哈维氏弧菌Y91301菌株培养工艺的研究

用大黄鱼分离的哈维氏弧菌Y91301进行试验,研究接种浓度、培养瓶装液量、起始pH值、培养时间、培养温度和培养液配方等因素对菌株生长的影响,确定静置培养时最适条件为:接种母液浓度1×108～1×109cfu ml,接种量6%～8%(相对培养瓶装液量),装液量40～50ml 250ml,培养液初始pH值为6 0～6 5,培养温度28℃;使用Zobell2216E培养配方更适合大量培养和生产的需要;旋转培养能够获得更高的生物量。     

磷对坛紫菜孢子囊枝形成的影响

主要研究了不同浓度、不同形式的磷源（磷酸二氢钾、磷酸氢二钾和甘油磷酸钠）对坛紫菜（Porphyra haitanensis）孢子囊枝形成的影响，以及丝状体对磷的利用情况。结果表明，氮磷比在2／1左右时有利于孢子囊枝形成；无机磷酸盐比有机磷酸盐更能促进坛紫菜孢子囊枝形成；当N，P为10／1、7／1和2／1时，磷吸收速率随该比值下降而上升；磷起始浓度过高不利于丝状体的生长发育，有规律地适量添加磷盐有利于坛紫菜孢子囊枝的形成。     

我国对虾养殖生产现状及展望

本文阐述了我国对虾养殖生产的基本情况及对虾养殖生产面临的潜在威胁。从科研,生产和销售三个方面提出了一些急待解决的问题和对策,并对我国养虾业发展的前途做了展望。     

Relationship between rate of infection and markers of inflammation/immunity in Holy Birman cats with feline coronavirus

The aim of this study was to assess whether Holy Birman cats (HB) have a peculiar immune profile and a higher rate of infection by feline coronaviruses (FCoV). Leucocyte and lymphocyte subsets, antibody titers, α₁-acid glycoprotein (AGP), globulin fractions, IL-4, IL-12 and IFN-γ in blood and fecal FCoV excretion were determined in HB (n = 75) and in cats from other breeds (n = 94). Significantly higher CD4/CD8 ratio, IFN-γ concentration and IL12/IL4 ratio and significantly lower IL-4 concentration and proportion of shedders were found in HB than in other breeds. No other differences were found. In conclusion, this study did not provide evidence of peculiar immune profiles in HB, except for a prevalent Th1 profile, that may explain why in our caseload the rate of shedders was lower in HB than in other breeds.     

The use of antibiotics on small dairy farms in rural Peru

Very little is known about the use of antibiotics on small dairy farms in lower/middle-income countries. The use of these drugs can have profound impacts on animal health, farmer income and public health. A survey of 156 farmers was conducted in Cajamarca, a major dairy-producing center in the highlands of Peru characterized by small farms (<15 cows) to assess patterns and determinants of antibiotic use and farmers’ knowledge of antibiotics. The reported incidence of disease on these farms was relatively low (0.571 episodes of disease per cow-year), but more than 83% of the reported episodes were treated with antibiotics. The most commonly used antibiotics were oxytetracycline, penicillin and trimethoprim-sulfamethoxazole drugs; antiparasitic drugs were also used to treat what were likely bacterial infections. An increased incidence of treated disease was significantly associated with smaller farm size, lower farmer income, the previous use of the Californian Mastitis test on the farm and antibiotic knowledge. Farmers’ knowledge of antibiotics was assessed with a series of questions on antibiotics, resulting in a “knowledge score”. Increased knowledge was significantly associated with the use of antibiotics for preventative reasons, the purchase of antibiotics from feed-stores, the experience of complications in animals after having administered antibiotics, the number of workers on the farm and the educational level of the farmer. Overall, antibiotics appeared to be used infrequently, most likely because therapeutic interventions were sought only when the animal had reached an advanced stage of clinical disease. Few farmers were able to define an antibiotic, but many farmers understood that the use of antibiotics carried inherent risks to their animals and potentially to the consumers of dairy products from treated animals. The results of this study are useful for understanding the patterns of antibiotic use and associated management, demographic and knowledge factors of farmers on small dairy farms in rural Peru.     

Murine xenograft model demonstrates significant radio-sensitising effect of liposomal doxorubicin in a combination therapy for Feline Injection Site Sarcoma

Therapy of cats suffering from feline injection site sarcomas (FISS) is still a challenging problem, as the recurrence rate after surgery is up to 70%. Four FISS-derived primary tumour cell lines and corresponding xenograft tumour mouse models were established to evaluate the efficacy of a concomitant chemo-/radiation therapy with doxorubicin. In vitro, strongly depending upon the timing of administration, pre-treatment with 0.25 µmol doxorubicin resulted in a significant enhancement of radiation-induced (3.5 Gy) tumour cell death. This result was confirmed in vivo, where only the combined chemo-/radiation therapy resulted in a significant reduction in tumour growth compared to the respective mono-therapies with either doxorubicin or radiation. These results support the use of the concomitant chemo-/radiation therapy for adjuvant treatment of FISS, particularly in advanced or recurrent disease where surgery alone is no longer feasible.     

