Genome-Wide Association Study of Chronic Dizziness in the Elderly Identifies Loci Implicating MLLT10, BPTF, LINC01224, and ROS1

PURPOSE

Chronic age-related imbalance is a common cause of falls and subsequent death in the elderly and can arise from dysfunction of the vestibular system, an elegant neuroanatomical group of pathways that mediates human perception of acceleration, gravity, and angular head motion. Studies indicate that 27-46% of the risk of age-related chronic imbalance is genetic; nevertheless, the underlying genes remain unknown.

METHODS

The cohort consisted of 50,339 cases and 366,900 controls in the Million Veteran Program. The phenotype comprised cases with two ICD diagnoses of vertigo or dizziness at least 6 months apart, excluding acute or recurrent vertiginous syndromes and other non-vestibular disorders. Genome-wide association studies were performed as individual logistic regressions on European, African American, and Hispanic ancestries followed by trans-ancestry meta-analysis. Downstream analysis included case-case-GWAS, fine mapping, probabilistic colocalization of significant variants and genes with eQTLs, and functional analysis of significant hits.

RESULTS

Two significant loci were identified in Europeans, another in the Hispanic population, and two additional in trans-ancestry meta-analysis, including three novel loci. Fine mapping revealed credible sets of intronic single nucleotide polymorphisms (SNPs) in MLLT10 - a histone methyl transferase cofactor, BPTF - a subunit of a nucleosome remodeling complex implicated in neurodevelopment, and LINC01224 - a proto-oncogene receptor tyrosine kinase.

CONCLUSION

Despite the difficulties of phenotyping the nature of chronic imbalance, we replicated two loci from previous vertigo GWAS studies and identified three novel loci. Findings suggest candidates for further study and ultimate treatment of this common elderly disorder.

Diversity and Scale: Genetic Architecture of 2,068 Traits in the VA Million Veteran Program

Genome-wide association studies (GWAS) have underrepresented individuals from non-European populations, impeding progress in characterizing the genetic architecture and consequences of health and disease traits. To address this, we present a population-stratified phenome-wide GWAS followed by a multi-population meta-analysis for 2,068 traits derived from electronic health records of 635,969 participants in the Million Veteran Program (MVP), a longitudinal cohort study of diverse U.S. Veterans genetically similar to the respective African (121,177), Admixed American (59,048), East Asian (6,702), and European (449,042) superpopulations defined by the 1000 Genomes Project. We identified 38,270 independent variants associating with one or more traits at experiment-wide P < 4.6 × 10 - 11 significance; fine-mapping 6,318 signals identified from 613 traits to single-variant resolution. Among these, a third (2,069) of the associations were found only among participants genetically similar to non-European reference populations, demonstrating the importance of expanding diversity in genetic studies. Our work provides a comprehensive atlas of phenome-wide genetic associations for future studies dissecting the architecture of complex traits in diverse populations.

1288 Colorectal Cancer Surgery Service Provision During The COVID-19 Pandemic: An Assessment of a Single Trust

Aim

Post-operative pulmonary complications in perioperative SARS-CoV-2 infection are associated with significant morbidity and mortality. To maintain a safe cancer service, the Countess of Chester Hospital adopted “Cold-site” operating and maintained ERAS principles for patients undergoing elective colorectal cancer surgery during the pandemic. A comparative assessment of service was undertaken for benchmarking purposes.

Method

A comparative retrospective audit was undertaken of consecutive patients undergoing elective colorectal cancer surgery from June to November 2019 and compared to June to November 2020. The Somerset Cancer Registry and electronic medical case records were used to obtain the dataset. Outcomes measured were approach to surgery; stoma rate; length of stay; level of care required; post-operative complications (&gt;Clavien-Dindo 2) and survival at 30 days. Mann-Whitney U test and Chi-squared were used for analysis.

Results

There were 33 and 24 elective colorectal cancer operations in 2019 and 2020 respectively. There was no difference in the median age (64:69; p = 0.3) or ASA grade (p = 0.9). The median length of stay was 5 and 4 days respectively (p = 0.3). There was a 32.2% reduction in laparoscopic approach to surgery in 2020 (69.7% vs 37.5%; p = 0.02). There was no difference in the stoma rate (p = 0.9), post-operative complication rate (p = 0.7), ITU admission rate (p = 0.3), length of ITU stay (p = 0.6) and 30-day mortality rates (p = 0.4).

