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Volume Expansion (volume + expansion)
Kinds of Volume Expansion Selected AbstractsLoop Diuretics Can Cause Clinical Natriuretic Failure: A Prescription for Volume ExpansionCONGESTIVE HEART FAILURE, Issue 1 2009Syed S. Ali MD Ultrafiltration enhances volume removal and weight reduction vs diuretics. However, their differential impact on total body sodium, potassium, and magnesium has not been described. Fifteen patients with congestion despite diuretic therapy had urine electrolytes measured after a diuretic dose. Ultrafiltration was initiated and ultrafiltrate electrolytes were measured. The urine sodium after diuretics (60±47 mmol/L) was less than in the ultrafiltrate (134±8.0 mmol/L) (P=.000025). The urine potassium level after diuretics (41±23 mmol/L) was greater than in the ultrafiltrate (3.7±0.6 mmol/L) (P=.000017). The urine magnesium level after diuretics (5.2±3.1 mg/dL) was greater than in the ultrafiltrate (2.9±0.7 mg/dL) (P=.017). In acute decompensated heart failure patients with congestion despite diuretic therapy, diuretics are poor natriuretics and cause significant potassium and magnesium loss. Ultrafiltration extracts more sodium while sparing potassium and magnesium. The sustained clinical benefits of ultrafiltration compared with diuretics may be partly related to their disparate effects on total body sodium, potassium, and magnesium, in addition to their differential efficacy of volume removal. [source] N -Acetylcysteine Added to Volume Expansion with Sodium Bicarbonate Does Not Further Prevent Contrast-Induced Nephropathy: Results from the Cardiac Angiography in Renally Impaired Patients StudyJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 3 2009CEZAR S. STANILOAE M.D. We reviewed data from the multicenter CARE (Cardiac Angiography in Renally Impaired Patients) study to see if benefit could be shown for N-acetylcysteine (NAC) in patients undergoing cardiac angiography who all received intravenous bicarbonate fluid expansion. Four hundred fourteen patients with moderate-to-severe chronic kidney disease were randomized to receive intra-arterial administration of iopamidol-370 or iodixanol-320. All patients were prehydrated with isotonic sodium bicarbonate solution. Each site chose whether or not to administer NAC 1,200 mg twice daily to all patients. Serum creatinine (SCr) levels and estimated glomerular filtration rate were assessed at baseline and 2,5 days after receiving contrast. The primary outcome was a postdose SCr increase 0.5 mg/dL (44.2 ,mol/L) over baseline. Secondary outcomes were a postdose SCr increase 25% and the mean peak change in SCr. The NAC group received significantly less hydration (892 ± 236 mL vs. 1016 ± 328 mL; P < 0.001) and more contrast volume (146 ± 74 mL vs. 127 ± 71 mL; P = 0.009) compared with no-NAC group. SCr increases 0.5 mg/dL occurred in 4.2% (7 of 168 patients) in NAC group and 6.5% (16 of 246 patients) in no-NAC group (P = 0.38); rates of SCr increases 25% were 11.9% and 10.6%, respectively (P = 0.75); mean post-SCr increases were 0.07 mg/dL in NAC group versus 0.11 mg/dL in no-NAC group (P = 0.14). In conclusion, addition of NAC to fluid expansion with sodium bicarbonate failed to reduce the rate of contrast-induced nephropathy (CIN) after the intra-arterial administration of iopamidol or iodixanol to high-risk patients with chronic kidney disease. [source] Cruciform fillet welded joint fatigue strength improvements by weld metal phase transformationsFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 2 2008PH. P. DARCIS ABSTRACT Arc welding typically generates residual tensile stresses in welded joints, leading to deteriorated fatigue performance of these joints. Volume expansion of the weld metal at high temperatures followed by contraction during cooling induces a local tensile residual stress state. A new type of welding wire capable of inducing a local compressive residual stress state by means of controlled martensitic transformation at relatively low temperatures has been studied, and the effects of the transformation temperature and residual stresses on fatigue strength are discussed. In this study, several LTTW (Low Transformation-Temperature Welding) wires have been developed and investigated to better characterize the effect of phase transformation on residual stress management in welded joints. Non-load-carrying cruciform fillet welded joints were prepared for measurement of residual stresses and fatigue testing. The measurement of the residual stresses of the three designed wires reveals a compressive residual stress near the weld toe. The fatigue properties of the new wires are enhanced compared to a commercially available wire. [source] Excessive volume expansion and neonatal death in preterm infants born at 27,28 weeks gestationPAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 2 2003Andrew K. Ewer Summary Volume expansion is used commonly in preterm infants to treat presumed hypovolaemia. However, the amount that should be given is uncertain. We present data that were obtained from anonymised regional case notes of Project 27/28, a national case,controlled study run by the Confidential Enquiry into Stillbirths and Deaths in Infancy. Various clinical parameters were analysed, including the volume expansion administered during the first 48 h of life. All deaths in the first year of the study in the West Midlands (cases, n = 22) and matched regional controls (survivors, n = 29) were included. The primary outcome was death within 28 days. Sixteen of the 22 deaths were considered ,not inevitable' on the basis of the neonates' condition at birth. These newborns received on average more than twice the volume expansion compared with controls in the first 48 h of life (38.2 vs. 18.2 mL/kg, P = 0.007). There were no significant differences between the groups in lowest blood pressure or base