面包干酵母致热病理模型的改良研究

目的改良干酵母悬液致热病理模型 ,消除动物皮下注射后存在的体温下降期。方法将酵母悬液在34℃恒温水浴中孵育 0 .5h ,与对照组 (未孵育酵母悬液 )比较大鼠皮下注射后 1、2、3、4、6、8h的肛温。结果孵育组体温无下降期 ,升温快。两组大鼠各测点经t检验 ,均有显著性差异P <0 .0 5或P <0 .0 1。结论 34℃体外孵育干酵母悬液 0 .5h后致热病理模型 ,大鼠体温无下降期。     

Effects of artificial eggs on prolactin secretion, steroid levels, brood patch development, incubation onset and clutch size in the yellow-eyed penguin (Megadyptes antipodes)

Several studies have shown that the transition from egg laying to incubation behavior in birds is associated with changes in plasma levels of prolactin and steroid hormones. However, any effect of the tactile and visual input provided by eggs at initiating these hormonal changes has not been fully investigated in wild birds. A few days before yellow-eyed penguins, Megadyptes antipodes, started egg laying, we placed an artificial egg into their nests or under cages next to their nest. We then investigated the effect of the tactile and/or visual stimulus of such an artificial egg on prolactin secretion, steroid hormone levels (total androgen, estradiol and progesterone), brood patch development, incubation onset and clutch size in these penguins. Prolactin levels rose in females in response to having an artificial egg in the nest, while they declined considerably in males. Total androgen concentrations in males were less than 7% of those of control males and the levels prior to egg placement. Brood patch width increased in both males and females. Additionally, an egg in the nest caused yellow-eyed penguin pairs to attend and sit prone on their nest more frequently. Females that initiated egg laying 1 or 2 days after placement of the artificial egg in the nest, laid a full clutch of two eggs, while most other females that were exposed to an artificial egg in their nest, laid only a single egg. In contrast, the visual stimulus of an artificial egg alone (that was placed under a cage) did not influence hormone levels, brood patch development, incubation behavior or clutch size. The stimulation of an egg in the nest influences prolactin and total androgen levels in yellow-eyed penguins, particularly in males. While brood patch development and incubation behavior were initiated and egg laying was terminated in response to an artificial egg in the nest, the exact endocrine mechanisms underlying these physiological and behavioral changes remain poorly understood. We encourage further studies on other bird species taking an experimental approach to investigate the direct influence of hormones in initiating brood patch development and incubation behavior. Moreover, such experimental studies will widen our understanding of the endocrine mechanisms that regulate clutch size.     

Kunststoffkompatibilitätsstudien

Zuaammenjmsung Zum Studium der Verträglichkeit von Kunststoffen mit Blut wurden einerseits Untersuchungen an implantierten Kunststoffherzen vorgenommen, andererseitsin vitro-Methoden erarbeitet, die es gestatten, mehrere, verschiedene Kunststoffproben gleichzeitig zu prüfen. Bei denin vivo-Untersuchungen handelte es sich im wesentlichen um Beobachtungen und lichtmikroskopische Dokumentationen der Oberflächen eingesetzter Kunststofforgane. Bei denin vitro—Tests wurden aufgetropfte sowie in Vertiefungen eingebrachte Blut— und Plasmaproben an folgenden Kunststoffsorten auf ihre Benetzungefähigkeit, Ausbreitungstendenz, ihr Verhalten nach längerer Inkubation untersucht: Silastic, Silastic mit Dacron-Velour, Silastic mit Dacron-Flock, Silastic mit Graphit, Teflon, Hydron sowie PVC. Schließlich wurden verschiedene Kunststoffe in Kontakt mit kultivierten Fibroblasten auf deren Beschichtungsfähigkeit bzw. Endothelbildung auf den Oberflächen dieser Kunststoffe geprüft.An Untersuchungstechniken wurden neben den genannten lichtmikroskopischen einige zusätzliche Mikroskopiermethoden, wie Phasenkontrasttechnik und Stereomikroskopie, verwendet, ferner immunologische sowie Gewebekulturmethoden.Die Befunde an implantierten Kunststoffherzen wiesen vor allem auf Fibrinund Thrombenauflagerungen, endo- sowie perikardial, hin, wobei die Bereiche der Vorhöfe und insbesondere der Gefäßabgänge des rechten Herzens besonders betroffen waren. — In der erstenin vitro Testreihe zeigte Teflon den stärksten Abstoßungseffekt gegenüber Blut und Plasma. — In der zweiten in vitro-Testreihe konnte an den verwendeten Kunststoffoberflächen ein Niederschlag von Fibrinogen (sowie Fibrin), in einigen Fällen aber auch von Albumin und Immuglobulinen, im inkubierten Plasma eine Reduzierung des Fibrinogens, festgestellt werden. — Bei den Versuchen mit Fibroblasten in Kontakt mit Kunststoffoberflächen erwies sich die glatte Silasticpräparation für die Entwicklung eines endothelialen Überzuges als am günstigsten.

