bluuebunny/crossref_metadata_2025 huggingface dataset:
Computer matching of oligonucleotide patterns on electrophoretic gels: an application to the epidemiology of cytomegalovirus
Authors: Ades A. E. , Garrett A. J. , Cowell J. , Chin K. S. , Peckham C. S.
Published: October 2009

A computer program was written to analyse oligonucleotide patterns displayed by gel electrophoresis following restriction endonuclease digestion of human cytomegaloviral DNA, and was applied to an epidemiological study of the transmission of infection in a hospital special care baby unit, with regard to infant-to-infant and mother-to-infant transmission.

The program calculates the molecular weight of oligonucleotides from their mobilities, using a cubic spline curve based on the mobilities of oligonucleotides from the AD169 strain. A matching algorithm then calculates the number of unmatched fragments for each pair of viral isolates. This was used as a similarity measure which successfully distinguished mother and infant isolate pairs from epidemiologically unrelated pairs.

The program is not intended to provide fully automatic matching, but could be recommended as a screening device to pick out pairs of strains which are sufficiently similar to suggest a common source of infection, and which may warrant closer comparison. Other applications are discussed, and the possible use of densitometers to automate data entry is considered.
Antibody responses of swine to type A influenza viruses during the past ten years in Japan
Authors: Goto H. , Ogawa Y. , Hirano T. , Miwa Y. , Piao F. Z. , Takai M. , Noro S. , Sakurada N.
Published: October 2009

A total of 6346 swine sera collected at an abattoir in the city of Obihiro, Hokkaido during the years 1978–87 were tested for the presence of antibodies to swine and human influenza viruses. A high incidence of antibody to A/New Jersey/8/76 (swine type H1N1) virus was observed throughout the 10 years except for the occasional month and a single long period of 15 months. Antibodies to human H3N2 virus in swine appeared to be related to the epidemics of human influenza which occurred in the study area during the years 1980–3, but unrelated to the epidemics during the years 1984–7. A large number of swine were found to be antibody positive to a human H1N1 virus during the period April to June 1964, and a smaller number, during the period November 1986 to June 1987. Both were in relation to human influenza epidemics. However, there were long periods where human H1N1 antibodies in swine could not be found.

The first occurrence of swine influenza in Japan was recognized in 1977, when it was presumed that the disease was introduced via imported swine (Shibataelal.1978). Further outbreaks of swine influenza and a high prevalence of antibody to the virus in Japanese swine populations have been reported by several workers (Yamane, Sukeno & Ishida, 1978; Sugimuraelal.1981; Ogawaelal.1983). An outbreak of influenza virus infection due to an H3N2 strain was previously seen in a herd of swine in Osaka, Japan (Sugimuraetal.1975). Later the co-existence of swine (H1N1) and human (H3N2) influenza viruses was confirmed by serological and virological studies on Japanese swine populations (Ontaet al.1978; Sugimuraet al.1980; Arikawaet al.1982). In a previous report (Miwaet al.1986), we suggested that the swine became infected with a human H1N1 virus as piglets during an epidemic of influenza which occurred in the human population at the same time. The present study was undertaken to evaluate the changes in the prevalence of antibodies against swine and human influenza viruses in Japanese swine during the past 10 years.
Epidemic cholera in Mali: high mortality and multiple routes of transmission in a famine area
Authors: Tauxe Robert V. , Holmberg Scott D. , Dodin Andre , Wells Joy V. , Blake Paul A.
Published: October 2009

During the 1984 cholera epidemic in Mali, 1793 cases and 406 deaths were reported, a death-to-case ratio of 23%. In four affected villages, the mean clinical attack rate was 17·5 and 29% of affected persons died. In 66% of cases the illness began more than 48 h after the village outbreak began, when supplies from outside the village were potentially available. Deaths occurred because patients failed to seek care or received only limited rehydration therapy when they did. Case-control studies identified two routes of transmission: drinking water from one well in a village outside the drought area, and eating left-over millet gruel in a droughtaffected village. Drought-related scarcity of curdled milk may permit millet gruel to be a vehicle for cholera. Cholera mortality in the Sahel could be greatly reduced by rapid intervention in affected villages, wide distribution of effective rehydration materials, and educating the population to seek treatment quickly.
The isolation of fusobacteria from tropical ulcers
Authors: Adriaans B. , Drasar B. S.
Published: October 2009

Tropical ulcer is a disease found most commonly in the tropics, although the disease is not confined to those areas. Young children are affected most frequently and the disease is thought to be a polymicrobial infection with fusobacteria, aerobic microorganisms and spirochaetes each playing a role. The fusobacteria have been reported on smears but have not been cultured thus far. We report the isolation and culture of these organisms from 46 ulcers and have also demonstrated the same organisms in skin biopsies from these lesions.
Antenatal survey for the seroprevalence of HTLV-1 infections in the West Midlands, England
Authors: Nightingale S. , Orton D. , Ratcliffe D. , Skidmore S. , Tosswill J. , Desselberger U.
Published: October 2009

