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101.
Effect of osmotic protection on nucleated cell killing by C5b-9: cell death is not affected by the prevention of cell swelling 总被引:2,自引:0,他引:2
Formation of C5b-9 channels in the plasma membrane can lead to erythrocyte lysis or nucleated cell death. Lysis of erythrocytes by complement occurs as a result of colloid osmotic swelling and rupture of the plasma membrane, due to the unregulated flux of ions and water through C5b-9 channels. This colloid osmotic mechanism of lysis is largely based on the evidence that the extent of hemolysis is reduced, when macromolecules are placed in the medium to balance the osmotic gradient created by intracellular macromolecules, which are too large to diffuse through complement channels. The role of colloid osmotic deregulation, as a cause of nucleated cell killing by C5b-9, however, has been recently questioned [Kim S., Carney D. F. and Shin M. L. J. Immun. 138, 1530 (1987)]. In the present study, we investigated the effect of osmotic protection, with an 81,000 mol. wt dextran or bovine serum albumin, on Ehrlich cell killing by complement channels. The results indicated that prevention of cell swelling by dextran did not reduce the extent or rate of nucleated cell killing by either small (C5b-9l), or large (C5b-9m), complement channels when assessed by vital dye stain. The release of cytoplasmic lactate dehydrogenase as an alternative measure of cell death, however, was retarded and/or reduced, in the presence of dextran or albumin, at concns that prevented cell swelling. These results indicate that C5b-9 can kill nucleated cells effectively, in the absence of colloidal osmotic cell swelling, and that release of cytoplasmic macromolecules may not be a reliable indicator of cell death, when osmotic protectants are employed. 相似文献
102.
Yoon HJ Kim H Kim HL Lee SG Zheng SH Shin JH Lim CS Kim S Lee JS Lee DS Kim YS 《Clinical genetics》2002,62(2):128-134
In order to investigate the interdependent action of the insertion/deletion polymorphism of the angiotensin-converting enzyme (ACE) gene and polymorphism in exon 11 (C1136-->T; Ala379Val) of the platelet-activating factor acetylhydrolase (PAF-AH) gene, which encodes a functional antagonist of PAF, on the progression of immunoglobulin A (IgA) nephropathy, we analysed both polymorphisms in patients with primary IgA nephropathy, who were followed-up for longer than 3 years. During the follow-up (87.3 +/- 50.0 months), the disease progressed in 38 of the 191 patients (19.9%). The D allele of the ACE gene in the absence of the T allele of the PAF-AH gene did not affect the prognosis [odds ratio (OR), 3.6; 95% confidence interval (CI), 0.8-16.4] and neither did the T allele in the absence of the D allele (OR, 3.0; 95% CI, 0.4-24.2). However, the presence of both was a significant prognostic factor (OR, 6.6; 95% CI, 1.4-31.3). After adjusting for other risk factors, the presence of both proved to be an independent risk factor (OR, 4.5; 95% CI, 1.6-12.7). These results suggest that the interdependent effects of ACE and PAF-AH polymorphisms on the progression of IgA nephropathy might be more important than the effect of the individual polymorphisms. 相似文献
103.
Euy Kyun Shin Fumihiko Matsuda Junji Fujikura Takashi Akamizu Hideo Sugawa Toru Mori Tasuku Honjo 《European journal of immunology》1993,23(9):2365-2367
In an Epstein-Barr virus-transformed human B cell line we found an unusual immunoglobulin heavy chain gene rearrangement. Restriction mapping and sequencing analysis led us to conclude that VH-D and D-JH recombination took place in a single allele. Both VH-D and D-JH complexes still had their recombination signal sequences adjacent and the DNA sandwiched by these two complexes retained a germ line configuration, suggesting the potential for a secondary rearrangement resulting in a VH-D(-D)-JH formation. With this finding, we propose a novel pathway, in which the VH-D complex is an intermediate in the formation of a functional VH exon. 相似文献
104.
105.
