bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bite performance in clariid fishes with hypertrophied jaw adductors as deduced by bite modeling
Authors: Herrel Anthony , Adriaens Dominique , Verraes Walter , Aerts Peter 
Published: October 2002

AbstractWithin clariid fishes several cranial morphologies can be discerned. Especially within anguilliform representatives an increase in the degree of hypertrophy of the jaw adductors occurs. The hypertrophy of the jaw adductors and skeletal modifications in the cranial elements have been linked to increased bite force. The functional significance of this supposed increase in bite force remains obscure. In this study, biomechanical modeling of the cranial apparatus in four clariid representatives showing a gradual increase in the hypertrophy of the jaw adductors (Clarias gariepinus, Clariallabes melas, Channallabes apus, and Gymnallabes typus) is used to investigate whether bite force actually increased. Static bite modeling shows that the apparent hypertrophy results in an increase in bite force. For a given head size, the largest bite forces are predicted for C. apus, the lowest ones for C. gariepinus, and intermediate values are calculated for the other species. In addition, also in absolute measures differences in bite force remain, with C. apus biting distinctly harder than C. gariepinus despite its smaller head size. This indicates that the hypertrophy of the jaw adductors is more than just a correlated response to the decrease in absolute head size. Further studies investigating the ecological relevance of this performance difference are needed. J. Morphol. 253:196–205, 2002. © 2002 Wiley‐Liss, Inc.
Magnetic resonance safety testing of a newly‐developed fiber‐optic cardiac pacing lead
Authors: Greatbatch Wilson , Miller Victor , Shellock Frank G. 
Published: October 2002

AbstractPurposeTo assess magnetic resonance (MR) safety for a newly developed, fiber‐optic cardiac pacing lead.Materials and MethodsMR safety was assessed for the fiber‐optic cardiac pacing lead by evaluating magnetic field interactions and heating. Translational attraction and torque were evaluated using a 1.5‐Tesla MR system and previously described, standardized techniques. MR imaging‐related heating was assessed using a 1.5‐Tesla MR system and a transmit/receive, body radiofrequency (RF) coil with the fiber‐optic lead positioned to simulate an in vivo condition in a saline‐filled phantom. The phantom had dimensions similar to a human subject's torso and head. A fluoroptic thermometry system was used to record temperatures on and near the electrodes of the fiber‐optic pacing lead at five‐second intervals immediately before and during 20 minutes of MR imaging performed at a whole‐body‐averaged specific absorption rate (SAR) of 1.5 W/kg. Temperatures were also recorded from a reference site during this experiment.ResultsMagnetic field interactions for the fiber‐optic lead were minimal (deflection angle, 23°; torque, +2). The highest temperature change recorded for the fiber‐optic cardiac pacing lead and reference site was +0.8°C.ConclusionThe minor magnetic field interactions and relative lack of heating for the fiber‐optic pacing lead indicate that it should be safe for patients with this device to undergo MR imaging procedures using MR systems operating at 1.5‐T or less and at a whole‐body‐averaged SARs up to 1.5 W/kg. J. Magn. Reson. Imaging 2002;16:97–103. © 2002 Wiley‐Liss, Inc.
Crossing the phase boundary to study protein dynamics and function: combination of amide hydrogen exchange in solution and ion fragmentation in the gas phase
Authors: Kaltashov Igor A. , Eyles Stephen J. 
Published: October 2002

AbstractProtein dynamics are the key to understanding their behavior. The static protein structure alone in most cases is insufficient to describe the vast array of complex functions they perform in vivo. Until recently there were relatively few techniques available to investigate the dynamic nature of these proteins. Mass spectrometry has recently emerged as a powerful biophysical method, capable of providing both structural and dynamic information. By utilizing the labile nature of amide hydrogens as a marker of the backbone dynamics in solution, combined with gas‐phase dissociation techniques, we now have a high‐resolution tool to locate these exchanging hydrogens within the sequence of the protein and to probe the functional importance of its structural elements. In this paper we describe several applications of these methodologies to illustrate the importance of dynamics to the biological functions of proteins. Copyright © 2002 John Wiley & Sons, Ltd.
Detection of human herpesvirus 8 DNA in serum from blood donors with HHV‐8 antibodies indicates possible bloodborne virus transmission
Authors: Enbom Malin , Urassa Willy , Massambu Charles , Thorstensson Rigmor , Mhalu Fred , Linde Annika 
Published: October 2002

