Biomedical subjects
Publications and source records attributed to T Yamamura.
A patient with ulcerative colitis previously treated with restorative proctocolectomy and ileal J-pouch anal anastomosis had recurrent pelvic abscess and poor functional results for 3 years postoperatively. To improve the quality of life, the J pouch was converted to a Kock's pouch. The successful result implies that Kock's continent ileostomy is a good replacement for failed pelvic pouch.
Clinical evaluation of continuous SvO2 monitoring during general anesthesia was made in 21 surgical patients utilizing a fiberoptic reflectometry system combined with a pulmonary artery flow-directed balloon catheter. On-line in vivo values for SvO2 by the system were closely related to those obtained in vitro from a Radiometer ABL-300. There was a good correlation between changes of in vivo SvO2 and corresponding changes in cardiac index. We also observed that there were significant correlations between SvO2 and oxygen extraction ratio, and SvO2 and oxygen delivery. These data indicate that continuous monitoring of SvO2 during general anesthesia can provide on-line information not only about hemodynamic state but also on oxygen transport, which will be especially helpful in managing hemodynamically unstable patients during anesthesia.
An endonuclease endogenous to rat-liver nuclei has been purified by a series of chromatographic procedures and finally by isoelectric focusing (IEF) electrophoresis. The nuclease fraction prepared by the IEF electrophoresis (IEF fraction) showed a pI value of 5.7 and migrated as a single band to a molecular weight position of 46,000 on an SDS-polyacrylamide gel. The activity for single-stranded DNA was enhanced by 10 mM MgCl2 and/or by 5-15 mM MgCl2 in the presence of 2 mM CaCl2 (an optimum pH, 7.0), but was lowered by CaCl2 alone and inhibited strongly by ZnCl2 or MnCl2. The activity for duplex DNA was rather low, although an optimum condition was 10 mM MgCl2. In fact, even under this condition, the activity was about 40% lower than that for single-stranded DNA. Moreover, the IEF fraction formed single-strand nicks much more rapidly than double-strand cuts in pBR322 DNA, and preferentially produced deoxyadenosine 5'-monophosphate termini in the DNA. In addition, RNAase activity was also detected in this fraction.
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Adoptive immunotherapy with lymphokine-activated killer (LAK) cells and systemic administration of recombinant Interleukin-2 (RIL-2) was carried out in a case of malignant melanoma with lung metastases. Histological specimens from the lung showed a metastatic melanoma heavily invaded by atypical lymphoid cells with convoluted nuclei of varying size. Immunohistochemistry revealed that these cells had the characteristic exclusively of natural killer cell (Leu-7+). Nodules of these cells mimicked the appearance of non-Hodgkin's lymphoma of pleomorphic type. Molecular cytogenetic analysis, however, showed the absence of rearranged bands for the T-cell receptor beta-chain gene, indicating the absence of T-cell clones. At autopsy, 1 month after the LAK therapy, the heavy invasion of convoluted cells had disappeared. These findings clearly indicate that the LAK cell plus RIL-2 therapy induced Leu-7+ lymphoid cells, phenotypically suggestive of natural killer cell aggregation in the tumours.
Transmural stimulation (TS) produced a frequency-dependent contraction of the longitudinal muscles from the lesser curvature of the guinea pig antrum, which was abolished by atropine. On the other hand, a response to TS of the strips from the greater curvature was biphasic: a rapid contraction followed by a relaxation, which was abolished by tetrodotoxin. By pretreatment with atropine, rapid contraction of the biphasic response evoked by TS in the greater curvature was abolished and relaxation was augmented. Relaxation to TS of the greater curvature was not affected by prazocine, yohimbine, phentolamine, propranolol, theophylline, apamin, alpha-chymotrypsin, and vasoactive intestinal polypeptide receptor antagonist. Different innervation mechanisms were suggested to be present in the longitudinal muscles between the lesser curvature (innervated with excitatory cholinergic neurons) and the greater curvature (innervated with excitatory cholinergic neurons and nonadrenergic inhibitory neurons) of the guinea pig antrum.
We have isolated and analyzed apolipoprotein E7 gene from a patient with hyperlipoproteinemia. Apolipoprotein E7 (apolipoprotein E-Suita) is a variant of apolipoprotein E with four additional units of positive charge compared to apolipoprotein E3, which is the major isoform of apolipoprotein E. The heterozygous gene of apolipoprotein E7/3 from the patient was cloned into lambda phage. The cloned apolipoprotein E genes were subcloned into a murine retrovirus shuttle vector and were expressed. Two out of five clones expressed apolipoprotein E7. The analysis of the nucleotide sequence of the exon and exon-intron boundary regions has shown two G-to-A nucleotide substitutions in the 548 and 551 nucleotide positions from the 5'-end of the fourth exon. These two base substitutions change the amino acid residues -Glu-Glu- to -Lys-Lys- at the 244 and 245 positions from the amino-terminus of the mature protein, and give four additional units of positive charge to the molecule.
