First report of Neospora caninum infection in pigs in China

Neospora caninum is a protozoan parasite which can infect many mammals and birds with a worldwide distribution. However, no molecular data are available about the occurrence of N. caninum in pigs. In this study, the serological and molecular prevalence of N. caninum infection in farmed pigs were investigated in Hunan province, China, between January 2017 and December 2018. A total of 1,500 serum samples collected from 10 herds in Hunan province were evaluated using a competitive‐inhibition enzyme‐linked immunoassay assay (cELISA). The overall seroprevalence of N. caninum in the examined pigs was 1.9%. The seroprevalence of N. caninum ranged from 0.3% to 4.6% among different regions in Hunan province of China (p < .05). DNA was extracted from brain samples, and the Nc‐5 gene and ITS‐1 region were amplified and then sequenced. Three (0.5%) of the examined 600 brain tissues were found to contain N. caninum DNA. Our phylogenetic analyses indicated that N. caninum samples were classified into two distinct groups. Although the prevalence is low within the pig groups investigated, our results revealed the emergence of N. caninum infection in pigs in China. The finding of the present study provides molecular evidence that the pigs are the natural intermediate host of N. caninum and may have major epidemiological importance.     

Does porcine circovirus type 3 (PCV3) interfere with porcine circovirus type 2 (PCV2) vaccine efficacy?

PCV2 is globally spread pathogen involved in a number of diseases (PCVD). Commonly used vaccines against PCV2 are proved to be highly efficacious. The role of recently discovered PCV3 for pig health and interference with PCV2 remains unknown. The study performed on serum samples from seven farms vaccinated against PCV2 and four non‐vaccinated showed very low prevalence of PCV2 viremia in the former (3 out of 106 positive serum pools) and high prevalence of PCV2 viremia in the latter (35 out of 60 positive pools). Mean log₁₀ PCV2 genome equivalents were lower in vaccinated farms (4.8 ± 0.6 log₁₀ copies/ml) than in non‐vaccinated farms (6.3 ± 1.3 log₁₀ copies/ml). PCV3 was detected in 31 out of 106 and 12 out of 60 serum pools from vaccinated and non‐vaccinated farms, respectively. Mean log₁₀ PCV3 genome equivalents were significantly (p < 0.05) lower in vaccinated farms (3.9 ± 0.8 log₁₀ copies/ml) than in non‐vaccinated farms (4.4 ± 0.6 log₁₀ copies/ml). Concurrent PCV2 and PCV3 infection was rare and found only in 1 out of 529 and 4 out of 292 individual serum samples from vaccinated and non‐vaccinated farms, respectively. Our results showed lack of impact of PCV3 circulation on PCV2 vaccine efficacy. On the other hand, intensive PCV2 circulation and high viremia detected in non‐vaccinated farms did not seem to increase the level of PCV3 infection.     

Low-molecular-weight chitosan relieves enterotoxigenic Escherichia coli-induced growth retardation in weaned pigs

The objective of the present study was to evaluate the effects of low-molecular-weight chitosan (LMWC) on the growth performance, immune responses and intestinal health of weaned pigs challenged by enterotoxigenic Escherichia coli (ETEC). A total of 32 weaned pigs were randomly allocated to four treatments: non-challenged (fed with basal diet), ETEC-challenged (fed with basal diet) and ETEC-challenged plus 50 or 100 mg/kg LMWC supplementation, respectively. After 11 days feeding, the non-challenged pigs were infused with sterilised Luria–Bertani culture, while the remaining pigs were infused with 2.6 × 10¹¹ colony-forming units of ETEC. At 3 days post-challenge, all pigs were administered d-xylose at 0.1 g/kg body weight. One hour later, blood samples were obtained, and the pigs then euthanised to collect intestinal samples. Data showed that only 100 mg/kg LMWC supplementation attenuated (P < 0.05) the average daily gain reduction caused by ETEC. Furthermore, besides the decreased (P < 0.05) serum tumour necrosis factor-α and immunoglobulin (Ig) G concentrations detected in ETEC-challenged pigs supplemented with LMWC at 50 or 100 mg/kg, the higher dose (100 mg/kg) also decreased (P < 0.05) the serum IgM concentration and increased (P < 0.05) the villus height and villus height-to-crypt depth ratio in both the jejunum and ileum, and the sucrase activity in the ileal mucosa. Moreover, LMWC supplementation (50 or 100 mg/kg) in ETEC-challenged pigs elevated (P < 0.05) the mRNA levels of jejunal mucosal peptide transporter 1 and ileal mucosal peptide transporter 1, divalent metal transporter 1 and zinc transporter 1, and decreased (P < 0.05) the ileal and caecal E. coli abundances, while 100 mg/kg LMWC additionally elevated (P < 0.05) the ileal Bacillus abundance, and caecal and colonic Bifidobacterium abundances. These results suggest that LMWC helps alleviate ETEC-induced growth retardation in weaned pigs, which could be associated with the inhibition of the immune responses and improved intestinal health.     

