Isolation of Streptococcus cuniculi from corneal lesion in laboratory-raised mice

Corneal lesions appearing as white mass beneath intact epithelium, with ocular discharge in one mouse, was observed in a batch of laboratory-raised BALB/c mice (n=9 of 56). The affected mice remained active, well-groomed and had normal appetite. Isolates recovered from swab cultures of the external and internal contents of the eye had partial 16S rRNA gene sequence of 99.1% similarity to Streptococcus cuniculi. No previous report of S. cuniculi infection in laboratory rodents has been presented. The isolate was susceptible to all antibiotics tested. We suggest S. cuniculi is an opportunistic bacteria in laboratory mice but are uncertain of its source. Our findings revealed that S. cuniculi is able to colonize laboratory mice and should be considered when mice present with eye lesion or ocular discharge.     

核桃楸树皮的没食子酸、鞣花酸及水解单宁成分研究

研究了核桃楸树皮丙酮-水提取物的水溶性萃取部位的化学成分.采用Sephadex LH-20柱色谱及薄层色谱等方法进行分离,经波谱分析及理化性质测定,鉴定了6个化合物:没食子酸(1)、鞣花酸(2)、1,2,6-三没食子酰葡萄糖(3)、1,3,6-三没食子酰葡萄糖(4)、1,2,4,6-四没食子酰葡萄糖(5)及1,2,3,4,6-五没食子酰葡萄糖(6).化合物2、4、6为首次从该植物中分得.     

MAGNETIC RESONANCE IMAGING OF THE CANINE BRAIN AT 7 T

The purpose of this study was to describe relevant canine brain structures as seen on T2-weighted images following magnetic resonance (MR) imaging at 7 T and to compare the results with imaging at 1.5 T. Imaging was performed on five healthy laboratory beagle dogs using 1.5 and 7 T clinical scanners. At 1.5 T, spin echo images were acquired, while gradient echo images were acquired at 3 T. Image quality and conspicuity of anatomic structures were evaluated qualitatively by direct comparison of the images obtained from the two different magnetic fields. The signal-to-nose ratio (SNR) and contrast-to-noise ratio (CNR) were calculated and compared between 1.5 and 7 T. The T2-weighted images at 7 T provided good spatial and contrast resolution for the identification of clinically relevant brain anatomy; these images provided better delineation and conspicuity of the brain stem and cerebellar structures, which were difficult to unequivocally identify at 1.5 T. However, frontal and parietal lobe and the trigeminal nerve were difficult to identify at 7 T due to susceptibility artifact. The SNR and CNR of the images at 7 T were significantly increased up to 318% and 715% compared with the 1.5 T images. If some disadvantages of 7 T imaging, such as susceptibility artifacts, technical difficulties, and high cost, can be improved, 7 T clinical MR imaging could provide a good experimental and diagnostic tool for the evaluation of canine brain disorders.     

Supplemental iron and phosphorus increase dietary inclusion of cottonseed and soybean meal in olive flounder (Paralichthys olivaceus)

A long‐term feeding experiment was conducted to investigate the use of cottonseed and soybean meal (CS) with iron and phosphorus supplements in diets for olive flounder (Paralichthys olivaceus). Olive flounder with an initial average size of 28.5 ± 0.35 g (mean ± SD) were divided into 15 groups (three tanks per dietary treatment) and fed 480 g kg^?1 crude protein diets in which each of five isonitrogenous diets was formulated to contain different levels of cottonseed/soybean meal (1 : 1) to replace fish meal (FM) with iron and phosphorus supplementations. The five experimental diets were as follows: diet 1 (control), 0%CS; diet 2, 20%CS; diet 3, 30%CS; diet 4, 30%CS + Fe&P; and diet 5, 40%CS + Fe&P. After 26 weeks of feeding trial, no significant differences were observed in weight gain, feed utilization and survival among all the treatments. The total gossypol accumulation in liver of fish fed diets supplemented with iron was significantly lower than that of fish fed diets without supplementation of iron. The results indicate that the addition of iron in diets could prevent the absorption of free gossypol. The findings in this study suggest that dietary supplements of iron and phosphorus could increase the inclusion of cottonseed and soybean meal for FM replacement in diets for marine fish species.     

