bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clinical Case Notes
Authors: Sharma Vidushi , Kashyap Seema , Betharia Subhash M , Gupta Somesh , Pathak Harish 
Published: February 2004

AbstractLipoid proteinosis is a rare disorder seen even more rarely by ophthalmologists. The interesting clinical and histopathological features of this disease are described in a brother and sister who presented predominantly with lid lesions, without any systemic complaints. Knowledge of the typical lid lesions may help to diagnose this disorder.
Attenuation of MPTP‐induced dopaminergic neurotoxicity by TV3326, a cholinesterase‐monoamine oxidase inhibitor
Authors: Sagi Yotam , Weinstock Marta , Youdim Moussa B. H. 
Published: February 2004

Abstract(R)‐[(N‐propargyl‐(3R) aminoindan‐5‐yl) ethyl methyl carbamate] (TV3326) is a novel cholinesterase and brain‐selective monoamine oxidase (MAO)‐A/‐B inhibitor. It was developed for the treatment of dementia co‐morbid with extra pyramidal disorders (parkinsonism), and depression. On chronic treatment in mice it attenuated striatal dopamine depletion induced by MPTP and prevented the reduction in striatal tyrosine hydroxylase activity, like selective B and non‐selective MAO inhibitors. TV3326 preferentially inhibits MAO‐B in the striatum and hippocampus, and the degree of MAO‐B inhibition correlates with the prevention of MPTP‐induced dopamine depletion. Complete inhibition of MAO‐B is not necessary for full protection from MPTP neurotoxicity. Unlike that seen after treatment with other MAO‐A and ‐B inhibitors, recovery of striatal and hippocampal MAO‐A and ‐B activities from inhibition by TV3326 did not show first‐order kinetics. This has been attributed to the generation of a number of metabolites by TV3326 that cause differential inhibition of these enzymes. Inhibition of brain MAO‐A and ‐B by TV3326 resulted in significant elevations of dopamine, noradrenaline and serotonin in the striatum and hippocampus. This may explain its antidepressant‐like activity, resembling that of moclobemide in the forced‐swim test in rats.
Protective effects of the antioxidant selenium on quinolinic acid‐induced neurotoxicity in rats:in vitroandin vivostudies
Authors: Santamaría Abel , Salvatierra‐Sánchez Raquel , Vázquez‐Román Beatriz , Santiago‐López Dario , Villeda‐Hernández Juana , Galván‐Arzate Sonia , Jiménez‐Capdeville María E. , Ali Syed F. 
Published: February 2004

AbstractQuinolinic acid (QUIN), a well known excitotoxin that produces a pharmacological model of Huntington's disease in rats and primates, has been shown to evoke degenerative events in nerve tissue via NMDA receptor (NMDAr) overactivation and oxidative stress. In this study, the antioxidant selenium (as sodium selenite) was tested against different markers of QUIN‐induced neurotoxicity under bothin vitroandin vivoconditions. In thein vitroexperiments, a concentration‐dependent effect of selenium was evaluated on the regional peroxidative action of QUIN as an index of oxidative toxicity in rat brain synaptosomes. In thein vivoexperiments, selenium (0.625 mg per kg per day, i.p.) was administered to rats for 5 days, and 2 h later animals received a single unilateral striatal injection of QUIN (240 nmol/µL). Rats were killed 2 h after the induction of lesions with QUIN to measure lipid peroxidation and glutathione peroxidase (GPx) activity in striatal tissue. In other groups, the rotation behavior, GABA content, morphologic alterations, and the corresponding ratio of neuronal damage were all evaluated as additional markers of QUIN‐induced striatal toxicity 7 days after the intrastriatal injection of QUIN. Selenium decreased the peroxidative action of QUIN in synaptosomes both from whole rat brain and from the striatum and hippocampus, but not in the cortex. A protective concentration‐dependent effect of selenium was observed in QUIN‐exposed synaptosomes from whole brain and hippocampus. Selenium pre‐treatment decreased thein vivolipid peroxidation and increased the GPx activity in QUIN‐treated rats. Selenium also significantly attenuated the QUIN‐induced circling behavior, the striatal GABA depletion, the ratio of neuronal damage, and partially prevented the morphologic alterations in rats. These data suggest that major features of QUIN‐induced neurotoxicity are partially mediated by free radical formation and oxidative stress, and that selenium partially protects against QUIN toxicity.
Microwave Studies of Collision-Induced Transitions between Rotational Levels. IV. Steady-State Measurements in NH3
Authors: Oka Takeshi 
Published: February 2004

