bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of hydrolysis products of FeCl3 · 6H2O by ESI‐MS
Authors: Hellman Heikki , Laitinen Risto S. , Kaila Leena , Jalonen Jorma , Hietapelto Vesa , Jokela Jukka , Sarpola Arja , Rämö Jaakko
Published: October 2006

The hydrolysis reactions of FeCl3 in 0.1 mM aqueous solutions were monitored by electrospray ionisation time‐of‐flight mass spectrometry (ESI‐ToF‐MS). In contrast to the other ionisation techniques, electrospray ionisation provides information on the composition of the elemental cores even in water and salt cluster ions. Therefore, the technique facilitates detection of the bonding of the chloride ions in the oxo–hydroxo–iron cores. A variety of mononuclear and polynuclear iron–oxohydroxo–chloride complexes were characterised from the cationic and anionic mass spectra of iron(III) solutions. Oxidation and reduction reactions of iron, as well as competition between OH− and Cl− ions within one iron core, were also observed. Copyright © 2006 John Wiley & Sons, Ltd.
Transplantation for hepatocellular carcinoma: The Milan criteria and beyond
Authors: Freeman Richard B.
Published: October 2006

Key Concepts:

1. Liver transplantation offers excellent results for selected candidates with hepatocellular carcinoma (HCC).

2. Selection strategies have evolved but are mainly based on size and number of tumors, which are surrogates for vascular invasion. Newer techniques show promise for identifying patients at high risk for recurrence and selecting those with low risk, even though they may exceed currently established tumor size criteria.

3. Evaluation of the effectiveness of liver transplantation for HCC requires an intent-to-treat approach that must include an accounting of the dropout rate of patients while waiting.

4. Locoregional pretransplantation adjuvant treatments may have some role for downstaging and/or reducing the dropout rate before transplantation, but their posttransplantation effect on outcome remains undetermined.

5. Liver allocation for HCC candidates in the context of increasing HCC prevalence requires better and evidence-based prioritization policies. Liver Transpl 12:S8–S13, 2006. © 2006 AASLD.
Histologic findings in recurrent HBV
Authors: Thung Swan N.
Published: October 2006

Key Concepts:

1. The histopathologic presentation of hepatitis B (HB) infection in liver allografts is generally similar to that seen in the nonallografts.

2. An atypical pattern of recurrent HB, i.e., fibrosing cholestatic hepatitis (FCH) occurs in a small number of patients. These patients present with a severe cholestatic syndrome, which may clinically resemble acute or chronic rejection.

3. There are several other possible causes of acute and chronic hepatitis in liver allografts that may need to be considered.

4. Hepatitis B virus (HBV) infection in the liver allograft can easily be confirmed by performing immunohistochemical stains for hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg). The expression pattern of these HBV antigens varies and is sometimes helpful in determining whether the liver injury is mainly from the HBV or from other causes in coexistence with the HBV infection.

5. Histological grading of the necroinflammatory activity and staging of the fibrosis should only be applied when the changes are related to the recurrent HB.

6. The pathology of liver transplantation is complex; therefore, clinical correlations remain extremely important in arriving at the final and correct diagnosis. Liver Transpl 12:S50–S53, 2006. © 2006 AASLD.
A difficult case of primary sclerosing cholangitis
Authors: Vargas Hugo E.
Published: October 2006

Key Concepts:

1. The immediate postoperative concerns in a patient with primary sclerosing cholangitis.

2. Recognize the difficulties in assessing biliary health in patients that have had complicated postoperative biliary concerns.

3. Recognize the difficulty in ascertaining the presence of chronic rejection vs. recurrent primary sclerosing cholangitis. Liver Transpl. 12:S65–S67. 2006. © 2006 AASLD.
Multimodal trivariate thematic maps with auditory and haptic display
Authors: Jeong Wooseob
Published: October 2006

The purpose of this study is to explore the possibility of multimodal trivariate thematic maps by utilizing auditory and haptic displays. With two different modes of display (color only displays and multimodal displays with color, audio, and haptic), the completion time of tasks and the recall (retention) rate were measured in two separate experiments. In terms of the completion time, with minimal learning experience, participants could accomplish the tasks at the same level of speed in both modes. For the recall rate, multimodal displays have much higher recall rates. It is speculated that the natural quantitative hierarchies in auditory and haptic displays provide an advantage in the use of multimodal displays. These findings confirmed the possibility of using auditory and haptic displays in visually dominant geographic information systems (GIS) for multi‐variate thematic maps.
Emotional design II: Affective information behavior research with adult and child populations
Authors: Nahl Diane , Bilal Dania , Druin Allison , Fisher Karen
Published: October 2006

“;Emotions, we now know, change the way the human mind solves problems—the emotional system changes how the cognitive system operates.” (Norman, 2004: 18). Affective variables drive cognitive information behavior through a person's interests, motivation, feelings, and persistence. Recent research suggests that uncertainty contributes to cognitive load and negatively affects success, while optimism positively affects it (Nahl, 2004; 2005). Therefore, a focus on the interaction of affect and cognition, particularly studies examining the varieties of affect that arise in different situations and their impact on cognition, is necessary to understanding the information behavior of various groups. The research presented includes international data, both child and adult populations, and a variety of information settings. The research domains of the presenters include affective load in information tasks (Nahl), emotion in international children's use of cross‐cultural interfaces (Bilal), emotional metadata of children (Druin), and information behavior in everyday life (Fisher). The panelists present findings from their current research on affective information behavior (AIB) that illustrates its determining effect on thinking and action, and provide a review of research in the affective domain from related fields.
“Information work” and chronic illness: Interpreting results from a nationwide survey of people living with HIV/AIDS
Authors: Hogan Timothy P. , Palmer Carole L.
Published: October 2006

