Measurement of plasma colloid osmotic pressure in neonatal foals under intensive care: comparison of direct and indirect methods and the association of COP with selected clinical and clinicopathologic variables

Objectives: To describe and compare admission colloid osmotic pressure (COP) measurement using both direct and indirect methods in neonatal foals under intensive care, and to evaluate for associations between COP and clinical/clinicopathologic parameters. Design: Prospective study. Setting: Intensive care unit at a veterinary medical teaching hospital. Animals: Twenty‐six critically ill neonatal foals were studied. A control group consisted of 9 clinically healthy neonatal foals. Interventions: Clinicopathologic data were collected at the time of admission. COP was measured directly using a colloid osmometer. Indirect COP was calculated using equations by both Landis–Pappenheimer (L–P) and Thomas and Brown. Measurements and main results: Measured admission COP values were 17.1±4.3 and 17.7±2.4 mmHg in critically ill and control foals, respectively, and these values were not significantly different. Critically ill foals with blood lactate concentrations >3 mmol/L had lower COP values than those with lactate ≤3 mmol/L. There was close agreement between indirect COP values calculated using the L–P equation and direct COP values measured in control foals (mean error=0.0±1.3 mmHg; R²=0.87). However, indirect values were not as predictive of direct COP in critically ill foals (mean error=0.8±3.8 mmHg; R²=0.64). As COP values increased, the indirect method tended to overestimate COP, whereas at lower values it slightly underestimated COP. Conclusion: While the L–P equation was a close approximation of direct COP in healthy foals, direct measurements of oncotic pressure cannot be replaced for monitoring of critically ill foals. Critically ill foals with higher lactate concentrations had lower COP values, suggesting a possible relationship between COP and lactate.     

Selective feeding behavior of calves is affected by basal diet

The present study examined the way the selective feeding behavior of calves was affected by basal diet. Three basal diets containing oat hay and concentrate, with the addition of different levels of roughage content (low, medium and high) were prepared by changing their mix ratios. Orchard grass (OG) and Japanese pampas grass leaf (JP) were used as testing foods. In the preliminary phase, all calves were fed each basal diet three times per day and then food selection between JP and OG was examined. Dry matter intake (DMI) of JP and OG throughout the test was significantly different. Increasing the roughage rate in the basal diet decreased the DMI of JP, whereas the DMI of OG was increased. There was no significant effect of basal diet condition on nutrient intake, whereas the acid detergent fiber and neutral detergent fiber ingestive efficiency were affected by the basal diet condition. It is suggested that calves prefer food that complement the basal diet, even if nutrient requirements are met.     

差压相关法确定水平管段塞流液塞速度及长度

分析了差压信号和波高信号之间的对庆关系,给出了利用差压信号求液塞速度的方法,提出了“假渡越时间”的新概念,根据这一概念给出了求液塞长度的方法,试验结果表明,该方法是求解液塞长度比较有效的一种方法。     

Advances in topical glaucoma therapy

Significant advances have recently been achieved in the development of topical glaucoma medications. The primary advantage of a topical preparation is the reduced incidence of adverse systemic effects attributable to a given drug compared to its systemically administered counterpart. However, the strong protective barrier of the eye forces topical ophthalmic preparations to be highly concentrated and in some cases, they have the potential to produce unwanted systemic effects, particularly in smaller animals. Oral carbonic anhydrase inhibitors are commonly associated with adverse effects in both humans and animals. Two recently developed topical carbonic anhydrase inhibitors, dorzolamide and brinzolamide, have shown promise in reducing intraocular pressure in animals and systemic side effects are apparently limited with their use. The topical alpha2-agonist apraclonidine, on the other hand, effectively reduces intraocular pressure in cats and dogs, but in its currently available form is likely to induce unwanted systemic effects. Latanoprost is a topical prostaglandin F2alpha analog that has proven effective in reducing intraocular pressure in dogs and horses, but while systemic side effects have not yet been reported, this topical preparation may exacerbate pre-existing or concurrent ocular inflammatory disease.     

Estimation of the viability ofHeterodera schachtii field populations by measuring ATP,ADP and AMP contents of eggs and juveniles using HPLC

An HPLC method has been developed to determine adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate (AMP) in eggs and juveniles ofHeterodera schachtii in cysts extracted from soils. ATP levels in eggs and juveniles were highly correlated with the numbers of hatched juveniles in root diffusate (r=+0.92) in series of soil samples originating from field trials testing different doses of fumigant nematicides. The measured ATP concentrations in the cysts explained 59% of the sugar-yield reduction on these fields, which was similar to the value based on the hatching test. After fumigation, carried out in a laboratory experiment, ATP and the adenylate energy charge, (AEC=ATP + 0.5 * ADP)/(ATP + ADP + AMP), decreased greatly within a few days. In a series of greenhouse trials in whichH. schachtii had been parasitized severely byVerticillium clamydosporium and other antagonists, there were significant correlations between the numbers of hatched juveniles and the ATP content of the cysts (r=+0.85), and between the percentages of hatched juveniles and the AEC (r=+0.75). The HPLC method is faster than conventional methods and can be used to establish the viability ofH. schachtii field populations affected by soil fumigation or egg pathogens.     

