共查询到20条相似文献,搜索用时 15 毫秒
1.
Vero cells growing on microcarriers in stirred suspension were observed calorimetrically using a vessel designed for use with the LKB 'BioActivity Monitor'. Rates of formation of carbon dioxide and lactate were followed in parallel. The results showed that the power and rate of lactate formation could be correlated to both cell number and amount of protein, while the rate of carbon dioxide formation was slightly better correlated to cell number. The power per cell was 27.4 +/- 2.1 pW. Only 33% of this power could be accounted for by the formation of lactate and carbon dioxide. 相似文献
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Lennart Nssberger Lennart Truedsson Mario Monti 《Biology of the cell / under the auspices of the European Cell Biology Organization》1988,62(1):33-37
In the present study, overall metabolism has been estimated in hybridoma cells by microcalorimetric measurement. Heat production rate was found to be 30-50 pW/cell at cell concentrations 0.65-4.5 x 10(5)/ml. High cell concentrations (1 x 10(6) cells/ml) caused unstable power-curves with an initial high peak and a rapid declining phase, whereas low cell concentrations (0.6-4.5 x 10(5) cells/ml) produced steady-state power-curves. Oxygen consumption was found to range between 1.5-6.1 x 10(-5) mol 02/cell/min, corresponding to about 80% of the total metabolic activity. The metabolic inhibitors sodium fluoride (50 nM), sodium azide (160 mM) and rotenone (0.1 mM) caused a reduction in overall cell metabolism of 60, 55 and 40% respectively. 相似文献
3.
Summary Microcalorimetrically determined heat production was used as parameter for microbial metabolism to study some aspects of anaerobic digestion.The heat production of sludge samples from a sufficiently active anaerobic digester is dependent upon the concentration of organic substances and is correlated with dehydrogenase activity.Microcalorimetric measurements were carried out to investigate the metabolisation of added substrates; H-values of 150–270 kJ/M of cellobiose were determined for the digestion of cellobiose. Heat flow during the adaptation of digester sludge to cellobiose showed a dramatic change.The action of heavy metals on the microcalorimetrically determined metabolic activity of sludge samples was tested and we show that the addition of heavy metals, in concentrations often detected in waste water treatment, reduced the heat flow by up to 75%. 相似文献
4.
Fischer A 《The Biochemical journal》1948,43(4):491-497
5.
Heat production, oxygen consumption, and lipolysis in isolated interscapular brown adipocytes from the rat were investigated. Epinephrine, norepinephrine, and isoproterenol increased heat production in a concentration-dependent manner, showing, about 6-, 4-, and 5-fold higher effects than controls, respectively. The concentration of isoproterenol for threshold heat production and glycerol release were 10(-10) M and 10(-9) M, respectively. The fact that 10(-9) M isoproterenol increased heat production by about 3-fold while glycerol release had no effect at all indicates that calorimetry is more appropriate for investigation of brown adipocytes. At least the method is more sensitive than that of measuring glycerol release. 相似文献
6.
V. A. Dubrovskii B. A. Dvorkin I. Yu. Yanina V. V. Tuchin 《Cell and Tissue Biology》2011,5(5):520-529
The effect of a change in the optical properties of human adipose tissue cells in vitro after photodynamic action was studied
experimentally. The study of kinetics of this process was carried out based on the digital microscopy of thin layers of tissue.
The statistical computer processing of the obtained microimages has allowed one to quantitatively estimate the kinetics of
the photodynamic after effects on the biotissue. The optical interpretation of images indicates that the observed phenomenon
corresponds to the partial lysis of the adipose tissue cells without their complete destruction. 相似文献
7.
《Journal of biochemical and biophysical methods》1996,31(3-4):189-193
We determined the thermogenesis curves of mitochondria isolated from fish liver tissue by using an LKB 2277 Bioactivity Monitor. After isolation from the fish liver, mitochondria still have activity and can live for a long time by using the stored nutrients. We calculated the recovery rate constants of mitochondria. We found that the thermogenesis curves of mitochondria are similar to those obtained from prokaryotic cells, but not similar to those obtained from eukaryotic cells. We determined the metabolic thermogenesis curves of mitochondria isolated from two kinds of carp liver tissue, scattered-scaled mirror carp and harvest carp. There are some important similarities and some important differences between these thermogenesis curves. 相似文献
8.
