Antibiotic-associated diarrhea (AAD) is caused by the treatments of broad-spectrum antimicrobials that seriously affect the activity and composition of the large intestinal microflora. The pathogenic bacteria or low concentration of short-chain fatty acids (SCFAs) has been repeatedly discussed in relation to AAD. Recently, we reported the detection of a large amount of succinate and lactate in the diarrheal feces in AAD-induced piglets. In this study, we investigated histologically the large intestinal mucosa in AAD-induced piglets, in which succinate and lactate were accumulated. AAD was induced in the piglets by an oral dose of polymyxin B sulfate (PL) or by an intra-muscular injection of enrofloxacin (ERFX). When the piglets were defecating diarrheal feces with a high concentration of succinate and/or lactate, the large intestine was removed and separated into four segments (cecum, gyri centripetales, gyri centrifugales, and rectum). Healthy piglets were used as the control. In the AAD-induced piglets, the lamina propria was edematous in the gyri centripetales. Piglets treated with ERFX were also edematous in gyri centrifugales. These edematous lamina propria contained larger amounts of inflammatory cells than observed in control tissues. ERFX-treated piglets had a more shallow crypt than PL-treated and control piglets. The mucosal tissue of the large intestine was more seriously damaged in the ERFX- than in the PL-treated piglets, which might have been caused by the high succinate and low SCFAs concentration in the digesta.
To accumulate histological information of cetaceans, the proper gastric gland of Minke whales was examined by light and electron microscopic observation. A small number of mucous neck cells and a large number of chief and parietal cells were observed in the gland. At the body to basal portions of the gland, the ratio of chief cells to other cells seemed to be large compared to the neck portion. Transmission electron microscopy revealed that the chief cell had secretory granules with middle level of electron density, and that the parietal cell contained abundant mitochondria and intracellular canaliculi. The proper gastric gland of the Minke whales may appear to secrete large amounts of digestive enzymes and have high digestive activity.
Subgroup J avian leucosis virus (ALV-J) causes great economic losses in the poultry industry. One in 3 grandparent farms was closed due to ALV-J infection in 1998 in Taiwan. The remaining 2 farms were forced to import breeding chicks from different breeding companies afterwards. We report on the ALV-J infection status among these breeders, their progeny and Taiwan native chickens during 2000-2002. The weekly mortality for the male line among the infected breeders was higher than that for the female line. Sixty-three percent (5/8) of the broiler flocks were infected with ALV-J. The surface (SU) portion of the env gene from the ALV-J field isolates was cloned and sequenced. The phylogenetic results show that all of the isolates fell into 2 clusters. Unexpectedly, the isolates from the same breeds fell into different clusters, with a cluster including isolates from different breeding companies. ALV-Js from native chickens crossbred with imported chickens were placed into the same clusters as those from the imported breeds. The high similarities observed in different ALV-J isolates suggest that different ALV-Js were mixed in the pedigree generations in different breeding lines.
CD80, CD86, CD28 and Cytotoxic T lymphocyte antigen-4 (CTLA-4) are well-known co-stimulatory molecules that form the major co-stimulatory pathway essential for full activation of T cells. To investigate their role in pathogenesis of immune-mediated diseases, 12 dogs were sensitized experimentally to Japanese cedar pollen antigen (CPAg) as models of allergic diseases in dogs. After sensitization, lymphocyte stimulation test (LST) was carried out to evaluate reactivity to CPAg, and semi-quantitative real-time RT-PCR analysis of CPAg-stimulated peripheral blood mononuclear cells (PBMCs) to evaluate the expression of co-stimulatory molecules. As a result, CPAg-specific enhancements of CD80 expression were detected in all sensitized dogs. Furthermore, two different kinetics of its enhancements according to the blastgenic responses to CPAg were also observed. Expression of CD28, CTLA-4 and CD86 were suppressed following CPAg-stimulation. The result of the present study indicated the potential role of the CD28-CD80 co-stimulation pathway in pathogenesis of allergic diseases in dogs.