deficit within the first 12 h of life. Newborns who received , 30 mL/kg volume expansion in the first 48 h of life were more likely to die than those who received < 30 mL/kg (OR 4.5 [95% CI 1.2, 17.2]). Our data suggest that administration of , 30 mL/kg volume expansion is associated with increased mortality in neonates of 27,28 weeks' gestation. Unless there is clear evidence of hypovolaemia, clinicians should exercise caution when prescribing volume expansion. [source] Forearm vascular and neuroendocrine responses to graded water immersion in humansACTA PHYSIOLOGICA, Issue 2 2000Gabrielsen The hypothesis that graded expansion of central blood volume by water immersion to the xiphoid process and neck would elicit a graded decrease in forearm vascular resistance was tested. Central venous pressure increased (P < 0.05) by 4.2 ± 0.4 mmHg (mean ± SEM) during xiphoid immersion and by 10.4 ± 0.5 mmHg during neck immersion. Plasma noradrenaline was gradually suppressed (P < 0.05) by 62 ± 8 and 104 ± 11 pg mL,1 during xiphoid and neck immersion, respectively, indicating a graded suppression of sympathetic nervous activity. Plasma concentrations of arginine vasopressin were suppressed by 1.5 ± 0.5 pg mL,1 (P < 0.05) during xiphoid immersion and by 2.0 ± 0.5 pg mL,1 during neck immersion (P < 0.05 vs. xiphoid immersion). Forearm subcutaneous vascular resistance decreased to the same extent by 26 ± 9 and 28 ± 4% (P < 0.05), respectively, during both immersion procedures, whereas forearm skeletal muscle vascular resistance declined only during neck immersion by 27 ± 6% (P < 0.05). In conclusion, graded central blood volume expansion initiated a graded decrease in sympathetic nervous activity and AVP-release. Changes in forearm subcutaneous vascular resistance, however, were not related to the gradual withdrawal of the sympathetic and neuroendocrine vasoconstrictor activity. Forearm skeletal muscle vasodilatation exhibited a more graded response with a detectable decrease only during immersion to the neck. Therefore, the forearm subcutaneous vasodilator response reaches saturation at a lower degree of central volume expansion than that of forearm skeletal muscle. [source] Acute Hypervolaemia Improves Arterial Oxygen Pressure in Athletes with Exercise-Induced HypoxaemiaEXPERIMENTAL PHYSIOLOGY, Issue 4 2003Gerald S. Zavorsky The aim of this study was to determine the effect of acute plasma volume expansion on arterial blood-gas status during 6.5 min strenuous cycling exercise comparing six athletes with and six athletes without exercise-induced arterial hypoxaemia (EIAH). We hypothesized that plasma volume expansion could improve arterial oxygen pressure in a homogeneous sample of athletes - those with EIAH. In this paper we have extended the analysis and results of our recently published surprising findings that lengthening cardiopulmonary transit time did not improve arterial blood-gas status in a heterogeneous sample of endurance cyclists. One 500 ml bag of 10% Pentastarch (infusion condition) or 60 ml 0.9% saline (placebo) was infused prior to exercise in a randomized, double-blind fashion on two different days. Power output, cardiac output, oxygen consumption and arterial blood gases were measured during strenuous exercise. Cardiac output and oxygen consumption were not affected by acute hypervolaemia. There were group × condition interaction effects for arterial oxygen pressure and alveolar-arterial oxygen pressure difference, suggesting that those with hypoxaemia experienced improved arterial oxygen pressure (+4 mmHg) and lower alveolar-arterial oxygen pressure difference (-2 mmHg) with infusion. In conclusion, acute hypervolaemia improves blood-gas status in athletes with EIAH. The impairment of gas exchange occurs within the first minute of exercise, and is not impaired further throughout the remaining duration of exercise. This suggests that arterial oxygen pressure is only minimally mediated by cardiac output. [source] Synthesis and Lithium Storage Properties of Co3O4 Nanosheet-Assembled Multishelled Hollow SpheresADVANCED FUNCTIONAL MATERIALS, Issue 10 2010Xi Wang Abstract Single-, double-, and triple-shelled hollow spheres assembled by Co3O4 nanosheets are successfully synthesized through a novel method. The possible formation mechanism of these novel structures was investigated using powder X-ray diffraction, scanning and transmission electron microscopies, Fourier transform IR, X-ray photoelectron spectroscopy, and thermogravimetric analysis. Both poly(vinylpyrrolidone) (PVP) soft templates and the formation of cobalt glycolate play key roles in the formation of these novel multishelled hollow structures. When tested as the anode material in lithium-ion batteries (LIBs), these multishelled microspheres exhibit excellent cycling performance, good rate capacity, and enhanced lithium storage capacity. This superior cyclic stability and capacity result from the synergetic effect of small diffusion lengths in the nanosheet building blocks and sufficient void space to buffer the volume expansion. This facile strategy may be extended to synthesize other transition metal oxide materials with hollow multishelled micro-/nanostrucutures, which may find application in sensors and catalysts due to their unique structural features. [source] Interdialytic blood pressure obtained by ambulatory blood pressure measurement and left ventricular structure in hypertensive hemodialysis patientsHEMODIALYSIS INTERNATIONAL, Issue 3 2008Siddig MOMINADAM Abstract Unlike in subjects with normal renal function, the relationship between hypertension and cardiovascular morbidity and mortality in dialysis patients is still being debated. In order to clarify this issue, we performed 44-hour ambulatory blood pressure measurements (ABPM) during the interdialytic period in a group of 164 hypertensive patients, the blood pressure (BP) control based on