This study was designed to demonstrate the broad utility of contrast-enhanced magnetic resonance imaging (MRI) for diagnosis of carcinoma. Twenty-six New Zealand White rabbits of either sex (1.7-3.4 kg) were used for the investigation. VX2 carcinoma (squamous cell carcinoma) was implanted in either the brain, lung, ovary, bone or muscle of rabbits. Contrast agent, Gadodiamide Injection, was administered intravenously at a dose of 0.1 mmol/kg. MR images were obtained by a 1.5 T, or a 2.0 T magnetic field strength super-conductive MRI unit. The intensity of the signal for the carcinoma was increased after administration of contrast agent, and the detectability or diagnostic information of post-contrast images was superior to that of pre-contrast images in all models. In addition, no significant side effects were observed during the MRI examination. After diagnosis using MRI, morphological damage in each model was assessed by gross and histopathological examinations. In contrast-enhanced MRI, though there were variations between the models employed, contrast effects in brain and muscle carcinoma models were generally related to differences in capillary permeability, while imaging in lung, ovary and bone carcinoma models was dependent on differences in blood flow rate and the size of interstitial spaces. Overall, our results demonstrate that contrast-enhanced MRI is a useful and safe method for diagnosing tumors.

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The effect of reflex closure of the esophageal groove induced by the accustomed milking procedure on absorption of sulfamethoxazole (SMX)-trimethoprim (TMP) combination was examined, using calves trained to suck through a nipple-bucket. The experiment was carried out with a two-way cross-over design in which 2 groups of 5 calves of 6 weeks old were used. SMX-TMP combination was administered to the calves in each group through a nipple-bucket or an esophageal catheter. Tmax of SMX after nipple-bucket dosing was about 40 min shorter than that after catheter dosing. Cmax and AUC of SMX after the nipple-bucket dosing were 7.5 times greater and 6.9 times larger than those after the catheter dosing, respectively. Plasma TMP concentration was measurable only after the nipple-bucket dosing. These results suggest that a large portion of the drugs administered by the nipple-bucket dosing, which induces closure of the esophageal groove, were transferred directly into the abomasum resulting in higher bioavailabilities of the drugs.

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Lactate dehydrogenase and alkaline phosphatase isoenzymes of the Mongolian gerbil were examined using electrophoretic techniques and were compared with those of the mouse, rat, and guinea pig. Five isoenzymes of lactate dehydrogenase (LDH) were detected in the gerbil with LDH₂ and LDH₅ being equally dominant. Two bands of alkaline phosphatase (ALP) were distinguished in sera treated with neuraminidase in the gerbil and the relative activity of the cathodic fraction was greater than those of the mouse and rat. Genetic polymorphism was not found among the coat color variants of the Mongolian gerbil. A comparative study on LDH and ALP revealed distinct interspecific differences in the rate of the electrophoretic migration of the respective isoenzymes among the mouse, rat, guinea pig, and the Mongolian gerbil.

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The changes in bone metabolism and morphology of chondrocytes in bovine Hyena disease caused by administration of vitamin AD₃E premix (V-AD₃E) or vitamin A (V-A) were examined. At the each age, 5 calves were used. Among them, Hyena disease was recognized in 3 calves; a calf administered a high dose of V-AD₃E premix (V-A 3, 000, 000, V-D₃ 300, 000, and V-E 1, 200 I.U./day), a calf administered a half dose of the V-AD₃E premix, and a calf administered only V-A 3, 000, 000 I.U./day. The remaining calves without Hyena disease were a calf administered only V-D₃ 300, 000 I.U./day and a control calf. Each agent was administered orally for 10 days from 1 week after birth. In the 3 calves with Hyena disease, the bone metabolism in bone histomorphometry of ilium was in the state of low turnover at the age of 50 days. The bone volume was small at the age of 12 months. The epiphysial growth plates of the distal femurs and the proximal tibias partially disappeared and the chondrocyte lacunas in them were flattened. The matrix fibers of epiphysial growth plates were thinner in diameter and higher in density than those of the control calf. In the calf administered only V-D₃, the values of bone volume decreased with aging. In conclusion, Hyena disease may be caused by excessive administration of V-A, because hypervitaminosis A suppressed the activity of differentiation and proliferation in chondrocytes and osteoblasts, and excessive administration of V-D₃ may promote these actions.

