Estrogen receptor alpha expression in the medial preoptic area and the medial basal hypothalamus under different physiological conditions in cattle

The distribution and morphology of immunoreactive estrogen receptor alpha (ERalpha)- containing cells were examined in the cattle brain. The brains were collected from two cows and a male calf. One of the cows was sacrificed one week after parturition. ERalpha expressions in the preoptic area of the rostral forebrain and the medial basal hypothalamic area were evaluated immunohistochemically using a mouse monoclonal antibody. In all animals, the signals that indicate ERalpha were detected in the medial preoptic area, the level of the organum vasculosum of the lamina terminalis and the bed nucleus of the stria terminalis. In the caudal hypothalamic region, they were detected in the arcuate nucleus, the periventricular and ventromedial hypothalamic nuclei. ERalpha-containing cells were characterized by a dense nuclear reaction product. In all the subjects examined, ERalpha signals were clearly detected in the cytoplasm as well. The density of ERalpha expression was different among the three cattle; the number of ERalpha containing cells in the postpartum cow was much lower than that in the other cow and the male calf. The present findings suggest that ERalpha expression in the forebrain is influenced by the reproductive status in the cattle.     

Evaluation of ligament fibroblast viability in ruptured cranial cruciate ligament of dogs

OBJECTIVE: To determine fibroblast viability, assess development of apoptosis, and evaluate tissue hypoxia via histochemical, in-situ hybridization, or immunohistochemical staining in ruptured and intact cranial cruciate ligaments (CCLs) of dogs. ANIMALS: 32 dogs with ruptured CCLs, and 8 aged and 19 young dogs with intact CCLs. PROCEDURE: Markers of cell viability (lactate dehydrogenase [LDH]), apoptosis (terminal deoxynucleatidyl transferase-mediated deoxyuridine triphosphate-nick end labeling [TUNEL] method), and hypoxia (hypoxia-inducible factor-1alpha [HIF-1alpha] monoclonal antibody) were applied to CCL specimens; positive cells were assessed objectively (LDH) and subjectively (TUNEL and HIF-1alpha) in the main axial tissue component (core) and synovial intima and subintima (epiligamentous tissue). RESULTS: Viable fibroblasts were seen in all intact and ruptured CCLs. More nonviable cells were found in the core regions of ruptured CCLs and intact CCLs of young dogs than in the epiligamentous regions. Number of nonviable cells in the core region of ruptured CCLs was greater than that in intact CCLs of young and aged dogs, whereas the number in the epiligamentous region was similar in all specimens. The TUNEL and HIF-1alpha staining was only found in the epiligamentous region of ruptured CCLs. CONCLUSIONS AND CLINICAL RELEVANCE: Ruptured CCLs contained a high number of nonviable cells but not a great number of apoptotic cells. Repair processes in the epiligamentous region of the CCL include a metabolic response to hypoxia, suggesting that necrosis of ligament fibroblasts and transformation of surviving cells to a spheroid phenotype may be a response to hypoxia cause by microinjury or inadequate blood flow.     

Intestinal spirochetosis in a 21-month-old thoroughbred colt

A 21-month-old Thoroughbred colt showed continuous diarrhea and developmental retardation for 7 months, and was thereafter subjected to euthanasia for necropsy and laboratory examinations. At necropsy, the cecal and colonic mucosae were diffusely rough and hyperemic. Histopathologically, the mucosa and submucosa were edematous and were infiltrated by numerous lymphocytes and macrophages. Meanwhile, three morphological types of Brachyspira antigen-containing spirochetes were found to be numerous in the crypts and in the mucus layer over the epithelium in the cecal and colonic lesions. They were frequently observed in intercellular gaps and in the cytoplasm of degenerative epithelial cells, and in the lamina propria, particularly in cavities around blood vessels. These invasive intestinal spirochetes might be one of pathogens inducing colitis and diarrhea in horses.     

Wortmannin, a radiation sensitizer, enhances the radiosensitivity of WKAH rat cells but not that of LEC rat cells

No significant cytotoxic effect was observed in WKAH rat cells by the treatment of wortmannin, a radiation sensitizer, at concentrations lower than 30 microM for 24 hr. The relative surviving fractions of LEC rat cells were slightly, but significantly, lower than those of WKAH rat cells at each concentration of wortmannin. When the wortmannin-treated WKAH rat cells were X-irradiated, the relative surviving fractions decreased in a wortmannin concentration-dependent manner. On the contrary, no significant difference was observed between the survival curves of untreated and wortmannin-treated LEC rat cells after X-irradiation.     

