The proliferative responses of UV-irradiated islets from fetal pancreas decreased to 53.8±4.7% (mean ±SEM) compared to that of UV-irradiated islets by allogeneic mixed islet-cell lymphocyte culture. In 5 pancreatectomized dogs, UV irradiated fetal dog pancreas was transplanted either into omentum pouches or the spleen without immunosuppressive agents. The diabetic status (daily insulin requirement for hyperglycemia, decrease in body weight, urine glucose) improved in dogs after allo-transplantation. The survival time after total pancreatectomy was significantly longer in allografted dogs than those treated only with daily insulin injections.

View full abstract

Serum lipid and lipoprotein concentrations in 10 obese and 16 control dogs were examined. The serum triglyceride (TG) concentration in obese dogs was significantly higher than in control dogs. The serum concentrations of TG and phospholipid (PL) in beta lipoprotein and PL in pre-beta lipoprotein were significantly higher in obese dogs, while the serum PL concentration in alphal lipoprotein was significantly lower in obese animals. In the serum total cholesterol concentration in obese dogs, a higher tendency for beta and pre-beta lipoproteins and lower tendency for alpha₁ lipoprotein were observed. These abnormal lipoprotein profiles were similar to those in diabetes mellitus in men and acute pancreatitis in dogs.

View full abstract

We found that the intramuscular injection of vitamin B₂ enhanced host resistance to E. coli infection in a dose-dependent manner (6.25 mg/kg-100 mg/kg). Furthermore, VB₂ exhibited the protective activity against Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, and Actinobacillus pleuropneurnoniae. The mechanism of action of VB₂ for enhancing resistance in mice may be, at least in part, its ability to stimulate the multiplication of neutrophils and monocytes, and to activate macrophages.

View full abstract

Chemotactic activities in the culture supernatants of Cos7 cells transfected with a cloned canine IL-8 cDNA (pcIL-8SRα14)were evaluated by using mononuclear cells (MNC) and polymorphonuclear cells (PMN) from the peripheral blood of dogs. The culture supernatants of Cos7 cells were collected 66 hr after the transfection of pcIL-8SRα14 (Cos7/cIL-8). Chemotactic activities in the culture supernatants for MNC and PMN were determined as migration distances in Millipore membrane filters in a modified Boyden's chamber method. Peroxidase staining for MNC was effective not only for cells in cytospun smears but also for cells migrated in the filters. PMN in cytospun smears were well stained by peroxidase staining, whereas migrated PMN in the filters were stained weakly. Chemotactic activities in the culture supernatant of Cos7/cIL-8 cells for both MNC and PMN were significantly higher than those of control Cos7 cells. In addition, the culture supernatant of Cos7/cIL-8 cells was chemotactic for peroxidase negative nonadherent MNC (lymphocytes), but not for peroxidase positive adherent MNC (monocytes). This Cos7/cIL-8 supernatant also showed chemotactic activities for neutrophils in a dose dependent manner. These results suggest that the culture supernatant of Cos7/cIL-8 is chemotactic for lymphocytes as well as for neutrophils.

View full abstract

A significant decrease in pH occurred in the culture medium when cells of Selenomonas ruminantium HD-4 were incubated in the presence of relatively high concentrations of glucose (0.4 and 1.0%). Forty μM lasalocid reduced cell growth to 35.5 and 35.7% of control growth, respectively, for 0.05 and 0.4% glucose, while growth was completely inhibited by 40 μM lasalocid in the presence of 1.0% glucose. In the presence of 80 μM lasalocid, cells were unable to grow within 24 hr at any glucose concentration. In the case of treatment with 10 μM lasalocid, growth was inhibited when pH decreased below 6.0 in the presence of 0.4 and 1.0% glucose. With 0.05% glucose, pH never reduced to below 6.4 within 24 hr and there was no significant effect of lasalocid on either growth or pH. When cultures were treated with 10 μM lasalocid at the mid-exponential phase, growth was moderately inhibited and abnormal cells which had outer membrane detached from the inner membrane layer resulting in cell lysis were found in thin sections. These results indicate that the presence of large amounts of glucose decreases pH in culture medium and that the decrease in pH to below about 6.0 causes the increased effect of lasalocid on the growth of S. ruminantium. These results suggest that the antimicrobial activity of lasalocid is potentiated by a decrease in extracellular pH.

