Comparative outcomes of phacoemulsification combined with micro-invasive glaucoma surgery plus: Schlemm canal microstent versus Ab interno trabecular excision

PURPOSE

To report the relative efficacy of combining phacoemulsification with a Schlemm's canal microstent (Phaco/Hydrus) or dual blade trabecular excision (Phaco/KDB).

DESIGN

Retrospective study.

METHODS

One hundred and thirty-one eyes of 131 patients who underwent Phaco/Hydrus or Phaco/KDB procedures from January 2016 to July 2021 at a tertiary care center were included and assessed for up to 36months postoperatively. Primary outcomes were intraocular pressure (IOP) and number of glaucoma medications, evaluated by generalized estimating equations (GEE). Two Kaplan-Meier estimates (KM) assessed survival without additional intervention or pressure lowering medication while maintaining: (1) IOP≤21mmHg and≥20% IOP reduction or (2) IOP≤preoperatively designated goal.

RESULTS

Mean preoperative IOP was 17.70±4.91 (SD) mmHg on 0.28±0.86 medications in the Phaco/Hydrus cohort (n=69) and 15.92±4.34mmHg on 0.19±0.70 medications in the Phaco/KDB cohort (n=62). At 12months, mean IOP was reduced to 14.98±2.77mmHg on 0.12±0.60 medications after Phaco/Hydrus and 13.52±4.13mmHg on 0.04±0.19 medications after Phaco/KDB. GEE models of IOP (P<0.001) and medication burden (P<0.05) showed significant patterns of reduction across all timepoints in both cohorts. There were no differences in IOP reduction (P=0.94), number of medications (P=0.95) or survival (P=0.72 by KM1, P=0.11 by KM2) between procedures.

CONCLUSIONS

Both Phaco/Hydrus and Phaco/KDB resulted in significantly reduced IOP and medication burden for over 12months. Phaco/Hydrus and Phaco/KDB confer similar outcomes in terms of IOP, medication burden, survival, and procedural time in a population with predominantly mild and moderate open-angle glaucoma.

HCV cure: an appropriate moment to reduce cannabis use in people living with HIV? (ANRS CO13 HEPAVIH data)

BACKGROUND

Thanks to direct-acting antivirals, hepatitis C virus (HCV) infection can be cured, with similar rates in HCV-infected and HIV-HCV co-infected patients. HCV cure is likely to foster behavioral changes in psychoactive substance use, which is highly prevalent in people living with HIV (PLWH). Cannabis is one substance that is very commonly used by PLWH, sometimes for therapeutic purposes. We aimed to identify correlates of cannabis use reduction following HCV cure in HIV-HCV co-infected cannabis users and to characterize persons who reduced their use.

METHODS

We used data collected on HCV-cured cannabis users in a cross-sectional survey nested in the ANRS CO13 HEPAVIH cohort of HIV-HCV co-infected patients, to perform logistic regression, with post-HCV cure cannabis reduction as the outcome, and socio-behavioral characteristics as potential correlates. We also characterized the study sample by comparing post-cure substance use behaviors between those who reduced their cannabis use and those who did not.

RESULTS

Among 140 HIV-infected cannabis users, 50 and 5 had reduced and increased their use, respectively, while 85 had not changed their use since HCV cure. Cannabis use reduction was significantly associated with tobacco use reduction, a decrease in fatigue level, paying more attention to one's dietary habits since HCV cure, and pre-HCV cure alcohol abstinence (p = 0.063 for alcohol use reduction).

CONCLUSIONS

Among PLWH using cannabis, post-HCV cure cannabis reduction was associated with tobacco use reduction, improved well-being, and adoption of healthy behaviors. The management of addictive behaviors should therefore be encouraged during HCV treatment.