Hemerythrin from Siphonosoma cumanense has a trimeric structure consisting of identical subunits, which have no cooperativity nor Bohr effect on oxygen-binding. The trimer was dissociated into its monomers by the modification of the SH group of its cysteines with p-chloromercuriphenylsulfonic acid (PCMPS), which was monitored by stopped-flow of both spectrophotomeric and small angle X-ray scattering methods. The results showed that the process involved sequential modification of the SH groups, dissociation into monomers, and auto-oxidation of ferrous iron in the active center. The modification of the SH groups with PCMPS followed second-order kinetics with a rate constant of 1.8 M-1.s-1. The dissociation and auto-oxidation followed first-order kinetics with rate constants of 4 X 10(-3) s-1 and 5 X 10(-4) s-1, respectively. The obtained rate of auto-oxidation was much faster than that in the native state. These findings lead to the conclusion that the trimeric state of S. cumanense hemerythrin is necessary to prevent auto-oxidation.
Chicken ovotransferrin, an iron binding protein, has two metal binding sites (amino (N) and carboxy (C) terminal sites). It binds Cu(II), Al(III), Co(II), and other metals, as well as Fe(III). In this study, the selectivity and cooperativity of the N and C sites on Al(III), Co(II), and Tb(III) binding were investigated. Metals were classified into two groups according to their site preference. Co(II) and Al(III) bound to the N site more preferably than to the C site, whereas Tb(III) bound to the C site more preferably. On Fe(III) binding, the binding constant of Fe(III) becomes larger when the other site is already occupied. Thus, positive cooperativity is seen. In the present study, the binding cooperativities of Co(II), Tb(III), and Al(III) as to the N and C sites were investigated. On Co(II) and Tb(III) binding, no cooperativity was observed, as in the case of Cu(II) [Yamamura, T. et al. (1985) in Proteins of Iron Storage and Transport (Spik, G., Montreuil, J., Crichton, R.R., & Mazurier, J., eds.) pp. 53-56, Elsevier Science Publ. B.V., Amsterdam]. In contrast, negative cooperativity was observed on Al(III) binding. Based on a model proposed by Yamamura et al. [Yamamura, T. et al. (1985) ibid.], the ratio of the binding constants, KC/KN, and the stacking coefficient, Kst, were estimated. KC/KN is 2.2 +/- 0.4 for the Tb(III) ion, 0.5 +/- 0.1 for the Co(II) ion, and 0.12 +/- 0.02 for the Al(III) ion. Kst (= 1 in a non-cooperative case) is 0.98 +/- 0.02 for the Tb(III) ion, 1.03 +/- 0.02 for the Co(II) ion, and 0.55 +/- 0.22 for the Al(III) ion.
The amount of bound water in the stratum corneum of the hairless rat was measured by using proton nuclear magnetic resonance (1H-NMR) spectrometry in the temperature range of -5 degrees C to -30 degrees C. A decrease in the bound water content was observed when the stratum corneum was extracted using water, a mixed solvent of chloroform:methanol (2:1), or a 1% sodium dodecyl sulfate (SDS) aqueous solution. However, extraction using a mixed solvent of acetone:ether (1:1) did not change the bound water content at temperatures above -20 degrees C. The lipids extracted by acetone:ether-extraction method consisted of sebaceous gland lipids, cholesterol, free fatty acids, and ceramides. In contrast, the lipids extracted by chloroform:methanol-extraction method contained more polar lipids such as sphingomyelin, which had the same amount of bound water in itself as that of the water-extracted stratum corneum. These results suggest that the polar lipids soluble in the chloroform and methanol mixture may contribute to enhance the bound water content. Therefore, it is hypothesized that the water-holding capacity of the stratum corneum is dependent on both the hygroscopic components such as the natural moisturizing factor (NMF) and the polar lipids, such as sphingolipids, existing in the intercellular spaces of the stratum corneum.
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We studied the immunomodulatory mechanism of 15-deoxyspergualin (DSG), a novel antitumor agent. To assess this, we used a mixed culture of antigen-primed lymph node cells (LNC) and spleen cells (SPC). In normal or untreated conditions, SPC suppressed the proliferative response of LNC to the antigens. In contrast, SPC from DSG-treated animals did not show any suppressive activity. This suppression was mediated by adherent cells in SPC but the suppression mechanism was recovered when DSG-treated spleen macrophages were reconstituted with control spleen nonadherent cells. These data suggest that DSG abrogates nonspecific suppressive activity of spleen cells by acting on both adherent and nonadherent cells.
