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101.
We investigated repair of acrylamide (AA) induced damage in intestines by administration of crocin. We used 40 male Wistar rats in four groups of 10 animals: control, AA, crocin, and AA + crocin groups. We investigated biochemical and histological changes to small and large intestine. AA ingestion decreased glutathione (GSH) levels and total antioxidant status (TAS) in the intestine compared to the control group, while superoxide dismutase (SOD) and catalase (CAT) activities, and total oxidant status (TOS) and malondialdehyde (MDA) levels were increased. Villi were shortened and villus degeneration was observed in ileum of the AA group. Degeneration of surface epithelium and Liberkühn crypts were observed in colon sections. GSH and TAS levels increased after administration of AA together with crocin, while SOD and CAT levels and TOS and MDA levels decreased; significant recovery of histological damage also was observed. We found that crocin exhibits protective effects on AA induced small and large intestine damage by inhibiting oxidative stress.  相似文献   
102.
It has been previously shown that tissue blocks prepared from the tail fins of tadpoles (Rana pipiens) survive in vitro for several weeks and respond to thyroxin by shrinkage after a latent period of four or more days (20°C). It has been postulated that this shrinkage corresponds to that of normal tail tissue during metamorphic climax. The long latent period of thyroid action is presumed to depend upon the time required to form the necessary cellular or biochemical intermediates. If such intermediates are activated by thyroxin in the amphibian tail tissue, it may be possible to shorten the latent period of the thyroxin response of fin tissue by fusing untreated blocks to blocks previously treated with thyroxin. Experiments are reported here in which tail fin blocks obtained from tadpoles previously immersed in thyroxin for 3 days were docked to recipient blocks not exposed to this hormone. Such recipient tissues responded with characteristic resorptive activity within 24 hr, instead of the minimum of 4 days required by control tissues exposed directly to thyroxin. It is inferred that some component other than thyroxin which is active in inducing resorption is transmitted from the treated to the untreated block. Presumably, this is a product normally present late in the latent period of thyroxin action.  相似文献   
103.
CrossFit is becoming increasingly popular as a method to increase fitness and as a competitive sport in both the Unites States and Europe. However, little research on this mode of exercise has been performed to date. The purpose of the present investigation involving experienced CrossFit athletes and naïve healthy young men was to investigate the relationship of aerobic capacity and anaerobic power to performance in two representative CrossFit workouts: the first workout was 12 minutes in duration, and the second was based on the total time to complete the prescribed exercise. The participants were 32 healthy adult males, who were either naïve to CrossFit exercise or had competed in CrossFit competitions. Linear regression was undertaken to predict performance on the first workout (time) with age, group (naïve or CrossFit athlete), VO2max and anaerobic power, which were all significant predictors (p < 0.05) in the model. The second workout (repetitions), when examined similarly using regression, only resulted in CrossFit experience as a significant predictor (p < 0.05). The results of the study suggest that a history of participation in CrossFit competition is a key component of performance in CrossFit workouts which are representative of those performed in CrossFit, and that, in at least one these workouts, aerobic capacity and anaerobic power are associated with success.  相似文献   
104.
105.
The 67-kDa laminin receptor (67LR) is a nonintegrin cell surface receptor that mediates high-affinity interactions between cells and laminin. Overexpression of this protein in tumor cells has been related to tumor invasion and metastasis. Thus far, only a full-length gene encoding a 37-kDa precursor protein (37LRP) has been isolated. The finding that the cDNA for the 37LRP is virtually identical to a cDNA encoding the ribosomal protein p40 has suggested that 37LRP is actually a component of the translational machinery, with no laminin-binding activity. On the other hand, a peptide of 20 amino acids deduced from the sequence of 37LR/p40 was shown to exhibit high laminin-binding activity. The evolutionary relationship between 23 sequences of 37LRP/p40 proteins was analyzed. This phylogenetic analysis indicated that all of the protein sequences derive from orthologous genes and that the 37LRP is indeed a ribosomal protein that acquired the novel function of laminin receptor during evolution. The evolutionary analysis of the sequence identified as the laminin-binding site in the human protein suggested that the acquisition of the laminin-binding capability is linked to the palindromic sequence LMWWML, which appeared during evolution concomitantly with laminin.   相似文献   
106.
Secondary ion mass spectrometry (SIMS) microscopy, a mass spectrometry method designed in the 1960s, offers new analytical capabilities, high sensitivity (ppm to ppb region), high specificity and improved lateral resolution, thus facilitating insight into many physiological and biomedical questions. Apart from the sample preparation and the physical characteristics of the detection, the biological model must also be considered. SIMS analysis of diffusible ions and molecules requires strict cryogenic procedures which always begin by a flash-freeze fixation. Cellular integrity can be checked by mapping the major element distributions since intra and extracellular ions are redistributed only in damaged cells. Cryofixing may be followed either by a freeze-fracture methodology or by cryoembedding and dry-cutting. Chemical sample preparation is only used for ions or molecules bound to fixed cell structures. The use of scanning procedures ameliorates the lateral resolution and chromosome imaging has been reported with probe size of below 50nm. Absolute quantification can be derived for embedded specimen by using internal references included in tissue equivalent resins. The sensitivity is limited by the ionization yield of the tag element and may be further impaired when working at high mass resolution (≥5000) to eliminate interfering cluster ions. SIMS drug mapping is usually performed after in vitro administration of a molecule to cell culture systems. Drug detection is accomplished indirectly by detecting a tag isotope naturally present or introduced by labelling, mainly with halogens,15N and14C. Molecular imaging with TOF-SIMS is an appealing alternative especially for heavier compounds. We stress some biological problems through a critical review of published SIMS drug studies. SIMS proved useful in assessing the targeting specificity of nuclear medicine pharmaceutics, even after in vivo administration. The first microscopic evidence of a thionamide induced follicular blockade of the iodine organification process is presented in a human sample.  相似文献   
107.
1. Antlions are opportunistic trap building predators that cannot control prey encounter. Their trap should ideally retain a great diversity of prey. However, building a single trap that captures many prey with varying characteristics can be challenging. 2. A series of five different ant species ranging from thin to large, of sizes ranging from 2.75 to 6.5 mm, and a mean weight ranging from 0.54 to 6.00 mg were offered in a random succession to antlions. The state of satiation of the antlions was controlled, and their mass and the depth of their pit were recorded. The reaction of antlion to the prey, the probability of capture as well as the time to escape were recorded. 3. The probability of an antlion reaction is an increasing function of the pit depth and a decreasing function of antlion mass. The probability of capture is highest for intermediate prey mass and is an increasing function of pit depth. The time to escape is a declining function of prey mass and an increasing function of pit depth. 4. There is an upper limit to prey mass given that large prey escape out of the pit. There is a lower limit to prey mass given the difficulty to apprehend the smallest, thin species. Consequently, there is a range of prey mass, corresponding to a medium‐sized ant of 2 mg, for which the pit functions best. The physics of insect locomotion on sandy slopes was identified as the key to understanding the functioning of antlion pits.  相似文献   
108.
Book review     
  相似文献   
109.
The hydraulic conductivity of plant roots (Lpr) is determined in large part by the activity of aquaporins. Mechanisms occurring at the post‐translational level, in particular phosphorylation of aquaporins of the plasma membrane intrinsic protein 2 (PIP2) subfamily, are thought to be of critical importance for regulating root water transport. However, knowledge of protein kinases and phosphatases acting on aquaporin function is still scarce. In the present work, we investigated the Lpr of knockout Arabidopsis plants for four Ca2+‐dependent protein kinases. cpk7 plants showed a 30% increase in Lpr because of a higher aquaporin activity. A quantitative proteomic analysis of wild‐type and cpk7 plants revealed that PIP gene expression and PIP protein quantity were not correlated and that CPK7 has no effect on PIP2 phosphorylation. In contrast, CPK7 exerts a negative control on the cellular abundance of PIP1s, which likely accounts for the higher Lpr of cpk7. In addition, this study revealed that the cellular amount of a few additional proteins including membrane transporters is controlled by CPK7. The overall work provides evidence for CPK7‐dependent stability of specific membrane proteins.  相似文献   
110.