Conclusions

“Cold-site” operating allows robust ERAS care to be adopted to ensure comparative outcomes for patients undergoing colorectal cancer surgery and was associated with a non-significant trend to shorter hospital stay during the COVID-19 pandemic.

1522 Management of Benign Anastomotic Strictures Post-Rectal Resection: A Systematic Review

Aim

Approximately a third of all colorectal cancers diagnosed in the UK each year are rectal in origin and will undergo surgical resection with formation of an anastomosis. Focus is placed on techniques to ensure anastomotic integrity however an anastomotic leak, pelvic sepsis, distance to the anal verge and stapler choice are all established risk factors for the formation of a benign anastomotic stricture. This review aimed to assess the use of endoscopic salvage techniques in an attempt to avoid surgical re-intervention.

Method

A literature search was performed for published full text articles using the PubMed, Cochrane and Scopus databases. Additional papers were detected by scanning the references of relevant papers.

Results

A total of 40 papers were included focusing upon balloon dilation, stent insertion, electroincision, stapler stricturoplasty and corticosteroid use. Endoscopic balloon dilatation remains the most commonly used technique in the management of anastomotic strictures, with a low complication rate despite the frequent requirement for repeated dilatations. Although established in the role for malignant obstruction, stent insertion is yet to gain an established role in the benign setting.

Conclusions

Benign anastomotic strictures can be a significant problem post-rectal resection, impacting upon quality of life and requiring repeated intervention. Endoscopic management should be utilised in the primary setting to avoid surgical re-intervention. Standardisation of these methods is imperative in establishing the best modality of treatment. For refractory strictures a low threshold of suspicion for malignant recurrence should be maintained.

457 Survey of Perceived Barriers to Medical Students for Progression into Surgery

Introduction

Applications for surgical training have been decreasing despite higher numbers of medical school graduates. We sought to explore the perceived barriers to medical students for progression into surgery.

Method

An online anonymised SurveyMonkey® questionnaire aimed at medical students was disseminated in May 2020, with survey invitations advertised through social media.

Results

A total of 271 responses were obtained, with 95% of respondents being undergraduates and a 7:3 female to male ratio. Approximately one-fifth (19%) were considering pursuing a career in surgery. 82% of students had observed in an operating theatre. 54% of respondents agreed that their surgical rotation was a positive experience, 21% neutral, 8% negative.

Most frequent perceived barriers included lack of work-life balance (77%), surgical culture (67%), lengthy post-graduate training pathway (63%), and competitive entry of surgical specialties (63%). Others included a lack of understanding of surgical career pathways (52%), limited exposure to surgery (47%), and lack of interest (37%). Notably, gender bias was a barrier for many (35%). Most wanted more exposure to surgery through surgical skills teaching (85%), theatre experience (67%), surgical placements (59%) and didactic teaching (33%).

Conclusions

Modifiable barriers need to be addressed in undergraduate and postgraduate training to boost the number of applications into surgical training.

667 Virtual Learning During The COVID-19 Pandemic Amongst Medical Students in The United Kingdom

Introduction

Throughout the COVID-19 pandemic medical education has predominantly been delivered through virtual learning (VL). This survey was conducted to evaluate the effectiveness of VL amongst medical students in the UK.

Method

An online anonymised SurveyMonkey© survey was distributed through social media amongst UK medical students.

Results

There were 142 completed surveys, 96.5% of students engaged in some form of VL during the pandemic, compared to 57.8% prior to the pandemic. The most frequently used method to deliver teaching was interactive online lectures (74.7%). The students perceived small group online teaching sessions to be the most effective delivery method (weighted average 7.4/10) followed by interactive online lectures (7.4/10). The least effective teaching method was online lecture notes (5.3/10).

Accessibility to coursework (8.6/10) and enhanced flexibility (8.4/10) were considered to be the biggest advantages of VL. Overall, 44% of students felt VL had a negative impact on their learning, with 23% of students considered to have failed to meet the learning objectives set out in these sessions.

Conclusions

Beyond the COVID-19 pandemic VL will continue to play a role in medical education. However, there is room for improvement in both delivery and engagement to improve student experience and satisfaction.

455 Proton Beam Therapy in Rectal Cancer: A Systematic Review and Meta-Analysis

Introduction

Radiotherapy for locally advanced rectal cancer is conventionally performed using photon-based radiotherapy (PBR), carrying significant risk of toxicity to organs at risk (OAR). Proton beam therapy (PBT) potentially delivers equivalent dosimetric radiation to the targeted tissue with improved sparing of OAR. We aimed to compare dosimetric irradiation of OAR for PBT versus PBR in patients with rectal cancer and assess any oncological outcomes.

