Effects of physical training and thyroxine on rodent cardiac functional and biochemical properties

The effects of 8 weeks of interval running and of 14 days of thyroxine treatment were studied on selected cardiac functional and biochemical parameters of contraction in both female guinea pigs and rats. Relative to their respective sendentary-control groups, both trained groups demonstrated typical exercise adaptations of resting bradycardia and of increases in skeletal muscle oxidative enzymes and relative heart mass (P<0.05). Myosin ATPase, Ca²⁺ regulated myofibril ATPase, and +dP/dt max were at least two-fold higher in rats compared to guinea pigs (P<0.001). Physical training did not augment any of these parameters in either species under the experimental conditions studied. However, biochemical and functional indices of intrinsic cardiac contractility in guinea pigs were increased by injections of thyroxine; whereas, the same treatment regimen was without effect on the rats. These findings suggest that chronic running does not alter the intrinsic cardiac contractility state in either species. Also, exercise doesn't change the thyroid state of the guinea pig to a level sufficient to affect cardiac function.     

Studies on cell proliferation and tracer localization in the kidneys of guinea pigs with experimental autoimmune anti-tubular basement membrane nephritis

The mitotic activity in kidneys of guinea pigs with experimental autoimmune anti-tubular basement membrane (TBM) nephritis was investigated using autoradiographic techniques to determine the uptake of [3H]thymidine by actively dividing cells. It was observed in these animals that cells of proximal tubules, distal tubules, cortical and medullary interstitium, medullary collecting ducts, and loops of Henle took up significantly greater amounts of [3H]thymidine when compared with normal animals. In addition, the behaviour of horseradish peroxidase (HRP) and goat anti-HRP IgG in extraglomerular sites in the kidneys of these animals was studied. Contrary to what was expected, these tracers appeared to be less concentrated in the tubules and interstitium of animals with anti-TBM disease, with tracer movement restricted in areas of disrupted TBM. The significance of these observations is discussed.     

骨髓间充质干细胞移植对豚鼠皮肤深Ⅱ度烧伤的治疗作用

目的探讨骨髓间充质干细胞 (MSCs)治疗皮肤深Ⅱ度烧伤的机制。方法体外培养扩增的MSCs悬液 ,以 2× 10 6/ml(A组 )和 2× 10 7/ml(B组 )两种细胞密度移植给皮肤深Ⅱ度烧的受体鼠创面 ,观察创面愈合速度 ,用免疫组织化学检测因子Ⅷ的表达。细胞移植后的第 15、3 0、5 0天 ,通过PCR方法检测创面皮肤组织中移植供体鼠的Y染色体基因表达。结果A、B组治疗侧的创面愈合速度均快于对照侧 ,A、B组治疗侧间无显著性差异。因子Ⅷ检测示第 15、3 0天时 ,A、B两组的微血管密度均多于对照侧 ,A、B组治疗侧间无显著性差异。PCR检测结果表明 ,第 15、3 0、5 0天时在部分受体鼠恢复的创面上有供体鼠Y染色体基因表达。结论骨髓MSCs对皮肤深Ⅱ度烧伤具有明显的疗效。     

微超声探头诊断食道隆起性病变的价值

目的 探讨经内镜微超声探头(TEMP)对食道隆起性病变的诊断价值。方法 对67例电子胃镜疑有食道隆起性病变者行经内镜微超声探头检查。结果 67例中平滑肌瘤8例，平滑肌肉瘤1例，早期和进展期癌各5例，囊肿24例，壁外压迫9例，食道静脉瘤6例，静脉曲张3例，炎症2例，异位胰腺1例，息肉2例。结论 经内镜微超声探头对食道隆起性病变有较大的诊断价值。     

Release of pig leukocytes and reduced human NK cell recruitment during ex vivo perfusion of HLA‐E/human CD46 double‐transgenic pig limbs with human blood

Background

In pig‐to‐human xenotransplantation, interactions between human natural killer (NK) cells and porcine endothelial cells (pEC) are characterized by recruitment and cytotoxicity. Protection from xenogeneic NK cytotoxicity can be achieved in vitro by the expression of the non‐classical human leukocyte antigen‐E (HLA‐E) on pEC. Thus, the aim of this study was to analyze NK cell responses to vascularized xenografts using an ex vivo perfusion system of pig limbs with human blood.

