Biomedical subjects

K Yamane

Publications and source records attributed to K Yamane.

At least 253 records · Page 14Linked to original sources

PubMed1989

Modification of length, hydrophobic properties and electric charge of Bacillus subtilis alpha-amylase signal peptide and their different effects on the production of secretory proteins in B. subtilis and Escherichia coli cells.

Bacillus subtilis alpha-amylase signal peptide, which consists of 33 amino acids, is functional in Escherichia coli cells. Lysine, glutamic acid, leucine, leucyl-leucine, or leucyl-leucyl-leucine was inserted between positions 28 and 29 of the alpha-amylase signal peptide using site directed mutagenesis. DNAs encoding the wild-type and modified signal peptides were then fused in-frame to DNAs encoding the mature regions of the beta-lactamase of pBR322 and a thermostable alpha-amylase. The secretion of beta-lactamase in E. coli cells was more inhibited by the modified signal peptides than that in B. subtilis cells, although the degree of inhibition varied and the inhibitory effect of each signal peptide was found to be similar in the two strains. In contrast, the difference in the inhibitory effect of each modified signal peptide was no longer detected in the case of the production of thermostable alpha-amylase, except for the insertion of glutamic acid. Nearly 50% of thermostable alpha-amylase in the precursor form was accumulated in the intracellular fraction of E. coli cells containing the DNAs for the modified signal peptides. The insertion of glutamic acid inhibited the secretion of the two enzymes in both B. subtilis and E. coli cells.

Amino Acid Sequence↗

PubMed1989

Sporadic motor neuron disease with Lewy body-like hyaline inclusions.

Lewy body-like hyaline inclusions were immunocytochemically and electron microscopically investigated in a patient with sporadic motor neuron disease. The hyaline inclusions were chiefly observed within the perikarya of both normal-looking and chromatolytic anterior horn cells in the lumbar spinal cord, but some were detected in the axons and dendrites. Usually, a single inclusion was found in the perikaryon, but in rare cases two or more were observed. Immunocytochemically, these inclusions were intensely immunostained with anti-ubiquitin antibody. Ultrastructurally, the hyaline inclusions were chiefly composed of randomly arranged linear structures associated with ribosome-like granules, varying from compactly arranged linear densities to more loosely packed ones. They contained scattered vesicles of various sizes and occasionally a focal accumulation of randomly arranged 10-nm neurofilaments or 13-25-nm filamentous structures.

Aged↗

PubMed1989

Signal peptide of Bacillus subtilis alpha-amylase.

Mature alpha-amylase of Bacillus subtilis is known to be formed from its precursor by the removal of the NH2-terminal 41 amino acid sequence (41 amino acid leader sequence). DNA fragments coding for short sequences consisting of 28 (Pro as the COOH terminus) 29 (Ala), 31 (Ala), and 33 (Ala) amino acids from the translation initiator, Met, in the leader sequence were prepared and fused in frame to the DNA encoding the mature alpha-amylase. The secretion activity of the 33 amino acid sequence was nearly twice as high as that of the parental 41 amino acid sequence, whereas the activity of the 31 amino acid sequence was 75% of that of the parent. In contrast, almost no secretion activity was observed with the 28 and 29 amino acid sequences. The signal peptide cleavage site of the precursor expressed from the plasmid encoding the 33 amino acid sequence was located between Ala and Leu at positions 33 and 34 and that from the 31 amino acid sequence between Thr and Ala at positions 33 and 34. The NH2-terminal amino acid from the latter corresponded to the 3rd amino acid of the mature enzyme. These results indicated that the functional signal peptide of the B. subtilis beta-amylase consists of the first 33 amino acids from the initiator, Met.

Amino Acid Sequence↗

PubMed1989

Interferon-gamma modulates messenger RNA levels of c-sis (PDGF-B chain), PDGF-A chain, and IL-1 beta genes in human vascular endothelial cells.