While there is a substantial body of research which describes how the HIV‐positive community seeks and uses information, much of that work fails to consider these activities in relationship to the experience of living with long‐term chronic illnesses. In this paper, we present results from our survey study on the information preferences and practices of the HIV‐positive community. We compare our results to previous findings on the HIV‐positive community and people living with another chronic condition, multiple sclerosis (MS). Applying the chronic illness trajectory model developed by Juliet Corbin and Anselm Strauss, we examine what this body of research tells us about the management of “information work.” We identify the information sources that are most important, the attributes of information that influence its use, and the tensions inherent in managing information in the day‐to‐day lives of the chronically ill. By extending Corbin and Strauss's model to the aspects of information emphasized across studies, we begin to articulate the fundamental nature of information work in living with chronic illnesses and how information services can be more responsive to the needs of the chronically ill.
The universal labeler: Plan the project and let your information follow
Authors: Jones William , Munat Charles F. , Bruce Harry , Foxley Austin
Published: October 2006

The Universal Labeler (UL) supports a single, unified scheme of “labeling“ which can be used to organize various kinds of information including electronic documents, email messages and web references. The UL takes a project‐centered approach to personal information management (PIM): 1. People often keep information to get things done ‐ to complete projects (“finish a course”, “re‐model a house“, etc.). 2. Project‐planning involves problem‐solving: A person's conceptualization of a project can often be characterized as a hierarchy of subproject/tasks. 3. Project structure, if made explicit, can aid not only in planning but also in the organization of related information. Projects, subprojects and tasks are represented by “labels” in the UL. Useful properties and behaviors can be associated with these labels ‐ “remind me by” or due dates, for example. The UL is a step towards the integration of information regardless of its form (e‐document, paper, web page) and towards the integration of information management with the management of tasks and projects.
Shifts between search stages during task‐performance in mediated information seeking interaction
Authors: Olah Judit
Published: October 2006

The research reported here focuses on the users' information seeking behavior. Set in the framework of the interactive information retrieval paradigm, the research examines the micro‐dynamics of the information seeking process, and explores search stages that users pursue as they proceed to solve their information problem. The research analyzes the users' information seeking behavior as they move between search stages, and looks for patterns in the transition. The observed shifting behavior allows for examining the question of predictability. The observed shifting patterns lead to the development of a new model for information seeking behavior that describes multiple search stages, aspects and dimensions. The model represents a non‐linear process of multiple re‐iterative cycles that make up the overall flow of communication with the information system. The model expands significantly earlier theoretical and empirical models as it represents a series of re‐iterative processes that characterize the information seeking interaction.
Experienced Web users' search behavior: Effects of focus and emotion control
Authors: Kim Kyung‐Sun
Published: October 2006

This study investigates how users' cognitive and affective characteristics influence the navigational and search behaviors on the Web among experienced Web users. Sixty‐seven undergraduate students participated in the study. Two standardized tests and a questionnaire were used to collect information on the participants' cognitive style, problem‐solving style, and demographics. Factor analysis was performed on the scores from the two standardized tests (Group Embedded Figures Test and Problem Solving Inventory), and extracted two user factors (Focus Control and Emotion Control). The Focus Control factor seemed to influence users' navigational behaviors, such as the use of links and back buttons, whereas the Emotion Control factor affected search behaviors including keyword searching, and also search performance measured by precision and recall.
Berrypicking in the real world: A wayfinding perspective on information behavior research
Authors: Lueg Christopher P. , Bidwell Nicola J.
Published: October 2006

In 1989 Bates introduced berrypicking as a powerful metaphor highlighting that searching is not a linear process but is more accurately described as an activity that is distributed in time and space. From an information seeking perspective there are interesting similarities between berrypicking and real world wayfinding. Wayfinding is also distributed in time and space but its success involves to a large extent embodied interaction with the environment. Trying to frame these interactions from an information seeking point of view revealed there is a lack of research on the relevance of embodiment to information behavior research.
What students say they know, feel, and do about cyber‐plagiarism and academic dishonesty? A case study
Authors: Ercegovac Zorana
Published: October 2006

This article presents results of a case study that used self‐reported paper‐and‐pencil questionnaire by thirty‐seven junior high school students with regard to their understanding of, attitudes, and behaviors toward plagiarism in the Web environment. Performance indicators used in the questionnaire were framed in the context of information literacy standards. The article identifies those areas that intervention programs should be designed on the basis of students' gaps and levels of understanding with respect to responsible uses of information in general, and especially of digital networked resources.
Consumer health digital divide: A research agenda for studying inequality in online health information access and use
Authors: Chong Jing
Published: October 2006

Driven by social, economic, academic and technological forces, the new field of E‐health has been developing quickly in recent years. Many E‐health applications are Internet‐based and therefore have the potential to help people throughout the world. However, this high dependence on the Internet also raises sobering questions about a health digital divide, i.e. unequal access and use as well as unequal rights to gain benefits of online information among health consumers. In this paper, we discuss social, cultural and economic factors which shape a research agenda for examining health digital divide issues. These factors are derived by means of a literature review. Future research questions include how to solve the discrepancies between health digital divide and digital divide among the general population, what is the role of content prejudice in health digital divide, and what is the status quo of health digital divide in developing countries, et al.
PROPELLER‐EPI with parallel imaging using a circularly symmetric phased‐array RF coil at 3.0 T: Application to high‐resolution diffusion tensor imaging
Authors: Chuang Tzu‐Chao , Huang Teng‐Yi , Lin Fa‐Hsuan , Wang Fu‐Nien , Juan Chun‐Jung , Chung Hsiao‐Wen , Chen Cheng‐Yu , Kwong Kenneth K.
Published: October 2006

