910 resultados para generalized solutions


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A prospective randomized trial was conducted to compare the efficacy of a rice-based oral rehydration solution (ORS) with glucose ORS in infants and children under 5 years of age with acute diarrhoea and mild to moderate dehydration (<10%). One hundred children presenting to a large metropolitan teaching hospital were eligible for entry to the study and were randomized to receive rice ORS or glucose ORS. Outcome measures were stool output (SO), duration of illness (DD) and recovery time to introduction of other fluids (RTF) and diet (RTD). Significant differences were found for all outcome measures in favour of the rice ORS group. Mean SO was lower (160 vs 213 mt; P<0.02), mean DD was reduced (17.3 vs 24.3 h; P = 0.03) and median RTF was decreased (12.7 vs 18.1 h; P< 0.001) in the rice ORS group compared with the glucose ORS group. The median rime to introduction of diet and mean length of hospital stay showed similar significant reductions. Our study has shown rice ORS to be an acceptable alternative to glucose ORS in young children and have shown that it is significantly more effective in reducing the course of diarrhoeal illness and the time taken to return to normal drinking and eating habits.

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Introduction. The quality and effectiveness of myocardial protection are fundamental problems to expand the use of and consequently good outcomes of donated hearts for transplantation. Objective. The purpose of this investigation was to compare the cardioprotective effects of Krebs-Henseleit, Bretschneider-HTK, St Thomas, and Celsior solutions using a modified nonrecirculating Langendorff column model of isolated perfused rat heart during prolonged cold storage. Materials and Methods. After removal 36 rat hearts underwent isolated perfusion into a Langendorff apparatus using Krebs-Henseleit solution for a 15-minute period of recovery; we excluded organs that did not maintain an aortic pressure above 100 m Hg. Subsequently, we equally distributed the hearts into four groups according to the cardioprotection solution; group 1, Krebs-Henseleit (control); group II, Bretschneider-HTK; group III, St Thomas; and group IV, Celsior. Each heart received the specific cardioplegic solution at 10 C for 2-hour storage at 20 C, before a 15 minutes perfusion with Krebs-Henseleit solution for recovery and stabilization. After 60 additional minutes of perfusion, every 5 minutes we determined heart rate (HR), coronary flow (CF), left ventricular systolic pressure (LVSP), and positive and negative peak of the first derivative of left ventricular pressure (+dP/dt and dP/dt, respectively). Results. Comparative analysis by Turkey`s test showed the following performances among the groups at 60 minutes of reperfusion: HR: II = IV > III > I; CF: II = IV > I = III; LVSP: IV > I = II = III; +dP/dt: IV > I = II = III; and dP/dt: IV = II > I = II. Conclusion. Cardioprotective solutions generally used in clinical practice are not able to avoid hemodynamic alterations in hearts exposed to prolonged ischemia. Celsior solution showed better performance than Bretschneider-HTK, St Thomas, and Krebs-Henseleit.

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The flux of a compound across a membrane from any formulation, whether it contains penetration enhancers or not, is limited by its saturated solubility in the vehicle. Under such conditions the concentration of the permeant in the outer layers of the stratum corneum is also saturated. Consequently, when the permeation of a drug from a supersaturated solution leads to enhanced penetration, the concentration of the drug in the outer layers of the membrane is also supersaturated. Therefore, the stratum corneum may possess antinucleant properties which inhibit or retard the crystallisation process. In this study, the enhanced in vitro permeation of supersaturated solutions of piroxicam across human skin in diffusion cells was demonstrated. The amount of permeant in the stratum corneum was determined using a tape stripping technique. Supersaturated solutions up to four degrees of saturation were investigated which produced a linear relationship between the degree of saturation and the amount of piroxicam in the stratum corneum (R-2 = 0.970). Furthermore, the amount of piroxicam in the viable layers of the skin also increased with increasing degree of saturation. An analysis of the results suggested that enhanced penetration across human skin from supersaturated solutions of piroxicam may occur as a result of the antinucleating ability of the intercellular lipids of the stratum corneum. (C) 1997 Elsevier Science B.V.

