Physiological and behavioural effects of an intracerebroventricular injection of corticotropin releasing hormone in goats

This study investigated the effects of an intracerebroventricular (ICV) injection of corticotropin releasing hormone (CRH) on physiological and behavioural responses in goats. In Experiment 1, saline (control) or saline plus 25 microg of ovine CRH was injected into the third ventricle of castrated male goats. CRH increased plasma cortisol (Cor) levels markedly within 15 min, but had little effect on plasma glucose (Glu). Compared with saline injected goats, CRH decreased the total duration of lying behaviour but increased its frequency, and suppressed rumination and self-grooming. In Experiment 2, the effects of an intravenous (IV) injection of human adrenocorticotropic hormone (ACTH) (1-24) (0.1mg) were examined and an IV injection of saline was used as control. ACTH increased plasma Cor levels markedly, but did not change any behaviour compared with controls. It was concluded that CRH mediated the response of the hypothalamus-pituitary-adrenal (HPA) axis and behaviour following stress in goats, although the CRH-induced behavioural changes were independent of the HPA axis and seemed to be the result of direct action within the central nervous system.     

A Case of Spontaneous Malignant Hibernoma in a Crl:CD(SD)IGS Rat

A firm, tan, well-circumscribed mass that measured 25 × 30 × 35 mm was observed in the thoracic cavity of a 53-week-old male Crl:CD(SD) IGS rat. Histologically, the mass was encapsulated by fibrous tissue and contained fibrovascular septae. Tumor cells were compactly arranged, and most were oval to polygonal in shape with multivacuolated cytoplasm and a centrally located nucleus. In some parts of the tumor, marked cellular atypia and frequent mitoses were evident. Vacuoles in cytoplasm were positive for oil red O. The tumor cells were characterized ultrastructurally by abundant, round to oval mitochondria with transverse closely-packed cristae. Tumor cells were immunohistochemically positive for uncoupling protein 1 (UCP-1). Several thrombi and hemorrhagic or necrotic foci were also observed within the tumor mass. Vascular invasion of the tumor capsule was observed; however, invasion of surrounding tissues or metastases were not observed. Based on the pathology findings, this case was diagnosed as a malignant hibernoma.     

A case of spontaneous Zymbal’s gland carcinoma with lung metastasis in an aged Fischer 344 rat

Zymbal’s gland neoplasms are induced in rats through the administration of various carcinogens, but spontaneous neoplasia is rare. This report describes a spontaneous Zymbal’s gland carcinoma with lung metastasis found in an aged male Fischer 344 rat. Macroscopically, the dome-like tumor nodule, approximately 30 mm in diameter with ulceration, was located near the ear canal of the rat. No healthy tissue or structure of Zymbal’s gland was identified on the corresponding side, while the normal salivary glands and a lacrimal gland were observed. Histologically, a large part of the tumor mass was occupied by poorly differentiated neoplastic cells, the shapes of which were oval to polygonal or fusiform. Additionally, clusters of sebaceous-like foamy cells and squamous metaplasia with prominent keratinization were observed. Tumor cells were found to metastasize to the lung; these cells displayed histological similarities, including a sebaceous gland-like pattern, to those in the primary site. The tumor cells were immunohistochemically positive for cytokeratin AE1/AE3 or vimentin but negative for CD68, S100, α-smooth muscle actin, von Willebrand factor, and desmin. Our results indicate that the tumor was a poorly differentiated Zymbal’s gland carcinoma with lung metastasis.     

Colitis associated with Clostridium difficile in specific-pathogen-free C3H-scid mice

Soft feces and a decreased delivery rate were observed in a specific-pathogen-free (SPF) C3H-scid mouse breeding colony. Grossly, the ceca were shrunken and edematous in the affected mice. Histopathologically, severe edema in the cecal submucosa as well as infiltration of inflammatory cells in the lamina propria and submucosa of the ceca and colon were observed. No pathogenic microorganisms were detected by the routine microbiological tests. By anaerobic bacterial-examination, Clostridium (C.) difficile with toxin A was isolated from the cecal contents of the affected mice. The mice were diagnosed with C. difficile-associated colitis. This case appears to be the first report of natural infection with C. difficile in SPF mice with clinical signs.     

An LRR receptor kinase involved in perception of a peptide plant hormone,phytosulfokine

The sulfated peptide phytosulfokine (PSK) is an intercellular signal that plays a key role in cellular dedifferentiation and proliferation in plants. Using ligand-based affinity chromatography, we purified a 120-kilodalton membrane protein, specifically interacting with PSK, from carrot microsomal fractions. The corresponding complementary DNA encodes a 1021-amino acid receptor kinase that contains extracellular leucine-rich repeats, a single transmembrane domain, and a cytoplasmic kinase domain. Overexpression of this receptor kinase in carrot cells caused enhanced callus growth in response to PSK and a substantial increase in the number of tritium-labeled PSK binding sites, suggesting that PSK and this receptor kinase act as a ligand-receptor pair.     

Regolith migration and sorting on asteroid Itokawa

High-resolution images of the surface of asteroid Itokawa from the Hayabusa mission reveal it to be covered with unconsolidated millimeter-sized and larger gravels. Locations and morphologic characteristics of this gravel indicate that Itokawa has experienced considerable vibrations, which have triggered global-scale granular processes in its dry, vacuum, microgravity environment. These processes likely include granular convection, landslide-like granular migrations, and particle sorting, resulting in the segregation of the fine gravels into areas of potential lows. Granular processes become major resurfacing processes because of Itokawa's small size, implying that they can occur on other small asteroids should those have regolith.     

Expression of cell adhesion molecules in canine choroid plexus tumors

Choroid plexus tumor (CPT) is a primary intracranial neoplasm of the choroid plexus epithelium in the central nervous system. In the current World Health Organization classification, CPT is classified into two categories; choroid plexus papilloma (CPP) and carcinoma (CPC). In the present study, we investigated immunohistochemical expressions of N-cadherin, E-cadherin and β-catenin in 5 canine CPT cases (1 disseminated CPC, 2 CPCs and 2 CPPs). One CPP case was positive for N-cadherin and β-catenin, but negative for E-cadherin. The disseminated CPC case was positive for E-cadherin and β-catenin, but negative for N-cadherin. The other cases were positive for the three molecules examined. These results suggest that loss of the N-cadherin expression might associate with the spreading of CPC cells.     

Cryopreservation of the semen collected by electroejaculation from the Hokkaido brown bear (Ursus arctos yesoensis)

Four adult Hokkaido brown bears were used as semen donors, and semen characteristics were examined before freezing and after thawing. A total of 10 electroejaculates were diluted with Tris-egg yolk extender and cooled to 4 degrees C over 90 min. Spermatozoa were equilibrated with 4.7% glycerol for 80 min. Semen packed in 0.25 ml plastic straws were frozen with liquid nitrogen vapor. Percentages (mean +/- SD) of motile and live sperm were 96+/-2 and 86.5+/-7.2% before freezing, and 43+/-5 and 67.4+/-3.9% after thawing, respectively. Although the number of progressively motile sperm after thawing varied among samples (1.8+/-1.2 x 10(8) cells/ejaculate), frozen semen in the present study might serve for artificial insemination.