AbstractHuman herpesvirus 8 (HHV‐8) is associated with Kaposi's sarcoma. There is a high seroprevalence of HHV‐8 in several African countries, but the transmission route is not known definitively. In this study 174 serum samples from blood donors in Tanzania were examined by immunofluorescence assays detecting antibodies to latent and lytic HHV‐8 antigens. Real‐time polymerase chain reaction was used for detection and quantification of HHV‐8 DNA in serum. In all, 83/174 (48%) of the subjects had antibodies to latent or lytic antigens. Forty (23%) had antibodies to both antigens and of those eight (20%) had detectable HHV‐8 DNA in serum. HHV‐8 DNA load correlated with antibody titres to lytic, but not latent, HHV‐8 antigens. This supports the usefulness of anti‐lytic antibodies in HHV‐8 serology and suggests that transmission of HHV‐8 by blood contact could be of importance in this region. J. Med. Virol. 68: 264–267, 2002. © 2002 Wiley‐Liss, Inc.
Mixed infections of adults and children with multiple TTV‐like mini virus isolates
Authors: Vasconcelos Helena C.F. , Cataldo Márcio , Niel Christian 
Published: October 2002

AbstractTesting of the DNA of TTV‐like mini virus (TLMV) was done with serum samples obtained from 184 patients (children and adults) who visited different outpatient clinics at a university hospital in Florianopolis, south of Brazil. TLMV DNA was detected by PCR primers from the non‐coding region of the genome. A global TLMV prevalence of 78% was found (94% among children below 11 years). PCR products from three serum samples (patients A–C) were cloned, and the sequences with a length of 201–227 nucleotides were determined for 16–19 clones derived from each of the sera. Among the 16 clones derived from patient C, 15 were identical, and the remaining one had a sequence homology of 99%. In contrast, eight different sequences were obtained among the 19 clones derived from patient A, and 10 distinct sequences were depicted among the 17 clones derived from the serum of patient B. Additionally, 13 clones derived from a saliva sample of patient B were sequenced, and seven different nucleotide sequences obtained. One particular sequence was predominant in both serum (8/17 clones) and saliva (7/13 clones) of patient B. On a phylogenetic tree, sequences derived from patient A (a 6‐year‐old boy), as well as those derived from patient B (a 24‐year‐old man), were located in five distinct evolutionary branches, taking a minimum divergence of 5% between branches. This suggested that adults and children are coinfected frequently with several TLMV isolates of different origins. J. Med. Virol. 68: 291–298, 2002. © 2002 Wiley‐Liss, Inc.
Genetic characterization of hepatitis A virus isolates from Buenos Aires, Argentina
Authors: Mbayed Viviana Andrea , Sookoian Silvia , Alfonso Victoria , Campos Rodolfo Héctor 
Published: October 2002

AbstractThe Hepatitis A virus (HAV) has been classified in seven different genotypes, which include human (I, II, III, and VII) and simian (IV, V, and VI) groups. The sequence analysis of HAV strains contributes to the molecular epidemiology of the virus. Although the infection with HAV is endemic in Argentina and vaccination is being implemented in this country, using both IA and IB strains, there are very few data on the genotypes of the circulating viruses. On the basis of the sequences of 20 isolates collected in Buenos Aires during a 2‐year period (extended to 3 years by two additional specimens), we observed the presence of a single sub‐genotype, IA, but with a high genetic diversity. We analyzed the VP1–2A junction and also the VP3–VP1 region. Most of the Argentine isolates grouped in at least two clusters. One of these was related to South American strains, thus suggesting a co‐circulation of related isolates in neighbor countries. The other cluster was composed only of Argentine specimens. Other sequences were more scattered along the phylogenetic tree. However, we demonstrated that a consistent genetic relatedness of sequences could only be inferred on the basis of a more extensive sequencing of each isolate. J. Med. Virol. 68: 168–174, 2002. © 2002 Wiley‐Liss, Inc.
Cytokines, chemokines, and cytokine receptors in human microglia
Authors: Lee Yong B. , Nagai Atsushi , Kim Seung U. 
Published: October 2002

