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Biomedical subjects

T Kikuchi

Publications and source records attributed to T Kikuchi.

At least 631 records · Page 35Linked to original sources
PubMed1986

[CT findings in acute spinal epidural hematoma caused by a ruptured cavernous angioma].

A case of acute spinal epidural hematoma due to the rupture of cavernous angioma is reported. A 68-year-old man was admitted to our hospital with a complaint of hematoemesis. After the successful treatment of bleeding from a gastric ulcer by using endoscopical method, he noticed severe motor weakness in his lower extremities. Complete paraparesis of his lower limbs, total sensory loss below the level of fifth thoracic vertebrae, and bladder disturbance were revealed on neurological examination. A metrizamide myelogram showed complete block at the level of fourth thoracic vertebrae. A computed tomography (CT) scan disclosed a dorsolateral heterogeneous high density area (92 Hounsfield Unit) on the right with displacement of the spinal cord to the left, extending from the level of second to fifth thoracic vertebrae. He was operated thirty hours after the onset. After the laminectomy, an epidural hematoma covering over the dural sac was recognized. Following the removal of the hematoma, a hemorrhagic mass was disclosed and removed successfully. A pathological examination revealed cavernous angioma. His symptoms improved partially in three months after the operation. There have been thirteen cases of non-traumatic spinal epidural hematoma which had been diagnosed by CT scan, as far as we are aware. Although only four cases out of 13 were diagnosed without using any contrast materials, we stress that the spinal epidural hematoma can be diagnosed only by plain CT scan because of its characteristic clinical feature, attenuation coefficient, and mass effect to the spinal cord.

Aged↗
PubMed1985

Amidase-like activity of calpain I and calpain II on substance P and its related peptides.

Porcine calpains (Ca2+-dependent cysteine proteinases) I and II, which had been purified each to a homogeneous state, were found to hydrolyze specifically carboxyl-terminal amide of substance P and several other biologically active peptidyl amides. This amidase-like activity was demonstrated both by determining released ammonia and by separating products on high-performance liquid chromatography followed by amino acid analysis. The calpain-catalyzed deamidation of substance P occurred exclusively at the carboxyl-terminal amide, leaving the side-chain glutamine intact. Enkepharinamide and MSH-release inhibiting factor were scarcely deamidated. Calpains I and II showed similar specificities for these amide substances and similar profiles of inhibitions by various protease inhibitors, but distinctly different Ca2+ requirements. The specificity constants, kcat/Km, for substance P were found to be three to four orders of magnitude higher than those for the synthetic substrates.

Amino Acid Sequence↗
PubMed1985

Quantification of picogram levels of specific DNA immobilized in microtiter wells.

A non-radioisotopic and sensitive method for quantification of specific DNA immobilized in microtiter wells has been developed. This method is based upon the immobilization of DNA in microtiter wells and hybridization with biotinylated DNA probe which is followed by complexing with avidin-beta-galactosidase. By measuring fluorescence emitted from the hydrolyzed product by beta-galactosidase of 4-methylumbelliferyl-beta-D-galactoside, it has become possible to quantify a few picograms of specific DNA in DNA samples immobilized in plastic microtiter wells.

Avidin↗
PubMed1985

Lysis of platelets and erythrocytes by the incorporation of a unique oxygenated sterol: 22R-hydroxycholesterol.

We have found that an oxygenated sterol, 22R-hydroxycholesterol [(22R)-5-cholestene-3 beta, 22-diol], lyses not only platelets but also erythrocytes in a dose-dependent manner. The lysis of platelets and erythrocytes were evidenced by the release of intracellular proteins, lactate dehydrogenase and hemoglobin, respectively. Their morphological change was shown by scanning electron microscopy. Elevated temperature was required for the lysis, probably to redistribute the sterol in the lipid bilayers in the plasma membranes. When the sterol was incorporated at low temperature, the temperature had to be raised to readily lyse cells. This lytic effect was, surprisingly enough, restricted to the R-isomer; the S-isomer was only marginally effective. Furthermore, sitosterol and other oxygenated sterols, with a hydroxyl group at different positions in the side chain of cholesterol, were much less lytic, regardless of the configuration of the hydroxyl group introduced. A possible mechanism for this interesting phenomenon will be discussed in relation with a structural alteration in lipid bilayers in plasma membranes brought about by the incorporation of this unique oxygenated sterol.