The concentrations of lactoferrin (Lf) in quarter milk from normal lactating cows and subclinical mastitic cows were measured to determine whether the Lf concentration in milk is influenced by the age of the cow, the stage of lactation, number of milk somatic cells and the presence of pathogens. Lf concentrations in 111 quarter milk samples from 28 normal lactating cows and 270 quarter milk samples from 198 subclinical mastitic cows were measured by means of a single radial immunodiffusion test. Lf concentrations (means ± standard deviations; logarithmic form) in normal cows and subclinical mastitic cows were 2.23 ± 0.39 and 2.70 ± 0.39, respectively. The mean milk Lf concentration (log) in subclinical mastitic cows was significantly (p<0.01) higher than that in normal cows. The mean milk Lf concentration (log) in normal lactating cows aged 5 years was lower than those in normal lactating cows aged 2 years (p<0.01) and 3 years (p<0.05). The results showed that the milk Lf concentration (log) is associated with age of the dairy cow (one-way analysis of variance test, p<0.01). The mean milk Lf concentration (log) in the latter lactational period tended to be higher than those in the peak and middle periods. Milk Lf concentrations (log) tended to be proportional to the level of the somatic cell count (SCC) score. Mean milk Lf concentrations (log) in subclinical mastitic cows infected with Staphylococcus aureus and with other streptococci species were significantly (p<0.01) higher than those in cows infected with coagulase-negative staphylococci and with Corynebacterium bovis.
A 9-month-old French bulldog was referred for signs of chronic large bowel diarrhea. The dog had an increased frequency of defecation, tenesmus and hematochezia. Flexible colonoscopy showed hyperemia, irregularities and ulcerations with multifocal hemorrhages in the mucosa from the descending colon to the proximal rectum. Multiple colonic biopsies were characterized by infiltrations of PAS positive histiocytes in the lamina propria. A diagnosis of histiocytic ulcerative colitis (HUC) was made, and the animal showed only minimal improvement, although it was treated with nutritional and medical therapies. This is the second case of HUC in French bulldog, a breed which has ancestral relations to Boxer dogs.
Accelerated neutrophil apoptosis was confirmed by TUNEL assay in two canine cases of hepatic disorder. One dog was diagnosed as having lymphocytic hepatitis and the other lymphocytic cholangitis by histopathology of liver biopsy specimen.
An in vitro evidence of IgE-mediated hypersensitivity to food allergens was detected by positive results of antigen-specific histamine release in dogs with food hypersensitivity. Eight dogs were diagnosed to have food hypersensitivity based on identification of offending food allergens with food elimination followed by oral food provocation. The percentages of histamine release against the stimulation of offending food allergens in the cases ranged from 2.1% to 70.9%. Six of the 8 cases showed histamine release higher than those of healthy control dogs. Four dogs showed relatively high histamine release at the percentage beyond 10% that was compatible with a positive value of histamine release in humans with food hypersensitivity. These findings would suggest that IgE-mediated hypersensitivity against food allergens could be involved in canine food hypersensitivity.
The ability of Plasmodium coatneyi-infected red blood cells (IRBCs) to bind to C32 amelanotic melanoma cells was examined under static and physiologic flow conditions in vitro. Six blood samples obtained from P. coatneyi-infected Japanese macaques (Macaca fuscata) with severe manifestations of disease were used in the static adhesion assay. All blood samples constantly exhibited binding of IRBCs to C32 cells under static conditions. Immunofluorescence staining with anti-CD36 mAb revealed a positive reaction at the surface of C32 cells with the infected erythrocytes, while the reaction with C32 cells without IRBCs was negative. To further examine the specificity of the interaction between P. coatneyi-infected erythrocytes and C32 cells, we carried out the binding assay under physiological flow conditions. In flow adhesion assay, three blood samples were used. Adhesion and rolling of IRBCs on C32 cells were detected at several rates of shear stress under flow conditions. At a shear stress of 1.0 dyne/cm2, the number of IRBCs adherent to C32 cell averaged 5 to 6, and the number of IRBCs rolling on C32 cells averaged 6 to 11. The anti-CD36 mAb OKM5 inhibited 75-100% of IRBC adhesion and rolling, while the inhibitory effect of anti-ICAM-1 mAb 84H10 varied between 20-40%. The combination of anti-CD36 and anti-ICAM-1 mAb resulted in 83-100% inhibition of rolling and 100% inhibition of adhesion. These findings suggest that CD36 is one of the principal adhesion receptors of P. coatneyi-infected erythrocytes.
