Quantitative DNA-PAINT imaging of AMPA receptors in live neurons.

DNA-point accumulation for imaging at nanoscale topography (DNA-PAINT) can image fixed biological specimens with nanometer resolution and absolute stoichiometry. In living systems, however, the usage of DNA-PAINT has been limited due to high salt concentration in the buffer required for specific binding of the imager to the docker attached to the target. Here, we used multiple binding motifs of the docker, from 2 to 16, to accelerate the binding speed of the imager under physiological buffer conditions without compromising spatial resolution and maintaining the basal level homeostasis during the measurement. We imaged endogenous α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) in cultured neurons-critical proteins involved in nerve communication-by DNA-PAINT in 3-dimensions using a monovalent single-chain variable fragment (scFv) to the GluA1 subunit of AMPAR. We found a heterogeneous distribution of synaptic AMPARs: ≈60% are immobile, primarily in nanodomains, defined as AMPARs that are within 0.3 µm of the Homer1 protein in the postsynaptic density; the other ∼40% of AMPARs have restricted mobility and trajectory.

Change in health outcomes for First Nations children with chronic wet cough: rationale and study protocol for a multi-centre implementation science study.

BACKGROUND: In children, chronic wet cough may be a sign of underlying lung disease, including protracted bacterial bronchitis (PBB) and bronchiectasis. Chronic (> 4 weeks in duration) wet cough (without indicators pointing to alternative causes) that responds to antibiotic treatment is diagnostic of PBB. Timely recognition and management of PBB can prevent disease progression to irreversible bronchiectasis with lifelong consequences. However, detection and management require timely health-seeking by carers and effective management by clinicians. We aim to improve (a) carer health-seeking for chronic wet cough in their child and (b) management of chronic wet cough in children by clinicians. We hypothesise that implementing a culturally integrated program, which is informed by barriers and facilitators identified by carers and health practitioners, will result in improved lung health of First Nations children, and in the future, a reduced the burden of bronchiectasis through the prevention of the progression of protracted bacterial bronchitis to bronchiectasis. METHODS: This study is a multi-centre, pseudorandomised, stepped wedge design. The intervention is the implementation of a program. The program has two components: a knowledge dissemination component and an implementation component. The implementation is adapted to each study site using a combined Aboriginal Participatory Action Research and an Implementation Science approach, guided by the Consolidated Framework of Implementation Research. There are three categories of outcome measures related to (i) health (ii) cost, and (iii) implementation. We will measure health-seeking as the proportion of parents seeking help for their child in a 6-month period before the intervention and the same 6-month period (i.e., the same six calendar months) thereafter. The parent-proxy, Cough-specific Quality of Life (PC-QoL) will be the primary health-related outcome measure. DISCUSSION: We hypothesise that a tailored intervention at each site will result in improved health-seeking for carers of children with a chronic wet cough and improved clinician management of chronic wet cough. In addition, we expect this will result in improved lung health outcomes for children with a chronic wet cough. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry; ACTRN12622000430730 , registered 16 March 2022, Retrospectively registered.

E-cigarette aerosol exposure of pulmonary surfactant impairs its surface tension reducing function.

INTRODUCTION: E-cigarette (EC) and vaping use continue to remain popular amongst teenage and young adult populations, despite several reports of vaping associated lung injury. One of the first compounds that EC aerosols comes into contact within the lungs during a deep inhalation is pulmonary surfactant. Impairment of surfactant's critical surface tension reducing activity can contribute to lung dysfunction. Currently, information on how EC aerosols impacts pulmonary surfactant remains limited. We hypothesized that exposure to EC aerosol impairs the surface tension reducing ability of surfactant. METHODS: Bovine Lipid Extract Surfactant (BLES) was used as a model surfactant in a direct exposure syringe system. BLES (2ml) was placed in a syringe (30ml) attached to an EC. The generated aerosol was drawn into the syringe and then expelled, repeated 30 times. Biophysical analysis after exposure was completed using a constrained drop surfactometer (CDS). RESULTS: Minimum surface tensions increased significantly after exposure to the EC aerosol across 20 compression/expansion cycles. Mixing of non-aerosolized e-liquid did not result in significant changes. Variation in device used, addition of nicotine, or temperature of the aerosol had no additional effect. Two e-liquid flavours, menthol and red wedding, had further detrimental effects, resulting in significantly higher surface tension than the vehicle exposed BLES. Menthol exposed BLES has the highest minimum surface tensions across all 20 compression/expansion cycles. Alteration of surfactant properties through interaction with the produced aerosol was observed with a basic e-liquid vehicle, however additional compounds produced by added flavourings appeared to be able to increase inhibition. CONCLUSION: EC aerosols alter surfactant function through increases in minimum surface tension. This impairment may contribute to lung dysfunction and susceptibility to further injury.

