Colchicine is not effective for reducing osteoarthritic hand pain compared to placebo: a randomised, placebo-controlled trial (COLAH).

BACKGROUND: Colchicine may offer relief in osteoarthritis. This has never been investigated for hand osteoarthritis. OBJECTIVES: To investigate the effect of 1 mg daily colchicine vs placebo on hand pain and function over 12 weeks in older adults with hand osteoarthritis. METHODS: Community-dwelling adults with diagnosed osteoarthritis of the hand aged 40-80 years were randomised to receive colchicine (0.5 mg twice daily) or matching placebo. Primary outcome measure was VAS hand pain score (0-100 mm). Secondary outcome measures included tender and swollen joint count, grip strength, C-reactive protein, and Michigan Hand Questionnaire total, function and pain scores. In an exploratory assessment, we compared synovial grade and power Doppler. All outcome measures were obtained at baseline and week 12. Stata v16 was used to perform constrained longitudinal data analysis models. RESULTS: 64 adults (54 females, 10 males) aged 48-79 years of age were enrolled. 59 participants completed the study (N = 28 colchicine, N = 31 placebo) (withdrawal rate 8%). Adverse reactions to the study medication occurred in nine patients. VAS score was not significantly different at baseline (61 ± 17 mm in the colchicine, 64 ± 17 mm in the placebo group). Between-group difference for VAS score at week 12 was 7.6 mm (95% CI -3.5-18.7, p-value 0.18). There were no significant differences between groups for any secondary outcomes at baseline or week 12. CONCLUSIONS: 1 mg colchicine daily for 12 weeks was not effective for reducing pain, tender and swollen joint count or increasing grip strength in symptomatic hand osteoarthritis. Our results do not support the use of colchicine in hand osteoarthritis.

Supplementation with omega-3 fish oil has no effect on bone mineral density in adults with knee osteoarthritis: a 2-year randomized controlled trial.

UNLABELLED: This study aimed to determine the effect of fish oil on bone mineral density (BMD). There were no differences in the 2-year BMD measures between high and low dose groups after adjusting for baseline BMD. This randomized controlled trial did not demonstrate any efficacy of omega-3 fatty acids on bone loss in adults. INTRODUCTION: The purpose of this study is to investigate whether supplementation with high dose omega-3 fish oil could have an impact on BMD. METHODS: In a multicentre, double-blind randomized controlled trial (RCT) (ACTRN 12607000415404), 202 Australian participants aged ≥40 with knee osteoarthritis (mean age, 61.0 ± 10.0 years; 49 % female) were randomized to receive either high dose (4.5 g eicosapentaenoic acid and docosahexaenoic acid daily) or low dose (0.45 g/day) omega-3 fish oil for 2 years. BMD was assessed at baseline and 2 years by dual energy X-ray absorptiometry. RESULTS: In subjects with baseline and 2-year assessments, mean standardized BMD at baseline for low or high dose group was 1198 ± 198 and 1157 ± 169 mg/cm(2), respectively, for the lumbar spine and was 1035 ± 165 and 1017 ± 174 mg/cm(2), respectively, for the femoral neck. There were no differences in the 2-year BMD measures between high and low dose groups after adjusting for baseline BMD in the complete case regression analyses (lumbar spine 3.7, 95 % confidence interval (CI) -7.9 to 15.3 mg/cm(2) and femoral neck -5.5, 95 % CI -14.9 to 3.9 mg/cm(2)). The findings did not change with additional adjustments of age, gender, study centre and uses of bone-related drugs during the study period as well as using the intention-to-treat analysis or limiting to older participants (≥55 years at the baseline) (all P ≥ 0.25). Mild adverse events such as headache and gastrointestinal intolerance were common but did not occur more frequently in either group. There were no serious adverse events related to the intervention. CONCLUSION: A 2-year supplementation with high-dose omega-3 fish oil did not alter bone loss among men and women with knee osteoarthritis.

Prevalence and associations of gout and hyperuricaemia: results from an Australian population-based study.