548 FRAILTY ANALYSIS ACROSS POPULATIONS: THE USE OF THE HOSPITAL FRAILTY RISK SCORE IN SPECIALISED SERVICES USING NHS NATIONAL DATA

Introduction

Frailty is increasingly used to risk stratify older people, but across specialised services there is no standardised approach. The aim of this study was to answer the question posed by NHS England to assess frailty could be measured and related to outcomes across Specialsed Services. The Hospital Frailty Risk Score (HFRS) was used and the data published in Age and Ageing in 2020.

Method

A retrospective cohort study was performed using the Secondary Uses Service (SUS) electronic database for people aged 75 or older admitted between April 2017 and March 2018. Based on HFRS, the populations were risk stratified into mild, moderate and severe frailty risk. The relationships with length of stay, readmission rate, mortality and some selected condition specific treatment complications were quantified using descriptive statistics.

Results

Frailty was differentially distributed across the specialties; around one-third had mild frailty; another third had moderate frailty and one-quarter severe frailty. Increasing frailty risk was associated with increased length of stay for the index admission, more days in hospital in the year following intervention and increased risk of dying in hospital. Severe frailty was a powerful discriminator of the risk of death; between 25 and 40% of those with severe frailty risk died at 30 months across all specialties.

Conclusions

This study demonstrates the first application of the HFRS to a national dataset to describe service outcomes and mortality for older people undergoing a range of specialised interventions. This information was used to identify those that might benefit from holistic assessment, aid prognostication, commissioning and service planning. It informed the promotion of quality improvement work in this area via the Specialised Clinical Frailty Network. By implementing the HFRS, changes in outcomes can be plotted across years to assess improvements, performance and benchmarking.

Norwich COVID-19 testing initiative pilot: evaluating the feasibility of asymptomatic testing on a university campus

Background

There is a high prevalence of COVID-19 in university-age students, who are returning to campuses. There is little evidence regarding the feasibility of universal, asymptomatic testing to help control outbreaks in this population. This study aimed to pilot mass COVID-19 testing on a university research park, to assess the feasibility and acceptability of scaling up testing to all staff and students.

Methods

This was a cross-sectional feasibility study on a university research park in the East of England. All staff and students (5625) were eligible to participate. All participants were offered four PCR swabs, which they self-administered over two weeks. Outcome measures included uptake, drop-out rate, positivity rates, participant acceptability measures, laboratory processing measures, data collection and management measures.

Results

798 (76%) of 1053 who registered provided at least one swab; 687 (86%) provided all four; 792 (99%) of 798 who submitted at least one swab had all negative results and 6 participants had one inconclusive result. There were no positive results. 458 (57%) of 798 participants responded to a post-testing survey, demonstrating a mean acceptability score of 4.51/5, with five being the most positive.

Conclusions

Repeated self-testing for COVID-19 using PCR is feasible and acceptable to a university population.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

0528 Insomnia as a Mechanism for Improvement in Alcohol Problems Among Young Adults

Introduction

More than half of heavy-drinking young adults report symptoms of insomnia, which have been associated with alcohol-related problems. This study examined improvement in insomnia (via Cognitive Behavioral Therapy for Insomnia; CBT-I) as a mechanism for improvement in alcohol-related problems.

Methods

Fifty-six heavy-drinking young adults with insomnia (ages 18-30y) were randomized to CBT-I (n=28) or single-session sleep hygiene control (SH; n=28). Of those, 43 (77%) completed post-treatment (24 SH, 19 CBT-I) and 48 (86%) completed 1-month follow-up (25 SH, 23 CBT-I). Multiple imputation was used to estimate missing data. Treatment outcomes were assessed using multilevel models. Mediation was tested using bootstrapped confidence intervals for indirect effects in the PROCESS macro.

