bluuebunny/crossref_metadata_2025_split huggingface dataset:
Endoscopic diagnosis of cytomegalovirus infection of upper gastrointestinal tract in solid organ transplant recipients: Hungarian single‐center experience
Authors: Péter Antal , Telkes Gábor , Varga Marina , Sárváry Enik˝ , Kovalszky Ilona 
Published: September 2004

Abstract: Background: Cytomegalovirus (CMV) is considered to be the major cause of upper gastrointestinal (GI) symptoms in organ transplant recipients. In the diagnosis of GI CMV infection the detection of the virus in the mucosa is essential. The aim of the study was to evaluate the significance of CMV, detected in biopsy specimens from stomach and duodenum of solid organ transplant recipients.Methods: Data of 227 elective upper endoscopies on symptomatic organ transplant recipients were evaluated for clinical symptoms, endoscopic changes and conventional histologic alterations of mucosal biopsy samples. Qualitative PCR was performed for detection of the presence of CMV‐DNA in each biopsy materials.Results: CMV‐DNA was detected in biopsy samples of 91 patients (40.1%) while only in 20 cases (8.8%) the signs of CMV infections were found by conventional histology (p < 0.00001). No considerable differences could be observed in symptomatic, histologic alterations between CMV‐PCR positive and negative groups. There were no endoscopic changes in 25.3% of CMV‐PCR positive and 5.1% of negative patients.Conclusions: Qualitative PCR is an accurate method for the detection of CMV in the mucosa of the GI tract. Further investigations are needed for determination of the exact pathological role of detected CMV.
Severe elevations of FK506 blood concentration due to diarrhea in renal transplant recipients
Authors: Sato Koichiro , Amada Noritoshi , Sato Takaomi , Miura Shunji , Ohashi Yoichi , Sekiguchi Satoshi , Satomi Susumu , Okazaki Hajime 
Published: September 2004

Abstract:  Background:  The rate of metabolism in the intestine of oral administered FK506 decreases as FK506 passes on to the lower intestine. In transplant recipients with diarrhea given oral FK506, the main areas for absorption of FK506 shift to the lower intestine, where the ability to metabolize FK506 is weaker. Therefore it is considered likely that when FK506 is administered to recipients with diarrhea, the blood concentration of FK506 will be higher.Material and Methods:  Twenty recipients experiencing episodes of diarrhea were investigated to determine the trough level of FK506 and the time required for the FK506 trough level to return to the level that obtained before diarrhea. AUC0−4h and Cmax of FK506 were investigated in eight recipients. In cases with severe diarrhea, the daily fluctuations of FK506 blood concentration were also investigated.Result:  The FK506 trough level (p < 0.0001), AUC (p = 0.0173), and Cmax (p = 0.0173) were found to be significantly higher during episodes of diarrhea. In almost all cases, it took between 2 and 4 wk for the elevated FK506 trough level to return to its previous level following a bout of diarrhea. In the daily fluctuations of FK506 concentration, Tmax was prolonged. In some cases, the concentration was highest just before administration of FK506, when it should have been at trough level.Conclusions:  Diarrhea caused significant elevations of trough level, AUC0−4h and Cmax of FK506, and the prolongation of Tmax in renal transplant recipients administered FK506.
Cardiovascular disease in stable renal transplant patients in Norway: morbidity and mortality during a 5‐yr follow‐up
Authors: Aakhus Svend , Dahl Ketil , Widerøe Tor Erik 
Published: September 2004

