Sugar or salt ("SOS"): A protocol for a UK multicentre randomised trial of mannitol and hypertonic saline in severe traumatic brain injury and intracranial hypertension

Hyperosmolar solutions are widely used to treat raised intracranial pressure following severe traumatic brain injury. Although mannitol has historically been the most frequently administered, hypertonic saline solutions are increasingly being used. However, definitive evidence regarding their comparative effectiveness is lacking. The Sugar or Salt Trial is a UK randomised, allocation concealed open label multicentre pragmatic trial designed to determine the clinical and cost-effectiveness of hypertonic saline compared with mannitol in the management of patients with severe traumatic brain injury. Patients requiring intensive care unit admission and intracranial pressure monitoring post-traumatic brain injury will be allocated at random to receive equi-osmolar boluses of either mannitol or hypertonic saline following failure of routine first-line measures to control intracranial pressure. The primary outcome for the study will be the Extended Glasgow Outcome Scale assessed at six months after randomisation. Results will inform current clinical practice in the routine use of hyperosmolar therapy as well as assess the impact of potential side effects. Pre-planned longer term clinical and cost effectiveness analyses will further inform the use of these treatments.

The Virtual Root : Mathematical Modeling of Auxin Transport in the Arabidopsis Root Tip Using the Open-Source Software SimuPlant

Hormone signals like auxin play a critical role controlling plant growth and development. Determining the mechanisms that regulate auxin distribution in cells and tissues is a vital step in understanding this hormone's role during plant development. Recent mathematical models have enabled us to understand the essential role that auxin influx and efflux carriers play in auxin transport in the Arabidopsis root tip (Band et al., Plant Cell 26(3):862-875, 2014; Grieneisen et al., Nature 449(7165):1008-1013, 2007; van den Berg et al., Development 143(18):3350-3362, 2016). In this chapter, we describe SimuPlant: The Virtual Root (SimuPlant, University of Nottingham. https://www.simuplant.org/ . Accessed 20 Sept 2019); an open source software suite, built using the OpenAlea (Pradal et al., Funct Plant Biol 35(10):751-760, 2008) framework, that is designed to simulate vertex-based models in real plant tissue geometries. We provide guidance on how to install SimuPlant, run 2D auxin transport models in the Arabidopsis root tip, manipulate parameters, and visualize model outputs.SimuPlant features a graphical user interface (GUI) designed to allow users with no programming experience to simulate auxin dynamics within the Arabidopsis root tip. Within the user interface, users of SimuPlant can select from a range of model assumptions and can choose to manipulate model and simulation parameter values. Users can then investigate how their choices affect the predicted distribution of auxin in the Arabidopsis root tip. The results of the model simulations are shown visually within the root geometry and can be exported and saved as PNG image files.

Low-Cost Automated Vectors and Modular Environmental Sensors for Plant Phenotyping

High-throughput plant phenotyping in controlled environments (growth chambers and glasshouses) is often delivered via large, expensive installations, leading to limited access and the increased relevance of "affordable phenotyping" solutions. We present two robot vectors for automated plant phenotyping under controlled conditions. Using 3D-printed components and readily-available hardware and electronic components, these designs are inexpensive, flexible and easily modified to multiple tasks. We present a design for a thermal imaging robot for high-precision time-lapse imaging of canopies and a Plate Imager for high-throughput phenotyping of roots and shoots of plants grown on media plates. Phenotyping in controlled conditions requires multi-position spatial and temporal monitoring of environmental conditions. We also present a low-cost sensor platform for environmental monitoring based on inexpensive sensors, microcontrollers and internet-of-things (IoT) protocols.

Beneficial re-use of industrial CO2 emissions using microalgae: Demonstration assessment and biomass characterization

A novel cyclic flow photobioreactor, designed for the capture and recycle of CO₂ using microalgae, was deployed at a coal-fired power plant. Scenedesmus acutus was cultured continuously for a four-month period, during which a biomass productivity of 0.1-0.2 g L^-1 day^-1 was observed. Samples taken for DNA sequencing showed a strong correlation between the composition of the culture and environmental conditions. Dry and liquid biomass samples and the industrial fertilizers used for preparation of the nutrient medium were analyzed to determine the presence of heavy metals (As, Cd, Hg, Se) and results were compared with standardized and/or regulated maximum contaminant levels (MCLs) for metals in several possible algae derived products. Concentrations of the metals in dry algae biomass were consistent with the incorporation of metals from the supplied nutrients.

Live video footage from scene to aid helicopter emergency medical service dispatch: a feasibility study

Background

Obtaining accurate information from a 112 caller is key to correct tasking of Helicopter Emergency Medical Services (HEMS). Being able to view the incident scene via video from a mobile phone may assist HEMS dispatch by providing more accurate information such as mechanism of injury and/or injuries sustained. The objective of this study is to describe the acceptability and feasibility of using live video footage from the mobile phone of a 112 caller as an HEMS dispatch aid.

Methods

Live footage is obtained via the 112 caller’s mobile phone camera through the secure GoodSAM app’s Instant-on-scene™ platform. Video footage is streamed directly to the dispatcher, and not stored. During the feasibility trial period, dispatchers noted the purpose for which they used the footage and rated ease of use and any technical- and operational issues they encountered. A subjective assessment of caller acceptance to use video was conducted.

Results

Video footage from scene was attempted for 21 emergency calls. The leading reasons listed by the dispatchers to use live footage were to directly assess the patient (18/21) and to obtain information about the mechanism of injury and the scene (11/21). HEMS dispatchers rated the ease of use with a 4.95 on a 5-point scale (range 4–5). All callers gave permission to stream from their telephone camera. Video footage from scene was successfully obtained in 19 calls, and was used by the dispatcher as an aid to send (5) or stand down (14) a Helicopter Emergency Medical Services team.

Conclusion

Live video footage from a 112 caller can be used to provide dispatchers with more information from the scene of an incident and the clinical condition of the patient(s). The use of mobile phone video was readily accepted by the 112 caller and the technology robust. Further research is warranted to assess the impact video from scene could have on HEMS dispatching.

TP1-9 Vestibular dysfunction in acute traumatic brain injury

Objectives

Vestibular dysfunction following traumatic brain injury (TBI) is a major cause of morbidity and unemployment and has impact on the patient’s ability to rehabilitate. Chronically, up to a quarter of TBI cases have cryptogenic dizziness and imbalance, possibly due to chronic brain adaptation that masks the diagnosis. Establishing the spectrum of vestibular diagnoses in acute TBI – when they may be more obvious – may aid diagnosis in chronic TBI cases.

Design

Prospective audit of referrals to specialist neuro-otology team.

Subjects

Consecutive Major Trauma Ward TBI in-patients admitted between June 2014 and May 2015.

Methods

All cases were screened by the therapists for vestibular symptoms and/or signs and referred for specialist neuro-otology review.

