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K Oda

Publications and source records attributed to K Oda.

At least 397 records · Page 22Linked to original sources
PubMed1992

[Fundamental and clinical studies of homologous immunoglobulin-free priming in cardiopulmonary bypass, with special reference to anaphylatoxin production].

In in-vitro study, human immunoglobulin (Ig) denatured by O2 bubbling markedly produced C4a, C3a, and C5a, whereas human albumin treated identically did not. White blood cells (WBC) treated by O2 bubbling significantly increased C3a levels alone, but at a much lesser grade than the Ig. A new priming method, i.e., homologous concentrated red cell (CRC) and human albumin was discerned from the experimental facts in-vitro, and we investigated the clinical effects of that priming method. C4a, C3a and C5a in BOG primed with homologous whole blood (HWB) were slightly higher than those in MOG during CPB. Those in the Ig-free priming group were more mildly increased than those in the HWB priming group, not only during CPB, but also after protamine administration; this tendency was clearer in BOG. It is concluded that (1) human immunoglobulin (Ig) denatured by O2 bubbling produces anaphylatoxins via the classical pathway; (2) WBC treated identically produces C3a at a far milder grade; (3) priming with CRC and human albumin reduces plasma anaphylatoxin levels; and (4) pulmonary function at an early postoperative period was improved in the homologous Ig-free priming group, especially with BOG.

Albumins↗
PubMed1991

Sequence requirements for proteolytic cleavage of precursors with paired basic amino acids.

When expressed in COS cells, human prorenin was secreted into the medium without being processed to an active renin. Co-expression of furin, a mammalian homologue of the yeast KEX2 gene product, did not affect proteolytic processing of prorenin. A mutant proreninR-4 constructed by site-directed mutagenesis of Pro (-4) to Arg was not cleaved by an endoprotease in the COS cell. However, proreninR-4 was detectably cleaved to yield the active renin upon co-transfection with furin DNA, indicating that Arg at position -4 is important for recognition and processing by furin in addition to the absolute requirement for paired basic amino acids. Another mutant precursor in which Leu (+1) of proreninR-4 was replaced with Ser was found to be much more efficiently processed than proreninR-4, regardless of co-expression of furin. The results suggest that not only a basic amino acid at position -4 but also Leu at position +1 significantly affect the processing of prorenin catalyzed by the COS cell endoprotease or furin.

Amino Acid Sequence↗
PubMed1991

Functional expression of furin demonstrating its intracellular localization and endoprotease activity for processing of proalbumin and complement pro-C3.

We have cloned a rat cDNA encoding furin which is structurally related to yeast Kex2 protease. Products of 88 and 94 kDa were obtained by in vitro transcription/translation of the cDNA in the absence and presence of microsomes. When the cDNA was transfected into COS-1 cells, furin was expressed as a major glycosylated form of 94 kDa, accompanied by a minor proteolytic form of 86 kDa, and found to be localized in the Golgi complex. Proalbumin and complement pro-C3 are intracellularly processed into their mature forms by cleavage at the dibasic residues Arg-Arg, a common cleavage signal found in many pro-type precursors. In cells transfected with the cDNA of C3 or albumin alone, only about half of each proform expressed was processed by an endogenous activity of the cells. When furin was coexpressed, the proforms of both C3 and albumin were completely processed into their mature forms. In addition, co-expression of rat alpha 1-protease inhibitor mutant (Met352----Arg) resulted in inhibition of the endogenous and exogenous processing activities, as observed for the naturally occurring mutant Pittsburgh which has been identified as a specific inhibitor for the processing enzyme. Taken together, these results indicate that furin is an endoprotease localized to the Golgi complex and capable of processing proalbumin and pro-C3 into the mature forms.

Amino Acid Sequence↗
PubMed1991

Cooperative effect of antisense-Rb and antisense-p53 oligomers on the extension of life span in human diploid fibroblasts, TIG-1.