BACKGROUND: Despite gout and hyperuricaemia being major comorbid health issues worldwide, there is a knowledge gap regarding their impact in the Australian community. AIMS: To determine the prevalence and associations of self-reported medically diagnosed gout and hyperuricaemia in an Australian population-based cohort. METHODS: The North West Adelaide Health Study is a longitudinal cohort study consisting of three stages of data collection. Each stage comprised a self-complete questionnaire, clinic assessment and computer-assisted telephone interview. In Stage 3 (2008-2010), participants were asked if a doctor had ever diagnosed them with gout. Additional data included demographics, comorbidities, laboratory data and Short Form 36 (SF-36). Participants were defined as having gout if they had self-reported medically diagnosed gout or were taking any gout-specific medication (allopurinol, colchicine, probenecid). Hyperuricaemia was defined as a serum uric acid (SUA) level >0.42 mmol/L in men and >0.34 mmol/L in women. RESULTS: The overall prevalence of gout was 5.2%. Males were significantly more likely to have gout than females (8.5 vs 2.1%, P < 0.001). The overall prevalence of hyperuricaemia was 16.6%, with being male again identified as a significant risk factor (17.8 vs 15.4%, P < 0.01). Both gout and hyperuricaemia were associated with male sex, body mass index and renal disease after multivariable adjustment. There was no significant difference reported in quality of life (mean SF-36) scores in participants with gout compared to unaffected individuals. CONCLUSION: The prevalence of gout and hyperuricaemia is high in the South Australian population. This study emphasises the need for optimal diagnosis and management of gout in Australia.

Utility of temporal artery biopsy samples for genome-wide analysis of giant cell arteritis.

Giant Cell Arteritis (GCA) is the most common vasculitis affecting the elderly. Archived formalin-fixed paraffin-embedded (FFPE) temporal artery biopsy (TAB) specimens potentially represent a valuable resource for large-scale genetic analysis of this disease. FFPE TAB samples were obtained from 12 patients with GCA. Extracted TAB DNA was assessed by real time PCR before restoration using the Illumina HD FFPE Restore Kit. Paired FFPE-blood samples were genotyped on the Illumina OmniExpress FFPE microarray. The FFPE samples that passed stringent quality control measures had a mean genotyping success of >97%. When compared with their matching peripheral blood DNA, the mean discordant heterozygote and homozygote single nucleotide polymorphisms calls were 0.0028 and 0.0003, respectively, which is within the accepted tolerance of reproducibility. This work demonstrates that it is possible to successfully obtain high-quality microarray-based genotypes FFPE TAB samples and that this data is similar to that obtained from peripheral blood.

Epidemiology of biopsy-proven giant cell arteritis in South Australia.

BACKGROUND/AIM: To determine the epidemiology and clinical features of biopsy-proven giant cell arteritis (GCA) in South Australia (SA). METHODS: Patients with biopsy-proven GCA were identified from pathology reports of temporal artery biopsies at SA Pathology laboratories, from 1 January 1992, to 31 July 2011. Epidemiological data were collected through patient questionnaires and standardised case note reviews. Incidence was estimated using Australian Bureau of Statistics population data for SA. Seasonality was analysed by Cosinor analysis, and time-to- event analysis was performed for the duration of steroid use. RESULTS: There were 314 cases of biopsy-proven GCA (72% female). The mean age at diagnosis of GCA was 78 years (interquartile range 72-82). The estimated population incidence for people over 50 was 3.2 per 100,000 person years. The female : male incidence ratio was 2.3 (P < 0.001), and incidence increased with each age decade. There was evidence of seasonal variation (P = 0.015), with higher rates observed in the summer months. Clinical data were available for 163 patients (68% female, median age 78 years). The most common presenting clinical features were temporal headache (74%), visual disturbance (68.4%), jaw claudication (59.3%) and symptoms of polymyalgia rheumatica (56%). The median initial steroid dose was 60 mg, with median duration of steroid use 4.5 years. Corticosteroid side-effects were common, affecting 89%, with 34% reporting five or more. CONCLUSIONS: This is the first epidemiological study of Australian biopsy-proven GCA patients. Age at onset and gender associations were similar to other Western populations. There was a high burden of steroid use in these patients.

