra") and from the corresponding contralateral side ("lesion's mirror") to determine intracellular calcium by fluorescence signals of Fura-2-loaded cells. Controls remained hypotensive and in a low-flow state, whereas fluid resuscitation improved hemodynamic profile. There was a significant increase in intracellular calcium in the injured hemisphere in CT (1035 nM +/- 782 nM), compared with both HS (457 nM +/- 149 nM, p = 0.028) and LR (392 nM +/- 178 nM, p = 0.017), with no differences between HS and LR (p = 0.38). Intracellular calcium at the contralateral, uninjured hemisphere was 438 nM +/- 192 nM in CT, 510 nM +/- 196 nM in HS, and 311 nM +/- 51 nM in LR, with no significant differences between them. Both small volume hypertonic saline and large volume lactated Ringer's blunts calcium influx in early stages of TBI associated to hemorrhagic shock. No fluid resuscitation strategy promotes calcium influx and further neural damage.

VIP/PACAP receptor mediation of cutaneous active vasodilation during heat stress in humans.

PubMed

Kellogg, Dean L; Zhao, Joan L; Wu, Yubo; Johnson, John M

2010-07-01

Vasoactive intestinal peptide (VIP) is implicated in cutaneous active vasodilation in humans. VIP and the closely related pituitary adenylate cyclase activating peptide (PACAP) act through several receptor types: VIP through VPAC1 and VPAC2 receptors and PACAP through VPAC1, VPAC2, and PAC1 receptors. We examined participation of VPAC2 and/or PAC1 receptors in cutaneous vasodilation during heat stress by testing the effects of their specific blockade with PACAP6-38. PACAP6-38 dissolved in Ringer's was administered by intradermal microdialysis at one forearm site while a control site received Ringer's solution. Skin blood flow was monitored by laser-Doppler flowmetry (LDF). Blood pressure was monitored noninvasively and cutaneous vascular conductance (CVC) calculated. A 5- to 10-min baseline period was followed by approximately 70 min of PACAP6-38 (100 microM) perfusion at one site in normothermia and a 3-min period of body cooling. Whole body heating was then performed to engage cutaneous active vasodilation and was maintained until CVC had plateaued at an elevated level at all sites for 5-10 min. Finally, 58 mM sodium nitroprusside was perfused through both microdialysis sites to effect maximal vasodilation. No CVC differences were found between control and PACAP6-38-treated sites during normothermia (19 +/- 3%max untreated vs. 20 +/- 3%max, PACAP6-38 treated; P > 0.05 between sites) or cold stress (11 +/- 2%max untreated vs. 10 +/- 2%max, PACAP6-38 treated, P > 0.05 between sites). PACAP6-38 attenuated the increase in CVC during whole body heating when compared with untreated sites (59 +/- 3%max untreated vs. 46 +/- 3%max, PACAP6-38 treated, P < 0.05). We conclude that VPAC2 and/or PAC1 receptor activation is involved in cutaneous active vasodilation in humans.

Arthroscopy of the fetlock joint of the dromedary camel.

PubMed

Ali, M M; Abd-Elnaeim, M

2012-01-01

To describe a technique for arthroscopy of the fetlock joint of the dromedary camel, and the problems that could occur during and after arthroscopy. Seven animals (4 cadaveric limbs and 3 living camels) were used in this study. Two dorsal arthroscopic portals (lateral and medial) and one palmaro-lateral portal were used. Distension of the joint capsule was effected by injecting Ringer´s lactate solution into the joint cavity. Landmarks for the dorsal arthroscopic portals were located at the centre of the groove bounded by the lateral branch of the suspensory ligament and the large metacarpus at a point 1 cm proximal to the joint. The palmaro-lateral portal was located in a triangular area between the branch of the suspensory ligament, the large metacarpus, and the sesamoid bone, with insertion of the arthroscope in a 45° joint flexion angle. Arthroscopy of the fetlock joint via the dorso-lateral portal allowed examination of the distal end of the large metacarpus and the proximal end of the first phalanx of the fourth digit. Arthroscopy via a dorso-medial approach allowed examination of the distal end of the large metacarpus and the proximal end of the first phalanx and the distal end of the third digit. The palmaro-lateral portal allowed examination of the sesamoid bones, the synovial membrane, and the synovial villi. The main complications recorded during arthroscopy were iatrogenic articular surface injury as well as obstruction of vision with the synovial villi. This is the first work to describe the normal arthroscopy of the fetlock joint in the dromedary camel, the arthroscopic portals, and the complications that could occur during and after arthroscopy. Further studies are required for diagnosis of pathological changes in the fetlock joint of the dromedary camel and for arthroscopy of other joints in the dromedary camel.

Effects of intraoperative administration of carbohydrates during long-duration oral and maxillofacial surgery on the metabolism of carbohydrates, proteins, and lipids.

PubMed

Yamamoto, Toru; Yoshida, Mitsuhiro; Watanabe, Seiji; Kawahara, Hiroshi

2015-12-01

Insulin resistance in patients undergoing invasive surgery impairs glucose and lipid metabolism and increases muscle protein catabolism, which may result in delayed recovery and prolonged hospital stay. We examined whether intraoperative administration of carbohydrates during long-duration oral and maxillofacial surgery under general anesthesia affects carbohydrate, proteins, and lipid metabolism and the length of hospital stay. We studied 16 patients with normal liver, kidney, and endocrine functions, and ASA physical status I or II, but without diabetes. Patients were randomly assigned to receive 0.1 g/kg/h of (n = 8) or lactated Ringer's solution (n = 8). Blood was collected before (T0) and 4 h after (T1) the start of surgery. We analyzed the plasma levels of glucose, ketone bodies, 3-methylhistidine (3-MH), and the length of hospital stay. At T0, no statistically significant differences were observed in the levels of glucose, ketone bodies, and 3-MH between the groups. At T1, no statistically significant difference in glucose levels was found between the groups. However, ketone bodies were significantly lower, and the changes in 3-MH levels were significantly less pronounced in the glucose-treated group compared with controls. No significant differences were observed between the groups in terms of length of hospital stay. The administration of low doses of glucose during surgery was safe, did not cause hyperglycemia or hypoglycemia, and inhibited lipid metabolism and protein catabolism. Additional experiments with larger cohorts will be necessary to investigate whether intraoperative management with glucose facilitates postoperative recovery of patients with oral cancer.

Dexmedetomidine-induced sedation does not mimic the neurobehavioral phenotypes of sleep in Sprague Dawley rat.

PubMed

Garrity, Abigail G; Botta, Simhadri; Lazar, Stephanie B; Swor, Erin; Vanini, Giancarlo; Baghdoyan, Helen A; Lydic, Ralph

2015-01-01

Dexmedetomidine is used clinically to induce states of sedation that have been described as homologous to nonrapid eye movement (NREM) sleep. A better understanding of the similarities and differences between NREM sleep and dexmedetomidine-induced sedation is essential for efforts to clarify the relationship between these two states. This study tested the hypothesis that dexmedetomidine-induced sedation is homologous to sleep. This study used between-groups and within-groups designs. University of Michigan. Adult male Sprague Dawley rats (n = 40). Independent variables were administration of dexmedetomidine and saline or Ringer's solution (control). Dependent variables included time spent in states of wakefulness, sleep, and sedation, electroencephalographic (EEG) power, adenosine levels in the substantia innominata (SI), and activation of pCREB and c-Fos in sleep related forebrain regions. Dexmedetomidine significantly decreased time spent in wakefulness (-49%), increased duration of sedation (1995%), increased EEG delta power (546%), and eliminated the rapid eye movement (REM) phase of sleep for 16 h. Sedation was followed by a rebound increase in NREM and REM sleep. Systemically administered dexmedetomidine significantly decreased (-39%) SI adenosine levels. Dialysis delivery of dexmedetomidine into SI did not decrease adenosine level. Systemic delivery of dexmedetomidine did not alter c-Fos or pCREB expression in the horizontal diagonal band, or ventrolateral, median, and medial preoptic areas of the hypothalamus. Dexmedetomidine significantly altered normal sleep phenotypes, and the dexmedetomidine-induced state did not compensate for sleep need. Thus, in the Sprague Dawley rat, dexmedetomidine-induced sedation is characterized by behavioral, electrographic, and immunohistochemical phenotypes that are distinctly different from similar measures obtained during sleep. © 2014 Associated Professional Sleep Societies, LLC.

Testosterone receptor blockade after trauma-hemorrhage improves cardiac and hepatic functions in males.

PubMed

Remmers, D E; Wang, P; Cioffi, W G; Bland, K I; Chaudry, I H

1997-12-01

Although studies have shown that testosterone receptor blockade with flutamide after hemorrhage restores the depressed immune function, it remains unknown whether administration of flutamide following trauma and hemorrhage and resuscitation has any salutary effects on the depressed cardiovascular and hepatocellular functions. To study this, male rats underwent a laparotomy (representing trauma) and were then bled and maintained at a mean arterial pressure (MAP) of 40 mmHg until the animals could not maintain this pressure. Ringer lactate was given to maintain a MAP of 40 mmHg until 40% of the maximal shed blood volume was returned in the form of Ringer lactate. The rats were then resuscitated with four times the shed blood volume in the form of Ringer lactate over 60 min. Flutamide (25 mg/kg) or an equal volume of the vehicle propanediol was injected subcutaneously 15 min before the end of resuscitation. Various in vivo heart performance parameters (e.g., maximal rate of the pressure increase or decrease), cardiac output, and hepatocellular function (i.e., the maximum velocity and the overall efficiency of indocyanine green clearance) were determined at 20 h after resuscitation. Additionally, hepatic microvascular blood flow (HMBF) was determined using a laser Doppler flowmeter. The results indicate that left ventricular performance, cardiac output, HMBF, and hepatocellular function decreased significantly at 20 h after the completion of trauma, hemorrhage, and resuscitation. Administration of the testosterone receptor blocker flutamide, however, significantly improved cardiac performance, HMBF, and hepatocellular function. Thus flutamide appears to be a novel and useful adjunct for improving cardiovascular and hepatocellular functions in males following trauma and hemorrhagic shock.

THE FORMATION OF MACROCYTES AND MICROCYTES FROM RED CORPUSCLES IN HANGING DROP PREPARATIONS

PubMed Central

Auer, John

1932-01-01

In hanging drop preparations of normal blood from various species of animals including man, the following processes were directly observed for the first time: 1. The process of fusion between two red corpuscles so as to form a round or slightly oval macrocyte with normal hemoglobin content, a diameter of 10µ± and no delle. These macrocytes appear to be slightly thicker in the centre than at the periphery. No thickness measurements could be made. 2. The process of fusion between two microcytes each 5µ± in diameter, so as to form a red corpuscle of approximately normal size but with dense hemoglobin and no delle. 3. The process of fusion between a red corpuscle and a microcyte, forming a macrocyte slightly larger than a normal red corpuscle and exhibiting a normal hemoglobin tint but no delle. 4. The process of microcyte formation from red corpuscles was seen occurring in four different ways: (a) By the intermittent compression of a single red corpuscle by the pull of three or more fibrin threads attached to the corpuscle. (b) By the steady, continuous compression of a single red corpuscle by the pull of two polar fibrin threads, (c) By intermittent rises of intracorpuscular pressure in a red corpuscle due to trauma, (d) By avulsion and retraction or contraction of the hemoglobin stroma from the intact surface layer of a red corpuscle. Thickness measurements in single microcytes were made in rabbit blood. 5. The process of a typical microcyte with dense hemoglobin and no delle changing back to a fairly large red corpuscle with practically normal hemoglobin tint and with a delle. 6. Macrocytes were seen expelling their hemoglobin in a fraction of a second and turning into shadows which were often paler than the background, but without any decrease in the visible surface area or change in the contour. 7. Extensibility and retractibility (or perhaps relaxation and contraction) may be exhibited by the corpuscle as a whole, by local sections of both surface layer and stroma, or retractility (contractility (?)) may be shown by the hemoglobin stroma alone. On the basis of observational evidence it is inferred that: 1. The surface layer of a red corpuscle is probably a condensed stroma rather than an anatomically defined membrane. 2. A pigment, probably hemoglobin, is present in the surface layer. 3. The surface layer of red corpuscles becomes rigid before or during spontaneous hemolysis. 4. Hemoglobin exists in an undissolved form in the intact red corpuscle. 5. The transverse diameter of microcytes (5µ±) represents the maximal shortening of which this diameter is capable in normal red corpuscles of man, rabbit and guinea pig under the conditions studied. 6. Fusing red corpuscle are destroyed by repeated washings with Ringer solution. 7. In stagnating blood there is no increase in fusion forms, nor in the production of microcytes. PMID:19870085

The effects of tetracaine on charge movement in fast twitch rat skeletal muscle fibres.

PubMed

Hollingworth, S; Marshall, M W; Robson, E

1990-02-01

1. The effects of tetracaine, a local anaesthetic that inhibits muscle contraction, on membrane potential and intramembrane charge movements were investigated in fast twitch rat muscle fibres (extensor digitorum longus). 2. The resting membrane potentials of surface fibres from muscles bathed in isotonic Ringer solution containing 2 mM-tetracaine were well maintained, but higher concentrations of tetracaine caused a time-dependent fall of potential. Muscle fibres bathed in hypertonic solutions containing 2 mM-tetracaine were rapidly depolarized. In both isotonic and hypertonic solutions, the depolarizing effect of tetracaine could not be reversed. 3. Charge movement measurements were made using the middle-of-the-fibre voltage clamp technique. The voltage dependence of charge movements measured in cold isotonic solutions was well fitted by a Boltzmann distribution (Q(V) = Qmax/(1 + exp(-(V-V)/k] where Qmax = 37.3 +/- 2.8 nC muF-1, V = -17.9 +/- 1.2 mV and k = 12.6 +/- 0.8 mV (n = 6, 2 degrees C; means +/- S.E. of means). Similar values were obtained when 2 mM-tetracaine was added to the isotonic bathing fluid (Qmax = 40.6 +/- 2.3 nC microF-1, V = -14.1 +/- 1.3 mV, k = 15.3 +/- 0.8 mV; n = 8, 2 degrees C). 4. Charge movements measured around mechanical threshold in muscle fibres bathed in hypertonic solutions were reduced when 2 mM-tetracaine was added to the bathing fluid. The tetracaine-sensitive component of charge was well fitted with an unconstrained Boltzmann distribution which gave: Qmax = 7.5 nC microF-1, V = -46.5 mV, k = 5.5 mV. The e-fold rise of the foot of the curve was 9.3 mV.

The effects of tetracaine on charge movement in fast twitch rat skeletal muscle fibres.

PubMed Central

Hollingworth, S; Marshall, M W; Robson, E

1990-01-01

1. The effects of tetracaine, a local anaesthetic that inhibits muscle contraction, on membrane potential and intramembrane charge movements were investigated in fast twitch rat muscle fibres (extensor digitorum longus). 2. The resting membrane potentials of surface fibres from muscles bathed in isotonic Ringer solution containing 2 mM-tetracaine were well maintained, but higher concentrations of tetracaine caused a time-dependent fall of potential. Muscle fibres bathed in hypertonic solutions containing 2 mM-tetracaine were rapidly depolarized. In both isotonic and hypertonic solutions, the depolarizing effect of tetracaine could not be reversed. 3. Charge movement measurements were made using the middle-of-the-fibre voltage clamp technique. The voltage dependence of charge movements measured in cold isotonic solutions was well fitted by a Boltzmann distribution (Q(V) = Qmax/(1 + exp(-(V-V)/k] where Qmax = 37.3 +/- 2.8 nC muF-1, V = -17.9 +/- 1.2 mV and k = 12.6 +/- 0.8 mV (n = 6, 2 degrees C; means +/- S.E. of means). Similar values were obtained when 2 mM-tetracaine was added to the isotonic bathing fluid (Qmax = 40.6 +/- 2.3 nC microF-1, V = -14.1 +/- 1.3 mV, k = 15.3 +/- 0.8 mV; n = 8, 2 degrees C). 4. Charge movements measured around mechanical threshold in muscle fibres bathed in hypertonic solutions were reduced when 2 mM-tetracaine was added to the bathing fluid. The tetracaine-sensitive component of charge was well fitted with an unconstrained Boltzmann distribution which gave: Qmax = 7.5 nC microF-1, V = -46.5 mV, k = 5.5 mV. The e-fold rise of the foot of the curve was 9.3 mV. PMID:2348406

Electrochemical behavior and biological response of Mesenchymal Stem Cells on cp-Ti after N-ions implantation

NASA Astrophysics Data System (ADS)

Rizwan, M.; Ahmad, A.; Deen, K. M.; Haider, W.

2014-11-01

Titanium and its alloys are most widely used as implant materials due to their excellent biocompatibility, mechanical properties and chemical stability. In this study Nitrogen ions of known dosage were implanted over cp-Ti by Pelletron accelerator with beam energy of 0.25 MeV.The atomic force microscopy of bare and nitrogen implanted specimens confirmed increase in surface roughness with increase in nitrogen ions concentration. X-ray diffraction patterns of ions implanted surfaces validated the formation of TiN0.3 and Ti3N2-xnitride phases. The tendency to form passive film and electrochemical behavior of these surfaces in ringer lactate (RL) solution was evaluated by Potentiodynamic polarization and electrochemical impedance spectroscopy respectively. It is proved that nitrogen ions implantation was beneficial to reduce corrosion rate and stabilizing passive film by increasing charge transfer resistance in RL. It was concluded that morphology and proliferation of Mesenchymal Stem Cells on nitrogen ions implanted surfaces strongly depends on surface roughness and nitride phases.

Characterization of the Micro-Abrasive Wear in Coatings of TaC-HfC/Au for Biomedical Implants

PubMed Central

Guzmán, Pablo; Yate, Luis; Sandoval, Mercy; Caballero, Jose

2017-01-01

The object of this work was the deposition of a Ta-Hf-C thin film with a gold interlayer on stainless steel, via the physical vapor deposition (PVD) technique, in order to evaluate the properties of different systems subjected to micro-abrasive wear phenomena generated by alumina particles in Ringer's solution. The surface characterization was performed using a scanning electron microscope (SEM) and atomic force microscope (AFM). The crystallographic phases exhibited for each coating were obtained by X-ray diffraction (XRD). As a consequence of modifying the composition of Ta-Hf there was evidence of an improvement in the micro-abrasive wear resistance and, for each system, the wear constants that confirm the enhancement of the surface were calculated. Likewise, these surfaces can be bioactive, generating an alternative to improve the biological fixation of the implants, therefore, the coatings of TaC-HfC/Au contribute in the development of the new generation of orthopedic implants. PMID:28773207

Diagnostic peritoneal lavage: volume of lavage effluent needed for accurate determination of a negative lavage.

PubMed

Sweeney, J F; Albrink, M H; Bischof, E; McAllister, E W; Rosemurgy, A S

1994-12-01

While the ability of diagnostic peritoneal lavage (DPL) to 'rule out' occult intra-abdominal injuries has been well established, the volume of lavage effluent necessary for accurate prediction of a negative lavage has not been determined. To address this, 60 injured adults with blunt (N = 45) or penetrating (N = 15) trauma undergoing DPL were evaluated prospectively through protocol. After infusion of 1l of Ringer's lactate solution, samples of lavage effluent were obtained at 100 cm3, 250 cm3, 500 cm3, and 759 cm3, and when no more effluent could be returned (final sample). DPL was considered negative if final sample RBC count was < or = 100,000/mm3 for blunt injury and < 50,000/mm3 for penetrating injury. The conclusion is that at 100 cm3 of lavage effluent returned, negative results are highly predictive of a negative DPL (98 per cent), though 250 cm3 of lavage effluent is required to predict a negative DPL uniformly (100 per cent).

Impact of simulated microgravity and caloric restriction on autonomic nervous system function in adipose tissue

NASA Astrophysics Data System (ADS)

Boschmann, Michael; Adams, Frauke; Tank, Jens; Schaller, Karin; Boese, Andrea; Heer, Martina; Klause, Susanne; Luft, Friedrich C.; Jordan, Jens

2005-08-01

Long term immobilization and reduced food intake is often associated with development of orthostatic intolerance. Blocking the norepinephrine transporter (NET) can also mimic symptoms of orthostatic intolerance. Therefore, we hypothesized that simulated microgravity (14 days bed rest at head down tilt, BR) can cause changes in postganglionic NET function and adrenoreceptor (AR) sensitivity and these changes can be aggravated by hypocaloric food intake. For testing, two microdialysis probes were inserted into subcutaneous adipose tissue of eight young healthy men at day 1 and 14 of BR and perfused with Ringer's solution and increasing doses of tyramine and isoproterenol in order to simulate NET blockade and stimulate AR, respectively. At day 14 of eucaloric diet and BR, isoproterenol induced lipolysis was greater, whereas at day 14 of hypocaloric diet and BR, tyramine induced lipolysis was greater when compared to day 1. Therefore, the nutritional state affects NET function and AR sensitivity differently during BR.

Failure of the human lumbar motion-segments resulting from anterior shear fatigue loading

PubMed Central

SKRZYPIEC, Daniel M.; NAGEL, Katrin; SELLENSCHLOH, Kay; KLEIN, Anke; PÜSCHEL, Klaus; MORLOCK, Michael M.; HUBER, Gerd

2016-01-01

An in-vitro experiment was designed to investigate the mode of failure following shear fatigue loading of lumbar motion-segments. Human male lumbar motion-segments (age 32–42 years, n=6) were immersed in Ringer solution at 37°C and repeatedly loaded, using a modified materials testing machine. Fatigue loading consisted of a sinusoidal shear load from 0 N to 1,500 N (750 N±750 N) applied to the upper vertebra of the motion-segment, at a frequency of 5 Hz. During fatigue experiments, several failure events were observed in the dynamic creep curves. Post-test x-ray, CT and dissection revealed that all specimens had delamination of the intervertebral disc. Anterior shear fatigue predominantly resulted in fracture of the apophyseal processes of the upper vertebrae (n=4). Exposure to the anterior shear fatigue loading caused motion-segment instability and resulted in vertebral slip corresponding to grade I and ‘mild’ grade II spondylolisthesis, as observed clinically. PMID:26829975

Corrosion behaviour and biocompatibility of a novel Ni-free intermetallic coating growth on austenitic steel by hot dipping in an Al-12.6%Si alloy.

PubMed

Arenas, M A; Frutos, E; Saldaña, L; Conde, A; Labajos-Broncano, L; González-Martín, M L; González-Carrasco, J L; Vilaboa, N

2011-04-01

Commercial 316 LVM austenitic stainless steel samples have been coated by immersion in a bath of molten Al-12.6%Si alloy for 120 s. The coating consists of the Al(12)(Fe,Cr)(3)Si(2) intermetallic. In vitro corrosion behaviour has been evaluated in the Ringer's solution by means of potentiodynamic curves and electrochemical impedance spectroscopy. The results reveal that the coated specimens exhibit lower susceptibility to localised corrosion with respect to the substrate. XPS analysis suggests that the ennoblement of the pitting potential is due to the formation of a chromium oxyhydroxide containing passive layer. The intermetallic coating shows a good biocompatibility, as demonstrated by culturing human mesenchymal stem cells isolated from bone marrow which attached, grew and differentiated to the osteoblastic lineage to a similar extent on coated and bare steels. In summary, this study proposes a method that generates Ni-free coatings of the stainless steel with useful properties for biomedical applications.

Sodium ion transport participates in non-neuronal acetylcholine release in the renal cortex of anesthetized rabbits.

PubMed

Shimizu, Shuji; Akiyama, Tsuyoshi; Kawada, Toru; Sata, Yusuke; Turner, Michael James; Fukumitsu, Masafumi; Yamamoto, Hiromi; Kamiya, Atsunori; Shishido, Toshiaki; Sugimachi, Masaru

2017-09-01

This study examined the mechanism of release of endogenous acetylcholine (ACh) in rabbit renal cortex by applying a microdialysis technique. In anesthetized rabbits, a microdialysis probe was implanted into the renal cortex and perfused with Ringer's solution containing high potassium concentration, high sodium concentration, a Na + /K + -ATPase inhibitor (ouabain), or an epithelial Na + channel blocker (benzamil). Dialysate samples were collected at baseline and during exposure to each agent, and ACh concentrations in the samples were measured by high-performance liquid chromatography. High potassium had no effect on renal ACh release. High sodium increased dialysate ACh concentrations significantly. Ouabain increased dialysate ACh concentration significantly. Benzamil decreased dialysate ACh concentrations significantly both at baseline and under high sodium. The finding that high potassium-induced depolarization does not increase ACh release suggests that endogenous ACh is released in renal cortex mainly by non-neuronal mechanism. Sodium ion transport may be involved in the non-neuronal ACh release.

Methods for stable recording of short-circuit current in a Na+-transporting epithelium.

PubMed

Gondzik, Veronika; Awayda, Mouhamed S

2011-07-01

Epithelial Na(+) transport as measured by a variety of techniques, including the short-circuit current technique, has been described to exhibit a "rundown" phenomenon. This phenomenon manifests as time-dependent decrease of current and resistance and precludes the ability to carry out prolonged experiments aimed at examining the regulation of this transport. We developed methods for prolonged stable recordings of epithelial Na(+) transport using modifications of the short-circuit current technique and commercial Ussing-type chambers. We utilize the polarized MDCK cell line expressing the epithelial Na(+) channel (ENaC) to describe these methods. Briefly, existing commercial chambers were modified to allow continuous flow of Ringer solution and precise control of such flow. Chamber manifolds and associated plumbing were modified to allow precise temperature clamp preventing temperature oscillations. Recording electrodes were modified to eliminate the use of KCl and prevent membrane depolarization from KCl leakage. Solutions utilized standard bicarbonate-based buffers, but all gasses were prehydrated to clamp buffer osmolarity. We demonstrate that these modifications result in measurements of current and resistance that are stable for at least 2 h. We further demonstrate that drifts in osmolarity similar to those obtained before prior to our modifications can lead to a decrease of current and resistance similar to those attributed to rundown.

Elicitation of spreading depression by rose bengal photodynamic action.

PubMed

Netto, M; Martins-Ferreira, H

1989-08-01

Spreading depression refers to a slowly propagating depression of the ordinary electrical activity of the nervous tissue. It can be elicited by different types of physical or chemical non-specific stimuli. Various evidences suggest that transient alterations of cell membranes are involved. For this reason, and considering the action of free radicals on cell membranes, the elicitation of the reaction by dye photoactivation has been investigated. Isolated chick retina superfused in the dark with Ringer solution was able to regularly exhibit spreading depression when submitted to 1 microM rose bengal pulse of 5 min in duration, followed by 2.1 x 10(4) to 4.2 x 10(4) Jm-2 light pulse. The phenomenon was monitored either by visual inspection of the light-scattering milky wave that accompanies the reaction or by recording its characteristic slow voltage variation. The reaction was not triggered if the retina, superfused with the dye, was (a) maintained in the dark; (b) illuminated with red light (3.75 x 10(2) to 2.25 x 10(4) Jm-2), or (c) stimulated by white light but superfused with nitrogen-saturated solutions. It is concluded that, under the present conditions, the elicitation of spreading depression is contingent on the photoactivation of rose bengal in the presence of oxygen.

Post-hypoxic cellular disintegration in glycine-preserved renal tubules is attenuated by hydroxyl radical scavengers and iron chelators.

PubMed

Moussavian, Mohammed R; Slotta, Jan E; Kollmar, Otto; Menger, Michael D; Gronow, Gernot; Schilling, Martin K

2008-05-01

Cellular stress during reoxygenation is a common phenomenon in solid organ transplantation and is characterized by production of reactive oxygen species. Herein, we studied in isolated tubular segments of rat kidney cortex the impact of oxygen radical scavengers and an iron chelator on post-hypoxic recovery. Tubules, suspended in Ringer's solution containing 5 mM glycine, underwent 30 min hypoxia and 60 min reoxygenation. Untreated tubules served as controls. Hypoxia-reoxygenation injury was measured by membrane leakage, lipid peroxidation and cellular functions. In hypoxia-reoxygenated-isolated tubular segments, protective effects of different scavengers and of the iron chelator deferoxamine on hypoxia-reoxygenation injury were analyzed. Scavengers protected isolated tubular segments from hypoxia-reoxygenation-induced cellular disintegration and dysfunction. Deferoxamine was found to exert the most distinct protection. It was further found to exert a dose-dependent protection on hypoxia-reoxygenation damage in isolated tubular segments, which was critically mediated by chelating tissue and bond iron. Our data demonstrate that radical scavengers effectively protect from hypoxia-reoxygenation injury in isolated tubular segments and that the iron chelator deferoxamine is especially a potent inhibitor of iron ion-mediated hypoxia-reoxygenation damage. Thus, inclusion of this iron chelator in organ storage solutions might improve post-transplant organ function and protect from reperfusion injury.

Influence of calcium precursors on the morphology and crystallinity of sol gel-derived hydroxyapatite nanoparticles

NASA Astrophysics Data System (ADS)

Vijayalakshmi Natarajan, U.; Rajeswari, S.

2008-10-01

Nanosized hydroxyapatite (HAP) particles were prepared by sol-gel method from the water-based solution of calcium and phosphorus precursor. In this study, two calcium precursors such as calcium nitrate tetrahydrate and calcium acetate were chosen as calcium precursors. The influence of aging period, pH, viscosity and sintering temperature on crystallinity and morphology of the HAP particles were investigated for the two calcium precursors with triethyl phosphate precursor. The morphology of nano-HAP towards phosphorous precursor was dependent on the type of calcium precursor used. The HAP prepared from calcium nitrate and triethyl phosphate was spherically shaped whereas the one from calcium acetate was found to be fibrous in structure. Both HAPs were stable up to 1200 °C and their crystallinity increased with respect to the sintering temperature. The obtained sample was characterized through X-ray diffraction (XRD), P 31 nuclear magnetic resonance (NMR), scanning electronic microscopy (SEM) and TEM analysis. The sol derived from the optimized aging period for the two different calcium precursors was coated on 316L stainless-steel (SS) implant and its corrosion resistivity during long-term implantation was studied by cyclic polarization in Ringer's solution. Both HAPs have their own desirable qualities and were found to be corrosion resistive.

Patients with glycogen storage diseases undergoing anesthesia: a case series.

PubMed

Gurrieri, Carmelina; Sprung, Juraj; Weingarten, Toby N; Warner, Mary E

2017-10-06

Glycogen storage diseases are rare genetic disorders of glycogen synthesis, degradation, or metabolism regulation. When these patients are subjected to anesthesia, perioperative complications can develop, including hypoglycemia, rhabdomyolysis, myoglobinuria, acute renal failure, and postoperative fatigue. The objective of this study was to describe the perioperative course of a cohort of patients with glycogen storage diseases. This is a retrospective review of patients with glycogen storage diseases undergoing anesthetic care at our institution from January 1, 1990, through June 30, 2015 to assess perioperative management and outcomes. We identified 30 patients with a glycogen storage disease who underwent 41 procedures under anesthesia management. Intraoperative lactic acidosis developed during 4 major surgeries (3 liver transplants, 1 myectomy), and in all cases resolved within 24 postoperative hours. Lactated Ringer solution was used frequently. Preoperative and intraoperative hypoglycemia was noted in some patients with glycogen storage disease type I, all of which responded to administration of dextrose-containing solutions. No serious postoperative complications occurred. Patients with glycogen storage disease, despite substantial comorbid conditions, tolerates the anesthetic management without major complications. Several patients who experienced self-limited metabolic acidosis were undergoing major surgical procedures, during which acidosis could be anticipated. Close monitoring and management of blood glucose levels of patients with glycogen storage disease type I is prudent.

Structural Analysis, Electrochemical Behavior, and Biocompatibility of Novel Quaternary Titanium Alloy with near β Structure

NASA Astrophysics Data System (ADS)

Popa, Monica; Calderon Moreno, Jose Maria; Vasilescu, Cora; Drob, Silviu Iulian; Neacsu, Elena Ionela; Coer, Andrej; Hmeljak, Julija; Zerjav, Gregor; Milošev, Ingrid

2014-06-01

This article analyses the microstructure, electrochemical behavior, and biocompatibility of a novel Ti-20Nb-10Zr-5Ta alloy with low Young's modulus (59 GPa) much closer to that of bone, between 10 and 30 GPa, than Ti and other Ti alloys used as implant biomaterial. XRD and SEM measurements revealed a near β crystalline microstructure containing β phase matrix and secondary α phase, with a typical grain size of around 200 μm. The corrosion behavior in neutral Ringer solution evidenced: self-passivation behavior characterizing a very resistant passive film; an easy passivation as a result of favorable influence of the alloying elements Nb, Zr, and Ta that participate with their passive oxides to the formation of the alloy passive film; low corrosion and ion release rates corresponding with very low toxicity. In MEM solution, the novel alloy demonstrated very high corrosion resistance and no susceptibility to localized corrosion. Biocompatibility was evaluated on in vitro human osteoblast-like and human immortalized pulmonary fibroblast cell (Wi-38) lines and the new Ti-20Nb-10Zr-5Ta alloy exhibited no cytotoxicity. The new Ti-20Nb-10Zr5Ta alloy is a promising material for implants due to combined properties of low elastic modulus, very low corrosion rate, and good biocompatibility.

Equivalent Aqueous Phase Modulation of Domain Segregation in Myelin Monolayers and Bilayer Vesicles

PubMed Central

Oliveira, Rafael G.; Schneck, Emanuel; Funari, Sergio S.; Tanaka, Motomu; Maggio, Bruno

2010-01-01

Purified myelin can be spread as monomolecular films at the air/aqueous interface. These films were visualized by fluorescence and Brewster angle microscopy, showing phase coexistence at low and medium surface pressures (<20–30 mN/m). Beyond this threshold, the film becomes homogeneous or not, depending on the aqueous subphase composition. Pure water as well as sucrose, glycerol, dimethylsulfoxide, and dimethylformamide solutions (20% in water) produced monolayers that become homogeneous at high surface pressures; on the other hand, the presence of salts (NaCl, CaCl2) in Ringer's and physiological solution leads to phase domain microheterogeneity over the whole compression isotherm. These results show that surface heterogeneity is favored by the ionic milieu. The modulation of the phase-mixing behavior in monolayers is paralleled by the behavior of multilamellar vesicles as determined by small-angle and wide-angle x-ray scattering. The correspondence of the behavior of monolayers and multilayers is achieved only at high surface pressures near the equilibrium adsorption surface pressure; at lower surface pressures, the correspondence breaks down. The equilibrium surface tension on all subphases corresponds to that of the air/alkane interface (27 mN/m), independently on the surface tension of the clean subphase. PMID:20816062

Effect of the colloids gelatin and HES 130/0.4 on blood coagulation in cardiac surgery patients: a randomized controlled trial.

PubMed

Kimenai, D M; Bastianen, G W; Daane, C R; Megens-Bastiaanse, C M; van der Meer, N J M; Scohy, T V; Gerritse, B M

2013-11-01

The choice of the prime solution for cardiopulmonary bypass can play an important role in limiting the effect on blood coagulation, but it is still unclear what the effect of colloids on blood coagulation is. The aim of this study was to investigate the effect of synthetic colloids on blood loss and blood coagulation in patients after on-pump coronary artery bypass graft (CABG) procedures. Sixty elective, on-pump CABG patients were randomly assigned to receive the prime solutions lactated Ringer's solution combined with hydroxyethyl starch 130/0.4 (HES, 6% Volulyte, Fresenius Kabi Nederland BV, Zeist, the Netherlands) (HES group) or gelatin (Gelofusin(®), B Braun Melsung AG, Melsungen, Germany) (Gelo group). Blood loss was assessed using post-operative chest tube output; secondary endpoints were number of blood component transfusions, routine coagulation test values and rotation thromboelastometry values (Rotem(®) delta, Pentapharm GmbH, Munich, Germany). Total post-operative chest tube output was 500 ± 420 ml in the HES group versus 465 ± 390 ml in the Gelo group (p = 0.48). No significant differences were observed in any of the routine coagulation tests values, thromboelastometry parameters or number of blood component transfusions between the groups. In this randomized, controlled trial of adults after on-pump CABG procedures, there was no significant difference in blood loss or blood coagulation between the HES group and the Gelo group.

Comparison of three methods of sampling for endometrial cytology in the mare. Preliminary study.

PubMed

Defontis, M; Vaillancourt, D; Grand, F X

2011-01-01

This prospective study aims to compare three different sampling techniques for the collection of endometrial cytological specimens in the mare: the guarded culture swab, the uterine cytobrush and the low volume uterine flush. The study population consisted of six healthy Standardbred mares in dioestrus. In each mare an acute endometritis was induced by performing a low- volume uterine flush 6days after ovulation using a sterile isotonic solution (lactated Ringer's solution or ViGro™ Complete Flush Solution). Two days after initiating inflammation, samples were collected from each mare using the three compared techniques: the double guarded cotton swab, the uterine cytobrush and the low volume uterine flush. The cytological evaluation of the samples was based on following criteria: the quality and cellularity of the samples and the number of neutrophils recovered. The uterine cytobrush yielded slides of significantly (p=0.02) better quality than the low volume uterine flush. There was no significant difference between the cytobrush and the double guarded swab technique for the quality. There was no difference between techniques in the number of endometrial cells (p=0.55) and neutrophils recovered (p=0.28). Endometrial cytology is a practical method for the diagnosis of acute endometrial inflammation in the mare. Since no difference in the number of neutrophils was found between the three techniques, the choice of the sampling method should be based on other factors such as practicability, costs and disadvantages of each technique.

Cerebrospinal fluid pulse pressure amplitude during lumbar infusion in idiopathic normal pressure hydrocephalus can predict response to shunting

PubMed Central

2010-01-01

Background We have previously seen that idiopathic normal pressure hydrocephalus (iNPH) patients having elevated intracranial pressure (ICP) pulse amplitude consistently respond to shunt surgery. In this study we explored how the cerebrospinal fluid pressure (CSFP) pulse amplitude determined during lumbar infusion testing, correlates with ICP pulse amplitude determined during over-night ICP monitoring and with response to shunt surgery. Our goal was to establish a more reliable screening procedure for selecting iNPH patients for shunt surgery using lumbar intrathecal infusion. Methods The study population consisted of all iNPH patients undergoing both diagnostic lumbar infusion testing and continuous over-night ICP monitoring during the period 2002-2007. The severity of iNPH was assessed using our NPH grading scale before surgery and 12 months after shunting. The CSFP pulse was characterized from the amplitude of single pressure waves. Results Totally 62 iNPH patients were included, 45 of them underwent shunt surgery, in whom 78% were shunt responders. Among the 45 shunted patients, resistance to CSF outflow (Rout) was elevated (≥ 12 mmHg/ml/min) in 44. The ICP pulse amplitude recorded over-night was elevated (i.e. mean ICP wave amplitude ≥ 4 mmHg) in 68% of patients; 92% of these were shunt responders. In those with elevated overnight ICP pulse amplitude, we found also elevated CSFP pulse amplitude recorded during lumbar infusion testing, both during the opening phase following lumbar puncture and during a standardized period of lumbar infusion (15 ml Ringer over 10 min). The clinical response to shunting after 1 year strongly associated with the over-night ICP pulse amplitude, and also with the pulsatile CSFP during the period of lumbar infusion. Elevated CSFP pulse amplitude during lumbar infusion thus predicted shunt response with sensitivity of 88 and specificity of 60 (positive and negative predictive values of 89 and 60, respectively). Conclusions In iNPH patients, shunt response can be anticipated in 9/10 patients with elevated overnight ICP pulse amplitude, while in only 1/10 with low ICP pulse amplitude. Additionally, the CSFP pulse amplitude during lumbar infusion testing was elevated in patients with elevated over-night ICP pulse amplitude. In particular, measurement of CSFP pulse amplitude during a standardized infusion of 15 ml Ringer over 10 min was useful in predicting response to shunt surgery and can be used as a screening procedure for selection of iNPH patients for shunting. PMID:20205911

The Weak-Line T Tauri Star V410 Tau

DTIC Science & Technology

2003-01-01

700052 Tashkent, Uzbekistan 7 USRA/USNO Flagstaff Station, PO Box 1149, Flagstaff, AZ 86002-1149, USA 8 Thüringer Landessternwarte, Karl ... Schwarzschild -Observatorium, Sternwarte 5, 07778 Tautenburg, Germany 9 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA 10

Primary afferent activity, putative excitatory transmitters and extracellular potassium levels in frog spinal cord.

PubMed Central

Davidoff, R A; Hackman, J C; Holohean, A M; Vega, J L; Zhang, D X

1988-01-01

1. Changes in extracellular K+ activity were measured with ion-selective microelectrodes in the grey matter of the isolated hemisected frog spinal cord. The magnitude of the elevation of [K+]o (delta[K+]o) produced by repetitive stimulation (25 Hz, 10 s) of afferent fibres in the sciatic nerve was monotonically related to the strength of the electrical stimuli applied to the sciatic nerve. Repetitive stimulation of the largest diameter A alpha and A beta fibres, which were found histologically to comprise only 11% of the afferent axons in the dorsal root, elevated [K+]o to approximately 60% of the maximum level seen when all afferent fibres were stimulated. 2. Addition of Mg2+ (20 mM) to Ringer solution devoid of Mg2+ reduced delta[K+]o by over 85% suggesting that about 15% of delta[K+]o results from action potentials in presynaptic primary afferents. When 20 mM-Mg2+ was added to spinal cords bathed in Ringer solution containing a physiological (i.e. 1.0 mM) concentration of Mg2+, delta[K+]o was reduced by ca. 65-75% indicating that in spinal cords bathed in medium containing 'physiological' concentrations of Mg2+ about 25-35% of the K+ is released from primary afferent fibres. 3. Application of excitatory amino acids and agonists increased [K+]o with the following potency pattern: quisqualate greater than kainate greater than NMDA (N-methyl-D-aspartate) greater than glutamate greater than aspartate. 4. D(-)-2-Amino-5-phosphonovalerate (APV), an NMDA antagonist, reduced [K+]o by only about 50%, but kynurenate, an NMDA and non-NMDA antagonist, reduced [K+]o by approximately 85%; i.e. the same levels observed when synaptic transmission was blocked with 20 mM-Mg2+. These findings support the idea that synaptic release of excitatory amino acids such as L-glutamate and/or L-aspartate and subsequent activation of specific receptors by these putative transmitters are necessary for the postsynaptic component of delta[K+]o. 5. Addition of tachykinins elevated [K+]o but the effect appeared to require the participation of excitatory amino acids because it was blocked by APV and by kynurenate. 6. The finding that tetrodotoxin substantially reduced the ability of excitatory amino acid agonists and tachykinins to elevate [K+]o suggests that discharges in interneurones as a result of excitatory amino acid receptor activation are responsible for the postsynaptic component of delta[K+]o. PMID:3261795

Primary afferent activity, putative excitatory transmitters and extracellular potassium levels in frog spinal cord.

PubMed

Davidoff, R A; Hackman, J C; Holohean, A M; Vega, J L; Zhang, D X

1988-03-01

1. Changes in extracellular K+ activity were measured with ion-selective microelectrodes in the grey matter of the isolated hemisected frog spinal cord. The magnitude of the elevation of [K+]o (delta[K+]o) produced by repetitive stimulation (25 Hz, 10 s) of afferent fibres in the sciatic nerve was monotonically related to the strength of the electrical stimuli applied to the sciatic nerve. Repetitive stimulation of the largest diameter A alpha and A beta fibres, which were found histologically to comprise only 11% of the afferent axons in the dorsal root, elevated [K+]o to approximately 60% of the maximum level seen when all afferent fibres were stimulated. 2. Addition of Mg2+ (20 mM) to Ringer solution devoid of Mg2+ reduced delta[K+]o by over 85% suggesting that about 15% of delta[K+]o results from action potentials in presynaptic primary afferents. When 20 mM-Mg2+ was added to spinal cords bathed in Ringer solution containing a physiological (i.e. 1.0 mM) concentration of Mg2+, delta[K+]o was reduced by ca. 65-75% indicating that in spinal cords bathed in medium containing 'physiological' concentrations of Mg2+ about 25-35% of the K+ is released from primary afferent fibres. 3. Application of excitatory amino acids and agonists increased [K+]o with the following potency pattern: quisqualate greater than kainate greater than NMDA (N-methyl-D-aspartate) greater than glutamate greater than aspartate. 4. D(-)-2-Amino-5-phosphonovalerate (APV), an NMDA antagonist, reduced [K+]o by only about 50%, but kynurenate, an NMDA and non-NMDA antagonist, reduced [K+]o by approximately 85%; i.e. the same levels observed when synaptic transmission was blocked with 20 mM-Mg2+. These findings support the idea that synaptic release of excitatory amino acids such as L-glutamate and/or L-aspartate and subsequent activation of specific receptors by these putative transmitters are necessary for the postsynaptic component of delta[K+]o. 5. Addition of tachykinins elevated [K+]o but the effect appeared to require the participation of excitatory amino acids because it was blocked by APV and by kynurenate. 6. The finding that tetrodotoxin substantially reduced the ability of excitatory amino acid agonists and tachykinins to elevate [K+]o suggests that discharges in interneurones as a result of excitatory amino acid receptor activation are responsible for the postsynaptic component of delta[K+]o.

