温度对奥尼罗非鱼受精卵孵化和仔鱼活力的影响

研究了温度对奥尼罗非鱼(Oreochromis niloticus×O.aureus)受精卵孵化和仔鱼活力的影响。在盐度为5不同温度(22、24、26、28、30、32和34℃)下,比较观察奥尼罗非鱼受精卵的培育周期、孵化周期、孵化率和畸形率。同时在以上不同温度条件下对初孵的奥尼罗非鱼仔鱼进行耐饥饿试验,测定其不投饵存活系数(Survivalactivity index,SAI)。结果表明:在温度为24~32℃,受精卵孵化率较高(84.3%~91%),温度高于34℃和低于22℃时,孵化率较低。温度与培育周期呈负相关关系,函数关系为y=0.3607x2-26.836x+553.5,R2=0.973。仔鱼生存适宜温度是24~30℃,最适的温度是24~26℃。温度为22℃时,SAI值分别为19.9,但是仔鱼发育的缓慢,部分仔鱼的身体色素一直没有出现,不适合仔鱼的培育。     

番茄裂果与果皮结构的关系及其杂种优势表现

以4份抗裂番茄为母本,3份易裂番茄和1份抗裂番茄为父本,按照不完全双列杂交设计配制4×4的杂交组合,研究8个亲本和16个F1的裂果特性与果皮结构的关系,分析它们的杂种优势表现.结果表明,易裂基因型的果皮较薄,抗裂基因型的果皮普遍较厚,但也有果皮薄而抗裂能力强的基因型.裂果特性有明显的杂种优势,优势的方向在不同组合间有很大的差异.亲本的一般配合力对杂种后代的抗裂时间发挥了决定性作用.对利用结构特征改良番茄抗裂能力的潜力进行了讨论.     

Re-evaluation of total sulphur amino acid requirement and determination of replacement value of cystine for methionine in semi-purified diets of juvenile Nile tilapia, Oreochromis niloticus

Two feeding experiments were conducted to re-evaluate the total sulphur amino acid (TSAA; methionine and cystine) requirement and determine the replacement value of cystine for methionine of juvenile Nile tilapia ( Oreochromis niloticus ). Semi-purified diets used in both experiments contained 3510 kcal gross energy and 280 g of protein per kilogram diet from casein, gelatin and crystalline amino acids. The basal diet of the first experiment contained 3.1 g methionine and 0.4 g cystine per kilogram. l -methionine was added to the seven remaining diets at 1.0 g kg⁻¹ increment to produce methionine levels ranging from 3.1 to 10.1 g kg⁻¹ diet. Each diet was fed to four replicate groups of juvenile Nile tilapia (1.28 g mean weight) in a recirculation system for 8 weeks. Broken-line regression analysis of weight gain data indicated that the TSAA requirement of juvenile Nile tilapia was 8.5 g kg⁻¹ of the diet or 30.4 g kg⁻¹ of dietary protein. In the second experiment, TSAA level was set at 95% of the requirement value determined in the first experiment. Seven diets were made with different ratios of l -methionine and l -cystine (20 : 80, 30 : 70, 40 : 60, 50 : 50, 60 : 40, 70 : 30 and 80 : 20, based on an equimolar sulphur basis). Each diet was also fed to four replicate groups of juvenile Nile tilapia (4.14 g mean weight) in a recirculation system for 8 weeks. Regression analysis of weight gain data using broken-line model indicated that cystine (on a molar sulphur basis) could replace up to 49% of methionine requirement in semi-purified diets for juvenile Nile tilapia.     