Creation of a Pediatric Sedation Risk Assessment Scoring System: A Novel Method to Stratify Risk.

This study aimed to create a pediatric sedation scoring system independent of the American Society of Anesthesiology Physical Status (ASA-PS) classification that is predictive of adverse events, facilitates objective stratification, and resource allocation. Multivariable regression and machine learning algorithm analysis of 134,973 sedation encounters logged in to the Pediatric Sedation Research Consortium (PSRC) database between July 2007 and June 2011. Patient and procedure variables were correlated with adverse events with resultant ß -regression coefficients used to assign point values to each variable. Point values were then summed to create a risk assessment score. Validation of the model was performed with the 2011 to 2013 PSRC database followed by calculation of ROC curves and positive predictive values. Factors identified and resultant point values are as follows: 1 point: age ≤ 6 months, cardiac diagnosis, asthma, weight less than 5th percentile or greater than 95 th , and computed tomography (CT) scan; 2 points: magnetic resonance cholangiopancreatography (MRCP) and weight greater than 99th percentile; 4 points: magnetic resonance imaging (MRI); 5 points: trisomy 21 and esophagogastroduodenoscopy (EGD); 7 points: cough at the time of examination; and 18 points: bronchoscopy. Sum of patient and procedural values produced total risk assessment scores. Total risk assessment score of 5 had a sensitivity of 82.69% and a specificity of 26.22%, while risk assessment score of 11 had a sensitivity of 12.70% but a specificity of 95.29%. Inclusion of ASA-PS value did not improve model sensitivity or specificity and was thus excluded. Higher risk assessment scores predicted increased likelihood of adverse events during sedation. The score can be used to triage patients independent of ASA-PS with site-specific cut-off values used to determine appropriate sedation resource allocation.

Prevalence and associations of hand pain in the community: results from a population-based study.

OBJECTIVES: To assess the prevalence and associations of hand symptoms in a community setting. METHODS: The North West Adelaide Health Study (NWAHS) is a longitudinal cohort study of people aged ≥ 18 years. Analysis was performed in participants who completed a telephone interview, a quality of life questionnaire [the 36-item short-form health survey, (SF-36)], and the Australian/Canadian (AUSCAN) Osteoarthritis (OA) Hand Index, and underwent grip strength measurement. RESULTS: Overall, 477 (13.7%) reported hand pain, aching, or stiffness. Of these, 169 (35.8%) had been diagnosed with hand arthritis. Women were more likely to have hand symptoms than men, as were those aged ≥ 50 years (p < 0.001). Hand symptoms were associated with lower quality of life scores (p < 0.05). Participants with hand arthritis had more severe pain, stiffness, and poorer physical functioning as reflected by higher AUSCAN scores. Grip strength was reduced in those with hand symptoms and hand arthritis (p < 0.05) and inversely associated with mean AUSCAN subscores and SF-36 physical functioning scores (p < 0.001). CONCLUSIONS: Hand symptoms were present in 14% of the population and were more common in women and those aged ≥ 50 years. Hand symptoms were associated with reduced grip strength and reduced quality of life. Hand arthritis was associated with higher AUSCAN scores. Hand symptoms and hand arthritis have a significant impact on physical functioning and quality of life.

The prevalence of gout and hyperuricaemia in Australia: An updated systematic review.

