bluuebunny/crossref_metadata_2025 huggingface dataset:
Fatal Actinobacillosis in a Dairy Buffalo
Authors: Muhammad G. , Saqib M. , Athar M.
Published: January 2007

The present report describes a case of fatal actinobacillosis in a dairy buffalo (Bubalus bubalis). Clinical signs included a large multilobular, firm abscess located caudo-ventral to the right ear base, submandiblar and prescapular lymphadenopathy, fever and dyspnoea. Haemogram revealed an accelerated erythrocyte sedimentation rate and erythropenia. Provisional diagnosis of actinobacillosis was confirmed by the demonstration of a Gram-negative pleomorphic organism in pus, microscopic examination of a compression preparation of a sulphur granule as well as growth of the organism on blood agar. Intraperitoneal inoculation of pus in guinea pigs was fatal at around 48 hours post-injection. The LD50 of the Actinobacillus lignieresii isolate in mice was 104 colony forming unit per milliliter of Hank's balanced salt solution. The animal died 12 hours after the initiation of surgical drainage of the abscess and administration of iodide, antibiotics and steroids. Necropsy findings included interlobular pneumonia, pulmonary abscessation and mediastinal lympadenopathy that were ascribed to metastatic spread of the organisms to the lungs which probably led to the death of the animal. This case report appears to be the first documentation of fatal actinobacillosis in the dairy buffalo.
Quality Assessment Of Clinical Trials
Authors: Moher David
Published: January 2007

Clinical trialists share several similarities with airline pilots. Many of them are investigators (and principal investigators) of large multi‐center randomized controlled trials (RCTs). It is not uncommon for these studies to cost millions of dollars to complete, and they are typically the end stage of a long development process that can easily cost in excess of $100 million dollars. Clinical trialists have often completed advanced training, such as clinical epidemiology, and very definitely have the safety and welfare of trial participants uppermost in their minds. What seems to be missing from the trialist's arsenal is standardization to the process of conducting such studies. More recently, some consensus has developed on how RCTs should be reported, although only a very small percent (2.5%) of the approximately 20,000 health care journals have bought into such reporting standards.
Association of acquired von Willebrand syndrome with AL amyloidosis
Authors: Kos Cynthia A. , Ward Jennifer E. , Malek Karim , Sanchorawala Vaishali , Wright Daniel G. , O'Hara Carl , Connors Lawreen , Skinner Martha , Seldin David C.
Published: January 2007

Acquired loss of functional von Willebrand factor (VWF) has been termed the acquired von Willebrand syndrome (AVWS). AVWS is a rare adult‐onset bleeding diathesis that is clinically similar to congenital von Willebrand disease (VWD), and occurs with a variety of autoimmune, lymphoproliferative, or myeloproliferative disorders. We have identified four patients with AVWS in association with immunoglobulin light chain (AL) amyloidosis. These patients, lacking any pre‐existing or family history of abnormal bleeding, developed cutaneous, mucosal, or gastrointestinal bleeding in the course of their disease without deficiency of clotting factor X or other factors; the activated partial thromboplastin time (aPTT) was prolonged in three out of the four cases. Despite normal VWF antigen levels, VWF ristocetin cofactor activity (VWF:RCo) was low. Electrophoresis patterns of high molecular weight (HMW) VWF multimers were abnormal in two of the four cases. Two of the patients were treated with high‐dose intravenous melphalan followed by autologous stem cell transplantation (HDM/SCT) and achieved hematologic remission. In these two patients, the bleeding diathesis improved and the coagulation parameters normalized, confirming a causal relationship between the plasma cell dyscrasia and the AVWS. AVWS should be considered in AL amyloidosis patients with hemorrhagic diatheses and normal clotting factor levels. Am. J. Hematol., 2007. © 2007 Wiley‐Liss, Inc.
Non-patient factors related to rates of ruptured appendicitis
Authors: Sicard N , Tousignant P , Pineault R , Dubé S
Published: January 2007

Background

Adult rates of ruptured appendicitis vary from 13·2 to 41·9 per cent in urban hospitals, despite controlling for individual factors. This suggests an effect of hospital organization. Surgeons report that appendicectomies may be delayed because of lack of access to operating rooms.

Methods

Combining interviews with hospital personnel and information from medical records for 1998–1999, a cross-sectional study using logistic regression, taking hospital clustering of patients into account, was conducted on 861 patients from 12 hospitals. Hospitals were grouped into organizational models. The diagnostic information was recoded to ensure interhospital validity.

Results

Hospitals with high activity and volumes of patients, but without an operating room designated for urgent surgery, were associated with a significantly higher risk of peritonitis (P < 0·050). Time to surgery was very long in all hospitals, particularly time after departure from the emergency department and for elderly patients.

Conclusion

Organizational characteristics, in unfavourable combinations, influence the course of time-dependent diseases such as appendicitis. Difficulties in gaining access to operating rooms, even for urgent operations, have emerged. Delays in treatment must be addressed when planning healthcare reforms.
A protocol is not enough to implement an enhanced recovery programme for colorectal resection
Authors: Maessen J , Dejong C H C , Hausel J , Nygren J , Lassen K , Andersen J , Kessels A G H , Revhaug A , Kehlet H , Ljungqvist O , Fearon K C H , von Meyenfeldt M F
Published: January 2007

Background

Single-centre studies have suggested that enhanced recovery can be achieved with multimodal perioperative care protocols. This international observational study evaluated the implementation of an enhanced recovery programme in five European centres and examined the determinants affecting recovery and length of hospital stay.

