Reference interval for the C-ACT activated clotting time test in healthy dogs using a water bath and manual assessment of clot formation.

AIMS: To establish a reference range for the canine C-ACT activated clotting time (ACT) test using a water bath and visual clot assessment technique. METHODS: Healthy, privately owned dogs (n = 48) were prospectively recruited to the study. Blood samples were collected via direct jugular venipuncture for complete blood count, serum biochemistry analysis and measurement of prothrombin time (PT) and activated partial thromboplastin time (aPTT). Five animals with major abnormalities or who became agitated during phlebotomy were excluded. For the 43 remaining animals, 2 mL of blood was collected via the cephalic vein and added directly to a C-ACT tube that was shaken vigorously before being placed in a water bath at 37°C. Tubes were visually assessed for clot formation and C-ACT was recorded in seconds when the magnet within the tube lodged in the clot. RESULTS: The nonparametric reference interval (capturing the central 95% of the data) was 50-80 seconds, with a 90% CI for the lower limit of 50-55 seconds and a 90% CI for the upper limit of 75-80 seconds. The C-ACT ACT test had a positive correlation with aPTT (0.42; 95% CI = 0.13-0.64). There was no evidence of a correlation between C-ACT ACT and age, weight, PT, haematocrit, white blood cell count, platelet count or total protein. CONCLUSIONS AND CLINICAL RELEVANCE: The results of this study suggest that the normal reference interval for ACT in dogs using C-ACT tubes in a 37°C water bath is 50-80 seconds. Care should be taken extrapolating the results of this study to the general population, as the smaller study design had less control for confounders than a larger study. However, when using the described analytical methods, C-ACT tube ACT test results >80 seconds should be considered prolonged in dogs and should prompt further investigation.

Elective cricothyrotomy in a dog with transient laryngeal paralysis secondary to Australian paralysis tick (Ixodes holocyclus) envenomation.

The tube cricothyrotomy (CTT) has recently been introduced to small animal medicine as a viable surgical airway access procedure; however, there are no reports documenting its clinical use. The author's objective is to describe the clinical application, complications, and management of an elective CTT in a dog. Furthermore, the characteristics of CTT that may be clinically advantageous over temporary tube tracheostomy (TT) will be discussed. A 2-year-old female spayed German shepherd dog required mechanical ventilation (MV) due to unsustainable work of breathing as a result of tick paralysis and aspiration pneumonia. After successful weaning from MV, the dog was diagnosed with laryngeal paralysis. A surgical airway was performed using CTT to allow extubation and patient management whilst conscious. Complications included frequent tube suctioning due to accumulation of airway secretions in the tube and a single dislodgement event. The dog made an uneventful recovery with complete stoma healing by the second intention within 15 days. To the authors' knowledge, this is the first clinical report of an elective CTT performed to successfully manage upper airway obstruction in the dog. Its efficacy, clinical management and patient outcome are described.

Food for all: designing sustainable and secure future seafood systems.

Food from the sea can make a larger contribution to healthy and sustainable diets, and to addressing hunger and malnutrition, through improvements in production, distribution and equitable access to wild harvest and mariculture resources and products. The supply and consumption of seafood is influenced by a range of 'drivers' including ecosystem change and ocean regulation, the influence of corporations and evolving consumer demand, as well as the growing focus on the importance of seafood for meeting nutritional needs. These drivers need to be examined in a holistic way to develop an informed understanding of the needs, potential impacts and solutions that align seafood production and consumption with relevant 2030 Sustainable Development Goals (SDGs). This paper uses an evidence-based narrative approach to examine how the anticipated global trends for seafood might be experienced by people in different social, geographical and economic situations over the next ten years. Key drivers influencing seafood within the global food system are identified and used to construct a future scenario based on our current trajectory (Business-as-usual 2030). Descriptive pathways and actions are then presented for a more sustainable future scenario that strives towards achieving the SDGs as far as technically possible (More sustainable 2030). Prioritising actions that not only sustainably produce more seafood, but consider aspects of access and utilisation, particularly for people affected by food insecurity and malnutrition, is an essential part of designing sustainable and secure future seafood systems. Supplementary Information: The online version contains supplementary material available at 10.1007/s11160-021-09663-x.

Translational outcomes in a full gene deletion of ubiquitin protein ligase E3A rat model of Angelman syndrome.

