Role of Doppler ultrasonography evaluation of superior mesenteric artery flow volume in the assessment of Crohn's disease activity

Objective To investigate superior mesenteric artery flow measurement by Doppler ultrasonography as a means of characterizing inflammatory activity in Crohn's disease. Materials and Methods Forty patients were examined and divided into two groups – disease activity and remission – according to their Crohn's disease activity index score. Mean superior mesenteric artery flow volume was calculated for each group and correlated with Crohn's disease activity index score. Results The mean superior mesenteric artery flow volume was significantly greater in the patients with active disease (626 ml/min ± 236 × 376 ml/min ± 190; p = 0.001). As a cut off corresponding to 500 ml/min was utilized, the superior mesenteric artery flow volume demonstrated sensitivity of 83% and specificity of 82% for the diagnosis of Crohn's disease activity. Conclusion The present results suggest that patients with active Crohn's disease have increased superior mesenteric artery flow volume as compared with patients in remission. Superior mesenteric artery flow measurement had a good performance in the assessment of disease activity in this study sample.

Volume of polyethylene bags for development of papaya seedlings in protected environments

The objective of this study was to test container of polyethylene bags and protected environments on the papaya seedlings production, from May to August of 2008, in Aquidauana state of Mato Grosso do Sul (MS), Brazil. Five bags of polyethylene were used: 7.5 cm x 11.5 cm, 205.9 cm³; 8.4 cm x 10.6 cm, 238.1cm³; 10.0 cm x 16.5 cm, 525.2 cm³; 12.0 cm x 12.0 cm, 550.0 cm³ and 15.0 cm x 21.5 cm, 1539.8 cm³. These containers were placed in three protected environments: greenhouse; screened nursery with Sombrite® and screened nursery with Aluminet®. Because there is no replication of growing environment, each one was considered an experiment. For each cultivation environment, it was adopted a completely randomized design with eight replications of two plants each. Initially, data were submitted to analysis of individual variance of the container (for each cultivation environment), then performing the evaluation of the residual mean squares and the combined analysis of these environments for comparison of protected environments. The greenhouse and nursery with thermal reflector screen produced the best seedlings. The bags of 15.0 x 21.5 cm produced the best papaya seedlings. The Dickson Quality Index pointed the nursery with screen of thermal reflector as the environment that produced the most vigorous seedlings, when using the best container.

Influence of first morning urine volume, fasting blood glucose and glycosylated hemoglobin on first morning urinary albumin concentration

The aim of the present study was to evaluate the effect of first morning urinary volume (collected on three different non-consecutive days), fasting blood glucose (determined on the first and third days of urine collection), and glycosylated hemoglobin (determined on the first and third days of urine collection) on the albumin concentration in first morning urine samples collected on three different days. We found 3.6% asymptomatic bacteriuria in the urine samples; therefore, every urine sample must be tested to exclude infection. One hundred and fifty urine samples were provided by 50 IDDM patients aged 21.9 ± 7 (12-38) years with a disease duration of 6.8 ± 5.8 (0.4-31) years attending the Diabetes Clinic at the State University Hospital of Rio de Janeiro. There were no differences in albumin concentration (6.1 vs 5.8 vs 6.2 µg/ml; P = NS) or urinary volume (222.5 vs 210 vs 200 ml) between the three samples. In addition, there were no differences in fasting blood glucose (181.9 ± 93.6 vs 194.6 ± 104.7 mg%; P = NS) or glycosylated hemoglobin (HbA1)(8.4 ± 1.3 vs 8.8 ± 1.5%; P = NS) between the first and third blood samples. Six patients (group 1) had a mean urinary albumin concentration of more than 20 µg/ml for the three urine samples. This group was compared with the 44 patients (group 2) with a mean urinary albumin concentration for the three urine samples of less than 20 µg/ml. No difference was found between groups 1 and 2 in relation to fasting blood glucose (207.1 ± 71.7 vs 187.6 ± 84.6 mg/dl), HbA1 (8.1 ± 0.9 vs 8.6 ± 1.1%) or urinary volume [202 (48.3-435) vs 246 (77.3-683.3) ml]. Stepwise multiple regression analysis with albumin concentration of first morning urine samples as the dependent variable, and urinary volume, fasting blood glucose and glycosylated hemoglobin as independent variables, showed that only 12% (P = 0.01) of the albumin concentration could be accounted for by the independent effect of morning urine volume on the first day of urine collection. No urine samples showed a change in the cutoff level of 20 µg/ml of albumin concentration as the result of volume. Fasting blood glucose and glycosylated hemoglobin did not influence the urinary albumin concentration. Considerable variability in urinary albumin concentration was found in the three morning urine samples with a mean intraindividual coefficient variation of 56%. In conclusion, in the present study, urinary volume had a minimal, though not constant, effect on first morning urinary albumin concentration. Day-to-day metabolic and clinical control of IDDM patients, except probably for ketoacidosis, should not contraindicate microalbuminuria screening in first morning urine samples

