Three new arylnaphthalene lignans from Schisandra propinqua var. sinensis

Three new arylnaphthalene lignans, named sinensisins A-C (1-3), together with three known compounds, were isolated from the aerial parts of Schisandra propinqua var. sinensis. Their structures were established by spectroscopic methods, and compound 1 exhibited weak anti-HIV-1 activity with an TI value of 6.7.     

Influence of dietary zinc and copper on digestive enzyme activity and intestinal morphology in weaned pigs

The current study was conducted to investigate the effects of high dietary concentrations of Zn as zinc oxide and Cu as copper sulfate on the activity of digestive enzymes in the pancreas and the intestinal mucosa, intestinal morphology, and mucin histochemistry in pigs after weaning. Thirty-two pigs were weaned at 4 wk of age. The pigs were fed standard weaning diets supplemented with Zn (100 or 2,500 ppm) and Cu (0 or 175 ppm) in a 2 x 2 factorial arrangement of treatments for a 14-d period. In pancreatic tissue, the activity of amylase, carboxypeptidase A, chymotrypsin, trypsin, and lipase increased (P < 0.01) in pigs fed 2,500 ppm of Zn, whereas the activity of carboxypeptidase B and carboxylester hydrolase was unaffected. Copper had no effect on the activity of pancreatic enzymes. In small intestinal contents, the total activity of amylase and carboxypeptidase A was greater in pigs fed 100 ppm of Zn (P < 0.05), whereas feeding 2,500 ppm of Zn increased the chymotrypsin activity (P < 0.001). The remaining enzymes were unaffected by dietary Zn concentration. The villi were longer in the cranial small intestine (P < 0.001) in pigs fed 100 ppm of Zn than in pigs fed 2,500 ppm of Zn, but otherwise there were no clear effects of Zn and Cu supplementation on intestinal morphology. In the cranial small intestine, the activity of maltase (P < 0.001), sucrase (P < 0.001), and lactase was greater in pigs fed 100 ppm of Zn, even though there was a Zn x Cu interaction (P < 0.05) in lactase activity. In the middle and caudal small intestine, no clear differences between dietary treatments were observed. The activity of gamma-glutamyl transpeptidase in the intestinal mucosa was not affected by dietary Zn or Cu. In pigs fed 100 ppm of Zn, the activity of aminopeptidase N was greater in the caudal small intestine, but dietary Zn or Cu had no effect on aminopeptidase N in the cranial and middle small intestine. No effect of dietary Zn or Cu supplementation was found on carbohydrate histochemistry in the caudal small intestine, whereas high dietary Zn increased the area of neutral, acidic, and sulfomucins in the cecum (P < 0.01) and in the colon (P < 0.001). In summary, high dietary Zn increased the activity of several enzymes in the pancreatic tissue and increased the mucin staining area in the large intestine, whereas Cu had no clear effect on these variables. However, no definite answers were found as to how the growth promoting and diarrhea reducing effects of excess dietary Zn are exerted.     

Molecular and biological characterization of a naturally occurring recombinant subgroup B avian leukosis virus with a subgroup J-like long terminal repeat

Infection of broiler chickens with subgroup J avian leukosis virus (ALV) results in the induction of myeloid tumors. However, although egg-type chickens are susceptible to infection with ALV-J, the tumor incidence is very low, and on rare occasions the tumors observed are of the myeloid lineage. We recently described the isolation of an ALV (AF115-4) from commercial egg-type chickens suffering from myeloid leukosis. AF115-4 was initially identified as an ALV-J isolate based on PCR analysis of the long terminal repeat (LTR). However, further characterization of the viral envelope indicated that the virus is recombinant with subgroups B envelope and J LTR. Here we further characterize this recombinant virus at both the molecular and biological levels. We show that the AF115-4 isolate expresses a recombinant envelope glycoprotein encoded by a subgroup B gp85 region and a subgroup E gp37 region. The host range ofAF115-4 was analyzed using cells resistant to infection by subgroups A/B, J, or E; this shows that no ALV-J was present in the isolates obtained from the affected chickens. Additional antigenic characterization of AF115-4 using chicken sera specific for subgroups B or J indicated that no ALV-J was present in the samples examined. Inoculation of AF 115-4 into ALV-susceptible 1515 X 71 chickens resulted in the induction of lymphoid leukosis but not the expected myeloid leukosis affecting the commercial chickens. These results suggest that differences in the genetic makeup of the chickens from which AF115-4 was isolated and the line 1515 X 71 used in the present experiments may be responsible for the observed differences in pathogenicity. In addition, the results suggest that ALV-J continues to evolve by recombination, generating new viruses with different pathological properties.     

Intracranial fat bodies and their potential effect on brain composition and behaviour in domestic ducks with feather crests (3 case studies)

Intracranial fat tissue was found in the brains of three crested ducks. The three ducks differed in the size of their crest and in the volume and the location of the fat body within their brains. The duck with the large crest showed a fat body which counts for 19 % of its brain volume. Due to this fat accumulation, brain structures, mainly the cerebellum, were moved laterally. This duck had serious problems in motor coordination. Fat body of the second duck with a middle sized crest was situated in neostriatum and constituted 0,6 % of total brain volume. Additionally this duck displayed an encephalocele. The last duck did show a small crest. Its fat body was found in the area of the tentorium cerebelli and made up 17 % of its brain volume. The later two ducks were not hampered behaviourally.     

