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Ringer's Solution (ringer + solution)

Distribution by Scientific Domains
Medical Sciences44%
Life Sciences34%
Polymers and Materials Science20%

Kinds of Ringer's Solution

  • lactated ringer solution
    		•

    Selected Abstracts

    Effect of dopamine on rat diaphragm apoptosis and muscle performance

    EXPERIMENTAL PHYSIOLOGY, Issue 4 2006
    Janet D. Pierce
    The purpose of this study was to determine whether dopamine (DA) decreases diaphragm apoptosis and attenuates the decline in diaphragmatic contractile performance associated with repetitive isometric contraction using an in vitro diaphragm preparation. Strenuous diaphragm contractions produce free radicals and muscle apoptosis. Dopamine is a free radical scavenger and, at higher concentrations, increases muscle contractility by simulating ,2 -adrenoreceptors. A total of 47 male Sprague,Dawley rats weighing 330,450 g were used in a prospective, randomized, controlled in vitro study. Following animal anaesthetization, diaphragms were excised, and muscle strips prepared and placed in a temperature-controlled isolated tissue bath containing Krebs,Ringer solution (KR) or KR plus 100 ,m DA. The solutions were equilibrated with oxygen (O2) at 10, 21 or 95% and 5% carbon dioxide, with the balance being nitrogen. Diaphragm isometric twitch and subtetanic contractions were measured intermittently over 65 min. The diaphragms were then removed and, using a nuclear differential dye uptake method, the percentages of normal, apoptotic and necrotic nuclei were determined using fluorescent microscopy. There were significantly fewer apoptotic nuclei in the DA group diaphragms than in the KR-only group diaphragms in 10 and 21% O2 following either twitch or subtetanic contractions. Dopamine at 100 ,m produced only modest increases in muscle performance in both 10 and 21% O2. The attenuation of apoptosis by DA was markedly greater than the effect of DA on muscle performance. Dopamine decreased diaphragmatic apoptosis, perhaps by preventing the activation of intricate apoptotic pathways, stimulating antiapoptotic mechanisms and/or scavenging free radicals. [source]

    Trimetazidine Reduces Basal Cytosolic Ca2+ Concentration During Hypoxia in Single Xenopus Skeletal Myocytes

    EXPERIMENTAL PHYSIOLOGY, Issue 3 2003
    C. M. Stary
    We tested the hypotheses that: (1) Ca2+ handling and force production would be irreversibly altered in skeletal muscle during steady-state contractions when subjected to severe, prolonged hypoxia and subsequent reoxygenation; and (2) application of the cardio-protective drug trimetazidine would attenuate these alterations. Single, living skeletal muscle fibres from Xenopus laevis were injected with the Ca2+ indicator fura 2, and incubated for 1 h prior to stimulation in 100 ,M TMZ-Ringer solution (TMZ; n = 6) or standard Ringer solution (CON; n = 6). Force and relative free cytosolic Ca2+ concentration ([Ca2+]c) were measured during continuous tetanic contractions produced every 5 s as fibres were sequentially perfused in the following manner: 3 min high extracellular PO2 (159 mmHg), 15 min hypoxic perfusion (3-5 mmHg) then 3 min high PO2. Hypoxia caused a decrease in force and peak [Ca2+]c in both the TMZ and CON fibres, with no significant (P < 0.05) difference between groups. However, basal [Ca2+]c was significantly lower during hypoxia in the TMZ group vs. the CON group. While reoxygenation generated only modest recovery of relative force and peak [Ca2+]c in both groups, basal [Ca2+]c remained significantly less in the TMZ group. These results demonstrated that in contracting, single skeletal muscle fibres, TMZ prevented increases in basal [Ca2+]c generated during a severe hypoxic insult and subsequent reoxygenation, yet failed to protect the cell from the deleterious effects of prolonged hypoxia followed by reoxygenation. [source]

    The Effect of Carbachol and ,-Bungarotoxin on the Frequency of Miniature Endplate Potentials at the Frog Neuromuscular Junction

    EXPERIMENTAL PHYSIOLOGY, Issue 2 2000
    Ela Bukharaeva
    The effects of an acetylcholine analogue, carbachol (CCh), and a purified irreversible nicotinic antagonist, ,-bungarotoxin (BTX), on the frequency of the miniature endplate potentials (mEPPs) at the neuromuscular junction of the frog were tested at 20 and 10°C. CCh (5 ± 10-6 m) reduced the frequency of mEPPs to about 60%; this reduction was not affected by 1 ± 10-7 g ml-1 BTX. BTX also reversibly decreased the mEPP frequency by 40%, but not in the presence of CCh or in Ringer solution with 0 or 8 mM Ca2+. The present data show that BTX, which inhibits a class of nicotinic ACh receptors, does not block the decrease of mEPP frequency evoked by CCh and can itself suppress the frequency of spontaneous quantal release. [source]

    The penetration enhancement and the lipolytic effects of TAT,GKH, both in in vitro, ex vivo, and in vivo

    INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 5 2004
    J. Lim
    It was demonstrated that the trans-activating transcriptional activator (TAT) protein from HIV-1 could enter cells when added to the surrounding media. TAT peptide chemically attached to various proteins was able to deliver these proteins to various cells and even at high levels in heart and spleen tissues in mice. In this study, the tri-peptide GKH (glycine,lysine,histidine) derived from the parathyroid hormone, which is known as a lipolytic peptide, was attached to 9-poly lysine (TAT) to be used as a cosmetic ingredient for eye-bag care product. When glycerol is released, expressed as the extracellular glycerol concentration (the so-called lipolysis index), TAT,GKH at 10,5m induces a maximal lipolytic effect of approximately 41.5% in epididymal adipocytes isolated from rats, compared with basal lipolysis. In a microdialysis study, TAT,GKH was perfused into epididymal adipose tissues of anaesthetized rats in increasing concentrations in a Ringer solution. The glycerol concentration in each dialysate was measured using an ultra-sensitive radiometric method. The perfusion of TAT,GKH induced a lipolytic effect. A penetration study showed that TAT,GKH resulted in a sevenfold higher penetration into excised hairless mice skin than GKH. An in vivo study showed that a TAT,GKH containing emulsion had a better effect upon the relative volume reduction of eye bag after 28 days of application on 22 healthy female volunteers than the placebo. It was therefore concluded that TAT,GKH increased skin penetration, which resulted in enhanced lipolytic effects in in vitro, ex vivo and in volume reduction of eye-bags in in vivo studies. [source]

    On Some Characteristics of Ti Oxynitrides Obtained by Pulsed Magnetron Sputtering

    PLASMA PROCESSES AND POLYMERS, Issue S1 2007
    Mariana Braic
    Abstract TiOxNy coatings were investigated as possible candidates for ion diffusion barrier layers. The elemental and phase composition, texture, hardness, adhesion, and corrosion resistance of the coatings were analyzed. The ion release in Ringer solution for uncoated and coated samples were also determined. The film properties were found to significantly depend on the reactive gas composition (O2/N2 ratio). The coatings proved to enhance the corrosion protection and to reduce the ion release of the uncoated specimens. [source]

    Exercise prevents age-related decline in nitric-oxide-mediated vasodilator function in cutaneous microvessels

    THE JOURNAL OF PHYSIOLOGY, Issue 14 2008
    Mark A. Black
    Ageing is associated with impaired endothelium-derived nitric oxide (NO) function in human microvessels. We investigated the impact of cardiorespiratory fitness and exercise training on physiological and pharmacological NO-mediated microvascular responses in older subjects. NO-mediated vasodilatation was examined in young, older sedentary and older fit subjects who had two microdialysis fibres embedded into the skin on the ventral aspect of the forearm and laser Doppler probes placed over these sites. Both sites were then heated to 42°C, with Ringer solution infused in one probe and N -nitro- l -arginine methyl ester (l -NAME) through the second. In another study, three doses of ACh were infused in the presence or absence of l -NAME in similar subjects. The older sedentary subjects then undertook exercise training, with repeat studies at 12 and 24 weeks. The NO component of the heat-induced rise in cutaneous vascular conductance (CVC) was diminished in the older sedentary subjects after 30 min of prolonged heating at 42°C (26.9 ± 3.9%CVCmax), compared to older fit (46.2 ± 7.0%CVCmax, P < 0.05) and young subjects (41.2 ± 5.2%CVCmax, P < 0.05), whereas exercise training in the older sedentary group enhanced NO-vasodilator function in response to incremental heating (P < 0.05). Similarly, the NO contribution to ACh responses was impaired in the older sedentary versus older fit subjects (low dose 3.2 ± 1.3 versus 6.6 ± 1.3%CVCmax; mid dose 11.4 ± 2.4 versus 21.6 ± 4.5%CVCmax; high dose 35.2 ± 6.0 versus 52.6 ± 7.9%CVCmax, P < 0.05) and training reversed this (12 weeks: 13.7 ± 3.6, 28.9 ± 5.3, 56.1 ± 3.9%CVCmax, P < 0.05). These findings indicate that maintaining a high level of fitness, or undertaking exercise training, prevents age-related decline in indices of physiological and pharmacological microvascular NO-mediated vasodilator function. Since higher levels of NO confer anti-atherogenic benefit, this study has potential implications for the prevention of microvascular dysfunction in humans. [source]

    Human cutaneous reactive hyperaemia: role of BKCa channels and sensory nerves

    THE JOURNAL OF PHYSIOLOGY, Issue 1 2007
    Santiago Lorenzo
    Reactive hyperaemia is the increase in blood flow following arterial occlusion. The exact mechanisms mediating this response in skin are not fully understood. The purpose of this study was to investigate the individual and combined contributions of (1) sensory nerves and large-conductance calcium activated potassium (BKCa) channels, and (2) nitric oxide (NO) and prostanoids to cutaneous reactive hyperaemia. Laser-Doppler flowmetry was used to measure skin blood flow in a total of 18 subjects. Peak blood flow (BF) was defined as the highest blood flow value after release of the pressure cuff. Total hyperaemic response was calculated by taking the area under the curve (AUC) of the hyperaemic response minus baseline. Infusates were perfused through forearm skin using microdialysis in four sites. In the sensory nerve/BKCa protocol: (1) EMLA® cream (EMLA, applied topically to skin surface), (2) tetraethylammonium (TEA), (3) EMLA®+ TEA (Combo), and (4) Ringer solution (Control). In the prostanoid/NO protocol: (1) ketorolac (Keto), (2) NG -nitro- l -arginine methyl ester (l -NAME), (3) Keto +l -NAME (Combo), and (4) Ringer solution (Control). CVC was calculated as flux/mean arterial pressure and normalized to maximal flow. Hyperaemic responses in Control (1389 ± 794%CVCmax s) were significantly greater compared to TEA, EMLA and Combo sites (TEA, 630 ± 512, P= 0.003; EMLA, 421 ± 216, P < 0.001; Combo, 201 ± 200, P < 0.001%CVCmax s). Furthermore, AUC in Combo (Keto +l -NAME) site was significantly greater than Control (4109 ± 2777 versus 1295 ± 368%CVCmax s). These data suggest (1) sensory nerves and BKCa channels play major roles in the EDHF component of reactive hyperaemia and appear to work partly independent of each other, and (2) the COX pathway does not appear to have a vasodilatory role in cutaneous reactive hyperaemia. [source]