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Studies on compatibility between plastics and blood

Summary Studying the compatibility of plastics and blood, at the one hand analyses were undertaken on artificial hearts implanted in calves, at the other hand in vitro techniques were gained by working for the purpose of testing several (different) fabrics simultaneously. Concerning the in vivo examinations there were made observations and documentations using light microscopy of the plastics surfaces. Concerning thein vitro-methods there were tested blood and plasma samples in drops and in cavities of the following plastic materials with the special respect of their moisteness, expansion and their relation to the surfaces during longer incubation: Silastic, Silastic combined with Dacron-Velour, Silastic with Dacron-Flock, Silastic with graphite, Teflon, Hydron as well as PVC. At least, several fabrics were tested after having seeded them with cultivated fibroblasts looking at the ability of forming endothelium-like membranes at the surfaces of those plastics.As to the techniques used in these experiments there were taken light microscopic methods — as told —, as well as phase contrast and stereomicroscopic techniques, moreover there were used immunologic and tissue culture methods.The findings of artificial hearts implanted, indicated layers of fibrin and thrombi in endo- and pericardial areas, especially in the part of atrium and in the region of vascular origins of the right heart. — In the firstin vitro series, Teflon showed the best repelling effect against blood and plasma. — In the secondin vitro row a deposit of fibrinogen (and fibrin), in some cases also of albumin and immunoglobulins on the plastics' surfaces and a diminution of fibrinogen in the plasma samples incubated on plastics could be seen. — In the experiments with fibroblasts in contact with fabrics' surfaces, the smooth Silastic preparation proved to be the best one for stimulating an endothelial layer.

     

Toward a model of drug relapse: an assessment of the validity of the reinstatement procedure

Background and rationale The reinstatement model is widely used to study relapse to drug addiction. However, the model’s validity is open to question.Objective We assess the reinstatement model in terms of criterion and construct validity.Research highlights and conclusions We find that the reinstatement model has adequate criterion validity in the broad sense of the term, as evidenced by the fact that reinstatement in laboratory animals is induced by conditions reported to provoke relapse in humans. The model’s criterion validity in the narrower sense, as a medication screen, seems promising for relapse to heroin, nicotine, and alcohol. For relapse to cocaine, criterion validity has not yet been established primarily because clinical studies have examined medication’s effects on reductions in cocaine intake rather than relapse during abstinence. The model’s construct validity faces more substantial challenges and is yet to be established, but we argue that some of the criticisms of the model in this regard may have been overstated.     