Methods

Four hundred and twenty-five consecutive patients undergoing elective open colorectal resection above the peritoneal reflection between January 2001 and January 2004 were enrolled in a protocol that defined multiple perioperative care elements. One centre had been developing multimodal perioperative care for 10 years, whereas the other four had previously undertaken traditional care.

Results

The case mix was similar between centres. Protocol compliance before and during the surgical procedure was high, but it was low in the immediate postoperative phase. Patients fulfilled predetermined recovery criteria a median of 3 days after operation but were actually discharged a median of 5 days after surgery. Delay in discharge and the development of major complications prolonged length of stay. Previous experience with fast-track surgery was associated with a shorter hospital stay.

Conclusion

Functional recovery in 3 days after colorectal resection could be achieved in daily practice. A protocol is not enough to enable discharge of patients on the day of functional recovery; more experience and better organization of care may be required.
MicroRNAs and cancer
Authors: Wijnhoven B P L , Michael M Z , Watson D I
Published: January 2007

Background

MicroRNAs (miRNAs) are small sequences of RNA, 21 to 22 nucleotides long, that have been discovered recently. They are produced from areas of the human genome that were previously thought to have no function. These sequences now appear to be important in the regulation of many fundamental processes. Evidence has recently emerged that deregulated miRNA activity is associated with human cancers.

Methods

The English literature was searched using PubMed for publications relevant to miRNAs and cancer. Relevant references from identified publications were also sourced. These publications were reviewed to identify existing evidence for the role of miRNAs in cancer.

Results

miRNAs inhibit the translation of mRNA from many target genes involved in cancer development. This leads to changes in the levels of protein encoded by these target genes and drives the development of cancer. The genes that produce miRNAs are frequently located in regions of the genome that are either lost, or amplified, in cancer cells.

Conclusion

Determination of the miRNA expression profile in cancer tissues should lead to a better understanding of the genetic pathways involved in tumour development.
Alkyl Abstraction from a Trialkylyttrium Complex [YR3(thf)2] (R = CH2SiMe3) Using a Group‐13 Element Lewis Acid ER3 (E = B, Al, Ga, In) – Structural Characterisation of the Ion Pair [YR2(thf)4]+[GaR4]– and of ER3 (E = B, Al, Ga)
Authors: Kramer Mathias U. , Robert Dominique , Nakajima Yumiko , Englert Ulli , Spaniol Thomas P. , Okuda Jun
Published: January 2007

The alkyl abstraction reaction of [YR3(thf)2] (R = CH2SiMe3) with group‐13 trialkyl complexes [(ER3)n] (E = B, Ga, In: n = 1; E = Al: n = 2) forming cationic yttrium species [YR2(thf)4]+[ER4]– (E = Al, Ga, In) shows a strong dependence on the Lewis acidic metal centre E and on the solvent basicity. Whilst the boron compound does not react with [YR3(thf)2], the heavier homologues form the ion pairs [YR2(thf)4]+[ER4]– (E = Al, Ga, In) which dissociate to give the neutral compounds in apolar solvents such as benzene. Single‐crystal structure analysis of the gallate [YR2(thf)4]+[GaR4]– shows the presence of an ion pair with cis‐arranged alkyl ligands in the octahedral yttrium cation and a tetrahedral gallate anion. Group‐13 trialkyl compounds [(ER3)n] (E = B, Al, Ga), all liquids at room temperature, and [Li(12‐crown‐4)2]+[AlR4]– were characterised by single‐crystal X‐ray diffraction and NMR spectroscopy. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Capillary electrophoretic method for nucleotide analysis in cells: Application on inherited metabolic disorders
Authors: Friedecký David , Tomková Jana , Maier Vitězslav , Janošt'áková Anna , Procházka Martin , Adam Tomáš
Published: January 2007

Purine and pyrimidine nucleotides influence many metabolic pathways and their analogs have been widely used in medicine. A capillary electrophoretic method was developed for measuring intracellular nucleotides. The final BGE consisted of 40 mM citric acid with addition of 0.8 mM CTAB titrated by γ‐aminobutyric acid to pH 4.4. The electrophoretic separations were carried out in an uncoated silica capillary (id/od – 75/375 µm; effective/total length – 90/97 cm). The method allows a complete separation of 21 nucleotides and deoxynucleotides within 15 min with separation efficiencies up to 400 000 theoretical plates per meter. Due to the use of an acidic separation medium, the method offers a high selectivity toward the studied analytes versus possible interferences from matrices. Sample preparation was optimized in order to shorten work‐time and prevent analyte degradation. The method was applied for analyzing nucleotides in human erythrocytes and Chinese hamster ovary cells. Diagnostic potential for inherited metabolic disorders of nucleotide metabolism is presented.
Systemic LPS causes chronic neuroinflammation and progressive neurodegeneration
Authors: Qin Liya , Wu Xuefei , Block Michelle L. , Liu Yuxin , Breese George R. , Hong Jau‐Shyong , Knapp Darin J. , Crews Fulton T.
Published: January 2007

