bluuebunny/crossref_metadata_2025 huggingface dataset:
The impact of anxiety on the accuracy of diagnostic decision‐making
Authors: Cumming Steven R. , Harris Lynne M.
Published: August 2002

The impact of anxiety on the accuracy of diagnostic decision‐making is a neglected area of research despite its clear implications for the welfare of clients receiving health care. This paper presents the findings of two studies examining the effects of experimentally‐induced performance anxiety (Study 1) and naturally‐occurring state anxiety (Study 2) on the ability of senior radiography students to make simple same–different decisions about simultaneously presented images and to carry out a secondary verbal memory task. In both studies the more anxious group was less accurate in the primary decision‐making task, but there was no decrement in performance on the secondary task. The results are difficult to reconcile with predictions from Eysenck and Calvo's9 processing efficiency account of the impact of anxiety on performance. Rather, the results are consistent with the notion that a primary adaptive purpose of anxiety is to disengage from tasks or stimuli currently occupying attention in order to allow organisms to attend to potential threats. Copyright © 2001 John Wiley & Sons, Ltd.
Strategic groups and competitive enactment: a study of dynamic relationships between mental models and performance
Authors: Osborne J. David , Stubbart Charles I. , Ramaprasad Arkalgud
Published: August 2002

This study used computer‐assisted content analysis of more than four hundred presidents' letters to shareholders to examine empirical linkages between cognitive strategic groups clustered by themes in the reports and strategic groups clustered by performance. We found these groups converged as predicted by the literature, and that mental models and performance are involved in a recursive process of competitive enactment which contributes to strategic group stability. Our research used inductively derived themes from the letters to structure a mental model widely shared in the pharmaceutical industry, and then employed thematic variations to find stable clusters of companies. These thematic clusters were triangulated with the strategic groups from a published study of the same industry, in the same period, and were shown to converge. Additionally, longitudinal linkages between earlier mental models of strategic goals and later reports of performance were found. The findings of our large‐scale empirical study support strategic group theory, demonstrate a novel approach to data mining, and pose questions for future research. Copyright © 2001 John Wiley & Sons, Ltd.
Who directs strategic change? Director experience, the selection of new CEOs, and change in corporate strategy
Authors: Westphal James D. , Fredrickson James W.
Published: August 2002

We develop a theory of board‐directed strategic change in which directors (1) conceive changes in corporate strategy that reflect the strategies of their own home companies, and (2) select new CEOs who have prior experience with similar strategies to facilitate implementation. The findings show that, while the experience of new CEOs appears to predict corporate strategic change, these effects disappear after accounting for board experience. Thus, our results suggest that executive effects on strategy can mask board effects. Copyright © 2001 John Wiley & Sons, Ltd.
Identifying liabilities of foreignness and strategies to minimize their effects: the case of labor lawsuit judgments in the United States
Authors: Mezias John M.
Published: August 2002

Most foreign direct investment (FDI) theories assume that foreign subsidiaries are at a disadvantage relative to domestic firms; that is, they suffer a liability of foreignness. Following this reasoning, most FDI research has focused on advantages foreign investors must possess to overcome whatever disadvantages they face. Research directly investigating the sources of foreign subsidiary disadvantages has been notably lacking, despite the fact that understanding disadvantages could uncover ways to reduce exposure to these liabilities of foreignness and improve management of FDI. This study focuses on whether labor lawsuit judgments represent a liability for foreign subsidiaries operating in the United States (U.S.). Specifically, I tested whether 486 British, German, and Japanese subsidiaries operating in the U.S. had more labor lawsuits brought to judgment than a matched sample of U.S.‐owned firms. Results indicate that foreign subsidiaries faced significantly more labor lawsuit judgments in both federal and state jurisdictions. I also investigated several variables hypothesized to be associated with a reduction in labor lawsuit judgments facing foreign subsidiaries. Foreign subsidiaries who used American top officers or whose parent firms had more U.S. operations faced fewer lawsuits, while foreign subsidiaries using human resource professionals actually faced more labor lawsuit judgments. Implications of these findings and avenues for future research are discussed. Copyright © 2002 John Wiley & Sons, Ltd.
Measuring and testing change in strategic management research
Authors: Bergh Donald D. , Fairbank James F.
Published: August 2002

This paper reviews some critical issues associated with measuring and testing change and then reports on how strategy researchers have addressed those matters. We first discuss three key methodological requirements: reliability assumptions of change variables, correlations between the change variable and its initial measure, and selection of unbiased measurement alternatives. Next, we present data from a content analysis of 126 change studies which suggest that strategy researchers tend not to recognize those requirements. Indeed, the typical approach used to measure and test change (as a simple difference between two measures of the same variable) is usually inappropriate and could lead to inaccurate findings and flawed conclusions. We conclude by offering suggestions for how change can be studied more rigorously. Copyright © 2002 John Wiley & Sons, Ltd.
Shimba—an environment for reverse engineering Java software systems
Authors: Systä Tarja , Koskimies Kai , Müller Hausi
Published: August 2002

Shimba is a reverse engineering environment to support the understanding of Java software systems. Shimba integrates the Rigi and SCED tools to analyze and visualize the static and dynamic aspects of a subject system. The static software artifacts and their dependencies are extracted from Java byte code and viewed as directed graphs using the Rigi reverse engineering environment. The run‐time information is generated by running the target software under a customized SDK debugger. The generated information is viewed as sequence diagrams using the SCED tool. In SCED, statechart diagrams can be synthesized automatically from sequence diagrams, allowing the user to investigate the overall run‐time behavior of objects in the target system.

