Intercollicular fibers terminating in the superficial layers of the superior colliculus: a WGA-HRP study in the rat

The intercollicular pathway in the albino rat was studied using a lectin, wheat germ agglutinin, conjugated to horseradish peroxidase (WGA-HRP) as a pathway tracer and a modified HRP histochemistry method. The results showed that a small number of intercollicular fibers were observed in the rostral half of the superficial layers and the caudal half of the intermediate layers of the superior coliculus, while the majority of the intercollicular fibers were distributed in the intermediate and deep layers in the rostral half of the colliculus. The fibers which terminated in the superficial layers of the colliculus were studied in some detail and were subdivided into 4 different morphological types. These results suggest that the intercollicular projection is more broadly distributed in the superior colliculus than has been reported previously in most of the mammalian species studied, and the optic portion of the colliculus receives direct input from different morphological types of intercollicular neurons located on the opposite side of the midbrain.     

小麦中DON的薄层色谱测定

作者对小麦中脱氧雪腐镰刀菌烯醇(DON)的薄层色谱的测定，主要改变了柱净化条件的薄层板展开方式以适合本地实验条件。用本法测定小麦中的DON在100ppb、500ppb两个水平，回收范围在75～90%、方法灵敏度为100ppb，本实验该项测定灵敏度可提高到40ppb．     

荧光假单胞菌AS1.867和3-PHB的luxAB基因标记及其在小麦根际的定殖

通过三亲本杂交方法成功地用发光酶基因 lux AB标记荧光假单胞菌 ( Pseudomonasflu-orescens) AS1 .86 7- L和 3 - PHB菌株 ,获得的标记菌株 AS1 .86 7- L和 3 - PHB- L在不同的条件下能稳定发光。将 AS1 .86 7- L和 3 - PHB- L制成固体微生物接种剂 ,并利用土壤微缩系统将其接种于小麦 ,研究它们在小麦根际的定殖动态和散布规律。结果发现 ,二株标记菌株在灭菌土壤上的定殖水平高于不灭菌土壤 ,在垂直方向上定殖主要发生于 0～ 8cm根段间 ,且随着深度的增加而降低。接种菌株在第 7天之前就已达到最高定殖水平 ,在每克根的初始接种量为 2 .3 2× 1 0 8cfu时 ,第 7天的灭菌土壤中 AS1 .86 7- L和 3 - PHB- L的根际菌数分别为 9.6 7× 1 0 6cfu和 6 .90× 1 0 6cfu,不灭菌土壤的根际菌数为 1 .41× 1 0 5cfu和 7.71× 1 0 5cfu。随着时间的延长 ,定殖数量均明显降低 ,3 - PHB- L在 40 d后就已无法检测到     

Concurrent cereal allergy in children with cow''s milk allergy manifested with atopic dermatitis

BACKGROUND: There is increasing consensus about the significance of food allergens in the pathogenesis of atopic dermatitis (AD) in infancy and childhood, with cow's milk and egg accounting for most of the reactions. Previous studies have indicated that multiple food sensitization, such as cereals, is very common in patients with cow's milk allergy (CMA). Evidence is lacking, however, as to its clinical relevance. OBJECTIVE: The purpose of this study was to determine the concurrent occurrence of cereal allergy among children with challenge-proven CMA who have residual symptoms, such as AD and/or gastrointestinal symptoms, during cow's milk elimination diet. Further, we sought to evaluate the utility of patch testing in prescreening foods other than cow's milk behind allergic symptoms in children. METHODS: The study population comprised 90 children, aged from 2.5 to 36 months (mean 1.1 years), with challenge-proven CMA. As a result of residual symptoms during meticulous cow's milk elimination diet (AD: n=80, and gastrointestinal: n=10), the children were put on a cereal elimination diet (oats, wheat, rye, and barley) and skin prick tests (SPT) and patch testing with cereals were performed. Open cereal challenge was performed to confirm cereal allergy. RESULTS: Cereal challenge was positive in 66 (73%) of the children with CMA. Of them, 17% reacted with immediate reactions and delayed-onset reactions were seen in 83% of the children. SPT was positive in 23%, patch test in 67%, and either SPT or patch test was positive in 73% of the children with cereal allergy. SPT gave the best positive predictive value, whereas SPT together with patch test gave the best negative predictive value. CONCLUSIONS: Residual symptoms, such as eczema or gastrointestinal symptoms in CMA children may be a sign of undetected allergy to other food antigens. SPT with cereals aids in diagnosing cereal allergy in small children, especially when used together with patch testing.     

