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1.
Callus cultures isolated from the stems of two clones of Dianthus were extracted for water-soluble proteins and the extracts were subsequently analyzed by acrylamide gel electrophoresis. Peroxidase, acid phosphatase, esterase, and 6-P-gluconate dehydrogenase (6-P-G DH) were studied under each of four combinations of light and dark, cold (0-5 C) and warm (25 C) environments. Marked differences in the isoenzyme patterns were observed under the four conditions with all the enzymes except 6-P-G DH. Acid phosphatase generally showed fewer isoenzymes than the usual stem complement, whereas the other enzymes showed the same or greater number of isoenzymes. Many of the isoenzymes from the callus tissue correlated well with those found in the stem; however, all but 6-P-G DH showed some different components. Of the four enzymes studied only peroxidase was recovered from the medium; these isoenzymes matched those found in the callus and in the stem. The isoenzymes in the medium were not influenced qualitatively by the growth conditions. The changes in the zymograms of the callus under the four environments were compared to the changes observed in the stem under stress environments.  相似文献   

2.
细根具有复杂的分支系统, 以根序(root order)为取样单元的细根生理生态学研究正在成为根系生态学研究领域的重要内容。该研究以海南岛尖峰岭4个热带阔叶树种海南蕈树(Altingia obovata)、厚壳桂(Cryptocarya chinensis)、山杜英(Elaeocarpus sylvestris)和黄桐(Endospermum chinense)为研究对象, 测定了1-5级细根的形态、解剖结构和组织碳(C)、氮(N)含量, 旨在探讨这些根系特征之间的联系。研究表明: 4个树种的细根形态差异较大, 但在树种水平上直径、根长和组织密度均随着根序的升高而增加, 比根长则随着根序的升高而降低; 低级根(前2级根或前3级根)具有皮层组织, 是典型的吸收根, 而高级根皮层组织消失, 是典型的运输和储藏根; 影响直径大小最重要的因子是皮层厚度, 它可以解释细根直径变异的97%, 而维管束直径仅能解释细根直径变异的70%; 根组织N和C浓度受维管束-根直径比(维根比)的影响, 随着维根比增加, 组织N浓度显著降低, 组织C浓度显著升高。4个树种细根的C/N比的变异受组织N浓度的影响程度为76%, 而受C浓度的影响程度不足10%。上述结果表明, 细根的形态特征、解剖结构和组织化学含量之间存在着紧密联系, 这为我们理解根系结构与功能变异提供了重要依据。  相似文献   

3.
Multiple changes in gene expression in chronic human Achilles tendinopathy.   总被引:11,自引:0,他引:11  
Atlas cDNA cell interaction arrays (CLONTECH) were used to examine degenerate tissue from four patients with Achilles tendon disorders, in order to identify changes in expression of genes important in cell-cell and cell-matrix interactions. The greatest difference between normal (post-mortem) and degenerate tissue samples was in the level of MMP-3 (stromelysin) mRNA, which was down-regulated in all the degenerate samples. Quantitative RT-PCR assay of RNA extracted from paired 'normal' and degenerate Achilles tendon tissue samples taken from tendons during surgery mirrored the results of the arrays. Levels of MMP-3 mRNA were lower, whereas levels of type-I and type-III collagen mRNAs were significantly higher, in the degenerate compared to the 'normal' samples. Immunoblotting of proteins extracted from the same tendon samples showed that three of four normal tissue samples taken from individuals without apparent tendon disorder had much higher levels of MMP-3 protein than 'normal' or degenerate samples from patients with tendinosis. We suggest that MMP-3 may play an important role in the regulation of tendon extracellular matrix degradation and tissue remodelling.  相似文献   

4.
The purpose of this study was to clarify the influence of iron on zinc status. The animals were divided into four groups, consisting of five rats in each group. The control group was fed on basal diet with adequate levels of zinc and iron, whereas the experimental group was fed diets containing different levels of iron ad libitum for 15 d. Low levels of iron (LFe) significantly increased the zinc absorption percentage but there was a decrease in high (HFe) and very high iron (VHFe) level groups (p<0.001). The retention percentage changes were found to be parallel to the changes in the absorption percentage curve. It was found that zinc (per total dry tissue) and Zn-65 (per total tissue) increased in the rats fed the LFe, whereas in general they decreased in the rats fed the HFe and VHFe diets. Significant changes were found in the duodenum and liver. Zn-65 (per g wet tissue) significantly increased in the brain and liver in the LFe group, but there was a decrease in the duodenum, ileum, kidney, liver, and brain in the HFe and VHFe groups. Changes in the level of zinc (per g dried tissue) were found to be parallel to the changes in Zn-65 in all the groups. The dietary proportions of iron appear to influence zinc metabolism at the intestinal and cellular transport levels over a given period of time.  相似文献   

