Hepatic myelolipoma incarcerated in a peritoneopericardial diaphragmatic hernia in a cat

Hepatic myelolipoma incarcerated in a peritoneopericardial diaphragmatic hernia was diagnosed in an 11-year-old, desexed female Persian cat. The cat was initially referred for investigation of tachypnoea and dyspnoea. Peritoneopericardial diaphragmatic hernia is a common incidental finding in cats and is usually asymptomatic. Myelolipoma is an extremely rare benign tumour, composed of extramedullary haematopoietic cells and adipose tissue. Myelolipomas are hypothesised to result from metaplastic alteration, rather than a neoplastic process, although this theory cannot be substantiated. The present case is only the fourth report of such an unusual occurrence in cats and displays significant differences to previous reports. Hepatic entrapment and burgeoning of the mass within the pericardial sac resulted in cardiac tamponade and overt signs of right-sided cardiac failure. Surgical intervention was successful and despite concerns regarding the cat's clinical presentation and the gross appearance of the lesion(s), a good long-term outcome is anticipated.     

Atomic structure of thymidylate synthase: target for rational drug design

The atomic structure of thymidylate synthase from Lactobacillus casei was determined at 3 angstrom resolution. The native enzyme is a dimer of identical subunits. The dimer interface is formed by an unusual association between five-stranded beta sheets present in each monomer. Comparison of known sequences with the Lactobacillus casei structure suggests that they all have a common core structure around which loops are inserted or deleted in different sequences. Residues from both subunits contribute to each active site. Two arginine side chains can contribute to binding phosphate on the substrate. The side chains of several conserved amino acids can account for other determinants of substrate binding.     

Silica sol as a nanoglue: flexible synthesis of composite aerogels

Low-density nanoscale mesoporous composites may be readily synthesized by adding a colloidal or dispersed solid to an about-to-gel silica sol. The silica sol can "glue" a range of chemically and physically diverse particles into the three-dimensional silica network formed upon gelation. If the composite gel is supercritically dried so as to maintain the high porosity of the wet gel, a composite aerogel is formed in which the nanoscopic surface and bulk properties of each component are retained in the solid composite. The volume fraction of the second solid can be varied above or below a percolation threshold to tune the transport properties of the composite aerogel and thereby design nanoscale materials for chemical, electronic, and optical applications.     

Origin and evolution of prebiotic organic matter as inferred from the Tagish Lake meteorite

The complex suite of organic materials in carbonaceous chondrite meteorites probably originally formed in the interstellar medium and/or the solar protoplanetary disk, but was subsequently modified in the meteorites' asteroidal parent bodies. The mechanisms of formation and modification are still very poorly understood. We carried out a systematic study of variations in the mineralogy, petrology, and soluble and insoluble organic matter in distinct fragments of the Tagish Lake meteorite. The variations correlate with indicators of parent body aqueous alteration. At least some molecules of prebiotic importance formed during the alteration.     

A GIS based approach to modelling the effects of land-use change on soil erosion in New Zealand

Abstract. The problem of soil erosion is particularly evident in New Zealand, given the combination of coarse-textured soils, steep relief, high rainfall, and intensification of agriculture. A study was undertaken to assess the effects of land use change on soil erosion and sediment transport for the Ngongotaha catchment in New Zealand's North Island, using a GIS based decision support and modelling system. Model simulations considered the effect of increased catchment area under deer farming and forestry on the amount of sediment delivered to the catchment outlet, averaged over a period of six years. The simulations predicted that sediment loss from land under deer farming was considerably greater than from land under other livestock or forestry. Further model simulations testing best management practices demonstrated that sediment yield could be halved if deer farming was restricted to slopes under 20%.     

Suspected fusariomycotoxicosis in sandhill cranes (Grus canadensis): clinical and pathological findings

In 1985 and 1986, large-scale natural die-offs of sandhill cranes in Texas were attributed to fusariomycotoxicosis. These birds demonstrated a progressive loss of motor control to the neck, wings, and legs. Based on necropsy and/or histopathology of 31 cranes, the most common lesions involved skeletal muscle and included hemorrhages, granulomatous myositis, thrombosis, and vascular degeneration. Serum chemistry results revealed that levels of creatinine kinase, aspartate aminotransferase, and alanine aminotransferase were above published normals. However, only alanine aminotransferase was higher in clinically affected cranes than in normal cranes collected from the same area.