Results

CBT-I participants reported greater decreases in insomnia severity than those in the sleep hygiene group [group X time interaction, F(2,59)=11.29, p&lt;.001], both post-treatment and at 1-month follow-up. Both groups decreased significantly in diary-assessed sleep quality [time, F(2,55)=40.30, p&lt;.001], with a marginally significant interaction in favor of the CBT-I group [F(2,55)=2.69, p=.08]. There were no significant group by time interactions in the prediction of actigraphy-assessed sleep variables, although again, there was a marginally significant interaction in the prediction of actigraphy-assessed sleep efficiency [F(2,66)=2.75, p=.07]. Both groups reported significant decreases in drinking quantity over time [time, F(2,58=13.88, p&lt;.001]. However, CBT-I participants reported greater decreases in alcohol-related consequences than those in the sleep hygiene group [F(2,67)=4.13, p=.02]. In the mediation model, CBT-I did not have a direct effect on change in alcohol-related consequences (B=1.49, SE=1.06, 95%CI=-0.65, 3.62); however, it influenced change in 1-month alcohol-related consequences indirectly through its influence on post-treatment insomnia symptoms (B=-1.09, SE=0.57, 95%CI=-2.30, -0.05).

Conclusion

CBT-I is effective in treating insomnia among heavy-drinking young adults and may be associated with reductions in alcohol-related problems due to its impact on insomnia symptoms.

Support

This work was supported by funding from the University of Missouri System Research Board Office (PI Miller). Mary Beth Miller’s contribution to this project was also supported by the National Institute on Alcohol Abuse and Alcoholism [grant number K23AA026895].

Switching from abacavir/lamivudine plus nevirapine to abacavir/lamivudine/dolutegravir in virologically controlled HIV-infected adults (SWAD study)

INTRODUCTION

The metabolic pathways of dolutegravir suggest a potential predator effect of nevirapine on dolutegravir pharmacokinetics and switching from a nevirapine- to a dolutegravir-containing regimen could lead to a lower and suboptimal exposure to dolutegravir several weeks after the switch in case of persistent inducer effect.

PATIENTS AND METHOD

Prospective, pilot, single-arm, open-label, non-comparative, bicentric study to evaluate the pharmacokinetics, virologic outcomes, safety, and patient satisfaction of switching from abacavir/lamivudine and nevirapine to a single tablet of abacavir/lamivudine/dolutegravir. The primary endpoint was the maintenance of virologic suppression (HIV-1 RNA<50 copies/mL) at week 12. Secondary endpoints were virologic suppression at week 48, safety and tolerability, patient satisfaction, and pharmacokinetic interaction between nevirapine and dolutegravir. Fifty-three adults on stable abacavir/lamivudine and nevirapine regimen for a median duration of 6years and virologically suppressed for 9.6years were included.

RESULTS

Dolutegravir reached steady state by week 4/week 12 when expected by day 5/day 10. All subjects maintained plasma HIV-RNA˂50 copies/mL at week 12 and week 48. Abacavir/lamivudine/dolutegravir was well-tolerated, with two cases of serious adverse events deemed unrelated to study drugs (coronary syndrome in both cases), and one discontinuation for renal impairment at week 24 with a slight improvement after dolutegravir discontinuation. Level of treatment satisfaction remained high after the switch.

CONCLUSION

The transient predator effect of nevirapine on dolutegravir had no clinical consequences after switching from nevirapine to dolutegravir, neither on safety nor maintenance of virologic suppression. It also had no consequences on patient satisfaction.

Manifesto for a European research network into Problematic Usage of the Internet

The Internet is now all-pervasive across much of the globe. While it has positive uses (e.g. prompt access to information, rapid news dissemination), many individuals develop Problematic Use of the Internet (PUI), an umbrella term incorporating a range of repetitive impairing behaviours. The Internet can act as a conduit for, and may contribute to, functionally impairing behaviours including excessive and compulsive video gaming, compulsive sexual behaviour, buying, gambling, streaming or social networks use. There is growing public and National health authority concern about the health and societal costs of PUI across the lifespan. Gaming Disorder is being considered for inclusion as a mental disorder in diagnostic classification systems, and was listed in the ICD-11 version released for consideration by Member States (http://www.who.int/classifications/icd/revision/timeline/en/). More research is needed into disorder definitions, validation of clinical tools, prevalence, clinical parameters, brain-based biology, socio-health-economic impact, and empirically validated intervention and policy approaches. Potential cultural differences in the magnitudes and natures of types and patterns of PUI need to be better understood, to inform optimal health policy and service development. To this end, the EU under Horizon 2020 has launched a new four-year European Cooperation in Science and Technology (COST) Action Programme (CA 16207), bringing together scientists and clinicians from across the fields of impulsive, compulsive, and addictive disorders, to advance networked interdisciplinary research into PUI across Europe and beyond, ultimately seeking to inform regulatory policies and clinical practice. This paper describes nine critical and achievable research priorities identified by the Network, needed in order to advance understanding of PUI, with a view towards identifying vulnerable individuals for early intervention. The network shall enable collaborative research networks, shared multinational databases, multicentre studies and joint publications.