Shimba provides facilities to manage the different diagrams and to trace artifacts and relations across views. In Shimba, SCED sequence diagrams are used to slice the static dependency graphs produced by Rigi. In turn, Rigi graphs are used to guide the generation of SCED sequence diagrams and to raise their level of abstraction. We show how the information exchange among the views enables goal‐driven reverse engineering tasks and aids the overall understanding of the target software system. The FUJABA software system serves as a case study to illustrate and validate the Shimba reverse engineering environment. Copyright © 2001 John Wiley & Sons, Ltd.
‘Devolution’ as an opportunity to test the ‘synergism hypothesis’ and a cybernetic theory of political systems
Authors: Corning Peter A.
Published: August 2002

‘Devolution’ is a political buzzword these days as empires, nations, bureaucracies and even business firms collapse, divide, downsize, outsource and in various ways become less than they once were. But what does devolution mean? How can we measure it? And, most important, how do we explain it? Some years ago it was proposed that synergistic functional effects of various kinds have been the underlying causal agency in the progressive evolution of complex, goal‐oriented (teleonomic) systems at all levels of biological organization, including human societies. (The term ‘synergy’ refers to otherwise unattainable combined effects that are produced by the interactions among various elements, parts or individuals.) Support for this theory has continued to mount over the past decade or so, and we will briefly review some of the evidence. One important corollary of this theory is the proposition that all teleonomic systems require cybernetic control processes which, in human societies, are typically referred to as political systems, management systems, or governments. In accordance with the synergism hypothesis, it is postulated that the fate of any cybernetic control process in a living system is ultimately contingent upon the underlying functional effects that the system produces; the functional synergies are the very cause of the differential selection and survival of complex systems and their cybernetic subsystems. Can this theory of government qua social cybernetics be tested? It is argued here that the phenomena often referred to as ‘devolution’ provide just such an opportunity. A causal explanation of socio‐political systems should be able to account not only for various ‘progressive’ trends but also for the many cases in which regression or collapse occurs. Some studies related to political devolution will be discussed, and the arguments for competing hypotheses will be considered. A major example of political devolution will also be invoked in support of this theory. Copyright © 2001 John Wiley & Sons, Ltd.
Recovery of neuromuscular junction morphology following 16 days of spaceflight
Authors: Deschenes Michael R. , Britt Amanda A. , Gomes Ronald R. , Booth Frank W. , Gordon Scott E.
Published: August 2002

It has previously been established that spaceflight elicits alterations in the morphology of the neuromuscular system that includes expansion of the neuromuscular junction (NMJ) and myofiber atrophy. The purpose of this study was to determine the capacity of the neuromuscular system to recover from spaceflight‐induced modifications upon return to normal gravity. Soleus muscles were obtained from rats participating in the 16‐day Neurolab space shuttle mission at 1 day and 14 days after returning to Earth: solei were also taken at the same time points from ground‐based control rats. Cytofluorescent techniques, coupled with confocal microscopy, were used to assess NMJ morphology. Histochemistry, in conjunction with phase contrast microscopy, was employed to examine myofiber size and type. Results indicate that 1 day after landing both pre‐ and postsynaptic stained areas of the NMJ were significantly (P ≤ 0.05) larger in the spaceflight group than in controls. Moreover, significant myofiber atrophy was demonstrated in animals subjected to 0 gravity. By 14 days following return to the Earth, however, NMJ stained areas and muscle fiber size were no longer different from control values at that same interval. These results suggest that the neuromuscular system possesses a robust capacity to recover from spaceflight‐induced perturbations upon return to normal gravitational influences. Synapse 42:177–184, 2001. © 2001 Wiley‐Liss, Inc.
Inhibition of glutamate release by fluspirilene in cerebrocortical nerve terminals (synaptosomes)
Authors: Wang Su‐Jane
Published: August 2002

Fluspirilene, a neuroleptic drug which is used clinically to treat schizophrenic patients, is a dopamine D2 receptor antagonist. Besides its well‐known actions on the dopamine receptors, fluspirilene also displays calcium channel‐blocking activity. The aim of this study was to investigate the effect of fluspirilene on the 4‐aminopyridine (4AP)‐evoked glutamate release in the cerebrocortical nerve terminals (synaptosomes). Fluspirilene reduced 4AP‐evoked glutamate release in a concentration‐dependent manner. This inhibitory effect was associated with a decrease in the depolarization‐evoked increase in the cytoplasmic free Ca2+ concentration ([Ca2+]C), which could be completely abolished by the Ca2+ channel blocker ω‐CgTX GVIA. Furthermore, fluspirilene did not produce any effect on ionomycin‐evoked glutamate release. These results suggest that fluspirilene inhibits glutamate release primarily by reducing presynaptic Ca2+ influx via N‐type Ca2+ channels in rat cerebrocortical nerve terminals. This finding implies that presynaptic Ca2+ channel blockade concomitant with inhibition of glutamate release and possibly other neurotransmitters release may contribute to the antischizophrenic action of fluspirilene. Synapse 44:36–41, 2002. © 2002 Wiley‐Liss, Inc.
Protection of dopaminergic nigrostriatal afferents by GDNF delivered by microspheres in a rodent model of Parkinson's disease
Authors: Gouhier Christelle , Chalon Sylvie , Aubert‐Pouessel Anne , Venier‐Julienne Marie‐Claire , Jollivet Christophe , Benoit Jean‐Pierre , Guilloteau Denis
Published: August 2002