Effects of all‐male,mixed‐sex and all‐female freshwater prawn in polyculture with major carps and molas in the fallow rice fields

This study was conducted to evaluate the effects of all‐male, mixed‐sex and all‐female freshwater prawn (Macrobrachium rosenbergii) in a polyculture with major carps (Catla catla and Labeo rohita) and self‐recruiting small fish molas (Amblypharyngodon mola) in the fallow rice fields of Bangladesh. There were three treatments with three replicates. All ponds were stocked with carps and molas plus either all‐male prawns (treatment MP), mixed‐sex prawns (MFP) or all‐female prawns (FP). Prawn, mola, catla and rohu were stocked 20 000, 20 000, 1750 and 750 ha^?1, respectively, in all treatments. The prawns were fed twice daily, starting at 8% body weight and gradually reduced to 3% body weight. The fish were fed in the morning with mustard oil cake and rice bran (1:2 ratios) at 3% body weight. Significantly higher production of prawns (697 kg ha^?1) was obtained in treatment MP, which yielded 34.7% and 56.2% more production than MFP and FP respectively. Significantly higher total production of 1620 kg ha^?1 and a higher benefit–cost ratio of 2.10:1 were also obtained in treatment MP. It can be concluded that an all‐male prawn culture is economically more viable than all‐female and mixed‐sex prawn cultures, along with other fish like major carps and the nutrient‐dense molas in the polyculture.     

桔皮提取物抑制霉菌试验

试验选用乙醚，丙酮，乙醇３种溶剂提取桔皮中有效成分，分别制成６０％的乳剂，用灭菌蒸馏水稀释成不同浓度梯度，加入培养其中进行抑制霉菌试验。     

Influence of dietary l-carnitine on growth, biological traits and meat quality in Tilapia

This study was designed to determine whether l -carnitine supplementation is necessary in a tilapia diet containing low-fish meal and a high lipid level, which is beneficial economically and for the environment. The effects of dietary l -carnitine on the growth, body composition, blood traits and post-thaw drip from muscle in hybrid tilapia were investigated. Five isonitrogenous and isocaloric diets were fed to the fish with a mean body weight of 141.7 g for 168 days. The control diet contained fish meal as the major protein source with 7% lipid. Other diets contained 7% or 12% lipid, in which fish meal was largely replaced by plant proteins, and supplemented with l -carnitine or not. Results showed that supplemental dietary l -carnitine did not affect the growth performance, feed efficiency or protein efficiency ratio, while the supplementation significantly reduced the mesenteric fat ratio. Whole body and muscle proximate compositions were unaltered by any dietary treatment. The total plasma lipid, triacylglycerol and cholesterol values of tilapia fed diets with alternative plant proteins were significantly lower than those of the control fish, whereas increasing the dietary lipid content increased the aforementioned blood traits. A decrease in plasma ammonia and an increase in urea were observed in dietary l -carnitine-supplemented fish. Post-thaw drip from muscle was reduced in fish fed supplemental dietary l -carnitine. The observations of this study revealed that neither the growth performance nor the feed utilization of hybrid tilapia was improved by a dietary l -carnitine treatment, but that it did lead to a reduced mesenteric fat ratio, altered nitrogen metabolism and improved meat quality.     

Fluorescence localization of epidermal cathepsins L and B in the Japanese eel

Histochemical localization of proteolytic activities in the dorsal epidermis of Japanese eel was demonstrated by fluorescent microscopy utilizing 4-methoxy-2-naphthylamide (4M$\beta$NA) derivatives as substrates and 5-nitrosalicylaldehyde as a trapping agent. Carbobenzoxy-L-phenylalanyl-L-arginyl-4M$\beta$NA (Cbz-Phe-Arg-4M$\beta$NA) and Cbz-Arg-Arg-4M$\beta$NA were used for direct detection of cathepsins L and B activities, respectively, in fresh frozen sections and unfixed cells of the eel epidermis. The fluorescing areas, where Cbz-Phe-Arg-4M$\beta$NA was hydrolyzed by cathepsin L, were shown in mucus secretory cells and club cells and broadly around skin surface. The fluorescing areas due to Cbz-Arg-Arg-4M$\beta$NA hydrolysis by cathepsin B were localized similarly in these tissues. The fluorescing intensity for both catheptic activities in mucus secretory cells was higher than that in club cells, where small fluorescing granules were distributed. These results indicate that eel cathepsins L and B are stored in epidermal secretory cells at different levels and probably serve as defense factors before or after secretion by these cells. Abbreviations: Cbz – carbobenzoxy; 4M$\beta$NA – 4-methoxy-2-naphthylamide; NSA – 5-nitrosalicylaldehyde.     

