Establishment of a syngeneic orthotopic model of prostate cancer in immunocompetent rats

We previously established 3 cell lines (PLS10, PLS20 and PLS30) from a chemically-induced prostate carcinoma in F344 rats, and demonstrated high potential for metastasis in nude mice. In the present study, we investigated the feasibility of establishing an orthotopic model using the 3 rat prostate cancer cell lines in immunocompetent rats with the aim of resolving species-mismatch problems and defects of immune systems. The PLS10, PLS20 and PLS30 cell lines were injected into the ventral prostates of 6-week-old rats, which were then sacrificed at experimental weeks 4 and 8. Tumor mass formation was found in rats with PLS10, but not in those with PLS20 or PLS30. Additionally, metastatic carcinomas could be detected in lymph nodes and lungs of PLS10-inoculated rats. Genetic analysis demonstrated K-ras gene mutations in PLS10 and PLS20, but not in PLS30 cells. There were no mutations in p53 and KLF6. In conclusion, we established a syngeneic orthotopic model for prostate cancer in immunocompetent rats simulating human castration-resistant prostate cancer (CRPC), which should prove useful for development and validation of therapeutic agents, especially with immunotherapy.     

二乙基亚硝胺诱发大鼠肝癌模型的建立及其应用

用二乙基亚硝胺诱发大鼠肝癌模型，通过病理学与影像学进行对照检查，证实成功诱发出肝癌病灶模型，并具有人相象的病变过程及病理学变化特征，同时具有人肝癌相似的影像学表现，是一种研究人类肝癌的理想动物模型。     

An alternative derivation method of mixed model equations from best linear unbiased prediction (BLUP) and restricted BLUP of breeding values not using maximum likelihood

Two mixed model equations (MME) for best linear unbiased prediction (BLUP) of breeding values and for restricted BLUP of breeding values were derived by maximum likelihood from the joint normal probability distribution of the observations and breeding values. As a result, MME is actually more general than maximum likelihood because we can prove that each set of solutions of MME are identical to BLUP and restricted BLUP of breeding values and then it does not depend on normality. In the present study, the author shows deriving directly each MME from BLUP and restricted BLUP equations for breeding values without assuming the joint normal distribution of the data and random effects. However, if we cannot assume the multivariate normal density distribution of the estimated aggregate breeding value and each breeding value for selected traits, the response to selection by restricted BLUP may deviate from the expected values.     

A vaccine formulation combining rhoptry proteins NcROP40 and NcROP2 improves pup survival in a pregnant mouse model of neosporosis

Currently there are no effective vaccines for the control of bovine neosporosis. During the last years several subunit vaccines based on immunodominant antigens and other proteins involved in adhesion, invasion and intracellular proliferation of Neospora caninum have been evaluated as targets for vaccine development in experimental mouse infection models. Among them, the rhoptry antigen NcROP2 and the immunodominant NcGRA7 protein have been assessed with varying results. Recent studies have shown that another rhoptry component, NcROP40, and NcNTPase, a putative dense granule antigen, exhibit higher expression levels in tachyzoites of virulent N. caninum isolates, suggesting that these could be potential vaccine candidates to limit the effects of infection. In the present work, the safety and efficacy of these recombinant antigens formulated in Quil-A adjuvant as monovalent vaccines or pair-wise combinations (rNcROP40 + rNcROP2 and rNcGRA7 + rNcNTPase) were evaluated in a pregnant mouse model of neosporosis. All the vaccine formulations elicited a specific immune response against their respective native proteins after immunization. Mice vaccinated with rNcROP40 and rNcROP2 alone or in combination produced the highest levels of IFN-γ and exhibited low parasite burdens and low IgG antibody levels after the challenge. In addition, most of the vaccine formulations were able to increase the median survival time in the offspring. However, pup survival only ensued in the groups vaccinated with rNcROP40 + rNcROP2 (16.2%) and rNcROP2 (6.3%). Interestingly, vertical transmission was not observed in those survivor pups immunized with rNcROP40 + rNcROP2, as shown by PCR analyses. These results show a partial protection against N. caninum infection after vaccination with rNcROP40 + rNcROP2, suggesting a synergistic effect of the two recombinant rhoptry antigens.     

