Inhibition of in vitro lymphocyte blastogenesis by chicken alpha-fetoprotein

Chicken alpha-fetoprotein (ch-AFP), purified from fetal chicken serum and embryo extracts, respectively, was examined for its immunomodulatory effect in vitro. Significant (P less than 0.05) suppression of the allogeneic mixed lymphocyte reaction (MLR) was observed, when these preparations were added to one-way mixed lymphocyte cultures (MLC) in quantities of 62.5-1000 micrograms/ml. Suppression of the MLR was depending on the presence of ch-AFP for at least 16 h after initiation of the MLC, suggesting that this fetal protein was acting mainly in the early phase of lymphoblastogenesis. Serum of chicken embryos (12th and 15th day of incubation), day-old chickens, and of 10-week-old chickens of four different inbred lines were also found to exert suppression of the MLR. From these data, it is hypothesized that ch-AFP plays an immunoregulatory role by maintaining a certain stage of self tolerance during differentiation of the avian immune system.     

Influence of route of administration on the humoral response of channel catfish (Ictalurus punctatus) to Yersinia ruckeri

Channel catfish were inoculated intraperitoneally, intramuscularly, or intraesophageally with Yersinia ruckeri. Three antigen doses were administered by each route of injection. Four fish from each treatment were sacrificed at 5-day intervals for 40 days. Serum from each individual was tested for antibody activity against Y. ruckeri by indirect enzyme-linked immunosorbent assay (ELISA). High titers of anti-Y. ruckeri antibody were elicited by all doses (10(5) to 10(9) cells/g of fish) regardless of the route of administration. Mean titers for saline injected fish ranged up to 1:64 for each route of inoculation while mean titers for bacteria injected fish ranged up to 1:4096. Mean titers of 1:128 or greater were observed by day 15 post injection; titers peaked about day 30 and diminished thereafter. Channel catfish were most responsive to the antigen (10(7) to 10(9) cells/g of fish) when administered intramuscularly although lower doses (10(5) to 10(6) cells/g of fish) administered intraperitoneally elicited a substantial response. There was little evidence of dose-dependent responses for any of the routes of immunization. The rapid onset of relatively high serum titers suggests that the fish were mounting a secondary response to Yersinia ruckeri.     

GPV VP1-VP3非重叠序列重组原核表达多肽的应用研究

鹅细小病毒感染(Goose parvovirus infection,GPVI)俗称小鹅瘟(Gosling plague,GP)或Derzys's病,在世界养鹅国家持续不断,始终未能得到有效控制。其原因相当复杂,除了长期以来缺乏科学的免疫程序和安全的基因工程疫苗外,在一定程度上与缺乏有效的检测方法有关。GPV全毒苗在预防     

Muscle biopsy using the muscle punch--removal technique, transport and evaluation ability

Histopathological striated muscle examination is one of the most important and sensitive tests in diagnosis of muscle and/or nerve diseases. Although muscle biopsy is a relatively easy procedure, it is not frequently performed in small animal practice conditions. Different biopsy techniques have been described in veterinary literature. Punch biopsy of striated muscle appears to be a less invasive and quicker method in comparison with traditional surgical excision technique. Additionally, punch biopsy provide good quality and adequate amount of muscle tissue for diagnostic histopathological evaluation. The aim of this study is to describe striated muscle punch biopsy technique and to encourage use of it under the conditions of small animal practice. The described biopsy method can be specially advantageous in screening of inherited muscle diseases in affected litters or even wider animal population.     

Drought sensitivity,root development and osmotic adjustment in field grown peas

Summary In order to study the drought sensitivity of pea (Pisum sativum L. cv. Bodil) during different growth phases, a field experiment was conducted in 1985 and 1986 on coarse textured sandy soil with low water-holding capacity. Drought occurred naturally or was imposed by shelters during the vegetative, the flowering and the pod filling growth phase, respectively. Drought sensitivities were assessed as the ratio between relative yield decrease (1 – Y_a/Y_m) and relative evapotranspiration deficit (1 – ET_a/ET_m) of the individual growth phases, where Y_a and ET_a are the actual yield and evapotranspiration, respectively, of a drought stressed plot and Y_m and ET_m are the maximum yield and evapotranspiration of the fully irrigated treatment. Root growth was followed by measuring root density (L _v ) in 10 cm soil layers to a depth of 50 cm. The leaf osmotic potential at full hydration ( _s ¹⁰⁰ ) was measured in the last fully developed leaf during the growing season.The available water capacity was estimated to be 42–50 mm on the basis of a plot of ET_a/ET_m versus soil water deficit measured by the neutron moderation method or direct measurement of the root depth. The root zone with L _v >0.1 cm^–2 only reached a depth of 35 cm at the end of the flowering phase and a depth of 45–50 cm at maturity. Root growth continued during the drought periods. The drought sensitivity of pea was high during the flowering phase, especially in 1986 when water stress developed rapidly, and considerably lower during the pod filling phase. The yield reduction caused by drought in the flowering phase was mainly the result of a lower number of pods per stalk. Severe drought did not occur during the vegetative phase. The leaf osmotic potential ( _s ¹⁰⁰ ) declined from c. -0.75 MPa to c. -1.30 MPa during the growing season. Osmotic adjustment was largest during drought in the early growth phases; in 1985 _s ¹⁰⁰ decreased 0.5 MPa under relatively slow drought development during the flowering phase while in 1986, when drought stress developed rapidly, _s ¹⁰⁰ only decreased 0.2 MPa. Osmotic adjustment may have caused the lower drought sensitivity in 1985 than in 1986 and mediated the continued root growth during drought.     