    Mechanisms of acetylcholine-mediated vasodilatation in young and aged human skin

    THE JOURNAL OF PHYSIOLOGY, Issue 3 2005
    Lacy A. Holowatz
    Thermoregulatory cutaneous vasodilatation (VD) is attenuated in aged skin. While acetylcholine (ACh) plays a role in thermally mediated VD, the precise mechanisms through which ACh-mediated VD acts and whether those downstream mechanisms change with ageing are unclear. We tested the hypotheses that both nitric oxide (NO)- and prostanoid-mediated pathways contribute to exogenous ACh-mediated VD, and that both are attenuated with advanced age. Twelve young (Y: 23 ± 1 years) and 10 older (O: 69 ± 1 years) subjects underwent infusions of 137.5 ,m ACh at four intradermal microdialysis sites: control (C, Ringer solution), NO synthase inhibited (NOS-I, 10 mml -NAME), cyclooxygenase inhibited (COX-I, 10 mm ketorolac) and NOS-I + COX-I. Red blood cell flux was monitored using laser-Doppler flowmetry, and cutaneous vascular conductance (CVC) was calculated (laser-Doppler flux/mean arterial pressure) and normalized to maximal CVC (%CVCmax) (28 mm sodium nitroprusside + local heating to 43°C). Baseline %CVCmax was increased in the O at COX-I sites (COX-I 16 ± 1, NOS-I + COX-I 16 ± 2 versus C 10 ± 1%CVCmax; P < 0.001) but not in the young, suggesting an age-related shift toward COX vasoconstrictors contributing to basal cutaneous vasomotor tone. There was no difference in peak %CVCmax during ACh infusion between age groups, and the response was unchanged by NOS-I (O: NOS-I 35 ± 5 versus C 38 ± 5%CVCmax; P= 0.84) (Y: NOS-I 41 ± 4 versus C 39 ± 4%CVCmax; P= 0.67). COX-I and NOS-I + COX-I attenuated the peak CVC response to ACh in both groups (COX-I O: 29 ± 3, Y: 22 ± 2%CVCmaxversus C; P < 0.001 both groups; NOS-I + COX-I O: 32 ± 3 versus Y: 29 ± 2%CVCmax; versus C; P < 0.001 both groups). ACh mediates cutaneous VD through prostanoid and non-NO-, non-prostanoid-dependent pathways. Further, older subjects have a diminished prostanoid contribution to ACh-mediated VD. [source]

    Response properties of isolated mouse olfactory receptor cells

    THE JOURNAL OF PHYSIOLOGY, Issue 1 2001
    Johannes Reisert
    1Response properties of isolated mouse olfactory receptor cells were investigated using the suction pipette technique. Cells were exposed to the odour cineole or to solutions of modified ionic content by rapidly changing the solution superfusing the cilia. All experiments were performed at 37°C. 2Mouse olfactory receptor cells displayed a steep dependence of action potential frequency on stimulus concentration, a 3-fold increase in stimulus concentration often saturating the firing frequency at 200-300 Hz. The receptor current increased more gradually with increasing cineole concentration and did not saturate within the 100-fold range of cineole concentrations applied. 3When stimulated for 30 s with a low odour concentration, cells responded with sporadic spike firing. Higher concentrations led to the generation of a large receptor current at the onset of stimulation which returned to baseline levels within a few seconds, accompanied during its rising phase by a short burst of action potentials. Thereafter an oscillating response pattern was observed during the remainder of the stimulus, consisting of repetitive increases in receptor current of around 1 s duration accompanied by short bursts of action potentials. 4Olfactory adaptation was studied by comparing the responses to two closely spaced odour stimuli. The response to the second odour stimulus recovered to 80% of its original magnitude when the cell was superfused with Ringer solution during the 5 s interval between odour exposures. In contrast, exposure to a choline-substituted low Na+ solution between odour stimuli had two effects. First, the receptor current response to the first odour stimulus did not terminate as quickly as in the presence of Na+, suggesting the presence of a Na+ -Ca2+ exchanger. Second, the response to the second stimulus only recovered to 55% of its original magnitude, demonstrating the involvement of Na+ -Ca2+ exchange in the recovery of sensitivity in mouse olfactory receptor cells following stimulation. [source]

    The effect of intracellular acidification on the relationship between cell volume and membrane potential in amphibian skeletal muscle

