Autonomous circadian rhythms in the human hepatocyte regulate hepatic drug metabolism and inflammatory responses

Critical aspects of physiology and cell function exhibit self-sustained ~24-hour variations termed circadian rhythms. In the liver, circadian rhythms play fundamental roles in maintaining organ homeostasis. Here, we established and characterized an in vitro liver experimental system in which primary human hepatocytes display self-sustained oscillations. By generating gene expression profiles of these hepatocytes over time, we demonstrated that their transcriptional state is dynamic across 24 hours and identified a set of cycling genes with functions related to inflammation, drug metabolism, and energy homeostasis. We designed and tested a treatment protocol to minimize atorvastatin- and acetaminophen-induced hepatotoxicity. Last, we documented circadian-dependent induction of pro-inflammatory cytokines when triggered by LPS, IFN-β, or Plasmodium infection in human hepatocytes. Collectively, our findings emphasize that the phase of the circadian cycle has a robust impact on the efficacy and toxicity of drugs, and we provide a test bed to study the timing and magnitude of inflammatory responses over the course of infection in human liver.

Direct capture of neutralized RBD enables rapid point-of-care assessment of SARS-CoV-2 neutralizing antibody titer

Neutralizing antibody (NAb) titer is a key biomarker of protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, but point-of-care methods for assessing NAb titer are not widely available. Here, we present a lateral flow assay that captures SARS-CoV-2 receptor-binding domain (RBD) that has been neutralized from binding angiotensin-converting enzyme 2 (ACE2). Quantification of neutralized RBD in this assay correlates with NAb titer from vaccinated and convalescent patients. This methodology demonstrated superior performance in assessing NAb titer compared with either measurement of total anti-spike immunoglobulin G titer or quantification of the absolute reduction in binding between ACE2 and RBD. Our testing platform has the potential for mass deployment to aid in determining at population scale the degree of protective immunity individuals may have following SARS-CoV-2 vaccination or infection and can enable simple at-home assessment of NAb titer.

High-Resolution Electrochemical Transistors Defined by Mold-Guided Drying of PEDOT:PSS Liquid Suspension

Ion-sensitive transistors with nanoscale or microscale dimensions are promising for high-resolution electrophysiological recording and sensing. Technology that can pattern polymer functional materials directly from a solution can effectively avoid any chemical damage induced by conventional lithography techniques. The application of a mold-guided drying technique to pattern PEDOT:PSS-based transistors with high resolution directly from the water-based suspension is presented in this paper. Gold electrodes with short channels were first defined by creating high-resolution polymer lines with mold-guided drying followed by pattern transfer through a lift-off process. Then, PEDOT:PSS lines were subsequently created through an identical mold-guided drying process on the predefined electrodes. Small-scale transistor devices with both shortened channel length and width exhibited a good high-frequency response because of the weak capacitive effect. This is particularly advantageous for electrochemical transistors since the use of conventional fabrication techniques is extremely challenging in this case. In addition, modified polymer chain alignment of the assembled PEDOT:PSS lines during the drying process was observed by optical and electrical measurement. The mold-guided drying technique has been proven to be a promising method to fabricate small-scale devices, especially for biological applications.

The precarious use of charm needles susuk in treatment of low back pain by traditional medicine practitioners and its possible risk to patient safety

A 68-year-old female presented with a 1-month history of lower back pain with right-sided radiculopathy and numbness. She was diagnosed with lumbar spondylosis and treated conservatively with analgesia and physiotherapy. Imaging showed multiple susuk, a metal alloy, in the lower back region and other regions of the body. The patient had undergone traditional medicine consultation 10 years earlier when the susuk was inserted in the lower back as talisman. The practice of the insertion of susuk is popular in rural East Malaysia and Indonesia. These foreign bodies act as possible causes of chronic inflammation and granuloma formation. In addition, the localised heighten peril upon imaging. This report suggests that the insertion of multiple susuk as talisman carries risk to safety of patients when imaging, and this practice complicates the management of musculoskeletal disorders.

Periventricular White Matter Abnormalities on Diffusion Tensor Imaging of Postural Instability Gait Disorder Parkinsonism

BACKGROUND AND PURPOSE

Postural instability gait disorder is a motor subtype of Parkinson disease associated with predominant gait dysfunction. We investigated the periventricular white matter comprising longitudinal, thalamic, and callosal fibers using diffusion tensor MR Imaging and examined clinical correlates in a cohort of patients with Parkinson disease and postural instability gait disorder and healthy controls.

MATERIALS AND METHODS

All subjects underwent the Tinetti Gait and Balance Assessment and brain MR imaging. The DTI indices (fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity) from ROIs dropped over the superior and inferior longitudinal fasciculi, inferior fronto-occipital fasciculus, anterior thalamic radiation, anterior and posterior limbs of the internal capsule, and the genu and body of corpus callosum were evaluated.

