Pulsed-field gel electrophoresis (PFGE) was used to determine genetic relationships among 15 methicillin-resistant Staphylococcus aureus (MRSA) isolates from mares with metritis and from a stallion with dermatitis in Hokkaido. All the 15 isolates showed phage pattern 6/47/54/75, coagulase type IV, and enterotoxin type A. The restriction endonuclease SmaI cut their genomic DNAs into 15 or 16 fragments ranging in size from 8 to 630 kb. Fourteen of the 15 isolates showed the same PFGE pattern, whereas the remaining one appeared to be closely related. The 9 human MRSA isolates showing the same phenotypic characteristics as the horse isolates gave different PFGE patterns from those of the horse isolates.
Sporicidal activities of glutaraldehyde, sodium hypochlorite, povidone iodine, ethylene oxide gas, chlorhexidine gluconate, and didecyl dimethylammonium chloride on wet and dry spores of Paenibacillus larvae (basonym: Bacillus larvae) were evaluated for control of honeybee American foulbrood. Glutaraldehyde was found to have a strong and rapid effect on both the wet and the dry spores among the disinfectants tested.
The protection conferred by egg antibody specific for F18-fimbriae against infection with F18+Escherichia coli was studied in controlled passive immunization trials involving weaned pigs. Parameters of protection consisted of body weight gain, frequency and severity of diarrhea and recovery of the challenge strain of F18+E. coli. Weaned pigs at four weeks of age were challenge exposed once daily for three days by oral inoculation with 1011 cfu of virulent F18+E. coli followed by daily administration of antibody supplemented feed for 9 days starting from the first challenge day 0. Results showed a dose-dependent response to antibody treatment. The group of pigs given 1:50 titer of antibody in feed had less frequency of diarrhea (P<0.01-0.05), higher rate of gain (P<0.01) and lower isolation rate of challenge strain in rectal and intestinal swabs (P<0.01) compared to non-treated control. In the same manner, the anti-F18 antibody significantly reduced adherence of F18+E. coli to pig intestinal epithelial cells in vitro (P<0.01). Results suggest that egg antibodies specific for the F18 fimbriae is a suitable immunotherapeutic agent for pigs infected with F18+E. coli and that pigs can be protected from overt clinical disease and the subsequent reduced performance arising from infection with this pathogen.
Few reference values for use in metabolic profile tests for the maintenance of high productivity and the prevention of production diseases have been reported in Japanese Black beef cattle. To obtain basic data, 101 healthy steers at farms with high productivity and low frequencies of disease and death in Miyazaki Prefecture, Japan, were examined for the values of their serum components in this preliminary study. At the later fattening stage (5 to 20 months after introduction), statistically significant increases were observed in the mean serum activities of lactic dehydrogenase, glutamic-oxalacetic transaminase, gamma-glutamyl transpeptidase, and creatine phosphokinase, the mean serum contents of triglyceride, total cholesterol, albumin (Alb), total protein, blood urea nitrogen, magnesium, and vitamin E, and the mean serum calcium (Ca)/inorganic phosphorus (IP) ratio, and statistically significant decreases were seen in the mean serum alkaline phosphatase activity and the mean serum contents of glucose, IP, and vitamin A. The mean serum Alb/globulin ratio and the mean serum Ca and nonesterified fatty acids contents demonstrated no statistically significant changes.
Three isoenzymes of total alkaline phosphatase (TALP) are known in canine serum: Bone alkaline phosphatase (BALP), liver alkaline phosphatase (LALP) and corticosteroid-induced alkaline phosphatase (CALP). Using an assay developed by combining selective precipitation of BALP by wheat germ lectin (WGA) and an automated levamisole inhibition method for quantifying CALP, age-related reference ranges of the isoenzymes in 75 canine serum samples were investigated. BALP comprised 96, 38 and 26% of TALP in young, middle aged and old dogs, respectively, and CALP was respectively 12, 11 and 27% of TALP. LALP was less than 10% in the young but represented more than 50% of TALP in middle aged and old dogs. Furthermore, the significance of monitoring LALP and CALP and their relationship to hepatopathy in dogs receiving long term prednisolone therapy was assessed. In this study, TALP increased in all dogs receiving prednisolone. But only LALP was responsible in dogs with minor vacuolization of the liver, while in severely degenerated cases both LALP and CALP increased. It is concluded that a high TALP due solely to LALP, rather than LALP and CALP represents lesser liver pathologic involvement. Monitoring the 2 isoenzymes has greater significancy in assessing the level of liver damage than relying on an increased TALP value alone. Quantifying the individual isoenzymes may further be useful in assessing the clinical significance of these isoenzymes in various conditions that result in elevated TALP values.
