bluuebunny/crossref_metadata_2025 huggingface dataset:
Curing of yeast [PSI
+
] prion by guanidine inactivation of Hsp104 does not require cell division
Authors: Wu Yue-Xuan , Greene Lois E. , Masison Daniel C. , Eisenberg Evan
Published: August 2005

Propagation of the yeast prion [
PSI
+
], a self-replicating aggregated form of Sup35p, requires Hsp104. One model to explain this phenomenon proposes that, in the absence of Hsp104, Sup35p aggregates enlarge but fail to replicate thus becoming diluted out as the yeast divide. To test this model, we used live imaging of Sup35p-GFP to follow the changes that occur in [
PSI
+
] cells after the addition of guanidine to inactivate Hsp104. After guanidine addition there was initially an increase in aggregation of Sup35p-GFP; but then, before the yeast divided, the aggregates began to dissolve, and after ≈6 h the Sup35-GFP looked identical to the Sup35-GFP in [
psi
+
] cells. Although plating studies showed that the yeast were still [
PSI
+
], this reduction in aggregation suggested that curing of [
PSI
+
] by inactivation of Hsp104 might be independent of cell division. This was tested by measuring the rate of curing of [
PSI
+
] cells in both dividing and nondividing cells. Cell division was inhibited by adding either alpha factor or farnesol. Remarkably, with both of these methods, we found that the rate of curing was not significantly affected by cell division. Thus, cell division is not a determining factor for curing [
PSI
+
] by inactivating Hsp104 with guanidine. Rather, curing apparently occurs because Sup35-GFP polymers slowly depolymerize in the absence of Hsp104 activity. Hsp104 then counteracts this curing possibly by catalyzing formation of new polymers.
BVD control in Europe: current status and perspectives
Authors: Moennig Volker , Houe Hans , Lindberg Ann
Published: August 2005

For several decades after the first description of bovine viral diarrhea and its causative agent (BVDV) the economic impact of the infection was underestimated and in addition there were no suitable diagnostics and procedures for a systematic control at hand. Today, there are several estimates on the real economic impact of the infection and during the last 15 years the serological and virological laboratory diagnosis of BVDV infections has improved. Also, successful procedures aimed at eradicating BVDV infections by using a strict test and removal policy for animals persistently infected (PI) with BVDV accompanied by movement restrictions for infected herds have been implemented in the Scandinavian countries. The success of these efforts has encouraged other European countries to follow the same procedures. However, the Scandinavian control strategy might—for a number of reasons—not be acceptable for all European countries. In such cases, the test and removal strategy, with its fundamental elements of biosecurity, removal of PI animals and monitoring of herd status, in combination with systematic vaccination, might be an acceptable compromise. The impact of the BVDV-free status of regions and nations on international trade is not yet clear. In any case, biosecurity measures will be of utmost importance for individual control programs as well as multiple control programs to co-exist in Europe.
Probiotic alternatives to reduce gastrointestinal infections: the poultry experience
Authors: Nava G. M. , Bielke L. R. , Callaway T. R. , Castañeda M. P
Published: August 2005

The intestinal mucosa represents the most active defense barrier against the continuous challenge of food antigens and pathogenic microorganisms present in the intestinal lumen. Protection against harmful agents is conferred by factors such as gastric acid, peristalsis, mucus, intestinal proteolysis, and the intestinal biota. The establishment of beneficial bacterial communities and metabolites from these complex ecosystems has varying consequences for host health. This hypothesis has led to the introduction of novel therapeutic interventions based on the consumption of beneficial bacterial cultures. Mechanisms by which probiotic bacteria affect the microecology of the gastrointestinal tract are not well understood, but at least three mechanisms of action have been proposed: production/presence of antibacterial substances (e.g., bacteriocins or colicins), modulation of immune responses and specific competition for adhesion receptors to intestinal epithelium. The rapid establishment of bacterial communities has been thought to be essential for the prevention of colonization by pathogenic bacteria. Some animal models suggest that the reduction in bacterial translocation in neonatal animals could be associated with an increase in intestinal bacterial communities and bacteriocin-like inhibitory substances produced by these species. This review emphasizes the role of the intestinal microbiota in the reduction of the gastrointestinal infections and draws heavily on studies in poultry.
Garden production systems and food security in Ghana: Characteristics of traditional knowledge and management systems
Authors: Yiridoe Emmanuel K. , Anchirinah Vincent M.
Published: August 2005

There is limited documented scientific information on garden production systems managed in developing countries, partly because both researchers and research administrators have, until recently, ignored them as legitimate areas of study, and because such production systems have been regarded as informal production activities, managed outside conventional market and economic channels. Yet in a developing country such as Ghana, these production systems are potentially able to contribute substantially to the food security and health needs of households. This study was aimed primarily at providing critical scientific information for understanding the complex web of production and management factors associated with garden production systems. A total of 300 survey responses, representing the Sudan savannah, Guinea savannah and moist deciduous forest agro-ecological zones of Ghana, were analyzed (27% of respondents were females and 73% were males). Several hypotheses from the field agriculture literature were tested to determine their relevance in garden production systems. Although, for the country as a whole, a variety of garden crops are cultivated, each agro-ecological zone concentrated on a set of four major crops, with the actual food crops differing across agro-ecological zones. The type of protective fencing used was not statistically associated with land tenure (i.e., own versus rented land) status of the gardener (χ2=3.285, P=0.4501). Gender responsibilities in garden production and management tended to be more equally shared in the forest agro-ecology, where garden crops are cultivated for household consumption and for generating family income. In contrast, in the two savannah zones, adult males undertook a disproportionate share of activities to produce garden crops that were primarily for marketing. Valuable information on production and management exist within the traditional garden production systems studied, and range from socio-economic, agronomic and medicinal considerations in selecting garden crops and fruit trees, to ecological monitoring systems and strategies for garden management.
Calibrating E-values for hidden Markov models using reverse-sequence null models
Authors: Karplus Kevin , Karchin Rachel , Shackelford George , Hughey Richard
Published: August 2005

Motivation: Hidden Markov models (HMMs) calculate the probability that a sequence was generated by a given model. Log-odds scoring provides a context for evaluating this probability, by considering it in relation to a null hypothesis. We have found that using a reverse-sequence null model effectively removes biases owing to sequence length and composition and reduces the number of false positives in a database search.