Method

An extensive electronic literature search was performed from inception till April 2020 and subsequent meta-analysis performed.

Results

Six articles met the inclusion criteria. Dosimetric data of irradiation delivered to OAR for PBT and PBR were calculated for the same patients. PBT had significantly less irradiated small bowel compared to 3DCRT and IMRT, (MD -16.95, 95% CI [-24.03, -9.88], p &lt; 0.00001) and (MD -6.96, 95% CI [-12.99, -0.94], p = 0.02) respectively. Similar results were observed for bladder and pelvic bone marrow. Two studies reported clinical and oncological results for PBT in recurrent rectal cancer with overall survival reported as 43% and 68%.

Conclusions

Dosimetric treatment plans have less irradiation of OAR for rectal cancer with PBT compared to PBR. There is a need for further research in PBT and rectal cancer, as promising results have been shown in recurrent rectal cancer.

Marked Increases in Resting-State MEG Gamma-Band Activity in Combat-Related Mild Traumatic Brain Injury

Combat-related mild traumatic brain injury (mTBI) is a leading cause of sustained impairments in military service members and veterans. Recent animal studies show that GABA-ergic parvalbumin-positive interneurons are susceptible to brain injury, with damage causing abnormal increases in spontaneous gamma-band (30-80 Hz) activity. We investigated spontaneous gamma activity in individuals with mTBI using high-resolution resting-state magnetoencephalography source imaging. Participants included 25 symptomatic individuals with chronic combat-related blast mTBI and 35 healthy controls with similar combat experiences. Compared with controls, gamma activity was markedly elevated in mTBI participants throughout frontal, parietal, temporal, and occipital cortices, whereas gamma activity was reduced in ventromedial prefrontal cortex. Across groups, greater gamma activity correlated with poorer performances on tests of executive functioning and visuospatial processing. Many neurocognitive associations, however, were partly driven by the higher incidence of mTBI participants with both higher gamma activity and poorer cognition, suggesting that expansive upregulation of gamma has negative repercussions for cognition particularly in mTBI. This is the first human study to demonstrate abnormal resting-state gamma activity in mTBI. These novel findings suggest the possibility that abnormal gamma activities may be a proxy for GABA-ergic interneuron dysfunction and a promising neuroimaging marker of insidious mild head injuries.

Hartmann's procedure versus intersphincteric abdominoperineal excision (HiP Study): a multicentre prospective cohort study

AIM

In patients with low rectal cancer it is occasionally necessary to avoid a low coloanal anastomosis due to patient frailty or poor function. In such situations there are two alternative approaches: Hartmann's procedure (HP) or intersphincteric abdominoperineal excision (IAPE). There are few data to guide surgeons as to which of these two procedures is the safest. The aim of this study was to determine the surgical complication rates associated with each procedure.

METHOD

This was a multicentre, nonrandomized prospective cohort study of patients undergoing either HP or IAPE. The primary objective was to determine surgical complication rates. Secondary objectives included length of stay, time to adjuvant therapy and quality of life at 90 days.

RESULTS

One hundred and seventy nine patients were recruited between April 2016 and June 2019; approximately two thirds of patients underwent HP and one third IAPE. The overall complication rate was high in both groups (54% for the HP group and 52% for the IAPE group). Surgery-specific complication rates were also high, but not significantly different: 43% for HP and 48% for IAPE. The pelvic abscess rate in HP was 11% and was significantly higher in patients with a palpable staple line (15% vs 2%). There was a higher incidence of serious medical complications following IAPE (16% vs 5%), along with a reduction in 90-day quality of life scores.

CONCLUSION

This is the largest prospective study to compare HP and IAPE in patients undergoing rectal cancer surgery where primary anastomosis is not deemed appropriate. With similar complication rates, these data support the ongoing use of either HP or IAPE in this patient group.

