Mycotoxins Affecting Animals, Foods, Humans, and Plants: Types, Occurrence, Toxicities, Action Mechanisms, Prevention, and Detoxification Strategies-A Revisit

Mycotoxins are produced by fungi and are known to be toxic to humans and animals. Common mycotoxins include aflatoxins, ochratoxins, zearalenone, patulin, sterigmatocystin, citrinin, ergot alkaloids, deoxynivalenol, fumonisins, trichothecenes, Alternaria toxins, tremorgenic mycotoxins, fusarins, 3-nitropropionic acid, cyclochlorotine, sporidesmin, etc. These mycotoxins can pose several health risks to both animals and humans, including death. As several mycotoxins simultaneously occur in nature, especially in foods and feeds, the detoxification and/or total removal of mycotoxins remains challenging. Moreover, given that the volume of scientific literature regarding mycotoxins is steadily on the rise, there is need for continuous synthesis of the body of knowledge. To supplement existing information, knowledge of mycotoxins affecting animals, foods, humans, and plants, with more focus on types, toxicity, and prevention measures, including strategies employed in detoxification and removal, were revisited in this work. Our synthesis revealed that mycotoxin decontamination, control, and detoxification strategies cut across pre-and post-harvest preventive measures. In particular, pre-harvest measures can include good agricultural practices, fertilization/irrigation, crop rotation, using resistant varieties of crops, avoiding insect damage, early harvesting, maintaining adequate humidity, and removing debris from the preceding harvests. On the other hand, post-harvest measures can include processing, chemical, biological, and physical measures. Additionally, chemical-based methods and other emerging strategies for mycotoxin detoxification can involve the usage of chitosan, ozone, nanoparticles, and plant extracts.

Anaphylaxis as a cause of hospitalization--a single academic centre experience

INTRODUCTION

In recent years, more and more often the increase in incidence of allergies is observed. According to the WHO, they are getting the fourth position amongst the most frequent diseases after cancers, cardiovascular diseases and AIDS. Anaphylaxis is a severe, life-threatening, systemic or generalised immediate hypersensitivity reaction. The analysis of the causes and the clinical picture of anaphylaxis in patients treated at single academic hospital centre was the purpose of the study.

MATERIAL AND METHODS

The study was based on retrospective analysis of case records of the patients hospitalised at the Chair and Department of Allergology, Clinical Immunology and Internal Diseases, the Jan Biziel University Hospital in Bydgoszcz in the years 2005-2010. 132 patients, in whom anaphylactic reaction appeared, were analysed. The examined population included 70 men and 62 women at 16-95 years of age.

RESULTS

The conducted examinations allowed to obtain information about the causes and the course of anaphylactic reactions. The problem of hypersensitivity to substances of various origin (biological or synthetic) can concern everyone irrespective of sex and age. Nevertheless, the phenomenon of anaphylaxis more often occurred in the examined men than women. Most cases of anaphylactic reactions were reported in the 26-50 age range. Based on the presented results, no regularity was observed in anaphylaxis clinical picture and its causative factor.

CONCLUSIONS

It is difficult to forecast the course of the reaction based on the causative factor, for anaphylactic reaction is characterised by a great individual changeability and intensity of the first symptoms.

Changes in germ cell population in young and adult female mice from two inbred strains: CBA/Kw and KE

Female mice from two inbred strains CBA/Kw and KE differ markedly in fertility. The gametes of females from KE strain are of poorer quality than those of CBA/Kw. We analyzed the number of oocytes per ovary in KE and CBA/Kw mice aged 5, 25, 90, 180 and 360 days. The ovaries were dissected and processed according to the routine histological methods. In case of five-day-old females we used a modified distributed point counting method while in order to examine the gonads of older females, the nucleoli counting method was applied. In general, we observed gradual decrease in germ cell number throughout the whole life of females from both strains. The noticeable wave of oocyte loss occurs between 5th and 25th days of life. The mice from KE inbred strain on day 25th (1650 +/- 322 vs. 1140 +/- 210) and 90(th) (1040 +/- 211 vs. 692 +/- 89) days have significantly (p<0.005) more germ cells than the females from CBA/Kw strain. In older females the differences were not statistically significant. Interestingly, CBA/Kw females were found to have more rapid loss of primordial follicles throughout their lives. This can explain their shortened reproductive lifespan which was observed earlier.

Fractionation of functional polystyrenes, poly(ethylene oxide)s and poly(styrene)-b-poly(ethylene oxide) by liquid chromatography at the exclusion-adsorption transition point

The paper reports the fractionation of functional polystyrenes (PSs) and poly(ethylene oxide)s (PEOs) as well as their block copolymers, by liquid chromatography at the exclusion adsorption transition point (EATP-LC), also called "critical conditions" mode. In this specific elution mode (EATP-LC), the fractionation is only governed by the nature and the number of functions attached to the polymer backbone, independent of the molar mass distribution of the whole sample. Functional polystyrenes (alpha- and/or alpha,omega-alcohol-, acetal-, aldehyde- and acidic-PS) could be readily separated from non-functional polystyrenes under various chromatographic conditions. The technique also allowed the fractionation of poly(ethylene oxide)s and PS-PEO block copolymers. In the latter cases, moderately polar columns (grafted silica) and water-based polar eluents were required to obtain a satisfactory fractionation.