The use of glial cell line‐derived neurotrophic factor (GDNF) appears to be a promising strategy to promote survival and function of the nigrostriatal dopaminergic pathway damaged in Parkinson's disease (PD). However, effective intracerebral administration is required for optimal therapeutic benefit and tools to evaluate such therapies must be developed. A rodent model of PD was therefore developed using striatal injection of 6‐hydroxydopamine (6‐OHDA) with simultaneous implantation of GDNF‐delivering microspheres. The effects of GDNF released from microspheres were assessed by classical methods such as amphetamine‐induced rotating behavior and tyrosine hydroxylase (TH) immunoreactivity, as well as by quantitative autoradiography using PE2I, a dopamine transporter (DAT) radiotracer, which is also suitable for SPET imaging in humans. 6‐OHDA‐lesioned animals that received microspheres without GDNF were used as controls. During the first 3 weeks after simultaneous lesion and implantation, the amphetamine‐induced rotating behavior of GDNF‐treated rats was improved compared to controls and an increase in TH expression (+26%) was measured in the striatum 6 weeks after lesion. In accordance with these results, an increase in striatal PE2I‐labeled DAT density was obtained (+17%) after 3 and 6 weeks of treatment. In conclusion, this study demonstrates the neuroprotective action of GDNF delivered by microspheres and suggests that PE2I may be an appropriate radiotracer for use in SPET scintigraphy to follow up treatment of PD in humans. Synapse 44:124–131, 2002. © 2002 Wiley‐Liss, Inc.
Regulation of striatal dopamine neurotransmission by nitric oxide: Effector pathways and signaling mechanisms
Authors: West Anthony R. , Galloway Matthew P. , Grace Anthony A.
Published: August 2002

An important role for the reactive gas nitric oxide (NO) in regulating striatal dopaminergic neurotransmission was identified shortly after initial observations indicated that this unorthodox neurotransmitter mediates many of the influences of glutamatergic neurotransmission in the cerebellum, cortex, and hippocampus. While the precise actions of NO on striatal presynaptic and postsynaptic elements remain to be fully characterized, the recent application of sophisticated anatomical, neurochemical, and electrophysiological approaches to the study of nitrergic signaling has revealed that NO exerts a powerful influence both on tonic extracellular dopamine (DA) levels and phasic DA neuron spike activity via the modulation of intrinsic striatal mechanisms and striatonigral feedback loops. Although the nature of the NO‐mediated modulatory influence on DA neurotransmission was initially clouded by seemingly conflicting neurochemical observations, a growing body of literature and understanding of the diverse signaling mechanisms and effector pathways utilized by NO indicates that NO exerts a primary facilitatory influence over tonic and phasic dopaminergic neurotransmission under physiological conditions. A review of neurochemical and electrophysiological studies examining the influence of endogenous and exogenous NO on DA neurotransmission indicates that NO signaling exerts multiple effects on local striatal circuits and projection neurons involved in regulating basal ganglia output and nigrostriatal DA neuron activity. In addition to summarizing these influences, the current review focuses on the mechanisms utilized by striatal NO signaling pathways involved in modulating DA transmission at the level of the terminal and cell body and attempts to integrate these observations into a functional model of NO‐dependent regulation of basal ganglia systems. Synapse 44:227–245, 2002. © 2002 Wiley‐Liss, Inc.
Quantitative methods for tradeoff analyses
Authors: Daniels Jesse , Werner Paul W. , Bahill A. Terry
Published: August 2002

A Corrigendum has been published for this article in Systems Engineering 4: 190–212, 2001.

Practicing engineers often find the tools and techniques used for investigating alternative system designs to be cumbersome or complicated. This article will show that these systems engineering tools and techniques are in fact quite simple and can provide critical insight into how stakeholder requirements drive the engineering design process. This helps ensure that customer requirements are satisfied throughout the entire system lifecycle and aids in reducing expensive design iterations due to poorly understood or poorly documented requirements. These goals are achieved by deriving figures of merit and combining them using standard scoring functions to steer efforts towards fulfilling the customer's objectives early in the design process. Few papers in the literature capture the basic elements of tradeoff analyses in a way that entices the engineer to utilize the techniques. We have attempted to ameliorate this problem. Most of the practices presented in the literature are written from a decision analysis perspective. The success of such techniques is dependent on the expertise of the analyst in that several of the methods require considerable analyst experience for them to be employed effectively. This paper presents standardized methodologies for carrying out tradeoff analyses, which are applicable to a wide array of problems and also demonstrates that these techniques are relatively simple to use. © 2001 John Wiley & Sons, Inc. Syst Eng 4: 190–212, 2001
Genotoxicity of di‐butyl‐phthalate and di‐iso‐butyl‐phthalate in human lymphocytes and mucosal cells
Authors: Kleinsasser Norbert H. , Wallner Barbara C. , Kastenbauer Ernst R. , Weissacher Herbert , Harréus Ulrich A.
Published: August 2002

