bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intracellular domain of nicotinic acetylcholine receptor: the importance of being unfolded
Authors: Kukhtina V. , Kottwitz D. , Strauss H. , Heise B. , Chebotareva N. , Tsetlin V. , Hucho F. 
Published: October 2005

AbstractBioinformatics methods with subsequent verification by experimental data were applied to the structural investigation of the intracellular loop of the δ‐subunit of the nicotinic acetylcholine receptor (nAChR). Three complementary methods were used: prediction of secondary structure elements, prediction of ordered/disordered protein regions and prediction of short functional binding motifs. The output of five different algorithms was used for the secondary structure construction. Most of the intracellular domain is predicted to be unfolded. The predictions correlate well with the experimental data of limited proteolysis and NMR performed on the mostly monomeric fraction of heterologously expressed Torpedo intracellular domain protein. Twelve functional binding motifs within the disordered regions of the nAChR intracellular domain are predicted. Identification of proteins that interact with the intracellular domain will provide a better understanding of protein–protein interactions involved in nAChR assembly, trafficking and clustering.
Amyloid precursor protein expression in the rat hippocampal dentate gyrus modulates during memory consolidation
Authors: Conboy Lisa , Murphy Keith J. , Regan Ciaran M. 
Published: October 2005

AbstractDespite advances in our understanding of the basic biology of amyloid precursor protein (APP), the normal physiological function(s) of APP in learning and memory remains unclear. Here we show increased APP degradation in the hippocampus to be associated with the consolidation of a passive avoidance response. Neurone‐specific APP695 expression became transiently reduced 2–4 h post‐training through association with endosomal adaptin proteins and enhanced internalization. By contrast, internalization of glial‐associated APP containing a Kunitz protease inhibitor‐like domain (APP‐KPI) was dependent on the low‐density lipoprotein receptor‐related protein (LRP). In addition, LRP expression and association with apolipoprotein E increased in the 2–4 h post‐training period. The LRP antagonist receptor‐associated protein prevented the APP‐KPI internalization and LRP–apolipoprotein E association and this resulted in amnesia. Degradation of APP695 and APP‐KPI did not appear to be related to α‐secretase activity, as no learning‐associated increase of secreted APP was observed in the CSF. Moreover, as internalization of APP isoforms was observed only in dentate gyrus, it probably relates to the learning‐associated restructuring of the perforant path terminals. Memory‐associated APP processing in both neuronal and glial compartments points to a role for glial unsheathing of synaptic connections, an event required for the synaptic restructuring that accompanies memory consolidation. These observations may have a direct relevance to understanding the pathophysiology of Alzheimer's disease as β/γ‐secretase‐derived β‐amyloid is formed following internalization of cell surface APP into the endosomal compartment.
Contribution of conserved glycine residues to ATP action at human P2X1receptors: mutagenesis indicates that the glycine at position 250 is important for channel function
Authors: Digby Helen R. , Roberts Jonathan A. , Sutcliffe Michael J. , Evans Richard J. 
Published: October 2005

AbstractGlycine residues can introduce flexibility in proteins, give rise to turns and breaks in secondary structure and are key components of some nucleotide binding motifs. In the P2X receptor extracellular ATP binding domain, 11 glycine residues are completely conserved and an additional five are conserved in at least five of the seven family members. We have mutated individual conserved glycine residues and determined their effect on the ATP sensitivity and time‐course of P2X1receptors expressed inXenopusoocytes. In the majority of cases, replacement by alanine had no or a less than 3‐fold effect on ATP sensitivity and time‐course of responses. G71A resulted in a 6‐fold decrease in ATP potency and ATP (10 mm) failed to evoke functional responses from G96A, G250A and G301A mutant receptors. However, proline or cysteine could substitute for glycine at positions 96 and 301, giving receptors that were essentially normal. At glycine 250 substitution by serine gave functional responses to ATP with no effect on ATP sensitivity but a reduction in peak amplitude; in contrast, functional responses were not recorded when glycine 250 was replaced by the amino acids alanine, cysteine, aspartate, phenylalanine, isoleucine, lysine, proline or asparagine. These results suggest that glycine 250 plays an important role in determining the function of P2X receptors.
High‐frequency, but not low‐frequency, transcutaneous electrical nerve stimulation reduces aspartate and glutamate release in the spinal cord dorsal horn
Authors: Sluka K. A. , Vance C. G. T. , Lisi T. L. 
Published: October 2005