Anatomy "Steeplechase" Online: Necessity Sometimes Is the Catalyst for Innovation

ERIC Educational Resources Information Center

Inuwa, Ibrahim Muhammad; Al Rawahy, Maimouna; Taranikanti, Varna; Habbal, Omar

2011-01-01

In most medical schools, summative practical examination in Anatomy usually takes the format of a "steeplechase" ("spotters" or "bell ringers") conducted in the gross anatomy laboratory using cadaveric material and prosected specimens. Recently, we have started to administer similar examinations online using the quiz…

Transcranial direct current stimulation transiently increases the blood-brain barrier solute permeability in vivo

NASA Astrophysics Data System (ADS)

Shin, Da Wi; Khadka, Niranjan; Fan, Jie; Bikson, Marom; Fu, Bingmei M.

2016-03-01

Transcranial Direct Current Stimulation (tDCS) is a non-invasive electrical stimulation technique investigated for a broad range of medical and performance indications. Whereas prior studies have focused exclusively on direct neuron polarization, our hypothesis is that tDCS directly modulates endothelial cells leading to transient changes in blood-brain-barrier (BBB) permeability (P) that are highly meaningful for neuronal activity. For this, we developed state-of-the-art imaging and animal models to quantify P to various sized solutes after tDCS treatment. tDCS was administered using a constant current stimulator to deliver a 1mA current to the right frontal cortex of rat (approximately 2 mm posterior to bregma and 2 mm right to sagittal suture) to obtain similar physiological outcome as that in the human tDCS application studies. Sodium fluorescein (MW=376), or FITC-dextrans (20K and 70K), in 1% BSA mammalian Ringer was injected into the rat (SD, 250-300g) cerebral circulation via the ipsilateral carotid artery by a syringe pump at a constant rate of ~3 ml/min. To determine P, multiphoton microscopy with 800-850 nm wavelength laser was applied to take the images from the region of interest (ROI) with proper microvessels, which are 100-200 micron below the pia mater. It shows that the relative increase in P is about 8-fold for small solute, sodium fluorescein, ~35-fold for both intermediate sized (Dex-20k) and large (Dex-70k) solutes, 10 min after 20 min tDCS pretreatment. All of the increased permeability returns to the control after 20 min post treatment. The results confirmed our hypothesis.

Work with Us | Advanced Manufacturing Research | NREL

Science.gov Websites

advanced manufacturing R&D project through analysis and our world-class facilities. Contact Us Headshot of a man Matthew Ringer Laboratory Program Manager, Advanced Manufacturing Email | 303-275-4469 facilities for your advanced manufacturing R&D projects. License Our Technologies See our technologies

Energy Innovation Portal Bridging Information Gap - Continuum Magazine |

Science.gov Websites

NASA and Sandia National Laboratories have adopted its architecture for their own tech transfer sites : Battelle Memorial Institute Colorado School of Mines Great Lakes Bioenergy Research Center NASA Naval Research Laboratory University of Colorado. NASA, which became a partner after Ringer approached them

Navigating the Grad School Application Process: A Training Schedule

ERIC Educational Resources Information Center

Swindlehurst, Garrett R.; Bullard, Lisa G.

2014-01-01

Through a simple step-by-step guide for navigating the graduate school application process, a graduate student who's been through the ringer and a faculty advisor who knows the ropes offer advice to walk prospective grad students through the process of successfully entering graduate school. A repeat printing.

A Filtering Method to Reveal Crystalline Patterns from Atom Probe Microscopy Desorption Maps

DTIC Science & Technology

2016-03-26

Gault, S.P. Ringer, J.M. Cairney, Atom probe crystallography : characterization of grain boundary orientation relationships in nanocrystalline...J.M. Cairney, Atom probe crystallography : atomic- scale 3-D orientation mapping, Scr. Mater. 66 (11) (2012) 907. L. Yao /MethodsX 3 (2016) 268–273 273

Further evidence for a potassium-like action of lithium ions on sodium efflux in frog skeletal muscle

PubMed Central

Beaugé, L. A.; Ortiz, Olga

1972-01-01

1. The efflux of labelled sodium as well as net sodium and lithium changes were studied in aged high sodium sartorius muscles of the South American frog Leptodactilus ocelatus. 2. In the presence of 2·5 mM potassium in the media, the replacement of external sodium with lithium or magnesium resulted in an increase in sodium efflux. The magnitude of such increase was always larger in lithium. 3. With the absence of potassium in the media, the response of sodium efflux to replacement of external sodium varied with the cation used as a substitute. In lithium Ringer there was always a noticeable increase, whereas in magnesium there was always a marked reduction. The same results were observed when calcium was substituted for magnesium. 4. The replacement of 60 mM external sodium with sucrose did not prevent the stimulating effect of 5 mM potassium on sodium efflux, nor the inhibitory action of 10-4 M ouabain. This indicates that neither sucrose by itself, nor the lowering of the ionic strength, modified to an appreciable extent the function of the sodium pump. 5. Net sodium extrusion took place against an electrochemical gradient in potassium-free — 50 mM sodium — mM lithium Ringer. About 75% of this efflux was ouabain sensitive. 6. Muscles made both sodium and lithium rich and incubated in potassium-free — 60 mM sodium — 50 mM lithium Ringer also showed net sodium extrusion against an electrochemical gradient, which was 85% ouabain sensitive. This extrusion took place even under conditions where the changes in free energy favouring lithium entry were always lower than the changes in free energy opposing sodium going out. This indicates that a sodium-lithium exchange by a counter-transport process is unlikely. 7. External potassium reduced the ouabain sensitive lithium influx in muscles incubated in lithium Ringer. The values found were 5·90 ± 0·39 μ-mole/g.hr and 2·66 ± 0·43 μmole/g.hr in potassium-free and 15 mM potassium respectively. At the same time potassium had no effect on the ouabain-insensitive lithium uptake. 8. Muscles incubated in potassium-free-magnesium Ringer had a residual sodium efflux which could not be accounted for by passive movement. About 40% of it was abolished by 10-4 M ouabain. This ouabain-sensitive part could be a consequence of some stimulation of the sodium pump by potassium leaking out of the cells. If this is correct it should be inhibited by external sodium and should not contribute to the total sodium efflux in potassium-free sodium media. 9. Magnesium was used as the reference cation to study the sodium-stimulated sodium efflux under potassium-free conditions. The total sodium efflux amounted to 0·668 hr-1 (rate constant) and was 71% ouabain sensitive. 10. The present experiments demonstrated that lithium ions have a direct stimulating effect on sodium efflux in high sodium skeletal muscle, and strongly support the notion that this effect is produced by an activation of the sodium pump through a potassium-like action. PMID:4637626

A comparative study of charge movement in rat and frog skeletal muscle fibres.

PubMed

Hollingworth, S; Marshall, M W

1981-12-01

1. The middle of the fibre voltage--clamp technique (Adrian & Marshall, 1977), modified where necessary for electrically short muscle fibres, has been used to measure non-linear charge movements in mammalian fast twitch (rat extensor digitorum longus), mammalian slow twitch (rat soleus) and frog (sartorius) muscles. 2. The maximum amount of charge moved in mammalian fast twitch muscle at 2 degrees C in hypertonic solution, was 3--5 times greater than in slow twitch muscle. The voltage distribution of fast twitch charge was 10--15 mV more positive when compared to slow twitch. 3. In both mammalian muscle types hypertonic Ringer solution negatively shifted the voltage distribution of charge some 6 mV. The steepness of charge moved around mechanical threshold was unaffected by hypertonicity. 4. The amount of charge in frog sartorius fibres at 2 degrees C in hypertonic solution was about half of that in rat fast twitch muscle; the voltage distribution of the frog charge was similar to rat soleus muscle. 5. Warming between 2 and 15 degrees C had no effect on either the amount of steady-state distribution of charge in mammalian or frog muscles. 6. At 2 degrees C, the kinetics of charge movement in fast and slow twitch mammalian muscles were similar and 2--3 times faster than frog muscle at the same temperature. In fast and slow mammalian fibres at 2 degrees C similar times were taken to shift the same fractions of the total amount of charge. The Q10 of charge movement kinetics was between 1.2 and 2.0 in the three muscles studied.

Ca2+-recruitment in tachykinin-induced contractions of gut smooth muscle from African clawed frog, Xenopus laevis and rainbow trout, Oncorhynchus mykiss.

PubMed

Johansson, Agot; Holmgren, Susanne

2003-04-01

Changes in intracellular Ca(2+) concentration control many essential cellular functions like the contraction of smooth muscle cells. The aim of this study was to investigate if the tachykinin substance P (SP) engages external Ca(2+)-sources, internal Ca(2+)-sources, or both in the contraction of the gastrointestinal smooth muscle of rainbow trout (Oncorhynchus mykiss) and the African clawed frog (Xenopus laevis). Strip preparations made of either longitudinal smooth muscle of proximal intestine or circular smooth muscle of cardiac stomach were mounted in organ baths and the tension was recorded via force transducers. Ca(2+)-free Ringer's solution containing the Ca(2+) chelating agent EGTA (2mM) abolished all spontaneous contractions. Exposure to SP in Ca(2+)-free solution decreased the response. Preparations were also treated with the Ca(2+)-ATPase inhibitor thapsigargin (10 microM) during 30 min. Thapsigargin reduced the effect of SP on intestinal longitudinal smooth muscle in rainbow trout and on stomach circular smooth muscle in the African clawed frog and to a less extent in the intestinal longitudinal smooth muscle. The results show that external Ca(2+) is of great importance, but is not the only source of Ca(2+) recruitment in SP-activation of gastrointestinal smooth muscle in rainbow trout and the African clawed frog.

[Space-time organization of systems of membrane hydrolysis and transport in rat small intestine].

PubMed

Loginov, G I

1977-05-01

Glucose transport by the concentration gradient with the incubation for 90 min in 0.2% glucose and soluble starch solutions was studied in Wistar rats in 5 segments of the small intestine by the "sac turned inside out" method. Serous fluid was completely replaced by a new portion of Ringer's solution every 15 or 30 min. Substrate load synchronized the enterocyte population and stabilized the transport systems. The changes of glucose absorption during the period of about an hour proved to differ in the 5 segments against the background of continuous and interrupted substrate load. These differences were due to the properties of the transported systems autocontrol and the reactivity level of the given enterocyte population. Areas with different reactivity were found to alternate along the intestine. Between the 8th and 16th hour (rats were sacrificed every 2 hours) starch glucose transport fell sharply in the proximal, and, to a lesser extent, in the middle segments. On the contrary, absorption between the 8th and the 12th hour was considerably intensified in the distal segments. The changes of the strach glucose transport during the period of about an hour along the intestine differed. The data obtained are discussed with consideration to the possible role of the undulating processes in the individual enterocyte population and in the small intestine as an integral system.

Electrochemical characterization of pulsed layer deposited hydroxyapatite-zirconia layers on Ti-21Nb-15Ta-6Zr alloy for biomedical application

NASA Astrophysics Data System (ADS)

Izquierdo, Javier; Bolat, Georgiana; Cimpoesu, Nicanor; Trinca, Lucia Carmen; Mareci, Daniel; Souto, Ricardo Manuel

2016-11-01

A new titanium base Ti-21Nb-15Ta-6Zr alloy covered with hydroxyapatite-zirconia (HA-ZrO2) by pulsed laser deposition (PLD) technique was characterized regarding its corrosion resistance in simulated physiological Ringer's solution at 37 °C. For the sake of comparison, Ti-6Al-4V standard implant alloy, with and without hydroxyapatite-zirconia coating, was also characterized. Multiscale electrochemical analysis using both conventional averaging electrochemical techniques, namely electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization, and spatially-resolved microelectrochemical techniques (scanning electrochemical microscopy, SECM) were used to investigate the electrochemical behaviour of the materials. In addition, scanning electron microscopy evidenced that no relevant surface morphology changes occurred on the materials upon immersion in the simulated physiological solution, despite variations in their electrochemical behaviour. Although uncoated metals appear to show better performances during conventional corrosion tests, the response is still quite similar for the HA-ZrO2 coated materials while providing superior resistance towards electron transfer due to the formation of a more dense film on the surface, thus effectively behaving as a passive material. It is believed corrosion of the HA-ZrO2 coated Ti-21Nb-15Ta-6Zr alloy will have negligible effect upon biochemical and cellular events at the bone-implant interface and could facilitate osseointegration.

Structure and properties of nitrided surface layer produced on NiTi shape memory alloy by low temperature plasma nitriding

NASA Astrophysics Data System (ADS)

Czarnowska, Elżbieta; Borowski, Tomasz; Sowińska, Agnieszka; Lelątko, Józef; Oleksiak, Justyna; Kamiński, Janusz; Tarnowski, Michał; Wierzchoń, Tadeusz

2015-04-01

NiTi shape memory alloys are used for bone and cardiological implants. However, on account of the metallosis effect, i.e. the release of the alloy elements into surrounding tissues, they are subjected to various surface treatment processes in order to improve their corrosion resistance and biocompatibility without influencing the required shape memory properties. In this paper, the microstructure, topography and morphology of TiN surface layer on NiTi alloy, and corrosion resistance, both before and after nitriding in low-temperature plasma at 290 °C, are presented. Examinations with the use of the potentiodynamic and electrochemical impedance spectroscopy methods were carried out and show an increase of corrosion resistance in Ringer's solution after glow-discharge nitriding. This surface titanium nitride layer also improved the adhesion of platelets and the proliferation of osteoblasts, which was investigated in in vitro experiments with human cells. Experimental data revealed that nitriding NiTi shape memory alloy under low-temperature plasma improves its properties for bone implant applications.

Transient, heat-induced thermal resistance in the small intestine of mouse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hume, S.P.; Marigold, J.C.L.

Heat-induced thermal resistance has been investigated in mouse jejunum by assaying crypt survival 24 h after treatment. Hyperthermia was achieved by immersing an exteriorized loop of intestine in a bath of Krebs-Ringer solution. Two approaches have been used. In the first, thermal survival curves were obtained following single hyperthermal treatments at temperatures in the range 42 to 44/sup 0/C. Transient thermal resistance, inducted by a plateau in the crypt survival curve, developed during heating at temperatures around 42.5/sup 0/C after 60 to 80 min. In the second series of experiments, a priming heat treatment (40.0, 41.0, 41.5, or 42.0/sup 0/Cmore » for 60 min) was followed at varying intervals by a test treatment at 43.0/sup 0/C. A transient resistance to the second treatment was induced, the extent and time of development being dependent upon the priming treatment. Crypt survival curves for thermally resistant intestine showed an increase in thermal D/sub 0/ and a decrease in n compared with curves from previously unheated intestine.« less

Fluorescence spectroscopy as a tool for determining microbial quality in potable water applications.

PubMed

Cumberland, Susan; Bridgeman, John; Baker, Andy; Sterling, Mark; Ward, David

2012-01-01

Building on previous work where fluorescence spectroscopy has been used to detect sewage in rivers, a portable LED spectrophotometer was used for the first time to establish bacterial numbers in a range of water samples. A mixed-method approach was used with standard bacteria enumeration techniques on diluted river water and sewage works final effluent using a number of diluents (Ringer's solution, tap water and potable spring water). Fluorescence from uncultured dilutions was detected at a 280 nm excitation/360 nm emission wavelength (corresponding to the region of tryptophan and indole fluorescence) and compared with bacteria numbers on the same cultured sample. Good correlations were obtained for total coliforms, E. coli and heterotrophic bacteria with the portable LED spectrophotometer (R2 = 0.78, 0.72 and 0.81 respectively). The results indicate that the portable spectrophotometer could be applied to establish the quality of drinking water in areas of poor sanitation that are subject to faecal contamination, where infrastructure failure has occurred in the supply of clean drinking water. This would be particularly useful where laboratory facilities are not at hand.

Laryngeal mucosa elasticity and viscosity in high and low relative air humidity.

PubMed

Hemler, R J; Wieneke, G H; Lebacq, J; Dejonckere, P H

2001-03-01

In earlier work we showed that low relative humidity (RH) of inhaled air causes acoustic voice parameters such as jitter and shimmer to deteriorate. Other authors have shown negative effects on vocal efficiency. To explain these changes in the mechanical properties of the vocal folds, the effects of changes in RH of the air passing over microdissected mucosa of sheep larynges were studied. The dissected surface of the tissue specimen just touched Ringer solution and air of varying RH was blown over the specimen. The mucosa specimen was subjected to sinusoidal oscillations of length (strain) and the resulting force (stress) was measured. The gain and phase angle between the imposed strain and resulting stress were measured, and elasticity and viscosity were calculated. Two different air conditions were tested: air with high RH (100%) vs air with low RH (0%). Viscosity and stiffness increased significantly in both ambient conditions (P < 0.01). Dry dehydrating air resulted in a stiffer and more viscous cover than humid air (P < 0.001). These changes in mechanical characteristics may contribute to the effects on voice parameters described in earlier work.

[Malignant hyperthermia in a black child. A case report].

PubMed

Hugo, J M; Ungerer, M J; Erasmus, F R; du Toit, P W; Muller, F O; van Velden, D J

1978-05-20

A case of malignant hyperthermia in a Black boy is presented. He developed this condition during repair of a cleft palate, with halothane as the triggering agent. The importance of the high incidence of malignant hyperthermia in patients with certain musculoskeletal abnormalities is stressed. Despite a cool and well air-conditioned theatre, the patient's temperature was 41 degree C when the condition was suspected. At that stage general muscle rigidity was present. The patient was successfully treated with procainamide, sodium bicarbonate and hydrocortisone; surface cooling (with ice packs) was instituted and the stomach was washed out with ice-cold Ringer's solution. Over a period of 14 days serum creatine phosphokinase values decreased from 630 IU (on the day of the incident) to 12 IU. A muscle biopsy showed variation in muscle fibre size. Electron microscopical studies showed myofibrillar disruption and folding of the basement membrane. A modified version of Denborough's technique was used for the in vitro exposure of muscle strips to halothane and suxamethonium. Isometric contraction was measured and recorded. A severe contraction followed the exposure of muscle strips to halothane, which confirmed the diagnosis.

Inositol uptake in rat aorta

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rapoport, R.M.; Van Gorp, C.; Chang, Ki-Churl

1990-01-01

{sup 3}H-inositol uptake into deendothelialized aorta was linear for at least 2 h and was composed of both a saturable, Na{sup +}-dependent, and a nonsaturable, Na{sup +}-independent component. The Na{sup +}-dependent component of inositol uptake had a K{sub m} of 50 {mu}M and a V{sub max} of 289 pmol/mg prot/h. Exposure to LiCl, ouabain, or Ca{sup 2+} - free Krebs-Ringer bicarbonate solution inhibited uptake. Metabolic poisoning with dinitrophenol, as well as incubation with phloretin, an inhibitor of carrier-mediated hexose transport, also inhibited uptake. Exposure to norepinephrine decreased inositol uptake, while phorbol myristate acetate was without effect. Isobutylmethylxanthine significantly increased inositolmore » uptake, while the increased uptake due to dibutyryl cyclic AMP and forskolin were not statistically significant. Sodium nitroprusside, and activator of guanylate cyclase, and 8-bromo cyclic GMP, were without effect on uptake, as was methylene blue, an inhibitor of guanylate cyclase. Inositol uptake into the aorta was increased when the endothelium was allowed to remain intact, although this effect was likely due to uptake in both the endothelial and smooth muscle cells.« less

Cardiac Transplantation in a Jehovah's Witness

PubMed Central

Lammermeier, David E.; Duncan, J. Michael; Kuykendall, R. Craig; Macris, Michael P.; Frazier, O. Howard

1988-01-01

Between July 1982 and October 1987, surgeons at our institution performed 215 cardiac transplantation procedures, 1 of which was in a 46-year-old Jehovah's Witness with congestive cardiomyopathy, who required preoperative intra-aortic balloon pump support. At surgery, the cardiopulmonary bypass system was primed with 1600 ml of Ringer's lactate solution and dextrose. In the 57 minutes during which the patient was on cardiopulmonary bypass, the intra-aortic balloon was removed and successful orthotopic heart transplantation was performed. No supplemental blood or blood product was used, either during or after the procedure. The estimated intraoperative blood loss was 300 ml, and the postoperative chest tube drainage amounted to 1495 ml. Postoperative hematologic abnormalities (mild hypoprothrombinemia, mild thrombocytopenia, mild platelet dysfunction, and moderate hypochromic microcytic anemia) were corrected with Imferon, vitamin K, and desmopressin acetate administered intravenously, and with ferrous sulfate administered orally. This case, which to our knowledge is only the 2nd cardiac transplant in a Jehovah's Witness, further establishes that these patients can undergo even the most major of open-heart procedures without supplemental blood. (Texas Heart Institute Journal 1988;15:189-191) PMID:15227251

Polypropylene fumarate/phloroglucinol triglycidyl methacrylate blend for use as partially biodegradable orthopaedic cement.

PubMed

Jayabalan, M; Thomas, V; Rajesh, P N

2001-10-01

Polypropylene fumarate/phloroglucinol triglycidyl methacrylate oligomeric blend-based bone cement was studied. Higher the percentage of phloroglucinol triglycidyl methacrylate, lesser the setting time. An optimum setting time could be arrived with 50:50 blend composition of the two oligomers. Composite cement of 50:50 blend prepared with hydroxyapatite granules of particle size 125 microm binds bovine rib bones. The tensile strength of this adhesive bond was found to be 1.11 kPa. The thermal studies suggest the onset of cross-linking reaction in the cured blend if the blend is heated. The absence of softening endotherm in the cured blend shows the thermosetting-like amorphous nature of blend system, which may restrict the changes in creep properties. The in vitro biodegradation studies reveal possible association of calcium ions with negatively charged units of degrading polymer chain resulting in slow down of degradation. Relatively slow degradation was observed in Ringer's solution. The study reveals the potential use of polypropylene fumarate/phloroglucinol triglycidyl methacrylate as partially degradable polymeric cement for orthopaedic applications.

Development of Ferrite-Based Temperature Sensors for Magnetic Resonance Imaging: A Study of Cu1 -xZnxFe2O4

NASA Astrophysics Data System (ADS)

Alghamdi, N. A.; Hankiewicz, J. H.; Anderson, N. R.; Stupic, K. F.; Camley, R. E.; Przybylski, M.; Żukrowski, J.; Celinski, Z.

2018-05-01

We investigate the use of Cu1 -xZnxFe2O4 ferrites (0.60

The first record of Gregarina typographi Fuchs (Protista: Apicomplexa: Gregarinidae) from the European spruce bark beetle, Ips typographus (Linnaeus) (Coleoptera: Curculionidae, Scolytinae) in Turkey.

PubMed

Yaman, Mustafa; Bakı, Hilal

2010-01-01

Aim of this study is determining pathogens of Ips typographus from Eastern Black Sea Region in Turkey. Samples collected from the field were taken to laboratuar as soon as possible. Microscopic examination was completed by dissection with Ringer's solution. 780 Ips typographus beetles from Giresun, Rize and Artvin were examined. Gregarines were observed in the populations of I. typographus in the three regions. 27 of 780 beetles were found to be infected by the Gregarina typographi. Total rate of infection was 3.4% in three localities. During the study several life stages of the gregarine pathogen (trophozoite, gamont, Cysts and associative form) were observed. Gametocysts were spherical and from 77 to 85 μm in diameter. Total lengths of solitary gamonts were measured. from 90 to 155 μm. Measurements of gamonts and gametocysts of G. typographi were given and compared with other gregarines isolated from bark beetles. This pathogen is described as Gregarina typographi. The gregarine pathogen of Ips typographus is reported from Turkey for the first time.

Effects of organic and inorganic compounds of diesel exhaust particles on the mucociliary epithelium: An experimental study on the frog palate preparation.

PubMed

Trindade, Sergio Henrique Kiemle; Seriani, Robson; Lorenzi-Filho, Geraldo; de Mello Júnior, João Ferreira; Sennes, Luiz Ubirajara; Saldiva, Paulo Hilário Nascimento; Macchione, Mariângela

2018-02-01

The toxic actions of acute exposition to different diesel exhaust particles (DEPA) fractions on the mucociliary epithelium are not yet fully understood due to different concentrations of organic and inorganic elements. These chemicals elements produce damage to the respiratory epithelium and exacerbate pre-existent diseases. In our study we showed these differences in two experimental studies. Study I (dose-response curve - DRCS): Forty frog-palates were exposed to the following dilutions: frog ringer, intact DEPA diluted in frog-ringer at 3mg/L, 6mg/L and 12mg/L. Study II (DEPF) (DEPA fractions diluted at 12mg/L): Fifty palates - Frog ringer, intact DEPA, DEPA treated with hexane, nitric acid and methanol. Variables analyzed: relative time of mucociliary transport (MCT), ciliary beating frequency (CBF) and morphometric analysis for mucin profile (neutral/acid) and vacuolization. The Results of DRCS: Group DEPA-12mg/L presented a significant increase in the MCT (p<0.05), proportional volume of acid mucus (p<0.05) and decreased proportional volume of neutral mucus and vacuoles (p<0.05). In relation of DEPF: A significant increase in the MCT associated to a decrease in the proportional volume of neutral mucus was founded in nitric acid group. In addition, a significant increase in the proportional volume of acid mucus was found in methanol group. We concluded that: 1) Increasing concentrations of intact DEPA can progressively increase MCT and promote an acidification of intra-epithelial mucins associated to a depletion of neutral mucus. 2) Intact DEPA seem to act as secretagogue substance, promoting mucus extrusion and consequently reducing epithelial thickness. 3) Organic fraction of low polarity seems to play a pivotal role on the acute toxicity to the mucociliary epithelium, by promoting a significant increase in the MCT associated to changes in the chemical profile of the intracellular mucins. Copyright © 2017 Elsevier Inc. All rights reserved.

AN OSMOTIC SYSTEM WITHIN THE CYTOPLASM OF CELLS

PubMed Central

Opie, Eugene L.

1948-01-01

The cytoplasm of cells of the liver and of the kidney is in large part occupied by bodies which respond to the water content of these cells and are modified by dissolved substances in the surrounding fluid or by physical change such as freezing. These bodies, in part mitochondria but designated more broadly cytochondria, constitute an osmotic system within the cytoplasm of cells. When the specific gravity of liver or kidney tissue is used as an index of changes in the water content of tissue, swelling of cytochondria in general follows the intake of water but this relation may be modified by a variety of conditions. When liver that has been frozen and thawed is immersed in water, cytochondria become swollen though the containing cells diminish in size. Solutions of sodium and of potassium chloride isotonic with blood plasma cause delayed swelling of cells and cytochondria, greater with the potassium salt; solutions of calcium chloride of equal molar concentration cause immediate swelling of cells and cytochondria. The basophile material of the cytoplasm (ribonucleic acid and related substances) and the material that gives to mitochondria their characteristic stain are removed by immersion in water but their disappearance is retarded by isotonic solutions of sodium or of potassium chloride and further delayed by hypertonic solutions. When the intensity of staining reactions is diminished by the partial loss of basophile substance or of the distinctive mitochondrial material, these are found at the surfaces of the cytoplasmic bodies, held perhaps by adsorption. When water, isotonic solutions of sodium chloride, or Ringer's solution comes into contact with immersed liver, they remove basophile and mitochondrial material from a superficial zone and substances with similar staining reactions appear in the cytoplasm of cells at a deeper level. Osmotic changes in the cytoplasmic bodies may be reversible. When liver tissue which has been for a short time immersed in water is transferred to a solution that is approximately isotonic in relation to blood plasma, swollen cytochondria return in part or completely to their former size; but with continued immersion in water, this reversibility becomes increasingly less complete. PMID:18912893

Granulocyte colony-stimulating factor improves host defense to resuscitated shock and polymicrobial sepsis without provoking generalized neutrophil-mediated damage.

PubMed

Patton, J H; Lyden, S P; Ragsdale, D N; Croce, M A; Fabian, T C; Proctor, K G

1998-05-01

Granulocyte colony-stimulating factor (G-CSF) increases production and release of neutrophil precursors and activates multiple functions of circulating polymorphonuclear neutrophils (PMNs). G-CSF has therapeutic effects in many experimental models of sepsis; its actions with superimposed reperfusion insults are unknown. In traumatic conditions, G-CSF could exacerbate unregulated, PMN-dependent injury to otherwise normal host tissue or, it could partially reverse trauma-induced immune suppression, which may improve long-term outcome. This study tested whether stimulating PMN proliferation and function with G-CSF during recovery from trauma+sepsis potentiated reperfusion injury or whether it improved host defense. Anesthetized swine were subjected to cecal ligation and incision, 35% hemorrhage, and 1 hr of hypotension. Resuscitation consisted of intravenous G-CSF (5 microg/kg) or placebo followed by shed blood and 40 mL/kg of lactated Ringer's solution. The control group received laparotomy only. G-CSF or placebo was given daily. Animals were killed at 4 days. Observers, blind to the protocol, graded autopsy samples for localization of infection and quality of abscess wall formation. Data included complete blood count, granulocyte oxidative burst after phorbol myristate acetate stimulation in vitro (GO2B), bronchoalveolar lavage (BAL) cell count, BAL noncellular protein, lipopolysaccharide-stimulated tumor necrosis factor production in whole blood in vitro (lipopolysaccharide-tumor necrosis factor), and lung tissue myeloperoxidase (MPO). Neutrophilia and localization of infection, were significantly improved by G-CSF. Variables altered by G-CSF, though not significantly, showed GO2B potential increased by 50%, lipopolysaccharide-tumor necrosis factor decreased by 50%, and improved survival versus placebo (100% vs. 70%). G-CSF did not increase lung MPO, BAL cell count, or BAL protein. Both arterial and venous O2 saturations were unaltered. Our data show that G-CSF initiated at the time of resuscitation reduced the sequelae of posttrauma sepsis by increasing PMN proliferation and function without potentiating PMN-mediated lung reperfusion injury.

Cross-talk between ATP-regulated K+ channels and Na+ transport via cellular metabolism in frog skin principal cells.

PubMed Central

Urbach, V; Van Kerkhove, E; Maguire, D; Harvey, B J

1996-01-01

Isolated frog skin epithelium, mounted in an Ussing chamber and bathed in standard NaCl Ringer solution, recycles K+ across the basolateral membrane of principal cells through an inward-rectifier K+ channel (Kir) operating in parallel with a Na+-K+-ATPase pump. Here we report on the metabolic control of the Kir channel using patch clamping, short-circuit current measurement and enzymatic determination of cellular (ATP (ATPi). 2. The constitutively active Kir channel in the basolateral membrane has the characteristics of an ATP-regulated K+ channel and is now classed as a KATP channel. In excised inside-out patches the open probability (Po) of KATP channels was reduced by ATPi with half-maximum inhibition at an ATPi concentration of 50 microM. 3. ATPi measured (under normal Na+ transport conditions) with luciferin-luciferase was 1.50 +/- 0.23 mM (mean +/- S.E.M.; range, 0.4-3.3 mM n = 11). Thus the KATP channel would be expected to be inactive in intact cells if ATPi was the sole regulator of channel activity. KATP channels which were inactivated by 1 mM ATPi in excised patches could be reactivated by addition of 100 microM ADP on the cytosolic side. When added alone, ADP blocks this channel with half-maximal inhibition at [ADPi] > 5 mM. 4. Sulphonylureas inhibit single KATP channels in cell-attached patches as well as the total basolateral K+ current measured in frog skin epithelia perforated with nystatin on the apical side. 5. Na+-K+-ATPase activity is a major determinant of cytosolic ATP. Blocking the pump activity with ouabain produced a time-dependent increase in ATPi and reduced the open probability of KATP channels in cell-attached membranes. 6. We conclude that the ratio of ATP/ADP is an important metabolic coupling factor between the rate of Na+-K+ pumping and K+ recycling. Images Figure 9 PMID:9011625

Reflex vasoconstriction in aged human skin increasingly relies on Rho kinase-dependent mechanisms during whole body cooling

PubMed Central

Jennings, John D.; Holowatz, Lacy A.; Kenney, W. Larry

2009-01-01

Primary human aging may be associated with augmented Rho kinase (ROCK)-mediated contraction of vascular smooth muscle and ROCK-mediated inhibition of nitric oxide synthase (NOS). We hypothesized that the contribution of ROCK to reflex vasoconstriction (VC) is greater in aged skin. Cutaneous VC was elicited by 1) whole body cooling [mean skin temperature (Tsk) = 30.5°C] and 2) local norepinephrine (NE) infusion (1 × 10−6 M). Four microdialysis fibers were placed in the forearm skin of eight young (Y) and eight older (O) subjects for infusion of 1) Ringer solution (control), 2) 3 mM fasudil (ROCK inhibition), 3) 20 mM NG-nitro-l-arginine methyl ester (NOS inhibition), and 4) both ROCK + NOS inhibitors. Red cell flux was measured by laser-Doppler flowmetry over each site. Cutaneous vascular conductance (CVC) was calculated as flux/mean arterial pressure and normalized to baseline CVC (%ΔCVCbaseline). VC was reduced at the control site in O during cooling (Y, −34 ± 3; and O, −18 ± 3%ΔCVCbaseline; P < 0.001) and NE infusion (Y, −53 ± 4, and O, −41 ± 9%ΔCVCbaseline; P = 0.006). Fasudil attenuated VC in both age groups during mild cooling; however, this reduction remained only in O but not in Y skin during moderate cooling (Y, −30 ± 5; and O, −7 ± 1%ΔCVCbaseline; P = 0.016) and was not altered by NOS inhibition. Fasudil blunted NE-mediated VC in both age groups (Y, −23 ± 4; and O, −7 ± 3%ΔCVCbaseline; P < 0.01). Cumulatively, these data indicate that reflex VC is more reliant on ROCK in aged skin such that approximately half of the total VC response to whole body cooling is ROCK dependent. PMID:19717729

Effects and cost of glycyrrhizin in the treatment of upper respiratory tract infections in members of the Japanese maritime self-defense force: Preliminary report of a prospective, randomized, double-blind, controlled, parallel-group, alternate-day treatment assignment clinical trial

PubMed Central

Yanagawa, Youichi; Ogura, Masatsune; Fujimoto, Eita; Shono, Satoshi; Okuda, Eriya

2004-01-01

Background: Upper respiratory tract infections (URTIs) account for at least half of all acute illnesses. Specific antiviral therapy has not been developed against most respiratory viruses thought to cause URTIs. The pharmacologic action of glycyrrhizin has been shown to produce anti-inflammatory activity, modulation of the immune system, inhibition of virus growth, and inactivation of viruses. Objective: The aim of this study was to assess the tolerability, efficacy, and cost of glycyrrhizin in improving the severity and duration of signs and symptoms of URTIs. The primary end point was tolerability, and the secondary and points included improvement in signs and symptoms of URTI and cost. Methods: Members of the Japanese Maritime Self-Defense Force (SDF) treated for URTIs from January 2002 to May 2002 in the SDF Etajima Hospital (Hiroshima, Japan) were eligible for this prospective, randomized, double-blind, controlled, parallel-group, alternate-day treatment assignment study. All patients in this study fulfilled the following enrollment criteria: admitted to the hospital on the first arrival day as an outpatient; fever (body temperature <38.0°C) with signs and symptoms of URTI (headache, sore throat, rhinorrhea, pharyngitis); and had not received antibiotics or oseltamivir phosphate for 4 weeks before the study. Patients who were admitted on an even day received an IV drip infusion of 40 mL of glycyrrhizin (0.2%) and 500 mL of lactated Ringer's solution daily during hospitalization (glycyrrhizin group). Patients who were admitted on an odd day received an IV drip infusion of 500 mL/d of lactated Ringer's solution only (control group). Adverse effects were assessed by the physicians during hospitalization, using patient interview and laboratory analysis. Results: Forty-one consecutive patients entered the study; 15 patients (15 men, 0 women; mean [SD] age, 25.2 [1.5] years) were assigned to the glycyrrhizin group and 269 patients (24 men, 2 women; mean [SD] age, 22.6 [0.9] years) were assigned to the control group. The 2 groups were similar in terms of baseline characteristics. The mean duration of hospitalization was shorter (P = 0.01), the mean maximum body temperature 24 to 48 hours after admission was less (P = 0.05), and the cost of therapy (P = 0.03) was less in the glycyrrhizin group than the control group. No AEs were reported. Conclusions: In this study of hospitalized patients with URTIs, glycyrrhizin therapy was associated with a shorter hospitalization, lower-grade fever, and lower cost of therapy compared with controls, showing that it may be beneficial to patients with URTIs without acute bacterial infections. PMID:24936101

Calcium homeostasis in the outer segments of retinal rods from the tiger salamander.

PubMed Central

Lagnado, L; Cervetto, L; McNaughton, P A

1992-01-01

1. The processes regulating intracellular calcium in the outer segments of salamander rods have been investigated. The main preparation used was the isolated rod loaded with the Ca(2+)-sensitive photoprotein aequorin, from which outer segment membrane current and free [Ca2+]i could be recorded simultaneously. Two other preparations were also used: outer segment membrane current was recorded from intact, isolated rods using a suction pipette, and from detached outer segments using a whole-cell pipette. 2. Measurements of free intracellular [Ca2+] in Ringer solution were obtained from two aequorin-loaded rods. Mean [Ca2+]i in darkness was 0.41 microM, and after a bright flash [Ca2+]i fell to below detectable levels ( < 0.3 microM). No release of intracellular Ca2+ by a bright flash of light could be detected ( < 0.2 microM). 3. Application of the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX) caused an increase in the size of the light-sensitive current and a rise in [Ca2+]i, but application of IBMX either when the light-sensitive channels had been closed by a bright light or in the absence of external Ca2+ caused no detectable rise in [Ca2+]i. It is concluded that IBMX increases [Ca2+]i by opening light-sensitive channels, and does not release Ca2+ from stores within the outer segment. 4. Removal of external Na+ caused a rise in [Ca2+]i to around 2 microM and completely suppressed the light-sensitive current. 5. The Na(+)-Ca2+, K+ exchange current in aequorin-loaded rods was activated in first-order manner by internal free calcium, with a mean Michaelis constant, KCa, of 1.6 microM. 6. The KCa of the Na(+)-Ca2+, K+ exchange was increased by elevating internal [Na+]. 7. The Michaelis relation between [Ca2+]i and the activity of the Na(+)-Ca2+, K+ exchange was used to calculate the change in [Ca2+]i occurring during the response to a bright light. In aequorin-loaded rods in Ringer solution the mean change in free [Ca2+]i after a bright flash was 0.34 microM. In these rods 10% of the dark current was carried by Ca2+. 8. Most of the calcium entering the outer segment was taken up rapidly and reversibly by buffer systems. The time constant of equilibration between free and rapidly bound Ca2+ was less than 20 ms. No slow component of calcium uptake was detected. 9. Two components of calcium buffering could be distinguished in the outer segments of aequorin-loaded rods.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:1282928

Antibodies to ependymin block the sharpening of the regenerating retinotectal projection in goldfish.

PubMed

Schmidt, J T; Shashoua, V E

1988-04-19

The regenerating optic nerve of goldfish first reestablishes a rough retinotopic map on the tectum, then goes through an activity dependent refinement that appears to involve the elimination of inappropriate branches from early regenerated arbors. Retinotopically appropriate branches and synapses may be stabilized because the normally correlated firing of neighboring ganglion cells could cause summation of their postsynaptic responses, making them more effective. Thus, refinement of the map may be similar in several ways to associative learning. In this study, we therefore tested whether ependymin, a major protein component of the extracellular fluid that has been implicated in synaptic changes thought to be associated with learning a simple task in goldfish, may also be involved in refinement of the retinotopic map. Goldfish that had undergone unilateral optic nerve crush received intraventricular infusion of antiependymin IgG or of control IgG's beginning at 21 days postcrush. Tectal recordings from these fish at 39-56 days postcrush showed that the projection had failed to sharpen, much as in the fish with activity blocked or synchronized; the average size of the multiunit receptive fields was 31 degrees vs 11 degrees normally. The field potentials elicited from these tecta by optic nerve shock were not significantly smaller than in controls, suggesting normal levels of synaptogenesis. Control projections, identically treated but infused with either unrelated IgG or Ringer's alone regenerated normally, giving multiunit receptive fields of 12 degrees. Intact (non-regenerating) projections of the experimental fish were not rendered abnormal by the IgG treatment. Histology showed the retinas and tecta of the infused fish to be normal in appearance. The results show a specific block of sharpening by antiependymin IgG. The ependymal glia of the tectum stain positively for ependymin in normal fish, particularly the cell bodies in the ependymal layer. The tectum, particularly the ependymal layer, stains more intensely during regeneration, which appears to trigger increased synthesis of ependymins in the ependymal glia. This increase and the block of sharpening by specific antibodies to ependymin suggest a possible role for ependymin in activity dependent synaptic stabilization, possibly through its polymerization when calcium is focally depleted at active synapses.

The structural and bio-corrosion barrier performance of Mg-substituted fluorapatite coating on 316L stainless steel human body implant

NASA Astrophysics Data System (ADS)

Sharifnabi, A.; Fathi, M. H.; Eftekhari Yekta, B.; Hossainalipour, M.

2014-01-01

In this study, Mg-substituted fluorapatite coatings were deposited on medical grade AISI 316L stainless steel via sol-gel dip coating method. Phase composition, crystallite size and degree of crystallinity of the obtained coatings were evaluated by X-ray diffraction (XRD) analysis. Fourier transform infrared (FTIR) spectroscopy was also used to evaluate functional groups of the obtained coatings. The surface morphology and cross-section of the final coatings were studied using scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy was used to determine elemental chemical composition of the obtained coatings. In order to determine and compare the corrosion behavior of uncoated and Mg-substituted fluorapatite coated 316L stainless steel, electrochemical potentiodynamic polarization tests were performed in physiological solutions at 37 ± 1 °C. Moreover, the released metallic ions from uncoated and coated substrates were measured by inductively coupled plasma-optical emission spectrometry (ICP-OES) within 2 months of immersing in Ringer's solution at 36.5 ± 1 °C as an indication of biocompatibility. The results showed that fluoride and magnesium were successfully incorporated into apatite lattice structure and the prepared coatings were nanostructured with crystallinity of about 70%. Obtained coatings were totally crack-free and uniform and led to decrease in corrosion current densities of 316L stainless steel in physiological solutions. In addition, coated sample released much less ions such as Fe, Cr and Ni in physiological media. Therefore, it was concluded that Mg-substituted fluorapatite coatings could improve the corrosion resistance and biocompatibility of 316L stainless steel human body implants.

Transient neurologic deficit after spinal anesthesia: local anesthetic maldistribution with pencil point needles?

PubMed

Beardsley, D; Holman, S; Gantt, R; Robinson, R A; Lindsey, J; Bazaral, M; Stewart, S F; Stevens, R A

1995-08-01

Recent reports of transient neurologic deficits have raised concern about the potential toxicity of single-dose spinal 5% lidocaine in 7.5% dextrose. Two cases of volunteers who experienced minor local sensory deficits after slow (60 s) injections of 2 mL 5% lidocaine via Whitacre needles are described. One case was a result of a double injection because of a "failed" block. It seemed possible that the neurologic deficit in these cases resulted from neurotoxicity associated with maldistribution of local anesthetic. Using an in vitro spinal model, we investigated drug distribution resulting from injections through side-port spinal needles to determine whether the use of these needles could result in high local concentrations of hyperbaric solutions. A spinal canal model was fabricated using human magnetic resonance measurements. The model was placed in a surgical supine position and filled with lactated Ringer's solution to simulate the specific gravity of cerebral spinal fluid at 22 degrees C. A hyperbaric solution of phthalocyanine blue dye and dextrose (SG 1.042), simulating the anesthetic, was injected through three different needles (27-gauge 4 11/16-in. Whitacre, 25-gauge 3 1/2-in. Whitacre, 25-gauge 3 1/2-in. Quincke). Triplicate injections were done at rapid (2 mL/10 s) and slow (2 mL/60 s) rates, with needle side ports oriented in a sacral and cephalad direction. At slow rates of injection, using 27- or 25-gauge sacrally directed Whitacre needles, injections showed evidence of maldistribution with extrapolated peak sacral lidocaine concentrations reaching 2.0%. In contrast, distribution after slow injection through sacrally directed Quincke needles was uniform.(ABSTRACT TRUNCATED AT 250 WORDS)

Small synthetic peptides homologous to segments of the first external loop of occludin impair tight junction resealing.

