Biomedical subjects
Publications and source records attributed to M Hashimoto.
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From 1990 to 1999, 19 patients underwent aortic root replacement. Annulo-aortic ectasia was observed in 14 patients, aortic dissection in 4, and aortitis in 1. Mean aortic cross-clamp times and cardiopulmonary bypass times were 163 +/- 44 and 247 +/- 99 min, respectively. Concomitant procedures were coronary artery bypass grafting in 3 patients, aortic arch replacement in 1 and aortic arch replacement and elephant trunk method in 2. There were two hospital deaths due to cardiac failure. There was one late death because of pharyngeal cancer 1.7 years after the operation. Seventeen survivors were followed for a mean duration of 4.4 years (0.6-9.3 years). There were no complications during this period. In conclusion, good results were obtained by modified Bentall operation.
BACKGROUND: A minimizing immunosuppression after a tracheal allotransplantation is desirable. METHODS: We examined the usefulness of a short-course of immunosuppression after tracheal allotransplantation in rat. Each transplant consisting of a 5-ring segment was heterotopically implanted into the omentum. Four animals underwent a syngeneic transplantation and thus served as controls (Group A). Thirty animals underwent an allogeneic transplantation and were randomly classified into 4 groups as follows: No immunosuppression (Group B, n=6), treatment with 0.5 mg/kg of Tacrolims (FK506) (Group C, n=8), 1.0 mg/kg of FK506 (Group D, n=8), and 1.5 mg/kg of FK506 (Group E, n=8). Different doses of FK506 were administered intramuscularly for only three consecutive days after heterotopic tracheal allotransplantation. The serum levels of FK506 were then investigated 3, 7, 14, 21, and 28 days after transplantation in groups C, D, and E. All rats were killed 28 days after transplantation and then the implanted tracheae were harvested, and evaluated histologically. RESULTS: All animals survived for the protocol period. The graft morphology of Group E was significantly better than that of groups B, C, and D regarding both macro- and microscopy, and also showed the same findings as that of Group A, except for low-grade mononuclear cell infiltration. Only in Group E, the FK506 blood level was maintained at over 0.5 ng/ml, which is the lowest detectable limit in this assay, until 21 days after transplantation. CONCLUSIONS: We thus conclude that 1.5 mg/kg of FK506 which was administered for only three consecutive days after surgery may be used to maintain the morphology of tracheal allografts in rats for 28 days after transplantation.
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A new endoscopic classification of reflux esophagitis was proposed in Los Angeles in 1994(LA classification). A mucosal break was defined as 'an area of slough or an area of erythema with a discrete lined demarcation from the adjacent or normal looking mucosa'. Reflux esophagitis is divided into four grades according to the severity of its mucosal break. We can find a minimal change during endoscopy which is not a mucosal break but is histologically or chromographically reflux esophagitis. I think Los Angeles classification must include the minimal change and I propose a modification of LA classification which includes the minimal change as grade M and the esophagus without any minimal change and mucosal break as grade N.
A 43-year-old man was admitted to our hospital because of hemophagocytic syndrome (HPS) in August, 1998. A CT scan, gallium scintigraphy, gastrofiberscopy and colonofiberscopy showed no evidence of malignant lymphoma. Virus-associated HPS was suspected because of an increased titer of anti-Epstein-Barr (EB) virus antibody (EBV VCA IgG 2,560x, EBV EA IgG 40x, EBNA 20x). The HPS resolved spontaneously for 40 hospital days, but two weeks into the period of HPS remission, the patient developed pain and marked swelling of the right thigh muscle, and pectoral, biceps brachii, quadriceps femoralis and masseter muscles. Otherwise, CT scan and gallium scintigraphy showed no abnormal findings. A biopsy of the right quadriceps femoralis muscle revealed non-Hodgkin's lymphoma with muscle infiltration. Immunohistologic examination confirmed T-cell type (CD3, CD43, CD45, CD45RO) lymphoma, and Southern blot analysis for T-cell receptor revealed a rearranged band. The lymphoma cells were negative for EBV genome monoclonality. The patient responded well to CHOP therapy and achieved a complete remission. This is considered a very rare case of T-cell lymphoma infiltrating multiple skeletal muscles following an episode of hemophagocytic syndrome.