Inflammation is implicated in the progressive nature of neurodegenerative diseases, such as Parkinson's disease, but the mechanisms are poorly understood. A single systemic lipopolysaccharide (LPS, 5 mg/kg, i.p.) or tumor necrosis factor alpha (TNFα, 0.25 mg/kg, i.p.) injection was administered in adult wild‐type mice and in mice lacking TNFα receptors (TNF R1/R2−/−) to discern the mechanisms of inflammation transfer from the periphery to the brain and the neurodegenerative consequences. Systemic LPS administration resulted in rapid brain TNFα increase that remained elevated for 10 months, while peripheral TNFα (serum and liver) had subsided by 9 h (serum) and 1 week (liver). Systemic TNFα and LPS administration activated microglia and increased expression of brain pro‐inflammatory factors (i.e., TNFα, MCP‐1, IL‐1β, and NF‐κB p65) in wild‐type mice, but not in TNF R1/R2−/− mice. Further, LPS reduced the number of tyrosine hydroxylase‐immunoreactive neurons in the substantia nigra (SN) by 23% at 7‐months post‐treatment, which progressed to 47% at 10 months. Together, these data demonstrate that through TNFα, peripheral inflammation in adult animals can: (1) activate brain microglia to produce chronically elevated pro‐inflammatory factors; (2) induce delayed and progressive loss of DA neurons in the SN. These findings provide valuable insight into the potential pathogenesis and self‐propelling nature of Parkinson's disease. © 2007 Wiley‐Liss, Inc.
Exploring the binding site of the human muscarinic M3 receptor: Homology modeling and docking study
Authors: Ostopovici Liliana , Mracec Maria , Mracec Mircea , Borota Ana
Published: January 2007

The human muscarinic M3 receptor (hM3) and its interactions with selective agonists and antagonists were investigated by means of combined homology and docking approach. Also, two pharmacophoric models for the hM3 agonist and antagonist binding sites were proposed. The three‐dimensional (3D) structure of hM3 receptor was modeled based on the high‐resolution X‐ray structure of bovine rhodopsin from the Protein Data Bank (PDB). To validate the reliability of the model obtained, the main chain torsion angles phi (Ψ) and psi (Φ) were examined in a Ramachandran plot, and all omega angles were measured for peptidic bond planarity. The characteristics of the active site, the position, and the orientation of ligands in situ, as well as the binding modes of the representative agonists and antagonists, were analyzed by applying a molecular docking technique using the AutoDock 3.0.5 program. Specific interactions responsible for recognition of the hM3 receptor, like ionic bond formed between protonated amine of the ligands and the Asp3.6 side chain were identified. Structure–reactivity relationships have been explained by analyzing the 3D structure of the hM3 model and the ligand conformations resulted from molecular docking simulation. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
FAB MS/MS for phosphatidylinostitol,‐glycerol,‐ethanolamine and other complex phospholipids
Authors: Jensen Nancy J. , Tomer Kenneth B. , Gross Michael L.
Published: January 2007

Fast atom bombardment (FAB) of phosphatidylinositol, phosphatidylethanolamine, cardiolipin, phosphatidic acid and phosphatidylglycerol produces a limited number of very informative negative ions. Especially significant is the formation of (M−H)− ions and ions that correspond to the carboxylate portions of these molecules. FAB desorption in combination with collisional activation allows for characterization of fragmentation and determination of structural features. Collisional activation of the carboxylate anion from complex lipids is especially informative. Structural characterization of the fatty acids can be achieved as the released saturated carboxylate anions undergo highly specific charge remote fragmentations that are entirely consistent with the chemistry of carboxylate anions desorbed from free fatty acids. This permits both identification of the modification and assignment of its location on the acid chain. FAB‐desorbed alkyl acetyl glycerophosphocholines (platelet‐activating factor) do not produce (M−H)− ions. However, significant high mass ions are formed, and these can be collisionally activated for structural characterization.
Effect of dietary fats on the incidence of 7,12‐dimethylbenz(a)‐anthracene‐induced tumors in rats
Authors: Hopkins G. J. , West C. E. , Hard G. C.
Published: January 2007

Female rats have been fed high fat diets containing either polyunsaturated or saturated fat. After being fed either of the diets for 4 weeks, some of the animals received an intragastric dose of 7,12‐dimethylbenz(a)anthracene (DMBA). At this point, the diets of half of the animals were interchanged so that animals previously fed the polyunsaturated fat diet were fed the saturated fat diet and vice versa. The cumulative incidence of tumor‐bearing rats among DMBA‐dosed rats was greater when the polyunsaturated fat diet was fed. The mean induction time of tumors decreased and the proportion of tumor‐bearing rats which developed malignant tumors increased when the polyunsaturated fat diet was fed. This promotional effect of the polyunsaturated fat diet was exerted only when the diet was fed after DMBA administration.
Platelet‐activating factor regulates phospholipid metabolism in human neutrophils
Authors: Tou Jen‐sie
Published: January 2007