AbstractEnriched populations of human microglial cells were isolated from mixed cell cultures prepared from embryonic human telencephalon tissues. Human microglial cells exhibited cell type‐specific antigens for macrophage‐microglia lineage cells including CD11b (Mac‐1), CD68, B7‐2 (CD86), HLA‐ABC, HLA‐DR and ricinus communis aggulutinin lectin‐1 (RCA‐1), and actively phagocytosed latex beads. Gene expression and protein production of cytokines, chemokines and cytokine/chemokine receptors were investigated in the purified populations of human microglia. Normal unstimulated human microglia expressed constitutively mRNA transcripts for interleukin‐ 1β (IL‐1β) ‐6, ‐8, ‐10, ‐12, ‐15, tumor necrosis factor‐α (TNF‐α), macrophage inflammatory protein‐1α (MIP‐1α), MIP‐1β, and monocyte chemoattractant protein‐1 (MCP‐1), while treatment with lipopolysaccharide (LPS) or amyloid β peptides (Aβ) led to increased expression of mRNA levels of IL‐8, IL‐10, IL‐12, TNF‐α, MIP‐1α, MIP‐1β, and MCP‐1. Human microglia, in addition, expressed mRNA transcripts for IL‐1RI, IL‐1RII, IL‐5R, IL‐6R, IL‐8R, IL‐9R, IL‐10R, IL‐12R, IL‐13R, and IL‐15R. Enzyme‐linked immunosorbent assays (ELISA) showed increased protein levels in culture media of IL‐1β, IL‐8, TNF‐α, and MIP‐1α in human microglia following treatment with LPS or Aβ. Increased TNF‐α release from human microglia following LPS treatment was completely inhibited with IL‐10 pretreatment, but not with IL‐6, IL‐9, IL‐12, IL‐13, or transforming growth factor‐β (TGF‐β). Present results should help in understanding the basic microglial biology, but also the pathophysiology of activated microglia in neurological diseases such as Alzheimer disease, Parkinson disease, Huntington disease, amyotrophic lateral sclerosis, stroke, and neurotrauma. © 2002 Wiley‐Liss, Inc.
d‐amphetamine‐induced increase in neurotensin and neuropeptide Y outflow in the ventral striatum is mediated via stimulation of dopamine D1 and D2/3 receptors
Authors: Gruber Susanne H.M. , Nomikos George G. , Mathé Aleksander A. 
Published: October 2002

AbstractThe neuroanatomical and functional relationships between dopamine (DA) and neurotensin (NT) and DA and neuropeptide Y (NPY) suggest a role for these neuropeptides in DA‐related neuropsychiatric disorders. By employing a microdialysis technique in conjunction with radioimmunoassay (RIA), the effects of d‐amphetamine per se or after pretreatment with DA receptor antagonists on NT and NPY outflow were determined in the ventral striatum (VSTR) of the rat. One hour after a subcutaneous (s.c.) injection of saline, the DA‐D1 receptor antagonist SCH 23390 (0.3 mg/kg), or the DA‐D2/3 receptor antagonist raclopride (1.0 mg/kg), animals were injected s.c. with either saline or d‐amphetamine (1.5 mg/kg). d‐Amphetamine significantly increased extracellular NT‐ and NPY‐like immunoreactivity (LI) concentrations compared with control animals. Administration of SCH 23390 or raclopride did not significantly affect NT‐LI or NPY‐LI concentrations. However, pretreatment with either SCH 23390 or raclopride abolished the stimulatory effect of d‐amphetamine on NT‐LI and NPY‐LI. These findings demonstrate that d‐amphetamine increases extracellular concentrations of NT‐LI and NPY‐LI in the VSTR through a mechanism that initially involves stimulation of either DA‐D1 or DA‐D2/3 receptors but appears to require both. In conclusion, changes in dopaminergic neurotransmission via DA‐D1 and DA‐D2/3 receptors affect the outflow of both NT and NPY in the VSTR. © 2002 Wiley‐Liss, Inc.
Reversal of amyloid β toxicity in Alzheimer's disease model Tg2576 by intraventricular antiamyloid β antibody
Authors: Chauhan Neelima B. , Siegel George J. 
Published: October 2002