The genotoxicity of phthalates, widely used plasticizers, has been shown previously for di‐butyl‐phthalate (DBP) and di‐iso‐butyl‐phthalate (DiBP) in human mucosal cells of the upper aerodigestive tract in a previous study using the Comet assay. Furthermore, higher genotoxic sensitivities of patients with squamous cell carcinomas of either the larynx or the oropharynx compared to non‐tumor patients were described. Other authors have demonstrated DNA damage by a different phthalate in human lymphocytes. It was the aim of the present study to determine whether there is a correlation between the genotoxic sensitivities to DBP and its isomer DiBP in either mucosal cells or lymphocytes. The single‐cell microgel electrophoresis assay (Comet assay) was applied to detect DNA strand breaks in human epithelial cells of the upper aerodigestive tract (n=132 specimens). Human mucosa was harvested from the oropharynx in non‐tumor patients and patients with squamous cell carcinomas of the oropharynx. Laryngeal mucosa of patients with laryngeal squamous cell carcinomas was harvested as well. Peripheral lymphocytes (n=49 specimens) were separated from peripheral blood. Xenobiotics investigated were DBP, DiBP, and N′methyl‐N′‐nitro‐N‐nitrosoguanidine (MNNG) as positive control, respectively. For statistical analysis, the SPSS™ correlation analysis according to Pearson and the Wilcoxon test were performed. Genotoxicity was found for DBP and DiBP in epithelial cells and lymphocytes (P<0.001). MNNG caused severe DNA damage. In analyzing DBP and DiBP results, genotoxic impacts in mucosal cells showed an intermediate correlation (r=0.570). Correlation in lymphocytes was the same (r=0.570). Phthalates have been investigated as a potential health hazard for a variety of reasons, including possible xenoestrogenic impact, peroxisome proliferation, and membrane destabilization. The present investigation suggests a correlated DNA‐damaging impact of DBP and DiBP in human mucosal cells and in lymphocytes, respectively. Teratogenesis Carcinog. Mutagen. 21:189–196, 2001. © 2001 Wiley‐Liss, Inc.
Potential teratogenicity of di‐n‐butyltin dichloride and other dibutyltin compounds
Authors: Farr Craig H. , Reinisch Katharine , Holson Joseph F. , Neubert Diether
Published: August 2002

The developmental toxicity of di‐n‐butyltin dichloride (DBT‐dC) was evaluated in Wistar rats following oral administration. No maternal toxicity, embryotoxicity, or malformations were observed at 1, 2.5, or 5 mg DBT‐dC/kg body weight. Signs of maternal toxicity, including decreased food consumption, body weight gain, and thymus weight, were observed at 10 mg/kg body weight DBT‐dC. At this dose, no evidence of embryotoxicity, including such measures as total resorptions, viable fetuses, or fetal weights, was noted in any litter data. There was a slightly increased frequency of total malformations at the 10 mg/kg dose level of 4/262 treated vs. 1/269 control fetuses. All defects occurred singly with no clustering nor organ system pattern of occurrence, which would be indicative of a teratogenic effect. The no‐observed‐adverse‐effect‐level (NOAEL) for prenatal as well as maternal toxicity was considered to be 5 mg DBT‐dC/kg body weight. The interpretation and utility of previously published studies on the developmental toxicity of dibutyltin compounds are confounded by dose regimen and data reporting deficiencies. These studies suggest that, after oral administration during days 6–17 of pregnancy, the NOAEL for malformations in rats of different strains ranges from 1.7 to 5 mg/kg body weight. In these studies, the maternal LD50 was reported to be about 8 mg/kg body weight in one study but at greater than 15 mg/kg in others. Thus, the NOAEL for teratogenicity may be roughly estimated to be from one‐tenth to one‐third of the maternal LD50. When evaluated, thymus involution, a typical but reversible effect of di‐ and tri‐butyltin compounds, was also observed at 5–10 mg/kg body weight. The most susceptible time for inducing teratogenic effects is reported to be days 7–9 of pregnancy, but malformations have also been found with dosing over longer duration at lower doses. It is doubtful that the findings of malformations at highly toxic doses in animals has any health hazard significance, especially when human exposure to dibutyltins typically occurs at several orders of magnitude lower than the doses used in these studies. Further comparative pharmacokinetic studies would be necessary in order to refine the hazard characterization. Teratogenesis Carcinog. Mutagen. 21:405–415, 2001. © 2001 Wiley‐Liss, Inc.
Gender differences in science attitude‐achievement relationships over time among white middle‐school students
Authors: Mattern Nancy , Schau Candace
Published: August 2002

Four causal models describing the longitudinal relationships between attitudes and achievement have been proposed in the literature. These models feature: (a) cross‐effects over time between attitudes and achievement, (b) influence of achievement predominant over time, (c) influence of attitudes predominant over time, or (d) no cross‐effects over time between attitudes and achievement. In an examin‐ation of the causal relationships over time between attitudes toward science and science achievement for White rural seventh‐ and eighth‐grade students, the cross‐effects model was the best fitting model form for students overall. However, when examined by gender, the no cross‐effects model exhibited the most accurate fit for White rural middle‐school girls, whereas a new model called the no attitudes‐path model exhibited the best fit for these boys. © 2002 Wiley Periodicals Inc. J Res Sci Teach 39: 324–340, 2002
Investigation of the effects of folate deficiency on embryonic development through the establishment of a folate deficient mouse model
Authors: Burgoon Jennifer M. , Selhub Jacob , Nadeau Marie , Sadler T.W.
Published: August 2002

Background

Folic acid (FA) has been shown to reduce the incidence of neural tube, craniofacial, and cardiovascular defects and low birth weight. The mechanism(s) by which the vitamin is effective, however, has not been determined. Therefore, a folic acid deficient mouse model was developed.