Release of plasma atrial natriuretic peptide after volume expansion is not related to pituitary-adrenal axis diurnal variation in normal subjects

The existence of a circadian rhythm of atrial natriuretic peptide (ANP) in humans is controversial. We studied the plasma ANP response to isotonic blood volume expansion in the morning and in the afternoon and its relationship with adrenocorticotropic hormone (ACTH)-cortisol diurnal variation in seven normal subjects. Basal plasma ANP level was similar in the morning (19.6 ± 2.4 pg/ml) and in the afternoon (21.8 ± 4.8 pg/ml). The ANP peak obtained with saline infusion (0.9% NaCl, 12 ml/kg) in the morning (49.4 ± 8 pg/ml) did not differ from that obtained in the afternoon (60.3 ± 10.1 pg/ml). There was no correlation between the individual mean cortisol and ACTH levels and the ANP peak obtained with saline infusion. These data indicate no diurnal variation in plasma ANP secretion induced by blood volume expansion and no relationship between plasma ANP peak and ACTH-cortisol diurnal variation

Acute extracellular fluid volume changes increase ileocolonic resistance to saline flow in anesthetized dogs

We determined the effect of acute extracellular fluid volume changes on saline flow through 4 gut segments (ileocolonic, ileal, ileocolonic sphincter and proximal colon), perfused at constant pressure in anesthetized dogs. Two different experimental protocols were used: hypervolemia (iv saline infusion, 0.9% NaCl, 20 ml/min, volume up to 5% body weight) and controlled hemorrhage (up to a 50% drop in mean arterial pressure). Mean ileocolonic flow (N = 6) was gradually and significantly decreased during the expansion (17.1%, P<0.05) and expanded (44.9%, P<0.05) periods while mean ileal flow (N = 7) was significantly decreased only during the expanded period (38%, P<0.05). Mean colonic flow (N = 7) was decreased during expansion (12%, P<0.05) but returned to control levels during the expanded period. Mean ileocolonic sphincter flow (N = 6) was not significantly modified. Mean ileocolonic flow (N = 10) was also decreased after hemorrhage (retracted period) by 17% (P<0.05), but saline flow was not modified in the other separate circuits (N = 6, 5 and 4 for ileal, ileocolonic sphincter and colonic groups, respectively). The expansion effect was blocked by atropine (0.5 mg/kg, iv) both on the ileocolonic (N = 6) and ileal (N = 5) circuits. Acute extracellular fluid volume retraction and expansion increased the lower gastrointestinal resistances to saline flow. These effects, which could physiologically decrease the liquid volume being supplied to the colon, are possible mechanisms activated to acutely balance liquid volume deficit and excess.

