Morphological variations in brachial plexus of beagle dogs: evaluation of utility as sources of allogeneic nerve grafts

Basic studies were carried out to apply frozen allogeneic nerve grafts in dogs after wide-ranging defects of the brachial plexus due to surgical resection of tumor. In this study, morphological variations in branching patterns of the brachial plexus were examined in ten beagle dogs, to evaluate whether the brachial plexus might represent a useful source of allogeneic nerve grafts. Spatial relationships between the axillary lymph node, which had the possibility of carcinomatous metastasis, and the musculocutaneous (MC) nerve, which was important for the function of the forelimbs, were also investigated. In all ten cases examined, the brachial plexus received ventral roots from the fifth cervical nerve to the first thoracic nerve. No significant variation in the branching pattern was found in any nerve except the phrenic, MC and dorsal thoracic nerves. Four communicating branches were observed and had some morphological variations which might be negligible for nerve grafting. Considering previous physiological and anatomical reports, the most important nerve to be reunited in graft operations for functional recovery is the radial nerve. The MC nerve and median or ulnar nerve should also be considered as possibilities for reuniting. Distances between the axillary lymph nodes and the MC nerve ranged from 11.2 mm to 21 mm (mean +/- SD: 16.1 +/- 2.3 mm). In conclusion, it was suggested that morphological variations in the brachial plexus were technically acceptable to apply allogeneic nerve grafts at least in beagle dogs.     

Establishment of a chicken monoclonal antibody panel against mammalian prion protein

A panel of chicken monoclonal antibodies (mAbs) was developed against prion protein (PrP), the sequence of which is a highly conserved molecule among mammals. A portion of the splenocytes from chickens immunized with recombinant mouse PrP was fused with the chicken B cell line, MuH1. The remaining splenocytes were used to generate the recombinant mAbs by phage display. A total of 36 anti-PrP mAbs, 2 from cell fusion and 34 from phage display were established. The specificity of these mAbs was determined by Western blot and ELISA using various PrP antigens including recombinant PrPs, synthetic PrP peptides and PrPs from brains or scrapie-infected neuroblastoma cell line. These mAbs were classified into three main groups, protease K (PK)-sensitive (Group I), PK cleavage site proximal (Group II) and PK-resistant (Group III), based on their abilities to recognize PrP following PK-treatment. Some mAbs were found to selectively recognize different glycoforms of PrP as well as the metabolic fragments of PrP. Furthermore, we found that PrP recognition by chickens differed from that by PrP-knockout mouse. These results indicate that these newly generated PrP antibodies from chickens will help to research the PrP and to establish the diagnosis of prion disease.     

Severe calcification of mucocutaneous and gastrointestinal tissues induced by high dose administration of vitamin D in a puppy

A three-month-old male Bull Terrier was referred to the Animal Medical Centre, Nihon University with chief complaints of subacute emesis and lethargy. Severe leukocytosis, high CRP, hypercalcemia and hypochloremia were detected. Moreover, severe calcification of gingival mucosa and abdominal skin, and abnormalities of the skeletal system were discerned. Abdominal X-ray and endoscopic examination revealed ulcer and hemorrhage on the mucosal membrane of the stomach. This might have been due to injections of high dose vitamin D at 3 and 2 weeks ago by another practioner, according to the detailed history of medication. After two months, a gastrointestinal and skin disorder disappeared, although calcification of the stomach membranes remained and abnormality of the skeletal system had worsened. Therefore, vitamin D should be carefully administrated to a puppy.     

The effect of killed Salmonella enteritidis vaccine prior to induced molting on the shedding of s. enteritidis in laying hens

Effects of administering killed Salmonella enterica serovar enteritidis (SE) vaccines to laying hens prior to induced molting on egg production and on shedding of SE were investigated. Forty hens were vaccinated with one of two SE vaccines available commercially in the United States and Japan. Twenty-five days after vaccination, feed was withdrawn for 2 wk from 20 vaccinated plus 10 unvaccinated hens to induce molt. Four days after molt induction, all hens were challenged with a dose of 2.4 X 10(9) of SE. For the 25 days following administration of the SE bacterins, egg production in vaccinated hens showed approximately a 15% decrease. After molt induction, egg production in molted hens ceased and then returned to normal levels 8 or 9 wk postvaccination. Through the 3-mo experimental period, the decreases in numbers of eggs laid in the unvaccinated/molted group and two vaccinated/molted groups were 225 (26.2%), 245 (28.4%), and 274 (31.9%), respectively, compared with 860 in the unvaccinated/unmolted group. There was no significant difference in egg lay at the P < 0.05 level among the former three groups. Hens in the vaccinated/molted groups shed about two logs less SE than hens in the unvaccinated/molted group 3 14 days postchallenge (P < 0.05 or 0.01). These results indicate that vaccination prior to induced molting might be effective in preventing the exacerbation of SE problems within flocks in which the potential for SE contamination may exist.     

