Clinicopathologic, histologic, and toxicologic findings in 70 cats inadvertently exposed to pet food contaminated with melamine and cyanuric acid

OBJECTIVE: To document clinicopathologic, histologic, and toxicologic findings in cats inadvertently exposed to pet food contaminated with melamine and cyanuric acid. DESIGN: Case series. ANIMALS: 70 cats from a single cattery inadvertently fed contaminated food that was the subject of a March 2007 recall. PROCEDURES: Clinical signs, clinicopathologic and histopathologic findings, and results of toxicologic analyses were recorded. RESULTS: Clinical signs were identified in 43 cats and included inappetence, vomiting, polyuria, polydipsia, and lethargy. Azotemia was documented in 38 of the 68 cats for which serum biochemical analyses were performed 7 to 11 days after consumption of the contaminated food. One cat died, and 13 were euthanized. Histologic examination of kidney specimens from 13 cats revealed intratubular crystalluria, tubular necrosis with regeneration, and subcapsular perivascular inflammation characterized by perivascular fibroplasia or fibrosis and inflammation with intravascular fibrin thrombi. Toxicologic analyses revealed melamine and cyanuric acid in samples of cat food, vomitus, urine, and kidneys. CONCLUSIONS AND CLINICAL RELEVANCE: In cats unintentionally fed pet food contaminated with melamine and cyanuric acid, the most consistent clinical and pathologic abnormalities were associated with the urinary tract, specifically tubular necrosis and crystalluria.     

Tripeptide structure of bursin, a selective B-cell-differentiating hormone of the bursa of fabricius

Differentiation of lymphoid precursor cells in a variety of species is induced by polypeptide hormones such as thymopoietin for T cells and bursin for B cells. In the present experiments, bursin isolated from the bursa of Fabricius of chicken was found to induce the phenotypic differentiation of mammalian and avian B precursor cells but not of T precursor cells in vitro. Similarly, bursin increased cyclic guanosine monophosphate in cells of the human B-cell line Daudi but not in cells of the human T-cell line CEM. These inducing properties of bursin are the reverse of the inducing properties of thymopoietin produced by the thymus and are appropriate to a physiological B-cell-inducing hormone. A tripeptide sequence (lysyl-histidyl-glycyl-amide) was determined for bursin and confirmed by synthesizing this proposed structure and demonstrating chemical identity of the natural and synthetic peptides. Similarity of biological action was indicated in induction assays by elevation of cyclic adenosine monophosphate and guanosine monophosphate in Daudi B cells but not in CEM T cells.     

Oral surgery. Basic techniques

Some of the clinical problems most frequently seen in veterinary dentistry and their surgical solutions are discussed. Extraction of teeth, surgical repositioning of teeth, tooth transplant, oral abscesses of tooth origin, impaction of teeth, repair of maxillary canine oronasal fistula, and simple techniques for oral wiring are among the issues considered.     

Effects of disk trench orientation and planting spot position on the ten-year performance of lodgepole pine

A disk-trenching experiment in thesub-boreal spruce zone of central British Columbia,Canada, established three plots (0.12 to 0.26 ha each)with trenches running east–west, and another threeplots with north–south trenches. Approximately 200Pinus contorta Dougl. seedlings were planted ineach of 13 microsites: berm, hinge, and trenchpositions in each of north, south, east, and westaspects, and in untreated locations between furrows.Soil temperature and soil moisture of representativemicrosites were monitored for 3 years; seedlingdiameter, height, and vigour were monitored annuallyfor ten growing seasons. Based on tenth-year stemvolumes, performance on south-, east-, and west-facingmicrosites was significantly greater than onnorth-facing or untreated microsites. Superior growthwas noted on all berm and hinge positions other thanthose facing north. Microsites identified as best inyear 5 were also best in year 10. On east-, south- orwest-facing berm positions, stem volume averaged 47%to 54% greater than that of control seedlings in year5, but had suffered greater mortality. Seedlings oneast-, south- or west-facing hinges were 46% to 61%(year 5), or 36% to 47% (year 10) larger thancontrol seedlings. Both east–west and north–southdisk-trenching treatments are useful for increasingseedling growth, with planting spot selection beingmore important overall than trench orientation. Thestand-level effectiveness of north–south disktrenching was greatest, because the creation of coolnorth-facing microsites was avoided.     

Jupiter's Magnetosphere: Plasma Description from the Ulysses Flyby

Plasma observations at Jupiter show that the outer regions of the Jovian magnetosphere are remarkably similar to those of Earth. Bow-shock precursor electrons and ions were detected in the upstream solar wind, as at Earth. Plasma changes across the bow shock and properties of the magnetosheath electrons were much like those at Earth, indicating that similar processes are operating. A boundary layer populated by a varying mixture of solar wind and magnetospheric plasmas was found inside the magnetopause, again as at Earth. In the middle magnetosphere, large electron density excursions were detected with a 10-hour periodicity as planetary rotation carried the tilted plasma sheet past Ulysses. Deep in the magnetosphere, Ulysses crossed a region, tentatively described as magnetically connected to the Jovian polar cap on one end and to the interplanetary magnetic field on the other. In the inner magnetosphere and lo torus, where corotation plays a dominant role, measurements could not be made because of extreme background rates from penetrating radiation belt particles.     

Phosphate uptake in an obligately marine fungus: a specific requirement for sodium

Phosphate uptake in the obligately marine fungus Thraustochytrium roseum is maximally stimulated by sodium chloride in a range of concentrations (0.2 to 0.4 molar) similar to those commonly encountered in littoral habitats. The effectiveness of sodium chloride for phosphate transport extends beyond its osmotic function and can be attributed specifically to sodium. Increases in respiration in the presence of the salt can be ascribed primarily to an osmotic effect.     

Melting in semiconductor nanocrystals

New physics occurs in semiconductors when one or more dimensions of the crystal are reduced to a size comparable to bulk electron delocalization lengths (tens to hundreds of angstroms). The properties of "quantum dots" or semiconductor nanocrystals are now being studied, as techniques to fabricate the crystallites are developed. Temperature-dependent electron diffraction studies on nanocrystals of CdS show a large depression in the melting temperature with decreasing size, as a larger fraction of the total number of atoms is on the surface. Thermal stability may play a role in determining the uses of semiconductor nanocrystals.     

Paleontology and Chronology of Two Evolutionary Transitions by Hybridization in the Bahamian Land Snail Cerion

The late Quaternary fossil record of the Bahamian land snail Cerion on Great Inagua documents two transitions apparently resulting from hybridization. In the first, a localized modern population represents the hybrid descendants of a 13,000-year-old fossil form from the same area, introgressed with the modern form now characteristic of the adjacent regions. In the second case, a chronocline spanning 15,000 to 20,000 years and expressing the transition of an extinct fossil form to the modern form found on the south coast was documented by morphometry of fossils dated by amino acid racemization and radiocarbon. Hybrid intermediates persisted for many thousands of years.