conventional antihypertensive strategy previously, on chronic hemodialysis treatment in the Mediterranean region of Turkey. These results were then compared with their echocardiographic data. This is a cross-sectional analysis. The mean ABPM during 44 hours was close to the manually measured predialysis value, but there was a gradual increase in the ABPM values in the interdialytic period. When divided into a group with mild or no left ventricular hypertrophy (LVH) (45 patients) and severe LVH (119 patients), the latter had significantly higher BP levels in all separate periods, while the difference in predialysis BP was not significant. Patients with severe LVH had larger left atrium and left ventricular diameters, and consumed more antihypertensive drugs. Systolic BP during the night before dialysis showed the strongest relation to LVH, but interdialytic weight gain was also independently related to LVH. Yet, 56% of the patients with systolic BP <135 had severe LVH. There is not only an association between BP and presence of LVH, but it is shown that volume expansion is also an important independent determinant of LVH. This may explain the difficulty in identifying hypertension as a cardiac risk factor in these patients. [source] Fabrication of Crack-Free C12A7 Nano-Ceramics Composite from Eutectic Glass in the C12A7,CaYAlO4 SystemINTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 4 2006Naonori Sakamoto Crack formation in the C12A7 nano-composite during crystallization was successfully avoided by using the eutectic glass in the C12A7,CaYAlO4 system. The crystal phases from the eutectic glass were identified to be C12A7 (major phase) and CaYAlO4 (minor phase) by X-ray diffraction and high-resolution transmission electron microscope. It was indicated that origin of cracks upon crystallization of C12A7 glass was the volume expansion caused by crystallization of C12A7 in the glass and the cracking could be avoided by the volume shrinkage by crystallization of CaYAlO4. By using a conventional molding technique, we have also succeeded to fabricate a bulk C12A7 composite with arbitrary shapes. [source] Obesity,hypertension: an ongoing pandemicINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 2 2007E. A. Francischetti Summary Considerable evidence has suggested that excessive weight gain is the most common cause of arterial hypertension. This association has been observed in several populations, in different regions of the world. Obesity,hypertension, a term that underscores the link between these two deleterious conditions, is an important public health challenge, because of its high frequency and concomitant risk of cardiovascular and kidney diseases. The obesity,hypertension pandemic imposes a considerable economic burden on societies, directly reflecting on healthcare system costs. Increased renal sodium reabsorption and blood volume expansion are central features in the development of obesity,hypertension. Overweight is also associated with increased sympathetic activity. Leptin, a protein expressed in and secreted by adipocytes, is the main factor linking obesity, increased sympathetic nervous system activity and hypertension. The renin,angiotensin,aldosterone system has also been causally implicated in obesity,hypertension, because angiotensinogen is expressed in and secreted by adipose tissue. Hypoadiponectinemia, high circulating levels of free fatty acids and increased vascular production of endothelin-1 (ET-1) have been reported as potential mechanisms for obesity,hypertension. Lifestyle changes are effective in obesity,hypertension control, though pharmacological treatment is frequently necessary. Despite the consistency of the mechanistic approach in explaining the causal relation between hypertension and obesity, there is yet no evidence that one class of drug is superior to the others in controlling obesity,hypertension. In this review, we present the current knowledge and research in obesity,hypertension, exploring the epidemiologic evidence of the association, its probable pathophysiological mechanisms and treatment issues. [source] Automated pre-ejection period variation predicts fluid responsiveness in low tidal volume ventilated pigsACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2010S. T. VISTISEN Introduction: The respiratory variation in the pre-ejection period (,PEP) has been used to predict fluid responsiveness in mechanically ventilated patients. Recently, we automated this parameter and indexed it to tidal volume (PEPV) and showed that it was a reliable predictor for post-cardiac surgery, mainly paced, patients ventilated with low tidal volumes. The aims of the present animal study were to investigate PEPV's ability to predict fluid responsiveness under different fluid loading conditions and natural heart rates during low tidal volume ventilation (6 ml/kg) and to compare the performance of PEPV with other markers of fluid responsiveness. Methods: Eight prone, anesthetized piglets (23,27 kg) ventilated with tidal volumes of 6 ml/kg were subjected to a sequence of 25% hypovolemia, normovolemia, and 25% and 50% hypervolemia. PEPV, ,PEP, pulse pressure variation (PPV), central venous pressure (CVP), and pulmonary artery occlusion pressure (PAOP) were measured before each volume expansion. Results: Sensitivity was 89% and specificity was 93% for PEPV, 78% and 93% for ,PEP, 89% and 100% for PPV, 78% and 93% for CVP, and 89% and 87% for PAOP. Conclusion: PEPV predicts fluid responsiveness in low tidal volume ventilated piglets. [source] Automated pre-ejection period variation indexed to tidal volume predicts fluid responsiveness after cardiac surgeryACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2009S. T. VISTISEN Background: Reliable continuous monitoring of fluid responsiveness is an unsolved issue in patients ventilated with low tidal volume. We hypothesised that variations in the