Enhanced expression of the Flt‐1 and Flk‐1 receptor tyrosine kinases in a newborn piglet model of ischemic tolerance

Vascular endothelial growth factor (VEGF), an angiogenic factor induced by hypoxia, also exerts direct effects on neural tissues. VEGF up‐regulation after hypoxia coincides with expression of its two tyrosine kinase receptors Flt‐1(VEGFR‐1) and Flk‐1 (KDR/VEGFR‐2), which are the key mediators of physiological angiogenesis. We have recently shown that hypoxic‐preconditioning (PC) leading to tolerance to hypoxia–ischemia in neonatal piglet brain resulted in increased expression of VEGF. In this study, we used a hypoxic‐preconditioning model of ischemic tolerance to analyze the expression and cellular distribution of VEGF receptors and phosphorylation of cAMP‐response element‐binding protein (CREB) in newborn piglet brain. The response of Flt‐1 and Flk‐1 mRNA to PC alone was biphasic with peaks early (6 h) and late (1 week) after PC. The mRNA expression of Flt‐1 and Flk‐1 in piglets preconditioned 24 h prior to hypoxia–ischemia was significantly higher than non‐preconditioned piglets and remained up‐regulated up to 7 days. Furthermore, PC prior to hypoxia–ischemia significantly increased the protein levels of Flt‐1 and Flk‐1 compared with hypoxia–ischemia in a time‐dependent manner. Double‐immunolabeling indicated that both Flt‐1 and Flk‐1 are expressed in neurons and endothelial cells with a similar time course of expression following PC and that PC leads to the growth of new vessels. Finally, our data demonstrate that PC significantly phosphorylated and activated cAMP‐response element‐binding protein in nucleus. These results suggest that mechanism(s) initiated by PC can induce VEGF receptor up‐regulation in newborn brain and that VEGF–VEGF receptor‐coupled signal transduction pathways could contribute to the establishment of tolerance following hypoxia–ischemia.     

Acute physiological responses to castration-related pain in piglets: the effect of two local anesthetics with or without meloxicam

Methods to reduce castration-related pain in piglets are still issues of concern and interest for authorities and producers. Our objectives were to estimate the effectiveness of two protocols of local anesthesia (lidocaine and the combination of lidocaine+bupivacaine) as well as the use of meloxicam as a postoperative analgesic in alleviating castration-related pain, measured by acute physiological responses. Eight groups (15 piglets/group) were included in the study: (1) castration without anesthesia or analgesia, without meloxicam (TRAD WITHOUT), (2) castration without anesthesia or analgesia, but with meloxicam (TRAD WITH), (3) handling without meloxicam (SHAM WITHOUT), (4) handling with meloxicam (SHAM WITH), (5) castration after local anesthesia with lidocaine but without meloxicam (LIDO WITHOUT), (6) castration after local anesthesia with lidocaine and meloxicam (LIDO WITH), (7) castration after local anesthesia with lidocaine+bupivacaine without meloxicam (LIDO+BUPI WITHOUT), (8) castration after local anesthesia with lidocaine+bupivacaine and meloxicam (LIDO+BUPI WITH). Acute physiological responses measured included skin surface temperature and serum glucose and cortisol concentrations. On days 4 and 11 post-castration BW was recorded and average daily gain was calculated over this period. Furthermore, piglet mortality was recorded over the 11-day post-castration period. Administration of local anesthetic or meloxicam did not prevent the decrease in skin surface temperature associated with castration. Lidocaine reduced the increase in glucose concentration associated with castration. For castrated pigs, the joint use of lidocaine and meloxicam caused a significant decrease in cortisol concentration; the combination of intratesticular lidocaine and bupivacaine did not seem to be more effective than lidocaine alone. No effect of treatments on mortality and growth were detected.     

Ear tagging in piglets: the cortisol response with and without analgesia in comparison with castration and tail docking

The objectives of the present study were to compare the cortisol response caused by ear tagging piglets with the distress caused by other known painful husbandry procedures (e.g. castration and tail docking) and to evaluate the effectiveness of analgesia with meloxicam to reduce the cortisol response caused by these procedures. In total, 210 male piglets were randomised to equal numbers (n=30) into one of seven groups: a control group which was only handled (H), an ear tagged group that received no analgesia (ET), an ear tagged group with analgesia (ETM), a castration group with no analgesia (C), a castration group with analgesia (CM), a tail-docked group with no analgesia (TD) and a tail-docked group with analgesia (TDM). The procedures were carried out on day 3 or 4 after farrowing. Five blood samples were taken from each piglet: 30 min before the respective procedure (baseline value), and 30, 60 min, 4 and 7 h after processing, to assess cortisol concentrations. Means as well as the area under the curve (AUC) value were analysed and the effective sizes of the procedures were established. At 7 h after the experimental treatment, cortisol concentrations had returned to base values in all groups. ET evoked a greater cortisol response than H piglets at 30 min (P<0.001) and 60 min (P=0.001). The cortisol response to ET was lower than C at 30 min (P=0.001) but did not differ significantly at the other sample times. The mean cortisol response was similar between ET and TD piglets over all sample times. Taking both intensity and duration of the cortisol response into account (AUC), ET evoked a greater response than TD. Analgesia (ETM) resulted in significantly lower cortisol levels than ET at 30 and 60 min post-procedure. Castration (C) provoked the highest cortisol response of all procedures; a significant analgesic effect (CM) was shown only at 4 h post-procedure. TD resulted in significantly higher cortisol levels than H piglets only at 30 min; analgesia (TDM) significantly reduced the cortisol response at 30 min. We conclude that ear tagging causes a dramatic increase in cortisol levels compared with handling alone in piglets, which suggests that this procedure causes substantial distress. However, further research is needed to confirm these results.     

