Mitochondrial dysfunction reactivates α-fetoprotein expression that drives copper-dependent immunosuppression in mitochondrial disease models

Signaling circuits crucial to systemic physiology are widespread, yet uncovering their molecular underpinnings remains a barrier to understanding the etiology of many metabolic disorders. Here, we identified a copper-linked signaling circuit activated by disruption of mitochondrial function in the murine liver or heart that resulted in atrophy of the spleen and thymus and caused a peripheral white blood cell deficiency. We demonstrated that the leukopenia was caused by α-fetoprotein, which required copper and the cell surface receptor CCR5 to promote white blood cell death. We further showed that α-fetoprotein expression was upregulated in several cell types upon inhibition of oxidative phosphorylation. Collectively, our data argue that α-fetoprotein may be secreted by bioenergetically stressed tissue to suppress the immune system, an effect that may explain the recurrent or chronic infections that are observed in a subset of mitochondrial diseases or in other disorders with secondary mitochondrial dysfunction.

Binding of adenovirus species C hexon to prothrombin and the influence of hexon on vector properties in vitro and in vivo

The majority of adenovirus (Ad) vectors are based on human Ad type 5, which is a member of Ad species C. Species C also includes the closely-related types 1, 2, 6, 57 and 89. It is known that coagulation factors bind to Ad5 hexon and play a key role in the liver tropism of Ad5 vectors, but it is unclear how coagulation factors affect vectors derived from other species C Ads. We evaluated species C Ad vectors both in vitro and following intravenous injection in mice. To assess the impact of hexon differences, we constructed chimeric Ad5 vectors that contain the hexon hypervariable regions from other species C types, including vectors with hexon mutations that decreased coagulation factor binding. After intravenous injection into mice, vectors with Ad5 or Ad6 hexon had strong liver tropism, while vectors with chimeric hexon from other Ad types had weaker liver tropism due to inhibition by natural antibodies and complement. In addition, we discovered a novel ability of hexon to bind prothrombin, which is the most abundant coagulation factor in blood, and we found striking differences in the affinity of Ads for human, mouse and bovine coagulation factors. When compared to Ad5, vectors with non-Ad5 species C hexons had considerably higher affinity for both human and mouse prothrombin. Most of the vectors tested were strongly dependent on coagulation factors for liver transduction, but vectors with chimeric Ad6 hexon showed much less dependence on coagulation factors than other vectors. We found that in vitro neutralization experiments with mouse serum predicted in vivo behavior of Ad5 vectors, but in vitro experiments did not predict the in vivo behavior of vectors based on other Ad types. In sum, hexons from different human Ad species C viruses confer diverse properties on vectors, including differing abilities to target the liver.

Going the (social) distance: Comparing the effectiveness of online versus in-person Internal Jugular Central Venous Catheterization procedural training

BACKGROUND

This study compares surgical residents' knowledge acquisition of ultrasound-guided Internal Jugular Central Venous Catheterization (US-IJCVC) between in-person and online procedural training cohorts before receiving independent in-person Dynamic Haptic Robotic Simulation training.

METHODS

Three surgical residency procedural training cohorts, two in-person (N = 26) and one online (N = 14), were compared based on their performance on a 24-item US-IJCVC evaluation checklist completed by an expert physician completed after training. Pre- and post-training US-IJCVC knowledge was also compared for the online cohort.

RESULTS

No significant change in the pass rates on the US-IJCVC checklist was found between in-person and online cohorts (p = 0.208). There were differences in the Economy of Time and Motion between in-person and online cohorts (p < 0.005). The online cohort had significant increases in US-IJCVC knowledge pre-to post-training (p < 0.008).

CONCLUSION

Online training with independent simulation practice was as effective as in-person training for US-IJCVC.

341 Is CT Imaging Mandated for Confirming the Diagnosis of Acute Appendicitis in Patients Over the Age of 40?

Aim

Acute appendicitis remains a largely clinical diagnosis, with clinical scoring systems such as the Alvarado score calculated to give a quantitative assessment of the diagnostic probability. It remains common practice amongst surgeons to rely on CT scanning to confirm the diagnosis however, especially in older patients. Our aim was to assess the diagnostic performance of CT scanning compared with that of the Alvarado score in patients aged over 40 years old.

Method

We conducted a retrospective observational study of 149 patients greater than 40 years old who had a diagnosis of acute appendicitis and had undergone an appendicectomy with subsequent histological analysis. Data was extracted from patients’ electronic medical records. This was recorded in Microsoft Excel and analysed using NCSS.

Results

When using an Alvarado score cut-off point of ≥7, the sensitivity and specificity were 44.1% and 60.0% respectively. The sensitivity of the test improved to 80.3% when using a cut-off point of ≥ 5, however the specificity decreased to 50%. The accuracy improved to 78.1% from 45.3%, when using ≥ 5 as a cut-off point. On the other hand, the sensitivity of the CT scan was 84.9% and the specificity was 45.5%. The accuracy of CT scanning was 81.8%.

Conclusions

When comparing performance, pre-operative CT scanning did not show a statistically significant improvement in the diagnosis of acute appendicitis relative to Alvarado score. We recommend using an Alvarado score cut-off point of ≥ 5 to aid in diagnosing appendicitis in patients older than 40, as it accounts for a higher sensitivity.

Abstract 430: GFP-tagging Of Rabbit ApoAI Decreases Expression And Cholesterol-efflux Activity

Introduction: Gene therapy using a helper-dependent adenovirus (HDAd) to express rabbit apolipoprotein (apo) AI in carotids of fat-fed rabbits reduces atherosclerosis. We hypothesize that transgenic apoAI promotes reverse cholesterol transport from the artery wall; however, this could not be tested because the transgenic rabbit apoAI is indistinguishable from endogenous rabbit apoAI. We therefore constructed an HDAd expressing GFP-tagged rabbit apoAI.

