Development of a radioimmunoassay procedure for aflatoxin B1 measurement

A radioimmunoassaay (RIA) procedure to measure aflatoxin B(1) (AfB(1)) in agricultural commodities was developed. AfB(1) oxime derivative was synthesized, characterized, and used for preparation of (125)I-labeled AfB(1). Antiaflatoxin B(1) serum was raised in-house using AfB(1)-bovine serum albumin conjugate as immunogen. The assay system was optimized in the range of 0.2-5 ng/mL, using a liquid phase (PEG) as well as a solid phase (coated polystyrene beads) separation system. Inter-assay and intra-assay variations, recovery, and parallelism studies validated the assay. AfB(1) analysis was carried out in nearly 130 samples of different agricultural commodities. The correlation coefficient was determined using commercial ELISA and in-house-developed RIA methods.     

Bioactivities of <Emphasis Type="Italic">Cocos nucifera</Emphasis> L. (Arecales: Arecaceae) and <Emphasis Type="Italic">Terminalia catappa</Emphasis> L. (Myrtales: Combretaceae) leaf extracts as post-harvest grain protectants against four major stored product pests

Compounds extracted from the leaves of coconut palm, Cocos nucifera L. (Arecales: Arecaceae) and the Indian almond, Terminalia catappa L. (Myrtales: Combretaceae) were assessed as potential grain protectants against four major pests of stored grains, Sitophilus oryzae (L.) (Coleoptera: Curculionidae), Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae), Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), and Callosobruchus chinensis (L.) (Coleoptera: Bruchidae). The crude leaf extracts and their fractions were obtained by solvent elution and bioassayed in the laboratory, focusing on (a) the duration of protection and (b) their effects on progeny production. Results showed that adults of C. chinensis, S. oryzae, and T. castaneum were equally susceptible to the fumigant toxicity of C. nucifera and T. catappa crude extracts as well as their column eluted fractions. On the contrary, adults of R. dominica showed tolerance to all the extracts tested in both fumigation and contact mode bioassays. Cocos nucifera crude extracts were highly effective in offering long-term protection in residual toxicity trials and along with the crude extracts of T. catappa showed strong repellent properties against the tested species except for R. dominica in a Y-tube olfactometer. Generally, the chromatographic fractions of crude leaf extracts eluted with ethyl acetate were significantly more effective than methanol, chloroform or hexane-eluted fractions. Further, all the tested plant extracts demonstrated a negative impact on several biological parameters such as feeding activity and progeny production of the tested species. These results highlight the potential of C. nucifera and T. catapa extracts as potent insecticides, feeding deterrents and progeny production inhibitors and consequently are suitable for the control of pests in stored commodities.     

Hydrocarbons Emissions from a Municipal Wastewater Treatment Pilot Plant in Vienna

Hydrocarbons emissions were measured from an aerationtank of a municipal wastewater treatment pilot plant. The collected off-gas samples werecharacterised for C₂–C₇ hydrocarbons usingGC-FID analytical technique while the total volatileorganic compounds (TVOC) were measured using acontinuous hydrocarbon gas analyser. Approximately,the estimated emission rates for 1 m³ of wastewaterfrom this aeration tank were 5 mgC of C₂–C₇hydrocarbons, and an average of 7 gC of TVOC. Withexception to toluene, all other measured hydrocarbonsare emitted less than 1 mgC day^-1. The results supportthe view that a significant reduction in annualemissions of hydrocarbons from wastewater treatmentplants in Vienna has taken place.     

Wound‐healing potential of curcumin in the carp,Labeo rohita

In this investigation, the effect of dietary administration of curcumin on the healing of skin wound in fish, Labeo rohita, has been reported. Fish were divided into three groups: control group (fish without skin wound), sham group (fish with skin wound without curcumin treatment) and curcumin‐treated group (fish with skin wound and subjected to dietary administration of 1% curcumin). Experiments were conducted for 30 days to assess the healing of skin wounds at different time intervals using scanning electron microscopy, histology, and mucopolysaccharide and enzyme histochemistry. In the curcumin‐treated group, healing of skin wounds was found to be enhanced than in the sham group as indicated by early restoration of morphology of the surface layer of epithelial cells; the density of the mucous goblet cells; the density of club cells in epidermal layer; and early granular tissue formation, collagen deposition and tissue remodelling in dermal layer. Furthermore, peroxidase and catalase enzyme activity showed increased endogenous defence system in the curcumin‐treated group compared with the sham group. It could be concluded that dietary administration of curcumin is beneficial in rapid healing of skin wounds in fish. Early healing of wounds could be considered to prevent the invasion of pathogens and to maintain the integrity of the surrounding tissue.     

