野外放归大熊猫肠道菌群变化的研究

对四川卧龙中国保护大熊猫研究中心的一只野外放归亚成体大熊猫肠道菌群的组成和季节变化规律进行了研究,同时与其圈养双胞胎兄弟的肠道菌群进行了比较。从放归大熊猫粪便中分离出17种肠道菌,优势菌群为肠杆菌、肠球菌和乳杆菌。与圈养大熊猫相比,放归大熊猫肠道菌群中优势菌群的种类未发生改变,但是肠球菌数量增加,肠杆菌和乳杆菌的数量减少。研究发现放归大熊猫肠道菌群中的肠杆菌和肠球菌的数量随季节变化有较大波动,乳杆菌的数量随季节变化波动不大;而圈养大熊猫三种优势菌的数量随季节变化波动都不大。     

野生鸟类高致病性禽流感抗体水平检测

高致病性禽流感对禽类及人类危害十分严重.高致病性禽流感流行病学特点之一是随野生鸟类的迁徙,该病在全球广泛扩散和蔓延.野生鸟类在紧急免疫后的血清抗体水平直接关系到疫情的控制、养禽业的发展以及人类的健康.我国GB/T 18936高致病性禽流感诊断技术对火鸡、鸭、鹅(包括野生鸟类)等禽类接种禽流感疫苗免疫效力评价缺乏足够的血清学依据,国际国内对野生鸟类血清抗体水平检测资料比较欠缺.因此对野生鸟类高致病性禽流感血清抗体水平进行检测,就显得十分重要和必要.     

Serological surveillance for Tahyna virus (California encephalitis orthobunyavirus,Peribunyaviridae) neutralizing antibodies in wild ungulates in Austria,Hungary and Romania

A serosurvey for Tahyna virus (TAHV), a mosquito‐borne California encephalitis orthobunyavirus (Peribunyaviridae) endemic to Europe, was performed to estimate the activity of TAHV on a broad geographic scale. Sera from wild boar (Sus scrofa), roe deer (Capreolus capreolus) and red deer (Cervus elaphus) were collected from Austria, Hungary and Romania. Samples were tested for neutralizing antibodies against TAHV using a virus microneutralization assay. The results demonstrate that TAHV transmission to mammals is widespread in Europe, particularly in the wild boar population where the mean rate of seroconversion is 15.2%.     

Involvement of spleen components of mature fowl in the primary and secondary humoral antibody response following experimental EDS'76 virus infection

Summary

Cellular changes in spleens of mature fowl in relation to both the primary and secondary humoral antibody response following experimentalEDS'76 virus infection were studied. The influence of splenectomy on humoral antibody response was also examined.

Experimental fowl had been naturally infected with fowl adenovirus (FAV) but did not possess precipitins to these viruses at the time of EDS’ 76 virus infection. Since EDS'76 infection provokes a recall of the group antibody to FAV, this infection simultaneously induces a primary response against EDS’ 76 virus and a secondary response due to the recall of the group antibody to FAV.

HI and precipitating antibodies toEDS'76 virus (primary response) werefirst detected at 6 and 8 days p.i. respectively. Curves of HI, precipating and neutralising antibody titres were biphasic; the first peak (IgM peak) occurred at 10–11 days p.i., the second (IgG peak) at 16–28 days p.i.

Precipitating antibodies to FAV (secondary response) were demonstrated from 4 days p.i. The curve of these antibody titres was also biphasic, with peaks at the same times as in the primary response.

Based on HI and AGP testing of primary and secondary immune response in both splenectomised and non‐splenectomised fowl it is concluded that in the primary response the spleen of the adult fowl is involved significantly in only IgM secretion, while in the secondary response it is likely that bothIgM and IgG are secreted in considerable amounts.

Clusters of lymphoblasts and plasmablasts were observed at 3 days p.i. in the red pulp. It is very likely that antigen‐antibody complexes are formed from that time and circulate bound to the surface of lymphocytes. These antigen‐loaded lymphocytes are ‘picked up’ from the blood stream by

– red pulp macrophages, leading to enhanced formation of lymphoblasts in the red pulp. Great numbers of these cells (which are very probably IgM secreting cells) were present on days 6 and 7 p.i., but were no longer detectable after day 10 p.i.

– macrophages of the macrophagalellipsoidal corona (MEC), leading to significant enlargement of the periellipsoidal lymphoid tissue(PELT) by an increase of the number of lymphocytes observedfrom days 4–12 p.i. The MEC was significantly enlarged from 7–12 days p.i., very likely due to an increased number of macrophages.

Following deposition of antigen in the white pulp, formation of follicles begins. The number of small, intact follicles includingfollicle precursors increasedfrom 6 days p.i. From 15 days p.i. to the end of the experiment both the number and size of follicles increased significantly.

