Bovine leukemia virus high tax molecular clone experimentally induces leukemia/lymphoma in sheep

Sheep were inoculated with high tax coded pBLV-IF (H group, Nos.1-5) of bovine leukemia virus (BLV), wild tax coded pBLV-IF (W group, Nos. 6-11), or control plasmid (C group, Nos. 12-14). During the observation period (4 to 46 months), 5 of 5 cases in H group and 3 of 6 cases (Nos. 6, 7, 9) in W group became positive for gp 51. Only 1 case in H group became leukemic, and one case each of H and W groups developed lymphoma. In No. 3, lesions were found in multiple organs including the lymph nodes, gastrointestinal tract following abomasum, and heart. In No. 6, lesions of lymphoma were found only in the jejunum and heart. Morphologically, small to middle-sized lymphocytic neoplastic (NP) cells were found in both cases, but lymphoblastic NP cells were found only in No. 3. By immunohistochemical examination, the phenotypes of NP cells were determined as CD1-, CD4-, CD5- -, CD8alpha-, sIgM+, lambda light chain+, B-B4+, MHC class II+ in both case. The results of this study indicate that inoculation of pBLV-IF can induce lymphocytic and lymphoblastic leukemia/lymphoma in sheep. Additionally, it is suggested that the expression rate of tax gene is not associated with the development of leukemia/lymphoma in sheep experimentally inoculated with pBLV-IF.     

Accumulation of short interfering RNAs characteristic of RNA silencing precedes recovery of tomato plants from severe symptoms of <Emphasis Type="Italic">Potato spindle tuber viroid</Emphasis> infection

Tomato plants infected with Potato spindle tuber viroid (PSTVd) had severe leaf curling and vein necrosis. The disease symptoms began to diminish during the late stages of infection, however, and almost healthy-looking leaves began to appear on the upper portion of the plants. PSTVd concentrations reached their highest levels in leaves with severe symptoms and decreased in upper leaves recovering from severe symptoms. PSTVd-specific short interfering RNAs (siRNAs), characteristic of RNA silencing, accumulated in all leaves in which PSTVd reached a detectable level, suggesting that recovery from severe disease was induced by RNA silencing via sequence-specific degradation of PSTVd.     

Protective effects of vaccination with bovine leukemia virus (BLV) Tax DNA against BLV infection in sheep

A DNA vaccination trial was performed on sheep to determine whether vaccination with bovine leukemia virus (BLV) transactivator Tax DNA is effective against BLV infection. Immunization was carried out with cationic liposomes containing the Tax-expressing plasmid DNA and subsequently all sheep were challenged with BLV. BLV titers in peripheral blood mononuclear cell (PBMC) determined by syncytium formation assay and BLV provirus load detected by genomic PCR analysis showed higher levels of virus titers in control sheep than those in Tax-vaccinated sheep. Higher levels of IFN-gamma mRNA expression have been demonstrated in vaccinated sheep after the challenge. These results suggested that Th1 type immune response induced by Tax DNA vaccine inhibited BLV propagation in vaccinated sheep at the early phase of infection.     

Positional effect of gene insertion on genetic stability of a clover yellow vein virus-based expression vector

The stability of the inserted genes in the viral expression vector varied depending on the sequence introduced and the position of insertion. Infectious cDNA to Clover yellow vein virus (pClYVV) was modified to insert a foreign gene at two independent sites: one, along with a polylinker, between the NIb and CP genes (pClYVV/CP/W) and the other between P1 and HC-Pro (pClYVV-Pst/CP). The green fluorescent protein (GFP) gene was inserted into either pClYVV/CP/W or pClYVV-Pst/CP. GFP gene was stably maintained and expressed in both vectors following serial passages in plants. Progeny viruses from both constructs accumulated in similar amounts and at rates of 70%–80% of that of the wild-type virus. On the other hand, progeny viruses carrying the human interferon- (hIFN) gene cloned in pClYVV-Pst/CP were genetically unstable owing to frequent deletions of the cloned gene during passage through plants. In contrast, the hIFN sequence cloned in pClYVV/CP/W was stably maintained in viruses after several passages in broad bean plants, and the progeny virus accumulated at the rate of about 50%–100% of that of the wild-type virus. The nucleotide sequence analyses indicated that the genetic instability of the inserted sequence results from homologous recombination of viral vector and inserted DNA sequences; it is not due to the inserted sequence alone.     