Normal human diploid fibroblasts, TIG-1, which have a replicative life span of about 62 population doublings (PD), tended to senesce after about 50 PD with a gradual decrease in sensitivity to serum. Treatment of TIG-1 cells with the antisense-Rb oligomer, which completely depleted the retinoblastoma susceptibility gene product (RB), extended life span by about 10 PD. Treatment with the antisense-p53 oligomer alone had no effect; however, cotreatment with the antisense-Rb oligomer further potentiated the extension and the increased sensitivity to serum caused by the antisense-Rb oligomer alone, suggesting that p53 and RB function in separate, yet complementary pathways in signal transduction to senescence. The c-fos expression, which is presumed to be regulated negatively by RB, was not stimulated in partially senescent TIG-1 cells by treatment with the antisense-Rb oligomer.

Base Sequence↗
PubMed1991

Interaction of nuclear factors with the regulatory region of the N-myc gene during differentiation of human embryonal carcinoma cells.

The human embryonal carcinoma cell line, NEC14, can be induced to differentiate by the addition of 10(-2) M N,N'-hexamethylene-bis-acetamide (HMBA). During the early stage of HMBA-induced differentiation, the level of N-myc expression decreased steeply and transiently, and then quickly returned to its original level after reaching a minimal level at 18 h after addition of HMBA. Nuclear run-on experiments indicated that this transient decrease is regulated at the transcription start point. To investigate the mechanism of this down-regulation, the 5'-flanking region of the human N-myc gene was cloned and sequenced. Computer analysis of the sequence revealed high homology with the 5'-flanking region of the mouse N-myc gene, especially (greater than 80%) in the region of nt positions -1777 to -1732, nt positions -763 to -501 and nt positions -260 to + 1. The patterns of protein binding to the upstream region during the early stage of NEC14 cell differentiation were analyzed by gel retardation assay. The DNA fragments VIII and X, containing the sequences of nt positions -1437 to -1237 and nt positions -1863 to -1710, respectively, formed the DNA-protein complexes which were greatly reduced in quantity in the cell extract prepared 18 h after the addition of HMBA. This reduction, however, was not observed with an extract similarly prepared from the NEC14 derivative cell line, H10, expressing the N-myc gene constitutively. These results suggest a causal connection between the complex formation and the high-level transcription of the N-myc gene.

Acetamides↗
PubMed1991

Bafilomycin A1 inhibits the targeting of lysosomal acid hydrolases in cultured hepatocytes.

Effects of bafilomycin A1, an inhibitor of vacuolar H(+)-ATPase, on the synthesis and processing of cathepsin D and cathepsin H were investigated in primary cultured rat hepatocytes. Pulse-chase experiments showed that after being synthesized as procathepsin D and procathepsin H the precursors were converted into mature forms in the control cells as the chase time elapsed. However, in the presence of 5 x 10(-7) M of bafilomycin A1, both precursors were largely secreted into the medium and no mature forms were found within the cells. Thus bafilomycin A1 mimics lysosomotropic amines with regard to perturbation of the targeting of lysosomal acid hydrolases. In contrast, bafilomycin A1 was found not to inhibit processings of proalbumin and procomplement component 3, which are thought to occur at the acidic trans-Golgi, implying that the proteolytic event of the proproteins is not sensitive to an increase of intra-Golgi pH. The results suggest that bafilomycin A1 is useful as a pH-perturbant to study the role of acidity in living cells.

Animals↗
PubMed1991

Meningeal involvement in Bence Jones multiple myeloma.

A case of Bence Jones kappa multiple myeloma with meningeal involvement in a 64-year-old woman is presented. Three years after the diagnosis of multiple myeloma, gait disturbances developed followed by visual disorders and impaired consciousness. A lumbar puncture revealed numerous atypical plasma cells in the cerebrospinal fluid. Craniospinal irradiation and intrathecal injections of methotrexate, cytarabine, and prednisolone were effective for a short period. At autopsy, the leptomeninges were infiltrated diffusely with atypical plasma cells. A review of the literature showed that multiple myeloma with meningeal involvement is accompanied frequently by circulating atypical plasma cells or plasma cell leukemia. Meningeal involvement is a rare complication and shows poor prognosis in cases of multiple myeloma.

