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1.
Precursor ([3H]uridine) incorporation studies in the presence or absence of actinomycin D (AMD) showed that AMD-insensitive nucleic acid synthesis occurred only in the nuclei in pea enation mosaic virus (PEMV)-infected pea plant tissues. Ferritin-labeled antibody studies showed that ds-RNA was present only in nuclei. In vitro hybridization of the nucleic acid from various infected or healthy cell fractions with [125I]PEMV-ss-RNA indicated that PEMV-ds-RNA was primarily associated with nuclei-enriched fractions from infected cells.An in situ hybridization technique, which utilized autoradiography to detect the subcellular location of material which hybridized with [125I]PEMV-ss-RNA, was developed. This method confirmed that PEMV-ds-RNA was localized in the nuclei of PEMV-infected tissues.  相似文献   

2.
3种钙激动剂促培养的大鼠血管平滑肌细胞增殖   总被引:3,自引:2,他引:1  
目的:探讨不同来源的细胞内钙离子([Ca2+]i)对血管平滑肌细胞(vascular smooth muscle cells, VSMCs)丝裂素活化蛋白激酶(MAPK)介导的增殖反应的作用。方法:以培养的大鼠VSMCs为靶细胞,用血管紧张素II(Ang Ⅱ)剌激VSMCs跨膜Ca2+内流、三磷酸肌醇(IP3)和雷尼丁(RY)剌激胞内Ca2+释放,[γ-32 P]-ATP掺入法和免疫印迹(Western blot)测MAPK活性及蛋白含量,氚-亮氨酸([3H]-Leu)、氚-胸腺嘧啶([3H]-TdR)掺入量作为VSMCs增殖的指标。结果:Ang Ⅱ、IP3和RY均能显著增加VSMCs的[Ca2+]i浓度、MAPK活性及蛋白含量,并提高[3H]-Leu、[3H]-TdR掺入量,与对照组VSMCs相比差异显著(P<0.01)。结论:钙激动剂诱导的MAPK活性及含量的增加参与了VSMCs的增殖,VSMCs的肥大增殖与[Ca2+]i浓度增加有关,而与[Ca2+]i的来源无关。  相似文献   

3.
The Clinical Laboratory Standards Institute ([CLSI] formerly NCCLS) reference broth microdilution testing method (protocol M27-A3) was compared with a commercially available methods (Sensititre YeastOne®) by testing two quality control strains and 102 isolates of Candida sp. and Cryptococcus sp. against fluconazole, itraconazole, ketoconazole, posaconazole, voriconazole, flucytosin, amphotericin B and caspofungin. Minimal inhibitory concentrations (MIC) endpoints were determined after 24 h of incubation for Sensititre YeastOne® and after 24 and 48 h for CLSI microdilution method. Essential agreements between methods vary from 70.6 to 92.2%. Categorical agreements vary from 94.1% for 5FC to 72.6% for AMB. Sensititre YeastOne® reading appears to be useful for avoiding very major errors and this confirms the interest of this method for evaluating new antifungals activity in vitro.  相似文献   

4.
Plasma human growth hormone ([HGH]), adrenaline ([A]), noradrenaline ([NA]) and blood lactate ([La]b) concentrations were measured during progressive, multistage exercise on a cycle ergometer in 12 endurance-trained athletes [aged 32.0 (SEM 2.0) years]. Exercise intensities (3 min each) were increased by 50 W until the subjects felt exhausted. Venous blood samples were taken after each intensity. The [HGH] and catecholamine concentrations increased negligibly during exercise of low to moderate intensities revealing an abrupt rise at the load corresponding to the lactate threshold ([La]-T). Close correlations (P < 0.001) were found between [La]b and plasma [HGH] (r = 0.64), [A] (r = 0.71) and [NA] (r = 0.81). The mean threshold exercise intensities for [HGH], [A] and [NA], detected by log-log transformation, [154 (SEM 19) W, 162 (SEM 15) W and 160 (SEM 17) W, respectively] were not significantly different from the [La]-T [161 (SEM 12) W]. The results indicated that the threshold rise in plasma [HGH] followed the patterns of plasma catecholamine and blood lactate accumulation during progressive exercise in the endurancetrained athletes.  相似文献   