Acute blood volume expansion delays the gastrointestinal transit of a charcoal meal in awake rats

The present study evaluates the effect of blood volume expansion on the gastrointestinal transit of a charchoal meal (2.5 ml of an aqueous suspension consisting of 5% charcoal and 5% gum arabic) in awake male Wistar rats (200-270 g). On the day before the experiments, the rats were anesthetized with ether, submitted to left jugular vein cannulation and fasted with water ad libitum until 2 h before the gastrointestinal transit measurement. Blood volume expansion by iv infusion of 1 ml/min Ringer bicarbonate in volumes of 3, 4 or 5% body weight delayed gastrointestinal transit at 10 min after test meal administration by 21.3-26.7% (P<0.05), but no effect was observed after 1 or 2% body weight expansion. The effect of blood volume expansion (up to 5% body weight) on gastrointestinal transit lasted for at least 60 min (P<0.05). Mean arterial pressure increased transiently and central venous pressure increased and hematocrit decreased (P<0.05). Subdiaphragmatic vagotomy and yohimbine (3 mg/kg) prevented the delay caused by expansion on gastrointestinal transit, while atropine (0.5 mg/kg), L-NAME (2 mg/kg), hexamethonium (10 mg/kg), prazosin (1 mg/kg) or propranolol (2 mg/kg) were ineffective. These data show that blood volume expansion delays the gastrointestinal transit of a charcoal meal and that vagal and yohimbine-sensitive pathways appear to be involved in this phenomenon. The delay in gastrointestinal transit observed here, taken together with the modifications of gastrointestinal permeability to salt and water reported by others, may be part of the mechanisms involved in liquid excess management.

Variations in gastric emptying of liquid elicited by acute blood volume changes in awake rats

We have observed that acute blood volume expansion increases the gastroduodenal resistance to the flow of liquid in anesthetized dogs, while retraction decreases it (Santos et al. (1991) Acta Physiologica Scandinavica, 143: 261-269). This study evaluates the effect of blood volume expansion and retraction on the gastric emptying of liquid in awake rats using a modification of the technique of Scarpignato (1980) (Archives Internationales de Pharmacodynamie et de Therapie, 246: 286-294). Male Wistar rats (180-200 g) were fasted for 16 h with water ad libitum and 1.5 ml of the test meal (0.5 mg/ml phenol red solution in 5% glucose) was delivered to the stomach immediately after random submission to one of the following protocols: 1) normovolemic control (N = 22), 2) expansion (N = 72) by intravenous infusion (1 ml/min) of Ringer-bicarbonate solution, volumes of 1, 2, 3 or 5% body weight, or 3) retraction (N = 22) by controlled bleeding (1.5 ml/100 g). Gastric emptying of liquid was inhibited by 19-51.2% (P<0.05) after blood volume expansion (volumes of 1, 2, 3 or 5% body weight). Blood volume expansion produced a sustained increase in central venous pressure while mean arterial pressure was transiently increased during expansion (P<0.05). Blood volume retraction increased gastric emptying by 28.5-49.9% (P<0.05) and decreased central venous pressure and mean arterial pressure (P<0.05). Infusion of the shed blood 10 min after bleeding reversed the effect of retraction on gastric emptying. These findings suggest that gastric emptying of liquid is subject to modulation by the blood volume.

Variations in gastric compliance induced by acute blood volume changes in anesthetized rats

The impact of acute volume imbalances on gastric volume (GV) was studied in anesthetized rats (250-300 g). After cervical and femoral vessel cannulation, a balloon catheter was positioned in the proximal stomach. The opposite end of the catheter was connected to a barostat with an electronic sensor coupled to a plethysmometer. A standard ionic solution was used to fill the balloon (about 3.0 ml) and the communicating vessel system, and to raise the reservoir liquid level 4 cm above the animals' xiphoid appendix. Due to constant barostat pressure, GV values were considered to represent the gastric compliance index. All animals were monitored for 90 min. After a basal interval, they were randomly assigned to normovolemic, hypervolemic, hypovolemic or restored protocols. Data were compared by ANOVA followed by Bonferroni's test. Mean arterial pressure (MAP), central venous pressure (CVP) and GV values did not change in normovolemic animals (N = 5). Hypervolemic animals (N = 12) were transfused at 0.5 ml/min with a suspension of red blood cells in Ringer-lactate solution with albumin (12.5 ml/kg), which reduced GV values by 11.3% (P<0.05). Hypovolemic rats (N = 12) were bled up to 10 ml/kg, a procedure that increased GV values by 15.8% (P<0.05). In the restored group (N = 12), shed blood replacement brought GV values back to basal levels in bled animals (P>0.05). MAP and CVP values increased (P<0.05) after hypervolemia but decreased (P<0.05) with hypovolemia. In conclusion, blood volume level modulates gastric compliance, turning the stomach into an adjustable reservoir, which could be part of the homeostatic process to balance blood volume.

