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51.
OBJECTIVE: To determine whether hemofiltration (HF) can eliminate cytokines and complement components and alter systemic hemodynamics in patients with severe sepsis. DESIGN: Prospective observation study. SETTING: Surgical intensive care unit of a university hospital. PATIENTS: 16 patients with severe sepsis. INTERVENTIONS: Continuous zero-balanced HF without dialysis (ultrafiltrate rate 2 l/h) was performed in addition to pulmonary artery catheterization, arterial cannulation, and standard intensive care treatment. MEASUREMENTS AND MAIN RESULTS: Plasma and ultrafiltrate concentrations of cytokines (the interleukins IL-1 beta, IL-6, IL-8, and tumor necrosis factor alpha) and of complement components (C3adesArg, C5adesArg) were measured after starting HF (t0) and 4 h (t4) and 12 h later (t12). Hemodynamic variables including mean arterial pressure (MAP), mean central venous pressure, mean pulmonary artery pressure, pulmonary capillary wedge pressure, and cardiac output were serially determined. During HF, cytokine plasma concentrations remained constant. However, C3adesArg and C5adesArg plasma concentrations showed a significant decline during 12-h HF (C3adesArg: t0 = 676.9 +/- 99.7 ng/ml vs t12 = 467.8 +/- 71, p < 0.01; C5adesArg: 26.6 +/- 4.7 ng/ml vs 17.6 +/- 6.2, p < 0.01). HF resulted in a significant increase over time in systemic vascular resistance (SVR) and MAP (SVR at t0: 669 +/- 85 dyne.s/cm5 vs SVR at t12: 864 +/- 75, p < 0.01; MAP at t0: 69.9 +/- 3.5 mmHg vs MAP at t12: 82.2 +/- 3.7, p < 0.01). CONCLUSIONS: HF effectively eliminated the anaphylatoxins C3adesArg and C5adesArg during sepsis. There was also a significant rise in SVR and MAP during high volume HF. Therefore, HF may represent a new modality for removal of anaphylatoxins and may, thereby, deserve clinical testing in patients with severe sepsis.  相似文献   
52.
The subcellular distribution in rat liver and the topography in intracellular and plasma membranes of connexin 32, a major protein component of gap junctions, was studied using sequence-specific anti-peptide antibodies generated to extracellular and intracellular domains of the protein. The distribution of connexin 32 in liver analyzed using SDS-polyacrylamide gel electrophoresis and Western blotting showed the relative protein levels in the subcellular fractions to be: lateral plasma membranes > Golgi membranes > sinusoidal plasma membranes > lysosomes. Low amounts of connexin 32 were detected in microsomes, endosomes, and bile canalicular plasma membranes. Six highly conserved cysteine residues are located in the amino acid sequences comprising the two extracellular loops of all connexins thus far isolated, and these loops are positioned to extend the channel in the lipid bilayers across the intercellular region of the gap junction. In the present work, the intramolecular disulfide bonds linking the extracellular loops in gap junctions were shown to be present in connexins located in plasma membranes, Golgi, and a microsomal fraction, and it was concluded that the disulfide linkages were formed in the endoplasmic reticulum. In addition, immature configurations of connexin 32, probably occurring during membrane insertion, were detected in liver microsomal fractions. The results contribute to charting of the biogenetic routes followed by connexins in hepatocytes and the general mechanisms of gap junction assembly.  相似文献   
53.
This review reports the different genetic factors that have been identified either as risk factor for Alzheimer's disease (AD) or directly causing the disease. First are reviewed epidemiological data and biological mechanisms about the apoplipoprotein E gene allele epsilon 4 that is a major risk factor for Alzheimer's disease. The second part describes the mutations responsible for early-onset autosomal dominant AD found in three different genes. The gene located on chromosome 21 encodes the amyloid precusor protein (APP). The presenilin 1 and presenilin 2 genes, located on chromosome 14 and 1 respectively, encode not yet known membrane proteins.  相似文献   
54.
We provide a unified framework for the investigation of convergence properties of the iterative algorithms for photon attenuation correction in SPECT, including the iterative Chang method--a commonly used approach in which an average attenuation factor calculated over all projection angles is employed in a pointwise correction scheme. A new average attenuation factor calculated along the projection line is introduced, which can compensate exactly for the attenuation effect in the case of a uniform activity distribution. We propose a new hybrid approach in which we use this new average attenuation factor initially and then shift to the iterative Chang method in later iterations. This hybrid approach was evaluated in a simulation study by use of a computer-generated phantom with both non-uniform activity and non-uniform attenuation distributions. The results demonstrate that this hybrid approach improves the convergence speed of the iterative Chang method and produces reconstructed images of high quality.  相似文献   
55.
In an attempt to validate the use of topographical mapping of EEG as a method of localising cerebral function, EEG was recorded during a simple motor task. A minimum of 20 sec artifact-free EEG was recorded from 24 healthy right handed subjects in each of 4 conditions: eyes open 1, motor task (left/right, order randomized), eyes open 2. EEG amplitude maps were computed in delta, theta, alpha, and beta (1 and 2). Differences were seen between the eyes open and the motor conditions in alpha, beta 1 and beta 2 localised to the motor and supplementary motor areas. It is argued that topographical mapping of EEG is a valid method of localising cognitive function in healthy individuals for the Luria task.  相似文献   
56.
We report a case of homozygous alpha-thalassaemia with hydrops fetalis presenting at 22 weeks of gestation. In utero exchange transfusion was performed with maternal blood at 23 weeks. 25 weeks and 29 weeks of gestation. The fetus was delivered at 29 weeks of gestation without significant neonatal complication. Post-transfusion haemoglobin pattern after transfusion suggested that a total haematocrit of 0.52 may be the desired post-exchange transfusion haematocrit to aim for and the total haematocrit of haemoglobin A and haemoglobin Portland dropped approximately one percent per day.  相似文献   
57.
Depression is one of the most common reasons for using complementary and alternative therapies. The aim of this article is to provide an overview of the evidence available on the treatment of depression with complementary therapies. Systematic literature searches were performed using several databases, reference list searching, and inquiry to colleagues. Data extraction followed a predefined protocol. The amount of rigorous scientific data to support the efficacy of complementary therapies in the treatment of depression is extremely limited. The areas with the most evidence for beneficial effects are exercise, herbal therapy (Hypericum perforatum), and, to a lesser extent, acupuncture and relaxation therapies. There is a need for further research involving randomized controlled trials into the efficacy of complementary and alternative therapies in the treatment of depression.  相似文献   
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59.
Atrial natriuretic peptide (ANP) and sodium nitroprusside (SNP) increase cGMP in vascular smooth muscle cells and act as vasodilators in some, but not all, blood vessels. In this present study, we attempted to correlate the ability of these two agents to dilate blood vessels with the ability to increase cGMP in cultured vascular smooth muscle cells. In the isolated guinea pig heart, SNP dose-dependently increased coronary flow while ANP was ineffective. In smooth muscle cells cultured from the coronary system, SNP increased intracellular cGMP in a dose-dependent manner while ANP had no effect on cGMP in these cells. In isolated guinea-pig thoracic aorta, precontracted with K+, both ANP and SNP produced relaxation and ANP was the more potent. In smooth muscle cells cultured from the aorta, ANP and SNP increased cGMP and the potency relationship was similar to the intact vessel. These results support the view that phenotypic properties of vascular smooth muscle cells can account for differences in the response of blood vessels to vasodilators.  相似文献   
60.
LR Goldman  WH Farland 《Canadian Metallurgical Quarterly》1998,279(5351):640-1; author reply 641
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