BACKGROUND: Gout continues to increase in prevalence in developed countries with Oceanic countries particularly affected. Both gout and hyperuricaemia are associated with the metabolic syndrome and its sequelae. Recently, the Australian Institute for Health and Welfare (AIHW) reported a prevalence rate of 0.8% which appeared incongruous with other published research. Thus, an updated systematic review was undertaken to review the literature on the prevalence of gout and hyperuricaemia in Australia from data published after 2011. METHODS: A comprehensive, systematic search was conducted in MEDLINE, Embase and Web of Science in addition to relevant websites to identify research reporting the prevalence of gout and/or hyperuricaemia in Australia from May 2011 until June 2020. Crude gout and hyperuricaemia prevalence data was obtained and presented alongside case ascertainment, time-period, age range and stratified by gender if available. RESULTS: 118 full text articles were screened. 12 articles were included for analysis of gout prevalence. 4 articles were identified for the hyperuricaemia analysis. Wide variation in prevalence figures exist largely due study design and sample age range. Studies using a case definition of self-reported diagnosis of gout reported prevalence rates between 4.5% and 6.8%. The remaining studies used either electronic coding data from general practitioners or wastewater estimation of allopurinol consumption and documented adult prevalence rates between 1.5% and 2.9%. Prevalence increases with age, male sex and over time in keeping with global data. Hyperuricaemia prevalence ranged between 10.5% and 16.6% in Caucasian or an Australian representative population. AIHW estimates applied a chronic condition status, defined as current and lasted or expected to last more than six months, to cases of gout in the Australian National Health Survey. This likely results in an under-estimation in reported Australian gout prevalence rates. CONCLUSIONS: Gout is highly prevalent in Australia compared to global comparisons and continues to increase over time. Hyperuricaemia prevalence is also high although contemporary data is limited.

Patient perspective on remission in rheumatoid arthritis: Validation of patient reported outcome instruments to measure absence of disease activity.

OBJECTIVE: Patients have identified pain, fatigue and independence as the most important domains that need to be improved to define remission in rheumatoid arthritis (RA). This study identified and validated instruments for these domains and evaluated their added value to the ACR/EULAR Boolean remission definition. METHODS: Patients with a 28-joint Disease Activity Score (DAS28) ≤3.2 or in self-perceived remission (declaring their disease activity 'as good as gone') from the Netherlands, Portugal, Australia, and Canada, were assessed at 0, 3 and 6 months for patient-reported outcomes and the WHO-ILAR RA core set. Instrument validity was evaluated cross-sectionally, longitudinally and for the ability to predict future good outcome in terms of physical functioning. Logistic regression quantified the added value to Boolean remission. RESULTS: Of 246 patients, 152 were also assessed at 3, and 142 at 6 months. Most instruments demonstrated construct validity and discriminative capacity. Pain and fatigue were best captured by a simple numerical rating scale (NRS). Measurement of independence proved more complex, but a newly developed independence NRS was preferred. NRS for pain, fatigue and independence, in addition to or instead of patient global assessment did not add enough information to justify modification of the current Boolean definition of remission in RA. CONCLUSION: Key elements of the patient perspective on remission in RA can be captured by NRS pain, fatigue, and independence. Although this study did not find conclusive evidence to improve the current definition of remission in RA, the information from these instruments adds value to the physician's assessment of remission and further bridges the gap between physician and patient.

Does leisure time physical activity protect against shoulder pain at work?

BACKGROUND: Shoulder pain is a common problem that can impact on work. Leisure time physical activity (LTPA) has the potential to reduce the impact of shoulder pain through its physiological, psychological and social benefits. AIMS: To determine whether LTPA reduces the prevalence of shoulder pain in a working population. METHODS: Participants were selected from a longitudinal population-based cohort study, the North West Adelaide Health Study. Information was gathered by questionnaire on LTPA, smoking, depression and socio-economic factors. Body mass index was measured in a clinic setting. Occupational physical activity (OPA) estimated by job title and shoulder pain was measured using the Shoulder Pain and Disability Index. Workers with and without shoulder pain were compared using logistic regression analysis. RESULTS: Of the 1502 working participants, 16% reported having current shoulder pain. Shoulder pain was associated with older age (OR 1.98, 95% CI: 1.31-2.99) (age >50 years), smoking (OR 1.44, CI: 1.02-2.04), secondary-level educational attainment (OR 1.68, 95% CI: 1.07-2.65), high body mass index (BMI) (OR 1.54, 95% CI: 1.14-2.08) and depression (OR 2.42, 95% CI: 1.60-3.64). There was no effect of LTPA on shoulder pain. CONCLUSIONS: In this community-based cohort, there was no statistically significant association seen between LTPA, OPA and shoulder pain. There was, however, an association between smoking, BMI, secondary-level education, depression and shoulder pain. These modifiable factors may be better targets for preventive efforts than LTPA to reduce the risk of shoulder pain.

