Anomalous right coronary artery originating from the left sinus of Valsalva in a Yucatan minipig

A 39.2-kg, castrated male Yucatan minipig (Sus scrofa domestica) was presented for enrollment in a coronary artery study. Angiography revealed an anomalous right coronary artery originating from the left sinus of Valsalva. The left anterior descending, left circumflex, and anomalous right coronary arteries were implanted with metallic stents without complications. The minipig remained on the study for 3 mo until it reached its predetermined study endpoint, during which time it showed no clinical signs of disease. Histologic examination of the implanted coronary arteries revealed no differences between the normal (left anterior descending and left circumflex arteries) and the anomalous right coronary artery. Swine are important models for coronary research. Although several cases of anomalous human coronary arteries have been documented, the current case is the first report of a coronary artery anomaly in a minipig.     

Immunization with a Recombinant Vaccinia Virus That Encodes Nonstructural Proteins of the Hepatitis C Virus Suppresses Viral Protein Levels in Mouse Liver

Chronic hepatitis C, which is caused by infection with the hepatitis C virus (HCV), is a global health problem. Using a mouse model of hepatitis C, we examined the therapeutic effects of a recombinant vaccinia virus (rVV) that encodes an HCV protein. We generated immunocompetent mice that each expressed multiple HCV proteins via a Cre/loxP switching system and established several distinct attenuated rVV strains. The HCV core protein was expressed consistently in the liver after polyinosinic acid–polycytidylic acid injection, and these mice showed chronic hepatitis C-related pathological findings (hepatocyte abnormalities, accumulation of glycogen, steatosis), liver fibrosis, and hepatocellular carcinoma. Immunization with one rVV strain (rVV-N25), which encoded nonstructural HCV proteins, suppressed serum inflammatory cytokine levels and alleviated the symptoms of pathological chronic hepatitis C within 7 days after injection. Furthermore, HCV protein levels in liver tissue also decreased in a CD4 and CD8 T-cell-dependent manner. Consistent with these results, we showed that rVV-N25 immunization induced a robust CD8 T-cell immune response that was specific to the HCV nonstructural protein 2. We also demonstrated that the onset of chronic hepatitis in CN2-29^(+/−)/MxCre^(+/−) mice was mainly attributable to inflammatory cytokines, (tumor necrosis factor) TNF-α and (interleukin) IL-6. Thus, our generated mice model should be useful for further investigation of the immunological processes associated with persistent expression of HCV proteins because these mice had not developed immune tolerance to the HCV antigen. In addition, we propose that rVV-N25 could be developed as an effective therapeutic vaccine.     

Bombyx small RNAs: genomic defense system against transposons in the silkworm, Bombyx mori

Selfish genetic elements called transposons can insert themselves at new locations in host genomes to modify gene structure and alter gene expression. Expansion of transposons can occur when novel transposition events are transmitted to subsequent generations after germline hopping. Therefore, organisms seem likely to have evolved defense mechanisms to silence transposons in the germline. Recently, small RNAs interacting with Piwi proteins (piwi-interacting RNAs: piRNAs) have been demonstrated to be involved in genomic defense mechanism against transposons. Here, we show that piRNA-like small RNAs are present abundantly in the Bombyx ovary. We cloned 38,493 kinds of Bombyx small RNA from the ovary and performed functional characterization. Bombyx small RNAs showed a unimodal length distribution with a peak at 28nt and a strong bias for U at the 5' end. We found that 12,869 kinds of Bombyx small RNAs were associated with transposons or repetitive sequences. We classified them as repeat-associated small interfering RNAs (rasiRNAs), a subclass of piRNAs. Notably, antisense rasiRNAs have a strong bias toward U at 5' ends; in contrast, sense rasiRNAs have a strong bias toward A at nucleotide position 10, indicating that the piRNA amplification loop proposed in Drosophila is evolutionarily conserved in Bombyx. These results suggest that Bombyx small RNAs regulate transposon activity.     