pre-ejection period (PEP) defined as the time interval between electrocardiogram (ECG) R-wave and onset of systolic upstroke in arterial blood pressure could reliably predict fluid responsiveness in patients ventilated with moderately low tidal volume. Furthermore, we hypothesised that indexing dynamic parameters to tidal volume would improve their prediction. The aim was to refine and automate a previously suggested algorithm for PEP variation (,PEP) and to test this new parameter indexed to tidal volume (PEPV), as a marker of fluid responsiveness along with central venous pressure (CVP), pulse pressure variation (PPV) and ,PEP. Additionally, the aim was to evaluate the concept of indexing dynamic parameters to tidal volume. Methods: Arterial pressure, CVP, ECG and cardiac index (CI) were acquired from 23 mechanically ventilated post-cardiac surgery patients scheduled for volume expansion. PEPV, PPV and ,PEP were extracted. Results: Using responder/non-responder classification (response=change in CI>+15%), sensitivity and specificity were 100% and 83%, respectively, for PEPV, 94% and 83% for ,PEP, and 94% and 83% for PPV. CVP offered no relevant information. Tidal volume indexing improved sensitivity for ,PEP to 100%. Conclusion: In this study in post-cardiac surgery patients, a refined parameter, PEPV, predicted fluid responsiveness better than PPV and ,PEP. Our results suggest that dynamic parameters using variations in PEP should be indexed to tidal volume. [source] Glial Limitans Elasticity Subjacent to the Supraoptic NucleusJOURNAL OF NEUROENDOCRINOLOGY, Issue 8 2004A. K. Salm Abstract Two previous studies from our laboratory have indicated that the ventral glial limitans subjacent to the hypothalamic supraoptic nucleus (SON-VGL) undergoes a reversible thinning upon chronic activation of the magnocellular neuroendocrine cells (MNCs) of the supraoptic nucleus (SON). Numerous other studies have shown that MNC somata hypertrophy with activation. One aim of the current study was to understand better how SON-VGL thinning occurs. A second aim was to quantify overall changes of the MNC somata region due to cellular hypertrophy to compare relative changes in dimensions. Here, we undertook a light microscopic stereological investigation of the SON and the subjacent SON-VGL of Nissl stained material under basal and activated conditions. Astrocyte numbers in the underlying SON-VGL remained stable across hydration state as did the overall volume of the SON-VGL and dendritic zone reference area. How these data are consistent with our earlier observations of SON-VGL thinning was resolved by the finding of a highly significant, 30% increase in the mediolateral dimension of the SON-VGL in dehydrated rats. These observations fit well with previous work from our laboratory that demonstrates a reorientation of SON-VGL astrocytes, from vertical to horizontal, which occurs in the activated SON-VGL. We found a significant, approximately 54%, increase in the overall volume of the MNC region of the SON. No significant rostrocaudal lengthening of the SON was detected, although a trend was evident. All the observed changes reversed with rehydration. These data indicate that elasticity of the SON-VGL acts to accommodate the volume expansion of the MNCs and enables the SON-VGL to continue as an interface between the underlying cerebrospinal fluid in the subarachnoid space and the expanded SON above. [source] Lateral parabrachial afferent areas and serotonin mechanisms activated by volume expansionJOURNAL OF NEUROSCIENCE RESEARCH, Issue 16 2008Lisandra Oliveira Margatho Abstract Recent evidence has shown that the serotonergic mechanism of the lateral parabrachial nucleus (LPBN) participates in the regulation of renal and hormonal responses to isotonic blood volume expansion (BVE). We investigated the BVE-induced Fos activation along forebrain and hindbrain nuclei and particularly within the serotonergic clusters of the raphé system that directly project to the LPBN. We also examined whether there are changes in the concentration of serotonin (5HT) within the raphé nucleus in response to the same stimulus. With this purpose, we analyzed the cells doubly labeled for Fos and Fluorogold (FG) following BVE (NaCl 0.15 M, 2 ml/100 g b.w., 1 min) 7 days after FG injection into the LPBN. Compared with the control group, blood volume-expanded rats showed a significant greater number of Fos-FG double-labeled cells along the nucleus of the solitary tract, locus coeruleus, hypothalamic paraventricular nucleus, central extended amygdala complex, and dorsal raphé nucleus (DRN) cells. Our study also showed an increase in the number of serotonergic DRN neurons activated in response to isotonic BVE. We also observed decreased levels of 5HT and its metabolite 5-hydroxyindoleacetic acid (measured by high-pressure liquid chromatography) within the raphé nucleus 15 min after BVE. Given our previous evidence on the role of the serotonergic system in the LPBN after BVE, the present morphofunctional findings suggest the existence of a key pathway (DRN-LPBN) that may control BVE response through the modulation of 5HT release. © 2008 Wiley-Liss, Inc. [source] Haemodilution induced by hydroxyethyl starches 130/0.4 is similar in septic and non-septic patientsACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2008P. MEYER Background: Fluid therapy induces haemodilution related to plasma volume expansion. The aim of our study was to compare haemodilution after a single hydroxyethyl starches (HES) 130/0.4 infusion in two groups of patients, one with and one without sepsis. We hypothesized that a single HES challenge would induce similar sustained haemodilution in both groups. Methods: In this prospective preliminary study, patients predicted to require a single further volume-expander infusion were included immediately before receiving 500 ml of 6% HES 130/0.4 over a 15-min