Maturation of functional antibody affinity in animals immunised with synthetic foot-and-mouth disease virus.

A good correlation exists between specific neutralising antibody titre and protection against challenge with foot-and-mouth disease virus (FMDV) in infected or virus-vaccinated cattle, but not in the case of animals immunised with synthetic FMDV peptides. Therefore, mechanisms other than simple neutralisation are likely to be important in vivo. Antibody affinity may influence the protective capacity of sera from immunised animals and experiments were carried out to measure the functional affinity for synthetic FMDV peptide of sera from guinea pigs and cattle given various synthetic vaccines. In guinea pigs given a single dose of synthetic vaccine, antibody affinity increased with time after immunisation. In cattle, however, administration of a second dose of peptide 21 days after the first markedly retarded the process of affinity maturation. For guinea pig sera of equivalent neutralising activity, those of higher functional affinity had higher protective indices than those of lower functional affinity. Knowledge of the importance of antibody affinity in protection against FMD is important for an improved understanding of the mechanisms of protection and for the design of novel vaccines.     

Presumptive subcutaneous surgical transplantation of a urinary bladder transitional cell carcinoma in a dog

A urinary bladder mass in a 12-year-old spayed female West Highland White Terrier was diagnosed after exploratory surgery and biopsy as a transitional cell carcinoma. Four months later the dog presented with an ulcerated plaque-like cutaneous lesion at the previous surgical incision site; concurrent inguinal lymphadenopathy and recurrence of the urinary bladder mass were identified. Transitional cell carcinoma was diagnosed at all 3 sites. Although a definitive relationship cannot be established between the initial surgery for urinary bladder mass and the resultant subcutaneous lesion, surgical implantation should be considered as a source for the neoplastic cells.     

Antitumor effect of adriamycin entrapped in liposomes conjugated with anti-bovine tumor antigen monoclonal antibody in leukemic cows

Monoclonal antibody c143 against tumor-associated antigen (TAA) expressed on bovine leukemia cells was conjugated to liposomes containing adriamycin (ADM), and therapeutic effects of conjugates were examined in leukemic or preleukemic cows to prevent the progression of the disease. Five cows with TAA-positive in their peripheral blood lymphocytes were divided into two groups. Each group of cows received 4 injections of ADM alone (0.4 mg/kg) or c143-conjugated liposomes containing the same dose of ADM (L-AMD-c143) through the jugular vein at about 4 day intervals. In three animals treated with L-ADM-c143, the TAA-positive cells gradually decreased with treatment and finally two animals became TAA-negative during a 6 week period and a 14 week period after treatment, respectively. In the control, two animals treated with ADM alone showed only a slight decrease of TAA-positive cells.     

Seasonal changes in serum total thyroxine, free thyroxine, and canine thyroid-stimulating hormone in clinically healthy beagles in Hokkaido.

The purpose of this study was to evaluate seasonal influences on thyroid hormone levels of healthy outdoor dogs in Hokkaido. We surveyed serum basal total thyroxine (tT4), free thyroxine (fT4), and canine thyroid-stimulating hormone (cTSH) levels, and tT4 levels after administration of TSH for a year. Basal tT4 levels decreased in January, and increased in August and September. fT4 levels increased in January and November. No significant seasonal variation was found in cTSH. tT4 levels after administration of TSH in August and November increased. These results suggested that the thyroid gland may have been activated in November. We should take seasonal variation into consideration when thyroid function is tested.     

Effects of Benzyl Adenine and Abscisic Acid on Grain Yield and Yield Components in Triticale and Wheat

Grain yield and yield components (grains per ear, grain weight, 1000-grain weight, ear weight, ear seed ratio and dry matter partitioning between ear and seed) were examined in a wheat genotype (PBW-343) with well-filled grains and a Triticale genotype (DT-46) with poorly filled grains (showing grain shrivelling) grown in pots. Six days after anthesis (DAA), benzyladenine (BA) @2 µg ear⁻¹ and abscisic acid (ABA) @4 µg ear⁻¹ were injected at the base of the mother shoot ear in both species. It was observed that, in both wheat and Triticale , BA increased the grain weight, grain number and partitioning of dry matter between ear and seed, whereas ABA decreased the grain weight, grain number and dry matter partitioning between ear and seed. However, these decreases were slower in Triticale than in wheat. BA treatment increased the grain dry matter accumulation, which in turn resulted in better filling of grains and increased the grain weight in both wheat and Triticale . The average grain weight of Triticale was lower than that of wheat. Thus, it appears that variation in grain weight between wheat and Triticale might be due to different availabilities of growth-promoting phytohormones such as cytokinins and assimilates.     

Survey of tick infestation and tick-borne ehrlichial infection of dogs in Ishigaki Island, Japan.