The sera of 3522 women who attended an antenatal clinic in Birmingham. England were tested anonymously for antibodies against HTLV-1. Samples from 5 women (0·14%) were positive, one serum showed indeterminate reactivity. Two of the women (0·06%) were born in the West Indies (of Afro-Caribbean ethnic origin), one (0·03%) in Africa (of African ethnic origin), and three (0·09%) were white Caucasian women born in the UK. Thus, HTLV-1 infection in pregnant women in the UK, though comparatively rare, is not negligible. As transmission of HTLV-1 to the newborn via breast milk has been observed and as seropositive mothers can be advised to refrain from breastfeeding or to treat their milk, the question of routine screening for HTLV-1 infection during antenatal care is discussed.
A nucleotide sequence comparison of coxsackievirus B4 isolates from aquatic samples and clinical specimens
Authors: Hughes M. S. , Hoey E. M. , Coyle P. V.
Published: October 2009

Ten coxsackievirus B4 (CVB4) strains isolated from clinical and environmental sources in Northern Ireland in 1985–7, were compared at the nucleotide sequence level. Dideoxynucleotide sequencing of a polymerase chain reaction (PCR) amplified fragment, spanning the VP1/P2A genomic region, classified the isolates into two distinct groups or genotypes as defined by Rico-Hesse and colleagues for poliovirus type 1. Isolates within each group shared approximately 99% sequence identity at the nucleotide level whereas ≤86% sequence identity was shared between groups. One isolate derived from a clinical specimen in 1987 was grouped with six CVB4 isolates recovered from the aquatic environment in 1986–7. The second group comprised CVB4 isolates from clinical specimens in 1985–6. Both groups were different at the nucleotide level from the prototype strain isolated in 1950. It was concluded that the method could be used to sub-type CVB4 isolates and would be of value in epidemiological studies of CVB4. Predicted amino acid sequences revealed non-conservation of the tyrosine residue at the VP1/P2A cleavage site but were of little value in distinguishing CVB4 variants.
Clonal diversity ofStreptococcus pyogeneswithin some M-types revealed by multilocus enzyme electrophoresis
Authors: Haase A. M. , Melder A. , Mathews J. D. , Kemp D. J. , Adams M.
Published: October 2009

Twenty-two reference isolates and 30 local isolates of group A Streptococci were classified into 36 electrophoretic types (ET) on the basis of allozyme variation at 27 enzyme loci. Local isolates were characterized by a high frequency of M-non typable strains. M-type and ET were more closely associated in local isolates from an endemically-infected population; nevertheless, amongst the local isolates there were also strains of the same ET type with different M-types. A possible explanation is that genetic exchange between strains may introduce different M-types into strains of defined ET when these are exposed to strong selection in the presence of heavy loads of infection.

In contrast to the reported clustering of strains associated with toxic shock-like syndrome into two closely related ET clones, we found no relationship of ET phenotype to acute poststreptococcal glomerulonephritis or rheumatic fever.
Serodiagnosis of Crimean-Congo haemorrhagic fever
Authors: Burt F. J. , Leman P. A. , Abbott J. C. , Swanepoel R.
Published: October 2009

Several methods for demonstrating antibody to Crimean-Congo haemorrhagic fever virus were compared on serum samples taken from 101 patients during the acute stage of illness and at intervals for up to 59 months thereafter, with emphasis on early detection of the immune response. The deaths of 23 patients on days 5–14 of illness were ascribed to the effects of the disease; two patients died later from other causes. Very few of the patients who died from the acute illness mounted an antibody response detectable by the methods tested. Four patients who died and 18 who recovered were treated with immune plasma collected from recovered patients. Treated patients acquired IgG antibody from the plasma, but it was possible to discern the onset of an endogenous IgM response in those individuals who survived the disease by all of the methods tested. Indirect immunofluorescence (IF) tests detected IgM and/or IgG antibodies at the earliest on day 4 of illness in about 10% of patients who survived the disease, and by day 9 all survivors had antibodies demonstrable by IF. A biotin-streptavidin IF technique offered no advantage over the standard IF test for the early detection of IgG antibody, but demonstrated higher antibody titles and detected IgM antibody earlier in about a quarter of the patients tested. An IgM-capture enzyme-linked immunoassay (ELISA) and an IgG sandwich ELISA demonstrated higher antibody titres than did IF tests, and detected antibody responses at an earlier stage of infection than did IF tests in about one-fifth of patients, but the reverse was true in a similar proportion of instances. A competition ELISA, which detected total antibody activity, produced lower titres than did the IgM and IgG ELISAs, but yielded results which were in close agreement with the findings in IF tests. It was concluded that the IF tests were most convenient for use in making a rapid serodiagnosis of the disease.
Learning, retrieval, and recognition are compromised in aMCI and mild AD: Are distinct episodic memory processes mediated by the same anatomical structures?
Authors: BALTHAZAR MARCIO L. F. , YASUDA CLARISSA L. , CENDES FERNANDO , DAMASCENO BENITO P.
Published: October 2009

Performance of different episodic memory processes in patients with amnestic mild cognitive impairment (aMCI) and mild Alzheimer’s disease (AD) and their anatomical correlates are not completely understood. We evaluated the performance of 48 subjects (17 with aMCI, 15 with mild AD, and 16 controls) on the Rey Auditory Verbal Learning Test (RAVLT). A brain MRI voxel-based morphometry (VBM) analysis was run with the aim of evaluating the correlations between RAVLT and gray matter density. All memory processes were compromised in aMCI and mild AD. Also, the same cerebral structures were involved in all RAVLT stages. Learning and delayed recall were more related to the medial prefrontal cortex and hippocampi, whereas recognition was more related to the thalamic nuclei and caudate nucleus, particularly in the left side. Our findings suggest that these structures may act as a complex functional system and are involved in the acquisition of new information. (JINS, 2010, 16, 205–209.)
Syntactic complexity, discourse status and animacy as determinants of grammatical variation in Modern English
Authors: SEOANE ELENA
Published: October 2009

