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91.
Periannan Kuppusamy Penghai Wang Michael Chzhan Jay L. Zweier 《Magnetic resonance in medicine》1997,37(4):479-483
The application of electron paramagnetic resonance imaging (EPRI) to obtain information from biological samples has been limited by the lack of ideal single line radical labels. The commonly used nitroxides exhibit multiple lines causing either hyperfine-based limitations in the maximum obtainable image resolution or hyperfine-based artifacts in the reconstructed image. The use of a novel single-line triarylmethyl paramagnetic label that enables marked enhancement in image quality and resolution is reported. This label exhibits a single line EPR spectrum that is sharp (linewidth ~60 mG in the absence of oxygen) and relatively stable in tissues. The potential of this label in enabling high resolution EPR imaging of biological samples was demonstrated in a series of phantoms and isolated biological organs such as the rat kidney. The images demonstrate that resolutions better than 100 μm could be obtained at L-band on samples of up to 20 mm in size. 相似文献
92.
A rat model of monitoring liver allograft rejection 总被引:5,自引:0,他引:5
Timi Martelius Heikki Mäkisalo Krister Höckerstedt Eero Taskinen Irmeli Lautenschlager 《Transplant international》1997,10(2):103-108
Rat models are often used to study liver allograft rejection. We have established a model for rat liver allograft rejection,
monitored by fine needle aspiration biopsy (FNAB), in the strain combination PVG-to-BN with a mean survival time of 37 ± 20
days. In this model, we observed acute rejection with an intense peak of lymphoid blasts and lymphocyte-dominated inflammation
in the FNAB [9.1 ± 3.0 corrected increment units (CIU)], and an eventual increase in macrophages (up to 4.2 ± 4.4 CIU), together
with fibrosis and parenchymal necrosis in the graft. Markers of immune activation, such as an increase in IL-2-receptor (from
1 % ± 2 % to 21 % ± 13 %) and class II (from 20 % ± 9 % to 43 % ± 13 %) expressing lymphoid cells and induction of ICAM-1
in the graft, were consistent with the overall cellular response. The FNAB correlated well with parallel graft histology.
In this rat model, the atraumatic monitoring makes a close follow-up possible without having to sacrifice the experimental
animals. This saves work, animals, and costs in the study of liver rejection.
Received: 2 July 1996 Accepted: 28 October 1996 相似文献
93.
雌、孕激素对IL-6基因在子宫内膜表达的影响 总被引:4,自引:1,他引:3
为了进一步了解白介素-6(IL-6)在生殖过程中的作用,应用斑点杂交和原位杂交方法,研究IL-6在小鼠子宫内膜的基因表达和雌、孕激素对这种表达的影响。实验证明,正常动情前期子宫内膜间质细胞有IL-6cRNA基因表达,切除动物卵巢,即可消除这种表达。如给去卵巢动物2mg孕激素加10ng雌激素或20mg孕激素加100ng雌激素,它们的光密度(IOD)值分别可达到2.3和2.5。结果证明,子宫内膜间质细胞是产生细胞因子IL-6的主要细胞之一,并受卵巢激素的调控。 相似文献
94.
采用高渗盐液,抗休克裤及两者联用纠正大鼠早期失血性休克。结果显示,单独使用AST,仅见动脉血压短时间回升,而单用HTS,血压则明显回升。若先用AST,再注入HTS,也能取得明显效果。失血休克大鼠血浆纤维连接蛋白水平显著降低,各组之间均无差异血浆脂质过氧化物-丙二醛的含量明显增加,且在HTS组,HTS+AST组与NS对照组之间有显著差异。 相似文献
95.
In the 12-day-old rat cochlea, the synthesis of inositol phosphates (IPs) can be activated via M3 cholinoceptors. This stimulation is blocked by ototoxins (mercury, ethacrynate, cisplatin, neomycin), drugs with side effects that lead to damage of hair cells and strial cells. As these toxic effects can be reversed in vivo by thiol molecules, we investigated whether modifications of thiol compounds could be involved in ototoxin-induced inhibition of the IP turnover in the cochlea. For this purpose, we assessed whether the sulphhydryl-modifying reagents N -ethylmaleimide and cadmium modify the carbachol-stimulated formation of IPs in the 12-day-old rat cochlea. Both molecules inhibit the carbachol effect on a dose-dependent way without altering the basal metabolism of IPs. As cadmium may block some calcium channels, the effect of verapamil, another calcium channel antagonist, was tested. Verapamil (1 –50 μM) does not alter carbachol-evoked IP formation, suggesting that the inhibitory effect of cadmium is not due to a calcium influx block. Binding experiments with the muscarinic ligand quinuclidinyl benzylate (QNB) showed that the sulphhydryl-modifying reagents do not displace QNB from binding sites. Combining ototoxins and reagents shows that N -ethylmaleimide acts synergistically with all ototoxins but ethacrynate while cadmium does so only with mercury. Both N -ethylmaleimide and cadmium have additive effects with ethacrynate. As a supplement, disulphide bond-modifying agents do not alter the carbachol-enhanced metabolism of IPs. These results suggest that molecules having thiol-modifying properties inhibit the carbachol-induced turnover of IPs without acting at the muscarinic sites. Since thiol modifiers and ethacrynate share similar features in both QNB binding and IP response it is hypothesized that they strike common targets, possibly G proteins. 相似文献
96.