The authors have investigated the effects of cytokines and lipopolysaccharide (LPS) on mRNA levels of c-sis (platelet-derived growth factor (PDGF)-B chain), PDGF-A chain, and interleukin 1 beta (IL-1 beta) genes in human vascular endothelial cells (EC). IL-1, tumor necrosis factor (TNF), and LPS not only enhanced the accumulation of c-sis mRNA, but also induced IL-1 beta gene expression. Interferon-gamma (IFN-gamma), in contrast, suppressed the accumulation of c-sis mRNA profoundly and PDGF-A chain mRNA to a lesser extent. The cytokine, in addition, suppressed the release of PDGF-like proteins by EC, while maintaining the growth of EC. IFN-gamma, however, augmented the levels of IL-1 beta mRNA in cultured EC in association with LPS or IL-1, suggesting that the suppression of c-sis expression was not mediated through modulation of IL-1 gene expression by IFN-gamma. These results raise the possibility that IFN-gamma may play a novel regulatory role in the pathogenesis of vascular diseases such as atherosclerosis and vasculitis.

Cells, Cultured↗

PubMed1989

[A case of recurrent Epstein-Barr virus meningitis].

A 17-year-old male was admitted to our hospital complaining of fever, headache and nausea. On physical examinations cervical and inguinal lymphadenopathy and hepatosplenomegaly were noted. Neurological examination revealed meningeal signs. Blood examination showed slightly increased lymphocytes and atypical lymphocytes (1-4%), increased ESR, CRP (2+), slightly elevated EBV VCA IgG (X20), and normal EBV VCA IgM (less than X 10). Initial pressure of CSF was 195mmH2O, cells 46/3mm3, protein 50mg/dl. Slowing of back ground activity of EEG such as theta and delta wave was noted. CT scan revealed normal. During the course EBV VCA IgG elevated to X160, EBV VCA IgM elevated to X20. Slight respiratory disturbance, photophobia, and dysosmia were noted. One month later, clinical symptoms and laboratory data improved, the patient was discharged. Forty days after the discharge, headache was excerbated and increased CSF protein (100mg/dl) and pleocytosis (33/3mm3) were noted. The patient was readmitted to the hospital. After 2 weeks in the hospital, symptoms were diminished and laboratory findings revealed normal. During 2 years before the third admission he was asymptomatic and could enjoy the college life. At age 19, he was admitted to our hospital complaining of fever, headache and nausea. Neurologically slight meningeal irritation was noted. Blood examination revealed 1% atypical lymphocytes. EBV VCA IgG was elevated (X320) and EBNA was X80. CSF protein was slightly increased (52mg/dl). During the clinical course CSF protein was elevated to 105mg/dl and cell count to 502/3mm3 (N: L = 27: 409, with 66 atypical lymphocytes). Persistent hiccup was noted. After 50 days CSF findings were improved and he was discharged.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

[Therapeutic embolization for bilateral renal angiomyolipomas with spontaneous rupture--a case report].

A 64-year-old woman of bilateral renal angiomyolipomas with spontaneous rupture, not associated with tuberous sclerosis was reported. Superselective embolization for tumors using ethanol was successfully performed, preserving normal renal function. Transcatheter embolization was considered the treatment of first choice for the urgent circumstances with spontaneous rupture.

Embolization, Therapeutic↗

PubMed1989

[Progress in laboratory tests of connective tissue diseases].

The presence of serum autoantibodies to nuclear antigens (ANA) and other antigens is a hallmark of connective tissue diseases. Antibodies to double-strand DNA were present in high titers in SLE patients. Antibodies to U1RNP correlated with Raynaud's phenomenon and finger erythema in SLE patients. Anticardiolipin antibody was present in 29% of 41 SLE patients. Antibody to Scl-70 was present in 52% of 21 PSS patients. Antibody to Jo-1 was present in patients with PM associated with pulmonary fibrosis. Two of our patients with PM had an autoantibody that precipitated 7SL RNA.

Autoantibodies↗

PubMed1989

[Clinical evaluation of SPECT in cerebrovascular disease].