C. Brunner W. Szymczak W. Li C. Hoeschen S. Mörtl F. Eckardt-Schupp U. Oeh 《Radiation and environmental biophysics》2011,50(1):209-217
A pilot study was performed to evaluate a new concept for a radiation biodosimetry method. Proton transfer reaction-mass spectrometry
(PTR-MS) was used to find out whether radiation induces changes in the composition of volatile organic compounds (VOCs) in
the headspace of in vitro cultured cells. Two different cell lines, retinal pigment epithelium cells hTERT-RPE1 and lung epithelium
cells A-549, were irradiated with gamma radiation at doses of 4 Gy and 8 Gy. For measuring the cell-specific effects, the
VOC concentrations in the headspace of flasks containing cells plus medium, as well as of flasks containing pure medium were
analyzed for changes before and after irradiation. No significant radiation-induced alterations in VOC concentrations in the
headspace could be observed after irradiation. 相似文献
9.
We consider here the problem of classifying a macro-level object based on measurements of embedded (micro-level) observations within each object, for example, classifying a patient based on measurements on a collection of a random number of their cells. Classification problems with this hierarchical, nested structure have not received the same statistical understanding as the general classification problem. Some heuristic approaches have been developed and a few authors have proposed formal statistical models. We focus on the problem where heterogeneity exists between the macro-level objects within a class. We propose a model-based statistical methodology that models the log-odds of the macro-level object belonging to a class using a latent-class variable model to account for this heterogeneity. The latent classes are estimated by clustering the macro-level object density estimates. We apply this method to the detection of patients with cervical neoplasia based on quantitative cytology measurements on cells in a Papanicolaou smear. Quantitative cytology is much cheaper and potentially can take less time than the current standard of care. The results show that the automated quantitative cytology using the proposed method is roughly equivalent to clinical cytopathology and shows significant improvement over a statistical model that does not account for the heterogeneity of the data. 相似文献
10.
Microcalorimetric measurements of heat production in brown adipocytes from control and cafeteria-fed rats. 下载免费PDF全文
The effects of the sequential addition of glucose, noradrenaline, propranolol and oleic acid on the rates of O2 consumption and heat production by isolated interscapular brown adipocytes from control and cafeteria-fed rats were compared. Although the chemical agents produced very similar changes in oxidative metabolism, the actual rates of O2 uptake and heat output in adipocytes from the cafeteria-fed rats, when expressed per g dry wt. of cells, were approx. 65% less than those obtained with cells from the control rats. However, when the same results were expressed per 10(8) multiloccular brown adipocytes, rather than gravimetrically, rates of O2 consumption and heat production were equivalent. Further interpretation of these data is complicated, because the average volume of multiloccular brown adipocytes from cafeteria-fed rats was 2.5 times that for multiloccular cells from control animals. 相似文献
11.
Changes in optical properties of human adipose tissue cells after photodynamic exposure in vitro were found and investigated. Analysis of the kinetics of the process was realized by means of photomicrography of the object investigated. The statistical computer processing of digital photos obtained gave us an opportunity to estimate quantitatively the kinetics of photodynamic effect upon the tissue. Optical interpretation of the photos obtained indicates that the observed phenomenon corresponds to the partial lysis of adipose tissue cells without their complete destruction. 相似文献
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13.
Nomoto-Kojima N Aoki S Uchihashi K Matsunobu A Koike E Ootani A Yonemitsu N Fujimoto K Toda S 《Cell and tissue research》2011,344(2):287-298
Adipose tissue exists in the gastric submucosa and subserosa. Thus, adipose tissue stromal cells (ATSCs), which include mesenchymal
stem cells (MSCs), seem critical for the progression of gastric cancer but their interaction with the cancer cells is unknown.
We demonstrated an interaction between these cells, using immunohistochemistry, Western blot and the collagen gel invasion
assay system, in which the adenocarcinoma cells (well and poorly differentiated types, MKN28 and MKN45, respectively) were
cultured on a ATSC-embedded or ATSC-non-embedded gel. ATSCs promoted the expression of the growth marker, proliferation cell
nuclear antigen but inhibited that of the apoptosis marker, single-stranded DNA, in the cancer cell types. ATSCs accelerated
the invasion of only MKN28 into the gel and promoted the expression of mitogen-activated protein kinase (MAPK, pERK-1/2) but
decreased that of the molecularly targeted protein, HER2, in the cancer cells. ATSCs did not affect the expression of the
prostaglandin biosynthetic enzyme cyclooxgenase-2 (COX-2) in the cancer cells. The COX-2 inhibitor celecoxib did not affect
the morphology or invasion of the cancer cells. The cancer cell types in turn promoted the display of the myofibroblast marker,
α-smooth muscle actin, whereas they decreased that of some MSC markers, e.g., CD44 and CD105, in ATSCs. The data suggest that
(1) ATSCs influence the progression of gastric cancer by increasing their growth/invasion and decreasing their apoptosis through
MAPK activation in a COX-2-independent way; (2) ATSCs adversely affect HER2-targeted therapy; (3) the cancer cells induce
the cancer-associated myofibroblast phenotype in ATSCs. 相似文献
14.
