OBJECTIVES: Oxidized LDL is thought to play a key role in atherogenesis. Among their wide variety of biological properties, oxidized LDL injures the endothelium as an early event of atherogenesis. However, the mechanisms by which oxidized LDL injures endothelial cells are not definitely known. In order to evaluate the involvement of GTP-binding protein on the mechanism of apoptosis, we studied the effects of pertussis and cholera toxin on oxidized LDL-induced apoptosis in bovine aortic endothelial cells(BAECs). METHODS: Oxidized LDL elicited apoptosis in cultured BAECs as shown by characteristic morphological and biochemical changes. Chromatin condensation and nucleus fragmentation were visualized by using fluorescence microscopy of intact cells staining by acridine orange/ ethidium bromide. DNA fragmentation was quantified by an ELISA with specific antibody for bromodeoxyuridine- labelled DNA fragments and confirmed with DNA ladder formation. RESULTS: Studies using a combination of bacterial toxins which change the function of GTP-binding protein suggest that oxidized LDL-induced apoptosis was regulated by GTP-binding protein. Oxidized LDL-induced apoptosis was not changed by pretreatment of BAECs with pertussis toxin. In contrast, pretreatment with cholera toxin completely prevented the oxidized LDL- induced apoptosis. CONCLUSION: These results show that oxidized LDL induces apoptosis of BAECs and suggest that cholera toxin-sensitive G-proteins are involved in signal transduction of oxidized LDL-induced apoptosis of BAEC.
Apoptosis* ; Atherosclerosis ; Bacterial Toxins ; Cholera Toxin* ; Cholera* ; Chromatin ; DNA ; DNA Fragmentation ; Endothelial Cells* ; Endothelium ; Enzyme-Linked Immunosorbent Assay ; Ethidium ; GTP-Binding Proteins ; Lipoproteins* ; Microscopy, Fluorescence ; Pertussis Toxin ; Signal Transduction ; Whooping Cough*

Animals ; Bacterial Toxins ; chemistry ; pharmacology ; therapeutic use ; Humans ; Neoplasms ; therapy ; Neurotoxins ; chemistry ; pharmacology ; therapeutic use ; Proteins ; chemistry ; pharmacology ; therapeutic use ; Toxins, Biological ; chemistry ; pharmacology ; therapeutic use

Botulism is a rare neuroparalytic disease caused by neurotoxins of Clostridium species. A ten-year-old girl and her mother were admitted to a hospital with symptoms of progressive dizziness, blurred vision, slurred speech, constipation and difficulty in swallowing. These characteristic manifestations and clinical course prompted an examination of the possibility of botulism. Mouse bioassay performed with mother's stool demonstrated type A botulinum toxin and culture of the mother's stool was positive for Clostridium botulinum type A. This is the first case of botulism in Korea.
Animals ; Biological Assay ; Botulinum Toxins ; Botulism* ; Clostridium ; Clostridium botulinum ; Clostridium botulinum type A ; Constipation ; Deglutition ; Dizziness ; Female ; Humans ; Korea* ; Mice ; Mothers ; Neurotoxins

The aim of this study was an examination of 240 multifloral honey samples collected from Polish apiaries to determine Clostridium botulinum occurrence. Honey was collected from apiaries directly after the extraction process. Samples were inoculated by using the dilution and centrifugation method. Suspected isolates were examined by using mouse bioassay, polymerase chain reaction (PCR), and real-time PCR methods. C. botulinum type A and B strains were detected in 5 of 240 examined honey samples (2.1%). Bacterial strains were also detected that were phenotypically similar to C. botulinum but that did not exhibit the ability to produce botulinum toxins and did not show the presence of the botulinum cluster (ntnh and bont genes) or expression of the ntnh gene. The methods used in the examination, especially the expression analysis of ntnh gene, enabled specific analysis of suspected strains and could be used routinely in environmental isolate analyses of C. botulinum occurrence.
Animals ; Biological Assay ; Botulinum Toxins ; Centrifugation ; Clostridium botulinum ; Clostridium ; Honey ; Methods ; Mice ; Neurotoxins ; Polymerase Chain Reaction ; Real-Time Polymerase Chain Reaction ; Spores

