Comparative analysis of heart functions in micropigs and conventional pigs using echocardiography and radiography

The production of miniature animals has been suggested for use in organ transplantation. At present, many of the studies about application of animal organs to human have been focused on pigs because of the number of advantages involved and due to their similarities with human. However, a physiological analysis of the organs to be transplanted has not yet been carried out. Therefore, this study analyzed whether or not there were physiological and morphological differences in the hearts of conventionally-reared pigs and micropigs. In this study, the morphological and physiological functions of the heart were examined using radiographic and echocardiographic equipment. In the lateral radiographic view, the heart of the micropig has a larger cardiac long axis : short axis ratio than does the conventional pig, but the difference in the vertebral heart score was not significant. In addition, there were no morphological differences on the X-ray fluoroscopic view. There were no differences in echocardiographic values, except for several values in the left ventricle traces. Overall, it is expected that the values measured in this study will contribute to understanding of the physiological characteristics of micropigs.     

Cardiac troponin I in the normal dog and cat

Cardiac troponin I (cTnI) has proven to be a highly specific and sensitive marker for myocardial cellular damage in many mammalian species. The structure of cTnI is highly conserved across species, and assays for human cTnI (including the one used in the current study) have been validated in the dog. Blood concentrations of cTnI rise rapidly after cardiomyocyte damage, and assay of cTnI potentially may be valuable in many clinical diseases. The purpose of this study was to establish the normal range of cTnI in heparinized plasma of dogs and cats. Forty one clinically normal dogs and 21 cats were included in the study. One to 3 milliliters of blood were collected by venipuncture into lithium heparin vacutainers for analysis of cTnI (Stratusz CS). The range of plasma cTnI concentrations in dogs was <0.03 to 0.07 ng/mL with a mean of 0.02 ng/mL, with the upper tolerance limit (0.07 ng/mL) at the 90th percentile with 95% confidence. In cats, the range was <0.03 to 0.16 ng/mL with a mean of 0.04 ng/mL, and the upper tolerance limit (0.16 ng/mL) at the 90th percentile as well with 90% confidence. This study establishes preliminary normal ranges of plasma cTnI in normal dogs and cats for comparison to dogs and cats with myocardial injury or disease.     

Allergen-induced production of IL-31 by canine Th2 cells and identification of immune,skin, and neuronal target cells

The canine cytokine IL-31 induces pruritus in dogs and can be detected in dogs with atopic dermatitis; however very little is understood around its interactions with specific canine cells. We hypothesize that IL-31 is involved in the progression of allergic skin disease by coordinating the interaction between the immune system with skin and neuronal systems. The goal of the following work was to identify cells that produce IL-31 as well as cells that may respond to this cytokine. Peripheral blood mononuclear cells (PBMCs) were collected from naïve and house dust mite (HDM) allergen-sensitized beagle dogs and used for ex vivo characterization of cytokine production assessed using ELISpot and quantitative immunoassay. Sensitization to HDM allergen induced a T-helper type 2 (Th2) cell phenotype characterized by an increase in the production of IL-4 protein. Interestingly, repeated allergen challenge over time also resulted in an increase in IFN-γ. Further evaluation showed that co-stimulation of Th2 polarized cells with antigen and the bacterial component Staphylococcus enterotoxin B (SEB) produced higher levels of IL-31 compared to either stimulant alone. Production of IL-31 when PBMCs were stimulated by T cell mitogens suggests T cells as a source of IL-31. Quantitative real-time PCR was utilized to determine expression of the IL-31 receptor alpha chain in canine cell lines and tissue. Canine monocytic cells, keratinocytes, and dorsal root ganglia were shown to express the IL-31 receptor alpha chain mRNA. In a multifaceted disease such as canine atopic dermatitis, the combination of Th2 polarization and microbial presence may lead to IL-31 mediated effects driving inflammation and pruritus by immune cells, keratinocytes, and direct neuronal stimulation.     

