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921.
922.
Takeda S 《The international journal of biochemistry & cell biology》2009,41(3):455-459
Osteoporosis is caused by a failure of bone homeostasis, but the precise molecular mechanisms controlling bone homeostasis are largely unknown. Increasing evidence that neurons and neurotransmitters are intimately involved in bone remodelling has shed light on a novel regulatory mechanism for bone homeostasis. Namely, like all other homeostatic functions, bone remodelling is under the control of the hypothalamus, and osteoporosis is considered to be a neuroskeletal disease. 相似文献
923.
The removal of dimethyl sulfide (DMS) from industrial gas streams has received a high priority due to its very low odorous threshold value and relatively low biodegradability compared to other reduced sulfur compounds. A variety of bacteria that utilize DMS as a carbon/energy source have been studied and the degradation pathway elucidated. However, to date, there have been few reports on the industrial application of such bacteria inoculated into a bioreactor for DMS treatment. An additional problem of such systems is the accumulation of intermediate metabolites that strongly impact on DMS removal by the microbe. The results reported here were obtained using a bioreactor inoculated with the H(2)S-degrader Pseudomonas putida and the DMS-degrader Microbacterium sp. NTUT26 to facilitate removal of metabolic intermediates and DMS. This bioreactor performed well (1.71 g-S/day/kg-dry packing material) in terms of DMS gas removal, based on an evaluation of the apparent kinetics and maximal removal capacity of the system. Under varying conditions (changes in start-up, inlet loading, shutdown, and re-start), the bioreactor inoculated with Microbacterium sp. NTUT26 and P. putida enhanced removal of high concentrations of DMS. Our results suggest that this type of bioreactor system has significant potential applications in treating (industrial) DMS gas streams. 相似文献
924.
925.
Hung-Kuan Tang Hsiang-Yun Tang Yue-Ru Chu Chin-Hang Shu 《Archives of biochemistry and biophysics》2009,485(2):120-3414
Dipetidyl peptidase 9 (DPP9) is a prolyl dipeptidase preferentially cleaving the peptide bond after the penultimate proline residue. The biological function of DPP9 is unknown. In this study, we have significantly improved the yield using Strep·Tactin® purification system and characterized the biochemical property of DPP9. Moreover, the dimer interaction mode was investigated by introducing a mutation (F842A) at the dimer interface, which abolished the enzymatic activity without disrupting its quaternary structure. Furthermore, DPP9 was found ubiquitously expressed in fibroblasts, epithelial, and blood cells. Surprisingly, contrary to previous report, we found that the expression levels of DPP8 and DPP9 did not change upon the activation of the PBMC or Jurkat cells. These results indicate that the biochemical property of DPP9 is very similar to that of DPP8, its homologous protease. DPP9 and DPP8 are likely redundant proteins carrying out overlapping functions in vivo. 相似文献
926.
Jie Jin Haiyan You Bin Yu Ning Tang Huiqun Shu Wenxin Qin 《Biochemical and biophysical research communications》2009,379(1):86-91
Recent findings have shown that SLIT2 appears to function as a novel tumor suppressor gene. In addition, hypermethylation of its promoter region has been detected in various cancers, including breast and lung cancer, colorectal carcinoma, and gliomas. Here, we report for the first time that there is epigenetic silencing of SLIT2 in human hepatocellular carcinoma (HCC). Downregulation of SLIT2 was detected in 6 of 8 (75%) HCC cell lines by quantitative real-time RT-PCR (qRT-PCR), and the downregulation of SLIT2 was generally dependent on the degree of methylation at the promoter region. Furthermore, expression of SLIT2 was restored in relatively low-expressing cell lines after treatment with 5-aza-2-deoxycytidine (5-Aza-dC). Downregulation of SLIT2 expression was also detected in 45 of 54 primary HCC samples (83.3%), and the decrease in expression was significantly correlated with CpG island hypermethylation. This decrease of SLIT2 expression was also associated with lymph node metastasis in HCC. Moreover, overexpression of SLIT2 in SMMC-7721 cells induced by recombinant adenovirus suppressed cell growth, migration, and invasion, These results suggest that epigenetic inactivation of SLIT2 in HCC may be important in the development and progression of HCC. Thus, SLIT2 may be useful as a therapeutic target in the treatment of HCC. 相似文献
927.
