Search PubMed⌕ Search

Biomedical subjects

Y Ando

Publications and source records attributed to Y Ando.

At least 289 records · Page 16Linked to original sources
PubMed1997

[Monitoring of inhibitors of the polymerase chain reaction for the detection of hepatitis C virus using the positive internal control].

In the direct detection of pathogens by polymerase chain reaction (PCR) from clinical samples, false negative results due to the presence of inhibitor are problematic. In order to monitor such an inhibitor, we evaluated the detection of the positive internal control in PCR assay for HCV-RNA in serum samples positive for anti-HCV antibodies, of which 41 samples were positive for HCV-RNA by competitive RT-PCR assay. The positive internal control was coamplified with HCV-RNA and hybridized to the specific probe on magnetic beads and then hybrids were detected by colorimetric measurement using automatic PCR machine (COBAS AMPLICOR). Detection of the positive internal control was negatively correlated with viral copy number in sera assayed by competitive RT-PCR. Five of 52 samples (9.6%) with high HCV-RNA copy number (10(7) or 10(8) copies/ml) showed negative results for the internal control. The negative results for the internal control turned out to be positive when the sera were diluted and re-assayed, suggesting competitively inhibitory effects of high viral copy number on amplification of the internal control. Addition of heparin in the serum sample showed an inhibitory effect with a dose dependent manner on the detection of both HCV-RNA and the internal control, with a more effect on the lower copy number of HCV. On the other hand, addition of hemoglobin in the sample with concentration of up to 450mg/dl had no inhibitory effect on the detection of either HCV-RNA or the internal control. Coamplification and detection of the positive internal control was demonstrated to be useful to estimate effects of inhibitors, which may be present in clinical samples, in the detection of HCV-RNA by PCR.

False Negative Reactions↗
PubMed1997

Infection of a human retinal pigment epithelial cell line with human herpesvirus 6 variant A.

A retinal pigment epithelial (RPE) cell line (K-1034) was examined for its susceptibility to human herpesvirus 6 variant A (HHV-6A). Exposure of K-1034 cells to HHV-6A induced the formation of multinucleated giant cells, which was suppressed by an inhibitor of viral DNA synthesis. In the giant cells, herpesvirus nucleocapsids were demonstrated by electron microscopy and the viral glycoprotein B was detected by immunofluorescence assay. These results indicate that K-1034 cells are susceptible to HHV-6A and suggest that HHV-6A has an ability to directly destroy epithelial cells.

Cells, Cultured↗
PubMed1997

K-ras and p53 gene mutations in colorectal cancer in 57 Japanese patients.

Fifty-eight tissue specimens from 57 Japanese patients with colorectal cancer were analyzed for the K-ras and p53 gene mutations by polymerase chain reaction-single strand conformation polymorphism analysis and direct sequencing. K-ras mutations were detected in 21 cases (36.2%) and p53 mutations in 20 cases (34.5%). Eight specimens had both gene mutations. The K-ras mutation was associated with higher degrees of differentiation (p = 0.0019). The P53 mutation was associated with Duke B to D staging (p = 0.028), lymph vessel invasion (p = 0.021), and venous invasion (p = 0.03). Interestingly, a mutation in only exon 7 of the P53 gene was associated with lymph node metastasis. These results suggest the important effect of the mutations of the K-ras and p53 genes, especially p53 gene on colorectal carcinogenesis in Japanese patients. The grades of malignancy of the specimens with the mutations in both genes were not different significantly from those with a single (K-ras or p53) or no mutation, suggesting no cooperation between K-ras and p53 gene mutations on carcinogenesis or tumorigenesis.

Adenocarcinoma↗
PubMed1997

Prognostic value of pleural effusion in patients with non-small cell lung cancer.