PubMed

Lacaz-Vieira, F; Jaeger, M M; Farshori, P; Kachar, B

1999-04-01

This study shows that resealing of opened tight junctions (TJs) is impaired by interaction with oligopeptides homologous to the external domain of chick occludin. The experiments were carried out with confluent A6 cell monolayers grown on collagen supports under stable transepithelial electrical resistance (TER). The monolayers were bathed on the apical side with a 75 mm KCl solution and on the basolateral side by NaCl-Ringer's solution. TJ opening was induced by basolateral Ca2+ removal and was characterized by a marked drop of TER. The reintroduction of Ca2+ triggered junction resealing as indicated by an elevation of TER to control values. Custom-made peptides SNYYGSGLSY (corresponding to the residues 100 to 109) and SNYYGSGLS (residues 100 to 108), homologous to segments of the first external loop of chick occludin molecule, impaired junction resealing when the peptides were included in the apical bathing fluid (concentrations in the range of 0.5 to 1.5 mg/ml). Peptide removal from the apical solution usually triggered a slow recovery of TER, indicating a slow recovery of the TJ seal. Changes in localization of ZO-1, a cytoplasmic protein that underlies the membrane at the TJs, were evaluated immunocytochemically following Ca2+ removal and reintroduction. The presence or absence of the oligopeptides showed no influence on the pattern of change of ZO-1 localization. These observations support the hypothesis that the TJ seal results from the interaction of specific homologous segments of occludin on the surface of adjacent cells. Additionally, our results show that small peptides homologous to segments of the occludin first external loop can be used as specific reagents to manipulate the permeability of tight junctions.

Creating Concussion Management Policy: How School Leaders, Coaches and Parents Can Work Together to Ensure Kids Stay Safer in Sport

ERIC Educational Resources Information Center

Faure, Caroline

2010-01-01

School leaders, parents and coaches are challenged to ensure the safety of athletes participating in interscholastic programs, including concussion management. With an estimated 300,000 sport-related concussions occurring annually in the United States and a public perception that bell ringers are not concussions, many head-injured children are…

Intravenous dextrose for children with gastroenteritis and dehydration: a double-blind randomized controlled trial.

PubMed

Levy, Jason A; Bachur, Richard G; Monuteaux, Michael C; Waltzman, Mark

2013-03-01

We seek to determine whether an initial intravenous bolus of 5% dextrose in normal saline solution compared with normal saline solution will lead to a lower proportion of hospitalized patients and a greater reduction in serum ketone levels in children with gastroenteritis and dehydration. We enrolled children aged 6 months to 6 years in a double-blind, randomized controlled trial of patients presenting to a pediatric emergency department. Subjects were randomized to receive a 20 mL/kg infusion of either 5% dextrose in normal saline solution or normal saline solution. Serum ketone levels were measured before and at 1- and 2-hour intervals after the initial study fluid bolus administration. Primary outcome was the proportion of children hospitalized. Secondary outcome was change in serum ketone levels over time. One hundred eighty-eight children were enrolled. The proportion of children hospitalized did not differ between groups (35% in the 5% dextrose in normal saline solution group versus 44% in the normal saline solution group; risk difference 9%; 95% confidence interval [CI] -5% to 22%). Compared with children who received normal saline solution, those who received 5% dextrose in normal saline solution had a greater reduction in mean serum ketone levels at both 1 hour (mean Δ 1.2 versus 0.1 mmol/L; mean difference 1.1 mmol/L; 95% CI 0.4 to 1.9 mmol/L) and 2 hours (mean Δ 1.9 versus 0.3 mmol/L; mean difference 1.6 mmol/L; 95% CI 0.9 to 2.3 mmol/L). Administration of a dextrose-containing bolus compared with normal saline did not lead to a lower rate of hospitalization for children with gastroenteritis and dehydration. There was, however, a greater reduction in serum ketone levels in patients who received 5% dextrose in normal saline solution. Copyright © 2012. Published by Mosby, Inc.

Effect of perfusion of bile salts solutions into the oesophagus of hiatal hernia patients and controls.

PubMed Central

Bachir, G S; Collis, J L

1976-01-01

Tests of the response to perfusion of the oesophagus were made in 54 patients divided into three groups. Group I consisted of patients with symptomatic hiatal hernia, group II hiatal hernia patients with peptic stricture, and group III normal individuals. Each individual oesophagus was perfused at a rate of 45-65 drops per minute over 25 minutes with six solutions: normal saline, N/10 HCl, taurine conjugates of bile salts in normal saline, taurine conjugates of bile salts in N/10 HCl, glycine conjugates of bile salts in normal saline, and taurine and glycine conjugates in a ratio of 1 to 2 in normal saline. It was found that acidified taurine solutions were more irritating than acid alone. With a 2mM/l solution of taurine in acid, symptoms are produced even in controls. With a 1 mM/l solution of the same conjugates, the majority of normal people feel slight heartburn or nothing, and therefore perfusion into the oesophagus of such a solution could be used as a test for oesophagitis. PMID:941112

Ethyl pyruvate ameliorates hepatic injury following blunt chest trauma and hemorrhagic shock by reducing local inflammation, NF-kappaB activation and HMGB1 release.

PubMed

Wagner, Nils; Dieteren, Scott; Franz, Niklas; Köhler, Kernt; Mörs, Katharina; Nicin, Luka; Schmidt, Julia; Perl, Mario; Marzi, Ingo; Relja, Borna

2018-01-01

The treatment of patients with multiple trauma including blunt chest/thoracic trauma (TxT) and hemorrhagic shock (H) is still challenging. Numerous studies show detrimental consequences of TxT and HS resulting in strong inflammatory changes, organ injury and mortality. Additionally, the reperfusion (R) phase plays a key role in triggering inflammation and worsening outcome. Ethyl pyruvate (EP), a stable lipophilic ester, has anti-inflammatory properties. Here, the influence of EP on the inflammatory reaction and liver injury in a double hit model of TxT and H/R in rats was explored. Female Lewis rats were subjected to TxT followed by hemorrhage/H (60 min, 35±3 mm Hg) and resuscitation/R (TxT+H/R). Reperfusion was performed by either Ringer`s lactated solution (RL) alone or RL supplemented with EP (50 mg/kg). Sham animals underwent all surgical procedures without TxT+H/R. After 2h, blood and liver tissue were collected for analyses, and survival was assessed after 24h. Resuscitation with EP significantly improved haemoglobin levels and base excess recovery compared with controls after TxT+H/R, respectively (p<0.05). TxT+H/R-induced significant increase in alanine aminotransferase levels and liver injury were attenuated by EP compared with controls (p<0.05). Local inflammation as shown by increased gene expression of IL-6 and ICAM-1, enhanced ICAM-1 and HMGB1 protein expression and infiltration of the liver with neutrophils were also significantly attenuated by EP compared with controls after TxT+H/R (p<0.05). EP significantly reduced TxT+H/R-induced p65 activation in liver tissue. Survival rates improved by EP from 50% to 70% after TxT+H/R. These data support the concept that the pronounced local pro-inflammatory response in the liver after blunt chest trauma and hemorrhagic shock is associated with NF-κB. In particular, the beneficial anti-inflammatory effects of ethyl pyruvate seem to be regulated by the HMGB1/NF-κB axis in the liver, thereby, restraining inflammatory responses and liver injury after double hit trauma in the rat.

Liposuction

PubMed Central

Dhami, Lakshyajit D.

2008-01-01

Advent of the tumescent technique in 1987 has allowed for safe contouring in ambulatory single session liposuction under regional or general anaesthesia. Safety and aesthetic issues define MegaLiposuction to be in Volume in litres of more than 10% of Body weight in Kgs. 870 cases of liposuction were performed between September 2000 and August 2008. In (65%) cases, the total volume of aspirate was greater then 5 liters. (Range: 5 to 25 liters). In 24% cases, the large volume liposuction was combined with a limited or a total block lipectomy. Regional anaesthesia with conscious sedation was preferred except where liposuction was for above the subcostal region (the Upper Trunk, Lateral Chest, Back, Gynaecomastia, Breast, Arms and Face) or when the patient so desired. Tumescent infiltration with Lactated ringer, adrenalin, triamcinalone and hyalase was made in all cases. This approach has clinically shown less tissue edema in the post operative period than when the conventional physiological saline was being used in place of Ringer Lactate. The amount injected varied from 1,000 ml to 12,500 ml depending on the size, site and area. Local anesthetic was included only to the terminal portion of the tumescent mixture while infiltrating the sub-costal regions, or when above costal region was combined with below costal region being anaesthetized with Spinal Anaesthesia. The aspirate was restricted to the unstained white / yellow fat and the amount of fat aspirated did not have any bearing to the amount of solution infiltrated. There was no major complication. Blood transfusion was given only on one occasion when the patient had been on aspirin and had also received Low Molecular weight Heparin intra-operative. The hospital stay ranged from 8 to 24 hours for liposuction as well as for liposuction with a lipectomy. Serous discharge from access sites, sero-sanguinous fluid accumulation requiring drainage were necessitated in less than 10% cases. Minor re-contouring touch ups were requested in 5% cases. Early ambulation was encouraged for mobilization of third space fluid shifts to expedite recovery and to prevent deep vein thrombosis. More than 10% patients were operated on for Liposuction of other areas, after a gap of 7 days to 6 months. Meticulous perioperative monitoring of systemic functions ensures safety in tumescent megaliposuction for the obese and rewarding results can be achieved in a single sitting. PMID:20174540

Metabolic routes along digestive system of licorice: multicomponent sequential metabolism method in rat.

PubMed

Zhang, Lei; Zhao, Haiyu; Liu, Yang; Dong, Honghuan; Lv, Beiran; Fang, Min; Zhao, Huihui

2016-06-01

This study was conducted to establish the multicomponent sequential metabolism (MSM) method based on comparative analysis along the digestive system following oral administration of licorice (Glycyrrhiza uralensis Fisch., leguminosae), a traditional Chinese medicine widely used for harmonizing other ingredients in a formulae. The licorice water extract (LWE) dissolved in Krebs-Ringer buffer solution (1 g/mL) was used to carry out the experiments and the comparative analysis was performed using HPLC and LC-MS/MS methods. In vitro incubation, in situ closed-loop and in vivo blood sampling were used to measure the LWE metabolic profile along the digestive system. The incubation experiment showed that the LWE was basically stable in digestive juice. A comparative analysis presented the metabolic profile of each prototype and its corresponding metabolites then. Liver was the major metabolic organ for LWE, and the metabolism by the intestinal flora and gut wall was also an important part of the process. The MSM method was practical and could be a potential method to describe the metabolic routes of multiple components before absorption into the systemic blood stream. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Clarification of serotonin-induced effects in peripheral artery disease observed through the femoral artery response in models of diabetes and vascular occlusion: The role of calcium ions.

PubMed

Stojanović, Marko; Prostran, Milica; Janković, Radmila; Radenković, Miroslav

2017-07-01

Recent findings have demonstrated that serotonin is an important participant in the development and progression of peripheral artery diseases. Taking this into consideration, the goals of this study were to investigate the effects of serotonin on isolated Wistar rat femoral arteries in both healthy and diabetic animals, with and without artery occlusion, with a particular focus on determining the role of calcium in this process. Contraction experiments with serotonin on intact and denuded femoral artery rings, in the presence or absence of nifedipine and ouabain (both separately, or in combination), as well as Ca 2+ -free Krebs-Ringer bicarbonate solution were performed. The serotonin-induced results were concentration dependent, but only in healthy animals. The endothelium-dependent contraction of the femoral artery was assessed. In healthy animals, the endothelium-reliant part of contraction was dependent on the extracellular calcium, while the smooth muscle-related part was instead dependent on the intracellular calcium. In diabetic animals, both nifedipine and ouabain influenced serotonin-induced vascular effects by blocking intracellular calcium pathways. However, this was diminished after the simultaneous administration of both blockers. © 2017 John Wiley & Sons Australia, Ltd.

Investigation of fatigue crack growth in acrylic bone cement using the acoustic emission technique.

PubMed

Roques, A; Browne, M; Thompson, J; Rowland, C; Taylor, A

2004-02-01

Failure of the bone cement mantle has been implicated in the loosening process of cemented hip stems. Current methods of investigating degradation of the cement mantle in vitro often require sectioning of the sample to confirm failure paths. The present research investigates acoustic emission as a passive experimental method for the assessment of bone cement failure. Damage in bone cement was monitored during four point bending fatigue tests through an analysis of the peak amplitude, duration, rise time (RT) and energy of the events emitted from the damage sections. A difference in AE trends was observed during failure for specimens aged and tested in (i) air and (ii) Ringer's solution at 37 degrees C. It was noted that the acoustic behaviour varied according to applied load level; events of higher duration and RT were emitted during fatigue at lower stresses. A good correlation was observed between crack location and source of acoustic emission, and the nature of the acoustic parameters that were most suited to bone cement failure characterisation was identified. The methodology employed in this study could potentially be used as a pre-clinical assessment tool for the integrity of cemented load bearing implants.

Studies on the ovarian motility of small laboratory rodents.

PubMed

Gimeno, M F; Gimeno, A L

1975-01-01

Guinea pig ovaries were isolated and immersed in Krebs-Ringer bicarbonate solution, gassed with carbogen and added with glucose as the substrate. The experiments were carried out at 37 degrees C and the preparations were subjected to a basal tension of 500 mg. The spontaneous motility (contractile tension and frequency) of guinea pig ovaries obtained in late proestrus was significantly greater than that of the estrus or early proestrus. The influence of oxytocin on ovarian motility was significantly more marked in late proestrus than in estrus or early proestrus. Both the spontaneous and induced mortility of guinea pig ovaries are augmented in the immediate prevoulatory moment. In isolated rat ovaries, the isometric contractile tension and the frequency of contractions increased as the estral cycle progressed. During late proestrus, left ovaries had a contractile activity of greater intensity and frequency than the right ones, whereas during early proestrus the magnitudes were comparable. Oxytocin elicited greater responses in left than right ovaries of the late proestrus, the effect becoming similar in estrus and early proestrus. Rat ovaries obtained immediately before ovulation are specifically sensitized to the influence of oxytocin and not to other smooth muscle stimulants.

[Study of the electrical properties of retinal horizontal cell syncytia by the technic of uniform polarization].

PubMed

Shura-Bura, T M; Trifonov, Iu A

1980-01-01

For uniform polarization of syncytial or cable structures at a large area with current passed via extracellular electrodes the extracellular longitudinal gradient of potential must be proportional to distance from the edge of preparation. In this paper the profile of conducting plate was found analytically which allows to obtain such a distribution of potentials. The profile is formed by hyperbola and its orthogonal asymptotes. Two polarizing electrodes are applied to places where the hyperbola is near to asymptotes. On the surfaces formed by asymptotes the gradient of potential is proportional to distance from intersection of these surfaces. Such a conducting plate was made as cavity in plexiglas filled by Ringer solution in agar. The plate was used for obtaining the voltage-current curves of horizontal cell membrane in gold fish retina. The area of uniform polarization was 4-5 mm long. Measurements inside this area allowed to determine the space constant of horizontal cell layer. The space constant measured in bright light (when resistance of subsynaptic membrane is high) depends on the membrane potential, being high (approximately 1,5 mm) during depolarization and low (0,2-0,4 mm) during hyperpolarization.

Na-KATPase activity and intracellular ion concentrations in the lactating guinea pig mammary gland. Studies on Na-K activated adenosine triphosphatase, XXXVI.

PubMed

Vreeswijk, J H; de Pont, J J; Bonting, S L

1975-01-01

The intracellular sodium, potassium and chloride concentrations in slices of lactating guinea pig mammary gland have been determined by chemical analysis and the use of appropriate values for extracellular space. These ion concentrations after 1 hr incubation at 37 degrees C in a Krebs-Ringer bicarbonate solution are 45mM Na+, 138 mM K+ and 44 mM Cl-, which values are in agreement with those found in fresh mammary gland slices. Inhibition of the NaK activated ATPase cation pump system of the tissue by 10(-4)M ouabain, anoxia or cooling to 0 degrees C Causes a gain of Na+ and an equimolar loss of K+ without a significant change in chloride concentration. The effect of cooling (0 degrees C) is reversible by reincubation at 37 degrees C. Water content of the tissue (76.5% of wet weight) and extracellular space (40.5%) do not change under these conditions. The results permit the conclusion that the NaK activated ATPase system is responsible for the maintenance of the intracellular Na+ and K+ concentrations, but do not support the presence of a chloride pump.

A comparative study of the mechanical behaviour of thermally oxidised commercially pure titanium and zirconium.

PubMed

Alansari, A; Sun, Y

2017-10-01

The objective of this study is to compare the mechanical behaviour of thermally oxidised commercially pure titanium (CP-Ti) and commercially pure zirconium (CP-Zr). For this purpose, these two bio-metals were thermally oxidised under the same condition (650°C for 6h) and the oxidised specimens were characterised using various analytical and experimental techniques, including oxygen uptake analysis, layer thickness and hardness measurements, scratch tests, dry sliding friction and wear tests and tribocorrosion tests in Ringer's solution. The results show that under the present thermal oxidation condition, 4 times more oxygen is introduced into CP-Zr than into CP-Ti and the oxide layer produced on CP-Zr is nearly 6 times thicker than that on CP-Ti. Thermally oxidised CP-Zr possesses a higher hardness, a deeper hardening depth and better scratch resistance than thermally oxidised CP-Ti. Under dry sliding and tribocorrosion conditions, thermally oxidised CP-Zr also possesses much better resistance to material removal and a higher load bearing capacity than thermally oxidised CP-Ti. Thus, thermally oxidised Zr possesses much better mechanical behaviour than thermally oxidised Ti. Copyright © 2017 Elsevier Ltd. All rights reserved.

A multi-center randomized trial of two different intravenous fluids during labor

PubMed Central

DAPUZZO-ARGIRIOU, Lisa M.; SMULIAN, John C.; ROCHON, Meredith L.; GALDI, Luisa; KISSLING, Jessika M.; SCHNATZ, Peter F.; RIOS, Angel GONZALEZ; AIROLDI, James; CARRILLO, Mary Anne; MAINES, Jaimie; KUNSELMAN, Allen R.; REPKE, John; LEGRO, Richard S.

2017-01-01

Objective To determine if the intrapartum use of a 5% glucose-containing intravenous solution decreases the chance of a cesarean delivery for women presenting in active labor. Methods This was a multi-center, prospective, single (patient) blind, randomized study design implemented at 4 obstetric residency programs in Pennsylvania. Singleton, term, consenting women presenting in active spontaneous labor with a cervical dilation of <6cm were randomized to lactated Ringer's with or without 5% glucose (LR versus D5LR) as their maintenance intravenous fluid. The primary outcome was the cesarean birth rate. Secondary outcomes included labor characteristics, as well as maternal or neonatal complications. Results There were 309 women analyzed. Demographic variables and admitting cervical dilation were similar among study groups. There was no significant difference in the cesarean delivery rate for the D5LR group (23/153 or 15.0%) versus the LR arm (18/156 or 11.5%), [RR (95%CI) of 1.32 (0.75, 2.35), P=0.34]. There were no differences in augmentation rates or intrapartum complications. Conclusions The use of intravenous fluid containing 5% dextrose does not lower the chance of cesarean delivery for women admitted in active labor. PMID:25758624

Use of isovolemic hemodilution in the management of arterial ischemia in patients with polycythemia.

PubMed

Shah, D M; Buchbinder, D; Balko, A; Karmody, A M; Leather, R P

1981-08-01

The management of patients with both polycythemia and limb-threatening ischemia presents many difficulties because in this population, vascular surgical procedures carry a particularly high incidence of hemorrhagic and thromboembolic complications. We evaluated the use of acute isovolemic hemodilution in 12 polycythemic patients who required urgent surgery due to severe ischemia and threatened limb loss. Within 48 hours, blood was withdrawn in units of 500 ml and simultaneously replaced with 1,500 ml of lactated Ringer's solution until a hematocrit of 35 to 40 percent was achieved. After hemodilution, two patients had such a marked improvement that no further therapeutic measures were required immediately. Four patients showed definite improvement in pulmonary vascular resistance tracings and segmental Doppler pressures, but ischemia was not fully ameliorated. These patients together with the remaining six patients underwent vascular surgery within 1 to 14 days after hemodilution. A hematocrit of 32 to 40 percent was maintained during the perioperative period. All arterial reconstructions were successfully completed and there were no perioperative failures. No pulmonary emboli, myocardial infarctions, or deaths occurred in this period. These results indicate that in polycythemic patients, urgent vascular surgery can be performed more safely with the concomitant use of acute isovolemic hemodilution.

HSD is a better resuscitation fluid for hemorrhagic shock with pulmonary edema at high altitude.

PubMed

Liu, Liang-Ming; Hu, De-Yao; Zhou, Xue-Wu; Liu, Jiang-Cang; Li, Ping

2008-12-01

To investigate the fluid tolerance of hemorrhagic shock with pulmonary edema (HSPE) at high altitude in unacclimated rats and the beneficial effect of 7.5% hypertonic saline/6% dextran (HSD). One hundred seventy-six Sprague-Dawley rats, transported to LaSa, Tibet, 3,760 m above the sea level, were anesthetized with sodium pentobarbital (30 mg/kg, i.p.) within 1 week. Hemorrhagic shock with pulmonary edema was induced by bloodletting (50 mmHg for 1 h) plus intravenous injection of oleic acid (50 microL/kg). Seventy-seven rats were equally divided into 11 groups (n = 7/group) including sham-operated control group; hemorrhagic shock control group; HSPE control group; HSPE plus 0.5-, 1.0-, 1.5-, 2.0-, or 3.0-fold volumes of lactated Ringer's solution (LR) groups; and HSPE plus 4, 6, and 8 mL/kg of HSD groups. Hemodynamic parameters including mean arterial blood pressure, left intraventricular systolic pressure, and the maximal change rate of intraventricular pressure rise or decline (+/-dp/dtmax) were observed at baseline and at 15, 30, 60, and 120 min after infusion; blood gases were measured at 30 and 120 min after infusion, and the water content of lung and brain was determined at 120 min after infusion. Additional 99 rats were used to observe the effect of these treatments on the survival time of HSPE rats; 0.5 volume of LR infusion slightly increased the mean arterial blood pressure, left intraventricular systolic pressure, and +/-dp/dtmax and prolonged the survival time of HSPE animals as compared with the HSPE group (P < 0.05 - 0.01); it did not increase the water content of lung and brain and had no marked influences on blood gases. One volume of LR infusion had somewhat improved the hemodynamic parameters for HSPE animals, but had no apparent effect on the survival time and the water content of lung and brain. Lactate Ringer's solution infusion, 1.5, 2, and 3 volumes, significantly deteriorated the hemodynamic parameters, increased the water content of lung, and decreased the survival time of HSPE animals. Hypertonic saline/6% dextran (4 - 8 mL/kg) significantly increased the hemodynamic parameters, improved the blood gases, decreased the water content of lung and brain, and prolonged the survival time of HSPE rats. Among the three dosages of HSD, 6 mL/kg of HSD had the best effect. The tolerance of fluid infusion for hemorrhagic shock with pulmonary edema at high altitude is significantly decreased. More than one volume of LR infusion would aggravate the pulmonary edema and exacerbate the resuscitation effect, but only one volume of LR cannot reach the effective volume resuscitation. Small volume of HSD could better resuscitate hemorrhagic shock with pulmonary edema at high altitude.

Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (84th, Washington, DC, August 5-8, 2001). Public Relations Division.

ERIC Educational Resources Information Center

Association for Education in Journalism and Mass Communication.

The Public Relations section of the proceedings contains the following 11 selected papers: "If We Build It, Will They Come? Testing the Theory of Planned Behavior as a Predictive Model for Use in Determining How Career Counseling Centers Can Better Promote Their Facilities and Services" (Carolyn Ringer Lepre); "Student Preferences…

BVRI photometry of ASASSN-15qi using the Tautenburg Schmidt telescope

NASA Astrophysics Data System (ADS)

Stecklum, Bringfried; Eisloeffel, Jochen; Scholz, Alexander

2015-10-01

We report on photometric observations of the optical transient ASASSN-15qi performed at the Th & uuml;ringer Landessternwarte Tautenburg. The brightening of this source was discovered by the All-Sky Automated Survey for Supernovae (ASAS-SN, Shappee et al. 2014, ApJ, 788, 48). The object is located west of the HII region SH2-148 and a likely member of the star forming region.

Effects of peptide YY on gallbladder motility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Conter, R.L.; Roslyn, J.J.; Taylor, I.L.

1987-06-01

The effects of peptide YY (PYY) on cholecystokinin-stimulated gallbladder contraction were investigated in the prairie dog model. Twelve animals underwent laparotomy with catheter placement into the gallbladder and common bile duct (vent). The gallbladder was continuously perfused with (/sup 14/C)polyethylene glycol-labeled lactated Ringer at 0.03 ml/min, and vent effluent was collected at 2.5-min intervals. All animals received 20 min of intravenous infusion of cholecystokinin octapeptide (CCK-OP), 2.5 ng x kg/sup -1/ x min/sup -1/, immediately followed by 60-min infusions of either lactated Ringer (LR) or synthetic PYY, 10 or 50 ng x kg/sup -1/ x min/sup -1/. When LR wasmore » infused after CCK-OP, gallbladder filling increased by 15.4 +/- 10.5% with minimal changes in gallbladder pressure. Infusion of PYY/sub 10/ resulted in a significant increase in gallbladder volume and filling with a significant decrease in intragallbladder pressure. Similar findings were noted with PYY/sub 50/. These data indicate that synthetic PYY significantly augments gallbladder filling after CCK-OP-stimulated gallbladder contraction. These finding, coupled with the observation that PYY inhibits pancreatic secretion, suggest that this peptide may be the anti-CCK hormone and may have an important role in regulating biliary activity postprandially.« less

EGSIEM: Combination of GRACE monthly gravity models on normal equation level

NASA Astrophysics Data System (ADS)

Meyer, Ulrich; Jean, Yoomin; Jäggi, Adrian; Mayer-Gürr, Torsten; Neumayer, Hans; Lemoine, Jean-Michel

2016-04-01

One of the three geodetic services to be realized in the frame of the EGSIEM project is a scientific combination service. Each associated processing center (AC) will follow a set of common processing standards but will apply its own, independent analysis method. Therefore the quality, robustness and reliability of the combined monthly gravity fields is expected to improve significantly compared to the individual solutions. The Monthly GRACE gravity fields of all ACs are combined on normal equation level. The individual normal equations are weighted depending on pairwise comparisons of the individual gravity field solutions. To derive these weights and for quality control of the individual contributions first a combination of the monthly gravity fields on solution level is performed. The concept of weighting and of the combination on normal equation level is introduced and the formats used for normal equation exchange and gravity field solutions is described. First results of the combination on normal equation level are presented and compared to the corresponding combinations on solution level. EGSIEM has an open data policy and all processing centers of GRACE gravity fields are invited to participate in the combination.

Vasopressin attenuates TNF-mediated inflammation in the rat cremaster microcirculation.

PubMed

McMahon, Paul J; Proctor, Kenneth G

2009-09-01

Our previous study in a swine polytrauma model suggested that equieffective systemic pressor doses of arginine vasopressin (AVP) versus phenylephrine (PE) have differential effects on the systemic and cerebral microcirculation. The purpose of this study was to directly observe the effects of AVP versus PE on inflammatory changes evoked by tumor necrosis factor alpha (TNF) in the skeletal muscle microcirculation. Seventy-five male rats (180-250 g) were anesthetized with isoforane, intubated and mechanically ventilated with 100% oxygen. The cremaster muscle microcirculation was prepared for intravital video microscopy while being suffused with a heated hetastarch-electrolyte solution. Fluorescein isothiocyanate-labeled albumin (100 mg/kg) was administered intravenously (i.v.) before one of five protocols. In series 1 (n = 20), either AVP (0.2 U/mL) or its vehicle was added to the suffusate for 10 minutes, washed out for 30 minutes, then TNF was suffused (5 ng/mL) for 30 minutes. In series 2 (n = 16), the protocol was similar, except AVP (0.2 U/mL) or an equieffective dose of PE (0.04 mg/mL) was administered i.v. (4.5 mL/h) for 15 minutes before, during, and 45 minutes after TNF suffusion. In series 3 (n = 12), the protocol was similar to series 2, except venous hemorrhage preceded i.v. AVP or PE. In series 4 (n = 15), the protocol was similar to series 3, except an AVP antagonist (vaprisol, 1 mg/kg i.v.) or its vehicle was administered after hemorrhage. In the control series (n = 13), inflammation was evaluated either with a different suffusate (lactated Ringers instead of hetastarch solution), different antigen (histamine instead of TNF), or hemorrhage with no antigen. In series 1, the TNF-evoked increase in leukocyte infiltration (i.e., rolling), leukocyte activation (i.e., sticking), and macromolecular permeability (i.e., albumin extravasation) were attenuated with topical AVP versus vehicle (both p < 0.05), with no effect on venular blood flow (which determines sheer stress). In series 2, the TNF-evoked increase in infiltration, activation, and permeability were all attenuated, and arteriolar blood flow (which determines perfused capillary surface area and hydrostatic pressure) was reduced with i.v. AVP versus i.v. PE (all p < 0.05). In series 3, after hemorrhage to mean arterial pressure <50 mm Hg for 30 minutes, the TNF-evoked increase in infiltration and activation was attenuated, and arteriolar and venular blood flow were both reduced with i.v. AVP versus PE (all p < 0.05). In series 4, after hemorrhage, the TNF-evoked increase in leukocyte activation was potentiated with the vaprisol versus vehicle (p < 0.05) with no effect on arteriolar or venular blood flow. In series 5 (controls), suffusion with lactated Ringers' versus hetastarch solution more than doubled the TNF-evoked increase in activation (p < 0.05). (1) AVP can attenuate TNF-evoked leukocyte infiltration, activation or permeability changes in the skeletal muscle microcirculation. (2) The mechanism is probably receptor mediated and does not entirely depend on sheer stress in venules or Starling forces in capillaries. (3) The magnitude of this anti-inflammatory effect is influenced by several conditions, including volume status, the colloid or crystalloid suffusion fluid, and is possibly specific to the antigenic stimulus (TNF vs. histamine).

Pyruvate in oral rehydration salt improves hemodynamics, vasopermeability and survival after burns in dogs.

PubMed

Liu, Rui; Hu, Xiao-Hang; Wang, Shu-Ming; Guo, Si-Jia; Li, Zong-Yu; Bai, Xiao-Dong; Zhou, Fang-Qiang; Hu, Sen

2016-06-01

To investigate whether pyruvate-enriched oral rehydration solution (Pyr-ORS), compared with citrate-enriched ORS (Cit-ORS), improves hemodynamics and organ function by alleviating vasopermeability and plasma volume loss during intra-gastric fluid rehydration in dogs with severe burn. Forty dogs subjected to severe burn were randomly divided into four groups (n=10): two oral rehydrated groups with Pyr-ORS and Cit-ORS (group PR and group CR), respectively, according to the Parkland formula during the first 24h after burns. Other two groups were the intravenous (IV) resuscitation (group VR) with lactated Ringer's solution with the same dosage and no fluid rehydration (group NR). During the next 24h, all groups received the same IV infusion. The hemodynamics, plasma volume, vasopermeability and water contents and function of various organs were determined. Plasma levels of vascular endothelial growth factor (VEGF) and platelet activating factor (PAF) were detected by ELISA. Hemodynamics parameters were significantly improved in group PR superior to group CR after burns. Levels of VEGF and PAF were significantly lower in group PR than in group CR. Organ function parameters were also greatly preserved in group PR, relative to groups CR and NR. Lactic acidosis was fully corrected and survival increased in group PR (50.0%), compared to group CR (20.0%). Pyr-ORS was more effective than Cit-ORS in improving hemodynamics, visceral blood perfusion and organ function by alleviating vasopermeability-induced visceral edema and plasma volume loss in dogs with severe burn. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

Microstructure, Mechanical Properties, and Electrochemical Behavior of Ti-Nb-Fe Alloys Applied as Biomaterials

NASA Astrophysics Data System (ADS)

Lopes, Éder Sócrates Najar; Salvador, Camilo Augusto Fernandes; Andrade, Denis Renato; Cremasco, Alessandra; Campo, Kaio Niitsu; Caram, Rubens

2016-06-01

New β metastable Ti alloys based on Ti-30Nb alloy with the addition of 1, 3, or 5 wt pct Fe have been developed using the bond order and the metal d-orbital energy level ( overline{{Bo}} {-} overline{{Md}} ) design theory. The samples were prepared by arc melting, hot working, and solution heat treatment above the β transus followed by water quenching (WQ) or furnace cooling (FC). The effect of the cooling rate on the microstructure of Ti-30Nb-3Fe wt pct was investigated in detail using a modified Jominy end quench test. The results show that Fe acts as a strong β-stabilizing alloying element. The addition of Fe also leads to a reduction in the ω and α phases volumetric fractions, although the ω phase was still detected in the WQ Ti-30Nb-5Fe samples, as shown by TEM, and α phase clusters were detected by SEM in the FC Ti-30Nb-3Fe samples. Among the WQ samples, the addition of 5 wt pct Fe improves the ultimate tensile strength (from 601 to 689 MPa), reduces the final elongation (from 28 to 16 pct), and impairs the electrochemical corrosion resistance, as evaluated by potentiodynamic polarization tests in Ringer's solution. The microstructural variation arising from the addition of Fe did not change the elastic modulus (approximately 80 GPa for all experimental WQ samples). This study shows that small Fe additions can tailor the microstructure of Ti-Nb alloys, modifying α and ω phase precipitation and improving mechanical strength.

The effect of light on outer segment calcium in salamander rods

PubMed Central

Matthews, Hugh R; Fain, Gordon L

2003-01-01

Calcium acts as a second messenger in vertebrate rods, regulating the recovery phase of the light response and modulating sensitivity during light-adaptation. Since light not only decreases the outer segment calcium concentration ([Ca2+]i) by closing cyclic nucleotide-gated channels but can also increase [Ca2+]i by releasing Ca2+ from buffer sites or intracellular stores, we examined in detail the effect of light and circulating current on [Ca2+]i by making simultaneous measurements of suction pipette current and [Ca2+]i from isolated rods of the salamander Ambystoma tigrinum after incorporation of the fluorescent dye fluo-5F. When the release of Ca2+ is measured in 0 Ca2+−0 Na+ solution, minimising fluxes of Ca2+ across the plasma membrane, it is substantial only for light bright enough to bleach a significant fraction of the photopigment and is restricted to the part of the outer segment in which the bleach occurred. It is unlikely, therefore, to make a large contribution to [Ca2+]i for most of the physiological operating range of the rod. Nevertheless, since release is half-maximal for a bleach of less than 10 %, it cannot be produced by a simple mechanism such as a change in the affinity of a binding site on rhodopsin itself but must instead require some more complex interaction. In Ringer solution, the Ca2+ in the light-releasable pool can be discharged merely by the decrease in [Ca2+]i that occurs as the outer segment channels close. In steady background light or after exposure to saturating illumination, the fraction of Ca2+ in the pool decreases essentially in proportion to [Ca2+]i as if Ca2+ were being removed from a buffer site within the cytoplasm. Furthermore, [Ca2+]i itself changes in proportion to the circulating current, with little evidence for a contribution from Ca2+ release or other mechanisms of Ca2+ homeostasis. This indicates that flux of Ca2+ across the plasma membrane is the major determinant of outer segment Ca2+ concentration within the rod's normal operating light intensity range. Once Ca2+ has been discharged from the releasable pool, it is restored following dim illumination apparently as the simple result of the subsequent restoration of dark [Ca2+]i and the rebinding of Ca2+ to its release site, but after brighter light perhaps also as a consequence of regeneration of the photopigment. PMID:12949220

The Effect of Acute Renal Failure on Muscle Protein Turnover in the Rat and Implications for Therapy.

DTIC Science & Technology

1984-10-01

Effect on Serum Glucose and Insulin: * a. The pattern of insulin secretion and concomitant blood suoar con- centrations are of interest in this...combat casualties suffering from extensive trauma and prolonger hypotension. Despite replacement of blood , fluids and electrolytes, expert surgical care...thin muscles ar incubated in oxygenated, buffered Krebs-Ringer medium for 2 hours. The basic media contain glucose , 14C-labeled phenylalanine. Muscle

The Effect of Acute Renal Failure on Muscle Protein Turnover in the Rat and Implications for Therapy.

DTIC Science & Technology

1983-06-15

are largely depleted, fat deposits grossly shrunken and gluconeogenesis from muscle protein a principal source for blood glucose maintenance. We were...casualties suffering from extensive trauma and prolonged hypotension. * Despite replacement of blood , fluids and electrolytes, expert surgf:al care...Ringer medium for 2 hours. The basic media contain glucose , 1C-labeled phenylalanine. Muscle synthesis is assayed by determining the incorporation of 1C

Hypothermic preservation of corneas in a hyperkalaemic solution (CPTES): I. Short-term storage in the absence of colloid osmotic agents.

PubMed Central

Taylor, M J; Hunt, C J

1989-01-01

Preservation solutions for short-term storage of isolated donor corneas for use in penetrating keratoplasty have all been based on tissue culture medium, on the assumption that media designed to maintain the viability of cells at physiological temperatures will also provide suitable conditions for preservation at reduced temperatures. But for hypothermic preservation of some other tissues and organs, when ionic pumps are inhibited, it is unnecessary to support metabolism, and beneficial control of ion and water distribution between intra- and extracellular compartments is achieved by storage in appropriately formulated 'intracellular-type' solutions. We have therefore designed a solution that will restrict ionic imbalances and minimise endothelial cell swelling in corneas during exposure at reduced temperatures. This potassium-rich solution contains the biological pH buffer TES as an impermeant anion and is designated CPTES (corneal-potassium-TES). The structural and functional integrity of rabbit corneas stored at 0 degrees C in CPTES, without the addition of colloid osmotic agents, is compared with that of corneas stored in glutathione bicarbonate Ringers' solution (GBR), an 'extracellular-type' medium formulated for the maintenance of endothelial integrity during in-vitro perfusion at 34 degrees C. Corneas swelled significantly less during storage in CPTES than in GBR and could be stored for five days before reaching the same degree of hydration as corneas stored for only three days in GBR. Gross structural integrity and endothelial ultrastructure were maintained during storage for three and five days in CPTES. The rate of thinning of corneas stored in CPTES was significantly greater than in comparable groups of corneas stored in GBR. However, the efficient dehydration of corneas stored in CPTES was always preceded during perfusion by a brief period of additional swelling which was shown to be an osmotic response during the elution of the buffer compound TES that had permeated the stroma during storage. The omission of calcium or the addition of adenosine and glutathione to the CPTES preservation medium had no detectable effect on the integrity of the endothelium, but the omission of bicarbonate was beneficial, producing significantly higher rates of stromal thinning during normothermic perfusion. Additional benefits for extending storage by including colloid osmotic agents are described in a companion paper. Images PMID:2818988

Construction of normal-regular decisions of Bessel typed special system

NASA Astrophysics Data System (ADS)

Tasmambetov, Zhaksylyk N.; Talipova, Meiramgul Zh.

2017-09-01

Studying a special system of differential equations in the separate production of the second order is solved by the degenerate hypergeometric function reducing to the Bessel functions of two variables. To construct a solution of this system near regular and irregular singularities, we use the method of Frobenius-Latysheva applying the concepts of rank and antirank. There is proved the basic theorem that establishes the existence of four linearly independent solutions of studying system type of Bessel. To prove the existence of normal-regular solutions we establish necessary conditions for the existence of such solutions. The existence and convergence of a normally regular solution are shown using the notion of rank and antirank.

Modeling serotonin uptake in the lung shows endothelial transporters dominate over cleft permeation

PubMed Central

Bassingthwaighte, James B.

2013-01-01

A four-region (capillary plasma, endothelium, interstitial fluid, cell) multipath model was configured to describe the kinetics of blood-tissue exchange for small solutes in the lung, accounting for regional flow heterogeneity, permeation of cell membranes and through interendothelial clefts, and intracellular reactions. Serotonin uptake data from the Multiple indicator dilution “bolus sweep” experiments of Rickaby and coworkers (Rickaby DA, Linehan JH, Bronikowski TA, Dawson CA. J Appl Physiol 51: 405–414, 1981; Rickaby DA, Dawson CA, and Linehan JH. J Appl Physiol 56: 1170–1177, 1984) and Malcorps et al. (Malcorps CM, Dawson CA, Linehan JH, Bronikowski TA, Rickaby DA, Herman AG, Will JA. J Appl Physiol 57: 720–730, 1984) were analyzed to distinguish facilitated transport into the endothelial cells (EC) and the inhibition of tracer transport by nontracer serotonin in the bolus of injectate from the free uninhibited permeation through the clefts into the interstitial fluid space. The permeability-surface area products (PS) for serotonin via the inter-EC clefts were ∼0.3 ml·g−1·min−1, low compared with the transporter-mediated maximum PS of 13 ml·g−1·min−1 (with Km = ∼0.3 μM and Vmax = ∼4 nmol·g−1·min−1). The estimates of serotonin PS values for EC transporters from their multiple data sets were similar and were influenced only modestly by accounting for the cleft permeability in parallel. The cleft PS estimates in these Ringer-perfused lungs are less than half of those for anesthetized dogs (Yipintsoi T. Circ Res 39: 523–531, 1976) with normal hematocrits, but are compatible with passive noncarrier-mediated transport observed later in the same laboratory (Dawson CA, Linehan JH, Rickaby DA, Bronikowski TA. Ann Biomed Eng 15: 217–227, 1987; Peeters FAM, Bronikowski TA, Dawson CA, Linehan JH, Bult H, Herman AG. J Appl Physiol 66: 2328–2337, 1989) The identification and quantitation of the cleft pathway conductance from these studies affirms the importance of the cleft permeation. PMID:23645496

Bipolar radiofrequency ablation of the kidney: comparison with monopolar radiofrequency ablation.

PubMed

Nakada, Stephen Y; Jerde, Travis J; Warner, Thomas F; Wright, Andrew S; Haemmerich, Dieter; Mahvi, David M; Lee, Fred T

2003-12-01

We report initial ex vivo and in vivo studies using bipolar radiofrequency (RF) ablation of porcine kidneys. An internal ground electrode is positioned in the kidney opposite the RF electrode, resulting in ablation of all the intervening renal tissue. Ex vivo preparations of 10 porcine kidneys were perfused continuously with Ringer's solution and treated with either standard external grounded RF (N = 3) or bipolar RF ablation with 1 (N = 2), 2 (N = 3), or 3 (N = 2) cm of separation between the ground probe and the RF probe using a Model 30 RITA generator (RITA, Mountain View, CA). Target temperatures were 90 degrees C for 8 minutes. Gross and histologic assessments were made acutely. Four domestic pigs were treated with monopolar RF ablation of the lower pole of one kidney and bipolar RF with a 12-mm separation between the probes of the contralateral lower pole. Animals were harvested 48 hours later to maximize tissue damage for gross measurements and histologic evaluation. Ex vivo studies revealed grossly monopolar lesions 1.5 cm in maximum diameter and 1.75 cm(3) in volume. In comparison, bipolar lesions were 2.8 cm in maximum diameter and 10.3 cm(3) in volume using 3 cm of electrode separation. There was histologic evidence of cell death in all specimens. In vivo studies showed two distinct gross lesions with RF: one blanched and one hemorrhagic. Using bipolar RF, larger blanched lesions were achievable than with monopolar RF (2.80 cm(3) v 1.63 cm(3)). Overall, the combinations of blanched and hemorrhagic lesions were similar with monopolar and bipolar RF (5.01 v 5.31 cm(3)). Histologic evaluation verified cell death in the blanched lesions and rare areas of normal tissue in the hemorrhagic lesions. As shown by ex vivo data, bipolar RF can create larger lesions than does monopolar RF. In vivo, at 48 hours, both blanched and hemorrhagic gross lesions were seen using RF. In this model, blanched lesions predominated when performing bipolar RF.

Prostaglandins as mediators of acidification in the urinary bladder of Bufo marinus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frazier, L.W.; Yorio, T.