Distribution of immunoglobulin isotypes and subisotypes in equine guttural pouch (auditory tube diverticulum)

To clarify the functions of the equine guttural pouch, the distribution of various immunoglobulin isotypes and subisotypes in the guttural pouch mucosa were examined in healthy horses. IgGa was present in the mucosa of guttural pouch, mucosal lymph nodules and submucosal lymph nodules. IgM was scattered in the mucosal lymph nodules and in the germinal centers of the submucosal lymph nodules. IgGc was recognized only in the submucosal lymph nodules. These immunoglobulin isotypes and subisotypes were found in lymphocytes and plasma cells. On the other hand, IgA was detected in glandular epithelial cells and the surface layer of the mucosal epithelium, as well as in free cells. This finding suggests that IgA is secreted through the glandular epithelium. Based on the above findings, we conclude that the guttural pouch has phylactic ability.     

Inhibitory effects of long-wave ultraviolet radiation of isolated chicken liver nuclei on the Mg2+-dependent transition of chromatin structure

Since the turbidity of nuclear suspensions is known to be correlated with the nuclear morphology, the effects of long-wave ultraviolet (UVA) radiation on Mg2+-dependent structural transition of chromatin in isolated chicken liver nuclei were monitored by measuring the relative turbidity of nuclear suspensions. UVA radiation of the nuclei inhibited the Mg2+-dependent change in relative turbidity of nuclear suspensions in a UVA dose-dependent manner under aerobic conditions but not under N2 conditions. No inhibitory effect of UVA radiation on the change in relative turbidity was observed in the presence of 50 mM NaN3, which scavenges singlet oxygen (1O2) and hydroxyl radicals (*OH). In contrast, 100 mM dimethyl sulfoxide, which primarily scavenges *OH, did not show the inhibitory effect of UVA radiation. The amounts of DNA-protein crosslinks increased with UVA dose under aerobic conditions but not under N2 conditions. The present study showed that UVA radiation of isolated nuclei inhibited the Mg2+-dependent unfolding of condensed chromatin and that O2 is likely to be involved in this process. Furthermore, the formation of DNA-protein crosslinks may contribute to the inhibition.     

Mutual antagonism between sterol demethylation inhibitors and phosphorothiolate fungicides on Pyricularia oryzae and the implications for their mode of action

Joint action between a phosphorothiolate (PTL) fungicide, iprobenfos, and a sterol demethylation inhibitor (DMI), pefurazoate, was tested by crossed paper technique on three types of field isolates of Pyricularia oryzae Cavara that differed in PTL sensitivity and metabolism. Mutual antagonism in anti-fungal action between iprobenfos and pefurazoate was observed in a wild-type field isolate of the fungus sensitive to PTL and in an isolate moderately resistant to PTL, but not in a PTL-resistant isolate lacking the ability to metabolize PTL. Antagonism of the antifungal action of iprobenfos by pefurazoate seemed to be a result of inhibition of activation by cleavage of the P-S bond of iprobenfos mediated by mixed-function oxygenase (mfo) activity, while antagonism of the anti-fungal action of pefurazoate by iprobenfos may be caused by the binding of pefurazoate by large amounts of an iprobenfos-induced mfo which results in reduced inhibition of ergosterol biosynthesis. In the PTL-resistant isolate, the mutually antagonistic action was not observed, presumably because the induction of the mfo-metabolizing iprobenfos was lacking. Similar antagonism was also observed when another PTL, edifenphos, was used instead of iprobenfos, and when other DMIs, propiconazole, prochloraz and hexaconazole were used instead of pefurazoate. The results of the present experiment indicate that DMIs may also bind to and inhibit an inducible type of fungal mfo which metabolizes xenobiotics, and that PTLs may be activated by an mfo prior to their anti-fungal action.     

Serological classification of Japanese isolates of Haemophilus paragallinarum using two serovar-specific monoclonal antibodies

A serological classification of 106 Japanese isolates of Haemophilus paragalinarum recovered from 1960 to 1984 was performed by dot-blotting and hemagglutination-inhibition (HI) tests using two serovar-specific monoclonal antibodies (MAbs), E5C12D10 and F2E6. By the dot-blotting test, 49 of the isolates were serovar A and 55 isolates were serovar C, and the two remaining isolates did not react with either MAb. These two nontypable strains had no hemagglutinating activity against chicken erythrocytes and were nonpathogenic to chickens. Although 49 serovar A isolates were serotyped by the HI test, only 23 of the 55 serovar C isolates could be serotyped. The remaining 32 isolates could not be serotyped because no or low hemagglutinating activity could be detected. Our results indicate that H. paragallinarum serovars A and C have both been present in Japan since 1960, with serovar A isolates being dominant before 1970 and serovar C isolates more prevalent than serovar A since 1970.