Transsphenoidal hypophysectomy for four dogs with pituitary ACTH-producing adenoma

Four dogs diagnosed as pituitary-dependent hyperadrenocorticism were treated with transsphenoidal hypophysectomy and postoperative hormone supplementation therapy. On histological examination of the resected tissues, the tumors were ACTH-producing adenoma of the anterior lobe. Clinical signs such as alopecia and calcinosis cutis, as well as endocrinological abnormalities, were markedly alleviated after surgery. The clinical courses of these 4 dogs suggest that transsphenoidal hypophysectomy may be a useful treatment for pituitary-dependent hyperadrenocorticism.     

Changes of biomechanical characteristics of the bone in experimental tibial osteotomy model in the dog

Experimental osteotomy model of canine tibia was prepared to investigate the changes in biomechanical characteristics during the healing process. After 16 weeks, although radiographs revealed that fracture healing proceeded, the recovery rates of the mechanical parameters ranged from 12.3 to 47.3%, compared to the intact side. After 32 weeks, those recovered to 68.9-93.2%. These results suggested that the biomechanical characteristics of the healing bone could not be recovered sufficiently even after the passage of the healing period which has been empirically proposed from clinical findings. It was also considered that evaluation of the mechanical parameters using this osteotomy model would be suitable for investigating the effect of osteoinductive growth factors on fracture healing.     

Efficacy of bovine viral diarrhea vaccine used in Japan against bovine viral diarrhea virus type 2 strain 890

Bovine viral diarrhea virus (BVDV) has been segregated into two genotypes, type 1 and type 2. To determine the efficacy of the commercially available bovine viral diarrhea type 1 vaccine used in Japan against BVDV type 2, calves were infected with BVDV type 2 strain 890 4 weeks after administration of the vaccine. The vaccinated calves did not develop any clinical signs and hematological changes such as observed in unvaccinated calves after the challenge. Furthermore, the challenge virus was not recovered from the vaccinated calves throughout the duration of the experiment, whereas it was recovered from all unvaccinated calves. The bovine viral diarrhea vaccine used in Japan is efficacious against infection with BVDV type 2 strain 890.     

Adjuvant effect of chicken interferon-gamma for inactivated Salmonella Enteritidis antigen

The adjuvant effect of chicken interferon-gamma (ChIFN-gamma) was examined for protecting chickens against intestinal colonization of Salmonella Enteritidis (SE) following oral exposure. Ten 7-week-old chickens per group were immunized with inactivated SE twice with or without co-administration of ChIFN-gamma intramuscularly, and all chickens were challenged with SE. Sera collected from immunized groups with or without ChIFN-gamma, and from unimmunized group were measured for SE antibody by agglutination test. The levels of antibodies were raised by 1 week post-immunization and did not show any difference between groups with and without ChIFN-gamma. No antibodies were detected in unimmunized group before challenge. Fecal samples from each group were cultured at 1, 4, 7, and 13 days post-challenge to determine the incidence of intestinal colonization and the numbers of SE shed into the environment. Co-administration of ChIFN-gamma, significantly reduced the incidence of intestinal colonization (P<0.05). At 13 days post-challenge, the bacterial counts of SE in organs were also reduced in ChIFN-gamma administered group. These data suggest co-administration of ChIFN-gamma with SE antigen enhances protection against SE challenge without acceleration of antibody production.     

The influence of early weaning on aggressive behavior in mice

Early postnatal experiences have been shown to have a tremendous influence on behavior development. In this study, we focused on weaning time and investigated the effects of early weaning on adulthood aggressive behavior in mice with the resident-intruder test. Early weaning resulted in decreased sideways threat and tail rattle. In addition, the frequency of attack bites was more variable in the early weaned group, although the mean frequency did not differ from the normally weaned group. The results of the present study suggest that aggressive behavior is also affected by early weaning manipulation.