1990-05-01

Experiments were performed to determine whether prostaglandins (PG) play a role in H+ and NH4+ excretion in the urinary bladder of Bufo marinus. Ten paired hemibladders from normal toads were mounted in chambers. One was control and the other hemibladder received PGE2 in the serosal medium (10(-5) M). H+ excretion was measured by change in pH in the mucosal fluid and reported in units of nmol (100 mg tissue)-1 (min)-1. NH4+ excretion was measured colorimetrically and reported in the same units. The control group H+ excretion was 8.4 +/- 1.67, while the experimental group was 16.3 +/- 2.64 (P lessmore » than 0.01). The NH4+ excretion in the experimental and control group was not significantly different. Bladders from toads in a 48-hr NH4+Cl acidosis (metabolic) did not demonstrate this response to PGE2 (P greater than 0.30). Toads were put in metabolic acidosis by gavaging with 10 ml of 120 mM NH4+Cl 3 x day for 2 days. In another experiment, we measured levels of PG in bladders from control (N) and animals placed in metabolic acidosis (MA). Bladders were removed from the respective toad, homogenized, extracted, and PG separated using high-pressure liquid chromatography and quantified against PG standards. The results are reported in ng (mg tissue)-1. PGE2 fraction in N was 1.09 +/- 0.14 and in MA was 3.21 +/- 0.63 (P less than 0.01). PGF1 alpha, F2 alpha and I2 were not significantly different in N and MA toads. Bladders were also removed from N and MA toads, and incubated in Ringer's solution containing (3H)arachidonic acid (0.2 microCi/ml) at 25 degrees C for 2 hr. Bladders were then extracted for PG and the extracts separated by thin layer chromatography. PG were identified using standards and autoradiography, scraped from plates, and counted in a scintillation detector. The results are reported in cpm/mg tissue x hr +/- SEM.« less

Origin and voltage dependence of asparagine-induced depolarization in intestinal cells of Xenopus embryo.

PubMed Central

Bergman, C; Bergman, J

1985-01-01

The kinetics and voltage dependence of asparagine (Asn)-induced depolarization in endoderm cells from Xenopus laevis embryos were analysed using current-clamp techniques. The depolarization is assumed to reflect the activation of an amino acid membrane carrier; it is accompanied by a slight increase in membrane resistance and cannot be explained by only the electrogenic character of the Asn carrier. It is proposed that the Asn depolarization arises, at least in part, from the decrease of the permeability ratio PK/PNa indirectly associated with the Na-coupled amino acid uptake. At room temperature (20-23 degrees C) the Asn response develops according to a single exponential function whose time constant is correlated with the final level of depolarization. Both amplitude and rise time of the depolarization are sensitive to variations of membrane potential and changes in Asn or Na external concentrations. Lowering the temperature decreases the amplitude of the Asn depolarization and increases its rise time with a Q10 factor of two; the kinetics remain of the Michaelis-Menten type, with a marked decrease in delta Emax and no change in Km. When the holding potential is altered by depolarizing and hyperpolarizing currents, the Asn response varies according to a bell-shaped characteristic presenting an optimum near the normal resting level. Membrane depolarizations induced by Na/K-pump inhibitors or high external K concentrations reduce the size of the Asn response; repolarizing the cell by current injection does not reverse the inhibitory effect of external K ions. Hyperpolarizing the membrane with a K-free Ringer solution increases the amplitude of the Asn response. In all these cases a decrease in delta Emax accounts for the apparent voltage sensitivity of the carrier mechanism. When induced by alterations of [K]o, an additional change in Km is observed, suggesting a K/Na-competitive inhibition of the Asn carrier. The results are discussed in terms of the amino acid carrier and passive membrane properties. It is suggested that the outward K-electrochemical gradient contributes an additional source of energy to the Na-dependent Asn uptake. PMID:4057089

Osmoregulatory processes and skeletal muscle metabolism

NASA Astrophysics Data System (ADS)

Boschmann, Michael; Gottschalk, Simone; Adams, Frauke; Luft, Friedrich C.; Jordan, Jens

Prolonged microgravity during space flight is associated with a decrease in blood and extracellular volume. These changes in water and electrolyte balance might activate catabolic processes which contribute finally to the loss of muscle and bone mass and strength. Recently, we found a prompt increase that energy expenditure by about 30% in both normal and overweight men and women after drinking 500 ml water. This effect is mediated by an increased sympathetic nervous system activity, obviously secondary to stimulation of osmosensitive afferent neurons in the liver, and skeletal muscle is possibly one effector organ. Therefore, we tested the hypothesis that this thermogenic response to water is accompanied by a stimulation of aerobic glucose metabolism in skeletal muscle. To this end, 16 young healthy volunteers (8 men) were studied. After an overnight fast (12h), a microdialysis probe was implanted into the right M. quadriceps femoris vastus lateralis and subsequently perfused with Ringer's solution (+50 mM ethanol). After 1h, volunteers were asked to drink 500 ml water (22° C) followed by continuing microdialysis for another 90 min. Dialysates (15 min fractions) were analyzed for [ethanol], [glucose], [lactate], [pyruvate], and [glycerol] in order to assess changes in muscle tissue perfusion (ethanol dilution technique), glycolysis and lipolysis. Blood samples were taken and heart rate (HR) and blood pressure (BP) were monitored. Neither HR and systolic and diastolic BP, nor plasma [glucose], [lactate], [insulin], and [C peptide] changed significantly after water drinking. Also, tissue perfusion and dialysate [glucose] did not change significantly. However, dialysate [lactate] increased by about 10 and 20% and dialysate [pyruvate] by about 100 and 200% in men and women, respectively. In contrast, dialysate [glycerol] decreased by about 30 and 20% in men and women, respectively. Therefore, drinking of 500 ml water stimulates aerobic glucose metabolism and inhibits lipolysis in skeletal muscle and this to a greater extent in women than men. These insulin-like effects after water drinking originate possibly from regulatory cell volume swelling in osmosensitive organs such as muscle. Therefore, a well-balanced water homeostasis might be important for preventing catabolic processes during long-term space expeditions.

Minimizing complications of ultrasound-assisted lipoplasty: an initial experience with no related complications.

PubMed

Tebbetts, J B

1998-10-01

Numerous complications and increased operating times were reported with ultrasonically assisted lipoplasty in the first several months after introduction of the technology in the United States. The purpose of this study was to review early reported complications and management regimens, evaluate possible causes of problems, and apply indications and techniques to attempt to minimize complications during an initial experience with this technique beginning in January of 1997. Seven specific indications and modifications of existing techniques were developed and applied to an initial clinical series of 70 consecutive patients who underwent ultrasound-assisted suction lipoplasty between January 10, 1997, and August 1, 1997. Follow-up ranged from 1 to 7 months. No perioperative or postoperative complication occurred in any patient in this series. In this series of ultrasound-assisted lipoplasty cases, application of the following criteria resulted in a series of 70 patients with 1 to 7-month follow-up without complications: (1) selecting patients with well localized fat deposits who were no more than 20 percent above their ideal body weight; (2) infusing a solution of Ringer's Lactate containing 1 cc of 1:1000 epinephrine per 1000 cc into the area of fat removal, stopping infusion when the tissues first become firm, not infusing to marked tissue turgor or skin induration; (3) restricting the level of energy application to a minimum of 1 cm from the undersurface of the dermis; (4) limiting ultrasonic energy application in each area to approximately 1 minute per estimated 100 cc of total aspirate in a wet to superwet environment; (5) not performing ultrasound-assisted lipoplasty in the same area as another procedure that could potentially compromise tissue vascularity; (6) using a Lysonix 2000 generator and 5-mm golf tee tip probe at a power setting of 8 to apply ultrasonic energy to the area of fat removal, ceasing energy application when tissue resistance to the passage of the probe decreases and moving the cannula as rapidly as tissue resistance allows; and (7) using a standard elastic garment without adherent foam or other materials for 2 weeks postoperatively, encouraging all normal activity immediately, and restricting aerobic activities for 2 weeks.

Mechanisms and time course of menthol-induced cutaneous vasodilation

PubMed Central

Craighead, Daniel H.; McCartney, Nathaniel B.; Tumlinson, James H.; Alexander, Lacy M.

2017-01-01

Menthol is a vasoactive compound that is widely used in topical analgesic agents. Menthol induces cutaneous vasodilation, however the underlying mechanisms are unknown. Determining the rates of appearance and clearance of menthol in the skin is important for optimizing topical treatment formulation and dosing. The purpose of this study was to determine the mechanisms contributing to menthol-mediated cutaneous vasodilation and to establish a time course for menthol appearance/clearance in the skin. Ten young (23±1 years, 5 males 5 females) subjects participated in two protocols. In study 1, four intradermal microdialysis fibers were perfused with increasing doses of menthol (0.1-500mM) and inhibitors for nitric oxide (NO), endothelium derived hyperpolarizing factors (EDHFs), and sensory nerves. Skin blood flow was measured with laser Doppler flowmetry and normalized to %CVCmax. In study 2, two intradermal microdialysis fibers were perfused with lactated Ringer's solution. 0.017mL•cm-2 of a 4% menthol gel was placed over each fiber. 5μL samples of dialysate from the microdialysis fibers were collected every 30 minutes and analyzed for the presence of menthol with high performance gas chromatography/mass spectrometry. Skin blood flow (laser speckle contrast imaging) and subjective ratings of menthol sensation were simultaneously obtained with dialysate samples. In study 1, menthol induced cutaneous vasodilation at all doses ≥100mM (all p<0.05). However, inhibition of either NO, EDHFs, or sensory nerves fully inhibited menthol-mediated vasodilation (all p>0.05). In study 2, significant menthol was detected in dialysate 30 minutes post menthol application (0.89ng, p=0.0002). Relative to baseline, cutaneous vasodilation was elevated from minutes 15-45 and ratings of menthol sensation were elevated from minute 5-60 post menthol application (all p<0.05). Menthol induces cutaneous vasodilation in the skin through multiple vasodilator pathways, including NO, EDHF, and sensory nerves. Topical menthol is detectable in the skin within 30 minutes and is cleared by 60 minutes. Skin blood flow and perceptual measures follow a similar time course as menthol appearance/clearance. PMID:27899298

[Anesthetic management of the ex-utero intrapartum treatment (EXIT) procedure for giant epignathus and of the tumor excision].

PubMed

Aoyama, Tadashi; Nakata, Jun; Sakakibara, Michiko; Takahashi, Tetsuyuki; Hara, Masato; Yamaguchi, Shinya; Maseki, Megumi; Teramoto, Yuzo

2008-10-01

We report an anesthetic management of the ex-utero intrapartum treatment (EXIT) procedure performed in a fetus with giant epignathus due to laryngeal atresia at 28 weeks' gestation. Anesthesia of the mother was induced with thiamylal and vecuronium, and maintained with 4% sevoflurane in 100% oxygen before delivery. Sevoflurane provided excellent uterine relaxation. To maintain the arterial pressure, the patient received acetate Ringer and ephedrine 4mg. After hysterotomy, a pulse oxymeter and an ultrasound transducer were applied to monitor fetal Sp(O2) and heart rate. No anesthetic agents were injected into the fetus in addition to transplacental sevoflurane. Tracheostomy was performed on the fetus by pediatric surgeons on placental support. The uterine tone improved soon after discontinuing sevoflurane, intramyometrial injection of oxytocin and ergometrine infusion after delivery. Excision of the tumor was performed on day 2 of life. Pediatric surgeons tried to excise it totally, but it was hard to differentiate the tumor from the normal tissue, and partial excision was performed. After the excision, the neonate weighed 944 g and excised specimen weighed 253 g. Though the neonate was immature and the tumor was very large, no perioperative complications were associated with EXIT and the tumor excision.

Copyright and Related Protections for Information Age Products. Proceedings and Related Documents of the Meeting of the Information Industry Association (Airlie House, Virginia on July 18 & 19, 1969).

ERIC Educational Resources Information Center

Information Industry Association, Washington, DC.

The welcome and reasons for the meeting, presented by Mr. William T. Knox is followed by these papers: (1) Copyright in Its Historical and Philosophic Setting by Miss Barbara Ringer; (2) Copyright and Standard Reference Data Publications by Dr. Ed Brady; (3) Copyright Revision - Issues and Interests by Mrs. Bella Linden; (4) Court of Claims and…

Comparison of Irrigation Solutions and Devices in a Contaminated Musculoskeletal Wound Survival Model

DTIC Science & Technology

2009-01-01

greatest reduction was seen with castile soap, which lowered the photon count to 13% of the pretreatment level. This was followed by benzalkonium chloride ...castile soap was significantly greater than that with the normal saline solution (p = 0.0069), while the reductions with benzalkonium chloride (p...the goats were assigned to four treatment groups: normal saline solution, bacitracin solution, castile soap, and benzalkonium chloride . All wounds

Electron-microscopical localization of gelsolin in various crustacean muscles.

PubMed

Unger, Andreas; Hinssen, Horst

2010-08-01

Gelsolin was localized by immunoelectron microscopy in fast and slow cross-striated muscles of the lobster Homarus americanus. When ultrathin sections of the muscles were labelled with anti-gelsolin and a gold-conjugated second antibody, 90% of all gold particles in the myoplasm were detected on myofibrils, preferentially in the I-band and AI-region of the sarcomeres. Both the region of the H-zone (lacking thin filaments) and the Z-disc contained no or little gold label. Under physiological conditions, a close association of gelsolin with the thin filaments was observed for both muscle types. The preferential localization of particles in the I- and AI-region indicated that gelsolin was distributed randomly over the whole length of the thin filaments. Preincubation of muscle strips with Ringer solution containing 0.5 mM EGTA resulted in a significantly different distribution pattern; gold particles were now localized preferentially in the cell periphery close to the sarcolemma, with significantly decreased abundance in the centre of the cell. Compared with the muscle under physiological conditions, the number of gold particles over sarcomeric structures was significantly reduced. Thus, binding of gelsolin to the thin filaments is apparently reversible in vivo and depends on the presence of calcium ions. We assume a functional role for gelsolin in the actin turnover processes in invertebrate muscle systems.

Development of strontium and magnesium substituted porous hydroxyapatite/poly(3,4-ethylenedioxythiophene) coating on surgical grade stainless steel and its bioactivity on osteoblast cells.

PubMed

Gopi, D; Ramya, S; Rajeswari, D; Surendiran, M; Kavitha, L

2014-02-01

The present study deals with the successful development of bilayer coatings by electropolymerisation of poly(3,4-ethylenedioxythiophene) (PEDOT) on surgical grade stainless steel (316L SS) followed by the electrodeposition of strontium (Sr) and magnesium (Mg) substituted porous hydroxyapatite (Sr, Mg-HA). The bilayer coatings were characterised by Fourier transform infrared spectroscopy (FT-IR) and high resolution scanning electron microscopy (HRSEM). Corrosion resistance of the obtained coatings was investigated in Ringer's solution by electrochemical techniques and the results were in good agreement with those obtained from chemical analysis, namely inductively coupled plasma atomic emission spectrometry (ICP-AES). Also, the mechanical and biological properties of the bilayer coatings were analyzed. From the obtained results it was evident that the PEDOT/Sr, Mg-HA bilayer exhibited greater adhesion strength than the Sr, Mg-HA coated 316L SS. In vitro cell adhesion test of the Sr, Mg-HA coating on PEDOT coated specimen is found to be more bioactive compared to that of the single substituted hydroxyapatite (Sr or Mg-HA) on the PEDOT coated 316L SS. Thus, the PEDOT/Sr, Mg-HA bilayer coated 316L SS can serve as a prospective implant material for biomedical applications. Copyright © 2013 Elsevier B.V. All rights reserved.

Goal-directed fluid therapy may improve hemodynamic stability in parturient women under combined spinal epidural anesthesia for cesarean section and newborn well-being.

PubMed

Xiao, Wei; Duan, Qingfang; Zhao, Lei; Chi, Xinzuo; Wang, Fengying; Ma, Daqing; Wang, Tianlong

2015-10-01

To investigate whether goal-directed fluid therapy (GDFT) with the LiDCOrapid system can reduce the incidence of maternal hypotension and improve neonatal outcome. One hundred healthy term parturient women scheduled for elective cesarean section were recruited. After loading with 10 mL/kg Lactated Ringer's solution, parturient women were randomized to the GDFT and control group. In the GDFT group, individualized fluid therapy was implemented to optimize stroke volume, guided by the LiDCOrapid system. The control group received routine fluid therapy. Primary endpoints included onset of maternal hypotension, and vasopressor doses prior to delivery. The secondary endpoints included umbilical blood gas abnormalities and neonatal adverse events. Incidence of hypotension and mean phenylephrine dose administered prior to delivery were significantly higher in the control group than in the GDFT group (P < 0.01). There was no difference in Apgar score between the two groups. In the control group, mean umbilical artery and vein blood pH were significantly lower, corresponding to significantly higher incidences of neonatal hypercapnia and hypoxemia, compared with the GDFT group (P < 0.05). LiDCOrapid -guided GDFT may provide benefit to healthy parturient women and their newborns. © 2015 Japan Society of Obstetrics and Gynecology.

Autoregulation and tubuloglomerular feedback in juxtamedullary glomerular arterioles.

PubMed

Casellas, D; Moore, L C

1990-03-01

Videometric measurements of changes in vessel lumen diameters were made to investigate autoregulatory and tubuloglomerular feedback (TGF) responses of early efferent arterioles (EA), mid-to-late afferent arterioles (MAA), and terminal, juxtaglomerular afferent arterioles (JAA) in rat juxtamedullary nephrons in vitro. High-contrast shadow-cast images of blood-perfused arterioles at the glomerular vascular pole were obtained with incident illumination and long-working-distance objectives fitted to a compound microscope. In response to an increase in blood perfusion pressure from 60 to 140 mmHg, strong autoregulatory vasoconstriction was observed in the MAA and JAA, with respective reductions in mean luminal diameter of 23 +/- 4 and 40 +/- 4% (mean +/- SE); EA diameter was unchanged. In response to TGF excitation by direct microinjection of Ringer solution into the cortical thick ascending limb segment near the macula densa, JAA luminal diameter decreased by 34 +/- 5%. The TGF responses were completely inhibited by the addition of 0.1 mM furosemide to the tubular injectate. Calcium channel blockade achieved by adding 1 microM nimodipine to the superfusate had no effect on early EA diameter but produced a blood pressure-dependent JAA and MAA vasodilation and complete inhibition of autoregulatory responses. These results provide direct evidence that the distal afferent arteriole in juxtamedullary nephrons is a major effector site for both renal autoregulation and tubuloglomerular feedback.

Characterisation of physico-mechanical properties and degradation potential of calcium alginate beads for use in embolisation.

PubMed

Forster, Richard E J; Thürmer, Frank; Wallrapp, Christine; Lloyd, Andrew W; Macfarlane, Wendy; Phillips, Gary J; Boutrand, Jean-Pierre; Lewis, Andrew L

2010-07-01

High molecular weight alginate beads with 59% mannuronic acid content or 68% guluronic acid were prepared using a droplet generator and crosslinked in calcium chloride. The alginate beads were compared to current embolisation microspheres for compressibility and monitored over 12 weeks for size and weight change at 37 degrees C in low volumes of ringers solutions. A sheep uterine model was used to analyse bead degradation and inflammatory response over 12 weeks. Both the in vitro and in vivo data show good delivery, with a compressibility similar to current embolic beads. In vitro, swelling was noted almost immediately and after 12 weeks the first signs of degradation were noted. No difference was noted in vivo. This study has shown that high molecular weight alginate gel beads were well tolerated by the body, but beads associated with induced thrombi were susceptible to inflammatory cell infiltration. The beads were shown to be easy to handle and were still observable after 3 months in vivo. The beads were robust enough to be delivered through a 2.7 Fr microcatheter. This study has demonstrated that high molecular weight, high purity alginate bead can be considered as semi-permanent embolisation beads, with the potential to bioresorb over time.

Validation of UHPLC-MS/MS methods for the determination of kaempferol and its metabolite 4-hydroxyphenyl acetic acid, and application to in vitro blood-brain barrier and intestinal drug permeability studies.

PubMed

Moradi-Afrapoli, Fahimeh; Oufir, Mouhssin; Walter, Fruzsina R; Deli, Maria A; Smiesko, Martin; Zabela, Volha; Butterweck, Veronika; Hamburger, Matthias

2016-09-05

Sedative and anxiolytic-like properties of flavonoids such as kaempferol and quercetin, and of some of their intestinal metabolites, have been demonstrated in pharmacological studies. However, routes of administration were shown to be critical for observing in vivo activity. Therefore, the ability to cross intestinal and blood-brain barriers was assessed in cell-based models for kaempferol (KMF), and for the major intestinal metabolite of KMF, 4-hydroxyphenylacetic acid (4-HPAA). Intestinal transport studies were performed with Caco-2 cells, and blood-brain barrier transport studies with an immortalized monoculture human model and a primary triple-co-culture rat model. UHPLC-MS/MS methods for KMF and 4-HPAA in Ringer-HEPES buffer and in Hank's balanced salt solution were validated according to industry guidelines. For all methods, calibration curves were fitted by least-squares quadratic regression with 1/X(2) as weighing factor, and mean coefficients of determination (R(2)) were >0.99. Data obtained with all barrier models showed high intestinal and blood-brain barrier permeation of KMF, and no permeability of 4-HPAA, when compared to barrier integrity markers. Copyright © 2016 Elsevier B.V. All rights reserved.

Complications of bladder distension during retrograde urethrography.

PubMed

Barsanti, J A; Crowell, W; Losonsky, J; Talkington, F D

1981-05-01

A severe, ulcerative cystitis that resulted in macroscopic hematuria occurred in 8 of 20 healthy dogs undergoing a series of diagnostic tests. Four of the remaining 12 dogs had mild bladder lesions consisting of submucosal edema and hemorrhage. Nine of the 20 dogs developed urinary tract infection after the procedures. These complications seemed associated with the radiographic technique of retrograde urethrography performed when the urinary bladder was distended. To test this hypothesis, retrograde urethrography was performed on 5 additional dogs. With the bladder undistended, no complications occurred. However, distention of these same dogs' bladders for 1 minute or less with sterile lactated Ringer's solution administered through a Foley catheter in the penile urethra resulted in a macroscopic hematuria in all 5 dogs which persisted for 24 hours. A microscopic hematuria continued for 5 days. One dog developed a bacterial urinary tract infection. A severe fibrinopurulent cystitis was present at necropsy of 2 dogs 2 days after distention. The morphologic changes in the bladder gradually diminished over 7 days, but mild submucosal edema and hemorrhage were still present when 2 dogs were necropsied, 7 days after distention. These studies indicated that retrograde urethrography in dogs may be complicated by hemorrhagic cystitis and urinary tract infection if performed with urinary bladder distention.

The action of chlorphenesin carbamate on the frog spinal cord.

PubMed

Aihara, H; Kurachi, M; Nakane, S; Sasajima, M; Ohzeki, M

1980-02-01

Studies were carried out to elucidate the mechanism of action of chlorphenesin carbamate (CPC) and to compare the effect of the drug with that of mephenesin on the isolated bullfrog spinal cord. Ventral and dorsal root potentials were recorded by means of the sucrose-gap method. CPC caused marked hyperpolarizations and depressed spontaneous activities in both of the primary afferent terminals (PAT) and motoneurons (MN). These hyperpolarizations were observed even in high-Mg2+ and Ca2+-free Ringer's solution, suggesting that CPC has direct actions on PAT and MN. Various reflex potentials (dorsal and ventral root potentials elicited by stimulating dorsal and ventral root, respectively) tended to be depressed by CPC as well as by mephenesin. Excitatory amino acids (L-aspartic acid and L-glutamic acid) caused marked depolarizations in PAT and MN, and increased the firing rate in MN. CPC did not modify the depolarization but abolished the motoneuron firing induced by these amino acids. However, mephenesin reduced both the depolarization and the motoneuron firing. The dorsal and ventral root potentials evoked by tetanic stimulation (40 Hz) of the dorsal root were depressed by the drugs. These results indicate that CPC has an apparent depressing action on the spinal neuron, and this action may be ascribed to the slight hyperpolarization and/or the prolongation of refractory period.

Changes in force and calcium sensitivity in the developing avian heart.

PubMed

Godt, R E; Fogaça, R T; Nosek, T M

1991-11-01

The aim of this study was to characterize the development of the contractile properties of intact and chemically skinned muscle from chicken heart and to compare these characteristics with those of developing mammalian heart reported by others. Small trabeculae were dissected from left ventricles of Arbor Acre chickens between embryonic day 7 and young adulthood (7 weeks post-hatching). At all ages, increasing extracellular calcium (0.45-3.6 mM) progressively increased twitch force of electrically stimulated trabeculae. Twitch force at 1.8 mM extracellular calcium, normalized to cross-sectional area, increased to a maximum at 1 day post-hatching, remained constant through 3 weeks post-hatching, but then decreased at 7 weeks post-hatching. The maximal calcium-activated force of trabeculae chemically skinned with Triton X-100 detergent increased to a maximum 2 days before the time of hatching and was not significantly changed up to 7 weeks post-hatching. Over the ages studied, average twitch force in 1.8 mM calcium was between 26 and 66% of maximal calcium-activated force after skinning, suggesting that the contractile apparatus is not fully activated during the twitch in normal Ringer. In skinned trabeculae, the calcium sensitivity of the contractile apparatus was higher in the embryo than in the young adult. These age-dependent changes in calcium sensitivity are correlated with isoform switching in troponin T. A decrease in pH from 7.0 to 6.5 decreased the calcium sensitivity of the contractile apparatus to a greater degree in skinned trabeculae from young adult hearts than in those from embryonic hearts. This change in susceptibility to acidosis is temporally associated with isoform switching in troponin I.(ABSTRACT TRUNCATED AT 250 WORDS)

A New Method to Determine the Half-Life for Penicillin Using Microcalorimeter

NASA Astrophysics Data System (ADS)

Li, Z. X.; Zhao, W. W.

2015-01-01

The dissolution process of penicillin in normal saline and isotonic glucose solution was reported using a microcalorimeter. Both the integral and differential heats of solution were measured. The quantitative relationships between the amount of heat released and the quantity of dissolved penicillin were established. Meanwhile, the kinetics and the half-life of the dissolution processes as well as the enthalpy of solution, the entropy of dissolution, and the free energy of dissolution were determined. The results showed that a change of the solvent from normal saline to isotonic glucose solution had little effect on the half-life of penicillin in the dissolution process, and there was no significant difference between the stabilities of penicillin in isotonic glucose solution and normal saline. Moreover, the dissolution process of penicillin in isotonic glucose solution followed the first-order kinetics. These results could provide a theoretical basis for the clinical applications of penicillin.

Comparisons of Lactated Ringer’s and Hextend Resuscitation on Hemodynamics and Coagulation following Femur Injury and Severe Hemorrhage in Pigs

DTIC Science & Technology

2013-01-01

resuscitation but not with Hextend. The lack of recovery after Hextend is likely caused by greater hemodilution and possible effects of starches on...coagulation substrates and further documents the need to restrict the use of high-molecular-weight starch in resuscitation fluids for bleeding casualties. (J...inex- pensive and have been widely used at prehospital and hospital settings. Colloids, such as albumin, gelatin, and hydroxyethyl starch (HES), are

The effects of near-UV radiation on elasmobranch lens cytoskeletal actin.

PubMed

Zigman, S; Rafferty, N S; Scholz, D L; Lowe, K

1992-08-01

The role of near-UV radiation as a cytoskeletal actin-damaging agent was investigated. Two procedures were used to analyse fresh smooth dogfish (Mustelus canis) eye lenses that were incubated for up to 22 hr in vitro, with elasmobranch Ringer's medium, and with or without exposure to a near-UV lamp (emission principally at 365 nm; irradiance of 2.5 mW cm-2). These were observed histologically using phalloidin-rhodamine specific staining and by transmission electron microscopy. In addition, solutions of purified polymerized rabbit muscle actin were exposed to the same UV conditions and depolymerization was assayed by ultracentrifugation and high-pressure liquid chromatography. While the two actins studied do differ very slightly in some amino acid sequences, they would react physically nearly identically. The results showed that dogfish lenses developed superficial opacities due to near-UV exposure. Whole mounts of lens epithelium exhibited breakdown of actin filaments in the basal region of the cells within 18 hr of UV exposure. TEM confirmed the breakdown of actin filaments due to UV exposure. SDS-PAGE and immunoblotting positively identified actin in these cells. Direct exposure of purified polymerized muscle actin in polymerizing buffer led to an increase in actin monomer of approximately 25% in the UV-exposed solutions within 3-18 hr, whether assayed by ultracentrifugation or HPLC. The above indicates that elasmobranch lens epithelial cells contain UV-labile actin filaments, and that near-UV radiation, as is present in the sunlit environment, can break down the actin structure in these cells. Furthermore, breakdown of purified polymerized muscle actin does occur due to near-UV light exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Olfaction and the homing ability of pigeons raised in a tropical area in Brazil.

PubMed

Benvenuti, Silvano; Ranvaud, Ronald

2004-12-01

Several workers have investigated the effect of anosmia on pigeon navigation in different geographical locations because it has been suggested that homing behavior is based on different cues, such as olfactory cues, the Earth's magnetic field or infrasound, and that in the absence of one cue another would be used. In this situation, no cue is universally indispensable, including olfactory ones. In order to extend such observations to a novel biome, we observed the behaviour of 192 young inexperienced birds raised in southeastern Brazil, a tropical area where olfactory tests had never been run before. The birds were released from eight symmetrically distributed sites 17 to 44 km from the loft. Half of these birds (experimentals) had been made temporarily anosmic by washing their olfactory mucosae with 4% solution of ZnSO4 the day before release, while controls were treated with Ringer solution. The results of release tests showed that anosmia totally impaired the navigational performance of experimental birds, which were unable to home from sites at relatively short distances from home (34-44 km) and whose pooled initial bearings produced a (negative) homeward component not significantly different from 0. Homing performance of controls was significantly better, and their pooled vanishing bearings had a significant homeward component, in spite of much scatter in individual releases. We conclude that pigeon homing in the study area depends on olfactory information, even though local environmental conditions in the interior of the State of Sao Paulo, as in several other parts of the world, do not appear to be as favorable as Italy for the development of efficient olfactory navigation.

Cold cardioplegia versus hypothermia for myocardial protection. Randomized clinical study.

PubMed

Conti, V R; Bertranou, E G; Blackstone, E H; Kirklin, J W; Digerness, S B

1978-11-01

Seventeen of 34 consecutive patients undergoing coronary artery bypass grafting were randomly assigned to one of two methods of myocardial preservation. With the cold cardioplegic method (Group A), a 4 degrees C. asanguineous solution with 30 mEq. of potassium per liter was infused into the aortic root for about 2 minutes immediately after aortic cross-clamping and again after about 45 minutes or when myocardial temperature rose above 19 degrees C. External cardiac cooling was provided by constant infusion of 4 degrees C. Ringer's solution into the pericardium. Seventeen patients were assigned to simple cardiac cooling by hypothermic systemic perfusion before aortic cross-clamping plus external cardiac cooling (Group B). Electromechanical activity ceased within 1 to 2 minutes in Group A but continued throughout the ischemic period in 14 patients in Group B. Myocardial temperature (mean for all observations) during aortic cross-clamping was 17.2 +/- 0.44 degrees C. In Group A and 24.0 +/- 0.70 degrees C. in Group B. Operating conditions were better in Group A. Card-ac function early postoperatively was good in both groups clinically and according to measurements, but only in the cold cardioplegic group (A) was cardiac index not adversely affected by longer cross-clamp time. Myocardial necrosis occurred in both groups but was probably less in the cold cardioplegic group. Thirteen patients (76 percent) in Group A had no electrocardiographic evidence of myocardial injury, compared with eight (47 percent) in Group B (p = 0.08). Eleven (65 percent of Group A had no or short-lived appearance of ceatine phosphokinase isoenzyme (CK-MB), compared with six (35 percent) of Group B (p = 0.08). Time-related CK-MB and SGOT mean levels were consistently lower in Group A.

Autoregulation of apical membrane Na+ permeability of tight epithelia. Noise analysis with amiloride and CGS 4270

PubMed Central

1985-01-01

Noise analysis of the Na+ channels of the apical membranes of frog skin bathed symmetrically in a Cl-HCO3 Ringer solution was done with amiloride and CGS 4270. Tissues were studied in their control states and after inhibition of transepithelial Na+ transport (Isc) by addition of quinine or quinidine to the apical solution. A critical examination of the amiloride-induced noise indicated that the single channel Na+ currents (iNa) were decreased by quinine and quinidine, probably because of depolarization of apical membrane voltage. Despite considerable statistical uncertainty in the methods of estimation of the Na+ channel density with amiloride-induced noise (NA, see text), the striking observation was a large increase of NA with amiloride inhibition of the rate of Na+ entry into the cells. NA was increased to 406% of control, whereas Isc was inhibited to 8.6% of control by 6 microM amiloride. Studies were done also with the Na+ channel blocker CGS 4270. Noise analysis with this compound was advantageous, permitting iCGSNa and NCGS to be measured in individual tissues with a relatively small inhibition of Isc. As with amiloride, inhibition of Isc with CGS 4270 caused large increases of the Na+ channel density (approximately 200% at approximately 35% inhibition of the Isc). Quinine and quinidine caused an approximately 50% increase of Na+ channel density while inhibiting iNa by approximately 60-70%. As inhibition of Na+ entry leads to an increase of Na+ channel density, a mechanism of autoregulation appears to be a major factor in adjusting the apical membrane Na+ permeability of the cells. PMID:2409219

Impact of N-acetylcysteine on the hepatic microcirculation after orthotopic liver transplantation.

PubMed

Koeppel, T A; Lehmann, T G; Thies, J C; Gehrcke, R; Gebhard, M M; Herfarth, C; Otto, G; Post, S

1996-05-15

Recent observations showed an improvement of hepatic macro- and microhemodynamics as well as survival rates after warm ischemia of the liver following treatment with N-acetylcysteine (NAC). In this study we assessed the influence of NAC on the hepatic microcirculation after orthotopic liver transplantation (OLT) using intravital fluorescence microscopy. OLT with simultaneous arterialization was performed in 16 male Lewis rats following cold storage in University of Wisconsin solution for 24 hr. Within the experimental group (n = 8) donors received NAC (400 mg/kg) 25 min before hepatectomy. In addition, high-dose treatment of recipients with NAC (400 mg/kg) was started with reperfusion. Control animals (n = 8) received an equivalent amount of Ringer's solution. Intravital fluorescence microscopy was performed 30-90 min after reperfusion assessing acinar and sinusoidal perfusion, leukocyte-endothelium interaction, and phagocytic activity. Treatment with NAC reduced the number of nonperfused sinusoid from 52.4 +/- 0.8% to 15.7 +/- 0.5% (p = 0.0001) (mean +/- SEM). Furthermore, we achieved a significant reduction of leukocytes adhering to sinusoidal endothelium (per mm2 liver surface) from 351.9 +/- 13.0 in controls to 83.6 +/- 4.2 in the experimental group (P = 0.0001). In postsinusoidal venules, treatment with NAC decreased the number of sticking leukocytes (per mm2 endothelium) from 1098.5 +/- 59.6 to 425.9 +/- 37.7 (P = 0.0001). Moreover, bile flow was significantly increased after therapy with NAC (4.3 +/- 1.2 vs. 2.2 +/- 0.7 ml/90 min x 100g liver) (P < 0.05). Phagocytic activity was not influenced by application of NAC. We conclude that high-dose therapy with NAC in OLT attenuates manifestations of microvascular perfusion failure early after reperfusion and should be considered as a means to reduce reperfusion injury.

In Vivo Microdialysis for Dynamic Monitoring of the Effectiveness of Nano-liposomes as Vehicles for Topical Psoralen Application.

PubMed

Zhang, Hongyu; Zhang, Kai; Li, Zhe; Zhao, Jihui; Zhang, Yongtai; Feng, Nianping

2017-01-01

In this study, the skin permeation of liposomes containing psoralen was investigated by in vivo skin microdialysis. Psoralen-loaded nano-sized liposomes were prepared with a mean size of 117.5 nm and a polydispersity index of 0.21, indicating the uniform dispersion of phosphatidylcholine vesicles in the liposomal solution. Based on in vivo microdialysis experiments, the drug concentration in local deep skin of rat increased rapidly and reached a peak concentration (C max ) of 319.35±23.72 µg/mL at 180 min, and decreased slowly thereafter. The local area under the concentration-time curve (AUC) 0-t was 3.81-fold higher than the compared aqueous suspension. The in vivo systemic pharmacokinetics were in agreement with the microdialysis results, in view of the C max and AUC 0-t from liposomal group were both significantly higher (p<0.05) than the compared group. Liposome-associated transdermal psoralen delivery was significantly more effective than delivery via an aqueous suspension. The enhanced skin permeability may be associated with improved skin hydration, lipid exchange and fusion with the stratum corneum (SC), and changes in SC structure, promoting drug permeation into deep skin. After 10 h of treatment with the perfusate, the microstructure of the microdialysis probe exhibited no obvious differences with control probes. The skin surface and the tissue around the probe showed no swelling or inflammation. These findings indicated that liposomes effectively enhanced the skin deposition of psoralen and showed good biocompatibility with skin tissues; additionally, ethanol at a low concentration in ringer's solution is an alternative perfusate for in vivo skin microdialysis studies.

Normal stress differences from Oldroyd 8-constant framework: Exact analytical solution for large-amplitude oscillatory shear flow

NASA Astrophysics Data System (ADS)

Saengow, C.; Giacomin, A. J.

2017-12-01

The Oldroyd 8-constant framework for continuum constitutive theory contains a rich diversity of popular special cases for polymeric liquids. In this paper, we use part of our exact solution for shear stress to arrive at unique exact analytical solutions for the normal stress difference responses to large-amplitude oscillatory shear (LAOS) flow. The nonlinearity of the polymeric liquids, triggered by LAOS, causes these responses at even multiples of the test frequency. We call responses at a frequency higher than twice the test frequency higher harmonics. We find the new exact analytical solutions to be compact and intrinsically beautiful. These solutions reduce to those of our previous work on the special case of the corotational Maxwell fluid. Our solutions also agree with our new truncated Goddard integral expansion for the special case of the corotational Jeffreys fluid. The limiting behaviors of these exact solutions also yield new explicit expressions. Finally, we use our exact solutions to see how η∞ affects the normal stress differences in LAOS.

Growth of plants in solution culture containing low levels of chromium. [Tomato, lettuce, duckweed

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huffman, E.W.D. Jr.; Allaway, W.H.

1973-01-01

Chromium was not required for normal growth of romaine lettuce (Lactuca sativa L. subsp. longifolia), tomato (Lycopersicon esculentum Mill.), wheat (Triticum aestivum L.), or bean (Phaseolus vulgaris L.) in solution culture containing 3.8 X 10/sup -4/ ..mu..M Cr. Plants grown on this purified nutrient solution contained an average of 22 ng Cr/g dry weight. Duckweed (Lemna sp.) grew and reproduced normally on a dilute nutrient solution containing 3.8 X 20/sup -5/ ..mu..M Cr.

Pretreatment with intravenous lipid emulsion reduces mortality from cocaine toxicity in a rat model.

PubMed

Carreiro, Stephanie; Blum, Jared; Hack, Jason B

2014-07-01

We compare the effects of intravenous lipid emulsion and normal saline solution pretreatment on mortality and hemodynamic changes in a rat model of cocaine toxicity. We hypothesize that intravenous lipid emulsion will decrease mortality and hemodynamic changes caused by cocaine administration compared with saline solution. Twenty male Sprague-Dawley rats were sedated and randomized to receive intravenous lipid emulsion or normal saline solution, followed by a 10 mg/kg bolus of intravenous cocaine. Continuous monitoring included intra-arterial blood pressure, pulse rate and ECG tracing. Endpoints included a sustained undetectable mean arterial pressure (MAP) or return to baseline MAP for 5 minutes. The log-rank test was used to compare mortality. A mixed-effect repeated-measures ANOVA was used to estimate the effects of group (intravenous lipid emulsion versus saline solution), time, and survival on change in MAP, pulse rate, or pulse pressure. In the normal saline solution group, 7 of 10 animals died compared with 2 of 10 in the intravenous lipid emulsion group. The survival rate of 80% (95% confidence interval 55% to 100%) for the intravenous lipid emulsion rats and 30% (95% confidence interval 0.2% to 58%) for the normal saline solution group was statistically significant (P=.045). Intravenous lipid emulsion pretreatment decreased cocaine-induced cardiovascular collapse and blunted hypotensive effects compared with normal saline solution in this rat model of acute lethal cocaine intoxication. Intravenous lipid emulsion should be investigated further as a potential adjunct in the treatment of severe cocaine toxicity. Copyright © 2013 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.

Normal evaporation of binary alloys

NASA Technical Reports Server (NTRS)

Li, C. H.

1972-01-01

In the study of normal evaporation, it is assumed that the evaporating alloy is homogeneous, that the vapor is instantly removed, and that the alloy follows Raoult's law. The differential equation of normal evaporation relating the evaporating time to the final solute concentration is given and solved for several important special cases. Uses of the derived equations are exemplified with a Ni-Al alloy and some binary iron alloys. The accuracy of the predicted results are checked by analyses of actual experimental data on Fe-Ni and Ni-Cr alloys evaporated at 1600 C, and also on the vacuum purification of beryllium. These analyses suggest that the normal evaporation equations presented here give satisfactory results that are accurate to within an order of magnitude of the correct values, even for some highly concentrated solutions. Limited diffusion and the resultant surface solute depletion or enrichment appear important in the extension of this normal evaporation approach.

Influence of Ophthalmic Solutions on Tear Components.

PubMed

Shigeyasu, Chika; Yamada, Masakazu; Akune, Yoko

2016-11-01

Tear fluids are a mixture of secretions derived from lacrimal glands, accessory lacrimal glands, conjunctiva, and meibomian glands. Compositional changes to tears occur in the normal state and during ocular surface disease, such as dry eye conditions. We have investigated compositional changes to tears after topical application of ophthalmic solutions, with regard to tear-specific proteins (secretory immunoglobulin A, lactoferrin, lipocalin-1, and lysozyme) and ocular surface mucin in normal and dry eye conditions using high-performance liquid chromatography. After application of saline solution (0.9% sodium chloride) in normal subjects, transient but significant decreases in all tear components were observed. The recovery of protein concentrations took up to 30 minutes and lasted longer when the saline solution was applied more frequently. When applying ophthalmic solutions, a balance between washout and dilutional effects should be considered in addition to the therapeutic effect. Investigation of the effect of diquafosol solution (3%) in normal subjects revealed a significant increase in sialic acid concentration, a marker of ocular mucin, at 5 minutes after application, whereas a significant decrease was observed with saline. This result indicates the accelerated secretion of mucin from ocular tissues induced by diquafosol. A clinical study to determine the efficacy of diquafosol in patients with dry eye revealed improvements in tear breakup time, keratoconjunctival staining scores, and Schirmer test score, accompanied by an increase in sialic acid concentration in tears. Investigating normal and dry eye conditions through tear analysis may clarify the pathophysiology of dry eye conditions and support the efficacy of treatments.

Analytical solution for the normal emission portion of the averaged Yarkovsky-O'Keefe-Radzvieskii-Paddack coefficient for a single facet

NASA Astrophysics Data System (ADS)

Albuja, Antonella A.; Scheeres, Daniel J.

2015-02-01

The Yarkovsky-O'Keefe-Radzvieskii-Paddack (YORP) effect has been well studied for asteroids. This paper develops an analytic solution to find the normal emission YORP component for a single facet. The solution presented here does not account for self-shadowing or self-heating. The YORP coefficient for all facets can be summed together to find the total coefficient of the asteroid. The normal emission component of YORP has been shown to be the most important for asteroids and it directly affects the rate of change of the asteroid's spin period. The analytical solution found is a sole function of the facet's geometry and the obliquity of the asteroid. This solution is universal for any facet and its orientation. The behaviour of the coefficient is analysed with this analytical solution. The closed-form solution is used to find the total YORP coefficient for the asteroids Apollo and 1998 ML14 whose shape models are composed of different numbers of facets. The results are then compared to published results and those obtained through numerical quadrature for validation.

Cone outer segment and Müller microvilli pericellular matrices provide binding domains for interphotoreceptor retinoid-binding protein (IRBP).