5.
Effects of Na and K ions on the active Na transport in guinea-pig auricles   总被引:1,自引:1,他引:0  
1.  The effect of Na and K ions on active Na transport was studied in guinea-pig auricles by means of flame photometry.
2.  The Na influx into preparations rewarmed in Tyrode's solution after cooling was estimated to be about 1.05 mmole/l fibre water·min ((l.f.w.·min) or c. 8 pmole/cm2·s. Intracellular Na ions enhanced the active Na efflux over a wide range of concentrations. A decrease in the extracellular Na concentration ([Na] o ) had no major effect on the active Na efflux.
3.  Extracellular K ions initiated an active Na efflux from rewarmed auricles with an elevated [Na] i over a narrow range of K concentrations ([K] o ).
4.  Assuming Michaelis-Menten kinetics the maximal active Na efflux activated by internal Na ions was calculated to be about 4 mmole/l.f.w.·min (30 pmole/cm2·s). Half maximal Na efflux occurred at about 22 mmole/l.f.w. [Na] i . The maximal K-activated active Na efflux was deduced to be about 3.7 mmole/l.f.w.·min (28 pmole/cm2·s) and was half maximal at a [K] o of about 0.2 mM.
5.  It is tentatively concluded that the maximal active Na efflux from guinea-pig atria is 3–4 times larger than the physiological flux. Under normal conditions active Na efflux in heart is mainly regulated by variations of [Na] i .
  相似文献   

6.
To evaluate the relationship between lactate release and [lac]art and to investigate the influence of the catecholamines on the lactate release, 14 healthy men [age 25±3 (SE) year] were studied by superimposing cycle on forearm exercise, both at 65% of their maximal power reached in respective incremental tests. Handgrip exercise was performed for 30 min at 65% of peak power. In addition, between the tenth and the 22nd minute, cycling with the same intensity was superimposed. The increase in venous lactate concentration ([lac]ven) (rest: 1.3±0.4 mmol·l−1; 3rd min: 3.9±0.8 mmol·l−1) begins with the forearm exercise, whereas arterial lactate concentration ([lac]art) remains almost unchanged. Once cycling has been added to forearm exercise (COMB), [lac]art increases with a concomitant increase in [lac]ven (12th min: [lac]art, 3.2±1.3 mmol·l−1; [lac]ven, 5.7±2.2 mmol·l−1). A correlation between oxygen tension (PvO2) and [lac]ven cannot be detected. There is a significant correlation between [lac]art and norepinephrine ([NE]) (y=0.25x+1.2; r=0.815; p<0.01) but no correlation between lactate release and epinephrine ([EPI]) at moderate intensity. Our main conclusion is that lactate release from exercising muscles at moderate intensities is neither dependent on PvO2 nor on [EPI] in the blood.  相似文献   

7.
Summary The effect of muscle contraction on lymphatic and plasma [K+], [Na+], [Ca2+], [Mg2+], [Cl], [Pi], [lactate] ([Lac]); [creatine] ([Cr]), ideal osmolality (OSM), and [protein] was evaluated in femoral venous blood and lymph specimens sampled from the calf muscles of rabbits before, in the course of, and after contractions. In addition, total [K+], [Na+], [Ca2+], [Mg2+], [Cl], and [H2O] were analyzed in the muscle tissue. To facilitate lymph sampling both hind limbs were passively flexed and extended, in imitation of natural running movements, by an electrically driven crank. The muscles of one side also performed superimposed rhythmic isotonic contractions. Before contractions, lymphatic [K+], [Na+], [Ca2+], [Mg2+], [Lac], [Cr], and OSM did not significantly differ from corresponding femoral venous concentrations, [Cl], and [Pi] were significantly higher, [protein] significantly lower in the lymph than in the plasma. During contractions lymphatic [K+], OSM, [Lac], and [Pi] were raised significantly more in the lymph compared with the plasma concentrations. [Na+], [Cl], [Ca2+], and [Mg2+] showed only small changes in the course of contractions and thereafter, and they were altered in a similar way in the lymph and plasma. It was suggested that lymphatic and interstitial concentrations were in equilibrium. Comparing inactive with active muscles, the latter lost K+ but gained Na+, Cl, and H2O, whereas minimal changes occurred in the [Ca2+] and [Mg2+]. The changes were discussed in connection with the hypothesis that electrolyte shifts might be involved in the activation of the muscular non-proprioceptive interstitial nerve endings which appear to play a role in reflexogenic cardiovascular and respiratory control.A preliminary report of this work has been given elsewhere [33]Supported by Deutsche Forschungsgemeinschaft  相似文献   