Any scoring system is an arbitrary measure of the quality of database matches. Significance estimates of scores are essential, because they eliminate model- and method-dependent scaling factors, and because they quantify the importance of each match. Accurate computation of the significance of reverse-sequence null model scores presents a problem, because the scores do not fit the extreme-value (Gumbel) distribution commonly used to estimate HMM scores' significance.

Results: To get a better estimate of the significance of reverse-sequence null model scores, we derive a theoretical distribution based on the assumption of a Gumbel distribution for raw HMM scores and compare estimates based on this and other distribution families. We derive estimation methods for the parameters of the distributions based on maximum likelihood and on moment matching (least-squares fit for Student's t-distribution).

We evaluate the modeled distributions of scores, based on how well they fit the tail of the observed distribution for data not used in the fitting and on the effects of the improved E-values on our HMM-based fold-recognition methods.

The theoretical distribution provides some improvement in fitting the tail and in providing fewer false positives in the fold-recognition test. An ad hoc distribution based on assuming a stretched exponential tail does an even better job. The use of Student's t to model the distribution fits well in the middle of the distribution, but provides too heavy a tail. The moment-matching methods fit the tails better than maximum-likelihood methods.

Availability: Information on obtaining the SAM program suite (free for academic use), as well as a server interface, is available at and the open-source random sequence generator with varying compositional biases is available at

Contact:  karplus@soe.ucsc.edu
Proton NMR spectroscopy shows lipids accumulate in skeletal muscle in response to burn trauma‐induced apoptosis
Authors: Astrakas Loukas G. , Goljer Igor , Yasuhara Shingo , Padfield Katie E. , Zhang Qunhao , Gopalan Suresh , Mindrinos Michael N. , Dai George , Yu Yong‐Ming , Martyn J. A. Jeevendra , Tompkins Ronald G. , Rahme Laurence G. , Tzika A. Aria
Published: August 2005

Burn trauma triggers hypermetabolism and muscle wasting via increased cellular protein degradation and apoptosis. Proton nuclear magnetic resonance (1H NMR) spectroscopy can detect mobile lipids in vivo. To examine the local effects of burn in skeletal muscle, we performed in vivo 1H NMR on mice 3 days after burn trauma; and ex vivo, high‐resolution, magic angle spinning 1H NMR on intact excised mouse muscle samples before and 1 and 3 days after burn. These samples were then analyzed for apoptotic nuclei using a terminal deoxynucleotidyl transferase‐mediated dUTP nick end‐labeling (TUNEL) assay. To confirm our NMR and cell biology results, we used transcriptome analysis to demonstrate that burn trauma alters the expression of genes involved in lipid metabolism and apoptosis. Our results demonstrate that burn injury results in a localized intramyocellular lipid accumulation, which in turn is accompanied by burn‐induced apoptosis and mitochondrial dysfunction, as seen by the up‐regulation of apoptotic genes and down‐regulation of genes that encode lipid oxidation and the peroxisomal proliferator activator receptor γ coactivator PGC‐1β. Moreover, the increased levels of bisallylic methylene fatty acyl protons (2.8 ppm) and vinyl protons (5.4 ppm), in conjunction with the TUNEL assay results, further suggest that burn trauma results in apoptosis. Together, our results provide new insight into the local physiological changes that occur in skeletal muscle after severe burn trauma. Astrakas, L. G., Goljer, I., Yasuhara, S., Padfield, K. E., Zhang, Q., Gopalan, S., Mindrinos, M. N., Dai, G., Yu, Y.‐M., Jeevendra Martyn, J. A., Tompkins, R. G., Rahme, L. G., Tzika, A. A. Proton NMR spectroscopy shows lipids accumulate in skeletal muscle in response to burn trauma induced apoptosis. FASEB J. 19, 1431–1440 (2005)
Nitric oxide mediates increased susceptibility to dopaminergic damage in Nurr1 heterozygous mice
Authors: Imam Syed Z. , Jankovic Joseph , Ali Syed F. , Skinner John T. , Xie Wenjie , Conneely Orla M. , Le Wei‐Dong
Published: August 2005