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Absorption kinetics of solutes given with the subcutaneous administration of fluids is ill-defined. The gamma emitter, technitium pertechnetate, enabled estimates of absorption rate to be estimated independently using two approaches. In the first approach, the counts remaining at the site were estimated by imaging above the subcutaneous administration site, whereas in the second approach, the plasma technetium concentration-time profiles were monitored up to 8 hr after technetium administration. Boluses of technetium pertechnetate were given both intravenously and subcutaneously on separate occasions with a multiple dosing regimen using three doses on each occasion. The disposition of technetium after iv administration was best described by biexponential kinetics with a V-ss of 0.30 +/- 0.11 L/kg and a clearance of 30.0 +/- 13.1 ml/min. The subcutaneous absorption kinetics was best described as a single exponential process with a half-life of 18.16 +/- 3.97 min by image analysis and a half-life of 11.58 +/- 2.48 min using plasma technetium time data. The bioavailability of technetium by the subcutaneous route was estimated to be 0.96 +/- 0.12. The absorption half-life showed no consistent change with the duration of the subcutaneous infusion. The amount remaining at the absorption site with time was similar when analyzed using image analysis, and plasma concentrations assuming multiexponential disposition kinetics and a first-order absorption process. Profiles of fraction remaining at the absorption sire generated by deconvolution analysis, image analysis, and assumption of a constant first-order absorption process were similar. Slowing of absorption from the subcutaneous administration site is apparent after the last bolus dose in three of the subjects and can De associated with the stopping of the infusion. In a fourth subject, the retention of technetium at the subcutaneous site is more consistent with accumulation of technetium near the absorption site as a result of systemic recirculation.

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The photodegradation of irinotecan (CPT-11), the semisynthetic derivative of the antitumor alkaloid 20(S)-camptothecin, has been investigated. The drug was exposed to laboratory light for up to 5 days in 0.9% saline solution (pH 8.5). Five significant photodegradation products were observed and a high-performance liquid chromatography (HPLC) assay was employed to isolate them from CPT-11 using gradient conditions. The structures were elucidated by nuclear magnetic resonance spectroscopy and tandem mass spectrometry and shown to be the result of extensive modifications of the lactone ring of CPT-11. Three of the compounds were found to belong to the mappicine group of alkaloids. In addition, the effect of light on the stability of CPT-11 in aqueous solutions and biological fluids was also assessed, Potassium phosphate buffers (0.05 M, pH 5.0-8.2) and saline, plasma, urine, and bile solutions containing 20 mu M CPT-11 were equilibrated in the dark for 24 h before being exposed to laboratory light for up to 171 h at ambient temperature. Four of the five identified photodegradation products were observed and quantitated by isocratic HPLC, using a different detection mode (fluorescence) than the one used for gradient elution, In general, CPT-11 was found to be unstable under neutral and alkaline conditions for all solutions investigated, with the exception of bile. We conclude that CPT-11 is photolabile and that care should be taken to protect samples, particularly those intended for the isolation and identification of novel metabolites of CPT-11.

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Animal and human studies indicate that cannabidiol (CBD), a major constituent of cannabis, has anxiolytic properties. However, no study to date has investigated the effects of this compound on human pathological anxiety and its underlying brain mechanisms. The aim of the present study was to investigate this in patients with generalized social anxiety disorder (SAD) using functional neuroimaging. Regional cerebral blood flow (rCBF) at rest was measured twice using (99m)Tc-ECD SPECT in 10 treatment-naive patients with SAD. In the first session, subjects were given an oral dose of CBD (400 mg) or placebo, in a double-blind procedure. In the second session, the same procedure was performed using the drug that had not been administered in the previous session. Within-subject between-condition rCBF comparisons were performed using statistical parametric mapping. Relative to placebo, CBD was associated with significantly decreased subjective anxiety (p < 0.001), reduced ECD uptake in the left parahippocampal gyrus, hippocampus, and inferior temporal gyrus (p < 0.001, uncorrected), and increased ECD uptake in the right posterior cingulate gyrus (p < 0.001, uncorrected). These results suggest that CBD reduces anxiety in SAD and that this is related to its effects on activity in limbic and paralimbic brain areas.