Background

Tools for authenticating cell lines are critical for quality control in cell-based biological experiments. Currently there are methods to authenticate human cell lines using short tandem repeat (STR) markers based on the technology and procedures successfully used in the forensic community for human identification, but there are no STR based methods for authenticating nonhuman cell lines to date. There is significant homology between the human and vervet monkey genome and we utilized these similarities to design the first multiplex assay based on human STR markers for vervet cell line identification.

Results

The following STR markers were incorporated into the vervet multiplex PCR assay: D17S1304, D5S1467, D19S245, D1S518, D8S1106, D4S2408, D6S1017, and DYS389. The eight markers were successful in uniquely identifying sixty-two vervet monkey DNA samples and confirmed that Vero76 cells and COS-7 cells were derived from Vero and CV-1 cells, respectively. The multiplex assay shows specificity for vervet DNA within the determined allele range for vervet monkeys; however, the primers will also amplify human DNA for each marker resulting in amplicons outside the vervet allele range in several of the loci. The STR markers showed genetic stability in over sixty-nine passages of Vero cells, suggesting low mutation rates in the targeted STR sequences in the Vero cell line.

Conclusions

A functional vervet multiplex assay consisting of eight human STR markers with heterozygosity values ranging from 0.53-0.79 was successful in uniquely identifying sixty-two vervet monkey samples. The probability of a random match using these eight markers between any two vervet samples is approximately 1 in 1.9 million. While authenticating a vervet cell line, the multiplex assay may also be a useful indicator for human cell line contamination since the assay is based on human STR markers.  相似文献   
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