Norio Fukuda Hideaki Fujita Takashi Fujita Shin’ichi Ishiwata 《Pflügers Archiv : European journal of physiology》1996,433(1-2):1-8
Skinned fibres from bovine ventricles exhibited spontaneous tension oscillations when MgADP and inorganic phosphate (Pi)
were added to the solution bathing fibres in the relaxed state (ADP-SPOC). A similar type of oscillation was observed at intermediate
concentrations of free Ca2+ in the absence of MgADP and Pi (Ca-SPOC). To investigate the correlation between ADP-SPOC and Ca-SPOC, we constructed two-dimensional
state diagrams of cardiac muscle using different concentrations of Pi (0–20 mM) and free Ca2+ [pCa=around 5 (+Ca2+), pCa=5.15–6.9 and +EGTA (–Ca2+)], with varying concentrations of MgADP (0–10 mM), with 2 mM MgATP and 2 mM free Mg2+ maintaining ionic strength at 0.15±0.01 M, pH 7.0, 25 °C. The three-dimensional (pCa-Pi-MgADP) state diagram thus obtained
was divided into three regions, i.e. the contraction region in which tension oscillation was undetectable, the spontaneous
tension oscillation (SPOC) region and the relaxation region. We found that the regions of ADP-SPOC and Ca-SPOC were continuously
connected by a single oscillation region sandwiched between the contraction and relaxation regions. The state diagram, which
encompasses physiological conditions, shows that the probability of SPOC is higher in cardiac muscle than in skeletal muscle.
From these results, we suggest that, despite distinct ionic conditions, the molecular state of cross-bridges during SPOC is
common to both ADP-SPOC and Ca-SPOC.
Received 19 February 1996 / Received after revision: 16 July 1996 / Accepted: 14 August 1996 相似文献
106.
Isometric and isokinetic torque curves at the knee joint 总被引:1,自引:0,他引:1
Isometric and isokinetic torques of bilateral quadriceps and hamstrings were measured with Isokinetic Rehabilitation and Testing System (Model No. Cybex 340) on 40 normal untrained subjects, 20 males and 20 females, ranging between the ages of 23 and 35 years. The mean peak isometric and isokinetic torque values of both muscle groups showed no significant differences between dominant (right) and nondominant (left) limbs in both sexes; however there were significant differences between the male and the female. As the angular velocity increased, the peak torque significantly decreased, and the point of peak torque output occurred significantly later in the range of motion for quadriceps and hamstrings (p less than 0.01). There were no significant changes in the hamstrings to quadriceps (H/Q) ratios as the angular velocity increased. However, there were significant differences of mean H/Q ratio between male and female (p less than 0.01). Height had significant positive correlation with peak isometric and isokinetic torques for both quadriceps and hamstrings (p less than 0.01). Weight was found to correlate significantly with peak isometric and isokinetic torques (p less than 0.01). The mean isometric torques were significantly higher than the mean isokinetic torques for any joint angles in both sexes (p less than .01). 相似文献
107.
Effects of thyroxine on hyperkalemia and renal cortical Na+, K+ - ATPase activity induced by cyclosporin A 总被引:1,自引:0,他引:1
Cyclosporin A (CsA)-induced hyperkalemia is caused by alterations in transepithelial K+ secretion resulting from the inhibition of renal tubular Na+, K+ -ATPase activity. Thyroxine enhances renal cortical Na+, K+ -ATPase activity. This study investigated the effect of thyroxine on CsA-induced hyperkalemia. Sprague-Dawley rats were treated with either CsA, thyroxine, CsA and thyroxine, or olive-oil vehicle. CsA resulted in an increase in BUN and serum K+, along with a decrease in creatinine clearance, fractional excretion of potassium, and renal cortical Na+, K+ -ATPase activity, as compared with oil vehicle administration. Histochemical study showed reduced Na+, K+ -ATPase activity in the proximal tubular epithelial cells of the CsA-treated compared with the oil-treated rats. Histologically, isometric intracytoplasmic vacuolation, disruption of the arrangement and swelling of the mitochondria, and a large number of lysosomes in the tubular epithelium were characteristic of the CsA-treated rats. Co-administration of thyroxine prevented CsA-induced hyperkalemia and reduced creatinine clearance, Na+, K+ -ATPase activity, and severity of the histologic changes in the renal tubular cells when compared with the CsA-treated rats. Thyroxine increased the fractional excretion of potassium via the preservation of Na+, K+ -ATPase activity in the renal tubular cells. Thus, the beneficial effects of thyroxine may be suited to treatment modalities for CsA-induced hyperkalemia. 相似文献
108.