The aim of this article is to provide an overview of the syntactic, pragmatic and semantic determinants of word-order variation in Modern English, exemplified by the specific case of the use of long passives as order-rearranging devices. Word order in English and in most other SVO languages is affected by a number of factors such as animacy, semantic role, discourse status and syntactic complexity (Sornicola 2006). In this article, which analyses the influence of such factors in the use of long passives, I will try to show that their effects are construction-specific; in particular, that factors which are crucial in determining word order in some constructions – factors such as the animacy of the constituents involved – are entirely overruled by others in the case of Modern English long passives. Corpus data presented here will also serve to address issues pertaining to the nature of the determinants of grammatical variation, such as their independent versus epiphenomenal character, their interactions, and the locus of their effects on word order.
The movement analysis of temporal adverbial clauses
Authors: HAEGEMAN LILIANE
Published: October 2009

In the literature it has been proposed that temporal adverbial clauses can be derived bywh-movement of an operator (e.g.when) to the left periphery (Geis 1970, 1975; Enç 1987: 655; Larson 1987, 1990; Dubinsky & Williams 1995; Declerck 1997; Demirdache & Uribe-Etxebarria 2004: 165–70). After reviewing the arguments that have been proposed in favour of such a movement analysis, the article provides additional empirical evidence in support of the analysis. The data concern so-called Main Clause Phenomena (MCP) or Root phenomena, that is, syntactic phenomena such as argument fronting, Locative Inversion, preposing aroundbe, VP preposing and Negative Inversion, which in English are by and large restricted to main clauses. The unavailability of these MCP in temporal adverbial clauses follows directly from the movement account. The movement analysis will be extended to conditional clauses and factive clauses.
Grammatical person and the variable syntax of Old English personal pronouns
Authors: ALCORN RHONA
Published: October 2009

The variable positioning of bare personal pronouns in Old English prose remains something of a mystery. In the role of prepositional object, for example, these elements are often found in positions where other prepositional object types are rarely attested. This article reports the results of an empirical study of a correlation between the variable placement of these pronouns and their specification for grammatical person. By demonstrating that this correlation defies a number of independent explanations, it is argued that person is an important aspect of the syntax of these constituents. The identification of two further correlations, one involving narrative mode and the other involving the relative positioning of preposition and verb, further demonstrates the value of quantitative methods in historical linguistics.
Impacts of climate change from 2000 to 2050 on wildfire activity and carbonaceous aerosol concentrations in the western United States
Authors: Spracklen D. V. , Mickley L. J. , Logan J. A. , Hudman R. C. , Yevich R. , Flannigan M. D. , Westerling A. L.
Published: October 2009

We investigate the impact of climate change on wildfire activity and carbonaceous aerosol concentrations in the western United States. We regress observed area burned onto observed meteorological fields and fire indices from the Canadian Fire Weather Index system and find that May–October mean temperature and fuel moisture explain 24–57% of the variance in annual area burned in this region. Applying meteorological fields calculated by a general circulation model (GCM) to our regression model, we show that increases in temperature cause annual mean area burned in the western United States to increase by 54% by the 2050s relative to the present day. Changes in area burned are ecosystem dependent, with the forests of the Pacific Northwest and Rocky Mountains experiencing the greatest increases of 78 and 175%, respectively. Increased area burned results in near doubling of wildfire carbonaceous aerosol emissions by midcentury. Using a chemical transport model driven by meteorology from the same GCM, we calculate that climate change will increase summertime organic carbon (OC) aerosol concentrations over the western United States by 40% and elemental carbon (EC) concentrations by 20% from 2000 to 2050. Most of this increase (75% for OC and 95% for EC) is caused by larger wildfire emissions with the rest caused by changes in meteorology and for OC by increased monoterpene emissions in a warmer climate. Such an increase in carbonaceous aerosol would have important consequences for western U.S. air quality and visibility.
An inverse problem to infer paleoflow conditions from turbidites
Authors: Falcini Federico , Marini Mattia , Milli Salvatore , Moscatelli Massimiliano
Published: October 2009

An inverse problem is here studied to infer paleoflow conditions from turbidites (i.e., from turbidity current deposits). Such a problem is constrained to outcrop data from the Laga Formation (Lower Messianian; central Apennines, Italy). Analytical solutions of layer‐averaged governing equations for net depositional turbidity currents flowing over a flat bottom are found. These allow recovering conditions for current velocity, thickness, and sediment concentration at the start of the net deposition by using the analytic solution of the Exner equation for net‐depositional turbidity currents. The Exner equation describes the along‐current profile of a sedimentary bed deposited by a single depositional event. For lobe deposits of the Laga Formation we obtain values of ∼1.5 m/s for layer‐averaged current velocities, 50–100 m for current thicknesses, and ∼0.5% for layer‐averaged sediment volume concentrations. The duration time of these flows is also computed and gives rather short time span values varying from 1 to 15 h. All of these values are in good agreement with those reported in literature.
The effect of N‐acetylcysteine on chloride efflux from airway epithelial cells
Authors: Varelogianni Georgia , Oliynyk Igor , Roomans Godfried M. , Johannesson Marie
Published: October 2009