Female↗
PubMed1991

Selective processing of proalbumin determined by site-specific mutagenesis.

Rat proalbumin is cleaved at the dibasic pair Arg-Arg and converted into a mature form with Glu at the NH2 terminus. In the present study site-directed mutagenesis of the albumin cDNA was designed to generate proalbumin variants in which Glu1 was substituted with various amino acid residues. The expression plasmids constructed were transfected into COS-1 cells, and the intracellular processing of proalbumins expressed was examined by labeling experiments. Substitution of Glu1----Ser allowed the expressed proalbumin to be processed as observed for the wild-type precursor. However, replacement of Glu1 with a hydrophobic residue (Val, Leu or Ile) resulted in no processing of proalbumin, despite retaining the same cleavage signal Arg-Arg as above. The results indicate that the residue at position 1 adjacent to the dibasic pair is also important for recognition by the proalbumin-processing enzyme.

Amino Acid Sequence↗
PubMed1991

CO2 laser-induced pain-related somatosensory evoked potentials in peripheral neuropathies: correlation between electrophysiological and histopathological findings.

Pain-related somatosensory evoked potentials (pain SEPs) following CO2 laser stimulation as well as conventional electrically stimulated SEPs (electric SEPs) were examined in 10 patients with peripheral neuropathies in whom the histopathological examination of the sural nerve was done. Results of pain SEPs showed a positive relationship with clinical impairment of pain sensation and densities of small myelinated fibers of the sural nerve. In contrast, results of electric SEPs showed a positive relationship with clinical impairment of deep and tactile sensations and with densities of large myelinated fibers of the sural nerve. Therefore, pain SEPs are considered to be generated by ascending signals mediated through nociceptive receptors and A delta fibers. The pain SEP is only one noninvasive and objective method currently available to investigate a physiological condition of the sensory pathway responsible for pain sense, and is especially useful when combined with the conventional electric SEPs.

Adolescent↗
PubMed1991

High level expression of isocitrate lyase gene of n-alkane-utilizing yeast Candida tropicalis in Saccharomyces cerevisiae.

The genomic DNA of peroxisomal isocitrate lyase (ICL) isolated from an n-alkane-assimilating yeast, Candida tropicalis, was truncated to utilize the original open reading frame under the control of the GAL7 promoter and was expressed in Saccharomyces cerevisiae. The recombinant ICL was synthesized as a functionally active enzyme with a specific activity similar to the enzyme purified from C. tropicalis, and was accounted for approximately 30% of the total extractable proteins in the yeast cells. This recombinant enzyme was easily purified to homogeneity. N-Terminal amino acid sequence, molecular masses of native form and subunit, amino acid composition, peptide maps, and kinetic parameters of the recombinant ICL were essentially the same as those of ICL purified from C. tropicalis. From these facts, S. cerevisiae was suggested to be an excellent micro-organism to highly express the genes encoding peroxisomal proteins of C. tropicalis.

Amino Acid Sequence↗
PubMed1991

Human renin activation by protease from the renin granule fraction of the dog kidney cortex.

To clarify the possible conversion of prorenin in renin granules where conversion reportedly occurred, we investigated whether the renin granule fraction of the kidney could activate prorenin to the active form. Renin granules were isolated from the dog kidney cortex by discontinuous sucrose density gradient centrifugation. Human active renin was quantified by immunoradiometric assay which could detect only the human active renin but not the inactive human renin or dog renin. Inactive renin from human amniotic fluid was incubated with the subcellular fraction of the dog kidney cortex. The renin granule fraction that showed the highest renin activity stimulated the inactive renin to become the active form. The membrane preparation obtained from the renin granule fraction by freezing and thawing the fraction in low osmolarity retained the activity of renin activation. Other subcellular fractions showed less renin activation. The optimal pH for renin activation by the membrane was pH 5.0 to 6.0. The activation depended on the time of incubation and concentration. The activation was inhibited by N-ethylmaleimide but not by EDTA or serine protease inhibitors. These results suggest that renin is processed by a membrane bound protease in renin granules.