    THE JOURNAL OF PHYSIOLOGY, Issue 3 2005
    James A. Fraser
    The relationship between cell volume (Vc) and membrane potential (Em) in Rana temporaria striated muscle fibres was investigated under different conditions of intracellular acidification. Confocal microscope xz -scanning monitored the changes in Vc, whilst conventional KCl and pH-sensitive microelectrodes measured Em and intracellular pH (pHi), respectively. Applications of Ringer solutions with added NH4Cl induced rapid reductions in Vc that rapidly reversed upon their withdrawal. These could be directly attributed to the related alterations in extracellular tonicity. However: (1) a slower and persistent decrease in Vc followed the NH4Cl withdrawal, leaving Vc up to 10% below its resting value; (2) similar sustained decreases in resting Vc were produced by the addition and subsequent withdrawal of extracellular solutions in which NaCl was isosmotically replaced with NH4Cl; (3) the same manoeuvres also produced a marked intracellular acidification, that depended upon the duration of the preceding exposure to NH4Cl, of up to 0.53 ± 0.10 pH units; and (4) the corresponding reductions in Vc similarly increased with this exposure time. These reductions in Vc persisted and became more rapid with Cl, deprivation, thus excluding mechanisms involving either direct or indirect actions of pHi upon Cl, -dependent membrane transport. However they were abolished by the Na+,K+ -ATPase inhibitor ouabain. The Em changes that accompanied the addition and withdrawal of NH4+ conformed to a Nernst equation modified to include realistic NH4+ permeability terms, and thus the withdrawal of NH4+ restored Em to close to control values despite a persistent change in Vc. Finally these Em changes persisted and assumed faster kinetics with Cl, deprivation. The relative changes in Vc, Em and pHi were compared to predictions from the recent model of Fraser and Huang published in 2004 that related steady-state values of Vc and Em to the mean charge valency (zx) of intracellular membrane-impermeant anions, X,i. By assuming accepted values of intracellular buffering capacity (,i), intracellular acidification was shown to produce quantitatively predictable decreases in Vc. These findings thus provide experimental evidence that titration of the anionic zx by increased intracellular [H+] causes cellular volume decrease in the presence of normal Na+,K+ - ATPase activity, with Cl, -dependent membrane fluxes only influencing the kinetics of such changes. [source]

    Oxytocin,ergometrine co-administration does not reduce blood loss at caesarean delivery for labour arrest,

    BJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 5 2008
    M Balki
    Objective, To determine if intravenous infusion of a combination of oxytocin and ergometrine maleate is better than oxytocin alone to decrease blood loss at caesarean delivery for labour arrest. Design, Prospective, double-blinded, randomised controlled trial. Setting, Mount Sinai Hospital, Toronto, Canada. Population, Women undergoing caesarean deliveries for labour arrest. Methods, Forty-eight women were randomised to receive infusion of either ergometrine maleate 0.25 mg + oxytocin 20 iu or oxytocin 20 iu alone, diluted in 1 l of lactated Ringer's Solution, immediately after delivery of the infant. Unsatisfactory uterine contractions after delivery were treated with additional boluses of the study solution or rescue carboprost. Blood loss was estimated based on the haematocrit values before and 48 hours after delivery. Main outcome measures, The primary outcome was the estimated blood loss, while the secondary outcomes included the use of additional uterotonics, need for blood transfusion and the incidence of adverse effects. Results, The estimated blood loss was similar in the oxytocin,ergometrine and oxytocin-only groups; 1218 ± 716 ml and 1299 ± 774 ml, respectively (P= 0.72). Significantly fewer women required additional boluses of the study drug in the oxytocin,ergometrine group (21 and 57%; P= 0.01). Nausea (42 and 9%; P= 0.01) and vomiting (25 and 4%; P= 0.05) were significantly more prevalent in the oxytocin,ergometrine group. Conclusions, In women undergoing caesarean delivery for labour arrest, the co-administration of ergometrine with oxytocin does not reduce intraoperative blood loss, despite apparently superior uterine contraction. [source]

    Effects of Delaying Fluid Resuscitation on an Injury to the Systemic Arterial Vasculature

    ACADEMIC EMERGENCY MEDICINE, Issue 4 2002
    James F. Holmes MD
    Abstract. Objectives: To determine the effects of delaying fluid on the rate of hemorrhage and hemodynamic parameters in an injury involving the arterial system. Methods: Twenty-one adult, anesthetized sheep underwent left anterior thoracotomy and transection of the left internal mammary artery. A chest tube was inserted into the thoracic cavity to provide a continuous measurement of blood loss. The animals were randomly assigned to one of three resuscitation protocols: 1) no fluid resuscitation (NR), 2) standard fluid resuscitation (SR) begun 15 minutes after injury, or 3) delayed fluid resuscitation (DR) begun 30 minutes after injury. All of the animals in the two resuscitation groups received 60 mL/kg of lactated Ringer's solution over 30 minutes. Blood loss and hemodynamic parameters were measured throughout the experiment. Results: Total hemorrhage volume (mean ± SD) at the end of the experiment was significantly lower (p = 0.006) in the NR group (1,499 ± 311 mL) than in the SR group (3,435 ± 721 mL) or the DR group (2,839 ± 1549 mL). Rate of hemorrhage followed changes in mean arterial pressure in all groups. Hemorrhage spontaneously ceased significantly sooner (p = 0.007) in the NR group (21 ± 14 minutes) and the DR group (20 ± 15 minutes) than in the SR group (54 ± 4 minutes). In the DR group, after initial cessation of hemorrhage, hemorrhage recurred in five of six animals (83%) with initiation of fluid resuscitation. Maximum oxygen (O2) delivery in each group after injury was as follows: 101 ± 34 mL O2/kg/min at 45 minutes in the DR group, 51 ± 20 mL O2/kg/min at 30 minutes in the SR group, and 35 ± 8 mL O2/kg/min at 60 minutes in the NR group. Conclusions: Rates of hemorrhage from an arterial injury are related to changes in mean arterial pressure. In this animal model, early aggressive fluid resuscitation in penetrating thoracic trauma exacerbates total hemorrhage volume. Despite resumption of hemorrhage from the site of injury, delaying fluid resuscitation results in the best hemodynamic parameters. [source]

    Identification of organic eluates from four polymer-based dental filling materials