Knocking out of Nurr1 gene, a member of nuclear receptor superfamily, causes selective agenesis of dopaminergic neurons in midbrain. Reduced expression of Nurr1 increases the vulnerability of mesencephalic dopamine neurons to dopaminergic toxins. We evaluated the role of nitric oxide as a possible mechanism for this increased susceptibility. Increased expression of neuronal nitric oxide synthase and increased 3‐nitrotyrosine were observed in striatum of Nurr1 heterozygous (Nurr1 +/−) mice as compared with wild‐type. Increased cytochrome C activation and consecutive release of Smac/DIABLO were also observed in Nurr1 +/− mice. An induction of active Caspase‐3 and p53, cleavage of poly‐ADP (RNase) polymerase and reduced expression of bcl‐2 were observed in Nurr1 +/− mice. Methamphetamine significantly increased these markers in Nurr1 +/− mice as compared with wild‐type. The present data therefore suggest that nitric oxide plays a role as a modulating factor for the increased susceptibility, but not the potentiation, of the dopaminergic terminals in Nurr1 +/− mice. We also report that this increased neuronal nitric oxide synthase expression and increased nitration in Nurr1 +/− mice led to the activation of apoptotic cascade via the differential alterations in the DNA binding activity of transcription factors responsible for the propagation of growth arrest as well as apoptosis. Syed Z.Imam, Jankovic,‡Joseph, Syed F.Ali, John T.Skinner, WenjieXie, Orla M.Conneely, Wei‐DongLe Nitric oxide mediates increased susceptibility to dopaminergic damage in Nurr1 heterozygous mice. FASEB J. 19, 1441–1450 (2005)
Brain mitochondria contain aquaporin water channels: evidence for the expression of a short AQP9 isoform in the inner mitochondrial membrane
Authors: Amiry‐Moghaddam Mahmood , Lindland Heidi , Zelenin Sergey , Roberg Bjørg Å. , Gundersen Brigitta B. , Petersen Petur , Rinvik Eric , Torgner Ingeborg A. , Ottersen Ole P.
Published: August 2005

Aquaporins are a family of water channels found in animals, plants, and microorganisms. A subfamily of aquaporins, the aquaglyceroporins, are permeable for water as well as certain solutes such as glycerol, lactate, and urea. Here we show that the brain contains two isoforms of AQP9—an aquaglyceroporin with a particularly broad substrate specificity—and that the more prevalent of these isoforms is expressed in brain mitochondria. The mitochondrial AQP9 isoform is detected as an ∼25 kDa band in immunoblots. This isoform is likely to correspond to a new AQP9 mRNA that is obtained by alternative splicing and has a shorter ORF than the liver isoform. Subfractionation experiments and high‐resolution immunogold analyses revealed that this novel AQP9 isoform is enriched in mitochondrial inner membranes. AQP9 immunopositive mitochondria occurred in astrocytes throughout the brain and in a subpopulation of neurons in the substantia nigra, ventral tegmental area, and arcuate nucleus. In the latter structures, the AQP9 immunopositive mitochondria were located in neurons that were also immunopositive for tyrosine hydroxylase, as demonstrated by double labeling immunogold electron microscopy. Our findings suggest that mitochondrial AQP9 is a hallmark of astrocytes and midbrain dopaminergic neurons. In physiological conditions, the flux of lactate and other metabolites through AQP9 may confer an advantage by allowing the mitochondria to adjust to the metabolic status of the extramitochondrial cytoplasm. We hypothesize that the complement of mitochondrial AQP9 in dopaminergic neurons may relate to the vulnerability of these neurons in Parkinson's disease. Amiry‐Moghaddam, M., Lindland, H., Zelenin, S., Roberg, B. A., Gundersen, B. B., Petersen, P., Rinvik, R., Torgner, I. A., Ottersen, O. P. Brain mitochondria contain aquaporin water channels: evidence for the expression of a short AQP9 isoform in the inner mitochondrial membrane. FASEB J. 19, 1459–1467 (2005)
Human HIF‐3α4 is a dominant‐negative regulator of HIF‐1 and is down‐regulated in renal cell carcinoma
Authors: Maynard Mindy A. , Evans Andrew J. , Hosomi Tomoko , Hara Shuntaro , Jewett Michael A. S. , Ohh Michael
Published: August 2005

A universal response to changes in cellular oxygen tension is governed by a family of heterodimeric transcription factors called hypoxia‐inducible factor (HIF). Tumor hypoxia, as well as various cancer‐causing mutations, has been shown to elevate the level of HIF‐1α, signifying a critical role of the HIF pathway in cancer development. The recently identified third member of the human HIF‐α family, HIF‐3α, produces multiple splice variants that contain extra DNA binding elements and protein‐protein interaction motifs not found in HIF‐1α or HIF‐2α. Here we report the molecular cloning of the alternatively spliced human HIF‐3α variant HIF‐3α4 and show that it attenuates the ability of HIF‐1 to bind hypoxia‐responsive elements located within the enhancer/promoter of HIF target genes. The overexpression of HIF‐3α4 suppresses the transcriptional activity of HIF‐1 and siRNAmediated knockdown of the endogenous HIF‐3α4 increases transcription by hypoxia‐inducible genes. HIF‐3α4 itself is oxygen‐regulated, suggesting a novel feedback mechanism of controlling HIF‐1 activity. Furthermore, the expression of HIF‐3α4 is dramatically down‐regulated in the majority of primary renal carcinomas. These results demonstrate an important dominant‐negative regulation of HIF‐1‐mediated gene transcription by HIF‐3α4 in vivo and underscore its potential significance in renal epithelial oncogenesis. Maynard, M. A., Evans, A. J., Hosomi, T., Hara, S., Jewett, M. A. S., Ohh, M. Human HIF‐3α4 is a dominant‐negative regulator of HIF‐1 and is down‐regulated in renal cell carcinoma. FASEB J. 19, 1396–1406 (2005)
The constancy of the internal environment: proteins in plasma
Authors: Rothman Stephen
Published: August 2005

The simple fact that there are normal concentrations of various proteins and peptides in blood has broad and surprising implications for how these molecules are released into and removed from the bloodstream by the cells of the body. If, as widely accepted, vesicle transport mechanisms such as exocytosis and endocytosis account for these events, then complex, presently unknown and seemingly unlikely mechanisms must exist to coordinate the rates of separate transport processes. The basis for this conclusion as well as the sole alternative method of transport, movement across permeable membranes, are discussed. Rothman, S. The constancy of the internal environment: proteins in plasma. FASEB J. 19, 1383–1388 (2005)
Motivation and Maternal Presence during Induction of Anesthesia
Authors: Caldwell-Andrews Alison A. , Kain Zeev N. , Mayes Linda C. , Kerns Robert D. , Ng Derek
Published: August 2005

Background

The authors developed a measure to determine whether maternal motivation to be present during induction (Motivation for Parental Presence during Induction of Anesthesia [MPPIA]) is related to children's anxiety during the induction process.