Methods: We constructed HDAdGFPapoAI by fusing the GFP sequence to the N-terminus of the rabbit APOA1 gene with a short linker. Bovine aortic endothelial cells (BAEC) were transduced with HDAdGFPapoAI, washed, and incubated in serum-free medium for 24h. Conditioned medium (CM) was collected and fluorescence measured. Cell extracts and CM were analyzed by western blotting for protein size, expression level, and presence of GFP and apoAI antigens. CM cholesterol-efflux activity was measured using cholesterol-loaded BHK cells expressing ABCA1.

Results: CM of HDAdGFPapoAI-transduced BAEC had green fluorescence and contained a protein of the size predicted for the GFP-apoAI fusion (~56 kDa), which was detected with antibodies to both GFP and apoAI. A smaller protein (~30 kDa) with GFP and apoAI antigens was also detected. Compared to a vector expressing WT rabbit apoAI, GFP-tagging decreased expression of apoAI protein by ~50% and the percentage of secreted apoAI from 55% to 13%. In combination, this reduced secreted GFP-apoAI to only 12% of levels of secreted WT apoAI. While CM containing WT rabbit apoAI strongly stimulated cholesterol efflux from BHK cells (46%), GFP-apoAI-containing CM did not promote cholesterol efflux compared to CM from untransduced BAEC (7.8% vs 7.4% efflux), even when present in CM at a concentration similar to that of WT apoAI.

Conclusion: GFP-rabbit apoAI protein has reduced expression and secretion (likely due to misfolding/degradation) and does not promote cholesterol efflux (n-terminal GFP may disrupt the phospholipid/cholesterol organization needed for efflux via ABCA1 to this dynamic apoprotein). It will not be useful to investigate mechanisms of atheroprotection by vessel wall-expressed apoAI. Alternatives include use of a smaller tag or expression of human apoAI.

809 USE OF NEW MOBILITY SCORE AND A TRANS-DISCIPLINARY APPROACH TO REDUCE HOSPITAL LOS, RETURN TO ORIGINAL RESIDENCE, AND MORTALITY

Introduction

The National Hip Fracture Database indicated Guy’s and St Thomas’ Trust ranked in the fourth quartile nationally with reference to hospital length of stay (LOS), return to original residence (ROR), and mortality in hip fracture patients in 2018. This quality improvement project aimed to improve and maintain these key factors via a two-stage process.

Methods

Stage one involved implementation of four key interventions through a trans-disciplinary focus group, comprising ortho-geriatricians, orthopaedic surgeons, physiotherapists (PT), occupational therapists (OT), nursing staff, and a transfer of care navigator (TCN). Firstly, the New Mobility Score (NMS) was employed as a tool to guide estimated length of stay. Secondly, use of preoperative OT assessment allowed early evaluation of patient expectations concerning discharge planning. Third, facilitation of the discharge process was optimised by the recruitment of a TCN. Lastly, attendance of a senior orthogeriatrician during the daily board round was established. Stage two involved education of new members of the trans-disciplinary team to ensure that the key interventions listed above were maintained on hip fracture patients.

Results

Following stage one, average acute hospital LOS and overall LOS decreased from 20.1 to 15.1 days and 22.4 to 18.3 days, respectively. Rate of ROR within 120 days of discharge improved from 72.4% to 86.9%, while mortality rates fell from 7.1 to 3.4. Following stage two, overall LOS improved to 17.1 days, while acute LOS and mortality were maintained at 15.6 and 3.9 days, respectively. While ROR fell to 82.8%, this remained higher than the national average at 69.9%.

Conclusions

Utilisation of NMS and multi-disciplinary input effectively improved ROR, while reducing length of hospital stay and mortality rates in hip fracture patients. Education of new members of the trans-disciplinary team allowed sustained improvement despite challenges faced during the COVID-19 pandemic.

Nitric oxide modulates bone anabolism through regulation of osteoblast glycolysis and differentiation

Previous studies have shown that nitric oxide (NO) supplements may prevent bone loss and fractures in preclinical models of estrogen deficiency. However, the mechanisms by which NO modulates bone anabolism remain largely unclear. Argininosuccinate lyase (ASL) is the only mammalian enzyme capable of synthesizing arginine, the sole precursor for nitric oxide synthase-dependent (NOS-dependent) NO synthesis. Moreover, ASL is also required for channeling extracellular arginine to NOS for NO production. ASL deficiency (ASLD) is thus a model to study cell-autonomous, NOS-dependent NO deficiency. Here, we report that loss of ASL led to decreased NO production and impairment of osteoblast differentiation. Mechanistically, the bone phenotype was at least in part driven by the loss of NO-mediated activation of the glycolysis pathway in osteoblasts that led to decreased osteoblast differentiation and function. Heterozygous deletion of caveolin 1, a negative regulator of NO synthesis, restored NO production, osteoblast differentiation, glycolysis, and bone mass in a hypomorphic mouse model of ASLD. The translational significance of these preclinical studies was further reiterated by studies conducted in induced pluripotent stem cells from an individual with ASLD. Taken together, our findings suggest that ASLD is a unique genetic model for studying NO-dependent osteoblast function and that the NO/glycolysis pathway may be a new target to modulate bone anabolism.

Correlation between ASA Grade with reversal of Hartmann's procedure - a retrospective study

Hartmann's procedure involves resecting the rectosigmoid colon, closure of the distal rectal stump, and forming an end colostomy for complicated left colon diverticulitis or malignancy. Recovery from the initial operation can, in a second stage, be followed by a reversal stage with the restoration of bowel continuity. This study aimed to assess the reversal rate and its correlation with demographic data, ASA grade, and length of hospital stay. All patients who underwent Hartmann's emergency procedure from 2014 to 2018 at Lewisham and Greenwich hospital were enrolled in this retrospective study. Data was collected from the inpatient electronic files and NELA (UK National Laparotomy Audit). 118 patients were included in the study, with 57.6% females and a median age of patients of 69 years (range 35-91). Findings of the study indicate that the most common indications for Hartmann's procedure were diverticular complications 60% (n=71) and benign perforated sigmoid or rectosigmoid cancer 16% (n=19). The average length of hospital stay was 24 days (range n=2 - 212 days). The reversal rate was 34.9% (41/118 cases). No significant difference was observed between gender and length of hospital stay in relation to the reversal rate while there was a significant correlation between age and ASA grade in relation to reversal rate; the calculated P values were recorded as (<0.000) and (<0.009) respectively. Our results show that the highest reversal rate was observed in younger and fitter (I-II) ASA grade patients. The most common medical complication from reversal of Hartmann's procedure was an anastomotic leak (n=6, 16.7%). Reversal rate of Hartmann's procedure was 34.9%. The average timeframe for reversal was within 18-20 months. There was a significant correlation between age and ASA grade in relation to reversal rate.