Effect of estradiol implants on reproductive behavior of female Lapland longspurs (Calcarius lapponicus)

The role of estrogens in reproductive behavior of free-living birds has been little investigated, despite the importance of estrogens in coordinating reproductive behavior and the need for information on potential effects of estrogenic contaminants on wildlife. We gave subcutaneous implants of estradiol (E₂) to 15 female Lapland longspurs (Calcarius lapponicus), an arctic bird with a six-week breeding season. Controls were 9 females with empty implants and 14 unimplanted females. After implantation, E₂ females had greater E₂ levels and greater body mass than controls. We did not detect any increases in, or prolongation of, sexual or nest-building behavior. The incubation period was longer for E₂ nests than for control nests. Nest videotapes showed that E₂ females and their mates exhibited normal nestling care, and nestling growth, fledging success, and overwinter survival were also unaffected. However, whenever the males arrived at the nests, E₂ females showed a significantly greater likelihood of begging from the male rather than leaving the nest. Courtship or incubation feeding have been considered atypical for this species, and it is not clear what role E₂ normally plays in promoting begging behavior. Overall, elevated E₂ levels did not result in any obvious costs for the female, save perhaps for slightly reduced incubation efficiency. The weak response to hormonal implants is similar to patterns seen in male Lapland longspurs, and may be related to the short breeding season. However, since little is presently known about the role of estrogens in behavior of wild female birds, it remains to be seen whether these patterns are typical of female passerines in general, or of short-season breeders. Further research on effects of estrogens (both exogenous and endogenous) on free-living female birds is needed.     

一起农村新型冠状病毒肺炎聚集性疫情的调查分析

目的 通过对南昌市一起农村新型冠状病毒肺炎聚集性疫情调查,了解农村疫情传播可能的危险因素,分析和比较确诊病例和无症状感染者的传染性。 方法 通过流行病学调查,结合大数据轨迹开展病例调查,用病例关系示意图展示传播关系。结果 确诊病例和无症状感染者的密切接触者续发率分别为45.45%和12.50%,两者无统计学差异（P=0.077）,罹患率分别为27.27%和0%,两者有统计学差异（P=0.025）;核酸全员筛检前后新冠病毒感染率分别为0.49%和0%,两者有统计学差异（〖XC小五号.EPS;P〗=7.09,P=0.008）;确诊病例发病前5天和无症状感染者具有传染性;农村居民串门聊天、聚众打牌等行为可能促进农村疫情的传播。结论 此次疫情因病例B引起,轨迹大数据分析可帮助寻找传染源;无症状感染者传染性可能弱于确诊病例。     

南昌市一起新型冠状病毒肺炎聚集性疫情传播链分析

目的 通过对南昌市一起新型冠状病毒肺炎（COVID-19）聚集性疫情调查,分析传播过程及病例发病前和无症状感染者的传染性,了解不同接触方式的传播风险。方法 通过传统流行病学调查,结合大数据轨迹开展病例调查,用传播链示意图展示传播关系。结果 传播关联病例27例,其中确诊病例25例,疑似病例1例（指征病例）,无症状感染者1例。搜索到密切接触者347人,密切接触者的感染率为7.2%（25/347）,其中,一代、二代、三代和四代病例的密切接触者感染率分别为52.6%（10/19）、6.1%（13/213）、2.3%（2/88）和0.0%（0/27）。无症状感染者能引起家庭内传播,与病例同餐、同住/同屋、工作接触、邻居间接触、诊疗护理/同病房和同一交通工具的密切接触者的感染率分别为10.6%（17/160）、10.0%（20/201）、5.3%（5/94）、0.0%（0/30）、0.0%（0/18）和0.0%（0/17）。结论 此次疫情传染源为来自武汉市的疑似病例D某,轨迹大数据分析可以帮助精准搜索病例和密切接触者,此次调查的基础上,提出的针对疫情防控措施有效。     

Temperature and ration effects on components of the IGF system and growth performance of rainbow trout (Oncorhynchus mykiss) during the transition from late stage embryos to early stage juveniles