Methods

Mothers and children (aged 2-12 yr) undergoing outpatient, elective surgery and general anesthesia were enrolled in this study (n = 289 dyads). Items to assess motivation for parental presence during induction were selected by experts in anesthesiology, psychology, and child development; mothers completed the resulting 14-item measure as well as assessments of anxiety and coping style. Children's anxiety and compliance was assessed during induction of anesthesia. Factor analysis was performed, and maternal motivation was then examined against children's anxiety during induction of anesthesia.

Results

Factor analysis resulted in four scales with a total variance of 72.3%: MPPIA-Desire, MPPIA-Hesitancy, MPPIA-Anxiety, and MPPIA-Preparation. Analysis supported the reliability (0.89-0.94) and validity of the MPPIA. The authors found that mothers with high MPPIA-Desire and low MPPIA-Hesitancy had children with significantly higher anxiety (P < 0.0001) during induction of anesthesia, as compared with mothers with low MPPIA-Desire and MPPIA-Hesitancy. The authors also found that highly motivated mothers reported significantly higher levels of anxiety (P = 0.007).

Conclusion

Clinicians should be aware that many mothers who have a high desire to be present in the operating room are very anxious and that their children are likely to exhibit high anxiety levels during induction of anesthesia.
Effect of Lateral Positioning on Upper Airway Size and Morphology in Sedated Children
Authors: Litman Ronald S. , Wake Nicole , Chan Lai-Ming Lisa , McDonough Joseph M. , Sin Sanghun , Mahboubi Soroosh , Arens Raanan
Published: August 2005

Background

Lateral positioning decreases upper airway obstruction in paralyzed, anesthetized adults and in individuals with sleep apnea during sleep. The authors hypothesized that lateral positioning increases upper airway cross-sectional area and total upper airway volume when compared with the supine position in sedated, spontaneously breathing children.

Methods

Children aged 2-12 yr requiring magnetic resonance imaging examination of the head or neck region using deep sedation with propofol were studied. Exclusion criteria included any type of anatomical or neurologic entity that could influence upper airway shape or size. T1 axial scans of the upper airway were obtained in the supine and lateral positions, with the head and neck axes maintained neutral. Using software based on fuzzy connectedness segmentation (3D-VIEWNIX; Medical Imaging Processing Group, University of Pennsylvania, Philadelphia, PA), the magnetic resonance images were processed and segmented to render a three-dimensional reconstruction of the upper airway. Total airway volumes and cross-sectional areas were computed between the nasal vomer and the vocal cords. Two-way paired t tests were used to compare airway sizes between supine and lateral positions.

Results

Sixteen of 17 children analyzed had increases in upper airway total volume. The total airway volume (mean +/- SD) was 6.0 +/- 2.9 ml in the supine position and 8.7 +/- 2.5 ml in the lateral position (P < 0.001). All noncartilaginous areas of the upper airway increased in area in the lateral compared with the supine position. The region between the tip of the epiglottis and vocal cords demonstrated the greatest relative percent change.

Conclusions

The upper airway of a sedated, spontaneously breathing child widens in the lateral position. The region between the tip of the epiglottis and the vocal cords demonstrates the greatest relative percent increase in size.
Desflurane Enhances Reactivity during the Use of the Laryngeal Mask Airway
Authors: Arain Shahbaz R. , Shankar Hariharan , Ebert Thomas J.
Published: August 2005

Background

Desflurane and sevoflurane have markedly different pungencies. The tested hypothesis was that patients breathing equivalent concentrations of desflurane or sevoflurane through a laryngeal mask airway (LMA) would have similar responses.

Methods

After institutional review board approval and informed consent were obtained, 60 patients were enrolled and given intravenous midazolam (14 microg/kg) and fentanyl (1 microg/kg) 5 min before induction of anesthesia. The LMA was inserted at loss of consciousness after 2 mg/kg propofol. When spontaneous breathing returned, a randomly assigned volatile anesthetic was started at an inspired concentration of either 1.8% sevoflurane or 6% desflurane at a fresh gas flow of 6 l/min in air:oxygen (50:50). After 5 min, a controlled movement of the LMA took place. Three minutes later, the inspiratory anesthetic concentration was changed to either 3.6% sevoflurane or 12% desflurane for 3 min. A blinded observer recorded movements and airway events during the start of anesthetic, LMA movement, deepening of the anesthetic, and emergence before LMA removal.

Results

There were no differences at anesthetic start and LMA movement. Desflurane titration to 12% increased heart rate, increased mean arterial blood pressure, and initiated frequent coughing (53% vs. 0% sevoflurane) and body movements (47% vs. 0% sevoflurane). During emergence, there was a twofold greater incidence of coughing and a fivefold increase in breath holding in the desflurane group.