In a survey of pathologic agents in the wild animals of central Japan, we found a Hepatozoon sp. in the lungs of Japanese black bears in Fukui, Shiga, and Gifu Prefectures, Japan. Histopathologic examination of organs and tissues from the 18 bears inspected showed hepatozoonosis in all. Immature and mature meronts were found in all lobules and between alveoli, with a few found between pleura and in connective tissue. In the lungs, inflammatory cells were not found around meronts, merozoites, or tubercles made of macro-phages including zoites, but inflammatory cells were found around degenerating cells, zoites, and tubercles. A Hepatozoon sp. has not been reported as being detected in bears of any species before.
Djungarian hamsters were examined for the susceptibility to Neospora caninum infection. After 29 Djungarian hamsters were intraperitoneally inoculated with 5 × 106N. caninum tachyzoites of JPA1 strain, some animals showed symptoms such as ataxia, and many tissue cysts were detected in the brain and a cyst in the muscular tunics of stomach. Especially, more than 100 cysts per head were observed after 5 weeks post inoculation. It is suggested that the Djungarian hamster is a model useful to examine neosporosis.
Composition of glycoconjugates was examined in small intestines naturally infected with Isospora suis in preweaned pigs by use of 21 biotinylated-labeled lectins with avidin-biotin-peroxidase complex method. As compared with control pig, staining of 18 lectins altered in jejunal villus brush border and goblet cells of pigs naturally infected with I. suis. These results indicate that I. suis infection alters carbohydrate residues on the jejunal intestines.
A stillborn bovine male fetus with abdominal distention, arthrogryposis and atresia ani was presented for diagnostic evaluation. At necropsy, this fetus had a large amount of ascites, urachal obstruction and marked bladder distention. The ventral surface of the bladder had ruptured and attached to the abdominal wall by fibrinous adhesions. There was bilateral hydronephrosis with moderate pelvic dilatation and cortical attenuation. The rectum was filled with meconium but the anus was imperforate. The right forelimb was contracted. The cause(s) of these abnormalities could not be determined; however, we believe that developmental abnormalities during embryogenesis may be the result of chromosomal abnormalities.
A 10-day old male calf exhibited multiple congenital anomalies of the urinary and gastrointestinal tracts, including renal fusion (horseshoe kidney), ureteral fusion, rectovesicular fistula, and atresia ani. In horseshoe kidney, the organs were fused together at the caudal poles. The left kidney and cranial half of right kidney were shrunken, while the remaining lobules were hypertrophic. Ureters were fused cranially and bifurcated caudally. The terminal rectum was narrowed and connected with the bladder. The anus was imperforate. The cause of these anomalies could not be determined.
To determine whether neurophysiological taste responses of young and old rats are different, recordings were made from the whole chorda tympani nerve which innervates taste buds on the anterior tongue. SHR-SP (Stroke-Prone Spontaneously Hypertensive Rats) in two age groups were studied. Chemical stimuli included single concentrations of 250 mM NH4Cl, 100 mM NaCl, 100 mM KCl, 500 mM sucrose, 20 mM quinine-hydrochloride, 10 mM HCl, 10 mM monosodium glutamate (MSG), 10 mM L- glutamic acid (L-Glu) and an NaCl concentration series. The magnitude of the neural response (response ratio) was calculated by dividing the amplitude of the integrated response by the amplitude of the spontaneous activity that preceded it. Substantial neural responses to all chemicals were obtained at both ages. The responses to KCl, sucrose, quinine-hydrochloride, HCl, monosodium glutamate (MSG) and glutamic acid (Glu) did not change with age, but the response to NaCl did decrease significantly. The profile of the response/concentration function for NaCl differed with age. In particular, the responses to solutions more concentrated than 100 mM NaCl were significantly weaker in aged than in young SHR-SPs. We also observed that recovery from amiloride treatment on the tongue of SHR-SPs was faster in aged rats than in young ones, suggesting that there is some functional difference in the sodium-specific channels on the taste cell. These results suggest that aged SHR-SP may be less able than young SHR-SPs to discriminate among higher concentrations of NaCl solutions.