This study extended the earlier finding that platelet‐activating factor (1‐O‐alkyl‐2‐acetyl‐sn‐glycero‐3‐phosphocholine) promotes arachidonic acid incorporation into neutrophil phosphatidylinositol (PI) and phosphatidylcholine (PC). In the present study the effect of PAF on fatty acid uptake by human neutrophils and the incorporation of extracellular linoleic acid and palmitic acid into phospholipids were investigated. Incubation of 10−7 M PAF with neutrophils and radiolabeled arachidonic acid or linoleic acid or palmitic acid for 1–10 min resulted in an increased rate of loss of label from the incubation medium. PAF stimulated the incorporation of linoleic acid and palmitic acid most significantly into PI and PC. The magnitude of stimulation was greater in PI than in PC for the incorporation of linoleic acid, and vice versa for the incorporation of palmitic acid. The positional distribution of linoleic acid and palmitic acid in PI and PC and the mass of these phospholipids were not altered in PAF‐stimulated neutrophils. An increased incorporation of all three fatty acids into both diacyl and alkylacyl species of PC was demonstrated after a two minute incubation of cells with PAF. While more radioactivity was recovered in the diacyl species, the magnitude of increase of radioactivity in the alkylacyl species was more pronounced than that in the diacyl species of PC. These results suggest that both increased fatty acid uptake and increased available lysophospholipids may be contributory to the increased phospholipid acylation induced by PAF.
α‐Glycerolphosphate dehydrogenase activity and levels of glyceride‐glycerol precursors in mouse mammary tissues
Authors: Rao G. Ananda , Abraham S.
Published: January 2007

Although α‐glycerolphosphate dehydrogenase activity in slow growing mouse mammary tumors is only 5% of that in normal mammary glands of lactating mice, the cellular concentration of α‐glycerolphosphate in both tissues is similar and is ca. 12 times that of dihydroxyacetone phosphate. Thus a positive correlation between the activity of glycerolphosphate dehydrogenase and the intracellular concentration of glyceride‐glycerol precursors could not be demonstrated.
Development changes in lipid composition of chick sciatic nerve myelin
Authors: Oulton Margaret , Mezei Catherine
Published: January 2007

Myelin isolated from the sciatic nerves of chicks by centrifugation on a discontinuous sucrose gradient was found to undergo marked changes in lipid composition during development from the 18 day embryonic to the adult stage, particularly in the phospholipid and cerebroside content. Significant changes in the content of individual phospholipids were also noted.
Grip Strength and Forearm Circumference in a Healthy Population
Authors: ANAKWE R. E. , HUNTLEY J. S. , MCEACHAN J. E.
Published: January 2007

Two hundred and fifty subjects were recruited. Age, sex, hand preference and anthropometric measurements were recorded for each subject. Grip strength was measured using a Jamar hydraulic dynamometer. Multiple regression analyses were performed. One hundred and seventy two subjects were men and 78 were women. Twenty-six subjects were left hand dominant. Hand grip strength was greatest for the 35 to 44 year old group for both sexes. Grip strength was consistently greater for men than women. Contralateral grip strength predicted maximum grip strength for both sexes. Forearm circumference predicted maximum hand grip strength for men. Although there was a large range of forearm circumferences in the population, there was little difference between sides for each subject (100% less than 2 cm). The demonstrated relationships between: (i) contralateral grip strengths and (ii) grip strength and forearm circumference lead us to suggest that for certain pathologies, a difference in forearm circumference greater than 2 cm may lend credence to a measurement of diminished grip strength.
IN THIS ISSUE
Authors: MORGAN CRAIG
Published: January 2007

This issue contains a review of studies of the effectiveness of compulsory interventions in the community. Other sets of papers report findings from twin studies and population surveys, and six individual papers examine a variety of topics.
Interview with Paul Oliver
Authors: HORN DAVID
Published: January 2007

DH: Perhaps I could begin in the present and ask you how you see the status of the blues today in the black community in the US.

PO: There are a number of black writers who are interested in the arts, but I don't think blues has any significance for the black community as a whole, as gospel still has. Gospel is held together by the religious side, it's a different kind of structure. Rap seems to have taken over, at least as far as the younger generations are concerned.

DH: Do you sense any connection between rap and hip hop and the blues?

PO: There are connections, certainly, but I don't know how significant they are. There are superficial connections – for example the ‘Stackolee’ theme runs through several rap songs – but I'm not sure that is of any depth of significance. But rap songs do provide opportunities for people to express themselves as individuals; otherwise, there isn't a music that does that. As much as anything it's a functional connection, therefore, rather than a stylistic one.

DH: Rap lyrics are more outspoken in many ways than blues lyrics.
A Daughter to ELSI – NILSI: A Northern Ireland Standard of Living Index or Problematising Wealth in the Analysis of Inequality and Material Well-being
Authors: Hillyard Paddy , Patsios Demi , Sevllion Fiona
Published: January 2007

When the measurement of inequality is being considered in Ireland and the UK the poor and socially excluded are routinely the focus of debate. Building on methodology developed in New Zealand this paper outlines the development of a more wide ranging approach through the construction of a Northern Ireland Living Standard Index (NILSI). It then utilises this tool to explore dimensions of inequality in Northern Ireland and present findings on the living standards of different subgroups.
All whistlers are not created equally: Scattering of strahl electrons in the solar wind via particle‐in‐cell simulations
Authors: Saito Shinji , Gary S. Peter
Published: January 2007

Solar wind observations show that suprathermal electrons (70 eV ≲ Energy ≲ 1 keV) of the magnetic‐field‐aligned “strahl” component have broader pitch‐angle distributions than are predicted by adiabatic theories of solar wind expansion. Magnetosonic‐whistler fluctuations propagating toward the Sun at k × Bo = 0 (where Bo is the background magnetic field) have a strong cyclotron resonance with suprathermal electrons propagating in the anti‐Solar direction along Bo. This resonance enables strong pitch‐angle scattering; thus whistlers are a likely source of the observed strahl broadening. Particle‐in‐cell simulations in a magnetized, homogeneous, collisionless plasma of electrons and protons are used to study the response of a strahl‐like electron component to whistler fluctuation spectra. If the whistler anisotropy instability is excited via the initial application of T⊥/T∥ > 1 to the electron core component, the resulting electron scattering leads to strahl pitch‐angle distributions which decrease in width as electron energy increases. In contrast, if a power spectrum of whistler fluctuations proportional to k−3 is initially applied to the simulations, the resulting electron scattering leads to strahl pitch‐angle distributions which increase in width as electron energy increases.
Kinetic diversity in G-protein-coupled receptor signalling
Authors: Katanaev Vladimir L. , Chornomorets Matey
Published: January 2007