Vapor pressure and volatility of β-asarone,the main ingredient of an indigenous stored-product insecticide,Acorus calamus oil

The effect ofAcorus calamus products on insects is reviewed briefly. A sudden, dramatic drop occurs in the insecticidal, gaseous phase activity of calamus oil on stored-product pests, when the exposure temperature is lowered from 30° to 25°C. In an attempt to explain this finding, the vapor pressure of the main constituent of IndianAcorus calamus essential oil, β-asarone, was determined by three methods: (i) extrapolation with a gas-chromatographic method according to Jensen and Schall; (ii) calculation from boiling points with the Clausius-Clapeyron equation; and (iii) direct measurement with the Knudsen cell. The values of vapor pressure of β-asarone at 30°C according to these three methods were 3.3 x 10^-3, 3.7 x 10^-3 and 9.8 x 10^-4 Torr, respectively. The volatility of β-asarone under the conditions of the fumigant experiments mentioned above was assayed by determining the weight loss from 50 mg asarone allowed to evaporate at 30°C from a filter paper disk into a 400 ml hermetically closed glass vessel. The weight loss was approximately 0.75 mg/400 ml receptacle space (≈1.9 mg/l) for every 10 days from day 0 to day 40.     

Development of ZWIPERO, A Model Forecasting Sporulation and Infection Periods of Onion Downy Mildew based on Meteorological Data

The weather-based forecasting model ZWIPERO was developed by the German Weather Service and determines the risk of sporulation and infection of Peronospora destructor quantitatively based on actual as well as predicted weather data (temperature, relative humidity, leaf wetness, precipitation). The model allows precise planning of disease monitoring and infection-related application of fungicides. ZWIPERO is a more complex mathematical model than the previously published models for downy mildew. In order to operate ZWIPERO independently of the actual field location and season, the time of sunrise and sunset of the location are exactly determined by a subroutine. Another subroutine provides simulated microclimatic input variables based on local production data as well as actual and hourly predicted (up to 4 days) standard weather data. Starting at the time of 'sunrise + 7 h', ZWIPERO calculates the number of sporangia produced, the time of onset of sporangia release, as well as the number of infections possible and the number of sporangia which may survive the day for each 24-h time step. Field evaluations of sporulation periods of downy mildew showed that the simulated micrometeorological input variables are reliable. As the actual plant development, the susceptibility and the disease incidence in the field are not taken into account, ZWIPERO has to be considered primarily as a decision support system for extension services and growers.     

SPF鸡屏障系统净化技术研究

本文从理论上较为系统地对SPF鸡实验动物房的净化管理技术进行研究,对净化原理,洁净度、压力梯度以及该动物房各个部位、洁净室的风量风速、压力损失和静压差进行了分析和计算,使读者对SPF鸡屏障系统有了较清晰的认识。希望对相关净化管理人员有一定的参考价值。     

Effects of Carbon Dioxide Insufflation and Body Position on Blood Gas Values in Horses Anesthetized for Laparoscopy

The objective of the study was to describe the effects of carbon dioxide pneumoperitoneum and Trendelenburg position on arterial blood gas values in horses anesthetized for laparoscopy. The study design was a prospective case series using 14 healthy adult horses anesthetized for elective laparoscopic surgery. All horses in the study were maintained under anesthesia with halothane in oxygen with intermittent positive-pressure ventilation. A pneumoperitoneum of 15 mmHg or less was achieved with carbon dioxide, and horses were tilted to a 35-degree Trendelenburg position to allow the completion of laparoscopic cryptorchidectomy (n = 13) or ovariectomy (n = 1). Heart rate, mean arterial pressure, and arterial blood gases were recorded at six time intervals throughout the procedure. Results of the study indicated a pH that decreased and partial pressure of carbon dioxide (PaCO₂) and mean arterial pressure that increased over time and differed significantly from baseline during Trendelenburg position. Partial pressure of oxygen (PaO₂) was significantly lower than baseline after assumption of Trendelenburg position and did not improve on return to normal recumbency and abdominal pressure. As body weight increased, pH and PaO₂ decreased and PaCO₂ increased. We concluded that horses placed in Trendelenburg position have changes that are transient, with the exception of PaO₂. Heavier horses have a greater change in pH, PaCO₂, and PaO₂ than lighter horses during abdominal insufflation and Trendelenburg position. The changes incurred during CO₂ abdominal insufflation and Trendelenburg position are transient, with the exception of a decreased PaO₂. Heavy horses undergoing abdominal insufflation and Trendelenburg position should be closely monitored for critical cardiopulmonary values.