bluuebunny/crossref_metadata_2025 huggingface dataset:
Co-Transmission of Dopamine and GABA in Periglomerular Cells
Authors: Maher Brady J. , Westbrook Gary L.
Published: January 2008

Most central neurons package and release a single transmitter. However co-transmission of fast-acting and modulatory transmitters has been observed in vertebrate and invertebrate systems. Here we describe a population of periglomerular cells in mouse brain slices (PND14-21) that co-release dopamine and GABA. We made whole cell recordings from periglomerular cells that expressed enhanced green fluorescent protein (EGFP) under the control of the tyrosine hyrdoxylase (TH) promoter. Immunolabeling confirmed that EGFP+ periglomerular cells synthesized TH as well as glutamic acid decarboxylase (GAD). Stimulation of olfactory receptor neuron (ORN) afferent input evoked excitatory postsynaptic currents (EPSCs) in EGFP+ cells that were inhibited by cocaine, which blocks dopamine transport. These effects were reversed by the D2 receptor antagonist sulpiride. Cocaine also increased the paired-pulse ratio of ORN-evoked EPSCs. These results demonstrate that TH+ periglomerular cells spontaneously release dopamine. In addition to dopamine, TH-EGFP+ cells also released GABA. Brief depolarizing voltage steps in labeled cells evoked a tail current that was completely blocked by the GABAA receptor antagonist gabazine and by cadmium, indicative of calcium-dependent self-inhibition in periglomerular cells. However, similar voltage steps were insufficient to cause D2-receptor mediated inhibition of ORN terminals. Our results indicate that TH+ periglomerular cells are directly activated by ORN input and release both dopamine and GABA. We suggest that concerted activation of multiple periglomerular cells may be required to detect dopamine release under normal physiological conditions.
GABA Actions in Hippocampal Area CA3 During Postnatal Development: Differential Shift From Depolarizing to Hyperpolarizing in Somatic and Dendritic Compartments
Authors: Romo-Parra Héctor , Treviño Mario , Heinemann Uwe , Gutiérrez Rafael
Published: January 2008

γ-Aminobutyric acid type A receptor (GABAA-R) activation leads to depolarization of pyramidal cells during the first postnatal week and produces hyperpolarization from the second week. However, immunohistochemical evidence has suggested that during the second and third postnatal weeks the NKCC1 cotransporter relocates from the soma to the dendrites of CA3 pyramidal cells. We hypothesized that this leads to depolarizing responses in apical dendrites. Here we show that the activation of GABAA-R in the distal dendrites of CA3 pyramidal cells at P15 by restricted application of muscimol or synaptic activation by stimulation of interneurons in stratum radiatum (SR) causes depolarizing postsynaptic potentials (PSPs), which are blocked by NKCC1 cotransporter antagonists. By contrast, activation of proximal GABAA-R by muscimol application or by stimulation of interneurons in s. oriens (SO) leads to hyperpolarizing PSPs. Activation of the dentate gyrus (DG) in the presence of glutamatergic blockers evokes hyperpolarizing responses during the second postnatal week; however, the reversal potential of the DG-evoked inhibitory (I)PSPs is more depolarized than that of IPSPs evoked by activation of SO interneurons. Despite the shift of GABA action from depolarizing to hyperpolarizing, DG-evoked field potentials (f-PSPs) recorded in s. lucidum/radiatum (SL/R) do not change in polarity until the third week. Current source density analysis yielded results consistent with depolarizing actions of GABA in the dendritic compartment. Our data suggest that GABAergic input to apical dendrites of pyramidal cells of CA3 evokes depolarizing PSPs long after synaptic inhibition has become hyperpolarizing in the somata, in the axon initial segments and in basal dendrites.
Neuronal Activity in the Cingulate Motor Areas During Adaptation to a New Dynamic Environment
Authors: Richardson Andrew G. , Lassi-Tucci Glenda , Padoa-Schioppa Camillo , Bizzi Emilio
Published: January 2008

Neurons in the cingulate motor areas (CMA) have been shown to be involved in many aspects of sensorimotor behavior, although their role in motor learning has received less attention. Here, we recorded single-cell activity in the CMA of monkeys while they adapted reaching movements to different dynamic environments. Specifically, we analyzed CMA activity during normal reaching to visual targets and during reaching in the presence of an applied velocity-dependent force field. We found that the cingulate neuronal activity was modulated during each phase of the task and in response to the applied forces. The neurons' involvement in the visuomotor transformation was influenced by their rostrocaudal location in the cingulate sulcus. Rostral CMA (CMAr) neurons were modulated by the visual instruction to a greater extent than caudal CMA (CMAc) neurons. In contrast, CMAc neurons had a greater amount of phasic and directionally tuned activity during movement than CMAr cells. Furthermore, compared with CMAr cells, the movement-related activity of CMAc cells was more frequently modulated by the applied force fields. The magnitude of the force-field–related neuronal response scaled with the amount of perturbation in each reaching direction. However, contrary to previous results from other cortical motor areas, force-field adaptation was not correlated with a shift in directional tuning of the CMA population. Based on these results, we suggest that although the CMA is clearly sensitive to applied forces, it is less involved in generating anticipatory responses to predictable forces than other cortical motor areas.
Three-Dimensional Mapping of Unitary Synaptic Connections by Two-Photon Macro Photolysis of Caged Glutamate
Authors: Matsuzaki Masanori , Ellis-Davies Graham C. R. , Kasai Haruo
Published: January 2008