Results

Of 111 patients screened, 96 had features of vestibular dysfunction. Of 96 cases, SYMPTOMS (i.e. subjective report) included: – imbalance (58.3%) – headache (50%) -dizziness (40%) Of 96 cases, SIGNS (i.e. examination) included: – gait ataxia (75.5%) – broken smooth pursuit (61.2%) – positive Hallpike (51%) – positive head impulse test (18%). The data indicate that BPPV affects 49% and headache with migraine-like features affect 40.8%. Acute peripheral unilateral vestibular loss affects 18% TBI cases.

Conclusions

Vestibular dysfunction in TBI is common, typically involving peripheral and central structures, often in the same case, and requires specialist neuro-otological management.

Redox regulation of cell proliferation: Bioinformatics and redox proteomics approaches to identify redox-sensitive cell cycle regulators

Plant stem cells are the foundation of plant growth and development. The balance of quiescence and division is highly regulated, while ensuring that proliferating cells are protected from the adverse effects of environment fluctuations that may damage the genome. Redox regulation is important in both the activation of proliferation and arrest of the cell cycle upon perception of environmental stress. Within this context, reactive oxygen species serve as 'pro-life' signals with positive roles in the regulation of the cell cycle and survival. However, very little is known about the metabolic mechanisms and redox-sensitive proteins that influence cell cycle progression. We have identified cysteine residues on known cell cycle regulators in Arabidopsis that are potentially accessible, and could play a role in redox regulation, based on secondary structure and solvent accessibility likelihoods for each protein. We propose that redox regulation may function alongside other known posttranslational modifications to control the functions of core cell cycle regulators such as the retinoblastoma protein. Since our current understanding of how redox regulation is involved in cell cycle control is hindered by a lack of knowledge regarding both which residues are important and how modification of those residues alters protein function, we discuss how critical redox modifications can be mapped at the molecular level.

Oxidative stress-triggered interactions between the succinyl- and acetyl-proteomes of rice leaves

Protein lysine acylations, such as succinylation and acetylation, are important post-translational modification (PTM) mechanisms, with key roles in cellular regulation. Antibody-based affinity enrichment, high-resolution liquid chromatography mass spectrometry analysis, and integrated bioinformatics analysis were used to characterize the lysine succinylome (K_suc ) and acetylome (K_ace ) of rice leaves. In total, 2,593 succinylated and 1,024 acetylated proteins were identified, of which 723 were simultaneously acetylated and succinylated. Proteins involved in photosynthetic carbon metabolism such as the large and small subunits of RuBisCO, ribosomal functions, and other key processes were subject to both PTMs. Preliminary insights into oxidant-induced changes to the rice acetylome and succinylome were gained from treatments with hydrogen peroxide. Exposure to oxidative stress did not regulate global changes in the rice acetylome or succinylome but rather led to modifications on a specific subset of the identified sites. De-succinylation of recombinant catalase (CATA) and glutathione S-transferase (OsGSTU6) altered the activities of these enzymes showing that this PTM may have a regulatory function. These findings not only greatly extend the list of acetylated and/or succinylated proteins but they also demonstrate the close cooperation between these PTMs in leaf proteins with key metabolic functions.

The Auxin-Regulated CrRLK1L Kinase ERULUS Controls Cell Wall Composition during Root Hair Tip Growth

Root hairs facilitate a plant's ability to acquire soil anchorage and nutrients. Root hair growth is regulated by the plant hormone auxin and dependent on localized synthesis, secretion, and modification of the root hair tip cell wall. However, the exact cell wall regulators in root hairs controlled by auxin have yet to be determined. In this study, we describe the characterization of ERULUS (ERU), an auxin-induced Arabidopsis receptor-like kinase, whose expression is directly regulated by ARF7 and ARF19 transcription factors. ERU belongs to the Catharanthus roseus RECEPTOR-LIKE KINASE 1-LIKE (CrRLK1L) subfamily of putative cell wall sensor proteins. Imaging of a fluorescent fusion protein revealed that ERU is localized to the apical root hair plasma membrane. ERU regulates cell wall composition in root hairs and modulates pectin dynamics through negative control of pectin methylesterase (PME) activity. Mutant eru (-/-) root hairs accumulate de-esterified homogalacturonan and exhibit aberrant pectin Ca²⁺-binding site oscillations and increased PME activity. Up to 80% of the eru root hair phenotype is rescued by pharmacological supplementation with a PME-inhibiting catechin extract. ERU transcription is altered in specific cell wall-related root hair mutants, suggesting that it is a target for feedback regulation. Loss of ERU alters the phosphorylation status of FERONIA and H⁺-ATPases 1/2, regulators of apoplastic pH. Furthermore, H⁺-ATPases 1/2 and ERU are differentially phosphorylated in response to auxin. We conclude that ERULUS is a key auxin-controlled regulator of cell wall composition and pectin dynamics during root hair tip growth.

Deep machine learning provides state-of-the-art performance in image-based plant phenotyping

In plant phenotyping, it has become important to be able to measure many features on large image sets in order to aid genetic discovery. The size of the datasets, now often captured robotically, often precludes manual inspection, hence the motivation for finding a fully automated approach. Deep learning is an emerging field that promises unparalleled results on many data analysis problems. Building on artificial neural networks, deep approaches have many more hidden layers in the network, and hence have greater discriminative and predictive power. We demonstrate the use of such approaches as part of a plant phenotyping pipeline. We show the success offered by such techniques when applied to the challenging problem of image-based plant phenotyping and demonstrate state-of-the-art results (>97% accuracy) for root and shoot feature identification and localization. We use fully automated trait identification using deep learning to identify quantitative trait loci in root architecture datasets. The majority (12 out of 14) of manually identified quantitative trait loci were also discovered using our automated approach based on deep learning detection to locate plant features. We have shown deep learning-based phenotyping to have very good detection and localization accuracy in validation and testing image sets. We have shown that such features can be used to derive meaningful biological traits, which in turn can be used in quantitative trait loci discovery pipelines. This process can be completely automated. We predict a paradigm shift in image-based phenotyping bought about by such deep learning approaches, given sufficient training sets.

Enhancing faba bean (Vicia faba L.) genome resources

Grain legume improvement is currently impeded by a lack of genomic resources. The paucity of genome information for faba bean can be attributed to the intrinsic difficulties of assembling/annotating its giant (~13 Gb) genome. In order to address this challenge, RNA-sequencing analysis was performed on faba bean (cv. Wizard) leaves. Read alignment to the faba bean reference transcriptome identified 16 300 high quality unigenes. In addition, Illumina paired-end sequencing was used to establish a baseline for genomic information assembly. Genomic reads were assembled de novo into contigs with a size range of 50-5000 bp. Over 85% of sequences did not align to known genes, of which ~10% could be aligned to known repetitive genetic elements. Over 26 000 of the reference transcriptome unigenes could be aligned to DNA-sequencing (DNA-seq) reads with high confidence. Moreover, this comparison identified 56 668 potential splice points in all identified unigenes. Sequence length data were extended at 461 putative loci through alignment of DNA-seq contigs to full-length, publicly available linkage marker sequences. Reads also yielded coverages of 3466× and 650× for the chloroplast and mitochondrial genomes, respectively. Inter- and intraspecies organelle genome comparisons established core legume organelle gene sets, and revealed polymorphic regions of faba bean organelle genomes.