5.
目的:观察白矾保肝降脂方对非酒精性脂肪肝大鼠肝组织脂联素(ADP)、肿瘤坏死因子α(TNF-α)的影响。方法:48只健康雄性Wistar大鼠随机分为4组,每组12只。高脂高糖饲料喂养制备大鼠非酒精性脂肪肝模型。8w病理显示造模成功后,每组给予相应干预,连续4w。酶联免疫吸附(ELISA)法测定各组大鼠肝组织中ADP、TNF-α浓度,HE染色观察肝脏病理变化。结果:与正常对照组大鼠比较,模型对照组肝组织中ADP浓度明显降低(P<0.05),TNF-α明显升高(P<0.05);与模型对照组大鼠比较,白矾保肝降脂方组与水林佳组肝组织中ADP浓度均明显升高(P<0.05),TNF-α明显降低(P<0.05);白矾保肝降脂方组大鼠较水林佳组,肝组织中ADP浓度显著升高(P<0.05),TNF-α无显著性差异(P>0.05)。结论:白矾保肝降脂方能显著升高肝组织中ADP浓度,降低TNF-α,明显改善肝细胞脂肪变性,缓解炎性浸润,可能是其治疗非酒精性脂肪肝的作用机制之一。  相似文献   

6.

Background

Ultrasound elasticity imaging provides biomechanical and elastic properties of vascular tissue, with the potential to distinguish between tissue motion and tissue strain. To validate the ability of ultrasound elasticity imaging to predict structurally defined physical changes in tissue, strain measurement patterns during angioplasty in four bovine carotid artery pathology samples were compared to the measured physical characteristics of the tissue specimens.

Methods

Using computational image-processing techniques, the circumferences of each bovine artery specimen were obtained from ultrasound and pathologic data.

Results

Ultrasound-strain-based and pathology-based arterial circumference measurements were correlated with an R2 value of 0.94 (p = 0.03). The experimental elasticity imaging results confirmed the onset of deformation of an angioplasty procedure by indicating a consistent inflection point where vessel fibers were fully unfolded and vessel wall strain initiated.

Conclusion

These results validate the ability of ultrasound elasticity imaging to measure localized mechanical changes in vascular tissue.  相似文献   

7.
The ability of rabbit renal cortical tissue to accumulate p-aminohippurate was low at two weeks, increased to a peak at four weeks and then declined to an intermediate value in adult tissue. These differences are not due to differences in the metabolism of p-aminohippurate, tissue composition or tissue viability but reflect real differences in the ability of the tissue to transport or retain p-aminohippurate. The estimated maximal rate of p-aminohippurate transport into slices increased to four weeks and declined whereas runout from tissue was greatest in adult tissue. Both of these changes could contribute to the decline in the slice to medium (S/M) concentration ratio after four weeks. p-Aminohippurate S/M ratio from tissue of all ages was enhanced by acetate. Inasmuch as the p-aminohippurate S/M ratio was greatest in adult tissue in the presence of acetate, the data suggest that the decline normally seen after four weeks reflects the presence of an inhibitor or changes in metabolic requirements in the tissue rather than a decline in intrinsic transport capacity.Preventing contact with solid food during development appeared to retard development of maximal transport capacity. Neomycin was without effect. These data suggest that substances in the diet might serve as substrates to “trigger” the development of anion transport in normal newborn kidneys. Conformation of this suggestion awaits experimental verification.  相似文献   

8.
The development and structure of the floral nectaries of Capsella bursa-pastoris (L.) Medic. were examined. The nectaries consisted of four separated parts which were semiorbicular and were morphologically and anatomically similar to one another. They were located at the receptacle between stamens, and each part was composed of secretory epidermis, nectariferous tissue and vascular bundles, belonging to structural nectary. When the various floral organs were developed, 2--3 superficial layer cells of the receptacle between stamens became meristemoid and contributed to primordia the formation of nectary. By intercalary meristematic activity, the four nectaries formed synchronously. During the different stages of nectary differentiation, the content of starch gra ins and vacuolation in the cells of epidermis and nectariferous tissue changed regularly. According to the structural and histochemical changes the pre-nectar might be supplied by phloem. The nectar formed in nectariferous tissue was then secreted to the sub-stomatal chamber and where it was finally excreted from the stoma.  相似文献   

