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Y Taguchi

Publications and source records attributed to Y Taguchi.

At least 109 records · Page 6Linked to original sources
PubMed1995

Evidence for the production of platelet-activating factor by murine embryos and its putative role in the maternal physiology.

Thrombocytopenia has been shown to be an initial maternal response to conception. We investigated a potent bioactive lipid, platelet-activating factor (PAF), as one of the candidates derived from embryos to induce the decrease of platelet counts in maternal blood. First, we examined the potential of murine embryos to liberate PAF. In brief, twenty to thirty murine two-cell embryos of C57BL/6 mice were cultured in Whitten's medium for 24 h. The supernatant of the medium was collected and the total was extracted. After developing the lipid on thin-layer chromatography, the area corresponding to authentic PAF was scraped off and the lipid was extracted. The embryo-derived PAF was quantified by platelet aggregation using rabbit whole blood, and the presence of PAF was further confirmed by the addition of a PAF-receptor antagonist, SRI63-441. The results showed that a significant amount of PAF (ca. 10 ng/ml) was recovered from the lipid extract, whereas little platelet-aggregating activity was observed in the presence of SRI63-441. Second, the physiological function of murine platelets was examined using authentic PAF. When PAF (up to 83 micrograms/ml) was added to the murine platelets suspended in the whole blood, it neither induced platelet aggregation nor reduced the number of platelets. Considering these results, it is considered that PAF released from the embryos does not directly act on maternal platelets, but transduces its signal to the maternal host via some other bioactive substance.

Animals↗
PubMed1994

Functional difference between the two oppositely oriented priming signals essential for the initiation of the broad host-range plasmid RSF1010 DNA replication.

The broad host-range plasmid RSF1010 contains two oppositely oriented priming signals, ssiA and ssiB, for DNA synthesis dependent on the origin of vegetative DNA replication (oriV). If either ssiA or ssiB was deleted or inverted, the RSF1010 miniplasmids containing engineered oriVs were maintained at low copy numbers, replicated abnormally as dimers, and accumulated specific single strands in the Escherichia coli strain supplying the three RSF1010-encoded RepA, RepB', and RepC proteins. Interestingly, an additional intracellular supply of the Sog primase (the sog gene product of plasmid CoIIb-P9) reversed the replication deficiency of these miniplasmids with respect to all three aspects described above. These were also true for the RSF1010 miniplasmids in which either ssiA or ssiB was replaced by the primosome assembly site (PAS) or by the G4-type ssi signal (G site). Furthermore, comparative analysis of the functional contribution of the two oppositely oriented ssi signals to the DNA replication of RSF1010 showed that, irrespective of their types, ssi signals conducting the initiation of DNA chain elongation away from the iterons were functionally more important than ones in the inverted orientation. We consider that this functional difference reflects the inherent properties of the initiation mechanism of RSF1010 DNA replication.

Bacterial Proteins↗
PubMed1994

Rapid fluorometric assay for mitochondrial proton adenosine triphosphatase activity for assessment of viability of liver graft tissue.

We developed an improved determination method of mitochondrial proton adenosine triphosphatase (ATPase) activity in the liver. The activity was measured fluorometrically with a 3,3'-dipropylthiodicarbocyanine iodide (diS-C3(5)), which is excited at 625 nm and emits fluorescence at 670 nm. This dye transmits the electric potential across the inner mitochondrial membrane. The fluorescence intensity of diS-C3(5) with mitochondria (100 microliters, 4-16 mg/ml protein) in a 2 ml potassium buffer (pH 7.4) was regarded as a standard electric potential. After confirming the activity of the mitochondrial electron transport chain by succinic acid (9 mumol), we inhibited the chain by antimycin A (1.25 micrograms). Fluorescence intensity decreased by adenosine 5'-triphosphate (ATP) (2 mumol) and oligomycin (25 micrograms) inhibited this depression. The value of mitochondrial proton ATPase activity was calculated as a percentage of the fluorescence intensity change by ATP per the standard electric potential. The activity of mitochondrial proton ATPase in the normal fresh rat livers was 50.3 +/- 2.2%. Good correlation (r2 = 0.807) between two methods for mitochondrial proton ATPase activity, our newly developed method and a conventional colorimetric method, was obtained in the rat livers with various conditions. This method has advantages that the proton ATPase activity can be measured in intact mitochondria, and all procedures can be completed within 40 min. It is suitable for the determination of mitochondrial viability of liver graft in the hepatic resections and transplantations.

Adenosine Triphosphate↗
PubMed1994

Functional features of oriV of the broad host range plasmid RSF1010 in Pseudomonas aeruginosa.

The broad host range plasmid RSF1010 requires for its replication in Escherichia coli three plasmid-encoded proteins and specific nucleotide sequences ssiA, ssiB, and iterons in the oriVRSF1010. In Pseudomonas aeruginosa, a recombinant mini-RSF1010 plasmid lacking ssiB lost its replication ability, but a miniplasmid lacking ssiA or carrying a primosome assembly site in place of ssiA could replicate. Moreover, ssiA, as a sole ssi signal, in the orientation that ssiB had originally taken was sufficient for replication of the miniplasmid. These results indicated that only one RSF1010-specific ssi signal in the orientation that ssiB takes in wild-type oriVRSF1010 was essential for replication of RSF1010. Replication of the miniplasmids was dependent on the three plasmid-encoded proteins, RepA, B', and C, as in E. coli.