    EUROPEAN JOURNAL OF ORAL SCIENCES, Issue 3 2003
    Vibeke Barman Michelsen
    Elution from polymer-based dental filling materials may have a potential impact on the biocompatibility of the materials. Since information from the manufacturers about ingredients in the materials often is incomplete, analyses of eluates from the materials are necessary for a better knowledge about possible harmful compounds. The aim of this study was to identify organic eluates from polymerized samples of two composites, one compomer and one resin-reinforced glass ionomer cement. Samples were immersed in ethanol or Ringer's solution. Organic leachables were analyzed by gas chromatography,mass spectrometry. Identification was confirmed with reference substances, if available. Among components detected were monomers, co-monomers, initiators, stabilizers, decomposition products and contaminants. Thirty-two substances were identified and 17 were confirmed with reference substances. From elution in Ringer's we identified 13 eluates from Tetric Ceram, 10 from Z250, 21 from Dyract and six from Fuji II LC; HEMA, HC and CQ were found in all samples. From elution in ethanol 12 eluates from Tetric Ceram, 18 eluates from Z250, 19 from Dyract and 10 from Fuji II LC were identified. The diversity of eluates from the four materials under study is demonstrated. Owing to variation between the materials, the biocompatibility including the allergenic potential may be different. [source]

    Characterization of Ti-Ta Alloys Synthesized by Cold Crucible Levitation Melting,

    ADVANCED ENGINEERING MATERIALS, Issue 8 2008
    D.-M. Gordin
    Ti-Ta alloys are potentially interesting for many applications including chemistry industries, marine environment and biomedical devices. In this study, the Ti-Ta alloys were synthesized by cold crucible levitation melting (CCLM) in the whole range of composition. The different microstructures were characterized by X-ray diffraction and optical microscopy, the ,-transus was detected by electrical resistivity, the mechanical properties were evaluated by compression tests and microhardness measurements and the electrochemical behavior was carried out in Ringer's solution. [source]

    Dorsal onlay augmentation urethroplasty with small intestinal submucosa: Modified Barbagli technique for strictures of the bulbar urethra

    INTERNATIONAL JOURNAL OF UROLOGY, Issue 11 2006
    IVO I DONKOV
    Aim: To present the results from one clinic's experience of using small intestinal submucosa (SIS) in augmentation urethroplasty for management of strictures of the bulbar urethra. Methods: Urethral surgery was performed in nine men with strictures 4,6 cm. All of the patients were evaluated by history, physical examination, retrograde urethrogram, and uroflowmetry. Four layers of SIS were soaked in saline or Ringer's solution for 15 minutes at 37°C, and the inner surface of the patch was gently fenestrated with a thin scalpel. The patch was spread-fixed onto the tunica albuginea. The mucosa was sutured to the submucosal graft first at 2,3 mm inwards from the SIS margins, then the spongiosum tissue was attached to the margins with interrupted absorbable sutures. Results: Of the nine patients who underwent augmentation urethroplasty using SIS, only one had re-stricture at 6 months due to urethral infection. At 18 months after the surgery the uroflowmetry of the other eight patients was 20,21 mL/s. In terms of complications, six patients reported having post-micturition dribbling, and seven patients reported lack of morning erections for 35,69 days after surgery. Conclusions: Using SIS is a safe procedure; however, long-term follow-up is needed to substantiate the good short-term results. [source]

    Infusion of hypertonic saline/starch during cardiopulmonary bypass reduces fluid overload and may impact cardiac function

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2010
    V. L. KVALHEIM
    Objective: Peri-operative fluid accumulation resulting in myocardial and pulmonary tissue edema is one possible mechanism behind post-operative cardiopulmonary dysfunction. This study aimed to confirm an improvement of cardiopulmonary function by reducing fluid loading during an open-heart surgery. Materials and methods: Forty-nine elective CABG patients were randomized to an intraoperative infusion of hypertonic saline/hydroxyethyl starch (HSH group) or Ringer's solution (CT group). Both groups received 1 ml/kg/h of the study solution for 4 h after baseline values were obtained (PICCO® transpulmonary thermodilution technique). Net fluid balance (NFB), hemodynamic and laboratory parameters were measured. Results: NFB was four times higher in the CT group compared with the HSH group during the first 6 h post-operatively. The total fluid gain until the next morning was lower in the HSH group, 2993.9 (938.6) ml, compared with the CT group, 4298.7 (1059.3) ml (P<0.001). Normalized values (i.e., %-changes from the baseline) of the cardiac index and the global end diastolic volume index increased post-operatively in both groups. Both parameters were significantly higher at 6 h in the HSH group compared with CT group (P=0.002 and 0.005, respectively). Normalized values of the intrathoracic blood volume index were lower in the HSH group at 6 h post-operatively when compared with the CT group. The PaO2/FiO2 ratio decreased similarly in both groups early post-operatively, but recovery tended to be more rapid in the HSH group. Although serum-sodium and serum-chloride levels were significantly higher in the HSH group, the acid,base parameters remained similar and within the normal range. Conclusions: An intraoperative infusion of HSH during cardiac surgery contributes to reduced fluid loading and an improvement in the post-operative cardiac performance. No adverse effects of the HSH infusion were observed. [source]

    Successful rotational thromboelastometry-guided treatment of traumatic haemorrhage, hyperfibrinolysis and coagulopathy

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 1 2010
    M. BRENNI
    Transfusion of allogeneic blood products is associated with increased morbidity and mortality. Therefore, strategies for reducing transfusion of these products during trauma management are valuable. We report a case of severe blunt abdominal trauma, successfully treated with antifibrinolytic medication and fibrinogen concentrate. Rotational thromboelastometry (ROTEM) was used to identify hyperfibrinolysis and afibrinogenaemia. In order to achieve haemostasis, over a 3-h period, the patient received a total of 1 g of tranexamic acid, 7 U of packed red blood cells, 16 g of fibrinogen concentrate (Haemocomplettan P), 3500 ml of colloids and 5500 ml of lactated Ringer's solution. Together with surgical measures, this treatment stopped the bleeding and stabilised the patient. There was no transfusion of either fresh-frozen plasma or platelets. The limited need for allogeneic blood products is of particular interest, and clinical studies of the approach used here appear to be warranted. [source]

