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排序方式: 共有61条查询结果,搜索用时 15 毫秒
1.
H Kopsa J Zazgornik P Schmidt H Pall SJ Pok PM Bayer P Balcke P Pils 《Canadian Metallurgical Quarterly》1977,107(27):942-947
Two cases with acute renal failure after prolonged hypothermia are presented. Both patients were found in come, became rapidly uremic and required hemodilaysis treatment. Although the laboratory findings were typical of severe muscle damage, e.g. elevated levels of serum creatinine phosphokinase, serum lactic dehydrogenase and serum aldolase activities, visible "crush-injuries" were not found. Acute renal failure was characterized by extreme catabolism and severe metabolic acidosis. After 4 and 10 hemodialyses respectively, the patients became polyuric and finally were discharges with normal renal and muscle function. Hypotension with diminished renal perfusion and nontraumatic rhabdomyolysis due to prolonged hypothermia are regarded as the dominant pathogenetic factors in the acute renal failure. 相似文献
2.
Skuladottir GV Olason PI Jonsson L Skarphedinsson JO Eriksdottir VH Atlason PT Franzson L Schiöth HB 《Lipids》2003,38(11):1127-1132
Hyperphagia was achieved by continuous intracerebroventricular infusion of a melanocortin receptor antagonist (HS024; Neosystem,
Strasbourg, France) in rats. The effects of hyperphagia on FA composition and concentration of plasma phospholipids (PL),
plasma FFA, and adipose tissue TAG were studied in rats for 8 d [short-term hyperphagia (STH); n=8], or 28 d [longterm hyperphagia (LTH); n=9]. The control rats were treated with artificial cerebrospinal fluid for 8 d (n=8) or 28 d (n=10). The rats were fed the same regular diet. In STH rats the plasma PL and fasting plasma FFA contained higher concentrations
of saturated FA (SFA) and monounsaturated FA (MUFA), and plasma FFA contained lower n−6 PUFA than in the control rats. In
LTH rats the plasma PL contained higher concentrations of SFA, MUFA, and n−3 PUFA and higher proportions of 16∶1n−7 and 18∶1n−9
at the expense of 18∶2n−6 than in the control rats. In LTH rats the abundant dietary intake of 18∶2n−6 did not enrich 18∶2n−6
of the plasma PL or adipose tissue TAG. In LTH rats the fasting plasma FFA contained more than twofold higher concentrations
of SFA and MUFA, and higher proportions of 16∶1n−7 and 18∶1n−9 at the expense of 18∶2n−6 than in the control rats. This animal
obesity model shows that LTH affects the FA composition and concentration of plasma PL, plasma FFA, and adipose tissue TAG,
a result consistent with changes associated with increased risk of various diseases in humans. These results also demonstrate
that LTH alters the FA composition of plasma PL and adipose tissue TAG in a way that does not reflect the FA composition of
dietary fat. 相似文献
3.
AC-coupled front-end for biopotential measurements 总被引:5,自引:0,他引:5
Spinelli EM Pallàs-Areny R Mayosky MA 《IEEE transactions on bio-medical engineering》2003,50(3):391-395
AC coupling is essential in biopotential measurements. Electrode offset potentials can be several orders of magnitude larger than the amplitudes of the biological signals of interest, thus limiting the admissible gain of a dc-coupled front end to prevent amplifier saturation. A high-gain input stage needs ac input coupling. This can be achieved by series capacitors, but in order to provide a bias path, grounded resistors are usually included, which degrade the common mode rejection ratio (CMRR). This paper proposes a novel balanced input ac-coupling network that provides a bias path without any connection to ground, thus resulting in a high CMRR. The circuit being passive, it does not limit the differential dc input voltage. Furthermore, differential signals are ac coupled, whereas common-mode voltages are dc coupled, thus allowing the closed-loop control of the dc common mode voltage by means of a driven-right-leg circuit. This makes the circuit compatible with common-mode dc shifting strategies intended for single-supply biopotential amplifiers. The proposed circuit allows the implementation of high-gain biopotential amplifiers with a reduced number of parts, thus resulting in low power consumption. An electrocardiogram amplifier built according to the proposed design achieves a CMRR of 123 dB at 50 Hz. 相似文献
4.
Masters Rich S. W.; MacMahon Ken M. A.; Pall Hardev S. 《Canadian Metallurgical Quarterly》2004,49(1):79
Objective: This study examined whether disruption of performance is moderated in Parkinson's disease (PD) patients who acquire their motor behaviors in an implicit manner. Method: Twenty-seven patients with PD learned a hammering task in errorless (implicit) or errorful (explicit) conditions and were tested for robustness of motor performance under a secondary task load, which required them to continuously count backward as they performed the hammering task. Results: Patients in the errorless (implicit) motor learning condition exhibited robustness to secondary task loading, whereas patients in the errorful (explicit) motor learning condition did not. Conclusions: Implicit motor learning techniques should be considered by PD rehabilitation specialists in cases in which existing disruption to movements is exacerbated by conscious control. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
5.