Dynamic regulation of auxin oxidase and conjugating enzymes AtDAO1 and GH3 modulates auxin homeostasis

The hormone auxin is a key regulator of plant growth and development, and great progress has been made understanding auxin transport and signaling. Here, we show that auxin metabolism and homeostasis are also regulated in a complex manner. The principal auxin degradation pathways in Arabidopsis include oxidation by Arabidopsis thaliana gene DIOXYGENASE FOR AUXIN OXIDATION 1/2 (AtDAO1/2) and conjugation by Gretchen Hagen3s (GH3s). Metabolic profiling of dao1-1 root tissues revealed a 50% decrease in the oxidation product 2-oxoindole-3-acetic acid (oxIAA) and increases in the conjugated forms indole-3-acetic acid aspartic acid (IAA-Asp) and indole-3-acetic acid glutamic acid (IAA-Glu) of 438- and 240-fold, respectively, whereas auxin remains close to the WT. By fitting parameter values to a mathematical model of these metabolic pathways, we show that, in addition to reduced oxidation, both auxin biosynthesis and conjugation are increased in dao1-1 Transcripts of AtDAO1 and GH3 genes increase in response to auxin over different timescales and concentration ranges. Including this regulation of AtDAO1 and GH3 in an extended model reveals that auxin oxidation is more important for auxin homoeostasis at lower hormone concentrations, whereas auxin conjugation is most significant at high auxin levels. Finally, embedding our homeostasis model in a multicellular simulation to assess the spatial effect of the dao1-1 mutant shows that auxin increases in outer root tissues in agreement with the dao1-1 mutant root hair phenotype. We conclude that auxin homeostasis is dependent on AtDAO1, acting in concert with GH3, to maintain auxin at optimal levels for plant growth and development.

The effect of deprivation on the incidence of mandibular fractures in a British city

AIM

To examine the relationship between social and material deprivation and mandibular fractures.

METHOD

Three hundred and forty three consecutive patients who underwent mandibular fracture fixation were selected for the study. After exclusions, 290 were divided into age groups and ranked according to their Index of Multiple Deprivation (IMD) score. Rankings were determined using postcodes, and divided into quintiles for statistical analysis.

RESULTS

Ages ranged from 7 to 82 with 146 (50%) patients aged between 20 and 29. Males accounted for 85% of cases. The most common site of fracture was the angle (n = 195) and assault was shown to be the most common mechanism of injury (63.3%). A strong relationship was demonstrated between fractures of the mandible and worsening deprivation, with the most striking relationship seen with fractures sustained as a consequence of assault. Females were less likely than males to sustain a fracture of the mandible as a consequence of assault; however, when assault was the mechanism of injury they were also likely to be from a deprived background.

CONCLUSION

This study has demonstrated that a strong relationship exists between deprivation and the incidence of mandibular fractures in our catchment area. Fractures that resulted from interpersonal violence were shown to have a particularly strong correlation with deprivation.

A practitioner's guide for exploring water quality patterns using principal components analysis and Procrustes

To design sustainable water quality monitoring programs, practitioners must choose meaningful variables, justify the temporal and spatial extent of measurements, and demonstrate that program objectives are successfully achieved after implementation. Consequently, data must be analyzed across several variables and often from multiple sites and seasons. Multivariate techniques such as ordination are common throughout the water quality literature, but methods vary widely and could benefit from greater standardization. We have found little clear guidance and open source code for efficiently conducting ordination to explore water quality patterns. Practitioners unfamiliar with techniques such as principal components analysis (PCA) are faced with a steep learning curve to summarize expansive data sets in periodic reports and manuscripts. Here, we present a seven-step framework for conducting PCA and associated tests. The last step is dedicated to conducting Procrustes analysis, a valuable but rarely used test within the water quality field that describes the degree of concordance between separate multivariate data matrices and provides residual values for similar points across each matrix. We illustrate the utility of these tools using three increasingly complex water quality case studies in US parklands. The case studies demonstrate how PCA and Procrustes analysis answer common applied monitoring questions such as (1) do data from separate monitoring locations describe similar water quality regimes, and (2) what time periods exhibit the greatest water quality regime variability? We provide data sets and annotated R code for recreating case study results and as a base for crafting new code for similar monitoring applications.

Focal atrophy of the masticatory muscles caused by pure trigeminal motor neuropathy: case report

Pure trigeminal motor neuropathy is rare and characterised by weakness of the mandibular motor branch with no signs of involvement of the trigeminal sensory or other cranial nerve. Its aetiology is unclear but it has been hypothesised that a viral infection may be a cause. Magnetic resonance imaging is useful in its diagnosis and typically shows loss of volume of the affected masticatory muscles and infiltration of fat. We describe the case of a 29-year-old woman who presented with a 12-year history of progressive facial asymmetry, which was later shown on imaging to be caused by unilateral atrophy of the masseter with compensatory contralateral hypertrophy.

Inference of the Arabidopsis lateral root gene regulatory network suggests a bifurcation mechanism that defines primordia flanking and central zones

A large number of genes involved in lateral root (LR) organogenesis have been identified over the last decade using forward and reverse genetic approaches in Arabidopsis thaliana. Nevertheless, how these genes interact to form a LR regulatory network largely remains to be elucidated. In this study, we developed a time-delay correlation algorithm (TDCor) to infer the gene regulatory network (GRN) controlling LR primordium initiation and patterning in Arabidopsis from a time-series transcriptomic data set. The predicted network topology links the very early-activated genes involved in LR initiation to later expressed cell identity markers through a multistep genetic cascade exhibiting both positive and negative feedback loops. The predictions were tested for the key transcriptional regulator AUXIN RESPONSE FACTOR7 node, and over 70% of its targets were validated experimentally. Intriguingly, the predicted GRN revealed a mutual inhibition between the ARF7 and ARF5 modules that would control an early bifurcation between two cell fates. Analyses of the expression pattern of ARF7 and ARF5 targets suggest that this patterning mechanism controls flanking and central zone specification in Arabidopsis LR primordia.

Multi-omics analysis identifies genes mediating the extension of cell walls in the Arabidopsis thaliana root elongation zone

Plant cell wall composition is important for regulating growth rates, especially in roots. However, neither analyses of cell wall composition nor transcriptomes on their own can comprehensively reveal which genes and processes are mediating growth and cell elongation rates. This study reveals the benefits of carrying out multiple analyses in combination. Sections of roots from five anatomically and functionally defined zones in Arabidopsis thaliana were prepared and divided into three biological replicates. We used glycan microarrays and antibodies to identify the major classes of glycans and glycoproteins present in the cell walls of these sections, and identified the expected decrease in pectin and increase in xylan from the meristematic zone (MS), through the rapid and late elongation zones (REZ, LEZ) to the maturation zone and the rest of the root, including the emerging lateral roots. Other compositional changes included extensin and xyloglucan levels peaking in the REZ and increasing levels of arabinogalactan-proteins (AGP) epitopes from the MS to the LEZ, which remained high through the subsequent mature zones. Immuno-staining using the same antibodies identified the tissue and (sub)cellular localization of many epitopes. Extensins were localized in epidermal and cortex cell walls, while AGP glycans were specific to different tissues from root-hair cells to the stele. The transcriptome analysis found several gene families peaking in the REZ. These included a large family of peroxidases (which produce the reactive oxygen species (ROS) needed for cell expansion), and three xyloglucan endo-transglycosylase/hydrolase genes (XTH17, XTH18, and XTH19). The significance of the latter may be related to a role in breaking and re-joining xyloglucan cross-bridges between cellulose microfibrils, a process which is required for wall expansion. Knockdowns of these XTHs resulted in shorter root lengths, confirming a role of the corresponding proteins in root extension growth.