Angelman syndrome (AS) is a rare neurodevelopmental disorder characterized by developmental delay, impaired communication, motor deficits and ataxia, intellectual disabilities, microcephaly, and seizures. The genetic cause of AS is the loss of expression of UBE3A (ubiquitin protein ligase E6-AP) in the brain, typically due to a deletion of the maternal 15q11-q13 region. Previous studies have been performed using a mouse model with a deletion of a single exon of Ube3a. Since three splice variants of Ube3a exist, this has led to a lack of consistent reports and the theory that perhaps not all mouse studies were assessing the effects of an absence of all functional UBE3A. Herein, we report the generation and functional characterization of a novel model of Angelman syndrome by deleting the entire Ube3a gene in the rat. We validated that this resulted in the first comprehensive gene deletion rodent model. Ultrasonic vocalizations from newborn Ube3am-/p+ were reduced in the maternal inherited deletion group with no observable change in the Ube3am+/p- paternal transmission cohort. We also discovered Ube3am-/p+ exhibited delayed reflex development, motor deficits in rearing and fine motor skills, aberrant social communication, and impaired touchscreen learning and memory in young adults. These behavioral deficits were large in effect size and easily apparent in the larger rodent species. Low social communication was detected using a playback task that is unique to rats. Structural imaging illustrated decreased brain volume in Ube3am-/p+ and a variety of intriguing neuroanatomical phenotypes while Ube3am+/p- did not exhibit altered neuroanatomy. Our report identifies, for the first time, unique AS relevant functional phenotypes and anatomical markers as preclinical outcomes to test various strategies for gene and molecular therapies in AS.

Inhibition of E. coli and S. aureus with selenium nanoparticles synthesized by pulsed laser ablation in deionized water.

Nosocomial diseases are mainly caused by two common pathogens, Escherichia coli and Staphylococcus aureus, which are becoming more and more resistant to conventional antibiotics. Therefore, it is becoming increasingly necessary to find other alternative treatments than commonly utilized drugs. A promising strategy is to use nanomaterials such as selenium nanoparticles. However, the ability to produce nanoparticles free of any contamination is very challenging, especially for nano-medical applications. This paper reports the successful synthesis of pure selenium nanoparticles by laser ablation in water and determines the minimal concentration required for ~50% inhibition of either E. coli or S. aureus after 24 hours to be at least ~50 ppm. Total inhibition of E. coli and S. aureus is expected to occur at 107±12 and 79±4 ppm, respectively. In this manner, this study reports for the first time an easy synthesis process for creating pure selenium to inhibit bacterial growth.

Continuous Video Electroencephalographic (EEG) Monitoring for Electrographic Seizure Diagnosis in Neonates: A Single-Center Study.

The objective of this study was to determine the diagnostic yield of continuous video electroencephalographic (EEG) monitoring in critically ill neonates in the setting of a novel, university-based Neonatal Neurocritical Care Service. Patient demographic characteristics, indication for seizure monitoring, and presence of electrographic seizures were obtained by chart review. Among 595 patients cared for by the Neonatal Neurocritical Care Service, 400 (67%) received continuous video EEG. The median duration of continuous video EEG monitoring was 49 (interquartile range = 22-87) hours. Electrographic seizures were captured in 105 of 400 (26% of monitored patients) and of those, 25 of 105 (24%) had no clinical correlate. In addition, 52 of 400 subjects (13%) were monitored due to paroxysmal events concerning for seizures, but never had electrographic seizures. Continuous video EEG monitoring helped confirm or rule out ongoing seizures in more than one-third of the cases. This finding helps to support the use of continuous video EEG in critically ill neonates.

A retrospective 15-year review: survival advantage after switching to sirolimus in hepatitis C virus infected liver graft recipients.

BACKGROUND: The use of sirolimus-based immune suppression in liver transplantation, particularly in hepatitis C virus (HCV)-infected recipients, remains contentious. There is some evidence that sirolimus retards hepatic fibrosis, is renal sparing and may be of benefit in preventing hepatocellular carcinoma (HCC) recurrence. Sirolimus has not been adopted by many transplant centres because of persistent concerns regarding an increased risk of hepatic artery thrombosis, graft loss and death with de novo sirolimus. AIM: To review the impact of switching to sirolimus monotherapy in HCV-infected liver recipients with respect to survival, graft loss and hepatic fibrosis. METHODS: A retrospective review of 190 patients from a single centre undergoing first liver transplantation for HCV over 15 years. 113 patients were switched from calcineurin inhibitor (CNI)-based therapy to low-dose sirolimus monotherapy at a median of 15 months after transplantation for HCV-related fibrosis (72%), renal impairment (14%) or high-risk HCC (5%). RESULTS: Patients switched to sirolimus had improved survival (P < 0.001) and slower progression to cirrhosis (P = 0.001). In patients with HCC (n = 91), sirolimus duration rather than strategy was an independent predictor of survival (P = 0.001) and extended time to HCC recurrence (33 vs. 16 months). Patients switched for renal dysfunction showed improvement in serum creatinine (140-108 µmol/L, P = 0.001). Those remaining on CNI-therapy were more likely to develop post-transplant diabetes (P = 0.03). CONCLUSION: These data suggest selective switching to low-dose sirolimus monotherapy in HCV-positive liver recipients improves clinical outcome.

