Peroxisomes containing fibrillar structures were induced after 1 week withdrawal of bezafibrate, a peroxisome proliferator. In this report, the relation between the duration of bezafibrate treatment and the induction of abnormal peroxisomes in rat hepatocytes was studied morphometrically. The abnormal peroxisomes did not appear during 3 to 90 days of treatment with bezafibrate, but they appeared after 1 week withdrawal of it. The number and frequency of abnormal peroxisomes were prominent in 3, 7, and 14 days of treatment followed by 1 week of withdrawal of bezafibrate. It was evident that the frequency of abnormal peroxisomes decreased with 30-90 days administration of bezafibrate. This means that long-term (30-90 days) treatment with bezafibrate suppresses the induction of abnormal peroxisomes.
A monoclonal antibody was produced by immunizing BALB/c mice with freshly prepared canine thymocytes and peripheral blood leukocytes. The antibody, designated 59.4, was of the IgG1 subclass type and mainly reacted with lymphocytes. In single-color flow cytometric analysis, lymphocytes from the peripheral blood, thymus and spleen were graded into three categories according to their fluorescence intensity labeling by antibody 59.4: weakly, moderately and intensely positive cells. Two-color analysis revealed that a major population of CD8-positive cells were intensely labeled by antibody 59.4, but less than 50% of CD4-positive cells were moderately reacted with antibody 59.4. Immunohistochemically, thymocytes in the medulla showed moderately intense immunoreactivity to 59.4, but most lymphocytes in the cortex were negative in reaction. Immunostaining using antibody 59.4 demonstrated characteristic aggregations of 59.4-positive lymphocytes in the reticulum cell-free region of the thymic medulla. In the spleen, scattered lymphocytes in the outer layer of the marginal zone and in the red pulp were intensely labeled by antibody 59.4, while lymphocytes gathering in the mantle zone and periarterial lymphatic sheath (PALS) were moderately stained. Antibody 59.4 appears to recognize an antigen which is expressed by a more-differentiated T cell-lineage but not by immature T cells in the thymic cortex.
Neutrophil functions and intracellular Ca2+ concentrations ([Ca2+]i) were evaluated in 15 Holstein cattle divided into the following 3 groups: 5 neonatal calves less than 1 week old (group 1), 5 young calves 2 to 4 weeks old (group 2) and 5 cows 2 to 3 years old (group 3). The ability of neutrophils to phagocytose Candida albicans (C. albicans) was significantly higher (p<0.05) in neonatal and young calves than in cows, whereas the phagocytosis by neutrophils of bovine IgG-coated yeasts (IgG-yeasts) was significantly lower (p<0.05) in neonatal and young calves than that in cows. The killing activity by neutrophils of C. albicans in neonatal and young calves was significantly lower (p<0.05) than that in cows. Luminol dependent chemiluminescent (LDCL) responses stimulated with opsonized zymosan (OPZ), heat-aggregated IgG (H-agg.IgG) and phorbol myristate acetate (PMA) were apparently lower in neonatal and young calves than in cows. No clearly different expressions of complement receptor type 3 (CR3) on neutrophils were observed among the 3 groups of cattle, although the values due to the binding of FITC-anti-bovine IgG to neutrophils in neonatal and young calves were lower than those in group 3. The OPZ-induced [Ca2+]i of neutrophils in neonatal and young calves were significantly higher (p<0.05) than those in cows, but they were lower in neonatal and young calves when stimulated with H-agg.IgG. These results indicate that CR3- and FcR-mediated phagocytic and killing activities of neutrophils in neonatal and young calves are different from those in cows. These phenomena may be associated with age-dependent changes in [Ca2+]i.
