Oral disorders of exotic rodents.

Our dental knowledge of rodents is still patchy but their increasing popularity and advances in technology allow us to make good strides toward better understanding. Cutting incisors with nail clippers and treating incisor problems without examining cheek teeth is no longer acceptable. Good practice dictates that a thorough examination is performed, a diagnosis is made, and treatment is planned and executed appropriately. Dentistry is expanding at a tremendous rate; the next few years should provide plenty of opportunities to solve most of the remaining problems with dental disease in rodents.     

Toll‐like receptor and related cytokine mRNA expression in bovine corpora lutea during the oestrous cycle and pregnancy

Improving our understanding of the mechanisms controlling the corpus luteum (CL) and its role in regulating the reproductive cycle should lead to improvements in the sustainability of today's global animal industry. The corpus luteum (CL) is a transient endocrine organ composed of a heterogeneous mixture steroidogenic, endothelial and immune cells, and it is becoming clear that immune mechanisms play a key role in CL regulation especially in luteolysis. Toll‐like receptors (TLR) mediate innate immune mechanisms via the production of pro‐inflammatory cytokines, especially within various tissues, although the role of TLR within CL remains unknown. Thus, the objectives of this study were to characterize TLR mRNA expression in the CL during the oestrous cycle and in pregnancy (day 30–50), and to examine the role of TLR signalling in luteal cells. Corpora lutea were collected at various stages of the cycle and pregnancy and analysed for TLR and cytokine mRNA expression. In addition, luteal cells were cultured with the TLR4 ligand (lipopolysaccharide, LPS) for 24 h to evaluate the role of TLR4 in regulating luteal function. Toll‐like receptors 1, 2, 4, 6, tumour necrosis factor alpha (TNF), interferon gamma (IFN‐G), and interleukin (IL)‐12, mRNA expressions were greatest in regressing CL compared with earlier stages (p < .05), whereas no change was observed for IL‐6 mRNA expression. Cytokine mRNA expression in cultured luteal cells was not altered by LPS. Based on these data, one or more of the TLRs found within the CL may play a role in luteolysis, perhaps via pro‐inflammatory cytokine mRNA expression.     

Solution properties of single-walled carbon nanotubes

Naked metallic and semiconducting single-walled carbon nanotubes (SWNTs) were dissolved in organic solutions by derivatization with thionychloride and octadecylamine. Both ionic (charge transfer) and covalent solution-phase chemistry with concomitant modulation of the SWNT band structure were demonstrated. Solution-phase near-infrared spectroscopy was used to study the effects of chemical modifications on the band gaps of the SWNTs. Reaction of soluble SWNTs with dichlorocarbene led to functionalization of the nanotube walls.     

Design of a surface alloy catalyst for steam reforming

Detailed studies of elementary chemical processes on well-characterized single crystal surfaces have contributed substantially to the understanding of heterogeneous catalysis. Insight into the structure of surface alloys combined with an understanding of the relation between the surface composition and reactivity is shown to lead directly to new ideas for catalyst design. The feasibility of such an approach is illustrated by the synthesis, characterization, and tests of a high-surface area gold-nickel catalyst for steam reforming.     

Interactions between temperature and size on the growth,size heterogeneity,mortality and cannibalism in cultured larvae and juveniles of the Asian catfish,Pangasianodon hypophthalmus (Sauvage)

Temperature effects vary throughout the ontogeny, but are proportionally more variable during the early life stages than in older fish. The larvae of a few species have been studied but contrasting trajectories were observed, thereby making it difficult to predict how temperature impacts on the growth, survival and size heterogeneity in a particular species. This study examined these interactions in young [0.9 mg–1 g wet mass (WM)] Pangasianodon hypophthalmus, one of the most extensively cultured tropical fish. Fish were raised at five temperatures from 23 to 33 °C in a recirculated water system, fed in excess with a high‐energy feed (Artemia then a formulated feed, >50% protein), and examined at 1‐day (first feeding days) or 4‐day intervals (older fish). The temperature that produced the fastest growth (T°_opt) was 31 °C at the start of exogenous feeding (0.9 mg); it increased to 32.7 °C at 8 mg then decreased by 0.7 °C for each 10‐fold increase of WM. Size heterogeneity was lower and survival was higher (70–85% from 0.9 mg to 1 g) when the temperature was close to T°_opt. Comparisons with other species suggest that the slope of the relationship between T°_opt and fish size has a strong latitudinal component, and may also reflect the fish sensitivity to oxygen.     

Itraconazole for the Treatment of Histoplasmosis in Cats

Eight cats with histoplasmosis were treated with itraconazole at 5 mg/kg per dose PO bid. There were multiple sites of infection, and 2 of the cats had hypercalcemia that was attributed to the histoplasmosis. All 8 cats were eventually cured, but 2 cats experienced recurrences of disease after completion of therapy, requiring 2 to 3 additional months of itraconazole. There were no clinically relevant adverse effects during treatment. Although a limited number of cats were treated, the study suggests that itraconazole is a well-tolerated and effective drug for the treatment of histoplasmosis in the cat.     

TREATMENT OF DIFFERENTIATED THYROID CARCINOMA IN 7 DOGS UTILIZING 131I

Seven dogs with thyroid gland carcinoma were treated with ¹³¹I and hormone suppressive therapy either alone (3 dogs) or in combination with surgery (3 dogs) or ¹³⁷Cs teletherapy and chemotherapy (1 dog). Empirically chosen doses of 75 to 137 mCi of ¹³¹I were given orally (2 dogs) and intravenously (5 dogs). Adverse effects were limited to acute, transient bone marrow hypoplasia and pancytopenia. Nominal objective reduction in tumor volume or size and number of pulmonary metastases was observed in 4 dogs treated with ¹³¹I and thyroxine. Of these 4 dogs, 2 had stable disease for periods of 4 and 12 months while a third dog had stable disease for 27 months following two ¹³¹I treatments at 3 month intervals. The fourth dog had progressive disease. Two dogs with mediastinal metastases showed reduction in localization of ^99mTc pertechnetate and radioiodine following 2 and 3 treatments using ¹³¹I. It appears that relatively high doses of ¹³¹I can be used safely for the treatment of canine thyroid tumors and that further investigation can be justified to define its efficacy.