This study examined the levels of serum tumor necrosis factor (TNF), interleukin-1 (IL-1) and plasma cortisol levels in adult cows after intravenous administration of lipopolysaccharide (LPS) extracted from Escherichia coli. The adult cows exhibited clinical signs of endotoxic shock. The mean concentrations of serum TNF was 557.9 U/ml and serum IL-1 was 90.6 U/ml at 2 hr after LPS administration following severe endotoxic shock. Plasma cortisol concentrations increased immediately and a peak level was 131.4 ng/m l at 1 hr after LPS challenge. These results suggested that circulating concentrations of TNF, IL-1, and cortisol may be associated with clinical signs of endotoxemia in adult cows.
A six-month-old male Golden Retriever with a three-month history of polyuria and polydipsia was examined. Hematological examinations revealed nonregenerative anemia, azotemia, high serum creatinine level, hypercalcemia, hyperphosphatemia, hypercholesterolemia, hyperamylasemia, and low level of total serum protein. Urinalysis indicated mild proteinuria, and low specific gravity. Radiographic and ultrasonographic examinations revealed bilateral small sized kidneys. Histological examination by renal biopsy confirmed the diagnosis of renal dysplasia. Treatment with a dietary protein restriction, oral adsorbents, and dried aluminum hydroxide gel have been performed in this dog, and then, azotemia, high serum creatinine level, hypercalcemia, and hyperphosphatemia were improved. During 10 months after the initiation of treatments, no significant clinical change except polydipsia and polyuria has been observed.
Plasma thymidine kinase (TK) activity was evaluated as a plasma marker for canine lymphoma and leukemia. A tentative "cut-off" value was set at 6.0 U/l as the upper level of plasma TK based on the mean + 2SD of plasma TK activity in 13 clinically healthy dogs. The levels of plasma TK activity in all of the 20 dogs with lymphoma and leukemia were higher than the cut-off value, whereas those in dogs with lymphoma decreased in parallel with the reduction of the tumor mass after chemotherapy. These findings suggested that estimation of plasma TK activity can be used as a plasma marker for lymphoma and leukemia in the dog.
Severe combined immunodeficiency (SCID) mice were inoculated with Hantaan virus strain 76-118 (HTN) or Seoul virus strain SR-11 (SR) of hantaviruses. Susceptibility of SCID mice was compared with those of immunocompetent adult mice, newborn mice and nude mice. SCID mice inoculated with HTN or SR died 32 to 35 days after infection. Unlike newborn mice which also died of hantavirus infection, SCID mice survived longer than newborn mice and showed typical wasting symptoms rather than nervous symptoms. Immunohistochemical staining and virus isolation indicated that both HTN and SR inoculated SCID and SR inoculated nude mice showed systemic infection, but nude mice inoculated with SR survived for longer than 8 weeks after inoculation. Passive transfer of spleen cells from immunocompetent BALB/c mice conferred protection on SCID mice within 2 weeks of HTN infection. Immune mediated pathologic mechanism was examined by transferring the spleen cells to SCID mice inoculated with HTN virus 3 weeks before the cell transfer. The recipient SCID mice showed an increase of serum BUN level coinciding with the appearance of serum antibody to HTN virus, suggesting the immune mediated pathogenicity.
