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Biomedical subjects

I Yoshida

Publications and source records attributed to I Yoshida.

At least 73 records · Page 4Linked to original sources
PubMed1999

Chromosomal assignment of a novel human gene D40.

We have previously reported an identification of a novel human cellular factor, D40. Here, we report the chromosomal localization of the gene that encodes D40. Fluorescent in situ hybridization (FISH) was performed to determine the chromosomal region that D40 gene resides. The chromosomes that derived from normal adult male lymphocytes were hybridized with a mixture of cDNA probes that cover the entire coding region of D40. D40 gene mapped to the long arm of chromosome 15q14-15.

Adult↗
PubMed1999

Human subtilisin-like proprotein convertase, PACE4 (SPC4) gene expression is highly regulated through E-box elements in HepG2 and GH4C1 cells.

PACE4 (SPC4) is a member of the mammalian subtilisin-like proprotein convertase (SPC) family, which participates in maturation of precursor proteins. PACE4 is expressed at high levels in the anterior pituitary, central nervous system, the developing olfactory bulb, heart, and liver. Recently, we determined the gene structure of human PACE4. [Tsuji et al. (1997) J. Biochem. 122, 438-452]. The 5'-flanking region of PACE4 gene contains 12 E-boxes (E1 to E12) within 1 kb upstream of the transcription initiation site. To examine the function of these E-box elements in the regulation of PACE4 expression, deletion and mutation constructs of the 5'-flanking region were ligated to the luciferase gene and analyzed for promoter activity in HepG2 and GH4C1 cells, which express PACE4 at high level. Some differences were observed in the activity of each promoter construct between HepG2 and GH4C1 cells, although the overall profiles of activity for the promoter fragment series were similar regardless of cell type. We showed that the basal promoter activity of the PACE4 gene is first determined by sequences lying between -315 and -1 bp and further regulated by positive and negative elements in the upstream region. Site-directed mutagenesis of E-boxes in these regulatory elements showed that the E10 E-box act as positive regulator, whereas an E-box cluster (E4-E9) acts as a negative regulator in both cells. E2 E-box acts as a positive regulator only in HepG2 cells. Other E-boxes (E1, E3, and E12) had no effect on the promoter activity. These results indicate that E-box elements play a critical role in controlling PACE4 expression in HepG2 and GH4C1 cells and that PACE4 expression is regulated by a mechanism distinct from that of other SPC family proteases.

Base Sequence↗
PubMed1999

Characteristics of Streptococcus species isolated from infectious skin diseases.

During the period from January of 1995 to June of 1998, 27 beta-hemolytic streptococci were isolated from 25 cases of infectious skin diseases including secondary infections, impetigo, phlegmone, and paronychia. The rate of beta-hemolytic streptococci among all kinds of the isolates was found to be similar during those 4 years, ranging from 3.5% to 5.6%. Staphylococcus aureus were found to coexist with beta-hemolytic streptococci in 20 (80%) out of 25 cases. beta-hemolytic streptococci were also often associated with coagulase-negative staphylococci, gram-positive rods, or other species. Twelve cases (48%) carried beta-hemolytic streptococci predominantly. Most beta-hemolytic streptococci showed high susceptibilities to all antimicrobials tested; however S. agalactiae showed no susceptibility to gentamicin. The evaluation of characteristics of Streptococcus species is very important for selecting the right antimicrobial agents and the proper term of chemotherapy.

Adolescent↗
PubMed1999

Insufficient resistance of trehalose-6,6-dimycolate-treated T-cell receptor delta gene mutant (TCR delta-/-) mice against influenza virus infection.