Conclusions

When airway responses to sevoflurane and desflurane were compared in elective surgical patients breathing through an LMA, there were significantly more adverse responses with desflurane at 12% concentrations and during emergence.
Xenon Acts by Inhibition of Non–N -methyl-d-aspartate Receptor–mediated Glutamatergic Neurotransmission in Caenorhabditis elegans
Authors: Nagele Peter , Metz Laura B. , Crowder C Michael
Published: August 2005

Background

Electrophysiologic experiments in rodents have found that nitrous oxide and xenon inhibit N-methyl-D-aspartate (NMDA)-type glutamate receptors. These findings led to the hypothesis that xenon and nitrous oxide along with ketamine form a class of anesthetics with the identical mechanism, NMDA receptor antagonism. Here, the authors ask in Caenorhabditis elegans whether xenon, like nitrous oxide, acts by a NMDA receptor-mediated mechanism.

Methods

Xenon:oxygen mixtures were delivered into sealed chambers until the desired concentration was achieved. The effects of xenon on various behaviors were measured on wild-type and mutant C. elegans strains.

Results

With an EC50 of 15-20 vol% depending on behavioral endpoint, xenon altered C. elegans locomotion in a manner indistinguishable from that of mutants in glutamatergic transmission. Xenon reduced the frequency and duration of backward locomotion without altering its speed or other behaviors tested. Mutation of glr-1, encoding a non-NMDA glutamate receptor subunit, abolished the behavioral effects of xenon; however, mutation of nmr-1, which encodes the pore-forming subunit of an NMDA glutamate receptor previously shown to be required for nitrous oxide action, did not significantly alter xenon response. Transformation of the glr-1 mutant with the wild-type glr-1 gene partially restored xenon sensitivity, confirming that glr-1 was necessary for the full action of xenon.

Conclusions

Xenon acts in C. elegans to alter locomotion through a mechanism requiring the non-NMDA glutamate receptor encoded by glr-1. Unlike for the action of nitrous oxide in C. elegans, the NMDA receptor encoded by nmr-1 is not essential for sensitivity to xenon.
Pulmonary Aspiration
Authors: Beck-Schimmer Beatrice , Rosenberger Dorothea S. , Neff Simona B. , Jamnicki Marina , Suter Dominik , Fuhrer Thomas , Schwendener Reto , Booy Christa , Reyes Livia , Pasch Thomas , Schimmer Ralph C.
Published: August 2005

Background

Acute lung injury caused by gastric aspiration is a frequent occurrence in unconscious patients. Acute respiratory distress syndrome in association with gastric aspiration carries a mortality of up to 30% and accounts for up to 20% of deaths associated with anesthesia. Although the clinical condition is well known, knowledge about the exact inflammatory mechanisms is still incomplete. This study was performed to define the role of alveolar macrophages in this inflammatory response. In addition, potentially modifying effects of intratracheally applied nuclear factor kappaB inhibitor pyrrolidine dithiocarbamate were investigated.

Methods

Rat alveolar macrophages were depleted by intratracheal administration of clodronate liposomes, and lung injury was evaluated 6 h after instillation of 0.1N hydrochloric acid. In a second set of experiments, pyrrolidine dithiocarbamate was intratracheally instilled 3 h after hydrochloric acid application, and injury parameters were determined.

Results

Depletion of alveolar macrophages resulted in decreased production of inflammatory mediators in acid aspiration (23-80% reduction of messenger RNA or protein of inflammatory mediators; P < 0.05) and consequently also in diminished neutrophil recruitment (36% fewer neutrophils; P < 0.01). Treatment with pyrrolidine dithiocarbamate was highly effective in decreasing neutrophil recruitment (66%; P < 0.01) and vascular permeability (80%; P < 0.001).

Conclusions

These data suggest that alveolar macrophages play an essential role in the inflammatory response of acid-induced lung injury. For the first time, attenuation of acid-induced lung injury with an inhibitor, applied after the onset of injury, is shown.
Thiopental-induced Apoptosis in Lymphocytes Is Independent of CD95 Activation
Authors: Keel Marius , Mica Ladislav , Stover John , Stocker Reto , Trentz Otmar , Härter Luc
Published: August 2005

Background

Barbiturate coma is used in patients with traumatic brain injury whenever increases in intracranial pressure remain unresponsive to less aggressive therapeutic regimens. However, barbiturate-mediated neuroprotection correlates with lymphopenia, which increases the risk of infection. The mechanisms by which barbiturates lead to lymphopenia remain to be determined.

Methods

Freshly isolated human lymphocytes and Jurkat cells were incubated with the barbiturate thiopental for 24 and 48 h. Apoptosis was measured by fluorescein isothiocyanate-Annexin and propidium iodide staining, rhodamine 123 staining, and the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling method. Caspase-3 activity was detected by Western blot and substrate cleavage assay.

Results

Thiopental dose-dependently (5-500 microg/ml) increased apoptosis in Jurkat cells from basal levels (4.4 +/- 1.9%) to 29.7 +/- 2.8% after 24 h and 39.7 +/- 3.2% after 48 h, whereas in lymphocytes, thiopental-induced necrosis was observed. Parallel to apoptosis, thiopental dose-dependently increased caspase-3-like activity in Jurkat cells. However, the pan-caspase inhibitor z-VAD-fmk (20 microm) only marginally reduced thiopental-induced (250 microg/ml) apoptosis in Jurkat cells (20.2 +/- 2.5 to 17.2 +/- 2.5%) and necrosis in lymphocytes (39.2 +/- 7.5 to 30.7 +/- 14%). In contrast, anti-CD95-induced apoptosis in Jurkat cells (27.0 +/- 2.0%) was completely blocked by z-VAD-fmk (8.1 +/- 1.8%). Neither expression of CD95 on Jurkat cells nor pretreatment with a neutralizing anti-CD95 antibody influenced thiopental-induced apoptosis, indicating that thiopental induces apoptosis independently of the CD95 system. The nuclear factor kappaB inhibitor gliotoxin accelerated both thiopental- and CD95-mediated apoptosis, indicating a mutual control mechanism of thiopental- and CD95-induced apoptosis.