Here we describe a protocol for generating 3D human intestinal tissues (called organoids) in vitro from human pluripotent stem cells (hPSCs). To generate intestinal organoids, pluripotent stem cells are first differentiated into FOXA2(+)SOX17(+) endoderm by treating the cells with activin A for 3 d. After endoderm induction, the pluripotent stem cells are patterned into CDX2(+) mid- and hindgut tissue using FGF4 and WNT3a. During this patterning step, 3D mid- or hindgut spheroids bud from the monolayer epithelium attached to the tissue culture dish. The 3D spheroids are further cultured in Matrigel along with prointestinal growth factors, and they proliferate and expand over 1-3 months to give rise to intestinal tissue, complete with intestinal mesenchyme and epithelium comprising all of the major intestinal cell types. To date, this is the only method for efficiently directing the differentiation of hPSCs into 3D human intestinal tissue in vitro. 相似文献
15.
Nakanishi M Hamazaki TS Komazaki S Okochi H Asashima M 《Differentiation; research in biological diversity》2007,75(1):1-11
The in vitro formation of organs and/or tissues is a major goal for regenerative medicine that would also provide a powerful tool for analyzing both the mechanisms of development and disease processes for each target organ. Here, we present a method whereby pancreatic tissues can be formed in vitro from mouse embryonic stem (ES) cells. Embryoid body-like spheres (EBSs) induced from ES cell colonies were treated with retinoic acid (RA) and activin, which are candidate regulators of pancreatic development in vivo. These induced tissues had decreased expression of the sonic hedgehog (shh) gene and expressed several pancreatic marker genes. ES cell-derived pancreatic tissue was composed of exocrine cells, endocrine cells, and pancreatic duct-like structures. In addition, the ratio of exocrine to endocrine cells in the induced tissue was found to be sensitive to the concentrations of RA and activin in the present experiment. 相似文献
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18.
Microcalorimetric study of the anaerobic growth of Escherichia coli: measurements of the affinity of whole cells for various energy substrates. 总被引:4,自引:0,他引:4 下载免费PDF全文
Microcalorimetry has been used to determine the affinity of whole cells of Escherichia coli for glucose, galactose, fructose, and lactose. Anaerobic growth thermograms were analyzed, and the Km and Vmax values for these energy substrates were measured at pH 7.8. Results obtained with this technique using various organisms growing anaerobically on different sugars are compared. This comparison shows that in practically all cases the cellular rate of catabolic activity is a hyperbolic function of the energy substrate concentrations at low sugar concentrations. In some cases this technique also allows determination of kinetics at high sugar concentrations. 相似文献
19.
Physical separation of colony stimulating cells from in vitro colony forming cells in hemopoietic tissue 总被引:6,自引:0,他引:6
Hemopoietic colony formation in agar occurred spontaneously in mass cultures of marrow cells obtained from a number of species (guinea pig, rat, lamb, rabbit, pig, calf, human and Rhesus monkey). This contrasted with the observation that colony formation by mouse bone marrow exhibited an absolute requirement for an exogenous source of a colony stimulating factor. Analysis of spontaneous colony formation in Rhesus monkey marrow cultures revealed the presence of a cell type in hemopoietic tissue, capable of elaborating colony stimulating factor when used to condition media or as feeder layers. Equilibrium density gradient centrifugation separated colony stimulating cells from in vitro colony forming cells in monkey bone marrow. Separation studies on spleen, blood and marrow characterized the stimulating cells as of intermediate density, depleted or absent in fractions enriched for cells of the granulocytic series and localized in regions containing lymphocytes and monocytes. Adherence column separation of peripheral blood leukocytes showed the stimulating cells to be actively adherent, unlike the majority of lymphocytes, and combined adherence column and density separation indicated that stimulating cells were present in hemopoietic tissue within the population of adherent lymphocytes or monocytes. 相似文献
20.
Summary The difference in DNA content of peripheral lymphocytes from normal males, normal females, and an individual with a 48 (xxxy) chromosome constitution was determined by rapid flow microfluorometric techniques. A similar comparison was performed using tissue culture fibroblasts derived from an individual with a 49 (xxxxy) chromosome constitution and WI-38 cells as a normal control. Less than 60 min were required to isolate the lymphocytes, to stain the cells fluorescently, and to measure the increased DNA content. The measured increase in DNA content is consistent with chromosome DNA analyses and chromosome length measurements. 相似文献