This study was performed to determine whether pleural effusion in patients with advanced non-small cell lung cancer (NSCLC) has a negative impact on survival. We evaluated 12 prognostic factors in 197 patients with stage IIIB or IV NSCLC. Each factor was dichotomized, and survival curves calculated by the Kaplan-Meier technique were compared using the log-rank test. The Cox proportional hazards regression model was used to confirm the significance of each prognostic factor selected by univariate analysis. We compared the survival times for stage IIIB with pleural effusion with those of stage IIIB without effusion and stage IV. To determine the impact of the cytological results of the effusion on survival, we compared the survival times for cytologically positive and negative effusions. Univariate analysis identified eight significant prognostic factors: pleural effusion, node status, stage, performance status, weight loss, hemoglobin, albumin, and lactate dehydrogenase. Pleural effusion was selected as a prognostic factor in the multivariate analysis, together with stage, performance status, albumin, and node status. Median survival times for stage IIIB without effusion, stage IIIB with effusion, and stage IV were 15.3, 7.5, and 5.5 months, respectively (P < 0.0001). Survival time for stage IIIB with effusion was significantly different from that of stage IIIB without effusion (P = 0.0129) but not from that of stage IV (P = 0.0797). Among patients with effusion, no significant difference in survival time was observed between cytologically positive and negative effusions. We conclude that pleural effusion in advanced NSCLC is a prognostic factor. Survival time for stage IIIB with pleural effusion is more similar to that of stage IV rather than that of stage IIIB without effusion.

Adult↗
PubMed1996

A new simple and rapid screening method for variant transthyretin-related amyloidosis.

To screen for transthyretin (TTR) related amyloidosis rapidly and reliably, we have developed a new method using a centrifugal concentrator device and electrospray ionization mass spectrometry (ESI-MS). Only 50 microliters of serum is needed for the analysis. After preparation of the samples with anti-TTR antibody they were passed through a 1000 kDa cut off centrifugal concentrator which retained the antibody. By analyzing the obtained filtrate with ESI-MS, variant forms of TTR was detected. TTR (Met30), with a molecular weight 32.0 Da higher than the normal form of TTR, was found in all FAP patients examined. In 3 liver transplanted FAP patients, the abnormal peaks had disappeared. In conclusion, The TTR Met30 mutation was easily detected in serum samples by electrospray ionization mass spectrometry after centrifugal concentration. The proposed method is simple to perform, as no HPLC is required, and offers a possibility to screen populations for TTR related amyloidosis.

Adult↗
PubMed1996

Autonomic dysfunction and anemia in neurologic disorders.

The effect of autonomic dysfunctions on anemia in various neurological disorders, such as familial amyloidotic polyneuropathy (FAP) Type I, pandysautonomia, and Shy-Drager syndrome was examined. As a control, hemograms of patients with amyotrophic lateral sclerosis (ALS), which is known to be free from autonomic dysfunction, was compared with patients with the above neurological disorders. FAP and pandysautonomia patients showed significant anemia comparable with the severity of the autonomic dysfunctions. Shy-Drager patients exhibited mild anemia. However, in ALS patients, no such anemia was recognized at all even in the end stage of this disease. In pandysautonomia patients, hypoplastic bone marrow was recognized, which was quite consistent with the data previously reported in FAP patients. Human recombinant erythropoietin improved orthostatic hypotension as well as anemia in 4 FAP patients. These results suggest that autonomic dysfunction may be deeply connected with erythropoiesis.

Adult↗
PubMed1996

Non-neurogenic periodic fluctuations in heart rate and vasomotion appearing in familial amyloid polyneuropathy (FAP) Type I (Met30).

In order to evaluate the function of the autonomic nervous system, power spectral analysis of heart rate fluctuation and waveform observation of cutaneous vasomotion were conducted in 3 patients with familial amyloid polyneuropathy Type 1 (FAP) (Met30) with autonomic disorders. In 2 FAP patients in the early stage, both high (HFC: 0.12-0.4 Hz) and low frequency components (LFC: 0.04-0.12 Hz) in the heart rate spectrum, and basic (BW) and reflex waves (RW) in the vasomotion were all markedly suppressed. However, in an FAP patient in the advanced stage, prominent spectral peaks were recognized in both the spectral bands of LFC and HFC. HFCs were neither correspondent with the respiratory frequency nor depressed by atropine, and BW was not affected by acute denervation using a local anesthetic. RW was absent irrespective of the denervation. These results suggest that the denervated heart and vascular smooth muscles might have newly acquired periodic fluctuations, although the physiological mechanism and meanings remain to be investigated.