Docking of sulfonamides to carbonic anhydrase II and IV

Starting with a known active site of a protein and a database of compounds, one would like to quickly identify a few compounds that "dock" into the active site and obtain "good" binding free energies. The main goal of current automated docking procedures is to predict the "best" substrate-enzyme complex while other programs such as UHBD and DelPhi can be used to compute binding free energies. In this paper, we will focus on the application of docking methods and parameters to study substrate-enzyme interactions of a metalloenzyme system. Specifically, we report on the docking of sulfonamides to carbonic anhydrase II and IV, which are of interest due to their application in glaucoma therapy. Using a standard docking protocol, it is possible to correctly predict not only the orientation of inhibitors to a specific isozyme, but also determine the qualitative affinity for a group of inhibitor for an isozyme.

Molecular recognition and binding of thermal hysteresis proteins to ice

Molecular recognition and binding are two very important processes in virtually all biological and chemical processes. An extremely interesting system involving recognition and binding is that of thermal hysteresis proteins at the ice-water interface. These proteins are of great scientific interest because of their antifreeze activity. Certain fish, insects and plants living in cold weather regions are known to generate these proteins for survival. A detailed molecular understanding of how these proteins work could assist in developing synthetic analogs for use in industry. Although the shapes of these proteins vary from completely alpha-helical to globular, they perform the same function. It is the shapes of these proteins that control their recognition and binding to a specific face of ice. Thermal hysteresis proteins modify the morphology of the ice crystal, thereby depressing the freezing point. Currently there are three hypotheses proposed with respect to the antifreeze activity of thermal hysteresis proteins. From structure-function experiments, ice etching experiments, X-ray structures and computer modeling at the ice-vacuum interface, the first recognition and binding hypothesis was proposed and stated that a lattice match of the ice oxygens with hydrogen-bonding groups on the proteins was important. Additional mutagenesis experiments and computer simulations have lead to the second hypothesis, which asserted that the hydrophobic portion of the amphiphilic helix of the type I thermal hysteresis proteins accumulates at the ice-water interface. A third hypothesis, also based on mutagenesis experiments and computer simulations, suggests that the thermal hysteresis proteins accumulate in the ice-water interface and actually influence the specific ice plane to which the thermal hysteresis protein ultimately binds. The first two hypotheses emphasize the aspect of the protein 'binding or accumulating' to specific faces of ice, while the third suggests that the protein assists in the development of the binding site. Our modeling and analysis supports the third hypothesis, however, the first two cannot be completely ruled out at this time. The objective of this paper is to review the computational and experimental efforts during the past 20 years to elucidate the recognition and binding of thermal hysteresis proteins at the ice-vacuum and ice-water interface.

Effect of bleeding site on clinical laboratory testing of rats: orbital venous plexus versus posterior vena cava

We sought to determine if there were any differences in the results of clinical laboratory tests between blood samples collected from the orbital venous plexus and the posterior vena cava of adult male rats. Thirty healthy adult male Sprague Dawley rats were anesthetized by ether inhalation, and blood samples were collected successively from the orbital venous plexus (OVP) and the posterior vena cava (PVC) for hematologic (n = 10), serum chemistry (n = 10), and coagulation (n = 10) analyses. The prothrombin and partial thromboplastin times of samples from the OVP were prolonged (17% and 288%, respectively) when compared with samples from the PVC. Respective hematologic biases were as follows: red blood cell count (7%), hemoglobin (6%), hematocrit (5%), mean corpuscular volume (-3%), mean corpuscular hemoglobin (-1%), mean corpuscular hemoglobin content (1%), white blood cell count (13%), and platelet count (-7%). Respective serum chemistry biases were as follows: sorbitol dehydrogenase (-7%), glucose (-7%), blood urea nitrogen (-10%), creatinine (-2%), total protein (4%), albumin (2%), globulin (9%), alkaline phosphatase (5%), lactate dehydrogenase (-6%), aspartate aminotransferase (-5%), alanine aminotransferase (-2%), total bilirubin (0%), direct bilirubin (0%), magnesium (-17%), sodium (4%), potassium (0), chloride (4%), calcium (-2%), phosphorous (-17%), cholesterol (3%), triglycerides (24%), creatinine kinase (-8%), 5'nucleotidase (0%), and total bile acids (4%). For hematologic testing, there were no biologically significant differences between samples collected from the OVP and PVC. The coagulation times and serum Mg and P showed biologically significant differences between samples collected from the OVP and PVC.(ABSTRACT TRUNCATED AT 250 WORDS)

Cleavage of human immunoglobulins by serine proteinase from Staphylococcus aureus

The serine proteinase (SP) released into the environment by most strains of S. aureus cleaves human IgG, IgM and IgA of both subclasses--IgA 1 and IgA 2. SP cleaves H chains of all immunoglobulin classes and the SC of S-IgA, the L chains are degraded partially. The SP-induced cleavage results in a large spectrum of fragments under reducing conditions within a broad range of Mr (approx. 41,000 to less than 12,400). This indicates that the enzyme does not affect the Ig molecule in the hinge region only. The degree of cleavage depends on the enzyme:substrate ratio and on the duration of incubation. The generation of small fragments is associated with the loss of antigenic determinants that results from the decreased binding of the cleaved material in the ELISA method. Partial cleavage of L chains suggests that the enzyme alters part of the molecule that is involved in antigen binding. Even if the ability of antigen binding remains preserved after cleaving Ig with SP, the antibody function is disturbed by splitting off the Fc region or by its degradation into small fragments. SP has to be considered as one of the virulence factors of S. aureus that may protect bacteria against the defence mechanisms of the host.

