To accumulate histological information of cetaceans and basic information about metabolic systems of marine mammals, the thyroid gland of Risso's dolphins was examined by gross anatomical and light and electron microscopic observations. Gross anatomically, right and left lobes of the thyroid were not clearly discriminated, and no isthmus was observed. By light microscopy, irregular or oval follicular lumens were seen, and surrounded by follicular epithelial cells. By electron microscopy, the rough endoplasmic reticulum (rER) was seen adjacently to mitochondria at the basal and lateral regions of the follicular epithelial cells. RERs at the basal side of the cells sometimes contained flocculent material with the same electron density as the follicular lumen component. Microvilli were poorly developed at the apical surface of the cells. In the apical regions of the cells, there were typical Golgi complexes, multivesicular bodies, and granules with various size and electron density. The parafollicular cells were recognized among the follicular epithelial cells and in the interstitial regions but never protruded into the follicular lumen. These cells were present singly and/or formed clusters among the follicular epithelial cells, and often located adjacent to capillaries. They were obviously discriminated from follicular epithelial cells by higher electron density of their granules. In their cytoplasm, well-developed rERs, primary lysosomes, secondary lysosomes, multivesicular bodies, and phagosomes were recognized.
Lectin staining pattern in Peyer's patches of porcine ileum was studied using twenty one biotinylated-labeled lectins as cell markers which were visualized with avidin-biotin-peroxidase complex method (ABC). WGA appears to be a selective marker for tingible body macrophages in the porcine germinal centers. ConA may be a positive marker for the lymphoid tissues, whereas 9 lectins (DBA, SBA, SJA, s-WGA, PNA, ECL, UEA-I, PHA-E, and PHA-L) may be negative markers for the lymphoid tissues in all areas.
Bovine serum contains N-acetyl-D-glucosamine (GlcNAc)-sensitive opsonin inhibitory factors. In the present study, a major component of chitin-binding protein (chitin-binding protein b01, CBPb01) was purified from bovine serum, and identified CBPb01 as bovine IgM by its subunit structure, antigenic properties, and partial sequences. The results of a lectin-binding assay showed that the heavy chain of CBPb01 had a GlcNAc structure, but the commercial IgM did not. It is possible that CBPb01 interconnects through its GlcNAc structure, subsequently forming complexes. We also demonstrated that CBPb01 had opsonin-inhibitory activity, and that this activity was dependent on the binding of CBPb01 to GlcNAc on the zymosan surface. These findings indicate the presence of a kind of IgM that recognizes GlcNAc structure in the regulation of opsonization.
To elucidate the mechanisms of ischemia-mediated myopathy using in vitro model, changes of purine nucleotides, membrane lipid peroxidation(TBARS), intracellular calcium ([Ca2+]i)levels, generation of free radicals, and deoxyribonucleic acid (DNA) fragmentation were examined in mouse-derived C2C12 myotubes under the condition with an inhibition of glycolytic and oxidative metabolism as the ischemic condition. In purine nucleotides, intracellular adenosine triphosphate (ATP) and guanosine triphosphate (GTP) concentrations rapidly and significantly decreased after the treatment with ischemia. No remarkable differences were observed in other purine nucleotides, with the exception of inosine monophosphate (IMP) and extracellular hypoxanthine levels, both of which increased significantly during the ischemia. The lactate dehydrogenase activity in culture supernatant of C2C12 myotubes increased significantly from 2 to 4 hr after the ischemia. On the generation of free radicals, no spectrum was detected in supernatants throughout the observation period, whereas supernatant TBARS concentration increased rapidly and significantly after the ischemia. The relative intensity of [Ca2+]i significantly increased after the ischemia. On the fragmented deoxyribonucleic acid(DNA), no TUNEL positive cells was detected in C2C12 myotubes after 1 hr of the ischemia, however the positive cell percentage subsequently increased. From these results, it was suggested that the ischemic condition induced changes of membrane permeability and increase of [Ca2+]i, both of which lead to cell membrane damage, although a free radical generation was not detected. The ischemic condition also induced the release of substrate hypoxanthine for free radical generation and might initiate the apoptotic pathway in C2C12 myotubes.
