Mast cells can enhance resistance to snake and honeybee venoms

Snake or honeybee envenomation can cause substantial morbidity and mortality, and it has been proposed that the activation of mast cells by snake or insect venoms can contribute to these effects. We show, in contrast, that mast cells can significantly reduce snake-venom-induced pathology in mice, at least in part by releasing carboxypeptidase A and possibly other proteases, which can degrade venom components. Mast cells also significantly reduced the morbidity and mortality induced by honeybee venom. These findings identify a new biological function for mast cells in enhancing resistance to the morbidity and mortality induced by animal venoms.     

Garlic allyl sulfides display differential modulation of rat cytochrome P450 2B1 and the placental form glutathione S-transferase in various organs

To investigate whether the regulation of garlic allyl sulfides on biotransformation enzyme expression is tissue-specific, the expression of cytochrome P450 2B1 (CYP 2B1) and the placental form of glutathione S-transferase (PGST) in liver, lung, and intestine, which are the three major organs responsible for drug metabolism, was examined. Rats were orally administrated 0.5 or 2 mmol/kg BW diallyl sulfide (DAS) or 0.5 mmol/kg BW diallyl disulfide (DADS) or diallyl trisulfide (DATS) three times per week for 6 weeks. The final body weights and the body weight ratio of liver and lung were not changed by any of these three allyl sulfide treatments as compared to the control rats. An 11- and 12-fold increase of 7-pentoxyresorufin O-dealkylase (PROD) activities was noted in rats treated with 0.5 or 2 mmol/mg BW DAS, respectively, as compared with the controls (P < 0.05). In contrast, DADS and DATS significantly increased hepatic PGST activity toward ethacrynic acid by 30 and 40%, respectively, as compared with the control rats (P < 0.05). An increase in PGST activity was only noted at 2 mmol/kg BW DAS group (P < 0.05). In addition, similar increases in PGST activity due to DADS and DATS were also noted in lung and jejunum tissue (P < 0.05). Immunoblot assay shows that the changes in CYP 2B1 and PGST proteins due to the three garlic allyl sulfide treatments on liver, lung, and jejunum were consistent with those observed for PROD and PGST activities. Northern blot further revealed that the DADS and DATS increased PGST mRNA levels in both liver (2.9- and 3.0-fold, respectively) and lung (4.1- and 2.6-fold, respectively) and DAS dose-dependently increased CYP 2B1 mRNA levels in the liver. Garlic allyl sulfides differentially induced CYP 2B1 and PGST expression, and this up-regulation of these two biotransformation enzymes is tissue-specific.     

Sperm chromatin condensation as an in vivo fertility biomarker in bulls:a flow cytometry approach

Background:Genetic selection in cattle has been directed to increase milk production.This,coupled to the fact that the vast majority of bovine artificial inseminations(AI)are performed using cryopreserved sperm,have led to a reduction of fertility rates over the years.Thus,seeking sensitive and specific sperm biomarkers able to predict fertility rates is of vital importance to improve cattle reproductive efficiency.In humans,sperm chromatin condensation evaluated through chromomycin A3(CMA3)has recently been purported to be a powerful biomarker for sperm functional status and male infertility.The objectives of the present study were:a)to set up a flow cytometry method for simultaneously evaluating chromatin condensation and sperm viability,and b)to test whether this parameter could be used as a predictor of in vivo fertility in bulls.The study included pools of three independent cryopreserved ejaculates per bull from 25 Holstein males.Reproductive outcomes of each sire were determined by non-return rates,which were used to classify bulls into two groups(highly fertile and subfertile).Results:Chromatin condensation status of bovine sperm was evaluated through the combination of CMA3 and Yo-Pro-1 staining and flow cytometry.Sperm quality parameters(morphology,viability,total and progressive motility)were also assessed.Pearson correlation coefficients and ROC curves were calculated to assess their capacity to predict in vivo fertility.Sperm morphology,viability and total motility presented an area under the ROC curve(AUC)of 0.54,0.64 and 0.68,respectively(P>0.05),and thus were not able to discriminate between fertile and subfertile individuals.Alternatively,while the percentage of progressively motile sperm showed a significant predictive value,with an AUC of 0.73(P=0.05),CMA3/Yo-Pro-1 staining even depicted superior results for the prediction of in vivo fertility in bulls.Specifically,the percentage of viable sperm with poor chromatin condensation showed better accuracy and precision to predict in vivo fertility,with an AUC of 0.78(P=0.02).Conclusions:Chromatin condensation evaluated through CMA3/Yo-Pro-1 and flow cytometry is defined here as a more powerful tool than conventional sperm parameters to predict bull in vivo fertility,with a potential ability to maximising the efficiency of dairy breeding industry.     

Combination CCNU and vinblastine chemotherapy for canine mast cell tumours: 57 cases

The purpose of this study was to evaluate the efficacy and toxicity of a CCNU and vinblastine chemotherapy protocol for canine mast cell tumours. Fifty-seven tumours in 56 dogs were evaluated, 37 had macroscopic disease and 20 had microscopic disease. A 57% response rate was seen in dogs with macroscopic disease for a median duration of 52 weeks. Dogs with macroscopic disease had a median progression free survival time (PFST) of 30 weeks and a median overall survival time (OST) of 35 weeks. Dogs with microscopic disease had a median PFST of 35 weeks and a median OST of 48 weeks. Toxicity was recorded in 54% of the dogs treated, with the majority of events being mild. This chemotherapy protocol appears to be well tolerated and should be considered for canine mast cell tumours.     