Human fetal thymus/liver engrafted SCID mice were constructed and studied for its susceptibility to HIVBRU infection by i.v. inoculation which seemed to represent an appropriate route of HIV infection in vivo. By the i.v. inoculation of HIV, the medulla in the engrafted thymus narrowed significantly when compared with that of the human thymic implant from virus-uninoculated mice. Further, immunohistochemical staining indicated the presence of HIV antigen predominantly in thymic epithelial cells in medulla of the engrafted thymus. Polymerase chain reaction (PCR) assays resulted in amplifications of HIV genome in the implanted grafts as well as in lymph nodes and PBMC. The virus infections to the implants were confirmed biologically by coculturing with PHA-stimulated human PBMC and the graft cells from the HIV-inoculated SCID-hu mice. Thus, the i.v. inoculation of HIV into Thy/Liv SCID-hu mice induce narrowing of medulla of the engrafted thymus and may become an efficient and useful tool for screening candidate anti-HIV agents.
Newly recognized rat parvovirus (rat orphan parvovirus: ROPV) was examined for viral excretion and persistence in infected rats, and also for infectivity to mice and hamsters. The virus appeared to replicate mainly in lymphoid or hematopoietic tissues, and was detected in feces, urine and oropharynx of the infected rats at 1 to 4 weeks postinfection. The infective virus was also detected in peripheral leukocytes and various tissues at an acute phase of infection, and decreased in every tissue at 8 weeks postinfection. Viral DNA, however, was persistent in lymphoid tissues at least up to 24 weeks postinfection. When the virus was inoculated to mice and hamsters, no evidence of viral production and antibody response was demonstrated. ROPV is assumed to be a variant of the known rat parvovirus which resulted to alter cell tropism and persist in lymphoid or hematopoietic tissues, in order to escape from host immune system.
This study was designed to seek the appropriate scanning parameters for T1 and T2 weighted images of rat head by use of a high (4.7 T) magnetic field strength magnetic resonance imaging unit. The optimum values of variables for T1 weighted images were considered to be a time of repetition of 1,000 msec, and for T2 weighted images, 8 echoes. When the sagittal images of a healthy rat head were scanned using these optimum values, the cerebrum, cerebellum, olfactory bulb, pituitary gland, pineal gland, spinal cord, tongue, nasopharynx, nasal conchae, vermis and cerebrospinal fluid were clearly observed in either T1 or T2 weighted images. Moreover, a primary brain tumor induced by ethylnitrosourea was depicted as a high signal intensity mass in T2 and contrast-enhanced T1 weighted images.
The mammary tissues of 6 cows with bovine leukemia virus (BLV) antibody and subclinical mastitis were investigated histopathologically, and their organ cultures were ultrastructurally observed. Numerous BLV particles, 110 to 120 nm in diameter, were seen around lymphocytes, which had infiltrated into mammary alveoli and showed blastogenesis under culture. Particles budding from the cell membrane were also found.
Extracts containing gymnemic acids, which were extracted from the leaves of Gymnema sylvestre (GS) as nine fractions, were evaluated for their effects on a high K+-induced contraction of guinea-pig ileal longitudinal muscles, on glucose transport mediated by the difference of glucose-evoked transmural potential difference (ΔPD) in the inverted intestine of guinea-pig and rat, and on blood glucose in rat. Among nine fractions obtained by high performance liquid chromatography from the extract, f-2 and f-4 strongly suppressed the high K+-induced contraction of the ileal muscle, f-3 and f-5 did so moderately, and f-8 and f-9 did so weakly, whereas the other fractions did not affect it. The degree of suppression of high K+-induced contraction by f-2 at 74% was almost the same as that of f-4 at 67%, at concentrations of 0.1 mg/ml. The suppressed contraction by f-2 or f-4 was recovered by adding 5.5 mM pyruvate. The ΔPD increased by 5.5 mM glucose in the inverted intestines of guinea-pig and rat were equally suppressed by 0.1 mg/ml of f-2 or f-4 to 40%. In a rat sucrose tolerance test, f-2 and f-4 suppressed the elevation of blood glucose level. Both f-2 and f-4 suppressed the contraction of guinea-pig ileal longitudinal muscle, interfered with the increase in ΔPD induced by glucose in the inverted intestines of guinea-pig and rat, and inhibited the elevation of blood glucose level. In conclusion, it is suggested that some of the extracts containing gymnemic acids from GS leaves suppress the elevation of blood glucose level by inhibiting glucose uptake in the intestine.