PubMed

Garlipp, Mary Alice; Gonzalez-Fernandez, Federico

2013-08-01

The close packing of vertebrate photoreceptors presents a challenge to the exchange of molecules between the outer segments, retinal pigmented epithelium (RPE), and Müller glia. An extracellular hyaluronan scaffold separates these cells while soluble interphotoreceptor matrix (IPM) proteins traffic visual cycle retinoids, fatty acids, and other molecules between them. In the IPM, retinoids and fatty acids are carried by interphotoreceptor retinoid-binding protein (IRBP). The fact that much of the retina's IRBP can be extracted by saline wash has led to the notion that IRBP does not bind to the retina, but freely distributes itself within the subretinal space. In this study, we challenge this idea by asking if there are specialized IPM domains that bind IRBP, perhaps facilitating its ability to target delivery/uptake of its ligands. Xenopus is an ideal animal model to study the role of the IPM in RPE-photoreceptor interactions. Here, we took advantage of the large size of its photoreceptors, ability to detach the retina in light, sustainability of the retina in short term organ culture, and the availability of recombinant full-length Xenopus IRBP and antisera directed against Xenopus IRBP. We compared the distribution of wash resistant native IRBP, and that of IRBP-Alexa 647 binding in Xenopus retina. IRBP and cone opsin were localized using anti-Xenopus IRBP serum, and monoclonal COS-1 respectively. Cone matrix sheath proteoglycans were localized with wheat germ agglutinin (WGA), and diffuse IPM proteoglycans with peanut agglutinin (PNA). Wholemounts and frozen sections were compared by immunofluorescence from retinas detached under Ringer's followed by additional washes, or detached directly under 4% paraformaldehyde without Ringer's wash. Undetached Lowicryl embedded retinas were subjected to IRBP immunogold electron microscopy (EM). Immunogold labeled a diffuse network of filamentous structures, and a separate distinct flocculant material directly coating the outer segments, filling the rod periciliary ridge, and associated with Müller microvilli. By immunofluorescence, Ringer's wash removed most of the diffuse IRBP, but not that coating the outer segments. IRBP-Alexa 647 bound to the cone outer segments and Müller villi region, and comparably less to rod outer segments. Co-incubation with unlabeled IRBP markedly reduced this binding; ovalbumin-Alexa 647 and Alexa 647 dye alone showed no binding. Our data suggest that the pericellular matrix of the cone outer segments and Müller microvilli provide specialized domains that facilitate IRBP's functions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Oral sapropterin augments reflex vasoconstriction in aged human skin through noradrenergic mechanisms.

PubMed

Stanhewicz, Anna E; Alexander, Lacy M; Kenney, W Larry

2013-10-01

Reflex vasoconstriction is attenuated in aged skin due to a functional loss of adrenergic vasoconstriction. Bioavailability of tetrahydrobiopterin (BH4), an essential cofactor for catecholamine synthesis, is reduced with aging. Locally administered BH4 increases vasoconstriction through adrenergic mechanisms in aged human skin. We hypothesized that oral sapropterin (Kuvan, a pharmaceutical BH4) would augment vasoconstriction elicited by whole-body cooling and tyramine perfusion in aged skin. Ten healthy subjects (age 75 ± 2 yr) ingested sapropterin (10 mg/kg) or placebo in a randomized, double-blind crossover design. Venous blood samples were collected prior to, and 3 h following ingestion. Three intradermal microdialysis fibers were placed in the forearm skin for local delivery of 1) lactated Ringer, 2) 5 mM BH4, and 3) 5 mM yohimbine + 1 mM propranolol (Y+P; to inhibit adrenergic vasoconstriction). Red cell flux was measured at each site by laser-Doppler flowmetry (LDF) as reflex vasoconstriction was induced by lowering and then clamping whole-body skin temperature (Tsk) using a water-perfused suit. Following whole-body cooling, subjects were rewarmed and 1 mM tyramine was perfused at each site to elicit endogenous norepinephrine release from the perivascular nerve terminal. Cutaneous vascular conductance was calculated as CVC = LDF/mean arterial pressure and expressed as change from baseline (ΔCVC). Plasma BH4 was elevated 3 h after ingestion of sapropterin (43.8 ± 3 vs. 19.1 ± 2 pmol/ml; P < 0.001). Sapropterin increased reflex vasoconstriction at the Ringer site at Tsk ≤ 32.5°C (P < 0.05). Local BH4 perfusion augmented reflex vasoconstriction at Tsk ≤ 31.5°C with placebo treatment only (P < 0.05). There was no treatment effect on reflex vasoconstriction at the BH4-perfused or Y+P-perfused sites. Sapropterin increased pharmacologically induced vasoconstriction at the Ringer site (-0.19 ± 0.03 vs. -0.08 ± 0.02 ΔCVC; P = 0.01). There was no difference in pharmacologically induced vasoconstriction between treatments at the BH4-perfused site (-0.16 ± 0.04 vs. -0.14 ± 0.03 ΔCVC; P = 0.60) or the Y+P-perfused site (-0.05 ± 0.02 vs.-0.06 ± 0.02 ΔCVC; P = 0.79). Sapropterin increases both reflex (cold-induced) and pharmacologically induced vasoconstriction through adrenergic mechanisms and may be a viable intervention to improve reflex vasoconstriction in aged humans.

Oral sapropterin augments reflex vasoconstriction in aged human skin through noradrenergic mechanisms

PubMed Central

Stanhewicz, Anna E.; Kenney, W. Larry

2013-01-01

Reflex vasoconstriction is attenuated in aged skin due to a functional loss of adrenergic vasoconstriction. Bioavailability of tetrahydrobiopterin (BH4), an essential cofactor for catecholamine synthesis, is reduced with aging. Locally administered BH4 increases vasoconstriction through adrenergic mechanisms in aged human skin. We hypothesized that oral sapropterin (Kuvan, a pharmaceutical BH4) would augment vasoconstriction elicited by whole-body cooling and tyramine perfusion in aged skin. Ten healthy subjects (age 75 ± 2 yr) ingested sapropterin (10 mg/kg) or placebo in a randomized, double-blind crossover design. Venous blood samples were collected prior to, and 3 h following ingestion. Three intradermal microdialysis fibers were placed in the forearm skin for local delivery of 1) lactated Ringer, 2) 5 mM BH4, and 3) 5 mM yohimbine + 1 mM propranolol (Y+P; to inhibit adrenergic vasoconstriction). Red cell flux was measured at each site by laser-Doppler flowmetry (LDF) as reflex vasoconstriction was induced by lowering and then clamping whole-body skin temperature (T̄sk) using a water-perfused suit. Following whole-body cooling, subjects were rewarmed and 1 mM tyramine was perfused at each site to elicit endogenous norepinephrine release from the perivascular nerve terminal. Cutaneous vascular conductance was calculated as CVC = LDF/mean arterial pressure and expressed as change from baseline (ΔCVC). Plasma BH4 was elevated 3 h after ingestion of sapropterin (43.8 ± 3 vs. 19.1 ± 2 pmol/ml; P < 0.001). Sapropterin increased reflex vasoconstriction at the Ringer site at T̄sk ≤ 32.5°C (P < 0.05). Local BH4 perfusion augmented reflex vasoconstriction at T̄sk ≤ 31.5°C with placebo treatment only (P < 0.05). There was no treatment effect on reflex vasoconstriction at the BH4-perfused or Y+P-perfused sites. Sapropterin increased pharmacologically induced vasoconstriction at the Ringer site (−0.19 ± 0.03 vs. −0.08 ± 0.02 ΔCVC; P = 0.01). There was no difference in pharmacologically induced vasoconstriction between treatments at the BH4-perfused site (−0.16 ± 0.04 vs. −0.14 ± 0.03 ΔCVC; P = 0.60) or the Y+P-perfused site (−0.05 ± 0.02 vs.−0.06 ± 0.02 ΔCVC; P = 0.79). Sapropterin increases both reflex (cold-induced) and pharmacologically induced vasoconstriction through adrenergic mechanisms and may be a viable intervention to improve reflex vasoconstriction in aged humans. PMID:23869061

Resuscitative therapy with erythropoietin reduces oxidative stress and inflammatory responses of vital organs in a rat severe fixed-volume hemorrhagic shock model.

PubMed

Ranjbaran, Mina; Kadkhodaee, Mehri; Seifi, Behjat; Mirzaei, Reza; Ahghari, Parisa

2018-01-01

Hemorrhagic shock (HS) still has a high mortality rate and none of the known resuscitative regimens completely reverse its adverse outcomes. This study investigated the effects of different models of resuscitative therapy on the healing of organ damage in a HS model. Male Wistar rats were randomized into six groups: Sham, without HS induction; HS, without resuscitation; HS+Blood, resuscitation with the shed blood; HS+Blood+NS, resuscitation with blood and normal saline; HS+Blood+RL, resuscitation with blood and Ringer's lactate; EPO, erythropoietin was added to the blood and RL. Blood and urine samples were obtained 3 h after resuscitation. Kidney, liver and brain tissue samples were harvested for multiple organ failure evaluation. Survival rate was the highest in the Sham, EPO and HS+Blood+RL groups compared to others. Plasma creatinine concentration, ALT, AST, urinary NAG activity and renal NGAL mRNA expression significantly increased in the HS+Blood+RL group compared to the Sham group. There was a significant increase in tissue oxidative stress markers and pro-inflammatory cytokines in HS+Blood+RL group compared to the Sham rats. EPO had more protective effects on multiple organ failure compared to the HS+Blood+RL group. EPO, as a resuscitative treatment, attenuated HS-induced organ damage. It seems that it has a potential to be attractive for clinical trials.

A Comparative Analysis of Nasogastric and Intravenous Fluid Resuscitation in Patients with Malignant Obstructive Jaundice Prior to Endoscopic Biliary Drainage

PubMed Central

Baghel, Kavita; Raj, Saloni; Awasthi, Induja; Gupta, Vishal; Chandra, Abhijit; Srivastava, Rajeshwar Nath

2013-01-01

Background: An alternative to intravenous is nasogastric fluid administration through normal functioning gut. Though not common, this practice has significance in mass causalities and elective situations. Aim: The study was designed to compare nasogastric and intravenous fluid resuscitation in malignant obstructive jaundice (OJ) and their effect on endotoxemia. Materials and Methods: Sixty patients with malignant OJ undergoing endoscopic biliary drainage were randomized into two groups. A total of 4 l of fluid (Ringer's lactate) was administered to Group A through nasogastric tube and to Group B through intravenous route for 48 h. Vital parameters, serum bilirubin, serum creatinine, creatinine clearance rate, electrolytes, and endotoxemia were monitored. Results: Significant improvement in blood pressure (Group A, P = 0.014; Group B, P = 0.020) and significant decrease in serum bilirubin level (Group A, P = 0.001; Group B, P > 0.0001) was observed in both groups after resuscitation. Significantly decreased (P = 0.036) post hydration endotoxin level was observed in Group A as compared to Group B. Febrile events were significantly higher (P = 0.023) in Group B as compared to Group A (6 vs 0). Electrolyte abnormalities were found more in Group B, however statistically insignificant. Conclusion: In OJ patient undergoing biliary drainage, preoperative fluid resuscitation through nasogastric tube may be helpful in reducing postoperative septic complications and endotoxemia. PMID:24251269

Integrated ZnO nanoparticles on paper-based microfluidic: toward efficient analytical device for glucose detection based on impedance and FTIR measurement

NASA Astrophysics Data System (ADS)

Yuwono, Rio Akbar; Izdiharruddin, Mokhammad Fahmi; Wahyuono, Ruri Agung

2016-11-01

Microfluidic paper-based analytical devices decorated with ZnO nanospherical (nanoSPs) aggregates (ZnO-μPAD) for glucose detection have been fabricated. ZnO nanoSPs were prepared by wet chemical synthesis and integrated on the optimized geometry of ZnO-μPAD has 0.2 and 0.4 mm of channel width and length, respectively. Glucose detection measurements were based on electrochemical and infrared transmission measurements. The glucose concentrations were adjusted as 5, 6.5, and 9 mmol, i.e. typical glucose level for normal, pre-diabetes and diabetes, in a mixture of ringer lactate as simulated biological fluid and red blood cells. ZnO nanoSPs in this study possess an average aggregate size of 160 nm formed by clustered 18 nm crystallite size and ordered porous matrix as well as a surface area of 15 m2·g-1.The separation process of the glucose sample on ZnO-μPAD requires approximately 45 s. The glucose detection results show that both electrochemical-based and FTIR-based measurements perform a linear measurement system (R2 of 0.81 to 0.99) with a relatively high sensitivity. A linearly decreasing impedance spanning from 2.2 - 0.6 Ohm and linearly increasing ΔIR transmission spanning from 3 - 19% are obtained for glucose level ranging from 5 - 9 mmol.

Peter Andreas Hansen und die astronomische Gemeinschaft - eine erste Auswertung des Hansen-Nachlasses.

NASA Astrophysics Data System (ADS)

Schwarz, O.; Strumpf, M.

The literary assets of Peter Andreas Hansen are deposited in the Staatsarchiv Hamburg, the Forschungs- und Landesbibliothek Gotha and the Thüringer Staatsarchiv Gotha. They were never systematically investigated. The authors present here some results of a first evaluation. It was possible to reconstruct the historical events with regard to the maintenance of the Astronomische Nachrichten and the Altona observatory in 1854. Hansen was a successful teacher for many young astronomers. His way of stimulating the evolution of astronomy followed Zach's tradition.

True Anomalous Osmosis in Multi-Solute Model Membrane Systems

PubMed Central

Grim, Eugene; Sollner, Karl

1960-01-01

The transport of liquid across charged porous membranes separating two electrolytic solutions of different composition consists of both a normal and an anomalous osmotic component. Anomalous osmosis does not occur with electroneutral membranes. Thus, with membranes which can be charged and discharged reversibly, normal osmosis can be measured with the membrane in the electroneutral state, and normal together with anomalous osmosis with the membrane in a charged state, the difference between these two effects being the true anomalous osmosis. Data are presented on the osmotic effects across an oxyhemoglobin membrane in the uncharged state at pH 6.75 and in two charged states, positive at pH 4.0 and negative at pH 10.0, in multi-solute systems with 0.2 and 0.4 osmolar solutions of a variety of electrolytes and of glucose against solutions of other solutes of the same, one-half, and twice these osmolarities. In the simpler systems the magnitude of the true anomalous osmosis can be predicted semiquantitatively by reference to appropriate single-solute systems. In isoosmolar systems with two electrolytic solutions the anomalous osmotic flow rates may reach 300 µl./cm.2 hr. and more; systems with electrolytic solutions against solutions of glucose can produce twice this rate. These fluxes are of the same order of magnitude as the liquid transport rates across such living structures as the mucosa of dog gall bladder, ileum, and urinary bladder. PMID:13708691

Role of rho-kinase (ROCK) in tonic but not phasic contraction in the frog stomach smooth muscle.

PubMed

Sahin, Leyla; Cevik, Ozge Selin; Koyuncu, Dilan Deniz; Buyukafsar, Kansu

2018-04-01

Rho/Rho-kinase (ROCK) signaling has extensively been shown to take part in mammalian smooth muscle contractions in response to diverse agents yet its role in the contraction of amphibian smooth muscle has not been investigated. Therefore, we aimed to explore any role of this pathway in the contractions of frog stomach smooth. The strips were prepared and suspended in organ baths filled with Ringer solution. Changes in the circular strips of the frog stomach muscle length were recorded isotonically with a force transducer in organ baths. Carbachol (CCh) exerted both phasic and tonic contractions. In contrast, atropin abolished all types of contractions by CCh. The phasic contractions were suppressed by a Ca 2+ channel blocker, nifedipine but not by the ROCK inhibitor, Y-27632. However, the tonic contractions were markedly attenuated by Y-27632. Selective M 1 receptor blocker, pirenzepin, selective M 3 receptor blocker and DAMP had no effects on CCh-elicited contractions. On the other hand, selective M 2 receptor blocker, AF-DX suppressed all types of contractile activity by CCh. These data suggest that M 2 receptor activation could mainly mediate CCh-induced phasic and tonic contractions, and ROCK seems to be involved in the CCh-induced tonic but not phasic contractions of the frog stomach smooth muscle. Copyright © 2018 Elsevier Inc. All rights reserved.

Perioperative fluid management: comparison of high, medium and low fluid volume on tissue oxygen pressure in the small bowel and colon.

PubMed

Hiltebrand, L B; Pestel, G; Hager, H; Ratnaraj, J; Sigurdsson, G H; Kurz, A

2007-11-01

Insufficient blood flow and oxygenation in the intestinal tract is associated with increased incidence of postoperative complications after bowel surgery. High fluid volume administration may prevent occult regional hypoperfusion and intestinal tissue hypoxia. We tested the hypothesis that high intraoperative fluid volume administration increases intestinal wall tissue oxygen pressure during laparotomy. In all, 27 pigs were anaesthetized, ventilated and randomly assigned to one of the three treatment groups (n = 9 in each) receiving low (3 mL kg-1 h-1), medium (7 mL kg-1 h-1) or high (20 mL kg-1 h-1) fluid volume treatment with lactated Ringer's solution. All animals received 30% and 100% inspired oxygen in random order. Cardiac index was measured with thermodilution and tissue oxygen pressure with a micro-oximetry system in the jejunum and colon wall and subcutaneous tissue. Groups receiving low and medium fluid volume treatment had similar systemic haemodynamics. The high fluid volume group had significantly higher mean arterial pressure, cardiac index and subcutaneous tissue oxygenation. Tissue oxygen pressures in the jejunum and colon were comparable in all three groups. The three different fluid volume regimens tested did not affect tissue oxygen pressure in the jejunum and colon, suggesting efficient autoregulation of intestinal blood flow in healthy subjects undergoing uncomplicated abdominal surgery.

Flow cytometric evaluation of antibiotic effects on viability and mitochondrial function of refrigerated spermatozoa of Nile tilapia

USGS Publications Warehouse

Segovia, M.; Jenkins, J.A.; Paniagua-Chavez, C.; Tiersch, T.R.

2000-01-01

Improved techniques for storage and evaluation of fish sperm would enhance breeding programs around the world. The goal of this study was to test the effect of antibiotics on refrigerated sperm from Nile tilapia (Oreochromis niloticus) by use of flow cytometry with 2 dual-staining protocols for objective assessment of sperm quality. Concentrations of 1 x 109 sperm/mL were suspended in Ringer's buffer at 318 mOsmol/kg (pH 8.0). The fluorescent stains Sybr 14 (10 ??M), propidium iodide (2.4 mM), and rhodamine 123 (0.13 ??M) were used to assess cell viability and mitochondrial function. Three concentrations of ampicillin, gentamicin, and an antibiotic/antimycotic solution were added to fresh spermatozoa. Motility estimates and flow cytometry measurements were made daily during 7 d of refrigerated storage (4 ??C). The highest concentrations of gentamicin and antibiotic/antimycotic and all 3 concentrations of ampicillin significantly reduced sperm viability. The highest of each of the 3 antibiotic concentrations significantly reduced mitochondrial function. This study demonstrates that objective sperm quality assessments can be made using flow cytometry and that addition of antibiotics at appropriate concentrations can lengthen refrigerated storage time for tilapia spermatozoa. With minor modifications, these protocols can be adapted for use with sperm from other species and with other tissue types.

Extracellular cyclic AMP-adenosine pathway in isolated adipocytes and adipose tissue.

PubMed

Strouch, Marci B; Jackson, Edwin K; Mi, Zaichuan; Metes, Nicole A; Carey, Gale B

2005-06-01

Our goal was to evaluate the presence and lipolytic impact of the extracellular cyclic adenosine monophosphate (AMP)-adenosine pathway in adipose tissue. Sixteen miniature Yucatan swine (Sus scrofa) were used for these in vitro and in situ experiments. Four microdialysis probes were implanted into subcutaneous adipose tissue and perfused at 2 microL/min with Ringer's solution containing no addition, varying levels of cyclic AMP, 10 microM isoproterenol, or 10 microM isoproterenol plus 1 mM alpha,beta-methylene adenosine 5'-diphosphate (AMPCP), a 5'-nucleotidase inhibitor. Dialysate was assayed for AMP, adenosine, inosine, hypoxanthine, and glycerol. Freshly isolated adipocytes were incubated with buffer, 1 microM isoproterenol, or 1 microM isoproterenol plus 0.1 mM AMPCP, and extracellular levels of AMP, adenosine, inosine, hypoxanthine, and glycerol were measured. Perfusion of adipose tissue with exogenous cyclic AMP caused a significant increase in AMP and adenosine appearance. Perfusion with AMPCP, in the presence or absence of isoproterenol, significantly increased the levels of AMP and glycerol, whereas it significantly reduced the level of adenosine and its metabolites. However, the AMPCP-provoked increase in lipolysis observed in situ and in vitro was not temporally associated with a decrease in adenosine. These data suggest the existence of a cyclic AMP-adenosine pathway in adipocytes and adipose tissue. The role of this pathway in the regulation of lipolysis remains to be clarified.

[Case of anaphylactic shock induced by an antibiotic after induction of anesthesia].

PubMed

Tanaka, Shinichiro; Satoh, Masaaki; Hirabayashi, Yoshihiro; Nunomiya, Shin; Seo, Norimasa

2006-10-01

We report a case of anaphylactic shock induced by an antibiotic administrated after induction. A 39-year-old man was scheduled for removal of right adrenal tumor. After insertion of an epidural catheter, anesthesia was induced with an intravenous bolus injection of fentanyl 100 microg, propofol 130 mg and vecuronium 6 mg. The trachea was intubated smoothly and anesthesia was maintained with sevoflurane. Sultamicillin tosilate was administrated intravenously. Soon, ephedrine 12 mg was given intravenously because his blood pressures decreased. However, his blood pressure did not recover, but fell down to 35/22 mmHg. He was turned to head-down position, and 100% oxygen was administrated. Following epinephrine 0.1 mg injection, his blood pressure increased to 80/40 mmHg. Epinephrine at 0.005-0.02 microg x kg(-1) x min(-1) was infused continuously to maintain his blood pressure. We found erhythemia on his face, shoulders and arms. Hydrocortisone sodium succinate and acetate Ringer's solution were administrated to treat his anaphylactic shock and the surgery was postponed. The blood samples indicated that this event was IgE-mediated anaphylactic reaction. From his past history, penicillin allergy was confirmed. The surgery was rescheduled and anesthesia was managed in the same way as previous one. Surgery was successfully performed using levofloxacin, which had been taken orally before induction of anesthesia.

Corrosion analysis of NiCu and PdCo thermal seed alloys used as interstitial hyperthermia implants.

PubMed

Paulus, J A; Parida, G R; Tucker, R D; Park, J B

1997-12-01

Ferromagnetic materials with low Curie temperatures are being investigated for use as interstitial implants for fractionated hyperthermia treatment of prostatic disease. Previous investigations of the system have utilized alloys, such as NiCu, with inadequate corrosion resistance, requiring the use of catheters for removal of the implants following treatment or inert surface coatings which may interfere with thermal characteristics of the implants. We are evaluating a palladium-cobalt (PdCo) binary alloy which is very similar to high palladium alloys used in dentistry. Electrochemical corrosion tests and immersion tests at 37 degrees C for both NiCu and PdCo alloy samples in mammalian Ringer's solution were performed. Long-term corrosion rates are 5.8 x 10(-5) microm per year (NiCu) and 7.7 x 10(-8) microm per year (PdCo) from average immersion test results, indicating higher corrosion resistance of PdCo (P < 0.02); immersion corrosion rates were much lower than initial corrosion rates found electrochemically. Both alloys had significantly lower corrosion rates than standard surgical implant rates of 0.04 microm per year (P < 0.001 for both alloys). Scanning electron microscopy illustrates changes in the NiCu alloy surface due to pitting corrosion; no difference is observed for PdCo. The data indicate that the PdCo alloy may be suitable as a long-term implant for use in fractionated hyperthermia.

Electrochemical properties of titanium nitride nerve stimulation electrodes: an in vitro and in vivo study

PubMed Central

Meijs, Suzan; Fjorback, Morten; Jensen, Carina; Sørensen, Søren; Rechendorff, Kristian; Rijkhoff, Nico J. M.

2015-01-01

The in vivo electrochemical behavior of titanium nitride (TiN) nerve stimulation electrodes was compared to their in vitro behavior for a period of 90 days. Ten electrodes were implanted in two Göttingen minipigs. Four of these were used for electrical stimulation and electrochemical measurements. Five electrodes were kept in Ringer's solution at 37.5°C, of which four were used for electrical stimulation and electrochemical measurements. The voltage transients measured in vivo were 13 times greater than in vitro at implantation and they continued to increase with time. The electrochemical properties in vivo and the tissue resistance (Rtissue) followed a similar trend with time. There was no consistent significant difference between the electrochemical properties of the in vivo and in vitro electrodes after the implanted period. The differences between the in vivo and in vitro electrodes during the implanted period show that the evaluation of electrochemical performance of implantable stimulation electrodes cannot be substituted with in vitro measurements. After the implanted period, however, the performance of the in vivo and in vitro electrodes in saline was similar. In addition, the changes observed over time during the post-implantation period regarding the electrochemical properties of the in vivo electrodes and Rtissue were similar, which indicates that these changes are due to the foreign body response to implantation. PMID:26300717

Acute kidney injury in critically burned patients resuscitated with a protocol that includes low doses of Hydroxyethyl Starch.

PubMed

Sánchez-Sánchez, M; Garcia-de-Lorenzo, A; Cachafeiro, L; Herrero, E; Asensio, M J; Agrifoglio, A; Flores, E; Estebanez, B; Extremera, P; Iglesias, C; Martinez, J R

2016-09-30

Acute kidney injury (AKI) is an important complication in burn patients. Recently, it has been recommended that hydroxyethyl starch (HES) be avoided in burn patients because it increases the incidence of AKI. Our purpose was to study incidence of AKI in critically ill burn patients resuscitated with Ringer's solution and supplements of HES. We conducted an observational study of 165 patients admitted to the critical care burn unit (with 30 ± 15% TBSA burned). The main outcome measures were incidence of AKI, contributions of colloids and crystalloids, various severity scores, comorbidities, complications and mortality. According to the RIFLE criteria, 10 (6.1%) patients presented with Risk, 11 (6.7%) presented with Injury and 11 (6.7%) presented with Failure. According to the AKIN criteria, 9.7% presented stage I, 3% stage II and 10.3% stage III. Replacement therapy (RRT) was performed in 15 patients (9.1%), but in 6 of them RRT was employed in the final stages of multi-organ failure. The incidence of AKI in severe burn patients is high according to the RIFLE or AKIN criteria and these patients experience more complications and higher mortality. Our study suggests that the use of HES in low doses in the burn resuscitation phase does not cause more AKI than resuscitation without HES, but further evaluation is required. Further studies should be conducted.

Canine blood volume and cardiovascular function during hyperthermia.

PubMed

Miki, K; Morimoto, T; Nose, H; Itoh, T; Yamada, S

1983-08-01

The effect of acute hyperthermia on hemodynamic functions and blood volume regulation was examined on eight splenectomized dogs. Elevation of core body temperature by 2 degrees C over 90 min caused significant increase in cardiac output (11.2 +/- 12.5 ml X min-1 X kg-1 or about 10%) and significant decrease in total peripheral resistance (TPR; -1.3 +/- 1.0 mmHg X s X ml-1 or about 20%), whereas blood volume (BV), plasma oncotic pressure, and intravascular protein mass remained unchanged. Thus the raised core temperature caused peripheral vasodilation with decreased TPR and compensatory increase in cardiac output. Because BV remained unchanged during warming, mobilization of extravascular fluid did not occur; only the redistribution of blood to the vasodilated cutaneous circulation took place. To assess the effects of heat stress on transvascular fluid equilibrium, Ringer solution (10.7 ml X kg-1 X 10 min-1) was infused under normothermic and hyperthermic conditions. The volume of fluid retained within the intravascular space under equilibrium state was 33.5% in hyperthermia and 9.4% in normothermia. In hyperthermia, the transvascular fluid shift and urinary output were decreased both during and after infusion. The role of preferential fluid retention within the intravascular space observed during hyperthermia was discussed in relation to the mechanism to maintain cardiovascular function and BV under heat stress.

Daily hemofiltration with a simplified method of delivery.

PubMed

Zimmerman, Deborah L; Swedko, Peter J; Posen, Gerald A; Burns, Kevin D

2003-01-01

Observational studies of daily hemodialysis (HD) and intermittent hemofiltration (HF) therapy have been associated with improved outcomes for patients with endstage renal disease. We conducted a prospective study to evaluate the feasibility of daily HF as an alternative to intermittent HD using a simplified HF system (NxStage Medical). Each patient received 1 week of intermittent HD followed by 4 weeks of daily HF. Ringers lactate was used as the initial replacement solution; however, Hemosol LG2/L0 was used subsequently to simplify patient management. Changes in quality of life, nutrition, and laboratory values were assessed. Seven patients have completed 168 HF treatments with Hemosol. Their treatment time on HD was 232 minutes 3 days per week, and 132 minutes on HF 6 days per week. Single pool Kt/V per treatment for HD was 1.69 compared with 0.44 for HF (standard Kt/V 2.38 vs 1.93). Despite these weekly differences in urea clearance, potassium, calcium, phosphate, and nutrition remained stable. Beta-2 microglobulin tended to decline. All parameters of the Kidney Disease Quality of Life Instrument Short Form (KDQOL-SF) either remained stable or improved. In addition, blood pressure declined, allowing for a reduction in the number of antihypertensive medications. In summary, these preliminary data suggest that daily HF with this system is safe, simple, efficacious, and could potentially be used as a home based renal replacement therapy.

Hypocretin and GABA interact in the pontine reticular formation to increase wakefulness.

PubMed

Brevig, Holly N; Watson, Christopher J; Lydic, Ralph; Baghdoyan, Helen A

2010-10-01

Hypocretin-1/orexin A administered directly into the oral part of rat pontine reticular formation (PnO) causes an increase in wakefulness and extracellular gamma-aminobutyric acid (GABA) levels. The receptors in the PnO that mediate these effects have not been identified. Therefore, this study tested the hypothesis that the increase in wakefulness caused by administration of hypocretin-1 into the PnO occurs via activation of GABAA receptors and hypocretin receptors. Within/between subjects. University of Michigan. Twenty-three adult male Crl:CD*(SD) (Sprague Dawley) rats. Microinjection of hypocretin-1, bicuculline (GABAA receptor antagonist), SB-334867 (hypocretin receptor-1 antagonist), and Ringer solution (vehicle control) into the PnO. Hypocretin-1 caused a significant concentration-dependent increase in wakefulness and decrease in rapid eye movement (REM) sleep and non-REM (NREM) sleep. Coadministration of SB-334867 and hypocretin-1 blocked the hypocretin-1-induced increase in wakefulness and decrease in both the NREM and REM phases of sleep. Coadministration of bicuculline and hypocretin-1 blocked the hypocretin-1-induced increase in wakefulness and decrease in NREM sleep caused by hypocretin-1. The increase in wakefulness caused by administering hypocretin-1 to the PnO is mediated by hypocretin receptors and GABAA receptors in the PnO. These results show for the first time that hypocretinergic and GABAergic transmission in the PnO can interact to promote wakefulness.

METHOD OF RECOVERING THORIUM

DOEpatents

Fisher, R.W.

1957-12-10

A method is described for recovering thorium from impurities found in a slag containing thorium and said impurities, comprising leaching a composition containing thorium with water, removing the water solution, treating the residue with hydrochloric acid, separating the solution from the insoluble residue, adjusting its acidity to 1 to 3 normal, adding oxalic acid, and thereafter separating the precipitated thorium oxalate digesting the residue from the hydrochloric acid treatment with a strong solution of sodium hydroxide at an elevated temperature, removing said solution and treating the insoluble residue with hydrochloric acid, separating the solution from the insoluble residue, adjusting the acidity of this solution to 1 to 3 normal, adding nitric acid to oxidize the iron present, adding oxalic acid and thereafter separating the thorium oxalate thus precipitated.

Experimental studies of methemoglobinemia due to percutaneous absorption of sodium nitrite.

PubMed

Saito, T; Takeichi, S; Nakajima, Y; Yukawa, N; Osawa, M

1997-01-01

Methemoglobin formation caused by a liniment solution containing sodium nitrite (30 g/L and 140 g/L) was studied in rats with normal or abraded skin, by measuring the methemoglobin concentration before and after application of liniment solutions with differing nitrite concentration. Each liniment solution (120 microL) was applied. Methemoglobin was measured for 180 minutes using a hemoximeter. Simultaneously, arterial blood pressure and cutaneous blood flow was measured by laser Doppler flowmetry and a pressure transducer. After the application of each liniment solution to normal skin, the methemoglobin concentration was not significantly modified depending on the time after application. Application of liniment solution to abraded skin (140 g/L) resulted in a marked increase in methemoglobin concentration. A remarkable decrease in arterial blood pressure and subcutaneous blood flow were observed after application of liniment solution to abraded skin (140 g/L). Each of these findings are characteristic of nitrite and they imply the percutaneous absorption of nitrite. Regardless of the nitrite concentration, the methemoglobin concentration was consistently higher in abraded skin than in normal skin.

On the existence, uniqueness, and asymptotic normality of a consistent solution of the likelihood equations for nonidentically distributed observations: Applications to missing data problems

NASA Technical Reports Server (NTRS)

Peters, C. (Principal Investigator)

1980-01-01

A general theorem is given which establishes the existence and uniqueness of a consistent solution of the likelihood equations given a sequence of independent random vectors whose distributions are not identical but have the same parameter set. In addition, it is shown that the consistent solution is a MLE and that it is asymptotically normal and efficient. Two applications are discussed: one in which independent observations of a normal random vector have missing components, and the other in which the parameters in a mixture from an exponential family are estimated using independent homogeneous sample blocks of different sizes.

THE CONTRIBUTIONS OF NORMAL AND ANOMALOUS OSMOSIS TO THE OSMOTIC EFFECTS ARISING ACROSS CHARGED MEMBRANES WITH SOLUTIONS OF ELECTROLYTES

PubMed Central

Grim, Eugene; Sollner, Karl

1957-01-01

The osmotic effect arising across a porous membrane separating the solution of an electrolyte from water (or a more dilute solution) is ordinarily due to both normal osmosis, as it occurs also with non-electrolytes, and to "anomalous" osmosis. It is shown that the normal osmotic component cannot be measured quantitatively by the conventional comparison with a non-electrolytic reference solute. Anomalous osmosis does not occur with electroneutral membranes. Accordingly, with membranes which can be charged and discharged reversibly (without changes in geometrical structure), such as many proteinized membranes, the osmotic effects caused by an electrolyte can be measured both when only normal osmosis arises (with the membrane in the electroneutral state) and when normal as well as anomalous osmosis occurs (with the membrane in a charged state). The difference between these two effects is the true anomalous osmosis. Data are presented on the osmotic effects across an oxyhemoglobin membrane in the uncharged state at pH 6.75 and in two charged states, positive at pH 4.0 and negative at pH 10.0, with solutions of a variety of electrolytes using a concentration ratio of 2:1 over a wide range of concentrations. The rates of the movement of liquid across the membrane against an inconsequentially small hydrostatic head are recorded instead of, as conventional, the physiologically less significant pressure rises after a standard time. PMID:13439166

In vitro effects of 6 % hydroxyethyl starch 130/0.42 solution on feline whole blood coagulation measured by rotational thromboelastometry.

PubMed

Albrecht, Nathalie A; Howard, Judith; Kovacevic, Alan; Adamik, Katja N

2016-07-26

The artificial colloid, hydroxyethyl starch (HES), is recommended for intravascular volume expansion and colloid-osmotic pressure enhancement in dogs and cats. A well-known side effect of HES solutions in humans and dogs is coagulopathy. However, HES-associated coagulopathy has thus far not been investigated in cats. The goal of this study was to assess the in vitro effects of 6 % HES 130/0.42 on feline whole blood samples using rotational thromboelastometry (ROTEM). A further goal was to develop feline reference intervals for ROTEM at our institution. In this in vitro experimental study, blood samples of 24 adult healthy cats were collected by atraumatic jugular phlebotomy following intramuscular sedation. Baseline ROTEM analyses (using ex-tem, in-tem and fib-tem assays) were performed in duplicate. Additionally, ROTEM analyses were performed on blood samples after dilution with either Ringer's acetate (RA) or 6 % HES 130/0.42 (HES) in a 1:6 dilution (i.e. 1 part solution and 6 parts blood). Coefficients of variation of duplicate measures were below 12 % in all ex-tem assays, 3 of 4 in-tem assays but only 1 of 3 fib-tem assays. Reference intervals were similar albeit somewhat narrower than those previously published. Dilution with both solutions lead to significantly prolonged CT (in-tem), CFT (ex-tem and in-tem), and reduced MCF (ex-tem, in-tem, and fib-tem) and alpha (ex-tem and in-tem). Compared to RA, dilution with HES caused a significant prolongation of CT in fib-tem (P = 0.016), CFT in ex-tem (P = 0.017) and in-tem (P = 0.019), as well as a reduction in MCF in in-tem (P = 0.032) and fib-tem (P = 0.020), and alpha in ex-tem (P = 0.014). However, only a single parameter (CFT in ex-tem) was outside of the established reference interval after dilution with HES. In vitro hemodilution of feline blood with RA and HES causes a small but significant impairment of whole blood coagulation, with HES leading to a significantly greater effect on coagulation than RA. Further studies are necessary to evaluate the in vivo effects and the clinical significance of these findings.

Transverse Stress Decay in a Specially Orthotropic Strip Under Localizing Normal Edge Loading

NASA Technical Reports Server (NTRS)

Fichter, W. B.

2000-01-01

Solutions are presented for the stresses in a specially orthotropic infinite strip which is subjected to localized uniform normal loading on one edge while the other edge is either restrained against normal displacement only, or completely fixed. The solutions are used to investigate the diffusion of load into the strip and in particular the decay of normal stress across the width of the strip. For orthotropic strips representative of a broad range of balanced and symmetric angle-ply composite laminates, minimum strip widths are found that ensure at least 90% decay of the normal stress across the strip. In addition, in a few cases where, on the fixed edge the peak shear stress exceeds the normal stress in magnitude, minimum strip widths that ensure 90% decay of both stresses are found. To help in putting these results into perspective, and to illustrate the influence of material properties on load 9 orthotropic materials, closed-form solutions for the stresses in similarly loaded orthotropic half-planes are obtained. These solutions are used to generate illustrative stress contour plots for several representative laminates. Among the laminates, those composed of intermediate-angle plies, i.e., from about 30 degrees to 60 degrees, exhibit marked changes in normal stress contour shape with stress level. The stress contours are also used to find 90% decay distances in the half-planes. In all cases, the minimum strip widths for 90% decay of the normal stress exceed the 90% decay distances in the corresponding half-planes, in amounts ranging from only a few percent to about 50% of the half-plane decay distances. The 90% decay distances depend on both material properties and the boundary conditions on the supported edge.

The effects of warmed intravenous fluids, combined warming (warmed intravenous fluids with humid-warm oxygen), and pethidine on the severity of shivering in general anesthesia patients in the recovery room

PubMed Central

Nasiri, Ahmad; Akbari, Ayob; Sharifzade, GholamReza; Derakhshan, Pooya

2015-01-01

Background: Shivering is a common complication of general and epidural anesthesia. Warming methods and many drugs are used for control of shivering in the recovery room. The present study is a randomized clinical trial aimed to investigate the effects of two interventions in comparison with pethidine which is the routine treatment on shivering in patients undergoing abdominal surgery with general anesthesia. Materials and Methods: Eighty-seven patients undergoing abdominal surgery by general anesthesia were randomly assigned to three groups (two intervention groups in comparison with pethidine as routine). Patients in warmed intravenous fluids group received pre-warmed Ringer serum (38°C), patients in combined warming group received pre-warmed Ringer serum (38°C) accompanied by humid-warm oxygen, and patients in pethidine group received intravenous pethidine routinely. The elapsed time of shivering and some hemodynamic parameters of the participants were assessed for 20 min postoperatively in the recovery room. Then the collected data were analyzed by software SPSS (v. 16) with the significance level being P < 0.05. Results: The mean of elapsed time in the warmed intravenous serum group, the combined warming group, and the pethidine group were 7 (1.5) min, 6 (1.5) min, and 2.8 (0.7) min, respectively, which was statistically significant (P < 0.05). The body temperatures in both combined warming and pethidine groups were increased significantly (P < 0.05). Conclusions: Combined warming can be effective in controlling postoperative shivering and body temperature increase. PMID:26793258

Polynomial compensation, inversion, and approximation of discrete time linear systems

NASA Technical Reports Server (NTRS)

Baram, Yoram

1987-01-01

The least-squares transformation of a discrete-time multivariable linear system into a desired one by convolving the first with a polynomial system yields optimal polynomial solutions to the problems of system compensation, inversion, and approximation. The polynomial coefficients are obtained from the solution to a so-called normal linear matrix equation, whose coefficients are shown to be the weighting patterns of certain linear systems. These, in turn, can be used in the recursive solution of the normal equation.

Hormonal priming, induction of ovulation and in-vitro fertilization of the endangered Wyoming toad (Bufo baxteri)

PubMed Central

Browne, Robert K; Seratt, Jessica; Vance, Carrie; Kouba, Andrew

2006-01-01

The endangered Wyoming toad (Bufo baxteri) is the subject of an extensive captive breeding and reintroduction program. Wyoming toads in captivity rarely ovulate spontaneously and hormonal induction is used to ovulate females or to stimulate spermiation in males. With hormonal induction, ovulation is unreliable and egg numbers are low. The sequential administration of anovulatory doses of hormones (priming) has increased egg numbers and quality in both anurans and fish. Consequently, we tested the efficacy of a combination of human Chorionic Gonadotrophin (hCG) and Luteinizing Hormone Releasing Hormone analogue (LHRHa) administered as one dose, or two or three sequential doses to Bufo baxteri on egg numbers, fertilization and early embryo development. Spawning toads deposited eggs into Simplified Amphibian Ringers (SAR) solution to enable controlled in-vitro fertilization (IVF) with sperm from hormonally induced male toads. Unprimed females receiving a single mixed normally ovulatory dose of 500 IU hCG plus 4 micrograms of LHRHa produced no eggs. Whereas females primed with this dose and an anovulatory dose (100 IU hCG and 0.8 micrograms of LHRHa) of the same hormones, or primed only with an anovulatory dose, spawned after then receiving an ovulatory dose. Higher total egg numbers were produced with two primings than with one priming. Moreover, two primings produced significantly more eggs from each individual female than one priming. The cleavage rate of eggs was not found to differ between one or two primings. Nevertheless, embryo development with eggs from two primings gave a significantly greater percentage neurulation and swim-up than those from one priming. Of the male toads receiving a single dose of 300 IU hCG, 80% produced spermic urine with the greatest sperm concentration 7 hours post-administration (PA). However, peak sperm motility (95%) was achieved at 5 hours PA and remained relatively constant until declining 20 hours PA. In conclusion, Bufo baxteri egg numbers and quality benefited from sequential priming with LHRHa and hCG whereas spermic urine for IVF was produced from males with a single dose of hCG. The power of assisted reproduction technology in the conservation of endangered amphibians is shown by the release of nearly 2000 tadpoles produced by IVF during this study. PMID:16790071

Folic acid supplementation improves microvascular function in older adults through nitric oxide-dependent mechanisms.

PubMed

Stanhewicz, Anna E; Alexander, Lacy M; Kenney, W Larry

2015-07-01

Older adults have reduced vascular endothelial function, evidenced by attenuated nitric oxide (NO)-dependent cutaneous vasodilatation. Folic acid and its metabolite, 5-methyltetrahydrofolate (5-MTHF), are reported to improve vessel function. We hypothesized that (i) local 5-MTHF administration and (ii) chronic folic acid supplementation would improve cutaneous microvascular function in ageing through NO-dependent mechanisms. There were two separate studies in which there were 11 young (Y: 22 ± 1 years) and 11 older (O: 71 ± 3 years) participants. In both studies, two intradermal microdialysis fibres were placed in the forearm skin for local delivery of lactated Ringer's solution with or without 5 mM 5-MTHF. Red cell flux was measured by laser-Doppler flowmetry. Cutaneous vascular conductance [CVC=red cell flux/mean arterial pressure] was normalized as percentage maximum CVC (%CVCmax) (28 mM sodium nitroprusside, local temperature 43°C). In study 1 after CVC plateaued during local heating, 20 mM NG-nitro-L-arginine methyl ester (L-NAME) was perfused at each site to quantify NO-dependent vasodilatation. The local heating plateau (%CVCmax: O = 82 ± 3 vs Y = 96 ± 1, P = 0.002) and NO-dependent vasodilatation (%CVCmax: O = 26 ± 6% vs Y = 49 ± 5, P = 0.03) were attenuated in older participants. 5-MTHF augmented the overall (%CVCmax = 91 ± 2, P = 0.03) and NO-dependent (%CVCmax = 43 ± 9%, P = 0.04) vasodilatation in older but not young participants. In study 2 the participants ingested folic acid (5 mg/day) or placebo for 6 weeks in a randomized, double-blind, crossover design. A rise in oral temperature of 1°C was induced using a water-perfused suit, body temperature was held and 20 mM L-NAME was perfused at each site. Older participants had attenuated reflex (%CVCmax: O = 31 ± 8 vs Y = 44 ± 5, P = 0.001) and NO-dependent (%CVCmax: O = 9 ± 2 vs Y = 21 ± 2, P = 0.003) vasodilatation. Folic acid increased CVC (%CVCmax = 47 ± 5%, P = 0.001) and NO-dependent vasodilatation (20 ± 3%, P = 0.003) in the older but not the young participants. Both local perfusion of 5-MTHF and supplementation with folic acid increase vasodilatation in ageing individuals through NO-dependent mechanisms.

Bipolar sealing of lung parenchyma: tests in an ex vivo model.

