Influence of post‐thawing thermal environment on bovine sperm characteristics and in vitro fertility

Our aim was to evaluate the effects of three thermal environments over time on kinetics, functionality and in vitro fertility of cryopreserved bovine spermatozoa. Four ejaculates from five bulls (n = 20) were cryopreserved. After thawing, semen was evaluated (0 hr), incubated for 4 hr in T36.0 (36.0°C), T38.0 (38.0°C) and T39.5 (39.5°C), and analysed every hour (1 hr, 2 hr, 3 hr, 4 hr). In vitro production of embryos was performed at 0 hr and 4 hr. Sperm motility and cell kinetics (Computer‐Assisted Sperm Analysis) were impaired after 2 hr at T38.0 and T39.5 (p < 0.05). Flow cytometry revealed an increase in the cells with injured plasma membrane to 39.5°C and a general reduction in the mitochondrial potential over time (p < 0.05). In vitro fertility was impaired in all temperatures after 4 hr, but there was no difference between 36.0°C and 38.0°C. Our results suggest that the ex situ resilience of semen at 36.0°C after thawing with no major damage to the quality is limited to 3 hr. In normothermia or in thermal stress, sperm cells present a gradual reduction of movement and functionality, which were more significant after 1 hr of incubation. The in vitro production of embryos is impaired when the semen is kept in a thermal environment ≥36.0°C for 4 hr.     

新型常压室温等离子体-紫外复合诱变选育埃莎霉素I高产菌株#br#

目的 通过对埃莎霉素Ⅰ产生菌WSJ-IA进行诱变选育研究,以期获得埃莎霉素Ⅰ高产菌株。方法 使用多功能等离子体诱变系统(multifunctional plasma mutagenesis system, MPMS)对出发菌株的孢子进行等离子体和紫外复合诱变,设定不同的诱变时间处理孢子悬液,通过致死率确定合适的诱变条件,利用突变株摇瓶发酵效价筛选出正突变菌株。结果 在MPMS射频功率为100W,处理距离5mm,气体流量12.5SLM,等离子体-紫外辐射时间为50s时,菌株致死率为96.08%。在此诱变条件下,以突变株的初筛效价为指标的突变率、正突变率分别达到63.96%和22.52%,复筛效价是出发菌株1.5倍以上的有5株,占复筛菌株的9%。最终筛选出一株发酵单位比出发菌株提高221%、埃莎霉素Ⅰ组分含量提高192%的正突变株IA-425。42L自动发酵罐发酵结果表明,该菌株埃莎霉素Ⅰ产量达到(2000±200)μg/mL左右。结论 新型等离子体复合紫外诱变方式,可有效提高菌株的埃莎霉素Ⅰ发酵产量和组分含量。这为埃莎霉素Ⅰ的大规模发酵和临床前研究奠定了良好基础。     

微生物来源的缩肽类化合物enopeptin A的研究(I)：菌种选育及发酵工艺研究

Enopeptin A是一种缩酚酸肽类化合物,具有抗菌、抗病毒等生物活性。以本实验室保藏的链霉菌SIIA-H7264为出发菌,通过紫外(UV)照射、甲基磺酸乙酯(EMS)诱变、亚硝基胍(NTG)诱变以及常压室温等离子体(ARTP)诱变,获得1株高产突变株A-21,其发酵产物Enopeptin A的产量较出发菌株提高了3倍。对发酵条件、发酵培养基组分进行单因素及响应面优化试验,最终Enopeptin A的产量达到1750μg/mL,较初始工艺提高了2.98倍。     