A Single "All-in-One" Helper-Dependent Adenovirus to Deliver Donor DNA and CRISPR/Cas9 for Efficient Homology-Directed Repair

In this study, we developed a single helper-dependent adenovirus (HDAd) to deliver all of the components (donor DNA, CRISPR-associated protein 9 [Cas9], and guide RNA [gRNA]) needed to achieve high-efficiency gene targeting and homology-directed repair in transduced cells. We show that these "all-in-one" HDAds are up to 117-fold more efficient at gene targeting than donor HDAds that do not express CRISPR/Cas9 in human induced pluripotent stem cells (iPSCs). The vast majority (>90%) of targeted recombinants had only one allele targeted, and this was accompanied by high-frequency indel formation in the non-targeted allele at the site of Cas9 cleavage. These indels varied in size and nature, and included large deletions of ∼8 kb. The remaining minority of recombinants had both alleles targeted (so-called bi-allelic targeting). These all-in-one HDAds represent an important platform for accomplishing and expanding the utility of homology-directed repair, especially for difficult-to-transfect cells and for in vivo applications.

Mapping axon initial segment structure and function by multiplexed proximity biotinylation

Axon initial segments (AISs) generate action potentials and regulate the polarized distribution of proteins, lipids, and organelles in neurons. While the mechanisms of AIS Na⁺ and K⁺ channel clustering are understood, the molecular mechanisms that stabilize the AIS and control neuronal polarity remain obscure. Here, we use proximity biotinylation and mass spectrometry to identify the AIS proteome. We target the biotin-ligase BirA* to the AIS by generating fusion proteins of BirA* with NF186, Ndel1, and Trim46; these chimeras map the molecular organization of AIS intracellular membrane, cytosolic, and microtubule compartments. Our experiments reveal a diverse set of biotinylated proteins not previously reported at the AIS. We show many are located at the AIS, interact with known AIS proteins, and their loss disrupts AIS structure and function. Our results provide conceptual insights and a resource for AIS molecular organization, the mechanisms of AIS stability, and polarized trafficking in neurons.

480 Successful anticoagulation treatment of an ascending aortic thrombus associated with myocardial infarction and systemic embolism

Background

The ascending aorta is an uncommon site for non-infective mural thrombus. The detection of such a thrombus is of particular importance, given the risk of systemic and coronary embolisation. We present a case of a 60-year-old female with an ascending aortic thrombus complicated by non-ST-elevation myocardial infarction (NSTEMI), and associated systemic embolism in the form of renal and splenic infarcts.

Case Report

A 60-year-old female was admitted to a local secondary hospital with a 4-day history of crampy abdominal pain and intermittent bilateral arm pain associated with nausea and vomiting. Past medical history included known hypertrophic cardiomyopathy, gastroesophageal reflux disease, carpal tunnel syndrome, hepatic steatosis, but no known thrombophilia or coronary artery disease. Computer tomography (CT) scan of the abdomen revealed subacute infarction of the right kidney and spleen in keeping with a thrombo-embolic event. A CT pulmonary angiogram revealed a small pulmonary embolus in the right lower lobe. Troponin I level was elevated at 11 mg/L (normal &lt;0.04 mg/L). She was treated with aspirin, clopidogrel and therapeutic enoxaparin for a NSTEMI, and transferred to a metropolitan tertiary centre for ongoing investigation. A transthoracic echocardiogram performed showed known hypertrophic cardiomyopathy, but negative for intracardiac shunting via bubble study. Coronary angiography revealed an acutely occluded distal left anterior descending (LAD) artery with no collaterals, and mild irregularities in all other coronary arteries. A transoesophageal echocardiogram performed to exclude any intracardiac sources of emboli showed a pedunculated and mobile non-calcific mass measuring 1.0cm X 0.5cm in the posterior aspect of the ascending aorta, associated with atheroma in the aortic arch. A laboratory workup for antiphospholipid syndrome, antithrombin III, protein S and protein C deficiency were negative.

After discussion with the multidisciplinary Heart team, the consensus was that the aortic mass was likely thrombus formation relating to erosion of aortic atheroma. It was hypothesised that this may have resulted in distal embolisation to the left kidney and spleen, and possibly also caused embolisation to the LAD artery, although the cause of the pulmonary embolism was still unknown. The patient was then discharged on rivaroxaban and aspirin.

A repeat transoesophageal echocardiogram was performed 4 months after discharge to assess the ascending aortic mass. It showed complete resolution of the mass in the ascending aorta, with no change in any other cardiac structures.

Discussion

Although thrombus formation is uncommon in the ascending aorta, certain conditions, such as pregnancy and thrombophilia increase its risk. Several case reports of ascending aortic thrombus were found in the literature, but this will be the first to report complete resolution with treatment using a direct oral anticoagulant.