    Prehospital therapeutic hypothermia for comatose survivors of cardiac arrest: a randomized controlled trial

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 7 2009
    A. KÄMÄRÄINEN
    Background: Intravenous infusion of ice-cold fluid is considered a feasible method to induce mild therapeutic hypothermia in cardiac arrest survivors. However, only one randomized controlled trial evaluating this treatment exists. Furthermore, the implementation rate of prehospital cooling is low. The aim of this study was to evaluate the efficacy and safety of this method in comparison with conventional therapy with spontaneous cooling often observed in prehospital patients. Methods: A randomized controlled trial was conducted in a physician-staffed helicopter emergency medical service. After successful initial resuscitation, patients were randomized to receive either +4 °C Ringer's solution with a target temperature of 33 °C or conventional fluid therapy. As an endpoint, nasopharyngeal temperature was recorded at the time of hospital admission. Results: Out of 44 screened patients, 19 were analysed in the treatment group and 18 in the control group. The two groups were comparable in terms of baseline characteristics. The core temperature was markedly lower in the hypothermia group at the time of hospital admission (34.1±0.9 °C vs. 35.2±0.8 °C, P<0.001) after a comparable duration of transportation. Otherwise, there were no significant differences between the groups regarding safety or secondary outcome measures such as neurological outcome and mortality. Conclusion: Spontaneous cooling alone is insufficient to induce therapeutic hypothermia before hospital admission. Infusion of ice-cold fluid after return of spontaneous circulation was found to be well tolerated and effective. This method of cooling should be considered as an important first link in the ,cold chain' of prehospital comatose cardiac arrest survivors. [source]

    Antibiotic resistance profile of the subgingival microbiota following systemic or local tetracycline therapy

    JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 6 2004
    Rosa Maria J. Rodrigues
    Abstract Background: Tetracyclines have been extensively used as adjunctives to conventional periodontal therapy. Emergence of resistant strains, however, has been reported. This study evaluated longitudinally the tetracycline resistance patterns of the subgingival microbiota of periodontitis subjects treated with systemic or local tetracycline therapy+scaling and root planing (SRP). Methods: Thirty chronic periodontitis patients were randomly assigned to three groups: SRP+500 mg of systemic tetracycline twice/day for 14 days; SRP alone and SRP+tetracycline fibers (Actsite®) at four selected sites for 10 days. Subgingival plaque samples were obtained from four sites with probing pocket depths (PPD)6 mm in each patient at baseline, 1 week, 3, 6 and 12 months post-therapy. Samples were dispersed and diluted in pre-reduced anaerobically sterilized Ringer's solution, plated on Trypticase Soy Agar (TSA)+5% blood with or without 4 ,g/ml of tetracycline and incubated anaerobically for 10 days. The percentage of resistant microorganisms were determined and the isolates identified by DNA probes and the checkerboard method. Significance of differences among and within groups over time was sought using the Kruskal,Wallis and Friedman tests, respectively. Results: The percentage of resistant microorganisms increased significantly at 1 week in the tetracycline groups, but dropped to baseline levels over time. The SRP+Actsite® group presented the lowest proportions of resistant species at 6 and 12 months. No significant changes were observed in the SRP group. The predominant tetracycline-resistant species included Streptococcus spp., Veillonela parvula, Peptostreptococcus micros, Prevotella intermedia, Gemella morbillorum and Actinobacillus actinomycetemcomitans (Aa). A high percentage of sites with resistant Aa, Porphyromonas gingivalis and Tanerella forsythensis was observed in all groups at baseline. However, T. forsythensis was not detected in any group and P. gingivalis was not present in the SRP+Actsite® group at 1 year post-therapy. Aa was still frequently detected in all groups after therapy. However, the greatest reduction was observed in the SRP+Actsite® group. Conclusion: Local or systemically administered tetracycline results in transitory selection of subgingival species intrinsically resistant to this drug. Although the percentage of sites harboring periodontal pathogens resistant to tetracycline were quite elevated in this population, both therapies were effective in reducing their prevalence over time. [source]

    Anandamide administration alone and after inhibition of fatty acid amide hydrolase (FAAH) increases dopamine levels in the nucleus accumbens shell in rats

    JOURNAL OF NEUROCHEMISTRY, Issue 2 2006
    Marcello Solinas
    Abstract Although endogenous cannabinoid systems have been implicated in the modulation of the rewarding effects of abused drugs and food, little is known about the direct effects of endogenous ligands for cannabinoid receptors on brain reward processes. Here we show for the first time that the intravenous administration of anandamide, an endogenous ligand for cannabinoid receptors, and its longer-lasting synthetic analog methanandamide, increase the extracellular dopamine levels in the nucleus accumbens shell of awake, freely moving rats, an effect characteristic of most drugs abused by humans. Anandamide produced two distinctly different effects on dopamine levels: (1) a rapid, transient increase that was blocked by the cannabinoid CB1 receptor antagonist rimonabant, but not by the vanilloid VR1 receptor antagonist capsazepine, and was magnified and prolonged by the fatty acid amide hydrolase (FAAH) enzyme inhibitor, URB597; (2) a smaller delayed and long-lasting increase, not sensitive to CB1, VR1 or FAAH blockade. Both effects were blocked by infusing either tetrodotoxin (TTX, 1 µm) or calcium-free Ringer's solution through the microdialysis probe, demonstrating that they were dependent on the physiologic activation of dopaminergic neurotransmission. Thus, these results indicate that anandamide, through the activation of the mesolimbic dopaminergic system, participates in the signaling of brain reward processes. [source]