MEG Working Memory N-Back Task Reveals Functional Deficits in Combat-Related Mild Traumatic Brain Injury

Combat-related mild traumatic brain injury (mTBI) is a leading cause of sustained cognitive impairment in military service members and Veterans. However, the mechanism of persistent cognitive deficits including working memory (WM) dysfunction is not fully understood in mTBI. Few studies of WM deficits in mTBI have taken advantage of the temporal and frequency resolution afforded by electromagnetic measurements. Using magnetoencephalography (MEG) and an N-back WM task, we investigated functional abnormalities in combat-related mTBI. Study participants included 25 symptomatic active-duty service members or Veterans with combat-related mTBI and 20 healthy controls with similar combat experiences. MEG source-magnitude images were obtained for alpha (8-12 Hz), beta (15-30 Hz), gamma (30-90 Hz), and low-frequency (1-7 Hz) bands. Compared with healthy combat controls, mTBI participants showed increased MEG signals across frequency bands in frontal pole (FP), ventromedial prefrontal cortex, orbitofrontal cortex (OFC), and anterior dorsolateral prefrontal cortex (dlPFC), but decreased MEG signals in anterior cingulate cortex. Hyperactivations in FP, OFC, and anterior dlPFC were associated with slower reaction times. MEG activations in lateral FP also negatively correlated with performance on tests of letter sequencing, verbal fluency, and digit symbol coding. The profound hyperactivations from FP suggest that FP is particularly vulnerable to combat-related mTBI.

Sphingolipids and acid ceramidase as therapeutic targets in cancer therapy

BACKGROUND

Sphingolipids have been shown to play a key part in cancer cell growth and death and have increasingly become the subject of novel anti-cancer therapies. Acid ceramidase, a sphingolipid enzyme, has an important role in the regulation of apoptosis. In this review we aim to assess the current evidence supporting the role of sphingolipids in cancer and the potential role that acid ceramidase may play in cancer treatment.

METHODS

A literature search was performed for published full text articles using the PubMed, Cochrane and Scopus databases using the search criteria string "acid ceramidase", "sphingolipid", "cancer". Additional papers were detected by scanning the references of relevant papers. A summary of the evidence for each cancer subgroup was then formed. Given the nature of the data extracted, no meta-analysis was performed.

RESULTS

Over expression of acid ceramidase has been demonstrated in a number of human cancers. In vitro data demonstrate that manipulation of acid ceramidase may present a useful therapeutic target. In the clinical setting, a number of drugs have been investigated with the ability to target acid ceramidase, with the most promising of those being small molecular inhibitors, such as LCL521.

CONCLUSION

The role of the sphingolipid pathway in cancer is becoming very clearly established by promoting ceramide accumulation in response to cancer or cellular stress. Acid ceramidase is over expressed in a variety of cancers and has a role as a potential target for inhibition by novel specific inhibitors or off-target effects of traditional anti-cancer agents. Further work is required to develop acid ceramidase inhibitors safe for progression to clinical trials.

68 Flux analysis of aerobic glycolysis in bovine blastocysts and CT1 cells

Embryo quality and maternal recognition are crucial for successful initiation of bovine pregnancy. Previous studies have proposed that better quality embryos use aerobic glycolysis to meet a high demand for biomass components. While hexoses are the principal carbon sources that provide energy to glycolysis, little is known about partitioning of hexoses into metabolic pathways or alteration of partitioning when different hexoses are simultaneously available. Specific metabolic utilisation of 13C-labelled substrates can be quantified by gas chromatography-mass spectrometry, an excellent noninvasive approach for studying cellular metabolism. To assess hexose flux through central metabolism, bovine blastocysts and CT1 cells (a bovine trophectoderm cell line) were cultured in SOF-based media supplemented with combinations of 50% uniformly labelled (U) and 50% naturally abundant (NA) glucose (Glc) or fructose (Fru) (U−13C Glc+NA Glc, U−13C Fru+NA Fru, U−13C Glc+NA Fru, and U−13C Fru+NA Glc), such that total hexose concentration was 1.5mM. Metabolites in spent media from 24-h cultures of single or 5 blastocysts (40-μL drops; 5% CO2, 5% O2, 90% N2) and 1-, 2-, 3-, 6-, 8-, and 24-h incubations of CT1 cells (150 μL; ~3×104 cells per well; 5% CO2, 95% air) were extracted with a MeOH-CHCl3 reagent, derivatized, and analysed by gas chromatography-mass spectrometry. Measurement of mass isotopomer distributions of metabolites, chiefly pyruvate, lactate, and amino acids, followed by correction for natural abundances and metabolic modelling, revealed several insights. For instance, five Day 7 or Day 8 blastocysts (Day 0=fertilization) supplied with U−13C Glc+NA Fru displayed 13C enrichments of 80.3%±1.4% for pyruvate and 71.6%±2.8% for lactate, whereas when supplied with U−13C Fru+NA Glc, they displayed lower 13C enrichments of 5.7%±2.4% for pyruvate and 2.8%±0.4% lactate (mean±standard deviation, n=3 to 4). Metabolic modelling revealed that when Glc and Fru are simultaneously available, the blastocysts used 2.5±0.2 moles of Fru per 100 moles of Glc used. Furthermore, 13C enrichment of pyruvate was 42.0±0.6% when U−13C Glc+NA Glc was supplied and 37.8±2.7% when U−13C Fru+NA Fru was supplied. Lactate enrichments followed a similar trend. This indicates that, individually, Glc and Fru were utilised majorly through aerobic glycolysis with some involvement of the pentose phosphate pathway. Alanine was negligibly labelled in all of the experiments, suggesting either a low TCA flux or that alanine is diluted by extra- or intracellular amino or fatty acids. Single blastocysts and CT1 cells showed a similar labelling pattern when hexoses were available. Following Glc depletion at 8h in CT1 cultures, the 13C enrichments of alanine and citrate in the media increased, suggesting a sharp alteration of metabolic state. These findings demonstrate that metabolic flux can be comprehensively analysed for single bovine blastocysts and CT1 cell metabolism models that of the blastocyst. This project was supported by Agriculture and Food Research Initiative Competitive Grant no. 2015-67015-23237 from the USDA National Institute of Food and Agriculture.