注射用糜蛋白酶中组胺类物质检查方法学研究

【摘要】目的：建立注射用糜蛋白酶中组胺类物质检查方法。 方法：采用组胺检查法对注射用糜蛋白酶中组胺类物质进行限度检查方法学研究,并与现行猫法进行比较研究。结果：加标回收率86%～117%;豚鼠法方法特异性(真阴性率)100%,灵敏度(真阳性率)70%,猫法方法特异性100%,灵敏度70%;四个实验室室内重复性分别为82%、75%、83%、81%;实验室间重复性为92.9%～96.4%.结论：该方法准确与猫法相当、重复性好,可作为降压物质检查法的替代方法。     

注射用益气复脉(冻干)安全性评价

目的 通过豚鼠离体回肠模型及小鼠类致敏实验评价注射用益气复脉（冻干,YQFM）的安全性。方法 建立豚鼠离体回肠模型,依次考察0.2、0.4、0.6、0.8、1.2、1.4、1.6 mg/mL质量浓度的YQFM对静息离体肠、乙酰胆碱（Ach）及组胺（His）诱导的离体肠收缩的抑制率;雄性ICR小鼠随机分为阴性对照组,阳性对照组（C48/80,25 mg/kg）,YQFM低、高剂量（780、3 135 mg/kg,分别为临床等效剂量的0.85和3.43倍）组,分为尾iv含0.4%伊文思蓝（EB）的药液及不含0.4% EB的药液两部分进行体内类致敏反应实验,依次比较各组小鼠耳廓蓝染情况;ELISA法测定血清中His和5-羟色胺（5-HT）的含量;并对耳、肺组织进行HE染色及病理检查。结果 体外实验显示,YQFM既能够抑制离体肠的自主收缩,又能抑制Ach和His导致的离体肠痉挛;体内实验表明,YQFM低剂量组耳廓蓝染率,His、5-HT含量均在正常范围,组织病理检查未见明显异常;3.43倍临床等效剂量时耳廓蓝染率,His、5-HT含量略高,病理结果见轻微炎症反应。结论 YQFM的安全性基本良好,临床使用时需对使用剂量稍加注意,以防轻微不良反应发生。     

The rests of Malassez and chronic marginal periodontitis

The structure of the rests of Malassez and the relationship which they bear to the junctional epithelium in the marginal region of pigs' molars was investigated. A 3-dimensional picture of the marginal rests and their relationship to the junctional epithelium was built up by means of standardized photomicrographs made from serial sections. In teeth involved in chronic marginal inflammation, the rests in this region appeared to form a continuous network and we confirmed the original suggestion of Grant & Bernick that, at frequent intervals, the junctional epithelium"... seemed to be continuous with the epithelial rests in the upper third of the root...". If the anatomical relationship of the rests in man resembles that seen in the pig and they form a continuous network communicating at intervals with the junctional epithelium, this relationship must inevitably lead to speculation about the effects of any potential for reactive proliferative equivalent to that which is frequently seen in the apical region. It is possible that the rests might be acting as the "thin end of the wedge", augmenting and facilitating apical migration of the junctional epithelium during the pathogenesis of the periodontal pocket.     

骨髓间质干细胞介导用于颌面整形的动物实验研究

目的体外扩增小型猪骨髓间质干细胞(bone marrow derived mesenchymal stem cells,BMMSCs),研究其介导颌面整形的可行性.方法分离培养小型猪BMMSCs,扩增后接种到预制的羟基磷灰石/磷酸三钙(hydroxyapatite/tricalcium phosphate,HA/TCP)材料上,分别自体回植入小型猪额骨骨膜下,定期行X线、CT检查.术后12周和20周分别处死动物,取材后进行组织学和扫描电镜检查分析.结果动物额部外形术后明显改变.植入之BMMSCs-HA/TCP复合体与额骨表面紧密融合,强度似骨,复合体内广泛分布着新生骨组织,成骨性好.结论经培养扩增的BMMSCs与HA/TCP复合植入额骨骨膜下在额骨表面形成骨组织,可用来改变面部形态,为颌面整形治疗提供了新的思路.     

Biocompatibility of Ricinus communis polymer with addition of calcium carbonate compared to titanium. Experimental study in guinea pigs

Objective

The aim of the present investigation was to determine whether the difference in inflammatory tissue reaction between the Riccinus communis (castor) polymer with calcium carbonate and the titanium implant is statistically significant.

Methods

Thirty-two Cavia porcellus were allocated into four groups of eight animals each. We implanted the two types of materials in the retroperitoneal space of all the animals. They were euthanized at 7, 20, 30 and 40 days after surgery, and an histological study of the samples was conducted.

Results

All implants showed characteristics of chronic inflammation regardless of the material and timepoint of evaluation. There was no statistically significant difference between Pm+CaCO₃ and Ti with regard to the presence of granulation tissue, tissue congestion, histiocytes, lymphocytes, neutrophils, giant cells, and fibrosis (P> 0.05).

Conclusion

The castor oil polymer plus calcium carbonate implant was not statistically different from the titanium implant regarding inflammatory tissue reaction.