驼羊放牧采食选择性的研究

本文利用链烷烃技术对驼羊放牧采食选择性进行了研究.研究表明驼羊喜食禾本科牧草,且在日粮中的采食比例最大,平均达70%以上,其次为鼠尾草科,平均达10%以上.另外,研究还表明驼羊对其它牧草的采食程度也不一样.     

BoLA class I polymorphism and in vitro immune response to M. bovis antigens

SUMMARY: From a sample of 119 Friesian calves, serologically typed for BoLA class I, 47 subjects were chosen expressing 9 different MHC types (A6, A6.9, A10, A11, A14, A15, A30, W16, M103) with the same age and reared in the same farm conditions. The animals were s.c. injected with a water in oil suspension of killed M. bovis and the treatment was repeated two days later. Before the treatment and 21 days later, calves were bled and on PBM (peripheral blood mononuclear leucocytes) were performed the following tests: 1. Lymphocyte Stimulation with bovine and avian PPDs (Purified protein derivative of Mycobacterium bovis and Mycobacterium avium, respectively). 2. Phagocytic activity towards M. bovis. 3. Class II molecules expression on cell surface. 4. Percentage of leucocyte populations and subpopulations. In the in vitro Lymphocyte Stimulation test, all the animals and classes were responders. Animals bearing A10 BoLA class I presented c.p.m. (counts per minute) and index values higher than the other cattle; these values were significantly positively related both to bovine and avian PPDs (P < .01). By variance analysis A14 BoLA type showed a slight positive significant correlation with more efficient phagocytic activity. BoLA class I type did not seem to significantly affect percentage of class II positive cells and leucocyte percentages on PBM. ZUSAMMENFASSUNG: Der BoLA Klasse I Polymorphismus und in vitro immunologische Antwort gegen die Antigene von M. bovis Aus einer Stichprobe von 119 für BoLA Klasse I serologisch typisierten Friesian K?lber, wurden 47 Subjekte ausgew?hlt, die 9 verschiedene MHC Typen ausdrückten (A6, A6.9, A10, A11, A14, A15, A30, W16, M103). Alle waren gleich alt und in gleichen Haltungsbedingungen. Die Tiere wurden mit einer Wasser-in-Ol Suspension abget?teter M. bovis subkutan injiziert und die Behandlung nach zwei Tagen wiederholt. Vor und 21 Tage nach Behandlung wurden die folgenden Tests ausgeführt: 1. Lymphozyten-Stimulationstest mit bovinen und Geflügel PPDs. 2. Phagozyten Aktivit?t gegen M. bovis. 3. Zeil-Oberfl?chen, Expression der Klasse II Moleküle. 4. Anteile der Lymphozyten Populationen und Subpopulationen. Im in vitro Lymphozyten-Stimulationstest waren alle Tiere und Klassen responder. Tiere mit A10 BoLA I zeigten h?here c.p.m. und Indexwerte als die anderen; diese Werte waren in signifikant positiver Beziehung mit der PPD von M. bovis und auch mit M. avium (P < .01). BoLA Typ A14 zeigte leicht signifikant positive Korrelation mit wirksamerer Phagozyten Aktivit?t. BoLA Klasse I Typ scheint nicht den Prozentsatz der positiven Zellen der Klasse II und der Leukozyten der PBM signifikant zu beeinflussen. RESUMEN: Polimorfismo de BoLA clase I y immunidad a los antigenos del M. bovis Se escojeron 47 novillos dentro de un grupo de 119 animales que segun analisis previamente hecha tenian BoLA de clase I. Estos 47 novillos fueron escojidos de manera que tuvieran 9 distintos tipos de MHC (A6, A6.9, A10, A11, A14, A15, A30, W16, M103), la misma edad, las mismas condiciones de cria. Estos animales fueron inoculados subcutaneo con M. bovis matados en una suspension oleosa y la misma inoculacion fue repetida una secunda vez despues de dos dias. Por cada animal se tomaron muestras de sangre antes y 21 dias despues de la inoculacion de arriba. Las muestras de sangre fueron pruebaoas con: 1. Stimulacion Lymhocitaria con PPD bovina y avicola. 2. Actividad phagocitaria a M. bovis. 3. Expresion sobre la superficie celular de moleculas de clase II. 4. Porcentaje de poblaciones y de subpob-laciones de leucocitos. Todos los animales y todos los tipos de MHC dieron respuestas positivas en las pruebas de Stimulacion Lymphocitaria. Los animales que tenian la BoLA A10 presentaron valores de c.p.m. y indices mas altos de los demas animales. Estos valores se encontraron significativamente y positivamente relacionados sea a la PPD bovina que a la PPD avicola. Por medio de la analisis de varianzas se encontro que el tipo BoLA A14 muestraba una correlacion significativa y algo positiva con una mejor actividad fagocitaria. Los tipos de clase BoLA I no parecieron que influenzaran de manera appreciable el porcentaje de positividad por la clase II y el porcentaje de leucocitos en la sangre PBM.     