period. No additional fluid was administered over the next 8 h. Haematocrit, and serum albumin and protein were determined immediately before HES infusion then after 1, 2, 3, 4, and 8 h. Results: Twelve patients were included in each group. In both groups, all three haemodilution markers had significantly lower values after 1 h than at baseline. None of the values after 1 and 3 h differed significantly between the two groups. Neither did any of the other study variables show significant differences between the groups with and without sepsis. Conclusion: We found that a starch-based compound was as effective in inducing haemodilution in patients with sepsis as in controls without sepsis, suggesting that HES may remain within the intravascular space even in patients with sepsis. Haemodilution parameters such as haematocrit, serum albumin and serum protein are useful for assessing the duration of plasma volume expansion induced by fluid therapy in critically ill patients. [source] Sintering Behavior of Gehlenite.JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 6 2007Macro-/Mesoporous Gehlenite, Mechanical, Microstructure, Part I: Self-Forming, Physical Properties, Pore-Forming Mechanism A novel kind of pore self-forming macro-/mesoporous gehlenite (2CaO·Al2O3·SiO2) ceramic (abbreviated C2AS) having a highest porosity of 80% corresponding to a volume expansion of 134% during sintering has been developed. The pore self-forming ability, microstructure, mechanical, and thermal physical properties of the porous ceramic are related to the sintering temperature. The gehlenite ceramic shows a very good pore self-forming ability over a very wide range of temperature from 900° to 1450°C. No vesicant is required and no hydrothermal treatment is needed, as is generally the case for other kinds of porous ceramics or glasses. The pore self-forming ability of the C2AS porous ceramic can be attributed to the escape of the adsorbed water vapor during the sintering process, due to automatic hydration of the fine, amorphous, flakey-shaped starting C2AS powder particles synthesized by the organic steric entrapment (PVA) method, as well as to their fine, porous microstructure. The pores of the ceramics can be either open or closed, and the average pore size ranges from 0.6 to 1.1 ,m, corresponding to a porosity of 75%,80%, respectively. The porous ceramic can preserve nanometer-sized (26,50 nm) crystallites up to 1000°C. Sintered or thermally treated under different conditions, the porous ceramics exhibit relatively high flexural strengths ranging from 9.1 to 15.4 MPa, with a standard deviation of 0.3 and 4.2 MPa, respectively. Thermal properties of the porous ceramic up to 1000°C, including thermal expansion coefficient, thermal diffusivity, specific heat, and thermal conductivity, were investigated, and the stability of the porous ceramic in boiling water was also studied. [source] Comparison of Two Oral Electrolyte Solutions and Route of Administration on the Abomasal Emptying Rate of Holstein-Friesian CalvesJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 3 2006Mohammad Nouri Dehydrated calves with diarrhea are routinely given an oral electrolyte solution (OES) by suckling or esophageal intubation. An important issue related to rehydration therapy is the rate of OES delivery to the small intestine. It is widely assumed that the glucose content of the OES does not impact the speed of resuscitation and that fluid administered by esophageal intubation provides a similar resuscitative response to that obtained by suckling. The aims of this study were to compare the abomasal emptying rate in calves suckling an OES containing a high or low glucose concentration and in calves administered a high-glucose OES by suckling or esophageal intubation. Seven male Holstein-Friesian calves were given the following treatments in random order: 2 L of a commercially available high-glucose OES ([glucose] = 405 mM) by suckling or esophageal intubation or 2 L of a commercially available low-glucose OES ([glucose] = 56 mM) by suckling. Abomasal emptying rate was determined by acetaminophen absorption, ultrasonography, and glucose absorption. High-glucose OES rapidly increased plasma glucose concentration after suckling but produced a slower rate of abomasal emptying than did low-glucose OES. Esophageal intubation of high-glucose OES produced the same initial change in abomasal volume as did suckling, but delayed the rate of OES delivery to the small intestine. Our results suggest that suckling a low-glucose OES provides the fastest rate of abomasal emptying and plasma volume expansion, whereas a high-glucose OES provides the most appropriate oral solution for treating hypoglycemic calves. [source] Immune effect of hypertonic saline: fact or fiction?ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2004J. A. Kølsen-Petersen Hypertonicity affects many parts of the immune system. Animal studies and experiments in isolated cell cultures show that hypertonicity reversibly suppresses several neutrophil functions and at the same time up-regulates T-lymphocyte function. Infusion of hypertonic saline with or without colloids may thus, besides providing efficient plasma volume expansion, ameliorate the detrimental consequences on the immune function of trauma, shock, reperfusion, and major surgery. However, the few clinical studies conducted to date, specifically addressing the immune effect of hypertonic saline infusion, have shown little, if any, effect on markers of immune function, and larger clinical trials have not demonstrated benefit in terms of morbidity or mortality. Thus, as opposed to animal and cell-culture studies, the immune-modulating properties of hypertonic saline infusion would appear to be of limited value in clinical practice. This review presents in vitro studies, animal experiments, and clinical trials which investigated the consequences