Preparation and partial characterization of monoclonal antibodies specific for the nascent non-triple helical form of the type IV collagen alpha 1 chain

This report describes the preparation and partial characterization of monoclonal antibodies that are reactive specifically with the nascently produced non-triple helical form of the type IV collagen α1 chain, designated as NTH α1(IV). These antibodies were nonreactive with the α1 chain of the type IV collagen in the triple-helical conformation. Three antibodies, #141, #179 and #370, with different epitopes in NTH α1(IV) were found to be reactive with the nascent polypeptide secreted from human normal cells and a human carcinoma cell line. The antibodies with different epitopes may provide a key method for elucidating the physiological function and tissue distribution of NTH α1(IV), which is distinct from the chain derived from triple-helical type IV collagen.     

Evaluation of the relative contribution of p53-mediated pathway in X-ray-induced apoptosis in human leukemic MOLT-4 cells by transfection with a mutant p53 gene at different expression levels

There are several pathways leading to apoptosis. It is not clear whether cells choose one of them or use multiple processes when they commit to apoptosis. MOLT-4 cells undergo apoptosis after X-irradiation through the p53-dependent pathway and/or ceramide signal. To evaluate the relative contribution of these pathways, we studied effects of the expression of various levels of transfected murine mutant p53 cDNA (TGC-->CGC of codon 173, corresponding to codonl76 in human p53) on the induction of apoptosis in X-irradiated or heated MOLT-4 cells. When survival was determined by the dye-exclusion test at 24 h after irradiation, the percentage of X-ray- or heat-induced dead cells was markedly decreased, depending on the expression level of mutant p53 protein in transfected clones. The appearance of apoptotic cells as determined by morphological changes was also decreased. These inhibitions were almost complete at 24 h after irradiation with X-rays in the case of the highest-expressing clone. p21 WAF1 protein was increased in MOLT-4 cells after X-irradiation, but not in the transfectant. These results suggest that murine mutant p53 protein has a dominant-negative effect against normal p53 in MOLT-4, and that the X-ray-induced apoptosis in MOLT-4 is fully p53-dependent.     

Thyroid hormone directly induces hepatocyte competence for estrogen-dependent vitellogenin synthesis during the metamorphosis of Xenopus laevis

Hepatocytes competent for estrogen-dependent vitellogenin synthesis appeared and increased in number in the liver at the metamorphic climax of Xenopus laevis (A. Kawahara, S. Kohara, Y. Sugimoto, and M. Amano, 1987, Dev. Biol. 122, 139-145). The present study was conducted to determine whether cells competent for vitellogenin synthesis could be induced by thyroid hormone in a primary culture of larval hepatocytes. The thyroid hormone, triiodothyronine (T3), directly induced the competent cells in a primary culture of premetamorphic larval hepatocytes in a dose- and duration-dependent manner. The competency acquired in response to T3 persisted after removal of the hormone. Aphidicholin, an inhibitor of DNA synthesis, failed to block this induction, suggesting the presence of a "precursor cell fraction." This cell fraction in the hepatocyte population increased with the progress of metamorphosis. The thyroid hormone is thus considered the cause of competent cell formation at metamorphic climax.     

Correlation of a subset of the pLC plasmids to the physical map of Escherichia coli K-12.

We determined map positions of the Escherichia coli K-12 portions of a subset of the hybrid E. coli-ColE1 plasmids constructed by Clarke and Carbon. The probe DNA of pLC plasmids was labeled with digoxigenine-dUTP, hybridized to the 476 phage clones of the E. coli ordered clone bank miniset, which was adsorbed on a strip of nylon membrane filters, and detected by enzyme-linked immunoassay and a subsequent enzyme-catalyzed color reaction. The total number of Clarke-Carbon plasmids we analyzed was 518, for which chromosomal locations of 297 clones were newly determined in the present study. Another 180 plasmids gave results that agreed with those reported previously, and the remaining 41 plasmids gave map positions different from those described in the previous report. A chromosome map of E. coli which shows the locations of 518 pLC plasmids on it is presented, as well as a table which correlates the pLC plasmids with the clones of the E. coli ordered clone bank miniset on the basis of the hybridization data. We estimate that approximately one-half of the entire genome of E. coli was covered by the pLC plasmids used in this study.