大鼠硫酸腺嘌呤预处理心肌酶活性及SDH的电镜细胞化学观察

本实验用硫酸腺嘌呤预处理方法与经典缺血预处理方法对比分析大鼠心肌酶活性及SDH的电镜细胞化学结构。雄性SD大鼠24只,分4组,即Ⅰ组:正常对照组,Ⅱ组：缺血再灌注组;Ⅲ组：经典缺血预处理组;Ⅳ组：硫酸腺嘌呤预处理组。检测肌酸激酶（CK)、细胞色素氧化酶（CCO）及琥珀酸脱氢酶（SDH）的活性。结果显示：与Ⅱ组比,Ⅲ组、Ⅳ组CK漏出减少,CCO、SDH活性增强,细胞超微结构保存良好。结果表明：硫酸腺嘌呤预处理方法具有类似经典缺血预处理效应。     

Phylogeographic past and invasive presence of Arion pest slugs in Europe

Arion vulgaris (syn. A. lusitanicus) is the most destructive pest slug in Europe. The species has been regarded a classic case of an ongoing biological invasion with negative economic and ecological impact in many European countries, but this status has recently been contested. In this study, we assessed mitochondrial and autosomal genetic diversity in populations of A. vulgaris across the entire distribution range in order to characterize its evolutionary history. Mitochondrial diversity in A. vulgaris was strongly reduced compared with the closely related and largely codistributed noninvasive species A. rufus and A. ater, indicating a very rapid spread of A. vulgaris through Europe. Autosomal diversity assessed in 632 individuals from 32 populations decreased towards eastern and northern Europe which is consistent with the reported expansion of the species towards these regions in the last decades. Demographic simulations supported very recent population founding events in most of the European range. The short periods between the first detection of A. vulgaris in different countries and only a very weak association of genetic structuring among populations with geographical distances suggest a human contribution in the ongoing expansion of the slug. We propose that this contribution may ultimately prevent the exact localization of the debated region of origin of A. vulgaris. However, the reclassification of A. vulgaris as noninvasive would be premature. Without counter measures, the Eastern and Northern European countries can expect to see this biological invasion continued in the future.     

ENZYMIC SYNTHESIS OF PSYCHOSINE SULPHATE

—An enzyme which catalyses the synthesis of psychosine sulphate by the transfer of [³⁵S]sulphate from 3′-phosphoadenosine 5′-phosphosulphate to galactosyl-sphingosine has been demonstrated in the brain of the young mouse. The enzyme activity appears to be bound to a microsomal fraction which is spun down with the synaptosomes. The product of the incubation mixture has been characterized as psychosine sulphate by a variety of TLC separations and other chemical procedures. Several parameters (detergent, cations, substrate and 3′-phosphoadenosine 5′-phosphosulphate concentrations, pH and incubation time), affecting the 3′-phosphoadenosine 5′-phosphosulphate-psychosine sulphotrans-ferase activity, have also been investigated. In the normal mouse brain there is a maximum enzyme activity at 17–19 days after birth, which is the period of most rapid myelin formation. In the brains of Jimpy mice, mutants with myelin deficiency, the activity is reduced and reaches a maximum around the 13th day. The lower activity correlates with the small amounts of sulphatides in Jimpy mouse brains. The results are discussed and related to present knowledge of galactolipid biosynthesis.     

THE TOXICITY OF ZINC SULPHATE TO RAINBOW TROUT

The toxicity of zinc sulphate to rainbow trout ( Salmo gairdnerii Richardson) has been investigated in waters of different chemical and physical properties.
Zinc sulphate was less toxic to rainbow trout in hard water than in soft water; when the log concentration of zinc was plotted against log median period of survival of the fish the dose response curve was linear in a very soft water, and curvilinear in a hard water, approaching an apparent threshold concentration. Solutions of zinc sulphate containing calcium chloride were less toxic than those containing an equivalent concentration of calcium as bicarbonate.
An increase in temperature decreased the survival time of rainbow trout in solutions of zinc sulphate in a hard water, but the threshold concentration was not appreciably affected by changes in temperature.
A reduction in the dissolved oxygen concentration of the water increased the toxicity of zinc sulphate, but the effect was reduced when the fish were previously acclimatized to the lower oxygen concentration of the test.
The cause of death of fish in solutions of zinc sulphate was not by the precipitation of mucus on the gills but probably by damage to the gill epithelium.     