The technique of high-power microwave double resonance has been applied to the study of collision-induced transitions between rotational levels of ammonia. The inversion doublets for selected J values have been “pumped” by high microwave power, and the increase of absorption in other inversion doublets have been observed. Because of the abundance and intensities of ammonia lines, a systematic choice of 18 four-level systems was possible. The observed results were analyzed by steady-state equations, and relative values of rate constants have been determined. The experiments and analysis have led to the following qualitative conclusions:
(i) Collision-induced transitions with dipole selection rules (ΔJ = 0, ± 1, parity + ↔ −) are “preferred.”
(ii) The ΔJ = 0 dipole-type transitions have much greater probability than the ΔJ = ± 1 dipole-type transitions for levels with J∼K, but they have probabilities of equal order of magnitude for levels with J≫K.
(iii) The ΔJ &gt; 1 transitions have much smaller probabilities than the ΔJ = ± 1 transitions.
(iv) The ΔK ≠ 0 transitions have much smaller probabilities than the ΔK = 0 transitions.
A comparison of the observed results with values calculated by using Anderson's theory suggests that the probabilities of the ΔJ = ± 1 quadrupole-type transition (parity +↔ +) are the same order of magnitude as those of the corresponding dipole-type transitions.
Electronic Zeeman Measurements on 1,4-Dibromonaphthalene
Authors: Castro George , Hochstrasser Robin M. 
Published: February 2004

A summary of interpretive methods regarding high-field electronic Zeeman measurements is presented. The equations calculated for two active spin substates (zero field) of the lowest triplet state, are applied to 1,4-dibromonaphthalene crystal spectra.
The Zeeman spectra of the electronic and vibronic origins of the lowest triplet state have different polarization, but they have very similar Zeeman effects indicating similar spin-substate activity. The complete analysis enables us to show that the lowest triplet state is of species 3B2 which correlates with 3B2u in D2h. The vibronic origins are shown to arise by spin-orbit coupling with singlet states that are vibronically mixed with other singlet states.
Certain crystal-field effects are apparent in the spectra and those are discussed in relation to two suggested types of mixing; namely, intermolecular spin-orbit coupling, and intermolecular exchange coupling.
Theory of Zeeman effect for rare earth ions in crystal field with D2 symmetry and application to rare earth garnets
Authors: Kambara T. , Haas W. J. , Spedding F. H. , Good R. H. 
Published: February 2004

Rare earth ions in solids frequently exhibit sharp-line optical spectra. In this paper a part of the theory of the Zeeman effect for the lines is developed, first for a single rare earth ion in D2 symmetry, and secondly for rare earth ions at different inequivalent sites in garnet crystals. The results for the case in which the crystal field and Zeeman splittings are comparable have application for magnetic garnets such as the rare earth iron garnets, while the results for the case where the Zeeman splittings are treated as a perturbation on the crystal field states have application for nonmagnetic garnets such as the rare earth aluminum or gallium garnets. In both cases it is found that when the magnetic field is restricted to the xy plane of the local site coordinate, there exists an antiunitary symmetry operation which simplifies the energy level and transition probability calculations, and which leads to the assignment of a quantum number ζ = ± 1 to the states. There are shown to be two types of states: Type A, for which the assignment of ζ value is not sensitive to the choice of coordinate axes, and Type B states for which it is. It is also shown, in the case of rare earth ions with an odd number of 4f electrons, that the Types of the states are determined by the relative signs of the principal values of the g factors. Furthermore, it is found that the dependence of line intensity on magnetic field direction for A→A and B→B transitions is clearly different from that of A→B and B→A transitions.
Finally, and most important, it is shown that studies of the energies and intensities of the Zeeman lines as a function of magnetic field direction in suitable crystal planes can be used to distinguish between spectra arising from different inequivalent rare earth ion sites in garnets. This result has immediate importance for experimental study of site selectivity problems in garnets, and, when combined with the other conclusions of this work, leads to definite suggestions for experimental determinations of at least some of the details of the states.
Diet, nutrition and the prevention of osteoporosis
Authors: Prentice A 
Published: February 2004

