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Biomedical subjects

N Yamaguchi

Publications and source records attributed to N Yamaguchi.

At least 415 records · Page 23Linked to original sources
PubMed1993

[Phenotypic analysis of immature T-lineage cells].

The characteristics of very immature T-lineage blasts including co-expression of myeloid properties and the distinctions between the phenotypes of pro-thymic (CD7+ CD5+ CD2+ CD3- CD4- CD8- or more immature) and thymic (CD3- CD4+ CD8+ or more mature) blasts are shown. The lineage-derivation of CD7+ CD5- CD2- and CD7+ CD5+ CD2- lymphoid blasts was investigated based on the gene expression of CD3 epsilon, CD3 delta and myeloperoxidase (MPO). The former group included 4 categories; undifferentiated blasts without commitment to myeloid or T-lineage, T-lineage blasts with mRNA of CD3 epsilon, T/myeloid blasts with mRNA of CD3 epsilon and MPO and blasts with mRNA of MPO. The latter included 2 categories; T-lineage blasts with CD3 epsilon and CD3 delta mRNA and T/myeloid blasts with CD3 epsilon, CD3 delta and MPO mRNA. Thus, CD3 epsilon was expressed at a more immature stage than CD3 delta. The blasts at the pro-thymic stage were different from those at the thymic stage in several respects. The T-cell receptor (TCR) beta-chain gene showed a germ-line configuration in most pro-thymic blasts. The CD13/CD33, CD11b and class II MHC antigens were expressed very frequently in the pro-thymic stage. The CD21 antigen was most selectively expressed at the thymic stage. Pro-thymic blasts were of RA type of CD45 antigen, while thymic blasts were of RO type. Recombination activation gene-1 (RAG-1) was only limitedly expressed at the pro-thymic stage, but was highly expressed at the thymic stage. These findings indicate that there are distinctive differences before and after the initiation of clonal selection which is unique and thymus-specific, and that the neoplastic cells represent each stage of T-lineage differentiation involving the unique thymic function.

Antigens, Surface↗
PubMed1993

[Serotonergic mechanisms of hippocampal kindled seizures in cats--effects of 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane and ketanserin].

Based on our previous findings that a serotonin (5-HT) precursor L-5-hydroxytryptophan and a 5-HT1 a receptor agonist 8-hydroxy-2-(di-n-propylamino) tetralin can suppress seizures kindled from the feline hippocampus (HIP), we have suggested that 5-HT1 a receptors play an inhibitory role in HIP seizure generation. In order to clarify the role of 5-HT2 receptors in epilepsy, the present study examined the effects of a 5-HT2 receptor agonist 1-(2,5-dimethoxy-4-iodophenyl)-2-amino-propane(DOI) and a 5-HT2 receptor antagonist ketanserin on HIP-kindled seizures. Following the completion of HIP kindling, five cats received intravenous injections of 0.9% saline, DOI (1.0mg/kg) or ketanserin (1.0mg/kg). Electrical stimulation at the generalized seizure triggering threshold was delivered to the kindled HIP 15 min after drug administration. The anticonvulsant effects were assessed by the behavioral seizure stage, afterdischarge duration, latency to the onset of stages 4 and 6, and duration of a generalized tonic-clonic convulsion (GTC). Although no significant change was found in the seizure stage following the administration of either drug, both DOI and ketanserin significantly altered the latency for seizure generalization. DOI significantly reduced the latency to the onset of stage 6 GTC as compared with saline, with a significant reduction in the afterdischarge duration. In contrast, ketanserin significantly increased the latency to the GTC onset as compared with saline. Neither the latency of the stage 4 onset nor the GTC duration was significantly affected by these drugs.(ABSTRACT TRUNCATED AT 250 WORDS)

Amphetamines↗
PubMed1993

[An evaluation of a therapy with antibacterial and antifungal agents infections with hematological disorders].

The primary objective of this study is to confirm the efficacy and safety of combination therapy with antibacterial and antifungal drugs for patients with hematological disorders complicated with infections of unknown causative organisms. The subjects consisted of 55 patients with hematological disorders, 28 males and 27 females, ranging from 1 to 78 years of age, with an average age of 34 years. The breakdown of the patients by disease was: 41 leukemias, 10 malignant lymphomas, 3 myelodysplastic syndromes and an aplastic anemia. All patients were treated with sulbactam/cefoperazone (SBT/CPZ) and aminoglycoside (AG) plus fluconazole (FLCZ) as an empiric therapy. Overall efficacy rate was 54.5% for all the patients: 57.7% for patients with suspected sepsis and 0% for those with pneumonia from which unknown organisms were detected. The efficacy rate was 59.4% for patient who had been previously treated with other antibiotics and 47.8% for those who had not previously been treated. The above results suggested that this combination therapy might be effective for severe infections of unknown causative organisms associated with hematological disorders.