尖角突脐孢菌侵染过程及稗草反应超微结构观察*

为了解尖角突脐孢菌侵染稗草植株的致病机理,应用电镜观察了该菌侵染稗草植株过程和寄主细胞的超显微结构变化。结果表明：尖角突脐孢菌分生孢子于接种8h后从突脐孢的基部开始萌发菌丝,接种13h后菌丝直接穿透稗草叶表面细胞连接处或经气孔侵入,接种后24～26h完成侵染过程。被侵染的寄主,膜结构发生变形,同时细胞线粒体的嵴变形膨大,叶绿体内的淀粉粒消失,寄主细胞内有大量酚物质出现。     

皮瓣移植结合骨牵张技术修复感染性胫骨复合皮肤组织缺损的临床效果观察

目的：观察皮瓣移植结合骨牵张技术修复感染性胫骨复合皮肤组织缺损的临床效果。方法：自2008年6月至2012年6月,共收治了胫骨感染性复合组织缺损16例,采用一期彻底去除病变坏死组织和病变的胫骨断端,切取同侧腓肠肌皮瓣、腓肠神经营养血管皮瓣转位、对侧小腿内侧皮瓣和游离皮瓣移植修复小腿皮肤缺损,二期行骨牵张延长术进行治疗。结果：所有16例胫骨复合组织缺损病例感染均得到了控制,移植的皮瓣顺利成活,胫骨截骨延长区成骨良好,断端骨愈合,其中2例出现针道感染,无血管神经并发症发生。骨延长2～9cm,平均延长5．5cm。外同定延长支架在停止骨延长8-20个月后拆除,双下肢等长,膝关节和踝关节功能良好。术后细菌培养＋药敏结果：金黄色葡萄球菌感染8例,表皮葡萄球菌感染4例,大肠杆菌感染1例,阴沟肠杆菌感染l例,肠球菌感染l例。结论：伤口彻底清创,胫骨断端坏死骨切除后一期行皮瓣移植,二期行骨牵张延长术是一种治疗感染性胫骨复合组织缺损的有效方法。     

Characterization of the NleF effector protein from attaching and effacing bacterial pathogens

Enterohemorrhagic Escherichia coli (EHEC) is a water- and food-borne pathogen that causes hemorrhagic colitis. EHEC uses a type III secretion system (T3SS) to translocate effector proteins that subvert host cell function. T3SS-substrates encoded outside of the locus of enterocyte effacement are important to E. coli pathogenesis. We discovered an EHEC secreted protein, NleF, encoded by z6020 in O-island 71 of E. coli EDL933 that we hypothesized to be a T3SS substrate. Experiments are presented that probe the function of NleF and its role in virulence. Immunoblotting of secreted and translocated proteins suggest that NleF is secreted by the T3SS and is translocated into host cells in vitro where it localizes to the host cytoplasm. Infection of HeLa cells with E. coli possessing or lacking nleF and transient expression of NleF-GFP via transfection did not reveal a significant role for NleF in several assays of bacterial adherence, host cytoskeletal remodeling, or host protein secretion. However, competitive coinfection of mice with Citrobacter rodentium strains possessing or lacking nleF suggested a contribution of NleF to bacterial colonization. Challenge of gnotobiotic piglets also revealed a role for NleF in colonization of the piglet colon and rectoanal junction.     

长白仔猪血常规及生化指标正常值探讨

目的探讨2-3月龄长白仔猪的血常规及生化指标的正常值,为长白仔猪用于实验研究提供实验依据。方法采用实验室评价方法对40头长白仔猪的主要血常规和生化指标进行检测,并与巴马小型猪的参考值进行对比。结果长白仔猪的血常规及生化指标无性别差异（P〉0．05）,长白仔猪的WBC、ALT、Ca^2＋的平均值与巴马小型猪相似,两者之间差异无显著性（P〉0．05）,其RBC、HGB、HCT、PLT、TP、Alb、BUN、AMY的平均值均低于巴马小型猪的相应值,而AST、TBIL、DBIL、Crea、CK-MB明显高于巴马小型猪,具有显著性差异（P〈0．01）。结论长白仔猪有其独特的生理生化特性。     

Interactions of Plasmodium falciparum erythrocyte membrane protein 3 with the red blood cell membrane skeleton