Plant-borne flavonoids released into the rhizosphere: impact on soil bio-activities related to plant nutrition. A review

Plants produce and release in the surrounding soil, the so-called rhizosphere, a vast variety of secondary metabolites. Among them, flavonoids are the most studied, mainly for their role in the establishment of rhizobium?Clegume symbiosis; on the other hand, some studies highlight that they are also important in the plant strategies to acquire nutrients from the soil, for example, by acting on its chemistry. The scope of this review is to give a quick overview on the types and amounts of plant-released flavonoids in order to focus on their effects on soil activities that in turn can influence nutrient availability and so plant mineral nutrition; emphasis is given to the different nutrient cycles, soil enzyme, and soil bacteria activities, and their influence on soil macrofauna and roots of other plants. Finally, the possible outcome of the climate change on these processes is discussed.     

Difference in spatiotemporal patterns of wildlife road-crossings and wildlife-vehicle collisions

Human–wildlife conflicts like wildlife–vehicle collisions pose major challenges for the management and conservation of mobile wildlife in human-dominated landscapes, particularly when large species are involved. Mitigation measures to reduce risk of collisions may be based on information given by wildlife movement and collision data. To test whether movement and collision data indicate different spatiotemporal risk zones, we predicted year-around probabilities of road-crossings of GPS-marked female moose (Alces alces) (n = 102), and compared them with spatiotemporal patterns of police recorded moose-vehicle collisions (n = 1158). Probability of moose road-crossings peaked in May, June, and between mid November and the beginning of January, i.e. during moose migration. Moose-vehicle collisions were more likely during autumn and winter. Comparing environmental attributes of crossing and collision sites showed significant differences. The likelihood of collisions increased with the abundance of human-modified areas and higher allowed speed, and was lower on forest roads. We found that animal movement data alone are insufficient to predict collision risk zones, while analyses of collision data alone overestimate the collision risk in certain habitats. Our findings suggest that higher collision risk is largely due to low light and poor road surface conditions rather than to more animal road-crossings. This suggests that efforts to reduce wildlife collisions should focus on driver attitudes and road conditions rather than animal movement, and any efforts to model the collision risk will require actual collision data, and not just movement data.     

Safety of a live attenuated Erysipelothrix rhusiopathiae vaccine for swine

The porcine reproductive and respiratory syndrome virus (PRRSV) is an enveloped RNA virus. Virions of PRRSV contain six membrane proteins: the major proteins GP5 and M and the minor proteins GP2, GP3, GP4, and E. The GP5 is the major envelope proteins, which was involved in the formation and infectivity of PRRSV by coaction with other membrane proteins. Here, to determine the function of alone GP5 envelope protein in viral entry, we investigated the formation and infectivity of GP5-pseudotyped virus particles. By co-transfection of GP5 expression plasmids with murine leukemia virus (MuLV) based retroviral vectors (pHIT60, encoding MuLV Gag-Pol; pHIT111, encoding an MuLV genome with a β-galactosidase reporter gene) into 293 T cells and analysis of the culture medium using ultracentrifugation, Western blot, and infection assay. We observed that the GP5 envelope protein was incorporated into the MuLV retroviral vectors to generate an pseudotyped murine leukemia virus, which was infectious to PAM and Mack-145 target cells and displayed the same host range with wild-type PRRSV. The infection of the pseudotyped virus on PAM target cells is effectively neutralized by polyclonal antibodies specific for PRRSV or GP5. The results suggested that the GP5 protein may play a key role in the viral entry by interacting with the host cell receptor. The GP5-pseudotyped virus will be useful in the identification of the cellular receptor binding with GP5 protein.