Adolescent↗
PubMed1993

[Urinary-plasmin alpha 2 plasmin inhibitor complex (PIC) in patients with diabetic nephropathy].

The levels of urinary PIC and FDP were studied in 86 diabetics. Urinary PIC or FDP were detected only in patients representing more than (++) urinary protein, suggesting that urinary PIC is not useful for diagnosis of early stage of diabetic nephropathy. On the other hand, positive rate of urinary PIC was much higher than that of chronic nephritis not due to diabetes mellitus. Plasma levels of PIC were elevated above normal range in all patients with advanced diabetic nephropathy tested. These results suggest that urinary PIC might be derived from circulating blood and reflect the level of systemic fibrinolytic activities in diabetics.

Adolescent↗
PubMed1993

[HLA tissue types in patients with acute tubulointerstitial nephritis accompanying uveitis].

Four cases of idiopathic acute tubulointerstitial nephritis (TIN) associated with uveitis (so-called TINU syndrome) were experienced between 1986 and 1990. Patients' ages ranged from 14 to 42 years old and three were female and one was male. All cases showed general symptoms, such as general malaise, anorexia and weight loss. All patients had initially TIN and became ill uveitis four to eight months after the onset of TIN. All cases had mild proteinuria, mild anemia, the lower serum levels of potassium, hyper gamma-globulinemia and the reduced glomerular filtration rate with the increased beta 2-microglobulin in urine and serum. All renal biopsies specimens showed mild edema and diffuse infiltration of inflammatory mononuclear cells in the interstitium without any glomerular or vascular abnormalities. Furthermore, numerous CD4 positive cells, CD8 positive cells and CD11c positive cells were seen in the interstitium. Of four patients, three cases were treated with both oral administration and eye drop of prednisolone (PSL), another one case was therapied with eye drop PSL only. In all cases TIN had good prognosis, but two patients had recurrences of uveitis. All patients underwent tissue typing for HLA-A, B, C and DR antigens. Three patients had identical HLA-Cw3 and all four cases revealed identical HLA-A24(9). These results suggest that immunological mechanism, especially cell-mediated, and HLA system may play an important role in the occurrence of TINU syndrome.

Acute Disease↗
PubMed1993

Identification of a DNA element that can enhance p53-mediated transactivation.

Recent studies have demonstrated that p53 binds to specific DNA sequences and the consensus sequence for the p53 binding site has been proposed. The p53 binding site has also been shown to act as positive p53-responsive element. Here we report the identification of a GC3 element that enhances p53-mediated transactivation when placed adjacent to the consensus p53 site. The GC3 element alone cannot act as a positive p53-responsive element. We also show that p53 activates transcription of the c-erbA-alpha gene through a DNA element that consists of the p53 quarter-sites and GC3 elements. Using gel mobility-shift assay, we identified a possible GC3 binding factor distinct from p53.

Base Sequence↗
PubMed1993

[Clinical usefulness of measurement of erythropoietin in blood].

Blood erythropoietin (EPO) concentration was measured by radioimmunoassay in 513 patients with various diseases. Untreated polycythemia vera showed lower EPO concentration than normal. Aplastic anemia (AA) revealed the highest EPO level among all anemic diseases in relation to hematocrit value. EPO level of AA patients who underwent bone marrow transplantation was as low as normal subjects even when the anemia has not fully recovered. Paroxysmal nocturnal hemoglobinuria (PNH) showed unusually high EPO concentration among hemolytic anemias. In normal subjects, blood EPO concentration showed a diurnal rhythm that was higher at night than during the daytime. These findings suggest the diagnostic usefulness of measurement of EPO in blood diseases.

Adult↗
PubMed1993

Distribution of epidermal growth factor receptors in rabbit lens epithelial cells.