Assessment of tidal volume and thoracoabdominal motion using volume and flow-oriented incentive spirometers in healthy subjects

The objective of the present study was to evaluate incentive spirometers using volume- (Coach and Voldyne) and flow-oriented (Triflo II and Respirex) devices. Sixteen healthy subjects, 24 ± 4 years, 62 ± 12 kg, were studied. Respiratory variables were obtained by respiratory inductive plethysmography, with subjects in a semi-reclined position (45º). Tidal volume, respiratory frequency, minute ventilation, inspiratory duty cycle, mean inspiratory flow, and thoracoabdominal motion were measured. Statistical analysis was performed with Kolmogorov-Smirnov test, t-test and ANOVA. Comparison between the Coach and Voldyne devices showed that larger values of tidal volume (1035 ± 268 vs 947 ± 268 ml, P = 0.02) and minute ventilation (9.07 ± 3.61 vs 7.49 ± 2.58 l/min, P = 0.01) were reached with Voldyne, whereas no significant differences in respiratory frequency were observed (7.85 ± 1.24 vs 8.57 ± 1.89 bpm). Comparison between flow-oriented devices showed larger values of inspiratory duty cycle and lower mean inspiratory flow with Triflo II (0.35 ± 0.05 vs 0.32 ± 0.05 ml/s, P = 0.00, and 531 ± 137 vs 606 ± 167 ml/s, P = 0.00, respectively). Abdominal motion was larger (P < 0.05) during the use of volume-oriented devices compared to flow-oriented devices (52 ± 11% for Coach and 50 ± 9% for Voldyne; 43 ± 13% for Triflo II and 44 ± 14% for Respirex). We observed that significantly higher tidal volume associated with low respiratory frequency was reached with Voldyne, and that there was a larger abdominal displacement with volume-oriented devices.

Effect of saline infusion for the maintenance of blood volume on pulmonary gas exchange during temporary abdominal aortic occlusion

We analyzed the effects of saline infusion for the maintenance of blood volume on pulmonary gas exchange in ischemia-reperfusion syndrome during temporary abdominal aortic occlusion in dogs. We studied 20 adult mongrel dogs weighing 12 to 23 kg divided into two groups: ischemia-reperfusion group (IRG, N = 10) and IRG submitted to saline infusion for the maintenance of mean pulmonary arterial wedge pressure between 10 and 20 mmHg (IRG-SS, N = 10). All animals were anesthetized and maintained on spontaneous ventilation. After obtaining baseline measurements, occlusion of the supraceliac aorta was performed by the inflation of a Fogarty catheter. After 60 min of ischemia, the balloon was deflated and the animals were observed for another 60 min of reperfusion. The measurements were made at 10 and 45 min of ischemia, and 5, 30, and 60 min of reperfusion. Pulmonary gas exchange was impaired in the IRG-SS group as demonstrated by the increase of the alveolar-arterial oxygen difference (21 ± 14 in IRG-SS vs 11 ± 8 in IRG after 60 min of reperfusion, P = 0.004 in IRG-SS in relation to baseline values) and the decrease of oxygen partial pressure in arterial blood (58 ± 15 in IRG-SS vs 76 ± 15 in IRG after 60 min of reperfusion, P = 0.001 in IRG-SS in relation to baseline values), which was correlated with the highest degree of pulmonary edema in morphometric analysis (0.16 ± 0.06 in IRG-SS vs 0.09 ± 0.04 in IRG, P = 0.03 between groups). There was also a smaller ventilatory compensation of metabolic acidosis after the reperfusion. We conclude that infusion of normal saline worsened the gas exchange induced by pulmonary reperfusion injury in this experimental model.