    In Vivo Modulation of Post-Spike Excitability in Vasopressin Cells by ,-Opioid Receptor Activation

    JOURNAL OF NEUROENDOCRINOLOGY, Issue 8 2000
    C. H. Brown
    Abstract An endogenous ,-opioid agonist reduces the duration of phasic bursts in vasopressin cells. Non-synaptic post-spike depolarizing after-potentials underlie activity during bursts by increasing post-spike excitability and ,-receptor activation reduces depolarizing after-potential amplitude in vitro. To investigate the effects of ,-opioids on post-spike excitability in vivo, we analysed extracellular recordings of the spontaneous activity of identified supraoptic nucleus vasopressin cells in urethane-anaesthetized rats infused with Ringer's solution (n = 17) or the ,-agonist, U50,488H (2.5 µg/h at 0.5 µl/h; n = 23), into the supraoptic nucleus over 5 days. We plotted the mean hazard function for the interspike interval distributions as a measure of the post-spike excitability of these cells. Following each spike, the probability of another spike firing in vasopressin cells recorded from U50,488H infused nuclei was markedly reduced compared to Ringer's treated vasopressin cells. To determine whether U50,488H could reduce post-spike excitability in cells that displayed spontaneous phasic activity, we infused U50,488H (50 µg/h at 1 µl/h, i.c.v.), for 1,12 h while recording vasopressin cell activity. Nine of 10 vasopressin cells were silenced by i.c.v. U50,488H 15 ± 5 min into the infusion. Six cells exhibited spontaneous phasic activity before U50,488H infusion and recordings from three of these phasic cells were maintained until activity recovered; during U50,488H infusion, the activity of these three cells was irregular. Generation of the mean hazard function before and during U50,488H infusion revealed a reduction in post-spike excitability during U50,488H infusion. Thus, ,-receptor activation reduces post-spike excitability in vivo; this may reflect inhibition of depolarizing after-potentials and may thus underlie the reduction in burst duration of vasopressin cells caused by an endogenous ,-agonist in vivo. [source]

    An in vitro assessment of the strength of porcelain veneers dependent on tooth preparation

    JOURNAL OF ORAL REHABILITATION, Issue 12 2000
    P. Hahn
    The treatment of teeth using veneer restorations combines aesthetic and functional improvements with a low destructive technique. Different kinds of tooth preparation techniques are described in the literature for this kind of restoration. This in vitro study aimed to examine the influence of the incisal preparation on the loadability of teeth restored with porcelain laminate veneers. Thirty-six selected mandibular incisors were randomly assigned to three groups with 12 teeth per group. In the first group, only the facial surface was prepared. In the second group, the preparation included a rounded incisal edge and a distinct chamfer lingually. The third group served as an unprepared control. Empress® veneers were then fabricated and cemented with a low viscous luting composite material. After 120 days storage in Ringer's solution, the specimens were loaded incisally to the point of failure. Statistical analysis of the results showed significant differences between the series (P=0·0103). Group 2 (with preparation of the incisal edge) exhibited the lowest fracture resistance (466±99 N) (N, mean forces). When prepared only facially, the teeth restored with Empress® veneers reached the strength of unprepared teeth. Compared with the biting force described for incisors in the literature, the in vitro loadability reached in this investigation seems to jusitify the clinical use of both preparation designs tested. [source]

    Calcium Phosphate Bioceramics with Various Porosities and Dissolution Rates

    JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 12 2002
    Soon-Ho Kwon
    Porous bioceramics, such as hydroxyapatite (HA), tricalcium phosphate (TCP), and biphasic HA/TCP, were fabricated using the polyurethane sponge technique. The porosity of the ceramics was controlled by a multiple coating of the porous body. When a porous body was produced by a single coating, the porosity was ,90%, and the pores were completely interconnected. When the sintered body was coated five times after the porous network had been made, the porosity decreased to 65%. As the porosity decreased, the strength increased exponentially. The TCP exhibited the highest dissolution rate in a Ringer's solution, and the HA had the lowest rate. The biphasic HA/TCP showed an intermediate dissolution rate. [source]

    Corrosion behavior of Ti-xNb-13Zr alloys in Ringer's solution

    MATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 12 2008
    A. Robin
    Abstract Ti-6Al-4V alloy has been widely used in restorative surgery due to its high corrosion resistance and biocompatibility. Nevertheless, some studies showed that V and Al release in the organism might induce cytotoxic effects and neurological disorders, which led to the development of V-free alloys and both V- and Al-free alloys containing Nb, Zr, Ta, or Mo. Among these alloys, Ti-13Nb-13Zr alloy is promising due to its better biomechanical compatibility than Ti-6Al-4V. In this work, the corrosion behavior of Ti, Ti-6Al-4V, and Ti-xNb-13Zr alloys (x,=,5, 13, and 20) was evaluated in Ringer's solution (pH 7.5) at 37,°C through open-circuit potential measurements, potentiodynamic polarization, and electrochemical impedance spectroscopy. Spontaneous passivity was observed for all materials in this medium. Low corrosion current densities (in the order of 10,7 A/cm2) and high impedance values (in the order of 105 ,cm2 at low frequencies) indicated their high corrosion resistance. EIS results showed that the passivating films were constituted of an outer porous layer (very low resistance) and an inner compact layer (high resistance), the latter providing the corrosion resistance of the materials. There was evidence that the Ti-xNb-13Zr alloys were more corrosion resistant than both Ti and Ti-6Al-4V in Ringer's solution. [source]