Conclusions

Thiopental directly induces cell death in lymphocytes and Jurkat cells by a CD95-independent mechanism.
Chronobiology of Subarachnoid Fentanyl for Labor Analgesia
Authors: Pan Peter H. , Lee Sherman , Harris Lynne
Published: August 2005

Background

Chronobiology studies the recurrent biologic rhythms that directly affect how an organism interacts with its environment and how its environment affects the organism. The purpose of this study is to determine whether the time of administration influences the analgesic duration of the commonly used subarachnoid fentanyl for labor analgesia.

Methods

After institutional review board approval and informed consent were obtained, 77 healthy nulliparous women in active labor requesting neuraxial analgesia were assigned to one of two groups, based on the time of combined spinal-epidural analgesia placement: the day group, for the time period from 12:00 to 18:00, and the night group, for the period from 20:00 to 02:00. Combined spinal-epidural analgesia was performed with 20 microg subarachnoid fentanyl. An epidural catheter was inserted but not dosed until patients requested further analgesia. Dynamic data were recorded at 5-min intervals for 20 min initially and then every 15 min. The analgesic duration was defined as the time from subarachnoid fentanyl injection to the time the patient requested further analgesia.

Results

Seventy evaluable patients completed the study, with 35 per group. Patient demographics, visual analog pain scale scores, and labor characteristics were similar between groups, but the duration (mean +/- SD) for subarachnoid fentanyl labor analgesia was 92 +/- 34 min for the day group and 67 +/- 21 min for the night group (P < 0.001).

Conclusions

The results indicate that chronobiology of subarachnoid fentanyl plays a significant role of up to 27% difference in labor analgesic duration between the two administration time periods studied. Chronobiology should be incorporated in future comparative studies or analysis of previous studies on subarachnoid fentanyl.
Nerve Stimulator–guided Paravertebral Blockade Combined with Sevoflurane Sedation versus General Anesthesia with Systemic Analgesia for Postherniorrhaphy Pain Relief in Children
Authors: Naja Zouheir M. , Raf Martin , El Rajab Mariam , Ziade Fouad M. , Al Tannir Mohamad A. , Lönnqvist Per Arne
Published: August 2005

Background

Improvement of the duration of postoperative analgesia is desirable in children undergoing inguinal hernia repair.

Methods

Fifty children aged 5-12 yr were prospectively randomized to receive either paravertebral nerve blockade or general anesthesia (sevoflurane-fentanyl-nitrous oxide-oxygen) combined with standardized postoperative systemic analgesia, both combined with light sevoflurane anesthesia, for inguinal hernia repair.

Results

Mean pain scores were significantly lower in paravertebral nerve blockade patients compared with patients treated with systemic analgesia during the entire 48-h observational period (P < 0.05). Analgesic consumption was significantly higher in the systemic analgesia group (88%) compared with the paravertebral nerve blockade group (32%) (P < 0.001). Parental satisfaction was significantly higher (80 vs. 48%; P < 0.05) and same-day discharge was possible in a higher proportion of patients in the paravertebral blockade group (80% vs. 52%; P < 0.05).

Conclusions

Paravertebral nerve blockade was associated with improved postoperative pain relief; reduced analgesic consumption, and faster hospital discharge compared with a systemic analgesia protocol in children undergoing herniorrhaphy.
Development and Preliminary Validation of the Questionnaire on Pediatric Gastrointestinal Symptoms to Assess Functional Gastrointestinal Disorders in Children and Adolescents
Authors: Caplan Arlene , Walker Lynn , Rasquin Andrée
Published: August 2005

Objective:

The aim of this study was to develop a questionnaire assessing symptoms associated with pediatric functional gastrointestinal disorders (FGIDs) and to provide preliminary evidence for its validity and reliability in a tertiary care setting.

Methods:

The Questionnaire on Pediatric Gastrointestinal Symptoms (QPGS) was designed as both a parent report and child self‐report measure based on the pediatric Rome II criteria for FGIDs. It was constructed in English, translated into French, and pilot tested in both languages. Initial validation was performed using the French version. Participants were 315 consecutive new patients aged 4 to 18, and their parents, presenting to a gastroenterology clinic and classified as having a functional problem. Content validity, item discrimination capacity, and reliability (parent‐child concordance and temporal stability) were examined.

Results:

Analyses of parent and child reports indicated that all items were pertinent and variably distributed. Although children were reliable reporters, up to 42% of parents did not know about their children's gastrointestinal functioning. As many as 60% of parents of children 10 to 18 could not respond to questions about defecation and subjective symptoms. Concordance was generally fair to good, with Kappas and intraclass correlations of 0.40 to 0.70 on most items. Test‐retest reliability was moderate to good for the majority of items.

Conclusion:

This study supports the content validity of the QPGS. Form A is a reliable measure for parents of children 4 to 9 years old, but the child self‐report Form C appears to be more reliable for 10 to 18 year olds.
Antroduodenal Motility and Feeding Outcome among Neonatal Extracorporeal Membrane Oxygenation Survivors
Authors: Jadcherla Sudarshan R , Berseth Carol Lynn
Published: August 2005

Objectives:

Feeding difficulties are common among survivors of extracorporeal membrane oxygenation (ECMO). In this study, we characterized antroduodenal motor patterns and feeding outcomes among 10 ECMO survivors.