Defective chloride transport in epithelial cells increases mucus viscosity and leads to recurrent infections with high oxidative stress in patients with CF (cystic fibrosis). NAC (N‐acetylcysteine) is a well known mucolytic and antioxidant drug, and an indirect precursor of glutathione. Since GSNO (S‐nitrosoglutathione) previously has been shown to be able to promote Cl− efflux from CF airway epithelial cells, it was investigated whether NAC also could stimulate Cl− efflux from CF and non‐CF epithelial cells and through which mechanisms. CFBE (CF bronchial epithelial cells) and normal bronchial epithelial cells (16HBE) were treated with 1 mM, 5 mM, 10 mM or 15 mM NAC for 4 h at 37°C. The effect of NAC on Cl− transport was measured by Cl− efflux measurements and by X‐ray microanalysis. Cl− efflux from CFBE cells was stimulated by NAC in a dose‐dependent manner, with 10 mM NAC causing a significant increase in Cl− efflux with nearly 80% in CFBE cells. The intracellular Cl− concentration in CFBE cells was significantly decreased up to 60% after 4 h treatment with 10 mM NAC. Moreover immunocytochemistry and Western blot experiments revealed expression of CFTR channel on CFBE cells after treatment with 10 mM NAC. The stimulation of Cl− efflux by NAC in CF airway epithelial cells may improve hydration of the mucus and thereby be beneficial for CF patients.
Blindness following Facial Fracture: Treatment Modalities and Outcomes
Authors: Bossert Ronald P. , Girotto John A.
Published: October 2009

Blindness is an uncommon, yet documented complication of facial trauma. Numerous case studies, series, and retrospective analyses have been published, with a reported incidence around 3%. Hippocrates first noted the association between maxillofacial trauma and blindness; millennia later, this was expounded upon by Berlin, who discovered such trauma may directly lead to fracturing of the optic canal. As diagnostic modalities such as computed tomographic scanning evolved, particularly over the past few decades, more specific, in-depth reports analyzing maxillofacial trauma and subsequent sequelae have emerged. It is the goal of this article to examine the current literature for those publications that have addressed the issue of blindness following facial trauma (including operative interventions) and create a concise review for maxillofacial surgeons.
Resonant soft x-ray scattering studies of interface reconstructions in SrTiO3/LaAlO3 superlattices
Authors: Wadati H. , Hawthorn D. G. , Geck J. , Higuchi T. , Hikita Y. , Hwang H. Y. , Kourkoutis L. Fitting , Muller D. A. , Huang S.-W. , Huang D. J. , Lin H.-J. , Schüßler-Langeheine C. , Wu H.-H. , Schierle E. , Weschke E. , Ingle N. J. C. , Sawatzky G. A.
Published: October 2009

We present resonant soft x-ray scattering studies of Ti 3d and O 2p states at the interfaces of SrTiO3/LaAlO3 superlattices. From reflectivity analyses, focusing on the (003) peak which is forbidden for our “ideal” superlattice structure, we concluded that the LaO∣TiO2/SrO and the SrO∣AlO2/LaO interfaces have distinct reconstructions, breaking the heterostructure symmetry.
Improvement of spatial resolution for local Seebeck coefficient measurements by deconvolution algorithm
Authors: Wu K. H. , Hung C. I. , Ziolkowski P. , Platzek D. , Karpinski G. , Stiewe C. , Mueller E.
Published: October 2009

A potential Seebeck microprobe apparatus is described such that a profile of Seebeck coefficients can be detected on a material sample surface for thermopower investigations. Due to its spatially resolved limit on detecting small inhomogeneities of dopants or composition changes, we here propose a constructive combination of numerical modeling and practical measurement to improve the spatial resolution by deconvolution algorithm. The relevant transfer function, obtained from numerical calculations, was successfully applied on real measurement data. Besides, an improvement in detecting the 1.5 μm inhomogeneity has been achieved by applying one transfer function of the known tip setup on a set of Seebeck line scan signals, obtained with 6 μm tip-sample contact length, 3 μs signal capture time after contact, and 0.75 μm scan period. The result showed that a system theoretical approach in terms of deconvolution algorithm could theoretically enhance the spatial resolution anyway, but is practically limited by the systemic preconditions (tip size, signal capture time, and scan period) and the signal to noise ratio of the captured thermovoltages. Therefore, we provide a clear understanding of systemic preconditions and their impacts on the detection of small inhomogeneities and thus the performance in the thermopower analysis.
Microscopic origin of bipolar resistive switching of nanoscale titanium oxide thin films
Authors: Jeong Hu Young , Lee Jeong Yong , Choi Sung-Yool , Kim Jeong Won
Published: October 2009

We report a direct observation of the microscopic origin of the bipolar resistive switching behavior in nanoscale titanium oxide films. Through a high-resolution transmission electron microscopy, an analytical transmission electron microscopy technique using energy-filtering transmission electron microscopy, and an in situ x-ray photoelectron spectroscopy, we demonstrated that the oxygen ions piled up at the top interface by an oxidation-reduction between the titanium oxide layer and the top Al metal electrode. We also found that the drift of oxygen ions during the on/off switching induced the bipolar resistive switching in the titanium oxide thin films.
Nonlinear laser-driven electron resonance acceleration in an inhomogeneous magnetic field
Authors: Li Jun , Xie Bai-Song , Sang Hai-Bo , Hong Xue-Ren , Zhang Shan , Yu M. Y.
Published: October 2009