福州市内河蚊虫孳生情况的调查

目的了解福州市内河的蚊虫孳生情况,为城市科学灭蚊提供依据。方法采用目测和勺捕相结合的方法,调查福州市城区和城乡接合部内河蚊虫孳生的情况,以500 ml勺捕捞幼虫,计算孳生严重的内河的蚊幼密度(条/勺);选取孳生严重的内河进行蚊虫孳生的季节消长调查。结果调查城区河道300处,孳生2处,孳生频率为0.67%,调查城乡接合部河道200处,孳生24处,孳生率为12.0%。主要孳生蚊种为致倦库蚊,伴有少量褐尾库蚊孳生,幼虫密度最高可达到657条/勺。幼虫主要孳生在内河两岸和水生植物周围。福州市内河蚊虫孳生有比较明显的季节变化,5和11月为密度的2个高峰,2和8月为密度的2个低谷。结论福州城市内河在一定条件下会成为超大型蚊虫孳生地,是城市灭蚊中不可忽视的孳生场所。     

Antigen-dependent effects of divergent selective breeding based on natural antibodies on specific humoral immune responses in chickens

NAb are defined as antigen binding antibodies present without a known previous exposure to this antigen. NAb are suggested to enhance specific antibody (SpAb) responses, but consequences of different NAb levels on immunization are largely unknown. Layer chickens were divergently selected and bred for keyhole limpet hemocyanin (KLH)-binding NAb titers, resulting in a High line and a Low line. In this study, we investigated: (1) the relation of NAb levels with SpAb titers; and (2) the effect of immunization on NAb titers. The 50 highest females of the High line and the 50 lowest females of the Low line of generation 2 were intramuscularly immunized at 33 weeks of age with 1 mL phosphate buffered saline (PBS) containing one of four treatments: (1) negative control (no antigen), (2) 500 µg KLH, (3) 100 µg avian tuberculin purified protein derivative of Mycobacterium avium (PPD), or (4) 250 µg human serum albumin (HuSA). IgM and IgG titers of NAb and SpAb in plasma were determined prior to immunization and weekly for 5 weeks post immunization by indirect ELISA. In addition, antibody affinity was investigated. No differences in SpAb and NAb response against KLH and PPD were observed as a consequence of different NAb titers, but increased and prolonged SpAb and NAb titer responses against HuSA were observed for the High line compared to the Low line. Different natural antibody titers did not impair SpAb dynamics and SpAb affinity. NAb titers were not, or for only short-term, affected by immunization. We show here that NAb may enhance SpAb responses, but that this effect is antigen-dependent. We hypothesize that NAb play a role in general disease resistance through enhancement of the humoral adaptive immune response.     

中国台湾省新竹市市售食物孳生粉螨的初步调查

目的 了解台湾地区储藏食物粉螨的孳生情况。 方法 采用直接镜检法对采集带回的样本螨进行分离，再将挑出的螨制成玻片标本置于显微镜下观察、鉴定。结果 共从采集的39种市售样本中分离出13种粉螨，隶属于6科11属，即粗脚粉螨（Acarus siro）、腐食酪螨（Tyrophagus putrescentiae）、长食酪螨（Tyrophagus longior）、椭圆食粉螨（Aleuroglyphus ovatus）、伯氏嗜木螨（Caloglyphus berlesei）、纳氏皱皮螨（Suidasia nesbitti）、河野脂螨（Lardoglyphus konoi）、害嗜鳞螨（Lepidoglyphus destructor）、棕脊足螨（Gohieria fuscus）、拱殖嗜渣螨（Chortoglyphus arcuatus）、甜果螨（Carpoglyphus lactis）、粉尘螨（Dermatophagoides farinae）、屋尘螨（Dermatophagoides pteronyssinus）。结论 台湾省新竹市市售食物中发现粉螨孳生，应采取相关措施控制粉螨的孳生。     

Periorbital Trauma from Pit Bull Terrier Attacks

Purpose: To report the nature of periorbital trauma after pit bull attacks. While these attacks have been well-characterized in the popular media, no case series has documented the ophthalmic manifestations of this trauma.

Methods: We retrospectively reviewed all cases of pit bull terrier attacks that presented to the oculoplastic and orbital surgery service at Albany Medical Center between 2008 and 2011. The age, gender, extent of the injuries, care provided, follow up interval, and complication rate were evaluated for each patient.