Validation of a human immunoturbidimetric assay to measure canine albumin in urine and cerebrospinal fluid.

The aim of this study was to validate an automated immunoturbidimetric assay used to quantify human albumin in urine and to accurately measure canine albumin concentrations in both urine and cerebrospinal fluid. The partial homology existing between human and canine albumin limited the accuracy of the human assays in measuring canine albumin without method modifications. Thus, the assay was modified by calibrating the analyzer with calibrators made in the laboratory containing known concentrations of canine albumin. To prepare the set of calibrators, the albumin concentration of pooled sera of healthy dogs was assessed in 5 replicates using the BromocresolGreen assay. Pooled samples were aliquoted and serially diluted to obtain the expected concentrations of albumin (0.5, 1, 5, 13, and 30 mg/dl) for establishing the canine calibration curve. Thereafter, the performance was assessed by analyzing canine urine and CSF The modified assay accurately quantified canine albumin in both specimens, as indicated by the following. Intra- and interassay variability was 0.92% and 2.74%, respectively; recovery was 99.66% and 99.07% in urine and 105.02% in CSF No interference was detected when hemolysate and glucose were added to urine. The test was linear within the verified range (0-225 mg/dl). These results demonstrate that the modified human albumin immunoturbidimetric assay can be a useful tool in the veterinary diagnostic laboratory. It is accurate and tends itself to automatization on chemistry analyzers.     

Tangential Chains of Neuroblasts in the Subpial Layer of the Adult Rabbit Cerebellum

Veterinary Research Communications -     

FEASIBILITY FOR USING HYPOFRACTIONATED STEREOTACTIC VOLUMETRIC MODULATED ARC RADIOTHERAPY (VMAT) WITH ADAPTIVE PLANNING FOR TREATMENT OF THYMOMA IN RABBITS: 15 CASES

Thymoma is a relatively common tumor in rabbits. Treatment with surgery, radiation therapy, and chemotherapy alone or in combination has been reported with varying outcomes. Stereotactic volumetric modulated arc radiotherapy delivered in a hypofractionated manner allows high doses of radiation to be delivered to the target volume while allowing sparing of adjacent critical structures. This therapy is ideally suited for thymomas in rabbits given their size, the difficulty of multiple anesthesia episodes and the complexity of the radiotherapy plans required due to the tumor's proximity to the heart, lungs, and mediastinal structures. Fifteen rabbits with thymoma were prospectively recruited for this observational, single institution, single arm clinical study. All rabbits were imaged with both computed tomography (CT) and magnetic resonance imaging (MRI). A total dose of 40 Gy in six fractions was delivered using a single arc over an 11‐day period with repeat CT simulation done every other fraction for adaptive planning. Follow‐up evaluation was done through repeat CT and MRI imaging and revealed complete responses using the Response Evaluation Criteria in Solid Tumors (RECIST) criteria. Two rabbits had died at 618 and 718 days, 10 were alive and three were lost to follow‐up. Observed acute and late effects were graded according to the Veterinary Radiation Therapy Oncology Group (VRTOG) criteria and were found to be minimal.     