A technique integrating multishot periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) and parallel imaging is presented for diffusion echo‐planar imaging (EPI) at high spatial resolution. The method combines the advantages of parallel imaging to achieve accelerated sampling along the phase‐encoding direction, and PROPELLER acquisition to further decrease the echo train length (ETL) in EPI. With an eight‐element circularly symmetric RF coil, a parallel acceleration factor of 4 was applied such that, when combined with PROPELLER acquisition, a reduction of geometric distortions by a factor substantially greater than 4 was achieved. The resulting phantom and human brain images acquired with a 256 × 256 matrix and an ETL of only 16 were visually identical in shape to those acquired using the fast spin‐echo (FSE) technique, even without field‐map corrections. It is concluded that parallel PROPELLER‐EPI is an effective technique that can substantially reduce susceptibility‐induced geometric distortions at high field strength. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Pyrrolizidine alkaloids from Melampyrum pratense
Authors: Roeder Erhard , Bourauel Thomas
Published: October 2006

Two toxic pyrrolizidine alkaloids were isolated from Melampyrum pratense and their structures determined by spectroscopic methods. © 1992 Wiley‐Liss, Inc.
Alkaloids of Stipa robusta (sleepygrass) infected with an Acremonium endophyte
Authors: Petroski Richard J. , Powell Richard G. , Clay Keith
Published: October 2006

Stipa robusta (= Stipa vaseyi) is a perennial grass found in certain areas of the southwestern United States. It is commonly known as sleepygrass, as horses that ingest this grass may become profoundly somnolent or stuporous for periods of time lasting up to several days. In an attempt to determine the active principle(s), fractionation of a methanolic extract of sleepygrass infected with an Acremonium endophyte has yielded lysergic acid amide (20 μg/g dry wt), isolysergic amide (8), 8‐hydroxylysergic acid amide (0.3), ergonovine (7), chanoclavine‐l (15), and N‐formylloline (18). Related alkaloids have been found in many endophyte‐infected grasses. The dominant alkaloid constituent in sleepygrass, lysergic acid amide, has not previously been identified in a grass in such high concentration. Lysergic acid amide is likely to be the basis for the extreme sedative effects on animals, given past pharmocological work on the compound from the ergot fungus Claviceps paspali. © 1992 Wiley‐Liss, Inc.
Inhibition of insect acetylcholinesterase by the potato glycoalkaloid α‐chaconine
Authors: Wierenga Joel M. , Hollingworth Robert M.
Published: October 2006

Homogenates from several insect species were assayed for inhibition of acetylcholinesterase by the potato gycoalkaloid α‐chaconine. Colorado potato beetle acetylcholinesterase was up to 150‐fold less sensitive than other species tested. Acetylcholinesterase from an insecticide‐resistant strain of Colorado potato beetles was more sensitive to inhibition than the susceptible strain. Most insect species tested had inhibitory concentrations causing a 50% reduction in activity in the 5 to 40 μM range. Sensitive insect acetylcholinesterases were similar to mammalian cholinesterases in their response to α‐chaconine. The results indicate that pesticides and host plant resistance factors may interact at the same target. Changes in the target due to selection pressure from either pesticides or host plant resistance factors could affect the efficacy of both control strategies. © 1992 Wiley‐Liss, Inc.
The β‐type toxin Ts II from the scorpion Tityus serrulatus: Amino acid sequence determination and assessment of biological and antigenic properties
Authors: Mansuelle Pascal , Martin‐Eauclaire Marie‐France , Chavez‐Olortegui Carlos , de Lima Maria Elena , Rochat Hervé , Granier Claude
Published: October 2006

The toxin Ts II from the venom of the Brazilian scorpion Tityus serrulatus was purified in two successive chromatographic steps. The amino acid sequence was then determined by automated Edman degradation of the reduced and S‐carboxymethylated protein and of proteolytic peptides derived from it. This sequence appears to differ from that of previously characterized toxins found in this venom. However, it is identical to the recently published sequence of protein III‐8 from the same venom [Possani et al., J Biol Chem 266:3178–3185, 1991], except that the C‐terminus was found to be amidated. Homologies were found between the sequence of Ts II and that of other toxins from Tityus; in particular, the amino acid sequence of Ts II displays 72% sequence identity with Ts VII (also cälled TiTx γ). Consistent with this structural similarity, some biological properties of Ts II were found to be similar to those of Ts VII: Ts II has an intracerebroventricular LD50 of 6 ng, as compared to 0.6 ng for Ts VII; in a receptor binding assay Ts II, like Ts VII, was found to behave as a β‐type toxin and to inhibit the binding of the reference labelled toxin with a K0.5 of 5 × 10−9 M, as compared to 7 × 10−11 M for Ts VII. Nevertheless, Ts II is unable to bind to anti‐Ts VII antibodies in radioimmunoassay experiments, indicating the non‐conservation between the two toxins of at least some antigenically important residues. In fact, the sequence differences between Ts II and Ts VII are mainly mapped in two regions believed to be antigenic by analogy with other scorpion toxins. © 1992 Wiley‐Liss, Inc.
Systematics, distribution, and host specificity of grass endophytes
Authors: Leuchtmann Adrian
Published: October 2006

