Model and Empirical Data-Based Cost-Utility Studies of Continuous Glucose Monitoring in Individuals with Type 1 Diabetes: A Protocol of a Systematic Review on Methodology and Quality

INTRODUCTION

This review aims to critically appraise differences in methodology and quality of model-based and empirical-data-based cost-utility studies to address key limitations, opportunities, and challenges to inform future cost-utility analyses of continuous glucose monitoring (CGM) in type 1 diabetes. This protocol is registered at PROSPERO (CRD42023391284).

METHODS

The review will be conducted in accordance with the PRISMA guideline for systematic reviews. Searches will be conducted in MEDLINE, Embase, Web of Science, Cochrane Library, and Econlit from 2000 to January 2023. Model and empirical data-based studies evaluating the cost-utility of any CGM system in type 1 diabetes will be considered for inclusion. Studies that only report on cost per life year or any other clinical outcome, or reporting only costs or only clinical outcomes studies in type 2 diabetes populations, and studies on bi-hormonal closed loops and do-it-yourself hybrid closed loop devices will be excluded. Two reviewers will independently screen each study for inclusion. Data on the intervention, population, model settings (such as perspective, time horizon), model type and structure, clinical outcomes used to populate the model, validation, and uncertainty will be extracted and qualitatively synthesised. Quality will be assessed using the Philips et al. 2006 (model-based studies) or Consensus Health Economic Criteria (empirical data-based studies) checklists. Model validation will be assessed using the AdViSHE checklist.

DISCUSSION

Now that CGM is being used more broadly in practice, critical appraisal of existing cost-utility methodology and quality is important to inform future cost-utility analyses of CGM in type 1 diabetes in various settings.

Metabolic syndrome and cardiovascular disease after haematopoietic cell transplantation (HCT) in adults: an EBMT cross-sectional non-interventional study

Metabolic syndrome (MetS) is associated with cardiovascular disease in the general population and is also a potential cardiovascular risk factor in survivors of haematopoietic cell transplantation (HCT). We report an EBMT cross-sectional, multi-centre, non-interventional study of 453 adult HCT patients surviving a minimum of 2 years post-transplant attending routine follow-up HCT and/or late effects clinics in 9 centres. The overall prevalence of MetS was 37.5% rising to 53% in patients >50 years of age at follow-up. There were no differences in rates of MetS between autologous and allogeneic HCT survivors, nor any association with graft-versus-host disease (GvHD) or current immunosuppressant therapy. Notably, there was a significantly higher occurrence of cardiovascular events (CVE, defined as cerebrovascular accident, coronary heart disease or peripheral vascular disease) in those with MetS than in those without MetS (26.7% versus 9%, p < 0.001, OR 3.69, 95% CI 2.09-6.54, p < 0.001), and, as expected, MetS and CVE were age-related. Unexpectedly, CVE were associated with occurrence of second malignancy. Screening for and management of MetS should be integrated within routine HCT long-term follow-up care for both allogeneic and autologous HCT survivors. Further research is warranted, including randomised controlled trials of interventional strategies and mechanistic studies of cardiovascular risk in HCT survivors.

COVA1-18 neutralizing antibody protects against SARS-CoV-2 in three preclinical models

One year into the Coronavirus Disease 2019 (COVID-19) pandemic caused by Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2), effective treatments are still needed 1-3 . Monoclonal antibodies, given alone or as part of a therapeutic cocktail, have shown promising results in patients, raising the hope that they could play an important role in preventing clinical deterioration in severely ill or in exposed, high risk individuals 4-6 . Here, we evaluated the prophylactic and therapeutic effect of COVA1-18 in vivo , a neutralizing antibody isolated from a convalescent patient 7 and highly potent against the B.1.1.7. isolate 8,9 . In both prophylactic and therapeutic settings, SARS-CoV-2 remained undetectable in the lungs of COVA1-18 treated hACE2 mice. Therapeutic treatment also caused a dramatic reduction in viral loads in the lungs of Syrian hamsters. When administered at 10 mg kg - 1 one day prior to a high dose SARS-CoV-2 challenge in cynomolgus macaques, COVA1-18 had a very strong antiviral activity in the upper respiratory compartments with an estimated reduction in viral infectivity of more than 95%, and prevented lymphopenia and extensive lung lesions. Modelling and experimental findings demonstrate that COVA1-18 has a strong antiviral activity in three different preclinical models and could be a valuable candidate for further clinical evaluation.

Baseline characteristics and clinical symptoms related to respiratory viruses identified among patients presenting with influenza-like illness in primary care

Objectives

We aimed to identify patients' clinical characteristics associated with respiratory viruses identified among patients presenting with influenza-like illness (ILI).