PURPOSE: The purpose of this study was to investigate the resource based relative values of visiting nursing services, and to analyze the relationships between the relative values and the dimensions of nursing service(time, mental effort and physical effort). METHODS: We interviewed nurses at 20 Home-visit nursing care stations (HVNCS) in the Metropolitan area using the resource based relative value questionnaires. We asked nurses about relative values of "Total Work", and also measured relative weight of 3 dimensions of nursing services. Total Work was defined as comprehensive evaluation of nursing services, with careful consideration of intensity as well as duration. With the dependent variable as Total Work and independent variables as the 3 dimensions, multiple regression analyses were carried out. Furthermore we examined the degree of influence on Total Work by service type and individual respondent. To examine the validity of the results, we timed nursing services and compared the measured time with the answered time. RESULTS: The 107 respondents were all female and their average age was 36.6 years old. They had HVNCS experience of 2.2 years and 95.3% nurses had experience of hospital nursing. "Total Work" and 3 dimension scores were standardized using common logarithms. "Total Work" of every service significantly differed among service types. The 3 dimensions explained 54.6% of Total Work in the multiple regression analysis. Service type explained 3.3% of Total Work. Individual respondent explained 16.0% of Total Work. Answered time and measured time were not significantly different with nursing services. CONCLUSIONS: Although Total Work was somewhat influenced by individual respondent, most of variation was explained by 3 dimensions. Thus, it could be concluded that Total Work is an index of nursing resource input. A further investigation about influence of patients' condition on Total Work is necessary in the future.
The p53 tumor suppressor gene is an important target for the gene therapy of cancers, and clinical trials targeting this gene have been conducted. Some cancers, however, are refractory to p53 gene therapy. Therefore, it has been combined with other therapies, including chemotherapy and radiotherapy, to enhance the cytopathic effect of p53 induction. The p33ING1 gene cooperates with p53 to block cell proliferation. In this study, we investigated whether adenovirus (Adv)-mediated coinduction of p33ING1 and p53 enhances apoptosis in glioma cells (U251 and U-373 MG), which showed no genetic alterations but low expression levels of p33ING1. Although the single infection of Adv for p33ING1 (Adv-p33) at a multiplicity of infection (MOI) of 100, or Adv for p53 controlled by myelin basic protein (MBP) promoter (Adv-MBP-p53), a glioma-specific promoter, at a MOI of 50, did not induce apoptosis in U251 and U-373 MG glioma cells; coinfection of Adv-p33 and Adv-MBP-p53 at the same MOIs induced drastically enhanced apoptosis in both cell lines. Apoptosis was not induced in NGF-treated PC-12 cells infected with a high MOI (300) of Adv-p33 nor in those coinfected with Adv-p33 (100) and Adv-MBP-p53 (50). Coinfection of Adv-p33 and Adv-MBP-p53 demonstrated morphological mitochondrial damage during the initial stage of apoptosis, which likely led to apoptotic cell death. Our results indicate that this coinfection approach can be used as a modality for the gene therapy of gliomas, sparing damage to normal tissues.
A transition metal-hydroperoxo species is formed by the oxygenation of a low-valent rhodium precursor followed by a protonation of the resulting eta(2)-O(2) ligand; the latter process is assisted by an intramolecular hydrogen-bonding interaction (see scheme). This process is the first structural evidence for an effective method for the activation of molecular oxygen as postulated for the cytochrome P-450 system.
alpha-Synuclein is a major component of aggregates forming amyloid-like fibrils in diseases with Lewy bodies and other neurodegenerative disorders, yet the mechanism by which alpha-synuclein is intracellularly aggregated during neurodegeneration is poorly understood. Recent studies suggest that oxidative stress reactions might contribute to abnormal aggregation of this molecule. In this context, the main objective of the present study was to determine the potential role of the heme protein cytochrome c in alpha-synuclein aggregation. When recombinant alpha-synuclein was coincubated with cytochrome c/hydrogen peroxide, alpha-synuclein was concomitantly induced to be aggregated. This process was blocked by antioxidant agents such as N-acetyl-L-cysteine. Hemin/hydrogen peroxide similarly induced aggregation of alpha-synuclein, and both cytochrome c/hydrogen peroxide- and hemin/hydrogen peroxide-induced aggregation of alpha-synuclein was partially inhibited by treatment with iron chelator deferoxisamine. This indicates that iron-catalyzed oxidative reaction mediated by cytochrome c/hydrogen peroxide might be critically involved in promoting alpha-synuclein aggregation. Furthermore, double labeling studies for cytochrome c/alpha-synuclein showed that they were colocalized in Lewy bodies of patients with Parkinson's disease. Taken together, these results suggest that cytochrome c, a well known electron transfer, and mediator of apoptotic cell death may be involved in the oxidative stress-induced aggregation of alpha-synuclein in Parkinson's disease and related disorders.