To determine the acute effects of carvedilol (β-blocker) on cardiovascular and renal function and its pharmacokinetics in dogs. Fifteen mature mongrel dogs (7-15 kg) of both sexes were used in these experiments. Eight dogs served as controls, and seven dogs served as iatrogenic mitral regurgitation (MR) experimental animals. Carvedilol (0.2, 0.4, and 0.8 mg/kg, P.O.) was administered, and the blood carvedilol concentration was analyzed by reverse-phase high-performance liquid chromatography. The response to isoproterenol or phenylephrine was also evaluated. Isoproterenol (0.025 μg/kg/min) was infused via the saphenous vein for 5 min, and phenylephrine (5 μg/kg) was injected with carvedilol (0.2, 0.4 mg/kg) or placebo for 4 days. The heart rate and arterial blood pressure were measured, and LV fractional shortening was measured by echocardiography. Glomerular filtration rate (GFR) and renal plasma flow (RPF) were measured by intravenous infusion of sodium thiosulfate and sodium para-aminohippurate. Carvedilol (0.2 mg/kg) decreased the heart rate, whereas renal function, arterial blood pressure, and left ventricular contractile function were not affected. Carvedilol (0.4 mg/kg) decreased heart rate, blood pressure, and renal function. The tachycardic response to isoproterenol was significantly diminished for 36 hr by 0.4 mg/kg carvedilol. Carvedilol 0.2 mg/kg inhibited this effect for 24 hr. Thus, it is necessary to titrate the dosage of carvedilol, it should be initiated at less than 0.2 mg/kg and titrated up to 0.4 mg/kg for heart failure dogs.
The type, ages of occurrence, primary complaints, clinical signs and mortality in forty-seven cases of uterine disorders diagnosed by ventrotomy in rabbits were analyzed retrospectively. Endometrial hyperplasia (29.8%) was most frequently observed, followed by uterine adenocarcinoma (21.3%). Tumorous lesions were seen in 46.8% of the cases. The age of occurrence ranged from two years and two months to seven years and six months, with a peak at four to five years of age. The most common primary complaint was bleeding (62.2%), followed by mammary gland abnormality (12.8%) and increased abdominal circumference (10.6%). Physical examinations revealed mammary gland disorders such as mammary cysts in 31.9% of the cases. Uterine disorders were detected by palpation in 15 out of 32 cases with a primary complaint of bleeding. Ultrasonography showed uterine disorders in 21 out of 24 cases, suggesting that ultrasonography could be useful in the diagnosis of uterine disorders. The outcome seemed to be influenced by physical status rather than malignancy of lesions. The mortality was higher in cases with symptoms such as anorexia, emaciation, severe anemia, and dehydration.
Using RT-PCR and semi-quantitative PCR, mRNA expression for canine interferon (IFN)-γ, interleukin (IL)-2, IL-4, IL-5, IL-10, tumor necrosis factor (TNF)-α and transforming growth factor (TGF)-β in peripheral blood mononuclear cells (PBMCs) was examined in dogs with or without demodicosis. mRNA expression for IFN-γ as well as TNF-α in dogs with demodicosis (localized (LD) and generalized (GD)) was slightly lower than those in dogs without demodicosis (healthy controls). Expression of IL-5 mRNA in dogs with demodicosis was higher than that in control dogs, but there were no significant differences in IL-4 and IL-10 mRNA expression levels among the three groups. On the other hand, expression levels of TGF-β mRNA in dogs with GD were higher than those in control dogs and dogs with LD. The expression levels of IL-5 and TGF-β mRNA decreased in all three dogs with GD which showed resolution of the clinical signs. Taken together, these results suggest that the Th2-like response in PBMCs from dogs with demodicosis is up-regulated, and that subsequent increased expression of IL-5 and TGF-β mRNA in dogs with GD is reversible after treatment. Therefore, these cytokines, particularly IL-5, might be a useful clinical index of the clinical course in demodicosis. Also, increased TGF-β mRNA expression might be a key factor for revealing the difference in the mechanism of onset between LD and GD.