In two previous reports, we have demonstrated that injection of bee venom (BV) into an acupoint produces a significant antinociceptive and anti-inflammatory effect in both a mouse model of visceral nociception and a rat model of chronic arthritis. The present study was designed to evaluate the potential antinociceptive effect of BV pretreatment on formalin-induced pain behavior and it associated spinal cord Fos expression in rats. Adult Sprague-Dawley rats were injected with BV directly into the Zusanli (ST36) acupoint or into an arbitrary non-acupoint located on the back. BV pretreatment into the Zusanli acupoint significantly decreased paw-licking time in the late phase of the formalin test. In contrast, BV injected into a non-acupoint in the back region did not suppress the paw-licking time. In addition, BV pretreatment into the Zusanli acupoint markedly inhibited spinal cord Fos expression induced by formalin injection. These findings indicate that BV pretreatment into the Zusanli acupoint has an antinociceptive effect on formalin-induced pain behavior.
A total of 1,335 archived human sera collected in 1985 from an area in Japan where a tick-borne disease is endemic were examined by indirect immunofluorescence antibody test (IFAT) to estimate seroprevalence against three serologically distinct types of Babesia microti-like parasites; namely, Hobetsu, Kobe, and U.S. types. Eighteen sera (1.3%) were found to be IFAT-positive (titer 1:100-1:6,400), of which 14 and three were ascertained by Western blot analysis to be positive against the Hobetsu and Kobe types, respectively. In addition, four sera showed an IFAT titer of 1:100 against the U.S. type, but they appeared to be false-positive because they were cross-reactive against the Hobetsu and Kobe types, and also because a U.S.-type parasite has not been found in Japan. Our results suggest that human babesiosis in Japan occurred prior to the discovery of the index case in 1999 and that the infections were caused mainly by Hobetsu-type parasites.
Interleukin (IL)-2 can induce large numbers of lymphokine-activated killer cells in peripheral blood lymphocytes (PBL), but IL-2 alone cannot induce proliferation of a large number of canine (c) PBL. We used the solid phase anti-CD3 antibody and soluble recombinant (r) IL-2 in order to establish a large scale culture method for cPBL. The number of lymphocytes seeded (3 × 10 7) increased to 1 × 109 after incubation for 10 days. The phenotype of cultured cPBL cells (after 2 weeks) showed a CD4+ or CD8+ predominant cell population. The cultured cell solutions were administered with physiological saline intravenously to each dog. After transfusion of the cultured cells, the cPBL counts, especially the number of CD4+, CD8+ and CD4-CD8 -(DN) cells increased significantly in the recipient dogs. Natural killer (NK) cells, γδT cells and B cells were considered to be present in the DN cell population. The NK cells and γδT cells showed no adverse reaction to the transfusion of the activated cPBL. Therefore, it is necessary to recognize the B cells present in the DN cell population by detecting CD21+ cells. In conclusion, the bulk culture system of cPBL with rIL-2 and solid phase anti-CD3 antibody may be useful for the development of novel immunotherapy in dogs.
The goal of the current study was to compare the efficiency of gas exchange and platelet conservation of a new extracapillary blood flow oxygenator versus an endocapillary blood flow oxygenator during open heart surgery with extracorporeal circulation in dogs. Dilation and remodeling of the right ventricular outflow tract of dogs was performed using a patch graft technique to simulate pulmonary stenosis. Sequential pre- and post-operative blood analysis revealed that gas exchange efficiency and platelet conservation was significantly greater with the extracapillary blood flow oxygenator than with the endocapillary blood flow oxygenator. However, the priming volume of the extracapillary blood flow oxygenator was significantly greater, leading to hemodilution. We conclude that while the extracapillary blood flow oxygenator provided benefits in terms of gas exchange and platelet conservation, development of a smaller extracapillary blood flow type oxygenator to reduce hemodilution effects would be beneficial.