The study investigated the effects of incubation temperature, and the size of ration fed to the transitional embryo/juvenile stage of rainbow trout (Oncorhynchus mykiss) on growth, liver and gastrointestinal (GI) tract IGF-1 content, and the expression of insulin-like growth factor-related genes (IGF-1, IGF-2, IGF-RIa, and IGF-RIb) by the liver and GI tract. Embryos were reared from zygote to "swim-up" at either 8.5 degrees C (E(8.5)) or 6.0 degrees C (E(6.0)); at "swim-up" (51-days post-fertilization [dpf] and 72-dpf for the E(8.5) and E(6.0) groups, respectively), the embryos were transferred to grow-up tanks supplied with water at 8.5 degrees C. Late stage embryos (LSEs) at the same developmental stage from the two temperature treatment groups (64-dpf and 86-dpf for the E(8.5) and E(6.0) groups, respectively) were fed with salmonid starter diet at levels of 5.0%, 2.0%, and 0.5% of live body mass per day. Embryos were sampled just prior to first feeding (PFEs), and before complete absorption of the yolk [late stage embryos (LSEs)], and early stage juveniles (ESJs) were sampled after yolk sac absorption when they were fully reliant on exogenous sources of food. The early incubation temperature and ration levels had significant affects on mortality (with lower mortalities in the E(6.0) group) and growth performance of the fish; dry body mass values for fish fed the 5.0% ration were significantly lower in the E(6.0) group of LSEs and ESJs compared with the respective treatment in the E(8.5) group; a similar pattern was seen for total body length, although this was only significant for the LSEs. Whole embryo IGF-1 content was significantly lower in the E(6.0) group compared with the E(8.5) group of PFEs, and hepatic IGF-1 content was significantly lower in the E(6.0) group fed the maintenance ration (0.5%) compared with the E(8.5) fed a similar ration; restricted ration significantly elevated hepatic IGF-1 content in the LSE stage for both temperature treatment groups. GI tract IGF-1 levels were considerably lower than in liver tissue, and there were no differences among treatment groups. Ration size-related differences were found for the expression of genes encoding for hepatic IGF-1, IGF-2, and IGF-RIb, and GI tract IGF-1, and IGF-2. Rearing temperature-related differences were also found for genes encoding for GI tract IGF-1, IGF-RIa, and IGF-RIb. The results of the study showed that the early rearing temperature of the embryos affected subsequent growth, and hepatic and GI tract gene expression by the LSEs and ESJs. As was the case for tissue IGF-1 content, with some exceptions, a restricted ration significantly elevated the expression of the targeted genes indicative of an important metabolic-regulating role for the IGF system during this transitional developmental phase. In addition, the higher abundance of IGF-2 mRNA compared with IGF-1 mRNA, and the higher abundance of IGF-RIa, relative to IGF-RIb, suggests that these two genes may also play a regulatory role during this transitional developmental phase.     

时间、二相性、pH环境对白色假丝酵母菌药物敏感性的影响

目的:研究孵育时间、二相性、pH环境对白色假丝酵母菌药物敏感性的影响。方法:参照美国临床实验室标准化委员会(NCCLS)推荐的M27-A方案的微量液基稀释法,测量5种常用抗真菌药物抗102株白色假丝酵母菌24h、48h的最低抑菌浓度(MIC)及在pH7.0和pH4.0环境下特比奈芬抗60株白色假丝酵母菌孢子相和菌丝相的MIC值。结果:(1)pH7.0环境下的孢子相液基中,咪康唑、伊曲康唑、克霉唑、氟康唑和制霉菌素24h与48h的MIC值基本符合率为91.2%～100%;(2)5种抗真菌药的药敏符合率均达80%以上。伊曲康唑24h与48h的药敏符合率稍低,为81.4%,其他4种药物药敏符合率为96.1%～100%;(3)pH7.0环境下,特比奈芬抗白色假丝酵母菌孢子相和菌丝相的MIC值差异无统计学意义(P=0.792),pH4.0环境下,孢子相液基的MIC值比菌丝相高,差异有统计学意义(P<0.001);(4)无论孢子相还是菌丝相液基,特比奈芬在pH4.0环境下的MIC值高于pH7.0环境,差异有统计学意义(P<0.001)。结论:孵育时间、二相性、pH环境对白色假丝酵母菌药物敏感性有影响。