T Oravecz M Pall J Wang G Roderiquez M Ditto MA Norcross 《Canadian Metallurgical Quarterly》1997,159(9):4587-4592
The role of cell surface proteoglycans in CC chemokine-mediated anti-HIV-1 activity in T cells and macrophages was investigated. Enzyme digestion of heparan sulfate (HS), but not chondroitin sulfate, from the surface of PM1(CD26H) cells (a human T cell line selected for high CD26 expression) rendered them resistant to the antiviral effects of RANTES and macrophage-inflammatory protein-1beta at otherwise inhibitory chemokine concentrations. HIV-1 infection of macrophages, however, was inhibited only partially, even at high concentrations of RANTES, and this inhibition was not prevented by HS removal. Flow cytometry revealed that digestion of cell surface proteoglycans, including HS, prevented the binding of RANTES at 10 to 100 nM concentrations to PM1(CD26H) cells. However, the binding of RANTES to activated macrophages occurred only at higher concentrations (100-300 nM) and was mostly chondroitin sulfate, and not HS, dependent. These results support a role for HS in facilitating the interaction of CC chemokines with the cell surface and the consequent inhibition of HIV-1 infection. The absence of HS-dependent binding of RANTES at lower concentrations to macrophages is consistent with the resistance of these cells to the antiviral effects of chemokines. 相似文献
6.
Douglas H. Adams Christian Sonne Rune Dietz Pall S. Leifsson 《The Science of the total environment》2010,408(23):5808-5816
Marine fishes in South Florida (Florida Keys-Florida Bay-Everglades region) accumulate higher concentrations of mercury (Hg) in their tissues than similar fishes from other areas of the southeastern U.S., though it is not known whether these elevated levels affect fish health. In this study, we used quantifiable pathological and biochemical indicators to explore Hg-associated differences in marine fish from South Florida, where Hg contamination is high, and from Indian River Lagoon, Florida, which served as a reference area. Hg concentrations in all tissues of mature spotted seatrout (Cynoscion nebulosus) from South Florida were significantly higher than those from Indian River Lagoon and were within the threshold range of those in studies where effects of Hg exposure have been observed. The distribution of Hg among tissues followed the same trend in both areas, with the greatest concentration in kidney tissue, followed by liver, muscle, brain, gonad, and red blood cells. Blood-plasma biochemistry showed that concentrations of iron, inorganic phosphate, lactate dehydrogenase, and aspartate aminotransferase were significantly less in South Florida. Also, fructosamine and alkaline phosphatase were significantly less in South Florida. Liver histology revealed that pyknosis/necrosis, interstitial inflammation, and bile duct hyperplasia were found only in seatrout from South Florida, and steatosis/glycogen was more frequently found in Indian River Lagoon specimens. In renal tissue, interstitial inflammation, glomerular dilatation and thickening, and tubular degeneration and necrosis were more frequently found in South Florida specimens. Changes in the liver cytoskeleton and morphology may explain some of the differences in blood parameters between study areas. Neurochemical analyses showed that brain N-methyl-d-aspartic acid (NMDA) receptors (but not those of muscarinic cholinergic receptors, monoamine oxidase, or acetylcholinesterase) were significantly less in fish from South Florida than from Indian River Lagoon. These findings provide compelling evidence that elevated Hg could cause quantifiable pathological and biochemical changes that might influence the health of spotted seatrout and could also affect other marine fish species. 相似文献
7.
Expression/shuttle vectors for the yeast Saccharomyces cerevisiae have usually been large plasmids with only one or a small number of sites that are suitable for cloning and expression. We report here the construction and properties of a series of 12 expression vectors with multiple (four to eight) unique sites in their polylinkers which allow directional cloning and expression of DNA sequences under four different promoters. Eleven of these plasmids replicate at high copy number in Escherichia coli, and all have the yeast TRP1 gene, and the 2 μm origin including REP3 sequence, allowing selection and high copy number replication in yeast. Six of the plasmids are designed for the construction and selection of cDNA libraries from various eukaryotic organisms, allowing directional cloning and expression of cDNAs. All of these six have similar polylinkers containing a unique promoter proximal EcoRI site and a unique promoter distal XhoI site, allowing for directional cloning and expression of ‘ZAP’-type cDNAs. cDNAs that complement a wide variety of yeast mutants can be selected from libraries constructed in this way. The four alternative promoters, ADH2, PGK, GAL10 and SV40 were compared for their relative activity, both in E. coli and in yeast. All yeast promoters showed substantial activity in E. coli with ADH2 showing the highest activity. ADH2 also was well-regulated in yeast, showing very high relative activity under derepressing conditions. cDNAs selected by genetic complementation from libraries constructed in these vectors should be easily subclonable into other vectors, allowing expression in different eukaryotic organisms, DNA sequencing or site-directed mutagenesis. 相似文献
8.