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The kidneys of fetal rats from uninephrectomized mothers were investigated morphometrically on days 18, 20, and 22 of gestation. Maternal uninephrectomy was performed on day 5. On days 20 and 22, the proximal tubular cell height in fetuses from uninephrectomized mothers was significantly lower than that in fetuses from sham-operated mothers. The luminal diameter, length and total volume of the proximal tubule were significantly larger in fetuses from uninephrectomized mothers than in those from sham-operated mothers. The total glomerular volume of mature type in fetuses from uninephrectomized mothers was significantly larger than that in fetuses from sham-operated mothers. On day 18, maternal uninephrectomy caused no significant difference in any kind of parameters used for the proximal tubule, but induced an increase in the total glomerular volume of immature type. These results suggest that maternal uninephrdctomy stimulates morphological development of the proximal tubule in the fetal kidney.

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We investigated the mechanism of anti-allergic action of Moku-boi-to (M-711) and effects on the skin reactions induced by chemical mediators as the model of allergic dermatitis. More than 20 mg/kg BW of M-711 significantly suppressed the enhancement of capillary permeability induced by histamine, LTC₄, and anti-serum in the rat skin. Anti-histaminic effect of 40 mg/kg BW of M-711 was equipotent to same as the optimal doses of azelastine and diphenhydramine, respectively. As to anti-LTC₄ action, 20 mg of M-711 was compared to the optimal dose of diphenhydramine. Those data showed that M-711 has the suppressive effects on the chemical mediators such as histamine and LTC₄ and reduced the skin reaction induced by antigen-antibody response.

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The antimicrobial effects of amikacin on Salmonella Typhimurium were investigated in fowls using pharmacokinetic parameters of amikacin and the minimum inhibitory concentration (MIC) of the drug for the bacteria. Pharmacokinetic parameters of amikacin after the intramuscular administration into the fowls were measured using the fluorescence polarization immunoassay. As there was no protein binding amikacin, the total concentration was identical to the free concentration. After inoculation of the bacteria, the following intramuscular dosage regimens were carried out to test the antimicrobial effects: injection with 20 mg/kg of amikacin sulfate every 9 hr for 72 hr, injection with 20 mg/kg every 18 hr for 72 hr, injection with 20 mg/kg every 36 hr for 72 hr, and injection with 10 mg/kg every 12 hr for 72 hr. The control birds were not injected with amikacin. Abdominal organs were collected from each bird after the treatment ended. The organs were cultured and the number of colonies on each plate was calculated. No significant differences were detected among the four amikacin-treated groups, whereas the number of colonies in the control group was significantly higher than that in the amikacin-treated groups. An antimicrobial drug concentration exceeding the bacterium's MIC for at least 1/4 of the administration interval might be effective for the treatment of the infection, and the degree of peak drug concentration had no effect on antibacterial activity as long as the duration of the drug concentration above the MIC value remained the same.

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After intraperitoneal infection with mouse hepatitis virus, strain JHM (JHMV), JHMV replicated in the spleen of C57BL/6 mice for a few days but cleared within a week. The acute viral clearance coincided with moderate expansion of CD8⁺T cells and modest expansion of CD4⁺T cells, and was impaired moderately in mice depleted of CD8⁺T cells and completely in mice depleted of both CD4⁺ and CD8⁺T cell subsets. Flow cytometric analysis showed that expression of cell surface markers on the spleen T cells changed during JHMV infection. CD8⁺T cells expressing increased amounts of CD11a, CD43, CD44 and CD49d, and those expressing decreased levels of T cell receptor αβ, CD8, CD45RB and L-selectin were expanded in the spleen after JHMV infection. However, they did not express CD11b, CD25 or NK1.1. They used highly heterogenous Vβ chains for their T cell receptors. In addition to CD11a^highCD8⁺T cells, CD11a^highCD4⁺T cells were detected transiently after JHMV infection. The virus-specific cytotoxic T lymphocyte (CTL) activity was observed in both CD4⁺ and CD8⁺ spleen T cells from mice 7 days post-infection. The present study shows the dynamics of CD8⁺ and CD4⁺T cells in the spleen during JHMV infection in mice and suggests that CD11a^highT cells may be involved in JHMV clearance in vivo because their appearance was temporally correlated with T cell-mediated viral clearance in vivo and antiviral CTL activity in vitro.