AbstractObjective:To review the evidence on diet and nutrition relating to osteoporosis and provide recommendations for preventing osteoporosis, in particular, osteopototic fracture.Approach:Firstly, to review the definition, diagnosis and epidemiology of osteoporosis, to discuss the difficulties in using bone mineral density to define osteoporosis risk in a world-wide context and to propose that fragility fracture should be considered as the disease endpoint. Secondly, to provide an overview of the scientific data, the strengths and weaknesses of the evidence and the conceptual difficulties in interpreting studies linking diet, nutrition and osteoporosis. The following were considered: calcium, vitamin D, phosphorus, magnesium, protein and fluorine. Other potential dietary influences on bone health were also discussed, including vitamins, trace elements, electrolytes, acid–base balance, phyto-oestrogens, vegetarianism and lactose intolerance.Conclusions:There is insufficient knowledge linking bone mineral status, growth rates or bone turnover in children and adolescents to long-term benefits in old age for these indices to be used as markers of osteoporotic disease risk. For adults, the evidence of a link between intakes of any dietary component and fracture risk is not sufficiently secure to make firm recommendations, with the exception of calcium and vitamin D. For other aspects of the diet, accumulating evidence suggests that current healthy-eating advice to decrease sodium intake, to increase potassium intake, and to consume more fresh fruits and vegetables is unlikely to be detrimental to bone health and may be beneficial.
Hormone Treatment Facilitates Penile Erection In Castrated Rats After Sleep Deprivation and Cocaine
Authors: Andersen M. Levy , Bignotto M. , Tufik S. 
Published: February 2004

AbstractSleep deprivation is associated with cocaine‐enhanced genital reflexes in male rats, and castration of the male rat causes a decline in sexual behaviour, which can be reversed by hormone administration. We conducted two experiments to determine whether sleep deprivation and cocaine administration could also induce spontaneous penile erection in castrated rats after hormonal treatment (testosterone, progesterone and oestradiol). Different doses of hormones or vehicle were administered to rats during the 4‐day period of sleep deprivation, and in home‐cage control rats. Testosterone did not restore penile erection in castrated sleep‐deprived rats. Progesterone triggered penile erection, and 100 mg/day of progesterone induced the highest proportion of rats displaying penile erection, and restored the frequency of penile erection observed in noncastrated sleep deprived rats. Penile erection was absent in vehicle as well as oestradiol‐treated sleep‐deprived castrated rats. Whereas sleep deprivation increased progesterone concentrations in noncastrated rats, sleep deprivation decreased progesterone concentrations in castrated rats. Corticosterone concentrations were lower in the castrated sleep‐deprived rats than in respective control group. These data show that progesterone treatment facilitates penile erection in sleep deprived‐cocaine castrated rats.
Swedish mental health nurses’ responsibility in supervised community care of persons with long‐term mental illness
Authors: Magnusson Annabella , Högberg Torbjörn , Lützén Kim , Severinsson Elisabeth 
Published: February 2004

AbstractThe aim of the present study was to describe psychiatric nurses’ experience of how the changing focus of mental health care in Sweden, from in‐patient treatment to community‐based care, has influenced their professional autonomy. Eleven psychiatric nurses were interviewed and a qualitative content analysis was used to identify major themes in the data. Three main themes were found: pattern of responsibility, pattern of clinical judgement, and pattern of control through support and supervision. All themes were related to the nurse's identity, moral responsibility and the feelings of loneliness and independence in his/her daily work. Together, the three themes were found to constitute a process. This study shows the complexity involved in nursing care provided in the patient's home. Achieving control over the patient's everyday life through support and supervision does not imply taking over the patient's autonomy, but rather reducing the stigma attached to mental illness and facilitating the process of rehabilitation.
Efficient Manipulation in a Repeated Setting
Authors: DEMSKI JOEL S. , FRIMOR HANS , SAPPINGTON DAVID E. M. 
Published: February 2004