Abstract 480 Figure. Ascending Aortic Thrombus + Resolution

Hepatic glutamine synthetase augmentation enhances ammonia detoxification

The urea cycle and glutamine synthetase (GS) are the two main pathways for waste nitrogen removal and their deficiency results in hyperammonemia. Here, we investigated the efficacy of liver-specific GS overexpression for therapy of hyperammonemia. To achieve hepatic GS overexpression, we generated a helper-dependent adenoviral (HDAd) vector expressing the murine GS under the control of a liver-specific expression cassette (HDAd-GS). Compared to mice injected with a control vector expressing an unrelated reporter gene (HDAd-alpha-fetoprotein), wild-type mice with increased hepatic GS showed reduced blood ammonia levels and a concomitant increase of blood glutamine after intraperitoneal injections of ammonium chloride, whereas blood urea was unaffected. Moreover, injection of HDAd-GS reduced blood ammonia levels at baseline and protected against acute hyperammonemia following ammonia challenge in a mouse model with conditional hepatic deficiency of carbamoyl phosphate synthetase 1 (Cps1), the initial and rate-limiting step of ureagenesis. In summary, we found that upregulation of hepatic GS reduced hyperammonemia in wild-type and Cps1-deficient mice, thus confirming a key role of GS in ammonia detoxification. These results suggest that hepatic GS augmentation therapy has potential for treatment of both primary and secondary forms of hyperammonemia.

Production of CRISPR/Cas9-Mediated Self-Cleaving Helper-Dependent Adenoviruses

Prolonged expression of CRISPR/Cas9 raises concerns about off-target cleavage, cytotoxicity, and immune responses. To address these issues, we have developed a system to produce helper-dependent adenoviruses that express CRISPR/Cas9 to direct cleavage of the vectors’ own genome after transduction of target cells. To prevent self-cleavage during vector production, it was necessary to downregulate Cas9 mRNA as well as inhibit Cas9 protein activity. Cas9 mRNA downregulation was achieved by inserting the target sequences for the helper-virus-encoded miRNA, mivaRNAI, and producer-cell-encoded miRNAs, hsa-miR183-5p, and hsa-miR218-5p, into the 3′ UTR of the HDAd-encoded Cas9 expression cassette. Cas9 protein activity was inhibited by expressing anti-CRISPR proteins AcrIIA2 and AcrAII4 from both the producer cells and the helper virus. After purification, these helper-dependent adenoviruses will perform CRISPR/Cas9-mediated self-cleavage in the transduced target cells, thereby limiting the duration of Cas9 expression and thus represent an important platform for improving the safety of gene editing by CRISPR/Cas9.

ABCA1 Overexpression in Endothelial Cells In Vitro Enhances ApoAI-Mediated Cholesterol Efflux and Decreases Inflammation

Atherosclerosis, a disease of blood vessels, is driven by cholesterol accumulation and inflammation. Gene therapy that removes cholesterol from blood vessels and decreases inflammation is a promising approach for prevention and treatment of atherosclerosis. In previous work, we reported that helper-dependent adenoviral (HDAd) overexpression of apolipoprotein A-I (apoAI) in endothelial cells (ECs) increases cholesterol efflux in vitro and reduces atherosclerosis in vivo. However, the effect of HDAdApoAI on atherosclerosis is partial. To improve this therapy, we considered concurrent overexpression of ATP-binding cassette subfamily A, member 1 (ABCA1), a protein that is required for apoAI-mediated cholesterol efflux. Before attempting combined apoAI/ABCA1 gene therapy, we tested whether an HDAd that expresses ABCA1 (HDAdABCA1) increases EC cholesterol efflux, whether increased cholesterol efflux alters normal EC physiology, and whether ABCA1 overexpression in ECs has anti-inflammatory effects. HDAdABCA1 increased EC ABCA1 protein (∼3-fold; p < 0.001) and apoAI-mediated cholesterol efflux (2.3-fold; p = 0.007). Under basal culture conditions, ABCA1 overexpression did not alter EC proliferation, metabolism, migration, apoptosis, nitric oxide production, or inflammatory gene expression. However, in serum-starved, apoAI-treated EC, ABCA1 overexpression had anti-inflammatory effects: decreased inflammatory gene expression (∼50%; p ≤ 0.02 for interleukin [IL]-6, tumor necrosis factor [TNF]-α, and vascular cell adhesion protein-1); reduced lipid-raft Toll-like receptor 4 (80%; p = 0.001); and a trend towards increased nitric oxide production (∼55%; p = 0.1). In ECs stimulated with lipopolysaccharide, ABCA1 overexpression markedly decreased inflammatory gene expression (∼90% for IL-6 and TNF-α; p < 0.001). Therefore, EC ABCA1 overexpression has no toxic effects and counteracts the two key drivers of atherosclerosis: cholesterol accumulation and inflammation. In vivo testing of HDAdABCA1 is warranted.

Conditional disruption of hepatic carbamoyl phosphate synthetase 1 in mice results in hyperammonemia without orotic aciduria and can be corrected by liver-directed gene therapy

Carbamoyl phosphate synthetase 1 (CPS1) is a urea cycle enzyme that forms carbamoyl phosphate from bicarbonate, ammonia and ATP. Bi-allelic mutations of the CPS1 gene result in a urea cycle disorder presenting with hyperammonemia, often with reduced citrulline, and without orotic aciduria. CPS1 deficiency is particularly challenging to treat and lack of early recognition typically results in early neonatal death. Therapeutic interventions have limited efficacy and most patients develop long-term neurologic sequelae. Using transgenic techniques, we generated a conditional Cps1 knockout mouse. By loxP/Cre recombinase technology, deletion of the Cps1 locus was achieved in adult transgenic animals using a Cre recombinase-expressing adeno-associated viral vector. Within four weeks from vector injection, all animals developed hyperammonemia without orotic aciduria and died. Minimal CPS1 protein was detectable in livers. To investigate the efficacy of gene therapy for CPS deficiency following knock-down of hepatic endogenous CPS1 expression, we injected these mice with a helper-dependent adenoviral vector (HDAd) expressing the large murine CPS1 cDNA under control of the phosphoenolpyruvate carboxykinase promoter. Liver-directed HDAd-mediated gene therapy resulted in survival, normalization of plasma ammonia and glutamine, and 13% of normal Cps1 expression. A gender difference in survival suggests that female mice may require higher hepatic CPS1 expression. We conclude that this conditional murine model recapitulates the clinical and biochemical phenotype detected in human patients with CPS1 deficiency and will be useful to investigate ammonia-mediated neurotoxicity and for the development of cell- and gene-based therapeutic approaches.