Methods

To create a folic acid deficiency, ICR female mice were placed on a diet containing no FA and including 1% succinyl sulfathiazole (SS) for 4 weeks before mating. Control mice were fed diets with either: 1) FA and 1% SS [+SS only diet]; 2) FA [normal diet]; or 3) a breeding diet. Dams and fetuses were examined during various days of gestation.

Results

Blood analysis showed that by gestational day 18, plasma folate concentrations in the −FA+SS fed dams decreased to 1.13 ng/ml, a concentration approximately 3% of that in breeding diet fed dams (33.24 ng/ml) and 8% of that in +SS only/normal fed dams (13.59 ng/ml). RBC folate levels showed a similar decrease, whereas homocysteine concentrations increased. Reproductive outcome in the −FA+SS fed dams was poor with increased fetal deaths, decreased fetal weight, and delays in palate and heart development.

Conclusions

Female mice fed a folic acid deficient diet and 1% succinyl sulfathiazole exhibited many of the characteristics common to human folic acid deficiency, including decreased plasma and RBC folate, increased plasma homocysteine, and poor reproductive outcomes. Thus, an excellent model has been created to investigate the mechanism(s) underlying the origin of birth defects related to folic acid deficiency. Teratology 65:219–227, 2002. © 2002 Wiley‐Liss, Inc.
Atlas of rat fetal skeleton double stained for bone and cartilage
Authors: Menegola Elena , Broccia Marisa L. , Giavini Erminio
Published: August 2002

Background

The double staining of fetal skeleton for bone and cartilage is a very useful method to evidence skeletal abnormalities in laboratory animals. However, this method has been rarely used in routine developmental toxicity tests. One reason could be the difficulty of comparing the single skeletal pieces and of having reference points. In this paper the fetal rat skeleton double stained with Alizarin red S and Alcyan Blue is described in detail to produce an atlas for developmental toxicity laboratories. Teratology 64:125–133, 2001. © 2001 Wiley‐Liss, Inc.
Stage‐specific skeletal and visceral defects of the IKr‐blocker almokalant: Further evidence for teratogenicity via a hypoxia‐related mechanism
Authors: Sköld Anna‐Carin , Wellfelt Katrin , Danielsson Bengt R.
Published: August 2002

Background

As a class effect, potent IKr‐blockers have been shown to induce stage‐specific external malformations. The aim of this study was to investigate whether IKr‐blockers also induce stage‐specific visceral and skeletal defects and to further elucidate a proposed arrhythmia–hypoxia hypothesis.

Methods

Single oral doses of the selective IKr‐blocker almokalant (ALM) 25–150 μmol/kg, 7–14 dams/group, were given to Sprague‐Dawley rats on gestation days (GD) 10–14, and the fetuses were examined for malformations on GD 21. One group was pretreated with the spin‐trapping agent, α‐phenyl‐N‐t‐butylnitrone (PBN), given intraperitoneally 1 hr before ALM on GD 11.

Results

Cardiac ventricular septum defects and vascular malformations were observed after dosing on GD 10–11 and, to a lesser degree, on GD 12–13. Urogenital defects, absence/malposition of the postcaval lung lobe, and attenuated diaphragm were observed mainly on GD 10–11. Skeletal examination showed a high incidence of vertebral abnormalities on thoracic level on GD 10, on lower thoracic to caudal level on GD 11, and sternebral defects were observed all days. On GD 13 brachy‐, oligo‐, and syndactyly of the forepaw were induced, and of the hindpaw on GD 14. PBN reduced the incidence of both visceral and skeletal defects.

Conclusions

The stage specificity of observed visceral and skeletal defects correlates well with what has been reported in the literature after temporary interruption of oxygen supply during the same stages of development. The protective effect by PBN present further evidence that the teratogenicity of potent IKr‐blockers is related to induction of hypoxia– reoxygenation injury due to embryonic cardiac arrhythmia. Teratology 64:292–300, 2001. © 2001 Wiley‐Liss, Inc.
Faculty Thoughts and Concerns About Student Ratings
Authors: Ory John C.
Published: August 2002

Although student ratings of instruction are used to determine whether a person is teaching effectively, many people who use them are not aware of the extensive research base for them.
Occurrence of compounds estrogenic to freshwater mussels in surface waters in an urban area
Authors: Gagné F. , Marcogliese D. J. , Blaise C. , Gendron A. D.
Published: August 2002

