Regional variations in the distribution of small intestinal intraepithelial lymphocytes in three inbred strains of mice

The regional variation in the intraepithelial lymphocytes (IELs) in the small intestine was examined in BALB/c male and female mice and C3H/He and C57BL/6 male mice. The small intestines were taken from 11 to 12-week-old mice and divided equally into 3 parts (the proximal, middle and distal parts). IELs were isolated from each part of the intestine and analyzed with flow cytometer. The number of IELs was highest in the proximal part and lowest in the distal part. The distribution of IEL subsets was markedly different between the proximal and the distal parts, and that in the middle part showed the intermediate pattern. The percentage of alphabeta T cells were higher in the distal part. In alphabeta T cell subset, the percentage of CD8alphaalpha T cells was higher in the proximal part, whereas those of CD4 and CD4CD8alphaalpha double positive T cells were higher in the distal part. In gammadelta T cell subset, no regional variations were found. The regional variations in the number and subsets of IELs showed almost the same patterns between male and female BALB/c mice and similar patterns among three strains of mice. This strongly suggests that the regional variations in the small intestinal IELs are common to mouse species.     

Medical dissolution of struvite nephrolithiasis using amino acid preparation in dogs

A new chemolytic therapy with amino acid preparation was tried for use on struvite renal stones in two dogs, which were admitted to Azabu University Veterinary Teaching Hospital. No other special diet, for the purpose of dissolving the stones, was fed during the treatment. Dissolution of the stones began at week 1, and no stone was detected on radiography at week 4 in both cases. The amino acid preparation thereafter has been administered every 2-3 days to prevent formation of the stones. After 6 months from treatment, complete dissolution was confirmed, and no relapse has been observed. Therefore, it is concluded that chemolytic therapy with amino acid preparation might be useful for the treatment of nephrolithiasis with struvite renal stones in dogs.     

Polymerase chain reaction (PCR) for the detection of herpesvirus in tortoises

A polymerase chain reaction (PCR)-based method using a herpesvirus consensus primer was assessed for the identification of herpesviral infections in tortoises. A single band of about 230 bp was detected in PCR products from two out of twenty swabs taken from the oral cavity, three out of three paraffin-embedded tissue sections from the liver (two cases) and oral mucosa (one case), and one out of two fresh tissue samples from the oral mucosa. Nucleotide sequencing of these PCR products indicated that the herpesvirus present in these tortoises might belong to the alphaherpesvirinae. PCR using swabs and biopsy tissues was a sensitive and highly specific method for the diagnosis of herpesviral infections in tortoises.     

Study of lipid in the ear canal in canine otitis externa with Malassezia pachydermatis

An epidemiological investigation of 120 canine otitis externa cases in 1,370 dogs was done on the incidence rate, ear pinna shapes, breeds and their relationships. Eighty-five cases (12.6%) in 672 dogs with pendulous ears and 35 cases (5.0%) in 698 dogs with erect ears had otitis externa, and the difference between them was significant (P<0.05). Ninety-five auditory cerumen specimens were cultured for Malassezia pachydermatis (M. pachydermatis) and analyzed for concentrations of major fatty acids. Although rates of cases positive for M. pachydermatis in both ear pinna shapes were almost the same, i.e. 55.2% in the pendulous group and 53.6% in the erect group, the average total fatty acid level of the pendulous ear group was significantly (P<0.05) higher than that in the erect ear group after dismissing extraordinary levels in the Siberian husky. Isolated M. pachydermatis strains were examined for the effects of fatty acid supplementation on their growth. The majority of the strains utilized fatty acids and grew faster in fatty acid supplemented broth. These results suggest that M. pachydermatis, the predominant causative agent of canine otitis externa, prefers the auditory canal of dogs with lipid-rich earwax and grows fast, but growth strongly depends upon the canine breed.     

Sequential observation of 2,6-dimethylaniline-induced nasal lesions in a rat two-stage nasal carcinogenesis model after initiation with N-bis(2-hydroxypropyl) nitrosamine

Male F344 rats received diet containing 3,000 ppm 2,6-dimethylaniline (DMA) after initiation with a single subcutaneous injection of 2,400 mg/kg of N-bis(2-hydroxypropyl)nitrosamine (DHPN), and histological and electron microscopic examinations of the nasal cavity were performed at 4, 13, 26 and 52 weeks to examine sequential changes induced by DMA. Severe atrophy of Bowman's glands and epithelial disarrangement were apparent from week 4, followed by dilatation and/or proliferation of Bowman's glands, degeneration of epithelial cells, and proliferation of undifferentiated epithelial cells from week 13. Focal glandular hyperplasias, dysplastic foci, and adenomas were observed from week 26, and carcinomas at 52 week. These nasal lesions were mostly evident in the olfactory mucosa in the nasal cavity, and their severity and/or incidences, other than atrophy of Bowman's glands, increased with the treatment period. Electron microscopically, carcinoma cells demonstrated desmosomes, dense secretory granules identical to those in normal Bowman's glands, a basement membrane, and microvilli. These results suggest that Bowman's glands are the target of DMA, giving rise to nasal carcinomas after DHPN-initiation.     