A Denacol EX-313 (Denacol)-treated bovine venous graft and an ultrafine polyester fiber (UFPF) graft were transplanted as patch graft into the right ventricular outflow tract under extracorporeal circulation in six dogs each experimentally. Hemodynamics in right heart and histological findings around the graft were compared between both groups over a period of one year after grafting. Pressure measurements and angiocardiography were performed through a cardiac catheter. Right ventricular pressure, pulmonary artery pessure, and right ventricle to pulmonary artery gradient were within normal limits in both groups at 1, 2, 3, 4, 6, and 12 months or more after grafting. No difference were seen between the values for the Denacol and the UFPF group. Histologically, the medial surface at the site of grafting was covered with vascular endothelial cells at one month after grafting in both groups. The density of the vascular endothelial cells increased with time after grafting, showing no clear difference between the two groups. Subendothelial layers comprised of collagen fibers, elastic fibers, and inflammatory cells decreased with time in both groups, but there was less cell infiltration in the Denacol group than in the UFPF group at all time points after grafting. In addition, the central cut thickness value of the graft tended to be thinner in the Denacol group than in the UFPF group at all observation time points after grafting. In the Denacol group, very slight metaplasia of cartilage was noted in a portion of the graft margin at six months or more after grafting, but no other abnormalities were observed. These results suggest that the Denacol-treated bovine venous graft has better grafting characteristics than the UFPF graft with easier intra-operative handlings and less tissue reactions after grafting.
Titanium columns (Ti-6A1-4V) were treated with arc-deposition to roughen the surface enough to anchor the bone, and then coated with hydroxyapatite (HA) at a thickness of 5 μm by the sputtering technique. Columns were implanted into dog femurs, and fixation of columns to bone due to bone-ingrowth was assessed histologically and with the push-out test. The HA-coated columns were inserted in the shafts of the right femurs of 2 dogs. As a control, columns that were only arc-deposited (non-coated columns) were inserted into the left femurs. The interfacial strength was higher for the HA-coated columns than for the non-coated columns. Coating a rough surface with an HA layer using a sputtering technique reinforces interfacial strength between bone and implants.
Attachment and migration of bovine chondrocytes cultured in vitro were significantly suppressed by the addition of interleukin (IL)-1α at the concentration of 1 ng/ml or more (p<0.05). The application of hyaluronic acid (HA) at the concentration of 10 μg/m l or more significantly recovered the attachment of chondrocytes (p<0.05) and the application of HA at 100 μg/ml concentration recovered the migration of chondrocytes suppressed by IL-1α. These results suggest that the application of HA for inflammatory arthropathies or chondrocyte transplantation might be helpful to preserve the properties of chondrocytes and its extracellular matrix against inflammatory conditions.
Cooled canine semen solutions for storage were investigated with three stock solutions: egg yolk-citrate-glycine-glucose solution, egg yolk Tris-fructose citrate solution (EYT-FC), and egg yolk sodium citrate dihydrate solution (EYCD). For the control group, the second fraction of semen was examined. Nine male beagles and 37 female (47 experimental cases) beagles for artificial insemination (AI) were used. The qualities of semen stored at 4°C deteriorated earlier in the control and EYCD groups. In the other two groups, sperm motility was 60% or higher after storage for 6 days and 20% or higher after storage for 12 days. On a comparison of these two groups, the sperm motility and viability were slightly higher in the EYT-FC group. A high conception rate was obtained by AI using semen stored at a low temperature for a maximum of two days in the control group and four days in the EYT-FC group.
Reproduction of feral raccoons (Procyon lotor) in Hokkaido, Japan, was examined during a 2-year period by analysis of placental scars or fetuses in the uterus. Of 242 collected females, 69 (29%) were juveniles, 71 (29%) yearlings, and 102 (42%) adults. The pregnancy rate averaged 66% in yearlings and was significantly lower than the 96% average observed in adults (p<0.01). Litter size ranged from 1 to 7 offspring per female, and averaged 3.6 in yearlings and 3.9 in adults. There was no significant difference in mean litter size between yearlings and adults. In Hokkaido, the raccoon mating season peaked in February and the majority of litters were born between March and May, similar to patterns described in North America, but some females mated in summer. The reproductive potential of feral raccoons in Hokkaido was similar to that reported in North America. The recent increase in raccoon numbers can be explained by their high productivity. Harvest data suggest that hunting pressure on juveniles is lower than that for older age classes when using box traps in summer. In order to reduce the feral raccoon population, alternative hunting methods that increase juvenile mortality rates are needed.