Local recurrence after 'standard' abdominoperineal resection: do we really need ELAPE?

Introduction Low rectal cancers requiring abdominoperineal resection tend to have a worse prognosis than higher tumours, which may be treated by anterior resection. One of the reasons for this may be inadequate local surgery, in particular the narrow waist of the resection specimen of a standard abdominoperineal resection may be associated with a high positive circumferential resection margin. The extralevator abdominoperineal excision (ELAPE) aims to improve the R0 resection rate but carries significant morbidity. We examined our own results of standard abdominoperineal resection to assess the need for a change of policy. Methods We operformed a retrospective analysis of consecutive standard abdominoperineal resections for rectal cancer in a single centre from June 2002 to December 2011. Results A total of 102 patients underwent standard abdominoperineal resection with curative intent; 19 had no preoperative treatment, 42 had short course radiotherapy, 9 had long course radiotherapy and 32 had neoadjuvant chemotherapy followed by long course chemoradiotherapy. In 17/102(16.6%), there was a positive circumferential resection margin. Over a median follow up of 32 months, 20 patients developed recurrence of any type. Local recurrence occurred in five patients (two of which also had distant recurrence), of whom two had a positive circumferential resection margin (P = 0.10). Actuarial two-year local only recurrence was 3.4% and any recurrence was 17.7%. Overall five-year cancer specific survival was 77%. Conclusions In this series we found low rates of local recurrence after standard abdominoperineal resection even with a circumferential margin rate positivity of 16.6%.Performing an ELAPE in selected cases may improve these results further but is not necessarily required for all patients.

Interest of proviral HIV-1 DNA genotypic resistance testing in virologically suppressed patients candidate for maintenance therapy

Switch of antiretroviral therapy in virologically suppressed HIV-infected patients is frequent, to prevent toxicities, for simplification or convenience reasons. Pretherapeutic genotypic resistance testing on RNA can be lacking in some patients, which could enhance the risk of virologic failure, if resistance-associated mutations of the new regimen are not taken into account. Proviral DNA resistance testing in 69 virologically suppressed patients on antiretroviral treatment with no history of virological failure were pair-wised compared with pre-ART plasma RNA resistance testing. The median time between plasma (RNA testing) and whole blood (proviral DNA testing) was 47 months (IQR 29-63). A stop codon was evidenced in 23% (16/69) of proviral DNA sequences; these strains were considered as defective, non-replicative, and not taken into consideration. Within the non defective strains, concordance rate between plasma RNA and non-defective proviral DNA was high both on protease (194/220 concordant resistance-associated mutations=88%) and reverse transcriptase (28/37 concordant resistance-associated mutations=76%) genes. This study supports that proviral DNA testing might be an informative tool before switching antiretrovirals in virologically suppressed patients with no history of virological failure, but the interpretation should be restricted to non-defective viruses.

Direct-acting antiviral treatment against hepatitis C virus infection in HIV-Infected patients - "En route for eradication"?

OBJECTIVES

Direct-Acting Antivirals (DAAs) opened a new era in HCV treatment. We report the impact of HCV treatment in French HIV-HCV coinfected patients.

