Inhibition of histamine release from dispersed canine skin mast cells by cyclosporin A, rolipram and salbutamol, but not by dexamethasone or sodium cromoglycate

Despite the important role that canine skin mast cells play in IgE-mediated allergic inflammation, clinically useful compounds for modulating mediator release from these cells or for suppressing cell response are lacking in the dog. The ability of five compounds to inhibit histamine release induced by non immunological (calcium ionophore A23187 and substance P) and IgE-dependent (concanavalin A) stimuli were compared. Sodium cromoglycate, a mast cell stabilizer, and dexamethasone, a glucocorticoid, failed to inhibit histamine release from isolated skin mast cells following any kind of stimulation. Salbutamol, a β-adrenergic agonist, exhibited inhibitory activity (46.0%) only after concanavalin A activation. In contrast, rolipram, a selective phosphodiesterase IV inhibitor and cyclosporin A, an immunosuppressor, showed potent anti allergic actions, inhibiting both IgE-dependent and -independent stimuli. Rolipram inhibited 42.8%, 44.7% and 19.2% of the mediator release induced by ionophore A23187, substance P and concanavalin A, respectively. Similarly cyclosporin A induced 85.9%, 14.9% and 67.3% inhibition after ionophore A23187, substance P and concanavalin A stimulation, respectively. These results suggest that rolipram and cyclosporin A merit to be clinically tested as agents for the treatment of chronic allergic diseases in the dog.     

Influence of terminal rig configuration on the anatomical hooking location of line-caught yellowfin bream, Acanthopagrus australis

Abstract  Experiments were carried out to test the dependence of anatomical hooking location on terminal rig configuration, and identify strategies by which hook ingestion can be minimised to reduce post-release mortality of angled yellowfin bream, Acanthopagrus australis (Günther). Eighty-five anglers targeted yellowfin bream using different designs and sizes of circle and J hooks and recorded technical, environmental and biological data for each landed fish. Considerably fewer fish (16.6 and 8.5%, respectively) ingested hooks than those hooked in the mouth (82.1 and 88.6%), and a greater percentage of J hooks were ingested than circle hooks or a J hook modified with a 15-mm horizontal bar. Irrespective of hook type, the rate of ingestion also declined with increasing hook weight and decreasing fish size. In cage experiments, significantly more hooks baited with natural soft baits (e.g. intestines and cephalopods) were ingested than those baited with artificial baits, crustaceans or teleosts, while in the field fewer hooks were ingested using artificial bait (e.g. bread and pellets) than terrestrial animals, teleosts, crustaceans, teleost or terrestrial animal intestines, cephalopods or polychaetes. Similarly, rigs with floats, short traces or a sinker only on the hook, along with angling in environments with at least some current reduced ingestion. Based on this study, anglers targeting yellowfin bream should be encouraged to use circle or modified J hooks and, regardless of the hook design, the largest hook size possible attached to short traces or a sinker only and hard baits.     

持续日变高温对肉鸡矿物质代谢的影响

为研究持续日变高温环境对肉仔鸡矿物质代谢的影响,选用体重接近的20只肉仔鸡,随机分为两组,另选体重接近的4只肉仔鸡,施人工肛门手术。试验组持续日变高温环境设为25～35℃,其中每日35℃持续3h。对照组为20℃恒温。在人工气候舱内适应8d后,每只鸡收集3d尿和总排泄物,并对其中矿物质排出量进行测量,分别对试验前及试验结束时血液中矿物质浓度进行测量。结果表明:持续日变高温使肉仔鸡血清中K浓度显著下降,Zn浓度上升,其它矿物质元素浓度无显著变化,在限饲相同进食量情况下,热应激使K、P、Mg、Na和Co的排出量明显低于对照组,而其它矿物元素排出量与对照组无显著差异,尿中矿物质浓度无显著变化。     

氧氟沙星缓释药栓的研制及体外药物释放实验研究

研究可植入眼内的氧氟沙星缓药栓的体外药物缓释过程和效果。方法：将分子量各为６１２０和１２５５０的聚乳酸分别混载５％和１０％氧氟沙星制成药栓，并体外药物释放以及高效液相色谱法药物浓度测定。结果３０ｄ内氧氟沙星体外释放率为７０％－９０％，释药时间与滞物分子量呈正相关，结论：由氧氟沙星和聚乳酸制成的缓释药栓满足眼内炎治疗的基本要求。     