Formulation of aquaculture development at an ox-bow lake in Malaysia: economic feasibility analysis

Abstract. This paper summarizes the economic aspects of production models and discusses the economic feasibilities and some marketing requirements of a proposed fisheries-aquaculture development at an ox-bow lake, isolated from the Perak River, at Teluk Intan, Perak, Malaysia. Measures of feasibility from a budgetary simulation model are expressed in terms of net present values of return (NPV), internal rate of return (IRR) and return on sale; their changes recalculated in relation to practical ranges of variations in sale prices and yields, and under conditions of normal and 20% increment in operational costs, are also expressed. Using appropriate real production data, the cage culture complex has an NPV of M$4.068 million with an IRR of 68% and return on sales of 31% at a sale price of M$10/kg and yield of 12kg/m³ (US$1.00 = M$2.30); capture fisheries integrated with livestock have an NPV of M$252410, IRR of 42% and return on sales of 18% at a sale price of M$2.50/kg and yield of 33 tonnes; the hatchery facility has an NPV of M$0.963 million, IRR of 38% and return on sales of 20% at a sale price of M$0.39/fry and yield of 2 million; and prawn pond culture has an NPV of M$314000, IRR of 43% and return on sales of 36% at a sale price of M$11/kg and yield of 2.5 tons/ha. Overall, the modular project has an NPV of M$5.596 million with an IRR and return on sales of 53% and 28% respectively. Should the operational costs increase by 20% above normal, project unviabilities are obvious at specific levels: cage culture is unviable at sale prices ≤M$8.00/kg and yields ≤10 kg/m³; capture fisheries at sale prices ≤M$1.5/kg; hatchery facility at sale prices of fry ≤M$0.30/fry; prawn culture at sale prices ≤M$8.00/kg and yields ≤2 tons/ha; and the overall project is unviable when the sale level of fisheries products drops to 80% of the normal and operational costs increase to 120%. With greater efforts at raising sales and securing better prices, and raising yields while reducing operational costs, the projects have a markedly improved economic profit.     

Adaptive evolutionary expansion of the ribonuclease 6 in Rodentia

Ribonuclease 6 (RNase6 or RNase K6) is a protein that belongs to a superfamily thought to be the sole verte‐brate‐specific enzyme known for a wide range of physiological functions, including digestion, cytotoxicity, angiogenesis, male reproduction and host defense. In our study, 51 functional genes and 11 pseudogenes were identified from 27 Rodentia species. Intriguingly, in the 3 main lineages of rodents there were multiple RNase6s identified in all species of Ctenohystrica, whereas only a single RNase6 was observed in other Rodentia species examined except for 2 species in the mouse‐related clade. The evolutionary scenario of “birth (gene duplication) and death (gene deactivation)” and gene sorting have been demonstrated in Ctenohystrica. In addition, bursts of positive selection, diversification of isoelectric point and positive net charge have been identified in Ctenohystrica, especially at two key sites that are involved in antimicrobial function. Site Trp30 has undergone positive selection and Ile45 has changed into other residues in Group B and Group C of the Ctenohystrica. Our results demonstrated a complex and intriguing evolutionary pattern of rodent RNase6, and indicated that functional modification may have occurred, which establishes an important theoretical foundation for future functional assays in rodent RNase6.     

Susceptibility of channel catfish (Ictalurus punctatus) fed with dietary sodium chloride to nitrite toxicity

Juvenile channel catfish (Ictalurus punctatus) were fed with nutritionally complete, basal diets supplemented with NaCl at 0, 10, 20 or 40 g kg^?1 diet (0, 1, 2, or 4%) to apparent satiation twice daily for 10 weeks. Catfish were exposed to nitrite after six (7.70 mg L^?1 nitrite‐N) and ten (7.18 mg L^?1 nitrite‐N) weeks of feeding to determine the effect of dietary NaCl supplementation on resistance to nitrite toxicity. Fish were sampled before (baseline, pre‐exposure) and after 24‐h nitrite exposure to determine the effects of dietary NaCl on haematology (haematocrit, haemoglobin and methaemoglobin) and plasma electrolyte dynamics (nitrite, chloride, sodium and potassium). Mortality from nitrite toxicity was also determined. Mortality from nitrite exposure tended to decrease with increasing NaCl in the diet at 6 weeks and was significantly lower in the 40 g kg^?1 NaCl group (12.5%) compared to the control group (57.5%). A similar trend in mortality occurred at 10 weeks as well; however, the differences among dietary treatments were not significant. The improvements in blood MetHb (non‐significant), chloride and nitrite levels in catfish may at least in part be responsible for the improved survival after nitrite exposure, which trended in support of the prevailing hypotheses for the positive effects of NaCl on nitrite toxicity.