PURPOSE: This study examined the growth-promoting effect of epidermal growth factor (EGF) on rabbit lens epithelial cells and the distribution of EGF receptors in these cells. METHODS: Rabbit lens epithelial cells were cultured in TC-199 medium containing 0.5% fetal bovine serum and EGF for 1 to 5 days, and the growth-promoting effects of EGF were calculated with absorbance of methylene blue staining method. EGF receptors in the cells were analyzed by Scatchard plots using 125I-EGF in serum-free culture. RESULTS: EGF, which enhanced the cell growth in a dose-dependent manner, was stimulatory at 0.1-100 ng/ml and maximal (328.2%) with 10 ng/ml on day 5. The cells had two different affinity receptors. The number and the dissociation constant of the low affinity receptors were 5.81 x 10(4)/cell and 1.488 nM, respectively, and those of the high affinity receptors were 1.53 x 10(4)/cell and 0.159 nM, respectively. CONCLUSION: EGF may contribute to the development of living lenses.

Animals↗
PubMed1993

Probable cerebellar abnormality on 123I-IMP SPECT scans in epileptic patients with long-term high-dose phenytoin therapy. Based on observation of multiple cases.

Quantitative assessment of regional cerebral blood flow (rCBF) in the bilateral cerebral and cerebellar cortices was performed in 13 epileptic patients receiving long-term high-dose phenytoin (PHT) therapy, using single photon emission computed tomography (SPECT) with N-isopropyl-(iodine 123) p-iodoamphetamine. In 4 of the 13 patients, both the cerebellar to frontal rCBF ratio and cerebellar to cerebral rCBF ratio showed low values as compared with those in 22 normal subjects matched for sex and age, probably reflecting abnormal relative cerebellar hypoperfusion. None of the 4 patients showed any abnormal findings on X-ray computed tomography or magnetic resonance brain imaging. The patients with a history of acute PHT intoxication tended to show the abnormal relative cerebellar hypoperfusion. These results suggest the utility of SPECT scans for early detection of cerebellar abnormalities known to be often present in epileptic patients, and imply a risk of long-term high-dose PHT therapy.

Adult↗
PubMed1993

Quantitative assessment of regional cerebral blood flow with 123I-IMP in normal adult subjects.

Quantitative assessment of regional cerebral blood flow (rCBF) in the bilateral cerebral and cerebellar cortices was performed in 22 normal adult subjects consisting of an early twenties group (5 men and 9 women, 20-22 years) and middle age group (3 men and 5 women, 41-52 years), using single photon emission computed tomography (SPECT) with N-isopropyl-(iodine 123) p-iodoamphetamine. Absolute rCBF values in each region in the 22 subjects ranged from 46 to 102 ml/100 g/min (mean 69.1, standard deviation 13.7 ml/100 g/min). The absolute rCBF values were significantly higher in women than in men, and in the early twenties group than in the middle age group. In addition, based on each absolute rCBF value, the interhemispheric asymmetry, anterior to posterior ratio and cerebellar to frontal ratio in rCBF were calculated. These results may be useful as indexes for detecting organic and functional brain abnormalities in various neuropsychiatric diseases.

Adult↗
PubMed1993

Relative abundance and the relationships between aniline, phenol and catechol degraders in fresh water.

Relative abundance and relationships between aniline, phenol and catechol degraders were investigated in unpolluted and polluted fresh waters in Osaka prefecture, Japan. Phenol and catechol degraders were found more frequently compared to aniline degraders. The results indicate that these degraders were more abundant in polluted waters than in unpolluted waters. Aniline degraders isolated from the Ina River water showed a higher capability of degrading catechol than phenol. Analysis on sequence homology among these three kinds of degraders indicated a possible relationship between aniline degraders and certain strains of both catechol and phenol degraders.

Alcaligenes↗
PubMed1993

[Determination of the standard level of serum erythropoietin in relation to hemoglobin concentration].

Serum erythropoietin (EP) concentration was measured by the recombinant EP-based radioimmunoassay and was examined to standardize the hemoglobin (Hb) related level of 144 normal control and 56 patients with iron deficiency anemia and hemolytic anemia excluding paroxysmal nocturnal hemoglobinuria. The standardization was achieved by logarithmic regression of the EP titier on Hb either by the two-phase linear form or by the third degree sigmoid form at a 95% confidence limit for each regression. The third degree regression was found to be preferable from the view point of both statistics and the negative feedback mechanism. The average and scattering of the deviation from the standard level thus determined of the disease groups indicated that the EP level is: (1) 12 fold higher than the standard level in 42 aplastic anemias (the most in excess and a few in standard). (2) three fold higher than that in 27 myelodysplastic syndromes (relatively higher dispersed state). (3) 29% of the standard level in 33 anemias associated with chronic renal failure (deficient state). (4) 105% of the extrapolated standard level in 22 polycythemia veras (standard state). The standardization of Hb-related Ep titer may provide new pathophysiological approaches in a variety of hematopoietic disorders.

