[Vectorcardiographic autodiagnosis by ADALINE and (adaptive linear neuron) analysis of its characteristics].
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Biomedical subjects
Publications and source records attributed to T Sano.
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Lymph node (LN) dissection along the upper border of the pancreas is one of the essential parts of curative surgery for gastric cancer, and the distal portion of the pancreas was frequently resected for complete removal of LNs along the splenic artery. However, pancreatic juice leakage, subphrenic abscess, and postoperative diabetes were common complications in patients treated by pancreatic resection. To avoid these problems a new surgical procedure, the pancreas-preserving operation, was developed by Maruyama in 1979. We found that lymphatic channels from the stomach did not flow into the pancreas parenchyma, and that the spleen, splenic artery, and fatty connective tissue including nodes could be removed completely without dissection of the pancreas parenchyma and splenic vein. The preserved pancreas receives its arterial blood supply through the transverse pancreatic artery, and its preservation prevents postoperative diabetes. A total of 299 patients were treated by this procedure. The operative mortality rate was 0.3%, the hospital death rate 1.6%, and the surgical complications rate 19.6%. The cumulative 5-year survival rate for those with stage II was 70.5% and for those with stage III 54.1%. These results were superior to those of the pancreas resection group.
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A 14-year-old boy with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) is reported. He had suffered blepharoptosis and cataracts prior to the stroke-like episodes, and was thus reported in 1984 as having Kearns-Shy (Sayre) syndrome. After his death, an A-to-G mutation of the mitochondrial DNA (mtDNA) at bp 3243 was identified in cardiac muscle and the liver. Neuropathologically, multiple old and recent necrotic foci were observed in the gray and white matter of the cerebrum and cerebellum. These lesions were occasionally observed in areas outside of the distribution of major blood vessels of the brain. In the recent necrotic foci, neural loss and sponginess were observed while some neurons were preserved intact. The latter finding has not been described in MELAS and suggests that metabolic degeneration had occurred in the neurons of this patient. This is the first report of a confirmed 3243 mutation of the mtDNA in an autopsied MELAS case.
Successful mitral valve replacement for severe mitral regurgitation in a patient with mitochondrial encephalomyopathy is reported. Renal failure due to low cardiac output improved dramatically after mitral valve replacement and he was discharged 10 weeks after surgery. The surgical indication and timing for valvular dysfunction in patients with mitochondrial cardiomyopathy are discussed.
Consideration is now being given to the use of avidin (or streptavidin) and biotin for radiotherapy of tumor. Accordingly, the goal of this study was to radiolabel a mouse metallothionein-streptavidin fusion protein with 188Re and to compare its properties to those of the same fusion protein radiolabeled with 99mTc. A recombinant metallothionein-streptavidin fusion protein was radiolabeled by transchelation with 99mTc- and 188Re-glucoheptonate. Labeling efficiency, which was not optimized for either radionuclide, was approximately 60% for 99mTc and 20% for 188Re. Radiochemical purity was demonstrated by size exclusion HPLC both by nearly quantitative shifts of the 188Re label to higher molecular weight upon the addition of biotinylated antibody and by the absence of a shift with biotinsaturated 188Re-metallothionein-streptavidin. Stability of the labels in 37 degrees C serum was evaluated by comparing the HPLC radiochromatograms of serum samples both before and after the addition of biotinylated antibody. The 188Re label behaved like 99mTc in that the same peaks were evident, including one prominent peak due to labeled cysteine. Recoveries during HPLC analysis of serum samples showed that oxidation rates to perrhenate and pertechnetate were identical. However, instability to cysteine challenge was greater for 188Re; for example, the loss of label to cysteine after 24 h under one set of conditions was 41% for 188Re and 22% with 99mTc. Analysis by HPLC of liver and kidney homogenates from mice administered the labeled antibodies were qualitatively and, in large measure, quantitatively independent of label. Biodistributions at 5 h in normal mice were statistically identical between the two labels in blood and in most tissues. In conclusion, streptavidin may be radiolabeled with radiorhenium using recombinant mouse metallothionein as a bifunctional chelator, and under one set of labeling conditions at least, 188Re showed similar in vitro and in vivo behavior to that of 99mTc labeled to the same fusion protein.
