Biomedical subjects
Publications and source records attributed to D Ikeda.
The case history is presented of a patient with Trousseau's syndrome in which tissue factor originating from lung cancer appeared responsible for recurrent DVT/PE. This is thought to be the first such case to be reported.
The change of the toxicity of chlorinated water after chlorine injection was examined. For the measurement of toxicity, chromosomal aberration test and transforming test were carried out as indexes to initiating activity and to promoting activity in the carcinogenesis process, respectively. Activity inducing chromosomal aberrations of chlorinated humic acid gradually decreased with time after chlorination. In contrast, activity inducing transformations measured by the two-stage assay gradually increased. Thus, the toxicity that decreases or increases is present in chlorinated water. Furthermore, activity inducing transformations measured by the non-two-stage assay gradually decreased. This direction of change was reverse to that of activity inducing transformations by the two-stage assay and consistent with that of activity inducing chromosomal aberrations. It is speculated that the main reason of decreasing activity inducing transformations by the non-two-stage assay is because initiating activity detected as activity inducing chromosomal aberrations in chlorinated water decreases drastically. Directions of changes of total organic halogen and carbonyl group were qualitatively consistent with that of activity inducing chromosomal aberrations. Directions of changes of chloroform and dichloroacetic acid were qualitatively consistent with that of activity inducing transformations by the two-stage assay. Findings of this study suggest that further research is necessary to compare carcinogenicity of tap water near water purification plant and distant tap water.
Oligonucleotide primers specific for gene clusters involved in the biosynthesis of serotype-specific polysaccharide antigens were designed to identify Actinobacillus actinomycetemcomitans serotypes a to e using the multiplex PCR. This method may be useful for serotype-specific genotyping rapidly and directly from clinical samples containing various organisms.
We experienced a curious case that hydronephrosis had caused spontaneous evacuation of calculi in a caliceal diverticulum. A 50-year-old woman was visited to our department complaining of right lower abdominal pain. Several right ureteral stones, right hydronephrosis and a great numbers of small round-shaped calculi in a right caliceal diverticulum were diagnosed. Many of the calculi moved from the diverticulum to ureter, and were evacuated spontaneously. The month after, the right hydronephrosis had already subsided and almost all of the calculi had disappeared. It was supposed that a hydronephrosis had widened the narrow channel between the diverticulum and the calyx and enabled the small calculi to pass through. Recent reports show that effectiveness of ESWL for symptomatic caliceal diverticular calculi is doubtful, because the narrow channel hinders the passage of stone fragments. However, this case suggests that an artificial hydronephrosis created by retrograde occlusion ureteral balloon catheter may lead to good drainage of gravel and better stone-free rate of caliceal diverticular calculi treated by ESWL.
The structures of tyropeptins A and B, new proteasome inhibitors produced by Kitasatospora sp. MK993-dF2, were determined by analysis of various NMR experiments. The 1H and 13C NMR of tyropeptins were complicated due to the presence of an aldehyde group. Therefore, tyropeptins were converted to their alcohols by sodium borohydride. These alcohol derivatives gave assignable NMR spectra. The stereochemistry of tyropeptins were determined by analysis of acid hydrolysis products from tyropeptins, and further confirmed by the total synthesis. The structures of tyropeptins A and B were found to be isovaleryl-L-tyrosyl-L-valyl-DL-tyrosinal and n-butyryl-L-tyrosyl-L-leucyl-DL-tyrosinal, respectively.
BACKGROUND: Recurrent lobar intracerebral hemorrhage is the hallmark of cerebral amyloid angiopathy. The factors that predispose patients to early recurrence of lobar hemorrhage are unknown. One candidate is the apolipoprotein E gene, since both the epsilon2 and the epsilon4 alleles of apolipoprotein E appear to be associated with the severity of amyloid angiopathy. METHODS: We performed a prospective, longitudinal study of consecutive elderly patients who survived a lobar intracerebral hemorrhage. The patients were followed for recurrent hemorrhagic stroke by interviews at six-month intervals and reviews of medical records and computed tomographic scans. RESULTS: Nineteen of 71 enrolled patients had recurrent hemorrhages during a mean follow-up period of 23.9+/-14.8 months, yielding a 2-year cumulative rate of recurrence of 21 percent. The apolipoprotein E genotype was significantly associated with the risk of recurrence. Carriers of the epsilon2 or epsilon4 allele had a two-year rate of recurrence of 28 percent, as compared with only 10 percent for patients with the common apolipoprotein E epsilon3/epsilon3 genotype (risk ratio, 3.8; 95 percent confidence interval, 1.2 to 11.6; P=0.01). Early recurrence occurred in eight patients, four of whom had the uncommon epsilon2/epsilon4 genotype. Also at increased risk for recurrence were patients with a history of hemorrhagic stroke before entry into the study (two-year recurrence, 61 percent; risk ratio, 6.4; 95 percent confidence interval, 2.2 to 18.5; P<0.001). CONCLUSIONS: The apolipoprotein E genotype can identify patients with lobar intracerebral hemorrhage who are at highest risk for early recurrence. This finding makes possible both the provision of prognostic information to patients with lobar hemorrhage and a method of targeting and assessing potential strategies for prevention.
A new bio-active bone cement, known as CAP, has been developed as an alternative to acrylic bone cement. CAP has improved mechanical properties, with a high modulus that is over five times that of PMMA. The effects of this high modulus are examined by finite element analysis, when the CAP is used in place of PMMA to fix the femoral component in total hip prostheses. The results show a higher tensile stress of 8.76 MPa in the CAP cement, compared with 1.99 MPa in the PMMA cement. However, it is also shown that CAP has a superior fatigue strength of approximately 40 MPa, obtained from a cyclic loading test.