Multi-omics analysis identifies genes mediating the extension of cell walls in the Arabidopsis thaliana root elongation zone

Plant cell wall composition is important for regulating growth rates, especially in roots. However, neither analyses of cell wall composition nor transcriptomes on their own can comprehensively reveal which genes and processes are mediating growth and cell elongation rates. This study reveals the benefits of carrying out multiple analyses in combination. Sections of roots from five anatomically and functionally defined zones in Arabidopsis thaliana were prepared and divided into three biological replicates. We used glycan microarrays and antibodies to identify the major classes of glycans and glycoproteins present in the cell walls of these sections, and identified the expected decrease in pectin and increase in xylan from the meristematic zone (MS), through the rapid and late elongation zones (REZ, LEZ) to the maturation zone and the rest of the root, including the emerging lateral roots. Other compositional changes included extensin and xyloglucan levels peaking in the REZ and increasing levels of arabinogalactan-proteins (AGP) epitopes from the MS to the LEZ, which remained high through the subsequent mature zones. Immuno-staining using the same antibodies identified the tissue and (sub)cellular localization of many epitopes. Extensins were localized in epidermal and cortex cell walls, while AGP glycans were specific to different tissues from root-hair cells to the stele. The transcriptome analysis found several gene families peaking in the REZ. These included a large family of peroxidases (which produce the reactive oxygen species (ROS) needed for cell expansion), and three xyloglucan endo-transglycosylase/hydrolase genes (XTH17, XTH18, and XTH19). The significance of the latter may be related to a role in breaking and re-joining xyloglucan cross-bridges between cellulose microfibrils, a process which is required for wall expansion. Knockdowns of these XTHs resulted in shorter root lengths, confirming a role of the corresponding proteins in root extension growth.

Mechanical modelling quantifies the functional importance of outer tissue layers during root elongation and bending

Root elongation and bending require the coordinated expansion of multiple cells of different types. These processes are regulated by the action of hormones that can target distinct cell layers. We use a mathematical model to characterise the influence of the biomechanical properties of individual cell walls on the properties of the whole tissue. Taking a simple constitutive model at the cell scale which characterises cell walls via yield and extensibility parameters, we derive the analogous tissue-level model to describe elongation and bending. To accurately parameterise the model, we take detailed measurements of cell turgor, cell geometries and wall thicknesses. The model demonstrates how cell properties and shapes contribute to tissue-level extensibility and yield. Exploiting the highly organised structure of the elongation zone (EZ) of the Arabidopsis root, we quantify the contributions of different cell layers, using the measured parameters. We show how distributions of material and geometric properties across the root cross-section contribute to the generation of curvature, and relate the angle of a gravitropic bend to the magnitude and duration of asymmetric wall softening. We quantify the geometric factors which lead to the predominant contribution of the outer cell files in driving root elongation and bending.

LAT gel, a powerful tool underused in the repair of paediatric lacerations

Paediatric lacerations presenting to emergency departments are a common cause of referral to surgical specialties in the UK. LAT gel (lidocaine, adrenaline, and tetracaine) is a safe and effective topical anaesthetic that can aid with the closure of uncomplicated lacerations, particularly in the paediatric trauma setting. The benefits to both the patient and management in terms of the avoidance of a general anaesthetic and the freeing up of hospital resources (e.g. beds, staffing, emergency theatre) make it an invaluable tool in the arsenal of the emergency department. The authors describe a reliable method of anaesthetizing lacerations with LAT gel and question its underuse within the emergency departments in the South West region of the UK.

Systems analysis of auxin transport in the Arabidopsis root apex

Auxin is a key regulator of plant growth and development. Within the root tip, auxin distribution plays a crucial role specifying developmental zones and coordinating tropic responses. Determining how the organ-scale auxin pattern is regulated at the cellular scale is essential to understanding how these processes are controlled. In this study, we developed an auxin transport model based on actual root cell geometries and carrier subcellular localizations. We tested model predictions using the DII-VENUS auxin sensor in conjunction with state-of-the-art segmentation tools. Our study revealed that auxin efflux carriers alone cannot create the pattern of auxin distribution at the root tip and that AUX1/LAX influx carriers are also required. We observed that AUX1 in lateral root cap (LRC) and elongating epidermal cells greatly enhance auxin's shootward flux, with this flux being predominantly through the LRC, entering the epidermal cells only as they enter the elongation zone. We conclude that the nonpolar AUX1/LAX influx carriers control which tissues have high auxin levels, whereas the polar PIN carriers control the direction of auxin transport within these tissues.

Neurotrauma - a multidisciplinary disease

Traumatic brain injury is one of the most important diseases of our time, both in terms of morbidity, mortality and economic loss. Public health policy is key to reducing its incidence. Integrated multidisciplinary clinical care is vital to minimise its morbidity and mortality.

Surgical management of acute subdural haematomas: current practice patterns in the United Kingdom and the Republic of Ireland

INTRODUCTION

Uncertainty remains as to the role of decompressive craniectomy (DC) for primary evacuation of acute subdural haematomas (ASDH). In 2011, a collaborative group was formed in the UK with the aim of answering the following question: "What is the clinical- and cost-effectiveness of decompressive craniectomy, in comparison with craniotomy for adult patients undergoing primary evacuation of an ASDH?" The proposed RESCUE-ASDH trial (Randomised Evaluation of Surgery with Craniectomy for patients Undergoing Evacuation of Acute Subdural Haematoma) is a multicentre, pragmatic, parallel group randomised trial of DC versus craniotomy for adult head-injured patients with an ASDH. In this study, we used an online questionnaire to assess the current practice patterns in the management of ASDH in the UK and the Republic of Ireland, and to gauge neurosurgical opinion regarding the proposed RESCUE-ASDH trial.

MATERIALS AND METHODS

A questionnaire survey of full members of the Society of British Neurological Surgeons and members of the British Neurosurgical Trainees Association was undertaken between the beginning of May and the end of July 2012.

RESULTS

The online questionnaire was answered by 95 neurosurgeons representing 31 of the 32 neurosurgical units managing adult head-injured patients in the UK and the Republic of Ireland. Forty-five percent of the respondents use primary DC in at least 25% of patients with ASDH. In addition, of the 22 neurosurgical units with at least two Consultant respondents, only three units (14%) showed intradepartmental agreement regarding the proportion of their patients receiving a primary DC for ASDH.