Shinichiro Yasumoto Jun Tsujita Shuhei Imayama Yoshiaki Hori 《The Journal of dermatology》1996,23(7):499-501
We report a case of Gianotti-Crosti syndrome associated with human herpesvirus-6 (HHV-6) infection. An eight-month-old girl developed monomorphous papules on her cheeks, buttocks, and extremities after the subsidence of exanthema subitum. Viral antibody analysis confirmed primary HHV-6 infection. HHV-6 may be added to the list of causative agents of Gianotti-Crosti syndrome. 相似文献
97.
KYOSUKE YAMAMOTO NOBUHIRO FUKUDA LEI ZHANG TAKAHIRO SAKAI 《Pharmacological research》1996,33(6):337-342
The aim of this study was to examine the effects of dietary fenofibrate (0.05% in the diet) on ketone body production and lipid secretion in isolated perfused rat liver. Feeding with fenofibrate for 7–9 days caused an increased liver weight. Ketone body production was significantly greater in the livers perfused with oleic acid than in those perfused without fatty acid, with the elevation of the ratio ofβ-hydroxybutyrate:acetoacetate indicating an increased redox potential in mitochondrial compartments by exogenous fatty acid. On the other hand, fenofibrate feeding caused a further stimulation of ketone body production from both endogenous and exogenous fatty acid substrates, respectively, with a decreased ratio ofβ-hydroxybutyrate:acetoacetate as compared to respective control livers, indicating a decreased redox potential. Hepatic secretion of triglyceride, but not of cholesterol, was decreased markedly in the fenofibrate-fed rats, especially when oleate was provided, suggesting an inverse relationship between rates of ketogenesis and triglyceride secretion. These results suggest that the altered hepatic metabolism of long-chain fatty acids between oxidation and esterification caused by fenofibrate may thus be a factor responsible for the decreased secretion of triglyceride, hence leading to hypotriglyceridaemiain vivo. 相似文献
98.
3-Methoxytyramine (3-MT) is a minor metabolite of dopamine which is suggested to reflect the turnover and utilization of dopamine. A novel, isocratic HPLC method has been developed which can be used to analyse 3-MT in homogenates of rat brain without the need for additional purification procedures. Furthermore, the coulometric electrochemical detection system is sensitive enough to measure 3 pg of 3-MT (equivalent to 0.6 ng/g tissue wet weight). 3-Methoxytyramine was measured in the striatum and n. accumbens after decapitation and rapid freezing, using 3-methoxy-4-hydroxybenzylamine as the internal standard. The effects of dopaminergic and other drugs on this metabolite were examined using this method. -Methyl-p-tyrosine (200 mg/kg i.v.) produced parallel linear decreases in dopamine and 3-MT in naive rats, but not those pretreated with tranylcypromine (5 mg/kg i.p.). Methamphetamine (0.3–10 mg/kg i.p.) and amphetamine (0.3–10 mg/kg i.p.) both dose-dependently increased 3-MT in naive and tranylcypromine-pretreated rats. In naive animals, 3-MT was not altered by intraperitoneal injection of the dopamine reuptake inhibitors, bupropion (10 mg/kg) and nomifensine (10 mg/kg) or by sibutramine HCl (3 mg/kg), amitriptyline (10 mg/kg), desipramine (10 mg/kg) and zimeldine (10 mg/kg). 3-Methoxy-tyramine was decreased by apomorphine (5 mg/kg i.p.) and also by large doses of the selective D2 antagonist, BRL 34778 (5 mg/kg i.p.) or
-DOPA (50 mg/kg i.p.). The selective D1 antagonist, SCH 23390 (0.1 or 5 mg/kg i.p.) was without effect. In tranylcypromine-pretreated rats, 3-MT was dose-dependently reduced and increased by apomorphine (0.01–5 mg/kg i.p.) and BRL 34778 (0.1–5 mg/kg i.p.), respectively. The drug SCH 23390 (0.1–5 mg/kg i.p.) produced much smaller increases in 3-MT which were probably mediated through the striatonigral pathway. Overall, the data suggest that measurement of 3-MT, after inhibition of monoamine oxidase, is a useful index of the release and utilization of dopamine. However, after substantial and prolonged depletion of dopamine, levels of 3-MT in naive animals are a better index. Also, the formation of 3-MT in naive rats provides a sensitive method for distinguishing between dopamine releasing agents and reuptake inhibitors. 相似文献
99.