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Generalized pustular psoriasis is a rare form of psoriasis consisting of a generalized eruption of sudden onset with erythema and sterile pustules. In children, generalized pustular psoriasis is even more uncommon and may present as a severe and potentially life-threatening disorder. In this study, we present demographics, clinical aspects, treatment response, and follow-up of seven children with generalized pustular psoriasis. Retrospective study reviewing the records of seven children with generalized pustular psoriasis including age, gender, age of onset, presence of scalp and nail involvement, family history, concomitant diseases, precipitating factors, treatment modalities, and outcome. Age of first symptoms ranged from 1 month to 11 years. All patients received systemic retinoids at one time of the follow-up period. Other treatment modalities included immunosuppressive drugs, biologics, phototherapy, and sulfasalazine. Two patients presented with severe constitutional illness, secondary infection and septic shock, including one fatal outcome. All further cases have remained free of recurrences for a mean period of up to 3 years. In our study, generalized pustular psoriasis presented a wide clinical spectrum in children ranging from mild, asymptomatic outbreaks to more severe, life-threatening episodes. One fatality was observed. Children generally responded well to systemic retinoids. Further studies and long-term follow-up periods are needed to define potential trigger factors, efficacy and safety of different treatment modalities in children with generalized pustular psoriasis.

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Background: Splanchnic perfusion is prone to early injury and persists despite normalization of global hemodynamic variables in sepsis. Volume replacement guided by oxygen derived variables has been recommended in the management of septic patients. Our hypothesis was that a hypertonic isoneotic solution Would improve the benefits of crystalloids replacement guided by mixed venous oxygen saturation. Methods: Seventeen anesthetized and mechanically ventilated mongrel dogs received an intravenous infusion of live E. coli in 30 minutes. They were then randomized into three groups: control group (n = 3) bacterial infusion without treatment; normal saline (n = 7), initial fluid replacement with 32 mL/kg of normal saline during 20 minutes; hypertonic solution (n = 7), initial fluid replacement with 4 mL/kg of hypertonic solution during 5 minutes. After 30 and 60 Minutes, additional boluses of normal saline were administered when mixed venous oxygen saturation remained below 70%. Mean arterial pressure, cardiac output; regional blood flows, systemic and regional oxygen-derived variables, and lactate levels were assessed. Animals were observed for 90 minutes and then killed. Hystopathological analysis including apoptosis detection using terminal deoxynucleotidil transferase mediated dUTP-biotin nick end labeling was performed. Results: A hypodynamic septic shock was observed after bacterial infusion. Both the fluid-treated groups presented similar transient benefits in systemic and regional variables. A greater degree of gut epithelial cells apoptosis was observed in normal saline-treated animals. Conclusions: Although normalization of mixed venous oxygen saturation was not associated with restoration of markers of splanchnic or other systemic perfusion variables, the initial fluid savings with hypertonic saline and its latter effect on gut apoptosis may be of interest in sepsis management.

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In this note, we present three independent results within generalized complex analysis (in the Colombeau sense). The first of them deals with non-removable singularities; we construct a generalized function u on an open subset Omega of C(n), which is not a holomorphic generalized function on Omega but it is a holomorphic generalized function on Omega\S, where S is a hypersurface contained in Omega. The second result shows the existence of a holomorphic generalized function with prescribed values in the zero-set of a classical holomorphic function. The last result states the existence of a compactly supported solution to the (partial derivative) over bar operator.

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Changes in 5-HT1A receptor-mediated neurotransmission at the level of the median raphe nucleus (MRN) are reported to affect the expression of defensive responses that are associated with generalized anxiety disorder (e.g. inhibitory avoidance) but not with panic (e.g. escape). The objective of this study was to further explore the involvement of MRN 5-HT1A receptors in the regulation of generalized anxiety-related behaviours. Results of experiment 1 showed that intra-MRN injection of the 5-HT1A/7 receptor agonist 8-OH-DPAT (0.6 nmol) in male Wistar rats impaired the acquisition of inhibitory avoidance, without interfering with the performance of escape in the elevated T-maze test of anxiety. Pre-treatment with the 5-HT1A receptor antagonist WAY-100635 (0.18 nmol) fully blocked this anxiolytic-like effect. As revealed by experiment 2, intra-MRN injection of 8-OH-DPAT (0.6, 3 or 15 nmol) also caused anxiolytic effect in rats submitted to the light-dark transition test, another animal model that has been associated with generalized anxiety. In the same test, intra-MRN injection of WAY-100635 (0.18, 0.37 or 0.74 nmol) caused the opposite effect. Overall, the current findings support the view that MRN 5-HT neurons, through the regulation of 5-HT1A somatodendritic autoreceptors, are implicated in the regulation of generalized anxiety-associated behaviours. (C) 2008 Elsevier Ireland Ltd. All rights reserved.