RESULTS

Our findings showed that the superior longitudinal fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, anterior thalamic radiation, genu of the corpus callosum, and body of the corpus callosum are more affected in postural instability gait disorder than in those with Parkinson disease or healthy controls, with more group differences among the longitudinal fibers. Only the callosal fibers differentiated the postural instability gait disorder and Parkinson disease groups. DTI measures in the superior longitudinal fasciculus, frontostriatal fibers (anterior thalamic radiation, anterior limb of the internal capsule), and genu of the corpus callosum fibers correlated with clinical gait severity.

CONCLUSIONS

Findings from this case-control cohort lend further evidence to the role of extranigral pathology and, specifically, the periventricular fibers in the pathophysiology of postural instability gait disorder.

Liver Transplant Waitlist Outcomes and the Allocation of Hepatocellular Carcinoma Model for End-Stage Liver Disease Exception Points at a Low-Volume Center

BACKGROUND

Organ scarcity continues to be the main problem limiting the number of liver transplants performed. Outcomes of patients waitlisted for an organ in an Asian country with low organ donation rate have not been well evaluated. Our current policy of allocating 15 exception points to patients with hepatocellular carcinoma (HCC) to render them competitive for a transplant also requires review.

METHODS

The waiting list registry and the organ transplant registry of a single institution in Asia were reviewed from December 2005 to June 2016 for all patients who underwent liver transplantation. Patient characteristics and outcomes of waitlist dropouts were evaluated. Statistical analyses were performed using SPSS version 20.0.

RESULTS

One hundred seventy-three patients were waitlisted for a deceased donor liver-only transplant. The most common etiology of liver disease was hepatitis B, followed by cholestatic diseases. Approximately half of the patients had HCC (45.6%). Priority listing for transplant comprised 15.6% of cases. Median Model for End-Stage Liver Disease (MELD) at listing was 15, and median waiting time to transplant was 17 weeks (interquartile range = 6.5-43.5). Overall, 89 (51.4%) patients underwent liver transplantation and 68 (39.3%) dropped out. For patients with HCC, the most common cause of dropout was progression beyond University of California San Francisco transplant criteria (62.5%). The cumulative incidence of dropout at 3 months among patients with HCC who received exception MELD scores was 11%. This was higher than those listed with physiologic MELD of 14-16 points (7%) but lower than those with 17-19 points (16%).

CONCLUSIONS

Hepatitis B-related liver disease and HCC comprise the majority of patients listed for liver transplant. Dropout rates are high and this is due to the lack of donor organs. The current policy of allocating 15 exception MELD points to patients with HCC within transplant criteria may underestimate the dropout risk of patients with HCC in our population.

Depression, anxiety, and apathy in Parkinson's disease: insights from neuroimaging studies

Depression, anxiety and apathy are common mood disturbances in Parkinson's disease (PD) but their pathophysiology is unclear. Advanced neuroimaging has been increasingly used to unravel neural substrates linked to these disturbances. A systematic review is provided of neuroimaging findings in depression, anxiety and apathy in PD. A PubMed, MEDLINE and EMBASE search of peer‐reviewed original research articles on these mood disturbances in PD identified 38 studies on depression, eight on anxiety and 14 on apathy in PD. Most of the imaging studies used either position emission tomography or single‐photon emission computed tomography techniques. These studies generally suggest increased neural activity in the prefrontal regions and decreased functional connectivity between the prefrontal−limbic networks in depressed patients. Functional imaging studies revealed an inverse correlation between dopaminergic density in the caudate and putamen with the severity of anxiety in PD. There was no consistent correlation between dopaminergic density of thalamus and anxiety. Studies demonstrated both positive and inverse correlations between apathy and metabolism or activity in the striatum, amygdalar, prefrontal, temporal and parietal regions. The clinical variability of study subjects and differences in image pre‐processing and analytical strategies may contribute to discrepant findings in these studies. Both nigrostriatal and extra‐nigrostriatal pathways (in particular the frontal region and its connecting areas) are affected in mood disorders in PD. Identifying the relative contributions of these neural pathways in PD patients with overlapping motor and mood symptoms could provide new pathophysiological clues for the development of better therapeutic targets for affected patients.

Stage-Specific Relationship between Frailty and Cognitive Impairment in a Specialist Memory Clinic Setting

BACKGROUND

It is unclear if the complex relationship between physical frailty and cognition varies across the severity of cognitive impairment.

OBJECTIVES

We therefore aimed to explore if there are stage-specific differences in the relationship between frailty and cognitive impairment.

DESIGN

Cross-sectional study.

SETTING

A specialist Memory Clinic setting.

PARTICIPANTS

Mild cognitive impairment (MCI) and mild-moderate Alzheimer's disease (AD) community-dwelling subjects.

MEASUREMENTS

We obtained data on demographics, multimorbidity, cognition-related measures, nutrition, neuroimaging measures, muscle mass, Vitamin D level, apolipoprotein - e (APOE) status and physical performance measures. Frailty measures of gait speed, hand grip strength, question on exhausation and weight loss, classified subjects according to the Buchmann criteria into non-frail and frail categories.