Uptake and processing of antigen by macrophages is probably accompanied by death of some of these cells. This might explain the degenerative changes observed in large mesenchymal cells, probably macrophages, at 3 and 5 days p.i. in the red pulp and at 5 and 6 days especially in the MEC. Splenitis which was present at 3 and 5 days p.i. and oedema observed in and around ellipsoidal cells at 5 days p.i. may be due to mediators released from these degenerative macrophages.

A significantly increased number of follicles with lymphoblasts was seen from 2–15 days p.i. while lymphoblasts and plasmablasts were present in the PELT from 5–15 days p.i., but predominantly at 6 and 7 days p.i. It is likely that disruption of follicles and blast transformation of white pulp lymphoid cells are secondary response events. White pulp lymphoblastsand plasmablastsare probably IgG secreting cells.

Splenomegaly was observed at 3, 5 and 6 days after infection and was mainly due to swelling of red pulp macrophages and infiltration of granulocytes in the red pulp. Ellipsoidal and periellipsoidal changes could contribute to the splenomegaly at 5 and 6 days p.i.     

黄河三角洲地区野生牧草种质资源的初步研究

研究牧草种质资源，无论是对野生牧草种质的保存，鉴定，还是对培育利用用牧草建立人工草地，改良天然草地都有很大意义。本文为更好地发掘，利用野生牧草种质资源提供了一定的科学依据。     

山东省野鸟栖息地情况调研

2021年1月,山东省东营市发生天鹅H5N8亚型高致病性禽流感疫情,给山东省禽流感疫情防控与净化带来了极大挑战.为了解山东省野鸟栖息地及野鸟分布信息,采用问卷调查方式,对山东省野鸟栖息地类型、分布、野鸟种类以及迁徙时间等进行调研.同时,采集野鸟粪便,用荧光定量RT-PCR或PCR方法进行H5亚型禽流感、新城疫、 鸭瘟、...     

野生高乌头开花习性及种子灌浆特性研究

利用甘肃永登县野生高乌头植株为研究材料,标记初花期一致的植株,每天测定单株开花数和蓇葖果数,并每隔3 d测定蓇葖果种子数、粒重和体积,对其开花结果动态和种子灌浆特性系统研究,旨在揭示其开花结果习性及其种子灌浆规律,为探寻高乌头种子发育规律及适宜采收期提供科学依据。结果表明,野生高乌头植株主花序花蕾自下而上依次开放。单花开放后第3天形成蓇葖果,第15天种子成形,并开始脱水形成干物质积累。单株开花数等于蓇葖果数,基本不落花,但仅主花序中部及以下部位蓇葖果具成熟种子。在种子整个灌浆过程中,百粒鲜重和干重的变化动态均呈“S”型曲线,符合Logistic方程。籽粒鲜重快增期在花后7～21 d,最大增长速率出现在花后14 d,在花后27 d达到最大,而干物质积累快增期在花后16～30 d,最大积累速率出现在花后23 d。开花36 d后蓇葖果脱落,种子灌浆和株上脱水中断,导致种子含水量达50%以上,采收后种子在快速脱水过程中可能形成深休眠特性,说明高乌头种子适宜采收期为开花后第36天左右(8月中下旬),蓇葖果尚未开裂时及时分批采收为宜。     

广东部分地区中小型猪场猪伪狂犬病野毒感染的血清学调查

采用阻断ELISA法,对广东省9个地区经猪伪狂犬基因缺失苗免疫的中小型猪场2005年-2006上半年送检的375份血清进行猪伪狂犬病野毒感染的血清学检测。结果表明,有9个地区猪场血清呈阳性,其中阳性血清174份,平均阳性率为46.4%,最高阳性率达65.0%,提示该地区中小型猪场有猪伪狂犬病野毒感染。     

4种野生早熟禾对土壤酸碱性的生理响应

以甘肃省境内采集的4种野生早熟禾为材料,设8个pH处理(3、4、5、6、7、8、9、10),探讨土壤pH对其生理特性的影响机制以及适宜生长的土壤pH,以期为早熟禾属草坪的养护管理和野生早熟禾的引种驯化提供依据。结果表明,随pH增大,4种野生早熟禾相对膜透性,游离脯氨酸(F-Pro)、可溶性糖(SS)和丙二醛(MDA)含量及过氧化物酶(POD)活性均呈先减小后增大的趋势,可溶性蛋白(SP)含量和超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性均呈先增大后减小的趋势;草地早熟禾(Poa pratensis)、一年生早熟禾(P.annua)和小药早熟禾(P.micrandra)在pH为7时,硬质早熟禾(P.sphondylodes)在pH为6时受到的伤害最小,是其最适宜生长的pH。