Anti-Thy-1.1 nephritis in the rat is a popular experimental model for mesangial proliferative glomerulonephritis (GN). This model is characterized by direct binding of anti-Thy-1.1 antibody with Thy-1.1 antigen expressed on mesangial cells (MCs) of glomeruli in the rat. A single injection of anti-rat thymocyte serum (ARTS) results in GN with proteinuria and extensive mesangiolysis. Development of mesangiolysis and proteinuria are complement-dependent. We previously demonstrated Thy-1.1 antigen, similar to the rat, in thymocytes, brain cells and MCs of the kidney in the Mongolian gerbil (MG). In this study, we attempted to develop a MG nephritis model, but an injection of ARTS did not induce GN. An additional injection of guinea pig serum as a complement after ARTS injection resulted in anti-Thy-1.1 nephritis in MG. Degeneration of MCs and neutrophil infiltration were observed 1 hr after GP serum injection. Mesangiolysis and fibrin exudation occurred 12 hr after the injection and MC proliferation was apparent 7 days after the injection. In the complement-dependent hemolytic test, MG serum could not hemolyze sheep erythrocytes. These results suggested low activity, or depletion of some factors, in complements of MG serum.
The effects of male and female sex hormones on the protective capacity of Wistar rats against infection with Strongyloides venezuelensis were investigated. Male rats were more susceptible than females in terms of worm recovery from the lungs. Orchidectomy of male animals significantly reduced the plasma testosterone concentration and increased host resistance to the migratory stages of S. venezuelensis larvae. In contrast, ovariectomy of female animals significantly decreased host resistance in association with a significant reduction of estrogen levels. To examine the direct effect of sex hormones, exogenous testosterone and estrogen were implanted into animals. Susceptibility significantly increased or decreased in ovariectomized females given testosterone or estrogen, respectively. These results suggest that male and female sex hormones are important in the down- and up-regulation of host resistance against S. venezuelensis in Wistar rats.
The effects of host age and sex on susceptibility to Strongyloides venezuelensis in Wistar rats were examined by counting larvae recovered from the lungs of animals 3 days after infection. The susceptibility of female rats to S. venezuelensis rapidly decreased with age and elevated estrogen. Resistance in female rats inoculated at 6 and 10 weeks of age was nine and twenty-fold higher, respectively than that in the youngest group (3 weeks). In contrast, the susceptibility of male animals was lowest in the youngest group, then increased with age and elevated testosterone. Sex differences in susceptibility were not evident in the youngest group, but became apparent with age.
In order to examine tumor modifying effects of phenolphthalein (PhP), female transgenic mice carrying human prototype c-Ha-ras gene (rasH2 mice) were given a single intraperitoneal injection of 60 mg/kg body weight of N-ethyl-N-nitrosourea (ENU), followed by the diet containing 12,000 ppm PhP for 26-week. Histopathologically, alveolar hyperplasias, adenomas and adenocarcinomas were observed in the ENU + PhP group, but only hyperplasias and adenomas were observed in the ENU alone group. The incidence and multiplicity of adenocarcinomas in the ENU + PhP group was significantly increased as compared to that in the ENU alone group. The combined multiplicity of adenomas and adenocarcinomas in this group was also significantly higher than that of the ENU alone group. In addition, the ratio of area of adenomas in the ENU + PhP group was significantly higher than that in the ENU alone group. The result of our study suggests that PhP has a clear tumor promoting effect in the lung of rasH2 mice.
A 37-day-old male Japanese black calf showing marked salivation and leucocytosis died and was examined the tissues histologically. Histological lesions were characterized by severe focal necrotic glossitis on the ventral side of the root of the tongue. Immunohistochemically, Fusobacterium necrophorum subsp. necrophorum antigen was detected in the necrotic tissues and its distribution corresponded to that of the gram-negative, nonsporeforming, long filamentous organisms. Ultrastructural similarities between the organism and F. necrophorum subsp. necrophorum, but not subsp. funduliforme were observed. These findings clearly demonstrated that the fatal necrotic glossitis was caused by F. necrophorum subsp. necrophorum. This is the first report of bovine fatal necrotizing glossitis with leucocytosis caused by F. necrophorum subsp. necrophorum infection, and this organism may be an important fatal pathogen in calves with glossal lesions.
Three sulphur-crested cockatoos (Cacatua galerita) were diagnosed as psittacine beak and feather disease (PBFD). Histopathology of the feather pulp and follicles showed intracytoplasmic botryoid clusters or granular inclusion bodies in epithelial cells and macrophages. Electron microscopy revealed multiple cytoplasmic clusters of electron dense viral particles corresponding to the inclusions. PBFD virus (circovirus) DNA-specific product was detected from formalin-fixed paraffin-embedded feathers by nested polymerase chain reaction (PCR) method.