The majority of intracellular signalling cascades in higher eukaryotes are initiated by GPCRs (G-protein-coupled receptors). Hundreds of GPCRs signal through a handful of trimeric G-proteins, raising the issue of signal specificity. In the present paper, we illustrate a simple kinetic model of G-protein signalling. This model shows that stable production of significant amounts of free GαGTP (GTP-bound Gα subunit) and βγ is only one of multiple modes of behaviour of the G-protein system upon activation. Other modes, previously uncharacterized, are sustained production of βγ without significant levels of GαGTP and transient production of GαGTP with sustained βγ. The system can flip between different modes upon changes in conditions. This model demonstrates further that the negative feedback of receptor uncoupling or internalization, when combined with a positive feedback within the G-protein cycle, under a broad range of conditions results not in termination of the response but in relaxed oscillations in GPCR signalling. This variety of G-protein responses may serve to encode signal specificity in GPCR signal transduction.
NMR characterization of the pH 4 β-intermediate of the prion protein: the N-terminal half of the protein remains unstructured and retains a high degree of flexibility
Authors: O'Sullivan Denis B. D. , Jones Christopher E. , Abdelraheim Salama R. , Thompsett Andrew R. , Brazier Marcus W. , Toms Harold , Brown David R. , Viles John H.
Published: January 2007

Prion diseases are associated with the misfolding of the PrP (prion protein) from a largely α-helical isoform to a β-sheet-rich oligomer. CD has shown that lowering the pH to 4 under mildly denaturing conditions causes recombinant PrP to convert from an α-helical protein into one that contains a high proportion of β-sheet-like conformation. In the present study, we characterize this soluble pH 4 folding intermediate using NMR. 15N-HSQC (heteronuclear single-quantum correlation) studies with mPrP (mouse PrP)-(23–231) show that a total of 150 dispersed amide signals are resolved in the native form, whereas only 65 amide signals with little chemical shift dispersion are observable in the pH 4 form. Three-dimensional 15N-HSQC-TOCSY and NOESY spectra indicate that the observable residues are all assigned to amino acids in the N-terminus: residues 23–118. 15N transverse relaxation measurements indicate that these N-terminal residues are highly flexible with additional fast motions. These observations are confirmed via the use of truncated mPrP-(112–231), which shows only 16 15N-HSQC amide peaks at pH 4. The loss of signals from the C-terminus can be attributed to line broadening due to an increase in the molecular size of the oligomer or exchange broadening in a molten-globule state.
Interaction of mammalian Hsp22 with lipid membranes
Authors: Chowdary Tirumala Kumar , Raman Bakthisaran , Ramakrishna Tangirala , Rao Ch. Mohan
Published: January 2007

Hsp22/HspB8 is a member of the small heat-shock protein family, whose function is not yet completely understood. Our immunolocalization studies in a human neuroblastoma cell line, SK-N-SH, using confocal microscopy show that a significant fraction of Hsp22 is localized to the plasma membrane. We therefore investigated its interactions with lipid vesicles in vitro. Intrinsic tryptophan fluorescence is quenched in the presence of lipid vesicles derived from either bovine brain lipid extract or purified lipids. Time-resolved fluorescence studies show a decrease in the lifetimes of the tryptophan residues. Both of these results indicate burial of some tryptophan residues of Hsp22 upon interaction with lipid vesicles. Membrane interactions also lead to increase in fluorescence polarization of Hsp22. Gel-filtration chromatography shows that Hsp22 binds stably with lipid vesicles; the extent of binding depends on the nature of the lipid. Hsp22 binds more strongly to vesicles made of lipids containing a phosphatidic acid, phosphatidylinositol or phosphatidylserine headgroup (known to be present in the inner leaflet of plasma membrane) compared with lipid vesicles made of a phosphatidylcholine head-group alone. Far-UV CD spectra reveal conformational changes upon binding to the lipid vesicles or in membrane-mimetic solvent, trifluoroethanol. Thus our fluorescence, CD and gel-filtration studies show that Hsp22 interacts with membrane and this interaction leads to stable binding and conformational changes. The present study therefore clearly demonstrates that Hsp22 exhibits potential membrane interaction that may play an important role in its cellular functions.
Understanding the saturation of proton-driven Weibel instabilities and implications for astrophysics
Authors: Ren Chuang , Blackman Eric G. , Fong Wen-fai
Published: January 2007

