Lipid A that contains mainly 2,3-diamino-2,3-dideoxy-D-glucose, phosphate and fatty acids in the molar ratio 2:1:5-6 was found in Pseudomonas diminuta lipopolysaccharide. The lipid A was considered ...to have a diamino-sugar disaccharide structure that carries a nonglycosidic phosphomonoester group and amide-bound acyloxyacyl and 3-hydroxy fatty acyl groups. The lipopolysaccharide exhibited endotoxic activities including lethal toxicity, pyrogenicity, local Shwartzman activity, body weight-decreasing toxicity and Limulus activity. The free lipid A was also endotoxic.
The effects of an intravenous administration of lipid A from Salmonella minnesota R595 lipopolysaccharide on the in vivo production of interleukin-2 (IL-2), IL-4, IL-5 and IL-6 in the spleens of mice ...intravenously immunized with sheep red blood cell (SRBC) antigen were investigated. The increased number of antigen-specific IgM antibody-producing cells and the titer of the IgM serum antibody were measured using the plaque-forming cell (PFC) assay and an enzyme-linked immunosorbent assay (ELISA). Simultaneous injections of SRBC antigen and lipid A adjuvant enhanced IgM-PFC number on days 3 and 4 and the serum IgM titer on days 4 and 5 after the immunization. We found that the enhanced IL-4 and IL-5 levels correlated with the PFC number and IgM titer. When lipid A was injected intravenously 2 days after immunization with SRBC, the PFC number in lipid A-treated groups were similar to those in controls 3 and 4 days after the immunization. However, it was found that a twofold increase in the IgM titer in serum was induced by lipid A 5 days after immunization. In relation to this increase, lipid A stimulated the production of only IL-5 among the cytokines tested.
Transforming growth factor(TGF)beta 1 is a potent inhibitor of growth in mouse osteoblastic MC3T3-E1 cells. To isolate genes that are induced by TGF beta 1, the differential screening method was ...adopted using a cDNA library constructed from cells treated with TGF beta 1 for 4 h. Six independent cDNA clones were isolated (TGF beta-stimulated clone, TSC-5, TSC-36, TSC-115, TSC-128, TSC-160 and TSC-161), the expression of which was increased by TGF beta 1-treatment with maximal expression at 6-10 h. The steady-state levels of TSC-36, TSC-128 and TSC-160 increased almost tenfold, whereas those of TSC-5, TSC-115 and TSC-161 were elevated at most threefold. From partial nucleotide sequences, TSC-160 was found to be identical to rrg (ras-recision gene, lysyl oxidase), and TSC-115 had 80% similarity with tropomyosin cDNA, whereas other genes seemed novel. Expression of TSC-36 and TSC-160 was dramatically decreased in v-Ki-ras-transformed MC3T3 cells or in transformed NIH 3T3 cells (DT), and was recovered to normal levels in a flat revertant (C11). A nearly full-length copy of TSC-36 cDNA was isolated, and an open reading frame indicated that it encodes a protein of 35 kDa. An antiserum was raised against the C-terminal peptide predicted from the nucleotide sequence, and a polypeptide with an approximate molecular mass of 38 kDa was detected in cultured medium of MC3T3-E1 cells. The amino acid sequence of TSC-36 protein was found to have some similarity with follistatin, an activin-binding protein, and a limited similarity with the secreted protein rich in cysteine (SPARC).
In order to prevent thrombo-embolism after prosthetic valve replacement, a high dose therapy with 450 mg/day of Dipyridamole and 3,000 mg/day of Aspirin was carried out for 1 year and 2 months in 91 ...cases (26 cases with aortic valve replacement, 40 cases with mitral valve replacement and 25 cases with multiple valve replacement). In the treated group, the incidence was 1.9% in cases more than 5 years after valve replacement and 2.9% in cases less than 5 years after valve replacement. In contrast, in the control group of 89 cases (47 cases of aortic valve replacement, 30 cases of mitral valve replacement and 12 cases of multiple valve replacement), the incidence was 9.1% and 14.7%, respectively. Thus, in both time intervals following prosthetic valve replacement the incidence of thrombo-embolism in the treated group was significantly lower than in the control group.
A high-performance liquid chromatographic method for monitoring serum levels of the aminoglycoside antibiotics sisomicin, netilmicin, astromicin, and micronomicin, using an amino acid analysis system ...is described. The procedure involves sample preparation with a CM-Sephadex column, and quantitation using internal standards chosen from each of the other aminoglycosides. The aminoglycosides were separated by reversed-phase ion-pair chromatography on Zorbax C8 and ODS columns, and detected by the post-column derivatization technique. The calibration curves of serum concentration for sisomicin, netilmicin, astromicin, and micronomicin were linear over the ranges 0.32-22.8 micrograms/ml, 0.17-11.6 micrograms/ml, 0.1-6.3 micrograms/ml, and 1.0-30 micrograms/ml, respectively. The coefficients of variation were 2.5, 2.8, 3.1 and 1.9%, at the serum concentrations of 1.3, 1.45, 1.58 and 2.5 micrograms/ml, respectively (n = 6). Determination by the internal standard method using another aminoglycoside gives accurate and reproducible results. This method is applicable also to other aminoglycoside antibiotics.
Tumor necrosis factor (TNP)‐inducing activities of lipid A preparations from P. diminuta and P. vesicularis, which contain mainly 2 mol of 2,3‐diamino‐2,3‐dideoxy‐D‐glucose and 1 mol of nonglycosidic ...phosphate as the backbone component and have partly different fatty acid compositions, were examined. TNF was induced by injecting various lipid A fractions into mice that had previously been sensitized with Mycobacterium bovis BCG vaccine. A major component of lipid A of both strains, referred to as A3 fraction, exhibited stronger TNF‐inducing activity than A2 fraction having incomplete acyl residues. The removal of ester‐linked fatty acyl groups by mild hydrazinolysis of the P. diminuta lipid A results in a marked decrease of the activity. These results suggest that the structure of the hydrophobic part, including the amide‐linked acyloxyacyl group(s), of the lipid A molecule play an important role in inducing TNF in the sera of mice.
Strength and fatigue tests were extracorporeally performed on silicone rubber, one of the materials of the artificial heart device pump, and the following results were obtained. 1) It is necessary to ...sandwich two mesh sheets between the silicone rubber membranes and to limit the directional expansion and contraction to a minimum level. 2) The connection between the housing and chamber was found to have sufficient strength through motion model tests performed 10 million times. In the fatigue test, fatigue associated with frequency of motion could not be demonstrated.
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