We have previously reported that the majority of base substitution mutations of the Escherichia coli supF gene induced by riboflavin mediated photosensitization were G:C to C:G changes, in addition to G:C to T:A changes which were probably caused by 8-hydroxyguanine (oh(8)Gua), in wild type and mutM mutator mutant strains. This implies that lesions other than oh(8)Gua are produced by riboflavin-photosensitization. G:C to C:G base substitutions have been found in the mutations induced by ionizing radiation and reactive oxygen species, as well as spontaneous mutation. To characterize the G:C to C:G mutation, riboflavin- photosensitized plasmid DNA carrying the supF gene was left at room temperature for 5 h in the dark before transfection. The delayed transfection gave a mutational spectrum different from that for immediate transfection. G:C to C:G transversions significantly increased in mutY mutator strain, in which the transversion was not detected in the immediate transfection. Lesions causing G:C to C:G changes increased during 5-h holding after photosensitization and MutY protein presumably takes part in this type of base change mutation.
The mitochondrial ADP/ATP carrier (AAC) is believed to function as a dimer. To characterize the oligomeric state of the yeast type 2 AAC (yAAC2), we tried to express its tandem-repeated homodimer, in which the C-terminus of the first repeat was fused to the N-terminus of the second repeat, in yeast mitochondria. The tandem dimer was expressed in the mitochondrial membrane at the same level as that of yAAC2, being inserted into the mitochondrial membrane as in yAAC2, and it showed very similar transport activity to that of yAAC2. It was suggested that the two carrier molecules in a dimeric form are located in the membrane facing each other in the same orientation.
This paper describes the relationship of a canine calicivirus, named No.48, to other human and animal caliciviruses, based on phylogeny of the 3' half of its genome. It was found that No.48 constitutes a unique lineage, most closely related but distinct from feline and San Miguel sea lion caliciviruses.
Pyothorax-associated lymphoma (PAL) is an Epstein-Barr virus (EBV) latent antigen-positive lymphoma resembling EBV-transformed lymphoblastoid cell lines (LCLs) and develops in non-immunocompromised patients. Thus, deficient anti-viral-antigen immune responses might be involved in the development of PAL. As MHC class I-restricted cytotoxic T lymphocytes (CTLs) are the major constituent of anti-viral immune responses, the HLA allele type and its expression may affect the development of PAL. Flow-cytometric analyses of PAL cell lines and LCLs using the W6/32 monoclonal antibody revealed that expression of HLA class I varied among cell lines. Although one PAL cell line, OPL-2, exhibited low expression, an LCL and another PAL cell line, OPL-1, strongly expressed HLA class I. Among the EBV latent infection genes, EBV nuclear antigens 2, 3, 4 and 6 and latent membrane proteins can induce efficient CTL responses in combination with HLA-A2 or -A11. HLA-A alleles of PAL patients were determined using low-resolution PCR-based typing with HLA-A locus sequence-specific primer combinations. The antigen frequencies of HLA-A2 and -A11 in PAL patients were not significantly different from those in the normal Japanese population. Although HLA class I antigen should be expressed during the course of lymphomagenesis, no HLA-A alleles influenced the development of overt PALs.
Chemiluminescence detection was combined with capillary isoelectric focusing to perform protein analysis with high sensitivity. Luminol-H2O2 chemiluminescence was utilized, and heme proteins such as cytochrome c, myoglobin and peroxidase were analyzed. The proteins were focused by use of Pharmalyte 3-10 as ampholytes. Hydroxypropylmethyl-cellulose was added to the sample solution in order to easily reduce protein interactions with the capillary wall as well as the electroendoosmotic flow. The focused proteins were transported by salt mobilization to chemiluminescence detection cell equipped with an optical fiber. The present method showed significantly high sensitivity and wide dynamic range; the detection limit for cytochrome c was 6 x 10(-9) M and the linear dynamic range was greater than two-orders of magnitude (up to 2 x 10(-6) M).
[formula: see text] The conformation of the retinal chromophore in rhodopsin is central for understanding the visual transduction process. The absolute twist around the 12-s bond of the chromophore in rhodopsin has been determined by studies with 11-cis-locked 11,12-cyclopropylretinal analogues (11S,12R)-2 and (11R,12S)-3, enantioselectively synthesized with the aid of an enzyme. The finding that enantiomer 2 binds to opsin while the other 3 does not defines the absolute sense of twist around the 12-s bond.