Feline head and neck squamous cell carcinoma: a natural model for the human disease and development of a mouse model

Head and neck squamous cell carcinoma (H/N SCC) is a devastating disease in humans and cats, and shares similar features between the two species. The large population of pet cats inthe United States, along with the high incidence of oral SCC in the cat, makes the cat an attractive candidate as a natural model for the human disease. There are similarities in pathology, progression, outcome, resistance to treatment, possible aetiologies and p53 expression, and we discuss the benefits of the cat as a natural model. We describe the development of a nude mouse xenograft model of feline oral SCC using the SCCF1 cell line transfected with a luciferase expression construct. In vivo tumour growth and metastasis were measured using serial bioluminescent imaging, and tumours grew best in the subcutis. The cat and nude mouse models will be useful to investigate the pathogenesis and the molecular basis of H/N SCC, and for preclinical drug screening.     

Oral bioavailability of sulphonamides in ruminants: A comparison between sulphamethoxazole,sulphatroxazole, and sulphamerazine,using the dwarf goat as animal model

Summary

The various sulphonamides show marked differences in disposition characteristics after administration to ruminants. For use in combination with a diaminopyrimidine derivative such as trimethoprim or baquiloprim, it is essential that a sulphonamide has similar pharmacokinetic properties in order to obtain optimal synergy. In the present study the pharmacokinetics of sulphamethoxazole, sulphatroxazole, and sulphamerazine were investigated in dwarf goats (n=6) after IV and intraruminal administration at a dose of 30 mg/kg bodyweight. In addition, the in vitro binding of sulphamerazine to ruminal contents was studied as a possible explanation for a reduced absorption rate. Sulphamethoxazole showed the most rapid absorption after intraruminal administration (mean t_max ± SD : 0.8 ± 0.2h). However, the drug was rapidly eliminated from the plasma (t_1/2ß : 2.4 ± 1.5h) and the bioavailability was only 12.4 ± 4.7 %, most likely due to an extensive ‘first‐pass’ effect. The bioavailability of orally administered sulphamerazine and sulphatroxazole was much higher (67.6 ± 13.5 % and 70.2 ± 32.3 %, respectively). After intraruminal administration, sulphatroxazole showed the highest plasma peak concentration (26.1 ± 6.3 mg/I) and the longest plasma half‐life (4.7 ± 1.8h) and mean residence time (13.9 ± 4.5 h). Sulphamerazine showed considerable binding to rumen contents in vitro. Based on its pharmacokinetic properties sulphatroxazole appears to be a suitable candidate to be used in combination with the more recently developed diaminopyrimidines such as baquiloprim.     

Effect of dasatinib in a xenograft mouse model of canine histiocytic sarcoma and in vitro expression status of its potential target EPHA2

Canine histiocytic sarcoma (HS) is an aggressive and highly metastatic tumor. Previously, the kinase inhibitor dasatinib was shown to have potent growth inhibitory activity against HS cells in vitro, possibly via targeting the EPHA2 receptor. Here, the in vivo effect of dasatinib in HS cells was investigated using a xenograft mouse model. Moreover, the expression status of EPHA2 was examined in six HS cell lines, ranging from insensitive to highly sensitive to dasatinib. In the HS xenograft mouse model, dasatinib significantly suppressed tumor growth, as illustrated by a decrease in mitotic and Ki67 indices and an increase in apoptotic index in tumor tissues. On Western blot analysis, EPHA2 was only weakly detected in all HS cell lines, regardless of sensitivity to dasatinib. Dasatinib likely results in the inhibition of xenograft tumor growth via a mechanism other than targeting EPHA2. The findings of this study suggest that dasatinib is a targeted therapy drug worthy of further exploration for the treatment of canine HS.     