The linear growth rate and saturation level of magnetic fields for Weibel instabilities driven by ion temperature anisotropy, defined as α=(T⊥∕T‖)−1 where T⊥ and T‖ are ion temperatures perpendicular and parallel to the wave vector, are derived in the small α limit. It is shown that the ratio of the saturated magnetic energy to the initial ion energy scales as the fourth power of the electron to ion mass ratio, m∕M, for an initially unmagnetized plasma with α≤M∕m. Particle-in-cell simulations confirm the mass scaling and also show that the electron energy gain is of the same order of magnitude as the magnetic field energy. This implies that the Weibel instabilities cannot provide a faster-than-Coulomb collisionless mechanism to equilibrate ion-electron plasmas with ions initially much hotter than electrons, a key component in low-luminosity astrophysical accretion flows. The results here also show that the large α limit formulas used in the study of magnetic field generation in collisionless shocks are only valid if α≥M∕m.
Temperature dependence of terahertz emission from InMnAs
Authors: Zhan Hui , Deibel Jason , Laib Jonathan , Sun Chanjuan , Kono Junichiro , Mittleman Daniel M. , Munekata Hiro
Published: January 2007

We have studied the terahertz radiation emitted by the dilute magnetic semiconductor InMnAs under femtosecond laser illumination, as a function of temperature. We observe a reversal of the polarity of the emitted terahertz field as the temperature is decreased, in both p-type and n-type materials. This effect is not observed in p-InAs. A competition between two oppositely directed currents, the photo-Dember current and the surface-field-induced current, can explain the observed polarity reversal. In contrast to nonmagnetic materials, these two currents are of comparable magnitude because the Mn impurity substantially reduces the carrier mobility in dilute magnetic semiconductors.
Nitrogen-mediated fabrication of transition metal-carbon nanotube hybrid materials
Authors: Yang Seong Ho , Shin Weon Ho , Lee Jung Woo , Kim Hyun Seok , Kang Jeung Ku , Kim Yoon Kee
Published: January 2007

The authors report the simple and easy method to fabricate transition-metal–carbon nanotube hybrid materials through nitrogen mediation. Ni nanoparticles were uniformly dispersed on carbon nanotubes without any pretreatment such as defect activation by strong acids or covalent functionalization processes. A theoretical study of the nitrogen-mediated mechanism using first-principles density functional theory calculations is also presented. The first-principles calculations reveal that pyridinelike nitrogen in carbon nanotubes significantly enhances the binding energy of Ni interacting with carbon nanotubes.
Ferromagnetic semiconductor nanoclusters: Co-doped Cu2O
Authors: Antony Jiji , Qiang You , Faheem Muhammad , Meyer Daniel , McCready David E. , Engelhard Mark H.
Published: January 2007

5% Co-doped cuprous oxide dilute magnetic semiconducting cluster film composed of two different sizes of crystalline nanoclusters, prepared using sputtering-aggregation technique is found to be ferromagnetic at 400K. With the increase in average crystallite size from 4.2to8nm, the coercivity increased. Magnetic field up to 2T is applied and saturation magnetization is achieved at 3kOe field in both cases. Cu2O phase is observed from cluster film deposited on Si wafer when analyzed using x-ray diffraction. Co in Cu2O host reveals a +2 oxidation state via x-ray photoelectron spectroscopy. Positive magnetoresistance from samples exhibits a temperature dependent decrease.
Prokineticin receptor 2 (Prokr2) is essential for the regulation of circadian behavior by the suprachiasmatic nuclei
Authors: Prosser Haydn M. , Bradley Allan , Chesham Johanna E. , Ebling Francis J. P. , Hastings Michael H. , Maywood Elizabeth S.
Published: January 2007

The suprachiasmatic nucleus (SCN), the brain's principal circadian pacemaker, coordinates adaptive daily cycles of behavior and physiology, including the rhythm of sleep and wakefulness. The cellular mechanism sustaining SCN circadian timing is well characterized, but the neurochemical pathways by which SCN neurons coordinate circadian behaviors remain unknown. SCN transplant studies suggest a role for (unidentified) secreted factors, and one potential candidate is the SCN neuropeptide prokineticin 2 (Prok2). Prok2 and its cognate prokineticin receptor 2 (
Prokr2
/
Gpcr73l1
) are widely expressed in both the SCN and its neural targets, and Prok2 is light-regulated. Hence, they may contribute to cellular timing within the SCN, entrainment of the clock, and/or they may mediate circadian output. We show that a targeted null mutation of
Prokr2
disrupts circadian coordination of the activity cycle and thermoregulation. Specifically, mice lacking Prokr2 lost precision in timing the onset of nocturnal locomotor activity; and under both a light/dark cycle and continuous darkness, there was a pronounced temporal redistribution of activity away from early to late circadian night. Moreover, the coherence of circadian behavior was significantly reduced, and nocturnal body temperature was depressed. Entrainment by light is not, however, dependent on Prokr2, and bioluminescence real-time imaging of organotypical SCN slices showed that the mutant SCN is fully competent as a circadian oscillator. We conclude that Prokr2 is not necessary for SCN cellular timekeeping or entrainment, but it is an essential link for coordination of circadian behavior and physiology by the SCN, especially in defining the onset and maintenance of circadian night.
32
P-Postlabeling analysis of DNA adduction in mice by synthetic metabolites of the environmental carcinogen, 7
H
-dibenzo[c,g]carbazole: chromatographic evidence for 3-hydroxy-7
H
-dibenzo[c,g]carbazole being a proximate genotoxicant in liver but not skin
Authors: Schurdak Mark E. , Stong David B. , Warshawsky David , Randerath Kurt
Published: January 2007

