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1.
Abstract. Registered nurses regarded as “experienced and good” in dementia care were interviewed about the feeding of a severely demented patient who showed refusal-like feeding behaviour. Not one of the twenty nurses could see herself using force against her patients. Most interviewees justified their decisions to feed a severely demented patient and answered questions about whether they would change their minds if there were certain circumstances in terms of words that could be interpreted as referring to the ethical principle of beneficence. The nurses stressed the difficulty to understand the meaning of severely demented patients' feeding behaviour and decide when force-feeding occurs. When asked to rank ethical principles of importance for the decision, however, the most common answer was that they would give priority to the ethical principle of autonomy. The nurses did not see the ethical principles as separate entities, that could be applied one by one, but tried to integrate them into a whole. The findings of this study were interpreted as indicating that principled ethics is not an adequate model to describe experienced nurses' ethical reasoning.  相似文献   
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Investigations of surface antigens of animal cells require sensitive and quantitative in vitro methods. A modification of the mixed haemadsorption technique (MHT) suitable for such purposes is presented. The indicator cells have been labelled with chromium-51. During studies of experimental conditions, including reproducibility and sensitivity, the technique was used in four model systems including histocompatibility (H-2, HL-A), species, organ and blood group antigens. Isotope labelling of the indicator cells has rendered the test more sensitive and in addition some qualitative properties of antigen—antibody interaction have been studied. The test procedure is simple and fast.  相似文献   
4.
Verapamil (V) is a specific inhibitor of the P-glycoprotein (mdr1) in the hepatocyte canalicular membrane. Cyclosporin A (CsA) as an essential immunosuppressive drug has potentially cholestatic adverse effects on the liver, but increases the expression of mdr1. In precision-cut liver slices from 34- to 40-day-old male Wistar rats 26 individual free and conjugated bile acids (BAs) as markers of hepatic transport and synthesis function were analysed after 4 h incubation with V (100 microM) or CsA (5 microM) in Krebs-Henseleit buffer. Some slices were loaded with cholic acid (CA 5 microM) or tauro-ursodeoxycholic acid (T-UDCA 5 microM) to investigate the V and CsA effects under conditions of BA supplementation. BAs were determined in tissue and medium by HPLC with postcolumn derivatisation and fluorescence detection. V and CsA, influencing different targets in BA transport, enhanced slice concentrations of T- and glyco- (G-) conjugated CA only when exogenous CA was given additionally. This BA accumulation in tissue is more reflected at decreased medium concentrations of these BAs after V and CsA incubations. Both V and CsA also inhibited CA uptake into the slices. The acidic chenodeoxycholic acid (CDCA) synthesis pathway is disturbed: T- and G-CDCA concentrations are diminished in slices and medium after V and CsA incubations. T-UDCA plus V or CsA enhanced not only its own slice concentration but also the concentration of the trihydroxylated tauro-muricholic acid (T-beta-MCA), reflecting the conversion of the accumulated dihydroxylated T-UDCA into the T-beta-MCA. The similar effects of V and CsA on BA transport and metabolism can be explained by mdr1 mediated disturbances of cellular ATP transport rather than by inhibition of individual BA transporters.  相似文献   
5.
Calcium was localized in the red cell membrane by light microscopy using chlorotetracycline hydrochloride (CTC) as chelate probe. Treating human erythrocytes with CTC dissolved in saline free of divalent cations, leads to a 530 nm fluorescence emission in the cell border and to characteristic cell shape changes which were evaluated to assess intramembrane calcium distribution. CTC prevented and reverted erythrocyte crenation induced either by washing or superfusing the cells with saline. The ionophore A23187, EGTA and glucose depletion depressed the shape modifying effect of CTC. Thus, CTC appears to act on red cell shape by complex formation with membrane associated calcium. This is further confirmed by the failure of degraded CTC, devoid of metal binding capacity, to modify the crenated shape. The CTC effect can be reverted by superfusing the erythrocytes with CTC-free medium. Thus, calcium binds more tightly to the membrane than to CTC and is not displaced by the antibiotic. If the bilayer couple hypothesis [Sheetz, M.P., Singer, S.J., Proc. Natl. Acad. Sci. USA 71, 4457-4461 (1974)]applies, crenation is reverted by expansion of the inner membrane half relative to the outer membrane half. Expansion of the inner membrane half results from intercalation of CTC which binds to calcium. Thus, calcium in the red cell membrane preferentially occupies the inner leaflet of the bilayer.  相似文献   
6.
Mixed haemadsorption should be regarded as an application of the mixed antiglobulin reaction to situations where the antigen is sessile on a glass surface. Antibody attached to the antigen when exposing the latter to an antiserum is traced by red cells carrying an antiglobulin layer which makes them adsorb to the antibody.

The indicator cells are prepared by coating them first with a layer of γ-globulin from the animal species, the antibody globulin of which they are intended to trace, and then with a layer of the corresponding antiglobulin. The most effective indicator cells were obtained by attaching antibody to natural receptors on the red cells to achieve their first coating of γ-globulin.

The preparation of indicator cells for tracing antibodies from a number of species, including human, is described.

The mixed haemadsorption technique is highly specific and has a sensitivity which is comparable to that of the most sensitive serological techniques.

Test procedures adapted for different purposes are outlined and a number of applications to experimental and clinical problems are reviewed.