Daily variation in the number of slugs under refuge traps

Daily variation in the number of slugs under and around 25 cm × 25 cm pad‐traps was recorded in plots of crop cultures. Grey field slugs Deroceras reticulatum and garden slugs (Arion distinctus and Arion hortensis) left traps at dusk and came back at the end of the night. The time of day at which the number of trapped slugs was maximal did not occur in the middle of the day, when slugs were inactive, but in the early morning and in the evening, a few hours before dusk. This was due to a rise in temperature under the traps in the middle of the day. However, the grey field slugs stayed under traps throughout the morning, when temperatures under the traps reached values more favourable for rest.     

CHARACTERIZATION OF A CHONDROITIN SULPHATE PROTEOGLYCAN FROM OVINE BRAIN

Abstract— A proteoglycan has been isolated from ovine brain tissue using a dissociative method of extraction. The preparation was then purified using ion-exchange and gel chromatography, and an apparent molecular weight of 2 ± 10⁶ was estimated. Chemical analysis together with β-elimination studies strongly suggested that the macromolecule contains chondroitin sulphate chains covalently bound to a common protein core through a serine-xylose linkage. Immunological studies showed that a common antigenic component exists between the respective protein moieties of the proteoglycan and a proteoglycan isolated from bovine nasal cartilage.     

人正常软骨和软骨肉瘤蛋白多糖的比较研究

取三例一般型一级的软骨肉瘤及不同年令正常人股骨头关节软骨,经4mol/L盐酸胍提取和氯化铯平衡等密度梯度离心,分析蛋白多糖组份的化学组成,并用Sepharose CL-2B层析分析蛋白多糖分子大小。初步结果,两例软骨肉瘤蛋白多糖的化学组成和分子大小与新生儿接近,另一例软骨肉瘤蛋白多糖的化学组成和分子大小与成年人相似。此结果说明软骨肉瘤生物学行为的多变性及其蛋白多糖的异质性。     

Colour polymorphism and genetic strains in Avion intermedins from Flores, Azores (Mollusca: Pulmonata)

Thirty specimens of Arion intermedins from Flores (and Corvo) were electrophoretically (PAGE) assayed for 11 enzymes, yielding information about 14 putative loci in two colour morphs of this species. One of these colour variants was tentatively identified as A. pascalianus (P morph). Except for the Mdh locus, all loci in A. intermedins sensu lato from Flores were monomorphic. Mdh , however, was diallelic for Mdh₁₀₀ and Mdh₁₂₂. This latter electromorph was absent in A. intermedins sensu stricto from Flores, but present in the P morph and A. intermedins from Belgium. As a consequence A. intermedins sensu lato from Flores consists of two genetic strains defined by the Mdh alleles. The genetic identity between these strains (7) is 0.929. The genetic identity between the P morph and A. intermedins sensu stricto in Flores is 0.951, while between the P morph and Belgian A. intermedins it is 0.973. These values suggest that the supposed A. pascalianus from Flores is only a colour morph of A. intermedins. This paper also provides the first published record of this species from the island of Corvo.     

THE EFFECT OF RUBIDIUM SULPHATE AND PALLADIUM CHLORIDE ON THE GROWTH OF PLANTS

1. Comparisons have been made between the action of rubidium sulphate and palladium chloride on the growth of barley, wheat, oats peas and beans in complete nutrient solutions.
2. Over a wide range of concentrations rubidium sulphate was not found to exercise either a beneficial or a harmful action on the growth of any of the species tested. The germination of the seeds was likewise not affected.
3. No benefit was derived from palladium chloride , but at a comparatively low concentration a harmful action occurred which became more intense with increasing concentration. Stunting of the main root and laterals was a characteristic feature of this toxicity. With the lower concentrations the check was temporary, and the roots eventually made normal growth, as good as that in the control plants. With increasing amounts of pallahum chloride the poisoning effect became more persistent, until a concentration was reached which did not allow of any root or shoot recovery.
4. The tolerance of palladium varies with the species, as was indicated b. the measure of recovery. Barley appeared to be the least, and oats the most sensitive of the three cereals tested. Peas responded at much the same concentrations as barley, but broad beans made so complete a recovery from the initial checking that the dry weights were ultimately not reduced even by the strongest concentration tested, the plants being indistinguishable from the controls.
5. The effect of palladium poisoning was similar whether the seeds were germinated in the presence of palladium or whether the seedlings were not introduced to it until they were about a week old.