Glomerular filtration is reduced by high tidal volume ventilation in an in vivo healthy rat model

Mechanical ventilation has been associated with organ failure in patients with acute respiratory distress syndrome. The present study examines the effects of tidal volume (V T) on renal function using two V T values (8 and 27 mL/kg) in anesthetized, paralyzed and mechanically ventilated male Wistar rats. Animals were randomized into two groups of 6 rats each: V T8 (V T, 8 mL/kg; 61.50 ± 0.92 breaths/min; positive end-expiratory pressure, 3.0 cmH2O; peak airway pressure (PAW), 11.8 ± 2.0 cmH2O), and V T27 (V T, 27 mL/kg; 33.60 ± 1.56 breaths/min; positive end-expiratory pressure, none, and PAW, 22.7 ± 4.0 cmH2O). Throughout the experiment, mean PAW remained comparable between the two groups (6.33 ± 0.21 vs 6.50 ± 0.22 cmH2O). For rats in the V T27 group, inulin clearance (mL·min-1·body weight-1) decreased acutely after 60 min of mechanical ventilation and even more significantly after 90 min, compared with baseline values (0.60 ± 0.05 and 0.45 ± 0.05 vs 0.95 ± 0.07; P < 0.001), although there were no differences between groups in mean arterial pressure or gasometric variables. In the V T8 group, inulin clearance at 120 min of mechanical ventilation remained unchanged in relation to baseline values (0.72 ± 0.03 vs 0.80 ± 0.05). The V T8 and V T27 groups did not differ in terms of serum thiobarbituric acid reactive substances (3.97 ± 0.27 vs 4.02 ± 0.45 nmol/mL) or endothelial nitric oxide synthase expression (94.25 ± 2.75 vs 96.25 ± 2.39%). Our results show that glomerular filtration is acutely affected by high tidal volume ventilation but do not provide information about the mechanism.

Molecular dynamics calculation of mean square displacement in alkali metals and rare gas solids and comparison with lattice dynamics

Molec ul ar dynamics calculations of the mean sq ua re displacement have been carried out for the alkali metals Na, K and Cs and for an fcc nearest neighbour Lennard-Jones model applicable to rare gas solids. The computations for the alkalis were done for several temperatures for temperature vol ume a swell as for the the ze r 0 pressure ze ro zero pressure volume corresponding to each temperature. In the fcc case, results were obtained for a wide range of both the temperature and density. Lattice dynamics calculations of the harmonic and the lowe s t order anharmonic (cubic and quartic) contributions to the mean square displacement were performed for the same potential models as in the molecular dynamics calculations. The Brillouin zone sums arising in the harmonic and the quartic terms were computed for very large numbers of points in q-space, and were extrapolated to obtain results ful converged with respect to the number of points in the Brillouin zone.An excellent agreement between the lattice dynamics results was observed molecular dynamics and in the case of all the alkali metals, e~ept for the zero pressure case of CSt where the difference is about 15 % near the melting temperature. It was concluded that for the alkalis, the lowest order perturbation theory works well even at temperat ures close to the melting temperat ure. For the fcc nearest neighbour model it was found that the number of particles (256) used for the molecular dynamics calculations, produces a result which is somewhere between 10 and 20 % smaller than the value converged with respect to the number of particles. However, the general temperature dependence of the mean square displacement is the same in molecular dynamics and lattice dynamics for all temperatures at the highest densities examined, while at higher volumes and high temperatures the results diverge. This indicates the importance of the higher order (eg. ~* ) perturbation theory contributions in these cases.