Normal mice inoculated intravenously with 50 microg trehalose-6,6'-dimycolate, a glycolipid component of the cell wall of Mycobacterium, in an oil-in-water emulsion (TDM emulsion) acquired a high resistance to intranasal lethal infection of an influenza virus. In contrast, TDM emulsion-treated T-cell receptor delta gene mutant (TCR delta-/-) mice acquired insufficient resistance against the lethal influenza virus infection. The patterns of insufficient resistance were identical to the results obtained previously with mice which were depleted of T-lymphocytes bearing gammadelta T-cell receptors (gammadelta T-cells) by in vivo administration of anti-gammadelta T-cell receptor monoclonal antibody (Hoq et al, J. Gen. Virol. 78: 1597-1603, 1997). These results strongly suggest that the gammadelta T-cells play an important non-specific role in resistance against influenza virus infection.

Animals↗
PubMed1999

Japanese encephalitis vaccine (inactivated, BIKEN) in U.S. soldiers: immunogenicity and safety of vaccine administered in two dosing regimens.

The safety and immunogenicity of Japanese encephalitis (JE) vaccine (Nakayama strain, monovalent / BIKEN) was studied in 538 U.S. soldiers in 1990. Three doses of vaccine from three consecutively manufactured lots were given on days 0, 7, and either 14 or 30. Serum for antibody determination was drawn at months 0, 2, and 6. Japanese encephalitis plaque reduction neutralization tests were performed by three laboratories on each specimen. Five hundred twenty-eight (98%) participants completed the immunization series. All recipients without antibody before immunization developed neutralizing antibody against JE virus. There were no differences in geometric mean titer among the three test lots at months 2 and 6. Soldiers who received the third dose on day 30 had higher titers at both time points. Antibody to yellow fever had no significant effect on immune response to vaccine. Conclusions drawn from analysis of serologic data from the three labs were nearly identical. Symptoms were generally limited to mild local effects and were reduced in frequency with each subsequent does in the series (21% to 11%; P < 0.0001). Generalized symptoms were rare (e.g., fever = 5%) with no reported cases of anaphylaxis.

Adult↗
PubMed1999

[Bacterial mutation in high magnetic fields and radiofrequency radiation].

Epidemiological studies recently have indicated that magnetic fields and radiofrequency (RF) radiation have an adverse influence on the living body. The purpose of this study was to examine the safety of magnetic resonance imaging (MRI) by observing whether bacterial mutation occurs in an approximate MRI environment. We employed a GX-270 FT-NMR unit (JEOL, Ltd.) with a magnetic field strength of 6.3 Tesla. The Salmonella typhimurium tester strains used in the AMES test were exposed, and the incidence of point and frameshift mutations was evaluated. TA98 and TA7001-7006 mixed strains were used to detect frameshift and point mutations, respectively. Tester strains were exposed to the 6.3 Tesla magnetic field with RF radiation (90 degrees and 180 degrees refocusing pulses were repeated using the hydrogen Lamor frequency at 2-second intervals) for 15, 30, 45, and 60 minutes. After each exposure, the rate of revertant mutation was counted. The rates of revertant mutation in mixed strains and the TA98 strain were not statistically significant. Therefore, it was concluded that bacterial mutation is not increased by RF radiation under a 6.3 Tesla magnetic field.

Electromagnetic Fields↗
PubMed1998

The inhibitory effect of laminin 1 and synthetic peptides deduced from the sequence in the laminin alpha1 chain on Abeta40 fibril formation in vitro.

We investigated whether or not laminin 1 and the two different synthetic peptides deduced from the sequence in the laminin alphal chain, both of which mediate cell attachment and neurite outgrowth in PC12 cells, have an effect on Abeta40 fibril formation in vitro. A thioflavine-T fluorometric assay showed a synthetic peptide containing the YFQRYLI sequence from the laminin alpha1 chain to inhibit Abeta40 fibril formation while the inhibitory effect of this peptide was found to be somewhat less than that of intact laminin 1. These results were confirmed by electron microscopic observations using negative staining. The findings of the present study suggested that the synthetic peptide derived from the laminin alpha1 chain may thus be an effective therapeutic agent for either preventing or slowing down the progression of amyloidogenesis in Alzheimer's disease.