To understand the precise microarchitecture of the cortical circuitry, it is crucial to know the distribution of synaptic connections and their synaptic strengths at the level of a single cell, rather than a group of cells. Here, we describe a new application of two-photon photolysis of caged glutamate that enabled us to induce an action potential in only a small number (about five) of pyramidal neurons by increasing the volume of two-photon excitation by reducing the effective numerical aperture of the objective. We performed whole cell patch-clamp recordings from layer 2/3 pyramidal neurons in the rat visual cortex and stimulated many neurons in a large three-dimensional space (∼600 × 600 × 100 μm) including neurons in layers 2/3 and 4 using this new technique. We mapped the density and amplitude of unitary excitatory postsynaptic currents and found that the basic microarchitecture of excitatory synaptic connections consists of two regions: a columnar, dense core region with a radius of 150 μm and an outer, sparse region. The dense core region includes the majority of strong synaptic connections in layer 2/3. Our results reveal the columnar organization of synaptic connectivity in the rat visual cortex, where functional columns have not been clearly demonstrated. Thus this technique will be a uniquely powerful tool for quantifying synaptic connectivity and manipulating neural activity at the single-cell level.
Contributions of Voltage- and Ca2+-Activated Conductances to GABA-Induced Depolarization in Spider Mechanosensory Neurons
Authors: Panek Izabela , Höger Ulli , French Andrew S. , Torkkeli Päivi H.
Published: January 2008

Activation of ionotropic γ-aminobutyric acid type A (GABAA) receptors depolarizes neurons that have high intracellular [Cl−], causing inhibition or excitation in different cell types. The depolarization often leads to inactivation of voltage-gated Na channels, but additional ionic mechanisms may also be affected. Previously, a simulated model of spider VS-3 mechanosensory neurons suggested that although voltage-activated Na+current is partially inactivated during GABA-induced depolarization, a slowly activating and inactivating component remains and may contribute to the depolarization. Here, we confirmed experimentally, by blocking Na channels prior to GABA application, that Na+current contributes to GABA-induced depolarization in VS-3 neurons. Ratiometric Ca2+imaging experiments combined with intracellular recordings revealed a significant increase in intracellular [Ca2+] when GABAAreceptors were activated, synchronous with the depolarization and probably due to Ca2+influx via low-voltage–activated (LVA) Ca channels. In contrast, GABAB-receptor activation in these neurons was previously shown to inhibit LVA current. Blockade of voltage-gated K channels delayed membrane repolarization, extending GABA-induced depolarization. However, inhibition of Ca channels significantly increased the amplitude of GABA-induced depolarization, indicating that Ca2+-activated K+current has an even stronger repolarizing effect. Regulation of intracellular [Ca2+] is important for many cellular processes and Ca2+control of K+currents may be particularly important for some functions of mechanosensory neurons, such as frequency tuning. These data show that GABAA-receptor activation participates in this regulation.
On the Nonlinear Theory of Micropolar Bodies with Voids
Authors: Marin Marin
Published: January 2008

This paper is concerned with the nonlinear theory of micropolar, porous, and elastic solids. By using the theory of Langenbach, within this context, we obtain some existence and uniqueness results.
Anti-CC-Groups and Anti-PC-Groups
Authors: Russo Francesco
Published: January 2008

A groupGhas Černikov classes of conjugate subgroups if the quotient groupG/coreG(NG(H))is a Černikov group for each subgroupHofG. An anti-CCgroupGis a group in which each nonfinitely generated subgroupKhas the quotient groupG/coreG(NG(K))which is a Černikov group. Analogously, a groupGhas polycyclic-by-finite classes of conjugate subgroups if the quotient groupG/coreG(NG(H))is a polycyclic-by-finite group for each subgroupHofG. An anti-PCgroupGis a group in which each nonfinitely generated subgroupKhas the quotient groupG/coreG(NG(K))which is a polycyclic-by-finite group. Anti-CCgroups and anti-PCgroups are the subject of the present article.
Hölder Continuity up to the Boundary of Minimizers for Some Integral Functionals with Degenerate Integrands
Authors: Bonafede S. , Cataldo V. , D'Asero S.
Published: January 2008

We study qualitative properties of minimizers for a class of integral functionals, defined in a weighted space. In particular we obtain Hölder regularity up to the boundary for the minimizers of an integral functional of high order by using an interior local regularity result and a modified Moser method with special test function.
Numerical Analysis of Blade Geometry Generation Techniques for Centrifugal Compressors
Authors: Iancu Florin , Trevino John , Sommer Steven
Published: January 2008