CONCLUSION

The survey results demonstrate that there is significant uncertainty as to the optimal surgical technique for primary evacuation of ASDH. The fact that the majority of the respondents are willing to become collaborators in the planned RESCUE-ASDH trial highlights the relevance of this important subject to the neurosurgical community in the UK and Ireland.

Identifying biological landmarks using a novel cell measuring image analysis tool: Cell-o-Tape

BACKGROUND

The ability to quantify the geometry of plant organs at the cellular scale can provide novel insights into their structural organization. Hitherto manual methods of measurement provide only very low throughput and subjective solutions, and often quantitative measurements are neglected in favour of a simple cell count.

RESULTS

We present a tool to count and measure individual neighbouring cells along a defined file in confocal laser scanning microscope images. The tool allows the user to extract this generic information in a flexible and intuitive manner, and builds on the raw data to detect a significant change in cell length along the file. This facility can be used, for example, to provide an estimate of the position of transition into the elongation zone of an Arabidopsis root, traditionally a location sensitive to the subjectivity of the experimenter.

CONCLUSIONS

Cell-o-tape is shown to locate cell walls with a high degree of accuracy and estimate the location of the transition feature point in good agreement with human experts. The tool is an open source ImageJ/Fiji macro and is available online.

Statistical evaluation of transcriptomic data generated using the Affymetrix one-cycle, two-cycle and IVT-Express RNA labelling protocols with the Arabidopsis ATH1 microarray

BACKGROUND

Microarrays are a powerful tool used for the determination of global RNA expression. There is an increasing requirement to focus on profiling gene expression in tissues where it is difficult to obtain large quantities of material, for example individual tissues within organs such as the root, or individual isolated cells. From such samples, it is difficult to produce the amount of RNA required for labelling and hybridisation in microarray experiments, thus a process of amplification is usually adopted. Despite the increasing use of two-cycle amplification for transcriptomic analyses on the Affymetrix ATH1 array, there has been no report investigating any potential bias in gene representation that may occur as a result.

RESULTS

Here we compare transcriptomic data generated using Affymetrix one-cycle (standard labelling protocol), two-cycle (small-sample protocol) and IVT-Express protocols with the Affymetrix ATH1 array using Arabidopsis root samples. Results obtained with each protocol are broadly similar. However, we show that there are 35 probe sets (of a total of 22810) that are misrepresented in the two-cycle data sets. Of these, 33 probe sets were classed as mis-amplified when comparisons of two independent publicly available data sets were undertaken.

CONCLUSIONS

Given the unreliable nature of the highlighted probes, we caution against using data associated with the corresponding genes in analyses involving transcriptomic data generated with two-cycle amplification protocols. We have shown that the Affymetrix IVT-E labelling protocol produces data with less associated bias than the two-cycle protocol, and as such, would recommend this kit for new experiments that involve small samples.

Medical emergencies in dental practice

Serious medical emergencies are fortunately a rare occurrence in the dental practice environment; however, if an emergency situation is encountered a delay in treatment may result in potentially avoidable consequences. The risk of mortality or serious morbidity can be reduced by ensuring that basic emergency equipment and medications are in place, and that the dental team is appropriately trained in basic life support measures. This article aims to provide an overview of the basic emergency medications and equipment that should be present in dental practices, and to discuss specific responses to some of the more common adverse medical events that can present while providing dental treatment.

Renal disease and chronic renal failure in dental practice

Patients with renal diseases are increasingly common in dental practice. This is due to advances in medicine, and the increasing life expectancy of western populations. Chronic renal failure is a serious condition that general dental practitioners may see in their practice. This article discusses the functions of the kidney, and the causes and medical management of chronic renal failure, as well as considerations in the dental management of these patients. Common complications such as infection and bleeding are discussed. General recommendations are made, based on current evidence with respect to prescribing of medications.

Epilepsy in dental practice

Epilepsy is a neurological condition characterised by seizure activity. It has an approximate incidence of 1%. General dental practitioners will encounter these patients in practice. This article discusses the types of epilepsy, the medical management and considerations in dental management of epileptic patients. General recommendations are made, based on current evidence, with respect to prescribing of medications. The management of an epileptic seizure is discussed. Status epilepticus is a rare but serious complication of epileptic seizures. An easy-to-follow algorithm is provided to assist the practitioner in managing seizures.

Increased and decreased activity elicits specific morphological adaptations of the neuromuscular junction

The objective of this investigation was to compare the effects of decreased vs. increased activity on the neuromuscular system. Twenty-four young adult (7 weeks old) Sprague-Dawley rats were randomly assigned to three treatment groups (N=8/group). Increased activity was achieved by treadmill running for up to 1 h/day. Decreased activity was induced by muscle unloading via the hindlimb suspension model. Control animals engaged in normal weight bearing and ambulatory activity. At the end of the 10 week intervention period, animals were killed and soleus muscles were removed, quickly frozen, and examined using cytofluorescent (neuromuscular junctions) and histochemical (myofibers) procedures. Pre-synaptic morphology was quantified by measuring nerve terminal branching, and post-synaptic assessment was conducted by staining acetylcholine receptors at the endplate. Myofiber profiles of solei were compiled by determining fiber size (cross-sectional area) and fiber type composition. Results show that exercise training significantly (P<or=0.05) enhanced nerve terminal branching without modifying endplate size. In contrast, muscle unloading failed to influence nerve terminal branching, but significantly reduced endplate dimensions. Likely, the diminution of endplate size among unloaded myofibers was caused by the dramatic loss of size (approximately 60%) observed among those fibers. Both increased and decreased activity evoked reductions in the ratio of endplate area to length of nerve terminal branches, thus altering the pre- to post-synaptic relationship of neuromuscular junctions. In conclusion, the present data demonstrate that both increased and decreased activity significantly remodels the neuromuscular junction, but the locus (pre- vs. post-synaptic) and nature (expansion vs. reduction) of that remodeling are specific to the form of the alteration in activity.

Push–pull effects and emission from ternary complexes of platinum(ii), substituted terpyridines, and the strong-field cyanide ion

As part of an effort to develop new lumaphors involving late transition metal ions, this report describes the synthesis and characterization of the first platinum(II) derivatives containing 2,2':6',2''-terpyridine (trpy) and cyanide as co-ligands. According to existing models, including cyanide in the coordination sphere should raise the energies and minimize the influence of short-lived d-d excited states that otherwise compromise the excited-state lifetime. Both [Pt(trpy)(CN)]+ and the 4'-cyano-2,2':6',2''-terpyridine analogue [Pt(CN-T)(CN)]+ are emissive in dichloromethane solution, but the signals are weak. Part of the problem is that the d-pi* charge-transfer excited states also rise in energy, so that the emission actually originates from a (3)pi-pi* state with a relatively low radiative rate constant. However, another member of the series, the 4'-dimethylamino-2,2':6',2''-terpyridine (dma-T) derivative [Pt(dma-T)(CN)]+, proves to be a very promising platform with an emission quantum yield of phi= 0.26 and an excited-state lifetime of tau = 22 micros in room-temperature, deoxygenated dichloromethane solution. In the dma-T complex the electron-rich dimethylamino substituent provides the basis for an emissive, but largely ligand-based, charge-transfer excited state. The orbital parentage is such that the photoluminescence persists in donating solvents like dimethylformamide, which ordinarily quenches d-pi* excited states in complexes of this type.