A streptavidin mutant has been designed and produced that allows the specific, covalent immobilization of streptavidin on solid surfaces. This streptavidin mutant was constructed by fusing a six-residue sequence, containing a single cysteine, to the carboxyl terminus of streptavidin. Because this mutant has no other cysteine residues, the reactive sulfhydryl group of the cysteine residue serves as a unique immobilization site for conjugation using sulfhydryl chemistry. This streptavidin mutant was efficiently immobilized on maleimide-coated solid surfaces via its unique immobilization site. Characterization of the immobilized streptavidin mutant for the ability to bind to biotinylated macromolecules and the dissociation rates of bound biotin showed that the biotin-binding properties of this mutant were minimally affected by immobilization on solid surfaces. This streptavidin could be readily incorporated into a wide variety of solid-phase diagnostic tests and biomedical assays. This could enhance the performance of streptavidin-based solid-phase assay systems.
A boron-enriched streptavidin has been prepared by chemical conjugation of a boron-rich compound, B(12)H(11)SH(2)(-) (BSH), to a genetically engineered streptavidin variant. The streptavidin variant used has 20 cysteine residues per molecule, derived from a C-terminal cysteine stretch consisting of five cysteine residues per subunit. Because natural streptavidin has no cysteine residues, the reactive sulfhydryl groups of the cysteine stretch serve as unique conjugation sites for sulfhydryl chemistry. BSH was conjugated irreversibly to the sulfhydryl groups of the streptavidin variant via a sulfhydryl-specific homobifunctional chemical cross-linker. Quantitative boron analysis indicates that the resulting streptavidin-BSH conjugate carries approximately 230 boron atoms/molecule. This indicates that the chemical conjugation of BSH to the streptavidin variant was highly specific and efficient because this method should allow the conjugation of a maximum of 240 boron atoms/streptavidin molecule. This boron-enriched streptavidin retained both full biotin-binding ability and tetrameric structure, suggesting that the conjugation of BSH has little, if any, effect on the fundamental properties of streptavidin. This boron-enriched streptavidin should be very useful as a component of targetable boron carriers for neutron capture therapy of cancer. For example, a monoclonal antibody against a tumor-associated antigen can be attached tightly to the boron-enriched streptavidin upon simple biotinylation, and the resulting conjugate could be used to target boron to tumor cells on which the tumor-associated antigen is overexpressed.
A new type of 1-nitropyrene--DNA adduct via addition--elimination reaction was synthesized. Treatment of fluorinated 1-nitropyrene with 3'- and 5'-O-protected 2'-deoxyribonucleoside in dimethyl sulfoxide at 140 degrees C afforded N-(1-nitropyren-6-yl or 8-yl)-2'-deoxyribonucleoside. These DNA adducts resulted from addition of the exocyclic amino group of deoxynucleosides to the fluorinated carbon of the fluoro-1-nitropyrene following elimination of fluoride anion. This is the first report that describes the 1-nitropyrene-DNA adducts in which aromatic ring moiety of 1-nitropyrene is covalently linked to the exocyclic amino group of the deoxyribonucleoside. From our findings, we suggest that the addition-elimination reaction may be responsible for the formation mechanism of the putative 1-nitropyrene--DNA adducts in vivo.