Linkage mapping of four chicken calpain genes

Calpains are intracellular Ca²⁺‐dependent proteases and enzymes that contribute to growth and meat quality. In the present study, we identified polymorphisms in four calpain genes (CAPN1, CAPN2, CAPN3, and CAPN1.5) expressed ubiquitously in chicken using polymerase chain reaction‐restriction fragment length polymorphism, and mapped them using two backcross families (East Lansing (EL) and Kobe University (KU)). CAPN2 and CAPN1.5 mapped to two locations on chromosome 3 about 30 cM apart, while CAPN3 mapped to chromosome 5. CAPN1 was linked to a previously unlinked microsatellite marker LEI0140 to form a new linkage group called E66. CAPN2 and CAPN3 extend the amount of conserved synteny between chicken chromosome 3 and human chromosome 1, and between chicken chromosome 5 and human chromosome 15, respectively. Although CAPN2, CAPN3, and CAPN1.5 were found in the University of California Santa Cruz chicken genome browser gateway, CAPN1 and LEI0140 were not in specific genomic positions.     

Kinetics of endotoxin concentration and tumor necrosis factor-alpha,interleukin-1beta,and interleukin-6 activities in the systemic and portal circulation during small intestinal ischemia and reperfusion in dogs

OBJECTIVE: To determine whether small intestinal ischemia and reperfusion induces bacterial translocation and proinflammatory cytokine response in either the systemic or portal circulation in dogs. ANIMALS: 17 healthy adult Beagles. PROCEDURE: The superior mesenteric artery (SMA) was occluded for 0 (group-3 dogs), 30 (group-1 dogs), or 60 (group-2 dogs) minutes, followed by reperfusion for 180 minutes; serum lactate and endotoxin concentrations and tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and IL-6 activities in the systemic and portal circulation and intramucosal pH were measured at various time points. RESULTS: In group-2 dogs, TNFalpha activity was found to be significantly increased in the portal circulation, peaking at 60 minutes of reperfusion; TNF-alpha activity, in the systemic circulation, gradually increased from 60 minutes of reperfusion to the end of the experiment; however, the increase was not significant. In group-1 and -2 dogs, IL-6 activities significantly and gradually increased in the systemic and portal circulation during the reperfusion phase, and the magnitude of these increases was dependent on the duration of the ischemic phase. There were no significant changes in IL-1beta activity or endotoxin concentration in any dog group. CONCLUSIONS AND CLINICAL RELEVANCE: Results of the our study indicate that intestinal ischemia and reperfusion leads to significant increases of the circulating TNF-alpha and IL-6 activities, depending on the duration of the ischemia phase, in the absence of detectable endotoxin in the circulation. This finding suggests that intestinal ischemia and reperfusion induces a systemic proinflammatory cytokine response in dogs.     

Dynamic left ventricular outflow tract obstruction secondary to hypovolemia in a German Shepard dog with splenic hemangiosarcoma

Dynamic left ventricular outflow tract obstruction (DLVOTO) is a common condition in cats and humans. In this case report, a dog is described with DLVOTO secondary to severe intra-abdominal hemorrhage caused by a hemangiosarcoma. The dog was a 9-year-old, 35.7-kg, spayed female German Shepard dog that presented with a history of tachypnea and collapse. A Levine II/VI systolic murmur was present at the heart base. Abdominal ultrasonography revealed a splenic mass and a large amount of ascites. Echocardiography showed a reduced left ventricular diameter and an increased aortic velocity caused by systolic anterior motion (SAM) of the mitral valve apparatus. The heart murmur and the SAM were resolved after treatment including a splenectomy and a blood transfusion.     

Comparison of extractive components in muscle and liver of three Loliginidae squids with those of one Ommastrephidae species

Extractive components were determined for the mantle muscle and liver of three species of Loliginidae squid, Sepioteuthis lessoniana, Loligo bleekeri, and L. edulis, and one species of Ommastrephidae, Todarodes pacificus, as a control. Total free amino acid levels and the major free amino acids in muscle, taurine, proline, glycine, alanine, and arginine, were significantly higher in Loliginidae squids than in T. pacificus. The main nucleotide was adenosine 5′-monophosphate, which did not differ significantly between species. Malate was the organic acid found in muscle in highest concentrations. The muscle of these species contained a large amount of trimethylamine oxide. A large amount of glycine betaine was also detected in the muscle, but showed no large species difference. From these results, the muscle of Loliginidae species is considered to have a much sweeter taste than that of T. pacificus. Compared with muscle, squid liver was characteristic with high contents of taurine, glutamate, bitter amino acids, succinate, propionate, trimethylamine, and glycine betaine, and with low contents of sweet amino acids, arginine, nucleotides, malate, and trimethylamine oxide. These results suggest that squid liver is characterized by a complicated taste containing umami, bitterness, sourness, fishy flavor, and less sweetness.