新生大鼠心肌细胞的分离和培养

为获得高纯度和高存活率的心肌细胞,探索心肌细胞大量培养的条件,并为进一步研究心肌细胞的细胞生物学特性奠定基础,同时为生理学和药理学研究提供细胞来源,试验采用胰蛋白酶顺序消化法及差速贴壁法,从1～2d龄新生大鼠的心肌组织中分离心肌细胞,观测心肌细胞的形态、结构、搏动状态和反映心肌细胞代谢状况的生化参数。结果表明,分离所得的心肌细胞纯度高,培养第3天就开始自发搏动,后连接成片,进而同步收缩;心肌细胞的亚显微结构包括肌丝、Z线、线粒体和大量糖原颗粒,葡萄糖比消耗率为7.44nmol/(个·d),乳酸比产率为3.83nmol/(个·d),乳酸转化率为51%,细胞代谢非常旺盛,说明试验培养条件有利于心肌细胞的气体交换和营养物质的摄取,从而有利于心肌细胞的生长。     

硝苯地平控释片治疗无痛性心肌缺血对左心功能的影响

硝苯地平（２０ｍｇ，ｑ１２ｈ×３ｗｋ）治疗无痛性心肌缺血２３例（男１５例，女８例，年龄５５±９．４ａ），对左心功能和ＲＡＡ检测结果显示：治疗后ＨＲ、ＳＢＰ、ＤＢＰ和ＭＡＰ均降低，以ＤＢＰ和ＭＡＰ降低显著（Ｐ＜０．０５）；缺血型ＳＴ段明显改善（Ｐ＜０．０１）；核素心功能ＬＶＥＦ、ＳＶ、ＥＲ和ＲＣＯ均升高（Ｐ＜０．０５～０．０１）；血浆ＰＲＡ和ＡｎｇⅡ降低明显（Ｐ＜０．０５）。表明该药有良好的降压和改善左心功能效应。     

Combined effects of dexmedetomidine and vatinoxan infusions on minimum alveolar concentration and cardiopulmonary function in sevoflurane-anesthetized dogs

ObjectiveTo evaluate the effects of combined infusions of vatinoxan and dexmedetomidine on inhalant anesthetic requirement and cardiopulmonary function in dogs.Study designProspective experimental study.MethodsA total of six Beagle dogs were anesthetized to determine sevoflurane minimum alveolar concentration (MAC) prior to and after an intravenous (IV) dose (loading, then continuous infusion) of dexmedetomidine (4.5 μg kg^–1 hour^–1) and after two IV doses of vatinoxan in sequence (90 and 180 μg kg^–1 hour^–1). Blood was collected for plasma dexmedetomidine and vatinoxan concentrations. During a separate anesthesia, cardiac output (CO) was measured under equivalent MAC conditions of sevoflurane and dexmedetomidine, and then with each added dose of vatinoxan. For each treatment, cardiovascular variables were measured with spontaneous and controlled ventilation. Repeated measures analyses were performed for each response variable; for all analyses, p < 0.05 was considered significant.ResultsDexmedetomidine reduced sevoflurane MAC by 67% (0.64 ± 0.1%), mean ± standard deviation in dogs. The addition of vatinoxan attenuated this to 57% (0.81 ± 0.1%) and 43% (1.1 ± 0.1%) with low and high doses, respectively, and caused a reduction in plasma dexmedetomidine concentrations. Heart rate and CO decreased while systemic vascular resistance increased with dexmedetomidine regardless of ventilation mode. The co-administration of vatinoxan dose-dependently modified these effects such that cardiovascular variables approached baseline.Conclusions and clinical relevanceIV infusions of 90 and 180 μg kg^–1 hour^–1 of vatinoxan combined with 4.5 μg kg^–1 hour^–1 dexmedetomidine provide a meaningful reduction in sevoflurane requirement in dogs. Although sevoflurane MAC-sparing properties of dexmedetomidine in dogs are attenuated by vatinoxan, the cardiovascular function is improved. Doses of vatinoxan >180 μg kg^–1 hour^–1 might improve cardiovascular function further in combination with this dose of dexmedetomidine, but beneficial effects on anesthesia plane and recovery quality may be lost.