Systematic review of treatment intensification using novel agents for chemoradiotherapy in rectal cancer

BACKGROUND

With the well established shift to neoadjuvant treatment for locally advanced rectal cancer, there is increasing focus on the use of radiosensitizers to improve the efficacy and tolerability of radiotherapy. There currently exist few randomized data exploring novel radiosensitizers to improve response and it is unclear what the clinical endpoints of such trials should be.

METHODS

A qualitative systematic review was performed according to the PRISMA guidelines using preset search criteria across the PubMed, Cochrane and Scopus databases from 1990 to 2017. Additional results were generated from the reference lists of included papers.

RESULTS

A total of 123 papers were identified, of which 37 were included; a further 60 articles were obtained from additional referencing to give a total of 97 articles. Neoadjuvant radiosensitization for locally advanced rectal cancer using fluoropyrimidine-based chemotherapy remains the standard of treatment. The oral derivative capecitabine has practical advantages over 5-fluorouracil, with equal efficacy, but the addition of a second chemotherapeutic agent has yet to show a consistent significant efficacy benefit in randomized clinical assessment. Preclinical and early-phase trials are progressing with promising novel agents, such as small molecular inhibitors and nanoparticles.

CONCLUSION

Despite extensive research and promising preclinical studies, a definite further agent in addition to fluoropyrimidines that consistently improves response rate has yet to be found.

Medication appropriateness tool for co-morbid health conditions in dementia: consensus recommendations from a multidisciplinary expert panel

Background

Medication management for people living with dementia is a complex task as it is unclear what constitutes optimal medication management in this population due to the shifting focus of health priorities and the balance between the benefits and harms of medications.

Aim

This study sought expert opinion to create a consensus list to define appropriate medication management of co‐morbidities for people with dementia.

Methods

This study used the Delphi technique. We invited multidisciplinary experts in geriatric therapeutics including pharmacists, doctors, nurse practitioners, a patient advocate and a psychologist to participate. Participants were asked to engage into three or more rounds of questioning. Round 1 was a questionnaire comprised of one question defining dementia and seven open‐ended questions about appropriate management of co‐morbidities in people with dementia. Two investigators qualitatively analysed the responses to questions from Round 1 using thematic analysis. The results of this analysis were provided to participants as statements in the Round 2 survey. The participants were asked to rate their agreement with each statement on a 5‐point Likert scale. The median and interquartile range (IQR) were calculated for the responses to each statement. Consensus was pre‐specified as an IQR less than or equal to 1. Statements where consensus was not achieved were presented to participants in Round 3. The Round 2 median and IQR values were provided and participants were again asked to rate their agreement with each statement on a 5‐point Likert scale. The statements where participants agreed or strongly agreed were included in the Medication Appropriateness Tool for Co‐morbid Health conditions in Dementia criteria.

Results

Fifty‐seven experts agreed to participate in the study, of whom 58% were pharmacists and 36% were medical practitioners. Fifty‐five participants completed the Round 1 (95% response rate). A total of 128 statements was included in the Round 2 survey. Consensus was reached on 93 statements in Round 2 (n = 48 responders, 84% response rate) and on 18 statements in Round 3 (n = 43 responders, 75% response rate). The participants reached consensus on 111 of 128 statements. Of these statements, 67 statements were included in the Medication Appropriateness Tool for Co‐morbid Health conditions in Dementia criteria. The statements were in the broad themes of preventative medication, symptom management, disease progression, psychoactive medication, treatment goals, principles of medication use, side‐effects and medication reviews.