Methods:

Intestinal motor patterns were recorded in 10 ECMO survivors within 48 hours of the initiation of enteral feeding. Subsequent feeding outcomes were tracked until discharge. We compared the motor patterns of infants achieving full oral feedings by 1 month postnatal age with those who did not achieve full oral feedings by 1 month postnatal age.

Results:

In infants failing to achieve full oral feedings, duodenal clusters occupied less of the total record (P < 0.05), and clusters had significantly lower amplitude (P < 0.05) than were seen in successful infants. Infants failing to achieve full oral feedings had greater time spent in motor quiescence (P < 0.05) than successful infants. Neither group had migrating motor complexes during fasting or mature duodenal motor responses to feeding. At discharge, six infants with feeding failure were more likely to require tube feeding, and the hospital stay was 3.6 times longer. Intracranial abnormalities were detected by computed tomography scan in five of six infants with feeding failure.

Conclusions:

Early intestinal dysmotility in infants surviving ECMO is associated with later feeding difficulties and prolonged hospitalization.
Predictors of Bone Mineral Density in Human Immunodeficiency Virus‐1 Infected Children
Authors: Jacobson Denise L , Spiegelman Donna , Duggan Christopher , Weinberg Geoffrey A , Bechard Lori , Furuta Lauren , Nicchitta Jeanne , Gorbach Sherwood L , Miller Tracie L
Published: August 2005

Objectives:

To compare bone mineral density (BMD) among human immunodeficiency virus (HIV)‐infected children with population norms and to determine predictors of BMD in HIV‐infected children.

Methods:

Total body BMD was measured by dual energy x‐ray absorptiometry in 37 HIV‐infected children and nine sibling controls at baseline. Clinical, dietary and anthropometric data were obtained at the time of the dual energy x‐ray absorptiometry examination. Age‐ and gender‐adjusted z scores were calculated for BMD, body mass index, weight and height from population standards. Age‐adjusted percentiles were determined for dietary intake of calcium and vitamin D. Differences in BMD z scores between HIV‐infected children and sibling controls were determined and adjusted for height and weight, as were independent risk factors for lower BMD among infected children. Eighteen HIV‐infected children and 5 controls had serial BMD measures.

Results:

Compared with population norms, HIV‐infected children had significantly lower BMD z scores (‐0.51 SD, P = 0.004), in contrast with controls who had normal z scores (0.38 SD, P = 1.0). However, there was no difference in BMD z scores between HIV‐infected children and the small number of sibling controls, adjusted for height and weight. Among HIV‐infected children, lower BMD z scores were independently associated with lower weight z scores (P < 0.0001), lower height z scores (P = 0.01), advanced (stage B or C) HIV stage (P = 0.01) and age greater than 8 years (P < 0.0001). In the same model, multivitamin use (P = 0.009) and African American race (P = 0.001) were associated with better BMD z scores, with nevirapine use showing borderline positive effect (P = 0.06). All results were adjusted for Tanner stage. Change in BMD z score over time showed that there was no change or an increase in BMD in 100% of controls but in only 44% of the HIV‐infected children (P = 0.09).

Conclusion:

When compared with population norms, HIV‐infected children had lower than expected bone mass for their age and gender that may be attributable to delays in growth, sexual maturity, time (length of HIV infection), ethnicity and disease severity. Dietary intake of calcium and vitamin D were not associated with bone loss, but most children had suboptimal intake. However, multivitamin use was strongly associated with better bone mineral density.
Screening Detected Celiac Disease in Children with Type 1 Diabetes Mellitus: Effect on the Clinical Course (A Case Control Study)
Authors: Rami Birgit , Sumnik Zdenek , Schober Edith , Waldhör Thomas , Battelino Tadej , Bratanic Nina , Kürti Kalman , Lebl Jan , Limbert Catarina , Madacsy Laszlo , Odink Roetloef J. H , Paskova Magdalena , Soltesz Gyula
Published: August 2005

Objective:

To investigate clinical and metabolic characteristics of diabetic children with screening detected celiac disease in a multicenter case‐control study.

Methods:

Cases: 98 diabetic patients were diagnosed as having silent celiac disease by screening with endomysial antibodies and subsequent biopsy. Controls: two controls in the same center were chosen, (stratified by age and age‐at‐diabetes onset) who were negative for endomysial antibodies (n = 195). Height, weight, HbA1c, insulin dosage and acute complications were documented for at least 1 year of follow up.

Results:

Mean age of diabetes manifestation was 6.5 ± 4.1 years and diagnosis of celiac disease was made at 10.0 ± 5.4 years. Biopsy showed total or subtotal mucosal atrophy in 74 patients. The mean observation period after the diagnosis of celiac disease was 3.3 ± 1.9 years. Mean HbA1c levels were similar between cases and controls (8.63% ± 1.45% versus 8.50% ± 1.39%; P = 0.35). There was also no difference in the frequency of severe hypoglycemia, ketoacidosis and the applied insulin dosage (P = 0.45). Body mass index‐standard deviation score at celiac disease diagnosis (0.57 ± 1.24 versus 0.52 ± 1.07) and height‐standard deviation score (0.14 ± 1.13 versus 0.30 ± 0.95) did not differ between cases and controls. After diagnosis of celiac disease, weight gain was diminished in boys with celiac disease compared with their controls (P < 0.05). Female cases also had a lower body mass index than female controls (P = 0.067).