METHODS

All HIV-HCV patients from the Dat'AIDS cohort followed between 2012 and 2015 were included. HCV status was defined yearly as naive, spontaneous cure, sustained virological response (SVR12), failure or reinfection.

RESULTS

Among 32,945 HIV-infected patients, 15.2% were positive for anti-HCV antibodies. From 2012 to 2015, HCV incidence rate increased from 0.35%PY to 0.69%PY in MSM, while median incidence was 0.08%PY in other patients. Median reinfection rate was 2.56%PY in MSM and 0.22%PY in other patients. HCV treatment initiation rate rose from 8.2% in 2012 to 29.6% (48.0% in pre-treated patients vs 22.6% in naïve patients). SVR12 rate increased from 68.7% to 95.2%. By the end of 2015, 62.7% of the patients were cured either spontaneously or following SVR.

CONCLUSIONS

HCV treatment dramatically increased in HIV-HCV patients in France from 2012 to 2015 resulting in HCV cure in nearly two-thirds of the patients in this cohort. Combined with a declining HCV prevalence, the prevalence of active HCV infection among HIV patients will drastically decrease in the forthcoming years.

Concerns, perceived need and competing priorities: a qualitative exploration of decision-making and non-participation in a population-based flexible sigmoidoscopy screening programme to prevent colorectal cancer

OBJECTIVE

Optimising uptake of colorectal cancer (CRC) screening is important to achieve projected health outcomes. Population-based screening by flexible sigmoidoscopy (FS) was introduced in England in 2013 (NHS Bowel scope screening). Little is known about reactions to the invitation to participate in FS screening, as offered within the context of the Bowel scope programme. We aimed to investigate responses to the screening invitation to inform understanding of decision-making, particularly in relation to non-participation in screening.

DESIGN

Qualitative analysis of semistructured in-depth interviews and written accounts.

PARTICIPANTS AND SETTING

People from 31 general practices in the North East and East of England invited to attend FS screening as part of NHS Bowel scope screening programme were sent invitations to take part in the study. We purposively sampled interviewees to ensure a range of accounts in terms of beliefs, screening attendance, sex and geographical location.

RESULTS

20 screeners and 25 non-screeners were interviewed. Written responses describing reasons for, and circumstances surrounding, non-participation from a further 28 non-screeners were included in the analysis. Thematic analysis identified a range of reactions to the screening invitation, decision-making processes and barriers to participation. These include a perceived or actual lack of need; inability to attend; anxiety and fear about bowel preparation, procedures or hospital; inability or reluctance to self-administer an enema; beliefs about low susceptibility to bowel cancer or treatment and understanding of harm and benefits. The strength, rather than presence, of concerns about the test and perceived need for reassurance were important in the decision to participate for screeners and non-screeners. Decision-making occurs within the context of previous experiences and day-to-day life.

CONCLUSIONS

Understanding the reasons for non-participation in FS screening can help inform strategies to improve uptake and may be transferable to other screening programmes.

Symptom appraisal and healthcare-seeking for symptoms suggestive of colorectal cancer: a qualitative study

OBJECTIVES

Timely diagnosis of colorectal cancer is important to improve survival. This study explored symptom appraisal and help-seeking among patients referred to specialist services with symptoms of colorectal cancer.

DESIGN

Qualitative in-depth interview study.

SETTING AND PARTICIPANTS

Participants were recruited on referral to gastroenterology clinics (North East and East of England); interviews were conducted soon after referral. We purposively sampled participants to ensure a range of accounts in terms of age, sex, diagnosis and geographical location.

METHODS

Data collection and analysis were underpinned by the Model of Pathways to Treatment. Framework analysis was used to explore the data within and across cases, focusing on patient beliefs and experiences, disease factors and healthcare influences.

