Note: Histology of the midgut and peritrophic membrane inLymantria dispar caterpillars fed on leaves ofQuercus cerris orRobinia pseudoacacia

The structure of the columnar cells, goblet cells and peritrophic membrane was studied in the midgut of gypsy moth (Lymantria dispar L.) caterpillars fed with a suitable (Quercus cerris L.) or an unsuitable (Robinia pseudoacacia L.) host. Columnar cells in the midgut of caterpillars fed onR. pseudoacacia leaves were elongated with small nuclei, partial loss of microvilli and vacuolated cytoplasm. The number and height of goblet cells and their nuclei were greater in caterpillars fed onQ. cerris leaves in comparison with larvae fed onR. pseudoacacia leaves. Peritrophic membranes were thin and delicate in the midgut of caterpillars fed onR. pseudoacacia leaves. http://www.phytoparasitica.org posting Nov. 8, 2005.     

Cultivation of Theileria. II. Attempts to cultivate erythrocytic stages of Theileria mutans

Blood from calves with a parasitaemia of Theileria mutans was cultivated in vitro in various ways. No significant increase in the percentage of infected red cells was observed, but the percentage of dividing forms of the parasite rose sharply during the first two days of incubation. The conditions of the cultures were apparently unsuitable for the invasion of erythrocytes.     

Characterization of some parameters of non-specific immunity in beef cattle (II)

Serum protein, immunoglobulins, complement, lysozyme, serum bactericidal activity and blast transformation of peripheral blood lymphocytes were tested in beef cattle in different herds and age groups. These parameters were evaluated in their time-kinetics, in comparison with age-matched groups of dairy cattle. Like dairy calves, beef calves up to 4 months of age were shown to have low levels of serum bactericidal activity and haemolytic complement; besides, a worse profile was detected in serum protein and gamma 2 globulin levels. Al(OH)3 and oil-adjuvanted vaccines had a favourable influence on immunoglobulin and lysozyme synthesis. An acute stressing event like transportation was shown to decrease mitogen-driven lymphocyte stimulation for at least 10 days after arrival.     

Theileria orientalis occurs in Central Africa

An outbreak of bovine theileriosis in Burundi was investigated and the occurrence of Theileria orientalis in Central Africa was confirmed for the first time. Its identity was established on morphological and serological grounds. The parasite was associated with clinical signs and further complicates the disease picture of bovine theileriosis in Africa. Amblyomma variegatum is suspected as being the local vector.     

Blood parasites of sheep in the Netherlands. II. Babesia motasi (Sporozoa, Babesiidae)

Summary A large Babesia species occurs in sheep on the North Sea islands of the Netherlands. The tick Haemaphysalis punctata is a vector. Its pathogenicity appears to be low. It is morphologically similar to a Turkish strain, considered to be B. motasi, which is also transmitted by Haemaphysalis ticks. It differs from the Turkish parasite serologically as well as in cross-immunity tests and in not being effective to goats. There may be a group of morphologically similar parasites with serological differences and different infectivity for sheep and goats. As it is impossible to know which one is to be considered as the original B. motasi, we designate the Dutch parasite as B. motasi (Netherlands). Anaplasma mesaeterum was found to occur on the island of Texel as well as on Ameland, where it had been found initially.     

Correlation between pruritus score and grossly visible erythema in dogs

The severity of pruritus and the extent and severity of erythema were quantified in 107 dogs presenting with various dermatoses. Pruritus was assessed using a previously validated scale, and erythema was quantified by assessing severity at 72 different body sites. Pruritus scores were either 0, or followed a normal type of distribution, with most dogs having a score in the middle of the range and a few dogs having low or high scores. The median pruritus score was 6.3/10. Erythema scores were heavily skewed towards lower values, with only a few dogs having high scores. The median diffuse erythema score was 6.0/216 and the median score for maculo‐papular/pustular erythema was 0/1080. Pruritus and erythema scores were significantly correlated with a Spearman rank correlation coefficient of 0.4062 (P < 0.001). However, visual assessment of the data representing the two variables revealed that this was not a consistent biological or clinically relevant correlation. Individual dogs could have a high pruritus score with low erythema score or vice versa. This study raises questions about the use of erythema scoring systems as a primary outcome measure in clinical trials, and also about the role of various inflammatory mediators in the pathogenesis of canine pruritus.     