Conclusion:

In a cohort of diabetic children, silent celiac disease had no obvious effect on metabolic control but negatively influenced weight gain.
Control of Gastrointestinal Motility by the “Gut Brain” ‐ The Enteric Nervous System
Authors: Schemann Michael
Published: August 2005

The enteric nervous system (ENS) as the “brain of the gut” is pivotal for normal muscle activity in the gut. Neuronal circuits within the ENS are designed to control gut motility independent of central inputs. To fulfill this task the ENS contains all necessary elements for coding mechanical and chemical stimuli, interneuronal communication and efferent output to the muscle. This review provides a summary of the ENS circuits that control muscle activity, the main transmitters and neuromodulators involved and the functional implications for the normal and diseased gut.
Sensory Signals from the Gastrointestinal Tract
Authors: Grundy David
Published: August 2005

The sensory input to the CNS provides a basis for reflexes that control and coordinate gut function, integrates this with behavioral responses such as the regulation of food intake and also mediate sensations. Diverse sub‐populations of afferents have been identified according to the morphologic appearance of their terminal distribution in mucosa, muscle and mesentery, their pathway to the CNS and their functional properties in detecting mechanical activity and the local chemical environment. Mechanosensitivity to distension shows remarkable plasticity and can be influenced by a wide range of chemical mediators released as a consequence of ischemia, injury and inflammation. Chemosensitivity is also a property of vagal mucosal afferents that sample the chemical milieu within the lamina propria for chemicals absorbed across the epithelium or released from enteroendocrine cells that are strategically positioned to “taste” luminal contents. A complex interplay between ion channels and receptors underlies gastrointestinal sensing mechanisms and determines appropriate responses during normal digestion and in pathophysiology.
Simple evolutionary pathways to complex proteins
Authors: Lynch Michael
Published: August 2005

A recent paper in this journal has challenged the idea that complex adaptive features of proteins can be explained by known molecular, genetic, and evolutionary mechanisms. It is shown here that the conclusions of this prior work are an artifact of unwarranted biological assumptions, inappropriate mathematical modeling, and faulty logic. Numerous simple pathways exist by which adaptive multi‐residue functions can evolve on time scales of a million years (or much less) in populations of only moderate size. Thus, the classical evolutionary trajectory of descent with modification is adequate to explain the diversification of protein functions.
Specificity inversion of Ochrobactrum anthropi D‐aminopeptidase to a D,D‐carboxypeptidase with new penicillin binding activity by directed mutagenesis
Authors: Delmarcelle Michaël , Boursoit Marie‐Caroline , Filée Patrice , Baurin Stéphane Lucius , Frère Jean‐Marie , Joris Bernard
Published: August 2005

The serine penicillin‐recognizing proteins have been extensively studied. They show a wide range of substrate specificities accompanied by multidomain features. Their adaptation capacity has resulted in the emergence of pathogenic bacteria resistant to β‐lactam antibiotics. The most divergent enzymatic activities in this protein family are those of the Ochrobactrum anthropi D‐aminopeptidase and of the Streptomyces R61 D,D‐carboxypeptidase/transpeptidase. With the help of structural data, we have attempted to identify the factors responsible for this opposite specificity. A loop deletion mutant of the Ochrobactrum anthropi D‐aminopeptidase lost its original activity in favor of a new penicillin‐binding activity. D‐aminopeptidase activity of the deletion mutant can be restored by complementation with another deletion mutant corresponding to the noncatalytic domain of the wild‐type enzyme. By a second step site‐directed mutagenesis, the specificity of the Ochrobactrum anthropi D‐aminopeptidase was inverted to a D,D‐carboxypeptidase specificity. These results imply a core enzyme with high diversity potential surrounded by specificity modulators. It is the first example of drastic specificity change in the serine penicillin‐recognizing proteins. These results open new perspectives in the conception of new enzymes with nonnatural specificities. The structure/specificity relationship in the serine penicillin‐recognizing proteins are discussed.
Aggregation of granulocyte‐colony stimulating factor in vitro involves a conformationally altered monomeric state
Authors: Raso Stephen W. , Abel Jeff , Barnes Jesse M. , Maloney Kevin M. , Pipes Gary , Treuheit Michael J. , King Jonathan , Brems David N.
Published: August 2005

Aggregation of partially folded intermediates populated during protein folding processes has been described for many proteins. Likewise, partially unfolded chains, generated by perturbation of numerous proteins by heat or chemical denaturants, have also been shown to aggregate readily. However, the process of protein aggregation from native‐state conditions is less well understood. Granulocyte‐colony stimulating factor (G‐CSF), a member of the four‐helix bundle class of cytokines, is a therapeutically relevant protein involved in stimulating the growth and maturation of phagocytotic white blood cells. Under native‐like conditions (37°C [pH 7.0]), G‐CSF shows a significant propensity to aggregate. Our data suggest that under these conditions, native G‐CSF exists in equilibrium with an altered conformation, which is highly aggregation prone. This species is enriched in 1–2 M GdmCl, as determined by tryptophan fluorescence and increased aggregation kinetics. In particular, specific changes in Trp58 fluorescence report a local rearrangement in the large loop region between helices A and B. However, circular dichroism, reactivity toward cyanylation, and ANS binding demonstrate that this conformational change is subtle, having no substantial disruption of secondary and tertiary structure, reactivity of the free sulfhydryl at Cys17 or exposure of buried hydrophobic regions. There is no indication that this altered conformation is important to biological activity, making it an attractive target for rational protein stabilization.