View full abstract

Differences and/or similarities of the accessory cell activity of circulating peripheral blood monocytes (PBM) and intestinal lamina propria macrophages (LPM) in the pig have never been evaluated. Therefore this study was designed to compare the accessory cell activity of these cells in the induction of primary allogeneic mixed leukocyte responses (MLR) and polyclonal mitogenesis. Splenic adherent cells (SPAC) were used as control accessory cells. It was observed that PBM, LPM and SPAC induced significant T cell proliferation in response to allo-antigens. Significantly higher responses were elicited by SPAC, followed by PBM whereas, LPM induced low responses when cultures were established a T cell: accessory cell ratio of 1:1. PBM was the only accessory cell which induced significant responses at a cell ratio of 10:1. Whereas LPM and SPAC were able to induce significant oxidative mitogenesis, PBM were poor stimulators of this response. The observed difference between PBM, SPAC and LPM is attributed partly to differences in number of major histocompatibility complex (MHC) class II positive cells and the intensity of expression of the glycoproteins.

View full abstract

The distribution and properties of sugar residues in germ and Sertoli cells of differentiating chick gonads were examined by light microscopy using twelve different lectins. Characteristic binding patterns of ConA, RCA-I, BPA, WGA and STA were observed in germ and Sertoli cells during testicular development. BPA preferentially bound to the cytoplasm and plasma membrane of primordial germ cells (PGCs). BPA reaction appeared prior to stage 29, continued until stage 36, and completely disappeared at stage 37. This finding indicates that dynamic changes in glycoconjugates containing N-acetyl-D-galactosamine residues may occur in the cytoplasm and plasma membrane of PGCs. During the formation of testicular cords (stages 36-39), ConA, WGA, STA and RCA-I also showed a positive reaction on the cell surface of differentiating Sertoli cells. Therefore, these glycoconjugates on Sertoli cell surfaces may play an important role in testicular cord formation.

View full abstract

A parvovirus (the H-45 strain) isolated from an outbreak of epizootic diarrhea in swine was examined to observe the infectivity and pathogenecity in swine. The virus infection by intranasal route was demonstrated in each group of 2- and 5-day-old colostrum-deprived pigs, 30- and 100-day-old pigs by virus recovery from the nasal and rectal swabs, and detecting seroconversion. The virus was recovered from rectal swabs up to 14 days after inoculation and from nasal swabs up to 9 days. Uninoculated pigs were infected with the virus by contacting with the inoculated pigs. Between 1 and 5 days after inoculation, the inoculated pigs of 2, 5 and 30 days old developed diarrhea and then all the pigs of 2 days old died, resulting from dehydration. In the pigs died after intranasal inoculation, the virus was recovered mainly from the respiratory and gastrointestinal tracts. One hundred-day-old pigs showed no clinical signs. The pathological change was characterised by congestion and edema with hemorrhage in the epithelium of the small intestines exhibiting additional degeneration and desquamation of the epithelial cells.

View full abstract

We investigated the effect of extracellular matrix (ECM) on the adhesion, morphology and proliferation of two Mongolian gerbil's melanoma cell lines (MGM-S, MGM-A) which differed in malignancy. Fibronectin matrix was detected on the cell surface of MGM-S by immunofluorescence techniques. MGM-A cells, showing a multipolar shape, were widely spread over the dishes coated with fibronectin, laminin or type IV collagen. The adhesion rate of MGM-A cells to ECM components was higher compared to that in controls. Attachment to laminin was conspicuously promoted. The effect of laminin on MGM-A cell growth was also the highest among the substrates examined. On the other hand, these ECM components did not affect MGM-S cells. These results suggest that laminin and fibronectin may participate in the malignancy of MGM cell lines.

View full abstract

Ten female cats were given a total dose of 200 IU PMSG over 3 days to induce superovulation. One to four-cell stage embryos were collected by flushing the oviducts 48 to 54 hr after the initia1 250 IU dose of hCG. Some of the normal embryos collected were examined for culture in Medium-199 supplemented with 20% FCS. After 72 hr of culture, 222/248 (89.5%) had developed to the morula stage, and by 96-168 hr, 110 (64.7%) out of 170 morulae had developed into blastocysts. Four to 12 embryos cultured in vitro per cat were transferred to one of the uterine horns of 12 recipients in which synchronous ovulation had been induced with hCG. All 4 recipients of embryos which had developed to the morula stage on culture day 3, 3 of the 5 recipients of blastocysts on culture days 4-6, and none of the 3 recipients of blastocysts on culture day 7 became pregnant. It is concluded that early feline embryos are capable of efficiently developing into transferable morulae in vitro by ordinary culture methods, but that there is partial developmental arrest from the morula to the blastocyst stage.

