Effects of dietary cadmium on calcium homeostasis, Ca mobilization and bone deformities in Atlantic salmon (Salmo salar L.) parr

Atlantic salmon parr were reared for 4 months on experimental fish‐meal‐based diets supplemented with 0 (control), 0.5, 5, 25, 125 or 250 mg Cd kg^?1 feed to assess the effects of dietary Cd on active Ca uptake, mobilization of Ca from internal reservoirs, and development of bone malformations. The accumulation of dietary Cd in tissues was, in decreasing order, intestine > kidney >> gill > bone. No significant accumulation of Cd in the scales was observed. Strongest inhibition of ATP dependent Ca uptake (measured as Ca²⁺‐ and Na⁺/K⁺‐ATPase) was observed in the intestine of salmon fed 25 mg Cd kg^?1. This suppression in active intestinal Ca uptake did not lead to disturbed plasma Ca levels. Significant reduction of Ca from the scales in salmon fed 25 mg Cd kg^?1, indicates remobilization of Ca to maintain Ca homeostasis. At the end of the experiment no significant differences were observed in bone Ca levels, nor were any bone malformations observed in any of the dietary Cd‐exposed salmon. This indicates that bone as an endogenous Ca reservoir is spared compared with scales. It was concluded that dietary Cd‐induced disturbance of Ca homeostasis did not lead to bone deformities, even when Atlantic salmon were fed high amounts of cadmium. This indicates a low risk of spinal deformations being developed in Atlantic salmon sub‐chronically exposed to high Cd concentrations in the feed.     

Teratogenicity of elevated egg incubation temperature and egg vitamin A status in Atlantic salmon, Salmo salar L

The present study was undertaken to investigate the possibility that high egg vitamin A (VA) status in combination with elevated egg incubation temperatures may cause deformities in Atlantic salmon, Salmo salar L. Egg batches selected for their total VA concentration were exposed to low (normal, 8 degrees C) or elevated (14 degrees C) egg incubation temperatures. Temperature was the main factor causing bone deformities such as warped gill opercula, fin and jaw deformities, but not for the development of spinal deformities where all groups displayed a 'baseline' occurrence of mild deformity (decreased vertebral size in the cephalic region) and no systematic variation in the occurrence of serious spinal deformities (fused vertebrae). A possible effect of egg incubation temperature fluctuation was found for the groups reared at low temperatures. An indication of a negative effect of elevated egg VA status for the development of organ deformities such as missing septum transversum and situs inversus was found in addition to temperature effects, however, no firm conclusions could be drawn from the present data. The phenotypes for temperature-induced deformities resembled the phenotype of VA-induced deformities, but no clear conclusions on the causality of the deformities found in the present study could be drawn. Egg incubation temperatures, both absolute temperature and temperature variations, should therefore be strictly controlled.     

Skeletal development and deformities in cultured larval and juvenile seven-band grouper, Epinephelus septemfasciatus (Thunberg)

The seven‐band grouper, Epinephelus septemfasciatus (Thunberg), is currently recognized as a potential new species for aquaculture in Japan. This study describes normal and abnormal skeletal development of the jaw and vertebrae in cultured larvae and early juveniles of E. septemfasciatus. The ontogenetic stages at which skeletal deformities of jaw and vertebra developed were also described for this species. Osteological observations were made using a clearing and staining method for larvae and soft X‐ray photographs for juveniles. A high incidence of skeletal deformities was observed in the jaws and vertebral column during the larval and juvenile stages. Most of the jaw deformities were explained by an abnormal maxilla curvature. Jaw deformities were visually evident from flexion stage after ossification of the deformed elements. Deformities in the vertebral column (mostly lordosis) were observed from the post‐larval stage and became more evident as growth proceeded. The lordosis generally occurred on the positions of the 8–11th vertebra. These types of deformities are compared with those of other species, and possible causative factors of the skeletal deformities are discussed.
     

Vertebral deformities in cultured red sea bream, Pagrus major, Temminck and Schlegel

Vertebral deformities were investigated in cultured red sea bream, Pagrus major. In the field, deformities in seedlings were categorized and their incidence was calculated. In the laboratory, the symptoms of major vertebral deformities were examined morphologically using radiographs and by making transparent skeletal specimens. The internal structure of deformed vertebrae was examined histologically. The shortened body condition had the highest incidence (0.9–8.3%) of all deformities in the seedlings. In individuals with the shortened body condition, the ratio of trunk and caudal part length to body height was smaller. These fish had skeletal anomalies in the vertebrae, mainly centrum defects (64.3%) or undersized centrums (25.2%). The specimens with centrum defects had a characteristic anomaly in the vertebrae, with plural pairs of neural and haemal spines on a single centrum. This anomaly was frequently observed in the posterior abdominal vertebrae. The internal skeletal structure of such abnormal centrums was basically the same as that of normal centrums. In all the specimens with undersized centrums, both the centrum length and diameter were shorter than normal except for the first and second centrum, and urostyle.     