The Yale-Brown Obsessive Compulsive Scale. I. Development, use, and reliability.

The Yale-Brown Obsessive Compulsive Scale was designed to remedy the problems of existing rating scales by providing a specific measure of the severity of symptoms of obsessive-compulsive disorder that is not influenced by the type of obsessions or compulsions present. The scale is a clinician-rated, 10-item scale, each item rated from 0 (no symptoms) to 4 (extreme symptoms) (total range, 0 to 40), with separate subtotals for severity of obsessions and compulsions. In a study involving four raters and 40 patients with obsessive-compulsive disorder at various stages of treatment, interrater reliability for the total Yale-Brown Scale score and each of the 10 individual items was excellent, with a high degree of internal consistency among all item scores demonstrated with Cronbach's alpha coefficient. Based on pretreatment assessment of 42 patients with obsessive-compulsive disorder, each item was frequently endorsed and measured across a range of severity. These findings suggest that the Yale-Brown Scale is a reliable instrument for measuring the severity of illness in patients with obsessive-compulsive disorder with a range of severity and types of obsessive-compulsive symptoms.

The nonluteal porcine ovary as a source of angiogenic activity.

Nonluteal ovarian tissue extracts were tested for their ability to stimulate migration and proliferation of cultured bovine capillary endothelial cells. Stimulation of migratory and proliferative activity was found in the 105,000 X g supernatant of homogenates of either whole nonluteal porcine ovaries or isolated theca (follicular walls). Maximal proliferative and migratory activity was obtained with 1-10 micrograms homogenate protein. Neither follicular fluid nor extracts of granulosa cells showed significant activity when tested over a broad concentration range. The proliferative and migratory activities were associated with a heat-labile, nondialyzable, protease-sensitive fraction that was soluble in 40%, but not 60% (NH4)2SO4. The tissue extracts that effectively stimulated growth and migration of capillary endothelial cells in vitro also stimulated the formation of new capillary blood vessels in an angiogenesis assay performed on chick chorioallantoic membranes.

Reduced E-cadherin expression correlates with increased invasiveness in colorectal carcinoma cell lines.

A reduction in cell adhesiveness and cell invasion are essential steps in tumour progression to metastasis. In the present study two out of seven colorectal carcinoma cell lines exhibited reduced expression of the cell-cell adhesion molecule E-cadherin as assessed by immunofluorescence. The same two cell lines were invasive in the collagen gel and membrane invasion culture system invasion assays. Addition of anti-E-cadherin antibody to a non-invasive carcinoma cell line caused the cells to assume a dissociated morphology on plastic and to become invasive in collagen gels. This demonstrates a causal role for E-cadherin in the maintenance of intercellular adhesion and the suppression of tumour cell invasion and possibly metastasis in colorectal tumour cells.

Induction of resistance to 6-thioguanine and cytarabine by a range of anticancer drugs in Chinese hamster AA8 cells.

A mutagenicity assay using AA8 Chinese hamster cells has been used to explore the potential of some currently used clinical anticancer drugs to induce cells resistant to 6-thioguanine and cytarabine. Preliminary experiments gave evidence of a "low dose" and "high dose" resistance to cytarabine, and subsequent work considered only the latter of these events. When ethyl methane sulphonate was used as a reference mutagen, induced resistance to cytarabine developed substantially later and at a lower frequency than resistance to 6-thioguanine. Of the clinical drugs tested, carmustine showed the highest ability to induce either 6-thioguanine or cytarabine resistant cells. Bleomycin, daunomycin and amsacrine showed moderate ability, while vincristine was essentially inactive in these assays. Such information could potentially be used in selecting new drug combinations or timing of drug administration in cancer chemotherapy.

Anti-HIV-1 activity, toxicity, and stability studies of representative structural families of polyoxometalates.