Shoji Matsushima Yuko Sakai Yoshiki Hira Masamichi Kato Tsukasa Shigemitsu Yoichi Shiga 《Journal of pineal research》1993,14(3):145-150
Abstract: Light microscopic observations on the superficial pineal gland of Wistar-King rats were made to examine whether or not pineal volume and pinealocyte size, expressed as nuclear density, at daytime or nighttime are affected by long-term exposure to 50 Hz rotating magnetic field (MF) at 5.0 μT. Determinations of pineal volume and pinealocyte size were repeated twice (April and October) during the year. Size of pinealocytes in MF-exposed and sham-exposed rats exhibited, in addition to the difference between peripheral and central regions, regional differences in a proximodistal direction; pinealocytes in the distal and middle-peripheral regions were usually larger than those in the proximal and middle-central regions at daytime or nighttime. In October, distal and proximal pinealocytes showed significant day-night changes in size in sham-exposed rats, but not in MF-exposed animals. The situations in the two groups were almost reversed in April. Significant day-night differences were scarcely found in pinealocyte size in the middle region in the two groups. Throughout the study, pineal volume and pinealocyte size in each region were generally the same between MF-exposed and sham-exposed rats at daytime or nighttime. The results suggest that pinealocytes in the distal and proximal regions, but not those in the middle region, are affected by MF-exposure; day-night differences in sizes of distal and proximal pinealocytes appear in April and disappear in October under the influence of MF. MF may exert an effect on mechanisms controlling day-night rhythms of pinealocyte size in the rat. 相似文献
100.
Ingrid Gouldsborough Nick Ashton 《Clinical and experimental pharmacology & physiology》1998,25(12):1024-1031
1. The aim of the present study was to compare electrolyte handling in naturally reared neonatal spontaneously hypertensive rats (SHR) with those reared by a Wistar-Kyoto (WKY) rat foster mother (denoted SHRX), as cross-fostering SHR pups to a WKY rat dam lowers adult blood pressure in the SHR. 2. The electrolyte content of WKY rat and SHR dams’ milk was determined and electrolyte intake and urinary excretion rates were calculated in both naturally reared and cross-fostered WKY rat and SHR pups. 3. The milk sodium concentration fell in both strains (WKY rat: 31.8 ± 2.0 to 15.2 ± 1.2 mmol/L; SHR 31.9 ± 2.5 to 18.2 ± 1.6 mmol/L; P < 0.001), as did potassium (P < 0.001), over lactation, but there were no differences between strains. Calcium and magnesium concentrations increased (P< 0.001), although SHR dam's milk contained less calcium (P < 0.001) than that of WKY rat dams during the third week of lactation. 4. Spontaneously hypertensive rat pups ingested less milk (P<0.05) than WKY rat pups; therefore, their cumulative sodium intake over postnatal days 4–15 was significantly lower than that of WKY rat pups (WKY rat vs SHR: 84.4 ± 3.6 vs 59.7 ± 2.6 μmol/g bodyweight, respectively; P < 0.05) and fostered SHRX pups (77.7 ± 7.0 μmol/g bodyweight; P < 0.05). Potassium and magnesium intakes were comparable between SHR, WKY rat and SHRX pups, but SHR pups ingested significantly less calcium than either WKY rat pups (136.1 ± 6.4 vs 200.1 ± 9.5p, mol/g bodyweight, respectively; P<0.05) or SHRX pups (200.0 ± 18.0 μmol/g bodyweight; P<0.05). 5. These data show that the neonatal SHR experiences a period of sodium deficiency during the developmental stage when cross-fostering is effective in lowering blood pressure. This is consistent with the reported up-regulation of the renin-angiotensin system observed in SHR at this time and may have a long-term influence on blood pressure. 相似文献