Bioavailabilities of oral rumen-protected and non-protected formulations of sulfamethoxazole (SMX) were compared in ruminating calves, since in vitro degradation of SMX in ruminal fluid was confirmed. The coated with a gastric-acid-soluble polymer and uncoated formulations were administered to 3 calves through a catheter. Neither formulation could produce sufficient blood concentration of the drug, though the bioavailability of SMX for the coated formulation was higher than that for the uncoated formulation. It was suggested that the rumen-protected drug could improve the bioavailability by escaping from degradation in the rumen, but scarcely attain the effective levels in blood.
Juvenile estuarine gastropods (Clithon retropictus), maintained in ultraviolet ray-irradiated recirculating artificial seawater with a salinity of 20% at 28°C, preserved thermostable direct hemolysin (TDH)-producing strain D-3 of Vibrio parahaemolyticus at a level of 104-105 colony forming units per gram (cfu/g) and TDH-non-producing strains N-18 and R-13 at a level of 101-102 cfu/g in the alimentary tract for at least 21 days after ingestion. In adults, the numbers of the three strains decreased to a level of 100 cfu/g within 21 days under the same conditions. This evidence supports our recent observations that TDH-producing strains increased to a high level in the summer months in the presence of high levels of TDH-non-producing strains in the alimentary tract of juvenile C. retropictus at estuaries in Japan.
Exploratory laparotomy was performed on a dog suspected of having idiopathic renal hematuria. Two catheters were inserted into the bilateral ureters, and hematuria from the left kidney was confirmed. The blood flow was occluded in the ventral and dorsal rami of the left renal artery in order to localize the site of hemorrhage. As hematuria disappeared when the dorsal ramus was occluded, the site of renal hematuria was localized to the area dominated by the dorsal ramus of the renal artery. As a result of ligating the dorsal ramus of the left renal artery in this dog, renal hematuria subsided, and the dog has shown a favorable course, to date, one year after surgery.
Effects of a combination of medetomidine-ketamine as a chemical restraint and antagonistic effects of atipamezole on this combination were investigated in 5 lions. The medetomidine (47.6-58.4 μg/kg) and ketamine (1.9-5.7 mg/kg) combination provided complete immobilization with good analgesia and muscle relaxation in 4 lions, while one lioness was poorly sedated by medetomidine, and additional injections of medetomidine and ketamine were required. The duration of anesthesia seemed to be much longer than one hour in 4 of the lions. Atipamezole, at four times the preceding dose of medetomidine, provided a smooth recovery and animals were able to stand up 17-61 min after its injection. Side effects were limited to vomiting after walking in 3 of 5 lions.
Blood samples from 796 Holstein dairy cows in 20 herds from 6 districts in Japan from June 1994 to August 1995 were examined to determine whether they were BLAD-free, BLAD carriers, or BLAD-affected by use of DNA-polymerase chain reaction (PCR) analysis. The usage of semen of confirmed BLAD-carriers for artificial insemination in the Hokkaido district and two selected dairy farms was examined to estimate the gene frequency of BLAD carriers of sires. BLAD-carrier prevalence in 20 herds (796 cows, over 2.5 years old) ranged from 0 to 23.5%, and the mean BLAD-carrier prevalence was 8.1%. The BLAD-carrier prevalence in 10 herds (363 cows) in which the occurrence of BLAD was not detected by the DNA-PCR test ranged from 0 to 12.5% with a mean of 5.4%. The BLAD-carrier prevalence in 10 herds (433 cows) in which the occurrence of BLAD was confirmed by DNA-PCR analysis ranged from 2.6 to 23.5% with a mean of 10.8%, and these values were significantly (P<0.05) higher than those of dairy herds in which the occurrence of BLAD was not detected. The age distribution in BLAD carriers in these cows ranged from 2.5 to 11 years. The mean gene frequencies of BLAD among 796 cows from 20 herds and 433 cows from 10 herds in which the occurrence of BLAD was detected were 0.041 and 0.054, respectively. The proportional usage of semen of BLAD carriers for artificial insemination in the Hokkaido district in 1992 was 12.6%, and its gene frequency was 0.058. On two selected farms in which higher BLAD-carrier rates were detected, the prevalences were 35.5% and 25.8%, and their gene frequencies were 0.177 and 0.129, respectively. The occurrence of BLAD-affected in Holstein dairy cattle was estimated to be 0.16-0.31% at birth in Japan without genetic control.