Genetic variation of viral protein 1 genes of field strains of waterfowl parvoviruses and their attenuated derivatives

To understand the genetic variations between the field strains of waterfowl parvoviruses and their attenuated derivatives, we analyzed the complete nucleotide sequences of the viral protein 1 (VP1) genes of nine field strains and two vaccine strains of waterfowl parvoviruses. Sequence comparison of the VP1 proteins showed that these viruses could be divided into goose parvovirus (GPV) related and Muscovy duck parvovirus (MDPV) related groups. The amino acid difference between GPV- and MDPV-related groups ranged from 13.1% to 15.8%, and the most variable region resided in the N terminus of VP2. The vaccine strains of GPV and MDPV exhibited only 1.2% and 0.3% difference in amino acid when compared with their parental field strains, and most of these differences resided in residues 497-575 of VP1, suggesting that these residues might be important for the attenuation of GPV and MDPV. When the GPV strains isolated in 1982 (the strain 82-0308) and in 2001 (the strain 01-1001) were compared, only 0.3% difference in amino acid was found, while MDPV strains isolated in 1990 (the strain 90-0219) and 1997 (the strain 97-0104) showed only 0.4% difference in amino acid. The result indicates that the genome of waterfowl parvovirus had remained highly stable in the field.     

Acceleration of post‐mortem changes in Tsaiya duck (Anas platyrhynchos) breast muscle by lactic acid marination

1. The effect of lactic acid marination at 5°C on post mortem changes in breast muscle pectoralis major of spent layer Tsaiya duck was studied.

2. Myofibrils were prepared from 0.1 M and 0.2 M lactic acid marinated muscle and control (non‐marinated samples) sampled at 0, 1, 3, 7 and 14 d post mortem.

3. Changes in myofibril fragmentation index (MFI), myofibrillar proteins and Z‐line structure were examined.

4. Marination of duck breast muscle in lactic acid at 5°C enhanced fragmentation of myofibrils and degradation of myofibrillar proteins and Z‐line structure as compared to control samples.

5. In summary, lactic acid marination at 5°C can accelerate the post mortem degradation of myofibrils in Tsaiya duck breast muscle.     

小麦丛矮病研究之二关于小麦丛矮病的病原病毒问题

在田间的小麦丛矮病非典型病株申常常分离到北方禾谷花叶病毒(NCMV)及玉米粗缩病毒(MRDV)两种病原物。单独用前者接种,仅表现小麦丛矮症,单独用后者接种,仅表现小麦蓝矮症,即植株矮化、暗绿、分蘖减少,叶坚挺。两者混合侵染时,往往表现两者的混合症状,但以何种病毒占优势而倾向于优势病毒的症状。典型丛矮症植株中电镜检出弹状病毒粒体,40—70×270—400nm尺度与日本报导的稍异。典型丛矮病株中不存在玉米粗缩病毒的粒体。小麦丛矮病毒很可能是北方禾谷花叶病毒的一种地方性株系。     

Three-Dimensional Tracking of Multiple Small Insects by a Single Camera

Many systems to monitor insect behavior have been developed recently. Yet most of these can only detect two-dimensional behavior for convenient analysis and exclude other activities, such as jumping or flying. Therefore, the development of a three-dimensional (3D) monitoring system is necessary to investigate the 3D behavior of insects. In such a system, multiple-camera setups are often used to accomplish this purpose. Here, a system with a single camera for tracking small insects in a 3D space is proposed, eliminating the synchronization problems that typically occur when multiple cameras are instead used. With this setup, two other images are obtained via mirrors fixed at other viewing angles. Using the proposed algorithms, the tracking accuracy of five individual drain flies, Clogmia albipunctata (Williston) (Diptera: Psychodidae), flitting about in a spherical arena (78 mm in diameter) is as high as 98.7%, whereas the accuracy of 10 individuals is 96.3%. With this proposed method, the 3D trajectory monitoring experiments of insects can be performed more efficiently.     

Using multiple metrics to estimate seasonal landscape connectivity for Blanding’s turtles (<Emphasis Type="Italic">Emydoidea blandingii</Emphasis>) in a fragmented landscape

Context

Landscapes and animal behavior can exhibit temporal variability and connectivity estimates should consider this phenomenon. In many species, timing of activities such as nesting, mate searching, and hibernation occurs during distinct periods in which movement events may differ, along with physical characteristics of the surrounding landscape.

Objectives

We estimate movement, landscape conductance, and patch importance for a turtle species across two seasonal activity periods (spring, late summer) in a fragmented agricultural region. Three connectivity approaches are compared to identify their advantages and disadvantages.

Methods

A least-cost distance model, circuit-based approach, and patch-based index were used to collectively describe the potential functional connectivity of Blanding’s turtle (Emydoidea blandingii) across a multi-temporal scale in an agricultural region of south western Ontario.

Results

Connectivity decreased further into the active season exhibited through lower conductance of the landscape and fewer pathways, while the importance of habitat nodes shifted due to temporal variability in the number and distribution of nodes. Models provided different yet complimentary information, with least-cost models overestimating discrete pathways yet providing a secondary measure of landscape barriers. The circuit-based model estimated corridors of least resistance providing an overall characterization of the landscape, while patch-based indices provided key information on the importance of individual habitat patches.

Conclusion

Findings highlight the importance of including a temporal aspect in connectivity modelling as results demonstrate a change in functional connectivity over time. We also recommend employing multiple connectivity metrics to capture variation in movement behavior.