New method using quantitative PCR to follow the tick blood meal and to assess the anti-feeding effect of topical acaricide against Rhipicephalus sanguineus on dogs

A 28-day study was conducted to assess the dynamic of blood feeding by Rhipicephalus sanguineus ticks on dogs treated or not with a novel topical combination of fipronil, amitraz and (S)-methoprene. Dogs were infested weekly through exposure to ticks in crates for 4 h. Ticks were then counted in the crates at 2 h and 4 h post dog exposure. Ticks were also counted and removed from the dogs at 2 h, 4 h, 6 h, 12 h and 24 h post tick exposure. The inhibition of blood feeding was assessed by both tick quantification and designing and performing a quantitative PCR (qPCR) to detect the canine hydroxymethylbilane synthase (HMBS) gene in ticks. The percentage of repellency sensu lato based on the ticks collected in crates at 2 h varied from 4.7% at day 28 to 48.3% at day 7. The immediate mortality rate of the ticks expelled at 2 h varied from 1.5% at day 21 to 31.7% at day 7. The efficacy calculation showed that the acaricidal combination started to kill ticks in as little as 2 h. The average efficacy reached 90.0% at 12 h post crate challenges and 100% at 24 h post exposure in crates. The inclusion of an internal amplification control was used to ensure that no significant template-derived PCR inhibition (≤6.2%) affected the overall results. The reduction of blood feeding was significant at 4 h (>80.0%) and >99.0% at 24 h post tick exposure in the crate. The high repellency rate and the lethal efficacy of CERTIFECT^® resulted in significantly fewer live attached ticks, consequently reducing blood intake and fluid exchanges.     

Investigation of the Role of Androstenedione-19-oic Acid in the Presence of 19-Norandrostenedione in Intact Male Horse Plasma Using Liquid Chromatography–Tandem Mass Spectrometry

A liquid chromatography–tandem mass spectrometry method was developed to confirm the presence of androstenedione-19-oic acid in intact male equine plasma and to show the source of 19-norandrostenedione in equine plasma. Androstenedione-19-oic acid was recovered from acidified plasma by liquid–liquid extraction using methyl tert-butyl ether and separated on an Ace 5 C₈ column. A triple quadrupole mass spectrometer was used to detect the analytes in negative electrospray ionization mode. Limits of detection, quantification, and confirmation of the method were 0.1, 0.5, and 1.0 ng/mL, respectively. The linear dynamic range of quantification was 0.5–50 ng/mL. The presence of androstenedione-19-oic acid was confirmed in all plasma samples obtained from intact male horses but not those from gelded and female horses; the average concentration was 3.1 ± 1.6 ng/mL, suggesting androstenedione-19-oic acid is an endogenous compound only in intact male horse plasma samples. The conversion of androstenedione-19-oic acid to 19-norandrostenedione in equine plasma was demonstrated by spiking androstenedione-19-oic acid into blank plasma and monitoring the generation of 19-norandrostenedione and its increase in concentration during storage. Results indicated that androstenedione-19-oic acid was readily converted into 19-norandrostenedione; the higher the storage temperature, the faster the conversion. The conversion was not affected by the types of plasma samples collected from gelded and female horses or by anticoagulants used in blood collection to harvest plasma. Compared with other matrices such as water, methanol, and phosphate-buffered saline, the conversion of androstenedione-19-oic to 19-norandrostenedione in equine plasma was faster, suggesting that there is an unknown factor(s) in equine plasma that enhances the conversion.     

Prematurational Culture with 3-Isobutyl-1-methylxanthine Synchronizes Meiotic Progression of the Germinal Vesicle Stage and Improves Nuclear Maturation and Embryonic Development in In Vitro-grown Bovine Oocytes

The objective of this study was to clarify the effects of prematurational culture (pre-IVM) supplemented with 3-isobutyl-1-methylxanthine (IBMX) on nuclear and cytoplasmic maturation of in vitro-grown bovine oocytes. In experiment 1, oocytes (95 μm in diameter) derived from early antral follicles (0.5–1 mm in diameter) were cultured for 12 days for in vitro growth (IVG). IVG oocytes with a normal appearance were subjected to examinations of diameter and chromatin structure in the germinal vesicle (GV) before IVM. In addition, percentages of metaphase II (M II) were examined after IVM. Regardless of pre-IVM, the mean diameters of IVG oocytes were about 115 μm. The proportions of GV3 (50.0%) and M II stages (80.1%) of IVG oocytes with pre-IVM were higher than those without pre-IVM (28.0 and 49.4%, respectively). In experiment 2, the fertilizability and developmental competence of IVG oocytes were examined. Regardless of pre-IVM, the normal fertilization rates of IVG oocytes were similar (around 70%) but were lower than that of in vivo-grown oocytes (88.0%). Cleavage and blastocyst rates of IVG oocytes with pre-IVM (63.0 and 26.1%, respectively) were higher than those without pre-IVM (45.8 and 12.7%, respectively). The blastocyst rate based on cleaved IVG oocytes with pre-IVM (41.7%) was similar to that of in vivo-grown oocytes (48.7%), although the cleavage rate of IVG oocytes with pre-IVM was lower than that of in vivo-grown oocytes. In conclusion, pre-IVM with IBMX improved the maturational and developmental competences of IVG oocytes, probably due to promotion of their chromatin transition and synchronization of meiotic progression.     

Purified Culture Systems for Bovine Oviductal Stromal Cells

Isolated stromal cells from the ampullary and isthmic parts of bovine oviductal tissues were cultured in monolayer and spheroid (cell aggregate) systems. Prostaglandin F2α (PGF) plays a crucial role in oviductal contraction and is produced by oviductal epithelial cells in cattle. Since stromal cells of many organs produce PGF, PGF production by bovine oviductal stromal cells was investigated. After PGF synthesis was confirmed, the utility of isolation and culture methods for oviductal stromal cells was evaluated by PGF production in the present study. The homogeneity of the cells was > 99%. PGF production of the cells was increased by tumor necrosis factor-α. The stromal cells aggregated and formed a spheroid by the treatments with several reagents. PGF production was higher in the spheroid culture than in the monolayer culture. The isolation and culture methods described here will facilitate studies of the physiological function of bovine oviductal stromal cells.