Abstract:  Background:  Although cardiovascular disease is a major cause of death after renal transplantation (Tx), predictors for cardiovascular events have not been well defined. Aims of this cross‐sectional study were first to assess cardiovascular morbidity and mortality in stable renal Tx patients, and to identify predictors for cardiovascular events during long‐term follow‐up.Methods:  In all, 406 renal Tx patients (mean age: 47 yr, 60.1% males, 70.9% using cyclosporine A) commenced a baseline registration (median) 48 months after Tx, and 405 was thereafter followed in 5 yr. Kaplan–Meier plots and multivariate regression analysis (Cox proportional hazards model) were used to identify and characterize predictors for cardiovascular events.Results:  There were 88 deaths (average annual mortality: 4.4%), and 74% of these were cardiovascular. In age groups 40–49, 50–59, and 60–69 yr, odds ratio for cardiovascular mortality in patients vs. general population was 46.2, 20.1, and 8.0, respectively. Death from ischemic heart disease (IHD) was independently predicted by baseline congestive heart failure (relative risk: RR 5.33), diabetes (RR 2.28), systolic blood pressure (mmHg, RR 1.02), age (yr, RR 1.06), and high‐density lipoprotein cholesterol (mmol/L, RR 0.36). Predictors for a major ischemic heart event (death from or onset of IHD) were in addition baseline total cholesterol (mmol/L, RR 1.18) and cerebrovascular disease (RR 2.98).Conclusions:  Thus, IHD was the major cause of death late after renal Tx, and a major ischemic heart event was predicted by baseline congestive heart failure, diabetes, age, hypertension, and hypercholesterolemia.
The Maintenance of Stable Dominance Hierarchies and the Pattern of Aggression: Support for the Suppression Hypothesis
Authors: Forkman B. , Haskell M. J. 
Published: September 2004

AbstractThree hypotheses have been proposed to explain the development and maintenance of dominance hierarchies. According to the first hypothesis the dominance hierarchy is a result of the animals fighting once at their first encounter and then using the outcome of that fight to determine the rank order. The second hypothesis proposes that a dominance hierarchy reflects the fighting ability of the individuals in the group at each moment and is therefore relatively fluid with individuals continuously fighting for position. A third hypothesis, the suppression hypothesis, states that the dominance hierarchy is based to a large extent on the outcome of the first fight between the individuals but the dominant animal in each pair continuously attacks the subdominant individuals to condition them to lose in future encounters. We studied six well‐established flocks containing six adult hens each (Gallus gallus domesticus). Five of the flocks had linear hierarchies. The aggression was significantly more often directed towards the next low‐ranking individual. There was a good correlation between rank and comb size (height × width), but no significant correlation between rank and weight, or rank and level of fluctuating asymmetry. There was no significant correlation between levels of aggression and similarity of comb size for individuals of neighboring ranks. Our results tentatively support the suppression hypothesis for the maintenance of dominance hierarchies in the domestic hen.
Winter Plumage Coloration in Male American Goldfinches: Do Reduced Ornaments Serve Signaling Functions in the Non‐Breeding Season?
Authors: McGraw Kevin J. 
Published: September 2004

AbstractThe signaling role of sexual ornaments that are displayed during the mating season is well known for many species, but dimorphisms that occur in the non‐breeding season have received much less attention, particularly when individuals only partially express their breeding condition during reproductively inactive periods. I assessed variation in the expression of colorful breeding and non‐breeding plumages in male American goldfinches (Carduelis tristis), a species in which males molt out of their colorful breeding ornaments in the fall but still display reduced carotenoid‐ and melanin‐based sexual dichromatism during the winter. I found that variability in the saturation of carotenoid‐based plumage pigmentation did not differ significantly between the breeding and non‐breeding seasons. Moreover, the area of melanin coloration in the cap was more variable in winter than when it is fully displayed during breeding. I also detected a significant positive correlation between the extent of melanin coloration during the winter and the saturation of non‐breeding carotenoid‐based plumage. Because of such variation in and correlated expression of these two color ornaments in winter, it is conceivable that male goldfinches display these hints of non‐breeding coloration for use as conspecific social or sexual signals. Natural selection pressures like predation and energetic demands are traditionally thought of as factors that restrict sex ornaments to breeding times alone, but this should not preclude animals from simply reducing their exaggerated features during winter and finding an expression optimum that balances signal costs and value. Such ‘remnant’ winter ornaments might be expected to evolve not only in animals that live in large non‐breeding groups (e.g. status‐signaling systems) but also in those where mates begin associating before breeding onset.
Approach Strategy by which Male Mediterranean Tarantulas Adjust to the Cannibalistic Behaviour of Females
Authors: Moya‐Laraño Jordi , Pascual Jordi , Wise David H. 
Published: September 2004

