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31.

Purpose

The purpose of this study was to verify whether the dynamic tumor tracking (DTT) feature of a Vero4DRT system performs with 10-mm-long and 0.28 mm diameter gold anchor markers.

Methods

Gold anchor markers with a length of 10 mm and a diameter of 0.28 mm were used. Gold anchor markers were injected with short and long types into bolus material. These markers were sandwiched by a Tough Water (TW) phantom in the bolus material. For the investigation of 4-dimensional (4D) modeling feasibility under various phantom thicknesses, the TW phantom was added at 2 cm intervals (in upper and lower each by 1 cm). A programmable respiratory motion table was used to simulate breathing-induced organ motion, with an amplitude of 30 mm and a breathing cycle of 3 s. X-ray imaging parameters of 80 kV and 125 kV (320 mA and 5 ms) were used. The least detection error of the fiducial marker was defined as the 4D-modeling limitation.

Results

The 4D modeling process was attempted using short and long marker types and its limitation with the short and long types was with phantom thicknesses of 6 and 10 cm at 80 kV and 125 kV, respectively. However, the loss in detectability of the gold anchor because of 4D-modeling errors was found to be approximately 6% (2/31) with a phantom thickness of 2 cm under 125 kV. 4D-modeling could be performed except under the described conditions.

Conclusions

This work showed that a 10-mm-long gold anchor marker in short and long types can be used with DTT for short water equivalent path length site, such as lung cancer patients, in the Vero4DRT system.  相似文献   
32.
A purple non-sulfur bacterium, Rhodopseudomonas sp. No. 7, was isolated from n-propanol–enrichment cultures under anaerobic-light conditions. Strain No. 7 can produce hydrogen from alcohols. The rate of hydrogen production from n-propanol was 34 μl/hr/mg dry cells. Strain No. 7 showed multiplication by budding and the best growth on n-propanol among other organic compounds tested. But its growth on n-propanol was poor under aerobic-dark conditions. NAD-linked alcohol dehydrogenase, NAD-linked aldehyde dehydrogenase, acyl-CoA synthetase and malate synthetase were found in strain No. 7. These enzymes were constitutive. On the other hand, isocitrate lyase was induced in cells grown on ethanol but not on n-propanol. No activity of phenazine methosulfate-linked alcohol dehydrogenase was detected in strain No. 7.  相似文献   
33.

Background and Purpose

The major obstacles to treatment of pancreatic cancer are the highly invasive capacity and resistance to chemo- and radiotherapy. Glycogen synthase kinase 3β (GSK3β) regulates multiple cellular pathways and is implicated in various diseases including cancer. Here we investigate a pathological role for GSK3β in the invasive and treatment resistant phenotype of pancreatic cancer.

Methods

Pancreatic cancer cells were examined for GSK3β expression, phosphorylation and activity using Western blotting and in vitro kinase assay. The effects of GSK3β inhibition on cancer cell survival, proliferation, invasive ability and susceptibility to gemcitabine and radiation were examined following treatment with a pharmacological inhibitor or by RNA interference. Effects of GSK3β inhibition on cancer cell xenografts were also examined.

Results

Pancreatic cancer cells showed higher expression and activity of GSK3β than non-neoplastic cells, which were associated with changes in its differential phosphorylation. Inhibition of GSK3β significantly reduced the proliferation and survival of cancer cells, sensitized them to gemcitabine and ionizing radiation, and attenuated their migration and invasion. These effects were associated with decreases in cyclin D1 expression and Rb phosphorylation. Inhibition of GSK3β also altered the subcellular localization of Rac1 and F-actin and the cellular microarchitecture, including lamellipodia. Coincident with these changes were the reduced secretion of matrix metalloproteinase-2 (MMP-2) and decreased phosphorylation of focal adhesion kinase (FAK). The effects of GSK3β inhibition on tumor invasion, susceptibility to gemcitabine, MMP-2 expression and FAK phosphorylation were observed in tumor xenografts.

Conclusion

The targeting of GSK3β represents an effective strategy to overcome the dual challenges of invasiveness and treatment resistance in pancreatic cancer.  相似文献   
34.
We have reported that acrolein-conjugated low-density lipoprotein (Acro-LDL) uptake by scavenger receptor class A type 1 (SR-A1) can mediate macrophage foam cell formation. The purpose of this study was to determine which amino acid residues of apoB protein in LDL are conjugated with acrolein. Acro-apoB was prepared by incubation of LDL with acrolein (10 to 60 μM) at 37 °C for 7 days. Identification of acrolein-conjugated amino acid residues in apoB was performed using LC-MS/MS. The levels of acrolein-conjugated amino acid residues of apoB as well as crosslinking apoB increased in proportion to acrolein concentration. The level of LDL uptake by macrophages was parallel with the acrolein-conjugated monomer apoB. Acrolein-conjugated amino acid residues in apoB were C212, K327, K742, K949, K1087, H1923, K2634, K3237 and K3846. The NH2-teriminal four amino acid residues (C212, K327, K742 and K949) were located at the scavenger receptor SR-A1 recognition site, suggesting that these four acrolein-conjugated amino acids are involved in the rapid uptake of Acro-LDL by macrophages. It is proposed that the rapid uptake of LDL by macrophages is dependent on acrolein conjugation of four amino acids residues at the scavenger receptor recognition site of apoB in LDL.  相似文献   
35.
Satoru Higashi  Kiyozo Kawai 《BBA》1970,216(2):274-281
1. The spermatozoa of the freshwater mussel (Hyriopsis schlegelii) contain cytochromes aa3, b and c, flavoproteins and nicotinamide nucleotides in molar ratios of 1.0:0.9:1.8:1.8:8.7. Cytochrome c1 is not detectable even at liquid-N2 temperature, but a c1-like cytochrome with an -band at 550 mμ is found at liquid-N2 temperature in a cell preparation from which cytochrome c is completely removed.