Prevalence of chronic respiratory diseases in Aboriginal children: A whole population study.

BACKGROUND: The burden of bronchiectasis is disproportionately high in Aboriginal adults, with early mortality. Bronchiectasis precursors, that is, protracted bacterial bronchitis (PBB) and chronic suppurative lung disease (CSLD), often commence in early childhood. We previously reported a 10% prevalence of PBB in Aboriginal children aged 0 to 7 years, however there are no data on prevalence of chronic lung diseases in older children. Our study aimed to determine the prevalence of PBB, CSLD, bronchiectasis, and asthma in Aboriginal children living in four communities. METHODS: A whole-population cross-sectional community co-designed study of Aboriginal children aged <18-years in four remote communities in Western Australia across two-time points, a month apart. Children were assessed by pediatric respiratory clinicians with spirometry undertaken (when possible) between March-September 2021. Children with respiratory symptoms were followed up via medical record audit from either the local medical clinic or via a respiratory specialist clinic through to March 2022 to establish a final diagnosis. FINDINGS: We recruited 392 (91.6%) of those in the selected communities; median age = 8.4 years (interquartile range [IQR] 5.1-11.5). Seventy children (17.9%) had a chronic respiratory pathology or abnormal spirometry results. PBB was confirmed in 30 (7.7%), CSLD = 13 (3.3%), bronchiectasis = 5 (1.3%) and asthma = 17 (4.3%). The prevalence of chronic wet cough significantly increased with increasing age. INTERPRETATION: The prevalence of PBB, CSLD and bronchiectasis is high in Aboriginal children and chronic wet cough increases with age. This study highlights the high disease burden in Aboriginal children and the urgent need for strategies to address these conditions.

Genetic Mapping of APP and Amyloid-ß Biology Modulation by Trisomy 21.

Individuals who have Down syndrome (DS) frequently develop early onset Alzheimer's disease (AD), a neurodegenerative condition caused by the buildup of aggregated amyloid-ß (Aß) and tau proteins in the brain. Aß is produced by amyloid precursor protein (APP), a gene located on chromosome 21. People who have DS have three copies of chromosome 21 and thus also an additional copy of APP; this genetic change drives the early development of AD in these individuals. Here we use a combination of next-generation mouse models of DS (Tc1, Dp3Tyb, Dp(10)2Yey and Dp(17)3Yey) and a knockin mouse model of Aß accumulation (AppNL-F ) to determine how chromosome 21 genes, other than APP, modulate APP/Aß in the brain when in three copies. Using both male and female mice, we demonstrate that three copies of other chromosome 21 genes are sufficient to partially ameliorate Aß accumulation in the brain. We go on to identify a subregion of chromosome 21 that contains the gene(s) causing this decrease in Aß accumulation and investigate the role of two lead candidate genes, Dyrk1a and Bace2 Thus, an additional copy of chromosome 21 genes, other than APP, can modulate APP/Aß in the brain under physiological conditions. This work provides critical mechanistic insight into the development of disease and an explanation for the typically later age of onset of dementia in people who have AD in DS, compared with those who have familial AD caused by triplication of APP SIGNIFICANCE STATEMENT Trisomy of chromosome 21 is a commonly occurring genetic risk factor for early-onset Alzheimer's disease (AD), which has been previously attributed to people with Down syndrome having three copies of the amyloid precursor protein (APP) gene, which is encoded on chromosome 21. However, we have shown that an extra copy of other chromosome 21 genes modifies AD-like phenotypes independently of APP copy number (Wiseman et al., 2018; Tosh et al., 2021). Here, we use a mapping approach to narrow down the genetic cause of the modulation of pathology, demonstrating that gene(s) on chromosome 21 decrease Aß accumulation in the brain, independently of alterations to full-length APP or C-terminal fragment abundance and that just 38 genes are sufficient to cause this.