A luminescent Pt(ii) complex with a terpyridine-like ligand involving a six-membered chelate ring

The ligand 2-(8'-quinolinyl)-1,10-phenanthroline (1) was prepared in 79% yield by the Friedlander condensation of 8-amino-7-quinolinecarbaldehyde and 8-acetylquinoline. The complex [Pt(1)Cl]+ was prepared and compared with the isomeric 2-(2'-quinolinyl)-1,10-phenanthroline (2) complex. An X-ray analysis indicated that the six-membered chelate ring in the tridentate complex resulted in a relief of angle strain as well as some non-planarity in the bound ligand 1. The control system for photophysical studies is [Pt3Cl]+ where denotes 2-(2'-pyridyl)-1,10-phenanthroline. Relative to the complex of 3, in dichloromethane solution [Pt(1)Cl]+ exhibits noticeably higher energy charge-transfer absorption but slightly lower energy emission. The gap between the onset of absorption and emission is larger because the emission from [Pt(1)Cl]+ originates from a triplet excited state with substantial intra-ligand character. At room temperature in deoxygenated dichloromethane, [Pt(1)Cl]+ has an excited-state lifetime of 310 ns vs. 230 ns for [Pt(1)Cl]+. Within the series, [Pt(1)Cl]+ also exhibits the largest activation barrier for thermally induced quenching at 2730 cm(-1) in fluid dichloromethane solution. However, the barrier is only about 50% larger than that found for [Pt(1)Cl]+. There is reduced ring strain in [Pt(1)Cl]+, but inter-ligand steric interactions weaken the ligand field.

Association between the risk of coronary artery disease in South Asians and a deletion polymorphism in glutathione S-transferase M1

South Asians living in Western societies show a greater risk of coronary artery disease (CAD) than the indigenous Caucasian population, probably related to the change to a Westernised lifestyle and an associated genetic susceptibility. Modulation of DNA damage and mutation caused by polymorphisms in detoxification enzymes, including the glutathione S-transferases (GSTs), is a well-established risk factor for tobacco-related carcinogenesis, and a similar change in cellular damage may be involved in the risk of vascular disease associated with tobacco smoking. In this study we examined whether polymorphisms in GST genes influence the risk of CAD in a case-control group of South Asians, following our recent observation of such an association in Caucasians from the same region of the UK. Blood was obtained from 170 patients of South Asian origin admitted for angiographic investigation of chest pain and from 203 controls. Patients were subdivided into those with and without previous acute myocardial infarction (AMI), and DNA was analysed for deletions in the GSTM1 and GSTT1 genes. An association was found between the prevalence of the GSTM1 null genotype and the risk of developing CAD in this study population. The frequency of the null genotype was 52.7% in healthy controls and 41.2% in patients (odds ratio [OR] 0.63, 95% confidence interval [95% CI] 0.42-0.95, p = 0.029). The effect was similar in subjects with or without a prior history of AMI. The association was also independent of smoking history, with both non-smokers and smokers showing a similar pattern of genotype distribution, the frequency of the null genotype being 51.2% in controls versus 37.0% in patients in 'never' smokers (OR 0.56, 95% CI 0.33-0.94, p = 0.037) and 60.0% in controls versus 46.2% in patients in 'ever' smokers (OR 0.57, 95% CI 0.25-1.28, p = 0.223). The association remained after adjusting for age, sex, body mass index and the presence or absence of stenosis. No significant associations were observed between the GSTT1 genotype and cardiovascular disease (chi(2) test, p > 0.1). The results of this study indicate that the GSTM1 null genotype is protective against both CAD and AMI. However, further study is required in order to elucidate the, as yet unexplained, mechanisms underlying this association.

Ultrasound measurement of transcranial distance during head-down tilt

Exposure to microgravity elevates blood pressure and flow in the head, which may increase intracranial volume (ICV) and intracranial pressure (ICP). Rhesus monkeys exposed to simulated microgravity in the form of 6 degrees head-down tilt (HDT) experience elevated ICP. With humans, twenty-four hours of 6 degrees HDT bed rest increases cerebral blood flow velocity relative to pre-HDT upright posture. Humans exposed to acute 6 degrees HDT experience increased ICP, measured with the tympanic membrane displacement (TMD) technique. Other studies suggest that increased ICP in humans and cats causes measurable cranial bone movement across the sagittal suture. Due to the slightly compliant nature of the cranium, elevation of ICP will increase ICV and transcranial distance. Currently, several non-invasive approaches to monitor ICP are being investigated. Such techniques include TMD and modal analysis of the skull. TMD may not be reliable over a large range of ICP and neither method is capable of measuring the small changes in intracranial volume that accompany changes in pressure. Ultrasound, however, may reliably measure small distance changes that accompany ICP fluctuations. The purpose of our study was to develop and evaluate an ultrasound technique to measure transcranial distance changes during HDT.

The role of a conserved inter-transmembrane domain interface in regulating alpha(2a)-adrenergic receptor conformational stability and cell-surface turnover

Functional and structural data from G protein-coupled receptors (GPCR) predict that transmembrane-domain (TM)2 is adjacent to TM7 within the GPCR structure, and that within this interface a conserved aspartate in TM2 and a conserved asparagine in TM7 exist in close proximity. Mutation at this D79(TM2)-N422(TM7) interface in the alpha(2A)-adrenergic receptor (alpha(2A)AR) affects not only receptor activation but also cell-surface residence time and conformational stability. Mutation at TM2(D79N) reduces allosteric modulation by Na(+) and receptor activation more dramatically than affecting cell-surface receptor turnover and conformational stability, whereas mutation at TM7(N422D) creates profound conformational instability and more rapid degradation of receptor from the surface of cells despite receptor activation and allosteric modulation properties that mirror a wild-type receptor. Double mutation of TM2 and 7(D79N/N422D) reveals phenotypes for receptor activation and conformational stability intermediate between the wild-type and singly mutated alpha(2A)AR. Additionally, the structural placement of a negative charge at this TM2/TM7 interface is necessary but not sufficient for receptor structural stability, because mislocalization of the negative charge in either the D79E alpha(2A)AR (which extends the charge out one methylene group) or the D79N/N422D alpha(2A)AR (placing the charge in TM7 instead of TM2) results in conformational lability in detergent solution and more rapid cell-surface receptor clearance. These studies suggest that this interface is important in regulating receptor cell-surface residence time and conformational stability in addition to its previously recognized role in receptor activation.

Factors preventing gun acquisition and carrying among incarcerated adolescent males

CONTEXT

Despite the wide availability of guns in the United States, not all delinquent adolescents own guns and not all adolescent gun owners carry them at all times. Research about the factors that prevent high-risk youth from acquiring and carrying guns is limited.

