母体埋植褪黑激素对子一代獭兔内脏组织中RORα基因表达的影响

本研究旨在探讨獭兔母体埋植褪黑激素(MT)对RORα基因在子一代獭兔内脏组织中的表达及影响,选择110只相近月龄的健康母獭兔同日配种,第5日后选出已确定妊娠的母兔76只,随机平均分为2组,对照组母兔不做处理,试验组母兔埋植10 mg MT。在仔兔出生第1天时每组选15只宰杀,取皮肤、肌肉、肺脏、心脏、肝脏、肾脏及十二指肠组织样品,测定仔兔组织样品中RORα基因的表达量,结果表明:RORα基因在子一代獭兔各组织中的表达量与表达模式均不同,该基因在子一代獭兔皮肤组织中的表达水平极显著上调,在肌肉、肺脏组织中显著上调,在肝脏组织中极显著下调,在心脏、肾脏组织中显著下调,在十二指肠中的表达与对照组相比无显著变化。     

Phenotype evaluation of human and canine isolates of Leishmania infantum

Human visceral leishmaniasis (VL) and canine leishmaniasis (CanL) in countries of South and Central America are caused by Leishmania infantum and has been endemic in Brazil for several years. The parasite biodiversity as well as the pharmacologic properties of drugs and the host species, are involved in the efficacy or inefficacy of leishmaniasis treatments. Although there are substantial number of reports describing the genetic characterization of the clinical field isolates of L. infantum,the phenotypic parameters have been less studied. In this study isolates from human and canine leishmaniasis (Hum1 and Can1) obtained in Campinas, São Paulo state, Brazil were identified as L. infantum. The Hum1 and Can1 isolates exhibited typical promastigote growth pattern. Regarding morphological features Can1 isolate differed in cell size. The infectivity in vitro of both isolatesis lower compared to the reference strain of L. infantum. Moreover, the in vivo infectivity of the three parasites is similar in Balb/c mice. The Hum1 isolate is more sensitive to leishmanial drugs (amphotericin B, miltefosine and glucantime) than the Can1 isolate when inside human macrophages, but not when inside canine macrophages. These findings indicated that L. infantum isolates differs in some phenotypic characteristics.     

Effect of the daily meal time on the growth of rainbow trout fed different ration levels

This study examined the effect of ration level and time of delivery of a single daily meal on the growth performance of rainbow trout held under constant water temperature and a natural photoperiod. Two similar trials were conducted, the first from March to July, 1992, using ration levels of 0.5, 1.5 and 2.5% BW d^–1 and the second from August 1992 to January 1993, using ration levels of 1.5, 2.0 and 2.5% BW d^–1.In five of the six treatment groups (three ration levels × two seasons), when the daily meal was presented in the post-dawn period the growth rate was lower than in trout fed at either mid-light or pre-dusk. No time-of-feeding effect was found when trout were fed excess rations. Specific growth rate (SGR) was not affected by feeding time, but was correlated with ration level; furthermore, there was a significant increase in SGR during the first section of the first trial and a significant decrease in the SGR throughout the duration of the second trial.Ration level was significantly correlated with condition factor, carcass visceral adipose tissue content and skeletal muscle lipid content, but there was no effect of the timing of the daily meal on these variables.     

木材对生物体调节特性的研究(Ⅰ)-冬季条件下不同内装环境对小白鼠生长的影响

以昆明种小白鼠作为实验动物，探讨冬季条件下不同的居室环境对小白鼠生长的影响。通过体重、脏器重量和行为学的观察比较与分析，说明不同的箱体材料对小白鼠的生长产生不同程度的影响，木质材料内装环境对小白鼠有良好的调节作用。     

The development of a real-time PCR assay for the quantification of Leishmania infantum DNA in canine blood

Recent research has demonstrated the high sensitivity of real time PCR (qPCR) in the diagnosis of Leishmania infantum infection. The goal of this study was to develop and evaluate a qPCR detection system for the diagnosis of visceral leishmaniosis (VL) in dogs. Specific primer sets were developed for the Leishmania donovani complex, in which a fragment of 132 bp of kDNA from L. infantum was amplified. The reaction was performed using the ABI PRISM 7000 system with ABI PRISM software used to carry out the analysis. When canine blood samples were assessed using this system the detection limit of the method was found to be 0.07 parasites per reaction, the efficiency was 94.17% (R² = 0.93, slope = −3.47) and the sensitivity and specificity were 100% and 83.33% respectively. The use of such a sensitive, reproducible and rapid qPCR-based assay will be useful in the diagnosis and control of L. infantum infection in endemic areas, where serological surveys often underestimate true disease prevalence.     

