Typing of Verotoxins by DNA Colony Hybridization with Poly- and Oligonucleotide Probes,a Bead-Enzyme-Linked Immunosorbent Assay,and Polymerase Chain Reaction

To identify the type of Verotoxins (VT) produced by Verocytotoxin-producing Escherichia coli (VTEC), a sensitive bead-enzyme-linked immunosorbent assay and polymerase chain reaction with common and specific primers to various VTs (VT1, VT2, VT2vha, VT2vhb, and VT2vp1) were developed. Together with colony hybridization tests with oligo- and polynucleotide probes, these methods were applied to VTEC isolates to type the VT produced. The toxin types of 26 of 37 strains were identified, but the reaction profiles in assays of the remaining 11 strains suggested the existence of new VT2 variants. The application of these identification procedures may be useful as a tool for clinical and epidemiological studies of VTEC infection.     

Effect of anthropometric characteristics and socio-economic status on physical performances of pre-pubertal children living in Bolivia at low altitude

We have previously observed that 11-year-old children of low socio-economic status (LSES) showed a delayed physical growth of approximately 2 years and developed lower normalized short-term power output than children of high socio-economic status (HSES) of the same age. In contrast, maximal oxygen uptake per unit of fat free mass was no different in either group. The aim of this study was to evaluate the effect of anthropometric characteristics between HSES and LSES prepubertal children in aerobic and anaerobic performance. To compare children of the same body dimensions, 11-year-old boys (n = 30) and girls (n = 31) of LSES and 9-year-old boys (n = 21) and girls (n = 27) of HSES were studied. Anthropometric measurements, (direct test), maximal anaerobic power (P _max, force-velocity test) and mean anaerobic power ( , Wingate test) were determined. In these children having the same body dimensions: mean were the same in LSES and HSES children [1.2 (SD 0.2)1-min^–1];P _max and were lower in LSES subjects [154.0 (SD 33.2) vs 174.6 (SD 38.4) W and 116.3 (SD 23.3) vs 128.2 (SD 28.0) W, respectively]; the linear relationships between and fat free mass were the same in LSES and HSES boys but, in the girls, the LSES group had lower values. For anaerobic performance, the relationships were significantly different: the slopes were the same but LSES values for the both sexes were lower. These results would suggest that factors other than differences in body dimensions alone were responsible for the lower performance of LSES girls and boys. Cultural factors and motor learning, structural and functional alterations of muscle induced by marginal malnutrition have been discussed.     

Combination of solid phase extraction and a microalgal test system based on pulse-amplitude modulated fluorescence to detect photosystem 11 herbicides up to 0.05 μeq l−1

This note reports a microalgal test system which usesin-vivo chlorophyll a-fluorescence in combination with a solid phase extraction procedure to monitor photosystem II-herbicides in natural waters up to 0.05 g L^–1.     

人胎胸腺细胞的异质性荧光及其与T淋巴细胞分化阶段关系的形态学研究

以７６９０－Ｘｕ荧光染色法结合ＷｕＴ３、ＷｕＴ４、ＷｕＴ８致敏红细胞花环实验观察经胸腺细胞分层液分离所得高密度亚群和低密度亚群人胎胸腺细胞的异质性荧光及其膜分化抗原ＣＤ３、ＣＤ４、ＣＤ８的表达。结果表明：不同胎龄胎儿胸腺细胞悬液呈现相似形态和相似分布特征的８种异质性荧光的细胞,其中,墨黑核细胞和桔红核细胞分布于两密度亚群,表型为ＣＤ３－ＣＤ４－ＣＤ８－;少数深蓝核和蓝核细胞分布于低密度亚群．表型为ＣＤ３＋,属成熟的胸腺细胞;大多数深蓝核和蓝核细胞、灰蓝核细胞、灰黄核细胞及部分淡桔黄核细胞分布于高密度亚群,表型为ＣＤ３－、ＣＤ４＋、ＣＤ８＋,为处于中间发育阶段的胸腺细胞。推测这些细胞胞核由深蓝、蓝、灰蓝、灰黄到淡桔黄的荧光光谱的偏移可能与中间发育阶段所发生的生物及理化变化有关。     

草鱼出血病病毒多肽的免疫原性

采用中和试验比较了草鱼出血病病毒ＧＣＨＶ８７３的１１个多肽的免疫原性,确定了主要中和抗原。纯化的单个病毒多肽免疫家兔获得抗血清,多太ＶＰ１、ＶＰ５、ＶＰ６和ＶＰ９的抗血清具有中和效价,而ＶＰ２、ＶＰ３、ＶＰ４、ＶＰ８、ＶＰ１０和ＶＰ１１则不能诱生中和抗体。其中ＶＰ５的抗血清中和效价最高,因此,ＶＰ６极可能是病毒多肽中的主要中和抗原。     