ABSTRACTWe analyze the optimal behavior of an organization when its employees can manipulate the organization's accounting system to their private advantage. We find that the organization may benefit by helping its employees manipulate the system. This help can reduce the employees' private returns from devoting effort to further manipulation of the accounting system, which reduces the cost of motivating the employees to devote their effort to improving the real (rather than the measured) performance of the organization.
Myxococcus xanthusChemotaxis Homologs DifD and DifG Negatively Regulate Fibril Polysaccharide Production
Authors: Black Wesley P. , Yang Zhaomin 
Published: February 2004

ABSTRACTThe extracellular matrix fibrils ofMyxococcus xanthusare essential for the social lifestyle of this unusual bacterium. These fibrils form networks linking or encasing cells and are tightly correlated with cellular cohesion, development, and social (S) gliding motility. Previous studies identified a set of bacterial chemotaxis homologs encoded by thediflocus. It was determined thatdifA,difC, anddifE, encoding respective homologs of a methyl-accepting chemotaxis protein, CheW, and CheA, are required for fibril production and therefore S motility and development. Here we report the studies of three additional genes residing at thediflocus,difB,difD, anddifG. difDanddifGencode homologs of chemotaxis proteins CheY and CheC, respectively.difBencodes a positively charged protein with limited homology at its N terminus to conserved bacterial proteins with unknown functions. Unlike the previously characterizeddifgenes, none of these three newly studieddifgenes are essential for fibril production, S motility, or development. ThedifBmutant showed no obvious defects in any of the processes examined. In contrast, thedifDand thedifGmutants were observed to overproduce fibril polysaccharides in comparison with production by the wild type. The observation that DifD and DifG negatively regulate fibril polysaccharide production strengthens our hypothesis that theM. xanthus difgenes define a chemotaxis-like signal transduction pathway which regulates fibril biogenesis. To our knowledge, this is the first report of functional studies of a CheC homolog in proteobacteria. In addition, during this study, we slightly modified previously developed assays to easily quantify fibril polysaccharide production inM. xanthus.
Benzoate Decreases the Binding of
cis
,
cis
-Muconate to the BenM Regulator despite the Synergistic Effect of Both Compounds on Transcriptional Activation
Authors: Clark Todd J. , Phillips Robert S. , Bundy Becky M. , Momany Cory , Neidle Ellen L. 
Published: February 2004

ABSTRACT

Fluorescence emission spectroscopy was used to investigate interactions between two effectors and BenM, a transcriptional regulator of benzoate catabolism. BenM had a higher affinity for
cis
,
cis
-muconate than for benzoate as the sole effector. However, the presence of benzoate increased the apparent dissociation constant (reduced the affinity) of the protein for
cis
,
cis
-muconate. Similar results were obtained with truncated BenM lacking the DNA-binding domain. High-level transcriptional activation may require that some monomers within a BenM tetramer bind benzoate and others bind
cis
,
cis
-muconate.
Integration of Environmental Signals Controls Expression of
Bordetella
Heme Utilization Genes
Authors: Vanderpool Carin K. , Armstrong Sandra K. 
Published: February 2004

ABSTRACT

The
Bordetella pertussis
heme utilization gene cluster
hurIR bhuRSTUV
encodes regulatory and transport functions required for assimilation of iron from heme and hemoproteins. Expression of the
bhu
genes is iron regulated and heme inducible. The putative extracytoplasmic function (ECF) σ factor, HurI, is required for heme-responsive
bhu
gene expression. In this study, transcriptional activation of
B. pertussis bhu
genes in response to heme compounds was shown to be dose dependent and specific for heme; protoporphyrin IX and other heme structural analogs did not activate
bhu
gene expression. Two promoters controlling expression of the heme utilization genes were mapped by primer extension analysis. The
hurI
promoter showed similarity to σ
70
-like promoters, and its transcriptional activity was iron regulated and heme independent. A second promoter identified upstream of
bhuR
exhibited little similarity to previously characterized ECF σ factor-dependent promoters. Expression of
bhuR
was iron regulated, heme responsive, and
hurI
dependent in
B. pertussis
, as shown in a previous study with
Bordetella bronchiseptica
. Further analyses showed that transcription originating at a distal upstream site and reading through the
hurR-bhuR
intergenic region contributes to
bhuR
expression under iron starvation conditions in the absence of heme inducer. The pattern of regulation of the readthrough transcript was consistent with transcription from the
hurI
promoter. The positions and regulation of the two promoters within the
hur-bhu
gene cluster influence the production of heme transport machinery so that maximal expression of the
bhu
genes occurs under iron starvation conditions only in the presence of heme iron sources.
Rapid Temporal Modulation of Synchrony by Competition in Cortical Interneuron Networks
Authors: Tiesinga P.H.E. , Sejnowski T. J. 
Published: February 2004

