Withdrawal of zinc oxide-containing diets from mature, female domestic fowl: effects on laying performance and the weights of selected tissues

1. Two hundred and sixteen laying hens of two strains were given diets containing ZnO to provide 0, 0.5, 0.75, 1.00, 1.25, 1.50, 2.00, 3.00 or 4.00 g added Zn/kg. These diets were given ad libitum for 5 consecutive 28-d periods. All hens subsequently received the control diet with no added ZnO for 5 weeks. 2. Four hens from each treatment were killed 0, 1 and 5 weeks after substitution of the ZnO-supplemented diets by the control diet. 3. The adverse effects of the ZnO-containing diets on body weight, food intake, egg production, pancreas, gizzard, oviduct and ovary weights/kg body weight were reversed by removal of the ZnO from the diets. 4. Five weeks after withdrawal egg production of the group which had received the diet with the highest concentration of added ZnO was only 50% of that of the control birds. 5. The beneficial effect of the added ZnO on internal egg quality was not maintained after withdrawal of the ZnO-containing diets.     

Comparison of the histology and immunohistochemistry of vaccination-site and non-vaccination-site sarcomas from cats in New Zealand

AIMS: To compare the histology and immunohistochemistry of vaccination-site sarcomas (VSSs) with non-vaccination-site sarcomas (NVSSs) in cats in New Zealand. To determine whether VSSs in cats in New Zealand have similar histological and immunohistochemical features to those previously described in feline vaccine-associated sarcomas (VASs) in North American studies. METHODS: A retrospective survey of skin biopsies submitted between 2004 and 2006 was performed to identify cutaneous sarcomas from both vaccination and non-vaccination sites in cats. Vaccination sites included the interscapular, shoulder, or dorsal or lateral cervical and thoracic regions. All sarcomas were examined histologically, and smooth muscle actin and desmin were assessed immunohistochemically. Features previously described in VASs were assessed and compared. RESULTS: Sarcomas from 34 cats were identified, 10 of which occurred at vaccination sites. Compared with NVSSs, VSSs were more likely to be located in the hypodermis and have greater cellular pleomorphism, higher mitotic rates, more frequent peripheral lymphocytic aggregates and multinucleated giant cells. VSSs were also more likely than NVSSs to show partial myofibroblastic differentiation, demonstrable using immunohistochemistry. The histological and immunohistochemical features of VSSs in cats in New Zealand are consistent with those previously described in VASs in cats in North America. CONCLUSIONS: The results of this study suggest that VASs occur in cats in New Zealand. CLINICAL RELEVANCE: The occurrence of VASs in cats in New Zealand would provide further support for restriction of the vaccination of cats to the minimum necessary to protect health, and adoption of the New Zealand Veterinary Association guidelines on vaccination.     

CSF from a puppy with a cerebral vascular hamartoma

A 9-week-old puppy with refractory seizures and a dome-shaped head presented to the Mississippi State College of Veterinary Medicine Specialty Center for suspected hydrocephalus. Computerized tomography (CT) findings included transtentorial herniation and an intra-axial mass with dystrophic mineralization. Cerebrospinal fluid analysis revealed an increased nucleated cell count of 1100/μl (RI < 5/μl), erythrocyte count of 2.2 × 10⁶/μl, and markedly increased microprotein of 1939 mg/dl (RI < 30 mg/dl). On cytologic examination of the CSF, numerous erythrophagocytic, and hemosiderin-laden macrophages were observed, which indicated chronic active hemorrhage. Many neutrophils, macrophages, and lymphocytes that contained numerous intracytoplasmic, pleomorphic, bright yellow crystals were observed. Considering the ongoing hemorrhage, the crystals were presumed to be hematoidin. A biopsy with histopathology was performed on the intra-axial mass, and the results were consistent with a vascular hamartoma. We speculate that the formation of these crystals was related to the ongoing hemorrhage associated with the vascular hamartoma. Identification of these crystals may be useful to aid in the identification of chronic hemorrhage associated with vascular malformations or lesions within the central nervous system.     

Synthesis and characterization of anisometric cobalt nanoclusters

Sonication of aqueous Co(2+) and hydrazine resulted in the formation of anisometric (disk-shaped) cobalt nanoclusters that averaged about 100 nanometers in width and 15 nanometers in thickness. Electron diffraction from single particles revealed that they were oriented (001) crystals that conformed to a trigonal or hexagonal unit cell four times the size of the cell adopted by bulk alpha-cobalt. Lorentz microscopy indicated that these were single-magnetic domain particles, with the axis of magnetization located in the (101) plane, offset at some appreciable angle from the (001) axis.     

Late cretaceous precessional cycles in double time: a warm-Earth milankovitch response

Late Cretaceous climatic cycles are reflected in lithological and magnetic variations in carbonate sediments from South Atlantic Deep-Sea Drilling Project site 516F at a paleolatitude of roughly 30 degrees S. Magnetic susceptibility cycles 20 to 60 centimeters in length appear to be controlled by the precession of the equinoxes. Cyclicity is particularly robust within a 24-meter interval in the lower Campanian, where overtone spectral peaks are observed as well as secondary susceptibility maxima within individual precession cycles. One model for this behavior is that sedimentation in the narrow Cretaceous South Atlantic was controlled by equatorial climate dynamics, with the precessional insolation signal rectified by the large land masses surrounding the ocean basin.