Plasmodium falciparum parasites express and traffick numerous proteins into the red blood cell (RBC), where some associate specifically with the membrane skeleton. Importantly, these interactions underlie the major alterations to the modified structural and functional properties of the parasite-infected RBC. P. falciparum Erythrocyte Membrane Protein 3 (PfEMP3) is one such parasite protein that is found in association with the membrane skeleton. Using recombinant PfEMP3 proteins in vitro, we have identified the region of PfEMP3 that binds to the RBC membrane skeleton, specifically to spectrin and actin. Kinetic studies revealed that residues 38-97 of PfEMP3 bound to purified spectrin with moderately high affinity (K_D(kin) = 8.5 × 10^− 8 M). Subsequent deletion mapping analysis further defined the binding domain to a 14-residue sequence (IFEIRLKRSLAQVL; K_D(kin) = 3.8 × 10^− 7 M). Interestingly, this same domain also bound to F-actin in a specific and saturable manner. These interactions are of physiological relevance as evidenced by the binding of this region to the membrane skeleton of inside-out RBCs and when introduced into resealed RBCs. Identification of a 14-residue region of PfEMP3 that binds to both spectrin and actin provides insight into the potential function of PfEMP3 in P. falciparum-infected RBCs.     

Climatic effects on sow fertility and piglet survival under influence of a moderate climate

Although the climate in Germany is moderate, heat stress conditions may occur during summer months. However, it is unknown to what extent sow fertility and piglet survival are affected under moderate climatic conditions in indoor systems. Therefore, this study estimated effects of temperature and temperature–humidity index (THI) on sow fertility and piglet survival under practical husbandry conditions. Temperature and relative humidity were recorded in six piglet-producing farms in Lower Saxony, Germany, from July 2011 to August 2012. Based on that, the THI was calculated. In one farrowing, waiting and servicing unit of each farm two data loggers were installed. Reproductive parameters of 8279 successful inseminations and 10 369 litters including total number of piglets born, liveborn, stillborn and weaned piglets as well as pre-weaning mortality were evaluated. The effects of temperature and THI on reproductive parameters were estimated for varying periods after breeding and before and after farrowing, respectively. Average daily temperature across all units ranged from 15.6°C to 29.0°C, and average THI from 62.4 to 75.1. Season and parity significantly affected total number of piglets born, number of liveborn, stillborn and weaned piglets (P<0.001). The number of piglets born increased with rising temperature and THI in the 1^st week post breeding. Higher temperatures and THI values before farrowing resulted in a reduced number of liveborn piglets. Elevated temperature and THI values after farrowing were associated with a greater number of weaned piglets. The pre-weaning mortality significantly decreased with increasing temperature and THI values after farrowing (P<0.05). In conclusion, temperature and THI affected the reproductive performance of the sows and the survival of the piglets in different ways. While increased climatic values at the time of breeding positively affected the total number of piglets born, increased values at the time of farrowing had negative impacts on the reproductive performance of the sows. Piglets benefited from higher temperature and THI values after farrowing.     

Sow environment during gestation: part I. Influence on maternal physiology and lacteal secretions in relation with neonatal survival

In pig husbandry, pregnant females are often exposed to stressful conditions, and their outcomes on maternal and offspring health have not been well evaluated. The present study aimed at testing whether improving the welfare of gestating sows could be associated with a better maternal health during gestation, changes in the composition of lacteal secretions and improvement in piglet survival. Two contrasted group-housing systems for gestating sows were used, that is, a French conventional system on slatted floor (C, 49 sows) and an enriched system using larger pens on deep straw (E, 57 sows). On the 105^th days of gestation (DG105), sows were transferred into identical farrowing crates on slatted floor. Saliva was collected from all sows on DG35, DG105 and DG107. Blood samples were collected on DG105 from all sows and on the 1^st day of lactation (DL1) from a subset of them (C, n=18; E, n=19). Colostrum and milk samples were collected from this subset of sows at farrowing (DL0) and DL4. Saliva concentration of cortisol was greater in C than in E sows at DG35 and DG105, and dropped to concentrations comparable to E sows after transfer into farrowing crates (DG107). On DG105, plasma concentrations of haptoglobin, immunoglobulins G (IgG) and A (IgA), blood lymphocyte counts and plasma antioxidant potential did not differ between groups (P > 0.10), whereas blood granulocyte count, and plasma hydroperoxide concentration were lower in E than in C sows (P < 0.05). Concentrations of IgG and IgA in colostrum and milk did not differ between the two groups. The number of cells did not differ in colostrum but was greater in milk from E than C sows (P < 0.05). Pre-weaning mortality rates were lower in E than C piglets (16.7% v. 25.8%, P < 0.001), and especially between 12 and 72 h postpartum (P < 0.001). Plasma concentration of IgG was similar in E and C piglets on DL4. In conclusion, differences in salivary cortisol, blood granulocyte count and oxidative stress markers between groups suggested improved welfare and reduced immune solicitation during late gestation in sows of the E compared with the C system. However, the better survival observed for neonates in the E environment could not be explained by variations in colostrum composition.