AbstractTranscutaneous electrical nerve stimulation (TENS) is a commonly utilized non‐pharmacological treatment for pain. Studies show that low‐ and high‐frequency TENS utilize opioid, serotonin and/or muscarinic receptors in the spinal cord to reduce hyperalgesia induced by joint inflammation in rats. As there is an increase in glutamate and aspartate levels in the spinal cord after joint inflammation, and opioids reduce glutamate and aspartate release, we hypothesized that TENS reduces release of glutamate and aspartate in animals with joint inflammation by activation of opioid receptors. Using microdialysis and HPLC with fluorescence detection, we examined the release pattern of glutamate and aspartate in the dorsal horn in response to either low‐frequency (4 Hz) or high‐frequency (100 Hz) TENS. We examined the effects of TENS on glutamate and aspartate release in animals with and without joint inflammation. High‐frequency, but not low‐frequency, TENS significantly reduced spinal glutamate and aspartate in animals with joint inflammation compared with levels in those without joint inflammation. The reduced release of glutamate and aspartate by high‐frequency TENS was prevented by spinal blockade of delta‐opioid receptors with naltrindole. Thus, we conclude that high‐frequency TENS activates delta‐opioid receptors consequently reducing the increased release of glutamate and aspartate in the spinal cord.
Normative nerve conductions in the tail of rhesus macaques (Macaca mulatta)
Authors: Graham W.A. , Ludlage E. , Mansfield K. , Magill D. , Nesathurai S. 
Published: October 2005

AbstractBackground  The aim of this study was to test the feasibility of using the tail of Macaca mulatta for neurophysiological testing of the peripheral nervous system.Methods  Motor and sensory nerve conduction studies (NCS) of the tail were obtained by surface stimulation and recording. The technique utilized was novel. Unlike other NCS obtained from other peripheral nerves, this technique did not require any special neurophysiological expertise.Results  The latency of the motor and sensory response was 2.5 ± 0.71 and 1.1 ± 0.27 ms respectively. The amplitude of the motor and sensory response was 8.1 ± 5.1 mV and 14.6 ± 9.4 μV respectively. Similar to human beings, there was a statistically significant relationship between age and motor amplitude, motor latency and sensory latency.Conclusions  Based on our results, a relatively simple, reproducible neurophysiological monitoring technique of the peripheral nervous system is possible.
Computer simulation of solution and growth processes during the initial stage of liquid phase sintering of tungsten heavy metal
Authors: Ekbom Lars , Antonsson Tomas , Ekbom Mikael 
Published: October 2005

In the initial stage of liquid phase sintering, particle dissolution and growth processes occur. The melting matrix penetrates the solid particle agglomerates. A fraction of the particles dissolves in the liquid matrix phase and the original powder size will initially be reduced. At the same time the agglomerates of particles are effectively separated. In a second stage larger particles grow in equilibrium with the matrix, whilst smaller, pure particles dissolve into the matrix and the mean particle size increases. When an equilibrium is reached, the solid particles start to grow in the liquid matrix phase in accordance with the ripening process. The initial stages of liquid phase sintering have been investigated by short time sintering under microgravity and are presented in a series of micrographs. Mathematical models for the 3 stages have been developed.Computer simulations of these different stages in the solution and growth processes have been used to visualise the change in particle size distribution.
Children's Asthma, Internalizing Problems, and Social Functioning: An Urban Perspective
Authors: Bender Berz Jennifer , Murdock Karla Klein , Koinis Mitchell Daphne 
Published: October 2005

PROBLEM:  Asthma may serve as a risk factor for higher levels of psychosocial problems in urban school‐aged children.METHOD:  Interview data were collected from 48 children (27 with asthma and 21 without asthma) and their mothers.FINDINGS:  Asthma did not function as a risk factor for psychosocial problems in this sample. Children with more symptoms of depression and anxiety experienced poorer social functioning, regardless of their health status.CONCLUSION:  These results highlight the importance of examining co‐occurring difficulties in psychosocial development among urban children in order to design interventions that minimize the impact of such challenges.
PRODUCTION OF A LOW‐CHOLESTEROL SHRIMP USING SUPERCRITICAL EXTRACTION
Authors: HIGUERA‐CIAPARA I. , TOLEDO‐GUILLEN A.R. , NORIEGA‐OROZCO L. , MARTINEZ‐ROBINSON K.G. , ESQUEDA‐VALLE M.C. 
Published: October 2005