Discussion

This research provides consensus‐based guidance for clinicians who manage co‐morbid health conditions in people with dementia.

EGR2 mutations define a new clinically aggressive subgroup of chronic lymphocytic leukemia

Recurrent mutations within EGR2 were recently reported in advanced-stage chronic lymphocytic leukemia (CLL) patients and associated with a worse outcome. To study their prognostic impact, 2403 CLL patients were examined for mutations in the EGR2 hotspot region including a screening (n=1283) and two validation cohorts (UK CLL4 trial patients, n=366; CLL Research Consortium (CRC) patients, n=490). Targeted deep-sequencing of 27 known/postulated CLL driver genes was also performed in 38 EGR2-mutated patients to assess concurrent mutations. EGR2 mutations were detected in 91/2403 (3.8%) investigated cases, and associated with younger age at diagnosis, advanced clinical stage, high CD38 expression and unmutated IGHV genes. EGR2-mutated patients frequently carried ATM lesions (42%), TP53 aberrations (18%) and NOTCH1/FBXW7 mutations (16%). EGR2 mutations independently predicted shorter time-to-first-treatment (TTFT) and overall survival (OS) in the screening cohort; they were confirmed associated with reduced TTFT and OS in the CRC cohort and independently predicted short OS from randomization in the UK CLL4 cohort. A particularly dismal outcome was observed among EGR2-mutated patients who also carried TP53 aberrations. In summary, EGR2 mutations were independently associated with an unfavorable prognosis, comparable to CLL patients carrying TP53 aberrations, suggesting that EGR2-mutated patients represent a new patient subgroup with very poor outcome.

Pulmonary delivery of d-methionine is associated with an increase in ALCAR and glutathione in cochlear fluids

In animals, hearing loss resulting from cochlear mechanosensory cell damage can be mitigated by antioxidants such as d-methionine (d-met) and acetyl-l-carnitine (ALCAR). The systemic routes of administration of these compounds, that must of necessity transit trough the cochlear fluids, may affect the antioxidant levels in the cochlea and the resulting oto-protective effect. In this study, we analyzed the pharmacokinetics of [(14)C]d-met in the cochlea and four other tissues after intratracheal (IT), intranasal (IN), and oral by gavage (OG) administration and compared it to intravenous administration (IV). We then analyzed the effect of these four routes on the antioxidant content of the cochlear fluids after d-met or ALCAR administration, by liquid chromatography/mass spectrometry. Our results showed that the concentration of methionine and ALCAR in cochlear fluids significantly increased after their respective systemic administration. Interestingly, d-met administration also contributed to an increase of ALCAR. Our results also showed that the delivery routes differently affected the bioavailability of administered [(14)C]d-met as well as the concentrations of methionine, ALCAR and the ratio of oxidized to reduced glutathione. Overall, pulmonary delivery via IT administration achieved high concentrations of methionine, ALCAR, and oxidative-related metabolites in cochlear fluids, in some cases surpassing IV administration, while IN route appeared to be the least efficacious. To our knowledge, this is the first report of the direct measurements of antioxidant levels in cochlear fluids after their systemic administration. This report also demonstrates the validity of the pulmonary administration of antioxidants and highlights the different contributions of d-met and ALCAR allowing to further investigate their impact on oxidative stress in the cochlear microenvironment.

Quantification of subclonal distributions of recurrent genomic aberrations in paired pre-treatment and relapse samples from patients with B-cell chronic lymphocytic leukemia

Genome-wide array approaches and sequencing analyses are powerful tools for identifying genetic aberrations in cancers, including leukemias and lymphomas. However, the clinical and biological significance of such aberrations and their subclonal distribution are poorly understood. Here, we present the first genome-wide array based study of pre-treatment and relapse samples from patients with B-cell chronic lymphocytic leukemia (B-CLL) that uses the computational statistical tool OncoSNP. We show that quantification of the proportion of copy number alterations (CNAs) and copy neutral loss of heterozygosity regions (cnLOHs) in each sample is feasible. Furthermore, we (i) reveal complex changes in the subclonal architecture of paired samples at relapse compared with pre-treatment, (ii) provide evidence supporting an association between increased genomic complexity and poor clinical outcome (iii) report previously undefined, recurrent CNA/cnLOH regions that expand or newly occur at relapse and therefore might harbor candidate driver genes of relapse and/or chemotherapy resistance. Our findings are likely to impact on future therapeutic strategies aimed towards selecting effective and individually tailored targeted therapies.