Clavicipitaceous endophytes (Ascomycetes) are distributed worldwide in many grasses and sedges forming a perennial and often mutualistic association with their hosts. Most endophytes appear to produce alkaloid toxins in infected plants. The high frequency of infection in many grasses and in certain grassland communities may indicate a selective advantage of infected over non‐infected host plants due to their toxic effects on grazing animals and insects. Field observations and artificial inoculations of seedings have demonstrated a high degree of specificity of most endophytes to their host plant, particularly in asexual, seed‐bome endophytes. Specific isozyme genotypes found on several host species suggest that host‐specific physiological races may occur. Knowledge of host range and host specificity is vital for potential applications of endophytes in pest control. © 1992 Wiley‐Liss, Inc.
Molecular biology and evolution of the grass endophytes
Authors: Schardl Christopher L. , Tsai Huei‐Fung
Published: October 2006

Acremonium coenophialum Morgan‐Jones et W. Gams is a maternally transmitted fungal symbiont (endophyte) of the important forage grass Festuca arundinacea Schreb. (tall fescue), and provides biological protection and enhanced fitness to its host, but its anti‐mammalian ergot alkaloids detract from the usefulness of tall fescue as forage for livestock. Molecular genetic techniques and materials are being developed in order to specifically eliminate the gene(s) encoding the first enzyme in ergot alkaloid biosynthesis. These techniques will also facilitate basic studies, such as host‐fungus compatibility or biosynthesis of insecticidal alkaloids. Molecular phylogenetics indicate that endophytes related to A. coenophialum have evolved on multiple occasions from strains of Epichloë typhina (Ascomycotina, Clavicipitaceae), for which the sexual cycle is known. These studies also reveal significant diversity among seedborne endophytes in individual grass species. Thus, the endophytes are an important source of biochemical potential and genetic diversity in grass‐fungus symbiota. © 1992 Wiley‐Liss, Inc.
Ecology of plant‐herbivore communities: A fungal component?
Authors: Hammon Kyle E. , Faeth Stanley H.
Published: October 2006

We consider how microorganisms may alter conventional theories of the organization of plant‐herbivore communities. We focus on endophytic fungi and their role in mediating interactions among herbivores, their host plants, and natural enemies. We propose hypotheses about the role of microbes in plant‐herbivore communities and suggest ways to test these hypotheses. An initial approach to the overwhelming complexity of interacting species is to view species as components of functional groups, be they micro‐ or macroscopic, that potentially affect the ecology and evolution of host plants. © 1992 Wiley‐Liss, Inc.
Quail spleen is enlarged by microcystin RR as a blue‐green algal hepatotoxin
Authors: Takahashi Shinji , Kaya Kunimitsu
Published: October 2006

Toxic effects of microcystin RR as a blue‐green algal hepatotoxin in laboratory quails were examined. In order to determine the microcystin RR LD50, purified microcystin RR was injected into the peritoneum of the quails. The value obtained was 256 μg/kg quail. Usually the quails died between 14 and 18 hr after the injection. After administration of the toxin, the quail spleens were enlarged to a doubling of the control spleens, whereas the livers did not change. These effects are quite different from those in mice and rats, indicating the toxic mechanism of the toxin in quails is different. © 1992 Wiley‐Liss, Inc.
Transfer of ochratoxin a from lactating rats to their offspring: A short‐term study
Authors: Breitholtz‐Emanuelsson Anna , Palminger‐Hallén Ira , Wohlin Pär Ola , Oskarsson Agneta , Hult Karl , Olsen Monica
Published: October 2006

A dose‐dependent transfer of ochratoxin A into the milk of lactating rats was found after a single oral dose of ochratoxin A, given in the dose levels of 10,50, and 250 μg ochratoxin A/kg body weight by gastric intubation. The milk/blood concentration ratio of ochratoxin A at 24 and 72 h was 0.4 and 0.7, respectively. A linear relationship was found between the concentration of ochratoxin A in the dam's milk and in the blood of the pups at 72 h, as well as in the dam's milk and in the kidneys of the pups. The pup blood/milk concentration ratio of ochratoxin A was approximately 6. At 72 h the sucklings had higher levels of ochratoxin A than their dams in both blood and kidneys. The results show that the concentration of ochratoxin A in milk can be used as an indicator of the continuously administered dose to the suckling. © 1992 Wiley‐Liss, Inc.
Production of a toxin stemphol by Stemphylium species
Authors: Solfrizzo Michele , Strange Richard N. , Sabia Cinzia , Visconti Angelo
Published: October 2006

Five of 11 isolates of Stemphylium botryosum Wallr. from oilseed rape produced the phytotoxin stemphol when cultured on rice, with yields varying from 15.0 to 98.4 mg/kg, and three of them also produced the toxin on Czapek Dox (CD) liquid medium supplemented with cations (0.12–0.31 mg/L) and potato‐dextrose (PD) broth (0.37–1.47 mg/L). In liquid cultures about 95% of stemphol was found in the mycelium, and toxin production was slightly increased when cultures were exposed to near UV light rather than being grown in the dark. The LD50 concentrations for stemphol against isolated cells of oilseed rape and chickpea were 8.4 and 7.0 μM, respectively. One isolate of S. msjusculum (strain no. 135459) produced much greater amounts of stemphol, i.e., 22.8 mg/L, 535.3 mg/L, and 548 mg/kg when grown on CD, PD, and rice, respectively. Leaves of oilseed rape, artificially infected with S. majusculum and bearing lesions that occupied an average of 70% of the lamina contained 0.9 μg stemphol per gram dry weight of leaf tissue. © 1994 Wiley‐Liss, Inc.
Production of polyclonal antibodies for cyclopaldic acid, a major phytotoxic metabolite produced by the plant pathogen Seiridium cupressi
Authors: Sorbo Giovanni Del , Evidente Antonio , Scala Felice
Published: October 2006