The authors report a case of intracranial meningioma with granulofilamentous inclusions. A 50-year-old man had right trigeminal neuralgia due to trigeminal nerve compression by a petroclival tumor and received tumor resection. Microscopically, tumor cells containing eccentric nuclei and intracytoplasmic hyaline inclusions were arranged in sheets and whorls. The inclusions were negative for periodic acid-Schiff reaction. No histological anaplasia was seen. Immunohistochemistry showed epithelial membrane antigen reactivity on the cytoplasmic membrane. Immunoreactivity for vimentin was recognized in cytoplasm adjacent to inclusions. However, confocal laser microscopic study revealed immunoreactivity for vimentin even inside some inclusions. Ultrastructurally, interdigitation of cytoplasmic processes and desmosomes connecting adjacent cells were noted. Inclusions were composed of numerous fine osmiophilic granules attached by intermediates filaments. These findings were consistent with a meningioma with the granulofilamentous inclusions described earlier. The findings demonstrated by confocal laser microscopy and electron microscopy suggest that these granular materials may be the metabolic products of vimentin filaments.
This report concerns a 66-year-old man with a melanocytoma arising at the foramen magnum. Magnetic resonance imaging disclosed a well-circumscribed tumor extending from the medulla oblongata to C1 with gadolinium enhancement. A heavily pigmented tumor located under the leptomeninges was removed surgically. Although the patient died 8 months later of renal cell carcinoma, no recurrence or metastasis of the melanocytoma was detected by radiographic examination. Microscopically, the resected tumor was composed of polygonal to spindle-shaped cells containing large amounts of melanin. The bland nuclei of the tumor cells were of uniform size. No mitotic figures were seen. The tumor cells were positively immunostained for S-100 protein and by antibody HMB-45. They were not stained using the Ki-67 (MIB-1) antibody, indicating low proliferative activity. The ultrastructural examination revealed numerous mature melanosomes and basal laminae surrounding nests of cells. The tumor was diagnosed as a melanocytoma on the bases of its microscopic features and the lack of Ki-67 immunoreactivity. The ultrastructural and immunohistochemical features of melanocytomas are distinct from those of meningiomas. It is likely that melanocytomas and melanotic schwannomas represent opposite extremes of the continuous spectrum of neuroectodermal tumors derived from the neural crest.
A case of recurrent soft part sarcoma with focal areas showing epithelial differentiation in the right thigh in a 78-year-old woman is reported. The primary tumor consisted of myxoid areas and solid areas, in which relatively uniform epithelioid tumor cells were arranged in sheets, whereas pleomorphism and a storiform pattern appeared in the recurrent tumors. Thus this tumor was suspected to be a malignant fibrous histiocytoma. However, further studies showed unexpected ultrastructural and immunohistochemical features. Cytokeratin immunoreactivity and tonofilamentlike structures probably indicated epithelial differentiation of some tumor cells. From the clinical and histological findings, this tumor should be identified as a malignant fibrous histiocytoma with phenotypic expressions of epithelial cell.
Six malignant schwannomas were studied by electron microscopy and immunohistochemistry for S-100 protein at the light and electron microscopic levels to clarify the nature of the tumor cells. Three tumors (group A) were composed of poorly differentiated tumor cells and showed no immunoreactivity for S-100 protein. One tumor (group B) was composed of perineurial cells that were S-100 protein-negative. Two tumors (group C) consisted of both Schwann cells and fibroblastic cells like neurofibromas, and only the former were found to contain S-100 protein. Thus, this study showed the heterogeneous nature of the malignant schwannomas and suggested that these tumors might arise from multipotential Schwann cells or different cellular components of peripheral nerve or primitive cells.
Seven malignant fibrous histiocytomas containing myxoid areas were studied to clarify the nature of the cells constituting the myxoid area with emphasis on multivacuolated cells known to be present in myxoid areas. Ultrastructurally, myxoid areas were, like conventional cellular areas, composed mainly of atypical tumor cells, small histiocytic cells, and occasional lymphoid cells. The tumor cells had large, indented nuclei and well-developed organelles. They showed, despite some variations in subcellular structures, strong resemblance to fibroblast and could be attributable to one cell type. The large vacuoles in multivacuolated tumor cells seemed to be formed by fusion of small vacuoles that appeared in the cytoplasm and later came to communicate with the extracellular space. The small histiocytic cells, cytologically bland and, occasionally, being in contact with lymphoid cells, were readily distinguishable from the tumor cells and were considered to be infiltrating reactive cells.