Biomedical subjects
Publications and source records attributed to M Maeda.
The case of an 8-month-old boy with aortic dissection caused by intraaortic balloon pumping is reported. The balloon was inserted during an operation for the anomalous origin of the left coronary artery. It is important to realize the potential risk of aortic dissection even in infants and to select an appropriately sized balloon. Modification of the balloon for use in infants is necessary.
A 35-year-old woman with clinical features of Budd-Chiari syndrome is presented. Abdominal ultrasonography, computed tomography, and venography disclosed that the venous congestion in this patient resulted from complex venous anomalies including azygos-hemiazygos continuation, absent superior hepatic veins, and retroaortic transposition of the left renal vein.
Pseudocyst formation is a well-known complication of acute or chronic pancreatitis. We report a case in which pseudocyst ruptured into the splenic and portal veins.
We present a patient with hepatocellular carcinoma accompanied by portal vein and bile duct tumor thrombi. The patient was treated with a spiral Z-stent covered by a polyethylene sheet placed in the bile duct, a Wallstent placed in the portal vein, chemoembolization, and external radiation therapy. The patient is alive with patency of both endoprostheses 18 months later.
PURPOSE: To evaluate the efficacy of antithrombotic agents in the prevention of stenosis of polytetrafluoroethylene (PTFE)-covered stents in the venous system. METHODS: Spiral Z stents covered with PTFE (PTFE-covered stents) were placed in the inferior vena cava (IVC) of 34 dogs. Nineteen dogs, used as a control group, were sacrificed at 2, 4, and 12 weeks. Fifteen dogs, previously given antithrombotic agents [cilostazol (n = 5), warfarin potassium (n = 5), cilostazol plus warfarin potassium (n = 5)] were sacrificed at 4 weeks, and then examined angiographically and histopathologically. The effect of the antithrombotic agents was compared between groups. RESULTS: The patency rate of the antithrombotic agent group was 93% (14/15), which was higher than the control group rate of 63% (12/19). The mean stenosis rate of the patent stent at both ends and at the midportion was lower at 4 weeks in the antithrombotic agent group than in the control group. In particular, the mean stenosis rate in the cilostazol plus warfarin potassium group was significantly lower than the control group (Tukey's test, p < 0.05). The mean neointimal thickness of the patent stent at both ends and at the midportion was thinner at 4 weeks in the antithrombotic agent group than in the control group. In particular, the thickness of the neointima in the cilostazol plus warfarin potassium group was significantly decreased when compared with the control group (Tukey's test p < 0.05). At 4 weeks, endothelialization in the antithrombotic agent group tended to be almost identical to that in the control group. CONCLUSION: The present study suggests that administration of an antithrombotic agent is an effective way of preventing the stenosis induced by a neointimal thickening of PTFE-covered stents in the venous system.
We have developed a new computerized dispensing system which reduces the time needed to dispense medicines. This system is so designed to assist the pharmacist with various tasks. These include receiving prescriptions, dispensing of medicines, checking for accuracy, and payment. This system consists of automated dispensing devices, a tray-transfer line, a reception number indicator screen installed in the waiting room, and a terminal to provide patients with additional information. The prescription data are instantly transmitted to the respective dispensing positions and the prescriptions are dispensed simultaneously. The trays travel efficiently on the tray-transfer line. The host computer performs such functions as input of information of prescriptions, accounting calculations, integrating prescription audit, and preparation of printing data for medicine bags. The control computer, which receives prescription data from the host computer, sorts and sends instruction data on prescriptions to the automated dispensing machines, outputs instructions on the preparation of medicines in the manual dispensing sector, and controls the tray-transfer line, the turn tables and the reception number indicator screen. This computerized dispensing system has produced the following results: (1) improvement in the quality of the dispensing work; (2) reduction in the time required for dispensing medicines; (3) improvement in the quality of service to patients; (4) improvement in the efficiency of the clerical work in non-dispensing work; (5) improvement in work efficiency.
When a mixture of creatinine, glycine and glucose was heated for 2 h at 128 degrees C in diethylene glycol containing 14% water, two mutagens were formed. One of them, responsible for 90% of the mutagenicity, has already been identified as 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx). The other mutagen was purified and characterized. The UV absorption, mass and NMR spectra suggested that this mutagen was 2-amino-3,7,8-trimethylimidazo[4,5-f]quinoxaline (7,8-DiMeIQx). Comparison of the spectral properties of the compound obtained from the heated model mixture with those of synthetic material confirmed this structure. 7,8-DiMeIQx is a newly identified compound which, at a dose of 1 microgram, induced 163 000 and 9900 revertants of Salmonella typhimurium TA98 and TA100, respectively, with S9 mix.