新的生物杀虫剂螨虫素对棉花、蔬菜害虫的毒力评价及应用技术研究

本文通过生物杀虫剂螨虫素对棉花、蔬菜害虫的毒力评价及田间应用研究表明,它对棉朱砂叶螨和菜青虫两种害虫杀伤力最强,其中LC90分别为0．078ppm和0．013ppm。兼有胃毒、触杀作用,残效期较长,分别达13天和9天。田间小区试验认为防治菜青虫和茄朱砂叶螨以2ppm浓度为宜。防治适期为卵孵化初期或低龄幼(若)虫（螨)期,其防效能达90%以上。该药特点用药量低、效果好、无公害、值得推广。     

c-fos expression in the amygdala:In vivo antisense modulation and role in anxiety

Summary 1. The amygdaloid complex is a key structure in mechanisms of fear and anxiety. Expression of the immediate-early gene c-fos has been reported in the central nucleus of the amygdala following various stressors, but the functional role of this phenomenon has remained unknown.2. c-fos expression was observed in the central nucleus when rats were subjected to a pharmacologically validated animal model of anxiety, the Vogel conflict test, but not after mere exposure to the test apparatus. Bilateral amygdala injection of a 15-mer phosphorothioate c-fos antisense oligodeoxynucleotide prior to testing blocked conflict-induced c-fos expression and had behavioral effects similar to those of established antianxiety drugs.3. Separate experiments determined that antisense treatment did not affect conflict behavior by acting on shock thresholds or drinking motivation.4. These findings provide evidence that neuronal activation and c-fos induction in the amygdala may be of importance for mechanisms of fear and anxiety.     

The Eiken Latex test for detection of a cryptococcal antigen in cryptococcosis

A latex agglutination test for cryptococcal antigen, the Eiken Latex test (Eiken, Tokyo, Japan), was compared with a monoclonal antibody-based agglutination assay, Pastorex^® Cryptococcus (Diagnostics Pasteur, Marneur-la-Coquette, France). In a murine model of disseminated cryptococcosis, the kinetics of the antigen titers by the Eiken Latex were similar to those by the Pastorex^® Cryptococcus, but sensitivity was much higher. In HIV-negative patients with pulmonary cryptococcosis, a cryptococcal antigen was detected in 6 of 10 patients by the Eiken Latex test and in only 3 of those patients by the Pastorex^® Cryptococcus. The results indicate that the Eiken Latex is more sensitive for the detection of the cryptococcal antigen, even in non-disseminated cryptococcosis. The sensitivity and specificity of the Eiken Latex were examined using 195 sera from 25 patients with pulmonary cryptococcosis and 170 patients with non-cryptococcosis. The cutoff value of 1:8 showed a sensitivity of 76% (19/25) and a specificity of 98.9% (168/170).     

Vanadium levels in urine and cystine levels in fingernails and hair of exposed and normal persons

Vanadium was determined by radiochemical neutron activation analysis (RNAA) with proven accuracy in urine of workers occupationally exposed to vanadium-rich dust in a vanadium pentoxide production plant, and values in the range of 3.02–762 ng/mL (median 33.0 ng/mL) were found. In a control group consisting of administrative workers of the plant, urinary vanadium levels were found in the range of 1.05–53.4 ng/mL (median 2.53 ng/mL), whereas in an another control group of occupationally nonexposed persons, these values amounted to 0.066–0.489 ng/mL (median 0.212 ng/mL). Accuracy of the results was tested by analysis of reference material IAEA A-13 Animal Blood and NIST SRM-1515 Apple Leaves, and very good agreement was found with literature and the NIST certified values, respectively. Unlike urine, no significant differences were found for cystine levels in fingernails and hair of exposed and control persons.     

Results and recommendations

In the first phase of a collaborative study by the International Programme on Chemical Safety (PRCS), four coded chemicals, i.e. azidoglycerol (AG, 3-azido-1,2-propanediol), methyl nitrosurea (MNU), sodium azide (NaN₃) and maleic hydrazide (MH), and ethyl methanesulfonate (EMS) as a positive control were tested in four plant bioassays, namely the Arabidopsis embryo and chlorophyll mutation assay, the Tradescantia stamen hair assay (Trad-SH assay), the Tradescantia micronucleus assay (Trade-MCN), and the Vicia faba root tip assay. Seventeen laboratories from diverse regions of the world participated with four to six laboratories each using one plant assay. For the Arabidopsis assay, laboratories were in agreement with MNU and AG giving positive responses and NaN₃ giving a negative response. With the exception of one laboratory which reported MH as weakly mutagenic, no mutagenic response was reported for MH by the other laboratories. For the Vicia faba assay, all laboratories reported a positive response for MNU, AG, and MH, whereas two of the six laboratories reported a negative response for NaN₃. For the Trad-SH assay, MH was reported as giving a positive response and a positive response was also observed for MNU with the exception of one laboratory. NaN₃, which exhibited a relatively high degree of toxicity, elicited a positive response in three of the five laboratories. AG was found positive in only one of the two laboratories which tested this chemical. For the Trad-MCN assay, MNU and MH were reported as positive by all laboratories, while four out of five laboratories reported NaN₃ to be positive. Only one of three laboratories reported AG to be positive. The major sources of variability were identified and considered to be in the same range as found in similar studies on other test systems. Recommendations were made for minor changes in methodology and for initiating the second phase of this study.