Frequency of protracted bacterial bronchitis and management pre-respiratory referral.

AIM: To determine the frequency of protracted bacterial bronchitis (PBB) in children referred to tertiary care with chronic cough and describe management prior to referral. METHODS: A retrospective cohort study of all new patients with a history of ≥4 weeks of cough seen at the only tertiary paediatric outpatient respiratory service in Western Australia between July 2018 and June 2019. Medical records were reviewed until a final diagnosis was documented or otherwise for a period of 18 months. RESULTS: PBB was the most common cause and comprised 37.9% of all children referred to tertiary respiratory care with chronic cough. In children with PBB, the median cough duration at the time of first specialist review was 5.1 months (IQR 2.1-12.0 months). The most common referral source of PBB was primary practice (40.9%) and the most common working diagnosis pre-referral was asthma (15.9%). Seventy-eight percent of children with PBB had an ongoing cough at their first respiratory review, and of these, only 13.5% had been prescribed 4 weeks of antibiotics prior to their respiratory review. Asthma treatment had been prescribed for 34.0% of children with PBB. CONCLUSION: PBB is the most common cause of chronic cough in children referred to tertiary respiratory care and is frequently misdiagnosed and undertreated pre-referral. There is a need to facilitate diagnosis and optimal management of PBB in primary care, which could result in earlier symptom resolution and potentially limit disease progression to bronchiectasis.

Characterising frailty, metrics of continuous glucose monitoring, and mortality hazards in older adults with type 2 diabetes on insulin therapy (HARE): a prospective, observational cohort study.

BACKGROUND: To our knowledge, no previous study has examined the inter-relationship between frailty, dysglycaemia, and mortality in frail older adults with type 2 diabetes who are on insulin therapy. We used continuous glucose monitors (CGMs) to profile this patient population and determine the prognostic value of CGM metrics. We hypothesised that incremental frailty was associated with increased hypoglycaemia or time below range (TBR). METHODS: HARE was a multicentre, prospective, observational cohort study with mortality hazard analysis carried out in four hospitals in Hong Kong. Eligible participants were community-living adults aged 70 years and older; had had type 2 diabetes for 5 years or more; were on insulin therapy; were frail; and were not hospitalised at the time of frailty assessment and CGM recording. Glucose control was characterised according to the Advanced Technologies and Treatments for Diabetes 2019 international consensus clinical targets. Frailty index was computed, and comprehensive frailty assessments and targeted serum metabolic profiling were performed. The Jonckheere-Terpstra test for trend was used to analyse frailty index tertiles and variables. Inter-relationships between CGM metrics and frailty, glycated haemoglobin A1c (HbA1c), and serum albumin were characterised using adjusted regression models. Survival analysis and Cox proportional hazard modelling were performed. FINDINGS: Between July 25, 2018, and Sept 27, 2019, 225 participants were recruited, 222 of whom had CGMs fitted and 215 of whom had analysable CGM data (190 were frail, 25 were not frail). Incremental frailty was associated with older age, greater HbA1c, worse renal function, and history of stroke. Eight of 11 CGM metrics were significantly associated with frailty. Decreased time in range (TIR; glucose concentration 3·9-10·0 mmol/L) and increased time above range (TAR) metrics were strongly correlated with increased frailty and hyperglycaemia, whereas TBR metrics were marginally or not different between frailty levels. Glucose-lowering agents did not significantly affect regression estimates. In patients with HbA1c of 7·5% or more, reduced serum albumin was associated with level 2 TAR (glucose concentration >13·9 mmol/L) and dysglycaemia. During a median follow-up of 28·0 months (IQR 25·3-30·4), increased level 2 TAR was predictive of mortality explainable by frailty in the absence of detectable interaction. Each 1% increment of level 2 TAR was associated with 1·9% increase in mortality hazard. INTERPRETATION: In older adults with type 2 diabetes who are on insulin therapy, incremental frailty was associated with increased dysglycaemia and hyperglycaemia rather than hypoglycaemia. Mortality hazard was increased with severe hyperglycaemia. Future clinical studies and trials targeting actionable CGM metrics highlighted in this study could translate into improved care and outcomes. FUNDING: Health and Medical Research Fund, Food and Health Bureau, The Government of the Hong Kong Special Administrative Region of China.