of hypertonic saline on markers of immune function. [source] Haemolytic uraemic syndrome: An overview (Review Article)NEPHROLOGY, Issue 3 2006IRADJ AMIRLAK SUMMARY: Haemolytic uraemic syndrome (HUS) is the most common cause of acute renal failure in children. The syndrome is defined by triad of microangiopathic haemolytic anaemia, thrombocytopenia and acute renal failure (ARF). Incomplete HUS is ARF with either haemolytic anaemia or thrombocytopenia. HUS is classified into two subgroups. Typical HUS usually occurs after a prodrome of diarrhoea (D+HUS), and atypical (sporadic) HUS (aHUS), which is not associated with diarrhoea (D,HUS). The majority of D+HUS worldwide is caused by Shiga toxin-producing Esherichia coli (STEC), type O157:H7, transmitted to humans via different vehicles. Currently there are no specific therapies preventing or ameliorating the disease course. Although there are new therapeutic modalities in the horizon for D+HUS, present recommended therapy is merely symptomatic. Parenteral volume expansion may counteract the effect of thrombotic process before development of HUS and attenuate renal injury. Use of antibiotics, antimotility agents, narcotics and non-steroidal anti-inflammatory drugs should be avoided during the acute phase. Prevention is best done by preventing primary STEC infection. Underlying aetiology in many cases of aHUS is unknown. A significant number may result from underlying infectious diseases, namely Streptococcus pneumoniae and human immunedeficiency virus. Variety of genetic forms include HUS due to deficiencies of factor H, membrane cofactor protein, Von Willebrand factor-cleaving protease (ADAMTS 13) and intracellular defect in vitamin B12 metabolism. There are cases of aHUS with autosomal recessive and dominant modes of inheritance. Drug-induced aHUS in post-transplantation is due to calcineurin-inhibitors. Systemic lupus erythematosus and catastrophic antiphospholipid syndrome may also present with aHUS. Therapy is directed mainly towards underlying cause. [source] The use of volume expansion in preterm infantsPAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 3 2004J. M. PREECE Dr No abstract is available for this article. [source] Excessive volume expansion and neonatal death in preterm infants born at 27,28 weeks gestationPAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 2 2003Andrew K. Ewer Summary Volume expansion is used commonly in preterm infants to treat presumed hypovolaemia. However, the amount that should be given is uncertain. We present data that were obtained from anonymised regional case notes of Project 27/28, a national case,controlled study run by the Confidential Enquiry into Stillbirths and Deaths in Infancy. Various clinical parameters were analysed, including the volume expansion administered during the first 48 h of life. All deaths in the first year of the study in the West Midlands (cases, n = 22) and matched regional controls (survivors, n = 29) were included. The primary outcome was death within 28 days. Sixteen of the 22 deaths were considered ,not inevitable' on the basis of the neonates' condition at birth. These newborns received on average more than twice the volume expansion compared with controls in the first 48 h of life (38.2 vs. 18.2 mL/kg, P = 0.007). There were no significant differences between the groups in lowest blood pressure or base deficit within the first 12 h of life. Newborns who received , 30 mL/kg volume expansion in the first 48 h of life were more likely to die than those who received < 30 mL/kg (OR 4.5 [95% CI 1.2, 17.2]). Our data suggest that administration of , 30 mL/kg volume expansion is associated with increased mortality in neonates of 27,28 weeks' gestation. Unless there is clear evidence of hypovolaemia, clinicians should exercise caution when prescribing volume expansion. [source] Atomistic characterization of structural and elastic properties of auxetic crystalline SiO2PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 3 2007Hajime Kimizuka Abstract The structural and elastic changes with volume expansion in , -quartz and , -cristobalite, the typical polymorphs of silicon dioxide (SiO2), have been studied through first-principles calculations using the projector-augmented-wave (PAW) method, with particular emphasis on their negative Poisson's ratio behavior under negative pressure. The dominant mechanism of expansion is the increase of the Si,O,Si angles within their crystalline structures, whereas the SiO4 tetrahedron undergoes only a slight distortion. We provide theoretical ab initio results for a complete set of independent elastic constants of quartz and cristobalite with volume expansion. The present simulations confirm that the negative Poisson's ratio behavior is enhanced in the expansive phases of both polymorphs under negative pressures, with retaining strong elastic anisotropy. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Structural dynamics of photoinduced molecular switching in the solid stateACTA CRYSTALLOGRAPHICA SECTION A, Issue 2 2010Hervé Cailleau Fast and ultra-fast time-resolved diffraction is a fantastic tool for directly observing the structural dynamics of a material rearrangement during the transformation induced by an ultra-short laser pulse. The paper illustrates this ability using the dynamics of photoinduced molecular switching in the solid state probed by 100,ps X-ray diffraction. This structural information is crucial for establishing the physical foundations of how to direct macroscopic photoswitching in materials. A key feature is that dynamics follow a complex pathway from molecular to material scales through a sequence of processes. Not only is the pathway indirect, the nature of the dynamical processes along the pathway depends on the timescale. This dictates which types of degrees of freedom are involved in the subsequent dynamics or kinetics and which