Artificial insemination with frozen cauda epididymal sperm was performed in cats. Sperm were transmigrated from the epididymides in 10 male cats. The mean sperm motility and viability were 67% and 82.5%, respectively, and 11.6 × 107 sperm were recovered. The mean sperm motility after thawing was 24.0%. Eleven female cats received unilateral intrauterine insemination of 5 × 107 sperm, and the conception rate was 27.3% (3/11). This was the first case of conception obtained with frozen epididymal sperm in cats.
A mongrel dog, aged 2 years, was found to have only a small number of sperm, immobilization of all sperm, and many sperm agglutinations in its ejaculates, and scrotal palpation revealed a small nodule in the left cauda epididymis. Addition of the dog's seminal plasma or serum to the semen of 2 normal dogs caused immobilization and agglutination of their sperm. Histological examination showed that the nodule was a sperm granuloma. Many lymphocytes were seen in the stroma around the sperm granuloma. Anti-sperm antibodies are presumed to be present in the semen and serum of the asthenozoospermic dog.
The use of Transgenic (Tg) mice expressing chimeric sheep/mouse (Sh/Mo) prion protein (PrP) and chimeric bovine/mouse (Bo/Mo) PrP genes was evaluated as a sheep scrapie model. We also investigated the potential for the transmission of sheep scrapie to a human/mouse (Hu/Mo) PrP Tg mouse line. The Sh/Mo PrP and Bo/Mo PrP Tg Prnp+/+ or Prnp0/0 mouse lines were inoculated intracerebrally with brain homogenates from three sheep with natural scrapie (KU, Y5 or S2). Incubation periods were slightly shorter in Sh/Mo PrP Tg Prnp+/+, than in non-Tg mice inoculated with KU brain homogenate. In contrast, the incubation period was significantly prolonged (p<0.05) in Bo/Mo PrP Tg Prnp+/+ mice inoculated with KU brain homogenate. The incubation period was significantly longer in all Tg Prnp+/+ and Prnp0/0, than in non-Tg mice (p<0.01) inoculated withY5 brain homogenate. None of the Tg Prnp0/0 mice inoculated with S2 brain homogenate developed clinical signs and PrPSc was undetectable in their brains. These results suggested that expression of the Sh/Mo PrP or Bo/Mo PrP transgenes does not confer susceptibility to sheep prions upon mice, and thus none of the Tg mouse lines could be a suitable model of sheep scrapie. Hu/Mo PrP Tg Prnp0/0 mice inoculated with natural and experimental scrapie or mouse prions did not develop clinical signs of scrapie and PrPSc was undetectable. These results suggested that neither sheep nor mouse strains of scrapie are highly transmissible to humans.
FS-L3 cells, originating from porcine kidney, were used for propagation of Hemagglutinating encephalomyelitis virus (HEV) and development of a virus neutralizing (VN) test. Sera of pigs, rats, cows and dogs had VN activities to HEV. On the other hand, sera of mice, rabbits, goats, sheep, horses, cats, chickens, hamsters and human did not have measurable VN activities, although these sera had high HI activities. Our results support the idea that the VN is a more reliable measure of HEV infection than the conventionally used HI test.
Porcine circovirus type 2 (PCV2) shedding patterns were investigated by polymerase chain reaction (PCR) for the detection of PCV2 DNA, and the diagnostic suitability of a sample for the PCR was examined by using different types of samples. In the experimental infection, sixteen pigs were inoculated intranasally with PCV2. The samples, including oropharyngeal and nasal swabs, feces, whole blood and serum became positive for PCV2 DNA by PCR immediately after the inoculation, and almost all samples remained positive during the observation period, post-inoculation-day 70. Field samples were collected from 313 pigs in five different age groups. The overall percentages of positive samples in the whole blood, nasal swabs, and feces detected by PCR were 30.4%, 19.2%, and 20.4%, respectively. The frequency of positive samples increased after the nursery stages and reached a peak in the 3 to 4-month-old pigs. These results indicate that PCV2 infection may occur after weaning, that PCV2 DNA may be present in whole blood for a long period after infection, and that whole blood and serum are the most suitable sample types for the PCR analysis of PCV2.