Ultrastructure and chemical composition of calcite urinary calculi in Chinese swamp buffalo

Four urinary calculi, derived from Chinese swamp buffalo, were studied by using qualitative chemical analysis, X-ray diffraction, scanning electron microscopy and qualitative energy dispersive (electron probe) microanalysis. Qualitative chemical analysis showed that the predominant ions were calcium and carbonate with small amounts of magnesium and ammonium. X-ray diffraction confirmed that the calculi were primarily composed of calcium carbonate (calcite). On ultrastructural examination, three apparently distinct structural regions were identified in the calculi: outer large laminations; cavities containing variable numbers of small spheres and rods; and large spheres. There did not appear to be material that acted as a nidus and all regions, on qualitative electron probe analysis, contained primarily calcium with trace amounts of magnesium, phosphorus, potassium and chloride. It was concluded that calcite calculi in Chinese swamp buffalo are probably formed through a process of asynchronous layering and that nidus formation may not be necessary. Moreover, the ultrastructure of the calcite calculi is similar to that reported for siliceous calculi in ruminants and this suggests that similar factors may be involved in their formation.     

The Efficacy of Some Commercially Available Insect Repellents for Aedes aegypti (Diptera: Culicidae) and Aedes albopictus (Diptera: Culicidae)

Reducing the number of host-vector interactions is an effective way to reduce the spread of vector-borne diseases. Repellents are widely used to protect humans from a variety of protozoans, viruses, and nematodes. DEET (N,N-Diethyl-meta-toluamide), a safe and effective repellent, was developed during World War II. Fear of possible side effects of DEET has created a large market for “natural” DEET-free repellents with a variety of active ingredients. We present a comparative study on the efficacy of eight commercially available products, two fragrances, and a vitamin B patch. The products were tested using a human hand as attractant in a Y-tube olfactometer setup with Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse), both major human disease vectors. We found that Ae. albopictus were generally less attracted to the test subject’s hand compared with Ae, aegypti. Repellents with DEET as active ingredient had a prominent repellency effect over longer times and on both species. Repellents containing p-menthane-3,8-diol produced comparable results but for shorter time periods. Some of the DEET-free products containing citronella or geraniol did not have any significant repellency effect. Interestingly, the perfume we tested had a modest repellency effect early after application, and the vitamin B patch had no effect on either species. This study shows that the different active ingredients in commercially available mosquito repellent products are not equivalent in terms of duration and strength of repellency. Our results suggest that products containing DEET or p-menthane-3,8-diol have long-lasting repellent effects and therefore provide good protection from mosquito-borne diseases.     

Corneal stromal abscess in a horse

A thoroughbred yearling presented with a focal, yellow, midstromal corneal opacity with concurrent iridocyclitis which was consistent with a corneal stromal abscess. When continued, appropriate, medical therapy failed to improve the patient's condition, penetrating keratoplasty was performed for diagnosis and therapy. Histopathology showed that the deep corneal stroma and Descemet's membrane were severely infiltrated with necrotic neutrophils and numerous, intralesional fungal hyphae. Culture was negative. Bacteria were not isolated, consistent with a fungal corneal stromal abscess. The resultant corneal scar did not interfere with the horse's racing career.     

Pharmacokinetics of voriconazole after oral administration of single and multiple doses in African grey parrots (Psittacus erithacus timneh)

OBJECTIVE: To determine the pharmacokinetics and safety of orally administered voriconazole in African grey parrots. ANIMALS: 20 clinically normal Timneh African grey parrots (Psittacus erithacus timneh). PROCEDURES: In single-dose trials, 12 parrots were each administered 6, 12, and 18 mg of voriconazole/kg orally and plasma concentrations of voriconazole were determined via high-pressure liquid chromatography. In a multiple-dose trial, voriconazole (18 mg/kg) was administered orally to 6 birds every 12 hours for 9 days; a control group (2 birds) received tap water. Treatment effects were assessed via observation, clinicopathologic analyses (3 assessments), and measurement of trough plasma voriconazole concentrations (2 assessments). RESULTS: Voriconazole's elimination half-life was short (1.1 to 1.6 hours). Higher doses resulted in disproportional increases in the maximum plasma voriconazole concentration and area under the curve. Trough plasma voriconazole concentrations achieved in the multiple-dose trial were lower than those achieved after administration of single doses. Polyuria (the only adverse treatment effect) developed in treated and control birds but was more severe in the treatment group. CONCLUSIONS AND CLINICAL RELEVANCE: In African grey parrots, voriconazole has dose-dependent pharmacokinetics and may induce its own metabolism. Oral administration of 12 to 18 mg of voriconazole/kg twice daily is a rational starting dose for treatment of African grey parrots infected with Aspergillus or other fungal organisms that have a minimal inhibitory concentration for voriconazole < or = 0.4 microg/mL. Higher doses may be needed to maintain plasma voriconazole concentrations during long-term treatment. Safety and efficacy of various voriconazole treatment regimens in this species require investigation.     

Bovine lineage-specific gamma delta (gammadelta) T cell GD3.5 antibody cross-reacts with cell surface antigens on ovine and caprine lymphocytes

A specifically defined function for gammadelta T cells is still a topic of intense debate. Thus, there is great importance in the identification of lineage-specific markers that characterize these cells. Early studies describe a family of lineage-specific cell-surface molecules on ruminant gammadelta T cells called WC1. More recently, a 220-240 kDa lineage-specific bovine gammadelta T cell surface marker, GD3.5Ag, was reported. Here, we used anti-bovine GD3.5Ab to study its cross-reactivity with caprine and ovine lymphocytes. Flow cytometric analysis demonstrated that GD3.5Ab binds ovine and caprine lymphocytes. In addition, immunoprecipitation experiments with GD3.5Ab demonstrate an ovine and caprine cross-reactive antigen that is similar in size to the bovine antigen. These results suggest that GD3.5Ag is well conserved among ruminant species and GD3.5Ag may play an important role in gammadelta T cell biology.