Induction of unseasonable hibernation and involvement of serotonin in entrance into and maintenance of its hibernation of chipmunks T. asiaticus

Chipmunks that had been housed at 22 degrees C under a light-dark cycle of 14L:10D for at least one year were exposed to a short photoperiod (10L:14D) and low temperature to induce unseasonable hibernation. We were able to induce hibernation at any time of year and there was no significant difference in the duration of the hibernation bout, the duration of interbout euthermia and duration of bouts of torpor throughout the year; however entrance into hibernation took about 60 days in summer but only about 30 days in any other seasons. In addition, interbout euthermia predominantly occurred during the light phase in winter, whereas in spring interbout euthermia occurred equally in the light and dark phases. These results suggest that both the circadian and circannual systems are linked to hibernation in chipmunks. Subcutaneous infusion of a serotonin antagonist, para-chlorophenylalanine (PCPA), facilitated entrance into and interrupted hibernation in aroused and hibernating chipmunks in summer, respectively. On the other hand, opioid antagonist, naloxone, did not affect hibernation, but extended the period of interbout euthermia. These results suggest that the role of serotonin in entrance into and maintenance of hibernation in chipmunks is independent of the circannual system, and that opioid system may not be involved in hibernation in chipmunks.     

Effect of liquid paraffin on antibody responses and local adverse reactions of bivalent oil adjuvanted vaccines containing newcastle disease virus and infectious bronchitis virus

Effects of liquid paraffin on antibody responses and local adverse reactions after intramuscular injection of oil adjuvanted vaccines containing Newcastle disease (ND) and infectious bronchitis (IB) virus were investigated in chickens. Each vaccine was prepared with a liquid paraffin such as Carnation, Crystol 52 and Lytol. These vaccines induced sustained antibody responses against ND and IB. Among local adverse reactions, Lytol induced granulomatous reactions and abscesses, but Carnation and Crystol 52 did not. The residual weight of liquid paraffin at the injection site decreased in the order Carnation, Crystol 52, Lytol. Crystol 52 was composed of relatively few short-chain hydrocarbons (i.e., n-C20H42). The vaccine with liquid paraffin mainly composed of n-C16H34-n-C20H42 was suggested to induce fewer adverse reactions.     

Adaptation of the muscles of mastication to the flat skull feature in the polar bear (Ursus maritimus)

The muscles of mastication of the polar bear (Ursus maritimus) and those of the brown bear (U. arctos) were examined by anatomical approach. In addition, the examination of the skull was carried out in the polar bear, brown bear and giant panda (Ailuropoda melanoleuca). In the polar bear, the rostro-ventral part of the superficial layer of the M. masseter possessed the abundant fleshy portion folded in the rostral and lateral directions like an accordion. Moreover, the rostro-medial area of the superficial layer became hollow in the nuchal direction when the mouth was closed. The M. temporalis of the polar bear covered up the anterior border of the coronoid process of the mandible and occupied the almost entire area of the cranial surface. The M. pterygoideus medialis of the polar bear was inserted on the ventral border of the mandible and on the ventral part of the temporal bone more widely than that of the brown bear. As results of our measurements of the mandible, an effect of the leverage in the polar bear was the smallest in three species. In the polar bear, the skull was flat, and the space between zygomatic arch and ventral border of the mandible, occupied by the M. masseter was the narrowest. It is suggested that the muscles of mastication of the polar bear is adapted to the flat skull feature for supplementing the functions.     

Effect of addition of Orvus ES paste to frozen canine semen extender on sperm acrosomes

Using the triple-stain technique, we investigated whether sperm acrosomes in frozen canine semen were protected during freezing and thawing by addition of a surfactant, Orvus ES Paste (OEP), to the extender. Acrosomes were clearly shown to be protected by the addition of OEP to the entender when compared with those in sperm frozen without OEP addition (p<0.05).     

Babesia bovis and B. bigemina DNA detected in cattle and ticks from Zimbabwe by polymerase chain reaction

From blood collected from 94 cattle at 12 locations in the eastern and northeastern areas of Zimbabwe, DNA was extracted and analysed by polymerase chain reaction with primers previously reported to be specific for Babesia bigemina and Babesia borvis. Overall, DNA of Babesia bigemina was detected in the blood of 33/94 (35%) cattle and DNA from B. bovis was detected in 27/58 (47%) of cattle. The prevalence of DNA of B. bigemina was significantly higher in young animals (<2 years) (23/46) than in animals over 2 years of age (10/48; chi2= 8.77; P <0.01%). Although tick sampling was not thorough, Boophilus decoloratus could be collected at 7/9 sites sampled and Boophilus microplus at 4/9 sites. Of the 20 B. decoloratus allowed to oviposit before PCR analysis, 1 (5%) contained DNA that could be amplified with primers for B. bigemina while 12 (60%) were positive with primers for B. bovis. Of the B. microplus allowed to oviposit, 11/16 (69%) were positive for B. bovis DNA by PCR and 2/16 (12%) were positive for B. bigemina.