S Pálmarsdóttir E Thordarson LE Edholm JA J?nsson L Mathiasson 《Canadian Metallurgical Quarterly》1997,69(9):1732-1737
A hollow fiber miniaturized supported liquid membrane (SLM) device for sample preparation is connected on-line with capillary electrophoresis and used for determination of a basic drug, bambuterol, in human plasma. The analyte is extracted from the outside of the hollow fiber (donor) through the liquid membrane (pores of the fiber impregnated with organic solvent) into the acceptor solution in the fiber lumen. The process is driven by differences in pH between the donor and acceptor solution. The whole volume of the acceptor solution can then be injected into the CZE capillary by using the double-stacking procedure for large volume-injection. Very clean extracts of low ionic strength are obtained from the SLM treatment, making this sample pretreatment method compatible with the CZE double-stacking procedure, which in turn makes it possible to inject large volumes of sample onto the separation capillary. Good performance of the whole procedure is demonstrated, and detection limits in the low nanomolar range were obtained in spite of the relatively weak UV absorbance of bambuterol. Extractions through the miniaturized SLM unit can be performed for 5-6 h without regenerating the fiber. The regeneration procedure was tested, and no relevant changes in the performance of the extraction could be found after seven regenerations, allowing the same fiber to be used for a week. 相似文献
9.
R Barnard G Thordarson MF Lopez M Yamaguchi A Edens SD Cramer L Ogren F Talamantes 《Canadian Metallurgical Quarterly》1994,140(1):125-135
GH-binding protein (GHBP) or GH receptor is present in numerous extrahepatic tissues in the rodent. From mid- to late gestation in the mouse, the maternal serum concentration of GHBP increases 30- to 50-fold. We have investigated whether the placenta might synthesize GHBP and potentially contribute to this increase. RNA was isolated from placentas and subjected to Northern analysis using a cDNA probe to the shared region of GHBP and GH receptor-encoding mRNAs. From day 8 to day 18 of gestation, the GHBP-encoding mRNA (1.4 kb) increased 45-fold in quantity. The GH receptor-encoding mRNA (4.2 kb) increased sixfold by day 14 and then remained steady until day 18. These changes which were not co-ordinated parallel reported changes in the steady-state concentrations of 1.4 and 4.2 kb mRNAs in maternal liver, suggesting shared regulatory factors. Extracts of freshly isolated trophoblasts were assayed for GHBP with a radioimmunoassay specific for GHBP with a hydrophilic carboxyl terminus. The cytosolic content of immunoreactive GHBP increased fourfold from mid- to late gestation. Trophoblasts were isolated from placentas and cultured for 2 days on collagen gels in defined medium. Cultured cells were at least 90% viable and secreted mouse placental lactogen-II (mPL-II). Immunocytochemistry was carried out simultaneously on cells cultured from day 7 to day 17 of gestation using a monoclonal antibody (MAb 4.3), which recognizes the hydrophilic C-terminus of GHBP. Cell-localized GHBP was present in trophoblasts cultured for 2 days, but GHBP was not detectable by radioimmunoassay or by immunoprecipitation in concentrated culture media from cultures treated with 100 ng mouse GH/ml or 100 ng mPL-II/ml or from untreated cultures. RNA was isolated from cells cultured in an identical manner to those analysed by immunocytochemistry. Three GH receptor/GHBP mRNA species of 8, 4.2 and 1.4 kb were observed. The quantity of 4.2 and 1.4 kb mRNAs did not change significantly in cultures from day 7 to day 15 of gestation but, in cultures from day 17 of gestation, the amount of 1.4 kb mRNA dropped significantly, while that of the 4.2 kb mRNA remained unchanged. GHBP- and GH receptor-encoding mRNAs are not co-ordinately regulated in vivo or in vitro. Although mPL-II was secreted into the medium by cultured trophoblasts, secretion of GHBP could not be detected. The culture medium may not contain the specific factors required for secretion of placental GHBP, or placental GHBP may not be destined for secretion.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
10.
OE Bechter W Eisterer G Pall W Hilbe T Kühr J Thaler 《Canadian Metallurgical Quarterly》1998,58(21):4918-4922
The telomere-telomerase hypothesis states that the vast majority of human tumors have a prolonged replicative life span throughout expressing telomerase, which compensates the cell division-associated loss of telomere DNA. The use of telomere length and telomerase expression as new biological markers in cancer patients requires their correlation with disease prognosis. We, therefore, correlated the mean telomere length based on a telomere restriction fragment assay and the activity of telomerase measured with a telomeric repeat amplification protocol with clinical data and overall survival in 58 patients with B cell chronic lymphocytic leukemia (B-CLL). Telomere length showed a highly inverse correlation to telomerase activity. Patients with telomeres below 6.0 kb were associated with high telomerase activity, whereas patients with a telomere length >6.0 kb generally showed low enzyme activity (P <0.001). Patients in Binet A exhibited significantly longer telomeres and had less telomerase activity than did patients in Binet B or Binet C, where significantly shorter telomeres and higher telomerase activity were observed (P=0.031). Short telomere length and high telomerase activity were significantly associated with a shorter median survival (P=0.02 and P <0.001), and telomerase activity was the most significant prognostic factor for overall survival in B-CLL (P <0.001). Our data provide evidence that telomere length, as well telomerase activity, exerts a strong impact on the survival of B-CLL patients and that telomerase activity can be used as a new prognostic marker in this disease. 相似文献