Electron resonance acceleration by an intense laser pulse in an inhomogeneous external magnetic field is investigated. The acceleration mechanism makes use of electron cyclotron resonance to increase the electron energy. By appropriately tailoring the radial gradient of the magnetic field, an electron in the rising front part of laser pulse will be attracted toward the cyclotron-resonance radius and be trapped there, so that it can gain much energy. It is shown that the electron net energy gain can be up to the GeV level.
Antagonism of microRNA-126 suppresses the effector function of T
H
2 cells and the development of allergic airways disease
Authors: Mattes Joerg , Collison Adam , Plank Maximilian , Phipps Simon , Foster Paul S.
Published: October 2009

Allergic asthma is an inflammatory disease of the lung characterized by abnormal T helper-2 (T
H
2) lymphocyte responses to inhaled antigens. The molecular mechanisms leading to the generation of T
H
2 responses remain unclear, although toll-like receptors (TLRs) present on innate immune cells play a pivotal role in sensing molecular patterns and in programming adaptive T cell responses. Here we show that in vivo activation of TLR4 by house dust mite antigens leads to the induction of allergic disease, a process that is associated with expression of a unique subset of small, noncoding microRNAs. Selective blockade of microRNA (miR)-126 suppressed the asthmatic phenotype, resulting in diminished T
H
2 responses, inflammation, airways hyperresponsiveness, eosinophil recruitment, and mucus hypersecretion. miR-126 blockade resulted in augmented expression of POU domain class 2 associating factor 1, which activates the transcription factor PU.1 that alters T
H
2 cell function via negative regulation of GATA3 expression. In summary, this study presents a functional connection between miRNA expression and asthma pathogenesis, and our data suggest that targeting miRNA in the airways may lead to anti-inflammatory treatments for allergic asthma.
HPV E6 protein interacts physically and functionally with the cellular telomerase complex
Authors: Liu Xuefeng , Dakic Aleksandra , Zhang Yiyu , Dai Yuhai , Chen Renxiang , Schlegel Richard
Published: October 2009

Telomerase activation is critical for the immortalization of primary human keratinocytes by the high-risk HPV E6 and E7 oncoproteins, and this activation is mediated in part by E6-induction of the hTERT promoter. E6 induces the hTERT promoter via interactions with the cellular ubiquitin ligase, E6AP, and with the c-Myc and NFX-1 proteins, which are resident on the promoter. In the current study we demonstrate that E6 protein interacts directly with the hTERT protein. Correlating with its ability to bind hTERT, E6 also associates with telomeric DNA and with endogenous active telomerase complexes. Most importantly, E6 increases the telomerase activity of human foreskin fibroblasts transduced with the hTERT gene, and this activity is independent of hTERT mRNA expression. Unlike its ability to degrade p53, E6 does not degrade hTERT protein in vitro or in vivo. Our studies of E6/hTERT interactions also reveal that the C-terminal tagged hTERT protein, although incapable of immortalizing fibroblasts, does immortalize keratinocytes in collaboration with the viral E7 protein. Thus, E6 protein mediates telomerase activation by a posttranscriptional mechanism and these findings provide a model for exploring the direct modulation of cell telomerase/telomere function by an oncogenic virus and suggest its potential role in both neoplasia and virus replication.
Getting a Better Grip on Research: The Comfort of Opinion
Authors: Maskrey Neal , Hutchinson Andy , Underhill Jonathan
Published: October 2009

In the 21st century, health care clinicians, managers and patients expect to see the findings of research incorporated into clinical practice, taking into account the needs and wishes of individual patients.
Halothane-induced Hypnosis Is Not Accompanied by Inactivation of Orexinergic Output in Rodents
Authors: Gompf Heinrich , Chen Jingqiu , Sun Yi , Yanagisawa Masashi , Aston-Jones Gary , Kelz Max B.
Published: October 2009

Background

One underexploited property of anesthetics is their ability to probe neuronal regulation of arousal. At appropriate doses, anesthetics reversibly obtund conscious perception. However, individual anesthetic agents may accomplish this by altering the function of distinct neuronal populations. Previously the authors showed that isoflurane and sevoflurane inhibit orexinergic neurons, delaying reintegration of sensory perception as denoted by emergence. Here the authors study the effects of halothane. As a halogenated alkane, halothane differs structurally, has a nonoverlapping series of molecular binding partners, and differentially modulates electrophysiologic properties of several ion channels when compared with its halogenated ether relatives.

Methods

c-Fos immunohistochemistry and in vivo electrophysiology were used to assess neuronal activity. Anesthetic induction and emergence were determined behaviorally in narcoleptic orexin/ataxin-3 mice and control siblings exposed to halothane.

Results

Halothane-induced hypnosis occurred despite lack of inhibition of orexinergic neurons in mice. In rats, extracellular single-unit recordings within the locus coeruleus showed significantly greater activity during halothane than during a comparable dose of isoflurane. Microinjection of the orexin-1 receptor antagonist SB-334867-A during the active period slowed firing rates of locus coeruleus neurons in halothane-anesthetized rats, but had no effect on isoflurane-anesthetized rats. Surprisingly, orexin/ataxin-3 transgenic mice, which develop narcolepsy with cataplexy because of loss of orexinergic neurons, did not show delayed emergence from halothane.