PubMed

Kirschbaum, A; Clemens, A; Steinfeldt, T; Pehl, A; Meyer, C; Bartsch, D K

2015-01-01

Almost every pulmonary lobe resection requires cutting the lung parenchyma in the area of a lung fissure. A monopolar cutter or stapler is often used for this purpose. The seal should be absolutely airtight to prevent post-operative pulmonary fistulas. In the present study, the bipolar sealing technique was evaluated regarding air tightness of the seals during normal ventilation and its burst pressure in an ex vivo animal model. The investigations were carried out on paracardial lung lobes obtained from heart-lung preparations taken from freshly killed pigs at a slaughter house. In the laboratory, each individual lobe was perfused with Ringer's solution at body temperature and protectively ventilated through a tube (frequency: 20 1/min, p insp = 20 mbar, PEEP +5 mbar). Non-anatomic resection was carried out in the periphery of the lung lobe. The two control groups (12 lobes per group; Group 1-stapler, Group 2-parenchyma suture) were compared to three groups in which different bipolar sealing instruments were used. They were Group 3-MARSEAL(®) 10 mm (KLS Martin, Tuttlingen); Group 4-MARSEAL(®) 5 mm; and Group 5-MARCLAMP(®) (KLS Martin, Tuttlingen). The SealSafe(®) G3 electric current was used in all cases. Ventilation was continued for 20 min following parenchymal resection. Parenchymal sealing was then judged visually in a water bath and given a score (0-3). Burst pressure (mbar) was measured by increasing the inspiration pressure stepwise. Group mean values were compared (nonparametric Mann-Whitney U test, p < 0.005). Parenchymal seals were airtight under ventilation throughout the observation period in all groups. Mean burst pressures were as follows: Group 1: 47.1 ± 6.2 mbar; Group 2: 32.9 ± 3.9 mbar; Group 3: 38.8 ± 2.2 mbar; Group 4: 25.0 ± 6.4 mbar; and Group 5: 32.9 ± 5.8 mbar. Group 1, the stapler group, thus exhibited the highest burst pressures. Burst pressures for Group 3 were significantly greater than those for Group 2 (p < 0.006). Burst pressures for groups 2 and 5 were similar (p = 0.97). However, the burst pressures for Group 4 were significantly lower than those for Group 2 (p < 0.001). MARSEAL(®) 10 mm and MARCLAMP(®) achieved adequate burst pressures compared to the two control groups and thus might be suitable for clinical use.

Protein C

MedlinePlus

... Normal Results Normal values are 60% to 150% inhibition. Normal value ranges may vary slightly among different ... Health Solutions. About MedlinePlus Site Map FAQs Customer Support Get email updates Subscribe to RSS Follow us ...

Protein S

MedlinePlus

... Normal Results Normal values are 60% to 150% inhibition. Normal value ranges may vary slightly among different ... Health Solutions. About MedlinePlus Site Map FAQs Customer Support Get email updates Subscribe to RSS Follow us ...

Probability density function of non-reactive solute concentration in heterogeneous porous formations.

PubMed

Bellin, Alberto; Tonina, Daniele

2007-10-30

Available models of solute transport in heterogeneous formations lack in providing complete characterization of the predicted concentration. This is a serious drawback especially in risk analysis where confidence intervals and probability of exceeding threshold values are required. Our contribution to fill this gap of knowledge is a probability distribution model for the local concentration of conservative tracers migrating in heterogeneous aquifers. Our model accounts for dilution, mechanical mixing within the sampling volume and spreading due to formation heterogeneity. It is developed by modeling local concentration dynamics with an Ito Stochastic Differential Equation (SDE) that under the hypothesis of statistical stationarity leads to the Beta probability distribution function (pdf) for the solute concentration. This model shows large flexibility in capturing the smoothing effect of the sampling volume and the associated reduction of the probability of exceeding large concentrations. Furthermore, it is fully characterized by the first two moments of the solute concentration, and these are the same pieces of information required for standard geostatistical techniques employing Normal or Log-Normal distributions. Additionally, we show that in the absence of pore-scale dispersion and for point concentrations the pdf model converges to the binary distribution of [Dagan, G., 1982. Stochastic modeling of groundwater flow by unconditional and conditional probabilities, 2, The solute transport. Water Resour. Res. 18 (4), 835-848.], while it approaches the Normal distribution for sampling volumes much larger than the characteristic scale of the aquifer heterogeneity. Furthermore, we demonstrate that the same model with the spatial moments replacing the statistical moments can be applied to estimate the proportion of the plume volume where solute concentrations are above or below critical thresholds. Application of this model to point and vertically averaged bromide concentrations from the first Cape Cod tracer test and to a set of numerical simulations confirms the above findings and for the first time it shows the superiority of the Beta model to both Normal and Log-Normal models in interpreting field data. Furthermore, we show that assuming a-priori that local concentrations are normally or log-normally distributed may result in a severe underestimate of the probability of exceeding large concentrations.

Does the biocompatibility of the peritoneal dialysis solution matter in assessment of peritoneal function?

PubMed

Parikova, Alena; Struijk, Dirk G; Zweers, Machteld M; Langedijk, Monique; Schouten, Natalie; van den Berg, Nicole; Duis, Saskia; Krediet, Raymond T

2007-01-01

Peritoneal function tests are performed in peritoneal dialysis (PD) patients to characterize peritoneal membrane status. A low pH/high glucose degradation product (GDP) dialysis solution is used as the test solution. The objective of the present study was to compare a 3.86% glucose, low pH/high GDP dialysis solution (pH 5.5) with a 3.86% glucose, normal pH/low GDP dialysis solution (pH 7.4) in assessments of peritoneal membrane function. Two standard peritoneal permeability analyses (SPA) were performed in 10 stable PD patients within 2 weeks. One SPA was done with the 3.86% low pH/high GDP solution, and the other with the 3.86% normal pH/low GDP solution. The sequence of the two tests was randomized. Fluid transport parameters and glucose absorption were not different between the two groups. No differences were found for the mass transfer area coefficients (MTACs) of low molecular weight solutes calculated over the whole dwell. However, MTAC urea in the first hour of the dwell was higher in the test done with low pH/high GDP dialysate, suggesting more peritoneal vasodilation. No difference was found in protein clearances. Sodium sieving at multiple time points during the dwell was similar with the two solutions. The results obtained with the glucose-containing normal pH/low GDP dialysis solution were similar to those obtained with the glucose-containing low pH/high GDP dialysate in assessments of peritoneal membrane function.

Chemical Stability of Telavancin in Elastomeric Pumps.

PubMed

Sand, Patrick; Aladeen, Traci; Kirkegaard, Paul; LaChance, Dennis; Slover, Christine

2015-12-01

VIBATIV is a once-daily, injectable lipoglycopeptide antibiotic approved in the U.S. for the treatment of hospital-acquired and ventilator-associated bacterial pneumonia (HABP/VABP) caused by susceptible isolates of Staphylococcus aureus when alternative treatments are not suitable. In addition, VIBATIV is approved in the U.S. for the treatment of adult patients with complicated skin & skin structure infections (cSSSI) caused by susceptible isolates of Gram-positive bacteria, including Staphylococcus aureus, both methicillin-susceptible (MSSA) and methicillin-resistant (MRSA) strains. To evaluate the chemical stability of telavancin (Vibativ; Theravance Biopharma US, Inc, Northbrook, Illinois), a lipoglycopeptide antibiotic with activity against methicillin-resistant Staphylococcus aureus, in 2 types of elastomeric pumps, the Intermate Infusion System (Baxter International Inc) and the Homepump Eclipse (I-Flow Corporation). Different sizes of the Baxter (Ontario, Canada) (105 mL and 275 mL) and I-Flow (Stoughton, Massachusetts) (100 mL and 250 mL) pumps were compared with glass controls. The telavancin drug product was reconstituted and diluted to concentrations of 0.6 mg/mL and 8.0 mg/mL using either 0.9% saline, 5% dextrose in water, or sterilized water for injection (0.6 mg/mL telavancin) or saline (8.0 mg/mL telavancin) followed by Ringer's Lactate solution. Pumps were filled and stored at 2°C to 8°C, protected from light. Aliquots from both pump types and for all telavancin reconstitution/dilution schemes and concentrations were taken over a period of 8 days and analyzed for appearance, pH, telavancin concentration and purity, and degradation products. The pH of all pump solutions remained consistent throughout the 8-day analysis period, within a range of 4.6 to 5.7 for the 0.6 mg/mL and 4.4 to 4.9 for the 8.0 mg/mL telavancin solutions. There was no significant change in the chromatographic purity for any of the pump solutions examined. All decreases in telavancin concentration were ≤2.7%. Comparison of each test sample solution to the corresponding glass control indicated no loss of active drug due to absorption by the elastomeric material of the pumps. The greatest increase in the amount of total degradants observed over the 8-day period was ~0.7 w/w%. The results of this study indicate that telavancin remains chemically stable when diluted in the Intermate Infusion System and the Homepump Eclipse elastomeric pumps and stored at 2°C to 8°C for up to 8 days protected from light at the concentration range and dilution schemes evaluated.

Liquid-core photonic crystal fiber platform for raman scattering measurements of microliter analyte solutions

NASA Astrophysics Data System (ADS)

Han, Yun; Oo, Maung Khaing; Zhu, Yinian; Sukhishvili, Svetlana; Xiao, Limin; Demokan, M. Süleyman; Jin, Wei; Du, Henry

2007-09-01

We have explored the use of index-guiding liquid-core photonic crystal fiber (LC-PCF) as a platform for sensing and measurements of analyte solutions of minute volume by normal and surface-enhanced Raman scattering (SERS). The index-guiding LC-PCF was fabricated by selectively sealing via fusion splicing the cladding air channels of a hollow-core PCF (HC-PCF) while leaving the center core open at both ends of the fiber. The center core of the resultant fiber was subsequently filled with water-ethanol solution mixtures at various ethanol concentrations for normal Raman scattering measurements and with water-thiocynate solutions containing Ag nanoparticle aggregates for SERS detection of thiocynate at trace concentrations. The light-guiding nature in the solution phase inside the LC-PCF allows direct and strong light-field overlap with the solution phase over the entire length of the PCF (~30 cm). This detection scheme also dramatically reduces the contribution of silica to Raman spectral background, compared with the solid-core counterpart, thus its potential interference in spectral analysis. These features attribute to ready normal Raman measurements of water, ethanol, and water (99 vol.%)-ethanol (1 vol.%) solutions as well as sensitive and reproducible SERS detection of ~10 ppb thiocynate in water, all at a volume of ~0.1 μL.

Compatibility Study of Nanofiltration and Reverse Osmosis Membranes with 1 Cyclohexylpiperidenium Bicarbonate Solutions

DOE Data Explorer

Adhikari, Birendra; Jones, Michael G.; Orme, Christopher J.; Wendt, Daniel S.; Wilson, Aaron D.

2015-10-01

The switchable polarity solvent forward osmosis (SPS FO) desalination process requires use of a polishing filtration step to remove trace quantities of draw solution from the product water stream. Selected nanofiltration (NF) and reverse osmosis (RO) membranes were tested for their ability to recover water from 1-cyclohexylpiperidenium bicarbonate solutions in this application. This submission includes the experimental data used to calculate NF and RO membrane flux-normalized net driving pressure (FNNDP) and flux-normalized rejection (FNR) performance in recovering water from 1-cyclohexylpiperidenium bicarbonate solutions. This data is further described and visualized in the manuscript entitled "Compatibility study of nanofiltration and reverse osmosis membranes with 1 cyclohexylpiperidenium bicarbonate solutions" (see attached Compatibility Study Manuscript).

VLBI-SLR Combination Solution Using GEODYN

NASA Technical Reports Server (NTRS)

MacMillan, Dan; Pavlis, Despina; Lemoine, Frank; Chinn, Douglas; Rowlands, David

2010-01-01

We would like to generate a multi-technique solution combining all of the geodetic techniques (VLBI, SLR, GPS, and DORIS) using the same software and using the same a priori models. Here we use GEODYN software and consider only the VLBI-SLR combination. Here we report initial results of our work on the combination. We first performed solutions with GEODYN using only VLBI data and found that VLBI EOP solution results produced with GEODYN agree with results using CALC/SOLVE at the 1-sigma level. We then combined the VLBI normal equations in GEODYN with weekly SLR normal equations for the period 2007-2008. Agreement of estimated Earth orientation parameters with IERS C04 were not significantly different for the VLBI-only, SLR-only, and VLBI+SLR solutions

Metabolic oxygen consumption measurement with a single-cell biosensor after particle microbeam irradiation

PubMed Central

Zhang, Bo; Messerli, Mark; Randers-Pehrson, Gerhard; Hei, Tom K.; Brenner, David J.

2015-01-01

A noninvasive, self-referencing biosensor/probe system has been integrated into the Columbia University Radiological Research Accelerator Facility Microbeam II end station. A single-cell oxygen consumption measurement has been conducted with this type of oxygen probe in 37°C Krebs–Ringer Bicarbonate buffer immediately before and after a single-cell microbeam irradiation. It is the first such measurement made for a microbeam irradiation, and a six fold increment of oxygen flux induced during a 15-s period of time has been observed following radiation exposure. The experimental procedure and the results are discussed. PMID:25335641

Peter Andreas Hansen and the astronomical community - a first investigation of the Hansen papers. (German Title: Peter Andreas Hansen und die astronomische Gemeinschaft - eine erste Auswertung des Hansen-Nachlasses. )

NASA Astrophysics Data System (ADS)

Schwarz, Oliver; Strumpf, Manfred

The literary assets of Peter Andreas Hansen are deposited in the Staatsarchiv Hamburg, the Forschungs- und Landesbibliothek Gotha and the Thüringer Staatsarchiv Gotha. They were never systematically investigated. We present here some results of a first evaluation. It was possible to reconstruct the historical events with regard to the maintenance of the Astronomische Nachrichten and the Altona observatory in 1854. Hansen was a successful teacher for many young astronomers. His way of stimulating the evolution of astronomy followed Zach's tradition.

The Effect of Testosterone Topical Solution in Hypogonadal Men With Suboptimal Response to a Topical Testosterone Gel.

PubMed

Burns, Patrick R; Kim, Edward D; Ruff, Dustin D; Seftel, Allen D

2018-05-01

This study evaluated the effect of axillary administration of a 2% testosterone solution (Axiron ® ) in hypogonadal (HGN) men who had had a suboptimal response to treatment with a commercially available topical testosterone gel. HGN men averaging 57 years old, with a mean body mass index of 31.9 kg/m 2 and median baseline testosterone level (T-level) of 185.2 ng/dL, who had failed to reach normal T-levels with a topical testosterone gel (Androgel 1.62%, Androgel, Testim, or Fortesta) were treated with a 2% testosterone solution until T-levels reached a normal range (from ≥300 to ≤1,050 ng/dL) or for up to 9 weeks. Outcomes included the cumulative percentage of men with a serum T-level in the normal range during treatment with Axiron and improvement in symptoms of low energy level and low sexual drive. During the study, 95% of HGN men (72/78) attained a T-level in the normal range. The median T-level at endpoint was 495.7 ng/dL, a threefold increase over baseline, p < .001, 70% achieving normal T-levels within the first 2 weeks of treatment. In a post hoc analysis, all subjects with baseline body mass indexes >35 kg/m 2 ( n = 19) achieved T-levels in the normal range. Prior to treatment, over 61% of subjects (48/78) reported impairment in either energy level or sexual drive. After treatment (or testosterone normalization), energy level improved in 75% of subjects and sexual drive improved in 70%. Topical 2% testosterone solution is a safe and effective treatment for HGN men who have had a suboptimal response to previous treatment with topical testosterone gels.

Padé approximant for normal stress differences in large-amplitude oscillatory shear flow

NASA Astrophysics Data System (ADS)

Poungthong, P.; Saengow, C.; Giacomin, A. J.; Kolitawong, C.; Merger, D.; Wilhelm, M.

2018-04-01

Analytical solutions for the normal stress differences in large-amplitude oscillatory shear flow (LAOS), for continuum or molecular models, normally take the inexact form of the first few terms of a series expansion in the shear rate amplitude. Here, we improve the accuracy of these truncated expansions by replacing them with rational functions called Padé approximants. The recent advent of exact solutions in LAOS presents an opportunity to identify accurate and useful Padé approximants. For this identification, we replace the truncated expansion for the corotational Jeffreys fluid with its Padé approximants for the normal stress differences. We uncover the most accurate and useful approximant, the [3,4] approximant, and then test its accuracy against the exact solution [C. Saengow and A. J. Giacomin, "Normal stress differences from Oldroyd 8-constant framework: Exact analytical solution for large-amplitude oscillatory shear flow," Phys. Fluids 29, 121601 (2017)]. We use Ewoldt grids to show the stunning accuracy of our [3,4] approximant in LAOS. We quantify this accuracy with an objective function and then map it onto the Pipkin space. Our two applications illustrate how to use our new approximant reliably. For this, we use the Spriggs relations to generalize our best approximant to multimode, and then, we compare with measurements on molten high-density polyethylene and on dissolved polyisobutylene in isobutylene oligomer.

Intravenous fluids for reducing the duration of labour in low risk nulliparous women.

PubMed

Dawood, Feroza; Dowswell, Therese; Quenby, Siobhan

2013-06-18

Several factors may influence the progression of normal labour. It has been postulated that the routine administration of intravenous fluids to keep women adequately hydrated during labour may reduce the period of contraction and relaxation of the uterine muscle, and may ultimately reduce the duration of the labour. It has also been suggested that intravenous fluids may reduce caesarean sections (CS) for prolonged labour. However, the routine administration of intravenous fluids to labouring women has not been adequately elucidated although it is a widely-adopted policy, and there is no consensus on the type or volume of fluids that are required, or indeed, whether intravenous fluids are at all necessary. Women may be able to adequately hydrate themselves if they were allowed oral fluids during labour.Furthermore, excessive volumes of intravenous fluids may pose risks to both the mother and her newborn and different fluids are associated with different risks. To evaluate whether the routine administration of intravenous fluids to low-risk nulliparous labouring women reduces the duration of labour and to evaluate the safety of intravenous fluids on maternal and neonatal health. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (13 February 2013). Randomised controlled trials of intravenous fluid administration to spontaneously labouring low-risk nulliparous women. The review authors independently assessed trials for inclusion, trial quality and extracted data. We included nine randomised trials with 1781 women. Three trials had more than two treatment arms and were included in more than one comparison.Two trials compared women randomised to receive up to 250 mL/hour of Ringer's lactate solution as well as oral intake versus oral intake only. For women delivering vaginally, there was a reduction in the duration of labour in the Ringer's lactate group (mean difference (MD) -28.86 minutes, 95% confidence interval (CI) -47.41 to -10.30). There was no statistical reduction in the number of CS in the Ringer's lactate group (risk ratio (RR), 0.73 95% CI 0.49 to 1.08).Three trials compared women who received 125 mL/hour versus 250 mL/hour of intravenous fluids with free oral fluids in both groups. Women receiving a greater hourly volume of intravenous fluids (250 mL) had shorter labours than those receiving 125 mL (MD 23.87 minutes, 95% CI 3.72 to 44.02, 256 women). There was no statistically significant reduction in the number of CS in the 250 mL intravenous fluid group (average RR 1.00, 95% CI 0.54 to1.87, three studies, 334 women). In one study the number of assisted vaginal deliveries was lower in the group receiving 125 mL/hour (RR 0.47, 95% CI 0.27 to 0.81).Four trials compared rates of intravenous fluids in women where oral intake was restricted (125 mL/hour versus 250 mL/hour). There was a reduction in the duration of labour in women who received the higher infusion rate (MD 105.61 minutes, 95% CI 53.19 to 158.02); P < 0.0001, however, findings must be interpreted with caution as there was high heterogeneity amongst trials (I(2) = 53%). There was a significant reduction in CS in women receiving the higher rate of intravenous fluid infusion (RR 1.56, 95% CI 1.10 to 2.21; P = 0.01). There was no difference identified in the assisted delivery rate (RR 0.78, 95% CI 0.44 to 1.40). There was no clear difference between groups in the number of babies admitted to the NICU (RR 0.48, 95% CI 0.07 to 3.17).Two trials compared normal saline versus 5% dextrose. Only one reported the mean duration of labour, and there was no strong evidence of a difference between groups (MD -12.00, 95% CI -30.09 to 6.09). A trial reporting the median suggested that the duration was reduced in the dextrose group. There was no significant difference in CS or assisted deliveries (RR 0.77, 95% CI 0.41 to 1.43, two studies, 284 women) and (RR 0.59, 95% CI 0.21 to 1.63, one study, 93 women) respectively. Only one trial reported on maternal hyponatraemia (serum sodium levels < 135 mmol/L ). For neonatal complications, there was no difference in the admission to NICU) or in low Apgar scores, however 33.3% of babies developed hyponatraemia in the dextrose group compared to 13.3 % in the normal saline group (RR 0.40, 95% CI 0.17 to 0.93) (P = 0.03). One trial reported a higher incidence of neonatal hyperbilirubinaemia in the dextrose group of babies. There was no difference in neonatal hypoglycaemic episodes between groups. Although the administration of intravenous fluids compared with oral intake alone demonstrated a reduction in the duration of labour, this finding emerged from only two trials. The findings of other trials suggest that if a policy of no oral intake is applied, then the duration of labour in nulliparous women may be shortened by the administration of intravenous fluids at a rate of 250 mL/hour rather than 125 mL/hour. However, it may be possible for women to simply increase their oral intake rather than being attached to a drip and we have to consider whether it is justifiable to persist with a policy of 'nil by mouth'. One trial raised concerns about the safety of dextrose and this needs further exploration.None of the trials reported on the evaluation of maternal views of being attached to a drip during their entire labour. Furthermore, there was no objective assessment of dehydration. The evidence from this review does not provide robust evidence to recommend routine administration of intravenous fluids. Interpreting the results from trials was hampered by the low number of trials contributing data and by variation between trials. In trials where oral fluids were not restricted there was considerable variation in the amount of oral fluid consumed by women in different arms of the same trial, and between different trials. In addition, results from trials were not consistent and risk of bias varied. Some important research questions were addressed by single trials only, and important outcomes relating to maternal and infant morbidity were frequently not reported.

Induction of hepatic protein synthesis by a peptide in blood plasma of patients with sepsis and trauma.

PubMed

Loda, M; Clowes, G H; Dinarello, C A; George, B C; Lane, B; Richardson, W

1984-08-01

Accelerated release of amino acids from muscle and their uptake for protein synthesis by liver and other visceral tissues are characteristic of trauma or sepsis. Experimentally, this response is induced by interleukin-1 (IL-1) generated by activated macrophages in vitro. However, IL-1 has not been demonstrated in human blood. A small 4000-dalton peptide recently isolated from plasma of patients with sepsis and trauma induces muscle proteolysis and is called "proteolysis-inducing factor" (PIF). To test whether this agent has the ability also to induce hepatic protein synthesis, a series of animal experiments and clinical observations were undertaken. The structural and secretory (acute-phase reactants) in vitro protein synthesis in livers of normal rats injected intraperitoneally with IL-1 or PIF was significantly greater than that of normal rats or those injected with Ringer's lactate (p less than 0.01). In patients with sepsis and trauma the central plasma clearance rate of amino acids, a measure of visceral (principally hepatic) amino acid uptake, was elevated and correlated with the rates of protein synthesis in incubated liver slices obtained by biopsy at operation from the same patients (p less than 0.05). Both in vivo measured central plasma clearance rate of amino acids and in vitro measured hepatic protein synthesis correlated with plasma levels of PIF in the same patients (p less than 0.01 and p less than 0.05, respectively). We conclude that since PIF, and not IL-1, is present in human plasma and both are produced by activated macrophages, PIF seems to be the stable circulating cleavage product of IL-1, which induces not only muscle proteolysis but also hepatic protein synthesis, principally in the form of acute-phase reactants during infection and other states in which inflammation is present.

Multiple normalized solutions for a planar gauged nonlinear Schrödinger equation

NASA Astrophysics Data System (ADS)

Luo, Xiao

2018-06-01

We study the existence, multiplicity, quantitative property and asymptotic behavior of normalized solutions for a gauged nonlinear Schrödinger equation arising from the Chern-Simons theory Δ u + ω u +|x|^2u+ λ ( {{h^2}(| x | )}/{{{| x | ^2}}} + \\int \\limits _{| x | }^{ + ∞} {{h(s)}/s} {u^2}(s)ds) u = {| u | ^{p - 2}}u,\\quad x\\in R^2, where ω \\in R, λ >0, p>4 and h(s) = 1/2\\int \\limits _0^s {r{u^2}(r)dr} . Combining constraint minimization method and minimax principle, we prove that the problem possesses at least two normalized solutions: One is a ground state and the other is an excited state. Furthermore, the asymptotic behavior and quantitative property of the ground state are analyzed.

Analysis of the dynamic response of a supersonic inlet to flow-field perturbations upstream of the normal shock

NASA Technical Reports Server (NTRS)

Cole, G. L.; Willoh, R. G.

1975-01-01

A linearized mathematical analysis is presented for determining the response of normal shock position and subsonic duct pressures to flow-field perturbations upstream of the normal shock in mixed-compression supersonic inlets. The inlet duct cross-sectional area variation is approximated by constant-area sections; this approximation results in one-dimensional wave equations. A movable normal shock separates the supersonic and subsonic flow regions, and a choked exit is assumed for the inlet exit condition. The analysis leads to a closed-form matrix solution for the shock position and pressure transfer functions. Analytical frequency response results are compared with experimental data and a method of characteristics solution.

Neural control of renal tubular solute and water transport.

PubMed

DiBona, G F

1989-01-01

The neural control of renal tubular solute and water transport is recognized as an important physiological mechanism in the overall regulation of solute and water homeostasis by the mammalian organism. Recent studies have expanded the understanding of this mechanism concerning the transport of diverse solutes with beginning insight into the precise nature of the cellular transport processes involved. The modulatory roles of both circulating and intrarenal hormonal systems on the responses to alterations in the magnitude of efferent renal sympathetic nerve activity are being understood from the nerve terminal release of neurotransmitter to influences on cellular transport processes which determine the overall effect. When dietary sodium intake is normal or only modestly reduced, intact renal innervation is not essential for normal renal sodium conservation. However, when dietary sodium intake is severely restricted, there is maximum engagement of all mechanisms known to participate in renal sodium conservation and, under these conditions, intact renal innervation is essential for normal renal sodium conservation.

pH changes in frog rods upon manipulation of putative pH-regulating transport mechanisms.

PubMed

Kalamkarov, G; Pogozheva, I; Shevchenko, T; Koskelainen, A; Hemila, S; Donner, K

1996-10-01

Rod intracellular pH (pHi) in the intact frog retina was measured fluorometrically with the dye 2',7'-bis(2-carboxyethyl)-5(and-6)-carboxyfluorescein under treatments chosen to affect putative pH-regulating transport mechanisms in the plasma membrane. The purpose was to relate possible pHi changes to previously reported effects on photoresponses. In nominally bicarbonate-free Ringer, application of amiloride (1 mM) or substitution of 95 mM external Na+ by K+ or choline triggered monotonic but reversible acidifications, consistent with inhibition of Na+/H+ exchange. Bicarbonate-dependent mechanisms were characterized as follows: (1) Replacing half of a 12 mM phosphate buffer by bicarbonate caused a sustained rise of pHi. (2) Subsequent application of the anion transport inhibitor 4,4'-diisothiocyanatostilbene-2',2'-disulphonic acid (DIDS, 0.2 mM) set off a slow acidification. (3) Substitution of external Cl- by gluconate (95 mM) caused a rapid pHi rise both in normal Na+ and low-Na+ perfusion. (4) This effect was inhibited by DIDS. The results support a consistent explanation of parallel electrophysiological experiments on the assumption that intracellular acidifications reduce and alkalinizations (in a certain range) augment photoresponses. It is concluded that both Na+/H+ exchange and bicarbonate transport control rod pHi, modulating the light-sensitive current. Part of the bicarbonate transport is by Na(+)-independent HCO3-/Cl- exchange, but a further Na(+)-coupled bicarbonate import mechanism is implicated.

Development of a bioassay system for investigating insulin resistance factors of pregnancy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hausman, D.B.; Singh, R.; Martin, R.J.

1986-03-01

To determine if late-term pregnant serum and/or placenta could induce insulin resistance in normal adipose cells, the authors have developed an insulin sensitive bioassay system. Cells isolated from epididymal fat pads of 250-275 g Sprague Dawley rats are preincubated for 3 hours at 37/sup 0/ in media 199 and serum or placental extract. The cells are washed free of serum and tested for metabolic activity in a 2 hour incubation which measures the conversion of U-/sup 14/C-glucose to /sup 14/CO/sub 2/ and to /sup 14/C-triglyceride fatty acids under basal and insulin stimulated conditions. Maximal insulin responsiveness (350-450% basal for CO/submore » 2/ and 1400-1700% basal for fatty acids) is achieved using Worthington Type II collagenase and a 45-60 minute digestion period for cell isolations and Krebs-Ringer bicarbonate buffer containing 0.5 mM glucose, 2% Armour bovine serum albumin (CRG-7), 1000 ..mu..U/ml insulin and 110,000 to 120,000 cells in the 2 hour incubations. Using this bioasssay system the authors have found that insulin responsiveness, in terms of glucose conversion to fatty acids, is unchanged when cells are preincubated with 5% control pig serum but reduced following preincubation with late pregnant (110 day) pig serum. In future experiments the authors hope to further characterize the factor(s) in pregnant serum responsible for inducing this metabolic effect.« less

Fretting properties of biodegradable Mg-Nd-Zn-Zr alloy in air and in Hank’s solution

NASA Astrophysics Data System (ADS)

Li, Wenting; Li, Nan; Zheng, Yufeng; Yuan, Guangyin

2016-11-01

Fretting is a significant cause for the failure of orthopedic implants. Currently, since magnesium and its alloys have been developed as promising biodegradable implant materials, the fretting behavior of the Mg alloys is of great research significance. In this study, a Mg-Nd-Zn-Zr alloy (hereafter, denoted as JDBM alloy) was selected as experimental material, and its fretting behaviors were evaluated under 5 N, 10 N and 20 N normal loads with a displacement of 200 μm under the frequency of 10 Hz at 37 °C in air and in Hank’s solution, respectively. The results indicated that while the friction coefficient decreased with the increment of the normal load, the wear volume of the alloy increased with the increment of the normal load both in air and in Hank’s solution. Both the friction coefficients and the wear volume of the fretting in Hank’s solution were much lower than those in air environment. The evolution trend of friction coefficients with time had different performance in air environment and the Hank’s solution group. Although oxidation occurred during the fretting tests in Hank’s solution, the damage of JDBM alloy was still reduced due to the lubrication effects of Hank’s solution. Moreover, the addition of Fetal bovine serum (FBS) could act as lubrication and result in the reduction of the fretting damage.

Cutaneous interstitial nitric oxide concentration does not increase during heat stress in humans

NASA Technical Reports Server (NTRS)

Crandall, C. G.; MacLean, D. A.

2001-01-01

Inhibition of cutaneous nitric oxide (NO) synthase reduces the magnitude of cutaneous vasodilation during whole body heating in humans. However, this observation is insufficient to conclude that NO concentration increases in the skin during a heat stress. This study was designed to test the hypothesis that whole body heating increases cutaneous interstitial NO concentration. This was accomplished by placing 2 microdialysis membranes in the forearm dermal space of 12 subjects. Both membranes were perfused with lactated Ringer solutions at a rate of 2 microl/min. In both normothermia and during whole body heating via a water perfused suit, dialysate from these membranes were obtained and analyzed for NO using the chemiluminescence technique. In six of these subjects, after the heat stress, the membranes were perfused with a 1 M solution of acetylcholine to stimulate NO release. Dialysate from these trials was also assayed to quantify cutaneous interstitial NO concentration. Whole body heating increased skin temperature from 34.6 +/- 0.2 to 38.8 +/- 0.2 degrees C (P < 0.05), which increased sublingual temperature (36.4 +/- 0.1 to 37.6 +/- 0.1 degrees C; P < 0.05), heart rate (63 +/- 5 to 93 +/- 5 beats/min; P < 0.05), and skin blood flow over the membranes (21 +/- 4 to 88 +/- 10 perfusion units; P < 0.05). NO concentration in the dialysate did not increase significantly during of the heat stress (7.6 +/- 0.7 to 8.6 +/- 0.8 microM; P > 0.05). After the heat stress, administration of acetylcholine in the perfusate significantly increased skin blood flow (128 +/- 6 perfusion units) relative to both normothermic and heat stress values and significantly increased NO concentration in the dialysate (15.8 +/- 2.4 microM). These data suggest that whole body heating does not increase cutaneous interstitial NO concentration in forearm skin. Rather, NO may serve in a permissive role in facilitating the effects of an unknown neurotransmitter, leading to cutaneous vasodilation during a heat stress.

Cold-induced fluid extravasation during cardiopulmonary bypass in piglets can be counteracted by use of iso-oncotic prime.

PubMed

Farstad, Marit; Kvalheim, Venny Lise; Husby, Paul

2005-08-01

Hypothermic cardiopulmonary bypass is associated with increased fluid extravasation. This study aimed to compare whether iso-oncotic priming solutions, in contrast to crystalloids, could reduce the cold-induced fluid extravasation during cardiopulmonary bypass in piglets. Three groups were studied: the control group (CT group; n = 10), the albumin group (Alb group; n = 7), and the hydroxyethyl starch group (HES group; n = 7). Prime (1000 mL) and supplemental fluid were acetated Ringer solution, 4% albumin, and 6% hydroxyethyl starch, respectively. After 1 hour of normothermic cardiopulmonary bypass, hypothermic cardiopulmonary bypass (cooling to 28 degrees C within 15 minutes) was initiated and continued to 90 minutes. Fluid needs, plasma volume, changes in colloid osmotic pressure in plasma and interstitial fluid, hematocrit levels, and tissue water content were recorded, and protein masses and fluid extravasation rates were calculated. Colloid osmotic pressure in plasma decreased immediately after the start of cardiopulmonary bypass in the CT group but remained stable in the Alb and HES groups. Colloid osmotic pressure in interstitial fluid tended to decrease in the CT group and remained unchanged in the Alb group, whereas a slight increase was observed in the HES group. Immediately after the start of cooling, fluid extravasation rates increased from 0.15 +/- 0.10 to 0.64 +/- 0.12 mL . kg -1 . min -1 in the CT group, whereas no such increase was observed in the Alb and HES groups. The changes in fluid extravasation rates were reflected by corresponding changes in tissue water content. The use of albumin or hydroxyethyl starch as prime to preserve the colloid osmotic pressure during cardiopulmonary bypass causes a reduction in the cold-induced fluid extravasation compared with that seen with crystalloids. Albumin seems more effective than hydroxyethyl starch to limit cold-induced fluid shifts during cardiopulmonary bypass.

Drug loaded biodegradable load-bearing nanocomposites for damaged bone repair

NASA Astrophysics Data System (ADS)

Gutmanas, E. Y.; Gotman, I.; Sharipova, A.; Psakhie, S. G.; Swain, S. K.; Unger, R.

2017-09-01

In this paper we present a short review-scientific report on processing and properties, including in vitro degradation, of load bearing biodegradable nanocomposites as well as of macroporous 3D scaffolds for bone ingrowth. Biodegradable implantable devices should slowly degrade over time and disappear with ingrown of natural bone replacing the synthetic graft. Compared to low strength biodegradable polymers, and brittle CaP ceramics, biodegradable CaP-polymer and CaP-metal nanocomposites, mimicking structure of natural bone, as well as strong and ductile metal nanocomposites can provide to implantable devices both strengths and toughness. Nanostructuring of biodegradable β-TCP (tricalcium phosphate)-polymer (PCL and PLA), β-TCP-metal (FeMg and FeAg) and of Fe-Ag composites was achieved employing high energy attrition milling of powder blends. Nanocomposite powders were consolidated to densities close to theoretical by high pressure consolidation at ambient temperature—cold sintering, with retention of nanoscale structure. The strength of developed nanocomposites was significantly higher as compared with microscale composites of the same or similar composition. Heat treatment at moderate temperatures in hydrogen flow resulted in retention of nanoscale structure and higher ductility. Degradation of developed biodegradable β-TCP-polymer, β-TCP-metal and of Fe-Ag nanocomposites was studied in physiological solutions. Immersion tests in Ringer's and saline solution for 4 weeks resulted in 4 to 10% weight loss and less than 50% decrease in compression or bending strength, the remaining strength being significantly higher than the values reported for other biodegradable materials. Nanostructuring of Fe-Ag based materials resulted also in an increase of degradation rate because of creation on galvanic Fe-Ag nanocouples. In cell culture experiments, the developed nanocomposites supported the attachment the human osteoblast cells and exhibited no signs of cytotoxicity. Interconnected system of nanopores formed during processing of nanocomposites was used for incorporation of drugs, including antibiotics and anticancer drugs, and can be used for loading of bioactive molecules enhancing bone ingrowth.

Effect of adrenaline and alpha-agonists on net rate of liquid absorption from the pleural space of rabbits.

PubMed

Zocchi, L; Raffaini, A; Agostoni, E

1997-05-01

Indirect evidence supporting a solute-coupled liquid absorption from the pleural space of rabbits has recently been provided; moreover, the beta 2-adrenoceptor agonist terbutaline has been found to increase this absorption. In this study the effect of adrenaline and alpha-adrenoceptor agonists on net rate of liquid absorption (Jnet) from albumin Ringer hydrothoraces of various sizes has been determined in anaesthetized rabbits. In hydrothoraces with adrenaline (5 x 10(-6) M) the relationship between Jnet and volume of liquid injected was displaced upwards by 0.09 ml h-1 relative to that in control hydrothoraces (P < 0.01). This displacement did not occur with lower adrenaline concentrations or after pretreatment with the beta-blocker propranolol. Hence, this increase in Jnet is mediated by stimulation of beta-receptors. It seems to be caused by an increase in solute-coupled liquid absorption, since beta-agonists inhibit lymphatic activity while, at relatively high concentrations, they may increase active transport. Conversely, the strong stimulation of lymphatic alpha-receptors that should occur with adrenaline after beta-blockade may fail to increase lymphatic drainage, because it has been shown that the increase in contraction frequency of lymphatics may be balanced by the decrease in their stroke volume. Arterial blood pressure during the hydrothoraces with adrenaline was unchanged. In hydrothoraces with the alpha 2-agonist clonidine (5 x 10(-6) M; a less potent agent than adrenaline) the slope of the relationship between Jnet and volume injected increased by 26% (P < 0.01), while its origin did not change. This increase in slope did not occur with a lower clonidine concentration or after pretreatment with the alpha-blocker phentolamine. Hence, it is caused by stimulation of alpha 2-receptors, which probably lead to an increase in lymphatic drainage related to liquid load. In hydrothoraces with the alpha 1-agonist phenylephrine (5 x 10(-6) or 10(-7) M) Jnet was simlar to control values.

Remediation of Hg(II) from solutions using Cajanus cajan husk as a new sorbent.

PubMed

Devani, Mallappa A; Munshi, Basudeb; Oubagaranadin, John U Kennedy; Lal, Bipin Bihari; Mandal, Sandip

2017-08-01

In this work, biosorption of mercury(II) from solutions by normal and chemically modified husk of Cajanus cajan has been explored under batch conditions. The thermogravimetric analysis of the normal biosorbent showed a surface water loss of 6.56%, 9.26% volatile matter, and 81.81% organic matter. The scanning electron microscope image indicates that the biosorbent exhibited irregular and porous structures. The Fourier transform infra-red spectrum confirmed the presence of functional groups which are responsible for biosorption of mercury (II) from solutions after activation. The influence of initial pH of solutions, initial metal concentrations, and temperature on mercury(II) uptake by the biosorbents was evaluated. The biosorption followed the Langmuir model. Maximum metal uptake was obtained as 68 and 82 mg/g for an initial mercury(II) concentration of 150 mg/L for normal and chemically activated biosorbents, respectively, at a most favorable solution pH of 5.5. The kinetics of sorption obeyed the pseudo-second-order model. An endothermic nature of the biosorption process was observed. A two-stage biosorber reduced the consumption of the biosorbents by 3.49% and 16.52% for 100 and 150 mg/L, respectively. The novelty of the work is C. cajan husk proves to be a potential biosorbent for mercury(II) from solutions.

A Comparison of Vasopressin, Terlipressin, and Lactated Ringers for Resuscitation of Uncontrolled Hemorrhagic Shock in an Animal Model

PubMed Central

Lee, Chien-Chang; Lee, Meng-Tse Gabriel; Chang, Shy-Shin; Lee, Si-Huei; Huang, Yu-Chi; Yo, Chia-Hung; Lee, Shih-Hao; Chen, Shyr-Chyr

2014-01-01

Aim The aim of this study is to compare the effect of lactated ringer (LR), vasopressin (Vaso) or terlipressin (Terli) on uncontrolled hemorrhagic shock (UHS) in rats. Methods 48 rats were divided into four treatment groups for UHS study. Vaso group was given bolus vasopressin (0.8 U/kg); the Terli group was given bolus terlipressin (15 mcg/kg); LR group was given LR and the sham group was not given anything. Mean arterial pressure (MAP), serum lactate level, plasma cytokine levels, lung injury and mortality are investigated for these different treatment groups. Results Compared with LR group, vasopressin and terlipressin-treated groups were associated with higher MAP, lowered mortality rates, less lung injury, lowered serum lactate level, less proinflammatory and more anti-inflammatory cytokine production at certain time points. Comparing between vasopressin and terlipressin treated groups, there is no statistical difference in mortality rates, lung injury, serum lactate level and cytokine level. However, there is a difference in the length of time in maintaining a restored level of MAP (80 to 110 mmHg). The terlipressin treated rats can maintain this restored level of MAP for 45 minutes, but the vasopressin treated rats can only maintain this restored level of MAP for 5 minutes before decreasing gradually to the MAP observed in LR group (40 mmHg). Conclusion Early optimization of hemodynamics with terlipressin or vasopressin in an animal model of UHS was associated with improved hemodynamics and inflammatory cytokine profile than the LR control. Compared with vasopressin, terlipressin has the advantage of ease of use and sustained effects. PMID:24759799

Brain Circuits of Methamphetamine Place Reinforcement Learning: The Role of the Hippocampus-VTA Loop.

PubMed

Keleta, Yonas B; Martinez, Joe L

2012-03-01

The reinforcing effects of addictive drugs including methamphetamine (METH) involve the midbrain ventral tegmental area (VTA). VTA is primary source of dopamine (DA) to the nucleus accumbens (NAc) and the ventral hippocampus (VHC). These three brain regions are functionally connected through the hippocampal-VTA loop that includes two main neural pathways: the bottom-up pathway and the top-down pathway. In this paper, we take the view that addiction is a learning process. Therefore, we tested the involvement of the hippocampus in reinforcement learning by studying conditioned place preference (CPP) learning by sequentially conditioning each of the three nuclei in either the bottom-up order of conditioning; VTA, then VHC, finally NAc, or the top-down order; VHC, then VTA, finally NAc. Following habituation, the rats underwent experimental modules consisting of two conditioning trials each followed by immediate testing (test 1 and test 2) and two additional tests 24 h (test 3) and/or 1 week following conditioning (test 4). The module was repeated three times for each nucleus. The results showed that METH, but not Ringer's, produced positive CPP following conditioning each brain area in the bottom-up order. In the top-down order, METH, but not Ringer's, produced either an aversive CPP or no learning effect following conditioning each nucleus of interest. In addition, METH place aversion was antagonized by coadministration of the N-methyl-d-aspartate (NMDA) receptor antagonist MK801, suggesting that the aversion learning was an NMDA receptor activation-dependent process. We conclude that the hippocampus is a critical structure in the reward circuit and hence suggest that the development of target-specific therapeutics for the control of addiction emphasizes on the hippocampus-VTA top-down connection.