Peripheral plasma estrone sulfate (E1-S) concentrations were characterized throughout gestation in singleton and twin bearing cows by a direct radioimmunoassay method. Maternal plasma E1-S was detectable from around day 100 and after that its concentration increased progressively to term in both singleton (n=5) and twin bearing (n=5) cows. Twin bearing cows had a significantly higher E1-S concentrations in some time from mid-gestation to term when compared to singleton cows. E1-S concentration in the twin bearing cows increased rapidly in the third trimester and peaked (16.7 ng/ml) on the day of calving. In the singleton cows the concentration increased gradually and peaked (7.1 ng/ml) about 10 days before calving and then subsequently decreased. Our results indicate that singleton and twin bearing cows show a disparate E1-S profile from mid-gestation to term.
Three feline coronavirus (FCoV) isolates KUK-H, M91-266, and M91-267 were examined to elucidate their biological and antigenic properties as well as disease potential in cats. Immune stainings of virus-infected cells by using FCoV type-specific monoclonal antibodies indicated that their antigenic specificity was serotype II. However, antigenic variations among these serotype II FCoVs were detected by neutralization assay with hyperimmune antisera against FCoVs and canine coronaviruses, and with experimentally infected cat sera; there were two subtypes in serotype II FCoVs. The isolates efficiently grew in fcwf-4 cell culture showing lytic CPE enough to form distinct plaques; when measured 48 hr after infection, plaque sizes of both M91-266 and M91-267 were approximately 1 mm in diameter, and a mixture of small (less than 1mm in diameter) and large (approximately 3 mm in diameter) plaques were produced in the case of KUK-H. Strains KUK-H, M91-266 and M91-267 produced feline infectious peritonitis (FIP) in 50%, 67% and 89% of experimentally inoculated kittens, respectively. Furthermore, 80% of the kittens inoculated with the small plaque former of KUK-H developed FIP accompanied by more prominent clinical signs as well as pathological changes when compared with 28.6% of kittens inoculated with the large plaque former. These results suggest that serotype II FIPVs producing smaller size of plaques are more virulent than those producing larger size of plaques.
Porcine reproductive and respiratory syndrome virus hemagglutinin (HAin) was readily adsorbed on mouse erythrocytes at 4, 22, or 37°C, but not on goose erythrocytes. The adsorbed HAin could not be eluted from the cells by resuspending in phosphate buffered saline, by incubating at 37 or 50°C, or by incubating in the presence of neuraminidase. The hemagglutinating activity was not dependent on the pH and NaCl molarity tested. The receptor of mouse erythrocytes for the HAin was relatively stable to trypsin, neuraminidase, sodium deoxycholate (DOC), potassium periodate (KIO4), dithiothreitol (DTT), 2-mercaptoethanol (2-ME) and formalin treatments. The HAin was inactivated by 2-ME and was gradually inactivated by pepsin, formalin and DTT, but not by β-glucosidase, trypsin, α-amylase, papain, phospholipase C, neuraminidase, KIO4, and ethylendiamine tetraacetic acid (EDTA) treatments. The HAin was stable at 37°C or lower temperatures, but not at 56°C or higher. The HAin was relatively resistant to ultraviolet irradiation and sonication. In the equilibrium centrifugation of the HAin preparation on a CsCl density gradient, the HAin activity showed a sharp peak at 1.17 g/cm3. In the SDS-PAGE analysis, the structural polypeptide of HAin in the peak fraction seems to be the nucleocapsid (N) polypeptide with molecular weight of 15 kDa.