Abstract 628: Overexpression of ABCA1 in Cultured Endothelial Cells Using Helper-Dependent Adenovirus Enhances ApoAI-Mediated Cholesterol Efflux and has Anti-Inflammatory Effects

Background: ABCA1 removes cholesterol from vascular wall cells via apoAI-mediated efflux, generating HDL that transports cholesterol to the liver for excretion. This process of reverse cholesterol transport is atheroprotective; therefore, strategies that increase vascular wall ABCA1 may prevent or reverse atherosclerosis. Cholesterol efflux mediated by ABCA1 and apoAI can also have anti-inflammatory effects; however, excess depletion of cellular cholesterol can cause cell stress and apoptosis. We tested whether transducing endothelial cells (EC) with a helper-dependent adenoviral vector that expresses ABCA1 (HDAdABCA1) enhances apoAI-mediated cholesterol efflux and reduces inflammatory markers without causing cellular toxicity.

Methods: We cloned rabbit ABCA1, constructed HDAdABCA1, transduced bovine aortic EC (BAEC) with either HDAdABCA1 or empty vector (HDAdNull). We measured ABCA1 protein by immunoblotting and apoAI-mediated cholesterol efflux by loading EC with 3 [H] cholesterol, then adding apoAI protein to serum-free medium. We assessed EC phenotype using MTT (metabolic activity), BrdU (proliferation), wound-healing assay (migration), and flow cytometry (apoptosis). We measured ICAM-1, VCAM-1, IL-6, and TNFα mRNA in transduced EC by qRT-PCR both under basal conditions and after serum-starvation, addition of apoAI, and LPS challenge.

Results: We observed a ~3-fold increase in ABCA1 protein in EC transduced with HDAdABCA1 and a ~2-fold increase in apoAI-mediated cholesterol efflux (P<0.01 for both). This level of ABCA1 overexpression did not alter EC metabolic activity, proliferation, migration, or apoptosis. Under basal conditions, HDAdABCA1 had no effect on inflammatory markers. However, after serum starvation and addition of apoAI, HDAdABCA1-transduced EC had reduced expression of inflammatory markers both before and after LPS treatment.

Conclusions: HDAdABCA1 increases EC ABCA1 expression and enhances apoAI-mediated cholesterol efflux, but does not cause toxicity or increase inflammatory markers. In contrast, ABCA1 overexpression appears to have anti-inflammatory effects. Future studies will test if HDAdABCA1 decreases lipid rafts, and whether overexpression of ABCA1 in EC in vivo is atheroprotective.

A Comparison of Ketoprofen and Diclofenac for Acute Musculoskeletal Pain Relief: a Prospective Randomised Clinical Trial

Objectives

To compare the efficacy and adverse effects of Ketoprofen and Diclofenac in the treatment of acute musculoskeletal pain.

Methods

In a prospective randomised clinical trial, patients admitted to an emergency department with acute musculoskeletal injuries requiring intramuscular (IM) injection for pain treatment were enrolled. The target study patients were Chinese adults who suffered from any musculoskeletal injuries of less than 12 hours. They received either 100 mg of Ketoprofen or 75 mg of Diclofenac. Pain was assessed by a 10-point visual analog score (VAS) and evaluations were performed at 30-minute intervals from treatment. Rescue analgesic was given if insufficient analgesia was achieved by one hour. The outcomes and the adverse effects were recorded.

Results

We recruited 77 cases in the Diclofenac group and 74 cases in the Ketoprofen group. The demographic data with regards to age, sex and patterns of injury were comparable in both groups. Following the administration of treatment, both groups showed highly statistically significant (P<0.001) reduction in pain level at 30-minute and 60-minute intervals. Comparing the mean decrease of pain level, there was no statistically significant difference between the two groups at 30-minute interval (P=0.6) and 60-minute interval (P=0.5). In each group, there was one patient experiencing skin rash after treatment. Four patients in the Ketoprofen group and one in Diclofenac group required rescue medicine. With respect to the number of admission following treatment, there was no statistically significant difference between the two groups.

Conclusions

Ketoprofen and Diclofenac are equally effective and safe in the treatment of acute musculoskeletal pain in Hong Kong Chinese population.

A Study of Orotracheal Intubation in Emergency Departments of Five District Hospitals in Hong Kong

Objective

To study the success rates and complications of orotracheal intubation in emergency departments of five district hospitals in Hong Kong in order to identify ways for improvement.

Method

This was a prospective observational study. The emergency department doctors performing the intubation were asked to complete an intubation study form immediately after the procedure over a period of four months. Data collected included vital signs, experiences of intubators, method of intubation and complications.

Results

A total of 347 cases were collected and 93% of them were non-trauma cases. Fifty-two percent (52%) of the cases were in cardiac arrest before intubation. Rapid sequence intubation (RSI) was applied in 36% of the cases. Junior doctors first intubated about 72% of the patients. Successful intubation was achieved in 1 and 2 attempts in 70% and 89% of the cases respectively. In 10 cases (3%), secondary methods such as laryngeal mask airway, Combitube, Trachlight or cricothyroidotomy were needed. The overall complication rate was 7.8% and the complication rate in the RSI group was 15.3%. The complication rate was even higher (20%) if intubation without medication was used in non-cardiac arrest patients. Significant drop in blood pressure was the most common complication and it could be attributed to the use of midazolam as induction medication. The success rate was found to correlate with the experience of the first intubator (p<0.05) and the laryngeal view (p<0.001). The complication rate increased with repeated attempts (p<0.001) and was higher among junior doctors (p<0.05). Early use of elastic gum bougie was associated with lower complication and higher success rates.

Conclusion

Orotracheal intubation in the emergency department was associated with high complication rate. Many complications came from junior intubators. Hypotension was the most common complication. Potentially avoidable complications may be a result of failure to use RSI in non-cardiac arrest patients and failure to use bougie in cases of poor laryngeal view.