3-Phosphoinositide-dependent protein kinase-1/Akt signalling and inhibition in a canine prostate carcinoma cell line

Deregulation of the 3‐phosphoinositide‐dependent protein kinase‐1 (PDK‐1)/Akt signalling pathway is associated with prostate cancer development and progression. Inhibition of PDK‐1/Akt signalling can be achieved using structurally optimized celecoxib derivatives such as OSU‐03012. In this study, we treated the novel canine prostate cancer cell line, Ace‐1, with OSU‐03012 or dimethyl sulphoxide in vitro. We found that Akt was constitutively phosphorylated in the canine prostate cancer cell line Ace‐1 and that there was a dose‐dependent decrease in cell viability, and Akt and glycogen synthase kinase‐3β phosphorylation, in response to OSU‐03012 treatment. This was accompanied by a dose‐dependent increase in apoptosis. These data suggest that Akt signalling pathway inhibition is a potential strategy for the treatment of dogs with prostate cancer and that canine prostate cancer is a relevant large animal model for evaluating Akt pathway inhibitors such as OSU‐03012 for use in people.     

Estimation of sensitivity and specificity of pregnancy diagnosis using transrectal ultrasonography and ELISA for pregnancy-associated glycoprotein in dairy cows using a Bayesian latent class model

AIMS: To determine the sensitivity (Se) and specificity (Sp) of pregnancy diagnosis using transrectal ultrasonography and an ELISA for pregnancy-associated glycoprotein (PAG) in milk, in lactating dairy cows in seasonally calving herds approximately 85–100 days after the start of the herd’s breeding period.

METHODS: Paired results were used from pregnancy diagnosis using transrectal ultrasonography and ELISA for PAG in milk carried out approximately 85 and 100 days after the start of the breeding period, respectively, from 879 cows from four herds in Victoria, Australia. A Bayesian latent class model was used to estimate the proportion of cows pregnant, the Se and Sp of each test, and covariances between test results in pregnant and non-pregnant cows. Prior probability estimates were defined using beta distributions for the expected proportion of cows pregnant, Se and Sp for each test, and covariances between tests. Markov Chain Monte Carlo iterations identified posterior distributions for each of the unknown variables. Posterior distributions for each parameter were described using medians and 95% probability (i.e. credible) intervals (PrI). The posterior median estimates for Se and Sp for each test were used to estimate positive predictive and negative predictive values across a range of pregnancy proportions.

RESULTS: The estimate for proportion pregnant was 0.524 (95% PrI?=?0.485–0.562). For pregnancy diagnosis using transrectal ultrasonography, Se and Sp were 0.939 (95% PrI?=?0.890–0.974) and 0.943 (95% PrI?=?0.885–0.984), respectively; for ELISA, Se and Sp were 0.963 (95% PrI?=?0.919–0.990) and 0.870 (95% PrI?=?0.806–0.931), respectively. The estimated covariance between test results was 0.033 (95% PrI?=?0.008–0.046) and 0.035 (95% PrI?=?0.018–0.078) for pregnant and non-pregnant cows, respectively. Pregnancy diagnosis results using transrectal ultrasonography had a higher positive predictive value but lower negative predictive value than results from the ELISA across the range of pregnancy proportions assessed.

CONCLUSIONS AND CLINICAL RELEVANCE: Pregnancy diagnosis using transrectal ultrasonography and ELISA for PAG in milk had similar Se but differed in predictive values. Pregnancy diagnosis in seasonally calving herds around 85–100 days after the start of the breeding period using the ELISA is expected to result in a higher negative predictive value but lower positive predictive value than pregnancy diagnosis using transrectal ultrasonography. Thus, with the ELISA, a higher proportion of the cows with negative results will be non-pregnant, relative to results from transrectal ultrasonography, but a lower proportion of cows with positive results will be pregnant.     

