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41.
The effect of -alany-L-histidinato zinc (AHZ) on bone cell function was investigated in osteoblastic MC3T3-E1 cells. Cells were cultured for 3 days at 37°C in a CO2 incubator in plastic dishes containing -modified minimum essential medium supplemented with 10% fetal bovine serum. After the cultures, the medium was exchanged for that containing 0.1% bovine serum albumin plus AHZ (10–7–10–5 M) or other reagents, and the cells were cultured further for appropriate periods of time. The presence of AHZ (10–7–10–5 M) produced a remarkable increase of alkaline phosphatase activity and protein concentration in osteoblastic cells. Thus increases were seen with the prolonged cultivation (12–21 days). With the culture of 1, 3 and 12 days, the effect of AHZ (10–6 M) to increase alkaline phosphatase activity and protein concentration was more intensive than the effect of zinc sulfate, (10–6 M). The AHZ effects were completely abolished by the presence of cycloheximide (10–6 M), indicating that AHZ stimulates protein synthesis in the cells. The present study suggests that AHZ has a stimulatory effect on cell differentiation, and that this effect is partly involved on protein synthesis in osteoblastic cells. 相似文献
42.
Substrate Preference in a Strain of Megasphaera elsdenii, a Ruminal Bacterium, and Its Implications in Propionate Production and Growth Competition 下载免费PDF全文
The NIAH 1102 strain of Megasphaera elsdenii utilized lactate in preference to glucose when the two substrates were present. Even when lactate was supplied to cells fermenting glucose, the cells switched substrate utilization from glucose to lactate and did not utilize glucose until lactate decreased to a low concentration (1 to 2 mM). Since substrate utilization was shifted gradually without intermittence, typical diauxic growth was not seen. The cyclic AMP content did not rise markedly with the shift in substrate utilization, suggesting that this nucleotide is not involved in the regulation of the shift. It was unlikely that propionate was produced from glucose, which was explicable by the fact that lactate racemase activity dropped rapidly with the exhaustion of lactate and cells actively fermenting glucose did not possess this enzyme. A coculture experiment indicated that M. elsdenii NIAH 1102 is overcome by Streptococcus bovis JB1 in the competition for glucose, mainly because M. elsdenii NIAH 1102 is obliged to utilize lactate produced by S. bovis JB1; i.e., glucose utilization by M. elsdenii NIAH 1102 is suppressed by the coexistence of S. bovis JB1. 相似文献
43.
Distribution of Vacuolar H+-Pyrophosphatase and a Membrane Integral Protein in a Variety of Green Plants 总被引:2,自引:0,他引:2
Vacuolar membranes isolated from several species including fernand moss exhibited pyro-phosphate-dependent H+ transport activity.On immunoblot analysis, H+ -pyrophosphatase was detected inthe vacuolar membranes. A membrane integral protein of 23,000daltons was not found in the membranes of Chara, Conocephalum,or Kalanchoë. Thus, H+-pyrophosphatase may be a universalenzyme among green plants, but the 23-kDa protein is not a commonprotein of central vacuoles. (Received September 10, 1993; Accepted November 29, 1993) 相似文献
44.
The effect of -alanyl-L-histidinato zinc (AHZ) on bone metabolism was investigated in osteoblastic MC3T3-El cells. Cells were cultured for 3 days at 37°C in a CO2 incubator in plastic dishes containing -modified minimum essential medium supplemented with 10% fetal bovine serum. After the cultures, the medium was exchanged for that containing 0.1% bovine serum albumin plus various concentrations of AHZ or other reagents, and the cells were cultured further for appropriate periods of time. The presence of AHZ (10–7–10–5M) stimulated the proliferation of cells. AHZ (10–6 and 10–5M) increased deoxyribonucleic acid (DNA) content in the cells with 48hr-culture. This increase was completely blocked by the presence of cycloheximide (10–6M) or hydroxyurea (10–3M). Also, the presence of cycloheximide (10–6M) completely inhibited the AHZ (10–5M)-induced increase in the proliferation of cells. Meanwhile, parathyroid hormone (10–7M), estrogen (10–9M) and insulin (10–M) significantly increased cellular DNA content. However, these hormonal effects clearly lowered in comparison with that of AHZ (10–5M). Dibutyryl cyclic AMP (10–4M) and zinc sulfate (10–5M) did not cause a significant increase in cellular DNA content. The present results support the view that AHZ has a direct specific proliferative effect on osteoblastic cellsin vitro and that this effect is dependent on protein synthesis. 相似文献
45.
Gerald Platteau Guido Stroehlein James Van Alstine Masayoshi Nagaya 《Biotechnology and bioengineering》2023,120(10):2907-2916
Prepacked chromatography columns and cassette filtration units offer many advantages in bioprocessing. These include reduced labor costs and processing times, ease of storage, and enhanced process flexibility. Rectangular formats are particularly attractive as they can be easily stacked and multiplexed together for continuous processing. Cylindrical chromatography beds have dominated bioprocessing even though their bed support and pressure-flow performance vary with bed dimensions. This work presents the performance of novel, rhombohedral chromatography devices with internally supported beds. They are compatible with existing chromatography workstations and can be packed with any standard commercial resin. The devices offer pressure-flow characteristics independent of container-volume, simple multiplexing, and separation performance comparable to cylindrical columns. Their bi-planar, internal bed support allows mechanically less-rigid resins to be used at up to four times higher maximal linear velocities, and productivities approaching 200 g/L/h for affinity resins, compared to the 20 g/L/h typical of many column-based devices. Three 5 L devices should allow processing of up to 3 kg of monoclonal antibody per hour. 相似文献
46.