Design and rationale of the WELCOME trial: A randomised, placebo controlled study to test the efficacy of purified long chainomega-3 fatty acid treatment in non-alcoholic fatty liver disease [corrected].

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) represents a range of liver conditions from simple fatty liver to progressive end stage liver disease requiring liver transplantation. NAFLD is common in the population and in certain sub groups (e.g. type 2 diabetes) up to 70% of patients may be affected. NAFLD is not only a cause of end stage liver disease and hepatocellular carcinoma, but is also an independent risk factor for type 2 diabetes and cardiovascular disease. Consequently, effective treatments for NAFLD are urgently needed. OBJECTIVES: The WELCOME study is testing the hypothesis that treatment with high dose purified long chain omega-3 fatty acids will have a beneficial effect on a) liver fat percentage and b) two histologically validated algorithmically-derived biomarker scores for liver fibrosis. DESIGN: In a randomised double blind placebo controlled trial, 103 participants with NAFLD were randomised to 15-18months treatment with either 4g/day purified long chain omega-3 fatty acids (Omacor) or 4g/day olive oil as placebo. Erythrocyte percentage DHA and EPA enrichment (a validated proxy for hepatic enrichment) was determined by gas chromatography. Liver fat percentage was measured in three discrete liver zones by magnetic resonance spectroscopy (MRS). We also measured body fat distribution, physical activity and a range of cardiometabolic risk factors. METHODS: Recruitment started in January 2010 and ended in June 2011. We identified 178 potential participants, and randomised 103 participants who met the inclusion criteria. The WELCOME study was approved by the local ethics committee (REC: 08/H0502/165; www.clinicalTrials.gov registration number NCT00760513).

The Community Connection Model: implementation of best evidence into practice for self-management of chronic diseases.

OBJECTIVE: With chronic diseases becoming an increasing burden for healthcare systems worldwide, self-management support has gained traction in many health regions and organizations. However, the real-world application of the findings from clinical trials into actual community programming is not self-evident. The aim of this study was to present a model of programme implementation, namely the Community Connection Model. METHODS: The process of implementing a chronic disease self-management programme has been documented in detail from its initial inception through to a sustainable programme. This account includes a description of the strategic activities undertaken (e.g. alignment with local policy and the formation of community partnerships) and the specific steps taken on the path to programme implementation (e.g. a scoping literature review, an environmental scan and a pilot programme with an evaluation component). RESULTS: Reflection on this case example suggests that a cognizance of the interactions between policy, partnership, planning and programme could act as a useful tool to guide programme implementation, evaluation and sustainability. RESULTS: Multiple types of self-management support have been implemented (as part of the Living Health Champlain programme), and are being evaluated and adapted in response to new evidence, shifting priorities and direction from more partners. The widespread access means that self-management support programmes are becoming part of the culture of care in the study region. CONCLUSION: Establishing a connection around an important health problem, ensuring active partnerships, adequate planning and early implementation of a programme grounded on the principles of applying best-available evidence can lead to successful solutions. The Community Connection Model is proposed as a way of conceptualizing these processes.

The kinetics of lanthanide complexation by EDTA and DTPA in lactate media.