Twelve (54.5%) of 22 free-roaming dogs in Ishigaki Island had tick infestation identified as Rhipicephalus sanguineus. There were 121 ticks recovered and consisted of 28 females, 58 males, 22 nymphs and 3 larvae. Infection of dogs possibly with canine ehrlichial pathogens was examined by both indirect immunofluorescence assay and polymerase chain reaction (PCR). Two dogs of the 13 examined were sero-positive for the human granulocytic ehrlichia agent, and one of two dogs was PCR positive for Ehrlichia platys. This dog had platelet numbers slightly lower than normal value, however, no morulae were found within platelet on peripheral blood smear stained with Giemsa.     

Identification of the porcine cytomegalovirus major capsid protein gene.

A major capsid protein (MCP) gene homologue of porcine cytomegalovirus (PCMV) was identified. Sequence analysis indicated that the PCMV MCP gene is 4,026 nucleotides in length encoding a protein of 1,341 amino acid residues. The predicted molecular weight of the PCMV MCP is 151,456 Da, equivalent to those of other herpesvirus MCP counterparts. Phylogenetic analysis using herpesviral MCP gene sequences confirmed that PCMV is a betaherpesvirus with higher homology with human herpesvirus-6 and -7 than human and mouse cytomegaloviruses. The serum of pig experimentally infected with PCMV did not react with bacterially expressed MCP, suggesting that the PCMV MCP may not be related to the humoral immune response in the course of PCMV infection. Also, we established polymerase chain reaction (PCR) protocols using primers corresponding to MCP gene sequences for detection of PCMV infection. The PCR protocol would be effective for the diagnosis of slow-growing PCMV infection, for which traditional methods involving virus-isolation are not useful.     

Doxorubicin affects the cardiac muscarinic system in the rat.

During the study on the mechanism of doxorubicin-induced cardiotoxicity, we observed that a long incubation (4 hr) with doxorubicin reduced the maximal negative inotropic effects of a muscarinic receptor agonist, carbachol. The mechanism responsible for this doxorubicin-induced reduction of the efficacy of carbachol was examined in isolated guinea pig hearts. In isolated left atrial muscle preparations, 1 hr incubation with 100 microM doxorubicin caused a parallel right-ward shift of the concentration-response curves for carbachol, but a longer (4 hr) incubation with this agent (30, 100 or 200 microM), caused a significant reduction of the magnitude of the negative inotropic effect of carbachol in addition to the concentration-dependent parallel right-ward shift. The 4-hr incubation with these concentrations of doxorubicin also reduced the maximal negative inotropic effect of an adenosine A1 receptor agonist, R-phenylisopropyl adenosine (R-PIA), without affecting the potency of this agonist. Doxorubicin (1 to 100 microM) reduced [3H]quinuclidinyl benzilate (QNB) binding in a concentration dependent manner, but failed to alter [3HIR-PIA binding. The decrease in the magnitude of the maximal negative inotropic effect by doxorubicin was caused by changes in the muscarinic system at steps common to the transduction of muscarinic and adenosine A1 receptor mechanisms.     

应用多重PCR检测人工感染鸡呼吸道疾病的研究

本文报道了IBV，NDV，ILTV，MG人工感染4周龄SPF鸡和非免疫鸡后，用多重PCR检测试验鸡的咽喉棉拭子和器官组织样品，并与传统的病原分离鉴定，血清学方法进行比较，多重PCR无论是对单一感染病原，还是对两种以上混合感染病原，其敏感性和检测速度都优于传统的鉴别诊断方法，具有较高的实用价值，可以直接应用于临床检测，服务于生产。     

Prevalence of ovine and bovine respiratory syncytial virus infections in cattle determined with a synthetic peptide-based immunoassay.

Subgroup-specific peptide-based enzyme-linked immunosorbent assays from the G-protein of the ovine and bovine respiratory syncytial virus (RSV), respectively, were used to determine the prevalence of the ovine and bovine subgroup strains of RSV infections in cattle. A total of 1,102 bovine serum samples were obtained from 6 diagnostic laboratories located in the northwestern and the southeastern USA and were tested for antibody to either the bovine or ovine subgroups of RSV. Antibody to viruses from each subgroup was present in samples from each region and all states tested. The Southeast had a higher prevalence of the bovine subgroup strains (69.5%). Then did the Northwest (40.9%). The prevalence of the ovine strain was similar for the two regions (16.7% in the southeast, 14.9% in the northwest). The overall prevalence was 56.6% for the bovine strain and 15.9% for the ovine strain. These results suggest members of the ovine subgroup of RSV circulate in the cattle population but with less frequency than those viruses of the bovine subgroup.