罗非鱼活性肽分离及抗氧化能力研究

利用正交试验L9(34),以清除超氧自由基能力为指标,分别对木瓜蛋白酶、中性蛋白酶水解罗非鱼肉的水解条件进行优化,并对最佳清除率下的两种酶解物进行Sephadex G-50凝胶柱分离,检测了各组分对超氧自由基清除率及活性肽分子量分布情况.结果表明:中性蛋白酶在45 ℃、酶的质量分数2.0%、水解105 min及肉水比1∶3的水解条件下对超氧自由基有较好清除作用;木瓜蛋白酶在60 ℃、酶的质量分数2.0%、时间150 min及肉水比1∶2的水解条件下对超氧自由基有较好清除效果.木瓜蛋白酶酶解物在分子量为660 Da的多肽洗脱峰具有最大超氧自由基清除率,中性蛋白酶酶产物在分子量为1320 Da多肽洗脱峰具有最大超氧自由基清除率.     

Advances in wound healing in small animal practice: current status and lines of development

Abstract In the past 5 years advances in the management of wounds in dogs and cats have included the development of materials and techniques used to enhance the healing of both open and closed wounds. New topical and locally injected medications as well as new bandaging materials have been evaluated. The use of omental flaps to enhance wound healing has been found to be promising. Ultrasonography has been found useful in assessing wound tissues to guide treatment. Because tension is a major factor in dealing with wound closure, skin expanders, skin stretchers, presutures and adjustable horizontal mattress sutures have been described as means of overcoming tension. Recently completed research projects at the Scott-Ritchey Research Center studied the woundhealing effects of fibrin sealants, topical bovine collagen, omega-3 fatty acid-enriched diets and magnetic field therapy. Projects underway are evaluating the healing effects of a new biological tissue adhesive, a macrophage stimulant and a thromboxane synthestase inhibitor. Parameters for evaluating wound healing have included histopathology, tensiometry, planimetry, laser Doppler image scanning, biochemistry and immunohistochemistry. Resumen En los últimos 5 años, algunos de los avances en la curación de heridas en perros y gatos ha incluido el desarrollo de materiales y técnicas utilizados para mejorar la curación tanto de heridas cerradas como abiertas. Se han evaluado nuevas medicaciones tópicas y sistémicas asi como nuevos marteriales de vendaje. El us0 de injertos omentales para estimular la curación de heridas ha mostrado resultados prometedores. La ecografia es un método éutil en la valoración de los tejidos lesionados para guiar el tratamiento. Debido a que la tensión es un factor importante en el caso de cerramiento de heridas, se describen como métodos de evitar la tensión productos como expansores cutáneos, estiradores cutáneos, presuturas y suturas cutáneas horizontales acolchonadas ajustables. Algunos proyectos de investigación recientemente finalizados en el Centro de Investigación Scott-Ritchey estudiaron los efectos sobre la curación de heridas de selladores de fibrina, colágeno tópico bovino, dietas enriquecidas con ácido graso omega-3 y terapia de campo magnético. Otros proyectos en realización están evaluando los efectos curativos de un nuevo adhesivo tisular biológico, un estimulante de macrófagos y un inhibidor de la tromboxano-sintetasa. Los parámetros para evaluar la curación de herida han incluido la histopatología, la tensiometría, la planimetría, el scanner por imágen doppler laser, bioquímica e inmunohistoquímica. [Swaim, S.F. Advances in wound healing in small animal practice: current status and lines of development (Avances en la curcion de heridas en pequeños animales: estado actual y lineas de desarrollo). Veterinary Dermatology 1997; 8 : 249–257] Zusammenfassung In den letzten 5 Jahren wurden Fortschritte in der Wundversorgung bei Hund und Katze unter anderem durch die Entwicklung von Materialien und Techniken erzielt, die zur besseren Heilung von offenen und geschlossenen Wunden verwendet werden. Neue lokale und systemische Medikamente sowie neue Verbandsmaterialien wurden untersucht. Die Verwendung von Omentumlappen zur Verbesserung der Wundheilung scheint vielversprechend zu sein. Ultraschalluntersuchungen