View full abstract

The infectivity of neutralized IBDV by normal chicken serum (NCS) was detected in day-old and 3-week-old chicken spleen adherent (CSA) cells, and that of neutralized IBDV by maternal antibody (MN-Ab) was detected in 3-week-old CSA cells. Moreover, CSA cells from day-old chickens had complement receptor (CR), and CSA cells from 1-week-old had both CR and Fc receptor (FcR). However, the infectivity of neutralized IBDV by MN-Ab was confirmed on CSA cells which Were blocked for FcR on CSA cells by heat-aggregated NCS (56°C, 60 min). These results indicated that infection of neutralized IBDV by NCS on CSA cells occurred via CR, and neutralized IBDV by MN-Ab was infected via FcR. In day-old specific pathogen free (SPF) chickens, the antibody level in NCS treated and non-treated IBD live vaccine subcutaneously inoculated groups was higher than the levels in the MN-Ab-treated IBDV inoculated group, and detected until 28 days old. Moreover, subcutaneously inoculated chickens were protected against the challenge of wild IBDV at 21 days old, whereas subcutaneously inoculated chickens were infected with MN-Ab-treated IBD live vaccine. In commercial layers which had MN-Ab, antibody levels of subcutaneously vaccinated group were higher than both the non-vaccinated and orally vaccinated groups, and virus isolation and viral antigen were positive with high detection rates on peripheral lymphocytes of each subcutaneously vaccinated group of SPF and commercial chickens. There were no distinct pathological changes, no decrease in complement activity measured via the alternative pathway, and no secondary antibody response of NCS-treated and/or non-treated IBDV subcutaneously vaccinated SPF chickens and commercial layers, after challenge. These results suggest that the subcutaneous application of live vaccine to day-old chickens has a more protective effect against a virulent IBDV exposure at 21 days old than the oral application.

View full abstract

In vivo efficacy of orally administered lufenuron, an insect growth regulator, in disinfesting cat fleas was evaluated, using flea-free cats and dogs which were purchased and infested every 10 days with cat fleas from a colony kept in our laboratory. Lufenuron was orally administered as a single dose of 15, 30, or 60 mg/kg to cats, and 5, 10 or 20 mg/kg to dogs. In cats, adult flea emergence was intensively prevented for 30 days by dosing of 15 mg/kg of lufenuron and 40 days by 30 or 60 mg/kg. The average egg hatch rate in 15mg/kg group was, however, significantly higher than those in 30 mg/kg or more, suggesting necessity to dose 30 mg/kg to cats to prevent development of cat fleas effectively. In dogs, a lower dose of the drug, 10 mg/kg seemed to be sufficient for the complete prevention of flea development.

View full abstract

Birth of malformed/stillborn calves is a liability to farmers and diagnosis of the condition early in gestation would be of immense economic benefit. We report on peripheral plasma progesterone (P₄), estrone (E₁) and estradiol (E₂) concentrations quantified by radioimmunoassay throughout gestation in twin embryo recipient cows carrying normal (cow N), freemartin (cow F) and schistosomus reflexus fetuses (cow S). The undulating plasma P₄ profiles were identical in all three cows throughout gestation apart from that the concentration in cow F dramatically declined on day 254 and it subsequently gave birth to stillborn calves. The plasma E₁ concentration progressively increased in cow N to peak at parturition and then rapidly declined a day after parturition. E₁ levels were lower in cow F than in cow N and exhibited a sudden increase in concentration at day 254 of gestation followed by a dramatic decline. Cow S had lower E₁ levels throughout gestation than cow N and showed an undulating profile. The plasma E₂ profile paralleled the plasma E₁ profile in all the cows but the E₂ concentration throughout gestation was lower than the E₁ levels. Plasma E₁ and E₂ levels declined to < 20 pg/ml in cow N a day after parturition as opposed to > 150 pg/ml E₁ and > 20 pg/ml E₂ levels, respectively, in cows F and S. Our results indicate that E₁ and E₂ are better than P₄ as prognostic indicators of fetal in-utero status as well as the number of fetuses a cow is gestating.

View full abstract

The development and degradation of temporary tooth buds and the development of rudiment of baleen plate were observed by gross-anatomical and histological examinations in twenty-four fetuses of the southern minke whale, Balaenoptera acutorostrata. The primary patterns of development of tooth buds were similar to those of deciduous tooth buds in the terrestrial species. Degradation of tooth buds was observed in the fetuses more than 615 mm body length (BL) and might proceed throughout the dental surface of the tooth buds. That degradation pattern was a little different from that of deciduous tooth buds in terrestrial species, which has a limited degradation area at the root of the tooth buds. In the fetuses with 135 and 153 mm BL, the upper jaw had a larger number of tooth buds than the lower jaw, although the number of buds varied in different individuals. Formation of rudiment of baleen plate was observed with degraded tooth buds in the fetus of 903 mm BL and it may be induced by the degradation of tooth buds.