RESULTS

Forty-five MCI, 64 mild AD and 13 moderate AD subjects (total n=122) were studied. The prevalence of frailty for MCI, mild AD and moderate AD was 35.6%, 21.9% and 46.2% respectively, indicating a u-shaped trend. Significant differences were noted in fatigue, grip strength and gait speed frailty sub-items. Significant correlation of frailty with cognition were noted in mild-moderate AD (Spearman's coefficient 0.26, p<0.05) but not in MCI (0.01, p=0.6). No other differences in multimorbidity, Vitamin D, APOE, nutritional measures, white matter lesions were observed. Sarcopenia interestingly had an inverse stage-specific relationship unlike frailty.

CONCLUSIONS

Our results suggest a U-shaped relationship between frailty and cognition, characterized by initial dissociation with cognitive impairment and subsequent convergence at later stages. Future studies incorporating immune markers and endocrine pathways with longitudinal follow-up could potentially elucidate intermediary mechanisms in the frailty cascade.

Autosomal Dominant Spinocerebellar Ataxias: An Asian Perspective

Autosomal dominant cerebellar ataxias, frequently referred to as spinocerebellar ataxias (SCAs) have been under intense scientific research limelight since expansions of coded CAG trinucleotide repeats were demonstrated to cause several dominantly inherited SCAs. The number of new SCA loci has expanded dramatically in recent years. At least ten genes have been identified for SCAs 1, 2, 3, 6, 7, 8, 10, 12, 17, dentatorubral-pallidoluysian atrophy (DRPLA), and six loci responsible for SCAs 4, 5, 11,13, 14, and 16 have been mapped. Genetic testing is essential for diagnosis due to the overlapping and varied phenotypic features of the different SCAs. While there is no effective treatment available, genetic counseling is important for addressing the many ethical, social, legal, and psychological issues facing SCA patients. Researchers have recently provided valuable information on the pathogenesis of the disease and hopefully a cure will be available in the near future.

Comparison of cryopreserved amniotic membrane and umbilical cord tissue with dehydrated amniotic membrane/chorion tissue

OBJECTIVE

To evaluate how the different processing methods cryopreservation and dehydration affect the structural integrity and biological composition of key signalling molecules within amniotic membrane and umbilical cord tissues.

METHOD

We directly compared cryopreserved amniotic membrane (AM) and umbilical cord (UC) tissues with dehydrated amniotic membrane/chorion (dHACM) tissue using biochemical and functional assays including histological and histochemical staining, BCA, agarose gel electrophoresis, western blot, ELISA, and proliferation and cell death assays.

RESULTS

Cryopreservation retains the native architecture of the AM/UC extracellular matrix and maintains the quantity and activity of key biological signals present in fresh AM/UC, including high molecular weight hyaluronic acid, heavy chain-HA complex, and pentraxin 3. In contrast, dehydrated tissues were structurally compromised and almost completely lacked these crucial components.

CONCLUSION

The results presented here indicate that cryopreservation better preserves the structural and biological signaling molecules of foetal tissues.

MCCC1/LAMP3 reduces risk of sporadic Parkinson's disease in Han Chinese

BACKGROUND

A recent large-scale replication and heterogeneity study reported the new described GWAS locus (MCCC1/LAMP3 rs11711441) was associated with a reduced risk of Parkinson disease (PD) in Asian and Caucasian populations. Its role is still unknown in a Han Chinese population from mainland China. We genotyped the rs11711441 variant to investigate the association with risk of PD.

METHODS

Using a case-control methodology, a total of 1428 Han Chinese study subjects were genotyped. We also conducted further stratified analysis according to age at onset and compared the clinical characteristics of GA + AA subjects with GG subjects.

RESULTS

In this study, we confirmed that the A allele of MCCC1/LAMP3 (rs11711441) polymorphism reduces the risk to develop sporadic PD (P = 0.043). Additionally, subjects with GA + AA genotypes have a reduced risk compared to those with GG genotype (P = 0.022). The association was seen among the older age group (P = 0.014), but was not significant among the younger age group (P = 0.641). No significant differences were observed in gender, age at onset, and onset symptoms between GA + AA subjects and GG subjects.

CONCLUSION

Our study, the first from Mainland China demonstrates that MCCC1/LAMP3 (rs11711441) is associated with a lower risk of PD. Further studies in additional Chinese populations and other cohorts will be useful.