An antiserum against cyclopaldic acid (CA), a phytotoxic metabolite produced by Seiridium cupressi, the fungal pathogen of a canker disease of cypress, was prepared by immunization of rabbits with a CA‐bovine serum albumin conjugate (CA‐BSA). Antibodies recognizing CA were purified by affinity chromatography through an immunoadsorbent prepared by conjugating CA to lysine‐Sepharose 48. The specificity of antibodies was assayed against CA and some of its derivatives by competitive indirect enzyme‐linked immunoassay. The homologous antigen CA‐BSA and CA showed the highest binding activity with antibodies. The derivatives of CA modified in 1 of the 2 aldehyde groups reacted with antibodies to a lesser extent compared with CA‐BSA and CA. Isocyclopaldic acid and the tetraacetylderivative of CA, which have more than one modified functional group, showed a further decrease in their reactivity. Other derivatives, which have more substantial structural modifications of the carbon skeleton, did not react. The possible use of these antibodies in studies concerning the involvement of CA in the canker disease of cypress is discussed. © 1994 Wiley‐Liss, Inc.
Isolation and purification procedures for the preparation of paralytic shellfish poisoning toxin standards
Authors: Laycock Maurice V. , Thibault Pierre , Ayer Stephen W. , Walter John A.
Published: October 2006

Paralytic shellfish poisoning (PSP) is caused by mixtures of saxitoxin analoss of which more than eighteen are known. Reliable and sensitive analytical methods and assays for these toxins are essential to protect the consumer and the shellfish industry, but research has been restricted by a shortage of the pure compounds. Only saxitoxin has so far been generally available as a PSP toxin standard, yet sulfated analogs usually occur in higher concentrations than saxitoxin in toxic marine algae and shellfish. Methods are described for the purification of some of the common PSP toxins, in quantities sufficient for the preparation of PSP standards from the dinoflagellate Alexandrium excavatum, the giant sea scallop (Placopecten megallanicus) hepatopancreas, and the cyanobacterium Aphanizomenon flos‐aquae. Purity was monitored by high performance liquid chromatography with fluorescence detection (HPLC‐FD), ionspray mass spectrometry (ISP‐MS), capillary electrophoresis (CE), and proton NMR spectroscopy. Published 1994 Wiley‐Liss, Inc.
Development of rapid and sensitive high throughput pharmacologic assays for marine phycotoxins
Authors: van Dolah F. M. , Finley E. L , Haynes B. L. , Doucette G. J. , Moeller P. D. , Ramsdell J. S.
Published: October 2006

The lack of rapid, high throughput assays is a major obstacle to many aspects of research on marine phycotoxins. Here we describe the application of microplate scintillation technology to develop high throughput assays for several classes of marine phycotoxin based on their differential pharmacologic actions. High throughput “drug discovery” format microplate receptor binding assays developed for brevetoxins/ ciguatoxins and for domoic acid are described. Analysis for brevetoxins/ciguatoxins is carried out by binding competition with [3H] PbTx‐3 for site 5 on the voltage dependent sodium channel in rat brain synaptosomes. Analysis of domoic acid is based on binding competition with [3H] kainic acid for the kainate/quisqualate glutamate receptor using frog brain synaptosomes. In addition, a high throughput microplate 45Ca flux assay for determination of maitotoxins is described. These microplate assays can be completed within 3 hours, have sensitivities of less than 1 ng, and can analyze dozens of samples simultaneously. The assays have been demonstrated to be useful for assessing algal toxicity and for assay‐guided purification of toxins, and are applicable to the detection of biotoxins in seafood. © 1994 Wiley‐Liss, Inc.
Toxic effect of the bloom‐forming Trichodesmium sp. (cyanophyta) to the copepod Acartia tonsa
Authors: Guo Chunzhi , Tester Patricia A.
Published: October 2006

The toxicity of the marine cyanobacterium Trichodesmium sp. to the copepod Acartia tonsa was assessed in a series of experiments during a Trichodesmium bloom off the North Carolina coast in late October 1992. Healthy intact cells of Trichodesmium sp. were not toxic to A. tonsa and were ingested by A tonsa when no other foods were available. However, homogenized Trichodesmium cells were toxic to A. tonsa, suggesting that Trichodesmium sp. contains certain type(s) of intracellular biotoxins. This hypothesis was consistent with the observed high mortality when A. tonsa was treated with aging Trichodesmium sp. cells or with filtered cell homogenate. The affected copepods showed weakness, recumbency, and reduced responsiveness. Many were observed to have distended intestines. Bioassays using aged Trichodesmium sp. cells and filtered homogenate demonstrated a dose‐dependent effect on A. tonsa survival. © 1994 Wiley‐Liss, Inc.
An incident of elevated levels of unsaturated free fatty acids in mussels from Nova Scotia and their toxic effect in mice after intraperitoneal injection
Authors: Lawrence James F. , Chadha Rajinder K. , Ratnayake W. M. Nimal , Truelove John F.
Published: October 2006