The entomopathogenic bacterium, Xenorhabdus nematophila was isolated from the hemolymph of Galleria mellonella infected with Steinernema carpocapsae. The bacterial cells and its metabolic secretions have been found lethal to the Galleria larvae. Toxic secretion in broth caused 95% mortality within 4 d of application whereas the bacterial cells caused 93% mortality after 6 d. When filter and sand substrates were compared, the later one was observed as appropriate. Similarly, bacterial cells and secretion in broth were more effective at 14% moisture and 25 degrees C temperature treatments. Maximum insect mortality (100%) was observed when bacterial concentration of 4x10(6) cells/ml was used. Similarly, maximum bacterial cells in broth (95%) were penetrated into the insect body within 2 h of their application. However, when stored bacterial toxic secretion was applied to the insects its efficacy declined. On the other hand, when the same toxic secretion was dried and then dissolved either in broth or water was proved to be effective. The present study showed that the bacterium, X. nematophila or its toxic secretion can be used as an important component of integrated pest management against Galleria.
Animals ; Bacterial Proteins ; pharmacology ; Bacterial Toxins ; pharmacology ; Larva ; drug effects ; microbiology ; Moths ; drug effects ; microbiology ; Nematoda ; microbiology ; Pest Control, Biological ; methods ; Survival Analysis ; Survival Rate ; Xenorhabdus ; metabolism ; pathogenicity

Background and OBJECTIVE: There has been a few case reports of anaphylaxis due to honeybee in Korea. In order to observe the clinical feature of bee sting anaphylaxis. Moderials and methods: Six patients living in Kyunggi province area were referred under history of anaphylaxis after the bee sting. Atopy was defined by skin prick test result to common inhalant allergen. Serum specific IgE antibody to each bee antigen was detected by radioimmunoassay to identify the causative bee. RESULTS: All six cases were female. Three had atopy and four had combined allergic diseases such as allergic rhinitis, asthma, and urticaria. The etiologic bees consisted of yellow jacket (6 cases), paper wasp (4 cases), yellow hornet (3 cases), white faced hornet (1 case) and honey bee (1 case). Four cases had experienced anaphylaxis after ant bite and they showed positive result on specific IgE to imported fire ant. Specific immunotherapy against causative bee venom was begun using bee venom extracts from Bayer (USA) based upon results of specific IgE anti-body to bee venom. CONCLUSION: The yellow jacket is the most common cause of bee venom anaphylaxis in this area. Further studies will be needed to evaluate possible cross-reactivity between bee and ant venom.
Anaphylaxis* ; Ant Venoms ; Ants ; Asthma ; Bee Venoms* ; Bees* ; Bites and Stings ; Female ; Fires ; Gyeonggi-do ; Honey ; Humans ; Immunoglobulin E ; Immunotherapy ; Korea ; Radioimmunoassay ; Rhinitis ; Skin ; Urticaria ; Wasps

OBJECTIVETo clone the LTB gene of E.coli and the CTB gene of V.cholerae, and to construct expression vectors of these genes.

METHODSThe LTB gene from E.coli strain 44815 and the CTB gene from V.cholerae strain eastern 74 were amplified by high fidelity PCR. The nucleotide sequences of the two target DNA amplification fragments were sequenced after T-A cloning. pET32a expression vectors with inserted LTB and CTB genes were constructed. The LTB and CTB fusion proteins were expressed in E.coli strain BL21DE3 inducted by IPTG at different dosages. The two expression products were identified by SDS-PAGE and G(M1)-ELISA.