We studied the effects of 6-chloro-2', 3'-dideoxyguanosine (6-Cl-ddG), an antiretroviral drug, in surface lymph nodes of rhesus monkeys (Macaca mulatta) chronically infected with simian immunodeficiency virus (SIV). The rhesus monkeys were treated with 25 mg/kg of 6-Cl-ddG every 8 hr for 2 weeks. We performed sequential biopsies of the surface lymph nodes three times: before, during, and after the drug treatment. The 6-Cl-ddG dramatically decreased the number of infectious virus (measured by limiting dilution assay) in lymph node mononuclear cells. This decrease was consistent with the decrease in the number of viral RNA-positive cells in lymph nodes (analyzed by in situ hybridization). Histopathological analysis revealed that hyperplastic lymphoid follicles were reduced in size, especially, enlarged areas of centroblasts in lymphoid follicles (the so-called dark areas of germinal centers) were declined. Our results demonstrated that 6-Cl-ddG decreased the viral burden concomitantly with reduced hyper-activation of germinal centers in lymphoid follicles of SIV-infected rhesus monkeys.
Focal infiltration of lymphocytes with parenchymal destruction was noted in both salivary and lacrimal glands of IQI/Jic mice. The sialadenitis was found in more than 80% of female mice at all ages examined. The lesion progressed after 6 months and became more prominent with age. In contrast, male mice had slight and stable salivary lesions independent of age, though the incidence increased with age. Infiltrating lymphocytes consisted of both T and B cells. The dominant lymphocytes in small foci were CD4+ cells, but the majority of infiltrating cells were B cells (B220+), followed by CD4+ T cells in larger lesions. The ductual epithelium in the foci aberrantly expressed MHC class II antigen. Eight of 24 15-month-old female mice with sialadenitis produced speckled-type IgG antinuclear autoantibody. These findings are similar to those in patients with Sjögren's syndrome. IQI/Jic mice could be a novel animal model of Sjögren's syndrome.
To clarify Dirofilaria immitis infection among cats in Saitama Prefecture, Japan, 1,840 cats were examined postmortem for adult worms and microfilariae in the blood from 1989 to 1995. As a reference control, 500 dogs from the same area were examined in the same way and period. D. immitis worms were found in 15 cats, one of which had microfilariae in the blood. Prevalence rate of D. immitis infection was 0.8% (15/1,840) in cats and 46.8% (234/500) in dogs examined, whereas it was 4.1% and 64.6% in cats and dogs, respectively, aged 2 years and over. Worm burden per positive cat was 1.5 ± 0.7 (mean ± SD), the maximum number of worm was 3 in 2 cats, and 10 cats had a single worm each. All the worm-positive cats were tested for antibodies to feline immunodeficiency virus (FIV) and antigens of feline leukemia virus (FeLV) in sera. Positive rates of coinfection with D. immitis were 26.7% and 13.3% for FIV and FeLV, respectively.
A nematode species belonging to the genus Eustrongylides (Dioctophymatidae) was obtained from the proventriculus of Tachybaptus ruficollis, found in December, 1995 in Kobe City, Hyogo Prefecture, Japan. Observation under a scanning electron microscope to investigate anterior extremity with the labial papillae in two circles showed that this species is identical to E. tubifex. This is the first record of this species in Japan.
Plasma level of diethylcarbamazine (DEC) was measured by using gas chromatography and was compared to the changes of microfilaremia after an intraperitoneal injection with 200 mg/kg of DEC in rats. The microfilaremia was induced artificially by an intravenous implantation with 2 × 105Brugia pahangi microfilariae (mf) 1 day before DEC treatment. The rats treated with DEC showed a rapid and significant decrease in mf number in the circulation within 30 min, continued for 4 hr, and then increased rapidly. DEC seemed to cause transient but significant suppression of microfilaremia of B. pahangi in rats directly.