Magnetic resonance imaging (MRI) was used in high-risk infants to assess the myelination process and its relationship with neurologic outcome. The time period when delayed myelination is best detected by MRI was also studied. MRI was performed in 39 high-risk infants (i.e., preterm infants, infants with respiratory distress syndrome, or with neonatal convulsions and asphyxia). In 10 of 11 infants with normal development, MRI revealed a normal myelination pattern before 2 months of age, and in 11 of 13 infants after 2 months of age. Conversely, in infants with poor outcomes, MRI demonstrated delayed myelination patterns in only 1 of 4 infants before 2 months of age but in 9 of 11 infants after 2 months of age. In patients with poor outcomes, delayed myelination was found more frequently after rather than before 2 months of age. These findings demonstrate that delayed myelination detected by MRI is useful in predicting the neurologic outcome of high-risk infants, especially after 2 months of age.
PURPOSE: To introduce myectomy of the lateral rectus muscle for correcting exotropia in patients with third nerve palsy. METHODS: The lateral rectus muscle of the paretic eye was myectomized without suturing it to the globe. This was combined with a medial rectus muscle resection and a contralateral lateral rectus muscle recession. Magnetic resonance imaging was performed to observe the re-attachment of the lateral rectus muscle to the globe. RESULTS: The patient was able to fuse in the primary position without any noticeable limitation in abduction. Magnetic resonance imaging showed that the lateral rectus muscle was attached to the globe through fibrous tissue. CONCLUSION: Myectomy of the lateral rectus muscle is an effective and simple procedure to accomplish a super-maximal weakening effect of abduction in patients with complete third nerve palsy.
PURPOSE: To investigate the prevalence of normal-tension glaucoma (NTG) and primary open-angle glaucoma (POAG) in patients with collagen diseases and determine whether an immunocompromised condition is present in a subset of glaucoma patients. METHODS: Three glaucoma specialists prospectively examined patients with collagen diseases. The diagnostic process included applanation tonometry, slit-lamp examination, gonioscopy, direct ophthalmoscopy, and automated static perimetry. Twenty-four-hour intraocular pressure monitoring was done when necessary. Using the results of a population-based survey conducted in Japan, we calculated an expected number of cases of NTG and POAG, and compared these with the actual number of cases. RESULTS: Of the 153 patients with collagen diseases examined, we found 6 patients with NTG and 2 patients with POAG. Of these 8 patients, 2 with progressive systemic sclerosis (PSS), one with NTG, and the other, POAG, had a history of being on systemic steroidal therapy. The prevalence of NTG and POAG was significantly higher in women patients having collagen diseases as compared with normal women (P = .027). CONCLUSION: Women patients with collagen diseases are highly susceptible to NTG and POAG.
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We have synthesized a vinyl monomer having a psoralen moiety, which can form a photoadduct with double-helical DNA. The monomer 1 was proved to have an ability to crosslink DNA double strands through a photochemical reaction when irradiated by UV light. The resulting DNA having vinyl groups was copolymerized with a comonomer such as acrylamide and N-isopropylacrylamide to give rise to a DNA-vinyl polymer conjugate. A conjugation based on covalent bondings was verified by using gel electrophoresis; the conjugation efficiency was found to be dependent upon concentration of the monomer which had been used in the antecedent photochemical reaction. This monomer will be a useful tool when anchoring double-helical DNA on polymeric materials for separating and sensing DNA-binding substances.
Poly(N-isopropylacrylamide) having a terminal psoralen group was synthesized and covalently bound to plasmid pBR 322 DNA through a photochemical reaction. The resulting conjugate exhibited temperature-responsive precipitation due to the aggregation of poly(N-isopropylacrylamide) chains when heated above 31 degreesC. This system was used for the one-pot separation of restriction endonuclease EcoRI.
The human interleukin-2 (IL-2) receptor was purified by affinity chromatography using the anti-Tac monoclonal antibody, and its N-terminal amino acid sequence was determined. Complementary DNA clones were isolated and sequenced to reveal the primary structure of the IL-2 receptor precursor, which has 272 amino acid residues. The receptor is separated into two domains by a putative 19-residue transmembrane region. Two mRNAs (1.4 and 3.5 kilobases) hybridizing to the cDNA clone were found in human T cells bearing the IL-2 receptor. The cDNA directed synthesis of the IL-2 receptor in COS cells.
Interleukin-2 (IL-2) in combination with the IL-2 receptor has an essential role in antigen-stimulated proliferation of T lymphocytes. It has been proposed that the constitutive expression of the IL-2 receptor on adult T-cell leukaemia (ATL) cells may be associated with transformation of T cells. Although we and others have isolated complementary DNA clones encoding a protein that binds IL-2, formal proof that this protein is the IL-2 receptor requires demonstration of IL-2-dependent growth stimulation of cells expressing the protein. In addition, a functional assay system other than binding of IL-2 is required to investigate the molecular mechanism of signal transmission through the IL-2 receptor using artificially mutated cDNA. The IL-2 receptor expressed in non-lymphoid cells by cDNA transfection did not mediate a growth signal, implying that lymphoid cells expressing the functional receptor might have specific accessory molecule(s) for signal transmission by the receptor. Therefore, we established a line of IL-2-dependent mouse cells (CT/hR) expressing both murine (endogenous) and human IL-2 receptors. Here, by blocking the endogenous mouse IL-2 receptors with monoclonal antibodies, we show that the human IL-2 receptor of CT/hR cells is functionally active. Although CT/hR expressed the human IL-2 receptor constitutively, growth of these cells was strictly dependent on IL-2, indicating that uncontrolled over-expression of the IL-2 receptor was not by itself sufficient for T-cell transformation.