8.
Summary The purpose of this study was to investigate middle-term influences of a marathon race on plasma volume (PV) and red cell production. We performed the following measurements in the blood of 15 male athletes: haemoglobin ([Hb]), haematocrit (Hct), plasma protein concentration ([Prot]), plasma osmolality, sodium concentration ([Na+]), potassium concentration ([K+]), aldosterone concentration ([Aldo]), haptoglobin concentration ([Hpto]), and the reticulocyte count, as well as the calculation of relative changes in PV, 3 days before and on 3-consecutive days after a marathon race. By the 2nd day of recovery PV had increased by 16%. Plasma osmolality and [K+] remained constant, whereas [Na+] had decreased slightly 2 days after the competition and [Aldo] tended to be elevated 1 day after the competition. [Hpto] was low before and 1 day after the competition and increased on the following days. Reticulocyte count was unaffected 1 day after the race, but increased by 106% on the 2nd day and was still elevated after 3 days. The causes for higher post-marathon plasma volumes and reticulocyte counts could be in the complex variations in hormonal regulation, which have not yet been sufficiently investigated. A preliminary report was presented at the 64th congress of the German Physiological Society in 1987  相似文献   

9.
The capsular polysaccharide of Neisseria meningitidis serogroup W135 is expressed in both O-acetyl-positive (OA+) and O-acetyl-negative (OA) forms. This study investigates the impact of OA status (OA+ versus OA) on serological measurements of anti-W135 immunoglobulin G (IgG) antibodies in immunized adults. W135-specific serum antibody assignments were made for 28 postimmunization sera from adults by enzyme-linked immunosorbent assay using the meningococcal standard reference serum CDC1992. The established IgG concentration in micrograms per milliliter ([IgG]μg/ml) for CDC1992 against OA+ antigen (16.2 μg/ml) was used as a reference to assign a concentration of 10.13 μg/ml IgG against OA antigen by cross-standardization. Overall, the IgG assignments for these sera were higher against OA+ antigen (geometric mean concentration [GMC] = 7.16 μg/ml) than against OA antigen (GMC = 2.84 μg/ml). However, seven sera showed higher specific [IgG]μg/ml values against the OA+ antigen than against the OA antigen. These sera were also distinguished by the inability of fluid-phase OA antigen to compete for antibody binding to OA+ solid-phase antigen. Although there was no overall difference in functional activity measured by complement-mediated serum bactericidal assay (SBA) against OA+ and OA target bacteria (geometric mean titers of 9,642 and 9,045, respectively), three serum specimens showed a large difference in SBA antibody titers against OA+ versus OA W135 target bacteria, which may reflect different epitope specificities for these sera. Our data indicate that, for some sera, the agreement in anti-OA+ versus anti-OA W135 IgG assignments is serum specific and does not reflect the functional (killing) activity in vitro.  相似文献   

10.
Characterization of the levamisole receptor was performed with total extracts of Trichinella spiralis muscle larvae using binding assays with tritiated levamisole ([3H]LEV, 291 GBq/mmol). We detected a specific [3H]LEV binding activity with a dissociation constant (Kd) of 4.76 μM and a receptor density (Bmax) of 2.14 pmol/mg of protein. In inhibition studies, only dimethylphenylpiperazinium iodide (DMPP) and hexamethonium were found to be competitive inhibitors of the [3H]LEV binding with an inhibition constant (Ki) of 31.04 and 4.43 μM, respectively, whereas d-tubocurarine and α-bungarotoxine had no effect on [3H]LEV binding activity, and procaine and atropine potentiated the [3H]LEV-receptor binding. All these data support the idea that levamisole acts as a cholinergic agonist in T. spiralis. Received: 6 April 1998 / Accepted: 24 April 1998  相似文献   

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