Microbial decomposition of skeletal muscle tissue (Ovis aries) in a sandy loam soil at different temperatures

A laboratory experiment was conducted to determine the effect of temperature (2, 12, 22 °C) on the rate of aerobic decomposition of skeletal muscle tissue (Ovis aries) in a sandy loam soil incubated for a period of 42 days. Measurements of decomposition processes included skeletal muscle tissue mass loss, carbon dioxide (CO₂) evolution, microbial biomass, soil pH, skeletal muscle tissue carbon (C) and nitrogen (N) content and the calculation of metabolic quotient (qCO₂). Incubation temperature and skeletal muscle tissue quality had a significant effect on all of the measured process rates with 2 °C usually much lower than 12 and 22 °C. Cumulative CO₂ evolution at 2, 12 and 22 °C equaled 252, 619 and 905 mg CO₂, respectively. A significant correlation (P<0.001) was detected between cumulative CO₂ evolution and tissue mass loss at all temperatures. Q₁₀s for mass loss and CO₂ evolution, which ranged from 1.19 to 3.95, were higher for the lower temperature range (Q₁₀(2-12 °C)>Q₁₀(12-22 °C)) in the Ovis samples and lower for the low temperature range (Q₁₀(2-12 °C)<Q₁₀(12-22 °C)) in the control samples. Metabolic quotient and the positive relationship between skeletal muscle tissue mass loss and cumulative CO₂ evolution suggest that tissue decomposition was most efficient at 2 °C. These phenomena may be due to lower microbial catabolic requirements at lower temperature.     

Bilateral distal radial epiphysectomy and pancarpal arthrodesis for correction of complex carpal deformities in an American Miniature horse

A 9‐day‐old American Miniature horse was referred for evaluation and treatment of congenital bilateral carpal deformities. Clinical examination revealed a combination of flexural, angular and rotational deformities affecting both carpi. Radiographic evaluation of both forelimbs revealed malformation of the distal radial epiphysis accompanied by flexural contracture and external rotation of the limb distal to the antebrachial carpal joint. Conservative therapy was attempted with splints and bandages and failed to result in improvement. Surgical intervention was elected and a bilateral distal radial epiphysectomy and pancarpal arthrodesis performed. Fourteen months later the mare was turned out to pasture and ambulating well.     

家兔骨骼肌肌球蛋白重链构成的电泳

[目的]探究家兔骨骼肌肌球蛋白重链构成的电泳的作用机制。[方法]应用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)检测成年家兔后肢肌胫前肌、腓肠肌和比目鱼肌的肌球蛋白重链异构体(MyHCs),采用大体解剖法依次取出家兔的每块骨骼肌,分别与样品缓冲液一起研磨成肌细胞匀浆,经高速冷冻离心后取出上清液,按照不连续SDS-聚丙烯酰胺小孔梯度凝胶电泳操作程序依次试验。[结论]该研究进一步证实3种快纤维型在成年啮齿动物肢体肌肉中的作用,但同源结构是否有这些肌纤维值得继续深入探索。     

猪肌肉组织双向电泳分离条件的建立及常见问题分析

为建立和优化猪肌肉组织蛋白质双向电泳技术,从提取方法、加样量、IPG胶条的选择、SDS-PAGE胶浓度、染色方法等多个方面对双向电泳分离效果进行比较研究.结果显示,液氮研磨+超声破碎法提取猪肌肉组织蛋白效果优于液氮研磨法,前者细胞破碎彻底蛋白质溶解性好且核酸污染少,图谱质量较好;18cm pH 4～7的IPG胶条分离效果比pH 3～10非线性IPG胶条好;对于银染,18 cm pH 4～7的IPG胶条150μg上样量比较适宜;同一肌肉样品的三块胶的重复性可达70％以上;同时,对双向电泳过程中的典型问题作了详尽分析.研究结果表明,通过优化的双向电泳条件获得了较高分辨率和较好重复性的猪肌肉组织双向电泳图谱,可用于后续蛋白质组学分析.     

槟榔不同部位水提液对小鼠生理指标的影响

本试验旨在探索槟榔鲜果不同部位水提液对小鼠生理指标的影响,试验分别选用4周龄和7周龄SPF级KM小鼠,体重分别为（18±2）g和（35±2）g,将48只4周龄小鼠随机分成4组,雌雄各半,4组分别采用槟榔鲜果果皮、果仁和全槟榔水提液及蒸馏水（对照组,CK）对小鼠灌胃,每天1次,连续14 d,测定小鼠的存活率、采食量、饮水量和体温。将36只7周龄雄鼠随机分为4组,灌胃方法同上,测定小鼠精子畸形率。结果表明,果仁处理组的小鼠在试验的第6天全部死亡,其它处理组均无死亡;与CK组相比,各槟榔处理组小鼠的采食量和饮水量均减少,其中果仁处理组最低且与其它处理组差异显著（P<0.05）,全槟榔组次之;各槟榔处理组小鼠的体温均低于CK组,其中果皮处理组体温变化最小并与CK组相似（P>0.05）,果仁处理组小鼠体温最低且与其它处理组差异显著（P<0.05）;与CK组相比,各槟榔处理组的小鼠精子畸形率均提高,其中果仁处理组的精子畸形率最高（P<0.01）,其次是全槟榔处理组（P<0.01）,然后是果皮处理组（P<0.05）,同时3个槟榔处理组间差异亦达极显著（P<0.01）。本试验结果说明槟榔鲜果果仁水提液对小鼠产生的影响最大,其次是全槟榔水提液,果皮水提液对小鼠影响较小。