The nonhealing scar

Pyogenic granulomas are common benign skin growths often present at sites of trauma. They can be difficult to treat in austere environments. A case report of a pyogenic granuloma in an austere environment has not previously been published. We submit this work to describe a case of a pyogenic granuloma arising from a properly treated laceration in an austere environment and to review current treatment options. Multiple treatment modalities are available to providers with limited resources to include topical Imiquimod, ethanol injection, silver nitrate application, and oral steroids.

Mercury-reactive lymphocytes in peripheral blood are not a marker for dental amalgam associated disease

OBJECTIVES

The popular press and publications associated with alternative medicine increasingly report that chronic ill health, particularly myalgic encephalitis like conditions, are associated with mercury amalgam fillings. There are no scientifically proven definitive tests to support these claims. One of the more scientific tests in vogue is to assess the level of blood-borne mercury-reactive lymphocytes and to conclude that patients with high levels have developed a hypersensitivity reaction to mercury. The objective of this study was to determine the diagnostic value of this test.

METHODS

This study represents an open comparison of mercury-reactive lymphocyte levels in healthy control individuals with those in patients complaining of symptoms associated with adverse effects of dental metal amalgam fillings. The healthy control group consisted of 51 male and female individuals, aged between 12 and 82 years, with and without dental amalgam fillings. The patient group consisted of 70 male and female individuals, aged between 12 and 87 years, and with the exception of one patient, with three or more mercury amalgam fillings of more than 1 year's duration. In vitro lymphocyte responses to mercury, and to nickel, as an example of a metal commonly associated with hypersensitivity reactions, and to more conventional protein antigens were determined.

RESULTS

In the blood of patients and controls, there were similar levels of specifically reactive lymphocytes to all of the in vitro stimulating agents, but there were significantly higher numbers of sub-normal and non-responders within the patient group.

CONCLUSIONS

The incidence and quantity of mercury-reactive lymphocytes in the blood are not pathogenic markers of illness associated with dental metal amalgams, but may rather reflect exposure to mercury. The clinical relevance of the decreased in vitro lymphocyte responses in the patient group needs further investigation.

High-throughput development and characterization of a genomewide collection of gene-based single nucleotide polymorphism markers by chip-based matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

We describe here a system for the rapid identification, assay development, and characterization of gene-based single nucleotide polymorphisms (SNPs). This system couples informatics tools that mine candidate SNPs from public expressed sequence tag resources and automatically designs assay reagents with detection by a chip-based matrix-assisted laser desorption/ionization time-of-flight mass spectrometry platform. As a proof of concept of this system, a genomewide collection of reagents for 9,115 gene-based SNP genetic markers was rapidly developed and validated. These data provide preliminary insights into patterns of polymorphism in a genomewide collection of gene-based polymorphisms.

Analysis of Medication Incidents and Development of a Medication Incident Rate Clinical Indicator

Most health service organisations depend solely upon spontaneous voluntary reporting of medication incidents and a wide variety of available denominators are used in order to calculate the Medication Incident Rate (MIR). This paper describes how nursing staff and clinical pharmacists reviewed medication incident data, revised and established new systems of reporting and developed a clinically useful, rate-based MIR Clinical Indicator. In order to make the MIR more meaningful, the frequency of occurrence of incidents was considered within the context of the total number of medications given to patients. This was achieved by undertaking a point prevalence audit of all inpatient medication charts (n=372) to determine the total number of doses of medication given to patients during a 24 hour period (n=3211). This value was then used as the denominator for the MIR indicator. During 1998, a total of 475 medication incidents were reported; the average number of incidents was 1.3 per 24 hours. The MIR per 1000 doses was calculated to be 0.4. In most cases (77%) the incident caused no harm to the patient and no change in treatment was required, and the most 'severe' category for any incident was that active treatment was required (3% of reported incidents). The most common type of incident was the omission of a dose of medication (50%). A wide range of drugs were involved in the incidents, most commonly morphine (3.4%). The authors consider that the development and use of the MIR Clinical Indicator has positively influenced clinical practice in some areas at the authors' hospital.