ABSTRACT A low‐cholesterol shrimp was produced using supercritical extraction. The processing sequence included freeze drying, cholesterol extraction and rehydration. The shrimp was freeze dried, kept under vacuum until an experimental central composite rotatory design was applied using Response Surface Analysis for the supercritical extraction process. Three variables at five levels each were tested during the experiment (pressure, volume and temperature). After the extraction procedure, various rehydration and cooking conditions were applied to obtain a processed product with characteristics similar to those of the natural shrimp. Two sensory analyses were performed: one which compared the attributes of fresh shrimp with those of the freeze‐dried and rehydrated products, and another one which compared the acceptability between fresh shrimp and low‐cholesterol shrimp after freeze drying, supercritical extraction and rehydration. Under the conditions of 310 bar, 1875 L of carbon dioxide and 37C, it was possible to obtain a low‐cholesterol shrimp with acceptable organoleptic properties.
REDUCTION OF SACCHAROMYCES CEREVISIAE, ESCHERICHIA COLI AND LISTERIA INNOCUA IN APPLE JUICE BY ULTRAVIOLET LIGHT
Authors: GUERRERO‐BELTRÁN JOSÉ A. , BARBOSA‐CÁNOVAS GUSTAVO V. 
Published: October 2005

ABSTRACT Apple juice was inoculated separately with Saccharomyces cerevisiae, Listeria innocua (ATCC 51742) or Escherichia coli (ATCC 11775) for treatment in a double tube ultraviolet (UV) disinfection system. The apple juice was treated at six flow rates (0.073–0.548 L/min) for selected fluences (75–450 kJ/m2). The juice was also inoculated with a mixture of these three microorganisms and UV light treated from 0.548 to 0.735 L/min for 30 min. The microbial reduction was described with a first order kinetic model. Average Duvvalues of 23.1–40.5, 8.2–20.6 and 6.0–17.7 min were obtained for S. cerevisiae, L. innocua and E. coli, respectively. A linear model was used to describe the relationship between log Duvversus flow rate for S. cerevisiae and L. innocua. However, a third order polynomial model was more adequate for describing the E. coli Duvvalues versus flow rate. Less than 10 (no growth), 190 and 200 cfu/mL of S. cerevisiae, L. inocua and E. coli, respectively, were observed in UV‐treated apple juice inoculated with a mixture of microorganisms.
COMPUTER‐CONTROLLED MICROWAVE HEATING TO IN‐PACKAGE PASTEURIZE BEEF FRANKFURTERS FOR ELIMINATION OF LISTERIA MONOCYTOGENES†
Authors: HUANG LIHAN 
Published: October 2005

ABSTRACT The objective of this study was to develop an in‐package pasteurization technology to kill Listeria monocytogenes in ready‐to‐eat meats using microwave heating. This technology utilized an infrared sensor to monitor the surface temperature of beef frankfurters during microwave heating. The aim was to increase the surface temperature of frankfurters to a set point lethal to L. monocytogenes. A feedback control mechanism was used to control the power to the microwave oven. Results indicated that the simple on‐off control mechanism was able to maintain the surface temperature of beef frankfurters near the respective set points of 75, 80 or 85C used in this study. This pasteurization process was able to achieve a 7‐log reduction of L. monocytogenes in inoculated beef frankfurters using a 600‐W nominally rated microwave oven within 12–15 min. If optimized, this system may provide the food industry with a terminal, postlethality pasteurization technology to kill L. monocytogenes in ready‐to‐eat meats within the final packages.
KINETICS OF ACRYLAMIDE FORMATION DURING TRADITIONAL AND VACUUM FRYING OF POTATO CHIPS
Authors: GRANDA CLAUDIA , MOREIRA ROSANA G. 
Published: October 2005