The interaction of trivalent lanthanide and actinide cations with polyaminopolycarboxylic acid complexing agents in lactic acid buffer systems is an important feature of the chemistry of the TALSPEAK process for the separation of trivalent actinides from lanthanides. To improve understanding of metal ion coordination chemistry in this process, the results of an investigation of the kinetics of lanthanide complexation by ethylenediamine-N,N,N',N'-tetraacetic acid (EDTA) and diethylenetriamine-N,N,N',N'',N''-pentaacetic acid (DTPA) in 0.3 M lactic acid/0.3 M ionic strength solution are reported. Progress of the reaction was monitored using the distinctive visible spectral changes attendant to lanthanide complexation by the colorimetric indicator ligand Arsenazo III, which enables the experiment but plays no mechanistic role. Under the conditions of these experiments, the reactions occur in a time regime suitable for study by stopped-flow spectrophotometric techniques. Experiments have been conducted as a function of EDTA/DTPA ligand concentration, total lactic acid concentration, and pH. The equilibrium perturbation reaction proceeds as a first order approach to equilibrium over a wide range of conditions, allowing the simultaneous determination of complex formation and dissociation rate constants. The rate of the complexation reaction has been determined for the entire lanthanide series (except Pm(3+)). The predominant pathway for lanthanide-EDTA and lanthanide-DTPA dissociation is inversely dependent on the total lactate concentration; the complex formation reaction demonstrates a direct dependence on [H(+)]. Unexpectedly, the rate of the complex formation reaction is seen in both ligand systems to be fastest for Gd(3+). Correlation of these results indicates that in 0.3 M lactate solutions the exchange of lanthanide ions between lactate complexes and the polyaminopolycarboxylate govern the process.

Transduction of E13 murine neural precursor cells by non-immunogenic recombinant adeno-associated viruses induces major changes in neuronal phenotype.

Neural precursor cells (NPCs) provide a cellular model to compare transduction efficiency and toxicity for a series of recombinant adeno-associated viruses (rAAVs). Results led to the choice of rAAV9 as a preferred candidate to transduce NPCs for in vivo transplantation. Importantly, transduction promoted a neuronal phenotype characterized by neurofilament M (NFM) with a concomitant decrease in the embryonic marker, nestin, without significant change in glial fibrillary acidic protein (GFAP). In marked contrast to recent studies for induced pluripotent stem cells (iPSCs), exposure to rAAVs is non-immunogenic and these do not result in genetic abnormalities, thus bolstering the earlier use of NPCs such as those isolated from E13 murine cells for clinical applications. Mechanisms of cellular interactions were explored by treatment with genistein, a pan-specific inhibitor of protein receptor tyrosine kinases (PRTKs) that blocked the transduction and differentiation, thus implying a central role for this pathway for inducing infectivity along with observed phenotypic changes and as a method for drug design. Implantation of transduced NPCs into adult mouse hippocampus survived up to 28 days producing a time line for targeting or migration to dentate gyrus and CA3-1 compatible with future clinical applications. Furthermore, a majority showed commitment to highly differentiated neuronal phenotypes. Lack of toxicity and immune response of rAAVs plus ability for expansion of NPCs in vitro auger well for their isolation and suggest potential therapeutic applications in repair or replacement of diseased neurons in neurodegeneration.

Video-EEG monitoring in newborns with hypoxic-ischemic encephalopathy treated with hypothermia.

BACKGROUND: Therapeutic hypothermia (TH) is becoming standard of care in newborns with hypoxic-ischemic encephalopathy (HIE). The prognostic value of the EEG and the incidence of seizures during TH are uncertain. OBJECTIVE: To describe evolution of EEG background and incidence of seizures during TH, and to identify EEG patterns predictive for MRI brain injury. METHODS: A total of 41 newborns with HIE underwent TH. Continuous video-EEG was performed during hypothermia and rewarming. EEG background and seizures were reported in a standardized manner. Newborns underwent MRI after rewarming. Sensitivity and specificity of EEG background for moderate to severe MRI brain injury was assessed at 6-hour intervals during TH and rewarming. RESULTS: EEG background improved in 49%, remained the same in 38%, and worsened in 13%. A normal EEG had a specificity of 100% upon initiation of monitoring and 93% at later time points. Burst suppression and extremely low voltage patterns held the greatest prognostic value only after 24 hours of monitoring, with a specificity of 81% at the beginning of cooling and 100% at later time points. A discontinuous pattern was not associated with adverse outcome in most patients (73%). Electrographic seizures occurred in 34% (14/41), and 10% (4/41) developed status epilepticus. Seizures had a clinical correlate in 57% (8/14) and were subclinical in 43% (6/14). CONCLUSIONS: Continuous video-EEG monitoring in newborns with HIE undergoing TH provides prognostic information about early MRI outcome and accurately identifies electrographic seizures, nearly half of which are subclinical.

A single centre experience of liver disease in adults with cystic fibrosis 1995-2006.