It is a known fact that machined impellers result in improved compressor performance compared to cast impellers of the same design. The performance improvements can be attributed to better surface finish, more accurate geometric definition (tighter dimensional tolerances), well-defined edges, and the lack of blade tip fillet on shrouded impellers. In addition, it has been observed through experimental investigations that the construction method of the impellers has an impact on performance. This paper presents computational fluid dynamic investigations of two types of impellers, with blade surfaces generated using straight-line elements (SLEs) and CAD arbitrary definitions. Because there are many different mathematical definitions that CAD tools employ for curves, the resulting arbitrary blade surface is not unique. The numerical results will help understand the causes of the performance differences as well as the effects of SLE blades on the flow through the impeller. Input conditions for computational dynamic simulations are based on experimental results. All references to experimental data in the present paper are for cast impellers. Therefore, the differences in performance are attributed to blade definition (SLE versus other) and not to differences resulting from manufacturing methods.
Approximating Fixed Points of Nonexpansive Mappings in Hyperspaces
Authors: Liu Zeqing , Feng Chi , Kang Shin Min , Ume Jeong Sheok
Published: January 2008

Two convergence theorems for the Ishikawa and Mann iteration sequences involving nonexpansive mappings in hyperspaces are established.
Effect of Blade Profile on the Performance of Wells Turbine under Unidirectional Sinusoidal and Real Sea Flow Conditions
Authors: Thakker A. , Abdulhadi R.
Published: January 2008

This paper presents the effect of blade profile and rotor solidity on the performance of Wells turbine operating under unidirectional unsteady flow conditions. In the study, four kinds of blade profile were selected, that is, NACA0020, NACA0015, CA9, and HSIM 15-262123-1576. The experiments have been carried out for two solidities,σ= 0.48 andσ= 0.64, under sinusoidal and irregular unsteady flow conditions based on Irish waves (site2). As a result, it was found that the preferable rotor geometry is the one with blade profile of CA9 with solidityσ= 0.64. In addition, the effect of blade profile and rotor solidity on hysteretic characteristics of the turbine has been clarified experimentally and it was found to be in good agreement qualitatively when compared to numerical results (Setoguchi et al. (2003)).
The Atkinson Theorem in HilbertC*-Modules overC*-Algebras of Compact Operators
Authors: Niknam A. , Sharifi K.
Published: January 2008

The concept of unbounded Fredholm operators on HilbertC*-modules over an arbitraryC*-algebra is discussed and the Atkinson theorem is generalized for bounded and unbounded Feredholm operators on HilbertC*-modules overC*-algebras of compact operators. In the framework of HilbertC*-modules overC*-algebras of compact operators, the index of an unbounded Fredholm operator and the index of its bounded transform are the same.
Diabetic Retinopathy in Native and Nonnative Canadians
Authors: Ross Stuart A. , McKenna Anne , Mozejko Sheila , Fick Gordon H.
Published: January 2008

High prevalence rates of type 2 diabetes are being observed in native Canadian communities. It is believed that native populations have a higher prevalence rate of vascular complications than nonnatives. The Southern Alberta Study of Diabetic Retinopathy (DR) examined the prevalence and incidence of DR and associated metabolic abnormalities in native and nonnative subjects. Prevalence rates of DR in type 2 diabetic native and nonnative subjects were identical, with a prevalence rate of 40%. Native subjects with retinopathy, however, tended to have more advanced changes of retinopathy compared to the nonnative subjects. Key factors such as A1c, blood pressure, duration of diabetes, and lipid values were not significantly different between the two cohorts. These data indicate that ethnicity does play a role in the development and severity of DR but potential risk factors that may affect the development of retinopathy are not significantly different between native and nonnative groups.
Stabilization for a Periodic Predator-Prey System
Authors: Aniţa Sebastian , Tarniceriu Carmen Oana
Published: January 2008

﻿A reaction-diffusion system modelling a predator-prey system in a periodic environment is considered. We are concerned in stabilization to zero of one of the components of the solution, via an internal control acting on a small subdomain, and in the preservation of the nonnegativity of both components.
A Mixture Theory for Micropolar Thermoelastic Solids
Authors: Galeş C.
Published: January 2008

We derive a nonlinear theory of heat-conducting micropolar mixtures in Lagrangian description. The kinematics, balance laws, and constitutive equations are examined and utilized to develop a nonlinear theory for binary mixtures of micropolar thermoelastic solids. The initial boundary value problem is formulated. Then, the theory is linearized and a uniqueness result is established.
Mesoporous Silica Coated CeF3:Tb3+ Particles for Drug Release
Authors: Kong Deyan , Yang Piaoping , Wang Zhenling , Chai Ping , Huang Shanshan , Lian Hongzhou , Lin Jun
Published: January 2008

CeF3:Tb3+ nanoparticles were successfully prepared by a polyol process using
diethylene glycol (DEG) as solvent. After being coated with dense silica, these
CeF3:Tb3+ nanoparticles can be coated with mesoporous silica using nonionic triblock
copolymer EO20PO70EO20 (P 123) as structure‐directing agent. The composite can load
ibuprofen and release the drug in the PBS. The composite was characterized by X‐ray diffraction
(XRD), transmission electron microscopy (TEM), nitrogen absorption/desorption isotherms,
fluorescence spectra, and UV/Vis absorption spectra, respectively. The composite particles
have considerable large pore volume and large surface area. In addition, the composite still emits
strong green fluorescence (Tb3+) and can be used as fluorescent probes in drug delivery system.
Estimating Salinity between 25° and 45°S in the Atlantic Ocean Using Local Regression
Authors: Thacker W. C.
Published: January 2008