Methods

Six pig forelimbs per group, respectively, stemming from either wild‐type (wt) or HLA‐E/hCD46 double‐transgenic (tg) animals, were perfused ex vivo with heparinized human blood for 12 hours. Blood samples were collected at defined time intervals, cell numbers counted, and peripheral blood mononuclear cells analyzed for phenotype by flow cytometry. Muscle biopsies were analyzed for NK cell infiltration. In vitro NK cytotoxicity assays were performed using pEC derived from wt and tg animals as target cells.

Results

Ex vivo, a strong reduction in circulating human CD45 leukocytes was observed after 60 minutes of xenoperfusion in both wt and tg limb groups. NK cell numbers dropped significantly. Within the first 10 minutes, the decrease in NK cells was more significant in the wt limb perfusions as compared to tg limbs. Immunohistology of biopsies taken after 12 hours showed less NK cell tissue infiltration in the tg limbs. In vitro, NK cytotoxicity against hCD46 single tg pEC and wt pEC was similar, while lysis of double tg HLA‐E/hCD46 pEC was significantly reduced. Finally, circulating cells of pig origin were observed during the ex vivo xenoperfusions. These cells expressed phenotypes mainly of monocytes, B and T lymphocytes, NK cells, as well as some activated endothelial cells.

Conclusions

Ex vivo perfusion of pig forelimbs using whole human blood represents a powerful tool to study humoral and early cell‐mediated rejection mechanisms of vascularized pig‐to‐human xenotransplantation, although there are several limitations of the model. Here, we show that (i) transgenic expression of HLA‐E/hCD46 in pig limbs provides partial protection from human NK cell‐mediated xeno responses and (ii) the emergence of a pig cell population during xenoperfusions with implications for the immunogenicity of xenografts.     

Inferring within‐herd transmission parameters for African swine fever virus using mortality data from outbreaks in the Russian Federation

Mortality data are routinely collected for many livestock and poultry species, and they are often used for epidemiological purposes, including estimating transmission parameters. In this study, we infer transmission rates for African swine fever virus (ASFV ), an important transboundary disease of swine, using mortality data collected from nine pig herds in the Russian Federation with confirmed outbreaks of ASFV . Parameters in a stochastic model for the transmission of ASFV within a herd were estimated using approximate Bayesian computation. Estimates for the basic reproduction number varied amongst herds, ranging from 4.4 to 17.3. This was primarily a consequence of differences in transmission rate (range: 0.7–2.2), but also differences in the mean infectious period (range: 4.5–8.3 days). We also found differences amongst herds in the mean latent period (range: 5.8–9.7 days). Furthermore, our results suggest that ASFV could be circulating in a herd for several weeks before a substantial increase in mortality is observed in a herd, limiting the usefulness of mortality data as a means of early detection of an outbreak. However, our results also show that mortality data are a potential source of data from which to infer transmission parameters, at least for diseases which cause high mortality.     

Co‐circulation of multiple genotypes of African swine fever viruses among domestic pigs in Zambia (2013–2015)

During 2013–2015, several and severe outbreaks of African swine fever (ASF ) affected domestic pigs in six provinces of Zambia. Genetic characterization of ASF viruses (ASFV s) using standardized genotyping procedures revealed that genotypes I, II and XIV were associated with these outbreaks. Molecular and epidemiological data suggest that genotype II ASFV (Georgia 2007/1‐like) detected in Northern Province of Zambia may have been introduced from neighbouring Tanzania. Also, a genotype II virus detected in Eastern Province of Zambia showed a p54 phylogenetic relationship that was inconsistent with that of p72, underscoring the genetic variability of ASFV s. While it appears genotype II viruses detected in Zambia arose from a domestic pig cycle, genotypes I and XIV possibly emerged from a sylvatic cycle. Overall, this study demonstrates the co‐circulation of multiple genotypes of ASFV s, involvement of both the sylvatic and domestic pig cycle in ASF outbreaks in Zambia and possible trans‐boundary spread of the disease in south‐eastern Africa. Indeed, while there is need for regional or international concerted efforts in the control of ASF , understanding pig marketing practices, pig population dynamics, pig housing and rearing systems and community engagement will be important considerations when designing future prevention and control strategies of this disease in Zambia.     

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。