2. The near-ultraviolet difference spectrum of whole cells reveals an absorption peak at 315 mμ with a shoulder around 350 mμ.

3. Both the endogenous respiration and motility of spermatozoa are completely blocked by 0.2 mM CN and by 0.2 μM antimycin A. 2,4-Dinitrophenol and pentachlorophenol completely inhibit motility at the maximal stimulation of respiration. Rotenone strongly inhibits NADH oxidase of spermatozoa, although it has no effect on the respiration of whole cells.

4. It is concluded that the motility of mussel spermatozoa is tightly coupled to respiration, and the respiratory chain phosphorylating process is the only energy-supplying system for motility.  相似文献   

36.
Enzymes from hyperthermophiles display extreme (thermo)stability and a wide range of enzymes have been examined to explore their potential for various biotechnological processes. In addition, recent years have witnessed the development of genetic systems in a number of hyperthermophilic archaea. This has provided the means to initiate cell engineering studies in these organisms. Biofuel production is now an important topic in microbial biotechnology, and the hydrogen producing capabilities of (hyper)thermophiles, as well as their thermostable hydrogenases, are now attracting much attention.  相似文献   
37.
Monoclonal antibodies (mAbs) specific for the human macrophage galactose-type calcium-type lectin (MGL) were established. The recombinant extracellular domain of MGL was used to immunize a mouse, and 10 hybridoma clones were obtained. Binding of recombinant MGL to asialo-bovine submaxillary mucin was shown to be blocked by mAbs MLD-1, 4 and 6. Immunoprecipitation of MGL from lysates of COS-1 cells transfected with MGL cDNA (form 6A) was achieved with mAbs MLD-1, 4, 7, 8 and 16. Chimeric recombinant proteins between human MGL and mouse MGL1 were used to determine the location of the epitopes for these mAbs. mAbs MLD-8, 13, 15 and 16 interacted with the amino terminal side of the conserved WVDGTD sequence immediately upstream of QPD, whereas mAbs MLD-7, 12 and 17 interacted with the other side. mAbs MLD-1, 4, and 6 apparently required both sides of this boundary. mAbs MLD-15 and 16 were shown to recognize the protein products of alternatively spliced mRNA 6A/8A and 6C/8A, having deletions at the boundary of exons 7 and 8, in addition to full length and other spliced forms of MGL (6A, 6B and 6C), whereas the other mAbs bound only full length and forms 6A, 6B and 6C.  相似文献   
38.
Successful or unsuccessful female transfers were observed seven times during a 32-month field study of proboscis monkeys (Nasalis larvatus) inhabiting a riverine forest along a tributary of the Kinabatangan River, Sabah, Malaysia. In all cases, the females voluntarily left their own groups and immediately joined with another one. When adult females tried to shift to other groups, adult males called them back to their own groups, but appeared to be indifferent to subadult females. When the adult females returned, the males never attacked the females physically, but instead often emitted herding sounds to them. One subadult female was repelled by a resident adult female. When one adult female transferred into a new one-male group, she left her behind son in an all-male group. The number of females often fluctuated in most study groups, with this fluctuation being more prominent among subadult females than adult females. It is likely that female transfer in proboscis monkeys is not a rare occurrence and that it is especially common among sub-adult females.  相似文献   
39.
We investigated the enzymatic properties and immunohistochemical localization of cuticular hemocyanin, a known oxygen transporter in the prawn Penaeus japonicus. The molecular weight of hemocyanin purified from the cuticle was estimated to be 67-77 k using SDS-PAGE, and the purified protein was effectively converted into a phenoloxidase-like enzyme by an SDS-treatment. The activated enzyme catalyzed the o-hydroxylation of monophenols and the oxidation of o-diphenols and was inhibited by typical inhibitors of phenoloxidase. These characteristics were nearly identical to the enzymatic properties of hemolymph hemocyanin. Immunological detection showed a diffuse distribution of hemocyanin over the exocuticle and endocuticle, and a higher signal level was observed in the latter. Based on these results, roles of hemocyanin in various physiological processes such as immune response and sclerotization of the cuticle were discussed.  相似文献   
40.
Summary The histochemical characteristics of spontaneous hepatocellular neoplasms in mice of both sexes were examined and compared with those of hepatocellular neoplasms induced in female mice by administration of polycyclic aromatic hydrocarbon carcinogens as initiators with or without subsequent phenobarbitone treatment. Controls treated with phenobarbitone alone were also included. Spontaneous neoplasms in the livers of mice rendered siderotic by subcutaneous iron injection were deficient in cellular accumulation of stainable iron. Glucose-6-phosphatase activity was deficient in the majority of spontaneous and induced neoplasms. ATPase activity was increased in about half of spontaneous and carcinogen-induced neoplasms but all induced neoplasms in mice treated with phenobarbitone showed deficient activity. -Glutamyltransferase activity was present in very few of the spontaneous neoplasms or in the neoplasms induced in the absence of phenobarbitone administration. However, all induced neoplasms in the mice receiving phenobarbitone showed some degree of -glutamyltransferase activity together with deficient glucose-6-phosphatase and ATPase activities. It is concluded that the histochemical characteristics of spontaneous or induced mouse hepatocellular neoplasms are variable and may be influenced by the inducing factors.  相似文献   
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