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Recently obtained evidence points to the involvement of the lateral habenular nuclei (LHb) in the mediation of coping defensive responses to threatening/stressful stimuli. Nevertheless, the role of this brain area in the regulation of defensive responses that have been associated with specific subtypes of anxiety disorders recognized in clinical settings is presently unknown. To address this question, we investigated the effects of either electrolytic lesions or chemical stimulation of the LHb on the defensive behaviors generated in rats by the elevated T-maze. This experimental model allows the measurement, in a same rat, of two defensive behaviors, inhibitory avoidance and escape, that have been related in terms of psychopathology to generalized anxiety and panic disorders, respectively. Bilateral electrolytic lesions of the LHb (1 mA, 10 s) impaired inhibitory avoidance acquisition and facilitated escape performance. On the other hand, chemical stimulation of the LHb by bilateral microinjection of kainic acid (30-60 pmol/0.2 mu L) had the opposite effect, i.e., facilitated inhibitory avoidance and impaired escape. The present results indicate that the LHb exerts an opposed regulatory control on generalized anxiety- and panic-related defensive responses in rats. (c) 2008 Elsevier Inc. All rights reserved.

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Formal Concept Analysis is an unsupervised machine learning technique that has successfully been applied to document organisation by considering documents as objects and keywords as attributes. The basic algorithms of Formal Concept Analysis then allow an intelligent information retrieval system to cluster documents according to keyword views. This paper investigates the scalability of this idea. In particular we present the results of applying spatial data structures to large datasets in formal concept analysis. Our experiments are motivated by the application of the Formal Concept Analysis idea of a virtual filesystem [11,17,15]. In particular the libferris [1] Semantic File System. This paper presents customizations to an RD-Tree Generalized Index Search Tree based index structure to better support the application of Formal Concept Analysis to large data sources.

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Background: Herpesviruses may be related to the etiology of aggressive periodontitis (AgP) and chronic periodontitis (CP) by triggering periodontal destruction or by increasing the risk for bacterial infection. This case-control study evaluated the presence of herpes simplex virus type 1 (HSV-1), Epstein-Barr virus type 1 (EBV-1), human cytomegalovirus (HCMV), Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans), Porphyromonas gingivalis, Prevotella intermedia, and Tannerella forsythia (previously T. forsythensis) in patients with generalized AgP (AgP group), CP (CP group), or gingivitis (G group) and in healthy individuals (C group). Methods: Subgingival plaque samples were collected with paper points from 30 patients in each group. The nested polymerase chain reaction (PCR) method was used to detect HSV-1, EBV-1, and HCMV. Bacteria were identified by 16S rRNA-based PCR. Results: HSV-1, HCMV, and EBV-1 were detected in 86.7%, 46.7%, and 33.3% of the AgP group, respectively; in 40.0%, 50.0%, and 46.7% of the CP group, respectively; in 53.3%, 40.0%, and 20.0% of the G group, respectively; and in 20.0%, 56.7%, and 0.0% of the C group, respectively. A. actinomycetemcomitans was detected significantly more often in the AgP group compared to the other groups (P<0.005). P. gingivalis and T. forsythia were identified more frequently in AgP and CP groups, and AgP, CP, and G groups had higher frequencies of P. intermedia compared to the C group. Conclusion: In Brazilian patients, HSV-1 and EBV-1, rather than HCMV, were more frequently associated with CP and AgP. J Periodontol 2008;79:2313-2321.