View full abstract

An intraerythrocytic large protozoan, tentatively designated Babesia sp.1, was recently isolated from cattle in Hokkaido Prefecture, Japan. This parasite closely resembled B. ovata in shape of piroplasms, but was distinguishable by other morphological, immunological, and biochemical characters. The paired pyriform piroplasm of B. sp.1 was larger than that of B. ovata. The results from serological and antigenic examination by enzyme-linked immunosorbent assay (ELISA) and Western blot analysis showed that there were cross- but distinguishable-reaction between B. sp.1 and B. ovata. Protein profiles of both Babesia parasites piroplasms analyzed by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) were apparently different from each other. Several major proteins revealed by 2D-PAGE and the immunodominant proteins resolved by Western blot analysis (40 kDa for B. sp.1 and 29 kDa for B. ovata) were unique to each parasite. The results of the present study indicate the possibility that B. sp.1 is a species different from B. ovata.

View full abstract

Bovine testicle (BT) cells infected with non-cytopathogenic (NCP) bovine viral diarrhoea virus (BVDV) developed cytopathogenic effect (CPE) after superinfection with 7 Orbiviruses, whereas no CPE was induced by them in the absence of NCP BVDV infection. The CPE was accompanied by the enhanced replication of Orbiviruses. Seven of 10 strains of NCP BVDV induced the enhanced replication of Ibaraki virus, a member of Orbivirus. These 7 strains of NCP BVDV were END phenomenon positive. In contrast, the absence of CPE and the suppression of growth of Ibaraki virus were seen in BT cells infected with the other 3 strains which were END phenomenon negative. The END phenomenon negative viruses were different markedly from the END phenomenon positive viruses with respect to interactions with Orbivirus. The mechanism of the enhanced replication of Orbivirus seems to be explained with the suppression by the END phenomenon positive NCP BVDV to the interferon production of Orbivirus in BT cells.

View full abstract

Four of 51 dogs with chronic dermatitis were made to react to crude Japanese cedar (Cryptomeria japonica, CJ) pollen allergen by the intradermal skin test (IDST). These four dogs had specific IgE to CJ as determined by Prausnitz-Kustner test. In the provocation test, nasal discharge increased 5 to 20 min after introduction of the crude CJ pollen allergen into the nasal cavities, in two of three dogs. These results demonstrated that these dogs had hypersensitive to CJ pollen, which might be a cause of atopic disease in dogs.

View full abstract

Electrocorticograms (ECoGs) were evaluated in young rats and in middle-aged (19 months) rats housed under three different environments. The standard condition (SC, N=5) indicated the condition where two rats stayed in a standard cage, enriched condition (EC, N=5) meant keeping 6-8 rats in a large cage and impoverished condition (IC, N=5) was referred to as housing a single rat in a small cage. All middle-aged rats were kept under one of these cage conditions for 12 months, starting at 7 months of age. An ECoG was recorded simultaneously from 6 different locations on the scalp and was subjected to comparisons among the SC, EC and IC by means of spectral analysis. The power of the occipital α band (8.1-10.0 Hz) was significantly increased in IC rats. Total occipital power in IC rats was also enhanced as compared to SC and EC rats. These findings demonstrate that ECoG changes are present in the neocortex of middle-aged rats in different environments. In addition, social interaction seems to have a stronger effect than the differences in living capacity. These results indicate that the aging process should be studied from the viewpoint of environmental influences.

View full abstract

Anophthalmia and caudal vertebral anomalies such as taillessness or wry tail were morphologically examined in ten Japanese Brown calves obtained in Kumamoto Prefecture. The anomalous calves lacked eyeball bilaterally or unilaterally but had small-sized eyelids and narrow palpebral fissures. A small cystic, solid or spot-like remnant of eyeball (REB) was buried in the mixture of vestigial extraocular muscles, lacrimal gland and adipose tissue of the orbit. The REB was composed of irregularly arranged elements of ocular wall such as sclera, choroid and retina. The retina was often dysplastic and connected to the hypoplastic optic nerve. These morphological changes might represent the defective processes after the formation of the optic vesicle or cup. Therefore, this eye defect may be defined as degenerative anophthalmia. The defects of the vertebral body such as wedge vertebra, hemivertebra, and sagittal cleft vertebra seen in the lumbar, sacral, and coccygial regions and the meandering of the axial line of abnormal vertebrae may suggest the failure of notochord formation in the early fetal period. From the embryological point of view, it seemed possible that the calves were exposed to teratogen at the critical time of optic organogenesis and notochordal formation. The cause of anomalies could not be determined in this study.