Identification of highly specific and cross-reactive antigens of Leishmania species by antibodies from Leishmania (Leishmania) chagasi naturally infected dogs

The Leishmania species present a genetic homology that ranges from 69 to 90%. Because of this homology, heterologous antigens have been used in the immunodiagnosis and vaccine development against Leishmania infections. In the current work, we describe the identification of species-specific and cross-reactive antigens among several New World Leishmania species, using symptomatic and asymptomatic naturally Leishmania chagasi-infected dog sera. Soluble antigens from five strains of New World Leishmania were separated by electrophoresis in SDS-PAGE and immunoblotted. Different proteins were uniquely recognized in the L. chagasi panel by either symptomatic or asymptomatic dog sera suggesting their use as markers for the progression of disease and diagnosis of the initial (sub-clinical) phase of the infection. Cross-reactive antigens were identified using heterologous antigenic panels (L. amazonensis strains PH8 and BH6, L. guyanensis and L. braziliensis). L. guyanensis panel showed the highest cross-reactivity against L. chagasi specific antibodies, suggesting that proteins from this extract might be suitable for the diagnosis of visceral canine leishmaniasis. Interestingly, the 51 and 97 kDa proteins of Leishmania were widely recognized (77.8% to 100%) among all antigenic panels tested, supporting their potential use for immunodiagnosis. Finally, we identified several leishmanial antigens that might be useful for routine diagnosis and seroepidemiological studies of the visceral canine leishmaniasis.     

(−)-α-Bisabolol attenuates visceral nociception and inflammation in mice

The study examined the antiinflammatory and antinociceptive effects of the sesquiterpene (−)-α-bisabolol (BISA). The antiinflammatory effect was evaluated on acute models of dermatitis induced by Croton oil, arachidonic acid, phenol and capsaicin, respectively, in mouse ear. BISA inhibited the dermatitis induced by all noxious agents, except capsaicin. BISA was assessed in two established mouse models of visceral nociception. Mice were pretreated orally with BISA, and the pain-related behavioral responses to intraperitoneal cyclophosphamide or to intracolonic mustard oil were analyzed. BISA showed a dose-unrelated significant antinociception. Collectively, the results suggest that BISA may be an topical antiinflammatory and visceral antinociceptive agent.     

Tissue distribution of Leishmania chagasi and lesions in transplacentally infected fetuses from symptomatic and asymptomatic naturally infected bitches

Visceral leishmaniasis (VL) is primarily transmitted by an invertebrate vector, but transmission in the absence of the vector has been reported. Vertical transmission of VL has been described in man and dogs. The aim of this study was to evaluate the distribution of Leishmania amastigotes in fetal organs and histopathologic changes associated with parasitism and to determinate the frequency of transplacental transmission and potential of vertical transmission by symptomatic and asymptomatic pregnant bitches. Symptomatic (n = 4) and asymptomatic (n = 4) pregnant bitches, serologically and parasitologically positive for Leishmania sp., carrying a total of 53 fetuses (26 from symptomatic and 27 from asymptomatic bitches) were selected at the Veterinary Hospital of the National University of Asuncion, Paraguay. Samples of placenta and fetal organs such as liver, spleen, lymph nodes, bone marrow, kidney and heart were histologically evaluated and processed for immunodetection of amastigotes and PCR. There were no lesions compatible with VL in fetal tissues in spite of the presence of amastigotes, particularly in lymphoreticular tissues. However, fetal hepatocytes had marked degenerative changes that were independent of the presence of amastigotes in liver. Twenty-six out of 53 placentas (13 symptomatic and 13 asymptomatic) and a total of 17 fetuses out of 53 (nine symptomatic and eight asymptomatic) were PCR positive. Together these findings indicate a high frequency of transplacental transmission and no differences in the potential of transmission when symptomatic were compared to asymptomatic pregnant bitches.     

饲粮中添加啤酒花渣对肉仔鸡内脏器官发育及肠道微生物的影响

[目的]探讨啤酒花渣的饲用价值,为其用作动物饲料提供依据.[方法]试验选用300只1日龄AA肉鸡,随机分为6组,在饲粮中分别加入0、4％、8％、12％、16％、20％啤酒花渣,探讨啤酒花渣对肉仔鸡内脏器官发育及肠道微生物的影响.[结果]各试验祖肉仔鸡的肝脏重、肝脏指数、心脏重、心脏指数、脾脏重、脾脏指数、肌胃重、肌胃指数差异均不显著(P＞0.05).在饲粮中添加8％和16％啤酒花渣显著降低了肠道乳酸杆菌的数量(P＜0.05),而对肠道大肠杆菌数量的影响不显著(P＞0.05).[结论]饲粮中添加啤酒花渣对肉仔鸡内脏器官发育及肠道大肠杆菌生长无不良影响,但添加8％和16％啤酒花渣会抑制肠道乳酸杆菌的生长.