The empirical relationship between salinity and temperature in the South Atlantic is quantified with the aid of local regression. To capture the spatial character of the TS relationship, models are fitted to data for each point on a three-dimensional grid with spacing of 1° in latitude, 2° in longitude, and 25 dbar in the vertical. To ensure sufficient data for statistical reliability each fit is to data from a region extending over several grid points weighted so that more remote data exert less influence than those closer to the target grid point. Both temperature and its square are used as regressors to capture the curvature seen in TS plots, and latitude and longitude are used to capture systematic spatial variations over the fitting regions. In addition to using statistics of residuals to characterize how well the models fit the data, errors for data not used in fitting are examined to verify the models’ abilities to simulate independent data. The best model overall for the entire region at all depths is quadratic in temperature and linear in longitude and latitude.
Low-Income Multigenerational Households
Authors: Pittman Laura D. , Boswell Michelle K.
Published: January 2008

This article compares characteristics of families, mothers, and children on the basis of whether their household is multigenerational, using data from Welfare, Children, and Families: A Three-City Study, which samples low-income culturally diverse families. Few differences were found between multigenerational and nonmultigenerational households, although mothers in multigenerational households reported more internalizing behaviors and fewer positive behaviors in their children. However, interactions between household type, mothers' age, and race/ethnicity reveal that all multigenerational households are not alike. Multigenerational households with younger mothers tend to use less effective parenting and have children who are experiencing more problem behaviors. Race/ethnicity further moderates these associations in models predicting mothers' mental health and children's academic achievement. Possible reasons for these differences by mothers' age and race/ethnicity are discussed.
Unpacking the 'Spare Embryo'
Authors: Svendsen Mette N. , Koch Lene
Published: January 2008

In 2003 it became legal to carry out human embryonic stem (hES) cell research in Denmark using embryos that are considered `spare' in connection with fertility treatment. The public debate preceding the change of the Fertility Act presented the `spare' embryo as a biological fact and discussed whether it was possible and morally acceptable to connect a given stock of `spare' embryos to the stem cell lab. This paper tells a different story. Based on ethnographic fieldwork in a fertility clinic in Copenhagen and among stem cell researchers, we argue that `spare' embryos are not straightforward biological facts. Rather, complex decision-making processes constitute embryos as `spare' and thus as possible objects of exchange between couples in fertility treatment, stem cell researchers and future citizens in need of regenerative medicine. The ongoing fact-making of the `spare' embryo in the fertility clinic reveals the network of relationships and conflicting responsibilities in which clinicians are positioned. Using the spatial metaphor of a moral landscape we explore how clinicians try out new moral pathways when seeking alternative ways to obtain and classify embryos as `spare'. We argue that changing moral landscapes and `spare' embryos are being co-produced in the development of hES cell research.
Mind the Gap
Authors: Vertesi Janet
Published: January 2008

This paper explores the effects of iconic, abstract representations of complex objects on our interactions with those objects through an ethnographic study of the use of the London Underground Map to tame and enframe the city of London. Official reports insist that the `Tube Map's' iconic status is due to its exemplary design principles or its utility for journey planning underground. This paper, however, presents results that suggest a different role for the familiar image: one of an essential visual technology that stands as an interface between the city and its user, presenting and structuring the points of access and possibilities for interaction within the urban space. The analysis explores the public understanding of an inscription in the world beyond the laboratory bench, the indexicality of the immutable mobile's visual language, and the relationship between representing and intervening. It further suggests fruitful crossovers between Science Studies, Urban Studies, and Human—Computer Interaction by approaching the individual as a `user' of a city and its graphical interface, applying the technique of cognitive mapping to overlapping virtual and analog spaces, and exploring the social and practical effects of strong and standardized visual languages on further narratives and interactions with scientific, technological, or everyday objects.
Measuring the Connotative Meanings of Foods
Authors: Fewster W. Jean , Bostian Lloyd R. , Powers Richard D.
Published: January 2008

Foods have many meanings, nutritive value being only one. Knowing some of the connotative or implied meanings that people associate with foods can help nutritionists define communication goals and plan educational programs.

This exploratory study sought to determine if certain connotative or implied meanings of foods can be measured and if common underlying dimensions of meaning can be identified. Other hypotheses related to the discriminating power, validity, and reliability of the instrument developed for the study.

The instrument, composed of a number of adjectival scales, was adapted from a behavioral science research technique, the semantic differential. Performance of the instrument was demonstrated by having homemakers in high‐ and low‐income groups use it to judge a number of foods and food groups. The selection of foods and populations was based on results of recent food consumption surveys in the United States.