Influence of fluid resuscitation on renal microvascular PO2 in a normotensive rat model of endotoxemia

PubMed Central

Johannes, Tanja; Mik, Egbert G; Nohé, Boris; Raat, Nicolaas JH; Unertl, Klaus E; Ince, Can

2006-01-01

Introduction Septic renal failure is often seen in the intensive care unit but its pathogenesis is only partly understood. This study, performed in a normotensive rat model of endotoxemia, tests the hypotheses that endotoxemia impairs renal microvascular PO2 (μPO2) and oxygen consumption (VO2,ren), that endotoxemia is associated with a diminished kidney function, that fluid resuscitation can restore μPO2, VO2,ren and kidney function, and that colloids are more effective than crystalloids. Methods Male Wistar rats received a one-hour intravenous infusion of lipopolysaccharide, followed by resuscitation with HES130/0.4 (Voluven®), HES200/0.5 (HES-STERIL® ® 6%) or Ringer's lactate. The renal μPO2 in the cortex and medulla and the renal venous PO2 were measured by a recently published phosphorescence lifetime technique. Results Endotoxemia induced a reduction in renal blood flow and anuria, while the renal μPO2 and VO2,ren remained relatively unchanged. Resuscitation restored renal blood flow, renal oxygen delivery and kidney function to baseline values, and was associated with oxygen redistribution showing different patterns for the different compounds used. HES200/0.5 and Ringer's lactate increased the VO2,ren, in contrast to HES130/0.4. Conclusion The loss of kidney function during endotoxemia could not be explained by an oxygen deficiency. Renal oxygen redistribution could for the first time be demonstrated during fluid resuscitation. HES130/0.4 had no influence on the VO2,ren and restored renal function with the least increase in the amount of renal work. PMID:16784545

Is gut the "motor" for producing hepatocellular dysfunction after trauma and hemorrhagic shock?

PubMed

Wang, P; Ba, Z F; Cioffi, W G; Bland, K I; Chaudry, I H

1998-02-01

Although studies suggest that the gut may be the "motor" responsible for producing sepsis and multiple organ failure after injury, it is not known whether enterectomy prior to the onset of hemorrhage alters proinflammatory cytokines TNF and IL-6 and, if so, whether hepatocellular dysfunction and damage are prevented or attenuated under such conditions. Under methoxyflurane anesthesia, an enterectomy in the rat was performed by excision of the duodenum, jejunum, and ileum. The rats were then bled to and maintained at a mean arterial pressure of 40 mm Hg until 40% of the maximal shed volume was returned in the form of Ringer's lactate. The animals were then resuscitated with four times the volume of shed blood with Ringer's lactate over 1 h. At 1.5 h after the completion of resuscitation, hepatocellular function [i.e., the maximal velocity (Vmax) and transport efficiency (Km) of indocyanine green (ICG) clearance] was assessed by an in vivo ICG clearance technique. Blood samples were taken for the measurement of TNF, IL-6, and liver enzymes (i.e., SGPT and SGOT). Cardiac output and microvascular blood flow were determined by ICG dilution and laser Doppler flowmetry, respectively. The increase in circulating levels of TNF but not IL-6 was prevented by enterectomy prior to hemorrhage. The reduced Vmax and K(m) and elevated SGPT and SGOT following hemorrhage and resuscitation, however, were not significantly affected by prior enterectomy. Moreover, enterectomy before hemorrhage further reduced hepatic perfusion. Since enterectomy prior to the onset of hemorrhage does not prevent or attenuate the reduced ICG clearance and elevated liver enzymes despite downregulation of TNF production, it appears that the small intestine does not play a significant role in producing hepatocellular dysfunction and injury following trauma and hemorrhagic shock.

Esophageal Epithelial Resistance and Lower Esophageal Sphincter Muscle Contraction Increase in a Chronic Diabetic Rabbit Model.

PubMed

Capanoglu, Doga; Coskunsever, Deniz; Olukman, Murat; Ülker, Sibel; Bor, Serhat

2016-07-01

Esophageal motility disorders and possibly gastroesophageal reflux disease are common in patients with diabetes mellitus. We aimed to investigate both the electrophysiological characteristics of the esophageal epithelium and the contractility of the lower esophageal sphincter (LES) muscle in alloxane-induced diabetic rabbits. Electrophysiological properties were measured using an Ussing chamber method. An acid-pepsin model was employed with pH 1.7 or weakly acidic (pH 4) Ringer and/or pepsin. Smooth muscle strips of the LES were mounted in an isolated organ bath. Contractile responses to an electrical field stimulation and cumulative concentrations of acetylcholine were recorded. Contractility of the muscle strips were tested in the presence of Rho-kinase inhibitor (Y-27632) and nonspecific nitric oxide inhibitor (L-NAME). The resistance of diabetic tissue perfused in the pH 1.7 Ringer decreased 17 %; pepsin addition decreased it by 49 %. The same concentrations caused a more distinct loss of resistance in the control tissues (22 and 76 %, p < 0.05). The perfusion of tissues in increased concentrations of luminal and serosal glucose did not change the tissue resistance and voltage. Diabetes significantly increased both the electrical field stimulation and acetylcholine-induced contractions in the LES muscle strips (p < 0.01). Incubation with Y-27632 significantly decreased the acetylcholine-induced contractions in a concentration-dependent manner (p < 0.01). The acid-pepsin model in the diabetic rabbit esophageal tissue had less injury compared with the control. The diabetic rabbit LES muscle had higher contractility, possibly because of the activation of the Rho-Rhokinase pathway. Our results show that in a chronic diabetic rabbit model the esophagus resists reflux by activating mechanisms of mucosal defense and increasing the contractility of the LES.

Mean flow generation mechanism by inertial waves and normal modes

NASA Astrophysics Data System (ADS)

Will, Andreas; Ghasemi, Abouzar

2016-04-01

The mean flow generation mechanism by nonlinearity of the inertial normal modes and inertial wave beams in a rotating annular cavity with longitudinally librating walls in stable regime is discussed. Inertial normal modes (standing waves) are excited when libration frequency matches eigenfrequencies of the system. Inertial wave beams are produced by Ekman pumping and suction in a rotating cylinder and form periodic orbits or periodic ray trajectories at selected frequencies. Inertial wave beams emerge as concentrated shear layers in a librating annular cavity, while normal modes appear as global recirculation cells. Both (inertial wave beam and mode) are helical and thus intrinsically non-linear flow structures. No second mode or wave is necessary for non-linearity. We considered the low order normal modes (1,1), (2,1) and (2,2) which are expected to be excited in the planetary objects and investigate the mean flow generation mechanism using two independent solutions: 1) analytical solution (Borcia 2012) and 2) the wave component of the flow (ω0 component) obtained from the direct numerical simulation (DNS). It is well known that a retrograde bulk mean flow is generated by the Ekman boundary layer and E1/4-Stewartson layer close to the outer cylinder side wall due to libration. At and around the normal mode resonant frequencies we found additionally a prograde azimuthal mean flow (Inertial Normal Mode Mean Flow: INMMF) in the bulk of the fluid. The fluid in the bulk is in geostrophic balance in the absence of the inertial normal modes. However, when INMMF is excited, we found that the geostrophic balance does not hold in the region occupied by INMMF. We hypothesize that INMMF is generated by the nonlinearity of the normal modes or by second order effects. Expanding the velocity {V}(u_r,u_θ,u_z) and pressure (p) in a power series in ɛ (libration amplitude), the Navier-Stokes equations are segregated into the linear and nonlinear parts at orders ɛ1 and ɛ^2, respectively. The former is used to find the analytical solution of the normal modes (Borcia 2012). Plugging two independent solutions into the latter we investigate the generation mechanism of INMMF. We found R1^1=overbar{partial_z(u_r1 u_z^1)}, R2^1=overbar{partial_r(u_r1 u_r^1)} as source terms responsible for the generation of INMMF. The helical structure of the inertial waves causes the nonlinear terms R1 and R2 to be nonzero, contributing to the generation of INMMF. We used u_ra and u_za obtained from the analytical solution (Borcia 2012) and computed the source terms R1a and R2a and found a structural correspondence with the corresponding field computed from the DNS solution for the three normal modes investigated. The sum of R11 and R21 exhibits a good structural correspondence with INMMF. Interestingly, INMMF magnitude depends on the inertial wave beams and normal modes. For instance we found that INMMF is generated more efficiently for the libration frequency ω=1.58, although the resonant frequency is predicted by the analytical solution to be at ω=1.576 (normal mode (2,1)). Separating the inertial wave beams from the flow field obtained by DNS, using the analytical normal mode solution, we explored the phase lag between inertial wave beams and normal mode. We inferred that the normal mode amplitude is high only if the phase lag between the inertial wave beam and the normal mode is predominantly positive. In this case a high amplitude INMMF amplitude can be found. This supports the hypothesis that the normal modes are generated by the inertial wave beam in analogy to resonant forcing in classical mechanics. Interestingly, the 'optimum' phase lag found is much smaller than π/2. {Acknowledgement:} This work is a part of the project "Mischung und Grundstromanregung durch propagierende Trgheitswellen: Theorie, Experiment und Simulation" supported by the German Science Foundation (DFG). We would like to thank M. Klein, U. Harlander, I. Borcia and E. Schaller for helpful discussions and invaluable contributions. {References:} Borcia, I. D. & Harlander, U. 2012 Inertial waves in a rotating annulus with inclined inner cylinder: comparing the spectrum of wave attractor frequency bands and the eigenspectrum in the limit of zero inclination. Theor. Comput. Fluid Dyn. 27, 397-413.

The Effect of Hydroxyapatite Coatings on the Passivation Behavior of Oxidized and Unoxidized Superelastic Nitinol Alloys

NASA Astrophysics Data System (ADS)

Etminanfar, M. R.; Khalil-Allafi, J.; Sheykholeslami, S. O. R.

2018-02-01

Nitinol alloys have been used in various biological applications due to their superior properties. In this study, a bipolar pulsed current electrodeposition technique was applied to produce a hydroxyapatite (HA) film on the Nitinol alloy. Also, the protection performance of the coating was evaluated on both abraded and thermochemically modified alloy. According to obtained data, reducing the electrocrystallization rate by the pulse deposition technique can promote HA formation on both abraded and modified substrates. Based on scanning electron microscopy and high-resolution transmission electron microscopy data, the HA coatings revealed a flake-like morphology and each flake was composed of nano-crystalline grains. Atomic force microscopy images revealed that flakes on the abraded substrate were smaller in size than that of the modified alloy. Comparing the corrosion resistance of the bare substrates revealed that the modified alloy has a higher corrosion resistance than the abraded alloy and the modified surface is well passivized during anodic polarization in Ringer's solution. However, this condition is reversed after the deposition of HA film. It seems that because of the lower crystallization sites on the abraded alloy, the produced HA film is denser and more protective against the corrosive mediums as compared to the coating on the modified alloy. Although the HA coating can improve the bioactivity of both substrates, the resulted film on the oxidized alloy is porous and deteriorates the implant permanence in the vicinity of body fluids.

The perfused swine uterus model: long-term perfusion

PubMed Central

2012-01-01

Background It has previously been shown that the viability of swine uteri can be maintained within the physiological range in an open perfusion model for up to 8 hours. The aim of this study was to assess medium- to long-term perfusion of swine uteri using a modified Krebs–Ringer bicarbonate buffer solution (KRBB) in the established open perfusion model. Methods In an experimental study at an infertility institute, 30 swine uteri were perfused: group 1: n = 11, KRBB; group 2: n = 8, modified KRBB with drainage of perfusate supernatant; group 3: n = 11, modified KRBB with drainage of perfusate every 2 h and substitution with fresh medium. Modified and conventional KRBB were compared with regard to survival and contraction parameters: intrauterine pressure (IUP), area under the curve (AUC), and frequency of contractions (F). Results Modified KRBB showed significantly higher IUP, AUC, and F values than perfusion with conventional KRBB. In group 3, the organ survival time of up to 17 h, with a 98% rate of effective contraction time, differed significantly from group 1 (P < 0.001). Conclusions Using modified KRBB in combination with perfusate substitution improves the open model for perfusion of swine uteri with regard to survival time and quality of contraction parameters. This model can be used for medium- to long-term perfusion of swine uteri, allowing further metabolic ex vivo studies in a cost-effective way and with little logistic effort. PMID:23241226

Hypertonic 15% sodium pyruvate offers no initial resuscitation advantage compared with 8% hypertonic NACl in sheep with multiple hemorrhages.

PubMed

do Nascimento, Paulo; Vaid, Sumreen U; Hoskins, Stephen L; Espana, Jonathan M; Kinsky, Michael P; Kramer, George C

2007-05-01

Initial fluid resuscitation of hemorrhagic shock might be enhanced by the infusion of monocarboxylate-energy substrates. We evaluated hemodynamics, metabolism, and fluid dynamics for initial resuscitation of hemorrhage using small volume 15% sodium pyruvate solution (HPY) compared with osmotically matched 8% hypertonic saline (HS). Instrumented conscious sheep were hemorrhaged 25 mL/kg at time zero through 15 min (T0-T15) and 5 mL/kg for 5 min at T50 to T55 and T70 to T75. Fluid resuscitation from T30 to T180 was performed by a computer-controlled closed-loop system, which titrated infusion rate to a mean arterial pressure of 90 mmHg. Initial infusion was 4 mL/kg of either HPY or HS, followed by the administration of lactated Ringer. Both HPY and HS restored cardiac index similarly. The lactate/pyruvate ratio was used to assess metabolic debt and was significantly higher (T180), whereas oxygen delivery was significantly lower (T120) with HPY versus HS. Total fluid administered was similar, with 43.7 +/- 6.2 mL/kg for HPY and 39.4 +/- 6.8 mL/kg for HS. Plasma volume was similarly increased and approached baseline values for both groups. Initial resuscitation with small volume HPY offered no hemodynamic or metabolic advantage compared with small volume HS when the fluids were infused to an end point pressure.

Small intestine mucosal adhesivity to in vivo capsule robot materials.

PubMed

Terry, Benjamin S; Passernig, Anna C; Hill, Morgan L; Schoen, Jonathan A; Rentschler, Mark E

2012-11-01

Multiple research groups are investigating the feasibility of miniature, swallowable, in vivo, untethered robots that are capable of traversing the small intestine for the purpose of acquiring biometrics and performing simple surgical procedures. A mathematical model of the intraluminal environment will speed the development of these so-called Robotic Capsule Endoscopes (RCEs), and to this end, the authors, in previous work, initiated a comprehensive program for characterizing both the active and passive forces exerted by the small intestine on an RCE-sized solid bolus. In this work, forces due to adhesivity between RCE materials and the mucosa are investigated. The experimental factors are adhesive modality (peel and tack), material (polycarbonate, micropatterned polydimethylsiloxane, stainless steel, and mucosa), and bowel region (proximal, middle, and distal). The mucosa is excised from a fasting pig, stored in lactated ringer's solution at 3 °C, and then tested at room temperature within 43 h of excision. The results show the mean tack strength of the mucosa to engineering materials was 0.198±0.070 mJ cm⁻². The mean peel strength was 0.055±0.016 mJ cm⁻². This study marks the first time, to the authors' knowledge, that adhesivity between small intestinal mucosa and RCE engineering materials has been measured. The adhesivity values acquired from this study will provide a valuable input into analytical and numerical models of the gastrointestinal tract, specifically models that account for the interfacial properties of the tissue. Copyright © 2012 Elsevier Ltd. All rights reserved.

Physiological characterization of a mouse model of cachexia in colorectal liver metastases.

PubMed

Murphy, Kate T; Struk, Adam; Malcontenti-Wilson, Cathy; Christophi, Christopher; Lynch, Gordon S

2013-05-15

Loss of skeletal muscle mass and function (cachexia) is severe in patients with colorectal liver metastases because of the large increase in resting energy expenditure but remains understudied because of a lack of suitable preclinical models. Our aim was to characterize a novel preclinical model of cachexia in colorectal liver metastases. We tested the hypothesis that mice with colorectal liver metastases would exhibit cachexia, as evidenced by a reduction in liver-free body mass, muscle mass, and physiological impairment. Twelve-week-old male CBA mice received an intrasplenic injection of Ringer solution (sham) or murine colorectal cancer cells (MoCR) to induce colorectal liver metastases. At end-point (20-29 days), the livers of MoCR mice were infiltrated completely with metastases, and MoCR mice had reduced liver-free body mass, muscle mass, and epididymal fat mass compared with sham controls (P < 0.03). MoCR mice exhibited impaired rotarod performance and grip strength (P < 0.03). Histochemical analyses of tibialis anterior muscles from MoCR mice revealed muscle fiber atrophy and reduced oxidative enzyme activity (P < 0.001). Adipose tissue remodeling was evident in MoCR mice, with reduced adipocyte diameter and greater infiltration of nonadipocyte tissue (P < 0.05). These findings reveal the MoCR mouse model exhibits significant cachexia and is a suitable preclinical model of cachexia in colorectal liver metastases. This model should be used for identifying effective treatments for cachexia to improve quality of life and reduce mortality in patients with colorectal liver metastases.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rapoport, J.; Abuful, A.; Chaimovitz, C.

Urea is actively transported inwardly (J{sub i}) across the skin of the green toad Bufo viridis. J{sub i} is markedly enhanced in toads adapted to hypertonic saline. The authors studied urea transport across the skin of Bufo viridis under a variety of experimental conditions, including treatment with amiloride and phloretin, agents that inhibit urea permeability in the bladder of Bufo marinus. Amiloride (10{sup {minus}4} M) significantly inhibited J{sub i} in both adapted and unadapted animals and was unaffected by removal of sodium from the external medium. Phloretin (10{sup {minus}4} M) significantly inhibited J{sub i} in adapted animals by 23-46%; theremore » was also a reduction in J{sub i} in unadapted toads at 10{sup {minus}4} and 5 {times} 10{sup {minus}4} M phloretin. A dose-response study revealed that the concentration of phloretin causing half-maximal inhibition (K{sub {1/2}}) was 5 {times} 10{sup {minus}4} M for adapted animals. J{sub i} was unaffected by the substitution of sucrose for Ringer solution or by ouabain. They conclude (1) the process of adaptation appears to involve an increase in the number of amiloride- and phloretin-inhibitable urea transport sites in the skin, with a possible increase in the affinity of the sites for phloretin; (2) the adapted skin resembles the Bufo marinus urinary bladder with respect to amiloride and phloretin-inhibitable sites; (3) they confirm earlier observations that J{sub i} is independent of sodium transport.« less

Assessing intravascular volume by difference in pulse pressure in pigs submitted to graded hemorrhage.

PubMed

Pestel, Gunther J; Hiltebrand, Luzius B; Fukui, Kimiko; Cohen, Delphine; Hager, Helmut; Kurz, Andrea M

2006-10-01

We assessed changes in intravascular volume monitored by difference in pulse pressure (dPP%) after stepwise hemorrhage in an experimental pig model. Six pigs (23-25 kg) were anesthetized (isoflurane 1.5 vol%) and mechanically ventilated to keep end-tidal CO2 (etCO2) at 35 mmHg. A PA-catheter and an arterial catheter were placed via femoral access. During and after surgery, animals received lactated Ringer's solution as long as they were considered volume responders (dPP>13%). Then animals were allowed to stabilize from the induction of anesthesia and insertion of catheters for 30 min. After stabilization, baseline measurements were taken. Five percent of blood volume was withdrawn, followed by another 5%, and then in 10%-increments until death from exsanguination occurred. After withdrawal of 5% of blood volume, all pigs were considered volume responders (dPP>13%); dPP rose significantly from 6.1+/-3.3% to 19.4+/-4.2%. The regression analysis of stepwise hemorrhage revealed a linear relation between blood loss (hemorrhage in %) and dPP (y=0.99*x+14; R2=0.7764; P<.0001). In addition, dPP was the only parameter that changed significantly between baseline and a blood loss of 5% (P<0.01), whereas cardiac output, stroke volume, heart rate, MAP, central venous pressure, pulmonary artery occlusion pressure, and systemic vascular resistance, respectively, remained unchanged. We conclude that in an experimental hypovolemic pig model, dPP correlates well with blood loss.

Greater resistance and lower contribution of free radicals to hypoxic neurotoxicity in immature rat brain compared to adult brain as revealed by dynamic changes in glucose metabolism.

PubMed

Maruoka, N; Murata, T; Omata, N; Fujibayashi, Y; Waki, A; Yoshimoto, M; Yano, R; Yonekura, Y; Wada, Y

2001-01-01

Seven-day-old rat brain slices were incubated at 36C in oxygenated Krebs-Ringer solution containing [(18)F]2-fluoro-2-deoxy-D-glucose ([(18)F]FDG), and serial two-dimensional time-resolved images of [(18)F]FDG uptake by the slices were obtained. The Gjedde-Patlak graphical method was applied to the image data, and the duration limit of hypoxia loading that allowed recovery of the fractional rate constant (k3*) of [(18)F]FDG (proportional to the cerebral glucose metabolic rate) after hypoxia loading to the unloaded control level was 50 min, and MK-801 as an N-methyl-D-aspartate antagonist had neuroprotective effects, but PBN as a free radical scavenger was ineffective. In our previous study in adult (7-week-old) rat brains [Murata et al., Exp Neurol 2000, 164:269-279], the limit of the hypoxia loading time was 20 min, and both MK-801 and PBN were effective. In the immature rat brains, the ratio of aerobic glucose metabolism to the total glucose metabolism was low compared with the adult rat brains, suggesting only a slight involvement of free radicals in hypoxic neurotoxicity. These data suggest that the higher resistance of immature brains to hypoxia compared to that of adult brains is attributable to a lower involvement of free radicals due to a lower aerobic glucose metabolic rate. Copyright 2002 S. Karger AG, Basel

[A case of minoxidil intoxication].

PubMed

Takahashi, Tetsuya; Takei, Tetsuhiro; Ito, Toshitaka; Sakamoto, Kazunari; Nara, Takeshi; Yagi, Keiichi

2014-09-01

A 26-year-old man was found unable to move after oral consumption of 120 mL of RiUP X5® (containing 5 g/100 mL minoxidil) as a suicidal attempt. The patient complaining of frequent vomiting and weakness was transferred to our hospital. Findings on arrival: GCS E4V5M6; respiratory rate 24/ min; blood pressure 83/43 mmHg; pulse 152/min, regular; SpO₂97% (oxygen by mask: 6 L/min); thus, the patient was in shock. The systolic blood pressure and the pulse rate improved to about 90 mmHg and to about 130/min, respectively, in response to rapid intravenous infusion of 2,000 mL of lactated Ringer's solution. His circulatory condition tended to improve with parenteral fluid infusion alone. Forty hours after admission, however, heart failure developed due to excessive I.V. fluid infusion and abnormal body fluid distribution associated with delayed vascular smooth muscle relaxation; therefore, mechanical ventilation was initiated. Simultaneously, intravenous noradrenaline infusion was started because of a fall of the blood pressure. Subsequently, as the patient's respiratory and circulatory conditions gradually improved, he was weaned from mechanical ventilation, and the noradrenaline infusion was discontinued at 108 hours after admission. The patient made favorable progress and was discharged home on the 9th hospital day. Minoxidil exerts adverse effects mainly on the cardiovascular system. Since minoxidil is an over-the-counter drug readily available to the public, and emergency physicians should be aware of its severe toxicity.

Effect of heat-assisted pulsed electric fields and bacteriophage on enterohemorrhagic Escherichia coli O157:H7.

PubMed

Walkling-Ribeiro, Markus; Anany, Hany; Griffiths, Mansel W

2015-01-01

Pulsed electric fields (PEF), heat-assisted PEF (H-PEF), and virulent bacteriophage (VP) are non-thermal techniques for pathogen inactivation in liquids that were investigated individually, and in combination (PEF/VP, H-PEF/VP) to control enterohemorrhagic Escherichia coli (EHEC) O157:H7 in Luria-Bertani broth (LBB) and Ringer's solution (RS). Treated cells were subsequently incubated at refrigeration (4°C) and temperature-abuse conditions (12°C) for 5 days. When EHEC cells grown in LBB were subjected to non-thermal processing and subsequently stored at 12°C for 5 days, reductions in count of between 0.1 and 0.6 log cycles were observed and following storage at 4°C the decrease in counts varied between 0.2 and 1.1 log10 . For bacteria cells suspended in RS values ranged from 0.1 to ≥3.9 log cycles at both storage temperatures. The most effective treatments were H-PEF and H-PEF/VP, both producing a >3.4 log cycle reduction of cells suspended in non-nutrient RS. Analysis of EHEC recovery on selective and non-selective media indicated no occurrence of sub-lethal damage for VP, PEF/VP, and H-PEF/VP-treated cells. The findings indicate that combining PEF and lytic phage may represent a suitable alternative to conventional fluid decontamination following further process optimization. © 2014 American Institute of Chemical Engineers.

Effects of in vitro hemodilution with crystalloids, colloids, and plasma on canine whole blood coagulation as determined by kaolin-activated thromboelastography.

PubMed

Morris, Bari R; deLaforcade, Armelle; Lee, Joyce; Palmisano, Joseph; Meola, Dawn; Rozanski, Elizabeth

2016-01-01

To investigate the effects of in vitro hemodilution with lactated Ringers solution (LRS), hetastarch (HES), and fresh frozen plasma (FFP) on whole blood coagulation in dogs as assessed by kaolin-activated thromboelastography. In vitro experimental study. University teaching hospital. Six healthy client-owned dogs. Whole blood was collected and diluted in vitro at a 33% and 67% dilution with either LRS, HES, or FFP. Kaolin-activated thromboelastography was performed on each sample as well as a control. Thromboelastographic parameters R (min), alpha (deg), K (min), and MA (mm) were measured and compared to the sample control for each dilution using mixed model methodology. Prolongation in coagulation times were seen at both dilutions with LRS and HES. There was no significant difference in R times at the 33% dilution, but R time was significantly prolonged at the 67% dilution with HES (P = 0.004). MA was significantly decreased for LRS at both dilutions (P = 0.013, P < 0.001) and more profoundly decreased for HES (P < 0.001, P = 0.006). No significant difference in any parameter was found for FFP. In vitro hemodilution of whole blood with both LRS and HES but not FFP resulted in significant effects on coagulation with HES having a more profound effect. In vivo evaluation of changes in coagulation with various resuscitation fluids is warranted and may be clinically relevant. © Veterinary Emergency and Critical Care Society 2015.

Effect of hydration on spontaneous labor outcomes in nulliparous pregnant women: a multicenter randomized controlled trial comparing three methods.

PubMed

Edwards, Rodney K; Reed, Christine A; Villano, Kathryn S; Holmes, Jennifer L; Tong, Suhong; Davies, Jill K

2014-06-01

To evaluate the effect of mode and amount of fluid hydration during labor. The authors conducted a randomized controlled trial of uncomplicated nulliparous women in spontaneous labor at 36 weeks or more gestational age. Women were randomized to receive lactated Ringer solution with 5% dextrose at (1) 125 mL/h intravenously with limited oral intake, (2) 250 mL/h intravenously with limited oral intake, or (3) 25 mL/h intravenously with ad libitum oral intake of clear liquids. Results were analyzed by intent-to-treat analysis. A total of 311 out of 324 women were available for analysis. Groups 1 (n = 105), 2 (n = 105), and 3 (n = 101) above did not differ significantly for mean labor duration (11.6 ± 5.9, 11.4 ± 5.5, and 11.5 ± 5.9 hours, respectively; p = 0.998), proportion of women in labor > 12 hours (all groups 41%; p = 0.998), proportion receiving oxytocin augmentation (59, 60, and 57%, respectively; p = 0.923), or proportion delivered by cesarean (22, 17, and 17%, respectively; p = 0.309). Indications for cesarean were similar between groups. No cases of pulmonary edema, maternal aspiration, or perinatal mortality occurred. Although apparently safe, neither increased intravenous hydration nor oral hydration during labor improves labor performance. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

[Perioperative management of a child with central diabetes insipidus who underwent two surgeries before and after desmopressin administration].

PubMed

Kiriyama, Keiji; Tachibana, Kazuya; Nishimura, Nobuyuki; Takeuchi, Muneyuki; Kinouchi, Keiko

2013-03-01

A 14-year-old girl weighing 32 kg was diagnosed with suprasellar tumor causing hydrocephalus, hypothyroidism, adrenal dysfunction and central diabetes insipidus. She was treated with levothyroxine and hydrocortisone and urged to take fluid to replace urine. She was scheduled to undergo ventricular drainage to relieve hydrocephalus prior to tumor resection. For the first surgery, desmopressin was not started and urine output reached 4,000 to 6,000 ml x day(-1), urine osmolality 64 mOsm x l(-1) and urine specific gravity 1.002. Anesthesia was induced with sevoflurane and maintained with propofol and remifentanil. Maintenance fluid was with acetated Ringer's solution and urine loss was replaced with 5% dextrose. Bradycardia and hypotension occurred after intubation, which was treated with volume load. Infusion volume was 750 ml and urine output was 1100 ml during 133 min of anesthesia. Postoperative day 1 nasal desmopressin was started. Ten days later, partial tumor resection was performed. Anesthesia was induced with propofol and fentanyl and maintained with sevoflurane and remifentanil. Infusion volume was 610 ml, urine output 380 ml, and blood loss 151 ml during 344 min of anesthesia. Hemodynamic parameters were stable throughout the procedure. Pathology of the tumor was revealed to be germinoma. Bradycardia and hypotension experienced during the first surgery was suspected to be caused by preoperative hypovolemia brought by polyuria. Desmopressin was proved to be effective to treat excessive urine output and to maintain good perioperative water balance.

Effects of 5,7-DHT Injection into the Optic Lobe on the Circadian Locomotor Rhythm in the Cricket, Gryllus bimaculatus.

PubMed

Germ, M; Tomioka, K

1998-06-01

The effect of direct 5,7-dihydroxytryptamine (5,7-DHT) injection into the medulla region of the optic lobe on the locomotor activity was investigated in the adult male cricket, Gryllus bimaculatus. After a 6 hr phase advance of a light-dark cycle, the 5,7-DHT injected animals needed significantly longer time for resynchronization to the new cycle (6.55 +/- 0.62 days) than the control, Ringer's solution injected animals (3.17 +/- 0.15 days; P < 0.001, t-test). Light induced a bout of activity (i.e., masking effect) when light-dark cycle was phase advanced by 6 hr and the duration of the masking effect was significantly longer in 5,7-DHT injected animals. An initial bout of the nocturnal activity was significantly greater in the 5,7-DHT injected animal. Under constant darkness, the freerunning periods of both groups were not significantly different. Under constant light, a significantly higher percentage of 5,7-DHT injected animals showed arrhythmicity compared with the control group. An analysis carried by high-pressure liquid chromatography with electro-chemical detection (HPLC-ECD) revealed that the serotonin content in the optic lobe was significantly reduced to less than 50% in the 5,7-DHT injected animals, even one month after the injection. These results suggest that serotonin plays important roles in the regulation of circadian locomotor rhythms of the cricket mainly by regulating the sensitivity of the photoreceptive system.

Microstructure and network organization of the microvasculature in the human macula.

PubMed

Yu, Paula K; Balaratnasingam, Chandrakumar; Cringle, Stephen J; McAllister, Ian L; Provis, Jan; Yu, Dao-Yi

2010-12-01

To characterize the topography and cellular structure of the macular microvasculature using a recently developed technique of arterial cannulation, perfusion, fixation, and staining of human donor eyes. Sixteen human donor eyes were used. The central retinal artery was cannulated and perfused with Ringer's, then fixative, membrane permeabilizing, and selected labeling solutions. The eyes were immersion fixed, and the retina was flat mounted for confocal microscopy. The macular area, including the foveola, fovea, and parafovea, was sampled. The intracellular cytoskeleton of vascular endothelial and smooth muscle cells was studied in different orders of arterioles and venules and in the capillaries. To evaluate the degree of asymmetry within vascular networks, the distribution of generation numbers and the Horton-Strahler approach to vessel naming were compared. The distribution of the microvascular network in the macular region was complex but followed a general theme. The parafoveal region was supplied by dense vasculature with approximately nine closely arranged pairs of arterioles and venules. Each arteriole had abundant branches and a high degree of asymmetry (∼10 generations and 3.5 orders within 1.2-mm length). Only a few arterioles (average ∼2.9) supplied the terminal capillary ring. Very long spindle endothelial cells were seen in the superficial and deep capillaries. Significant heterogeneity of distribution and shape of the endothelial and smooth muscle cells was evident in different orders of the macular vasculature. The authors have demonstrated for the first time the cellular structure and topographic features of the macular microvasculature in human donor eyes.

Fluid balance, glomerular filtration rate, and urine output in dogs anesthetized for an orthopedic surgical procedure.

PubMed

Boscan, Pedro; Pypendop, Bruno H; Siao, Kristine T; Francey, Thierry; Dowers, Kristy; Cowgill, Larry; Ilkiw, Jan E

2010-05-01

To determine fluid retention, glomerular filtration rate, and urine output in dogs anesthetized for a surgical orthopedic procedure. 23 dogs treated with a tibial plateau leveling osteotomy. 12 dogs were used as a control group. Cardiac output was measured in 5 dogs, and 6 dogs received carprofen for at least 14 days. Dogs received oxymorphone, atropine, propofol, and isoflurane for anesthesia (duration, 4 hours). Urine and blood samples were obtained for analysis every 30 minutes. Lactated Ringer's solution was administered at 10 mL/kg/h. Urine output was measured and glomerular filtration rate was estimated. Fluid retention was measured by use of body weight, fluid balance, and bioimpedance spectroscopy. No difference was found among control, cardiac output, or carprofen groups, so data were combined. Median urine output and glomerular filtration rate were 0.46 mL/kg/h and 1.84 mL/kg/min. Dogs retained a large amount of fluids during anesthesia, as indicated by increased body weight, positive fluid balance, increased total body water volume, and increased extracellular fluid volume. The PCV, total protein concentration, and esophageal temperature decreased in a linear manner. Dogs anesthetized for a tibial plateau leveling osteotomy retained a large amount of fluids, had low urinary output, and had decreased PCV, total protein concentration, and esophageal temperature. Evaluation of urine output alone in anesthetized dogs may not be an adequate indicator of fluid balance.

Experimental dissociation of the effects of prostaglandins on renal sodium and water reabsorption by cyclo-oxygenase inhibitors in the rat.

PubMed

Bartoli, E; Branca, G F; Faedda, R; Olmeo, N A; Satta, A; Soggia, G

1982-07-01

1 The relative importance of the effect of prostaglandins on renal sodium and water reabsorption was assessed in rats. 2 Clearance experiments were performed on 24 anaesthetized rats divided into 3 groups. Each group was infused throughout either with Ringer solution at 9 ml/h (Protocol I), or at 3 ml/h (Protocol II) or with hypotonic fluid at 5 ml/h (Protocol III). Clearance periods were performed before and after intravenous injection of indomethacin (5 mg/kg) and then of aspirin (20 mg/kg). The natriuretic response to different degrees of volume expansion was not modified during the action of the inhibitors. 3 When baseline urine osmolality (Uosm) was high (Protocol II) no further increase occurred in the presence of prostaglandin inhibition. Conversely, Uosm rose from 771 +/- 134 to 1356 +/- 414 and from 575 +/- 245 to 841 +/- 407 mosm/kg (P less than 0.05) in Protocol I and Protocol III respectively, when antidiuretic hormone secretion was inhibited by the higher degree of volume expansion. 4 There was a significant correlation between the change in urine flow rate induced by cyclooxygenase inhibitors and the attendant variations in Na excretion, r = 0.42, n = 41, P less than 0.01. 5 Thus, prostaglandins affect Na loss during saline load as a side effect of their action on water permeability. They could play an important role in volume depletion by counterbalancing the large secretion rate of renal vasoconstrictors.

The effect of nonablative laser energy on joint capsular properties. An in vitro histologic and biochemical study using a rabbit model

NASA Technical Reports Server (NTRS)

Hayashi, K.; Thabit, G. 3rd; Vailas, A. C.; Bogdanske, J. J.; Cooley, A. J.; Markel, M. D.

1996-01-01

The purpose of this study was to evaluate the effect of laser energy at nonablative levels on joint capsular histologic and biochemical properties in an in vitro rabbit model. The medial and lateral portions of the femoropatellar joint capsule from both stifles of 12 mature New Zealand White rabbits were used. Specimens were divided into three treatment groups (5 watts, 10 watts, and 15 watt) and one control group using a randomized block design. Specimens were placed in a 37 degrees bath of lactated Ringer's solution and laser energy was applied using a holmium:yttrium-aluminum-garnet laser in four transverse passes across the tissue at a velocity of 2 mm/sec with the handpiece set 1.5 mm from the synovial surface. Histologic analysis revealed thermal alteration of collagen (fusion) and fibroblasts (pyknosis) at all energy densities, with higher laser energy causing significantly greater morphologic changes over a larger area (P < 0.05). Application of laser energy did not significantly alter the biochemical parameters evaluated, including type I collagen content and nonreducible crosslinks (P > 0.05). This study demonstrated that nonablative laser energy caused significant thermal damage to the joint capsular tissue in an energy-dependent fashion, but type I collagen content and nonreducible crosslinks (P > 0.05). This study demonstrated that nonablative laser energy caused significant thermal damage to the joint capsular tissue in an energy-dependent fashion, but type I Collagen content and nonreducible corsslinks were not significantly altered.

Effects of olsalazine in the jejunum of the rat.

PubMed Central

Mohsen, A Q; Mulvey, D; Priddle, J D; Parsons, D S; Jewell, D P

1987-01-01

Olsalazine (ADS) is the azo-linked dimer of 5-aminosalicylic acid (5-ASA). It is of value for the management of patients with ulcerative colitis but may be associated with increasing diarrhoea in a few. This study examines the effect of 5-ASA and ADS on small intestinal transport systems of the rat. Krebs-Ringer-bicarbonate solution was circulated through the lumen of a jejunal segment and the appearance of fluid, glucose and lactate on the serosal surface was shown to be linear over a two hour period. Addition of 5-ASA (10 mmol/l) or ADS (5 mmol/l and 10 mmol/l) caused a significant inhibition both of fluid transport (p less than 0.001), and of the appearance of glucose (p less than 0.001) and lactate (p less than 0.001 for 5 mmol/l and 10 mmol/l ADS, p less than 0.01 for 10 mmol/l 5-ASA). The uptake of glucose by rings of rat jejunum was shown to be markedly reduced by ADS. Experiments substituting glucose with either sucrose of 2-aminoisobutyric acid showed that ADS (5 mmol/l, 10 mmol/l) also inhibited the serosal appearance of fructose and the amino acid. These results show that 5-ASA and ADS, at concentrations which could be expected in the jejunum of patients receiving therapeutic doses, are able to inhibit small intestinal transport systems. The resulting increase in load on the diseased colon could be important for the pathogenesis of diarrhoea. PMID:3570038

Novel findings in the management of acute pancreatitis.

PubMed

Bolado, Federico; de-Madaria, Enrique

2016-09-01

Acute pancreatitis (AP) is a potentially serious disease whose incidence is on the increase. Pancreas divisum does not meet the required criteria to be considered an aetiological factor. Sphincter of Oddi dysfunction may be another cause of idiopathic AP. Less invasive methods cannot replace Sphincter of Oddi manometry in diagnosis. Almost half of patients with systemic inflammatory response syndrome develop organ failure, but the mechanisms involved are not completely understood. Obesity is a risk factor for severity in AP; the cause could be the presence of free unsaturated fatty acids, which have pro-inflammatory activity. Prognosis is better in patients with isolated extra-pancreatic necrosis than in those with parenchymal necrosis or with both. The mortality rate among those with infected pancreatic necrosis is 15-20%. The "moderately severe" group is widely heterogeneous and this category may require redefinition. Laparoscopic treatment of pseudocysts is an alternative to endoscopic drainage and could be the first-line option in patients requiring cholecystectomy. The use of lumen-apposing metal stents to treat pancreatic necrosis is cost-effective. Quality of life in some patients following an attack of AP is significantly impaired even at 1 year. Aggressive fluid therapy is not superior to standard fluid therapy in preventing post-ERCP AP. The role of statins in AP prevention is still unclear. Aggressive fluid resuscitation and the use of lactated Ringer solution seem to be beneficial in the treatment of AP. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

Caffeine-induced [Ca2+] oscillations in neurones of frog sympathetic ganglia

PubMed Central

Cseresnyés, Zoltán; Bustamante, Alexander I; Schneider, Martin F

1999-01-01

Single cell fluorimetry was used to monitor caffeine-induced oscillations of cytosolic [Ca2+] in frog sympathetic ganglion neurones in 2.0 mm K+ Ringer solution.[Ca2+] oscillations decreased in frequency and exhibited three different amplitude patterns after the first large peak of [Ca2+]: (a) a series of big oscillations (BOs) of constant large amplitude (300–;400 nm), (b) a series of much smaller oscillations (SOs) (40–60 nm), or (c) a series of decaying oscillations (DOs) of rapidly decreasing amplitude.A model in which the oscillation amplitude was determined by the Ca2+ content of the endoplasmic reticulum (ER) whereas the oscillation frequency was controlled by how rapidly the cytosolic [Ca2+] reached the threshold for Ca2+-induced Ca2+ release (CICR) was able to simulate each observed pattern by varying the level of activity of the ER Ca2+ pump (SERCA), CICR and release-activated Ca2+ transport (RACT). A cumulative, cytosolic Ca2+-dependent inactivation of the plasma membrane (PM) Ca2+ influx or of the Ca2+-sensitive leak coefficient of the ryanodine receptors caused the oscillation frequency to decrease in the model.Transitions between BOs and SOs and changes in [Ca2+] oscillations caused by ryanodine, thapsigargin, lanthanum and FCCP could also be simulated.We conclude that RACT, SERCA, CICR and Ca2+-dependent PM Ca2+ influx are major mechanisms underlying [Ca2+] oscillations in these neurones. PMID:9831718

Experimental dissociation of the effects of prostaglandins on renal sodium and water reabsorption by cyclo-oxygenase inhibitors in the rat.

PubMed Central

Bartoli, E.; Branca, G. F.; Faedda, R.; Olmeo, N. A.; Satta, A.; Soggia, G.

1982-01-01

1 The relative importance of the effect of prostaglandins on renal sodium and water reabsorption was assessed in rats. 2 Clearance experiments were performed on 24 anaesthetized rats divided into 3 groups. Each group was infused throughout either with Ringer solution at 9 ml/h (Protocol I), or at 3 ml/h (Protocol II) or with hypotonic fluid at 5 ml/h (Protocol III). Clearance periods were performed before and after intravenous injection of indomethacin (5 mg/kg) and then of aspirin (20 mg/kg). The natriuretic response to different degrees of volume expansion was not modified during the action of the inhibitors. 3 When baseline urine osmolality (Uosm) was high (Protocol II) no further increase occurred in the presence of prostaglandin inhibition. Conversely, Uosm rose from 771 +/- 134 to 1356 +/- 414 and from 575 +/- 245 to 841 +/- 407 mosm/kg (P less than 0.05) in Protocol I and Protocol III respectively, when antidiuretic hormone secretion was inhibited by the higher degree of volume expansion. 4 There was a significant correlation between the change in urine flow rate induced by cyclooxygenase inhibitors and the attendant variations in Na excretion, r = 0.42, n = 41, P less than 0.01. 5 Thus, prostaglandins affect Na loss during saline load as a side effect of their action on water permeability. They could play an important role in volume depletion by counterbalancing the large secretion rate of renal vasoconstrictors. PMID:6809089

Comparison of the chloride channel activator lubiprostone and the oral laxative Polyethylene Glycol 3350 on mucosal barrier repair in ischemic-injured porcine intestine.

PubMed

Moeser, Adam-J; Nighot, Prashant-K; Roerig, Birgit; Ueno, Ryuji; Blikslager, Anthony-T

2008-10-21

To investigate the effects of lubiprostone and Polyethylene Glycol 3350 (PEG) on mucosal barrier repair in ischemic-injured porcine intestine. Ileum from 6 piglets (approximately 15 kg body weight) was subjected to ischemic conditions by occluding the local mesenteric circulation for 45 min in vivo. Ileal tissues from each pig were then harvested and mounted in Ussing chambers and bathed in oxygenated Ringer's solution in vitro. Intestinal barrier function was assessed by measuring transepithelial electrical resistance (TER) and mucosal-to-serosal fluxes of (3)H-mannitol and (14)C-inulin. Statistical analyses of data collected over a 120-min time course included 2-way ANOVA for the effects of time and treatment on indices of barrier function. Application of 1 micromol/L lubiprostone to the mucosal surface of ischemic-injured ileum in vitro induced significant elevations in TER compared to non-treated tissue. Lubiprostone also reduced mucosal-to-serosal fluxes of (3)H-mannitol and (14)C-inulin. Alternatively, application of a polyethylene laxative (PEG, 20 mmol/L) to the mucosal surface of ischemic tissues significantly increased flux of (3)H-mannitol and (14)C-inulin. This experiment demonstrates that lubiprostone stimulates recovery of barrier function in ischemic intestinal tissues whereas the PEG laxative had deleterious effects on mucosal repair. These results suggest that, unlike osmotic laxatives, lubiprostone stimulates repair of the injured intestinal barrier.

Therapeutic apheresis in the Republic of Macedonia - our five years experience (2000-2004).