View full abstract

The hepatic oxygen supply-uptake relationship was investigated during hypovolemic shock using a right heart bypass technique. The results were dissimilar to those previously reported in that the ratio of liver oxygen delivery to systemic oxygen delivery was significantly decreased during shock. The decreased ratio was due to a significant decrease in the portal venous oxygen delivery when compared to the decrease in the systemic oxygen delivery. The decrease in portal venous oxygen delivery was caused not only by the decrease in portal venous blood flow, but also by the decrease in oxygen content of portal blood. The ratio of hepatic arterial oxygen delivery, on the other hand, was significantly increased during shock. Hypovolemic shock increased the liver oxygen extraction ratio to nearly 100% of the pre-shock value. These findings suggest a hepatic protective mechanism for matching oxygen uptake to rising hepatic oxygen requiremdnts. Liver oxygen delivery returned to pre-shock value after correction of hypovolemia primarily due to a significant increase in hepatic arterial oxygen delivery. A significant negative correlation between the liver oxygen extraction ratio and the oxygen content of hepatic venous blood was observed. The hepatic venous oxygen content appears to be a simple and appropriate index of liver oxygenation in clinical medicine because it is difficult to evaluate the liver oxygen extraction ratio directly.

View full abstract

Liver blood flow was investigated in hypovolemic shock using a modified right heart bypass technique which can obtain accurate portal blood flow. Findings were similar to those previously reported: hepatic blood flow accounted for 34% of cardiac output in this study; 76% of hepatic blood flow was delivered from the portal vein and 24% from the hepatic artery. Hypovolemic shock markedly decreased total liver blood flow by a reduction in portal venous blood flow. The findings of this study provide evidence that mesenteric blood flow is a peripheral circulation circuit where blood flow is restricted during reduced circulatory volume. Development of a hepatic arterial buffer response during hypovolemic shock was confirmed by an increased ratio of hepatic arterial flow to cardiac output. Reduced total hepatic blood flow during hypovolemic shock returned to control flow by an increase in hepatic arterial flow after reperfusion. The results of this study demonstrate that compensated reactions for maintaining liver blood flow mainly due to the hepatic arterial buffer response were functioned both during hypovolemic shock and after elimination of shock.

View full abstract

We constructed a recombinant virus containing defined deletion within thymidine kinase (TK) gene from feline herpesvirus type 1 (FHV-1) C7301, which was isolated in Japan, by standard rescue procedures with thymidine arabinoside (araT) selection. The araT resistant recombinant virus was designated as C7301dlTK. Southern blot analysis, together with polymerase chain reaction, revealed a deletion with the expected size, based on agarose gel electrophoresis, of the TK gene region in the C7301dlTK. Growth kinetics of the C7301dlTK in CRFK cells was similar to that of the parent C7301 that possesses TK activity. However, plaques produced by the C7301dlTK were significantly smaller than those of the parent virus. This report might be applicable for the development of a new genetically engineered FHV- 1 vaccine.

View full abstract

The pathogenicity of Corynebacterium kutscheri isolated for the first time from Syrian hamster was experimentally studied in hamsters. In hamsters given intramuscular (i.m.) or subcutaneous (s.c.) inoculation with 10 or 10³ bacteria, neither clinical signs nor gross lesions were found. In those given 10⁵ bacteria i.m., moderate proliferation of granulation tissue was found in the muscle of the inoculation region at necropsy. In the animals given 10⁵ bacteria s.c., a nodular lesion was observed at the inoculation site 2 days post-inoculation (p.i.), but the nodules subsided gradually from 6 days p.i. and were unclear 10 days p.i. At necropsy, small abscesses were found in all the animals in this group. In those given 10⁷ bacteria either i.m. or s.c., lesions were clearly observed at the inoculation site 1 to 10 days p.i., and a large abscess was noted at necropsy. The organisms were isolated only from the lesions in the groups. Agglutinating antibody in the sera was detected only in the animals given 10⁵ or 10⁷ bacteria. This suggests that 10⁵ of C. kutscheri are needed to form localized nodular abscesses in Syrian hamsters.

View full abstract

To reliably detect early pregnancy factor (EPF) in cattle, monoclonal antibody specific for bovine CD2 molecule, which is the sheep fed blood cell (SRBC) receptor on bovine T cell surface, was applied to the rosette inhibition test. The rosette inhibition titers (RITs) were significantly higher in pooled sera from early pregnant cattle than in those of non-pregnant cattle using two anti-bovine CD2monoclonal antibodies, B26A4 (P<0.001) and BAQ95A (P<0.01). The dissociation value of RITs between pregnancy and non-pregnancy with B26A4 was greater than that with BAQ95A. The B26A4 monoclonal antibody was therefore applied to the rosette inhibition test in subsequent experiments. The RITs in serum of individual pregnant and non-pregnant cows 8 days after estrus were significantly different (P<0.001) by three or more dilutions. When the rosette inhibition test was carried out in sera from individual pregnant and non-pregnant cows at estrus and at 24, 72 and 168 hr after ovulation, the RITs of pregnancy sera increased significantly at 24 hr after ovulation as compared with non-pregnancy sera (P<0.001). These results indicate anti-bovine CD2 monoclonal antibody can be utilized with the rosette inhibition test to detect EPF in cattle, and that this assay detects bovine EPF for pregnancy serum at least 24hr after ovulation.

