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Summary Growth and glucose isomerase biosynthesis in Streptomyces bambergiensis ATCC 13879 have been studied under different conditions. Some data concerning correlation between cultivation conditions and elemental analysis of the cells are also presented. 相似文献
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Immunocytolocalization of glutamine synthetase in mesophyll and phloem of leaves ofSolanum tuberosum L. 总被引:1,自引:0,他引:1
Summary Localization of glutamine synthetase inSolanum tuberosum leaves was investigated by techniques of Western tissue printing and immunogold electron microscopy. Anti-GS antibodies used in immunolocalization recognize two peptides (45 kDa and 42 kDa) on Western blots. Antibody stained tissue prints on nitrocellulose membranes allowed low resolution localization of GS. Immunostaining was most evident in the adaxial phloem of the leaf midribs and petiole veins. High-resolution localization of glutamine synthetase by immunogold electron microscopy revealed that this enzyme occurs in both the chloroplasts and the cytosol ofS. tuberosum leaf cells. However, GS was specifically associated with the chloroplasts of mesophyll cells and with the cytoplasm of phloem companion cells. The evidence for cell-specific localization of chloroplast and cytosolic GS presented here agrees with the recently reported cell-specific pattern of expression of GUS reporter gene, directed by promoters for chloroplast and cytosolic GS form in tobacco transgenic plants. These data provide additional clues to the interpretation of the functional role of these different isoenzymes and its relationship with their specific localization.Abbreviations BSA
bovine serum albumin
- EM
electron microscope
- GOGAT
glutamate synthase
- GS
glutamine synthetase
- GUS
-glucuronidase
- IgG
immunoglobulin
- PBS
phosphate buffer saline
- SDS-PAGE
sodium dodecyl sulphate-polyacrylamide gel electrophoresis 相似文献
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The plasma membrane of mammalian cells can mediate the cytotoxic and cytocidal effects of colicin E3. As little as 102 lethal units of purified colicin E3 per cell exert a pronounced cytocidal effect on human epithelial HeLa cells and as little
as 104 lethal units per cell also on line L mouse fibroblasts in tissue culture. Cells in complete monolayers are rapidly killed,
become spherical and shrink, they are detached from the support and finally autolyzed. The percentage of killed cells in both
lines is directly proportional to the multiplicity of colicin used. Theld
50 for HeLa cells is about 30 times lower than for L cells. At the multiplicity of 105 l.u., usually 100 % HeLa cells and 90 % L cells are killed in 2–3 days. Purified colicins E2 and D have no demonstrable cytological
effect on HeLa cells, although DNA synthesis in L cells appears to be partly inhibited by colicin E2. The profound effect
of colicin E3 on mammalian cells could be interpreted in a similar way as in bacteria,viz. as a specific cleavage of rRNA. 相似文献
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Citrobacter freundii was grown aerobically in a chemostat on a mineral medium witn galactose or glucose as carbon and energy sources under limitation
by carbon or nitrogen source respectively. At various specific growth rates ranging from 7 to 95% μmax the culture in steady state was analysed and growth yield, specific metabolic rate of substrate utilization, intracellular
concentration of pyruvate, ATP, ADP, AMP and energy charge were determined and plotted as functions of dilution rate. In all
four types of experiments the physiological state of cells remained practically independent of dilution rate up toD = 0.6 μmax, and at a given specific growth rate nearly independent on μmax and type of limitation. At approximatelyD = 0.6 μmax, which is close to the maximum output dilution rateD
m, the physiological state of the cells changed: growth yields decreased and intr cellular pyruvate and adenylates concentrations
increased. Consequently, in a given medium two dilution rates exist at which growth rate dx/dt is the same but the physiology
of the population is quite different. 相似文献
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Nasser Fardousi Everton Nunes da Silva Roxanne Kovacs Josephine Borghi Jorge O. M. Barreto Sren Rud Kristensen Juliana Sampaio Helena Eri Shimizu Luciano B. Gomes Letícia Xander Russo Garibaldi D. Gurgel Timothy Powell-Jackson 《PLoS medicine》2022,19(7)
BackgroundPay-for-performance (P4P) programmes to incentivise health providers to improve quality of care have been widely implemented globally. Despite intuitive appeal, evidence on the effectiveness of P4P is mixed, potentially due to differences in how schemes are designed. We exploited municipality variation in the design features of Brazil’s National Programme for Improving Primary Care Access and Quality (PMAQ) to examine whether performance bonuses given to family health team workers were associated with changes in the quality of care and whether the size of bonus mattered.Methods and findingsFor this quasi-experimental study, we used a difference-in-differences approach combined with matching. We compared changes over time in the quality of care delivered by family health teams between (bonus) municipalities that chose to use some or all of the PMAQ money to provide performance-related bonuses to team workers with (nonbonus) municipalities that invested the funds using traditional input-based budgets. The primary outcome was the PMAQ score, a quality of care index on a scale of 0 to 100, based on several hundred indicators (ranging from 598 to 660) of health care delivery. We did one-to-one matching of bonus municipalities to nonbonus municipalities based on baseline demographic and economic characteristics. On the matched sample, we used ordinary least squares regression to estimate the association of any bonus and size of bonus with the prepost change over time (between November 2011 and October 2015) in the PMAQ score. We performed subgroup analyses with respect to the local area income of the family health team. The matched analytical sample comprised 2,346 municipalities (1,173 nonbonus municipalities; 1,173 bonus municipalities), containing 10,275 family health teams that participated in PMAQ from the outset. Bonus municipalities were associated with a 4.6 (95% CI: 2.7 to 6.4; p < 0.001) percentage point increase in the PMAQ score compared with nonbonus municipalities. The association with quality of care increased with the size of bonus: the largest bonus group saw an improvement of 8.2 percentage points (95% CI: 6.2 to 10.2; p < 0.001) compared with the control. The subgroup analysis showed that the observed improvement in performance was most pronounced in the poorest two-fifths of localities. The limitations of the study include the potential for bias from unmeasured time-varying confounding and the fact that the PMAQ score has not been validated as a measure of quality of care.ConclusionsPerformance bonuses to family health team workers compared with traditional input-based budgets were associated with an improvement in the quality of care.Nasser Fardousi and colleagues investigate the association between performance bonuses and the quality of primary health care delivered by family health teams in Brazil. 相似文献
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