Ultrastructural alteration of anionic sites (ASs) in the glomerular basement membrane (GBM) was studied in 10 cases of swine mesangial proliferative glomerulonephritis using a cationic ultrastructural tracer, 0.5% polyethyleneimine (M.W.= 1,800). Glomerular ASs were seen as discrete electron-dense particles in the GBM, mesangial matrix and epithelial cell surfaces by electron microscopy. In the lamina rara externa (LRE) of the normal GBM, ASs were distributed regularly in a single layer. In those areas of the LRE that contained electron dense deposits or clusters of spherical microparticles (SMPs), however, a distinct reduction or loss of ASs was observed in all the pigs. Quantitative assessment of ASs in the LRE over 1,000 nm of the GBM revealed a significant reduction in ASs in one case with diffuse global thickening of the GBM as compared with the remaining nine pigs without GBM thickening (P<0.001, Mann-Whitney's U-test). There were no ASs in the lamina densa (LD) of the normal GBM, but an irregular distribution of ASs was seen within the LD of the pig showing diffuse global thickening of the GBM. These results suggest that a disturbance of the charge-selective barrier in the GBM may be induced by electron-dense deposits or SMPs in the LRE as well as thickening of the GBM in swine glomerulonephritis.
Distinct glycoconjugate expression between dome enterocytes and villus enterocytes in ileum from twelve 3-week-old conventional pigs was examined by the use of twenty one biotinylated lectins with avidin-biotin-peroxidase complex method. Three patterns of staining were seen. First, lectins bind to dome enterocyte and villus enterocyte to approximately equal staining, i.e. DSL, WGA, s-WGA and ConA. Second, lectins display a markedly higher affinity for villus enterocyte than dome enterocyte, i.e. DBA, SBA, RCA I, SJA, VVA, BSL II, LEL, PNA, Jacalin, and ECL. Third, lectins exhibit negative staining to dome enterocyte only, i.e. PSA, LCA, UEA-I, and STL. Four lectins; PSA, LCA, UEA-I, STL may be useful negative marker to differentiate glycoconjugate expression between dome enterocyte and villus enterocyte. The staining patterns are slightly different among these negative markers. Three lectins, PSA, LCA, and UEA-1, are negative marker to differentiate dome enterocytes and villus enterocytes. But STL is also negative to dome epithelial surface and moderately positive to villus brush border. It is suggested that the present lectin-binding studies provide the marker of dome enterocyte as compared with villus enterocytes.
Nude mice were infested with bovine Neospora by intraperitoneal inoculation of the brain and spinal cord from an aborted bovine fetus due to neosporosis. Inoculated mice showed severe emaciation and tetraplegia at about 2 to 4 months post-inoculation. Histopathologically, polyradiculoneuritis and peripheral neuritis were the major findings, and lesions in the central nervous system were located at periventricular and submeningeal areas of the cerebrum or at the white matter around the roots of radices of the spinal cord. These findings may suggest the protozoa inocualted into the abdominal cavity invaded the spinal cord via the spinal nerve and later reached the brain through the cerebrospinal fluid.
A mass of glomus tumor was found on the skin of the right foreleg of a ten-year old male mongrel dog. Histologically the mass contained some vasculatures and sheet-like proliferation of epithelioid tumor cells. Some blood vessels were rimmed by the tumor cells, which had a round to ovoid nucleus and plump eosinophilic cytoplasm. Immunohistochemically, smooth muscle actin and vimentin were demonstrated in the tumor cells. By electron microscopic examination, actin-like filaments with dense bodies were observed in the cytoplasm of the tumor cells. This is the first case report of a canine glomus tumor.
Effects of central nervous stimulants on the spino-bulbo-spinal reflex potential were evaluated in anesthetized intact cats, and compared with those on segmental spinal reflex potentials in anesthetized spinal cats. In spinal cats, strychnine augmented polysynaptic reflex potential, picrotoxin inhibited dorsal root reflex potential, aminopyrine potentiated mono- and poly-synaptic reflex potentials but inhibited dorsal root reflex potential, and 4-aminopyridine potentiated all the three types of segmental reflex potentials. A combination of fenbufen, a non-steroidal antiinflammatory agent, and enoxacin, a new quinolone antimicrobial, inhibited all the three types of segmental reflex potentials. In contrast, all these drugs consistently produced an augmentation of the spino-bulbo-spinal reflex potential in anesthetized intact cats. From these findings, we suggest that the spino-bulbo-spinal reflex potential may be used as an electrophysiological parameter for the evaluation of central nervous stimulants.