View full abstract

Cell-free-antigen (CFA) vaccines of strain Y-1 (serotype 1), G-4 (serotype 2) and E-3 (serotype 5) of Actinobacillus pleuropneumoniae (A. pleuropneumoniae) were prepared by emulsifying concentrated culture supernatant with oil-adjuvant. Mice immunized with the CFA vaccine had a high survival rate (90-100%) against challenge with the homologous strain. They also had cross-protective activity against challenge with the heterogeneous strains but their survival rate was low (20-50%). On the other hand, mice immunized with whole cell vaccine showed serotype specific protection and only a little cross protection. The protective antigens of the CFA were investigated. MAbs were produced by the standard method using spleen cells of mice immunized with CFA. MAbs to Apx I, II, III and capsular antigen of serotype 5 were obtained. Only MAbs to Apx I showed hemolysin neutralization activity among them. The protective effect of these MAbs against A. pleuropneumoniae infection were examined by passive immunization. Administration of Apx I MAb to mice extended survival time after challenge with serotype 5. The mice showed partial cross-protection against challenge with serotype 1. Survival rate was considerably low after the challenge infection. None of the mice given MAbs to Apx II or III were protected against challenge with serotype 5. The mice given MAb to capsular antigen of serotype 5 had a high survivalrate (70%) against a challenge with a homologous serotype. Furthermore, mice given MAbs against Apx I and capsular antigen of serotype 5 were completely protected against a challenge with A. pleuropneufnoniae serotype 5. In this study, we concluded that capsular antigen and Apx I are identified as protective antigens and their antibody play an important role in protection against infection with A. Pleuropneumoniae serotype 5.

View full abstract

The effects of starvation on fat cells and blood capillaries of the first abdomino-inguinal mammary gland in mice were investigated by light and transmission electron microscopy. The body weight of starved mice abruptly decreased to approximately 70% of that of controls at 3 days of starvation and, thereafter, gradually decreased. In adipose tissues of mammary stroma, multilocular fat cells increased in number and clustered during starvation to a glandular appearance at 6 days. Collagen fibers increased in amount around mammary ducts and buds. By electron microscopy, multilocular fat Cells possessed numerous mitochondria, small lipid droplets, and plasmalemmal vesicles, while endothelial cells of the blood capillaries showed numerous pinocytotic vesicles plus short marginal folds and microvillous processes. These observations prove that the number of pinocytotic vesicles in blood capillary endothelium is closely related with the increased amount of lipid of fat cells in the mammary gland during starvation.

View full abstract

The relationship between serum lipoprotein levels and the grades of marbling in muscle tissue was analyzed by gel filtration of lipoprotein fraction obtained from sera of 80 Japanese black beef cattle in the final stage of fattening. It was found that the increase in the Beef Marbling Standard number was positively correlated with the concentration of low-density lipoprotein cholesterol (r=0.79) and negatively with that of high-density lipoprotein cholesterol (r=-0.47).

View full abstract

Four strains designated as OB94-1 to OB94-4 of group A bovine rotavirus (BRV) were isolated from 35 fecal samples of calves with diarrhea in sporadic outbreaks. In VP7 (G) and VP4 (P) serotyping of these isolates, OB94-1 to OB94-3 were determined as G6P5, G6P5 and G10P5, respectively, by cross neutralization (NT) test and the G- and P- serotyping polymerase chain reaction (PCR) analysis. OB94-4 showed a one-way antigenic relation with the Lincoln strain (G6P1) and a weak antigenic relationship with the KK3strain (G10P11), and was determined as G6P11 by the PCR method. Thus, OB94-4 was shown to be a new G6 BRV with different antigenic properties from the others in the NT test.

View full abstract

The ovary of rat possessed a neutral proteinase which had an optimum pH at around 8.5 in the presence of 0.5 M NaCl. The proteinase was soluble only in media of high ionic strength such as 2 M NaCl. In order to prevent the reprecipitation in media of low ionic strength of the enzyme solubilized, it is necessary to add protamine sulfate to the solubilizing medium. When the solubilized enzyme was applied to a Sephadex column, the proteinase activity was eluted at the same position as bovine α-chymotrypsinogen. The results using some protease inhibitors showed that the proteinase was a chymotrypsin-like serine enzyme. When rats were treated with compound 48/80, the proteinase activity almost completely disappeared, suggesting that the enzyme is of mast cell origin.