AbstractIn sexually cannibalistic species, selection is thought to have favoured the evolution of male approaching behaviour that reduces the probability that the female will kill the male. However, investigations of behaviours that could reduce the probability of sexual cannibalism are few. We examine the hypothesis that male wolf spiders,Lycosa tarantula(L.) (Araneae, Lycosidae), decides to approach females in periods when they are less dangerous. Males of this species approach females for mating during the daytime only. While attending females, males stay farther from the female's burrow at night than during the daytime. In field experiments, we offered a grasshopper (typical prey) or a maleL. tarantulato females at night and during the day, and our findings show that the diel changes in the male's approaching behaviour matches diurnal changes in the female's tendency to attack both the grasshopper and the male spider. These findings support our hypothesis that a diel change in female responsiveness to prey has been a selection pressure influencing the evolution of male approach behaviour in a sexually cannibalistic species.
Multicentre analysis of treatment planning information: Technical requirements, possible applications and a proposal
Authors: Ebert MA , Blight J , Price S , Haworth A , Hamilton C , Cornes D , Joseph DJ 
Published: September 2004

SummaryDigital data from 3‐D treatment planning computers is generally used for patient planning and then never considered again. However, such data contains enormous quantities of information regarding patient geometries, tissue outlining, treatment approaches and dose distributions. Were such data accessible from planning systems from multiple manufacturers, there would be substantial opportunities for undertaking quality assurance of radiotherapy clinical trials, prospective assessment of trial outcomes and basic treatment planning research and development. The technicalities of data exchange between planning systems are outlined, and previous attempts at producing systems capable of viewing and/or manipulating imaging and radiotherapy digital data reviewed. Development of a software system for enhancing the quality of Australasian clinical trials is proposed.
Functional mapping of GABAA receptor subtypes in the amygdala
Authors: Marowsky Anne , Fritschy Jean‐Marc , Vogt Kaspar E. 
Published: September 2004

AbstractThe physiological significance of the large diversity of GABAA receptors is poorly understood. Using mice, which carry a point mutation that renders specific subtypes of GABAA receptors diazepam insensitive, it was recently discovered that particular types of GABAA receptors are involved in specific, behaviorally relevant signaling pathways. We have used these mice to study inhibitory synaptic transmission in the amygdala. GABAA receptor‐mediated inhibitory postsynaptic currents (IPSCs) per se were not affected by the point mutations. Their modulation by diazepam, however, was altered depending on the genotype of the mice studied. Based on the different responses to diazepam, we found that IPSCs in the lateral/basolateral amygdala were mediated by both α2‐ and α1‐subunit‐containing GABAA receptors whereas those in the central amygdala were mediated only by α2‐subunit‐containing GABAA receptors. Immunohistochemical staining corroborated these findings at a morphological level. To investigate a possible link between interneuron and receptor diversity, we selectively depressed release from the subset of GABAergic terminals carrying type 1 cannabinoid receptors. These receptors are known to modulate amygdala‐mediated behavior. Application of a type 1 cannabinoid receptor agonist resulted in a selective reduction of inhibitory current mediated by α1‐subunit‐containing GABAA receptors. Mice with specific diazepam‐insensitive GABAA receptor subtypes therefore provide a novel tool to investigate GABAA receptor distribution and the organization of inhibitory circuits at a functional level. The crucial role of the amygdala for the mediation of anxiety is in agreement with the part that α2‐subunit‐containing GABAA receptors play in anxiolysis and their important function in this area of the brain.
Endogenous acetylcholine lowers the threshold for long‐term potentiation induction in the CA1 area through muscarinic receptor activation: in vivo study
Authors: Ovsepian Saak V. , Anwyl Roger , Rowan Michael J. 
Published: September 2004