Foliar N/P ratio and nutrient limitation to vegetation growth on Keerqin sandy grassland of North‐east China

To examine whether the critical leaf N/P ratios (of 14, 16) are valid to test nutrient limitation in the context of semi‐arid sandy grasslands, an experiment was conducted on a Keerqin sandy grassland in North‐east China to investigate the responses of plant biomass and nutrient concentrations to fertilization. Plant biomass production and leaf nutrient concentrations were measured after five consecutive years of fertilization with N (20 g N m^?2 year^?1) and/or P (10 g P₂O₅ m^?2 year^?1). Nitrogen fertilization increased the shoot biomass by twofold and consequently the shoot/root ratio, whereas P fertilization had little effect on either shoot biomass or shoot/root ratio. Leaf N/P ratio varied among species with an average of 5·6 in the control, while the mean leaf N/P ratio (7·5) under the N fertilization treatment remained below the threshold of 14. Our results suggest that the critical N/P ratio (14, 16) is not applicable as a test for nutrient limitations in the context of semi‐arid, sandy grassland.     

Evaluation of radical scavenging activity of fresh and air-dried tomatoes by three model reactions.

The radical scavenging activity and the antioxidant content of fresh and air-dried tomatoes were investigated. Tomato halves were dried in a pilot-scale dryer under the following conditions: air temperature, 80 degrees C; air flow rate, 1.5 m/s; drying time, 400 min; final moisture, 25%. Carotenoid (lycopene, beta-carotene, lutein) and ascorbic acid were analyzed by HPLC with a spectrophotometric and an electrochemical detector, respectively. Total phenolics were determined by using the Folin-Ciocalteu reagent. The radical scavenging activity was studied in three model systems: (a) the xanthine oxidase and xanthine system, which generates superoxide radical and hydrogen peroxide; (b) the 3-morpholinosydnonimine system, which releases spontaneously superoxide radical and nitrogen monoxide, forming peroxynitrite; (c) the linoleic acid and CuSO(4) system, which promotes lipid peroxidation. These model systems allow the simulation of key reactions involved in the pathogenesis of certain chronic diseases and may be related to the in vivo activity of tomato antioxidants. Hence, these measurements can be used for optimizing tomato processing and storage. The drying process resulted in a decrease of ascorbic acid content, whereas phenol reagent reducing compounds increased. Carotenoid levels were substantially unchanged upon drying. Fresh and air-dried tomato extracts could act as radical scavengers both in the reactive oxygen species-mediated reactions and in lipid peroxidation. Drying affected the antioxidant effectiveness as measured in the xanthine/xanthine oxidase system, which was found to be the most sensitive method for the measurement of tomato antioxidant activity (lower I(50)) but retained the antioxidant effectiveness in the other two systems.     

Properties of tomato powders as additives for food fortification and stabilization

The antioxidant activities of two freeze-dried tomato powders as additives for food fortification and stabilization were studied. The two tomato powders were obtained from the whole fruit and from the pulp after "serum" separation, respectively. The antioxidant activity was studied by measuring (a) the inhibition of the singlet oxygen-catalyzed oxidation of alpha-linolenic acid, in the presence or absence of copper ions, as a model of the oxidative processes occurring in foods, and (b) the inhibition of xanthine oxidase (XOD)- and myeloperoxidase (MPO)-catalyzed reactions and copper-induced lipid peroxidation. The partial separation of "serum" decreased the freeze-drying time by 50%. The partially fractionated tomato powder had a 60% lower phenolic content and an 11-fold higher lycopene content than the whole tomato powder, on a dry weight basis. Ascorbic acid was almost completely removed by fractionation. Both the powder obtained from the whole tomato and that obtained from the partially fractionated tomato had antioxidant activity in all the model systems used. Based on these results, we conclude that tomato powders have multifunctional properties, which could address the prevention of oxidative degradations both in foods and in vivo. Therefore, tomato can be regarded as source of food additives for fortification and stabilization, even if it is submitted to technological processes that can cause the loss of the more labile hydrophilic antioxidants.