RESULTS

40 participants were interviewed (aged 43-87 years, 17 women, 18 diagnosed with colorectal cancer). Patients diagnosed with and without colorectal cancer had similar symptom pathways. We found a range of interacting and often competing biopsychosocial, contextual and cultural influences on the way in which people recognised, interpreted and acted on their symptoms. People attempted to 'maintain normality' through finding benign explanations for their symptoms. Bodily changes were appraised within the context of usual bowel patterns, comorbidities and life events, and decisions to seek help were made in relation to expectations about the course of symptoms. The 'private nature' of colorectal cancer symptoms could affect both their identification and discussions with others including healthcare professionals. Within the context of the National Health Service, people needed to legitimise appropriate use of healthcare services and avoid being thought of as wasting doctors' time.

CONCLUSIONS

Findings provide guidance for awareness campaigns on reducing stigma around appraising and discussing bowel movements, and the importance of intermittent and non-specific symptoms. Altering perceptions about the appropriate use of health services could have a beneficial effect on time to presentation.

Symptoms and other factors associated with time to diagnosis and stage of lung cancer: a prospective cohort study

BACKGROUND

This prospective cohort study aimed to identify symptom and patient factors that influence time to lung cancer diagnosis and stage at diagnosis.

METHODS

Data relating to symptoms were collected from patients upon referral with symptoms suspicious of lung cancer in two English regions; we also examined primary care and hospital records for diagnostic routes and diagnoses. Descriptive and regression analyses were used to investigate associations between symptoms and patient factors with diagnostic intervals and stage.

RESULTS

Among 963 participants, 15.9% were diagnosed with primary lung cancer, 5.9% with other thoracic malignancies and 78.2% with non-malignant conditions. Only half the cohort had an isolated first symptom (475, 49.3%); synchronous first symptoms were common. Haemoptysis, reported by 21.6% of cases, was the only initial symptom associated with cancer. Diagnostic intervals were shorter for cancer than non-cancer diagnoses (91 vs 124 days, P=0.037) and for late-stage than early-stage cancer (106 vs 168 days, P=0.02). Chest/shoulder pain was the only first symptom with a shorter diagnostic interval for cancer compared with non-cancer diagnoses (P=0.003).

CONCLUSIONS

Haemoptysis is the strongest symptom predictor of lung cancer but occurs in only a fifth of patients. Programmes for expediting earlier diagnosis need to focus on multiple symptoms and their evolution.

Phylogenomics of the killer whale indicates ecotype divergence in sympatry

For many highly mobile species, the marine environment presents few obvious barriers to gene flow. Even so, there is considerable diversity within and among species, referred to by some as the 'marine speciation paradox'. The recent and diverse radiation of delphinid cetaceans (dolphins) represents a good example of this. Delphinids are capable of extensive dispersion and yet many show fine-scale genetic differentiation among populations. Proposed mechanisms include the division and isolation of populations based on habitat dependence and resource specializations, and habitat release or changing dispersal corridors during glacial cycles. Here we use a phylogenomic approach to investigate the origin of differentiated sympatric populations of killer whales (Orcinus orca). Killer whales show strong specialization on prey choice in populations of stable matrifocal social groups (ecotypes), associated with genetic and phenotypic differentiation. Our data suggest evolution in sympatry among populations of resource specialists.

Host-Parasite interactions in Entamoeba histolytica and Entamoeba dispar: what have we learned from their genomes?

Invasive amoebiasis caused by Entamoeba histolytica is a major global health problem. Virulence is a rare outcome of infection, occurring in fewer than 1 in 10 infections. Not all strains of the parasite are equally virulent, and understanding the mechanisms and causes of virulence is an important goal of Entamoeba research. The sequencing of the genome of E. histolytica and the related avirulent species Entamoeba dispar has allowed whole-genome-scale analyses of genetic divergence and differential gene expression to be undertaken. These studies have helped elucidate mechanisms of virulence and identified genes differentially expressed in virulent and avirulent parasites. Here, we review the current status of the E. histolytica and E. dispar genomes and the findings of a number of genome-scale studies comparing parasites of different virulence.