混播草地建植、施肥和割草利用优化模式研究

选择牧草播期、混播草地中禾本科和豆科牧草的混合比例、施氮量、施磷量和刈割次数5个试验因子,进行了产量分析,建立该草地的综合管理优化模式,确定最佳的管理因子和水平;同时对混播草地的营养成分进行了分析。结果表明:在9月播种,豆禾比例为1∶3,施氮量为0.15 t/hm2,施磷量为0.3 t/hm2,刈割4次时,其营养成分含量达15.37%,综合效果最好。     

Quantitative assessment of the effects of outside temperature on farrowing rate in gilts and sows by using a multivariate logistic regression model

It is well known that pigs are sensitive to heat stress, but few studies have assessed the critical temperature that affects farrowing rate. Therefore, the objective of the present study was to assess the effects of outside temperature on farrowing rate by using a multivariate logistic regression model. Data were obtained from 25 commercial farms, including 26,128 service records for gilts and 120,655 service records for sows. Two variables, maximum temperature (MAX) and temperature humidity index (THI), were used as an indicator for climate conditions. In gilts, an interaction between climate conditions and service number was associated with farrowing rate (p < .05). In the first service, farrowing rate decreased as climate conditions increased, whereas no relationship was found in the second service or later. In sows, farrowing rate at first service decreased as MAX increased from 22°C or THI increased from 66 (p < .05), but no apparent reduction under heat conditions was found in the second service or later. Additionally, effect of heat stress on farrowing rate in parities 1–2 was higher than those in parities 3–5 and ≥6 (p < .05). These results can be applied to field conditions as a standard for the critical temperature for farrowing rate.     

基于光能利用率模型的内蒙古天然草原植被净初级生产力动态监测与气候因子的响应

利用光能利用率模型和MODIS数据对内蒙古天然草原2000-2018年植被生长期草原净初级生产力进行连续动态监测,并在像元尺度利用最小二乘法分析了近20年植被净初级生产力(NPP)时空变化规律。结果表明:近20年中,内蒙古天然草原NPP在空间上呈由西向东递增分布规律,年均NPP为198.04 g C·m-2·a-1,潜在草地退化面积16.22万km 2,其中重度、较重度面积分别为0.20万和1.11万km 2,主要分布于人类活动密集区域,如矿区、建设用地及周边;在草地类型上,温性草原、温性草甸草原、温性荒漠以及温性荒漠草原潜在退化面积分别为5.22万、1.40万、4.04万和2.21万km 2。通过分析NPP与气候因子的相关性表明:近20年,内蒙古草原NPP与降水具有显著相关性,与温度无相关性;温性草甸草原NPP对降水的响应最敏感,温性荒漠草原其次,温性草原对降水响应最低。研究还根据上述结果,围绕草地生态保护提出了建议。     

Development of a simple IgE‐independent anaphylactic model using buckwheat antigen and B‐type CpG oligodeoxynucleotide from Streptococcus thermophilus

We developed a severe anaphylactic model in mice using buckwheat antigen and B‐type CpG‐oligodeoxynucleotides (CpG‐ODNs) from Streptococcus thermophilus genome. In typical systemic anaphylaxis models, animals are challenged with large quantity of antigens via an intravenous (i.v.) route. Here, we showed a simple anaphylactic shock after challenge via intraperitoneal (i.p.) route. The i.p. method is simpler than i.v. administration and has a lower risk for failure. To generate this anaphylactic model, 5‐week‐old female BALB/c mice were first i.p. sensitized with buckwheat antigen mixed with B‐type CpG‐ODN. After 2 weeks, mice were challenged with antigen to induce anaphylactic shock, which was evaluated by scoring the severity symptoms and measuring serum levels of various proteins and splenic cell producing cytokines. Immunoglobulin (Ig)G_2a production and interferon‐γ positive cells were markedly increased in mice immunized with antigen mixed with B‐type CpG‐ODN, whereas serum IgE levels were decreased by B‐type CpG‐ODN. We also examined the effects of various ODNs (A, B and C‐type CpG‐ODNs) and antigens (buckwheat, α‐casein, β‐lactoglobulin and ovalbumin) on anaphylactic severity, and found that the combination of buckwheat and B‐type CpG‐ODN induced the most intense anaphylactic shock. This model is expected to contribute to the study of the prevention of anaphylactic shock.     