Adult↗
PubMed1996

Decreased affinity of apolipoprotein AII to high-density lipoprotein in patients with transthyretin-related amyloidosis (Met30, Gln89, Pro36, and Thr34).

We previously reported that patients with familial amyloidotic polyneuropathy (FAP) (Met30) showed low plasma apolipoprotein AII (apoAII) levels and apolipoprotein AII/AI (apoAII/AI) ratio as the progression of the disease while plasma levels of apoAI, B, CII, CIII, and E were all within normal ranges. In the present study, we investigated these apolipoproteins contained in high density lipoprotein (HDL) extracted from plasma of FAP (Met30), and the levels of apoAII gene expression in the liver from patients with FAP (Met30). Plasma apoAII levels and the apoAII/AI ratio in extracted HDL in all the FAP types examined decreased compared with those in normal control subjects. Levels of apoAII mRNA expression in the liver of FAP (Met30) patients did not show significant changes compared with those in control subjects. These results suggest that decreased affinity of apoAII to HDL could not be compensated by overproduction of apoAII in the liver of the FAP patients and as a result of this phenomenon, plasma apoAII levels might decrease as the progression of FAP.

Amino Acid Sequence↗
PubMed1996

Genomic rearrangement in genome segment 12 of rice dwarf phytoreovirus.

The genome segment 12 (S12) of rice dwarf phytoreovirus (RDV) isolated from the Philippines (RDV-P) and of a variant (RDV-S-6) of RDV severe strain (RDV-S) migrated abnormally slower during polyacrylamide gel electrophoresis than that of the isolate maintained at Hokkaido University (RDV-H). Nucleotide sequence analysis revealed that rearrangement had occurred in these segments, affecting the open reading frame. A polypeptide encoded by S12 (Pns12) of RDV-P had a duplication of 28 amino acids while 1/3 of the carboxyl terminus of Pns12 was deleted in RDV-S-6 by premature termination due to a frameshift. RDV-S is always present in plants infected with the RDV-S-6 variant, suggesting that Pns12 of RDV-S-6 is defective. On the other hand, Pns12 of RDV-P was expressed and appeared to be functional in infected cells in spite of the duplication, as demonstrated by immunoblot analyses using antibody raised against Pns12 expressed in Escherichia coli.

Base Sequence↗
PubMed1996

Two levels of help for B cell alloantibody production.

We have examined whether T cell stimulation by direct or indirect pathways contributes to alloantibody production by B cells after major histocompatibility complex (MHC)-disparate skin graft rejection in mice. Experiments were performed using normal mice, MHC class II-deficient mice, MHC class II-deficient mice with an intact peripheral CD4+ cell population (due to expression of class II antigens only on thymic epithelium), mice lacking the cytoplasmic tail of their MHC class II antigens, and mice depleted of CD4+ cells by anti-CD4 monoclonal antibody treatment. Depletion of recipient CD4+ cells reduced alloantibody production to barely detectable levels. Absence of donor MHC class II antigens did not affect the production of either immunoglobulin (Ig)M or IgG antibodies directed at class I alloantigens. Absence of recipient MHC class II antigens, however, led to production of only IgM but not IgG antibodies, even if the recipients had an intact CD4+ cell population. Absence of the cytoplasmic tail of the recipient's MHC class II antigens led to the production of slightly reduced amounts of IgG antibody. These findings indicate that (a) CD4+ cells are essential helper cells for B cell alloantibody production; (b) production of IgM alloantibody can occur with help from CD4+ cells, which recognize either donor class II antigens or modified recipient class II antigens; (c) isotype switching from IgM to IgG alloantibody requires help from CD4+ cells activated by antigens presented by recipient MHC class II molecules; and (d) the cytoplasmic domain of the recipient MHC class II molecules may be involved in the mechanism that leads to isotype switching by B cells. Thus, there are two levels of CD4-mediated help available for B cells responding to alloantigens: one (involving a noncognate interaction) can produce B cell activation, and a second (involving a cognate interaction) is required for differentiation and IgG alloantibody production.

Animals↗