Multivariate and univariate analyses of these data attested to the validity and reliability of the instrument. These analyses showed that the instrument measured differences between income groups and foods, both food groups and single foods. Major dimensions of meaning were identified by factor analysis. On the basis of the statistical tests, scales were selected for retention in the instrument for use in further testing with other foods and populations.
Focus groups and the study of violence
Authors: Pösö Tarja , Honkatukia Päivi , Nyqvist Leo
Published: January 2008

The article examines the focus group method as a tool to study violence in youth residential care based on an empirical study of 38 young people in two Finnish reform schools. The key issue here is to reflect upon the processes of knowledge production as we trace the ways in which the institutional and situational context and the very form of focus groups affect the ways of talking about violence. Special attention is given to strong and weak themes in the focus group interviews.
The tip of the iceberg: working on the Victoria Climbié Data Corpus Project
Authors: Taylor Yvette
Published: January 2008

In this article I provide an overview of the methodological approaches of the Victoria Climbié Data Corpus Project, which aims to provide researchers, educators and policy makers with an invaluable source of data, based upon the coding of witness statements given to the Victoria Climbié Inquiry. I assess my own research role within this, making a case for the need to incorporate more grounded theory techniques, research reflexivity and subjective interpretation, alongside the `objective' coding frame being used, derived from a Delphi exercise. I include witness testimonies to highlight the kind of issues that lay beyond the codes and which cannot be effectively grasped by them. In using the specific example of the Climbié case, I argue that research surrounding emotive issues must be qualitatively sensitive to the social and discursive nuances present in the data, as opposed to solely relying upon objective a priori codes.
Naturalistic inquiry and the saturation concept: a research note
Authors: Bowen Glenn A.
Published: January 2008

Saturation is mentioned in many qualitative research reports without any explanation of what it means and how it occurred. Recognizing the saturation point presents a challenge to qualitative researchers, especially in the absence of explicit guidelines for determining data or theoretical saturation. This research note examines the saturation concept in naturalistic inquiry and the challenges it presents. In particular, it summarizes the saturation process in a grounded theory study of community-based antipoverty projects. The main argument advanced in this research note is that claims of saturation should be supported by an explanation of how saturation was achieved and substantiated by clear evidence of its occurrence.
A museum, the city, and a nation
Authors: Lepawsky Joshua
Published: January 2008

The purpose of this article is to understand how a corporate museum in Kuala Lumpur, Malaysia works to create proleptic myths of nationhood to under-gird a broader state-centric project of nationalist—capitalist modernization. The article examines how these myths are expressed in the museum's design plans and are manifested in the museum's displays and spatial layout. From this analysis it becomes apparent that, first, the museum's designers intend for Malaysian museum-goers to both learn and embody particular myths of national modernization. Second, the museum's displays are dedicated to establishing a Malay-centric origin narrative for the contemporary nation-state. Third, as one moves through the museum, Malay-centrism gives way to narratives of a `multi-racial' society that link technological modernization with social progress. Eventually, however, `race' is trumped by `class' as the social identity category deemed appropriate for `information age' citizenship and nationhood in Malaysia in a story that parallels broader cultural and political—economic state-centric aspirations to achieve `development'. The deployment of `class' in this context melds strategies of government with selective aspects of neoliberalism that seek to manage the possible cultural and political experiences of nationalist—capitalist accumulation and democratic authoritarianism in contemporary Malaysia. I suggest that while these aspirations expressed through the design of the museum might appear to overcome certain limitations of racial communalisms among different Malaysians, they also dissemble underlying symbolic and material violence that enforces a state-centric stability on the possible meanings of citizenship and national identity in contemporary Malaysia.
Transspecies urban theory: chickens in an African city
Authors: Hovorka Alice
Published: January 2008

New cultural animal geography offers conceptual tools for a reinterpretation of urbanization in Africa. This article applies transspecies urban theory to the existing literature on urban livestock in the developing world, as well as a case study of chickens in Botswana to demonstrate how cities are inextricably wrapped up in human—animal relations. A focus on animals as influential actors, and interspecies mingling encourages one to acknowledge that animals are shaped by, and are themselves central actors in the constitution of, urban form, function, and dynamics. Recognition of subaltern `animal towns' challenges the perceived centrality of human existence.
Prostate Cancer Screening in African American Men: Barriers and Methods for Improvement
Authors: Reynolds Diane
Published: January 2008

African American men have the highest rate of incidence for prostate cancer in the world and are more likely to die from the disease than other ethnic groups (National Institutes of Health, 1996). Routine screening for prostate cancer can lead to early detection of the disease, thereby reducing negative outcomes, but studies have shown that African American men are less likely than Caucasian men to engage in screening practices. Lack of access to health care, socioeconomic status, inadequate knowledge, fear, patient-provider communication, distrust of the medical profession, and aversion to digital rectal exam have been identified as possible barriers to prostate cancer screening in African American men. This literature review explores causes of this striking disparity between prostate cancer incidence and mortality in African American men and cites strategies used to improve prostate cancer screening rates among this population.
The Relationship of Depressive Symptoms, Self-Esteem, and Sexual Behaviors in a Predominantly Hispanic Sample of Men Who Have Sex With Men
Authors: De Santis Joseph P. , Colin Jessie M. , Provencio Vasquez Elias , McCain Gail C.
Published: January 2008

