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Biomedical subjects

N Ishiguro

Publications and source records attributed to N Ishiguro.

At least 109 records · Page 6Linked to original sources
PubMed1994

A spontaneous internal deletion of the c-myb protooncogene enhances transcriptional activation in bovine T lymphoma cells.

Three double negative (BoCD4-, BoCD8-) bovine T cell lines, BTL-PC3, BLT2, and Pr2181, which have been established from bovine lymphosarcomas, were examined for expression and molecular function of bovine c-myb genes. BTL-PC3 expressed 4.0- and 3.6-kilobase c-myb transcripts, and BLT2 and Pr2181 expressed a 3.8-kilobase c-myb message. The c-Myb protein (75 kDa) was detected in Pr2181 but not as a clear band in BLT2, while BTL-PC3 exhibited a 65-kDa c-Myb band in immunoprecipitation tests with anti-Myb antiserum. Nucleotide sequences for c-myb cDNA clones from BTL-PC3 and BLT2 indicated that the predicted bovine wild-type c-Myb from BLT2 consists of 640 amino acids whereas that from BTL-PC3 consists of 555 amino acids lacking 85 internal amino acids. This deleted DNA region (255 base pairs consisting of 85 amino acids) corresponds to the human genomic exon 9 encoding a negative regulatory domain in the c-myb gene. Upon cotransfections with reporter plasmids containing myb binding sites, the internally deleted c-Myb exhibited a 3-fold higher transcriptional activity than the wild-type c-Myb in chloramphenicol acetyltransferase assays. These results indicate that internal DNA deletion in the c-myb gene is directly involved in the enhancement of transcriptional activation in bovine T lymphoma cells.

Amino Acid Sequence↗
PubMed1994

Detection of measles virus from clinical samples using the polymerase chain reaction.

OBJECTIVE: To evaluate the usefulness of the polymerase chain reaction to detect the measles virus sequence using clinical samples. DESIGN: Centers for Disease Control and Prevention case definition of measles with or without IgM serology as a standard. SETTING: A laboratory in the Department of Pediatrics of the Hokkaido University Hospital, Sapporo, Japan. PATIENTS: Thirty-two serum samples, 16 throat swab samples, and nine cerebrospinal fluid samples from 32 patients with measles, including four patients with central nervous system involvement, and one serum sample and two throat swab samples from two patients with modified courses of measles were obtained. Ten serum samples, 10 throat swab samples, and 10 cerebrospinal fluid samples were obtained from patients without apparent measles infection as negative controls. MEASUREMENTS AND MAIN RESULTS: Sensitivity and specificity were comparable with those as obtained by culture or other methods reported in the literature. The polymerase chain reaction was positive in 24 (75.0%) of 32 by serum samples and in 13 (81.3%) of 16 by throat swab samples from the patients with measles, in contrast to none within the negative control group. In three of the four patients with central nervous system involvement, the measles virus sequence was detected in cerebrospinal fluid samples obtained within 1 day following the onset of the manifestations. All three samples from the patients with modified measles yielded positive results. CONCLUSIONS: The polymerase chain reaction can be used with sufficient sensitivity and specificity to detect the measles virus sequence using clinical samples. Transient and direct invasion of the central nervous system by this virus at the initial stage of the central nervous system involvement was strongly suggested.

Adolescent↗
PubMed1994

Detection of PrPSc in sheep at the preclinical stage of scrapie and its significance for diagnosis of insidious infection.

A field sheep insidiously infected with natural scrapie was diagnosed at the preclinical stage through detection of the core fragment of PrpSc (PrPcore) in peripheral lymph nodes by the biopsy method. Three out of 32 euthanized healthy sheep were found positive for PrPcore in the spleen and lymph nodes. Mice that were inoculated with spleen homogenate of one of these sheep showed clinical signs of scrapie and were positive for PrPcore in their brain samples. These results suggest that the detection of PrPcore is significant for diagnosis in the preclinical phase of scrapie.

Animals↗
PubMed1994

Detection of stromelysin in synovial fluid and serum from patients with rheumatoid arthritis and osteoarthritis.

Stromelysin levels were measured using a one-step sandwich immunoassay in synovial fluid (SF) obtained from 31 patients with rheumatoid arthritis (RA) (31 samples) and 13 patients with osteoarthritis (OA) (13 samples) and in serum from 81 patients with RA (106 samples), 12 with OA (14 samples), 12 with gouty arthritis (gout) (14 samples), and 8 with osteoporosis (OP) (14 samples) to identify differences in the levels in these diseases as well as correlations with clinical parameters in RA. SF stromelysin levels were significantly higher in RA than in OA, and rose with increasing joint destruction in the former. No significant correlations were found between the SF stromelysin level in RA and various clinical parameters, except for the volume of SF which showed a correlation. Serum levels of stromelysin were highest in RA, gout, OA, and osteoporosis in decreasing order, and in RA were correlated with the Steinbrocker Stage. A significant correlation was also found between the serum stromelysin level and number of swollen joints, and correlations with the Lansbury index, ESR, CRP, WBC and Plt. The stromelysin level in SF was thought to be a useful parameter of local joint involvement and that in serum of the severity of systemic joint inflammation.

Aged↗
PubMed1994

Putative bovine B cell lineage tumor in sporadic bovine leukosis.

Two calves (C924 and C928) clinically identified as suffering from the calf type of sporadic bovine leukosis (SBL) were examined for immunophenotypical distribution of their peripheral blood lymphocytes (PBL) with T cell or B cell specific monoclonal antibodies (mAbs). Flow cytometric profile analysis indicated that both calves possessed a high population of MHC class II positive cells and a low population carrying T cell associated markers. More than 93% of the PBL of C928 were positive for MHC class II and BoCD5, but were not IgM positive, indicating that clonal tumor cells (MHC-II+, BoCD5+ and IgM-) accounted for most of the PBL of C928. A tumor cell line, BLC3, established from calf C924 in nude mice was examined for immunophenotype, DNA rearrangement of immunoglobulin (Ig) genes and expression of cellular oncogenes c-abl, c-myc and c-myb. BLC3 showed a characteristic profile, being MHC class I and MHC class II positive, but without T cell associated markers. Although the rearranged configuration in the Ig loci was not clearly found in Southern blot analysis using sheep Ig probes, steady-state levels of c-myb transcripts were detected in tumor cell line BLC3 by Northern blot hybridization. Taken together, our data show that the calf type of SBL found in these two calves is induced by immature pre-B cells, including tumor cell line BLC3 established in nude mice.

Animals↗
PubMed1994

Differentiation analysis of bovine T-lymphosarcoma.

The tumor cells from three different types (calf, skin and thymic) of bovine lymphosarcoma identified as sporadic bovine leukosis (SBL) were transplanted to nude mice and established as lymphoid tumor lines. To clarify the T-cell lineage, clonality and differentiation stage, these cell lines were examined for the immunophenotypic profile, the expression and the gene rearrangement of T-cell receptor (TCR) genes. The tumor cells from all three types showed alpha-naphthyl acetate esterase-positive staining and the absence of surface immunoglobulin (sIg). Moreover, the tumor cells appeared to be all BoCD5+ BoCD6+ BoCD4- BoCD8- cells in the FACS analysis with mAbs. Rearrangement of TCR-beta and -delta, but not of TCR-alpha and -gamma, genes was found to be unique for each tumor line showing T-cell clonality. Mature or truncated TCR-beta, -gamma and -delta transcripts were detected in the tumor cells, but all of them were found to be non-functional in cDNA cloning analysis. These results suggested that tumor cells from SBL are immature double-negative T-cells expressing non-functional TCR gamma delta transcripts to somewhat differentiated degrees.

Amino Acid Sequence↗
PubMed1994

Effect of parathyroid hormone (PTH) on replantation of amputated legs in a rat model.

Bone atrophy following replantation of an amputated extremity is related to the decrease of blood flow and to disuse. The effect of parathyroid hormone (PTH) on bone atrophy and bone formation was the subject of the reported study. Lewis rats were divided into amputated and replanted, and non-amputated groups, with the groups further divided into subgroups, with and without the administration of PTH. The agent (0.8 U/0.2 ml) was administered subcutaneously three times a week for 5 consecutive weeks, while controls were given 0.1 percent BSA buffer solution (0.2 ml) subcutaneously three times a week for 5 consecutive weeks. Subsequently, the animals were anesthetized, blood samples were taken, and tibias were extracted before sacrifice. Laboratory evaluations included bone assays and the measurement of bone mass and volume. In the group given PTH after amputation and replantation, there was increased bone formation, together with significant increases in bone Ca, bone P, ash content volume, and volume and serum alkaline phosphatase (Al-p), in comparison with the other groups. The administration of PTH after amputation and replantation was comparatively effective in mitigating the amount of bone damage.

Alkaline Phosphatase↗
PubMed1994

Morphologic and metabolic study of the effect of oxygenated perfluorochemical perfusion on amputated rabbit limbs.

The purpose of this investigation was to examine the effect of oxygenated perfluorochemical perfusion on ischemia injury to skeletal muscle in rabbits. Forty-two hindlimbs of white rabbits were divided into six groups: 3-hr perfusion; 6-hr perfusion; 3-hr hypothermia; 6-hr hypothermia; sham operation without perfusion or hypothermia preservation; and biopsy. Endothelial cells in these muscles were evaluated using electron microphotography. The areas of both the inner and outer sides of cross-sectioned endothelial cells without cell nuclei were measured, and a new "capillary index" was calculated: (outer area--inner area)/outer area. The values of the capillary index in the perfusion groups were similar to those in the biopsy group. However, the values in the hypothermia groups were significantly greater than those in the biopsy group. These measurements suggested that the perfluorochemical perfusion method preserved the capillary endothelial cells in a nearly normal condition. The adenine nucleotides of these muscles were also evaluated. ATP levels in the 6-hr hypothermia group showed a substantial decrease to 57 percent of those in the sham-operated group. The 6-hr perfusion group levels, however, decreased only to 80 percent of those in the sham-operated group. Although application of the oxygenated perfluorochemical perfusion method did not maintain normal ATP levels, the maintenance of ATP levels was clearly higher than levels maintained in the hypothermia-preservation group. These findings suggest that oxygenated perfluorochemical perfusion is a satisfactory method for preserving amputated limbs.

Adenine Nucleotides↗
PubMed1994

Basic fibroblast growth factor has a beneficial effect on the viability of random skin flaps in rats.

We investigated the effect of exogenous basic fibroblast growth factor (bFGF) on the viability of random skin flaps in rats. Thirty-six rats were divided into three groups of 12 animals: a saline control group and two bFGF-treated groups. Caudally based random skin flaps were raised on the backs of the rats. In the control group, saline was instilled under the flap after skin closure. Twelve other rats were treated with bFGF (20 micrograms) just after skin closure. The remaining 12 rats were treated twice with bFGF (20 micrograms), both just after the operation and 48 hours later. There was a significant improvement in viability in the bFGF-treated groups on postoperative day 7 compared with the control group. Total adenine nucleotide levels in the flaps on postoperative day 10 were significantly higher in the group receiving two doses of bFGF than in the other groups. Thus, bFGF can improve the viability of endangered skin flaps.

Adenine Nucleotides↗
PubMed1994

Mapping of determinants of the host range for canine cells in the genome of canine parvovirus using canine parvovirus/mink enteritis virus chimeric viruses.

Feline panleukopenia virus (FPLV), mink enteritis virus (MEV) and canine parvovirus (CPV) are more than 98% similar in DNA and predicted amino acid sequences, but they show different host-cell specificities; CPV is able to replicate in canine cells in culture, whereas FPLV and MEV cannot or replicate only to a low titre. To map the genomic region responsible for the host range of CPV in vitro, CPV/MEV chimeric viruses were generated by transfecting infectious CPV/MEV chimeric plasmids into a cultured feline kidney cell line, and their host cell ranges were analysed. The 60 to 91 map units (m.u.) region of the CPV genome, which contains a part of the capsid protein (VP) gene encoding from amino acid 91 (in the VP2 sequence) to the carboxy terminus of VP protein, was required to impart the ability to replicate in canine cells to MEV, although the chimeric virus containing the 60 to 91 m.u. region of the CPV genome in the MEV background did not replicate in canine cells as efficiently as did CPV derived from the infectious plasmid of CPV. Not only the VP gene, but also a part of the NS gene of CPV were considered to participate in the full expression of the ability to replicate in canine cells. Within the 60 to 91 m.u. region, five of nine amino acid changes between MEV-Abashiri and CPV-Y1 were thought to be phylogenetically CPV-common; however, a recombinant virus containing all five amino acid changes of CPV in the MEV background replicated minimally in canine cells.

Animals↗
PubMed1994

Effects of thromboxane A2 synthetase inhibitor (CV-4151) on reperfused skeletal muscle in rats.

To clarify the role of thromboxane A2 synthetase inhibitor (CV-4151) in the ischemia-reperfusion injury, the effect of CV-4151 was investigated in the gastrocnemius muscles of female Lewis rats. All tissues except femoral vessels were transected at the midthigh level and 4 h of ischemia was induced by vascular clamping of the femoral artery and vein, followed by 1 h of reperfusion. The sham group (n = 8) underwent the operation without ischemia-reperfusion; the control group (n = 8) with ischemia-reperfusion, and the CV-4151 group (n = 8) was pretreated with CV-4151 20 mg/kg. Skeletal muscle blood flow was measured by a hydrogen gas clearance method; the blood flow restored fully in the CV-4151 group, while it remained significantly low in the control group after 1 h of reperfusion (p < 0.05). Tissue levels of adenosine triphosphate (ATP) and creatine phosphate (PCR) were measured after 1 h of reperfusion; ATP decreased to 25% of nonischemic values in the control group. In contrast, premedication with CV-4151 significantly improved the recovery of ATP (p < 0.01). PCR showed the same tendency as ATP; CV-4151 also improved the recovery of PCR significantly (p < 0.05), but CV-4151 did not prevent the production of lipid peroxides. Serum thromboxane B2 was determined by radioimmunoassay; in the sham and the CV-4151 group the level was significantly lower than in the control group (p < 0.05). was significantly lower than in the control group (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenine Nucleotides↗
PubMed1994

Prolonged occurrence of Moraxella bovis infection on a restricted heifer farm.

An epizootiologic study was conducted for infectious bovine keratoconjunctivitis (IBK) on a large grassland farm rearing a total of 1,300-1,400 heifers during May to October in both 1991 and 1992. Heifers were examined for infection with Moraxella bovis, and isolation of M. bovis from the affected eyes and from Asian face flies (Musca bezzii Patton et Cragg) swarming on the heifer face was carried out. During the observation period, 10.7% of the heifers in 1991 and 5.3% of the heifers in 1992 were affected with IBK. Eight M. bovis isolates were isolated from the ocular swabs of affected heifers with IBK for 2 years and identified by biochemical examinations and Southern DNA-DNA hybridization, but no M. bovis was obtained from 331 Asian face flies tested. Plasmid profile analysis showed that two plasmids (35-kb and 4.0-kb) were commonly found in all 8 M. bovis isolates. This indicates that M. bovis isolates with the same plasmid profile were widely disseminated on this farm for 2 years.

Animals↗
PubMed1994

Survey of natural scrapie in Japan: analysis of RFLP types of the PrP gene and detection of PrPSc mainly in Suffolk sheep.

We examined the brains, spleens and/or lymph nodes of 197 mainly suffolk sheep collected from Hokkaido, and the Tohoku, Kanto and Chubu districts to detect PrPSc and thus to estimate scrapie contamination in Japan. Sixteen sheep in Hokkaido and 2 sheep in other districts that were introduced from Hokkaido were positive for PrPSc. By comparison of the frequencies of the restriction fragment length polymorphism (RFLP) types of these 18 scrapie sheep with 128 healthy sheep, we confirmed the association of specific RFLP types of the PrP gene with natural scrapie. The frequency of RFLP type I in scrapie sheep was significantly higher than that in healthy sheep and those of other types in scrapie sheep. In contrast, the frequencies of type II and VI in healthy sheep were higher than those in scrapie sheep. Therefore, type I sheep seemed to be susceptible but type II and VI sheep seemed to be resistant to natural scrapie in Suffolk sheep in Japan. Furthermore, we investigated the distribution of the RFLP types of the PrP gene in 161 sheep in Japan to learn about the genetic background of the susceptibility to scrapie. There were variations in the distribution of the RFLP types in each district.

Animals↗
PubMed1994

Characterization of monoclonal antibodies against sporadic bovine leukosis cell lines.

We report here distributions of antigens expressed on sporadic bovine leukosis (SBL) cells by a total of 38 monoclonal antibodies (mAbs) directed against three different types of SBL-cell lines, BLT2 (thymic type), BTL-PC3 (calf type) and BLS1 (skin type). Most mAbs had high reactivities with some bovine lymphoma cell lines and less reactivity with normal lymphocytes except for some peripheral blood mononuclear cells (PBM) in cattle and certain other species. They were more reactive with cultured T-cell line BTL-PC3 and B-cell lines, BL312 and KU-1, than naturally occurring lymphoid tumor cells. Among the 38 mAbs, 27 was determined the molecular weights of their recognized antigens in Western blot analyses. A mAb C419 had high reactivity with lymphoma cell lines but no reactivity with normal lymphocytes, indicating that it recognizes tumor-associated antigens of SBL.

Animals↗
PubMed1994

Monoclonal antibody S37 induces apoptosis in bovine T lymphoma cells.

Influences of 38 monoclonal antibodies (mAbs) on the growth of bovine T lymphoma cells (BTL-27) were examined. One of them, S37, inhibited the cell growth strikingly when it was added to the cultures. S37-treated cells showed DNA fragmentation containing approximately 200-base pair multiple patterns and chromatin condensation. This evidence suggested that mAb S37 induced apoptosis in BTL-27 cells.

Animals↗