Anemia, Hemolytic↗
PubMed1992

Use of an epitope-tagged cDNA library to isolate cDNAs encoding proteins with nuclear localization potential.

We have combined epitope tagging with an expression cDNA library in order to isolate cDNAs encoding nuclear proteins. This system allows us to detect proteins expressed from the cDNA library by using antibodies against the epitope tag. As a tag, we used the 85-aa N-terminal peptide of the SV40 T antigen which lacks the nuclear localization signal (NLS). A strong expression vector, pEF204 [Kim et al., Gene 91 (1990) 217-223], was modified into an epitope-tagging vector, pTkim, by putting the tag-coding region and a cDNA cloning site immediately after its promoter. From cDNA libraries constructed using pTkim, we isolated eight cDNA clones whose tagged proteins were localized within the nuclei. From partial sequence analysis, two cDNAs were shown to code for the ribosomal (r-) proteins, simian L44 and human L21, and the others were shown to be new. Furthermore, six cDNAs including those encoding the r-proteins could direct a non-karyophilic T antigen [Fischer-Fantuzzi et al., Virology 153 (1986) 87-95] into nuclei, showing that they have NLSs. These results indicate that this system is useful for isolating new cDNAs which code for nuclear proteins.

Animals↗
PubMed1992

Endoglycosidase H digestion of Yukb (Pena) alloantigen.

We characterized a platelet specific alloantigen (Yukb). In immunoblotting, anti-Yukb antibody was found to react with both 110 kDa and 96 kDa bands under nonreducing condition. Immunoblotting followed by separation by two-dimensional electrophoresis (isoelectric focusing/SDS-PAGE) showed that the 96 kDa band had a pI of 5.1-5.8, while the 110 kDa band had a pI of 5.2-5.7. The 96 kDa band was identified as glycoprotein (GP) IIIa on the basis of periodic acid Schiff staining, but the 110 kDa band was not characterized. These results implied that it is difficult to determine differences in antigenic epitopes between Yukb and PlA1 antigens by the electrophoresis. Yukb antigen, unlike PlA1 antigen, was partially destroyed by chymotrypsin treatment. Furthermore, endoglycosidase H digestion resulted in loss of the Yukb epitope, while the PlA1 determinant was retained on the three bands with lower molecular weights after endoglycosidase H digestion. The transfer of Yukb antigens recognized by anti-Yukb antibody into the supernatant of platelets treated with endoglycosidase H was also found using mixed passive hemagglutination test. The results indicated that the Yukb epitope might be located to the endoglycosidase H digested N-linked high mannose carbohydrate chains of GP IIIa or hybrid type chains of GP IIIa, which is different from the location of PlA1 epitope.

Antibodies↗
PubMed1992

Role of serotonin receptor subtype in seizures kindled from the feline hippocampus.

This study assessed the effects of a serotonin (5-HT)1A agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), a 5-HT2 agonist 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) and a 5-HT2 antagonist ketanserin on fully kindled seizures from the hippocampus. 8-OH-DPAT produced a marked suppression in hippocampal kindled seizures, while producing behavioral signs similar to those seen in the 5-HT syndrome. Although DOI and ketanserin did not affect kindled focal epileptic activity, DOI shortened and ketanserin prolonged the latency to onset of generalized convulsions. Our data suggest that 5-HT1A receptors play an inhibitory role in the generation of hippocampal seizures, whereas 5-HT2 receptors may participate in kindled seizure generalization from this region.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1992

Negative regulation of Rb expression by the p53 gene product.

Mutation of the p53 gene is one of the most frequent genetic changes found in human cancers. Recent experiments indicated that p53 might contain a transcription-activating domain, which functions when directed to a promoter. This study shows that wild-type p53 suppresses transcription of the retinoblastoma (Rb) gene. From deletion and mutagenesis experiments, a cis-acting element (GGAAGTGA) susceptible to regulation by p53 was mapped within the Rb promoter. This element overlaps the basal transcription unit of the Rb promoter, suggesting that p53 suppresses Rb transcription through inhibition of the basal promoter activity. The N-terminal acidic and C-terminal basic domains of p53 were both required for this suppression. These findings indicate that p53 can act as a transcriptional regulator in vivo.

Base Sequence↗