Despite public health campaigns and safer sex messages, many men who have sex with men (MSM) continue to participate in high-risk sexual behaviors, which may make them vulnerable to HIV infection and sexually transmitted infections. The purpose of this study was to determine the relationship of depressive symptoms, self-esteem, and sexual behaviors in a predominantly Hispanic sample of MSM. This correlational study sampled 205 MSM ( M = 37 years of age, SD = ±8) representing the diverse ethnic composition of South Florida. This sample consisted of ethnic minorities (79%) with a large number of foreign-born men (69%). Participants completed measures of depressive symptoms, self-esteem, and sexual behaviors. Results indicated that higher levels of depressive symptoms and higher levels of self-esteem had a statistically significant relationship to lower levels of safer sexual behaviors. Lower income, lower educational level, and preference for Spanish language were associated with higher levels of depressive symptoms; lower income was associated with lower levels of self-esteem; and foreign birth and a preference for Spanish language were associated with lower levels of safer sex behaviors. Higher levels of depressive symptoms and higher levels of self-esteem were associated with high-risk sexual behaviors in this sample of MSM. Further research needs to be directed at culturally specific mental health and HIV prevention strategies for these vulnerable MSM.
Later That Night: Descending Alcohol Intoxication and Men's Sexual Arousal
Authors: George William H. , Cue Davis Kelly , Schraufnagel Trevor J. , Norris Jeanette , Heiman Julia R. , Schacht Rebecca L. , Stoner Susan A. , Kajumulo Kelly F.
Published: January 2008

Although men often have sex when intoxicated, basic questions remain about how alcohol affects erection. It may depend on whether blood alcohol level is ascending or descending and whether the situation calls for maximizing or suppressing erection. Objective. To evaluate whether descending intoxication affects erection when men are instructed to maximize or suppress arousal. Method. Seventy-eight heterosexual men were randomized to intoxication (descending from .08% vs. no alcohol) and arousal instruction (maximize vs. suppress) conditions. Response to erotica was examined using penile plethysmography. Results. Compared to similarly instructed sober men, intoxicated men instructed to maximize exhibited less erection yet reported greater effort to maximize. Interestingly, intoxicated men instructed to suppress exhibited more erection than those instructed to maximize. In general, however, observed effects were modest. Conclusions. Findings suggest there is no simple answer regarding how alcohol affects sexual arousal. Descending intoxication, depending on context, appears to affect erection capacity and control.
Methodological issues in therapeutic trials of COPD
Authors: Suissa S. , Ernst P. , Vandemheen K. L. , Aaron S. D.
Published: January 2008

The recent Towards a Revolution in COPD Health (TORCH) randomised trial replicated the findings of previous trials in chronic obstructive pulmonary disease (COPD) on the apparent effectiveness of inhaled corticosteroids (ICS) in reducing exacerbation rates, but not so for mortality.

In the present article, the authors review methodological issues in the TORCH and previous trials, such as patients already receiving ICS before randomisation and the absence of follow-up after study drug discontinuation, using data from two trials.

First, among previous ICS users in the Canadian Optimal Therapy of COPD Trial, the hazard ratio of the first exacerbation with ICS relative to bronchodilators was 0.71 (95% confidence interval (CI) 0.53–0.96), while among those not using ICS prior to randomisation, it was 1.11 (95% CI 0.69–1.79). Secondly, the rate ratio of exacerbations with ICS was 0.78 (95% CI 0.61–0.99) prior to drug discontinuation during follow-up and 1.23 (95% CI 0.78–1.95) thereafter. Finally, a 2×2 factorial analysis of the TORCH data found a rate ratio of mortality for the salmeterol component to be 0.83 (95% CI 0.74–0.95), while for the fluticasone component it was 1.00 (95% CI 0.89–1.13).

In conclusion, after proper consideration of the various methodological shortcomings in the design and analysis of randomised trials, the effectiveness of inhaled corticosteroids in treating chronic obstructive pulmonary disease remains doubtful, while the benefit observed with combination therapy may be due exclusively to the beneficial effects of the long-acting bronchodilator alone.
Budesonide/formoterol maintenance and reliever therapy: impact on airway inflammation in asthma
Authors: Sears M. R. , Boulet L-P. , Laviolette M. , Fitzgerald J. M. , Bai T. R. , Kaplan A. , Smiljanic-Georgijev N. , Lee J. S-M.
Published: January 2008

The aim of the present study was to compare the effectiveness, safety and health economics of budesonide/formoterol maintenance and a novel reliever therapy with conventional best practice in patients with persistent asthma in Canada.

After 2 weeks of usual therapy, 1,538 patients were randomised for 6 months to open-label budesonide/formoterol maintenance and reliever therapy 160/4.5 μg twice daily and as needed, or to guideline-based conventional best practice. Severe asthma exacerbations, reliever medication use and total inhaled corticosteroid dose were analysed in all patients and airway inflammation was assessed in a sub-study of 115 patients.

No differences were seen in time to first severe exacerbation and severe asthma exacerbation rate. There were numerically fewer emergency room visits or hospitalisations with budesonide/formoterol maintenance and reliever therapy (4.4versus7.5 events per 100 patients·yr−1, 41% reduction); however, this did not reach statistical significance. Mean total inhaled corticosteroid dose, reliever use, asthma medication costs and total annual costs per patient were all significantly lower with budesonide/formoterol maintenance and reliever therapy. Mean sputum eosinophil cell counts remained in the range for controlled inflammation in both groups.

