猪败血型链球菌病的诊疗报告

本文阐述了猪链球菌病的临床症状、实验室检验及防治方法，力求为科学防控猪链球菌病提供有益的探索和参考。     

Local macrophage proliferation, rather than recruitment from the blood, is a signature of TH2 inflammation

A defining feature of inflammation is the accumulation of innate immune cells in the tissue that are thought to be recruited from the blood. We reveal that a distinct process exists in which tissue macrophages undergo rapid in situ proliferation in order to increase population density. This inflammatory mechanism occurred during T helper 2 (T(H)2)-related pathologies under the control of the archetypal T(H)2 cytokine interleukin-4 (IL-4) and was a fundamental component of T(H)2 inflammation because exogenous IL-4 was sufficient to drive accumulation of tissue macrophages through self-renewal. Thus, expansion of innate cells necessary for pathogen control or wound repair can occur without recruitment of potentially tissue-destructive inflammatory cells.     

Influence of temperature on toxicity of propylene oxide at low pressure against<Emphasis Type="Italic">Tribolium castaneum</Emphasis>

Toxicity of propylene oxide (PPO) at low pressure against the most common stored-product insect,Tribolium castaneum (Herbst), over a short exposure time, was tested at three different temperatures (16°, 22° and 30°C). Toxicities of PPO at 100 mm Hg were strongly influenced by ambient temperature. LD₅₀ and LD₉₉ toxicities ranged from 4.7 to 28.9 mgl ⁻¹ and from 10.5 to 72.6 mgl ⁻¹ respectively, showing that susceptibility was positively correlated to the temperature. The LD₉₉ values for all life stages (except the larval stage) were significantly lower at 30° than those at 16° and 22°C. However, the LD₉₉ values for all life stages (except the pupal stage) at 16° were not significantly different from those at 22°C. A concentration × time (Ct) product of 291, 171 and 98 mg h/l was required to obtain complete mortality (99%) ofT. castaneum at 16°, 22° and 30°C, respectively. Thus, the efficacy of PPO at 100 mm Hg to all life stages ofT. castaneum also decreased as the temperature decreased from 30° to 16°C. http://www.phytoparasitica.org posting Sept. 28, 2004.     

Short‐term tolerance of equine spermatozoa to various abiotic factors

The aim of this study was to determine the effects of various abiotic factors, such as light, physical stress (pipetting) and thermal shock, on the quality of fresh and cooled equine sperm. In experiment I, four sperm aliquots were subjected to different light exposures: (i) protected control samples (CTRL), (ii) exposed to UV light at 10 cm (UV10), (iii) exposed to UV light at 20 cm (UV20) and (iv) exposed to laboratory lighting (LAB). In experiment II, four semen aliquots were subjected to repeated pipetting for 0, 10, 20 and 30 times (CTRL, P10, P20 and P30, respectively). In experiment III, four semen aliquots at 15°C were subjected to thermal oscillations: (i) cooled control sperm at 15°C (CTRL), (ii) oscillations of 1.9°C/min to a temperature of 30°C (T30), (iii) oscillations of 1.4°C/min, with the temperature rapidly falling until reaching 1.3°C (T0R) and (iv) oscillations of 1.1°C/min, with the temperature slowly falling until reaching 4.2°C (T0S). The results revealed that after 30 min, UV10 and UV20 sperm samples showed significantly (p < .05) lower total and progressive motility values, sperm kinematic parameters and mitochondrial potential. After 45 min of exposure, differences were highly significant (p < .001). No significant differences (p > .05) were found for pipetting or thermal oscillations. The results suggest that, even if equine sperm samples are not handled in the laboratory under optimal conditions, fresh and cooled equine spermatozoa are able to resist the impact of various abiotic stimuli without any reduction in their quality. This study analyses the effect on normospermic samples, but future research could look at the tolerance that asthenozoospermic equine samples have to these abiotic influences.     

Assessment of the accuracy of estimation of gestational age in cattle from placentome size using inverse regression

AIMS: To assess, in dairy cows between 60–160 days of gestation, whether the agreement between actual gestational age and that predicted by placentome size could be improved by using individual placentome measurements rather than a single average, and to identify how increasing the number of placentomes measured improved the prediction.

METHODS: Data were obtained from 58 cows examined using transrectal ultrasonography every 10 days between 60–130 days, and every 15 days between 130–160 days of gestation. For each cow, four to six placentomes in each of the pregnant and non-pregnant horns were examined from the region of the uterus near to the cervix. A mixed-effects model, which included cow as a random effect, and a simple linear regression which ignored within-cow correlation, were fitted to the data. Inverse regression was used to compare the 95% prediction bands obtained for estimating gestational age using the means of three, five or eight placentome measurements.