Assessment of microbial biocontrol agent (BCA) viability to mechanical and thermal stress by simulating spray application conditions

Background

In order to improve the biological control agent (BCA) efficacy, stress factors threatening the viability of microorganisms during spray application need to be determined. The effect of spray mixture temperature and exposure time on Trichoderma harzianum T 22 and Bacillus amyloliquefaciens QST713 viability were tested. Concurrently the combined effect of mechanical and thermal stress effect on BCA viability were tested at two initial spray mixture temperatures (14 and 25 °C) by simulating a spray application using airblast sprayers featured by different tank capacity and a spray liquid circuit (without and with hydraulic agitation system). To assess the BCA microorganism viability, spray mixture samples were collected at time intervals along trials and plated to count the colony forming units (CFU).

Results

The critical temperature threshold that inhibited BCA viability was 35 °C with 30 min of exposure. The sprayer type, the initial temperature of the spray mixture and the temperature increment during the trials significantly decreased the number of CFU recovered. When simulating a spray application, the spray mixture temperature increase rate was determined mainly by the residual amount of spray mixture in the tank. Even if the tank capacity does not substantially affect the final temperature reached by the spray mixture, the higher residual spray mixture in bigger tanks can expose the BCAs for a longer time to critical temperatures.

Conclusions

Experimental trials allowed us to identify the effect of factors affecting the viability of tested BCAs, providing information about the actual chance to guarantee the biological efficacy of BCA treatments. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Supercritical CO2 extract of Cinnamomum zeylanicum: chemical characterization and antityrosinase activity

The volatile oil of the bark of Cinnamomum zeylanicum was extracted by means of supercritical CO2 fluid extraction in different conditions of pressure and temperature. Its chemical composition was characterized by GC-MS analysis. Nineteen compounds, which in the supercritical extract represented >95% of the oil, were identified. (E)-Cinnamaldehyde (77.1%), (E)-beta-caryophyllene (6.0%), alpha-terpineol (4.4%), and eugenol (3.0%) were found to be the major constituents. The SFE oil of cinnamon was screened for its biological activity about the formation of melanin in vitro. The extract showed antityrosinase activity and was able to reduce the formation of insoluble flakes of melanin from tyrosine. The oil also delayed the browning effect in apple homogenate. (E)-Cinnamaldehyde and eugenol were found to be mainly responsible of this inhibition effect.     

Presence of Cocaine in the Tissues of the European Eel, Anguilla anguilla, Exposed to Environmental Cocaine Concentrations

The presence of illicit drugs and their metabolites in surface waters has to be considered a new type of hazard, still unknown, for the aquatic ecosystem, due to the potent pharmacological activities of all the illicit drugs. Our research was therefore aimed at evaluating the impact of illicit drugs on the aquatic fauna, till now still undervalued. To this aim, we verified the ability of the European eel (Anguilla anguilla), a well-known biomonitor of environmental contamination, to bioaccumulate cocaine, one of the most abundant illicit drugs found in surface waters. Silver eels were exposed to a nominal cocaine concentration of 20?ng/l for 1?month; at the same time, control, carrier, and post-exposure recovery groups were made. Brains, gills, liver, kidney, muscle, gonads, spleen, digestive tract, and sections of dorsal skin were assayed by high-pressure liquid chromatography. Cocaine was found in the tissues of the treated eels and, at low concentrations, in almost all tissues of post-exposure recovery eels. These results indicate that cocaine is able to accumulate into the eel tissues; its presence suggests potential risks for eels since cocaine could affect their physiology and contribute to their decline, and for humans consuming contaminated fish.     

The molecular mechanism of thermal noise in rod photoreceptors

Spontaneous electrical signals in the retina's photoreceptors impose a limit on visual sensitivity. Their origin is attributed to a thermal, rather than photochemical, activation of the transduction cascade. Although the mechanism of such a process is under debate, the observation of a relationship between the maximum absorption wavelength (λ(max)) and the thermal activation kinetic constant (k) of different visual pigments (the Barlow correlation) indicates that the thermal and photochemical activations are related. Here we show that a quantum chemical model of the bovine rod pigment provides a molecular-level understanding of the Barlow correlation. The transition state mediating thermal activation has the same electronic structure as the photoreceptor excited state, thus creating a direct link between λ(max) and k. Such a link appears to be the manifestation of intrinsic chromophore features associated with the existence of a conical intersection between its ground and excited states.