Characterization of carboxylesterase in skin mucus of Cirrhinus mrigala and its assessment as biomarker of organophosphate exposure

Presence of carboxylesterase (CbE) activity in the skin mucus of Cirrhinus mrigala was investigated. CbE activity in skin mucus showed higher substrate preference for α-naphthyl acetate over p-nitrophenyl acetate. Four CbE isozymes—CbE-1, CbE-2, CbE-3, and CbE-4 were observed in skin mucus during zymography. The isozyme CbE-4 was characterized as typical serine esterase, whereas CbE-1, CbE-2, and CbE-3 were identified as sulphhydryl group-dependent serine esterases. In vitro treatment of skin mucus with the organophosphorus insecticide, Nuvan^® showed strong inhibition of CbE activity. In vivo exposure of the fish to sublethal test concentrations (5 and 15 mg/l) of the insecticide also revealed significant inhibition of CbE activity in mucus. After the cessation of exposure, CbE activity recovered to its control level during the recovery periods. Thus, CbE activity in skin mucus could be considered a biomarker of the organophosphorus insecticide exposure to fish and a useful tool in monitoring environmental toxicity.     

Morphological and Functional Parameters in Calves with Intestinal Diseases

The survey focused on studying the dynamics of the morphological and functional parameters for calves with the intestinal diseases. The data on the quantity and species composition of the intestinal microbiota were compiled; the haematological, biochemical, and immunological parameters were measured. In case of domination of the pathogenic microorganisms in the intestinal microbiocenoses, the serous edema and the leukocyte infiltration into the epithelial layer and the lamina propria of intestinal mucosa could be observed; multiple embolizations caused by bacteria in the blood vessels were revealed. Multiple small necrotic foci infiltrated with leukocytes in the liver were recorded. Extensive haemorrhage of blood vessels, cyanosis, hyperaemia, multiple blot haemorrhages, and dystrophic and necrotic processes were found in all the segments of the intestine. Therefore, the above-listed symptoms represent the risk factors for toxemia and bacteremia.     

胚胎移植技术的应用及其发展

动物胚胎移植首次成功(Heape 1891)距今已近一百年了。在这期间,又有多种动物胚胎移植试验成功,技术也不断改进。但是,进展较大的还是近二十年间。1981年Betterid-ge总结了胚胎移植历史,列出了13种动物胚胎移植首次成功的时间和试验者[兔1891Heape;大鼠1933 Nicholas;绵羊1934Warwick等;山羊(自身重移植)1934Warwick等;小鼠1942 Fekete＆Lit-tle;奶牛(流产)1949 Umbaugh;山羊1949 Warwick＆Berry;奶牛1951Willett等;猪1951 Kvasnickii;奶牛     

Bioactivities of caffeic acid methyl ester (methyl-(E)-3-(3,4-dihydroxyphenyl)prop-2-enoate): a hydroxycinnamic acid derivative from Solanum melongena L. fruits

Feeding deterrent and growth inhibitory effects of caffeic acid methyl ester (CME) isolated from the fruit extract of eggplant, Solanum melongena L. along with two known phenolic acids, caffeic acid (CA) and chlorogenic acid (CG) and azadirachtin (taken as active control), were evaluated against Spodoptera litura Fab. and Achaea janata L. (Lep., Noctuidae). The structure of CME was determined on the basis of extensive spectroscopic (UV, FTIR, ¹H, and ¹³C NMR) data analysis. CME has exhibited strong feeding deterrent activity against S. litura and A. janata larvae with ED₅₀ values of 52.02 and 41.02 μg/cm² leaf area, respectively. CA and CG were relatively less effective compounds when compared with CME. The results also revealed that the isolated compound CME caused marked larval growth inhibition in S. litura and A. janata larvae after 7 days of feeding on a treated diet. The effect on growth of larvae was concomitant with the reduced feeding and digestibility of ingested food. So the activities of digestive proteases within the midgut of larvae were examined using specific substrates to understand the digestive physiology in the larval guts. The bulk of the activity was associated with serine proteases comprising trypsin-, chymotrypsin-, and elastase-like enzymes, which decreased in diets containing CME, whereas, interestingly increased with CG. From the results, we conclude that CME isolated from S. melongena fruit extract shows feeding deterrent and larval development inhibitory activities that may prove useful in the management of S. litura and A. janata larvae.     

Environmentally benign scouring of wool fibers using mesophile acidic lipase

Surfaces of raw wool fibers possess high amounts of greasy substances that need to be removed prior to further processing. Acidic lipases using Bacillus licheniformis (MTCC 2618) were produced with the optimum activity levels closer to the room temperature. Scouring of wool fibers using mesophile acidic lipase has been attempted, in the present work, as an alternative to the existing alkaline treatment and the samples were assessed in terms of weight loss, moisture regain, tenacity, elongation, surface appearance, and friction of the fibers. The lipase scoured wool fibers showed moisture regain and weight loss values comparable to that of alkaline treatment, with lower static and dynamic frictional coefficients. Higher tenacity and elongation values were observed in the lipase scoured fibers compared to the alkaline scoured samples and clear appearance of the surface, compared to the raw wool fibers, was also observed in the lipase scoured samples.