A new paradigm emerges from the study of de novo mutations in the context of neurodevelopmental disease

The study of de novo point mutations (new germline mutations arising from the gametes of the parents) remained largely static until the arrival of next-generation sequencing technologies, which made both whole-exome sequencing (WES) and whole-genome sequencing (WGS) feasible in practical terms. Single nucleotide polymorphism genotyping arrays have been used to identify de novo copy-number variants in a number of common neurodevelopmental conditions such as schizophrenia and autism. By contrast, as point mutations and microlesions occurring de novo are refractory to analysis by these microarray-based methods, little was known about either their frequency or impact upon neurodevelopmental disease, until the advent of WES. De novo point mutations have recently been implicated in schizophrenia, autism and mental retardation through the WES of case-parent trios. Taken together, these findings strengthen the hypothesis that the occurrence of de novo mutations could account for the high prevalence of such diseases that are associated with a marked reduction in fecundity. De novo point mutations are also known to be responsible for many sporadic cases of rare dominant mendelian disorders such as Kabuki syndrome, Schinzel-Giedion syndrome and Bohring-Opitz syndrome. These disorders share a common feature in that they are all characterized by intellectual disability. In summary, recent WES studies of neurodevelopmental and neuropsychiatric disease have provided new insights into the role of de novo mutations in these disorders. Our knowledge of de novo mutations is likely to be further accelerated by WGS. However, the collection of case-parent trios will be a prerequisite for such studies. This review aims to discuss recent developments in the study of de novo mutations made possible by technological advances in DNA sequencing.

A prospective pilot study of repetitive transcranial magnetic stimulation for gait dysfunction in vascular parkinsonism

OBJECTIVE

Vascular Parkinsonism (VP) causes significant gait dysfunction in patients who otherwise have good lower limb strength. Its pathophysiology is not clearly understood, and current treatment with physical therapy remains unsatisfactory. The study explores repetitive transcranial magnetic stimulation (rTMS) as a potential new and safe therapy for VP.

MATERIALS AND METHODS

We prospectively applied 5 Hz rTMS treatment to 5 patients who satisfied all the criteria for VP. Repetitive TMS was performed on 5 consecutive days and patients were assessed on (1) timed 10 m walk (T10MW), (2) Unified Parkinson's Disease Rating Scale (UPDRS) motor subsection, (3) Clinician's Global Impression of Change (CGIC), and (4) Patient's Global Impression of Change (PGIC), for up to 6 weeks post-rTMS.

RESULTS

All the outcome measures were found to have improved ratings post-rTMS when compared with baseline, and were statistically significant. The T10MW showed significant improvement at 4 weeks post-rTMS with a trend towards improvement at 2 weeks post-rTMS. The UPDRS motor subscores was significantly reduced at 2 weeks, 4 weeks and 6 weeks post-rTMS. The PGIC and CGIC scores were significantly better post-rTMS. The treatment was well-tolerated and all patients completed the study.

CONCLUSION

This study demonstrated for the first time that 5 sessions of rTMS could improve gait in a measurable way for up to 6 weeks without any significant side-effects. Repetitive TMS could be a potentially useful adjunct in rehabilitation of VP patients and further research is warranted.

Influenza and seasonal influenza vaccination among diabetics in Singapore: knowledge, attitudes and practices

INTRODUCTION

Seasonal influenza vaccination is recommended for diabetics; however, the vaccination uptake rate among diabetics remains low. This study explored the knowledge, attitudes and practices among diabetics in Singapore with regard to influenza and influenza vaccination.

METHODS

A survey was conducted among type 1 and 2 diabetes mellitus patients who attended three management centres of the Diabetic Society of Singapore in January 2007. The pilot-tested questionnaire covered influenza and influenza vaccination in terms of the patient demographics, medical history and knowledge, attitudes and practices.

RESULTS

A total of 307 diabetics participated in the study. Of these, 139 (45.3 percent) claimed to know the difference between influenza and the common cold, while 98 (31.9 percent) and 18 (5.9 percent) participants thought that influenza vaccines protected against all influenza strains and provided lifelong immunity, respectively. 247 (80.4 percent) participants were aware that they were at a moderate or higher risk for influenza-related complications, while 181 (58.9 percent) considered vaccination to be effective in preventing influenza and its complications. Only 94 (30.6 percent) participants were previously vaccinated. Among those unvaccinated, 117 (54.9 percent) did not think vaccination was necessary, while 104 (48.8 percent) had never considered it. As observed from the multivariate analysis, income was a key predictor of influenza vaccination. While 241 (78.5 percent) participants cited healthcare professional advice as the main guiding factor for getting vaccinated, 199 (64.8 percent) had never been advised on influenza vaccination. Of the 108 (35.1 percent) participants who had received previous advice on influenza vaccination, the majority had received it from their healthcare professionals.

CONCLUSION

Uptake of influenza vaccination among diabetics in Singapore is low, and the key predictor is income. Perception and knowledge are the main barriers, and hence, healthcare professionals should educate and encourage vaccination among diabetics.

A randomized controlled trial of rivastigmine in patients with cognitive impairment no dementia because of cerebrovascular disease

OBJECTIVES

The safety and efficacy of early acetylcholinesterase inhibitors therapy in patients with cognitive impairment no dementia (CIND) after a cerebrovascular accident have not been examined. In this study, we investigated the safety and efficacy of rivastigmine in cognition, particularly executive function in patients with CIND because of cerebrovascular disease.