Conclusion

Coordinated inhibition of hypothalamic orexinergic and locus coeruleus noradrenergic neurons is not required for anesthetic induction. Normal emergence from halothane-induced hypnosis in orexin-deficient mice suggests that additional wake-promoting systems likely remain active during general anesthesia produced by halothane.
Metoprolol Reduces Cerebral Tissue Oxygen Tension after Acute Hemodilution in Rats
Authors: Ragoonanan Tenille E. , Beattie W Scott , Mazer C David , Tsui Albert K.Y. , Leong-Poi Howard , Wilson David F. , Tait Gordon , Yu Julie , Liu Elaine , Noronha Melissa , Dattani Neil D. , Mitsakakis Nicholas , Hare Gregory M. T.
Published: October 2009

Background

Perioperative beta-blockade and anemia are independent predictors of increased stroke and mortality by undefined mechanisms. This study investigated the effect of beta-blockade on cerebral tissue oxygen delivery in an experimental model of blood loss and fluid resuscitation (hemodilution).

Methods

Anesthetized rats were treated with metoprolol (3 mg x kg) or saline before undergoing hemodilution with pentastarch (1:1 blood volume exchange, 30 ml x kg). Outcomes included cardiac output, cerebral blood flow, and brain (PBrO2) and kidney (PKO2) tissue oxygen tension. Hypoxia inducible factor-1alpha (HIF-1alpha) protein levels were assessed by Western blot. Systemic catecholamines, erythropoietin, and angiotensin II levels were measured.

Results

Hemodilution increased heart rate, stroke volume, cardiac output (60%), and cerebral blood flow (50%), thereby maintaining PBrO2 despite an approximately 50% reduction in blood oxygen content (P < 0.05 for all). By contrast, PKO2 decreased (50%) under the same conditions (P < 0.05). Beta-blockade reduced baseline heart rate (20%) and abolished the compensatory increase in cardiac output after hemodilution (P < 0.05). This attenuated the cerebral blood flow response and reduced PBrO2 (50%), without further decreasing PKO2. Cerebral HIF-1alpha protein levels were increased in beta-blocked hemodiluted rats relative to hemodiluted controls (P < 0.05). Systemic catecholamine and erythropoietin levels increased comparably after hemodilution in both groups, whereas angiotensin II levels increased only after beta-blockade and hemodilution.

Conclusions

Cerebral tissue oxygen tension is preferentially maintained during hemodilution, relative to the kidney, despite elevated systemic catecholamines. Acute beta-blockade impaired the compensatory cardiac output response to hemodilution, resulting in a reduction in cerebral tissue oxygen tension and increased expression of HIF-1alpha.
Pulmonary Capillary Blood Flow and Cardiac Output Measurement by Partial Carbon Dioxide Rebreathing in Patients with Acute Respiratory Distress Syndrome Receiving Lung Protective Ventilation
Authors: Allardet-Servent Jérôme , Forel Jean-Marie , Roch Antoine , Chiche Laurent , Guervilly Christophe , Bouzana Fouad , Vincent Agnès , Gainnier Marc , Loundou Anderson , Papazian Laurent
Published: October 2009

Background

Partial carbon dioxide rebreathing noninvasively measures the pulmonary capillary blood flow and estimates the cardiac output with the use of a predicted shunt value. It has been reported that the accuracy of the method is decreased in patients with high pulmonary shunt. The aim of this study was to investigate the agreement between partial rebreathing and thermodilution for the determination of pulmonary capillary blood flow and cardiac output in the setting of acute respiratory distress syndrome.

Methods

Twenty consecutive patients with the acute respiratory distress syndrome were enrolled. Ventilator settings include low tidal volume (6 ml x kg(-1)) and positive end-expiratory pressure + 2 cm H2O higher than the lower inflection point if present or 10 cm H2O if not. Seven pairs of cardiac output and pulmonary capillary blood flows were recorded every 20 min over a 2-h period. The authors determined bias, SD, limit of agreement (95% confidence interval) and percentage error.

Results

Bias and agreement for cardiac output measurement were 0.8 +/- 1.2 l x min(-1) (-2.1 to 3.7 l x min(-1)), and percentage error was 36%. Bias and agreement for pulmonary capillary blood flow measurement were -0.1 +/- 0.8 l x min(-1) (-2.1 to 1.9 l x min(-1)), and percentage error was 35%. Dead space, arteriovenous oxygen content difference, mean pulmonary arterial pressure, and baseline cardiac output were independently associated with differences between methods.

Conclusions

In patients with the acute respiratory distress syndrome, partial rebreathing cannot yet replace thermodilution for measuring pulmonary capillary blood flow or cardiac output. However, accuracy of the method is close to the boundary of clinical relevance.
Mathematical Modeling of the Pain and Progress of the First Stage of Nulliparous Labor
Authors: Debiec Jozef , Conell-Price Jessamyn , Evansmith Jennifer , Shafer Steven L. , Flood Pamela
Published: October 2009

Background

Patient characteristics may contribute to the progress and pain of labor. Quantitative evaluation of the effects of patient characteristics requires robust mathematical models of labor progress and labor pain.