PubMed

Milovanceva-Popovska, M; Stojkovski, Lj; Grcevska, L; Dzikova, S; Ristovska, V; Gogovska, L; Polenakovic, M

2006-07-01

Membrane plasma exchange (PE) is a mode of extracorporeal blood purification. Since 1985 membrane PE has been in regular use at the Department of Nephrology, Medical Faculty of Skopje, R.Macedonia. In this paper we report on five years (2000-2004) of single centre plasma exchange activity. We performed 540 PE treatments (108 PE/per year) on 99 patients. The M/F ratio was 40/48. The patients underwent a median of 5.45 procedures (range, 1-16). The treated patients were from different Departments. Protocols for PE depend on the disease and its severity. PE were performed 2-4 times weekly using Gambro PF 2000 N filters with an adaptation of the Gambro AK10 dialysis machine or with the Gambro Prizma machine (2 cases). Blood access was achieved through femoral vein. Substitution was made with fresh frozen plasma and/or with 20% human albumin combined with Ringer's solution. An average amount of 2150 ml plasmafiltrate per treatment (respectively 30 to 40 ml plasmafiltrate/kg body weight) was eliminated. Most therapeutic procedures were performed on patients from the Department of Neurology. 63.6% of all patients were referred for Myasthenia gravis and the Guillian Barre syndrome. The total number of procedures per year has remained fairly stable, corresponding to a median of 5.4 treatments/100 000 inhabitants. We observed hypocalcaemia in 8% of the patients, urticarial reactions in 7.3%, pruritic reactions in 12%, and hypotension/headache in 6.8%. No major procedural complications were seen.

Dantrolene Reduces the Threshold and Gain for Shivering

PubMed Central

Lin, Chun-Ming; Neeru, Sharma; Doufas, Anthony G.; Liem, Edwin; Shah, Yunus Muneer; Wadhwa, Anupama; Lenhardt, Rainer; Bjorksten, Andrew; Kurz, Andrea

2005-01-01

Dantrolene is used for treatment of life-threatening hyperthermia, yet its thermoregulatory effects are unknown. We tested the hypothesis that dantrolene reduces the threshold (triggering core temperature) and gain (incremental increase) of shivering. With IRB approval and informed consent, healthy volunteers were evaluated on two random days: control and dantrolene (≈2.5 mg/kg plus a continuous infusion). In study 1, 9 men were warmed until sweating was provoked and then cooled until arterio-venous shunt constriction and shivering occurred. Sweating was quantified on the chest using a ventilated capsule. Absolute right middle fingertip blood flow was quantified using venous-occlusion volume plethysmography. A sustained increase in oxygen consumption identified the shivering threshold. In study 2, 9 men were given cold Ringer's solution IV to reduce core temperature ≈2°C/h. Cooling was stopped when shivering intensity no longer increased with further core cooling. The gain of shivering was the slope of oxygen consumption vs. core temperature regression. In Study 1, sweating and vasoconstriction thresholds were similar on both days. In contrast, shivering threshold decreased 0.3±0.3°C, P=0.004, on the dantrolene day. In Study 2, dantrolene decreased the shivering threshold from 36.7±0.2 to 36.3±0.3°C, P=0.01 and systemic gain from 353±144 to 211±93 ml·min−1·°C−1, P=0.02. Thus, dantrolene substantially decreased the gain of shivering, but produced little central thermoregulatory inhibition. PMID:15105208

The effect of the corneal epithelium on the intraocular penetration of fluoroquinolone ophthalmic solution.

PubMed

Fukuda, Masamichi; Inoue, Amane; Sasaki, Kazuyuki; Takahashi, Nobuo

2004-01-01

Pharmacokinetic studies of antibacterial agents for infectious eye diseases have usually been performed on normal rabbit eyes. In this study, the intraocular penetration of fluoroquinolone ophthalmic solutions was determined in normal rabbit eyes and in rabbit eyes that had the corneal epithelium intentionally removed. We determined the intraocular penetration of ofloxacin (OFLX), levofloxacin (LVFX), and norfloxacin (NFLX), fluoroquinolone ophthalmic solutions that are already on the market and undergoing clinical studies, by injecting 50 microl of each solution into the cul-de-sacs of rabbit eyes three times at 15-min intervals. The drug concentration at 10, 30, 60, 120, and 240 min after final instillation was determined by high-performance liquid chromatography. The maximum concentration in the aqueous humor of normal rabbit eyes was 2.09 +/- 1.56 microg/ml (60 min, OFLX), 2.57 +/- 1.00 microg/ml (30 min, LVFX), and 0.42 +/- 0.12 microg/ml (120 min, NFLX). The drug concentration in the aqueous humor of eyes with intentionally removed corneal epithelium was 12.50 +/- 5.62 microg/ml (30 min, OFLX), 9.02 +/- 2.45 microg/ml (60 min, LVFX), and 8.54 +/- 5.17 microg/ml (30 min, NFLX). The drug penetration of the eye drops into eyes with removed corneal epithelium was around 6 times (OFLX), 3.5 times (LVFX), and 20 times (NFLX) higher than the penetration into the eye with normal cornea. Among the pharmacokinetic parameters of the three ophthalmic solutions according to the one-compartment model, the maximum concentration in the aqueous and the area under the concentration-time curve in the aqueous tended to be higher in the eyes with intentionally removed corneal epithelia than in those with normal corneas.

The Dirac equation and the normalization of its solutions in a closed Friedmann- Robertson-Walker universe

NASA Astrophysics Data System (ADS)

Finster, Felix; Reintjes, Moritz

2009-05-01

We set up the Dirac equation in a Friedmann-Robertson-Walker geometry and separate the spatial and time variables. In the case of a closed universe, the spatial dependence is solved explicitly, giving rise to a discrete set of solutions. We compute the probability integral and analyze a spacetime normalization integral. This analysis allows us to introduce the fermionic projector in a closed Friedmann-Robertson-Walker geometry and to specify its global normalization as well as its local form. First author supported in part by the Deutsche Forschungsgemeinschaft.

Solution stability of Captisol-stabilized melphalan (Evomela) versus Propylene glycol-based melphalan hydrochloride injection.

PubMed

Singh, Ramsharan; Chen, Jin; Miller, Teresa; Bergren, Michael; Mallik, Rangan

2016-12-14

The objective of this study was to compare the stability of recently approved Captisol-stabilized propylene glycol-free melphalan injection (Evomela™) against currently marketed propylene glycol-based melphalan injection. The products were compared as reconstituted solutions in vials as well as admixture solutions prepared from normal saline in infusion bags. Evomela and propylene glycol-based melphalan injection were reconstituted in normal saline and organic custom diluent, respectively, according to their package insert instructions. The reconstituted solutions were diluted in normal saline to obtain drug admixture solutions at specific drug concentrations. Stability of the solutions was studied at room temperature by assay of melphalan and determination of melphalan-related impurities. Results show that based on the increase in total impurities in propylene glycol-based melphalan injection at 0.45 mg/mL, Evomela admixture solutions are about 5, 9, 15 and 29 times more stable at concentrations of 0.45, 1.0, 2.0 and 5.0 mg/mL, respectively. Results confirmed that reconstituted Evomela solution can be stored in the vial for up to 1 h at RT or for up to 24 h at refrigerated temperature (2-8 °C) with no significant degradation. After storage in the vial, it remains stable for an additional 3-29 h after preparation of admixture solution in infusion bags at concentrations of 0.25-5.0 mg/mL, respectively. In addition, Evomela solution in saline, at concentration of 5.0 mg/mL melphalan was bacteriostatic through 72 h storage at 2-8 °C. Formulation of melphalan with Captisol technology significantly improved stability compared to melphalan hydrochloride reconstituted with propylene-glycol based diluents.

Alfvén simple waves

NASA Astrophysics Data System (ADS)

Webb, G. M.; Zank, G. P.; Burrows, R. H.; Ratkiewicz, R. E.

2011-02-01

Multi-dimensional Alfvén simple waves in magnetohydrodynamics (MHD) are investigated using Boillat's formalism. For simple wave solutions, all physical variables (the gas density, pressure, fluid velocity, entropy, and magnetic field induction in the MHD case) depend on a single phase function ϕ, which is a function of the space and time variables. The simple wave ansatz requires that the wave normal and the normal speed of the wave front depend only on the phase function ϕ. This leads to an implicit equation for the phase function and a generalization of the concept of a plane wave. We obtain examples of Alfvén simple waves, based on the right eigenvector solutions for the Alfvén mode. The Alfvén mode solutions have six integrals, namely that the entropy, density, magnetic pressure, and the group velocity (the sum of the Alfvén and fluid velocity) are constant throughout the wave. The eigenequations require that the rate of change of the magnetic induction B with ϕ throughout the wave is perpendicular to both the wave normal n and B. Methods to construct simple wave solutions based on specifying either a solution ansatz for n(ϕ) or B(ϕ) are developed.

Alfven Simple Waves

NASA Astrophysics Data System (ADS)

Webb, G. M.; Zank, G. P.; Burrows, R.

2009-12-01

Multi-dimensional Alfvén simple waves in magnetohydrodynamics (MHD) are investigated using Boillat's formalism. For simple wave solutions, all physical variables (the gas density, pressure, fluid velocity, entropy, and magnetic field induction in the MHD case) depend on a single phase function ǎrphi which is a function of the space and time variables. The simple wave ansatz requires that the wave normal and the normal speed of the wave front depend only on the phase function ǎrphi. This leads to an implicit equation for the phase function, and a generalisation of the concept of a plane wave. We obtain examples of Alfvén simple waves, based on the right eigenvector solutions for the Alfvén mode. The Alfvén mode solutions have six integrals, namely that the entropy, density, magnetic pressure and the group velocity (the sum of the Alfvén and fluid velocity) are constant throughout the wave. The eigen-equations require that the rate of change of the magnetic induction B with ǎrphi throughout the wave is perpendicular to both the wave normal n and B. Methods to construct simple wave solutions based on specifying either a solution ansatz for n(ǎrphi) or B(ǎrphi) are developed.

Steady normal shock wave solution tables of parahydrogen for total temperatures from 30 K to 290 K and for total pressure from 1 ATM to 10 ATM

NASA Technical Reports Server (NTRS)

Haut, R. C.; Adcock, J. B.

1976-01-01

The steady normal shock wave solutions of parahydrogen at various total pressures and total temperatures were numerically determined by iterating the upstream Mach number and by using a modified interval halving technique. The results obtained are compared with the ideal diatomic gas values and are presented in tabulated form.

Silver-modified mobile phase for normal-phase liquid chromatographic determination of prostaglandins and their 5,6-trans isomers in prostaglandin bulk drugs and triacetin solutions.

PubMed

Kissinger, L D; Robins, R H

1985-03-15

A silver-modified, normal-phase, high-performance liquid chromatographic system has been developed for prostaglanding bulk drugs and triacetin solutions. Silver nitrate present in the mobile phase results in high selectivity for cis/trans isomers with conventional silica columns. Prostaglandins were esterified with alpha-bromo-2'-acetonaphthone prior to chromatography to provide high detectability at 254 nm. For dilute triacetin solutions, a sample preparation scheme based on gravity-flow chromatography with silica columns was developed to isolate the prostaglandin from triacetin prior to derivatization. The analytical technique was applied to triacetin solutions containing as little as 10 micrograms/ml arbaprostil [15-(R)-methyl-PGE2].

Triple loop heat exchanger for an absorption refrigeration system

DOEpatents

Reimann, Robert C.

1984-01-01

A triple loop heat exchanger for an absorption refrigeration system is disclosed. The triple loop heat exchanger comprises portions of a strong solution line for conducting relatively hot, strong solution from a generator to a solution heat exchanger of the absorption refrigeration system, conduit means for conducting relatively cool, weak solution from the solution heat exchanger to the generator, and a bypass system for conducting strong solution from the generator around the strong solution line and around the solution heat exchanger to an absorber of the refrigeration system when strong solution builds up in the generator to an undesirable level. The strong solution line and the conduit means are in heat exchange relationship with each other in the triple loop heat exchanger so that, during normal operation of the refrigeration system, heat is exchanged between the relatively hot, strong solution flowing through the strong solution line and the relatively cool, weak solution flowing through the conduit means. Also, the strong solution line and the bypass system are in heat exchange relationship in the triple loop heat exchanger so that if the normal flow path of relatively hot, strong solution flowing from the generator to an absorber is blocked, then this relatively, hot strong solution which will then be flowing through the bypass system in the triple loop heat exchanger, is brought into heat exchange relationship with any strong solution which may have solidified in the strong solution line in the triple loop heat exchanger to thereby aid in desolidifying any such solidified strong solution.

Fretting properties of biodegradable Mg-Nd-Zn-Zr alloy in air and in Hank’s solution

PubMed Central

Li, Wenting; Li, Nan; Zheng, Yufeng; Yuan, Guangyin

2016-01-01

Fretting is a significant cause for the failure of orthopedic implants. Currently, since magnesium and its alloys have been developed as promising biodegradable implant materials, the fretting behavior of the Mg alloys is of great research significance. In this study, a Mg-Nd-Zn-Zr alloy (hereafter, denoted as JDBM alloy) was selected as experimental material, and its fretting behaviors were evaluated under 5 N, 10 N and 20 N normal loads with a displacement of 200 μm under the frequency of 10 Hz at 37 °C in air and in Hank’s solution, respectively. The results indicated that while the friction coefficient decreased with the increment of the normal load, the wear volume of the alloy increased with the increment of the normal load both in air and in Hank’s solution. Both the friction coefficients and the wear volume of the fretting in Hank’s solution were much lower than those in air environment. The evolution trend of friction coefficients with time had different performance in air environment and the Hank’s solution group. Although oxidation occurred during the fretting tests in Hank’s solution, the damage of JDBM alloy was still reduced due to the lubrication effects of Hank’s solution. Moreover, the addition of Fetal bovine serum (FBS) could act as lubrication and result in the reduction of the fretting damage. PMID:27812007

Incidence and Determinants of Port Occlusions in Cancer Outpatients: A Prospective Cohort Study.

PubMed

Milani, Alessandra; Mazzocco, Ketti; Gandini, Sara; Pravettoni, Gabriella; Libutti, Livio; Zencovich, Claudia; Sbriglia, Ada; Pari, Chiara; Magon, Giorgio; Saiani, Luisa

Normal saline is considered a safe alternative for heparin as a locking solution in totally implantable venous access devices. The incidence rate of partial occlusion with the use of normal saline (easy injection, impossible aspiration) is estimated at 4%. The aim of this study was to investigate determinants of partial occlusions with the use of normal saline solution and the maintenance of positive pressure in the catheter. We enrolled 218 patients with different solid tumors who underwent pharmacologic treatment through the port with different frequencies: from once every week to at least once every month. The port was flushed with normal saline solution keeping a positive pressure in the catheter. We performed 4111 observations and documented normal port functioning in 99% of observations (n = 4057) and partial occlusions in 1% of observations (n = 54). Partial occlusions were significantly associated with frequency of port flushing (P < .05), chemotherapy (P < .001), and blood sample collection (P < .001). The use of positive pressure in addition to normal saline reduces the incidence rate of partial occlusions. The type of treatment, blood sample collection, and treatment schedule are important determinants of partial occlusions. Nurses play a key role in maintaining a functioning port using positive pressure during the flushing techniques. Certain risk factors must be monitored to prevent partial occlusions, and certain patients are more likely to present with port-related problems.

Elastic parabolic equation and normal mode solutions for seismo-acoustic propagation in underwater environments with ice covers.

PubMed

Collis, Jon M; Frank, Scott D; Metzler, Adam M; Preston, Kimberly S

2016-05-01

Sound propagation predictions for ice-covered ocean acoustic environments do not match observational data: received levels in nature are less than expected, suggesting that the effects of the ice are substantial. Effects due to elasticity in overlying ice can be significant enough that low-shear approximations, such as effective complex density treatments, may not be appropriate. Building on recent elastic seafloor modeling developments, a range-dependent parabolic equation solution that treats the ice as an elastic medium is presented. The solution is benchmarked against a derived elastic normal mode solution for range-independent underwater acoustic propagation. Results from both solutions accurately predict plate flexural modes that propagate in the ice layer, as well as Scholte interface waves that propagate at the boundary between the water and the seafloor. The parabolic equation solution is used to model a scenario with range-dependent ice thickness and a water sound speed profile similar to those observed during the 2009 Ice Exercise (ICEX) in the Beaufort Sea.

Application of low-order potential solutions to higher-order vertical traction boundary problems in an elastic half-space

PubMed Central

Taylor, Adam G.

2018-01-01

New solutions of potential functions for the bilinear vertical traction boundary condition are derived and presented. The discretization and interpolation of higher-order tractions and the superposition of the bilinear solutions provide a method of forming approximate and continuous solutions for the equilibrium state of a homogeneous and isotropic elastic half-space subjected to arbitrary normal surface tractions. Past experimental measurements of contact pressure distributions in granular media are reviewed in conjunction with the application of the proposed solution method to analysis of elastic settlement in shallow foundations. A numerical example is presented for an empirical ‘saddle-shaped’ traction distribution at the contact interface between a rigid square footing and a supporting soil medium. Non-dimensional soil resistance is computed as the reciprocal of normalized surface displacements under this empirical traction boundary condition, and the resulting internal stresses are compared to classical solutions to uniform traction boundary conditions. PMID:29892456

Exact Solutions for Nonlinear Development of a Kelvin-Helmholtz Instability for the Counterflow of Superfluid and Normal Components of Helium II.

PubMed

Lushnikov, Pavel M; Zubarev, Nikolay M

2018-05-18

Relative motion of the normal and superfluid components of helium II results in the quantum Kelvin-Helmholtz instability (KHI) at their common free surface. We found the integrability and exact growing solutions for the nonlinear stage of the development of that instability. Contrary to the usual KHI of the interface between two classical fluids, the dynamics of a helium II free surface allows reduction to the Laplace growth equation, which has an infinite number of exact solutions, including the generic formation of sharp cusps at the free surface in a finite time.

Exact Solutions for Nonlinear Development of a Kelvin-Helmholtz Instability for the Counterflow of Superfluid and Normal Components of Helium II

NASA Astrophysics Data System (ADS)

Lushnikov, Pavel M.; Zubarev, Nikolay M.

2018-05-01

Relative motion of the normal and superfluid components of helium II results in the quantum Kelvin-Helmholtz instability (KHI) at their common free surface. We found the integrability and exact growing solutions for the nonlinear stage of the development of that instability. Contrary to the usual KHI of the interface between two classical fluids, the dynamics of a helium II free surface allows reduction to the Laplace growth equation, which has an infinite number of exact solutions, including the generic formation of sharp cusps at the free surface in a finite time.

Real-gas effects associated with one-dimensional transonic flow of cryogenic nitrogen

NASA Technical Reports Server (NTRS)

Adcock, J. B.

1976-01-01

Real gas solutions for one-dimensional isentropic and normal-shock flows of nitrogen were obtained for a wide range of temperatures and pressures. These calculations are compared to ideal gas solutions and are presented in tables. For temperatures (300 K and below) and pressures (1 to 10 atm) that cover those anticipated for transonic cryogenic tunnels, the solutions are analyzed to obtain indications of the magnitude of inviscid flow simulation errors. For these ranges, the maximum deviation of the various isentropic and normal shock parameters from the ideal values is about 1 percent or less, and for most wind tunnel investigations this deviation would be insignificant.

Lung plethysmography

MedlinePlus

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The ionic selectivity and calcium dependence of the light-sensitive pathway in toad rods.

PubMed Central

Hodgkin, A L; McNaughton, P A; Nunn, B J

1985-01-01

A new method is described for determining the effects of rapid changes in ionic concentration on the light-sensitive currents of rod outer segments. Replacing Na with another monovalent cation caused a rapid change in current followed by an exponential decline of time constant 0.5-2 s. From the magnitude of the initial rapid change in current we conclude that Li, Na, and K and Rb ions pass readily through the light-sensitive channel in the presence of 1 mM-Ca, whereas Cs crosses with difficulty and choline, tetramethylammonium and tetraethylammonium not at all. The effect of reducing Ca in the external medium indicates that the residual inward current recorded for a few seconds when Na is replaced by an impermeant ion is carried largely by Ca ions. With 1 microM-Ca in the external medium the relative ability of monovalent cations to carry light-sensitive current is Li:Na:K:Rb:Cs = 1.4:1:0.8:0.6:0.15. The same order applied in the physiological region but the values are less certain. Large transient inward currents are seen if external Ca is raised form 1 microM to 5 mM or more; these currents which are maximal in an isotonic Ca solution are presumably carried by Ca. The effect of monovalent cations on the number of open light-sensitive channels was tested by adding the cation to a solution containing 55 mM-Na. Na ions open light-sensitive channels with a delay, probably by promoting Na-Ca exchange; K and Rb close channels by inhibiting exchange; Li and Cs seem inert in the exchange mechanism. The rate at which inward current declines in low [Na]o or high [Ca]o is accelerated by weak background lights and slowed by 3-isobutyl-1-methylxanthine (IBMX), which inhibits the hydrolysis of cGMP. On returning to Ringer solution after a period in low [Na]o the current recovers with a delay of about 1 s which decreases as the Ca concentration of the low [Na]o medium is reduced. We conclude that intracellular Ca has a strong effect on the number of open light-sensitive channels. None the less, several observations are inconsistent with channel closure being dependent simply on combination with internal Ca. PMID:2580087

Low pH irrigation fluids have positive effect on intra-articular chondral healing.

PubMed

Ulku, Tekin Kerem; Kocaoglu, Baris; Gereli, Arel; Uslu, Serap; Nalbantoglu, Ufuk

2017-12-02

The aim of this study was to evaluate the effect of Ringer's lactate (RL) solutions with different pH values on early histologic healing in a microfracture model in vivo. The null hypothesis of the presented study is that irrigation fluids with lower pH (6.4) have negative effects on fibrous cartilage healing. Eighteen Wistar albino rats were randomly divided into three groups. Anterior midline incision was performed. Microfracture procedure was performed with a 1.2 mm k-wire at the lateral femoral condyle of each knee. the skin was sutured and joints were irrigated for 30 min with low pH (6.4) RL in Group 1, high pH (7.6) RL in Group 2 and no irrigation in Group 3. Three rats from each group were randomly selected and killed on the 3rd and 7th day. On the 3rd day, the healed chondral area was examined. On the 3rd and 7th day, the chondral depth and morphology were evaluated. On the 7th day, bone cellularity was assessed with osteoblast; osteoclast number and bone quality were evaluated with trabecular area and the number of trabeculae. Chondral healing area on the 3rd day was significantly higher in Group 1 compared to other groups. Chondral morphology was also qualitatively superior in Group 1 compared to other groups on the 3rd and 7th day. There were no differences in chondral depths between the groups on the 3rd day; however, increased chondral depths were observed in Group 1 on the 7th day. There were statistically significant increases in trabecular area and the number of trabeculae, as well as the number of osteoblasts and osteoclasts in Group 1 on the 7th day. The presented study revealed that low pH irrigation fluids have positive effects on the healing characteristics of intra-articular fibrous cartilage after microfracture procedure in vivo. In light of this study, we can assume that lower pH solutions could be safely used during microfracture procedures and it can also facilitate intra-articular fibrous cartilage formation and cartilage healing. Selection of irrigation solution is also important for intra-articular fibrous cartilage healing after microfracture procedure in vivo.

Metal Complexation in Xylem Fluid 1

PubMed Central

White, Michael C.; Decker, A. Morris; Chaney, Rufus L.

1981-01-01

Xylem fluid was analyzed for numerous solutes to characterize chemically the sap as a medium for forming and transporting metal complexes. The stem exudate was collected hourly for 8 hours from topped 31-day-old soybean (Glycine max L. Merr.) and 46-day-old tomato (Lycopersicon esculentum Mill.) plants grown in normal (0.5 micromolar) and Za-phytotoxic nutrient solutions. Soybean plants were grown in the normal and high-Zn solutions for 24 days; tomato plants were grown for 32 days. The exudate was analyzed for seven organic acids, 22 amino acids, eight inorganic solutes, apparent ionic strength, and pH. Significant changes in many solutes occurred over the 8-hour sampling period. These fluctuations depended on plant species, individual solute, and Zn treatment, and demonstrated that extrapolation of xylem-fluid analyses to whole-plant xylem sap is valid only for sap samples collected shortly after topping a plant. Exudate pH decreased over the 8-hour period for both species; exudate ionic strength increased for tomato and decreased for soybean. At the normal-Zn treatment (0 to 1 hour), the highest acid micromolar concentrations in soybean exudate were: asparagine, 2,583; citric, 1,706; malic, 890; and malonic, 264. Under the same conditions, the highest acid micromolar concentrations in tomato exudate were: maleic, 1,206; malic, 628; glutamine, 522; citric, 301; and asparagine, 242. Cysteine and methionine were above detection limits only in soybean exudate. Zinc phytotoxicity caused significant changes in many solutes. The analyses reported here provide a comprehensive data base for further studies on metal-complex equilibria in xylem fluid. PMID:16661664

THE PRESERVATION OF LIVING RED BLOOD CELLS IN VITRO

PubMed Central

Rous, Peyton; Turner, J. R.

1916-01-01

The erythrocytes of some species are much damaged when handled in salt solutions, as in washing with the centrifuge after the ordinary method. The injury is mechanical in character. It may express itself in hemolysis only after the cells have been kept for some days. It is greatest in the case of dog corpuscles, and well marked with sheep and rabbit cells. The fragility of the red cells, as indicated by washing or shaking them in salt solution is different, not only for different species, but for different individuals. It varies independently of the resistance to hypotonic solutions. The protection of fragile erythrocytes during washing is essential if they are to be preserved in vitro for any considerable time. The addition of a little gelatin (⅛ per cent) to the wash fluid suffices for this purpose, and by its use the period of survival in salt solutions of washed rabbit, sheep, and dog cells is greatly prolonged. Plasma, like gelatin, has marked protective properties. Though gelatin acts as a protective for red cells it is not preservative of them in the real sense. Cells do not last longer when it is added to the fluids in which they are kept. Locke's solution, though better probably than Ringer's solution, or a sodium chloride solution, as a medium in which to keep red cells, is ultimately harmful. The addition of innocuous colloids does not improve it. But the sugars, especially dextrose and saccharose, have a remarkable power to prevent its injurious action, and they possess, in addition, preservative qualities. Cells washed in gelatin-Locke's and placed in a mixture of Locke's solution with an isotonic, watery solution of a sugar remain intact for a long time,—nearly 2 months in the case of sheep cells. The kept cells go easily into suspension free of clumps, they pass readily through paper filters, take up and give off oxygen, and when used for the Wassermann reaction behave exactly as do fresh cells of the same individual. The best preservative solutions are approximately isotonic with the blood serum. If the cells are to be much handled gelatin should be present, for the sugars do not protect against mechanical injury. Different preservative mixtures are required for the cells of different species. Dog cells last longest in fluids containing dextrin as well as a sugar. The mixture best for red cells is not necessarily best for leukocytes. A simple and practical method of keeping rabbit and human erythrocytes is in citrated whole blood to which sugar solution is added. In citrated blood, as such, human red cells tend to break down rather rapidly, no matter what the proportion of citrate. Hemolysis is well marked after little more than a week. But in a mixture of 3 parts of human blood, 2 parts of isotonic citrate solution (3.8 per cent sodium citrate in water), and 5 parts of isotonic dextrose solution (5.4 per cent dextrose in water), the cells remain intact for about 4 weeks. Rabbit red cells can be kept for more than 3 weeks in citrated blood; and the addition of sugar lengthens the preservation only a little. The results differ strikingly with the amount of citrate employed. Hemolysis occurs relatively early when the smallest quantity is used that will prevent clotting. The optimum mixture has 3 parts of rabbit blood to 2 of isotonic citrate solution. In the second part of this paper experiments are detailed which prove that cells preserved by the methods here recorded function excellently when reintroduced into the body. PMID:19867981

The pH dependent Raman spectroscopic study of caffeine

NASA Astrophysics Data System (ADS)

Kang, Jian; Gu, Huaimin; Zhong, Liang; Hu, Yongjun; Liu, Fang

2011-02-01

First of all the surface enhanced Raman spectroscopy (SERS) and normal Raman spectra of caffeine aqueous solution were obtained at different pH values. In order to obtain the detailed vibrational assignments of the Raman spectroscopy, the geometry of caffeine molecule was optimized by density functional theory (DFT) calculation. By comparing the SERS of caffeine with its normal spectra at different pH values; it is concluded that pH value can dramatically affect the SERS of caffeine, but barely affect the normal Raman spectrum of caffeine aqueous solution. It can essentially affect the reorientation of caffeine molecule to the Ag colloid surface, but cannot impact the vibration of functional groups and chemical bonds in caffeine molecule.

Partial differential equations of 3D boundary layer and their numerical solutions in turbomachinery

NASA Astrophysics Data System (ADS)

Zhang, Guoqing; Hua, Yaonan; Wu, Chung-Hua

1991-08-01

This paper studies the 3D boundary layer equations (3DBLE) and their numerical solutions in turbomachinery: (1) the general form of 3DBLE in turbomachines with rotational and curvature effects are derived under the semiorthogonal coordinate system, in which the normal pressure gradient is not equal to zero; (2) the method of solution of the 3DBLE is discussed; (3) the 3D boundary layers on the rotating blade surface, IGV endwall, rotor endwall (with a relatively moving boundary) are numerically solved, and the predicted data correlates well with the measured data; and (4) the comparison is made between the numerical results of 3DBLE with and without normal pressure gradient.

Variational and numerical analysis of a quasistatic viscoelastic problem with normal compliance, friction and damage

NASA Astrophysics Data System (ADS)

Han, Weimin; Shillor, Meir; Sofonea, Mircea

2001-12-01

We consider a model for quasistatic frictional contact between a viscoelastic body and a foundation. The material constitutive relation is assumed to be nonlinear. The mechanical damage of the material, caused by excessive stress or strain, is described by the damage function, the evolution of which is determined by a parabolic inclusion. The contact is modeled with the normal compliance condition and the associated version of Coulomb's law of dry friction. We derive a variational formulation for the problem and prove the existence of its unique weak solution. We then study a fully discrete scheme for the numerical solutions of the problem and obtain error estimates on the approximate solutions.

Effect of povidone-iodine addition on the corrosion behavior of cp-Ti in normal saline.

PubMed

Bhola, Rahul; Bhola, Shaily M; Mishra, Brajendra; Olson, David L

2010-05-01

The effect of various concentrations of povidone-iodine (PI) on the corrosion behavior of a commercially pure titanium alloy (Ti-1) has been investigated in normal saline solution to simulate the povidone-iodine addition in an oral environment. The open circuit potential, electrochemical impedance spectroscopy and potentiodynamic polarization measurements have been used to characterize the electrochemical phenomena occurring on the alloy surface. The open circuit potential values for Ti-1 in various concentrations of PI shift considerably towards noble direction as compared to pure normal saline. In the potentiodynamic polarization curve for Ti-1 in various solutions, the cathodic current density has increased for all concentrations of PI and the anodic current density has decreased. Only the 0.1% PI concentration is able to inhibit corrosion of Ti-1 in normal saline and the other higher concentrations studied, accelerate corrosion. The EIS data for Ti-1 in normal saline and in various concentrations of PI follows a one time constant circuit, suggesting the formation of a single passive film on Ti-1 which is not altered by the addition of PI to normal saline.

Numerical schemes for anomalous diffusion of single-phase fluids in porous media

NASA Astrophysics Data System (ADS)

Awotunde, Abeeb A.; Ghanam, Ryad A.; Al-Homidan, Suliman S.; Tatar, Nasser-eddine

2016-10-01

Simulation of fluid flow in porous media is an indispensable part of oil and gas reservoir management. Accurate prediction of reservoir performance and profitability of investment rely on our ability to model the flow behavior of reservoir fluids. Over the years, numerical reservoir simulation models have been based mainly on solutions to the normal diffusion of fluids in the porous reservoir. Recently, however, it has been documented that fluid flow in porous media does not always follow strictly the normal diffusion process. Small deviations from normal diffusion, called anomalous diffusion, have been reported in some experimental studies. Such deviations can be caused by different factors such as the viscous state of the fluid, the fractal nature of the porous media and the pressure pulse in the system. In this work, we present explicit and implicit numerical solutions to the anomalous diffusion of single-phase fluids in heterogeneous reservoirs. An analytical solution is used to validate the numerical solution to the simple homogeneous case. The conventional wellbore flow model is modified to account for anomalous behavior. Example applications are used to show the behavior of wellbore and wellblock pressures during the single-phase anomalous flow of fluids in the reservoirs considered.

An inexact log-normal distribution-based stochastic chance-constrained model for agricultural water quality management

NASA Astrophysics Data System (ADS)

Wang, Yu; Fan, Jie; Xu, Ye; Sun, Wei; Chen, Dong

2018-05-01

In this study, an inexact log-normal-based stochastic chance-constrained programming model was developed for solving the non-point source pollution issues caused by agricultural activities. Compared to the general stochastic chance-constrained programming model, the main advantage of the proposed model is that it allows random variables to be expressed as a log-normal distribution, rather than a general normal distribution. Possible deviations in solutions caused by irrational parameter assumptions were avoided. The agricultural system management in the Erhai Lake watershed was used as a case study, where critical system factors, including rainfall and runoff amounts, show characteristics of a log-normal distribution. Several interval solutions were obtained under different constraint-satisfaction levels, which were useful in evaluating the trade-off between system economy and reliability. The applied results show that the proposed model could help decision makers to design optimal production patterns under complex uncertainties. The successful application of this model is expected to provide a good example for agricultural management in many other watersheds.

Preparation of acetylated waxy, normal, and high-amylose maize starches with intermediate degrees of substitution in aqueous solution and their properties.

PubMed

Luo, Zhi-Gang; Shi, Yong-Cheng

2012-09-19

Acetylated waxy, normal, and high-amylose maize starches with intermediate degrees of substitution (DS) were prepared in aqueous solution with 20% (w/w) sodium hydroxide as a catalyst. The level of DS was in the order high-amylose maize starch > waxy maize starch > normal maize starch. Settling volume indicated that during the early reaction, normal maize starch swelled to a lesser extent compared with waxy and high-amylose maize starches. The settling volume of all three starches increased initially but decreased after long reaction time. Aggregation of granules was observed as DS increased. The A-type X-ray diffraction pattern of acetylated normal and waxy maize starches weakened as DS increased, whereas the diffraction peaks disappeared in acetylated high-amylose starch when DS was 0.95. Low DS promoted the swelling of the starches in water, but at high DS, the starches became more hydrophobic and the peak viscosity of acetylated starches decreased.

Heat exchanger bypass system for an absorption refrigeration system

DOEpatents

Reimann, Robert C.

1984-01-01

A heat exchanger bypass system for an absorption refrigeration system is disclosed. The bypass system operates to pass strong solution from the generator around the heat exchanger to the absorber of the absorption refrigeration system when strong solution builds up in the generator above a selected level indicative of solidification of strong solution in the heat exchanger or other such blockage. The bypass system includes a bypass line with a gooseneck located in the generator for controlling flow of strong solution into the bypass line and for preventing refrigerant vapor in the generator from entering the bypass line during normal operation of the refrigeration system. Also, the bypass line includes a trap section filled with liquid for providing a barrier to maintain the normal pressure difference between the generator and the absorber even when the gooseneck of the bypass line is exposed to refrigerant vapor in the generator. Strong solution, which may accumulate in the trap section of the bypass line, is diluted, to prevent solidification, by supplying weak solution to the trap section from a purge system for the absorption refrigeration system.

Preemptive hemodynamic intervention restricting the administration of fluids attenuates lung edema progression in oleic acid-induced lung injury.

PubMed

Gil Cano, A; Gracia Romero, M; Monge García, M I; Guijo González, P; Ruiz Campos, J

2017-04-01

A study is made of the influence of preemptive hemodynamic intervention restricting fluid administration upon the development of oleic acid-induced lung injury. A randomized in vivo study in rabbits was carried out. University research laboratory. Sixteen anesthetized, mechanically ventilated rabbits. Hemodynamic measurements obtained by transesophageal Doppler signal. Respiratory mechanics computed by a least square fitting method. Lung edema assessed by the ratio of wet weight to dry weight of the right lung. Histological examination of the left lung. Animals were randomly assigned to either the early protective lung strategy (EPLS) (n=8) or the early protective hemodynamic strategy (EPHS) (n=8). In both groups, lung injury was induced by the intravenous infusion of oleic acid (OA) (0.133mlkg -1 h -1 for 2h). At the same time, the EPLS group received 15mlkg -1 h -1 of Ringer lactate solution, while the EPHS group received 30mlkg -1 h -1 . Measurements were obtained at baseline and 1 and 2h after starting OA infusion. After 2h, the cardiac index decreased in the EPLS group (p<0.05), whereas in the EPHS group it remained unchanged. Lung compliance decreased significantly only in the EPHS group (p<0.05). Lung edema was greater in the EPHS group (p<0.05). Histological damage proved similar in both groups (p=0.4). In this experimental model of early lung injury, lung edema progression was attenuated by preemptively restricting the administration of fluids. Copyright © 2016 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

Chelidonium majus and its effects on uterine contractility in a perfusion model.

PubMed

Kuenzel, Julian; Geisler, Klaudija; Strahl, Olga; Grundtner, Philipp; Beckmann, Matthias W; Dittrich, Ralf

2013-07-01

The herbal agent celandine is thought to have mainly spasmolytic effects, but in the uterus it is regarded as promoting contractions, which can offer promising and innovative options for optimizing artificial reproduction. The aim of the present study was to investigate the effect of celandine on the uterine muscle, using a perfusion model of swine uteri. Sixteen swine uteri were perfused with Krebs-Ringer solution. Celandine (Chelidonium, Paverysat; Johannes Bürger Ysatfabrik Ltd., Bad Harzburg, Germany) was administered at increasing dosages. Intrauterine pressure (IUP) was recorded using an intrauterine double-chip microcatheter (Urobar 8 DS-F, Raumedic, Rehau AG & Co., Rehau, Germany). Differences in pressure (ΔP) and area under the curve (ΔAUC) after drug administration in the uterine body and uterine horn in the various dilution series were noted. A paired Student's t-test was used to evaluate differences between groups, with significance set at P<0.05. A significant initial increase in uterine activity was visible at each dosage. Inhibition of uterine activity was seen over longer periods of 5 and 10 min, particularly for a medium-dose range of 1-2mg/ml. At a dosage of 2mg/ml in particular, celandine almost always led to significant values. Following intra-arterial administration in a swine uterus perfusion model, celandine initially causes a significant increase in contractility, which is followed over time by a relaxation phase. This suggests interesting hypotheses on whether Chelidonium majus might be used to promote targeted sperm transport. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Cryopreservation of sperm in Grey mullet Mugil cephalus (Linnaeus, 1758).

PubMed

Balamurugan, Ramachandran; Munuswamy, Natesan

2017-10-01

The aim of this study was to document the effects of cryopreservation on sperm motility and viability in Grey mullet Mugil cephalus. Cryopreservation of sperm was attempted by using two extenders ringer solution for marine fish (RSMF) and V2 extender (V2E) and cryoprotectants dimethylacetamide (DMA), dimethylsulfoxide (DMSO), ethylene glycol (EG), glycerol (GLY), propylene glycol (PG) and methanol (MeOH). Cryoprotectants were assessed at different concentrations individually as well as in combination with varying equilibration times (10 and 30min). For optimization of freezing rate, four freezing protocols (-5, -10, -20 and -30°C/min) were evaluated. After achieving final temperature, samples were plunged in liquid nitrogen (-196°C) and stored for a week. Samples were subsequently thawed in a water bath at 30°C for assessment of sperm motility and viability. Results indicated that cryomedium constituting of V2E extender+10% glycerol with a dilution ratio of 1:1 (sperm: cryomedium) at an equilibration time of 5 to- 10min and freezing rate of -20°C/min was more desirable compared with other factors that were assessed. Use of this protocol resulted in retaining the greatest sperm motility grade 3.0±0.0 (50%-80% sperm movement, fast swimming) and 48.19±3.12% of sperm viability. The results of the present study, therefore, provide base-line data for establishing a protocol for sperm cryopreservation in M.cephalus. Further studies are, however, required for optimization of most suitable sperm cryopreservation protocol. Copyright © 2017 Elsevier B.V. All rights reserved.

[Implementation of transgingival antibacterial photodynamic therapy (PDT) supplementary to scaling and root planing. A controlled clinical proof-of-principle study].

PubMed

Mettraux, Gérald; Hüsler, Jürg

2011-01-01

The antibacterial photodynamic therapy (PDT) has been effective in the periodontal therapy. The laser light application reported in the literature so far is the subgingival placement of a light fibre. To study the effect of PDT with a transgingival laser application. In 19 patients with untreated periodontitis 1 test and 1 control site were selected. Both pockets were treated by scaling, root planing. the Test site received additional PDT (LASOTRONIC MED 701 by ORCOS MEDICAL, Switzerland) at baseline, after 2 and 6 months. The control sites were rinsed with ringer solution. Clinical parameters (ST, BOP, CAL) and bacterial monitoring (PADO, IAI, Switzerland) at baseline, 2 and 6 months were recorded. Mean pocket reduction was after 6 months 2.1 mm (+/-1.4) in the test group, 1.5 mm (+/-1.6) in the control group significantly different. The 95% confidence interval for the difference of the mean reductions of the test and control group after 6 months is (1.5, 3). Mean CAL gain after 6 months was 1.5 mm (+/-1.3) in the test, 0.9 mm (+/-1.7) in the control group. T. denticola showed lower number after 2 and 6 months in the test versus the control. The total bacterial load (TBL) showed significantly better reduction in the test group at 6 months. The transgingival application of PDT with the MED 701 showed clinical and bacteriological effects which are comparable to those reported in the literature with the subgingival method. The transgingival method is convenient, harmless and easy to perform.

The embryotoxic effects of ultrasound exposure in pregnant ICR mice.

PubMed

Kimmel, C A; Stratmeyer, M E; Galloway, W D; Laborde, J B; Brown, N; Pinkavitch, F

1983-04-01

The embryotoxicity of ultrasound exposure during pregnancy was investigated in DUB:(ICR) mice. On day 0 of gestation (day of plug), pregnant mice were assigned to one of five groups: cage control, sham exposed (0 W/cm2), 0.05 W/cm2, 0.50 W/cm2. or 1.00 W/cm2. Females were anesthetized on day 8 of gestation and their abdomens were shaved to assure good acoustic coupling. The animals were strapped on a lucite board and placed vertically into a distilled degassed water bath (30 degrees C) so that the abdomen was fully submerged and centered in the axis of the ultrasonic beam. Insonation was carried out using a PZT transducer with a radius of 1.27 cm and a frequency of 1 MHz under continuous wave conditions. Each animal was placed at a distance of 25 cm from the transducer and exposed to the appropriate intensity for 120 seconds. On day 17 of gestation, the maternal animals were killed, the uterine contents were examined, and live fetuses were weighed and then shipped in cold lactated Ringer's solution from Maryland to Arkansas. Fetuses were examined on the day following maternal sacrifice for external and visceral defects and skeletons were prepared and examined subsequently. Slight but significant differences were detected between the cage control and sham-exposed groups. No statistically significant changes were seen that could be attributed to ultrasound exposure, although there was a slight increase in the incidence of malformed fetuses and the occurrence of multiple malformations in individual fetuses as intensity of the ultrasonic exposure increased.

Effect of ramosetron on shivering during spinal anesthesia

PubMed Central

Kim, Min Soo; Kim, Dong Won; Woo, Seung-Hoon; Yon, Jun Heum

2010-01-01

Background Shivering associated with spinal anesthesia is uncomfortable and may interfere with monitoring. The aim of this study is to evaluate the effect of ramosetron, a serotonin-3 receptor antagonist, on the prevention of shivering during spinal anesthesia. Methods We enrolled 52 patients who were ASA I or II and who had undergone knee arthroscopy under spinal anesthesia. Warmed (37°) lactated Ringer's solution was infused over 15 minutes before spinal anesthesia. Patients were randomly allocated to a control group (group S, N = 26) or study group (group R, N = 26). Spinal anesthesia was performed with a 25-G Quincke-type spinal needle between the lumbar 3-4 interspace with 2.2 ml 0.5% hyperbaric bupivacaine. For patients allocated in groups S and R, 2 ml 0.9% saline and 0.3 mg ramosetron, respectively, was intravenously injected immediately before intrathecal injection at identical times. Shivering and spinal block levels were assessed immediately after the completion of subarachnoid injection, as well as 5, 10, 15, 20, 25, 30, 60, and 120 minutes after spinal anesthesia. Systolic and diastolic blood pressures, heart rate, and peripheral oxygen saturation were also recorded. Core temperatures were measured by tympanic thermometer and recorded before and during spinal anesthesia at 30-minute intervals. Results Shivering was observed in 2 patients in group R and 9 patients in group S (P = 0.038, odds ratio = 6.14, 95% C.I. = 1.08-65.5). The difference in core temperature between the groups was not significant. Conclusions Compared to control, ramosetron is an effective way to prevent shivering during spinal anesthesia. PMID:20498774