ABSTRACT Acrylamide is considered a carcinogen in animals and a possible carcinogen in humans. It has been found in starch‐rich foods cooked at high temperatures. Vacuum frying (10 Torr) was investigated as a possible alternative to reduce acrylamide formation in potato chips. The cultivar Atlantic was used to determine the kinetics of acrylamide formation during traditional and vacuum frying at different temperatures. There was a 94% decrease in acrylamide content when potatoes were fried to the same final moisture content (1.5% ± 0.3% w.b.) under vacuum compared to those fried under atmospheric conditions. Acrylamide accumulation under vacuum frying was modeled using first‐order kinetics (during traditional frying, the logistic kinetic model was used). The behavior of the kinetics of acrylamide content in potato chips fried under the two processes was different mainly because of the different temperatures used. During traditional frying, higher temperatures are used (150 to 180C) and acrylamide after some time is produced but starts degrading, producing a constant level of acrylamide content at longer times. During vacuum frying (10 Torr), acrylamide increased exponentially (but at lower levels) for all frying times.
Measurement of acoustic impedance and reflectance in the human ear canal
Authors: Voss Susan E. , Allen Jont B. 
Published: October 2005

The pressure reflectance R(ω) is the transfer function which may be defined for a linear one-port network by the ratio of the reflected complex pressure divided by the incident complex pressure. The reflectance is a function that is closely related to the impedance of the 1-port. The energy reflectance ℛ(ω) is defined as ‖R‖2. It represents the ratio of reflected to incident energy. In the human ear canal the energy reflectance is important because it is a measure of the inefficiency of the middle ear and cochlea, and because of the insight provided by its simple frequency domain interpretation. One may characterize the ear canal impedance by use of the pressure reflectance and its magnitude, sidestepping the difficult problems of (a) the unknown canal length from the measurement point to the eardrum, (b) the complicated geometry of the drum, and (c) the cross-sectional area changes in the canal as a function of distance. Reported here are acoustic impedance measurements, looking into the ear canal, measured on ten young adults with normal hearing (ages 18–24).
The measurement point in the canal was approximately 0.85 cm from the entrance of the canal. From these measurements, the pressure reflectance in the canal is computed and impedance and reflectance measurements from 0.1 to 15.0 kHz are compared among ears. The average reflectance and the standard deviation of the reflectance for the ten subjects have been determined. The impedance and reflectance of two common ear simulators, the Brüel & Kjaer 4157 and the Industrial Research Products DB–100 (Zwislocki) coupler are also measured and compared to the average human measurements. All measurements are made using controls that assure a uniform accuracy in the acoustic calibration across subjects. This is done by the use of two standard acoustic resistors whose impedances are known. From the experimental results, it is concluded that there is significant subject variability in the magnitude of the reflectance for the ten ear canals. This variability is believed to be due to cochlear and middle ear impedance differences. An attempt was made at modeling the reflectance but, as discussed in the paper, several problems presently stand in the way of these models. Such models would be useful for acoustic virtual-reality systems and for active noise control earphones.
Answer to criticism of my treatment of nonscattering of sound by sound
Authors: Westervelt Peter J. 
Published: October 2005