Pre- and post-intervention study examining immunisation rates, documentation, catch-up delivery and the impact of a dedicated immunisation service at a tertiary paediatric hospital.

AIM: To explore immunisation rates and catch-up delivery to children admitted to hospital before and after an immunisation service was commenced. METHODS: This pre- and post-intervention study examined 300 admissions prior to (cohort 1) and 300 following (cohort 2) the introduction of an immunisation service. Immunisation rates, documentation, catch-up delivery and accuracy of the Australian Immunisation Register (AIR) were examined. RESULTS: On admission, 75% (cohort 1) and 89% (cohort 2) were up-to-date with immunisations. Immunisation history was documented in the medical record in 78% and requirement for catch-up documented in 10%. AIR was incorrect in one-third of cases. By 3 months following discharge, 28% (cohort 1) and 64% (cohort 2) of patients were immunised. CONCLUSIONS: Children admitted to hospital have lower immunisation rates than the national average. Documentation was poor, opportunities for catch-up were missed and AIR is error-prone. Catch-up rates increased following the introduction of an immunisation service.

An audit of the reporting of depression & anxiety in COPD patients.

Anxiety and depression contribute to a substantial burden of Chronic Obstructive Pulmonary Disease-related morbidity by impairing quality of life and by reducing adherence to treatment. The identification of COPD patients with comorbid depression or anxiety symptoms is vital, as it is estimated that only a third of patients with these co-morbidities are receiving appropriate treatment. The aim of this audit was therefore to identify whether current methods of anxiety and depression screening in elderly patients (over the age of 65) with severe COPD (FEV1 <50% at most recent spirometry reading) are adequate by assessing how frequently anxiety and depression is reported as "discussed with patient" in COPD review appointments across two practices. SystmOne was used to identify a total of 83 patients, and the recording of depression and anxiety discussions in this cohort's review appointments was analysed and compared with the incidence of QOF-coded depression and anxiety in the patient notes. The results show that both the rate and the quality of depression and anxiety reporting in these review appointments is highly heterogeneous, and has led to 'missed' patients suffering from comorbid mental health issues. Additionally, this audit identified a number of patients with depression or anxiety directly related to their COPD, and it highlighted a trend among this cohort towards more frequent appointments with their General Practitioner, and towards related presentations at the Emergency Department. The results of this audit suggest there is room for amelioration of the current practice, such as the implementation of a structured screening tool into System One's COPD review appointment template.

Physical Health Checks in Patients on Antipsychotic Medication.

Schizophrenic patients have traditionally suffered from high rates of cardiovascular disease and early mortality. NICE guidelines suggest that several physical health measures be monitored regularly in these patients, and particularly those on antipsychotic medication, which has a wide side-effect profile that may potentiate the risk of cardiovascular disease and other comorbidities. This general practice audit aimed to determine the rates of physical health monitoring in primary care in patients on antipsychotic medication for over a year for psychotic symptoms or schizophrenia. The search was conducted in three different general practices in March 2019, yielding 19, 8 and 30 patients respectively, with a total of 57 patients. This audit aims to record and analyse rates of monitoring of a range of physical health measures recommended by NICE guidelines over the past year. The results demonstrated that physical health monitoring was poor amongst all the practices audited, especially that of prolactin and waist circumference. We recommend that these rates of monitoring be improved, through implementing templates or the delivery of targeted education to general practitioners and nurses.

