DETECTION OF PORTAL BLOOD FLOW USING PER-RECTAL 99mTc-PERTECHNETATE SCINTIGRAPHY IN NORMAL CATS

This study reports data obtained from per-rectal ^99mTc-pertechnetate portal scintigraphy in normal cats. It examines the effects of chemical restraint and the methods employed in defining regions of interest (ROIs) on the shunt index derived from this data. Six normal cats were used for the study; all six were chemically restrained for imaging using propofol and later four of them were manually restrained for comparison. Portal blood flow was studied and the mean shunt index was found to be 5.9%± 3.9 when ROIs were operator defined and 9.2%± 4.4 when ROIs were defined using an isocontour program. In cats that were restrained using propofol and operator defined ROIs, the mean value for the time between detection of radioactivity in the liver and in the heart was 14 ± 1 seconds.     

Flow cytometric patterns in blood from dogs with non-neoplastic and neoplastic hematologic diseases using double labeling for CD18 and CD45

BACKGROUND: In dogs, flow cytometry is used in the phenotyping of immunologic cells and in the diagnosis of hemic neoplasia. However, the paucity of specific antibodies for myeloid cells and B lymphocytes and of labeled antibodies for multicolor techniques limits the ability to detect all leukocyte subpopulations. This is especially true for neoplastic and precursor cells. CD18 and CD45 are expressed on all leukocytes and are involved in cell activation, and together could be useful in helping determine cell lineage. OBJECTIVES: The purpose of this study was to double label canine blood for CD18 and CD45 and to use the differential expression of antigens to identify leukocyte populations in dogs with non-neoplastic and neoplastic hematologic diseases. METHODS: A template was developed using blood samples from 10 clinically healthy dogs and a back-gating technique. Differential leukocyte counts obtained with the template were compared with those obtained by manual and automated methods on blood samples from 17 additional healthy dogs. Blood samples obtained from 9 dogs with non-neoplastic (reactive) hematologic diseases and 27 dogs with hemic neoplasia were double stained for CD18 and CD45 using mouse anticanine CD18 monoclonal antibody (mAb) plus phycoerythrin-conjugated rat anticanine CD45 mAb and fluorescein isothiocyanate-conjugated rabbit antimouse IgG. Hemic neoplasms were diagnosed by cell morphology, and immunophenotypic and cytochemical markers. RESULTS: With the double label, neutrophils, eosinophils, monocytes, and T- and B-lymphocytes were identified. In reactive disorders, a population of activated neutrophils with high CD45 and CD18 expression was detected. In hemic neoplasia, cell lineage was easily determined, even in acute leukemia. CONCLUSIONS: Double labeling for CD18/CD45 may be useful as a screening method to evaluate hematologic diseases and help determine cell lineage, and to aid in the selection of a panel of antibodies that would be useful for further analysis.     

Evaluation of cardiac performance of the dog after induction of portal hypertension and gastric ischemia

Objective: To determine changes in hemodynamic and cardiac energetic parameters in dogs after induction of portal hypertension and gastric ischemia. These blood flow alterations are similar to changes seen in splanchnic blood flow in dogs with gastric dilatation volvulus syndrome (GDV). Design: Original experimental study. Setting: Veterinary teaching hospital. Animals: Seven purpose‐bred, intact male dogs. Interventions: Standard midline laparotomy and median sternotomy were performed under general anesthesia. Dogs were instrumented to obtain arterial blood pressure, aortic flow, cardiac chamber pressures, central venous pressure, portal flow, and portal pressure. Colored microsphere technology was used for the determination of myocardial blood flow. Measurements and samples were obtained at baseline, following induction of portal hypertension, and after induction of portal hypertension and gastric ischemia. Measurements and main results: Left ventricular myocardial blood flow was increased from 81.8±20.1 mL/100 g/min at baseline to 127.7±57.2 mL/100 g/min (P=0.02) after induction of portal hypertension and gastric ischemia. Myocardial oxygen consumption increased from 142.2±27.4 J/min/100 g at baseline to 219.1±33.4 J/min/100 g (P=0.003) after induction of portal hypertension and gastric ischemia, but cardiac external work remained unchanged (13.67±6.2 to 13.27±9.6 J/min; P=0.78; power=0.79). Cardiac efficiency decreased from 11.6±6.1% at baseline to 7.6±5.1% (P=0.017) after induction of portal hypertension and gastric ischemia. Conclusions: Transfer of energy within the myocardium was less efficient after induction of portal hypertension and ischemia of the stomach wall. On the basis of these results, alterations in cardiac function associated with GDV may result from deterioration of cardiac efficiency.     

REPEATABILITY OF DOPPLER ULTRASONOGRAPHIC MEASUREMENT OF EQUINE DIGITAL BLOOD FLOW

The repeatability and sensitivity of Doppler ultrasonographic measurement of lateral digital arterial and venous blood flow has not been previously determined. Doppler ultrasonography was used to measure blood flow within the forelimb lateral digital vessels in one normal adult Thoroughbred horse on six occasions and in six normal adult Thoroughbred horses on three occasions, each occasion being at least 1 h apart, to determine the within- and between-horse variation. The values obtained from the right and left lateral digital vessels did not differ significantly. The within-horse coefficients of variation (CV) for arterial and venous measurements were all acceptable (< 11%); the between-horse CV were acceptable (< 7%) for all parameters except TaVa (average velocity of first peak of arterial waveform) and TaVb (average velocity of remainder of arterial waveform). The within-horse intraclass correlation coefficients (ICC) demonstrated excellent repeatability (> or = 0.71) for all parameters except venous diameter; the between-horse ICC demonstrated good to excellent repeatability (> or = 0.67) for all parameters except TaVb. Doppler ultrasonography can detect differences of 0.005 and 0.01 ml/ min in digital arterial and venous flow, respectively, using measurements from six horses on three occasions (80% power; P < 0.05). Thus, the technique is sufficiently repeatable and sensitive to be able to detect changes in flow during different physiological or pathological states or following pharmacologic intervention.     