Possibility of vancomycin-resistant enterococci transmission from human to broilers, and possibility of using the vancomycin-resistant gram-positive cocci as a model in a screening study of vancomycin-resistant enterococci infection in the broiler chick

In this study, vancomycin‐resistant enterococci (VRE) from humans and vancomycin‐resistant gram‐positive cocci (VRPC) from pigs were examined for their ability to transmit in the chick intestine (Experiment 1). A model study on the spread speed of VRPC was also estimated from chick to chick under semi‐production conditions with different administration routes (not inoculated, oral administration to a chick, sprayed on the floor) (Experiment 2). Furthermore, the disappearance of VRPC from their litter with composting processes was examined (Experiment 3). Each of six chicks was inoculated with VRPC or VRE at 1 day old in Experiment 1. All the chicks had VRPC or VRE in their glandular stomach at 22 days of age. In Experiment 2, 6 floor pens covered with sawdust were prepared and 20 chicks were allotted to each pen. The chicks were inoculated with VRPC at 1 day of age. The VRPC were detected in each group in cloacal swabs at 2 days of age (detection rate; 20–80%). And they were also detected in the not‐inoculated group. The VRPC detection rate gradually decreased, and detection was rare (0–10%) in the packing chicks (50 days old). VRPC were detected in the litter of each pen in Experiment 2. A composting process was effectively used to eliminate VRPC by the 6th week (Experiment 3).     

Assessment of stiffness and strength of 4 different implants available for equine fracture treatment: a study on a 20 degrees oblique long-bone fracture model using a bone substitute

OBJECTIVE: To compare the mechanical properties of 4 stabilization methods for equine long-bone fractures: dynamic compression plate (DCP), limited contact-DCPlate (LC-DCP), locking compression plate (LCP), and the clamp-rod internal fixator (CRIF--formerly VetFix). STUDY DESIGN: In vitro mechanical study. SAMPLE POPULATION: Bone substitute material (24 tubes) was cut at 20 degrees to the long axis of the tube to simulate an oblique mid-shaft fracture. METHODS: Tubes were divided into 4 groups (n=6) and double plated in an orthogonal configuration, with 1 screw of 1 implant being inserted in lag fashion through the "fracture". Thus, the groups were: (1) 2 DCP implants (4.5, broad, 10 holes); (2) 2 LC-DCP implants (5.5, broad, 10 holes); (3) 2 LCP implants (4.5/5.0, broad, 10 holes) and 4 head locking screws/plate; and (4) 2 CRIF (4.5/5.0) and 10 clamps in alternating position left and right of the rod. All constructs were tested in 4-point bending with a quasi-static load until failure. The implant with the interfragmentary screw was always positioned on the tension side of the construct. Force, displacement, and angular displacement at the "fracture" line were determined. Construct stiffness under low and high loads, yield strength, ultimate strength, and maximum angular displacement were determined. RESULTS: None of the implants failed; the strength of the bone substitute was the limiting factor. At low loads, no differences in stiffness were found among groups, but LCP constructs were stiffer than other constructs under high loads (P=.004). Ultimate strength was lowest in the LCP group (P=.01), whereas yield strength was highest for LCP constructs (409 N m, P=.004). CRIF had the lowest yield strength (117 N m, P=.004); no differences in yield strength (250 N m) were found between DCP and LC-DCP constructs. Differences were found for maximum angular displacement at the "fracture" line, between groups: LPC相似文献   

A Cox proportional-hazards model with time-dependent covariates to evaluate the relationship between body-condition score and the risks of first insemination and pregnancy in a high-producing dairy herd

The objective of this study was to determine the relationship between body-condition score and postpartum reproductive efficiency in dairy cattle. Data on body-condition score, reproduction, diseases, and production from 1404 lactations of 639 cows, calving between January 1984 and November 1996 on a commercial farm, were used. The Cox proportional-hazards model with time-dependent covariates was used to qualify the relationship between body-condition score on a scale of 1 to 5 and risks of first insemination and pregnancy. Cows with body condition at calving <3 had lower first-insemination risks. Loss of body-condition score between calving and 45 days after calving was associated with increased days open and days-to-first insemination. Cows with body-condition scores <2 after Day 45 and before first insemination were less likely to be inseminated and become pregnant compared with cows that had higher body condition. Milk yield, mastitis, lameness, milk fever and genital infection were associated with a reduction in reproductive efficiency. The results indicated that loss of body-condition and actual body-condition scores before conception or first insemination or both can be used as a prognosis for days open and days-to-first insemination in dairy herds.     

Genetic analysis of fat‐to‐protein ratio,milk yield and somatic cell score of Holstein cows in Japan in the first three lactations by using a random regression model

We estimated the genetic parameters of fat‐to‐protein ratio (FPR) and the genetic correlations between FPR and milk yield or somatic cell score in the first three lactations in dairy cows. Data included 3 079 517 test‐day records of 201 138 Holstein cows in Japan from 2006 to 2011. Genetic parameters were estimated with a multiple‐trait random regression model in which the records within and between parities were treated as separate traits. The phenotypic values of FPR increased soon after parturition and peaked at 10 to 20 days in milk, then decreased slowly in mid‐ and late lactation. Heritability estimates for FPR yielded moderate values. Genetic correlations of FPR among parities were low in early lactation. Genetic correlations between FPR and milk yield were positive and low in early lactation, but only in the first lactation. Genetic correlations between FPR and somatic cell score were positive in early lactation and decreased to become negative in mid‐ to late lactation. By using these results for genetic evaluation it should be possible to improve energy balance in dairy cows.     

Identification and examination of a novel 9‐bp insert/deletion polymorphism on porcine SFTPA1 exon 2 associated with acute lung injury using an oleic acid‐acute lung injury model

The pulmonary surfactant‐associated protein (SFTPA1, SP‐A) gene has been studied as a candidate gene for lung disease resistance in humans and livestock. The objective of the present study was to identify polymorphisms of the porcine SFTPA1 gene coding region and its association with acute lung injury (ALI). Through DNA sequencing and the PCR‐single‐strand conformation polymorphism method, a novel 9‐bp nucleotide insertion (+) or deletion (‐) was detected on exon 2 of SFTPA1, which causes a change in three amino acids, namely, alanine (Ala), glycine (Gly) and proline (Pro). Individuals of three genotypes (?/?, +/? and +/+) were divided into equal groups from 60 Rongchang pigs that were genotyped. These pigs were selected for participation in the oleic acid (OA)‐ALI model by 1‐h and 3‐h injections of OA, and there were equal numbers of pigs in the control and injection groups. The lung water content, a marker for acute lung injury, was measured in this study; there is a significant correlation between high lung water content and the presence of the 9‐bp indel polymorphism (P < 0.01). The lung water content of the OA injection group was markedly higher than that of the control group and lung water content for the +/+ genotype was significantly higher than that of the others in the 1‐h group (P < 0.01). No differences in the expression of the SFTPA1 gene were found among individuals with different SFTPA1 genotypes, indicating that the trait is not caused by a linked polymorphism causing altered expression of the gene. The individuals with the ?/? genotype showed lower lung water content than the +/+ genotype pigs, which suggests that polymorphism could be a potential marker for lung disease‐resistant pig breeding and that pig can be a potential animal model for human lung disease resistance in future studies.