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Since 1978, J. Utsunomiya has performed total colectomy, mucosal proctectomy and ileoanal anastomosis (IAA) in 105 patients and analysed their results in 97 patients consisting of 61 of familial polyposis (FP) and 36 of ulcerative colitis (UC) those who have been observed for two months to 10 years after operation. The operative procedures were classified in the three modalities. I. the "end to end-long cuff", II. "J-pouch-long cuff" and III. "J-pouch-short cuff" procedure. The success rate has been improved to 93.0% in the procedure III. compare with 74.1% in the II and 61.5% in the I. This improvement was achieved by preservation of reservoir continence, reduction of pelvic sepsis and less damaging of the internal sphincter during operation. Through a series of evolutional modification, the surgical technique has been established to the present method which is constructed with the four principal components: direct anastomosis of J-ileal pouch to the anus, short rectal cuff mucosectomy, anoabdominal approach at prone jack-knife position and routine use of defunctioning ileostomy. With this technique, both FP and UC patients enjoyed excellent or good function in 90% of the cases. Sex of the patient did not influence the functional result, but older patients showed poorer results compared with the younger patients. This procedure can provide a function comparable with ileorectal anastomosis with a technical difficulty similar to that of the abdominal pouch. All patients with FP or UC who require colectomy are candidates for IAA unless they are 60 years or older. For UC a three stage surgical procedure of IAA proceeded by open rectal excluding colectomy could improve the result.(ABSTRACT TRUNCATED AT 250 WORDS)
Response of the cervical sympathetic activity (CSA) to acute hypoxemia was studied in dogs in the absence and in the presence of either halothane (H), enflurane (E), isoflurane (I) or sevoflurane (S). Multifiber potentials of CSA, EEG, heart rate (HR), arterial blood pressure (ABP) and arterial oxygen saturation (SaO2) were continuously monitored. CSA increased responding to acutely induced hypoxemia at a speed of -6 - 9% (SaO2).min-1. The response of CSA was estimated in two ways as a function of SaO2: The threshold was determined at the SaO2 level where CSA increased by 3% over the basal level and the gain was determined by the slope of CSA increase divided by the SaO2 span. They were 92% and -1.88 in the absence of volatile anesthetics, respectively. The threshold and the gain decreased markedly in the presence of various concentrations of volatile anesthetics. They were 89.2% and -1.16; 81% and -0.74; 84.2% and -1.16 and 86.2% and -0.94 with 1 MAC of H, E, I and S, respectively. The depressant effects of volatile anesthetics on the CSA responses to acutely induced hypoxemia can cause depressed control of the autonomic nervous system against hypoxemia and conceal the manifestation of clinical signs of hypoxemia.
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Auto-oxidation of human adult hemoglobin and Siphonosoma cumanense and Lingula unguis hemerythrins were investigated in the presence and absence of perturbants. In the presence of urea, there were no drastic increases in auto-oxidation rates for the three proteins. In contrast, thiocyanate and laurate enhanced the auto-oxidation rates remarkably. In the presence of thiol reagents such as PCMB and NEM, auto-oxidation rates were enhanced with dissociation into subunit, but not enhanced so much with SH-modification only. Thus oligomerization is probably necessary to protect auto-oxidation.
We investigated the properties of very low density lipoprotein (VLDL) from two types of Watanabe heritable hyperlipidemic (WHHL) rabbits: one with a high incidence of coronary atherosclerosis (type 1), and the other with a low incidence (type 2). When incubated with mouse peritoneal macrophages, VLDL from type 1 WHHL rabbit (type 1-VLDL) stimulated cholesteryl ester synthesis 10.5-fold more than VLDL from the type 2 WHHL rabbit (type 2-VLDL) did. Moreover, a similar difference was seen in the stimulation of cholesteryl ester synthesis in peritoneal macrophages isolated from the WHHL rabbits. The mass ratios of cholesterol to protein in type 1- and type 2-VLDL were 5.69 and 2.05, respectively. Agarose gel electrophoresis of type 1-VLDL showed beta mobility, and that of type 2-VLDL showed pre-beta mobility. No difference was seen between the sizes of VLDL particles of the two types. The amount of apolipoprotein E in type 1-VLDL was greater than that in type 2-VLDL. In conclusion, the difference between type 1 and type 2 WHHL rabbits is at least partly due to the presence in type 1 animals of VLDL particles rich in cholesteryl esters and apolipoprotein E, particles which are very similar to beta-VLDL in conformation.