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71.
A previously healthy woman developed streptococcal cellulitis of the leg after falling and lacerating her knee. On admission her blood pressure was unrecordable and her respiratory rate greater than 60 beats/minute. Mechanical ventilation was necessary, and plasma volume expansion was started, with little effect. Infusion of dopamine restored the blood pressure to 150/90 mm Hg, but interrupting the infusion for as little as 30 seconds resulted in profound hypotension. Insertion of a second central venous catheter allowed the dopamine to be given continuously, and the infusion was stopped successfully four days after her admission. She eventually made a complete recovery. This case highlights the need for intensive supportive treatment in many streptococcal infections and, in particular, the need for inotropic support. 相似文献
72.
A method of quantifying bands on polyacrylamide gels based on image processing of digitized photographic negatives is presented. 相似文献
73.
Yuliya V. Skorobogatko John Deuso Jared Adolf-Bergfoyle Matthew G. Nowak Yuesong Gong Carol Frances Lippa Keith Vosseller 《Amino acids》2011,40(3):765-779
Neuronal synaptic functional deficits are linked to impaired learning and memory in Alzheimer’s disease (AD). We recently
demonstrated that O-GlcNAc, a novel cytosolic and nuclear carbohydrate post-translational modification, is enriched at neuronal synapses and
positively regulates synaptic plasticity linked to learning and memory in mice. Reduced levels of O-GlcNAc have been observed in AD, suggesting a possible link to deficits in synaptic plasticity. Using lectin enrichment and
mass spectrometry, we mapped several human cortical synaptic O-GlcNAc modification sites. Overlap in patterns of O-GlcNAcation between mouse and human appears to be high, as previously mapped mouse synaptic O-GlcNAc sites in Bassoon, Piccolo, and tubulin polymerization promoting protein p25 were identified in human. Novel O-GlcNAc modification sites were identified on Mek2 and RPN13/ADRM1. Mek2 is a signaling component of the Erk 1/2 pathway involved
in synaptic plasticity. RPN13 is a component of the proteasomal degradation pathway. The potential interplay of phosphorylation
with mapped O-GlcNAc sites, and possible implication of those sites in synaptic plasticity in normal versus AD states is discussed. iTRAQ
is a powerful differential isotopic quantitative approach in proteomics. Pulsed Q dissociation (PQD) is a recently introduced
fragmentation strategy that enables detection of low mass iTRAQ reporter ions in ion trap mass spectrometry. We optimized
LTQ ion trap settings for PQD-based iTRAQ quantitation and demonstrated its utility in O-GlcNAc site mapping. Using iTRAQ, abnormal synaptic expression levels of several proteins previously implicated in AD pathology
were observed in addition to novel changes in synaptic specific protein expression including Synapsin II. 相似文献
74.
H Haines T M McKenna R M Edwards 《Comparative biochemistry and physiology. A, Comparative physiology》1987,87(3):597-601
1. Total water (TW), and extracellular water (ECW) (as sodium and chloride space) were determined in skeletal muscle and carcass of Mus musculus acclimated to long-term water shortage. 2. The presence of fat in control mice and those in early stages of acclimation resulted in an apparent increase in TW and ECW as acclimation proceeded. 3. In contrast, fluid volumes per fat-free weight were either unchanged from controls or reduced. 4. Sodium space exceeded chloride space. 5. Muscle and carcass had essentially the same pattern of fluid shifts. 6. We conclude that ECW maintenance is a preeminent component of the acclimation process in this species. 相似文献
75.
Pei Dong Jessica Flores Kristine Pelton Keith R. Solomon 《Journal of cellular biochemistry》2010,111(5):1367-1374
Cholesterol is essential in establishing most functional animal cell membranes; cells cannot grow or proliferate in the absence of sufficient cholesterol. Consequently, almost every cell, tissue, and animal tightly regulates cholesterol homeostasis, including complex mechanisms of synthesis, transport, uptake, and disposition of cholesterol molecules. We hypothesize that cellular recognition of cholesterol insufficiency causes cell cycle arrest in order to avoid a catastrophic failure in membrane synthesis. Here, we demonstrate using unbiased proteomics and standard biochemistry that cholesterol insufficiency causes upregulation of prohibitin, an inhibitor of cell cycle progression, through activation of a cholesterol‐responsive promoter element. We also demonstrate that prohibitin protects cells from apoptosis caused by cholesterol insufficiency. This is the first study tying cholesterol homeostasis to a specific cell cycle regulator that inhibits apoptosis. J. Cell. Biochem. 111: 1367–1374, 2010. © 2010 Wiley‐Liss, Inc. 相似文献
76.