RESULTS: The fit of the mixed effects model was better than a simple linear regression (p<0.001) but the fitted lines from the two models were very similar. Using the simple regression model, for a mean placentome length of 15?mm estimated gestational age was 100 days, with 95% CI of 68–131 days for measurement of three placentomes, and 80–120 days for eight placentomes.

CONCLUSIONS: The agreement between placentome size and gestational age was improved by increasing the number of placentomes measured. Direct comparison of these CI with those for other published fetal measures was not possible as similar prediction bands have not previously been calculated for fetal measures; however one study reported a residual SD which had been calculated using size measurements as the predictor variable and age as the response variable. Using these data 95% CI were calculated to be ±9 days for crown-rump length and ±25 days for uterine diameter. These are likely to be an underestimate of the true CI and do not take account of the increase in variance of the difference between predicted and actual gestational age as gestational age increases.

CLINICAL RELEVANCE: Placentome measurement may be useful for estimating fetal age in late gestation. Further research is required to better establish the agreement between gestational age and the fetal measurements which are currently used to estimate fetal age.     

Lunar soil: size distribution and mineralogical constituents

The lunar soil collected by Apollo 11 consists primarily of submillimeter material and is finer in grain size than soil previously recorded photographically by Surveyor experiments. The main constituents are fine-grained to glassy rocks of basaltic affinity and coherent breccia of undetermined origin. Dark glass, containing abundant nickel-iron spheres, coats many rocks, mineral, and breccia fragments. Several types of homogeneous glass occur as fragments and spheres. Colorless spheres, probably an exotic component, are abundant in the fraction finer than 20 microns.     

Propylene oxide: A potential quarantine and pre-shipment fumigant for disinfestation of nuts

Propylene oxide (PPO) was evaluated at a low pressure of 100 mm Hg for toxicity to different life stages of the Indianmeal mothPlodia interpunctella (Hübner) in the presence and absence of three species of nuts. Eggs and larvae were generally the most tolerant life stages in empty chambers and on the nut crops. Complete mortality of all life stages was achieved at a concentration x time (CT) product of 61.2 mg hl ⁻¹ for empty space fumigation. Dosages of 13.9, 60.3, 72.1 and 93.1 mgl ⁻¹ were required to kill 99% of the larvae when fumigation of 4-h duration took place in an empty chamber and in the presence of peanuts, almonds and walnuts, respectively. After an initial dose of 68.7 mgl ⁻¹ and a 5-h exposure time, sorption of PPO by peanuts, almonds and walnuts was relatively high, ranging from 87% of the initial concentration for peanuts to 91% for walnuts. PPO residues measured in peanuts, almonds and walnuts were 111, 46 and 80 ppm, respectively, 1 day after termination of fumigation. All of these values were below the 300 ppm maximum tolerance set by the FDA of the United States. These data show that the combination of PPO and low pressure has the potential to replace methyl bromide fumigation for quarantine and pre-shipment purposes. http://www.phytoparasitica.org posting July 22, 2006     

Use of heat for disinfestation and control of insects in dates: Laboratory and field trials

Heat treatment of dates at the time of harvest, was examined as an alternative to fumigation with methyl bromide, which has been phased out in Israel under the Montreal Protocol. In laboratory studies, the influence of 40°, 45°, 50° and 55°C on the levels of disinfestation and mortality ofCarpophilus hemipterus larvae was examined over a 2-h exposure period. The ratio of the number of insects found outside the feeding sites to the total number of insects, was greatest at 50°C (92.3%), significantly greater than at 40° and 55°C. At 50° and 55°C, 100% mortality was obtained. Since drying temperatures for most date varieties is between 45° and 50°C, and because percent disinfestation and control was most effective at 50°C, these findings were examined under field conditions. Field trials were carried out at a commercial drying station where the crated dates are placed on the ground inside a plastic-clad hothouse. The stacks were covered with plastic liners to form ‘drying ducts’ through which heated air was sucked using fans positioned at the opposite end of the ducts. It was shown that from 1 to 2 h were required for the dates to reach the set temperature of 50°C. During the following 2-h aeration, the dates were exposed to 50°C heated air, after which an examination of infested dates inserted into the drying ducts, and natural infestations showed that successful control and emigration were obtained. This method produced results comparable to those obtained with methyl bromide fumigation, and was suitable as a replacement technology for infestation control. http://www.phytoparasitica.org posting Nov. 7, 2005.