are frozen or statistically averaged. We present a recent investigation of the structural dynamics in multifunctional spin-crossover materials, which are prototypes of molecular bistability in the solid state. The time-resolved X-ray diffraction results show that the dynamics span from subpicosecond molecular photoswitching followed by volume expansion (on a nanosecond timescale) and additional thermoswitching (on a microsecond timescale). [source] QTL analysis of cooked rice grain elongation, volume expansion, and water absorption using a recombinant inbred populationPLANT BREEDING, Issue 2 2005X. J. Ge Abstract The traits of elongation, volume expansion, and water absorption are very important in determining the quality of cooked rice grains. In this study, quantitative trait loci (QTL) analysis of these traits was performed using a recombinant inbred population derived from a cross between two indica cultivars, ,Zhenshan 97' and ,Minghui 63,' which are the parents of the most widely grown hybrid rice in China. Using a linkage map based on 221 molecular marker loci covering a total of 1796 cM, a total of 33 QTLs were identified for the nine traits tested. QTLs were detected on chromosomes 1,3, 5,9, and 11, respectively. The QTLs identified included three for cooked rice grain length elongation (chromosomes 2, 6, and 11), six for width expansion (chromosomes 1- 3, 6, 9, and 11) and two for water absorption (chromosomes 2 and 6). Interestingly, a single QTL located near the wx gene on chromosome 6 seemed to influence all the traits tested for the cooked rice quality. [source] Effect of thermal aging on the crystal structural characteristics of poly(tetra fluoro ethylene)POLYMER ENGINEERING & SCIENCE, Issue 11 2007Anjana Jain The residual effects of cumulative thermal aging on the crystal structural characteristics of the fluoro carbon poly(tetra fluoro ethylene) (PTFE) have been studied by X-ray diffraction methods. The initial hexagonal arrangement of the PTFE chains in a 157 helical conformation is left unaffected by the exposures to temperatures (T), up to and beyond its melting point, Tm. The unit cell registers a residual anisotropic volume expansion. The anisotropy arises from the enhanced enlargement of the basal plane dimension a compared with the axial dimension c. Conformational changes contributing to the observed increase in the chain length have been examined. Enhancement of residual crystallinity of samples aged at T's < Tm suggests that the selective thermal aging could be used as an effective tool to improve the initial crystallinity of commercially available PTFE. The activation energy for 50% enhancement in initial crystallinity has been estimated as 53.9 kJ mol,1. Aging at 400°C, a temperature above Tm, is accompanied by markedly different features viz., deterioration in crystallinity and other structural characteristics. The overall behavior of thermally aged PTFE bears a marked similarity to many polyamides. POLYM. ENG. SCI., 47:1724,1729, 2007. © 2007 Society of Plastics Engineers [source] Maternal renal dysfunction in sheep is associated with salt insensitivity in female offspringTHE JOURNAL OF PHYSIOLOGY, Issue 1 2009A. E. Brandon To examine the programming effects of maternal renal dysfunction (created by subtotal nephrectomy in ewes prior to mating; STNx), renal and cardiovascular function were studied in 6-month-old male and female offspring of STNx and control pregnancies. After studies were conducted on a low salt diet (LSD) some female offspring underwent salt loading (0.17 m NaCl in the drinking water for 5,7 days; HSD). On LSD both male and female offspring of STNx had similar mean arterial pressures (MAP), heart rates, cardiac outputs and renal function to those measured in offspring of control ewes. In female STNx offspring on a HSD, plasma sodium levels increased and haematocrits fell, indicating volume expansion (P < 0.05). Plasma renin levels were not suppressed despite the increases in plasma sodium concentrations, but aldosterone levels were reduced. In control animals plasma renin levels fell (P < 0.05) but there was no change in plasma aldosterone concentrations. There was a positive relationship between GFR and MAP which was present only in female STNx offspring. In conclusion, in STNx offspring there was an impaired ability to regulate glomerular filtration independent of arterial pressure, renin release was insensitive to a high salt intake and control of aldosterone secretion was abnormal. This study provides evidence of abnormal programming of the renin,angiotensin system and glomerular function in offspring of pregnancies in which there is impaired maternal renal function. [source] Modulation of body fluids and angiotensin II receptors in a rat model of intra-uterine growth restrictionTHE JOURNAL OF PHYSIOLOGY, Issue 3 2005Sophie Bédard We previously reported that sodium restriction during pregnancy reduces plasma volume expansion and promotes intra-uterine growth restriction (IUGR) in rats while it activates the renin,angiotensin,aldosterone system (RAAS). In the present study, we proceeded to determine whether expression of the two angiotensin II (ANGII) receptor subtypes (AT1 and AT2) change in relation to maternal water,electrolyte homeostasis and fetal growth. To this end, pregnant (gestation day 15) and non-pregnant Sprague-Dawley rats were randomly assigned to two groups fed either normal, or Na+ -restricted diets for 7 days. At the end of the treatment period, plasma aldosterone and renin activity as well as plasma and urine electrolytes were measured. Determinations for AT1 and AT2 mRNA and protein were made by RNase protection assay and photoaffinity labelling, respectively, using a number of tissues implicated in volume regulation and fetal growth. In non-pregnant rats, Na+ restriction decreases Na+ excretion without altering plasma volume, plasma Na+ concentration