Animals↗
PubMed1985

Isolation and characterization of a lethal hemolysin in the sea anemone Parasicyonis actinostoloides.

Four species of sea anemones in the coastal waters of Japan were surveyed for hemolysins. Powerful hemolysins were detected in Parasicyonis actinostoloides and Anthopleura japonica, whereas extracts of A. fuscoviridis showed much weaker hemolytic activity and those of of Haliplanella luciae no activity. Among the animal erythrocytes tested sheep were most sensitive to the hemolysins of the three positive species. The major hemolysin (parasitoxin) in whole bodies of P. actinostoloides was isolated by ion exchange chromatography, gel filtration and chromatofocusing. In addition to hemolytic activity (119900 HU/mg) it exhibited lethal activity in mice (LD50 65 micrograms/kg, i.v.) and fish Oryzias latipes (approximate minimum lethal concentration 1.5 micrograms/ml). Parasitoxin was slightly basic (pI 7.9) in nature and its amino acid composition was characterized by the absence of half-cystine. The molecular weight was 19,000 by SDS-polyacrylamide gel electrophoresis or 17,000 by sedimentation equilibrium, indicating that parasitoxin has no subunit structure.

Amino Acids↗
PubMed1985

Detection of tetrodotoxin-like compounds in two species of puffer fishes (Lagocephalus lunaris lunaris and Fugu niphobles).

The toxins in the muscle, skin and liver of the puffer fish Lagocephalus lunaris lunaris and those in the skin and liver of another puffer fish Fugu niphobles were purified by successive column chromatography on activated charcoal, Bio-Gel P-2 and Bio-Rex 70 and analyzed by electrophoresis and thin layer chromatography. Although, regardless of the tissues and species, tetrodotoxin was predominant and accounted for more than 90% of the total toxins, the following minor toxins were newly detected; toxin A and toxin B in L. lunaris lunaris and toxin C in F. niphobles. Since these minor toxins, like tetrodotoxin, were positive to the Weber reagent and 10% KOH, but negative to 1% H2O2, they were assumed to be tetrodotoxin-like compounds. Interestingly, the electrophoretic and thin layer chromatographic analyses showed that toxin A and toxin C are probably identical with AFT3 and AFT1, the minor toxins in the crab Atergatis floridus from Chiba, Japan, respectively.

Animals↗
PubMed1985

A putative Ca2+-binding protein: structure of the light subunit of porcine calpain elucidated by molecular cloning and protein sequence analysis.

cDNA clones specific for the light subunit of porcine calpain I have been isolated from a porcine kidney cDNA library. The complete primary structure of the light subunit has been revealed by nucleotide sequence analysis of the cDNA clones isolated and amino acid sequence analysis of peptides isolated from the purified mature protein. We found that the light subunit contains two distinct domains. Domain I, the amino-terminal half, has two unusually long, paired polyglycyl sequences and may serve as a binding site to the heavy subunit. Domain II, the carboxyl-terminal half, is a region highly homologous to the putative Ca2+-binding domain of the heavy subunit of chicken calpain elucidated recently. This region has four potential Ca2+-binding sites, each having the "E-F hand" structure. Our results suggest that the Ca2+-mediated proteolytic activity of calpain is controlled through the cooperative and/or sequential actions of multiple Ca2+-binding sites present in both two-subunit molecules, heavy and light subunits of calpain.

Amino Acid Sequence↗
PubMed1985

Lymphomatoid granulomatosis. Light microscopic, electron microscopic and immunohistochemical study.

A case of lymphomatoid granulomatosis (LYG) involving the lungs, skin, stomach, and possibly the left kidney in a 60-year-old man is presented. The infiltrates in the lungs, stomach, and skin showed a polymorphic appearance, and consisted predominantly of lymphocytes of mature and blastic form and of a few neutrophils, plasma cells, and histiocytes. Most lymphoid cells showed irregularly shaped nuclei and clustered dense bodies, characteristics indicative of T lymphocytes. An immunohistochemical study confirmed the T cell origin of the lymphocytes; i.e. they were positive for Leu-1, Leu-3a and Ia-like antigens but negative for Leu-2a antigen and the antibodies against light chains. The homogeneity of the major population of infiltrates in LYG indicates that at least some forms of LYG may be neoplastic or pre-neoplastic lymphocytic disorders which may ultimately progress to malignant lymphoma.