J L Valatx L Paut-Pagano M Fevre-Montange J B Dumas Milne Edwards M Jouvet 《Comptes rendus de l'Académie des sciences. Série III, Sciences de la vie》1992,315(7):295-301
By means of immunocytochemistry, a central neuronal network containing a prolactin-like substance has been described in the rat. In order to demonstrate the synthesis of this peptide in these cells, we examined the presence of prolactin messenger RNA (PRL mRNA) in several brain samples including the pituitary gland. Amplification of the PRL mRNA was performed by the polymerase chain reaction technique, followed by southern blotting and hybridization with a specific oligonucleotide. Results showed the presence of the expected cDNA (468 bp) in the hypothalamus. Another cDNA with a lower molecular weight was also observed. 相似文献
77.
Keith G. Danielson Janice E. Knepper Frances S. Kittrell Janet S. Butel Daniel Medina Elisa M. Durban 《In vitro cellular & developmental biology. Plant》1989,25(6):535-543
Summary Clonal populations were isolated from the mouse mammary cell line, COMMA-D, by transfection with a dominant-selectable gene,
pSV2Neo, which confers resistance to the antibiotic, G418. Seven of twenty-four clones isolated retained the ability of the
parental line to repopulate cleared mammary fat pads in vivo as ductal-alveolar hyperplasias. Two sublines designated CDNR2
and CDNR4 retained hyperplastic growth potential after multiple passages in vitro with low incidence of tumor formation. A
third subpopulation, CDNR1, contained a single integration site for the pSV2Neo plasmid indicating a bonafide clonal origin
for this subline. CDNR1 cells displayed heterogeneous growth phenotypes in vivo including hyperplasia, adenocarcinoma, and
bone formation. Functional differentiation of CDNR1 cells organized as alveolarlike structures in vivo or on floating collagen
gels in vitro was observed as determined by immunoperoxidase staining for the milk-specific protein, casein. Overall, the
results indicate that a subset of cells from the COMMA-D cell line may be functionally analogous to stem cells existing in
the mammary gland.
Supported by NCI research grants CA-38650, CA-33369, CA-39017, and CA-25215. 相似文献
78.
79.
Keith W.T.Goulding 《中国科学:生命科学英文版》2005,48(Z2)
The nitrogen (N) cycle is essentially 'leaky'. The losses of small amounts of nitrate to waters and of ammonia and nitrous oxide to the atmosphere are a part of the global biogeo-chemical N cycle. However, intensive agricultural production, industry and vehicle use have more than doubled the amount of 'reactive' N in the environment, resulting in eutrophication, ecosystem change and health concerns. Research has identified agricultural practices that cause large losses of N and, in some cases, developed solutions. This paper discusses the problems of maintaining productivity while reducing N losses, compares conventional with low input (integrated) and organic farming systems, and discusses wider options. It also looks at the need to integrate studies on N with other environmental impacts, set in the context of the whole farm system, to provide truly sustainable agricultural systems. 相似文献
80.
Jaclyn S. Long Yuko Fujiwara Joanne Edwards Claire L. Tannahill Gabor Tigyi Susan Pyne Nigel J. Pyne 《The Journal of biological chemistry》2010,285(46):35957-35966
We demonstrate here that the bioactive lipid sphingosine 1-phosphate (S1P) uses sphingosine 1-phosphate receptor 4 (S1P4) and human epidermal growth factor receptor 2 (HER2) to stimulate the extracellular signal regulated protein kinase 1/2 (ERK-1/2) pathway in MDA-MB-453 cells. This was based on several lines of evidence. First, the S1P stimulation of ERK-1/2 was abolished by JTE013, which we show here is an S1P2/4 antagonist and reduced by siRNA knockdown of S1P4. Second, the S1P-stimulated activation of ERK-1/2 was almost completely abolished by a HER2 inhibitor (ErbB2 inhibitor II) and reduced by siRNA knockdown of HER2 expression. Third, phyto-S1P, which is an S1P4 agonist, stimulated ERK-1/2 activation in an S1P4- and HER2-dependent manner. Fourth, FTY720 phosphate, which is an agonist at S1P1,3,4,5 but not S1P2 stimulated activation of ERK-1/2. Fifth, S1P stimulated the tyrosine phosphorylation of HER2, which was reduced by JTE013. HER2 which is an orphan receptor tyrosine kinase is the preferred dimerization partner of the EGF receptor. However, EGF-stimulated activation of ERK-1/2 was not affected by siRNA knockdown of HER2 or by ErbB2 (epidermal growth factor receptor 2 (or HER2)) inhibitor II in MDA-MB-453 cells. Moreover, S1P-stimulated activation of ERK-1/2 does not require an EGF receptor. Thus, S1P and EGF function in a mutually exclusive manner. In conclusion, the magnitude of the signaling gain on the ERK-1/2 pathway produced in response to S1P can be increased by HER2 in MDA-MB-453 cells. The linkage of S1P with an oncogene suggests that S1P and specifically S1P4 may have an important role in breast cancer progression. 相似文献