Amino Acid Sequence↗
PubMed1998

Laminin inhibits A beta 40 fibril formation promoted by apolipoprotein E4 in vitro.

The aggregation of soluble A beta into insoluble amyloid fibrils is believed to be an important step in the pathogenesis of Alzheimer's disease (AD) and the prevention of this process therefore seems to be a promising strategy for the treatment of AD. Both apolipoprotein E(apoE) and laminin are known to play important roles in the regeneration of the central nervous system and both are known to accumulate in the senile plaques of the AD brains. In the present study, we therefore investigated whether or not laminin has any effect on A beta 40 fibril formation promoted by apoE4 in vitro. A thioflavine-T fluorometric assay and electron microscopic observations using negative staining together demonstrated that laminin inhibits A beta 40 fibril formation in vitro while it also inhibits A beta 40 fibril formation promoted by apoE4. These results suggested that either laminin or its derivatives may thus be effective as therapeutic agents for AD.

Amyloid beta-Peptides↗
PubMed1998

Laminin inhibits Abeta42 fibril formation in vitro.

In the present study, we investigated whether or not laminin inhibits Abeta42 fibril formation in the same manner as Abeta40. Both a thioflavine-T fluorometric assay and electron microscopy by negative staining demonstrated laminin to have a concentration-dependent inhibitory effect on Abeta42 fibril formation. The amyloid fibril formation was inhibited approximately by 70% due to the presence of 1.0 mg/ml laminin co-incubated with 1. 0 mg/ml Abeta42 peptide (molar ratio; Abeta42 peptide:laminin=200:1). These results thus suggested that laminin or its derivatives may be effective as therapeutic agents to either prevent or slow down the progression of amyloidogenesis in Alzheimer's disease.

Amyloid beta-Peptides↗
PubMed1998

Two CPT2 mutations in three Japanese patients with carnitine palmitoyltransferase II deficiency: functional analysis and association with polymorphic haplotypes and two clinical phenotypes.

Carnitine palmitoyltransferase II (CPT II) deficiency manifests as two different clinical phenotypes: a muscular form and a hepatic form. We have investigated three nonconsanguineous Japanese patients with CPT II deficiency. Molecular analysis revealed two missense mutations, a glutamate (174)-to-lysine substitution (E174K) and a phenylalanine (383)-to-tyrosine substitution (F383Y) in the CPT II cDNA. Transfection experiments in COS-1 cells demonstrated that the two mutations markedly decreased the catalytic activity of mutant CPT II. Case 1 (hepatic form) was homozygous for the F383Y mutation, whereas case 3 (muscular form) was homozygous for the E174K mutation. Case 2 and her brother, who were compound heterozygotes for E174K and F383Y, exhibited the hepatic phenotype. We also identified a novel polymorphism in the CPT2 gene, a phenylalanine (352)-to-cysteine substitution (F352C), which did not alter CPT II activity in transfected cells. It was present in 21 out of 100 normal alleles in the Japanese population, but absent in Caucasian populations. Genotyping with the F352C polymorphism and the two previously reported polymorphisms, V368I and M647V, allowed normal Japanese alleles to be classified into five haplotypes. In all three families with CPT II deficiency, the E174K mutation resided only on the F1V1M1 allele, whereas the F383Y mutation was observed on the F2V2M1 allele, suggesting a single origin for each mutation.

Adult↗
PubMed1998

Noncancerous pulmonary lesions in patients with metastatic testicular germ cell cancer.

By thoracoscopic surgery, we confirmed pulmonary noncancerous lesions in two patients with metastatic nonseminomatous testicular germ cell cancer. The purpose of thoracoscopic surgery was complete resection of postchemotherapeutic residual tumour in one patient or a biopsy for new lesions during chemotherapy. Histological findings were normal lymph node and pulmonary fibrosis. We demonstrated CT findings of these lesions and made some discussion on management of disseminated testicular cancer.