View full abstract

Erythropoietin (EPO) levels in plasma from 124 clinically anemic dogs were determined by in vivo bioassay. In 81 anemic dogs with normal renal function, the concentration of plasma EPO showed a close correlation with the hemoglobin concentration. The plasma EPO level was obviously decreased in 43 anemic dogs with renal failure. Of these dogs with renal failure, 17 showed no detectable plasma EPO and resulted in the death of these dogs. In the remaining 26 dogs having detectable plasma EPO, the plasma concentration rate of EPO related to blood urea nitrogen and serum creatinine values.

View full abstract

The effect of TCV-309, a newly developed platelet activating factor (PAF) antagonist, on the wet/dry weight ratio of the lung (index of pulmonary edema) and the pulmonary surface activity (index of pulmonary compliance) was evaluated in comparison with that of CV-3988 (PAF-antagonist). Administration of TCV-309 (1 mg/kg) or CV-3988 (10 mg/kg) significantly reduced the wet/dry weight ratio which was increased by endotoxin administration (3 mg/kg). It also augmented the pulmonary surface activity. Administration of either TCV-309 or CV-3988 alleviated the histologic lesions caused by endotoxic shock. These results suggest that lung injury during endotoxic shock can be controlled by TCV-309 as by CV-3988.

View full abstract

Measurements for blood and bone marrow cell counts were carried out in male CBA/N mice aged 3, 6, 9, 12, and 26 weeks and the values were compared with those in normal mice. In the peripheral blood, CBA/N mice showed decreasing numbers of leukocytes with age, without marked changes in the differential cell count. In the bone marrow of CBA/N mice, the total number of femoral bone marrow cells was low in later life (26 weeks of age), and differential cell counts revealed a high granuloid/erythroid ratio at 3 weeks of age due to a low erythroblast count.

View full abstract

Minimal inhibitory concentrations (MICs) of 20 antimicrobial agents were determined for 67 field strains of Actinobacillus pleuropneumoniae isolated from the lungs of piglets with pleuropneumonia during the period 1992 to 1994, in Japan. Of these 67 strains, all 29 strains that were identified as serotypes 1 and 7 were resistant to chloramphenicol and tiamphenicol, whereas all of those identified as serotypes 2, 5 and 8 were susceptible to these antibiotics. Furthermore, 20 of 23 streptomycin-resistant strains were serotype 1, while, only 3 strains were serotype 2. These results suggest that the different serotypes of A. pleuropneumoniae vary in terms of antimicrobial-resistance.

View full abstract

For detection of antibodies against canine distemper virus (CDV), an enzyme-linked immunosorbent assay (ELISA) was developed using a crude extract from cells infected with the Onderstepoort strain of CDV as antigen. Twenty-six sera from dogs experimentally vaccinated with the Snyder-Hill strain of CDV were compared by ELISA and a standard virus neutralization (NV) test. Since a good correlation between the titers obtained by both tests was observed, ELISA was considered to be a rapid and reliable method for a serological survey of CDV infection. When a total of 167 sera from dogs suspected of canine distemper under natural conditions were examined by the ELISA, 29 of the sera (17%) were found to have low VN antibody titers and high ELISA titers. The reason for the discrepancy in the titers was discussed.

View full abstract

An abscess was developed experimentally by a subcutaneous inoculation of Stapylococcus (S.) aureus T-6 with a 4-cm silk suture in dogs. After draining the pus, the abscess was treated with a suspension of finely granulated chitosan (chitosan group), ampicillin (ampicillin group), or saline (control group) (Day 0). The chitosan group was further divided into 3 subgroups (0.01, 0.1, and 1.0 mg/ subgroups). Similar treatment was repeated after 4 days (Day 4), followed by euthanasia on Day 8. The wound cavity contraction rate was calculated by measuring the wound cavity diameter by a sound on Days 0, 4 and 8. The wound cavity contraction rate was significantly higher in the ampicillin, 0.1 mg chitosan, and 1.0 mg chitosan groups than in the 0.01 mg chitosan and control groups on Days 4 and 8 (p<0.05). In the 0.1 and 1.0 mg chitosan groups, the abscess healed completely in 6 out of 11 (55%), and 9 out of 10 cases (90%), respectively, by Day 8. In the ampicillin group, 4 out of 10 cases (40%) healed completely by Day 8. No healing occurred in the 0.01 mg chitosan and control groups. Histologically, the granulation tissue formed had abundant vascularization in the 0.1 and 1.0 mg chitosan groups on Day 8.