On the equation of state and atomic mean square displacement of crystals

We have presented a Green's function method for the calculation of the atomic mean square displacement (MSD) for an anharmonic Hamil toni an . This method effectively sums a whole class of anharmonic contributions to MSD in the perturbation expansion in the high temperature limit. Using this formalism we have calculated the MSD for a nearest neighbour fcc Lennard Jones solid. The results show an improvement over the lowest order perturbation theory results, the difference with Monte Carlo calculations at temperatures close to melting is reduced from 11% to 3%. We also calculated the MSD for the Alkali metals Nat K/ Cs where a sixth neighbour interaction potential derived from the pseudopotential theory was employed in the calculations. The MSD by this method increases by 2.5% to 3.5% over the respective perturbation theory results. The MSD was calculated for Aluminum where different pseudopotential functions and a phenomenological Morse potential were used. The results show that the pseudopotentials provide better agreement with experimental data than the Morse potential. An excellent agreement with experiment over the whole temperature range is achieved with the Harrison modified point-ion pseudopotential with Hubbard-Sham screening function. We have calculated the thermodynamic properties of solid Kr by minimizing the total energy consisting of static and vibrational components, employing different schemes: The quasiharmonic theory (QH), ).2 and).4 perturbation theory, all terms up to 0 ().4) of the improved self consistent phonon theory (ISC), the ring diagrams up to o ().4) (RING), the iteration scheme (ITER) derived from the Greens's function method and a scheme consisting of ITER plus the remaining contributions of 0 ().4) which are not included in ITER which we call E(FULL). We have calculated the lattice constant, the volume expansion, the isothermal and adiabatic bulk modulus, the specific heat at constant volume and at constant pressure, and the Gruneisen parameter from two different potential functions: Lennard-Jones and Aziz. The Aziz potential gives generally a better agreement with experimental data than the LJ potential for the QH, ).2, ).4 and E(FULL) schemes. When only a partial sum of the).4 diagrams is used in the calculations (e.g. RING and ISC) the LJ results are in better agreement with experiment. The iteration scheme brings a definitive improvement over the).2 PT for both potentials.

Testing Mean-Variance Efficiency in CAPM with Possibly Non-Gaussian Errors : An Exact Simulation-Based Approach

In this paper we propose exact likelihood-based mean-variance efficiency tests of the market portfolio in the context of Capital Asset Pricing Model (CAPM), allowing for a wide class of error distributions which include normality as a special case. These tests are developed in the frame-work of multivariate linear regressions (MLR). It is well known however that despite their simple statistical structure, standard asymptotically justified MLR-based tests are unreliable. In financial econometrics, exact tests have been proposed for a few specific hypotheses [Jobson and Korkie (Journal of Financial Economics, 1982), MacKinlay (Journal of Financial Economics, 1987), Gib-bons, Ross and Shanken (Econometrica, 1989), Zhou (Journal of Finance 1993)], most of which depend on normality. For the gaussian model, our tests correspond to Gibbons, Ross and Shanken’s mean-variance efficiency tests. In non-gaussian contexts, we reconsider mean-variance efficiency tests allowing for multivariate Student-t and gaussian mixture errors. Our framework allows to cast more evidence on whether the normality assumption is too restrictive when testing the CAPM. We also propose exact multivariate diagnostic checks (including tests for multivariate GARCH and mul-tivariate generalization of the well known variance ratio tests) and goodness of fit tests as well as a set estimate for the intervening nuisance parameters. Our results [over five-year subperiods] show the following: (i) multivariate normality is rejected in most subperiods, (ii) residual checks reveal no significant departures from the multivariate i.i.d. assumption, and (iii) mean-variance efficiency tests of the market portfolio is not rejected as frequently once it is allowed for the possibility of non-normal errors.

Dominant Mean Percentage Score Factors Of The Consumer Purchase Behaviour Of Passenger Cars

Globalization and liberalization, with the entry of many prominent foreign manufacturers, changed the automobile scenario in India, since early 1990’s. World Leaders in automobile manufacturing such as Ford, General Motors, Honda, Toyota, Suzuki, Hyundai, Renault, Mitsubishi, Benz, BMW, Volkswagen and Nissan set up their manufacturing units in India in joint venture with their Indian counterpart companies, by making use of the Foreign Direct Investment policy of the Government of India, These manufacturers started capturing the hearts of Indian car customers with their choice of technological and innovative product features, with quality and reliability. With the multiplicity of choices available to the Indian passenger car buyers, it drastically changed the way the car purchase scenario in India and particularly in the State of Kerala. This transformed the automobile scene from a sellers’ market to buyers’ market. Car customers started developing their own personal preferences and purchasing patterns, which were hitherto unknown in the Indian automobile segment. The main purpose of this paper is to come up with the identification of possible parameters and a framework development, that influence the consumer purchase behaviour patterns of passenger car owners in the State of Kerala, so that further research could be done, based on the framework and the identified parameters.