FOG-2, a novel F-box containing protein, associates with the GLD-1 RNA binding protein and directs male sex determination in the C. elegans hermaphrodite germline

Male sex determination in the Caenorhabditis elegans hermaphrodite germline requires translational repression of tra-2 mRNA by the GLD-1 RNA binding protein. We cloned fog-2 by finding that its gene product physically interacts with GLD-1, forming a FOG-2/GLD-1/tra-2 3′untranslated region ternary complex. FOG-2 has an N-terminal F-box and a novel C-terminal domain called FTH. Canonical F-box proteins act as bridging components of the SCF ubiquitin ligase complex; the N-terminal F-box binds a Skp1 homolog, recruiting ubiquination machinery, while a C-terminal protein-protein interaction domain binds a specific substrate for degradation. However, since both fog-2 and gld-1 are necessary for spermatogenesis, FOG-2 cannot target GLD-1 for ubiquitin-mediated degradation. We propose that FOG-2 also acts as a bridge, bringing GLD-1 bound to tra-2 mRNA into a multiprotein translational repression complex, thus representing a novel function for an F-box protein. fog-2 is a member of a large, apparently rapidly evolving, C. elegans gene family that has expanded, in part, by local duplications; fog-2 related genes have not been found outside nematodes. fog-2 may have arisen during evolution of self-fertile hermaphroditism from an ancestral female/male species.

Expression-based genetic/physical maps of single-nucleotide polymorphisms identified by the cancer genome anatomy project

SNPs (Single-Nucleotide Polymorphisms), the most common DNA variant in humans, represent a valuable resource for the genetic analysis of cancer and other illnesses. These markers may be used in a variety of ways to investigate the genetic underpinnings of disease. In gene-based studies, the correlations between allelic variants of genes of interest and particular disease states are assessed. An extensive collection of SNP markers may enable entire molecular pathways regulating cell metabolism, growth, or differentiation to be analyzed by this approach. In addition, high-resolution genetic maps based on SNPs will greatly facilitate linkage analysis and positional cloning. The National Cancer Institute's CGAP-GAI (Cancer Genome Anatomy Project Genetic Annotation Initiative) group has identified 10,243 SNPs by examining publicly available EST (Expressed Sequence Tag) chromatograms. More than 6800 of these polymorphisms have been placed on expression-based integrated genetic/physical maps. In addition to a set of comprehensive SNP maps, we have produced maps containing single nucleotide polymorphisms in genes expressed in breast, colon, kidney, liver, lung, or prostate tissue. The integrated maps, a SNP search engine, and a Java-based tool for viewing candidate SNPs in the context of EST assemblies can be accessed via the CGAP-GAI web site (http://cgap.nci.nih.gov/GAI/). Our SNP detection tools are available to the public for noncommercial use.

Disperse: a simple and efficient approach to parallel database searching

SUMMARY

A general system for performing multiple independent database searches in parallel is presented. Run-time addition and removal of clients, robust failure and error trapping and near 100% efficiency with very large numbers of clients are achieved by a flexible asynchronous, client-driven approach.

Monitoring for nitrate in UK-grown lettuce and spinach

To comply with European Commission requirements, the UK is carrying out a monitoring programme on nitrate concentrations in lettuce and spinach. This paper reports the results obtained between June 1996 and April 1998. A total of 182 samples of protected lettuce, 131 samples of outdoor-grown lettuce and 34 samples of fresh spinach were taken from the main growing areas of the UK. Nitrate concentrations in protected lettuce were influenced by the season with summer-grown crops (mean of 2382 mg/kg) having lower levels than those grown in the winter (mean of 3124 mg/kg). Weather conditions also affected concentrations in protected lettuces with long hours of sunshine and low rainfall associated with low nitrate levels. Nitrate concentrations in outdoor-grown lettuces were lower (mean of 1085 mg/kg) than those in protected lettuces but there were insufficient data to determine if they were affected by the weather conditions or season. Similarly there were insufficient data to determine if weather conditions or season influenced nitrate concentrations in spinach (mean of 1900 mg/kg) but regional differences were observed.

A pilot study of alcohol and drug-related traffic accidents and death in two Jamaican parishes, 1991

This study is a preliminary effort to document the role of drugs in motor vehicle accidents as it examines the presence of alcohol, marijuana and cocaine in blood samples of thirty-one motor vehicle fatalities. The study identified that males (90.3%) and pedestrians (41.9%) were killed most often. Evidence of alcohol intake was found in 77.5% of the fatalities and 35.5% had alcohol levels above the legal acceptable limits. Traces of marijuana were found in 22.5% and a combination of alcohol and marijuana in 22.5% of the victims.