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The biological properties and susceptibility to antimicrobial agents of Bacillus larvae were examined. Twenty-nine strains, 28 isolates from each outbreak of American foulbrood in Japan and a B.larvae type strain (ATCC 9545^T) were used. Our B.larvae isolates had almost the same biological properties as the type strain. The isolates were more susceptible to penicillins, macrolides and lincomycin, a lincosamide, than other antimicrobials. Mirosamicin among the macrolides and ampicillin among the penicillins appeared to be the most effective agents.

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Detailed observation of the growth process of the embryos and fetuses (hereafter, referred to as just fetus) of 6 pregnant Beagle bitches (14-27 months old) was carried out using ultrasonography. From daily measurements of the transversal diameter of the fetal abdomen, diameter of the fetal head and diameter of the fetal heart, significant growth curves (secondary regression equations) were obtained from the day of gestation and the measured values (p<0.01). The results of this study showed that this method can be applied to estimate the gestation age of dogs in cases when the mating day is unknown, and determine the state of fetal growth.

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Alveolar hydatidosis by Echinococcus multilocularis (Em) infection occurred on a 22-year-old (approx.) male gorilla (Gorilla gorilla) and a 4-year-old female ring-tailed lemur (Lemur catta) in a zoo, in Hokkaido, Japan. Case 1: The gorilla presented neurologic signs in course of nine months and died. Pathologically, alveolar hydatid lesions were found in the liver, the liver-associated lymph nodes, the cerebrum, and the lungs. A protoscolex was found only in one hepatic cyst. Case 2: In the lemur, large masses of hydatide cysts were found on the liver and at the lung-associated lymph nodes. Cysts contained numerous calcareous corpuscles and protoscolices. The lemur appears a favorable intermediate-host for Em. The identification of Em in both cases were confirmed by PCR.

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Cardiac arrest occurred in a male Labrador Retriever dog weighing 27.8 kg during induction to anesthesia. Immediately after the failure of resuscitation by the external cardiac compression, thoracotomy was performed and open chest direct current (DC) counter shocks were applied with routine emergency medications. Then the dog recovered consciousness. Although cardiac rhythm just after resuscitation was sinus tachycardia with paroxysmal supraventricular tachycardia, multifocal ventricular arrhythmia occurred 2 hr after resuscitation. This arrhythmia might be the result from reversible cardiac lesions due to DC counter shock.

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Serological survey of bovine immunodeficiency-like virus (BIV) infection was performed in cattle of 3 different farms in Hokkaido, where a relatively high seroprevalence was recorded for bovine leukemia virus (BLV). About a half of 120 cattle tested were seropositive for BLV, while 7.5% of the cattle were seropositive for BIV. Though increased numbers of leukocytes were frequently observed in BLV-seropositive cows, no such changes were observed in BIV-positive but BLV-negative cows. No correlation was demonstrated between BIV- and BLV-seroprevalence of the cattle.

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Infectious bovine rhinotracheitis (IBR) virus antigen was demonstrated by the immunoperoxidase method in tissues of two aborted bovine fetuses, which had been stored for 25 years after fixing in formalin and embedding in paraffin. Necrotic foci were detected in the liver, kidney. adrenal gland, and thymus of the fetuses. Coincidenting with the distribution of the necrotic foci, IBR virus antigen was demonstrated by immunostaining. The present study proved the immunoperoxidase method in one of useful techniques to demonstrate IBR virus antigen in tissue sections from preserved paraffin blocks.

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Japanese Black fattening cattle in Miyazaki prefecture, Japan were examined for serum vitamin A (V.A) and vitamin E (V.E) by automatic column-switching high performance liquid chromatography with automated deproteinization. Results indicated that most Japanese Black fattening cattle in Miyazaki prefecture may be provided with V.A supplement and diets including little V.E, moderate β-carotene and V.A during the early fattening stage, and diets including little β-carotene, V.A and V.E during the middle and later fattening stages. Therefore, monitoring serum V.A and V.E in Japanese Black fattening cattle throughout the fattening period seems necessary for farmers in Miyazaki prefecture to avoid economic loss attributable to these deficiencies.