Coeliac disease — all questions answered?

Gliadin specific T cells in the small intestines of coeliac disease patients use the disease associated human leukocyte antigen-DQ2 molecules in their antigen recognition. In an exciting interplay with tissue transglutaminase, the immune system recognises modified gliadin peptides and mounts a phlogistic response. Moreover, the role for autoimmune phenomena and the mechanism of breaking of immunological tolerance remain elusive.     

Characterized allergens causing bakers' asthma

Although airborne allergens in bakeries and confectioneries cause one of the most common forms of occupational asthma, namely, bakers' asthma, only a few of them are known in detail so far. Here we summarize current knowledge of bakery allergens and describe our own two-dimensional (2-D) immunoelectrophoresis studies of wheat-flour allergens as well as the allergenic baking enzyme Asp o 2. Out of approximately 700 soluble wheat polypeptides, 70 show IgE binding; the following wheat-flour allergens could be identified and characterized: members of the a-amylase inhibitor family (14–18 kDa), acyl-CoA oxidase (26 kDa), peroxidase (36 kDa), and fructose-bisphosphate aldolase (37 kDa). However, the great majority ofthe soluble wheat-flour allergens, mainly located in the 27-, 55-, and 70-kDa areas of the 2-D immunoblots with pi values of 5.8–6.8, 5.9–6.5, and 5.5–6.1, respectively, are not known at present. Asp o 2, to which approximately 25% of all bakers with respiratory symptoms are sensitized, is a well-characterized starch-cleaving enzyme. We conclude that great effort is still needed to describe all major wheat-flour allergens. As shown by Asp o 2, knowledge of the causative allergens and their characteristics enables us to initiate very effective preventive measures such as the introduction of granulated allergenic products.     

Reaction of spice proteins with serum antibodies from celiac patients and rabbit antibodies raised to specific glutamine/proline-containing peptides

The aim of this study was to determine if extracts from selected spices (caraway, ginger, chili, sweet peppers, anise, sesame, nutmeg and black pepper) might be harmful to people suffering from celiac disease, wheat allergy or non-celiac gluten sensitivity. All of these spice extracts exhibited some reaction to antibodies found in sera from two celiac patients and to sera from rabbits that had been sensitized with the specific peptides, QQQPP, PQQQ and QQQP. These peptides had sequences that might be included in active epitopes for celiac disease and wheat allergy. Methodology followed in this study included ELISA, SDS-PAGE and immunoblotting. The observed reactivities suggest that spice proteins might produce adverse reactions in celiac patients, patients with various wheat allergies or with non-celiac gluten sensitivity. However, further work would be needed to elucidate this possibility.     

Nitrate assimilation in plant shoots depends on photorespiration

Photorespiration, a process that diminishes net photosynthesis by approximately 25% in most plants, has been viewed as the unfavorable consequence of plants having evolved when the atmosphere contained much higher levels of carbon dioxide than it does today. Here we used two independent methods to show that exposure of Arabidopsis and wheat shoots to conditions that inhibited photorespiration also strongly inhibited nitrate assimilation. Thus, nitrate assimilation in both dicotyledonous and monocotyledonous species depends on photorespiration. This previously undescribed role for photorespiration (i) explains several responses of plants to rising carbon dioxide concentrations, including the inability of many plants to sustain rapid growth under elevated levels of carbon dioxide; and (ii) raises concerns about genetic manipulations to diminish photorespiration in crops.