Two-dimensional electrophoretic gel profiles were compared between rat 3Y1 fibroblasts cultured in the presence and absence of 30 mM L-carnosine (beta-alanyl-L-histidine) for one week without any replenishment of medium. While a number of cellular proteins changed their expression levels by the addition of carnosine, we identified one of the most prominently varied proteins as vimentin. Immunoblot analysis with anti-vimentin antibody demonstrated that the vimentin levels increased about 2-fold after one-week culture in the presence of carnosine. We also confirmed that the increase of vimentin expression was dependent on the concentration of carnosine added to the medium. Moreover, when cultured cells were stained with anti-vimentin antibody and observed by light microscopy, most cells grown in the presence of carnosine were found to have markedly developed vimentin filaments. The increase of vimentin expression was also observed by adding with carnosine related dipeptides, N-acetylcarnosine and anserine.
The structures of decatromicins A and B that strongly inhibit the growth of MRSA were elucidated by the analysis of various NMR experiments. The planar structure was determined by 1H, 13C, COSY, HMQC and HMBC NMR spectra. The relative configuration of aglycone was elucidated by NOESY experiments and the absolute structure was determined by application of the modified Mosher's method. The absolute structure of glycosyl moiety was determined by X-ray analysis of the O-(p-bromobenzoyl) derivative.
Supplementation of a carbohydrate-free minimal medium with a high level (100 mM) of histidine, methionine, valine, isoleucine, proline and leucine, in particular isoleucine, markedly increased toxin production by Clostridium difficile VPI 10463. The effect of isoleucine was further examined. Increasing the concentration of isoleucine from 20 to 100 mM remarkably increased toxin production, while bacterial growth decreased gradually. Amino acid analysis of the culture revealed that, at 100 mM isoleucine, consumption of isoleucine was remarkably increased. During the incubation period when toxin titers increased markedly but bacterial growth was declining, isoleucine, leucine and cysteine were taken up preferentially and alanine and cystathionine, which were not found at 1 mM isoleucine, were produced in large quantities. These findings suggest that isoleucine may play an important role in toxin production by C. difficile and that alanine and cystathionine production may be co-regulated with the toxin production in the absence of fermentable carbohydrates.
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We present a case of bilateral renal vein thrombosis extending into the inferior vena cava associated with nephrotic syndrome. A 55-year-old Japanese woman who had complained of severe median lumbago for 4 months was referred to our department because of bilateral renal vein thrombosis extending into the inferior vena cava demonstrated on CT. Investigations confirmed the diagnosis of nephrotic syndrome. Although treatments using interventional radiology had been planned, she died suddenly probably owing to pulmonary embolism before the commencement of the treatments.
The structure of heliquinomycin which was isolated from the culture broth of Streptomyces sp. MJ929-SF2 was studied by NMR spectroscopies, X-ray crystallographic analysis and degradation experiments. Heliquinomycin is the first member of glycosylated rubromycins and griseorhodins group antibiotics.
5,6-Dihydrobenzo[a]naphthacenequinone has been constructed by Diels-Alder reaction of an outer-ring diene with a naphthoquinone regioselectively. Similarly, the 14-hydroxy-5,6-dihydrobenzo[a]naphthacenequinone (13) has also been synthesized via the reaction of vinylketene acetal (11) with naphthoquinone.
The key intermediate tri-substituted alpha-tetralone (8) has been synthesized, either via tandem Michael addition-Dieckmann condensation reaction between dienolate and methyl crotonate in a low yield or via Barton's radical decarboxylation of diester (9) without 4-dimethylaminopyridine in 75% yield, and applied to the synthesis of the substituted 5,6-dihydrobenzo[a]naphthacenequinone.
The selective modifications of phenolic hydroxy groups in the chromophore of benanomicin A are described. Hydride reduction of 9-O-tosylate with sodium borohydride/nickel chloride led to 9-deoxybenanomicin A. Methylation of 1-O-diphenylmethylbenanomicin A diphenylmethyl ester with sodium hydride/iodomethane gave 9-O-methyl derivative and with Hünig's base/diazotrimethylsilylmethane afforded the 14-O-methyl derivative. These compounds showed the diminished activity against fungi.
Serotype b-specific polysaccharide antigen (SPA) was extracted from whole cells of Actinobacillus actinomycetemcomitans Y4 by autoclaving and purified by chromatography on DEAE-Sephadex A-25 and Sephacryl S-300. SPA induced the release of monocyte and leukocyte chemotactic factors by human monocytes. Polymyxin B had almost no effect on the release of monocyte chemotactic factor, but a monoclonal antibody against SPA markedly inhibited it. Human monocytes stimulated with SPA exhibited the increased mRNA expression of monocyte chemoattractant protein 1 (MCP-1) and a neutrophil chemotactic factor, interleukin-8 (IL-8). On the other hand, SPA induced the release of IL-1, IL-6, and tumor necrosis factor (TNF) and enhanced the expression of IL-1alpha, IL-1beta, IL-6, and TNF alpha (TNF-alpha) mRNAs. Human monocytes expressed MCP-1 and IL-8 mRNAs when stimulated by human recombinant IL-1alpha, I1-1beta, IL-6, and TNF-alpha, suggesting that these inflammatory cytokines induced by SPA might participate in the production of chemotactic factors in human monocytes.