OBJECTIVE

To determine, from the perspective of incarcerated adolescent males, factors that prevent acquiring or carrying guns, either on a temporary or permanent basis.

DESIGN AND SETTING

In-depth, semistructured interviews were conducted with randomly selected incarcerated adolescent males at a residential juvenile justice facility from January to May 1998. Transcribed interviews were examined for recurrent themes.

PARTICIPANTS

Forty-five incarcerated adolescent males.

MAIN OUTCOME MEASURES

Reported factors limiting gun acquisition and carrying.

RESULTS

Seventy-one percent of the sample had either owned or carried a gun out of their home. We identified 6 recurring themes that, at least on occasion, prevented or delayed delinquent youth from acquiring or carrying guns. The most commonly cited factors were fear of being arrested and incarcerated and lack of perceived need for a gun. Other themes included not wanting to hurt oneself or others, respect for the opinions of others, inability to find a source for a desired gun, and lack of money to acquire a desired gun.

CONCLUSIONS

We identified 6 factors that limited gun acquisition and carrying among a sample of incarcerated male adolescents. Knowledge of these factors should inform intervention efforts to reduce youth gun acquisition and carrying.

Screening for iron deficiency anemia by dietary history in a high-risk population

BACKGROUND

Iron deficiency anemia (IDA) in young children is important to identify because of its adverse effects on behavior and development. Because of costs and inconvenience associated with blood test screening and the decline in prevalence of IDA, the Institute of Medicine and the Centers for Disease Control and Prevention recommend that blood test screening for IDA be targeted to children first identified by dietary and health history.

OBJECTIVE

To evaluate a parent-completed dietary and health history as the first stage of 2-stage screening for IDA.

DESIGN AND METHODS

A cross-sectional study was conducted in inner-city clinics in children 9 to 30 months old having routine anemia screening as part of a scheduled visit. Parents completed a questionnaire and children had venous blood sampling for complete blood count and ferritin. Anemia was defined as Hb <11.0 g/dL. Iron deficiency (ID) was defined as ferritin <10 microg/L or mean corpuscular volume <70 fL and red cell distribution width >14.5%. Children were categorized into 1 of 4 groups: iron-sufficient, not anemic (ISNA); iron-sufficient, anemic (ISA); iron-deficient, not anemic (IDNA); and iron-deficient anemic (IDA). The questionnaire consisted of 15 dietary items in domains of infant diet, intake of solid food, intake of beverages, and participation in the Special Supplemental Nutrition Program for Women, Infants, and Children together with 14 historical items in domains of birth history, recent illness, chronic medical conditions, history of anemia, and maternal history. Analysis was performed on individual items, domains, and combinations of selected items.

RESULTS

In the 282 study subjects, the prevalence of anemia (35%), IDNA (7%), and IDA (8%) did not vary significantly by age. Among individual historical and dietary questions, maternal history of anemia and drinking >2 glasses of juice per day identified the highest proportion of children with IDA: 50% sensitivity (95% confidence interval [CI]: 16,81) and 77% sensitivity (95% CI: 54,89), respectively. However, specificities for these questions were 60% (95% CI: 55,65) and 22% (95% CI: 17,27), respectively. Domains of questions with the highest sensitivity for IDA were beverage intake (91%; 95% CI: 68,99) and intake of solid food (91%; 95% CI: 68,99). However, specificities of the domains were only 14% (95% CI: 10,18) and 29% (95% CI: 24,35), respectively. The dietary items used by Boutry and Needlman were 95% (95% CI: 77, 99) sensitive but only 15% (95% CI: 11,19) specific for IDA. The recommendations of the Centers for Disease Control and Prevention for health and dietary screening were 73% (95% CI: 56,92) sensitive and 29% (95% CI: 24,35) specific for IDA. The individual questions, domains of questions, and interdomain groups of questions had similar sensitivity and specificity for anemia and ID (IDA + IDNA).

CONCLUSION

In this high-risk population, neither individual nor combinations of parental answers to dietary and health questions were able to predict IDA, anemia, or ID well enough to serve as a first-stage screening test.

Glutathione S-transferase M1 null genotype is associated with a decreased risk of myocardial infarction

Tobacco smoke is a major cause of both cancer and vascular disease. Although its carcinogenic role via induction of DNA damage and mutation is well established, the mechanisms involved in vascular disease remain unclear. One possibility is that DNA damage causes smooth muscle cell proliferation in the intima of arteries, thereby contributing to atherothrombotic processes. The binding of chemicals to DNA is modulated by detoxification enzymes, including glutathione S-transferases (GST) and microsomal epoxide hydrolase (EPXH). We therefore examined whether polymorphisms in these genes influence risk of cardiovascular disease. Blood was obtained from 398 patients admitted for angiographic investigation of chest pain and 196 age- and sex-matched controls. Patients were subdivided into those with and without previous acute myocardial infarction (AMI). DNA was analyzed for deletions in the GSTM1 and T1 genes and for substitutions in EPXH and GSTP1 genes. The GSTM1 null genotype occurred at a significantly lower frequency in the AMI patient group (48%) compared both to patients with no history of AMI (59%) and to the control group (57.2%). When subjects were stratified for smoking status, a significant association was observed only in smokers, suggesting the polymorphism is more important in the presence of tobacco smoke exposure. The association remained significant after adjusting for age, sex, and stenosis (presence or absence). No significant associations were observed between the other genotypes and cardiovascular disease (chi(2) test; P>0.1). The results of this study indicate that the GSTM1 null genotype is protective against AMI, an effect that is more marked in smokers. However, further study is required in order to elucidate the as yet unexplained, mechanisms underlying this association.

Mechanisms regulating the cell surface residence time of the alpha 2A-adrenergic receptor

Despite considerable insights concerning the mechanisms regulating short-term agonist-mediated G protein-coupled receptor (GPCR) internalization, little is known about the mechanisms regulating GPCR surface residence over long periods of time. Herein, we experimentally evaluated mechanisms regulating the surface t(1/2) of various alpha(2A)-adrenergic receptor (alpha(2A)AR) structures. The Delta 3i alpha(2A)AR (lacking the third intracellular loop), D79N alpha(2A)AR (impaired G protein coupling), and CAM alpha(2A)AR (enhanced G protein coupling) all exhibited a cell surface alpha(2A)AR turnover in Chinese hamster ovary cells that was faster than that of the wild type (WT). Cell surface receptor turnover could be slowed with ligand occupancy of D79N alpha(2A)AR (agonist or antagonist) and CAM alpha(2A)AR (antagonist only) but not the Delta 3i- or WT alpha(2A)AR. This selective ligand-induced surface stabilization was paralleled by a dramatic ligand-dependent receptor density upregulation for D79N- and CAM alpha(2A)AR structures. Receptors which exhibited surface turnover and density that could be modulated by ligand (D79N and CAM) also demonstrated structural instability, measured by a loss of radioligand binding capacity in detergent solution over time without parallel changes in receptor protein content. In contrast, the shorter surface t(1/2) of the Delta 3i alpha(2A)AR, whose cell surface t(1/2) and steady state density were not altered by ligand occupancy, occurred in the context of a structurally stable receptor in detergent solution. These results demonstrate that changes in receptor structure which alter receptor-G protein coupling (either an increase or decrease) are paralleled by structural instability and ligand-induced surface stabilization. These studies also provide criteria for assessing the structural instability of the alpha(2A)AR that can likely be generalized to all GPCRs.