9.
The relative roles of tissue glutathione and vitamin E concentrations in the pneumotoxicity of 3-methylindole were studied. Thirty-two goats were divided into four groups and pretreated with (i) vitamin E + cysteine, (ii) vitamin E + diethylmaleate, (iii) cysteine, and (iv) diethylmaleate to vary tissue concentrations of glutathione and (or) vitamin E. Lung tissue concentrations of glutathione, vitamin E, and cytochrome P-450 were measured after pretreatments in four of eight animals in each group. Groups pretreated with cysteine had higher glutathione levels in the lung than those of diethylmaleate-pretreated goats. Goats receiving vitamin E had significantly higher concentrations of vitamin E than unsupplemented groups. After pretreatments the other four goats in each group were challenged with 3-methylindole (0.03 g/kg body weight) by intrajugular infusion. The severity of lung lesions was evaluated and scored by gross and microscopic examination at 72 h after infusion. 3-Methylindole-induced lung lesions were severe when tissue glutathione was reduced and were mild when tissue glutathione was induced. Enhancement of tissue vitamin E did not significantly affect 3-methylindole toxicity. These results indicate that the initial toxicological event is likely to be the result of binding of 3-methylindole free radical covalently to cellular protein rather than lipid peroxidation.  相似文献   

10.
The degree of genetic variability in the hypervariable region 1 of hepatitis C virus (HCV) was analyzed by cloning and sequencing HCV genomes obtained in paired samples of serum, liver tissue, and peripheral blood mononuclear cells (PBMC) from four chronic hepatitis C patients. Genetic variability in serum was higher than in liver tissue or PBMC at the level of complexity (the number of different sequences obtained from each type of tissue) as well as at the level of genetic distance between all pairs of sequences within each tissue (compared by the Student t test; P < 0.001 for two patients and P < 0.01 for another). The spectrum of viral genomes differed among the three types of tissue, as shown by segregation of sequences according to their tissue of origin in phylogenetic analysis and by statistical analysis of mean genetic distances observed between sequences obtained from different tissues (P < 0.001), but sequences from liver tissue and PBMC were more closely related to each other than to those from serum.  相似文献   

11.
12.
13.
The fascicle material properties in bone-fascicle-bone units were determined for the anterior and posterior cruciate ligaments (ACL, PCL), the lateral collateral ligament (LCL) and the patellar tendon (PT) from three young human donor knees. Groups of fascicles from each tissue were isolated with intact bone ends and failed at a high strain rate in a saline bath at 37 degrees C. In each knee tested the load related material properties (linear modulus, maximum stress and energy density to maximum stress) for the patellar tendon were significantly larger than corresponding values for the cruciate and collateral ligaments. Bundles from different ligaments in the same knee were similar to each other in their mechanical behavior. In addition, no significant differences were present in the maximum strains recorded for any of the four tissue types examined. The results presented have implications in studies of ligament injury. They are also important in the design and use of synthetic and biological ligament replacements and in tissue and whole knee modeling.  相似文献   

14.
Cellular and enzymatic changes in porcine adipose tissue during growth   总被引:6,自引:0,他引:6  
Experiments were designed to define some of the cellular and metabolic changes in various areas of porcine adipose tissue during growth and to establish a relationship between these changes and the accumulation of fat in the domestic pig. 35 male castrate pigs were killed at various ages from late fetal to 6.5 months. The following determinations were made on each animal: (1) total carcass fat, (2) adipose cell size and number by fixation of adipose tissue with osmium tetroxide, and (3) the activities of acetyl CoA carboxylase, citrate cleavage enzyme, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and malic enzyme from perirenal adipose tissue and each of the three layers of subcutaneous backfat. Carcass adipose tissue expanded by a combination of adipocyte hyperplasia and hypertrophy up to 5 months, after which adipose expansion was accomplished by cellular hypertrophy only, with no significant increase in cell number. The activities of the selected lipogenic enzymes (expressed on an adipose cell basis) increased markedly at weaning and again during the rapid increase in percentage of body fat between 3.5 and 5 months. Enzyme activities reached a peak at 5 months, after which activities decreased to values approaching mature levels.  相似文献   