Chi‐Tai Chiang Wing‐Keung Chu Shu‐Er Chow Jan‐Kan Chen 《Journal of cellular physiology》2009,219(1):117-122
p63 belongs to a member of the tumor suppressor protein p53 family. Due to alternative promoter usage, two types of p63 proteins are produced. The ΔNp63 isoform lacks the N‐terminal transactivation domain and is thought to antagonize TAp63 and p53 in target gene regulation. ΔNp63 has been found to be overexpressed in numerous human squamous cell carcinomas, including nasopharyngeal carcinoma (NPC). However, the role of ΔNp63 overexpression in NPC pathogenesis has not been clear. In this study, we use a ΔNp63 overexpressing human NPC cell line (NPC‐076) to explore the possible roles of ΔNp63 in cell proliferation and cell‐cycle regulation. We found that the proliferation of NPC‐076 cell is greatly suppressed when the overexpressed ΔNp63 is silenced by specific ΔNp63 siRNA. Further studies show that ΔNp63 silencing results in the upregulation of CKIs, including p27kip1 and p57kip2 in both mRNA and protein levels. Cell‐cycle analysis shows that ΔNp63 silencing also results in an increased G1 phase cell and apoptotic cell population. Our findings indicate that ΔNp63 plays important roles in the regulation of NPC‐076 cell‐cycle progression, and may play a role in the maintenance of NPC‐076 tumor cell phenotype. J. Cell. Physiol. 219: 117–122, 2009. © 2008 Wiley‐Liss, Inc. 相似文献
928.
Ke Shen Hao-Jie Wang Lin Shao Jin-Ping Shu Guo-Qing Li 《Journal of insect physiology》2009,55(1):78-84
C. kiangsu adults were observed visiting human urine, especially on hot summer days. The main chemicals in fresh human urine include inorganic salts and CO(NH2)2. When human urine was incubated, NH4HCO3 became the richest nitrogenous compound. The phagostimulants, repellents and attractants in urine were identified here. On the filter papers treated with fresh or incubated urine samples, the 5th instar nymphs and the adults started and continued gnawing around the edges, in contrast to the 3rd and the 4th instar nymphs. The consumed areas were dramatically greater on the filters treated with the urine samples incubated for 3-6 days. The feedings of both male and female adults were also stimulated by several urine-borne components such as NaCl, NaH2PO4, Na2SO4, KCl, NH4Cl and NH4HCO3 but not by CO(NH2)2. Among them NaCl was the most powerful phagostimulant. The repelling, or attractive/arresting effects of CO(NH2)2 and NH4HCO3 were also evaluated by a two-choice test. When exposed to water- and CO(NH2)2 solution-immersed filters simultaneously, the adults prefer to stay on water-immersed filter. In contrast, when provided water- and NH4HCO3 solution-treated filters, the adults prefer to stay on NH4HCO3 solution-treated filter. This demonstrated that CO(NH2)2 acted as a repellent and NH4HCO3 as an attractant/arrestant. In the bamboo forest, similar feeding behavior was also elicited by NaCl, NH4HCO3 but not by CO(NH2)2. Comparing to NaCl solution, a mixed solution of NaCl and CO(NH2)2 (1:1) significantly decreased the consumed area of the treated filters whereas a mixed solution of NaCl and NH4HCO3 (1:1) dramatically increased the consumed area. These results demonstrated that the phagostimulatory effect by NaCl was reduced by CO(NH2)2 in fresh urine and was enhanced by NH4HCO3 in incubated urine. 相似文献
929.
The detailed structure of the lophophore is a key diagnostic character in the definition of higher brachiopod taxa. The problematic Heliomedusa orienta Sun and Hou, from the Lower Cambrian Chengjiang Lagerstätte of Yunnan, southwestern China, has a well-preserved lophophore, which is unlike that of any known extant or extinct brachiopods. Based on a comparative study of lophophore disposition in H. orienta and the extant discinid Pelagodiscus atlanticus, the in- and excurrent pattern and shell orientation of H. orienta are described and discussed. Reconstructions of lophophore shape and function are based on numerous specimens and comparison with P. atlanticus. The lophophore is composed of a pair of lophophoral arms that freely arch posteriorly rather than coiling anteriorly as commonly seen in fossil and recent lingulids. The lophophore is attached to the dorsal lobe of the mantle; it has neither calcareous nor chitinous supporting structures, and is disposed symmetrically on either side of the valve midline. The mouth can be inferred to be located at the base of the two brachial tubes, slightly posterior to the anterodorsal projection of the body wall. The lophophoral arms bear laterofrontal tentacles with a double row of cilia along their lateral edge, as in extant lingulid brachiopods. The main brachial axes are also ciliated, which presumably facilitated transport of mucous-bound nutrient particles to the mouth. The unique organization of the lophophore in Heliomedusa is not like any known fossil and living brachiopods. This clearly demonstrates that H. orienta is not a member of any crown group. It is here considered as a member of the brachiopod stem group, which challenges recent interpretations of a close discinid affinity. 相似文献
930.