Antigens, Surface↗
PubMed1985

Expression of receptors for Fc portion of IgM (Fc mu . R) and surface neuraminic acid on the human peripheral lymphocytes.

The purpose of this investigation is to establish a method of quantitation of sialic acid on the lymphocyte membrane surface and to clarify the importance of sialic acid in the functional manifestation of the lymphocyte receptor for the Fc portion of IgM (Fc mu . R) as well as the cell surface. The experiments yielded results leading to the following conclusions: Cell surface sialic acid can be exclusively recovered at consistent rates by treatment of lymphocytes with 0.1 IU of neuraminidase in the presence of Ca++ at 37 degrees C for 30 min. The sialic acid obtained, though in minute quantities, was accurately quantitated by the TBA method. By these procedures, the amount of sialic acid present on the cell membrane of human peripheral blood lymphocytes was determined to be 2.46 micrograms/10(7). Surface sialic acid on lymphocytes cultured at 37 degrees C after treatment with neuraminidase was resynthesized sufficiently at about 6 hr. On the cell membrane of lymphocytes deprived of Fc mu . R by treatment with neuraminidase, the receptor for IgM Fc became redetectable following incubation of the cells at 37 degrees C; the time-course of redevelopment of Fc mu . R showed a striking coincidence with that of sialic acid resynthesis. A sufficient redevelopment of Fc mu . R occurred in 6 hr of incubation of neuraminidase-treated Fc mu . R-deprived lymphocytes; the time required for sufficient redevelopment was comparable to that reported for pronase-treated lymphocytes. It is concluded from these findings that Fc mu . R deprived of sialic acid is no longer repaired while the receptor is resynthesized de novo on incubation of lymphocytes under adequate conditions.

Cell Membrane↗
PubMed1985

[A clinical study on testicular tumor].

The 19 cases of testicular tumors treated at our Hospital between 1974 and 1983, were reviewed retrospectively. The incidence of testicular tumors among the male outpatients in our urologic clinic was 0.31%. The patients ranged in age from 1 to 76 years old (average: 27.8 years old). The affected side was the left side in 11 and the right side in 8 cases. The most frequent symptom was a painless mass of the testis. Histopathological diagnosis according to the classification by Dixon and Moore was type I in 9 cases, type II in 4 cases, type II in 1 case, type IV in 4 cases. Thus germinal tumors accounted for 18 (94.7%) of the cases. One case (5.3%) of malignant lymphoma was non-germinal. As for the age distribution, two peaks were noted in testicular tumors, especially in cases with potential embryonal carcinoma, between 1 and 2 years and between 19 and 32 years. On the other hand, the cases with potential seminoma showed one peak between 25 and 44 years. The treatment consisted of high orchiectomy alone, orchiectomy with radiation, orchiectomy with chemotherapy or orchiectomy with radiation and chemotherapy. Retroperitoneal lymphadenectomy was not done in any case. The over-all 3-year and 5-year actual survival rates were both 92%.

Adolescent↗
PubMed1985

[Preoperative combination therapy involving local administration of a non-specific immunoactivated preparation (OK-432) and chemotherapeutic preparations for patients with stomach cancer].

OMF therapy, which is a combination therapy consisting of OK-432 administered locally, Mitomycin C and 5-Fluorouracil, was administered to 50 cases of stomach cancer (52 episodes) preoperatively. Judging the criterion for a positive (+) effect as being the existence of degeneration or necrosis in 1/3-1/2 of carcinomas visible within whole fields, the ratio of histological effectiveness shown by this therapy was 75%. As for its effect on metastatic foci of lymph nodes, when 70 case from an n1 group and 8 from an n2 group with metastatic positive lymph nodes, including 17 cases (4 in Stage II and 13 in Stage III) ablated for curing were studied, a greater than positive (+) effect was shown in 51 out of the total of 78. Consequently the effective ratio was 65%. The survival ratio of 16 cases in Stage III on the 48th month calculated by the Kaplan Meier method was 78.6%. The survival time of 50% of 9 cases in Stage IV (absolute non-curing ablation) was 15 months. Tissue samples were examined constantly after local administration of OK-432. Exudation of neutrocytes was shown on the 1st day, and that of histiocytes, lymphocytes and plasmacytes on the 4th day. At this stage, degeneration of the primary focus or necrotizing change was observed. Interstitial reaction peaked on the 14th day, but histiocytes tended to decrease.

Adult↗