Tarsal-carpal coalition syndrome: importance of early diagnosis.

Tarsal-carpal coalition syndrome is a progressive condition involving synostosis of the wrist, ankle and digits. We describe a mother and her newborn that have this rare inherited condition where the diagnosis was made only after the baby's birth. The baby's condition was suspected on antenatal scanning, and he was born with reduced range of motion of his digits, elbows and ankles. The mother's condition has progressed to involve a fixed flexion deformity of her bilateral elbows, synostoses of her second to fifth digits and extensive coalition of her tarsal and carpal bones. She has required regular osteotomies to improve limb functioning and quality of life.

Ferumoxytol versus iron sucrose treatment: a post-hoc analysis of randomized controlled trials in patients with varying renal function and iron deficiency anemia.

BACKGROUND: Iron deficiency anemia is highly prevalent in patients with chronic kidney disease and is often treated with intravenous iron. There are few trials directly comparing the safety and efficacy of different intravenous iron products. METHODS: This post-hoc analysis pooled data from 767 patients enrolled in two randomized, controlled, open-label trials of similar design comparing the treatment of iron deficiency anemia with ferumoxytol and iron sucrose across patients with all stages of renal function. One trial was conducted in adults with CKD either on or not on dialysis and the second in adults with IDA of any underlying cause and a history of unsatisfactory oral iron therapy or in whom oral iron could not be used who had normal to no worse than moderately impaired renal function. Patients were categorized by chronic kidney disease stage (i.e., estimated glomerular filtration rate), and the primary efficacy endpoint was the mean change in hemoglobin from Baseline to Week 5. RESULTS: The overall incidence of adverse events was numerically lower in ferumoxytol-treated patients compared to those treated with iron sucrose (42.4 vs. 50.2 %, respectively); the incidence of treatment-related adverse events was generally similar between the two treatment groups (13.6 vs. 16.0 %, respectively). Adverse events of Special Interest (i.e., hypotension, hypersensitivity) occurred at lower rates in those treated with ferumoxytol compared to those treated with iron sucrose (2.5 vs. 5.3 %, respectively). Overall, mean hemoglobin increased in both treatment groups, regardless of degree of renal insufficiency, although greater increases were seen among those with less severe kidney damage. Mean increases in hemoglobin from Baseline to Week 5 were significantly greater with ferumoxytol than with iron sucrose treatment in the subgroup with an estimated glomerular filtration rate ≥90 mL/min (Least Squares mean difference = 0.53 g/dL; p < 0.001). There were no other consistent, significant differences in hemoglobin levels between treatment groups for the other chronic kidney disease categories except for isolated instances favoring ferumoxytol. CONCLUSIONS: The efficacy and safety of ferumoxytol is at least comparable to iron sucrose in patients with varying degrees of renal function. TRIAL REGISTRATION: (CKD-201; ClinicalTrials.gov identifier: NCT01052779; registered 15 January, 2010), (IDA-302; ClinicalTrials.gov identifier: NCT01114204; registered 29 April, 2010).

Specificity for a CCR5 Inhibitor Is Conferred by a Single Amino Acid Residue: ROLE OF ILE198.

The chemokine receptors CCR5 and CCR2b share 89% amino acid homology. CCR5 is a co-receptor for HIV and CCR5 antagonists have been investigated as inhibitors of HIV infection. We describe the use of two CCR5 antagonists, Schering-C (SCH-C), which is specific for CCR5, and TAK-779, a dual inhibitor of CCR5 and CCR2b, to probe the CCR5 inhibitor binding site using CCR5/CCR2b chimeric receptors. Compound inhibition in the different chimeras was assessed by inhibition of chemokine-induced calcium flux. SCH-C inhibited RANTES (regulated on activation, normal T cell expressed and secreted) (CCL5)-mediated calcium flux on CCR5 with an IC50 of 22.8 nM but was inactive against monocyte chemoattractant protein-1 (CCL2)-mediated calcium flux on CCR2b. However, SCH-C inhibited CCL2-induced calcium flux against a CCR5/CCR2b chimera consisting of transmembrane domains IV-VI of CCR5 with an IC50 of 55 nM. A sequence comparison of CCR5 and CCR2b identified a divergent amino acid sequence located at the junction of transmembrane domain V and second extracellular loop. Transfer of the CCR5 sequence KNFQTLKIV into CCR2b conferred SCH-C inhibition (IC50 of 122 nM) into the predominantly CCR2b chimera. Furthermore, a single substitution, R206I, conferred partial but significant inhibition (IC50 of 1023 nM) by SCH-C. These results show that a limited amino acid sequence is responsible for SCH-C specificity to CCR5, and we propose a model showing the interaction with CCR5 Ile(198).