Methods

The authors retrospectively studied 100 sequential deliveries from each of five self-reported ethnic groups (Asian, Black, Hispanic, Other, and White). Demographic variables, cervical dilation, and numerical rating scores for pain before analgesia and cervical dilation were abstracted from the automated medical record. Labor progress was modeled with a biexponential function describing the latent and active phases of labor. Labor pain was modeled as a sigmoid function of cervical dilation by using a previously validated mathematical model. The covariates, including self-described ethnicity, were analyzed with NONMEM.

Results

The biexponential function described the time course of labor progress better than several alternative functions, including the sigmoidal function introduced by Friedman. The sigmoidal function of labor pain described its dynamic nature well, with substantial intersubject variability. Asian women had slower active labor than other ethnicities (P < 0.01). Asian women also reported less pain during their labor compared to all other patients (P < 0.001). Slower labor progress was associated with less rapid progression of pain, but this did not obviate the effect of Asian ethnicity on pain. Neuraxial analgesia is strongly associated with slower labor (P < 0.0001). Greater maternal weight was associated with slower active labor (P < 0.0001).

Conclusions

Mathematical models can be used to detect subtle effects of patient covariates on the progress and pain of the first stage of labor. Asian women and heavier women had slower labor and slower onset of labor pain than others. These effects were modest compared with the substantial remaining unexplained subject-to-subject variability in labor progress and labor pain.
Differences in Quantitative Architecture of Sciatic Nerve May Explain Differences in Potential Vulnerability to Nerve Injury, Onset Time, and Minimum Effective Anesthetic Volume
Authors: Moayeri Nizar , Groen Gerbrand J.
Published: October 2009

Background

In sciatic nerve (SN) blocks, differences are seen in risk of nerve damage, minimum effective anesthetic volume, and onset time. This might be related to differences in the ratio neural:nonneural tissue within the nerve. For the brachial plexus, a higher proximal ratio may explain the higher risk for neural injury in proximal nerve blocks. A similar trend in risk is reported for SN; however, equivalent quantitative data are lacking. The authors aimed to determine the ratio neural:nonneural tissue within SN in situ in the upper leg.

Methods

From five consecutive cadavers, the region between the sacrum and distal femur condyle was harvested and frozen. Using a cryomicrotome, consecutive transversal sections (interval, 78 mum) were obtained and photographed. Reconstructions of SN were made strictly perpendicular to its long axis in the midgluteal, subgluteal, midfemoral, and popliteal regions. The epineurial area and all neural fascicles were delineated and measured. The nonneural tissue compartment inside and outside SN was also delineated and measured.

Results

The amount of neural tissue inside the epineurium decreased significantly toward distal (midfemoral/popliteal region) (P < 0.001). The relative percentage of neural tissue decreased from midgluteal (67 +/- 7%), to subgluteal (57 +/- 9%), to midfemoral (46 +/- 10%), to popliteal (46 +/- 11%). Outside the SN, the adipose compartment increased significantly toward distal (P < 0.007).

Conclusion

In SN, the ratio neural:nonneural tissue changes significantly from 2:1 (midgluteal and subgluteal) to 1:1 (midfemoral and popliteal). This suggests a higher vulnerability for neurologic sequelae in proximal SN, and may explain differences observed in minimum effective anesthetic volume and onset time between proximal and distal SN blocks.
Mechanisms of Impaired Glucose Tolerance and Insulin Secretion during Isoflurane Anesthesia
Authors: Tanaka Katsuya , Kawano Takashi , Tomino Takehito , Kawano Hiroaki , Okada Tsuyoshi , Oshita Shuzo , Takahashi Akira , Nakaya Yutaka
Published: October 2009

Background

Volatile anesthetics impair insulin secretion and glucose utilization; however, the precise mechanism of action that underlies these effects is unknown. The authors hypothesized that isoflurane inhibits glucose-induced inhibition of adenosine triphosphate-sensitive potassium channel activity in pancreatic beta cells, which could result in impaired insulin secretion and glucose tolerance.

Methods

Intravenous glucose tolerance tests were performed on 28 male Japanese White rabbits anesthetized with sodium pentobarbital. Glibenclamide (50 microg/kg + 33.5 microg x kg x h) or vehicle was administered 75 min before intravenous administration of 0.6 g/kg glucose. Half of the animals (n = 7) in the vehicle and glibenclamide groups received isoflurane at 1.0 minimum alveolar concentration 30 min before administration of glucose, and the other half received a vehicle control. Hemodynamics, blood glucose, and plasma insulin were measured. A cell-attached patch clamp configuration was used to record single channel currents in the pancreas from male Swiss-Webster mice.

Results

Isoflurane alone or a combination of isoflurane and glibenclamide inhibited the insulinogenic index to a greater extent than in the vehicle and glibenclamide groups. In the patch clamp experiments, channel activity was significantly decreased as the glucose concentration was increased from 0 to 10 mm. The subsequent application of 0.5 mm isoflurane reversed the effects of glucose on channel activity.

Conclusion

These results show that isoflurane impairs insulin secretion and glucose utilization. The mechanism of action responsible for these effects may involve a decrease in glucose-induced inhibition of adenosine triphosphate-sensitive potassium channel activity in pancreatic beta cells.
Perineural Dexmedetomidine Added to Ropivacaine Causes a Dose-dependent Increase in the Duration of Thermal Antinociception in Sciatic Nerve Block in Rat
Authors: Brummett Chad M. , Padda Amrita K. , Amodeo Francesco S. , Welch Kathleen B. , Lydic Ralph
Published: October 2009

Background

The current study was designed to test the hypothesis that dexmedetomidine added to ropivacaine would increase the duration of antinociception to a thermal stimulus in a dose-dependent fashion in a rat model of sciatic nerve blockade.