CYP2A6 is the main enzyme that catalyzes nicotine into cotinine. Interindividual differences in nicotine metabolism result at least partially from polymorphic variation of CYP2A6 gene. In this study, we evaluated the influence of CYP2A6 polymorphisms on clinical phenotypes of smoking, such as smoking habit and withdrawal symptoms. Japanese smokers (n = 107) were genotyped for CYP2A6*1, *4 and *9. Consistent with the previous reports, CYP2A6 genotypes have a tendency to correlate with the number of cigarettes per day and with daily intake of nicotine. Interestingly, CYP2A6 high-activity group (CYP2A6*1/*1, *1/*9, *1/*4, *9/*9) smoked the first cigarette of the day earlier than low-activity group (CYP2A6*4/*9, *4/*4), indicating more remarkable nicotine dependence. Furthermore, nicotine withdrawal symptoms were more serious in smoking cessation in CYP2A6 high-activity group. Collectively, CYP2A6 genotypes are related with nicotine dependence, influencing smoking habits and withdrawal symptoms in quitting smoking. It is proposed that individualized smoking cessation program could be designed based on CYP2A6 genotypes.
With future exploration of macrophage properties in mind, we established a novel cell line (HS-P) from a transplantable histiocytic sarcoma, derived originally from a tumour in an aged F344 rat. HS-P was subjected to 70 serial passages, in which the mean doubling time was 15.7 h. The cells, which were round, oval or polygonal in shape, were arranged in a compact sheet. They reacted to varying degrees for lysosomal enzymes (acid phosphatase and non-specific esterase) and with the following antibodies: ED1/ED2 (rat macrophage/histiocyte-specific), OX6 (rat MHC class II-specific), lysozyme antibody and alpha1-antichymotrypsin antibody. Electron microscopically, HS-P cells showed lysosomes and prominent cell projections. These findings indicated that the cultured cells were macrophage-like. Syngeneic rats inoculated subcutaneously or intraperitoneally with HS-P cells invariably developed sarcomatous tumours consisting of monomorphic mononuclear cells, which exhibited cytochemical properties similar to those of cultured HS-P cells. Bioassay and reverse transcription-polymerase chain reaction methods revealed that tumour necrosis factor-alpha increased on addition of lipopolysaccharide (LPS), indicating that HS-P cells remained LPS-responsive. HS-P cells may prove to be a useful tool for in-vitro studies of macrophage function.
Transforming growth factor-beta1 (TGF-beta1) produced by infiltrating macrophages plays a role in fibrotic disorders through the induction of myofibroblasts. To explore possible mechanisms by which TGF-beta1 may act in this context, we investigated effects of TGF-beta1 on macrophage-like (HS-P) and myofibroblastic (MT-9) cells, two novel cell lines developed by us. Immunocytochemically, the addition of TGF-beta1 (0, 0.1, 0.5, and 1.0 ng/ml) dose-dependently suppressed the expressions of antigens recognized by macrophage/histiocyte-specific antibodies (ED1 and ED2) in HS-P cells, whereas the addition concomitantly increased the number of anti-alpha-smooth muscle actin antibody-positive myofibroblastic cells, suggesting a possible phenotypical modulation of macrophages into myofibroblasts in the fibrotic lesions. By contrast, MT-9 cells did not show such immunophenotypical changes following TGF-beta1 addition. DNA synthesis, measured by tritiated thymidine-incorporation, was inhibited in a dose-dependent manner in MT-9 cells by TGF-beta1 addition (0, 0.1, 0.2, 0.5, 1.0, 5, and 10 ng/ml), but that in HS-P cells was unchanged. Northern blot analysis revealed that expressions of cell cycle-related early genes, c-jun and c-myc, were increased in HS-P cells after TGF-beta1 (1 ng/ml) addition, with c-jun showing peak expression prior to c-myc. By contrast, the peak expressions of c-jun and c-myc were delayed in TGF-beta1 (1 ng/ml)-added MT-9 cells, and their levels were less in MT-9 cells than in HS-P cells. Furthermore, TGF-beta1 (1 and 10 ng/ml) induced DNA laddering in MT-9 cells, but did not in HS-P cells. Based on these findings, it was speculated that TGF-beta1 could have induced G1 arrest in cell cycle and apoptosis in MT-9 cells. The present study showed that there were significant differences in the effects of TGF-beta1 between macrophage-like HS-P cells and myofibroblastic MT-9 cells, presumably depending on divergent susceptibilities to TGF-beta1 between both cell types. Because such cell types are key cells in the fibrogenesis, HS-P and MT-9 might be useful models for investigating the pathogenesis of fibrosis in vitro.