AbstractThere are considerable data on synaptic dysfunction in Alzheimer's disease (AD). However, the precise molecular basis for synaptotoxicity in AD is not known. We tested the hypothesis that amyloid β (Aβ), as produced in Tg2576 mice overexpressing a mutant form of amyloid precursor protein, leads to changes in SNAP‐25, a molecule required for Ca‐sensitive neurotransmitter vesicle exocytosis. Anti‐Aβ antibody was injected into the third ventricle (icv) of 10‐month‐old Tg2576 mice, preceding formation of plaques. Immunodensity of glial fibrillary acidic protein (GFAP) and SNAP‐25 were quantitated in the hippocampus 1 month later. SNAP‐25 was reduced by 96% in the inner molecular layer (SMi) of dentate gyrus, by 95% in the hilum, and by 75–76% in stratum lucidum (SL), stratum oriens (SO), and stratum radiatum (SR) of CA1–CA3 of the Tg2576 mice. GFAP was increased by more than 50‐fold, specifically within the neuropil of CA1–CA3, and by twofold in portions of fimbria. One injection of 10 μg of anti‐Aβ antibody into the third ventricle at 10 months completely prevented or restored changes in GFAP at 11 months of age. The restoration of SNAP‐25 by anti‐Aβ antibody compared with wild type was 69% in CA1‐SO, 93% in CA1‐SR, 85% in CA3‐SL, 77% in SMi, and 60–73% in hilum. In addition, whereas control injections of saline or IgG produced greatly increased GFAP diffusely in the hippocampus of Tg2576 animals, there was no increase in GFAP after anti‐Aβ injection, suggesting a synergistic interaction of nonspecific trauma with Aβ in the transgenic mice. This is the first report of depleted SNAP‐25 immunoreactivity in Tg models and the first report of icv injection of anti‐Aβ antibody in this model of AD. The largest reductions of the SNAP‐25 are in hilum and SMi, so either reduction in the septal‐hilum‐SMi path is primary or reduction in this path begins at an earlier age than in CA3–CA1 fields. A single icv injection of anti‐Aβ antibody is potent in reversing Aβ effects and, therefore, represents a suitable model for investigating early Aβ toxicity. In addition, intrathecal or icv antibody may be an efficient means of treating or preventing toxicity in AD, particularly under conditions of immune hyporesponsivity. Published 2002 Wiley‐Liss, Inc.
Oxidative stress induced by phenylketonuria in the rat: Prevention by melatonin, vitamin E, and vitamin C
Authors: Martinez‐Cruz Francisco , Pozo David , Osuna Carmen , Espinar Auxiliadora , Marchante Concepcion , Guerrero Juan M. 
Published: October 2002

AbstractPhenylketonuria (PKU) is an autosomal recessive disorder caused by a deficiency of the phenylalanine hydroxylation system and is characterized by a block in the conversion of phenylalanine (PHE) to tyrosine. We examined the effects of maternal hyperphenylalaninemia on the morphological and biochemical development of pup rat brain and cerebellum. In our model of PKU we evaluated a number of markers of oxidative stress such as Ehrlich adducts formation, lipid peroxidation, as well as the levels of reduced and oxidized glutathione, and the activities of the enzymes glutathione peroxidase and glutathione reductase. We also studied the expression of heme‐oxigenase‐1 and mitogen‐activated protein kinase 1/2 (MAPK 1/2) as additional markers of oxidative stress. We demonstrate that PKU strongly increased most of the oxidative stress markers studied and induced significant morphological damage. We also showed that daily administration of melatonin (20 mg/kg BW), vitamin E (30 mg/kg BW), and vitamin C (30 mg/kg BW) until delivery prevented the oxidative biomolecular damage in the rat brain and cerebellum. Although no significant differences were observed among the antioxidants studied, it should be noted that the doses of melatonin were less than those for vitamins E and C. We conclude that PKU induces a clear state of oxidative stress that is somehow involved in the brain and body damage occurring in this inborn error. Moreover, melatonin and other antioxidants are capable of preventing completely the damage induced by PKU. © 2002 Wiley‐Liss, Inc.
Activation of adenosine triphosphate‐sensitive potassium channels confers protection against rotenone‐induced cell death: Therapeutic implications for Parkinson's disease
Authors: Tai Kwok‐Keung , Truong Daniel D. 
Published: October 2002