waren von Nutzen, um Wundgewebe zu beurteilen und die Behandlung zu lenken. Spannung ist ein wesentlicher Faktor im Wundverschluss, Hautexpander, Hautdehner, vorbereitende Nähte und regulierbare, horizontale Matratzennähte wurden zur Überwindung der Wundspannung beschrieben. Kürzlich fertiggestellte Forschungsprojekte am Scott-Ritchie Research Center erforschten die Effekte von Fibrindichtungsmitteln, lokalem bovinen Kollagen, Futtermitteln mit Omega-3 Fettsäurenzusatz und Magnetfeldtherapie. Gegenwärtige Forschungsprojekte bewerten die Heilungseffekte eines neuen, biologischen Gewebehaftmittels, eines Makrophagenstimulans und eines Thromboxansynthetasehemmers. Parameter zur Bewertung der Wundheilung waren Histopathologie, Tensiometrie, Planimetrie, Laser Doppler, physiologische Chemie und Immunhistochemie. [Swaim, S.F. Advances in wound healing in small animal practice: current status and lines of development (Fortschritte bei der Wundheilung in der Kleintierpraxis: Derzeitiger Stand und Entwicklung). Veterinary Dermatology 1997; 8: 249–257] Résumé Durant les 5 dernières années, le progrés dans le traitement des plaies chez les chiens et les chats ont inclus le développement de matériaux et de techniques utilisés pour augmenter la cicatrisation des plaies ouvertes et fermées. De nouvelles médications topiques et systémiques ainsi que de nouveaux matériaux de bandages ont étéévalués. L'utilisation de lambeaux d'éplipon s'est révélée prometteuse dans l'amélioration de la cicatrisation des plaies. L'ultrasonographie s'est montrée utile dans le traitement de guidance de l'évaluation des plaies tissulaires. La tension étant un facteur major lors de la fermeture de plaies, expansseurs cutanés, étireurs cutanés et surjets de matelassier ajustables ont tous été décrits comme moyens permettant de vaincre la tension. Récemment des projets de recherche achevés au Scott-Ritchey Research Center ont étudiés les effets des joints de fibrine, du collagène bovin topique, des régimes enrichis en acides gras omega-3 et de la thérapies de champs magnétiques sur la cicatrisation des plaies. Les projets mis en route sont l'évaluation des effets sur la cicatrisation d'un nouvel adhésif tissulaire biologique, d'un stimulant de macrophages et d'un nouvel inhibiteur de la thromboxane synthase. Les paramètres intervenant dans l'évaluation de la cicatrisation des plaies ont inclus l'histopathologie, la tensiométrie, la planimétrie, le laser Doppler, l'imagerie, la biochimie et l'immunohistochimie. [Swaim, S.F. Advances in wound healing in small animal practice: current status and lines of development (Progres de la cicatrisation en pratique des petits animaux: etat actuel et lignes de developpement). Veterinary Dermatology 1997; 8 : 249–257]     

Malassezia dermatitis in the dog: a retrospective histopathological and immunopathological study of 86 cases (1990–95)

A retrospective histopathological and immunopathological study was conducted on 86 dogs with Malassezia dermatitis. West Highland White terriers, English Setters, Shih Tzus, Basset Hounds, American Cocker Spaniels, spayed females, and castrated males were found to be at increased risk. The histopathological reaction pattern of lymphocytic superficial perivascular to interstitial dermatitis with parakeratotic hyperkeratosis, irregular epidermal hyperplasia, diffuse intercellular oedema and lymphocytic exocytosis was found to be consistent with a diagnosis of Malassezia dermatitis whether yeast were histologically visible (73.3% of the cases) or not (26.7%). Immunopathological studies revealed that 60– > 90% of the inflammatory cells within the epidermis, and 25–75% of those within the dermis were CD3+T lymphocytes, and that the only immunoglobulin-positive cells were dermal plasma cells.