Estrogens play a major role in the sexual differentiation, gonad development, and oocyte growth of most oviparous organisms. They also stimulate vitellogenesis, the formation of high‐density glycolipophosphoprotein that serves as an energy source for the developing embryo. Surface waters from the St. Lawrence River, obtained in the vicinity of an urban area (Montreal, Quebec, Canada), were studied with respect to their estrogenic potential to the freshwater mussel Elliptio complanata. Estrogenicity was measured in water extracts by means of a competitive assay of estradiol binding to cytosolic proteins and by the vitellin‐inducing ability of mussel hemolymph following direct extract injection. Surface‐water samples drawn downstream of a municipal outfall plume and in a river draining a large farming and agricultural area had high levels of total and fecal coliform bacteria. High levels of estrogen competitors were also found and were able to induce vitellins in injected mussels. Moreover, the estrogen‐competing potential of the extracts was found to be significantly correlated with total and fecal coliform bacteria (R=0.9, p<0.01) and with the levels of vitellins in the hemolymph (R=0.62, p=0.03). The results indicate that water samples drawn from within the municipal effluent plume and from a river draining an agricultural area are estrogenic to freshwater mussels. Thus, the environmental inputs of estrogens are likely to be associated with human sewage and pesticide products. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 260–268, 2001
Detection of DNA damage in two cell lines from rainbow trout, RTG‐2 and RTL‐W1, using the comet assay
Authors: Nehls Sebastian , Segner Helmut
Published: August 2002

Screening methods to indicate the genotoxic potential of individual chemicals or environmental mixtures rely mainly on short‐term bacterial tests. Differences in the genotoxic response of prokaryotic and eukaryotic cells necessitate the development of nonbacterial screening assays. A promising approach for this purpose could be the comet (single‐cell gel electrophoresis) assay performed with fish cells in vitro. In the present study, we evaluated the comet assay with two different fish cell lines from rainbow trout (Oncorhyhnchus mykiss), the fibroblast‐like RTG‐2 cell line established from gonad tissue, and the epitheloid RTL‐W1 cell line established from liver tissue. The cells were exposed in vitro during 2 hr to the genotoxins, 4‐nitroquinoline‐1‐oxide (NQO), and benzo(a)pyrene (BaP), as well as to environmental samples. The LOEC values for NQO were similar in both cell lines, whereas for BaP, the RTL‐W1 cells were found to be more sensitive than the RTG‐2 cells. The slopes of the concentration–response curves of the two test compounds differed between the two cell lines, with RTG‐2 cells showing a steeper slope for NQO, and RTL‐W1 cells showing a steeper slope for BaP. When exposed to environmental samples from a remediation site, the RTL‐W1 cell line, but not the RTG‐2 cell line, indicated a genotoxic potential of the samples. The differences in the genotoxic response pattern of the two cell lines could be only partly explained in relation to metabolic enzymes, cytochrome P4501A, glutathione‐S‐transferase, and xenobiotic reductase. The findings of this study demonstrate that the comet assay with fish cell lines is suitable as in vitro screening assay in environmental genotoxicity testing, but the choice of test cell line may be critical. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 321–329, 2001
Time‐dependent accumulation of cyanobacterial hepatotoxins in flounders (Platichthys flesus) and Mussels (Mytilus edulis) from the Northern Baltic Sea
Authors: Sipiä Vesa O. , Kankaanpää Harri T. , Flinkman Juha , Lahti Kirsti , Meriluoto Jussi A. O.
Published: August 2002

There is only limited information about the accumulation of algal toxins in aquatic organisms in the Baltic Sea. In this study we measured total cyanobacterial hepatotoxin levels in blue mussel (Mytilus edulis) and flounderi (Platichthys flesus) tissues. Flounder were caught with gillnets from the western Gulf of Finland during July and August 1999. Blue mussels were collected from an enclosure at 3 m depth and from an artificial reef (wreck, 25–35 m depth) in the western Gulf of Finland between June and September 1999. Flounder liver and muscle samples and soft tissues of mussels were analyzed for the cyanobacterial hepatotoxins (nodularin, NODLN and/or microcystins, MCs) using an enzyme‐linked immunosorbent assay (ELISA). Results showed a time‐dependent accumulation of hepatotoxins in flounder and mussels. In flounder, the maximum concentration 399±5 (sd) ng NODLN or MC/g dry weight (dw) was found in the liver of specimens caught on 21 August 1999. No hepatotoxins were detected in muscle samples. The maximum concentration of 2150 ng±60 (sd) ng hepatotoxin/g dw was found in the mussel soft tissues collected on 20 August 1999. Temporal NODLN or MC trends indicated depuration of cyanobacterial hepatotoxin from mussels at surface level and an increase in NODLN or MC concentrations in those from the sea bed. These studies showed that despite the low cyanobacteria cell numbers the cyanobacterial hepatotoxins can accumulate in flounder and mussels. This may allow the further transfer of cyanobacterial hepatotoxins in the food web. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 330–336, 2001
Degradation of the cyanobacterial hepatotoxin microcystin by a new bacterium isolated from a hypertrophic lake
Authors: Park Ho‐Dong , Sasaki Youhei , Maruyama Tomoko , Yanagisawa Eiji , Hiraishi Akira , Kato Kenji
Published: August 2002

A bacterium capable of degrading microcystins‐RR, ‐YR, and ‐LR was isolated from a hypertrophic lake. The bacterium, designated Y2 and classified phenotypically as a member of the genus Sphingomonas, was shown to be distinct phylogenetically from any established species of Sphingomonas on the basis of 16S rDNA sequencing. The bacterium was tentatively identified as Sphingomonas by manual chemotaxonomy, but 16S rRNA sequencing analysis suggests that it is in fact a new species or even a new genus. When the Y2 bacterium was added to microcystins present in culture medium, the microcystins were degraded thoroughly in 4 days. The highest degradation rates of microcystins‐RR and ‐LR were 13 and 5.4 mg L−1 day−1, respectively. The degradation rates were strongly dependent on temperature and the maximum rate was at 30°C. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 337–343, 2001
An SSB encoded by and operating on linear killer plasmids from Kluyveromyces lactis
Authors: Schaffrath Raffael , Meacock Peter A.
Published: August 2002