Two Pregnant Women Presenting with Umbilical Cord Prolapse

Cord prolapse is an obstetric emergency as delay in management is associated with significantly increased neonatal morbidity and mortality. If the accident occurred outside the hospital, many babies would be dead or severely asphyxiated upon arrival in the hospital. The role of Accident & Emergency (A&E) department is to arrive at this diagnosis promptly and deliver appropriate intervention. Immediate cesarean delivery is the treatment of choice. The clinical presentations of two cases with umbilical cord prolapse presenting to our A&E department within two weeks were described. The pathophysiology, risk factors, diagnosis, management as well as outcome were discussed.

A Review on the Management of Acute Gastroenteritis in Children

Acute gastroenteritis represents a frequent cause of morbidity among children in Hong Kong. Despite the large number of potential etiologic agents, principles of management of gastroenteritis are uniform and aim to prevent the two major complications - dehydration and malnutrition. A review of the literature was performed. Selected articles were appraised, graded, and synthesised qualitatively. Statements on recommendations were generated. Current evidence emphasises the use of oral rehydration and the early reintroduction of age-appropriate foods. Apart from these two, important aspects of management reviewed included laboratory investigations, role of anti-diarrhoeal agents, and use of antimicrobial agents. Criteria for admission of high-risk children are also addressed.

A Combined In Vivo HSC Transduction/Selection Approach Results in Efficient and Stable Gene Expression in Peripheral Blood Cells in Mice

We recently reported on an in vivo hematopoietic stem cell (HSC) gene therapy approach. It involves the subcutaneous injections of G-CSF/AMD3100 to mobilize HSCs from the bone marrow into the peripheral blood stream and the intravenous injection of an integrating helper-dependent adenovirus vector system. HSCs transduced in the periphery homed back to the bone marrow, where they persisted long-term. However, high transgene marking rates found in primitive bone marrow HSCs were not reflected in peripheral blood cells. Here, we tested small-molecule drugs to achieve selective mobilization and transduction of HSCs. We found more efficient GFP marking in bone marrow HSCs but no increased marking in the peripheral blood cells. We then used an in vivo HSC chemo-selection based on a mutant of the O⁶-methylguanine-DNA methyltransferase (mgmt^P140K) gene that confers resistance to O⁶-BG/BCNU and should give stably transduced HSCs a proliferation stimulus and allow for the selective survival and expansion of progeny cells. Short-term exposure of G-CSF/AMD3100-mobilized, in vivo-transduced mice to relatively low selection drug doses resulted in stable GFP expression in up to 80% of peripheral blood cells. Overall, the further improvement of our in vivo HSC transduction approach creates the basis for a simpler HSC gene therapy.

The impact of CT head scans on ED management and length of stay in bizarre behavior patients

METHODS

A 5-year retrospective chart review was conducted at 3 EDs. Inclusion criteria were patients ≥18years old triaged as "mental health - bizarre behavior" (deviation from normal cognitive behaviour with no obvious cause) with a CT head scan ordered in the ED. Exclusion criteria were focal neurologic deficits on exam, alternative medical etiology (i.e. delirium, trauma) and/or pre-existing CNS disease. Clinical, demographic and administrative data were extracted with 10% of charts independently reviewed by an Emergency Physician for inter-rater reliability.

RESULTS

266 cases met study criteria. Population demographics: 49% percent female, average age 51years old, 28% homeless, 58% arrived by police or ambulance. CT head results: 1 (0.4%) case with possible acute findings, 105 (39%) with incidental findings (i.e. cerebral atrophy) that did not impact clinical management. Average time to physician assessment was 1:48 (hour:min) (sd 1:11), time to CT completion was 5:05 (sd 7:28) and an average delay of 3:17 awaiting results. Subgroup analysis revealed a net increase in ED length of stay (ED LOS) of 5:02 from obtaining neuroimaging. 85% of patients were referred to a consultant, 92% were to psychiatry.

CONCLUSIONS

CT head results prolonged ED LOS, delayed patient disposition and did not change the patient's clinical management. A prospective trial for ordering CT head scans in these patients is warranted.

Gene therapy with helper-dependent adenoviral vectors: lessons from studies in large animal models

Helper-dependent adenoviral vectors (HDAd) are deleted of all viral genes and they can efficiently transduce a wide variety of dividing and non-dividing cells to mediate high transgene expression levels. Unlike early generation adenoviral vectors, the absence of viral genes in HDAd results in long-term transgene expression without chronic toxicity and permits a large cloning capacity of 36 kb. Moreover, HDAd genomes exist extra-chromosomally thus minimizing the risks of germline transmission and insertional mutagenesis. For these reasons, HDAd offers tremendous potential for in vivo gene therapy. This chapter reviews preclinical studies using HDAd in large animal models to assess safety and efficacy in a wide variety of gene therapy applications.

Gene Editing with Helper-Dependent Adenovirus Can Efficiently Introduce Multiple Changes Simultaneously over a Large Genomic Region

Helper-dependent adenoviral vectors (HDAds) possess long homology arms that mediate high-efficiency gene editing. These long homology arms may permit simultaneous introduction of multiple modifications into a large genomic region or may permit a single HDAd to correct many different individual mutations spread widely across a gene. We investigated this important potential using an HDAd bearing 13 genetic markers in the region of homology to the target CFTR locus in human iPSCs and found that all markers can be simultaneously introduced into the target locus, with the two farthest markers being 22.2 kb apart. We found that genetic markers closer to the HDAd’s selectable marker are more efficiency introduced into the target locus; a marker located 208 bp from the selectable marker was introduced with 100% efficiency. However, even markers 11 kb from the selectable marker were introduced at a relatively high frequency of 21.7%. Our study also revealed extensive heteroduplex DNA formation of up to 10 kb with no bias toward vector or chromosomal repair. However, mismatches escape repair at a frequency of up to 15%, leading to a genetically mixed colony and emphasizing the need for caution, especially if the donor and target sequences are not 100% homologous.