METHODS

This study was a 24-week, double-blind, randomized, placebo-controlled trial of ischemic stroke patients seen at a tertiary hospital who had cognitive impairment no dementia because of cerebrovascular disease. The intervention was either rivastigmine or placebo up to 9 mg/day. The primary outcome of interest was mean change from baseline in the Ten-Point Clock Drawing and Color Trails 1 and 2.

RESULTS

Fifty patients were randomized into rivastigmine (n = 25) and placebo (n = 25) arms. Patients in the rivastigmine group showed statistically significant improvement (1.70 vs 0.13, P = 0.02) on the animal subtask of the verbal fluency measure compared with placebo. There was also a trend (non-significant) towards improvement in Color Trails II.

CONCLUSIONS

In this pilot study, we demonstrated that rivastigmine was well tolerated in patients with CIND because of cerebrovascular disease and may potentially improve executive functioning.

LRRK2 variant associated with Alzheimer's disease

Overlapping neurodegenerative pathologies (including Alzheimer's disease, AD) have been described in Parkinson's disease (PD) patients with leucine-rich repeat kinase-2 (LRRK2) mutations. We analyzed a LRRK2 PD (R1628P) risk variant in a group of 885 subjects comprising of AD and controls. The frequency of the R1628P allele was higher in AD compared to controls (3.5% vs. 1.6%, OR 2.3, 95 CI 1.2-4.4, p=0.018). In vitro, the mean percentage of apoptosis and cell death observed for the R1628P transfected human cell lines was higher compared to wild type 21.8 ± 1.9, vs. 17.1 ± 1.3, p<0.05, 30.2 ± 2.2 vs. 25.7 ± 1.3, p<0.05). The LRRK2 R1628P variant increases the risk of AD in our population and our in vitro findings suggest that it is a functional variant and predisposes to apoptosis.

LRRK2 in Parkinson's disease: genetic and clinical studies from patients

Mutations in leucine-rich repeat kinase 2 (LRRK2) (PARK8) are associated with both familial and sporadic forms of Parkinson's disease. Most studies have shown that LRRK2 mutations may explain between 5% and 13% of familial and 1-5% of sporadic Parkinson's disease. Importantly, a common recurrent mutation (G2019S) located in the kinase domain has been reported across most ethnic populations, with the highest prevalence among Ashkenazi Jews and North African Arabs. A recent worldwide meta-analysis pooling data from 24 populations reported a higher occurrence of G2019S in southern than in northern European countries and the penetrance is estimated to be approximately 75% at the age of 79 years. The R1441 'hotspot' amino acid codon residue (G/H/C) in the Ras of complex proteins domain is the second most common site of pathogenic LRRK2 substitutions after G2019S, with most carriers developing symptoms by the age of 75 years. Two polymorphic variants found almost exclusively among Asians (G2385R and R1628P) have been shown to increase the Parkinson's disease risk by approximately two-fold. The mutational event associated with R1628P is more recent, occurring approximately 2500 years ago, compared to estimates of 4000 years for G2385R carriers. LRRK2 mutation carriers generally simulate late onset Parkinson's disease and present with the usual typical clinical features. Genetic testing for G2019S in sporadic late-onset Parkinson's disease can be considered in some situations and may be useful in populations with high carrier status. The identification of asymptomatic mutation and risk variant carriers provides a unique opportunity for recruiting these subjects in potential neuroprotective trials and longitudinal studies to identify biomarkers of neurodegeneration.

CALHM1 variant is not associated with Alzheimer's disease among Asians

In a case control study involving 484 study subjects, we showed that the CALHM1 allele (13.5% vs 16.7%) and genotype frequency was not significantly different between Alzheimer's disease (AD) and controls. Logistic regression analysis did not reveal any interaction between ApoE4 allele and CALHM1 allele.

Thromboprophylaxis post vaginal delivery: Are we forgetting it? Audit on thromboprophylaxis prescription post vaginal births

Pulmonary thromboembolism is the leading direct cause of maternal deaths in the UK. The majority of deaths occur in the puerperium. Caesarean section has been recognised as a risk factor but there is concern that more attention to thromboprophylaxis after vaginal births is needed. The hospital maternity unit in Dumfries has written guidelines on thromboprophylaxis after vaginal births. This audit assessed the compliance with these guidelines within this maternity unit. The case notes relating to spontaneous vaginal births over a 2-month period (n=148) and instrumental vaginal births over a 7-month period (n=29) were reviewed. Information concerning venous thromboembolism risk and any thromboprophylaxis given was extracted. The audit showed that 9% of spontaneous vaginal births and 62% of instrumental vaginal births required specific thromboprophylaxis. However, only 31% of the spontaneous vaginal births and 22% of the instrumental vaginal births in which thromboprophylaxis was indicated did indeed receive the required treatment. Failure to respond to venous thromboembolism risk factors was common. Measures to increase the awareness of maternity staff to these factors are suggested.