In 131 patients with cerebrovascular disease, regional cerebral blood flow was determined by 123I-IMP (N-isopropyl (123I)-iodoamphetamine) or 99mTc-HM-PAO (99mTc (d, l)-hexamethyl propyleneamine oxime) SPECT and findings were compared with those of X-CT or MRI. The perfusion deficit detected by SPECT was larger than the deficit by X-CT or MRI in every cases. The perfusion deficit area was more clearly demonstrated by SPECT than by X-CT or MRI in patients with acute cerebral infarction. The hypoperfusion area determined by 123I-IMP SPECT was wider than that by 99mTc-HM-PAO SPECT. The crossed cerebellar diaschisis was observed in 56 out of 131 cases (43%). The results of operation were quantitatively evaluated by 123I-IMP SPECT in 25 patients.

Aged↗

PubMed1989

[Basilar artery migraine associated with transient global amnesia].

Transient global amnesia (TGA) is an unusual form of the amnestic syndrome, clinically characterized by profound disturbance of short-term memory with preservation of immediate recall and long-term memory. Spontaneous recovery is the rule and is usually complete within several hours. The etiology of TGA is not clear. It is considered to be caused by transient ischemia confined to the medial temporal lobe, an area supplied by branches of the vertebrobasilar system. Basilar artery migraine is a well-known syndrome, first described by Bickerstaff. Besides pulsating headache, the dominant symptoms are vertigo, ataxic gait, tinnitus, dysarthria, paraeshesia in the hands, homonymous hemianopsia and sometimes drop-attacks. These symptoms are associated with vertebrobasilar system dysfunction. In this paper, three migraine patients, suffering from one episode of TGA, were reported. All patients were women. Case 1 was a 48-year-old woman with a history of common migraine. Case 2 was a 48-year-old woman with a history of classic migraine. Case 3 was a 59-year-old woman with a common migraine. Family history of migraine exists in case 1 and case 3. Their migrainous attacks began in their twenties and thirties. They suddenly suffered migraine with the symptoms of vertebrobasilar dysfunction. These symptoms are ataxic gait (Case 1, 2, 3), dysarthria (Case 1, 2), vertigo (Case 1, 3) and homonymous hemianopsia (Case 1, 3). Simultaneously three patients had TGA. Duration of retrograde amnesia were about twenty-four hours (Case 1), about thirty minutes (Case 2) and about three hours (Case 3).(ABSTRACT TRUNCATED AT 250 WORDS)

Amnesia↗

PubMed1989

[Experimental focal cerebral ischemia produced by embolization with silicone cylinder in normotensive (NTR) and spontaneously hypertensive rats (SHR): comparison of neurological and pathological findings].

A focal cerebral ischemic model was produced by occlusion of the intracranial main cerebral artery with a silicone cylinder in normotensive (NTR) and spontaneously hypertensive rats (SHR). Main cerebral artery could be successfully occluded in approximately 90%. The most frequent embolized site was the distal part of the internal cerebral artery (ICb) and less frequently the horizontal segment of the anterior cerebral artery (Al). Mortality rate of NTR with ICb occlusion (NTR-ICb) was 43% at 72 hours after embolization and that of SHR with ICb occlusion (SHR-ICb) was 67% at 24 hours after embolization. NTR-ICb showed neurological signs (i.e. circling movement, hemiparesis, poor response to pain stimuli) and histologically, showed infarction in the deep cerebral structures (i.e. thalamus, hypothalamus, hippocampus, and internal capsule) accompanied with mild disruption of blood-brain barrier (BBB). SHR-ICb showed more serious neurological signs and more severe cerebral infarction in the deep cerebral structures with severe disruption of BBB. In SHR-ICb, ischemic cerebral edema was more prominent which may deteriorate symptoms and pathological findings compared to NTR-ICb. This embolization model is proposed to be useful for studying the pathophysiology of focal cerebral ischemia, especially, early ischemic edema.

Animals↗

PubMed1989

[Clinical studies and sputum levels of ceftriaxone once daily administration in respiratory tract infection].