Following a suggestion by Professor M. Korman, the transient solution of an undamped oscillator as a simple analogy to ρs=−Ẇ being the solution of ⧠2(ρs+Ẇ)=0 has been used. Berntson etal. [J. Acoust. Soc. Am. 86, 1968 (1989)] criticized the solution stating that solutions to the homogeneous equation need to be appended in order to satisfy boundary conditions. This is not the case here. Say the forcing function F(t) for the oscillator mẍ+kx=F(t) is derivable from F(t)=mG̈(t)+kG(t) then x(t)=G(t). As an example, if the arbitrary transient starts at t0 and ends T later then G(t)=[U(t−t0)−U(t−t0−T)]H(t) and F(t)= m[δ̈(t−t0)−δ̈(t−t0−T)]H(t)+2m[δ̇(t−t0) −δ̇(t−t0−T)]Ḣ(t)+[U(t−t0)−U(t−t0−T)] [mḦ(t)+kH(t)]. Let us obtain the solution for the case H(t)=b, a constant. In this case F(t)=f1(t)+f2(t), where f1(t)=bk[U(t−t0)−U(t−t0−T)] and f2(t)=bm[δ̈(t−t0) −δ̈(t−t0−T)]. f1(t) is a square wave and the response to it is x1(t)=bU(t−t0)(1−cos ω0t) for t0&lt;t&lt;t0+T and x1(t)= bU(t−t0−T)[cos ω0(t−t0−T)−cos ω0(t−t0)] for t≳t0+T. In f2 the δ̈ generate displacement boundary conditions and x2(t)=bU(t−t0)cos ω0(t−t0) for t0&lt;t&lt;t0+T while x2(t)=−bU(t−t0−T) ×[cos ω0(t−t0−T)] at t≳t0+T.
The complete solution x=x1+x2 is x(t)=0 for t&lt;t0, x(t)=bU(t−t0) for t0&lt;t&lt;t0+T and x(t)=0 for t≳t0+T confirming the fact that x(t)=G(t). This one-dimensional analogy confirms the fact that there is no response outside the interaction region t0&lt;t&lt;t0+T.
Genetic and Epigenetic Modeling of the Origins of Multidrug-Resistant Cells in a Human Sarcoma Cell Line
Authors: Chen Kevin G. , Wang Yan C. , Schaner Marci E. , Francisco Brian , Durán George E. , Juric Dejan , Huff Lyn M. , Padilla-Nash Hesed , Ried Thomas , Fojo Tito , Sikic Branimir I. 
Published: October 2005

Abstract
The origin of drug-resistant cells in human cancers has been a fundamental problem of cancer pharmacology. Two major contrasting hypotheses (genetics versus epigenetics) have been proposed to elucidate the mechanisms of acquired drug resistance. In this study, we answer these fundamental questions through investigation of the genetic and epigenetic pathways that control the origin of ABCB1 (MDR1) gene activation with acquired multidrug resistance in drug-sensitive human sarcoma (MES-SA cells). The genetic and epigenetic bases of this selected activation involve the initiation of transcription at a site 112 kb upstream of the ABCB1 proximal promoter (P1) in the drug-resistant cells. This activation was associated with a chromatin-remodeling process characterized by an increase in acetylated histone H3 within a 968-bp region 5′ of the ABCB1 upstream promoter. These alterations provide both genetic and epigenetic susceptibility for ABCB1 expression in drug-resistant cells. Complete activation of the ABCB1 gene through the coding region was proposed by interactions of selected trans-alterations or epigenetic changes on the ABCB1 proximal promoter, which occurred during initial drug exposure. Thus, our data provide evidence for a major genomic alteration that changes the chromatin structure of the ABCB1 upstream promoter via acetylation of histone H3 initiating ABCB1 activation, further elucidating the genetic and epigenetic bases that determine chemotherapeutic response in drug-resistant derivatives of MES-SA cells.
A Gene Expression Signature of Genetic Instability in Colon Cancer
Authors: Giacomini Craig P. , Leung Suet Yi , Chen Xin , Yuen Siu Tsan , Kim Young H. , Bair Eric , Pollack Jonathan R. 
Published: October 2005

Abstract
Genetic instability plays a central role in the development and progression of human cancer. Two major classes of genetic instability, microsatellite instability (MSI) and chromosome instability (microsatellite stable; MSS), are best understood in the context of colon cancer, where MSI tumors represent ∼15% of cases, and compared with MSS tumors, more often arise in the proximal colon and display favorable clinical outcome. To further explore molecular differences, we profiled gene expression in a set of 18 colon cancer cell lines using cDNA microarrays representing ∼21,000 different genes. Supervised analysis identified a robust expression signature distinguishing MSI and MSS samples. As few as eight genes predicted with high accuracy the underlying genetic instability in the original and in three independent sample sets, comprising 13 colon cancer cell lines, 61 colorectal tumors, and 87 gastric tumors. Notably, the MSI signature was retained despite genetically correcting the underlying instability, suggesting the signature reflects a legacy of the tumor having arisen from MSI, rather than sensing the ongoing state of MSI. Our findings support a model in which MSI and MSS preferentially target different genes and pathways in cancer. Further, among the MSI signature genes, our findings implicate a role of elevated metallothionein expression in the clinical behavior of MSI cancers.