Analysis of the UCHL1 genetic variant in Parkinson's disease among Chinese

The inverse association of the functional ubiquitin carboxy-terminal hydrolase L1 (UCHL1) S18Y variant with Parkinson's disease (PD) among Caucasian populations has been debated. We conducted a large-scale analysis to investigate the age-of-onset effect of the UCHL1 variant in PD among ethnic Chinese. Individual data sets from 5 centers comprising a total of 4088 study subjects were analyzed. In the univariate analysis, only data from 1 center showed a trend towards a protective effect among young subjects. However, in the combined analysis, no significant association between the UCHL1 variant and PD was detected (A allele frequency 0.531 vs. 0.528, p=0.87, OR 1.01, 95% CI 0.92-1.1). Among subjects less than 60 years old, the OR is 0.99 (95% CI 0.84-1.16, p=0.88). A multivariate logistic regression analysis showed that family history, UCHL1 variant and the interaction of UCHL1 variant and age at onset (p=0.816) were not significantly associated with PD.

Case control analysis of LRRK2 Gly2385Arg in Alzheimer's disease

Alzheimer's disease (AD) pathology has been described in Parkinson's disease (PD) patients with leucine-rich repeat kinase-2 (LRRK2) mutations. A common LRRK2 Gly2385Arg variant has been widely shown to be associated with a twofold increased risk of PD in various Asian populations. In a case control study, the frequency of the heterozygous Gly2385Arg genotype was demonstrated in 4.3% of AD compared to 4.5% in controls (odds ratio=0.94, 95% CI 0.37-2.42, p=1.0). The Gly2385Arg variant does not appear to modulate the risk of AD in our population.

Meta-analysis: narrow band imaging for lesion characterization in the colon, oesophagus, duodenal ampulla and lung

BACKGROUND

Narrow band imaging is a new endoscopic technology that highlights mucosal surface structures and microcapillaries, which may be indicative of neoplastic change.

AIM

To assess the diagnostic precision of narrow band imaging for the diagnosis of epithelial neoplasia compared to conventional histology both overall and in specific organs.

METHODS

We performed a meta-analysis of studies which compared narow band imaging-based diagnosis of neoplasia with histopathology as the gold standard. Search terms: 'endoscopy' and 'narrow band imaging'.

RESULTS

Five hundred and eighty-two patients and 1108 lesions in 11 studies were included. Overall, sensitivity was 0.94 (95% confidence interval 0.92-0.95), specificity 0.83 (0.80-0.86); weighted area under the curve was 0.96 (standard error 0.02), diagnostic odds ratio (DOR) 72.74 (34.11-155.15). DORs were 66.65 (25.84-171.90), 61.19 (7.09-527.97), 69.74 (8.04-605.24) for colon, oesophagus and lung respectively. Studies with more than 50 patients had higher diagnostic precision, relative DOR 4.96 (1.28-19.27), P = 0.022. There was no difference in accuracy between microvessel and mucosal (pit) pattern based measures, relative DOR 1.29 (0.05-35.16), P = 0.87. There was significant heterogeneity overall between studies, Q = 31.2, P = 0.003.

CONCLUSION

Narrow band imaging is accurate with high diagnostic precision for in vivo diagnosis of neoplasia across a range of organs, using simple microvessel-based measures.

A cost-effectiveness analysis of delayed sphincteroplasty for anal sphincter injury

OBJECTIVE

Anal-sphincter injury may result in faecal incontinence. Sphincteroplasty is usually performed as a primary (immediate) procedure. Delayed sphincteroplasty (DS) can be performed if there is significant trauma or soiling, if the primary procedure has failed, and if the injury was not recognized initially. This study aimed to determine the cost to patient and health service in the event a DS is performed.

METHOD

Patients with anal-sphincter-injury who underwent primary sphincteroplasty (PS)/DS were identified from the published literature (primary, n = 103; delayed, n = 777) using Medline, Embase, Ovid and Cochrane databases for studies published between 1976 and 2006. Studies included described at least one of the measured outcomes--probability of functional success/failure and quality of life (QOL). An economic model was constructed and decision analysis performed using a decision tree based on a Markov process. Main outcomes were quality-adjusted-life-years (QALYs) gained from each strategy, costs incurred and incremental cost-effectiveness ratio (ICER) over a 10- and 15-year time horizon.

RESULTS

Over 10 years, primary sphincteroplasty (PS) produced a gain of 5.72 QALYs for an estimated 2750 pounds, giving an ICER of 487 pounds per QALY. DS produced a gain of 3.73 QALYs for a cost of 2667 pounds, giving an ICER of 719 pounds per QALY. Both procedures fell below the 10,000 pounds per QALY willingness-to-pay threshold, but PS produced the highest QALYs. Both procedures performed poorly beyond the 10-year mark.