Why don't physicians follow clinical practice guidelines? A framework for improvement

CONTEXT

Despite wide promulgation, clinical practice guidelines have had limited effect on changing physician behavior. Little is known about the process and factors involved in changing physician practices in response to guidelines.

OBJECTIVE

To review barriers to physician adherence to clinical practice guidelines.

DATA SOURCES

We searched the MEDLINE, Educational Resources Information Center (ERIC), and HealthSTAR databases (January 1966 to January 1998); bibliographies; textbooks on health behavior or public health; and references supplied by experts to find English-language article titles that describe barriers to guideline adherence.

STUDY SELECTION

Of 5658 articles initially identified, we selected 76 published studies describing at least 1 barrier to adherence to clinical practice guidelines, practice parameters, clinical policies, or national consensus statements. One investigator screened titles to identify candidate articles, then 2 investigators independently reviewed the texts to exclude articles that did not match the criteria. Differences were resolved by consensus with a third investigator.

DATA EXTRACTION

Two investigators organized barriers to adherence into a framework according to their effect on physician knowledge, attitudes, or behavior. This organization was validated by 3 additional investigators.

DATA SYNTHESIS

The 76 articles included 120 different surveys investigating 293 potential barriers to physician guideline adherence, including awareness (n = 46), familiarity(n = 31), agreement (n = 33), self-efficacy (n = 19), outcome expectancy (n = 8), ability to overcome the inertia of previous practice (n = 14), and absence of external barriers to perform recommendations (n = 34). The majority of surveys (70 [58%] of 120) examined only 1 type of barrier.

CONCLUSIONS

Studies on improving physician guideline adherence may not be generalizable, since barriers in one setting may not be present in another. Our review offers a differential diagnosis for why physicians do not follow practice guidelines, as well as a rational approach toward improving guideline adherence and a framework for future research.

Use of social services by pregnant Medicaid eligible women in Baltimore

OBJECTIVES

To use linked health and social service databases to determine differences in the use of social services by pregnant women in different managed care systems.

METHODS

Comparison of service use by women enrolled in a fee-for-service primary care case management program (Maryland Access to Care or MAC), in a capitated health maintenance organization (HMO), or not assigned to managed care using six state databases. Participants included 5181 women receiving Medical Assistance (MA) and delivering in Baltimore City in 1993. Outcome measures were receipt of WIC, AFDC, and Food Stamps.

RESULTS

The overall proportions of women receiving WIC, AFDC, and Food Stamps at delivery were 52.7%, 89.2%, and 62.7%, respectively. Women enrolled in an HMO at delivery were less likely to be receiving WIC (adjusted odds ratios, 0.8, 95% CI, 0.69 to 0.93), AFDC (OR, 0.20; CI, 0.03 to 0.43 for women with prior children and OR 0.13; CI, 0.09 to 0.20 for women without prior children), and Food Stamps (OR 0.77; CI, 0.59 to 0.95 for women with prior children and OR, 0.49; CI, 0.35 to 0.67 for women without prior children) than their MAC counterparts. Women not assigned to managed care also generally were less likely than their MAC counterparts to receive WIC (OR 0.55; CI, 0.46, 0.66), AFDC (OR 1.07; CI 0.83, 1.30 for women with prior children and OR 0.24; CI 0.18, 0.34 for women without prior children), and Food Stamps (OR 0.31; CI 0.08, 0.55 for women with prior children and OR 0.31; CI 0.23, 0.41 for women without prior children).

CONCLUSIONS

Although many low-income pregnant women qualify for select social services, receipt of WIC and Food Stamps was low. Increasing efforts are needed by managed care systems and public health agencies to ensure delivery of appropriate services for women.

Relationship between primary care practices in medical school admission and the matriculation of underrepresented-minority and female applicants

PURPOSE

To determine whether primary care-oriented (generalist) admission practices at U.S. medical schools address physician workforce diversity issues by resulting in the admission of more members of underrepresented-minority populations or more women.

METHOD

The authors performed cross-sectional, secondary analyses of databases from the Association of American Medical Colleges (AAMC). The independent variables were four generalist admission practices: generalist admission committee chair, greater representation of generalists on admission committee, offering preferential admission to likely generalists, and having a premedical recruitment activity targeting likely generalists. The control variable was public/private school ownership. The dependent variables were the mean ages of the matriculating classes and the proportions of students at each school who were African American, (total) underrepresented minorities, women, and married.

RESULTS

Ninety-five percent of medical schools completed the AAMC's Survey of Generalist Physician Initiatives in either 1993 and 1994; 94% of matriculants replied to the AAMC's 1994 Matriculating Student Questionnaire. In multivariable analyses, no admission practice was associated with percentages of African Americans, total underrepresented minorities, or women.

CONCLUSIONS

Schools with primary care-oriented admission practices did not admit greater percentages of underrepresented-minority students or women. Additional efforts may be required to attract and admit minority and female applicants.

Evaluation of the alpha(2A)-adrenergic receptor gene in a heritable form of temporal lobe epilepsy

An autosomal dominant form of human temporal lobe epilepsy (TLE) has been mapped to a region of chromosome 10q that contains the intronless alpha(2A)-adrenergic receptor (alpha(2A)AR) gene. Because mutation of the alpha(2A)AR gene in the mouse fosters epileptogenesis, we developed methods for analysis of the alpha(2A)AR coding region applicable to any pathophysiologic state in which the alpha(2A)AR could be implicated in the disease mechanism. This study rules out mutations in the alpha(2A)AR coding region as causal for this form of autosomal dominant TLE.

Associations between primary care-oriented practices in medical school admission and the practice intentions of matriculants

PURPOSE

To assess associations of primary-care-oriented medical school admission practices with matriculants practice intentions.

METHOD

The authors performed cross-sectional, secondary analyses of databases from the Association of American Medical Colleges (AAMC). The independent variables were four medical school admission practices. The control variable was school ownership (public vs private). The dependent variables were the proportions of matriculants at each school interested in generalism, rural practice, and locating in a socioeconomically deprived area.

RESULTS

One hundred and twenty medical schools (95%) completed the AAMC's Survey of Generalist Physician Initiatives in either 1993 or 1994; 94% of matriculants replied to the AAMC's 1994 Matriculating Student Questionnaire. Twenty-five percent of the schools had admission committee chairs who were generalists, half had over 25% generalists on their admission committees, 64% gave admission preference to students likely to become generalists, and 33% reported premedical recruitment efforts that targeted applicants likely to become generalists. In multivariable analyses, premedical recruitment efforts and public school ownership (all p < .01) were associated with greater interest of matriculants in both generalism and rural practice.

CONCLUSIONS

Public medical schools and schools with premedical recruitment activities targeting future generalists admitted greater proportions of students interested in primary care and rural practice.