Ceftriaxone (CTRX), a new cephalosporin, was investigated by once daily administration for its clinical efficacy and safety on respiratory tract infections. The results obtained are summarized as follows: 1. Clinical responses to CTRX of a total of 39 cases with respiratory tract infections were excellent in 12 cases, good in 23, fair in 3, poor in 1 with an efficacy rate of 89.7%. Against acute bronchitis, lung abscess, bronchiectasis, chronic bronchitis and obstructive pneumonia, efficacy rates were 100%. 2. Serum levels and urinary excretion rates of CTRX were investigated in 2 cases after intravenous drip infusion of the drug at doses of 1 g and 2 g, respectively. Although urinary excretion rate tended to decrease with the deterioration of renal functions, prolongation of serum half-life was slight in those patients with normal liver function. In 1 case, it remained at 1.9 micrograms/ml at 12 hours and in another at 0.9 microgram/ml at 22 hours in sputum. According to the results, it appears that once daily administration of CTRX is effective and well tolerated in patients with acute respiratory infections.

Adult↗

PubMed1989

[Comparison of two dimensional and three dimensional CBF measurements in stroke patients].

The purpose of this study is to compare the detectability of the reduction in cerebral blood flow (CBF) using the two versus the three dimensional technique of CBF measurement. Both techniques were simultaneously carried out 85 times on 52 stroke patients. In the two dimensional technique, CBF was measured by the Xe-133 inhalation method and the value was calculated by the initial slope index. In the three dimensional technique, CBF was measured by single photon emission CT with Xe-133 inhalation method. CBF reduction was studied in the middle cerebral artery (MCA) territory on a CBF map in both techniques. Additionally, mean CBF was also calculated for the same territory. On the CBF map, the CBF reduction was shown in 25 of 85 measurements with the two dimensional technique and in 41 of 85 with the three dimensional technique. In comparing the imagings of both techniques, the CBF reduction seen extensively along the cortical surface and in the entire MCA territory with the three dimensional technique was also detected with the two dimensional technique. However, focal CBF reduction observed at the cortical surface and in the deep cerebral tissue with the three dimensional technique was not detected with the two dimensional technique. In order to evaluate both techniques quantitatively, we calculated the ratio of the mean CBF difference between the MCA territories of both hemispheres to mean CBF in the non-affected MCA territory. This ratio represented the asymmetry index. Firstly, the relationship between asymmetry index and the imaging of CBF reduction on the CBF map was studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗

PubMed1988

Introduction of basic amino acid residues after the signal peptide inhibits protein translocation across the cytoplasmic membrane of Escherichia coli. Relation to the orientation of membrane proteins.

The introduction of positive charges at the amino terminus of the mature domain of secretory proteins resulted in strong inhibition of their translocation across the cytoplasmic membrane of Escherichia coli, both in vitro and in vivo. The model secretory proteins used were OmpF-Lpp chimeric proteins possessing a cleavable or uncleavable signal peptide, beta-lactamase (Bla) and Bla-Lpp chimeric proteins. It is suggested that positively charged residues preceding the hydrophobic domain of the signal peptide have a positive effect, and ones following the hydrophobic domain, a negative effect on the translocation. These findings are discussed in relation to the orientation of membrane proteins, of which positive charges are predominant on the cytoplasmic surface.

Amino Acid Sequence↗

PubMed1988

NH2-terminal processing of Bacillus subtilis alpha-amylase.

Mature alpha-amylase of Bacillus subtilis is known to be formed from its precursor by removal of the NH2-terminal 41-amino acid sequence. To study the mechanism of this processing, the extracellular forms of alpha-amylase were analyzed for B. subtilis N7 alpha-amylase cloned and expressed in B. subtilis. The major form (form N34) isolated from log phase cultures in L-broth had an NH2 terminus corresponding to position 34 from the initiator Met but appeared to be microheterogeneous, as judged by native gel electrophoresis. The major forms from stationary phase cultures had NH2 termini at positions 40 (form N40) or 42 (form N42) and were homogeneous. The conversion of the larger to smaller forms could be achieved in culture supernatants or partially purified samples. The process N34----N40 was inhibited by EDTA; N40----N42 was facilitated by Ca2+. Phenylmethylsulfonyl fluoride inhibited the former but not the latter process. These results suggest that the signal peptidase cleavage site 30 decreases 35 is -Ala-Ala-Ala-Ser-Ala-Glu-Thr- (arrow or further upstream) and that proteolytic maturation occurs after secretion, which involves at least two different processing enzymes.

