摘要:

ABSTRACTRecent advances in the in vivo control and regulation of glycolysis and oxidative phosphorylation in yeast and tumor cells is revised. New insigths are presented from old and new experimental data interpreted in the light of powerful new technologies (e.g. NMR confocal microscopy) and quantitative techniques combined with mathematical modeling. Those new aspects are mainly concerned with the dynamical organization of glycolysis and oxidative phosphorylation which emerges from the multiple interactions between compartments and processes inside the cells. Those compartments may be of structural origin, e.g. plasma membrane defining the cell boundary, mitochondrial‐cytoplasmic, or functional ones such as the alternative association‐dissociation of enzymes to subcellular structures (e.g. mitochondria, cytoskeleton) with different kinetic properties in each state. A novel regulatory mechanism concerning polymerization‐depolymerization of microtubular protein may add a new dimension to the in vivo physiological properties of cells. One main suggestion coming from the modulatory power of the polymeric status and concentration of cytoskeleton components is that it could function as an intracellular mechanism of synchronization between microscopic (local) to macroscopic (global) processes. How the cell "mixes" or switches on or off those regulatory steps or effectors under different physiological and environmental conditions and for different genetic backgrounds, is a main avenue of systematic research for the f

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1099

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTGelatinase A and elastase type proteinase (Homsy, et al., 1988) present at plasma membranes of human skin fibroblasts (HSF) were separated by anion exchange chromatography on a DEAE Tris acryl M column. Elastase type proteinase (HSFE1) was able to convert 72 kDa progelatinase A to a lower 66 kDa M.W. active enzyme. Several cytokines (IL‐1β, 1L4, IL6), interferon γ (IFN γ) and tumor growth factor β (TGFβ) were studied for their ability to modify the levels of those plasma membrane associated proteinases. Among these mediators, only IL‐1β was found to enhance the amounts of HSF membrane‐bound HSFE1and G

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1100

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTPlacentas of women suffering from pregnancy‐induced hypertension (PIH) were found to contain a greater amount of Na,K‐ATPase molecules, estimated from anthroyl ouabain binding, than normotensive individuals. Both the microsomal fraction of placental cells and purified Na,K‐ATPase showed an increased affinity for the specific inhibitor ouabain which, in the case of the microsomes, bound with a dissociation constant of 0.9 nM as compared with 3.4 nM in the controls. Likewise, the dissociation constant of the ouabain complex with purified Na,K‐ATPase was about 3.5 times lower in the hypertensive patients. The differences are apparently caused by a different microenvironment of the ouabain‐binding site, as reflected in the quantum yield of bound anthroyl ouabain. If an endogenous digitalis‐like factor is present in the body fluids to regulate Na,K‐ATPase activity, the present results render its role qu

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1101

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTThe spreading behaviour of dissociated hypoblast cells on and besides a band of aligned fibrils associated with the basal lamina of the epiblast was investigated by the use of scanning electron microscopy. A horse‐shaped band of aligned fibrils, first demonstrated by Wakely and England (1979), is present during the gastrulation stages of chicken embryos on the ventral side of the epiblast at the cranial and lateral borders of the area pellucida. The basal lamina of the area pellucida situated inside the fibrillar band enables the spreading and probably the locomotion of dissociated cells, which appeared as polarized cells. Numerous cells were also found on the fibrillar band, and these cells lacked distinct lamellae and a polarized shape. Extensions of the cells contacted the extracellular fibrils and, at these sites of contact, the pattern of the fibrils was frequently deformed. From these observations and from previous results emerged the concept that spreading and locomotion of dissociated hypoblast cells, as well as single mesoblast cells and healing hypoblast epithelium, are inhibited by the band of extracellular fibrils, which acts as a physical barrier. The cell biological basis of the mechanism by which extracellular fibrils associated with the basal lamina arrest the migration of hypoblast and mesoblast cells, but guide the migration of primordial germ cells, is discusse

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1102

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTLike RIE‐1 cells, two of the IEC series of rat intestinal epithelial cell lines were found to express functional angiotensin receptors. As in RIE‐1 cells, treatment of IEC‐6 or IEC‐18 cells with angiotensin II (AII) activated phosphatidylinositol‐4,5‐bisphosphate (PIP2) hydrolysis although (in contrast to RIE‐1 cells) the magnitude of AII‐induced PIP2hydrolysis was small and not associated with a mitogenic response in either IEC cell line. In terms of their other functional responses to AII (activation of protein kinase C (PKC) and a small elevation of cyclic AMP), IEC‐6 cells are otherwise similar to RIE‐1 cells whereas IEC‐18 cells exhibit some phenotypic differences to the other two cell types. Thus, whereas IEC‐6 and RIE‐1 cells each express the AT1subtype of angiotensin receptor, the higher affinity receptors on IEC‐18 cells are 'atypical', being insensitive to both AT1‐ and AT2‐specific angiotensin receptor antagonists. Furthermore, in contrast to its effects in IEC‐6 and RIE‐1 cells, AII neither activates PKC nor modulates cyclic AMP levels in IEC‐18 cells. Whereas IEC‐18 cells express the myristoylated alanine‐rich C‐kinase substrate (MARCKS), immunoreactive MARC

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1103

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTThe aim of this study was to determine the effect of maternal nicotine exposure (1 mg nicotine/kg body mass/day, subcutaneously) on the status of the alveolar septa of the 1 to 21 day old offspring. The data obtained showed swelling of type II and interstitial cell mitochondria. The type I:type II cell ratio decreased as a result of type II cell proliferation. The number of capillaries per unit length of septum was also significantly lower than that of control lung. Ruptured blood‐air barriers also occur in the nicotine exposed lungs of rats of all age groups. The results show that maternal nicotine exposure interfered with the morphometric and morphologic characteristics of the septa of lung tissue of the offsprin

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1104

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTDuring the implantation period (days 14 to 30 post coitum) in Large White pigs substantial numbers of endometrial sub‐epithelial leucocytes were observed from about day 18 p.c. These were predominantly MHC Class II+, CD45+and reactive for an accessory cell determinant carried by polymorphs and macrophages. Maternal lymphocytes of the CD2+, CD4−, CD8−, and a γδTcR+subtype identified by the mAb 86D, were also present. Few CD4+, CD8+, or double‐positive lymphocytes were seen. CD2−CD4−CD8−γδTcR+"Null" cells were seen in stroma adjacent to endometrial glands, as were CD2+lymphocytes. There was no apparent upregulation of CD18, VLA‐4 or CD25. E‐selectin could not be detected on endothelium within uterine tissues or on trophectoderm, nor was a ligand for L‐selectin detectable. The luminal aspect of the uterine epithelium was strongly reactive with anti‐CD15 mAb, which was specifically blocked by lacto‐N‐fucopentaose III, indicating the pres

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1105

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1106

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1107

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY