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Biomedical subjects

T Kunieda

Publications and source records attributed to T Kunieda.

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

Prion protein (PrP) is not involved in the pathogenesis of spongiform encephalopathy in zitter rats.

In order to elucidate the relationship between the prion protein (PrP) structure and the development of spongiform encephalopathy in zitter rats, we analyzed the nucleotide sequences and restriction fragment length variation (RFLV) of the Prn gene encoding PrP in zitter rats and inbred SD/J rats as a control. Prn genes from two strains had identical nucleotide sequences in their coding sequences. Obvious RFLV on the locus was not detected in zitter rats by a Southern blot hybridization. Consistently, zitter rat brains express the normal cellular PrP (PrPC), but do not accumulate the protease-resistant modified isoform (PrPSC). These results indicate that PrP is not involved in the pathogenesis of spongiform encephalopathy in zitter rats.

Amino Acid Sequence↗
PubMed1994

A genetic linkage map of rat chromosome 5 reveals extensive linkage conservation with mouse chromosome 4.

Linkages among three biochemical loci (Aco1, Ahd2, and Mup1) and four microsatellite loci (A8, Glut1, Jun, and Pnd) were determined to construct a linkage map of rat Chromosome (Chr) 5. Consequently, an extensive linkage map on rat Chr 5 was constructed with the following gene order: A8-Aco1-Mup1-Jun-Glut1-Ahd2-Pnd. In this linkage map, the Jun and A8 loci are newly placed, and two previously reported linkage groups on rat Chr 5 are connected by the Jun locus. The linkage map indicates an extensive linkage conservation between the loci on rat Chr 5 and those on mouse Chr 4.

Animals↗
PubMed1994

A restriction fragment length polymorphism of a p53-related sequence in rat (Rattus norvegicus).

Polymorphisms of the p53 tumor-suppressor gene and its related sequences were investigated among inbred rat strains. In a series of Southern blot hybridizations using the human p53 cDNA probe with various restriction endonucleases, HindIII digests and PstI digests showed interstrain variation in the length of hybridizing fragments. Distribution of the HindIII variant fragments among 17 inbred rat strains was identical with that of PstI variant fragments. The variant fragments were segregated as codominant alleles in backcross progeny, and the locus for this restriction fragment length polymorphism of the p53-related sequence was found to correspond to a p53-related sequence located on rat chromosome 9.

Alleles↗
PubMed1994

Localization of a N-ras-related sequence on rat chromosome 1.

Location of the locus for a restriction fragment length polymorphism of N-ras-related sequences (NRAS2) on the rat chromosome 1 was determined by linkage analysis using a microsatellite locus (KAL) and a coat-color locus (C). The recombination frequencies between NRAS2 and C, NRAS2 and KAL, and C and KAL in 57 backcross progeny obtained from crosses of (WKS/Iar x IS/Iar) x WKS/Iar were 7.0 +/- 3.4%, 28 +/- 5.9%, and 23 +/- 5.6%, respectively. The order of the three loci on the rat chromosome 1 was determined as follows: KAL-C-NRAS2.

Animals↗
PubMed1993

PCR sexing and developmental rate differences in preimplantation mouse embryos fertilized and cultured in vitro.

A two-step polymerase chain reaction (PCR) assay was used to determine the sex of mouse preimplantation embryos obtained from oocytes fertilized and cultured in vitro, to investigate the differences in the developmental rates of mouse embryos according to the sex. All the in vitro developed embryos could be analyzed by this method. When the embryos were classified according to the time of morula to blastocyst transition as fast-intermediate- and slow-growing embryos, a significantly high percentage (78.0%) of the fast-developing embryos were identified as males; while a significantly lower percentage (42.5%) of slow-developing embryos were identified as males. The intermediate-developing embryos presented a sex ratio not significantly different from the total (57.5%). The deviation of sex ratio was further confirmed by embryo transfer experiment, where fast- and slow-developing embryos gave 76.2% and 25.7% male fetuses, respectively. We concluded that male mouse embryos fertilized and cultured in vitro develop faster than female embryos.

Animals↗
PubMed1993

Pulmonary hypertension due to tumor emboli: a report of three autopsy cases with morphological correlations to radiological findings.

Three cases of pulmonary hypertension caused by tumor emboli to the lungs are described. Two of the three cases had a clinical diagnosis of pulmonary thromboembolism until surgical embolectomy, and the other had a diagnosis of primary pulmonary hypertension. Autopsy disclosed chondrosarcoma, choriocarcinoma and gastric cancer as the primary tumors, respectively. Pulmonary vascular obstruction due to tumor embolism leading to pulmonary hypertension is a previously rare clinical entity, and obstructed pulmonary vessels are believed to tend to be small vessels. We compared the autopsy and radiological findings and concluded that pulmonary tumor embolism involved not only the small peripheral arteries but also the segmental and/or lobar arteries.

Adult↗
PubMed1993

Identification of inbred rat strains by using DNA fingerprinting method.

DNA fingerprinting method was applied to identify inbred strains of laboratory rats. By Southern blot hybridization with core sequence of minisatellite DNA as a probe, typical hypervariable patterns of DNA fingerprint were obtained in inbred rat strains. The patterns were completely different among 15 rat strains examined, and the patterns of the DNA fingerprint of samples obtained from the same strain were completely identical. The patterns of the DNA fingerprint of two substrains derived from the same strain were identical, indicating relative stability of the patterns over a large number of generations. Therefore, we concluded that the DNA fingerprinting method was useful for the identification of inbred strains in genetic monitoring of laboratory rats.

Animals↗
PubMed1993

Right-to-left interatrial shunt in rats with progressive pulmonary hypertension.

A right-to-left interatrial shunt may prolong survival in patients with pulmonary hypertension presumably because of decompression of the right side of the heart. To test this hypothesis, 74 rats with monocrotaline-induced pulmonary hypertension were followed up weekly with cardiopulmonary exercise testing with a metabolic treadmill system for exercise tolerance, heart rate, oxygen uptake, carbon dioxide production, and survival until subsequent or induced death 8 weeks after monocrotaline treatment. In rats with an interatrial shunt, oxygen uptake and carbon dioxide production were higher and survival was better (n = 22, 27%) than those in rats without a shunt (n = 52, 0%; p < 0.05). For the prospective assessment of the effects of a reversed shunt, 24 other rats underwent a left superior vena cava-to-left atrial appendage anastomosis as a functional interatrial shunt (atrial septal defect group) 4 weeks after monocrotaline treatment when severe pulmonary hypertension had developed and were compared with an additional 25 rats receiving a sham operation. Both groups had exercise capacity depressed to the resting levels by 2 weeks after operation. Although transcutaneous oxygen levels decreased in response to exercise in the atrial septal defect group, uptake and carbon dioxide production stayed higher than those in the sham operation group with significantly better survival 4 weeks after operation (atrial septal defect 30% versus sham operation, 0%; p < 0.05), at which time a reversed shunt was determined with systemic embolization of intravenously infused microspheres. A right-to-left interatrial shunt, anatomic or functional, preserved basal metabolism and prolonged survival in rats with progressive pulmonary hypertension.

Animals↗
PubMed1992

Polymorphic microsatellite loci of the rat (Rattus norvegicus).

The EMBL and GenBank DNA databases were searched for microsatellite sequences of the rat containing dinucleotide repeats of (CA)n and (GA)n. Among those obtained, 23 sequences were analyzed by polymerase chain reaction to examine the size variation of the amplified fragment in inbred rat strains. All of the 23 microsatellite sequences varied in size among the strains tested. The 23 microsatellite loci in a pair of substrains separated from the same progenitor strain were then analyzed. Fragments identical in size were observed in all loci of the two substrains, indicating the stability of the microsatellite over a large number of generations. The microsatellite loci, therefore, should be useful markers for linkage analyses in the rat.

Animals↗
PubMed1992

A polymorphism detected in a variable number of tandem repeats (VNTR) of the seminal vesicle secretion (SVS) IV gene in inbred rats.

The second intron of the rat SVS IV gene contains a tandem repeat region of 20-bp sequences. This region was amplified using the polymerase chain reaction to detect variations. Three alleles, characterized by amplified fragments of 750, 490, and 390 bp, respectively, were found in 24 strains examined. This variation segregated in F1 and backcross progeny in an autosomal codominant manner. We tentatively designated this locus Svs-4. Analysis of linkages between the Svs-4 locus and other loci revealed that it was closely linked to the Svp-1 (less than 2.9%) and the a (10.0 +/- 6.7%) loci, which belong to rat linkage group IV. The Svp-1 and Svs-4 loci, however, were differently distributed among the inbred rat strains.

Alleles↗
PubMed1992

A restriction fragment length polymorphism (RFLP) locus of rat (Rattus norvegicus) linked to the Cs-1 locus of rat linkage group XIII.

A novel restriction fragment length polymorphism (RFLP) in inbred rats was revealed by Southern blot analysis with a clone arbitrarily chosen from a rat genomic library as a probe. A clone named alpha 403 showed interstrain variations in the length of the EcoRI and HindIII fragments. The EcoRI fragments were either 0.7 or 3 kb, those of HindIII were either 4.5 or 5 kb, and three types were identified as combinations of those fragments in 20 inbred rat strains. These types segregated in backcross progeny as codominant alleles. The locus for the RFLP was thus named A403. Analysis of linkage between the RFLP locus and 13 other loci reveal that the A403 locus was closely linked to the Cs-1 locus (15 +/- 5.2%), which belongs to rat linkage group XIII.

Animals↗