The Kluyveromyces lactis linear plasmids k1 and k2 belong to the family of protein‐primed linear DNA genomes, which includes adenoviruses. Here we identify the 18 kDa gene product of k2ORF5 as a novel putative single‐stranded DNA binding protein, SSB. As judged from Western analysis using an epitope‐tagged fusion protein and ssDNA–agarose affinity chromatography, the Orf5 protein preferentially binds to ssDNA in vitro. Consistently, electrophoretic mobility shift assays demonstrate that ssDNA plasmid probes from k1 and k2 are retarded by this Orf5‐associated SSB activity. ORF5 gene shuffle‐mediated mutagenesis in vivo results in k1/k2 plasmid instability, pointing towards a role for the Orf5 protein in plasmid replication. Consistently, the Orf5 protein protects ssDNA from exonuclease digestion and stimulates Klenow enzyme. Our findings suggest a functional role for the Orf5 protein as a putative SSB probably required during k1/k2 plasmid DNA synthesis. Copyright © 2001 John Wiley & Sons, Ltd.
Functional analysis of the hexose transporter homologue HXT5 in Saccharomyces cerevisiae
Authors: Diderich Jasper A. , Merijn Schuurmans J. , Van Gaalen Monique C. , Kruckeberg Arthur L. , Van Dam Karel
Published: August 2002

The HXT5 gene encodes a functional hexose transporter that has moderate affinity for glucose (Km=10 mM), moderate to low affinity for fructose (Km=40 mM) and low affinity for mannose (Km>100 mM). The sole presence of Hxt5p in an otherwise hexose transport null mutant is sufficient to sustain a flux through glycolysis from glucose to fermentative products. However, the presence of HXT5 as the sole hexose transporter gene results in extremely poor growth on glucose, which suggests the involvement of glucose repression in the transcriptional regulation of HXT5. From Northern blot analysis on the members of the HXT family and studies with HXT5 tagged with the green fluorescent protein (GFP), it is evident that HXT5 is transcribed and translated during conditions of relatively slow growth, during growth on non‐fermentable carbon sources and in particular during sporulation. In wild‐type batch cultivations on fermentable carbon sources, Hxt5p is abundant in stationary phase or after depletion of the fermentable carbon source, which seems independent of the carbon source. The deletion of HXT5 does not result in a clear phenotype. A shift of stationary phase cells to fresh glucose medium resulted in somewhat slower resumption of growth in the hxt5 deletion strain compared to the wild‐type strain. The abundance of Hxt5p during stationary phase, sporulation and low glucose conditions suggests that HXT5 is a ‘reserve’ transporter, which might be involved in the initial uptake of glucose after the appearance of glucose. Other possible functions of the protein encoded by HXT5 will be discussed in the context of the results. Copyright © 2001 John Wiley & Sons, Ltd.
Enzymatic activities of Ura2 and Ura1 proteins (aspartate carbamoyltransferase and dihydro‐orotate dehydrogenase) are present in both isolated membranes and cytoplasm of Saccharomyces cerevisiae
Authors: Voříšek J. , Techniková Z. , Schwippel J. , Benoist P.
Published: August 2002

Computational analysis predicted three potential hydrophobic transmembrane α‐helices within the Ura2 multidomain protein of Saccharomyces cerevisiae, the C‐terminal subdomain of which catalyses the second step of uridine‐monophosphate biosynthesis by its L‐aspartate carbamoyltransferase activity (EC 2.1.3.2). The fourth step of pyrimidine biosynthesis is catalysed by dihydro‐orotate dehydrogenase (Ura1 protein; EC 1.3.99.11), which was similarly characterized as a peripheral membrane protein. Ex situ, the activities of the investigated enzymes were associated both with isolated yeast membranes, fractionated by differential centrifugation to remove intact nuclei, and with soluble cytoplasmic proteins. Copyright © 2002 John Wiley & Sons, Ltd.
Posterolateral aspect and stability of the knee joint. II. Posterolateral instability and effect of isolated and combined posterolateral reconstruction on knee stability: a biomechanical study
Authors: Krudwig Wilfried K. , Witzel Ulrich , Ullrich Karin
Published: August 2002

This study evaluated the correlation between the number of transected posterolateral structures (PLS) and the grade of posterolateral rotational instability, determined the effect of the popliteus muscle‐tendon unit on the tibial rotation, and examined the effect of an isolated posterior cruciate ligament (PCL) and combined PCL‐PLS reconstruction on knee stability. Sectioning the popliteofibular and lateral collateral ligaments both caused an increase in tibial external rotation. Cutting the PT resulted in a statistically highly significant excessive external rotation and externally shifted neutral position of the tibia over the full range of motion. Tensioning the popliteus muscle‐tendon unit led to a statistically highly significant internally shifted neutral tibial rotation and a decreased internal and an increased external rotation without affecting the total rotational arcs. The isolated PCL reconstruction did not affect the external rotation, whereas the combined PCL‐PLS reconstruction reset the knee to nearly physiological laxity patterns.
Surgical Treatment for Severe Acute Pancreatitis: Extent and Surgical Control of Necrosis Determine Outcome
Authors: Götzinger Peter , Sautner Thomas , Kriwanek Stephan , Beckerhinn Philipp , Barlan Murat , Armbruster Christian , Wamser Peter , Függer Reinhold
Published: August 2002