In conclusion, budesonide/formoterol maintenance and reliever therapy achieved similar or improved clinical control compared with conventional best practice, with significantly lower total inhaled corticosteroid dose and lower cost, while maintaining similar control of eosinophilic inflammation.
meis1regulatescyclin D1andc-mycexpression, and controls the proliferation of the multipotent cells in the early developing zebrafish eye
Authors: Bessa José , Tavares Maria J. , Santos Joana , Kikuta Hiroshi , Laplante Mary , Becker Thomas S. , Gómez-Skarmeta José Luis , Casares Fernando
Published: January 2008

During eye development, retinal progenitors are drawn from a multipotent,proliferative cell population. In Drosophila the maintenance of this cell population requires the function of the TALE-homeodomain transcription factor Hth, although its mechanisms of action are still unknown. Here we investigate whether members of the Meis gene family, the vertebrate homologs of hth, are also involved in early stages of eye development in the zebrafish. We show that meis1 is initially expressed throughout the eye primordium. Later, meis1 becomes repressed as neurogenesis is initiated, and its expression is confined to the ciliary margin, where the retinal stem population resides. Knocking down meis1 function through morpholino injection causes a delay in the G1-to-S phase transition of the eye cells, and results in severely reduced eyes. This role in cell cycle control is mediated by meis1 regulating cyclin D1 and c-myctranscription. The forced maintenance of meis1 expression in cell clones is incompatible with the normal differentiation of the meis1-expressing cells, which in turn tend to reside in undifferentiated regions of the retinal neuroepithelium, such as the ciliary margin. Together, these results implicate meis1 as a positive cell cycle regulator in early retinal cells, and provide evidence of an evolutionary conserved function for Hth/Meis genes in the maintenance of the proliferative, multipotent cell state during early eye development.
Outcome Scores Collected by Touchscreen: Medical Audit as it Should be in the 21st Century?
Authors: Dixon Sean , Bunker Timothy , Chan Daniel
Published: January 2008

INTRODUCTION

Collecting outcome scores in paper form is fraught with difficulty. We have assessed the feasibility of, and patient's attitude towards, entering scores using a touchscreen.

PATIENTS AND METHODS

A touchscreen was installed in the orthopaedic out-patient clinic. If relevant, patients were asked to complete either an Oswestry Disability Index (ODI) or Oxford Shoulder Score (OSS) using the screen. Patients were given written instructions and their hospital number by the receptionist who had no further input. Scores were completed with two identifiers. A paper questionnaire was used to assess computer experience and attitude towards the touchscreen.

RESULTS

A total of 1348 patients, average age 50 years, successfully completed a score in the first 12 months. One-third were over 60 years. Overall, 91% correctly entered their hospital number and date of birth, falling to 84% in patients over 70 years. All patients were identifiable. The average time to complete the scores was 4.7 min rising with age. Of 170 patients completing the paper assessment of the touchscreen, one-third had little or no experience of computers and a third were over 60 years. Of patients, 93% were willing to repeat the score using the touchscreen to monitor progress. Two-thirds found it easier to use than expected. Only 10% would prefer a paper score. These results were maintained among patients over 60 years. Only two were unable to complete the score and 80% of those potentially eligible did so. The remainder were called to clinic before the touchscreen was free.

CONCLUSIONS

Orthopaedic outcome scores can be collected in very large volumes using a touchscreen. Data are then in an immediately usable form. The method is acceptable to patients, independent of age and computer experience. Even in the oldest patients, the accuracy is higher than for paper versions of the score. Combined with operative data, this simple method has the potential to provide a very powerful audit tool indeed.
Vascular Surgery within General Surgery: An Analysis of Workload 1989–2005
Authors: Ashraf SQ , Bajwa A , Magee TR , Galland RB
Published: January 2008

INTRODUCTION

There is considerable debate as to whether vascular surgery should be a subspecialty separate from general surgery. This study examines the changing relationship between general and vascular surgery in a district general surgical unit over 16 years.

PATIENTS AND METHODS

A detailed survey of referrals, admissions and operations to one unit was carried out over 3 months in 003. This was compared with similar surveys in 1989, 1990 and 1995. In addition a 3-month audit of operations performed was carried out in 2005 following a decision by the Primary Care Trust (PCT) to reduce varicose vein referrals.

RESULTS

There was a significant increase in the number of varicose vein and arterial referrals 1989–2003 (P = 0.0001 and P < 0.0001, respectively). This was reflected in increased number of vascular admissions (P < 0.0001). In 1989, 14% of the arterial cases were admitted as emergencies. This figure rose to 52% in 2003 (P < 0.0001). There was a significant increase in the number of arterial operations performed between 1989 and 1995; however, from 1995 to 2003 this number fell P < 0.0001). The number of varicose vein procedures increased significantly 1989–2003 (P < 0.0001), with a significant fall after the PCT decision (P < 0.0001). However, the number of operations carried out in 2005 increased slightly with the proportion of general surgical cases, mostly hernia repairs and laparoscopic cholecystectomies, increasing.