The DNA adduction by the environmental carcinogen 7 H -dibenzo[c,g]carbazole (DBC) and chemically synthesized 2-OH, 3-OH, and 4-OH metabolites of DBC was investigated in liver and skin of female CD-1 mice. After topical application to the skin of 37 μmol/kg of DBC or the phenolic metabolites, DNA adducts were measured by a 32 P-post-labeling assay employing carrier-free [γ- 32 P]ATP and ATP-deficient conditions. In liver, DBC produced four major and several minor chromatographically distinct adducts of as yet undetermined chemical structure. The adduct pattern elicited by 3-OH-DBC was qualitatively similar to the DBC adduct pattern, while this was not the case for 2-OH-DBC and 4-OH-DBC. On the basis of co-chromatography experiments under various conditions, the DBC and 3-OH-DBC adducts appeared identical, and the total level of adduction elicited by these compounds in liver was substantial. Similar results were observed when DBC or 3-OH-DBC were administered i.p. As a major difference between the two compounds, one 3-OH-DBC adduct (no. 3) was 4.4- and 7.0-fold lower than the corresponding DBC adduct after i.p. and topical dosing, respectively. In skin, DBC produced two major adduct fractions after topical application, one of which could be chromatographically resolved into three subcomponents. Prominent adducts produced in skin DNA by each of the three metabolites were different from those elicited by DBC, and the level of adduction by the metabolites was significantly lower than that by DBC. Comparison of the skin and liver DBC-DNA adduct patterns after topical application of DBC showed that only one of the four major chromatographically resolved skin adducts corresponded to a major liver adduct (no. 3), and that total adduction in liver was 13.5-fold higher than in skin. These results suggested that (i) activation of DBC to DNA-binding compounds in liver occurs through at least two pathways with 3-OH-DBC being a proximate carcinogen involved in the formation of most of the adducts; (ii) 3-OH-DBC and the other two phenolic metabolites investigated play a minor role, if any, in the formation of DBC-DNA adducts in skin; (iii) metabolic activation of DBC to DNA-binding compounds in liver and skin appears to follow pathways that are different in terms of both the chemical nature and the amount of the adducts formed; and iv) DBC and 3-OH-DBC exhibit a strong preference for liver versus skin DNA.
Prostate-Specific Antigen as Predictor of Prostate Cancer in Black Men and White Men
Authors: Whittemore Alice S. , Lele Chitra , Friedman Gary D. , Stamey Thomas , Vogelman Joseph H. , Orentreich Norman
Published: January 2007

Background

The increasing incidence of prostate cancer creates complex issues in health care management and cost containment. There is a need to evaluate serial measurements of prostate-specific antigen (PSA) as a marker for long-term risk of clinically important prostate cancer (stages B through D).

Purpose

We used a nested case-control design within a retrospective cohort study to evaluate serial PSA concentrations in relation to subsequent prostate cancer diagnoses.

Methods

Participants included 40 black and 96 white men with subsequent diagnoses of prostate cancer and 84 black and 100 white men without such diagnoses (control subjects) in a multiphasic health screening program conducted by the Kaiser Permanente Medical Care Program of Northern California. Serial serum samples were collected 1.5–23 years before prostate cancer diagnosis.

Results

Median serum PSA concentrations, specific for age and subsequent cancer status, were similar in blacks and whites. Concentrations in control subjects increased exponentially with age, with a doubling time of 24.9 years. Concentrations in men with stage A cancer were similar to those in control subjects. Until about 13 years before diagnosis, PSA in men with subsequent cancer stages B through D increased exponentially with age, with a doubling time similar to that of control subjects. Thereafter, the PSA concentrations increased exponentially, with a doubling time of 4.3 years. Rapid increase in PSA concentration started about 1.5 years earlier for men with stage D cancer than for men with stage B or C cancer. The single PSA measurement drawn closest to diagnosis was a more sensitive marker of stages B through D cancer within the next 7 years than was any index of change that also took account of earlier PSA readings.

Conclusions

These data suggest that 1) age-specific PSA concentrations are similar in black men and white men and 2) current PSA concentration, specific for age, outperforms changes in past concentrations in identifying the man who will develop stage B, C, or D cancer within 7 years, albeit at the cost of a slightly higher rate of false-positive results. This interpretation needs confirmation in other data containing many serial PSA measurements within a few years of diagnosis. [J Natl Cancer Inst 87:354-360,1995]
Planned Postradiotherapy Neck Dissection: Rationale and Clinical Outcomes
Authors: Sewall Gregory K. , Palazzi‐Churas Kerrin L. , Richards Gregory M. , Hartig Gregory K. , Harari Paul M.
Published: January 2007

Objectives: In this study, we examine pathology results and clinical outcome for patients with locoregionally advanced squamous cell carcinoma of the head and neck (SCCHN) who present with advanced neck disease and undergo planned postradiotherapy neck dissection.

Study Design: Review of all patients with SCCHN treated with primary radiation (or chemoradiation) and postradiotherapy neck dissection at the University of Wisconsin between 1992 to 2005 was performed. One hundred seven neck dissections were identified in 93 patients, 79 unilateral and 14 bilateral. All major treatment and outcome parameters were examined with particular emphasis on the postradiotherapy neck dissection.

Results: Thirty of 107 neck dissection specimens (28%) showed evidence of residual carcinoma on pathologic review. The mean number of lymph nodes identified at neck dissection for the entire cohort was 21 per specimen (range, 1–60) with 1.3 nodes per positive neck dissection demonstrating residual carcinoma. No correlation was found between the type of neck dissection performed and the presence of residual nodal disease. Eighty‐two evaluated patients (93%) remain free of regional disease recurrence, whereas six patients have subsequently manifested neck recurrence. Four of the six patients who developed regional recurrence showed residual carcinoma in their neck dissection specimen. Five of these patients underwent comprehensive neck dissection (levels I–V); one underwent selective neck dissection (<levels I–V).