  相似文献   
7.
Psoriasis is a multifactorial skin disease characterised by epidermal abnormalities and infiltration by lymphocytes and polymorphonuclear leukocytes (PMN). Skin-derived antileukoproteinase (SKALP), also known as elafin, is a potent inhibitor of human leukocyte elastase and proteinase 3, two PMN-derived proteinases implicated in tissue destruction and leukocyte migration. We have shown that, at least at the protein level, SKALP is significantly decreased in lesional skin of patients with pustular psoriasis compared with plaque-type psoriasis. This finding raised the possibility that SKALP could be one of the candidate genes for pustular forms of psoriasis. We therefore performed single strand conformation polymorphism (SSCP) analysis on the SKALP gene to screen for mutations/polymorphisms in the exons of 30 patients with plaque-type psoriasis, 15 patients with pustular psoriasis and 48 healthy controls. In exon 1 a polymorphism was detected at position + 43 relative to the translation start site, resulting in a substitution of threonine for alanine in the signal peptide. In the promoter region a dinucleotide repeat polymorphism was identified. Both polymorphisms were not associated with pustular psoriasis, or psoriasis in general. Our data indicate that the decrease in SKALP activity in pustular psoriasis is not caused by mutations in the coding region of the gene, and that there is no allelic association between pustular psoriasis and SKALP gene polymorphisms.  相似文献   
8.
Depth and field size dependence of the sensitometric curves of radiographic films have been studied by various groups. Limited information is, however, available on the magnitude of the variations in sensitometric curves applied in clinical practice in different institutions. In this study we assessed in a systematic way the effect of the various parameters influencing the shape of the sensitometric curve: batch composition, irradiation conditions, film processing, and film scanning. Two types of film, Kodak X-Omat V and CEA TVS, were irradiated, processed, and analyzed in three different institutions. The interinstitutional variation of the sensitometric curves, expressed as the OD variation at 50 cGy, can be up to 32% and is mainly caused by differences in film processing and to a lesser degree to differences in batch composition, film scanning, and irradiation conditions. For the Kodak films, the average OD difference at 50 cGy between the three institutions is 17% as a result of differences in batch composition and 25% due to differences in processing conditions. For the CEA films these data are 6% and 24%, respectively. The long-term variation of the sensitometric curves of KODAK films in one institution was smaller than the differences in batch composition between the three institutions. The sensitometric curves of CEA films showed in one institution a large variation with time; the shape gradually varied from sigmoidal to quasilinear. By using relative OD values rather than absolute OD values, variations in sensitometric curves of KODAK films can be reduced to 2%. Consequently, one sensitometric curve is sufficient to derive relative dose values. If processing conditions are well controlled, it might therefore be advantageous to determine the absolute OD only at one or two dose values, in combination with a "universal" relative sensitometric curve.  相似文献   
9.
Limiting dilution analysis has been used in the context of allogeneic bone marrow transplantation to determine anti-recipient interleukin-2 (IL-2) producing helper T lymphocyte precursor (HTLp) frequencies, which in several studies have been predictive of graft-versus-host disease (GVHD). Recently high anti-recipient IL-4 producing HTLp frequencies have been reported and associated with a decreased risk of GVHD. The aim of the present study was to define the optimal conditions for combined determination of IL-2 and IL-4 producing anti-recipient HTLp frequencies. We have optimised the CT.h4S bioassay with regards to specificity, sensitivity, detection limit, and reproducibility. We have found the optimal assay conditions to be 1 x 10 (4) CT.h4S cells/well deprived of IL-4 for 24 h and preincubated for 7 h followed by 18 h of incubation with tritiated methyl-thymidine. In this setting the CT.h4S bioassay detects 5 pg/ml of human recombinant IL-4 with no detection of IL-2 in concentrations below 500 pg/ml. We have found 72 h of culture optimal for detection of IL-2 and IL-4 produced by human mononuclear cells (MNC) in response to stimulation with phytohaemaglutinin and for detection of IL-2 in human leukocyte antigen (HLA)-mismatched mixed leukocyte culture (MLC). An interindividual variation in cytokine accumulation was demonstrated for IL-4 but not for IL-2. With the use of 5x10(4) responder cells/well no IL-4 could be detected in HLA-mismatched MLC between days 1 and 16. The lack of IL-4 detection was not due to high amounts of soluble IL-4 receptor. With the use of 1x10(6) responder cells/well in HLA-mismatched MLC, we found limited IL-4 accumulation still increasing at day 12. We conclude that the CT.h4S bioassay is a reliable and specific method for quantification of IL-4 accumulation in cultures of human MNC. The difference in optimal timing for IL-2 (day 3) and IL-4 (>/=day 12) detection and evidence of very low IL-4 producing HTLp frequencies makes the relevance of a combined IL-2/IL-4 HTLp assay questionable.  相似文献   
10.
The aim of the study was to demonstrate an activation of polymorpho-nuclear leukocytes (PMNs) in chronic progressive atherosclerosis (ATH). A group of patients with ATH, and a group of ATH patients under aspirin (ASA) therapy were compared with control persons without atherosclerotic alterations (healthy controls). Each group comprised 15 male age-matched subjects. The following inflammatory parameters related to PMN activities were measured: the polymorphonuclear leukocyte (PMN) blood count; blood PMN migration and reactive oxygen species release in vitro; the blood levels of PMN elastase, malondialdehyde, antibodies to oxidized LDL and soluble ICAM-1. In ATH patients, the PMN blood counts and the share of blood PMNs migrating upon platelet activating factor and leukotriene B4 stimulation were significnatly above the values of the healthy controls, while the other parameters were not significantly altered. ASA treatment attenuated the inflammatory response and reduced the differences between ATH and the healthy controls. It can be concluded that, in patients with chronic progressive atherosclerosis, PMNs are involved in the inflammatory process underlying the disease.  相似文献   
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