Bacteriophage phi X 174↗
PubMed1994

Importance of recall and follow-up screening for chronic hepatitis C in children receiving blood products prior to 1990 in Japan.

The objective was to detect chronic hepatitis C virus infection in recipients of blood products using retrospective analysis by recall and enrollment of recipients. 226 patients who received blood products for open heart surgery from January 1983 to June 1992 were examined for HCV antibody by using a second generation assay and liver function test. 22 (14%) of the 161 patients who received blood products before November 1989 had detectable HCV antibody, but none of the 65 recipients receiving blood products after 1990, the year the Japanese blood bank began to screen for HCV-antibody. Abnormal alanine aminotransferase (ALT) levels, more than 25 iu/L, during the chronic phase of HCV infection was recognized in nine of 22 (41%) seropositive patients. The liver function test and second generation HCV antibody in the serum are effective markers to screen for chronic hepatitis C in blood product recipients transfused before 1990.

Adolescent↗
PubMed1994

Serologic, virologic, and histologic characteristics of chronic phase hepatitis C virus disease in children infected by transfusion.

OBJECTIVE: We studied the time course of hepatic dysfunction, seropositivity to hepatitis C virus (HCV) antibodies, viremia, and histologic evidence of hepatic injury to evaluate the course of HCV infection in children infected by blood transfusion. PATIENTS AND METHODS: Twenty-nine patients (ages 4 to 18 years) who underwent open-heart surgeries for congenital heart disease were grouped into three categories based on alterations in serum alanine aminotransferase (ALT) levels: Group A, acute infection; Group B, subacute infection; and Group C, chronic infection. RESULTS: In Group C, all 13 patients had detectable HCV RNA in serum. In contrast, all patients in Group A had no detectable HCV RNA: In Group B, one of nine patients had detectable HCV RNA and two of four patients examined had persistent chronic hepatitis by histologic criteria. Antibodies directed against C100-3 antigen or core-antigen were more useful than second-generation HCV antibody assays in determining the relationship between viremia and immunologic response. Infection with HCV genotype II and the presence of higher HCV RNA copy numbers were associated with histologic evidence of hepatic damage. CONCLUSION: An abnormal ALT value is frequently associated with viremia, and biochemically resolved acute infection reflects clearance of HCV. However, a normal ALT does not always reflect an absence of hepatocyte damage and HCV replication in patients with subacute disease. The measures outlined in this study are useful indicators of disease activity during the chronic

Acute Disease↗
PubMed1994

[Long-term renal function after nephrectomy in living related kidney donors].

The purpose of this study is to evaluate the long-term renal function of donors after nephrectomy in living related renal transplantation (n = 100). The survival rate of donors was 98% and causes of death in the other 2% were not associated with the donation. Serum creatinine (Scr) and Creatinine clearance (Ccr) deteriorated just after the donation, but gradually improved. The number of donors with proteinuria increased after donation. In Scr and Ccr there was no significant difference between donors with and without proteinuria. In the donors with hypertension (25.3%) mean urine protein was higher than in those without hypertension. There was a correlation between systolic blood pressure and proteinuria. These results strongly suggest that renal function of donors deteriorates once just after the donation, but gradually improves year by year, and that hypertension is strongly associated with renal dysfunction, especially proteinuria, after the donation.

Adult↗
PubMed1994

[A case of intracerebral tuberculoma: clinical characteristics and MRI findings].

A case of intracerebral tuberculoma treated surgically was reported. A 47-year-old man was admitted to our hospital because of progressive left hemiaparesis over the previous 5 months. A computerized tomography scan showed a well enhanced mass associated with a marked perifocal edema. T1 weighted magnetic resonance imaging (MRI) revealed an isosignal ring around the heterogenous low intensity mass. A low intensity area just interior to this ring was also visualized both in T1 and T2 weighted images. Although the clinical course was unusually long, this was diagnosed as a metastatic brain tumor. He underwent a right frontal craniotomy and a well circumscribed, yellowish, firm mass was totally extirpated. Pathohistologically, this mass was considered to be a tuberculoma though the tuberculous bacilli could not be identified in Ziehl-Neelsen staining. His hemiplegia improved much and his ambulation was restored. Since tuberclomas are quite rare in developed countries, the diagnosis of intracerebral tuberculomas would be extremely difficult unless tuberculosis was verified in some other organs. The auxiliary examinations even by using MRI have often given little information which would assist diagnosis. However, based on pathological findings, the ring appearance and low intensity area medial to the ring in the outer part of the tuberculoma shown in MRI of our patient seemed to represent a chronic granulomatous inflammation and gave a clue to rule out the suspicion of metastatic brain tumors. To make a correct diagnosis of intracerebral tuberculomas, multidisciplinary consideration is mandatory.

Antitubercular Agents↗
PubMed1994

[A case of desmoplastic infantile ganglioglioma].

We have been experienced a rare case of large supratentorial neuroepithelial tumor with a subdural cyst originated from the left fronto-parietal lobe in a 14-month-old boy. The tumor was characterized by its voluminous size, a leptomeningeal growth pattern with intense desmoplasia and divergent astrocytic and ganglionic differentiation. Schwann cell differentiation and melanocytes were also minutely demonstrated. These histological findings are characteristic of desmoplastic infantile gangliogliomas, reported by VandenBerg et al in 1987. And this tumor tissue architecture strongly suggests the hamartomatous nature, rather than the ordinary neoplastic lesion.

Brain↗