In vitro binding capacity of zeolite A to calcium, phosphorus and magnesium in rumen fluid as influenced by changes in pH

An in vitro experiment was designed to mimic the transport of ingested zeolite A in the forestomachs and proximal part of the small intestine so as to evaluate the binding capacity of zeolite A to Ca, P and Mg as influenced by changes in pH. This was done by incubation of rumen fluid solutions with and without zeolite, as well as varying the content of Ca and/or P. The pH was lowered by addition of HCl so as to mimic abomasal conditions, followed by subsequent HCO3- addition to mimic small intestinal pH. Rumen fluid samples were taken at strategic time points in the experiment. All samples were centrifuged and the supernatant analysed for Ca, P and Mg as indicators of the amount of unbound mineral. The addition of zeolite to rumen fluid solutions reduced the amount of supernatant Ca and Mg at rumen pH, whereas the level of P was not reduced. After adding HCl, a large proportion of the zeolite-bound Ca and Mg was released, increasing supernatant Ca and Mg levels; whereas, HCl addition led to a profound drop in supernatant P in zeolite samples, indicating binding of P. A low level of supernatant P was maintained after HCO3- addition. Neutralization by HCO3- led to a zeolite-induced drop in supernatant Ca and Mg. The reduction in supernatant Ca observed in the present study concurs well with the theoretical rationale of prepartum zeolite supplementation in milk fever prevention. Furthermore, the apparent binding of P by the zeolite may also contribute because of the connection between the calcium and phosphorus homeostasis. The zeolite-induced reduction in supernatant Mg indicates that zeolite supplementation should probably be avoided in Mg-deficient herds unless Mg supplementation is initiated.     

绵羊腺病毒分离物RTS-42-5溶血性巴斯德氏菌相继实验感染羔羊的病理学

4组5至10日龄禁食初乳的羔羊,用于评价对绵羊腺病毒RTS—42株与5天后继之以溶血性巴斯德氏菌(1A型)感染的反应。A组(13头)羔羊以腺病毒与巴斯德氏菌相继感染,B组(4头)以RTS—42株感染继之以无菌肉汤注射,C组(4头)注射以无菌细胞培养液继之以巴斯德氏菌的肉汤培养物感染。D组(4头)以无菌细胞培养液与无菌肉汤相继注射,作为假感染对照。所有羔羊均用气管与鼻腔内接种,序贯地扑杀,以研究它们的形态学病变。 A组羔羊在病毒感染后第6、8、10、12、14天扑杀,肺的主要病变为支气管炎、细支气管炎与间质性肺炎。支气管炎与细支气管炎的特征是气道腔内渗出物里含有嗜酸粒细胞与少量中性粒细胞。间质性肺炎的特征为肺泡中隔增厚,这种增厚是由网状内皮细胞增生、嗜酸粒细胞与少量中性粒细胞和淋巴细胞浸润所引起。2例羔羊的间质性肺炎并发急性肺炎病灶,其中1例见到1个燕麦细胞(Oat-cell)灶。2例羔羊有胸膜炎,同时在气管周围有炎性渗出物。B组(病毒单独感染)羔羊肺里的主要病变为萎陷,并有一些肺泡中隔轻度增厚肺泡间插其间。在病毒单独感染的羔羊,既未见到支气管炎和肺炎,也未见到胸膜炎。C组(溶血性巴斯德氏菌单独感染)羔羊的肺形态学特征与A组羔羊者相似,但每例羔羊肺里都存在燕麦细胞灶,还存在于一些羔羊的鼻甲、纵膈淋巴结、肝和脾里。这些羔羊的胸膜炎(4例中有2例)也比A组羔羊多见。     

杜洛克猪生长和胴体性状的遗传参数 表型参数 选择指数的研究

本文对杜洛克猪的主要生长和胴体性状作了遗传、表型参数的研究。生长测定805头猪,胴体测定279头猪,结果表明前期(25—6c千克阶段)日增重596克,后期(60—90千克阶段)787克,全期平均668克,三个阶段的饲料利用率分别为2.57,3.27和2.91。宰前体重90千克时,屠宰率71.42％,胴体长79.22厘米,皮厚0.20厘米。平均膘厚1.85厘米,瘦肉率62.0％,眼肌面积31.26厘米~2,后腿率32.59％。遗传力估测为:三个阶段日增重分剐为0.32,0.48和0.29,屠宰率0.51,胴体长0.68,平均瞟厚0.53,瘦肉率0.61,眼肌面积0.31,后腿率0.57。利用本次估计的参数制订两个综合选择指数,选择指数1包括日增重、背膘厚和瘦肉率三个性状;指数2还包括饲料利用率性状。并对两个指数的选择效果进行了估计。     

Electronic Characterization of Solid Surfaces: Determination of the energy levels of electrons at surfaces is now possible over a wide energy range

At this point it would be presumptuous to suggest either that we understand very much about the electronic structure of solid surfaces or that we can specify in detail exactly what each of our tools for studying such structure is telling us. I think it is fair to say, however, that FES, UPS, and INS do make it possible for us to determine energy level spectra which can with some confidence be ascribed to the resonances of electrons in surface orbitals. It is true that INS is the more surface-selective of the two electron spectroscopies capable of producing data over at least a 10-ev energy range. We have seen intriguing differences between INS and UPS which, when we come to understand them, will most certainly reveal important characteristics of surface electronic structure and greatly expand our ability to distinguish electronic states in the surface from those in the selvedge. Possibly it is not too much to hope that the combined use of INS and UPS with incidence angle as an independent variable will give us information on the geometrical extent of surface orbitals, as well as the net electrical charge and the electric potential gradient in the region of the surface in which the orbitals lie.