In patients operated on for severe acute pancreatitis (SAP), the factors determining outcome remain unclear.
From 1986 to 1998 a total of 340 patients with a diagnosis of SAP and in need of operative treatment were admitted to the intensive care unit (ICU) of a university hospital and a secondary care hospital. The mean APACHE II score on the day of admission was 16.1 (range 8–35).
All patients required operative therapy. Among the 340 patients, 270
(79.4%) had to be reoperated: 196 patients (72.6%) underwent operative revisions on demand, and 74 (27.4%) patients had preplanned reoperation. The overall mortality was 39.1% (133 patients). Septic organ failure in 126 patients (37.1%) and myocardial infarction or pulmonary embolism in 7 patients (2%) were the causes of death. The patient’s age (p <0.0002), APACHE II scores at admission (p <0.0001), presence or development of
(single or multiple) organ failure (p <0.002),
infection (p <0.02) and extent (p <0.04) of pancreatic necrosis, and surgical control of local necrosis
(p <0.0001) significantly determined survival. SAP that requires surgical treatment is associated with high in‐hospital mortality. Surgical control of local necrosis is the precondition for survival. Advanced age of the patient, high APACHE II score at admission, development of organ failure, and the extent and infection of pancreatic necrosis influence the outcome.
Pancreatic Function after Acute Biliary Pancreatitis: Does It Change?
Authors: Ibars Eugenia Pareja , Sánchez de Rojas Enrique Artigues , Quereda Luis Aparisi , Ramis Ricardo Fabra , Sanjuan Vicente Martínez , Peris Ramón Trullenque
Published: August 2002

According to the Cambridge and Marseilles symposia, morphologic and functional recovery from acute biliary pancreatitis (ABP) occurs if the initial cause and complications are eradicated. Nevertheless, in recent years there has been controversy over this topic, and varying results have been reported. These differing results may be due to different diagnostic methods, number of patients studied with regard to etiologic factors, severity of the disease, and differences in the tests used. A total of 63 ABP patients
[17 male (27%), 46 female (73%); 45 mild, 18 severe] were prospectively studied. All patients underwent cholecystectomy. No patient in this series underwent necrosectomy or pancreatectomy. During the acute phase the severity of the disease was assessed following the Atlanta criteria, and the occurrence and rate of necrosis were determined by dynamic computed tomography. Exocrine and endocrine pancreatic functions were assessed at 1 month, 6 months, and 1 year after the ABP episode by means of various pancreatic function tests. We evaluated the occurrence of pancreatic failure following ABP and if this deficiency was associated with the severity of the episode.
According to the classic symposia criteria, the study showed no deficit in exocrine or endocrine pancreatic function. No statistically significant differences were found when the pancreatic function and severity of the process were assessed.
Natural History of Early Colorectal Cancer
Authors: Matsui Toshiyuki , Yao Tsuneyoshi , Iwashita Akinori
Published: August 2002

Since superficial tumors have been found, their peculiar pathologic features have evoked questions concerning their biologic behavior, their natural history. The aim of the present study was to elucidate the natural history of colorectal cancers (CRCs) including superficial cancers, using a retrospective radiologic method. Forty nine cancers that had had initial configurations of early cancer seen by previous radiography and that were examined pathologically were the subject of the present study. Growth speeds [doubling time (DT) calculation] and configurational changes at the various stages (invasion depth) were compared between polypoid growth (PG) and nonpolypoid growth (NPG). Growth speeds of mucosal cancer and submucosal cancer were also compared. The results showed that early CRC grows slowly (DT 31.2 months) when the cancer is limited to the mucosa. However, as tumors grow down to the submucosa, their growth speed accelerates (DT 25.8 months). The DT of these early cancers were longer than that of advanced cancers. The pathologic growth pattern (NPG or PG) of the CRCs did not affect the tumor growth speed. In respect to tumor configuration, when the tumor is limited to the submucosa the antecedent growth pattern may be easily deduced. It seems difficult, however, to know the initial growth patterns in advanced cancers because cancers with polyloid growth frequently change to a nonpolypoid growth pattern when in advanced stages. Among 32 advanced cancers, only 6 (19%) derived from IIc/IIc+IIa cancer. The most common (more than 70%) origin of advanced cancer seems to be IIa, Is, and Isp lesions. These results suggest that NPG cancers or superficial depressed cancers are not the main origins of advanced cancers, and that these cancer do not show extraordinarily rapid growth.
Thyroid Gland and Surgery of the Thyroglossal Duct: Exercise in Applied Embryology
Authors: Organ Gregory M. , Organ Claude H.
Published: August 2002

Thyroglossal duct cysts (TDCs), the most common congenital cervical abnormality, originates from the medial anlage of the thyroid gland and presents as a painless asymptomatic midline suprahyoid mass. It does not represent a diagnostic challenge. The tract may persist as a fibrous cord or leave nests of cells anywhere along its embryonic path, and it gives rise to the development of TDC. The Sistrunk operation described in 1920 consists of en bloc cystectomy and central hyoidectomy, with tract excision up to the foramen cecum. This procedure remains an effective treatment for TDC. Malignant degeneration of TDC is rare (0.7%).