Amniotic Fluid↗
PubMed1991

Immunohistochemical studies of chromogranins (A and C) in pituitary adenomas.

Expression of Chromogranin A and C was examined immunohistochemically on 45 surgically obtained pituitary adenomas. Positive rate of chromogranin A was 40.0% and chromogranin C was positive in 8.0% of 45 pituitary adenomas. Chromogranin A was expressed frequently in adenomas in which at least one of the FSH alpha, FSH beta, LH beta and TSH beta subunits was positive. It also expressed frequently in non-functioning adenomas. The positive rate of chromogranin A was low in GH or PRL positive adenomas. These findings suggest that chromogranin could be a parameter of the functional differentiation of the pituitary adenomas.

Adenoma↗
PubMed1991

Changes in motoneuron excitability during postnatal life in the mouse.

H-reflex recovery, H-amplitude and H/M ratio were recorded in 54 mice aged 3-12 weeks to study the motoneuron excitability and changes in it during various stages of development. The H-reflex recovery curve at 12 wk showed 3 phases: an early, relative facilitation (before 10 ms), an almost total inhibition at 10 ms and a rapid recovery thereafter. At 3 wk, however, there was only slow recovery after 10 ms and the H-reflex recovery was significantly low during the 40-100 ms period as compared to those in the other age groups, indicating that between 3 and 6 wk, there was a significant increase in the motoneuron excitability. The H-reflex amplitude also showed a significant increase during the 3-6 wk period. However, the H/M ratio did not show any significant increase either during the 3-6 wk period or thereafter. It is concluded that the H-reflex recovery at 3 wk suggests hypoexcitability of the motoneurons, possibly due to immaturity. Since there was a significant increase in the H-reflex recovery during the 3-6 wk period without any parallel increase in the H/M ratio, it is concluded that presynaptic and polysynaptic mechanisms acting on the motoneurons develop during this period. The increase in the H-reflex amplitude is possibly due to the increase in the muscle mass. The H-reflex recovery pattern at 12 wk, without the phase of late inhibition observed in man, is suggestive of less supra-spinal control mechanisms acting upon the motoneurons.

Animals↗
PubMed1991

Subtractive cDNA cloning using oligo(dT)30-latex and PCR: isolation of cDNA clones specific to undifferentiated human embryonal carcinoma cells.

The human embryonal carcinoma cell line NEC14 can be induced to differentiate by the addition of 10(-2)M N,N'-hexamethylene-bis-acetamide (HMBA). A subtractive cDNA library specific to undifferentiated NEC14 cells was constructed using oligo(dT)30-Latex and polymerase chain reaction (PCR). The method was designed to improve the efficiency of subtraction and the enrichment of cDNA clones corresponding to low abundance mRNAs. The single strand of cDNA was made from mRNA prepared from the HMBA-treated NEC14 cells using an oligo(dT)30 primer covalently linked to Latex particles. After removal of the mRNA template by heat-denaturation and centrifugation, the subtractive hybridization was carried out between the cDNA-oligo(dT)30-Latex and mRNA from untreated NEC14 cells. Unhybridized mRNA collected by centrifugation was hybridized repeatedly to the cDNA-oligo(dT)30-Latex and subtractive mRNA was converted to cDNA. The subtractive cDNA was then amplified by PCR and cloned into pBluescript II KS-. The cDNA library thus constructed consisted of approximately 10,000 independent clones with cDNA inserts of 1.7 Kb on average. Differential hybridization of these transformants indicated that approximately 3% of them contained cDNA inserts specific to the undifferentiated EC cells, some of which were derived from low abundance mRNAs.