This study examined the long-term substance use outcomes of 2 brief interventions designed for general population families of young adolescents. Thirty-three public schools were randomly assigned to 3 conditions: the 5-session Preparing for the Drug Free Years Program, the 7-session Iowa Strengthening Families Program, and a minimal contact control condition. The pretest involved 667 6th graders and their families. Assessments included multiple measures of initiation and current use of alcohol, tobacco, and marijuana. Pretest data were collected in the 6th grade and the reported follow-up data were collected in the 10th grade. Significant intervention-control differences in initiation and current use were found for both interventions. It is concluded that brief family skills-training interventions designed for general populations have the potential to reduce adolescent substance use and thus have important public health implications. 相似文献
109.
Shin TY 《Immunopharmacology and immunotoxicology》2004,26(4):621-630
The effect of aqueous extract of Stachys riederi var. japonica Miq. (Labiatae) (SRAE) on the mast cell-mediated allergic and inflammatory reactions were investigated. SRAE inhibited systemic allergic reaction induced by compound 48/80. SRAE dose-dependently inhibited passive cutaneous anaphylaxis (PCA) activated by anti-dinitrophenyl (DNP) IgE. SRAE also dose-dependently inhibited the histamine release from rat peritoneal mast cells (RPMC) activated by compound 48/80 or anti-DNP IgE. Moreover, SRAE inhibited the secretion of tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-6 in phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore A23187-stimulated human mast cells (HMC-1 cells). These results provide evidences that SRAE may be beneficial in the treatment of acute and chronic allergic diseases. 相似文献
110.
Ahn HW Shin WG Park KJ Suh OK Choi JH 《Research communications in molecular pathology and pharmacology》1999,105(1-2):105-113
Theophylline has been widely used to treat apnea of premature neonates. The purpose of this study was to compare the pharmacokinetic parameters of theophylline and caffeine after intravenous administration of aminophylline to seven Korean low-birthweight neonates with apnea to those in other countries. The serum concentrations of theophylline and caffeine were measured simultaneously by high-performance liquid-chromatography (HPLC). The mean (+/- S.E.M.) birth weight and gestational period were 1190 +/- 253 g and 31.5 +/- 1.99 weeks, respectively. The mean (+/- S.E.M.) theophylline maintenance dosage was 1.28 +/- 0.15 mg/kg (given as equivalent aminophylline solution) every six hours. The mean (+/- S.E.M.) volume of distribution, 0.937 +/- 0.232 l/kg, elimination rate constant, 0.0249 +/- 0.0095/h, elimination half-life, 32.1 +/- 12.1 h, and total body clearance, 21.7 +/- 6.18 ml/h/kg, of theophylline in Korean premature neonates were comparable to the values of neonates in other countries. For caffeine, the mean (+/- S.E.M.) elimination half-life was 95.1 +/- 25.4 h and the elimination rate constant was 0.0079 +/- 0.0024/h. The mean (+/- S.E.M.) serum concentrations of theophylline and caffeine on the sixth day after aminophylline infusion were 10.4 +/- 2.28 microg/ml (range, 6.38-13.4 microg/ml) and 2.94 +/- 0.98 microg/ml (range, 1.80-4.44 microg/ml), respectively. The mean (+/- S.E.M.) caffeine to theophylline concentration ratio on the day after discontinuation of aminophylline infusion was 0.71 +/- 0.23 (range, 0.39-1.03). 相似文献