The synchrony of neurons in extrastriate visual cortex is modulated by selective attention even when there are only small changes in firing rate (Fries, Reynolds, Rorie, & Desimone, 2001). We used Hodgkin-Huxley type models of cortical neurons to investigate the mechanism by which the degree of synchrony can be modulated independently of changes in firing rates. The synchrony of local networks of model cortical interneurons interacting through GABAA synapses was modulated on a fast timescale by selectively activating a fraction of the interneurons. The activated interneurons became rapidly synchronized and suppressed the activity of the other neurons in the network but only if the network was in a restricted range of balanced synaptic background activity. During stronger background activity, the network did not synchronize, and for weaker background activity, the network synchronized but did not return to an asynchronous state after synchronizing. The inhibitory output of the network blocked the activity of pyramidal neurons during asynchronous network activity, and during synchronous network activity, it enhanced the impact of the stimulus-related activity of pyramidal cells on receiving cortical areas (Salinas & Sejnowski, 2001). Synchrony by competition provides a mechanism for controlling synchrony with minor alterations in rate, which could be useful for information processing. Because traditional methods such as cross-correlation and the spike field coherence require several hundred milliseconds of recordings and cannot measure rapid changes in the degree of synchrony, we introduced a new method to detect rapid changes in the degree of coincidence and precision of spike timing.
Systematic status of Campydora Cobb, 1920 (Nematoda: Campydorina)
Authors: Mullin Peter , Harris Timothy , Powers Thomas 
Published: February 2004

AbstractThe systematic position of Campydora Cobb, 1920, which possesses many unique morphological features, especially in pharyngeal structure and stomatal armature, has long been a matter of uncertainty with the 'position of the Campydorinae' (containing only Campydora) being questionable. A review of the morphology of C. demonstrans, the only nominal species of Campydora concluded that the species warranted placement as the sole member of a monotypic suborder, Campydorina, in the order Dorylaimida. Others placed Campydorina in the order Enoplida. We conducted phylogenetic analyses, using 18s small subunit ribosomal DNA sequences generated from a number of taxa in the subclasses Enoplia and Dorylaimia, to evaluate these competing hypotheses. Although precise taxonomic placement of the genus Campydora and the identity of its closest living relatives is in need of further investigation, our analyses, under maximum parsimony, distance, and maximum likelihood criteria, unambiguously indicate that Campydora shares a common, more recent, ancestry with genera such as Alaimus, Pontonema, Tripyla and Ironus (Enoplida), rather than with any members of Dorylaimida, Mononchida or Triplonchida.
Intraspecific variation in RFLP patterns and morphological studies on Steinernema feltiae and S. kraussei (Rhabditida: Steinernematidae) from Hokkaido, Japan
Authors: Yoshida Mutsuhiro 
Published: February 2004

AbstractSteinernema feltiae and S. kraussei were isolated from Hokkaido, Japan. This is the first record of S. kraussei and the first definitive record of S. feltiae from Japan. The morphological variation of the infective juveniles and the first generation males of Japanese isolates of both species are reported. Intraspecific variation in the PCR-RFLP analysis of the ITS region of ribosomal DNA was observed in both species. The Japanese isolates of S. feltiae showed different RFLP patterns from European isolates with Dde I and Hinf I restriction digests. The Japanese isolate of S. kraussei also showed an RFLP variation from the UK and Russian isolates upon Dde I restriction digestion. Moreover, in each isolate of S. kraussei, some intra-population variations were observed with some restriction digestions. The intraspecific variation in the ITS region of the rDNA could be used as a molecular marker to distinguish the Japanese isolates from European isolates of S. feltiae if the latter was introduced as a biological insecticide.