Conclusion: Approximately one‐fourth of the patients in this series showed pathologic evidence of residual carcinoma in the neck at the time of postradiotherapy neck dissection. The majority of these cases showed microscopic residual carcinoma in a single lymph node. Although in the early postradiotherapy setting, we cannot accurately predict the viability and growth potential of microscopic residual carcinoma in lymph nodes, these findings, combined with the modest overall morbidity of selective neck dissection, suggest that planned postradiotherapy neck dissection should be strongly considered for patients presenting with advanced neck disease. This remains a prevailing clinical practice at our institution.
Using a Virtual Reality Temporal Bone Simulator to Assess Otolaryngology Trainees
Authors: Zirkle Molly , Roberson David W. , Leuwer Rudolf , Dubrowski Adam
Published: January 2007

Objective: The objective of this study is to determine the feasibility of computerized evaluation of resident performance using hand motion analysis on a virtual reality temporal bone (VR TB) simulator. We hypothesized that both computerized analysis and expert ratings would discriminate the performance of novices from experienced trainees. We also hypothesized that performance on the virtual reality temporal bone simulator (VR TB) would differentiate based on previous drilling experience.

Study Design: The authors conducted a randomized, blind assessment study.

Methods: Nineteen volunteers from the Otolaryngology–Head and Neck Surgery training program at the University of Toronto drilled both a cadaveric TB and a simulated VR TB. Expert reviewers were asked to assess operative readiness of the trainee based on a blind video review of their performance. Computerized hand motion analysis of each participant's performance was conducted.

Results: Expert raters were able to discriminate novices from experienced trainees (P < .05) on cadaveric temporal bones, and there was a trend toward discrimination on VR TB performance. Hand motion analysis showed that experienced trainees had better movement economy than novices (P < .05) on the VR TB.

Conclusion: Performance, as measured by hand motion analysis on the VR TB simulator, reflects trainees' previous drilling experience. This study suggests that otolaryngology trainees could accomplish initial temporal bone training on a VR TB simulator, which can provide feedback to the trainee, and may reduce the need for constant faculty supervision and evaluation.
Wireless Video Capsule in Pediatric Patients With Functional Abdominal Pain
Authors: Shamir R , Hino B , Hartman C , Berkowitz D , Eshach‐Adiv O , Eliakim R
Published: January 2007

Objectives:

Upper endoscopy (esophagogastroduodenoscopy [EGD]) has a limited role, if any, in the evaluation of functional abdominal pain (FAP). Nevertheless, children with intractable FAP are occasionally referred to EGD to rule out intestinal pathology. We evaluated the role of wireless video capsule endoscopy (VCE) in children referred for EGD with a diagnosis of FAP.

Patients and Methods:

Ten children older than 10 years of age were prospectively enrolled. Children were first studied with the PillCam SB (VCE; Given Imaging, Yokneam, Israel) followed by standard EGD within 2 weeks. After the completion of the study, a questionnaire of tolerance and content regarding the 2 procedures was completed by the patients.

Results:

Physical examinations and laboratory tests were within normal limits in all of the patients. Patients swallowed the endoscopic capsules without difficulty. There were no complications. VCE identified gastritis in 4 patients (confirmed by biopsies), whereas EGD detected erosive gastritis in only 1 of the 4 children. EGD detected no duodenal abnormalities. VCE detected Crohn disease in the small intestine and cecum in 1 patient. VCE was ranked by 8 patients as convenient and as a preferable procedure compared with EGD.

Conclusion:

The results of this small cohort suggest that in children with FAP, VCE is more sensitive than EGD for detection of macroscopic gastric and small bowel pathologies.
The clinical utility of ADAMTS13 activity, antigen and autoantibody assays in thrombotic thrombocytopenic purpura
Authors: Starke Richard , Machin Samuel , Scully Marie , Purdy Gordon , Mackie Ian
Published: January 2007

Thrombotic thrombocytopenic purpura (TTP) has been linked to a severe deficiency in ADAMTS13 (a disintegrin and metalloprotease with thrombospondin type 1 motif, member 13) activity. Since the identification of ADAMTS13, and its target cleavage sequence in von Willebrand factor (VWF), several novel ADAMTS13 activity, antigen and autoantibody assays have been developed. Our aim was to evaluate the potential use of these novel assays. ADAMTS13 activity and inhibitors were measured by overnight incubation of patient plasma with pure VWF followed by multimer or collagen binding analysis. ADAMTS13 activity (Rapid peptide assay), antigen and immunoglobulin G anti‐ADAMTS13 were measured by enzyme‐linked immunosorbent assay. 118 samples from seven TTP patients (six adult idiopathic, one congenital) were studied longitudinally during episodes of TTP, their treatment and prophylaxis. ADAMTS13 antigen levels varied considerably between patients and sample times, but in new cases of acute TTP, rapid assays of ADAMTS13 antigen, on serial samples, maybe helpful in confirming the diagnosis. The rapid peptide ADAMTS13 activity assay showed good concordance of results with the older activity assay methods. The change in ADAMTS13 activity mirrored the autoantibody level and in 5/6 acquired TTP cases, a fall in antibody appeared to predict a rise in ADAMTS13 activity, potentially allowing modification of patient management based on autoantibody levels.