The anti-HIV-1 activity and toxicity of representative structural families of polyoxotungstates in human lymphocytes was determined. The 21 compounds examined include those derived from the following structural families: [NaSb9W21O86]18- (HPA-23), Xn+W12O40(8-n)- (Keggin), P2W18O62(6-) (Wells-Dawson), W6O19(2-) (Lindqvist), [NaP5W30O110]14- (Preyssler), and W10O32(4-) (decatungstate). The molecular architecture of each of these structural families is constituted principally by a network of bonds between d0 WVI and oxide ions. Of these, 10 show median effective concentration (EC50) values of approximately 1 microM and six have marked toxicity with a median inhibitory concentration (IC50) of less than 50 microM. Only compounds containing more than six metal atoms showed appreciable antiviral activity. Beyond this, however, no marked correlation existed between the molecular size, charge, or charge density of the polyoxometalates and their anti-HIV-1 activity. Examination of an exemplary class of polyoxotungstates, the phosphotungstates of formula A- and B-PW9O34(9-) under physiological conditions (buffered neutral aqueous media), illustrates that both isomers equilibrate rapidly to generate the same distribution of products and that this distribution depends principally on the buffer. These heretofore unappreciated complexities in the chemistry of these compounds under neutral aqueous conditions indicates interpretation or evaluation of these compounds in cell culture and other biological screens must be done with care.

Synthesis, characterization, and anti-human immunodeficiency virus activity of water-soluble salts of polyoxotungstate anions with covalently attached organic groups.

The cesium and tetramethylammonium (TMA) salts of polyoxotungstate anions with covalently attached organosilyl groups of formula [(RSi)2O]SiW11O39(4-), where R = CH2CH2COCH3, (CH2)3CN, and CH==CH2 (1-R, cesium salt, unless otherwise noted) have been prepared, purified, and spectroscopically characterized. The water solubility (25 degrees C) of these 10 new compounds ranges from 0.14 mM to 2.16 mM. All appear to be stable in aqueous media over a period of several hours as assessed by 1H NMR. The activities (EC50) of the new compounds against human immunodeficiency virus in primary human lymphocytes range from 3.3 microM to 39.0 microM. Their toxicities (IC50) are all greater than 100 microM. The inhibition constants of the new compounds against purified virion-derived HIV-1 reverse transcriptase are in the 1-10 microM range.

Synthesis, characterization, and biological activity of a new potent class of anti-HIV agents, the peroxoniobium-substituted heteropolytungstates.

The mono- and trisubstituted peroxyniobium polyoxotungstates of formulas [(CH3)3NH]7[Si-(NbO2)3W9O37], Cs7[Si(NbO2)3W9O37], alpha-K5[Si(NbO2)W11O39] and alpha-[(CH3)3NH]5[Si(NbO2)-W11O39], have been prepared, purified, and characterized spectroscopically by 29Si NMR, 183W NMR, and IR. The presence of peroxo groups was verified by the yellow color of the product and quantified by iodometric titration. The potency of both the complexes and the precursor complexes was evaluated in human peripheral blood mononuclear cells (PBMC) acutely infected with human immunodeficiency virus type 1 (HIV-1). Hexaniobate (K7H[Nb6O19]) was the least effective with a median effective concentration (EC50) of > 100 microM, while Cs7[Si(NbO2)3W9O37] was one of the most effective compounds with an EC50 of 1.0 microM. None of the compounds were toxic to uninfected PBMC with the exception of alpha-K8[SiW11O39], which had a median inhibitory concentration (IC50) of 79 microM. The potency and selectivity of the complexes against HIV-1 reverse transcriptase was also evaluated and shown to be quite high (IC50 values from 0.03 to 0.06 microM). The trimethylammonium salts of the complexes were tested for their ability to inhibit the interaction between gp120 and CD4 using a cell-free system. The complex [(CH3)3NH]7[Si(NbO2)3W9O37] inhibited this interaction by 70% at 25 microM.

Potent inhibition of respiratory syncytial virus by polyoxometalates of several structural classes.