AbstractLittle is known how synaptically released endogenous ACh affects hippocampal synaptic plasticity in vivo. Here, we examined the role of cholinergic drive in the regulation of the induction of long‐term potentiation (LTP) at basal dendrites in the CA1 area of the anaesthetized rat hippocampus. The non‐subtype selective muscarinic acetylcholine receptor antagonist, scopolamine, (0.3 mg/kg, i.p.) inhibited the induction of LTP by weak, but not strong, high frequency conditioning stimulation. A relatively M1 subtype‐selective receptor antagonist, pirenzepine, (50 nmol/5 µL, i.c.v.) also inhibited LTP induction by the weak protocol. As the medial septum (MS) is a major source of endogenous ACh in the hippocampus, we also examined the effect of high frequency pre‐conditioning stimulation of the MS on LTP induction. The pre‐conditioning MS tetanus reduced the threshold for LTP induction at basal synapses in a narrow time window. Such an effect of MS pre‐conditioning was prevented by scopolamine, strong evidence of a direct MS control of LTP threshold through a mechanism dependent on muscarinic receptor activation. These results suggest that the cholinergic drive to the hippocampus is critically involved in the control of the LTP induction threshold in vivo. To the extent that LTP mechanisms may underlie certain types of learning and memory, the septo‐hippocampal cholinergic regulation of synaptic plasticity may constitute an important target for the treatment of cognitive disorders associated with ACh deficits.
Regional pattern of metabolic activation is reflected in the sleep EEG after sleep deprivation combined with unilateral whisker stimulation in mice
Authors: Vyazovskiy Vladyslav V. , Welker Egbert , Fritschy Jean‐Marc , Tobler Irene 
Published: September 2004

AbstractRegional differences in EEG slow wave activity (SWA) during sleep after sleep deprivation (SD) may be a consequence of differential metabolic activation of cortical areas. We investigated the relationship between the regional EEG dynamics and 2‐deoxyglucose (DG) uptake after SD in mice. Six hours' SD were combined with natural unilateral whisker stimulation in an enriched environment to selectively activate the barrel cortex and motor areas. As expected, an interhemispheric asymmetry of 2‐DG uptake was found in the barrel cortex immediately after SD. To test whether sleep contributes to recovery of the asymmetry, the stimulation was followed by either undisturbed sleep or by an additional SD. The asymmetry vanished after recovery sleep but also after the additional period of wakefulness without stimulation. In addition, relative 2‐DG uptake in the primary motor cortex and retrosplenial area was significantly higher immediately after the SD than after the additional sleep or wakefulness, whereas no other region differed between the groups. Whisker stimulation elicited a greater increase in EEG SWA during non rapid eye movement sleep in the stimulated hemisphere than in the control hemisphere; this increase lasted for 10 h. Within a hemisphere, the initial increase in SWA was higher in the frontal than in the parietal derivation. We conclude that the regional SWA differences during sleep are use‐dependent and may be related to the regional pattern of metabolism during the previous waking episode. However, the regional metabolic recovery is not dependent on sleep, and is not directly reflected in changes in SWA during sleep.
Attention and executive function deficits in chronic low‐dose MPTP‐treated non‐human primates
Authors: Decamp E. , Schneider J. S. 
Published: September 2004

AbstractParkinson's disease (PD) is a complex disorder consisting of motor deficits coupled with dysfunction in cognitive domains that are dependent upon the integrity of the frontal lobes and/or the fronto‐striatal axis. Although it is increasingly acknowledged that PD patients have attentional and executive function deficits, it has been difficult to model these in nonhuman primates because of the nature of the cognitive tasks that have been used previously. The present studies were conducted to further define the nature of the cognitive impairment in a nonhuman primate model of early parkinsonism consequent to chronic low dose MPTP exposure and to further validate this model in monkeys trained to perform a battery of attentional and executive function tasks. Following chronic low dose MPTP exposure, monkeys developed deficits in maintenance of a response set as well problems in shifting attentional sets, suggesting decreased mental flexibility. On other tasks inattentiveness, an impaired ability to sustain spatial attention or to focus attention, a deficit in motor readiness and planning, and impaired time estimation were also observed. These results provide direct evidence of attention and executive function deficits in a nonhuman primate model of early parkinsonism. Based on these findings, we suggest that in addition to being useful for studying the cognitive deficits related to early PD and for developing new therapeutics for these problems, this model and these testing procedures may also provide a useful large animal model for studying attention deficit disorder and for developing new therapeutics for that condition as well.
An evolutionarily conserved mechanism for sensitization of soluble guanylyl cyclase reveals extensive nitric oxide‐mediated upregulation of cyclic GMP in insect brain
Authors: Ott Swidbert R. , Delago Antonia , Elphick Maurice R. 
Published: September 2004