Amino Acid Sequence↗

PubMed1988

Efficient in vitro translocation into Escherichia coli membrane vesicles of a protein carrying an uncleavable signal peptide. Characterization of the translocation process.

The translocation into Escherichia coli cytoplasmic membrane vesicles of a protein containing an uncleavable signal peptide was studied. The signal peptide cleavage site of the ompF-lpp chimeric protein, a model secretory protein, was changed from Ala-Ala to Phe-Pro through oligonucleotide-directed site-specific mutagenesis of the ompF-lpp gene on a plasmid. The mutant protein was no longer processed by the signal peptidase. When proteinase K treatment was adopted as a probe for protein translocation into inverted membrane vesicles, the mutant protein exhibited rapid and almost complete translocation, most likely due to the lack of premature cleavage of the signal peptide before the translocation. This result also indicates that cleavage of the signal peptide is not required for translocation of the mature domain of the protein. The establishment of an efficient system made it possible to perform precise and quantitative analysis of the translocation process. The translocation was time-dependent, vesicle-dependent, and required ATP and NADH. Translocation into membrane vesicles was also observed with the uncleavable precursor protein purified by means of immunoaffinity chromatography, although the efficiency was appreciably low. The translocation required only ATP and NADH. Addition of the cytosolic fraction did not enhance the translocation.

Adenosine Triphosphate↗

PubMed1988

Nucleotide sequence of the maltohexaose-producing amylase gene from an alkalophilic Bacillus sp. #707 and structural similarity to liquefying type alpha-amylases.

The nucleotide sequence of the gene for maltohexaose-producing amylase from an alkalophilic Bacillus sp. #707 was determined. Starting at an ATG initiation codon, an open reading frame was composed of 1554 bp (518 amino acids). The NH2-terminal portion encoded a 33 amino acid-long signal peptide. The deduced amino acid sequence of the extracellular mature enzyme was more than 60% homologous to those of the liquefying type alpha-amylases but not to those of the saccharifying type alpha-amylases. The sequence of its signal peptide was completely different from those of other alpha-amylases.

Amino Acid Sequence↗

PubMed1988

Enhanced secretion of beta-lactamase on structural modification of the Bacillus subtilis alpha-amylase signal peptide.

Prediction of the secondary structure, a sequence of 33 amino acids, for the Bacillus subtilis alpha-amylase signal peptide suggested the presence of a beta-turn structure in it. Through substitution of Gly27 and/or Pro28 with Ala residues by means of the site-directed mutagenesis method, the secondary structure was predicted to consist of an alpha-helix conformation throughout the signal peptide containing a small region of random coil. The effect of the structural modification upon the secretion of proteins was analyzed as to the production of beta-lactamase after the DNA regions encoding the parental and modified signal peptides had been fused in frame to the DNA fragment for the beta-lactamase using HindIII linker DNA. The production of beta-lactamase increased to 4 to 6 times in B. subtilis cells and to 1.5 to 2.0 times in Escherichia coli with the modified signal peptides. The modification of the signal peptide affected the transcription level of the fused genes.

Amino Acid Sequence↗

PubMed1988

Generation of intracellular active oxygens in mouse FM3A cells by 3-hydroxyamino-1-methyl-5H-pyrido[4,3-b]indole, the activated Trp-P-2.

Mouse FM3A cells in culture were treated with a reactive metabolite of 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), 3-hydroxyamino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2-(NHOH]. When the treated cells, which were judged as viable on the basis of trypan-blue exclusion, were subjected to nitroblue tetrazolium staining, formazan was formed inside the cells, a fact suggesting the intracellular presence of superoxide. No formazan formation was detected on treatment of the cells with Trp-P-2. Single-strand breaks in the cellular DNA took place during this treatment with Trp-P-2(NHOH). Since Trp-P-2(NHOH) in solution generates superoxide anion accompanying its oxidative degradation, we conclude that the Trp-P-2(NHOH) treatment produces intracellular active oxygens that can damage DNA.

Animals↗