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The mechanism of CD11a^highCD8⁺ T cell induction after mouse hepatitis virus infection, which has been suggested to play a key role in the elimination of infectious virus from the spleen in C57BL/6 mice, was studied. In CD4⁺ T cell-depleted mice, CD11a^highCD8⁺ T cells were induced in the spleen and spleen cells showed virus-specific cytotoxic T lymphocyte activity after mouse hepatitis virus Infection. The same results were obtained in adult thymectomized mice. These results indicate that CD11a^highCD8⁺ T cells can be generated after mouse hepatitis virus infection in the absence of either CD4⁺ T cells or the thymus.

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A new cell line derived from a spontaneous canine leukemia was established and designated GL-1. The cells have been cultured in a floating fashion and passaged for over two years. They were round with rich cytoplasm containing many rough endoplasmic reticula and mitochondria. Peroxidase staining was negative. The nuclei of many cells were round, but segmented nuclei were seen frequently. The doubling time of the cells was 27.3 hr and they had 78 chromosomes. Surface marker analysis using monoclonal antibodies (MABs) and flowcytometry revealed that GL-1 possessed CD45 and surface IgG. However, the cells did not react with MABs detecting T-cell markers. These results indicate that GL-1 has a lymphocytic lineage and is derived from a B-cell leukemia.

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Here we report the first canine infectious cyclic thrombocytopenia (CICT) found in Taiwan. Platelet-specific inclusions were detected in the blood smear of a military working dog. To identify the etiologic agent, the patient's blood was transmitted to three six-month-old German Shepherd dogs. The Ehrlichia platys-like inclusions were observed six to eight days after inoculation. Indirect fluorescent antibody test showed that the serum from the patient reacted specifically with the microorganisms within the platelets. Typical hematologic manifestations of E.platys infection, cyclic parasitemia and concomitant thrombocytopenia, were observed in these dogs. The prevalence of CICT in north Taiwan was also studied, and the incidence was 8.9% (4 out of 45) in civilian dogs and 97.1% (34 out of 35) in dogs from a heavily tick infested kennel.

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To prepare mycoplasmal DNA template for PCR from biological samples rapidly and easily, surfactants which can solubilize cell membrane effectively were investigated. 3-[(3-Cholamidopropyl) dimethylammonio]-1-propanesulfonate (CHAPS) was considered an effective surfactant. This surfactant could solubilize mycoplasma cell membrane without suppressing the polymerase reaction. In addition, proteinase K treatment played an important role in preparing mycoplasmal DNA template from a simulated biological sample. It was therefore considered that a combination of proteinase K- and CHAPS- added lysis buffer would be more useful in preparing mycoplasmal DNA template. We could detect PCR products by using the lysis buffer with a simulated lung emulsion sample containing mycoplasma organisms at 10⁴ CFU per gram.

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The classification of the cycle of the seminiferous epithelium was carried out in the common tree shrew (Tupaia glis). The tree shrew captured in Thailand were fixed with Bouin's fixative, embedded in paraffin wax, and stained with PAS-hematoxylin. The cycle was classified into twelve stages on the basis of the acrosomal changes of spermatids. Relative frequencies of stages from I to XII were 11.9, 7.2, 8.9, 22.5, 12.9, 9.7, 8.0, 5.9, 4.0, 3.2, 2.9, and 3.6%, respectively. Different stages did not appear in a cross-sectioned tubule as did in primates. The head of matured spermatid was discoidal in shape and different from that of primates and rodents. Spermatogenesis of the common tree shrew is different from that of primates and rodents according to its morphological features.

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Field potentials evoked in the accessory olfactory bulb (AOB) of the mouse by a vomeronasal organ (VNO) volley were analyzed with current source-density (CSD) techniques. The potentials were recorded with an electrode oriented in the direction perpendicular to the laminae of the centre of the AOB in five tracks of equal spatial lattice for identical coordinates. There were little or no differences in the amplitude or time course of the potentials at equal depth among the five tracks. The CSD profile from a one-dimensional CSD analysis corresponded closely with that of a three-dimensional CSD analysis of a central track in the AOB. Furthermore, VNO-evoked field potentials were recorded in the AOB external plexiform layer while an electrode was being moved in the direction parallel to this layer. The potentials recorded at adjacent points were nearly identical and hence the related one-dimensional CSD calculations revealed no net currents along this layer. These results indicate that a one-dimensional CSD analysis is applicable to the mouse AOB.

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