Engineered LINE-1 retrotransposition in nondividing human neurons

Half the human genome is made of transposable elements (TEs), whose ongoing activity continues to impact our genome. LINE-1 (or L1) is an autonomous non-LTR retrotransposon in the human genome, comprising 17% of its genomic mass and containing an average of 80-100 active L1s per average genome that provide a source of inter-individual variation. New LINE-1 insertions are thought to accumulate mostly during human embryogenesis. Surprisingly, the activity of L1s can further impact the somatic human brain genome. However, it is currently unknown whether L1 can retrotranspose in other somatic healthy tissues or if L1 mobilization is restricted to neuronal precursor cells (NPCs) in the human brain. Here, we took advantage of an engineered L1 retrotransposition assay to analyze L1 mobilization rates in human mesenchymal (MSCs) and hematopoietic (HSCs) somatic stem cells. Notably, we have observed that L1 expression and engineered retrotransposition is much lower in both MSCs and HSCs when compared to NPCs. Remarkably, we have further demonstrated for the first time that engineered L1s can retrotranspose efficiently in mature nondividing neuronal cells. Thus, these findings suggest that the degree of somatic mosaicism and the impact of L1 retrotransposition in the human brain is likely much higher than previously thought.

Long-term, high-level hepatic secretion of acid α-glucosidase for Pompe disease achieved in non-human primates using helper-dependent adenovirus

Pompe disease (glycogen storage disease type II (GSD-II)) is a myopathy caused by a genetic deficiency of acid α-glucosidase (GAA) leading to lysosomal glycogen accumulation causing muscle weakness, respiratory insufficiency and death. We previously demonstrated in GSD-II mice that a single injection of a helper-dependent adenovirus (HD-Ad) expressing GAA resulted in at least 300 days of liver secretion of GAA, correction of the glycogen storage in cardiac and skeletal muscles and improved muscle strength. Recent reports suggest that gene therapy modeling for lysososomal storage diseases in mice fails to predict outcomes in larger animal models. We therefore evaluated an HD-Ad expressing GAA in non-human primates. The baboons not only tolerated the procedure well, but the results also confirmed that a single dose of the HD-Ad allowed the livers of the treated animals to express and secrete large amounts of GAA for at least 6 months, at levels similar to those achieved in mice. Moreover, we detected liver-derived GAA in the heart, diaphragm and skeletal muscles of the treated animals for the duration of the study at levels that corrected glycogen accumulation in mice. This work validates our proof-of-concept studies in mice, and justifies future efforts using Ad-based vectors in Pompe disease patients.

Preclinical Efficacy and Safety Profile of Allometrically Scaled Doses of Doxycycline Used to Turn "On" Therapeutic Transgene Expression from High-Capacity Adenoviral Vectors in a Glioma Model

Glioblastoma multiforme (GBM) is the most commonly occurring primary brain cancer in adults, in whom its highly infiltrative cells prevent total surgical resection, often leading to tumor recurrence and patient death. Our group has discovered a gene therapy approach for GBM that utilizes high-capacity "gutless" adenoviral vectors encoding regulatable therapeutic transgenes. The herpes simplex type 1-thymidine kinase (TK) actively kills dividing tumor cells in the brain when in the presence of the prodrug, ganciclovir (GCV), whereas the FMS-like tyrosine kinase 3 ligand (Flt3L) is an immune-stimulatory molecule under tight regulation by a tetracycline-inducible "Tet-On" activation system that induces anti-GBM immunity. As a prelude to a phase I clinical trial, we evaluated the safety and efficacy of Food and Drug Administration (FDA)-approved doses of the tetracycline doxycycline (DOX) allometrically scaled for rats. DOX initiates the expression of Flt3L, which has been shown to recruit dendritic cells to the brain tumor microenvironment-an integral first step in the development of antitumor immunity. The data revealed a highly safe profile surrounding these human-equivalent doses of DOX under an identical therapeutic window as proposed in the clinical trial. This was confirmed through a neuropathological analysis, liver and kidney histopathology, detection of neutralizing antibodies, and systemic toxicities in the blood. Interestingly, we observed a significant survival advantage in rats with GBM receiving the 300 mg/day equivalent dosage of DOX versus the 200 mg/day equivalent. Additionally, rats rejected "recurrent" brain tumor threats implanted 90 days after their primary brain tumors. We also show that DOX detection within the plasma can be an indicator of optimal dosing of DOX to attain therapeutic levels. This work has significant clinical relevance for an ongoing phase I clinical trial in humans with primary GBM and for other therapeutic approaches using Tet-On transactivation system in humans.

A cautionary tale; squamous cell carcinoma of the gingiva

BACKGROUND AND OBJECTIVES

Oral squamous cell carcinoma is characterised by varied clinical manifestations and is often diagnosed at an advanced stage. This article highlights a case of gingival squamous cell carcinoma which was initially diagnosed and treated as localised periodontitis.

METHODS

A 64-year-old Caucasian male had a 2-year history of discomfort and swelling around his upper anterior teeth. His dentist diagnosed localised periodontitis around tooth 11. The patient was treated with regular scaling but showed no improvement. Teeth 11 and 21 were subsequently extracted. He returned later with a swelling in his anterior maxilla and was referred to the Whangarei Hospital Dental Department.

RESULTS

The histopathological report confirmed a diagnosis of squamous cell carcinoma. The patient was referred to Auckland for treatment and underwent a tracheostomy, maxillectomy, bilateral selective neck dissection and fibula free flap reconstruction. All lymph nodes retrieved and margins of the lesion were clear, and the patient did not require radiotherapy. He will be monitored over the next 5 years for recurrence.

CONCLUSIONS

Gingival squamous cell carcinoma can be easily misdiagnosed. Suspicious lesions which are non-responsive to conventional therapy should be biopsied, even if they are not in the classic high risk anatomical areas of the oral cavity.