15.
The objective of this study was to compare levels of four elements (zinc, copper, selenium, and iron) in the serum and tissue of 68 breast tumor patients (benign and malignant), from a teaching hospital in central Taiwan. Samples of normal tissue (5 cm away from tumor) were also taken from patients with malignant tumors. Only serum was taken from the 25 healthy persons in the control group. Results showed that Zn, Cu, Se, Fe, Cu/Zn, Cu/Se, and Cu/Fe were present in different amounts in the serum of each of the three groups. Zn and Se levels were lower in the serum of the two tumor groups compared to the control group. In tissue samples, Zn, Cu, Se, and Fe concentrations were different in each of the three groups. The malignant tissue had the highest levels of all four elements. In advanced-stage malignant tumors, levels of Cu and the ratios of Cu/Fe and Cu/Zn (in both serum and tissue) were highest. The ratios of serum Cu/Zn, Cu/Fe, and Cu/Se were also higher in malignant patients. The cutoff value of serum Cu/Zn was 1.2 (sensitivity and specificity were both 100%). The Cu/Zn ratio was highest in the advanced stages of cancer and was a better diagnostic tool for breast cancer than Cu/Se and Cu/Fe. The authors suggest that change of trace elements in serum and tissue might be useful and significant as biomarkers involving the initial plastic process.  相似文献   

16.
17.
Tobacco plants derived from herbicide (paraquat)-resistant cell lines and from wild type (non-resistant) cell lines were self-pollinated and crossed with sexually-derived wild type plants. Analysis of the seed germination frequencies from these crosses indicated that seed viability and thus the ability of tissue culture-derived plants to intercross with sexually derived plants was reduced. Partial reduction was observed when tissue culture-derived plants were the female parent. Significant reduction in ability to intercross was observed when tissue culture-derived plants were the male parent. Self pollinations of tissue culture-derived plants and crosses between tissue culture-derived plants, both wild type and mutant, did not show the presence of a crossing barrier. The crossing barrier (reduction of seed viability) is due to either: 1) failure of a fertilized ovule to undergo embryonic development, or 2) failure of pollen to fertilize ovules. It is apparently not due to in viable pollen. A possible explanation of the crossing barrier is that genetic changes accumulate as a result of the tissue culture process which reduces the ability of tissue culture-derived plants to cross with sexually-derived plants. Since tissue culture-derived plants are able to intercross with each other and produce viable seed, the genetic changes would be similar in all of our tissue culture-derived lines, regardless of mutant or wild type origin.  相似文献   

18.
19.
重度创伤性脑损伤后肠黏膜屏障应激性变化的模型   总被引:1,自引:0,他引:1  
目的建立一种观察重度创伤性脑损伤(TBI)后肠黏膜屏障(IMB)应激性变化的模型。方法选用雄性Wistar大鼠64只,随机分为两组。TBI组(32只):采用改良的Feeney自由落体撞击法,建立TBI模型;假手术对照组(32只):只开骨窗,不行落体致伤。两组大鼠分别按术后6、12、24和48h时相点分为4个亚组(每组均为8只),观察脑组织、肠黏膜组织病理以及扫描和透射电镜下肠黏膜超微结构的变化。结果光镜下TBI组肠黏膜上皮细胞受损,电镜下还可见细胞间紧密连接较对照组明显增宽。结论用改良的Feeney自由落体撞击法,建立的重度TBI大鼠模型肠黏膜上皮细胞受损,细胞间紧密连接增宽,提示其IMB的功能的确发生了应激性损害,说明这种用来观察重度TBI后IMB应激性变化的模型是成功的。  相似文献   

20.
Several commerical batches of heparitin sulfate extracted from beef lung tissue were fractionated into at least four distinct mucopolysaccharides by a combination of polyacrylamide and agarose gel electrophoresis. The four heparitin sulfates (A, B, C and D) were distinguished from each other and from heparin by several physical and chemical properties such as electrophoretic migration, molecular weight, presence of N-acetyl, N- and )-sulfate residues, optical rotation and enzymatic degradation. Of particular significance was the isolation of a heparitin sulfate (heparitin sulfate C) with a homogeneous molecular weight.  相似文献   

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