Fifty-four canine cutaneous mast cell tumors were evaluated immunohistochemically for the expression of P-glycoprotein (PGP) and multidrug-resistance-associated protein (MRP). All tumors examined were graded according to the histological malignancy, ranging from grade I to III. The expression of PGP was confirmed in 15% (8/54) of whole, 33% (5/15) of grade I, 10% (3/31) of grade II, and 0% (0/8) of grade III tumors. The expression of MRP was found in 18% (10/54) of whole, 26% (4/15) of grade I, 19% (6/31) of grade II, and 0% (0/8) of grade III tumors. The cases positive to at least one of these 2 multidrug markers were 26%, 47%, 23% and 0% of whole and grade I to III tumors, respectively. These results indicate that at least 26% of canine cutaneous mast cell tumors express PGP and/or MRP and that these tumors may be resistant to several anti-cancer drugs.
Histopathologic and electron microscopic observations were given on Langerhans cells (LCs) within the follicular epithelium (FE) and intradermal sweat duct (ISD) of equine "Kasen". By light microscopy, LCs were present in the greatest numbers within the FE and ISD than within the epidermal layer and the normal skin, with an occasional formation of several aggregated foci. By electron microscopy, LCs within the FE and ISD widely extended their dendritic processes between the keratinocytes and contained Birbeck granules (Bgs), mitochondria, rough endoplasmic reticula and ribosomes in the cytoplasm. Numerous Type 2 LCs, with a number of Bgs and endocytosis, and Type 3 LCs, with multivesicular bodies and endosomes of various sizes, were recognized within the FE and ISD, although inactive Type 1 LCs, with a narrow and lucid cytoplasm, were rarely seen. LCs observed within the FE and ISD in the "Kasen"skin lesions might express the particular stage corresponded to recognize, intake and process the antigens which permeate them.
Milrinone, a therapeutic agent for acute congestive heart failure, has both inotropic and vasodilatory effects, but investigations of these effects of milrinone were almost all conducted under normoxia, and few reports have investigated how milrinone affects the hemodynamics and redistribution of regional blood flow under severe hypoxia. By using colored microspheres, we investigated how milrinone affects hemodynamics and the redistribution of regional blood flow under severe hypoxia. Twelve healthy mongrel dogs were divided into 2 groups. The milrinone group was infused with milrinone cumulatively at 25, 75 and 250 μg/kg for 5 min each. The intact group was infused with saline instead of milrinone. We measured the hemodynamics and cerebrum, cerebellum and kidney blood flow in both groups. Both groups were inspired with 10% oxygen. Milrinone induced significant decrease in mean pulmonary artery and pulmonary vascular resistance, compared with the intact group. In both groups slight decreases in mean arterial pressure, systemic vascular resistance and double-product were seen. In regional blood flow, milrinone-induced increases in blood flow were seen in the cerebrum, cerebellum, and especially in the kidneys. Milrinone's vasodilatory effects were sufficient even under hypoxia. And milrinone increased regional blood flow slightly in the cerebrum and cerebellum, and significantly in the kidneys. These results suggested that milrinone protects against hypoxia-induced organ damage especially in the kidneys. In addition, milrinone is very potent in improving severe congested hemodynamics which complicates hypoxic pulmonary vasoconstriction.
A method for sex identification of the Japanese black bear was examined using a polymerase chain reaction (PCR) and sequencing of a part of the amelogenin gene. This gene is located on the X and Y chromosomes, and there are 54 nucleotide deletions on the Y chromosome-specific gene. Forty-seven (26 male and 21 female) DNA samples and 23 (13 male and 10 female) DNA samples, respectively extracted from white blood cells and hairs of Japanese black bears were analyzed. The primers SE47 and SE48 from this X-Y homologous region were used in sex identification by PCR amplification. These primers amplified X- and Y-specific bands, which could be used to discriminate between sexes by a length polymorphism in all samples. We suggest that PCR amplification using the primers SE47 and SE48 is useful for sex determination of the Japanese black bear and could be applied to DNA analysis of small samples such as hairs.