Methanol extracts of the hepatopancreas of mussels (Mytilus edulis) harvested at two locations (Ship Harbour and Wine Harbour) in eastern Nova Scotia, Canada, were found to be toxic to mice after intraperitoneal injection. The commonly known toxins, such as those associated with diarrhetic shellfish poison (DSP), paralytic shellfish poison, and domoic acid, were not present in the extracts. However, they were found to contain elevated levels of free fatty acids. Using a modified DSP extraction procedure the quantities of free fatty acids determined (by latroscan TLC/FID) in the hepatopancreases of mussels were 2.9 mg/g (Ship Harbour 1), 2.2 mg/g (Ship Harbour 2), 1.2 mg/g (Wine Harbour), and 0.15 mg/g (Prince Edward Island, control). After further investigation it was determined that certain unsaturated fatty acids were mainly responsible for the toxicity. These included palmitoleic, linoleic, linolenic, octadecatetraenoic, and eicosapentenoic acids. Artificial mixtures of pure standards of these acids prepared in the same concentrations as found in the shellfish samples were also toxic to mice. These results indicate that elevated levels of free fatty acids in mussel hepatopancreas from locations in eastern Canada can lead to mouse deaths when using the DSP mouse bioassay procedure. © 1994 wiley‐Liss, Inc.
Bracken fern (Pteridium spp.) carcinogenicity and human health—a brief review
Authors: Smith Barry L. , Seawright Alan A.
Published: October 2006

Bracken fem (Pteridium spp.), one of the most abundant plants on the planet, is well known to cause cancer naturally in sheep and cattle. It contains, in some locations, extremely high concentrations of ptaquiloside which almost certainly is its major carcinogen. Ptaquiloside is transferred through milk. There is epidemiological evidence that the bracken carcinogen, in special situations, may cause cancer in man. Ptaquiloside and its animal models of carcinogenesis also offer good tools for the study of cancer. © 1995 Wiley‐Liss, Inc.
Purification and characterization of myotoxin IV, a phospholipase A2 variant, from Bothrops asper snake venom
Authors: Diaz Cecilia , Lomonte Bruno , Zamudio Fernando , Gutiérrez José María
Published: October 2006

A basic myotoxic protein was purified from Bothrops asper venom. Like other basic Bothrops myotoxins, myotoxin IV induces acute muscle damage after intramuscular injection in mice and disrupts negatively charged liposomes but not positively charged ones. Furthermore, this protein exerts a weak anticoagulant effect only at concentrations of 40 μg/ml or higher, and is devoid of phospholipase A2 activity. Rabbit polyclonal antibodies to B. asper myotoxin II, a related lysine‐49 isoform, cross‐react strongly with myotoxin IV by enzyme immunoassay, indicating a high degree of antigenic similarity between these two proteins. The fact that both toxins have similar amino acid compositions and amino‐terminal sequences, including leucine‐5 and glutamine‐11, 2 amino acid residues conserved in all lysine‐49 phospholipase A2 variants purified, strongly suggests that B. asper myotoxin IV is a lysine‐49 phospholipase A2. © 1995 Wiley‐Liss, Inc.
Isolation and characterization of microcystins from laboratory cultures and environmental samples of Microcystis aeruginosa and from an associated animal toxicosis
Authors: Lawton Linda A. , Edwards Christine , Beattie Kenneth A. , Pleasance Stephen , Dear Gordon J. , Codd Geoffrey A.
Published: October 2006

Six microcystins were identified in a laboratory culture of the cyanobacterium (blue‐sreen alga) Microcystis aeruginosa PCC 7813 using high‐performance liquid chromatography coupled with diode array detection (HPLG‐DAD) and mass spectrometry (LC‐MS). The toxins were purified and further characterized by amino acid analysis and tandem mass spectrometry (MS‐MS). The presence of the previously reported microcystin‐LR and microcystinly was confirmed. Two further microcystins were characterized as microcystin‐LW and microcystin‐LF. Another two toxins were partially characterized and are believed to be an analog of microcystin‐LR (molecular weight 1008) and microcystin‐LM (molecular weight 969). Natural bloom material of M. aeruginosa collected from 2 reservoirs was found to have similar microcystin profiles using HPLC‐DAD and LC‐MS, indicating the widespread occurrence of these microcystin variants. In addition, the presence of 5 of the microcystins was confirmed in the rumen contents of a lamb by LC‐MS and LC‐MS‐MS, providing the first report of microcystins identified in an animal suspected of being poisoned by cyanobacterial hepatotoxins. © 1995 Wiley‐Liss, Inc.
Novel monoclonal antibodies against microcystin and their protective activity for hepatotoxicity
Authors: Nagata Satoshi , Soutome Hiroshi , Tsutsumi Tomoaki , Hasegawa Akihiro , Sekijima Masaru , Sugamata Masao , Harada Ken‐Ichi , Suganuma Masami , Ueno Yoshio
Published: October 2006

Six monoclonal antibodies (MAbs) to microcystin‐LR (MCLR), a cyclic heptapeptide hepatotoxin isolated from the cyanobacterium Microcystis aeruginosa, were produced. They showed the protective effects on hepatotoxicity of MCLR in vitro and in vivo, and on the inhibition of protein phosphatase by MCLR. Competitive enzyme‐linked immunosorbent assays with various microcystins revealed that the six MAbs recognized a part of the molecule, in particular, a tertial structure around Adda, 3‐amino‐9‐methoxy‐2,6,8‐trimethyl‐10‐phenyldeca‐4,6‐dienoic acid. The specificity of these MAbs varied slightly. In primary rat hepatocyte cultures, all MAbs showed protective effects against the MCLR‐induced cell damages, assessed by morphological changes, lactate dehydrogenase release into the medium, and a calorimetric assay to measure the cell viability using a tetrazolium dye. The M8H5 MAb showing the highest affinity for MCLR blocked the lethal effects and hepatocellular damage to mice. In addition, M8H5 MAb recovered protein phosphatase 2A inhibition by MCLR in a dose‐dependent manner, while phosphatase inhibition by okadaic acid was not affected. Thus, the MAbs specifically reacted with the microcystins and prevented their biological activities. This is the first report on the protective effects of specific monoclonal antibodies on MCLR‐induced toxicity. © 1995 Wiley‐Liss, Inc.
Fusaric acid in Fusarium moniliforme cultures, corn, and feeds toxic to livestock and the neurochemical effects in the brain and pineal gland of rats
Authors: Porter James K. , Bacon Charles W. , Wray Emma M. , Hagler Winston M.
Published: October 2006