CONCLUSIONS

With increasing specialisation comes the risk that reduction in any aspect of a particular specialty may result in that unit becoming unsustainable. In vascular surgery this will inevitably lead to centralisation of services. In a large district general hospital having two general surgeons with a vascular interest, the general surgical component has maintained the workload of the unit following reduction in varicose vein referrals.
Surgery in Malawi – A National Survey of Activity in Rural and Urban Hospitals
Authors: Lavy Chris , Tindall Alistair , Steinlechner Colin , Mkandawire Nyengo , Chimangeni Sandy
Published: January 2008

INTRODUCTION

Malawi is a poor country with few doctors. It has 21 district hospitals all of which have operating theatres but none of which has a permanent surgeon. It also has 4 central hospitals, each with one or more surgeons. Most district hospitals are manned by a single doctor and two or more paramedical clinical officers.

PATIENTS AND METHODS

All district and central hospitals were visited, and theatre logbooks analysed. All cases performed in 2003 were recorded.

RESULTS

In 2003, a total of 48,696 surgical operations were recorded, of which 25,053 were performed in 21 district hospitals and 23,643 in 4 central hospitals. Caesarean section is the commonest major surgical procedure in district hospitals and is performed in approximately 2.8% of all births, compared to 22% in the UK. Very few major general surgical or orthopaedic procedures are carried out in district hospitals.

CONCLUSION

This study underlines Malawi's need for more surgeons to be trained and retained.
The Pedicled ‘Policeman’ Flap Salvage of Exposed Vascular Prosthesis – A Case Report
Authors: Ellabban Mohammed , Oudit Deemish , Lambert Mark , Juma Ali
Published: January 2008

A case report of a patient with exposed, infected, subcutaneous, extra-anatomical, vascular prosthesis is presented, which was successfully salvaged using pedicled omental flap after other reconstructive procedures had failed.
Using Marker Pens on Patients: a Potential Source of Cross Infection with MRSA
Authors: Tadiparthi S , Shokrollahi K , Juma A , Croall J
Published: January 2008

INTRODUCTION

Marker pens are widely used in surgery but pre-operative marking of patients may be a cause of bacterial cross-infection.

PATIENTS AND METHODS

Two experiments were performed to assess whether marking pens can be cause of cross-infection: (i) 26 indelible marker pens were collected from surgical wards for analysis; and (ii) ‘fresh’ as well as ‘dry’ (artificially dried by removing cap and exposing tip for 2 h) new permanent marker pens, and whiteboard marker pens were inoculated by dipping the tips into various concentrations of methicillin-resistant Staphylococcus aureus (MRSA). Each pen was inoculated onto 2 blood agar plates at 0 (immediately after inoculation) to 30 min at various intervals, 4 h and 24 h. The plates were incubated for 18 h at 35°C in an incubator.

RESULTS

Of 26 pens collected from the wards, 2 cultured Micrococci spp. (skin commensals). The constituents of new ‘fresh’ pen tips rapidly kill MRSA – in all cases by 4 h, but usually within minutes. At high inoculum concentrations, MRSA is not killed immediately. Dry marker pens harbour MRSA for at least 30 min and probably longer.

CONCLUSIONS

Marker pens can act as fomites for nosocomial infection. The ethanol-based ink in permanent marker pens has a bactericidal action against MRSA that starts within seconds, and they are likely to be safe to use with a gap of at least 2 min between patients. Usually, harmless skin commensals are not pathogenic except in immunocompromised patients. Old or dried-out marker pens can harbour pathogens and should be discarded before attempted use on patients. We recommend disposable markers for the immunocompromised and patients with a known positive MRSA status.
Impact of Surgeon-Specific Data Reporting on Surgical Training
Authors: Khan Omar A , Iyengar Srikanth , Pontefract David E , Rogers Vanessa , Ohri Sunil K , Livesey Steven A
Published: January 2008

INTRODUCTION

Since April 2002, collection and publication of surgeon-specific data in adult cardiac surgery has become mandatory in the UK. It has been suggested that this may discourage consultants from allowing trainees to perform cases. The aim of this study was to attempt to analyse the effect of the introduction of surgeon-specific data (SSD) on surgical training in a large cardiac surgical centre.

PATIENTS AND METHODS

A retrospective analysis was performed on 2111 consecutive patients undergoing elective coronary artery bypass surgery, aortic and mitral valve surgery at Southampton General Hospital between April 2000 and April 2004. Results were analysed and compared over a 2-year period prior to and a 2-year period following the introduction of SSD.

RESULTS

There were no changes in the overall mortality rate following the introduction of SSD. SSD was associated with a reduction in the overall proportion of cases performed by trainees (49% versus 42.8%; P = 0.004) and, in particular, a reduction in the proportion of aortic and mitral valve procedures performed by trainees. In addition, the proportion of cases performed by the trainees without consultant supervision declined significantly following SSD (18.7% versus 10.4%; P < 0.001).

CONCLUSIONS

Publication of surgeon-specific data has coincided with a decrease in both the proportion and variety of cases performed by trainees.