RESULTSIn comparison with the reported LTB and CTB sequences, the nucleotide sequence homologies of the cloned LTB gene and CTB gene were from 99.12% approximate, equals 99.71% and 98.54% approximate, equals 99.42%, while their putative amino acid sequence homologies were as high as 97.58% approximate, equals 99.19% and 96.77% approximate, equals 99.19%. The expression outputs of LTB and CTB fusion proteins in pET32a LTB BL21DE3 and pET32a-CTB-BL21DE3 systems were approximately 30% and 10% of the total bacterial proteins, respectively. The LTB and CTB fusion proteins were able to combine with bovine G(M1) confirmed by ELISA.

CONCLUSIONThe expression systems of LTB and CTB genes have been successfully established. Both the expressed LTB and CTB fusion proteins possess mucosal adjuvant immunoactivity.

Adjuvants, Immunologic ; pharmacology ; Animals ; Bacterial Toxins ; genetics ; pharmacology ; Base Sequence ; Cholera Toxin ; genetics ; pharmacology ; Cloning, Molecular ; Enterotoxins ; genetics ; pharmacology ; Escherichia coli ; genetics ; Escherichia coli Proteins ; Immunity, Mucosal ; Rabbits ; Vibrio cholerae ; genetics

Animals ; Bacterial Toxins ; administration & dosage ; Biological Transport ; Cell Membrane Permeability ; Drug Delivery Systems ; Endocytosis ; Liposomes ; chemistry ; Peptides ; administration & dosage ; Viral Envelope Proteins ; administration & dosage

Bt Cry toxin is the mostly studied and widely used biological insect resistance protein, which plays a leading role in the green control of agricultural pests worldwide. However, with the wide application of its preparations and transgenic insecticidal crops, the resistance to target pests and potential ecological risks induced by the drive are increasingly prominent and attracting much attention. The researchers seek to explore new insecticidal protein materials that can simulate the insecticidal function of Bt Cry toxin. This will help to escort the sustainable and healthy production of crops, and relieve the pressure of target pests' resistance to Bt Cry toxin to a certain extent. In recent years, the author's team has proposed that Ab2β anti-idiotype antibody has the property of mimicking antigen structure and function based on the "Immune network theory" of antibody. With the help of phage display antibody library and specific antibody high-throughput screening and identification technology, Bt Cry toxin antibody was designed as the coating target antigen, and a series of Ab2β anti-idiotype antibodies (namely Bt Cry toxin insecticidal mimics) were screened from the phage antibody library. Among them, the lethality of Bt Cry toxin insecticidal mimics with the strongest activity was close to 80% of the corresponding original Bt Cry toxin, showing great promise for the targeted design of Bt Cry toxin insecticidal mimics. This paper systematically summarized the theoretical basis, technical conditions, research status, and discussed the development trend of relevant technologies and how to promote the application of existing achievements, aiming to facilitate the research and development of green insect-resistant materials.
Insecticides/metabolism* ; Bacillus thuringiensis ; Endotoxins/pharmacology* ; Bacillus thuringiensis Toxins/metabolism* ; Hemolysin Proteins/pharmacology* ; Bacterial Proteins/chemistry* ; Plants, Genetically Modified/genetics* ; Pest Control, Biological

Bacillus thuringiensis is widely used as an insecticide which is safe and environmentally friendly to humans and animals. One of the important insecticidal mechanisms is the binding of Bt toxins to specific toxin receptors in insect midgut and forming a toxin perforation which eventually leads to insect death. The resistance of target pests to Bt toxins is an important factor hampering the long-term effective cultivation of Bt crops and the continuous use of Bt toxins. This review summarizes the mechanism of insect resistance to Bt toxins from the perspective of important Bt toxin receptors in midgut cells of Lepidopteran insects, which may facilitate the in-depth study of Bt resistance mechanism and pest control.
Animals ; Bacillus thuringiensis/genetics* ; Bacillus thuringiensis Toxins ; Bacterial Proteins/metabolism* ; Endotoxins/metabolism* ; Hemolysin Proteins/metabolism* ; Insecta/metabolism* ; Insecticide Resistance/genetics* ; Insecticides/pharmacology* ; Pest Control, Biological