Thought-action fusion as a mediator of religiosity and obsessive-compulsive symptoms.

BACKGROUND AND OBJECTIVES: Thought-action fusion (TAF), or maladaptive cognitions regarding the relationship between mental events and behaviours, has been implicated in the development and maintenance of obsessive-compulsive disorder (OCD). As some religions promote TAF-like appraisals, it has been proposed that religiosity may play a role in the transformation of normally occurring intrusive thoughts into clinically distressing obsessions. No research, however, has experimentally investigated the mediating role of TAF on the relationship between religiosity and OC symptoms. METHODS: 85 Christian, Jewish, and Atheist/Agnostic participants were exposed to an experimental thought-induction protocol and reported on their associated levels of distress, guilt, feelings of responsibility, and urge to suppress target intrusions experienced during a 5-min monitoring period. Participants also completed measures of obsessive-compulsive symptomatology, TAF beliefs, and general psychopathology. RESULTS: Using PROCESS and bootstrapping analyses, a test of the conditional indirect effects of religiosity on obsessive-compulsive symptoms revealed that Christianity moderated the effects of religiosity on moral TAF beliefs, which in turn mediated the relationship between religiosity and obsessive-compulsive symptoms. Furthermore, in the Christian group, moral TAF beliefs mediated the relationship between religiosity and ratings of guilt and responsibility following the experimental protocol. LIMITATIONS: The use of university students with moderate levels of religiosity. CONCLUSIONS: Collectively the results suggest that obsessional thinking is not attributable to religion per se, but that teachings underlying certain religious doctrines may fuel TAF beliefs that are implicated in the maintenance of OCD.

The molecular pharmacology of AMD11070: an orally bioavailable CXCR4 HIV entry inhibitor.

In order to enter and infect human cells HIV must bind to CD4 in addition to either the CXCR4 or the CCR5 chemokine receptor. AMD11070 was the first orally available small molecule antagonist of CXCR4 to enter the clinic. Herein we report the molecular pharmacology of AMD11070 which is a potent inhibitor of X4 HIV-1 replication and the gp120/CXCR4 interaction. Using the CCRF-CEM T cell line that endogenously expresses CXCR4 we have demonstrated that AMD11070 is an antagonist of SDF-1α ligand binding (IC50 = 12.5 ± 1.3 nM), inhibits SDF-1 mediated calcium flux (IC50 = 9.0 ± 2.0 nM) and SDF-1α mediated activation of the CXCR4 receptor as measured by a Eu-GTP binding assay (IC50 =39.8 ± 2.5 nM) or a [(35)S]-GTPγS binding assay (IC50 =19.0 ± 4.1 nM), and inhibits SDF-1α stimulated chemotaxis (IC50 =19.0 ± 4.0 nM). AMD11070 does not inhibit calcium flux of cells expressing CXCR3, CCR1, CCR2b, CCR4, CCR5 or CCR7, or ligand binding to CXCR7 and BLT1, demonstrating selectivity for CXCR4. In addition AMD11070 is able to inhibit the SDF-1ß isoform interactions with CXCR4; and N-terminal truncated variants of CXCR4 with equal potency to wild type receptor. Further mechanistic studies indicate that AMD11070 is an allosteric inhibitor of CXCR4.

Prospective CCR5 small molecule antagonist compound design using a combined mutagenesis/modeling approach.