AbstractSoluble guanylyl cyclase (SGC) is the main receptor for the gaseous signalling molecule nitric oxide (NO) in vertebrates and invertebrates. Recently, a novel class of drugs that regulate mammalian SGC by NO‐independent allosteric mechanisms has been identified [e.g. 3‐(5′‐hydroxymethyl‐2′‐furyl)‐1‐benzyl indazole, YC‐1]. To assess the evolutionary conservation and hence the potential physiological relevance of these mechanisms, we have tested YC‐1 on the brains of two model insects, the cockroach Periplaneta americana and the locust Schistocerca gregaria. YC‐1 strongly potentiated the NO‐induced elevation of total cyclic 3′,5′‐guanosine monophosphate (cGMP) and amplified the intensity and consistency of NO‐induced cGMP‐immunoreactivity in the brain. Our data indicate that the effect of YC‐1 was independent of phosphodiesterase inhibition and thus mediated by direct sensitization of SGC. Immunohistopharmacology and co‐labelling with antibodies against the SGC α‐subunit confirmed that cGMP induced by co‐application of NO and YC‐1 is predominantly attributable to SGC. The staggering number of NO‐responsive neurons revealed by YC‐1 suggests that previous studies may have considerably underestimated the number of cellular targets for NO in the insect brain. Moreover, a subset of these targets exhibited cGMP‐immunoreactivity without application of exogenous NO, demonstrating that YC‐1 can be exploited for visualization of physiological cGMP signals in response to endogenous NO production. In conclusion, our discovery that YC‐1 is a potent sensitizer of insect SGC indicates that a NO‐independent regulatory site is an evolutionarily conserved feature of SGC. Our findings add considerable momentum to the concept of an as yet unidentified endogenous ligand that regulates the gain of the NO–cGMP signalling pathway.
Neural contributions to the motivational control of appetite in humans
Authors: Hinton Elanor C. , Parkinson John A. , Holland Anthony J. , Arana F. Sergio , C. Roberts Angela , Owen Adrian M. 
Published: September 2004

AbstractThe motivation to eat in humans is a complex process influenced by intrinsic mechanisms relating to the hunger and satiety cascade, and extrinsic mechanisms based on the appetitive incentive value of individual foods, which can themselves induce desire. This study was designed to investigate the neural basis of these two factors contributing to the control of motivation to eat within the same experimental design using positron emission tomography. Using a novel counterbalanced approach, participants were scanned in two separate sessions, once after fasting and once after food intake, in which they imagined themselves in a restaurant and considered a number of items on a menu, and were asked to choose their most preferred. All items were tailored to each individual and varied in their incentive value. No actual foods were presented. In response to a hungry state, increased activation was shown in the hypothalamus, amygdala and insula cortex as predicted, as well as the medulla, striatum and anterior cingulate cortex. Satiety, in contrast, was associated with increased activation in the lateral orbitofrontal and temporal cortex. Only activity in the vicinity of the amygdala and orbitofrontal cortex was observed in response to the processing of extrinsic appetitive incentive information. These results suggest that the contributions of intrinsic homeostatic influences, and extrinsic incentive factors to the motivation to eat, are somewhat dissociable neurally, with areas of convergence in the amygdala and orbitofrontal cortex. The findings of this study have implications for research into the underlying mechanisms of eating disorders.