Adolescent↗
PubMed1998

Growing mediastinal metastatic tumour in a patient with burned out testicular cancer.

A 27-year-old man was referred to us for resection of a post-chemotherapy growing mass in the mediastinum. He had been treated with 4 courses of combination chemotherapy for his testicular cancer. The primary lesion was burned out and the anterior mediastinal metastatic tumour contained immature teratoma. After normalization of tumour marker levels, the mediastinal mass was resected completely and the resected specimen showed teratoma with rhabdomyosarcoma. Two rare clinical conditions have been seen in this case.

Adult↗
PubMed1998

[Open distal anastomosis or aortic balloon occlusion technique during complete aortic arch replacement].

The technique of open distal anastomosis or application of aortic balloon occlusion catheter designed to occlude the descending thoracic aorta have been used in 33 and 19 patients, respectively, to control bleeding during the procedure of distal anastomosis for complete aortic arch replacement with a prosthetic graft. These two techniques allowed us a simple approach to the lesion and the avoidance of clamp injury to the fragile aortic tissue. Open distal anastomosis was applied for 91% patients of operated aortic dissection and all emergent cases, it's duration ranged from 10 to 110 minutes with an average of 58 minutes under 18.2 degrees C of lowest esophageal temperature. On the other hand, aortic occlusion balloon was inserted for mainly true aortic aneurysm patients without an emergency, and helped to maintain the perfusion pressure on a lower part of body around 50 mmHg by the 1550 ml/min in an average of perfusion flow femoral artery under 21.2 degrees C of temperature. The difference of postoperative renal and liver function evaluated by serum enzyme levels of total bilirubin, GOT, GPT, LDH, creatinine and BUN did not reach to statistical significance between the patients using open distal anastomosis and balloon occlusion, however, the incidence of postoperative complication including either renal, liver dysfunction, abdominal problem or paraplegia was significantly higher in the patient group with open distal technique. Either open distal anastomosis or aortic balloon occlusion technique would be appropriately selected according to the patient's characteristics or the condition of aortic disease to be operated.

Aged↗
PubMed1998

A novel member of the bombyxin gene family: structure and expression of bombyxin G1 gene, an insulin-related peptide gene of the silkmoth Bombyx mori.

Bombyxin G1 gene, a novel insulin-related peptide gene of the silkmoth Bombyx mori, has been identified. The G1 gene encodes a precursor peptide which shows 41-56% and 28% sequence identities with preprobombyxins previously characterized and human preproinsulin, respectively. The G1 gene forms a pair with bombyxin C2 gene with opposite transcriptional orientation in a bombyxin gene cluster. The bombyxin G1 mRNA in Bombyx brain was shown to locate in four pairs of medial neurosecretory cells.

Amino Acid Sequence↗
PubMed1998

Photoinduction of arginine decarboxylase activity in leaves of Pharbitis nil.

The activity of arginine decarboxylase (ADC) in leaves of Pharbitis nil was induced by light. The ADC activity increased to a maximum 1 h after illumination, followed by a gradual decrease. This suggested light either induced synthesis of ADC protein de novo or was involved in its activation. Cycloheximide inhibited the photoinduction of ADC activity, and the half life of ADC in leaves was 30-40 min. The temperature and relative humidity in darkness before illumination had no effect on the photoinduction of ADC activity, contrary to the photoresponse of S-adenosylmethionine decarboxylase (SAMDC) activity where the conditions of darkness before lights-on have a marked effect. The light response of the polyamine (PA)-biosynthetic enzyme activity produced transient accumulation of PA. The level of spermidine increased in leaves in which activities of both SAMDC and ADC increased after illumination, while the level of putrescine increased in leaves in which the activity of ADC increased but that of SAMDC did not.

Adenosylmethionine Decarboxylase↗