BACKGROUND: Liver disease is an important cause of death in adults with cystic fibrosis (CF). Ursodeoxycholic acid (UDCA) may slow progression. Managing varices and timely evaluation for liver transplantation are important. METHODS: Adults with CF underwent annual review. Abnormalities of liver function tests or ultrasound prompted referral to the CF/liver clinic where UDCA was commenced. Endoscopic surveillance for varices was undertaken if ultrasound suggested portal hypertension. RESULTS: 154 patients were followed for a median 5 years. 43 had significant liver disease, 29 had cirrhosis with portal hypertension and 14 had ultrasound evidence of cirrhosis without portal hypertension. All started UDCA. Only one patient developed chronic liver failure and none required liver transplantation. 27 underwent endoscopy; 1 required variceal banding, the others had insignificant varices. Ultrasound was normal in 97 patients while five had steatosis; nine further patients had splenomegaly but no other evidence of portal hypertension. Neither spleen size nor platelet count correlated with portal hypertension. CONCLUSIONS: Liver disease was common in adults with CF but disease progression was rare. Thus liver disease detected and closely monitored in adults appeared to have a milder course than childhood CF. Splenomegaly, unrelated to portal hypertension may be a consequence of CF.

Cystic fibrosis liver disease: to transplant or not to transplant?

Biliary cirrhosis complicates some adults with cystic fibrosis (CF) and may require transplantation. Cardio-respiratory disease severity varies such that patients may require liver transplantation, heart/lung/liver (triple) grafts or may be too ill for any procedure. A 15-year experience of adults with CF-related liver disease referred for liver transplantation is presented with patient survival as outcome. Twelve patients were listed for triple grafting. Four died of respiratory disease after prolonged waits (4-171 weeks). Eight underwent transplantation (median wait 62 weeks); 5-year actuarial survival was 37.5%. Four died perioperatively; only one is alive at 8-years. Eighteen patients underwent liver transplant alone (median wait 7 weeks); 1- and 5-year actuarial survival rates were 100% and 69%. Three long-term survivors required further organ replacement (two heart/lung and one renal). Two others were turned down for heart/lung transplantation and four have significant renal impairment. Results for triple grafting were poor with unacceptable waiting times. Results for liver transplant alone were satisfactory, with acceptable waiting times and survival. However, further grafts were required and renal impairment was frequent. The policy of early liver transplantation for adults with CF with a view to subsequent heart/lung or renal transplantation needs assessment in the context of long-term outcome.

Orthotopic liver transplantation for subacute hepatic failure following partial treatment of isoniazid-resistant tuberculosis.

The management of patients with pre-existing tuberculosis (TB) undergoing liver transplantation is challenging. Cautious immunosuppression is required to prevent reactivation of disease, and second-line anti-tuberculous treatment may be necessary to prevent graft hepatotoxicity. Furthermore, liver transplantation in the context of isoniazid-resistant TB has seldom been reported. We report on a 44-year-old man with recent isoniazid-resistant extra-pulmonary TB who developed subacute hepatic failure requiring emergency liver transplantation and treatment with second-line anti-tuberculous therapy. We demonstrate that patients who have pre-existing TB can be successfully treated with alternative anti-tuberculous medication while under immunosuppression post transplantation. Pre-existing TB, including resistant strains, should not be an absolute contraindication to liver transplantation.

Identifying the behavioural phenotype in Fetal Alcohol Spectrum Disorder: sensitivity, specificity and screening potential.