    Influence of microstructural changes on corrosion behaviour of thermally aged Ti-6Al-7Nb alloy

    MATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 5 2004
    L. Thair
    Abstract Solution treatment and ageing (STA) is an effective strengthening method for , + , titanium alloys. This paper reports the effect of solution treatment and aging on the corrosion behaviour of Ti-6Al-7Nb alloy in a simulated body fluid (Ringer's solution). Ti-6Al-7Nb alloy is hot rolled in the , + , field and subjected to solution treatment above and below its beta transus temperature (1283 K). The solution treated specimens are water quenched (WQ), air-cooled (AC), and furnace cooled (FC) at three different rates, and subsequently aged at 823 K for 4 h. Microstructural changes were examined using optical microscopy and phases developed were analyzed using XRD. The influence of microstructure on the corrosion performance of the alloys are discussed in detail based on the Open Circuit Potential (OCP), passive current density and area of repassivation loop values obtained from the cyclic polarization study in Ringer's solution. The passive current density was low (0.5 ,A/cm2) for the specimen with duplex microstructure obtained for specimen solution treated at 1223 K, air-cooled, and aged, in comparison with that for as-rolled specimen (1.5 ,A/cm2). The corrosion aspects resulting from various heat treatments are discussed in detail. [source]

    Marked sperm dimorphism in the ground beetle Scarites terricola: a novel type of insect sperm polymorphism

    PHYSIOLOGICAL ENTOMOLOGY, Issue 4 2009
    KŌJI SASAKAWA
    Abstract. Sperm polymorphism describes the phenomenon of male ejaculates containing two or more distinct types of sperm. In insects, four types of sperm polymorphism are recognized in species from the orders Diptera, Hemiptera, Hymenoptera, Lepidoptera and Coleoptera. The present study describes dimorphic sperm of the ground beetle Scarites terricola (Coleoptera: Carabidae) as a novel type of sperm polymorphism in insects. Sperm from the spermatophore and male seminal vesicles are examined at the light-microscopic level, and both display marked dimorphism. One type has sperm formed into bundles, in which the head of numerous spermatozoa are ,glued' together, with tails free-moving. The other type are free as single spermatozoa and have a disproportionately large-sized head and an elongated tail. Both types are motile in Ringer's solution. The adaptive and phylogenetic importance of these findings is discussed. [source]

    Evaluation of Membrane Oxygenators and Reservoirs in Terms of Capturing Gaseous Microemboli and Pressure Drops

    ARTIFICIAL ORGANS, Issue 11 2009
    Yulong Guan
    Abstract An increasing amount of evidence points to cerebral embolization during cardiopulmonary bypass (CPB) as the principal etiologic factor of neurologic complications. In this study, the capability of capturing and classification of gaseous emboli and pressure drop of three different membrane oxygenators (Sorin Apex, Terumo Capiox SX25, Maquet QUADROX) were measured in a simulated adult model of CPB using a novel ultrasound detection and classification quantifier system. The circuit was primed with 1000 mL heparinized human packed red blood cells and 1000 mL lactated Ringer's solution (total volume 2000 mL, corrected hematocrit 26,28%). After the injection of 5 mL air into the venous line, an Emboli Detection and Classification Quantifier was used to simultaneously record microemboli counts at post-pump, post-oxygenator, and post-arterial filter sites. Trials were conducted at normothermic (35°C) and hypothermic (25°C) conditions. Pre-oxygenator and post-oxygenator pressure were recorded in real time and pressure drop was calculated. Maquet QUADROX membrane oxygenator has the lowest pressure drops compared to the other two oxygenators (P < 0.001). The comparison among the three oxygenators indicated better capability of capturing gaseous emboli with the Maquet QUADROX and Terumo Capiox SX25 membrane oxygenator and more emboli may pass through the Sorin Apex membrane oxygenator. Microemboli counts uniformly increased with hypothermic perfusion (25°C). Different types of oxygenators and reservoirs have different capability of capturing gaseous emboli and transmembrane pressure drop. Based on this investigation, Maquet QUADROX membrane oxygenator has the lowest pressure drop and better capability for capturing gaseous microemboli. [source]

    Effect of intravenous infusion time on the pharmacokinetics and pharmacodynamics of the same total dose of torasemide in rabbits

    BIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 5 2004
    Yu C. Kim
    Abstract The pharmacokinetics and pharmacodynamics of torasemide were evaluated after intravenous administration of the same total dose of torasemide at a dose of 1mg/kg to rabbits with different infusion times, 1 min (treatment I), 30 min (treatment II) and 2 h (treatment III). The loss of water and electrolytes in urine induced by torasemide was immediately replaced with infusion of an equal volume of lactated Ringer's solution. All the pharmacokinetic parameters of torasemide, such as total area under the plasma concentration,time curve from time zero to time infinity (AUC), total body clearance (CL), apparent volume of distribution at steady state (Vss), terminal half-life and mean residence time (MRT), were independent of infusion times. However, the 8h urine output (235, 534 and 808 ml) and 8h urinary excretion of sodium (24.2, 80.1 and 89.2 mmol) and chloride (27.1, 89.2 and 94.0 mmol) were significantly greater in treatments II and III than those in treatment I, although the total 8 h urinary excretion of unchanged torasemide (1210, 1210 and 1310 µg) were not significantly different among the three treatments. This could be due to the higher diuretic efficiencies in treatments II and III. Copyright © 2004 John Wiley & Sons, Ltd. [source]