CONCLUSION

If DS has to be performed, the resultant cost is greater with concurrently lower QALYs gained. Successful PS substantially improves QOL and reduces overall cost-of-treatment.

Surgical strategies for faecal incontinence--a decision analysis between dynamic graciloplasty, artificial bowel sphincter and end stoma

BACKGROUND

Artificial bowel sphincter (ABS) and dynamic graciloplasty (DG) are surgical treatments for faecal incontinence (FI). FI may affect quality of life (QOL) so severely that patients are often willing to consider a permanent end stoma (ES). It is unclear which is the more cost-effective strategy.

METHOD

Probability estimates for patients with FI were obtained from published data (ABS, n = 319; DG, n = 301), supplemented by expert opinion. The primary outcome was quality-adjusted life years (QALYs) gained from each strategy. Factors considered were the risk of failure of the primary and redo operation and the consequent risk of permanent stoma. Results were assessed as incremental cost-effectiveness ratio (ICER).

RESULTS

Over the 5-year time horizon, ES gave a QALY gain of 3.45 for 16,280 pounds sterling, giving an ICER of 4719 pounds sterling/QALY. ABS produced a gain of 4.38 QALYs for 23,569 pounds sterling, giving an ICER of 5387 pounds sterling/QALY. DG produced a gain of 4.00 QALYs for 25,035 pounds sterling, giving an ICER of 6257 pounds sterling/QALY. With the willingness-to-pay threshold set at 30,000 pounds sterling/QALY, ES was the most cost-effective intervention. The ABS was most cost-effective after 10 years.

CONCLUSION

All three procedures were found to be cost-effective. The ES was most cost-effective over 5 years, while the ABS was most cost-effective in excess of 10. DG maybe considered as an alternative in specialist centres.

SORL1 haplotypes modulate risk of Alzheimer's disease in Chinese

Genetic variants of the neuronal sortilin-related receptor (SORL1) have been demonstrated to modulate the risk of Alzheimer's disease (AD) in different American and European populations [Rogaeva, E., Meng, Y., Lee, J.H., Gu, Y., Kawarai, T., Zou, F., Katayama, T., Baldwin, C.T., Cheng, R., Hasegawa, H., Chen, F., Shibata, N., Lunetta, K.L., Pardossi-Piquard, R., Bohm, C., Wakutani, Y., Cupples, L.A., Cuenco, K.T., Green, R.C., Pinessi, L., Rainero, I., Sorbi, S., Bruni, A., Duara, R., Friedland, R.P., Inzelberg, R., Hampe, W., Bujo, H., Song, Y.Q., Andersen, O.M., Willnow, T.E., Graff-Radford, N., Petersen, R.C., Dickson, D., Der, S.D., Fraser, P.E., Schmitt-Ulms, G., Younkin, S., Mayeux, R., Farrer, L.A., St George-Hyslop, P., 2007. The neuronal sortilin-related receptor SORL1 is genetically associated with Alzheimer disease. Nat. Genet. 39 (2), 168-177]. We conducted haloptype analysis involving two genetic clusters of SORL1 in AD and controls among Han Chinese. rs3824968 (SNP 23) was associated with an increased risk of AD, and there was a trend towards association for rs1699102 (SNP 22) and rs2282649 (SNP 24). More robust associations were found for three-loci haplotypes. In particular, the GCA haplotype at SNPs 19-22-23 was associated with an increased risk (odds ratio 1.4), and CTC haplotype at SNPs 19-22-23 and TCT at SNPs 22-23-24 a decreased risk (odds ratio 0.67) of AD. The complete absence of some at-risk North European haplotypes in our Chinese study subjects was likely due to different ancestral origins, with allelic heterogeneity among races. However, our study suggests that certain SORL1 haplotypes at SNPs 19-24 modulated risk of AD in our Chinese population.

Epithelial-mesenchymal interactions in keloid pathogenesis modulate vascular endothelial growth factor expression and secretion

Vascular endothelial growth factor (VEGF) plays an important role in angiogenesis during the wound healing process. As epithelial-mesenchymal interactions have been shown to regulate a plethora of genes in wound healing, we hypothesized that these interactions might have a role in modulating VEGF expression and angiogenesis. A two chamber co-culture model was used, wherein normal and keloid keratinocytes and fibroblasts were physically separated by membrane inserts while allowing cytokine diffusion. Cell lysates obtained from keratinocytes co-cultured with fibroblasts demonstrated increased expression of VEGF. An enzyme-linked immunosorbent assay (ELISA) showed significant increase in VEGF expression in co-culture conditioned media compared with controls. Additionally, the conditioned medium from keloid keratinocyte and fibroblast co-cultures increased proliferation and formation of complex three-dimensional capillary-like structures in human umbilical vein endothelial cells, emphasising the importance of epithelial-mesenchymal interactions in the angiogenic process. Immunostaining of keloid tissue localized VEGF in the basal layer of the epidermis and also demonstrated higher blood vessel density than normal skin. Keloid tissue extract also demonstrated increased expression of VEGF compared with normal skin. It is likely that epidermal VEGF exerts significant paracrine control over the dynamics and expression profile of underlying dermal fibroblasts. Addition of the inhibitors WP631, mitoxantrone, and Rapamycin to keloid keratinocyte and fibroblast co-cultures, downregulated secreted VEGF expression in a dose-dependent manner, suggesting therapeutic potential for these compounds in the treatment of keloid scars.