BACKGROUND: In most cases of Fetal Alcohol Spectrum Disorder (FASD), the pathognomonic facial features are absent making diagnosis challenging, if not impossible, particularly when no history of maternal drinking is available. Also because FASD is often comorbid with Attention Deficit Hyperactivity Disorder (ADHD), children with FASD are frequently improperly diagnosed and receive the wrong treatment. Since access to psychological testing is typically limited or non-existent in remote areas, other diagnostic methods are needed to provide necessary interventions. OBJECTIVES: To determine if a characteristic behavioural phenotype distinguishes children with FASD from typically developing children and children with ADHD and use this information to create a screening tool for FASD diagnosis. METHODS: Parents and caregivers completed the Child Behavior Checklist (CBCL), a well-established standardized tool for evaluating children's behavioural problems. Results from 30 children with Fetal Alcohol Syndrome or Alcohol-Related Neurodevelopmental Disability, 30 children with ADHD, and 30 typically developing healthy children matched for age and socioeconomic status with FASD were analyzed. Based on our previous work, 12 CBCL items that significantly differentiated FASD and control groups were selected for further analyses. Stepwise discriminant function analysis identified behavioural characteristics most strongly differentiating groups and Receiver Operating Characteristics (ROC) curve analyses determined sensitivity and specificity of different item combinations. RESULTS: Seven items reflecting hyperactivity, inattention, lying and cheating, lack of guilt, and disobedience significantly differentiated children with FASD from controls. ROC analyses showed scores of 6 or higher on these items differentiated groups with a sensitivity of 86%, specificity of 82%. For FASD and ADHD, two combinations of items significantly differentiated groups with high sensitivity and specificity (i) no guilt, cruelty, and acts young (sensitivity = 70%; specificity = 80% (ii) acts young, cruelty, no guilt, lying or cheating, steals from home, and steals outside (sensitivity = 81%; specificity = 72%). These items were used to construct a potential FASD screening tool. CONCLUSIONS: Our findings identifying the behavioural characteristics differentiating children with FASD from typically developing children or children with ADHD have the potential for development of an empirically derived tool for FASD tool to be used in remote areas where psychological services are not readily available. This technique may speed up diagnosis and intervention for children without ready access to formal assessments.

Molecular characterisation of Haemophilus influenzae type a and untypeable strains isolated simultaneously from cerebrospinal fluid and blood: novel use of quantitative real-time PCR based on the cap copy number to determine virulence.

This study investigated the genetic structure of the cap region of an isolate of Haemophilus influenzae serotype a (Hia) from the cerebrospinal fluid (CSF) of a child with meningitis. In addition, the genetic structure of the cap region of a non-serotypeable H. influenzae isolate, obtained simultaneously from the blood of the same patient, was determined. According to restriction fragment length polymorphism analysis, the CSF and blood isolates were identical, with the exception of a single band shift of c. 35 kb. PCR analyses suggested that the CSF isolate possessed the IS1016-bexA gene and cap region II, whereas the blood isolate only had the IS1016 element. Furthermore, Southern analysis of DNA from both isolates showed that the CSF isolate carried the cap gene(s), while the blood isolate did not. Using a novel quantitative real-time PCR approach for determining the cap copy number, it was demonstrated that the CSF isolate had two intact tandem repeats of the cap gene containing three copies of IS1016, whereas the blood isolate had only one copy of IS1016. This study provided evidence that H. influenzae serotypes other than serotype b can cause serious disease, and that the virulence of these non-serotype b strains relates primarily to the cap gene copy number and the structure of the cap locus. Therefore, the quantitative real-time PCR assay described in this study should be useful for the rapid and definitive identification of strains of H. influenzae type a that represent a risk for serious disease.

Inhibition of hepatitis B virus by lentiviral vector delivered antisense RNA and hammerhead ribozymes.

Chronic hepatitis B virus (HBV) infection is an important cause of cirrhosis and hepatocellular carcinoma. Current treatments are limited and may be ineffective. Nucleic acid-mediated targeting of viral mRNA is an attractive and specific approach for viral infection and lentiviral vectors provide a means to express antisense sequences or ribozymes stably in target cells permitting continuous production within that cell and its progeny. To demonstrate long-term gene expression by lentiviral vectors in hepatocytes and to introduce lentiviral vectors expressing anti-HBV genes to assess their effect against HBV, lentiviral vectors expressing a reporter gene were assessed for longevity of gene expression in hepatocytes in vitro. Hammerhead ribozymes and antisense sequences targeting the HBV encapsidation signal (epsilon), X or surface antigen on mRNAs were cloned into lentiviral vectors and used to transduce HBV expressing hepatocytes where the effect on HBV mRNA level was assessed using ribonuclease protection. Gene expression in hepatocytes from integrated vectors continued for over 4 months without selection. Antisense RNA targeting HBs mRNA reduced this transcript, whilst antisense RNA to HBX mRNA was ineffective. Sense RNAs corresponding to epsilon and HBX mRNA also reduced HBV mRNA levels. Ribozymes targeting HBs and HBX mRNA effectively reduced HBV mRNA levels compared with inactive constructs indicating their effect to be enzymatic rather than antisense. Lentiviral vectors can produce long-term gene expression in hepatocytes and thus permit prolonged expression of antiviral genes targeting the HBV encapsidation signal, surface and X mRNAs as treatments for chronic HBV infection.