Results: Seven patients were identified, with a mean age of 17.2 years. Six of the seven patients were in the pediatric age group. All patients suffered eyelid lacerations, and only one patient had additional injuries. Four patients (57.2%) suffered a canalicular laceration. Despite the lack of post-operative oral antibiotic use, no patient developed a wound infection.

Conclusions: In the ophthalmic setting, pit bull terrier attacks most frequently involve children and result in eyelid lacerations. Canalicular injuries are common after these attacks.     

福建北部地区斯氏并殖吸虫疫源地宿主感染情况分析

目的考察福建北部地区斯氏并殖吸虫中间宿主螺、蟹种群及其孳生地,比较生态环境改变前后感染率,并分析其变化原因。方法 2009-2019年,以并殖吸虫病例为线索,对福建省北部南平市的建瓯市小桥镇涤上村、东峰镇桂林村、城关镇七里街村和建阳区崇雒乡上洋村、政和县东平镇西表村、岭腰乡前溪村以及三明市的三元区居阳村等11处调查点进行现场采集螺、蟹,并考察其生态环境,设框(33 mm2)检测螺分布密度,计算螺的并殖吸虫尾蚴感染率和蟹的并殖吸虫囊蚴感染率、感染度。囊蚴采用人工感染健康犬(2只)和PCR扩增内转录间隔区2 (ITS2)序列、线粒体细胞色素氧化酶1 (CO1)基因进行鉴定。考察原孳生地生态环境的变化,复查螺、蟹的感染率、感染度,分析环境变化对感染率的影响。结果 11处调查点查见唐氏拟小豆螺、建瓯拟小豆螺和小桥拟钉螺等3种螺。山涧水源小沟或渗水湿地等微型生态环境为螺的适宜孳生地,螺多栖息于沟内水线上下5 mm的潮湿环境,主要附着于沟内潮湿的陈旧落叶、枯枝,其次为石块上,泥砂中较少。唐氏拟小豆螺、建瓯拟小豆螺和小桥拟钉螺的平均分布密度分别为156/框、179~291/框和12~266/框;各调查点均有螺查出斯氏并殖吸虫尾蚴,唐氏拟小豆螺、建瓯拟小豆螺和小桥拟钉螺的感染率分别为0.22%(4/1 851)、0.38%(36/9 420)、1.10%(102/9 247)。11处调查点查见福建华溪蟹、福建博特溪蟹、角肢华南溪蟹和待定种华南溪蟹等4种溪蟹。溪蟹多栖息于水流缓慢的山涧,白天潜伏于石块下,夜间四出觅食。溪蟹的斯氏并殖吸虫囊蚴感染率为38.99%~96.77%,平均感染率为80.21%(231/288),平均感染度为19.8个囊蚴/蟹。PCR结果显示,囊蚴样品扩增出的ITS2序列约500 bp,与GenBank中斯氏并殖吸虫相似性为99%;CO1基因序列约450 bp,与GenBank中宫崎并殖吸虫相似性为100%。人工感染实验结果显示,2只感染犬解剖后分别获得6和8条成虫,经鉴定均为斯氏并殖吸虫。孳生地环境改变有山洪暴发、垦植、干旱和人为破坏等原因,孳生地环境改变后对11处19次复查中,有10次未采集到螺,有5次未采集到蟹。5个调查点孳生地环境变化为山洪暴发所致,灾后进行7次调查均未查见螺,其中3处未查见溪蟹。11处调查点孳生地环境改变后,蟹的斯氏并殖吸虫囊蚴感染率为36.11%(91/252),平均感染度为4.9个囊蚴/蟹。孳生地环境改变前后的感染率差异具统计学意义(P<0.05)。结论福建北部建瓯等地为斯氏并殖吸虫高度感染的自然疫源地。孳生地生态环境改变后螺、蟹斯氏并殖吸虫尾蚴/囊蚴感染率下降明显,其中山洪暴发和垦植等是影响螺、蟹感染率下降的主要因素。