The viral resistance of marketed antiviral drugs including the emergence of new viral resistance of the only marketed CCR5 entry inhibitor, maraviroc, makes it necessary to develop new CCR5 allosteric inhibitors. A mutagenesis/modeling approach was used (a) to remove the potential hERG liability in an otherwise very promising series of compounds and (b) to design a new class of compounds with an unique mutant fingerprint profile depending on residues in the N-terminus and the extracellular loop 2. On the basis of residues, which were identified by mutagenesis as key interaction sites, binding modes of compounds were derived and utilized for compound design in a prospective manner. The compounds were then synthesized, and in vitro evaluation not only showed that they had good antiviral potency but also fulfilled the requirement of low hERG inhibition, a criterion necessary because a potential approved drug would be administered chronically. This work utilized an interdisciplinary approach including medicinal chemistry, molecular biology, and computational chemistry merging the structural requirements for potency with the requirements of an acceptable in vitro profile for allosteric CCR5 inhibitors. The obtained mutant fingerprint profiles of CCR5 inhibitors were used to translate the CCR5 allosteric binding site into a general pharmacophore, which can be used for discovering new inhibitors.

HIV-1 entry inhibition by small-molecule CCR5 antagonists: a combined molecular modeling and mutant study using a high-throughput assay.

Based on the attrition rate of CCR5 small molecule antagonists in the clinic the discovery and development of next generation antagonists with an improved pharmacology and safety profile is necessary. Herein, we describe a combined molecular modeling, CCR5-mediated cell fusion, and receptor site-directed mutagenesis approach to study the molecular interactions of six structurally diverse compounds (aplaviroc, maraviroc, vicriviroc, TAK-779, SCH-C and a benzyloxycarbonyl-aminopiperidin-1-yl-butane derivative) with CCR5, a coreceptor for CCR5-tropic HIV-1 strains. This is the first study using an antifusogenic assay, a model of the interaction of the gp120 envelope protein with CCR5. This assay avoids the use of radioactivity and HIV infection assays, and can be used in a high throughput mode. The assay was validated by comparison with other established CCR5 assays. Given the hydrophobic nature of the binding pocket several binding models are suggested which could prove useful in the rational drug design of new lead compounds.

Design and synthesis of pyridin-2-yloxymethylpiperidin-1-ylbutyl amide CCR5 antagonists that are potent inhibitors of M-tropic (R5) HIV-1 replication.

A novel series of CCR5 antagonists were identified based on the redesign of Schering C. An SAR was established based on inhibition of CCR5 (RANTES) binding and these compounds exhibited potent inhibition of R5 HIV-1 replication in peripheral blood mononuclear cells.

Handwriting characteristics among secondary students with and without physical disabilities: a study with a computerized tool.

The purpose of the present study was to investigate the handwriting characteristics of secondary school students with and without physical disabilities (PD). With the use of a computerized Chinese Handwriting Assessment Tool (CHAT), it was made possible to objectively assess and analyze in detail the handwriting characteristics of individual students. Fifty participants (age range: 15-19-years-old) were recruited from one mainstream secondary school and 20 participants (age range: 17-24-years-old) were recruited from two secondary schools for students with PD. They were asked to perform three consecutive handwriting tasks: copying 90 characters using the computerized CHAT, an English passage copying task, and a Chinese passage copying task. The data indicated that students with PD were significantly slower in copying both Chinese and English characters in passages when compared to the typical students. Significant differences in the measures of writing speed, air/ground time ratio, standard deviation of speed, standard deviation of size per character, and number of stroke errors measured by the CHAT were found between the two groups of students. Further analysis on the data of typical students indicated no significant difference in handwriting speed among students of different classes (i.e. arts or science) on copying Chinese and English passages, and on individual Chinese words (from CHAT). The academic results of students also showed no significant correlation with their handwriting speed measured by the three writing tasks. To conclude, the CHAT system was able to identify a number of characteristics of handwriting on students with and without PD. It was suggested that the CHAT should further be developed into an objective evaluation tool to explore the handwriting characteristics of the students with a wider range of disabilities in the future, and to make recommendations to arrange special examination arrangements (SEA) for students with physical disabilities or other special needs.