Optimization of a real-time RT-PCR assay reveals an increase of genogroup I norovirus in the clinical setting

Although norovirus has been identified as the most common cause of gastroenteritis, the majority of cases have no etiologic agent identified. In this study, we describe the optimization of a real-time RT-PCR assay for the improved detection of genogroup I norovirus in patient specimens based upon sequence data from a collection of representative clinical norovirus sequences. The redesigned assay demonstrated a 64 fold increase in sensitivity, a 2 log decrease in the limit of detection, and an 18% increase in amplification efficiency, when compared to the standard assay. The optimized test also detected GI norovirus in clinical specimens that were initially negative by the standard assay. Use of the optimized assay increased the annual positivity of GI norovirus in Iowa from 1.2% to 4.5%, indicating the prevalence of GI norovirus may be higher than previously identified. Laboratory confirmation of the etiologic agent involved in gasteroenteritis cases is essential for better understanding of the prevalence and transmission of noroviruses.

The association of visuospatial working memory with dysthymic disorder in pre-pubertal children

BACKGROUND

Visuospatial working memory (VSWM) deficits have not been investigated specifically in children with dysthymic disorder (DD), although they are associated with impairments in attention that commonly occur in DD. This study investigates VSWM impairment in children with DD.

METHOD

A cross-sectional study of VSWM in 6- to 12-year-old children with medication-naive DD (n=26) compared to an age-, gender- and 'performance IQ' (PIQ)-matched healthy control group (n=28) was completed.

RESULTS

The DD group demonstrated impairment in VSWM, including impairment in the spatial span and strategy components of VSWM. Furthermore, the VSWM impairment remained after controlling for spatial span. Inattentive symptoms were significantly associated with the VSWM impairment.

CONCLUSIONS

This study of children with DD found deficits in performance on VSWM tasks, suggesting that fronto-striatal-parietal neural networks that underlie processes of attention and the executive component of VSWM are dysfunctional in children with DD. These findings further our understanding of DD and suggest more specific interventions that might improve functioning.

A deformation-based morphometry study of patients with early-stage Parkinson's disease

BACKGROUND AND PURPOSE

Previous volumetric magnetic resonance imaging (MRI) studies of Parkinson's disease (PD) utilized primarily voxel-based morphometry (VBM), and investigated mostly patients with moderate- to late-stage disease. We now use deformation-based morphometry (DBM), a method purported to be more sensitive than VBM, to test for atrophy in patients with early-stage PD.

METHODS

T1-weighted MRI images from 24 early-stage PD patients and 26 age-matched normal control subjects were compared using DBM. Two separate studies were conducted, where two minimally-biased nonlinear intensity-average were created; one for all subjects and another for just the PD patients. The DBM technique creates an average population-based MRI-average in an iterative hierarchical fashion. The nonlinear transformations estimated to match each subject to the MRI-average were then analysed.

RESULTS

The DBM comparison between patients and controls revealed significant contraction in the left cerebellum, and non-significant trends towards frontal, temporal and cingulate sulcal expansions with frontal and temporal white matter contractions. Within the patient group, the unified PD rating scores were highly correlated with local expansions in or near sulci bordering on frontal and temporal cortex.

CONCLUSION

Our results suggest that DBM could be a sensitive method for detecting morphological changes in early-stage PD.

A low-noise differential microphone inspired by the ears of the parasitoid fly Ormia ochracea

A miniature differential microphone is described having a low-noise floor. The sensitivity of a differential microphone suffers as the distance between the two pressure sensing locations decreases, resulting in an increase in the input sound pressure-referred noise floor. In the microphone described here, both the diaphragm thermal noise and the electronic noise are minimized by a combination of novel diaphragm design and the use of low-noise optical sensing that has been integrated into the microphone package. The differential microphone diaphragm measures 1 x 2 mm(2) and is fabricated out of polycrystalline silicon. The diaphragm design is based on the coupled directionally sensitive ears of the fly Ormia ochracea. The sound pressure input-referred noise floor of this miniature differential microphone has been measured to be less than 36 dBA.