High-level production of replication-defective human immunodeficiency type 1 virus vector particles using helper-dependent adenovirus vectors

Gene transfer vectors based upon human immunodeficiency virus type 1 (HIV) are widely used in bench research applications and increasingly in clinical investigations, both to introduce novel genes but also to reduce expression of unwanted genes of the host and pathogen. At present, the vast majority of HIV-based vector supernatants are produced in 293T cells by cotransfection of up to five DNA plasmids, which is subject to variability and difficult to scale. Here we report the development of a HIV-based vector production system that utilizes helper-dependent adenovirus (HDAd). All necessary HIV vector components were inserted into one or more HDAds, which were then amplified to very high titers of ~10¹³ vp/ml. These were then used to transduce 293-based cells to produce HIV-based vector supernatants, and resultant VSV G-pseudotyped lentiviral vector (LV) titers and total IU were 10- to 30-fold higher, compared to plasmid transfection. Optimization of HIV-based vector production depended upon maximizing expression of all HIV vector components from HDAd. Supernatants contained trace amounts of HDAd but were free of replication-competent lentivirus. This production method should be applicable to other retroviral vector systems. Scalable production of HIV-based vectors using this two-step procedure should facilitate their clinical advancement.

Efficient genome editing in hematopoietic stem cells with helper-dependent Ad5/35 vectors expressing site-specific endonucleases under microRNA regulation

Genome editing with site-specific endonucleases has implications for basic biomedical research as well as for gene therapy. We generated helper-dependent, capsid-modified adenovirus (HD-Ad5/35) vectors for zinc-finger nuclease (ZFN)– or transcription activator-like effector nuclease (TALEN)–mediated genome editing in human CD34+ hematopoietic stem cells (HSCs) from mobilized adult donors. The production of these vectors required that ZFN and TALEN expression in HD-Ad5/35 producer 293-Cre cells was suppressed. To do this, we developed a microRNA (miRNA)-based system for regulation of gene expression based on miRNA expression profiling of 293-Cre and CD34+ cells. Using miR-183-5p and miR-218-5p based regulation of transgene gene expression, we first produced an HD-Ad5/35 vector expressing a ZFN specific to the HIV coreceptor gene ccr5. We demonstrated that HD-Ad5/35.ZFNmiR vector conferred ccr5 knock out in primitive HSC (i.e., long-term culture initiating cells and NOD/SCID repopulating cells). The ccr5 gene disruption frequency achieved in engrafted HSCs found in the bone marrow of transplanted mice is clinically relevant for HIV therapy considering that these cells can give rise to multiple lineages, including all the lineages that represent targets and reservoirs for HIV. We produced a second HD-Ad5/35 vector expressing a TALEN targeting the DNase hypersensitivity region 2 (HS2) within the globin locus control region. This vector has potential for targeted gene correction in hemoglobinopathies. The miRNA regulated HD-Ad5/35 vector platform for expression of site-specific endonucleases has numerous advantages over currently used vectors as a tool for genome engineering of HSCs for therapeutic purposes.

Functional recovery of consumers discharged from mental hospital and participating in a community-based psychosocial programme provided by a non-governmental organisation

OBJECTIVE

To explore the 1-year functional recovery rate and identify factors predicting functional recovery of consumers in the Hong Kong context.

METHODS

By adopting a prospective longitudinal follow-up research design, a cohort of Chinese people discharged from the mental hospital and participating in a community-based psychosocial programme provided by a non-governmental organisation were followed up for 1 year. These individuals were assessed on their social functioning, psychiatric symptoms, self-efficacy, and quality of life using standardised assessment scales at baseline, 6 months, and 12 months of follow-up.

RESULTS

Of 87 participants, about one quarter (23.0%, n = 20) achieved functional recovery and about three quarters (79.3%, n = 69) achieved symptom remission at 12 months of follow-up. Also, the group showing functional recovery achieved better quality of life than those not showing recovery. Logistic regression analysis indicated that current functioning, current psychiatric symptoms, and achieving open employment at 12 months were significant predictors of functional recovery. These 3 predicting factors altogether accounted for half (54.4%) of the variance of functional recovery.

CONCLUSIONS

It is more difficult to achieve functional recovery than symptom remission for consumers. Helping consumers to improve social skills, achieve open employment, and reduce psychiatric symptoms is recommended as important elements in facilitating functional recovery in the local context.

Retinal transduction profiles by high-capacity viral vectors

Retinal gene therapy with adeno-associated viral (AAV) vectors is safe and effective in humans. However, the limited cargo capacity of AAV prevents their use for therapy of those inherited retinopathies (IRs) due to mutations in large (>5kb) genes. Viral vectors derived from Adenovirus (Ad), Lentivirus (LV) and Herpesvirus (HV) can package large DNA sequences but do not target efficiently retinal photoreceptors (PRs) where the majority of genes responsible for IRs are expressed.

Here, we have evaluated the mouse retinal transduction profiles of vectors derived from 16 different Ad serotypes, 7 LV pseudotypes, and from a bovine HV. Most of the vectors tested transduced efficiently the retinal pigment epithelium (RPE). We found that LV-GP64 tends to transduce more PRs than the canonical LV-VSVG albeit this was restricted to a narrow region. We observed more extensive PR transduction with HdAd1, 2 and 5/F35++ than with LV, although none of them outperformed the canonical HdAd5 or matched the extension of PR transduction achieved with AAV2/8.

Quality of life in people with mental illness in non-residential community mental health services in Hong Kong

OBJECTIVE

To identify the subjective quality of life in people with chronic mental health problems who were in non-residential community mental health services, and to investigate factors affecting their quality of life after the illness.

METHODS

People with mental illness (n = 105) were recruited. They were assessed with the self-rated Hong Kong Chinese version of the World Health Organization Quality of Life Brief questionnaire.

RESULTS

The participants had lower total quality-of-life and the 4 domain scores of the questionnaire than the general population. They were particularly dissatisfied with their financial situation. Duration of illness was positively correlated with subjective quality-of-life variables while age at onset of the mental illness was negatively correlated with subjective quality of life, in particular the physical health, psychological health, and environmental domains.

CONCLUSION

This study highlighted the significance of duration and age at onset of illness in subjective quality of life of people with mental illness. A longitudinal study to test the causal relationships between these factors and the quality of life in people with mental illness is recommended.