A series of polyoxometalates (POM) were synthesized and evaluated for anti-respiratory syncytial virus (RSV) activity. POM containing zirconium, tungsten, silicon, platinum, niobium or germanium of a variety of structural types have been evaluated. Sixteen of the compounds had very striking anti-RSV activity against a clinical isolate, Utah 89, with median effective concentration (EC50) values < or = 3 microM and selective indices > 80 as determined by viral cytopathic inhibition effect, neutral red uptake and virus yield reduction assays. The EC50 values for all three assays correlated very well (Pearson correlation coefficients > 0.90). POM containing sodium cations were totally inactive. Germanium-, niobium-, tin- and zirconium-containing compounds were found to be highly potent and selective. The antiviral activity was not cell line-dependent. The median cytotoxic concentration (IC50) values were generally greater than 100 microM. The compounds were also comparably active against a known laboratory RSV strain, A2, as well as other RSV strains. To detect any virus strain-specific inhibitory activity, seven POM were tested against other RSV strains; all were nearly equally inhibitory to the human virus strains, suggesting no strain specificity. Timing studies suggested that these compounds were most inhibitory during virus adsorption and penetration, although RSV was still significantly inhibited when the compound was added 3 h post-infection; which is considered well into the eclipse period. These data suggest that these potent, non-toxic compounds should be further studied as potential chemotherapeutic agents for treating RSV infections.

Lipofectin increases the specific activity of cypovirus particles for cultured insect cells.

Cytoplasmic polyhedrosis viruses (CPV) are classified as 14 distinct species (electropherotypes) within the genus Cypovirus, family Reoviridae. Cypovirus research has been limited by a lack of appropriate cell culture systems (for each of these virus species) in which the majority of cells can become productively infected. Lipofection increased the infection rate of Lymantria dispar 652 cells, by virus particles (derived from polyhedra) of Orgyia pseudosugata type 5 cypovirus (Op-5 CPV), from 3 to 44%. Lipofection also significantly increased the percentage of Trichoplusia ni 368 cells infected with the same virus (from < 1 to approximately 7%). The spread of cypovirus infection between cells was either very slow or insignificant, and infected cells appeared to remain viable for long periods. Virus infection was detected by the observation of polyhedra formation in individual cells and it was therefore possible to develop a simple quantitative assay system to measure virus titre (TCID50). Cryo-electron microscopy showed that cypovirus particles formed a complex with the lipid, involving their envelopment within the liposome membrane. It was concluded that the increased infectivity of the virus by lipofection was due to a more efficient cell entry mechanism, probably involving fusion between liposome and cell membranes.

Differential susceptibility of retroviruses to nucleoside analogues.

Retroviruses may cause diseases in their vertebrate hosts. They are distinguished by their common means of replication involving reverse transcription, a process inhibited by nucleoside reverse transcriptase inhibitors (NRTIs) and other compounds used in antiretroviral chemotherapy. Previous work on NRTIs has been limited to their effect on human immunodeficiency virus (HIV) (for review see Ho & Hitchcock, 1989; Weller, 1999) and little information exists regarding the efficacy and therapeutic potential of these drugs against other retroviruses. We have tested all six NRTIs licensed for HIV treatment [didanosine (ddI), zalcitabine (ddC), lamivudine (3TC), stavudine (d4T), zidovudine (AZT) and abacavir (ABC)] against seven retroviruses representative of the traditional subfamilies: Spumavirinae, Lentivirinae and the Oncovirinae. As expected, each drug showed a range of activities against the panel of retroviruses, some drugs inhibiting other viruses at concentrations well below those required for HIV. Overall, AZT was the most active inhibitor (IC50 range, 0.032-1.0 microM), being most active against the Spuma (foamy) viruses. Abacavir was inhibitory for HIV-1, MN strain (HIV-1 MN), amphotrophic murine leukemia virus (MLV-A) and simian foamy virus type 6 (SFV-6). The least effective inhibitor, 3TC (IC50 range, 0.32->100 microM), was most potent against simian retrovirus types 1 and 2 (SRV-1, SRV-2) and HIV-1, but did not inhibit foamy viruses and MLV-A. Additionally, there were differences in the concentration of drug required to inhibit closely related viruses. Taken together, these data suggest that NRTIs have a wide spectrum of antiretroviral activity and the activity of compounds, even against closely related retroviruses, cannot be predicted.