or the expression of AT1 and AT2 mRNA or protein in the tissues examined. In normally fed pregnant rats when compared to non-pregnant controls, AT1 mRNA increases in the hypothalamus as well as pituitary and declines in uterine arteries, while AT1 protein decreases in the kidney and AT2 mRNA declines in the adrenal cortex. In pregnant rats, Na+ restriction induces a decrease in plasma Na+, an increase in plasma urea, as well as a decline in renal urea and creatinine clearance rates. Protein levels for both AT1 and AT2 in the pituitary and AT2 mRNA in the adrenal cortex are lower in the Na+ -restricted pregnant group when compared to normally fed pregnant animals. Na+ restriction also induces a decrease in AT1 protein in the placenta. In conclusion, these results suggest that pregnancy may increase sensitivity to Na+ depletion by the tissue-specific modulation of ANGII receptors. Finally, these receptors may be implicated in the IUGR response to low Na+. [source] One-year infant outcome in women with early-onset hypertensive disorders of pregnancyBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 2 2008A Rep Objectives, To evaluate the role of plasma volume expansion on 1-year infant outcome after severe hypertensive disorders of pregnancy and to determine prognostic factors for adverse neurodevelopmental infant outcome. Design, Randomised controlled trial, observational prognostic study. Setting, Two university hospitals in Amsterdam, The Netherlands. Population, One hundred and seventy-two infants alive of 216 mothers with severe hypertensive disorders of pregnancy who were randomised for a temporising management strategy with or without plasma volume expansion. Methods, At 1 year of corrected age, a neurological examination according to Bayley (mental development index [MDI] and psychomotor development index [PDI]) and Touwen was performed. Main outcome measures, Adverse neurodevelopmental infant outcome was defined as a MDI/PDI score below 70 and/or an abnormal Touwen. Risk factors for adverse neurodevelopmental outcome were explored by univariate and multivariate analyses. Results, Adverse neurodevelopmental infant outcome was observed in 31 infants (18%). There were no differences between the randomisation groups. In multivariate analysis, an association with abnormal umbilical artery/middle cerebral artery Doppler ratio higher than the median, major neonatal morbidity, higher education of the parents, multiparity and Caucasian ethnicity was observed. Conclusion, Nearly 70% of the infants were alive at 1 year without adverse neurodevelopmental outcome. Maternal plasma volume expansion during pregnancy has no effect on 1-year infant outcome. The prediction of adverse outcome at 1 year by perinatal parameters is limited. [source] Successful treatment of profound hypothermia of the newbornACTA PAEDIATRICA, Issue 1 2009P Konopova Abstract We report a case of a profoundly hypothermic newborn with a core temperature of 25°C with a successful recovery and normal neurological outcome at 3 and 6 months. This term male infant had been exposed to a temperature of ,3°C for approximately 30 min. Slow re-warming, using external modalities was used in addition to volume expansion, heparinization, antibiotics and sedation. There is limited information available concerning the safest and most effective method of re-warming hypothermic newborns. Slow re-warming has been advocated as it replicates the normal physiological process in a neonate, which minimizes a negative therapy impact. Conclusion: The most significant decision regarding treatment is the identification of the most appropriate method and speed of re-warming. This report supports recommendations for gradual re-warming of a severely hypothermic newborn. Physiological cardiovascular mechanisms seemed to be intact during slow re-warming; this might be applicable to the treatment of profound hypothermia of the newborn. [source] An antidiabetic thiazolidinedione induces eccentric cardiac hypertrophy by cardiac volume overload in ratsCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 1-2 2004Kenji Arakawa Summary 1.,To assess the involvement of volume overload in the development of cardiac hypertrophy during treatment with an antidiabetic thiazolidinedione, changes in cardiac anatomy and parameters of cardiac volume overload were evaluated in female Sprague-Dawley rats treated with the thiazolidinedione derivative T-174. 2.,Two week administration of T-174 (13 and 114 mg/kg per day) increased absolute and relative heart weights by 11,24%, demonstrating the development of cardiac hypertrophy. There was no evidence of oedema in hearts from treated rats. 3.,Both plasma and blood volumes were increased in T-174-treated rats without any changes in systolic blood pressure and heart rate, whereas haematocrit was decreased. In accordance with the existence of volume overload, both left ventricular end-diastolic pressure and right atrial pressure were increased. Morphometric analysis of hearts revealed that T-174 induced eccentric heart hypertrophy, as characterized by a small increase in wall thickness and a large increase in the chamber volume, which is characteristic of volume overload. Volume overload is suggested as the possible trigger mechanism because blood volume expansion preceded cardiac hypertrophy and there was a high correlation between heart weight and blood volume. 4.,T-174-treated streptozotocin-induced diabetic rats also exhibited blood volume expansion and cardiac hypertrophy. 5.,These findings suggest that cardiac volume overload is induced by plasma volume expansion and contributes to the development of eccentric cardiac hypertrophy during treatment with antidiabetic thiazolidinediones. Although thiazolidinediones are insulin-sensitizing agents, these cardiac effects are likely to be mediated independently of insulin. [source] | ||||||||||||||||||||||||||||