Methods

Fifty adult Sprague-Dawley rats (10 rats/group) received unilateral sciatic nerve blocks with 0.2 ml ropivacaine (0.5%) or 0.2 ml ropivacaine (0.5%) plus dexmedetomidine (2.7 microm [0.5 microg/kg], 11.7 microm [2 microg/kg], 34.1 microm [6 microg/kg], or 120.6 microm [20 microg/kg]) in a randomized, blinded fashion. Time to paw withdrawal latency to a thermal stimulus for both paws and an assessment of motor function were measured every 30 min after the nerve block until a return to baseline.

Results

Dexmedetomidine added to ropivacaine increased the duration of dense sensory blockade and time for return to normal sensory function in a dose-dependent fashion (P < 0.005). There was a significant time (P < 0.005), dose (P < 0.005), and time-by-dose effect (P < 0.005) on paw withdrawal latencies of the operative paws. There were no significant differences in paw withdrawal latencies of the control paws, indicating little systemic effect of the dexmedetomidine. The duration of motor blockade was also increased with dexmedetomidine. High-dose dexmedetomidine (120.6 mum) was not neurotoxic.

Conclusion

This is the first study showing that dexmedetomidine added to ropivacaine increases the duration of sensory blockade in a dose-dependent fashion in rats. The findings are an essential first step encouraging future efficacy studies in humans.
Space–time adaptive numerical methods for geophysical applications
Authors: Castro C. E. , Käser M. , Toro E. F.
Published: October 2009

In this paper we present high-order formulations of the finite volume and discontinuous Galerkin finite-element methods for wave propagation problems with a space–time adaptation technique using unstructured meshes in order to reduce computational cost without reducing accuracy. Both methods can be derived in a similar mathematical framework and are identical in their first-order version. In their extension to higher order accuracy in space and time, both methods use spatial polynomials of higher degree inside each element, a high-order solution of the generalized Riemann problem and a high-order time integration method based on the Taylor series expansion. The static adaptation strategy uses locally refined high-resolution meshes in areas with low wave speeds to improve the approximation quality. Furthermore, the time step length is chosen locally adaptive such that the solution is evolved explicitly in time by an optimal time step determined by a local stability criterion. After validating the numerical approach, both schemes are applied to geophysical wave propagation problems such as tsunami waves and seismic waves comparing the new approach with the classical global time-stepping technique. The problem of mesh partitioning for large-scale applications on multi-processor architectures is discussed and a new mesh partition approach is proposed and tested to further reduce computational cost.
Genetic structure of Eurasian cattle (Bos taurus) based on microsatellites: clarification for their breed classification1
Authors: Li M.‐H. , Kantanen J.
Published: October 2009

We pool three previously published data sets and present population genetic analyses of microsatellite variation in 48 Bos taurus cattle breeds from a wide range of geographical origins in Eurasia, mostly its northern territory. Bayesian model‐based clustering reveals six distinct clusters: besides a single‐population cluster of the Yakutian Cattle from Far Eastern Siberia and a cluster of breeds characteristic of an early origin, the other four major clusters largely correspond to previously defined morphological subgroups of Red Lowland, Lowland Black‐Pied, Longhorned Dairy and North European Polled cattle breeds. The results highlighted past expansion events of the productive breeds such as Danish Red, Angeln, Holstein‐Friesian and Ayrshire in northern and Eastern Europe. Based on genetic assignment of the breeds and the availability of breed information, we provide a preliminary classification of the five breeds that were to date undefined. Furthermore, in the analysis of molecular variance, despite some correspondence between geographical proximity and genetic similarity, the breed classification appears to be a better predictor of genetic structure in the cattle populations (the among‐group variance component: breed classification, 2.47%, P < 0.001; geographical division, 0.77%, P < 0.001).
Emplacement mechanics of sandstone intrusions: insights from the Panoche Giant Injection Complex, California
Authors: Vétel W. , Cartwright J.
Published: October 2009

The Panoche Giant Injection Complex (PGIC; California) constitutes the most complete sandstone intrusion network yet described, and is an excellent analogue for subsurface hydrocarbon reservoirs modified by sand remobilisation. Sandstone dykes and sills were intruded during the Late Palaeocene into slope mudstones of the Great Valley forearc basin, and are exposed for more than 300 km2. The PGIC consists of dykes and sills and represents upwards infilling of natural hydraulic fractures sourced from highly overpressured Cretaceous sand bodies. Over 1300 orientation measurements show that dykes are almost randomly oriented with only a slight orientation bias trending NE–SW, N–S or NW–SE, suggesting either a horizontally isotropic state of stress during intrusion or modification of stress by newly‐formed fractures that override the remote stress. Dykes are segmented in a pattern consistent with radial propagation with fingering towards tips similar to that observed for other mixed mode fractures. Kinematic indicators reveal there was no systematic sense of opening for the intrusions. This is interpreted as the result of short‐range mechanical interactions. Cross‐cutting relationships between injections imply a diachronous timing and a fluid pressure in the source units that was in excess of the lithostatic load. Finally we document a suite of minor structures within the host section that allowed the strain of the forcefully intruded sand to be accommodated.