Ota Yoko; Ario Takeshi; Hayashi Koji; Nakagawa Tsuyoshi; Hattori Tsukaho; Maeshima Masayoshi; Asahi Tadashi 《Plant & cell physiology》1992,33(3):225-232
Catalases purified from endosperm glyoxysomes and non-specializedmicrobodies from hypocotyls of castor bean seedlings differedin their specific activity [90164 and 0.894.9kunits (mg protein)1, respectively] and in their constituentsubunits [two subunits of 54 and 56 kDa for the endosperm enzymeand only one of 56 kDa for the hypocotyl enzyme]. Immunoblotanalysis also showed that particulate fractions from the endospermsand from etiolated and green cotyledons contained two catalasesubunits of 54 and 56 kDa, whereas such fractions from the hypocotylsand roots contained only the 56-kDa subunit. Leaf peroxisomesfrom green leaves had two catalase subunits of around 55 kDaeach. Results of translation in vitro indicated that the 54-and 56-kDa subunits were translated from distinct mRNAs andlevels of both mRNAs increased in the endosperms during germination,prior to increases in levels of catalase proteins. In the hypocotyls,the 56-kDa subunit seemed to be synthesized constitutively.
1Present addresses: YO, Toyota Central Institute, 31-9 Musashizuka,Nagabuchi, Nagakute, Aichi 480-11, Japan 相似文献
47.
48.
Hasegawa Ryo; Maruyama Akiko; Sasaki Hiroshi; Tada Tomoko; Esashi Yohji 《Journal of experimental botany》1995,46(5):551-556
A possible involvement of ß-cyanoalanine synthase(CAS: EC 4.4.1.9
[EC]
) in germination processes of seeds was demonstratedusing pre-soaked upper seeds of cocklebur (Xanthium pennsylvanicumWallr.). Pretreatment in anoxia not only with KCN but also cysteine,as the substrates for CAS, stimulated the subsequent germinationof cocklebur seeds in air. However, the effect of cysteine wasmanifested even in air when applied together with C2H4, andits effect was further enhanced in combination with KCN. Thegermination-stimulating effect of KCN was intensified by C2H4only when 02 was present. In contrast, serine, another substrateof CAS, was effective in air only when combined with C2H4 and/orKCN. The addition of cysteine greatly reduced the cyanogenicglycoside content of seeds, but increased HCN evolution. Onthe other hand, glutathione did not have any effect on cockleburseed germination, HCN evolution or bound cyanogen content, suggestingthat cysteine is not acting as a reducing reagent. It is suggestedthat CAS regulates the process of cocklebur seed germinationby the dual action of enlarging the pool of amino acids andsupplying sulphydryl bases, the latter being more determinatelyimportant. Serine is effective only via the former action, whilecysteine would act via both. Key words: Cyanide, cyanogenic glycoside, ß-cyanoalanine synthase, seed germination, Xanthium pennsylvanicum 相似文献
49.
T. Ito Naoko Udaka Yoshiaki Inayama Hitoshi Kitamura Masayoshi Kanisawa 《Histochemistry and cell biology》1997,109(1):67-73
We have examined the distribution of calcium-binding proteins (CaBPs) in adult and fetal lungs of Syrian golden hamsters
(Mesocricetus auratus) using immunostaining with confocal laser microscopy and electron microscopy. Single and grouped (neuroepithelial body; NEB)
endocrine cells were distributed from bronchi to alveolar ducts in the adult lung. Serial frozen sections immunostained for
CaBPs in combination with immunostaining for endocrine markers such as calcitonin gene-related peptide, serotonin, PGP9.5,
and synaptophysin revealed that positive immunostaining for calbindin-D28K (CB-D28K) was seen in single endocrine cells and NEBs. However, other so-called EF-hand family CaBPs, parvalbumin and calretinin,
were not detected. Electron microscopically, positive immunoreaction for CB-D28K was mainly in the organelle-free cytoplasmic
matrix of endocrine cells, and partly in nuclei and associated with secretory granules and endoplasmic reticulum. In fetal
developing lungs, endocrine cells appeared first on gestational day 13, and they were positive for all the endocrine markers
used. However, pulmonary endocrine cells were positively immunostained for CB-D28K from gestational days 15 and 16 onward.
In summary, our observations suggest that CB-D28K is a useful marker for endocrine cells of the lung, and CB-D28K could function
as a mediator of endocrine stimulation or calcium homeostasis in pulmonary endocrine cells.
Accepted: 17 June 1997 相似文献
50.
Shinichi Watanabe Masayoshi Osumi Takamitsu Ohnishi Eiko Ichikawa Hisashi Takahashi 《Histochemistry and cell biology》1995,103(6):425-433
In order to investigate the re-epithelialization process during wound healing, the hair on the back of guinea pigs was shaved and then excisional wounds were made through the entire thickness of the skin. Histological changes were observed and changes in the expression of different cytokeratin polypeptides were examined using an immunohistochemical technique. Immunohisto chemical study revealed that the proliferating and migrating keratinocytes expressed the same cytokeratins as the basal cells of normal epidermis. In addition, the entire epidermis of fairly remote areas from the edges of the wound where no thickening was observed showed a temporarily abnormal staining pattern. The suprabasal cells in the regenerating epidermis temporarily expressed cytokeratins not only specific for suprabasal cells but also specific for basal cells. The cytokeratins expressed in normal basal keratinocytes were also present in the thickened granular layers. These data indicate that the expression of cytokeratins in the epidermal keratinocytes (even in fairly remote areas from the wound edges) changes during wound healing, that the origin of the migrating keratinocytes from the remaining epidermis seems to be the basal cells in the epidermis, and that the appearance of keratohyalin granules is not related to changes in cytokeratin expression. 相似文献