Acetamides↗
PubMed1991

Growth complementation of influenza virus temperature-sensitive mutants in mouse cells which express the RNA polymerase and nucleoprotein genes.

In order to establish cell lines which complement the growth of temperature-sensitive (ts) mutants of influenza virus, three RNA polymerase and nucleoprotein (NP) genes each linked to the mouse mammary tumor virus LTR were cloned into the bovine papillomavirus vector DNA. After co-transfection of mouse C127 cells with these recombinant plasmids, a cell line, clone 76, in which the expression of the three polymerase and NP genes could be stimulated by dexamethasone, was established. The clone 76 cells could complement the growth of ts-mutants defective in one of the polymerase subunit genes at the nonpermissive temperature in response to dexamethasone. The results suggest that the simultaneous expression of the three polymerase genes in the same compartment of protein synthesis machinery is required for an efficient complementation of ts-mutant growth.

Animals↗
PubMed1991

A transient decrease in N-myc expression and its biological role during differentiation of human embryonal carcinoma cells.

The human embryonal carcinoma (EC) cell line, NEC14 can be induced to morphologically differentiate by the addition of 10(-2) M N,N'-hexamethylene-bis-acetamide (HMBA) in vitro. The expression of several cellular oncogenes (c-onc) in NEC14 cells was examined after induction of differentiation by HMBA. The level of N-myc expression was the highest in undifferentiated cells but decreased transiently to less than 1/10 of the original level shortly after the induction of differentiation. To investigate the role of the transient decrease in N-myc level on NEC14 cell differentiation, a chimeric human N-myc gene in which transcription is initiated at the human beta-actin gene promoter was constructed and introduced into NEC14 cells. Several transformants expressing the exogenous N-myc gene constitutively were established. These transformants showed 10- to 70-fold increases in plating efficiency and shorter population doubling times as compared with the parental NEC14 cells. The transformants were hard to induce, spontaneously differentiated cells on the periphery of cell clusters in culture, unlike parental NEC14 cells, and took longer for HMBA-induced morphological differentiation. The populations of the cells expressing HLA and SSEA-1 antigens increased from 10%-20% to nearly 100% in NEC14 cells after the induction of differentiation, while the populations expressing these antigens increased only to 50%-60% in one of the transformants, S11. The transformants gained an increased tumorigenic potential in nude mice, and the tumors produced consisted exclusively of EC stem cells. These results suggest that the additional expression of the exogenous N-myc gene (increased about two-fold) confers the more transformed state on the cells.

Antigens, Surface↗
PubMed1991

[Alpha-hemolytic streptococcal septicemia and meningitis in immunocompromised children].

Many kinds of microorganisms can produce toxic septicemia in immunocompromised hosts. We are reporting alpha-hemolytic streptococcal septicemia and meningitis in two children with hematological malignancies. [Case 1] 6 year old girl who had been suffering from acute lymphocytic leukemia. She had sepsis and bacterial meningitis in maintenance-therapy for leukemia. Streptococcus sanguis was isolated from the blood and cerebrospinal fluid (CSF). [Case 2] 11 year old girl who had had malignant lymphoma (non-Hodgkin type). She also had sepsis and bacterial meningitis due to Streptococcus mitis which was isolated from blood and CSF in maintenance-therapy. Both cases had been treated with anti-cancer drugs and had severe granulocytopenia. Positive rate of blood cultures during the recent 6 years (1984.1-1989.12) at our department was 6.0% (total number of cultures were 2,019, positive cultures were 121). Strains of 131 bacteria were determined; Gram-positive cocci were 70 strains (53.4%) and Gram-negative rods were 52 strains (39.7%). Fifteen strains (11.5%) of alpha-hemolytic Streptococci were isolated during 6 years. One hundred thirteen cases of septicemia were analysed in medical charts and 12 cases of alpha-hemolytic streptococcal septicemia were observed (5 cases with infective endocarditis and 7 cases in immunocompromised states).

Child↗