View full abstract

Enzymatic detection of polymerase chain reaction (ED-PCR) was applied for rapid and easy identification of mycoplasmas from contaminated cell culture. This method was based on the capture of amplified products via biotin-streptavidine affinity and the detection of an incorporated hapten in amplified products with enzyme-linked antibody. Primers corresponding to common sequence of Mollicutes in 16S ribosomal RNA dominated gene was used. Nineteen of twenty Mollicutes so far reported as cell contaminants appeared positive by ED-PCR, whereas remaining one, Acholeplasma axanthum, appeared negative. Samples from sixty-two cell culture were tested for contamination of mycoplasmas by means of ED-PCR, cultivation, and electronmicroscopy. The results of ED-PCR were the same as those of cultivating method. The time required for all the detection process in ED-PCR was about 5 hr for 20 samples. We suggest that ED-PCR can be used in the rapid detection of mycoplasmas from cell culture.

View full abstract

A total of 3, 120 swine sera collected for the years 1990-94 were tested for the presence of hemagglutination-inhibition (HI) antibodies against swine (H1N1) and human (H1N1 and H3N2) strains of influenza virus. No HI antibody against the swine strains was recognized during 18 months, though a slight prevalence (1.5-9.2%) of the antibodies was observed over the entire period. A wide variance in the incidence (0-26.3%) of antibodies against the human H3N2 strains was observed among the swine population.

View full abstract

In a Muscovy duck breeding-growing farm in Aomori prefecture, most of ducklings hatched during spring in 1994 died within two-week-old. The mortality was nearly 100%. In most cases, birds died without clinical signs and some with leg weakness. By serological and virological tests, the outbreak was identified as a goose parvovirus infection. In pathological test, however, no typical manifestations of goose parvovirus infections (hepatitis and intranuclear inclusion bodies in hepatic cells) were detected.

View full abstract

Kittens inoculated orally with 10² PFU of feline enteric coronavirus developed no antibody to the virus despite the repeated challenges. However, they developed antibody for a long period with 5×10³-1.6×10⁵ (mean 3×10⁴) and with 2.5×10³-2×10⁴ (mean 6×10³) immunoperoxidase antibody titer when they were challenged with 10⁵ and 10³ PFU of virus following previous challenges, respectively. Viremia was found when kittens were inoculated with 10⁵ PFU of virus, but not with 10³ PFU of virus. The dose of 10³ PFU of virus seemed to be a lower limit to establish infection. These results indicate that local infection induces a low antibody response and systemic infection induces a high antibody response.

View full abstract

The aim of this study was to estimate the accuracy of the quantitative measurement of renal blood flow using the non-invasive method, Doppler ultrasonography. First, we determined a method of approach to the renal artery in order to detect the rate and pattern of flow, using 8 adult beagles under general anesthesia. Secondly, we examined the renal arterial blood flow using the Doppler method and electromagnetic flowmeter using 7 mongrel dogs. A significant correlation (r=0.879; p<0.01) was found between two methods, though the Doppler system tended to indicate high values than the electromagnetic flowmeter. Our study suggests that the Doppler method is a useful non-invasive technique of measuring renal blood flow in the dog.

View full abstract

A new analytical method for observation of the metabolic status of butyltin compounds in the mouse liver was devised by a combination of extraction, purification and separation followed by quantitative analysis of each butyltin compound. After the extraction of all tin compounds from liver homogenate with ethyl acetate, these compounds were purified by combination of the fractional extract with organic solvents and column chromatography. The purified fraction was also analyzed by thin-layer chromatography, identifying each tin compound from differences in mobility on a silica gel plate. The tin content in the each separated spot on the plates was measured by flameless atomic absorption spectrophotometry after extraction by acid treatment. About 90% of tin was recovered by this method from the liver of mice which had been administered tri- or dibutyltin compound orally. This method will be useful for quantification of each metabolic product formed from butyltin compounds in vivo.

View full abstract

One thousand two hundred and forty pigs' sera collected from 1975 to 1992 on 240 farms in Chiba Prefecture were subjected to a neutralization test for the encephalomyocarditis (EMC) virus. Seven (23.3%) of 30 pigs in 1975 had neutralizing antibodies against the EMC virus. The antibody positive rates each year ranged from 16.7% (1976) to 56.3% (1981). The differences of antibody positive rates between districts were not great after 1985. These serological results suggested that the EMC virus infection had already been introduced by 1975 and that it is prevalent among pigs in Chiba prefecture.

View full abstract

A 9-month-old male Japanese Black calf with subcutaneous edema in mainly both limbs was investigated. Necropsy revealed about 20 l of ascites and severe edema in the large omentum, abomasal folds, conjunctiva and rectum. Only small internal iliac and hepatic lymph nodes were found. Histopathology revealed lymph node dysplasia showing excess trabecular formation, reticular cell proliferation, and obvious dilation of both afferent and efferent lymphatics. These findings suggest that disturbance of lymphatic flow with congenital lymph nodes dyspalsia or aplasia resulted in lymphedema in this calf.

View full abstract