野菊和神农香菊毛状体及叶片表面分泌物的比较

本研究以野菊(Dendranthema indicum)和神农香菊(D.indicumvar.aromaticum)为研究对象,对比分析了其叶片的表皮毛形态、密度以及叶片表面分泌物种类和含量。结果表明,其叶片表皮毛主要有两种类型,一类是没有分泌功能的T-形非腺毛,一类是具有分泌功能的头状腺毛。T-形非腺毛在上下表皮的密度差异不大,而头状腺毛差异较大,主要集中在叶片的下表皮。两种植物材料叶片表面分泌物里共分析出73种化合物,其中大部分为萜类及其衍生物,共有的化合物有18种;野菊和神农香菊中分别分析出48、43种化合物,分别占分泌物总相对含量的90.96%和84.33%。     

不同放牧强度下羊草十大针茅草地植被与土壤氮素的空间异质性分析

以河北坝上的羊草(Leymus chinensis)+大针茅(Stipa grandis)典型草原为研究对象,用方差和地统计分析相结合的方法,研究了不同放牧强度对植被和土壤氮素的空间分布格局的影响.结果表明,植被密度与土壤氮素的变异函数大多符合球状和指数模型;轻牧与中牧的植被群落密度的空间分布受随机因素的影响较大,禁牧与重牧地受空间结构性因素影响较大,但重牧区土壤氮素的空间分布受随机因素影响相对较大;放牧降低了植被密度的空间异质性,而禁牧区的空间异质性(基台值0.116 8)大于放牧区(基台值均值0.019 5);随放牧强度的增加,土壤铵态氮、硝态氮的空间异质性均呈降低-增加的趋势,且重牧明显增加了土壤铵态氮和硝态氮的空间异质性,基台值分别为5.642 0和2.681 0,大于其余3个处理铵态氮和硝态氮的均值(0.315 8和0.168 7);整体上,在相同放牧处理的植被密度与土壤硝态氮的空间分布有相近的变化趋势.     

不同刺激剂PHA和ConA对绒山羊淋巴细胞有丝分裂中期化的影响

试验旨在探索使较高比例的淋巴细胞富集在有丝分裂G2/M期的最佳条件。运用植物血凝素(PHA)和刀豆蛋白A(ConA)对淋巴细胞进行刺激使其增殖,培养一定时间后加秋水仙素对淋巴细胞进行同步化处理,用流式细胞仪检测G2/M期的细胞数量进行比对,观察试剂的最佳作用浓度和加秋水仙素的最佳时间。结果表明,采用PHA和ConA刺激淋巴细胞增殖的最佳作用浓度是60和5 μg/mL,且淋巴细胞经ConA刺激培养45 h再加秋水仙素处理5 h G2期的比例最高为58.38%。结果提示,就绒山羊的淋巴细胞来说,ConA刺激绒山羊淋巴细胞增殖的效果比PHA好,且摸索出细胞G2/M期的时间点至关重要。     

野生硬雀麦栽培驯化研究

通过硬雀麦Bromus rigidus与3种一年生黑麦草Lolium multiflorum和莜麦Avena nuda的品种比较试验,结果表明:硬雀麦产草量达76 095.0 kg/hm2,仅次于阿伯德多花黑麦草(77 589.0 kg/hm2),略高于邦德一年生黑麦草(74 212.5 kg/hm2),三者之间差异不显著(P>0.05);高于赣选1号多花黑麦草(67 033.5 kg/hm2)和莜麦(66 697.5 kg/hm2),差异极显著(P<0.01)。硬雀麦的播种量以73.3125 kg/hm2,行距15 cm为最佳,平均产量可达98 227.5 kg/hm2。硬雀麦可作为过渡带冬闲田种植的优良牧草。     

草原毛虫幼虫的食性及其空间格局

以禾草及嵩草在高寒草甸中的优势度为指标,研究草原毛虫(Gynaephora alpherakii)的食性、空间格局及其与植物群落的相关性。结果表明:草原毛虫的食性具有较强的选择性,其喜食程度排序为莎草科(Cyperaceae)>禾本科(Gramineae)>杂类草,特别对嵩草属(Kobresia Willd.)植物表现出强烈的偏好和倾向性;草原毛虫的分布型受制于其喜食植物的空间格局,在总体上呈聚集分布,但在小尺度下则常呈均匀分布;虫口密度依赖于喜食植物的丰富度和多样性,随着喜食植物的增加而显著上升,随着植物多样性的减少而显著下降;草原毛虫在高寒草甸生态系统中具有平衡物种关系、调控群落结构的功能;采用定向改变草地植物组成的农艺措施实现对草原毛虫数量的人工调控是实施虫害生态防治的有效途径。     

狗舌草提取物诱导淋巴细胞性白血病L1210细胞分化的研究

以单猪屎豆碱（MO）、槲皮素（QU）和环磷酰胺（CY）为参照，观察了狗舌草600mL／L乙醇提取物（EX）对淋巴细胞性白血病L1210细胞体外试验的形态变化；利用流式细胞术，从DNA分子水平上检查了EX对L1210细胞各周期相的影响，探讨EX对L1210细胞的分化机理。结果发现，EX能够使L1210细胞向淋巴细胞方向发展；经EX作用24h后，L1210细胞G0＋G1期的百分比较对照组明显升高。提示EX对L1210细胞增殖的抑制作用可能是由于G1期的阻滞所致。