The relationship between adiponectin, progesterone, and temperature across the menstrual cycle

BACKGROUND

The mechanisms regulating adiponectin, a highly abundant adipokine produced by adipocytes, have not been fully elucidated. Adiponectin levels are significantly higher in women when compared to men, suggesting sex-hormone involvement in its regulation. Previously, we have observed an inverse association between adiponectin and basal body temperature in pregnant women. These findings suggest that states where progesterone and temperature fluctuate, such as the menstrual cycle, could be associated with fluctuating adiponectin levels.

AIM

The aim of this study was to examine the relationship between adiponectin, progesterone, and temperature across the menstrual cycle.

SUBJECTS AND METHODS

A prospective study was performed. Fifteen non-obese pre-menopausal female subjects, all with regular cycles, and on no medication recorded a daily temperature and underwent blood sampling, indirect calorimetry, and bio-impendence studies in both the follicular and luteal phases of the menstrual cycle.

RESULTS

Serum adiponectin levels did not vary significantly across the menstrual cycle or between those who did and did not ovulate. No correlation was found between adiponectin levels and sex steroids, insulin and glucose levels or basal energy expenditure and body composition.

CONCLUSIONS

Our results indicate that adiponectin is not related to sex steroids or body composition in healthy premenstrual women.

The genome of the simian and human malaria parasite Plasmodium knowlesi

Plasmodium knowlesi is an intracellular malaria parasite whose natural vertebrate host is Macaca fascicularis (the 'kra' monkey); however, it is now increasingly recognized as a significant cause of human malaria, particularly in southeast Asia. Plasmodium knowlesi was the first malaria parasite species in which antigenic variation was demonstrated, and it has a close phylogenetic relationship to Plasmodium vivax, the second most important species of human malaria parasite (reviewed in ref. 4). Despite their relatedness, there are important phenotypic differences between them, such as host blood cell preference, absence of a dormant liver stage or 'hypnozoite' in P. knowlesi, and length of the asexual cycle (reviewed in ref. 4). Here we present an analysis of the P. knowlesi (H strain, Pk1(A+) clone) nuclear genome sequence. This is the first monkey malaria parasite genome to be described, and it provides an opportunity for comparison with the recently completed P. vivax genome and other sequenced Plasmodium genomes. In contrast to other Plasmodium genomes, putative variant antigen families are dispersed throughout the genome and are associated with intrachromosomal telomere repeats. One of these families, the KIRs, contains sequences that collectively match over one-half of the host CD99 extracellular domain, which may represent an unusual form of molecular mimicry.

Array comparative genomic hybridization in global developmental delay

OBJECTIVE

Array-based comparative genomic hybridization (array CGH) is an emerging technology that allows for the genome-wide detection of DNA copy number changes (CNC) such as deletions or duplications. In this study, array-based CGH was applied to a consecutive series of children with previously undiagnosed non-syndromal global developmental delay (GDD) to assess potential etiologic yield.

METHODS

The children in this study were drawn from a previously reported consecutive series of children with well-defined GDD. Almost all subjects had undergone prior karyotyping and neuroimaging studies with non-diagnostic results. Array-based CGH was undertaken using the SignatureChip(R) (1887 BACs representing 622 loci) with abnormalities verified by subsequent FISH analysis and testing of parents to distinguish between pathogenic and familial non-pathogenic variants.

RESULTS

On CGH analysis in our study, 6 of 94 children (6.4%) had a causally related pathogenic CNC. Three were sub-telomeric in location. An analysis of a variety of clinical factors revealed that only the presence of minor dysmorphic features (<3) was predictive of etiologic yield on CGH analysis (4/26 vs. 2/68, P = 0.05). Severity of delay was not found to be predictive.

INTERPRETATION

In children with non-syndromal GDD, array-based CGH has an etiologic yield of 6.4%. This suggests that this emerging technology may be of diagnostic value when applied subsequent to detailed history, physical examination, and targeted laboratory testing. Array CGH may merit consideration as a first-tier test in the context of a child with unexplained GDD.