Fusaric acid is produced by several species of Fusarium, which commonly infect corn and other agricultural commodities. Since this mycotoxin may augment the effects of other Fusarium toxins, a gas chromatography/mass spectrometry method of analysis in feeds was developed. Fusaric acid was analyzed as the trimethylsilyl‐ester from F. monilifotme‐cultures, ‐contaminated corn screenings, and feeds toxic to livestock. The mycotoxin was found in all samples and ranged from 0.43 to 12.39 μg/g sample. Also, fusaric acid was tested for its neurochemical effects in the brain and pineal gland of rats. Animals were dosed intraperitoneally (100 mg/kg body weight) 30 min prior to the onset of the dark phase (lights out) and the effects were studied at 1.5, 3.5, and 5.5 h after treatment. Brain serotonin (5HT), 5‐hydroxyindoleacetic acid (5HIAA), tyrosine (TYRO), and dopamine (DA) were increased (P < 0.05) by fusaric acid, and norepinephrine (NEpi) was decreased (P < 0.05). Analogously, DA in the pineal gland increased and NEpi decreased (P < 0.05). Pineal N‐acetylserotonin (NAcSHT) was increased (P < 0.05), whereas pineal 5HT and its two major metabolites 5HIAA and 5‐hydroxytrytophol (5HTOL) decreased (P < 0.05). Elevated brain TYRO and brain and pineal DA, with decreased NEpi, may be consistent with fusaric acid's partial inhibitory effect on tyrosine‐hydroxylase and its inhibitory effect on dopamine‐β‐hydroxylase, respectively. Elevated pineal Nac5HT is consistent with decreased pineal 5HT and the increased pineal DA, and support the dopaminergic stimulatory activity of the enzyme responsible for the conversion of 5HT to NAc5HT. This is the first report of fusaric acid's in vivo effect on pineal DA, NEpi, 5HT, and NAc5HT in rats, and a relation for the effects on TYRO, 5HT, and 5HIAA in brain tissue. The results indicate fusaric acid alters brain and pineal neurotransmitters and may contribute to the toxic effects of Fusarium‐contaminated feeds. © 1995 Wiley‐Liss, Inc.
Toxicokinetics of ochratoxin A in rat following intratracheal administration
Authors: Breitholtz‐Emanuelsson Anna , Fuchs Radovan , Hult Karl
Published: October 2006

The toxicokinetic parameters of ochratoxin A in rat following intratracheal administration of 50 ng ochratoxin A/g body weight were studied. The absorption of ochratoxin A from the lungs was very efficient. The elimination pattern of the toxin was studied by the analysis of blood samples. The biological half‐life of ochratoxin A was 127 h and the calculated apparent volume of distribution equalled 168 ml/kg. The bioavailability of the toxin was very high, 98%. The plasma clearance of the toxin was 0.92 ml/kg·h. © 1995 Wiley‐Liss, Inc.
Comparative pathology of microcystin‐lr in cultured hepatocytes, fibroblasts, and renal epithelial cells
Authors: Khan Safdar All , Ghosh Shushmita , Wickstrom Mark , Miller Lou Ann , Hess Rex , Haschek Wanda M. , Beasley Val R.
Published: October 2006

The cyanobacterial toxin microcystin‐LR (MCLR) is a potent inhibitor of protein phosphatases 1 and 2A, and is selectively toxic to the liver in vivo and to isolated hepatocytes in vitro. This selectivity is believed to be due to toxin uptake via bile acid carriers. We investigated at the light and ultrastructural levels the effects of high concentrations of MCLR and long incubation times to determine in vitro whether fibroblasts and kidney cells (non‐target cells) respond in the same manner as do hepatocytes (target cells) at low concentrations and short incubation times. Cultured rat skin fibroblasts (ATCC 1213) and rat kidney epithelial cells (ATCC 1571) were incubated with MCLR at 133 μM 1‐24 hr. Lesions in these cells were compared with those in cultured hepatocytes incubated with MCLR at 13.3 μM from 1 to 32 min. Lesions in hepatocytes, kidney cells, and fibroblasts were noted at 4 min, 1 hr, and 8 hr, respectively, after initial exposure to MCLR. Lesions in all three cell types progressed and included plasma membrane blebbing, loss of cell‐to‐cell contact, clumping and rounding of cells, cytoplasmic vacuolization, and redistribution of cytoplasmic organelles. Loss of microvilli, whorling of rough endoplasmic reticulum, dense staining and dilated cristae in mitochondria, and pinching off of membrane blebs were noted only in hepatocytes. Nuclear changes typical of apoptosis were observed only in fibroblasts and kidney cells. Similarities in responses of different cell types to MCLR exposure probably reflect a common biochemical mechanism of action, i.e., inhibition of protein phosphatases 1 and 2A as described by others. The observed differences in the responses of the cell types examined in this study may reflect differences in the proteins phosphorylated and the severity of hyperphosphorylation. © 1995 Wiley‐Liss, Inc.
Ion selectivity of the channels formed by pardaxin, an lonophore, in bilayer membranes
Authors: Shi Yu Liang , Edwards Charles , Lazarovici Philip
Published: October 2006