Meta-analysis: Alvimopan vs. placebo in the treatment of post-operative ileus

BACKGROUND

Alvimopan is a selective, competitive mu-opioid receptor antagonist with limited oral bioavailability which may be used to reduce length of post-operative ileus.

AIM

The study compared alvimopan with placebo following bowel resection or total abdominal hysterectomy.

METHODS

A meta-analysis of randomized-controlled trials published between 2001 and 2006 of alvimopan vs. placebo was performed. The primary efficacy end-points were composite measures of passage of flatus, stool, and tolerance of solid food (GI-3) and passage of stool and tolerance of solid food (GI-2). The incidence of treatment emergent adverse events was assessed.

RESULTS

Five trials matched the selection criteria, reporting on 2195 patients. A total of 1521 (69.3%) had alvimopan and 674 (30.7%) placebo. GI-3 significantly improved (hazard ratio 1.30; 95% confidence intervals 1.16, 1.45, P < 0.001), as did GI-2 (hazard ratio 1.61; 95% confidence intervals 1.26, 2.05, P < 0.001) on alvimopan 12 mg. Time to discharge (hazard ratio 1.26; 95% confidence intervals 1.13, 1.40, P < 0.001), time to bowel motion (hazard ratio 1.74; 95% confidence intervals 1.29, 2.35, P < 0.001), and time to solid food (hazard ratio 1.14; 95% confidence intervals 1.01, 1.30, P < 0.04) also improved significantly. No difference was noted in the incidence of treatment emergent adverse events.

CONCLUSIONS

Alvimopan showed significant advantages over placebo in restoring gastro-intestinal function, and reduced time to discharge following major abdominal surgery, with acceptable side effects.

Analysis of 14 LRRK2 mutations in Parkinson's plus syndromes and late-onset Parkinson's disease

The pleomorphic pathology of postmortem LRRK2-positive patients and the frequent association with late-onset Parkinson's disease (LOPD) symptoms suggest that LRRK2 mutations may play a role in Parkinson's Plus disorders and LOPD. Published studies primarily focus on the common G2019S mutation. Analysis of a spectrum of LRRK2 mutations in Parkinson's Plus disorders has yet to be reported. We investigated 14 leucine-rich repeat kinase 2 (LRRK2) mutations in a cohort of Parkinson's Plus disorders and LOPD. A total of 458 patients with progressive supranuclear palsy (PSP), multiple system atrophy (MSA), corticobasal ganglionic degeneration (CBGD), atypical Parkinsonism (AP), and LOPD were screened for 14 mutations that span exons 19 to 41 of the LRRK2 gene. Among the LOPD cases, 1 patient was found to harbor the R1441C mutation. He presented with typical features of PD at age of 58 years old and responded well to levodopa. We did not detect any of the 14 mutations in PSP, MSA, CBGD, and AP patients. We highlight the first case of LRRK2 R1441C mutation in late onset sporadic PD of non-European ancestry. Furthermore, extensive mutational screen found LRRK2 mutations to be rare among patients who presented with PSP, MSA, CBGD, and AP.

Clinical features of childhood onset essential tremor

Childhood onset essential tremor (ET) is uncommon. It is not clear as to whether ethnicity-specific differences may influence the phenotypic features. To determine the frequency and clinical characteristics of childhood ET in a tertiary referral center. In a prospective evaluation of 120 consecutive ET patients in a movement disorders clinic, we found a 15.5% (19) frequency of childhood onset ET patients. The mean age of onset and mean age was 10.8 +/- 4.1 (6-16) years and 25.7 +/- 15.0 (16-73) years consisting of 73.6% (14/19) men and 26.4% (5/19) women. A positive family history of ET was present in 11 of 19 (52.6%). Presence of a head tremor was observed in 2/19 (10.5%). We highlighted a relatively high frequency (15,5%) of childhood ET in our Asian cohort. In addition, we drew attention to the male preponderance and the low frequency of head tremor in childhood ET corroborating study findings in white ET patients. These observations appear to transcend ethnic and cultural differences and lend further support that gender difference may play a role in the pathogenesis and expression of ET.

Knowledge about the genetics of essential tremor in patients and their relatives

In a face-to-face questionnaire-based survey involving a total of 111 essential tremor (ET) patients and their relatives, we demonstrated a general lack of genetic insight amongst our study subjects. There was no significant correlation between genetic knowledge of ET and age, level of education, disease duration or severity. A proactive effort is needed to encourage physicians managing ET patients to incorporate genetic information and education into their practice.