This study was aimed at characterizing the superior laryngeal nerve (SLN) afferent activities under four different respiratory conditions, i.e., tracheostomy breathing (TB), upper airway breathing (UAB), tracheal occlusion (TO) and upper airway occlusion (UAO), and investigating respiratory changes in response to transmural pressures applied to the larynx in anesthetized Shiba goats. The activity recorded from the whole SLN increased at both inspiration and expiration during TB, UAB and TO, while an expiratory augmentation accompanied by an inspiratory inhibition was found during UAO. Based on recordings from 109 thin filament-preparations, 47 units were identified as `drive' receptors, 31 as `pressure' receptors (22 `positive' and 9 `negative' pressure receptors), and the rest 31 as `non-modulated type' of receptors. The posterior cricoarytenoid (PCA) muscle activity showed a clear inspiratory modulation during UAB and was significantly enhanced by negative pressure applied to the isolated upper airway, where such an augmented activity was abolished by bilateral section of the SLN. No significant changes were found in the respiratory cycle during application of negative pressures to the larynx. The respiratory modulation of the SLN in Shiba goats was essentially identical to that reported for rabbits, rats and guinea pigs, but not in dogs. The reflex response of the upper airway muscles to the laryngeal pressure changes in Shiba goats were found to be less noticeable than in rabbits and dogs.
This experiment investigated the effects of mesencephalic locomotor region (MLR) stimulation on cervical and trunk motoneurons in decerebrated cats. The experiments were performed on 28 adult cats (2.1-3.9 kg) of either sex. Stimulation of MLR produced the rhythmical discharge of muscle nerves of the splenius (SP), the longissimus lumborum (LL) and the obliquus externus abdominis (OEA). There was a close relationship between rhythmical discharge of SP, LL or OEA muscle nerve and hindlimb muscle nerve. This fact suggests that rhythmical discharges of cervical and trunk muscle nerves relate to locomotion.
The conditioned suppression technique was employed to examine the acute effects of aspirin on auditory function in rats. Lever pressing behavior for water reinforcement was suppressed in the presence of an auditory stimulus that had been previously paired with electric shocks. A single intravenous injection of aspirin at a dose of 225 mg/kg caused an erroneous lever pressing response in the broad sound intensities of 2 kHz tone stimulus during the conditioned stimulus period. A statistically significant increase in the threshold for 2 kHz was found 1 to 72 hr after dosing but not for 4, 8 and 10 kHz. These results suggest that the hearing for low sound frequency in rats is vulnerable to the effects of aspirin. This paradigm in rats may be useful to further assess the different outer hair cells along the cochlear duct and provide an additional evidence for the aspirin ototoxicity research.
Role of asparagine-linked (N-linked) oligosaccharide side chains in the maturation and the function of influenza virus neuraminidase (NA) subtype N8 was examined by site-directed mutagenesis and vaccinia virus expression system. Mutations in the consensus sequence for N-linked glycosylation at Asn 84 or 398 prevent the proper maturation of mutant NAs. On the contrary, mutation at Asn 144, that is conserved in all except two strains of influenza virus NA ever sequenced, did not affect the proper maturation and the transport of the mutant NA to the cell surface. Furthermore, this mutation led the alternation of substrate preference of this enzyme. These observations indicate that N-glycosylation at Asn 144 of N8 NA may be conserved from the functional requirement, but not from the structural necessity.
Equine arteritis virus (EAV) grown on RK13 cell cultures was tested for hemagglutination (HA) with erythrocytes from a variety of species at 4°C, room temperature and 37°C. HA was observed at all temperatures with erythrocytes from mouse and chicken but not with those of cattle, horse, rabbit, guinea pig, mongolian gerbil, goose or chick embryo. Chickens showed an individual variation in agglutinability of their erythrocytes, requiring selection of birds to obtain erythrocytes for HA. The HA activity was enhanced by treatment of virus materials with Tween 80 followed by treatment with ether. The HA reaction was inhibited by specific antiserum. Higher HA-inhibiting (HI) antibody titers were obtained by the incubation of serum-HA antigen mixture at 4°C for 24 hr. HI antibody titers of individual horse sera showed a significant positive correlation with their neutralizing antibody titers.