Using the method of bilayer membranes at the tip of a patch pipette, the properties of the ionic channels produced by the ionophore toxin pardaxin were investigated. At low toxin concentrations, voltage‐dependent, single‐channel events were measured. The current‐voltage curves were non‐linear when determined in Tris‐CI solution, but were linear in K+‐HEPES solution. Using asymmetric ion solutions, the ionic selectivity of pardaxin channels was estimated from the reversal potentials obtained. The sequence of the relative permeabilities for monovalent cations was Tl+ > Rb+ > Cs+ > K+,NH4+ > methylamine+ > Li+ > dimethylamine+ > Na+. Except for Li+, the selectivity sequence fitted the cations relative hydrated size. For bivalent ions the permeability of Ba2+, Sr2+, and Mn2+ relative to Mg2+ changed according to the relative hydrated size. For anions the selectivity sequence was I− > NO3− > Br− > CI− > CIO4− > SCN− > BF− > HCOO− > F− > CH3COO−. The selectivity sequence for the small anions (I−, NO3−, Br−, CI−) was different from their hydrated size. Pardaxin channel showed a modest ion selectivity between small anions and cations (PK:PCI:PNa = 1.28:1.00:0.56). Pardaxin is proposed as a biophysical model to study ionic channel selectivity. © 1995 Wiley‐Liss, Inc.
Biological activity of cyclopaldic acid, a major toxin of Seiridium cupressi, its six derivatives, and iso‐cyclopaldic acid
Authors: Sparapano Lorenzo , Evidente And Antonio
Published: October 2006

Cyclopaldic acid (CA), its six derivatives, and iso‐cyclopaldic acid (IsoCA) were assayed for toxicity to cuttings of three species of cypress, as well as to mung bean, oat, and tomato explants. Toxicity to host and non‐host plants of CA derivatives having one or both of the aldehyde groups transformed was less than that of CA. Shoot tissues of Cupressus macrocarpa artificially infected by Seiridium cupressi leached electrolytes more than those of C. sempervirens and C. arizonica. CA, IsoCA, and to a lesser extent the monoacetylated, phenylhydrazone and hydrogenated derivatives of CA caused loss of electrolytes from cypress tissures. CA, IsoCA, and monoacetyl CA caused limited callus development of cypress tissue. Diacetylhydrazone CA enhanced the yield of cypress callus tissue. CA derivatives having both aldehyde groups modified induced root formation on cypress cuttings. The antifungal activity showed by CA toward species of Botrytis, Fusarium, and Geotrichum markedly decreased in its derivatives. The inhibitory effect of CA on esterases was exhibited also by IsoCA and the monoacetylated derivative. © 1995 Wiley‐Liss, Inc.
Economic losses and decontamination
Authors: Charmley Lynne L. , Trenholm H. Locksley , Prelusky Dan B. , Rosenberg Alex
Published: October 2006

Mycotoxin contamination of crops may cause economic losses at all levels of food and feed production including crop and animal production, and crop distribution and processing. The national economy would be affected adversely by losses incurred by crop and livestock producers and the multiplier effect this has on other industries as a result of the reduced spending power of producers. Costs of chemical analyses, quality control and regulatory programs, research and development, extension services, law suits, and the cost of human illnesses must all be bome by the national economy. The value of the losses encountered depends on grain, animal, and animal product prices, interest rates, degree of contamination, and other economic variables. Even during favourable seasons it is likely that millions of dollars are lost as a result of the contamination of crops with mycotoxins.

Many compounds and treatments have been tested in order to reduce mycotoxin concentrations in food and feed or to alleviate their adverse effects on animals. Some of these treatments show promising prospects for commercial application, while others have had commercial applications already. However, until reliable, cost‐effective, commercially applicable methods are more widely available, problems associated with mycotoxin contamination and the economic losses resulting, will continue to be seen in food and agriculture industries. Published 1995 Wiley‐Liss, Inc.
Toxicological data needed for safety evaluation and regulation on inherent plant toxins
Authors: Spcijers Gerrit J. A.
Published: October 2006

Although the awareness that natural compounds in foodstuffs can have implications for human health is growing, there is a lack of data on the toxicology and occurrence. To enable the safety evaluation of inherent plant toxins adequate texicological data are necessary. Of most inherent plant toxins at best only limited toxicological data are available, which makes it impossible to perform an accurate safety evaluation. This limited knowledge of inherent plant toxins permits the mystical claim of safety on the basis of history of food use, and thus the development of specific food safety regulation has been postponed. To further develop flexible and adequate regulation, for at least some inherent plant toxins, an adequate set of toxicological data should be available in order to verify and validate the initial regulation. Several problems (e.g., availability of the plant toxin or accuracy of historical human toxicity data) which arise when gathering the necessary data and the development of regulations are discussed and elaborated with a few examples such as solanum alkaloids and glucosinolates.

As long as nobody is held responsible to study safety aspects of inherent plant toxins, the lack of data will persist. Therefore a certain level of regulation should be recommended to provide the data needed. Such safety research projects integrated with new agricultural developments should be endorsed by the European Union and other international bodies. © 1995 Wiley‐Liss, Inc.