AbstractIt is anticipated that further understanding of the protective mechanism induced by ischemic preconditioning will improve prognosis for patients of ischemic injury. It is not known whether preconditioning exerts beneficial actions in neurodegenerative diseases, in which ischemic injury plays a causative role. Here we show that transient activation of ATP‐sensitive potassium channels, a trigger in ischemic preconditioning signaling, confers protection in PC12 cells and SH‐SY5Y cells against neurotoxic effect of rotenone and MPTP, mitochondrial complex I inhibitors that have been implicated in the pathogenesis of Parkinson's disease. The degree of protection is in proportion to the bouts of exposure to an ATP‐sensitive potassium channel opener, a feature reminiscent of ischemic tolerance in vivo. Protection is sensitive to a protein synthesis inhibitor, indicating the involvement of de novo protein synthesis in the protective processes. Pretreatment of PC12 cells with preconditioning stimuli FeSO4 or xanthine/xanthine oxidase also confers protection against rotenone‐induced cell death. Our results demonstrate for the first time the protective role of ATP‐sensitive potassium channels in a dopaminergic neuronal cell line against rotenone‐induced neurotoxicity and conceptually support the view that ischemic preconditioning‐derived therapeutic strategies may have potential and feasibility in therapy for Parkinson's disease. © 2002 Wiley‐Liss, Inc.
Not seeing eye to eye: differences in supervisor and subordinate perceptions of and attributions for psychological contract breach
Authors: Lester Scott W. , Turnley William H. , Bloodgood James M. , Bolino Mark C. 
Published: October 2002

AbstractThis study examines supervisor and subordinate perceptions of and attributions for psychological contract breach. The data suggest that supervisor and subordinate perceptions are most likely to differ on the extent to which the organization violated its obligations to provide fair pay, advancement opportunities, and a good employment relationship. In addition, the results indicate that the greater the degree of psychological contract breach reported by subordinates, the less committed they are to the organization and the lower their job performance (as rated by their supervisor). Moreover, when psychological contract breach is perceived, supervisors' and subordinates' attributions regarding the reasons for the breach are likely to differ. Specifically, the findings suggest that subordinates are more likely to attribute breach to the organization's intentional disregard for the commitments that it had made to the employee, while supervisors are more inclined to attribute breach to situations beyond the organization's direct control. Copyright © 2001 John Wiley & Sons, Ltd.
Differential effects of strain on two forms of work performance: individual employee sales and creativity
Authors: Van Dyne Linn , Jehn Karen A. , Cummings Anne 
Published: October 2002

AbstractIn this research, we develop and test a model of the links between psychological strain (subjective experiences of feeling conflict and tension) and work performance. Our model includes two types of strain (work strain and home strain) and two forms of work performance (quantity of individual sales performance and creativity). Thus we acknowledge the importance of work and non‐work sources of strain as well as the multidimensional nature of work performance. We test the proposed relationships with data collected over six months from a field sample of 195 hair salon stylists (personal service workers who interact directly with customers and provide services directly to individuals and not to other firms). Results demonstrate a positive relation between work strain and individual employee sales performance and a negative relation between home strain and employee creativity at work. Leader–member exchange moderated the effects of work strain and home strain on creativity. We discuss findings and implications, emphasizing multiple roles, the importance of differentiating types of strain, and the multidimensionality of work performance. We conclude by suggesting that strain may be particularly relevant to work performance of employees in jobs like those in our sample which are characterized by high social interdependence and low task interdependence. Copyright © 2001 John Wiley & Sons, Ltd.
The social construction of fairness: social influence and sense making in organizations
Authors: Lamertz Kai 
Published: October 2002

AbstractThis paper explores how the social relationships employees have with peers and managers are associated with perceptions of organizational justice. These relationships are theoretically modelled as the conduits for social comparison, social cues, and social identification, which are sources of sense making about fairness ‘in the eyes of the beholder.’ It is argued that perceptions of procedural and interactional justice are affected by this type of social information processing because: (1) uncertainty exists about organizational procedures; (2) norms of interpersonal treatment vary between organizational cultures; and (3) interpersonal relationships symbolize membership in the organization. A structural equations model of data from workers in a telecommunications company showed that an employee's perceptions of both procedural and interactional fairness were significantly associated with the interactional fairness perceptions of a peer. In addition, employees' social capital, conceived as the number of relationships with managers, was positively associated with perceptions of interactional fairness. In the structural model, both procedural and interactional justice were themselves significant predictors of satisfaction with managerial maintenance of the employment relationship. The discussion highlights the key role which the fairness of interpersonal treatment appears to play in the formation of justice judgements. Copyright © 2001 John Wiley & Sons, Ltd.