Effect of metalloproteinase from Staphylococcus aureus on in vitro stimulation of human lymphocytes

Metalloproteinase (MP) produced by the majority of Staphylococcus aureus strains exerts, in a wide concentration range (0.1-100 micrograms/ml), no cytotoxic action on mononuclear leukocytes of human peripheral blood. The enzyme itself does not appreciably stimulate proliferation and differentiation of lymphocytes in culture, but affects the stimulation of both T and B lymphocytes by polyclonal activators. The action is dose-dependent. High doses of MP (100 micrograms/ml) lower the blastic transformation after stimulation with Con A, SpA, NDCM, S. aureus strain Wood 46 and with suboptimal doses of PWM. Optimal concentrations of the enzyme potentiate the stimulation of lymphocytes by PWM, PHA, S. aureus strains Cowan 1 and Wood 46, and by NDCM. The same potentiation effect was achieved whether the enzyme was added concurrently with the mitogen or 18 h later. This implies that the beginning of cell activation is not affected. A high MP concentration decreases the production of Ig in culture after stimulation with PWM whereas lower concentrations of MP enhance this production. Production of Ig after stimulation with NDCM and Wood 46 is decreased by MP. The possible action of exoproteinase from S. Aureus on the immune response during infection is discussed.

Chemoattractant activity of Staphylococcus aureus serine proteinase modified human plasma alpha-1-proteinase inhibitor

S. aureus serine proteinase inactivates human alpha-1-proteinase inhibitor (alpha-1-PI) by attacking a single peptide bond between Glu354 and Ala355 giving a modified inhibitor which is a tight complex of Mr = 4,000 and 48,000 fragments. In the present paper we show that this proteolytically inactivated alpha-1-PI is a potent chemotactic factor for human neutrophiles at a nanomolar concentration, and we discuss its potential involvement in the inflammatory reaction due to S. aureus infections.

Effects of serine proteinase from Staphylococcus aureus V8 cells on Con A stimulation of human lymphocytes

The combined effect of serum and Staphylococcus aureus serine proteinase on human lymphocyte Con A stimulation was assayed. Serum was found to protect the proteinase-treated lymphocytes. It is suggested that not only the immunogenicity of proteinase itself, but also proteinase modified serum and lymphocyte-derived components affect lymphoproliferative response.

Effect of serine proteinase from Staphylococcus aureus on in vitro stimulation of human lymphocytes

In a broad concentration range (0.1-100 micrograms/ml) the serine proteinase (SP) from Staphylococcus aureus has no cytotoxic effect on human peripheral blood lymphocytes and does not stimulate them in culture. However, it affects the action of a number of polyclonal activators. In a concentration of 100 micrograms/ml SP completely eliminates blastic transformation after stimulation with B cell mitogens (NDCM, S. aureus and Escherichia coli), lowers the blastic transformation after stimulation with PWM and SPA, and does not affect the blastic transformation after stimulation with PHA. SP (100 micrograms/ml) reduces the concentration of Ig in stimulated cultures (stimulation with PWM, NDCM, S. aureus and E. coli) far below the Ig level of unstimulated controls. This effect can be ascribed to an influence on cell stimulation, not to the proteolytic cleavage of secreted Ig, although SP can partially digest Ig. The effect on lymphocyte stimulation takes place when the SP is added to the culture together with the mitogen, or 18 h after the mitogen. This implies that SP does not affect the first stage of stimulation.

Preliminary estimation of chemoattractant activity of staphylococcal serine proteinase in vitro. Chemoattractant activity of staphylococcal serine proteinase

Human polymorphonuclear leukocytes isolated from peripheral blood of healthy donors migrated toward the staphylococcal serine proteinase.

Effect of calcium binding on conformational changes of staphylococcal metalloproteinase measured by means of intrinsic protein fluorescence

The removal by EDTA of Ca2+ from the two-tryptophan-containing metalloproteinase isolated from Staphylococcus aureus leads to an increase in its intrinsic fluorescence intensity. Based on acrylamide fluorescence quenching results, analyzed by the non-linear least-squares method, we have shown that this protein molecule undergoes irreversible conformational change upon removal of Ca2+, which include the exposure to the solvent of buried tryptophan residues. Steady-state fluorescence anisotropy measurements indicate that the loss of Ca2+ leads to a significant increase in internal mobility of previously buried tryptophan residues.