低甲醛释放脲醛树脂研究进展

从脲醛树脂胶粘剂的合成工艺、使用时加入添加剂、人造板的后处理等几个方面,综述了近几年来脲醛树脂及其胶接制品降低甲醛释放研究的新进展。     

微囊化沙门菌SP4噬菌体的制备及其缓释特性分析

通过采用阳离子醚化淀粉/海藻酸钠/黄原胶/纳米TiO₂/壳寡糖为原料制备微囊化SP4噬菌体,为控制沙门菌感染提供生物制剂。选用沙门菌SP4噬菌体,采用液滴法来制备微囊化SP4噬菌体,并对其效价、阳离子醚化淀粉浓度、海藻酸钠浓度、黄原胶浓度、壳寡糖浓度、pH稳定性、热稳定性、模拟胃液稳定性、模拟肠液释放行为以及保存稳定性进行分析。结果显示,当阳离子醚化淀粉浓度为2.4%、海藻酸钠浓度为2%、黄原胶浓度为1%、壳寡糖浓度为0.6%时,微囊化SP4噬菌体微球外形规则,包封率为97.5%,在pH5.0~8.0、温度10~30℃、模拟胃液pH2.0、0~30 min和pH3.0、0~150 min噬菌体保持较高的生物学活性,模拟肠液中4 h,噬菌体完全释放,4℃环境下保存6周噬菌体效价无明显降低。综上表明,微囊化沙门菌SP4噬菌体显著提高了噬菌体的稳定性和缓释性能,其耐酸特性利于抵御胃酸的分解,具有应用于生物防治的潜力,为进一步采用多因素试验制备微囊化沙门菌SP4噬菌体奠定了基础。     

E_1级麻屑板用脲醛树脂胶的研究

根据亚麻屑的胶接特性,从脲醛胶的固体含量、粘度、游离甲醛、耐水性、固化时间、施工胶液特性及经济效益等方面系统地研究了适合低甲醛释放量麻屑板生产用脲醛树脂胶的物理力学及化学性能。研究结果表明,使用改进的脲醛树脂胶(命名为DN—9号和DN—11号低毒腮醛胶)可以压制出甲醛释放量小于10mg/100g的E1级麻屑板,其物理力学性能达到GB 4896—4905—35标准     

Leaf-litter decomposition of 15 tree species in a lowland tropical rain forest in Sarawak: dynamics of carbon,nutrients, and organic constituents

The effects of tree species on the dynamics of nutrient transformations during leaf-litter decomposition are not well understood in tropical rain forests. To examine differences in the dynamics of C, nutrients, and organic constituents during decomposition among tree species, the leaf-litter decomposition of 15 trees was assessed using a litter-bag method in a lowland tropical rain forest in Sarawak. The dynamics of C was parallel to that of weight loss. The dynamics of nutrients were grouped into three patterns. The dynamics of K was characterized by a high leaching loss in the initial stages, and that of Ca and Mg generally showed a gradual decrease over the course of decomposition. The dynamics of N and P showed highly different patterns with the weight loss, and was characterized by relatively higher remaining mass at the end of the experiment. The variations or exceptions of nutrient dynamics among tree species were considered to be related to the initial concentration of each nutrient. For the dynamics of organic constituents, water-soluble carbohydrates disappeared quickly at the initial stages, and acid-soluble carbohydrates were the second fastest decomposing fraction; the decomposition of acid-insoluble residue (AIS) was the slowest. The release of limiting nutrients (N and P) generally followed the disappearance of AIS, but was independent of the disappearance of AIS when the initial concentrations of these nutrients were very low.     

人造板游离甲醛释放量测定的主要影响因素的研究

试验表明，人造板在存放过程中，板材的游离甲醛释放量逐渐下降并趋于稳定。在测定中的萃取时间、样品大小、甲苯的重复使用对测定结果都有一定的影响。     

Growth and nutritional responses of bareroot Jeffrey pine on a Sierra Nevada surface mine to minisite applications of fertilizer and lime

The effects of two controlled release fertilizers, Forestcote 22-4-6 + Minors and Dry Site 21-6-2 + Minors, and also dolomitic lime, on growth and nutrition of bareroot Jeffrey pine (Pinus jeffreyi Grev. & Balf.) were investigated. Forestcote, which consists of loose prills, and Dry Site, consisting of prepackaged prills, were administered with two rates, while a single liming rate was used. An acidic Sierra Nevada surface mine provided the study site, and all amendments were applied at outplanting to the backfill of augered planting holes. Without impacting survival, both fertilizer formulations enhanced seedling growth, particularly at a 16 g rather than an 8 g application rate, although Forestcote was marginally more effective in this regard. In contrast, liming at a 27 g rate induced severe mortality and offset much of the growth gains resulting from fertilization. Improvements in N and P nutrition, as revealed by foliar analysis, probably accounted for much of the growth stimulation exhibited by fertilized seedlings, but reductions in the uptake of potentially phytotoxic trace elements such as Mn and Al and increases in base cation/metallic element ratios likely also contributed. The high application rate was generally preeminent in eliciting these nutritional responses. Liming induced little alteration of seedling nutrition. Impaired water relations may have caused the unfavorable responses to this treatment.