Methods

A sample of patients of all ages presenting with ILI was included by physicians of the French Sentinelles network during two seasons (2015/16 and 2016/17). Nasopharyngeal samples were tested for the presence of influenza virus (IV), respiratory syncytial virus (RSV), human rhinovirus (HRV) and human metapneumovirus (HMPV). Patients' characteristics associated with each of the four virus classes were studied using multivariate logistic regressions.

Results

A total of 5859 individuals were included in the study: 48.0% tested positive for IV, 7.9% for HRV, 7.5% for RSV and 4.1% for HMPV. Cough was associated with IV (OR 2.14, 95% CI 1.81–2.52) RSV (OR 2.52, 95% CI 1.75–3.74) and HMPV detection (OR 2.15, 95% CI 1.40–3.45). Rhinorrhoea was associated mainly with HRV detection (OR 1.75, 95% CI 1.34–2.32). Headache was associated with IV detection (OR 1.75, 95% CI 1.34–2.32), whereas absence of headache was associated with RSV and HMPV detection. Dyspnoea was associated with RSV detection (OR 2.33, 95% CI 1.73–3.12) and absence of dyspnoea with IV detection. Conjunctivitis was associated with IV detection (OR 1.27, 95% CI 1.08–1.50). Some associations were observed only in children: dyspnoea and cough with RSV detection (age <5 years), conjunctivitis with IV detection (age <15 years). Period of onset of symptoms differed among aetiological diagnoses. Seasonal influenza vaccination decreased the risk of IV detection (OR, 0.67, 95% CI 0.51–0.86).

Conclusions

This study allowed the identification of symptoms associated with several viral aetiologies in patients with ILI. A proper knowledge and understanding of these clinical signs may improve the medical management of patients.

Influenza B burden during seasonal influenza epidemics in France

CONTEXT

Seasonal flu outbreaks are linked to the circulation of influenza virus type A or B. Special attention has always been paid to influenza A epidemics; but recently, several studies have investigated the impact of influenza B virus epidemics, particularly as, since the 1980s, two antigenically different influenza B lineages co-circulate, raising the issue of vaccine matching.

OBJECTIVES

We present the results of influenza B burden during nine influenza seasons (2003-2013) and vaccine matching of the circulating lineages.

PATIENTS AND METHODS

Clinical and virological influenza surveillance data, collected by the Regional Groups for Influenza Surveillance Network in France, allows for studying the burden of influenza in the practice of the population of ambulatory care physicians.

RESULTS AND CONCLUSION

Our analysis is based on 37,801 samples, of which 12,036 were virologically confirmed influenza cases (31.8%), including 3576 cases of influenza B (29.7% of influenza cases). Influenza B viruses significantly circulated during six seasons. For each season, the influenza B epidemic peaked later than the influenza A epidemic. Influenza B is very common in children of school age but also affects other age groups. Finally, more than one-third of the analyzed influenza B viruses belonged to a different lineage than the one used in the composition of the trivalent vaccine. Our results are comparable to those described in other countries.

Allogeneic hematopoietic stem cell transplantation in solid organ transplant recipients: a retrospective, multicenter study of the EBMT

We conducted a questionnaire survey of the 565 European Society for Blood and Marrow Transplantation centers to analyze the outcome of allogeneic hematopoietic stem cell transplantation (alloSCT) in recipients of solid organ transplantation (SOT). We investigated 28 patients with malignant (N = 22) or nonmalignant diseases (N = 6), who underwent 31 alloSCT procedures: 12 after kidney, 13 after liver and 3 after heart transplantation. The incidence of solid organ graft failure at 60 months after first alloSCT was 33% (95% confidence interval [CI], 16-51%) for all patients, 15% (95% CI, 2-40%) for liver recipients and 50% (95% CI, 19-75%) for kidney recipients (p = 0.06). The relapse rate after alloSCT (22%) was low following transplantation for malignant disorders, despite advanced stages of malignancy. Overall survival at 60 months after first alloSCT was 40% (95% CI, 19-60%) for all patients, 51% (95% CI, 16-86%) for liver recipients and 42% (95% CI, 14-70%) for kidney recipients (p = 0.39). In summary, we show that selected SOT recipients suffering from hematologic disorders may benefit from alloSCT and experience enhanced long-term survival without loss of organ function.

Kinetics and pattern of viral excretion in biological specimens of two MERS-CoV cases

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Lower respiratory tract excretion of MERS-CoV can be observed for more than one month.

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Viral excretion in multiple organs is possible, including viraemia.

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Prolonged infection prevention and control measures are necessary.

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Prolonged monitoring of respiratory excretion seems necessary.

Background

Middle East respiratory syndrome coronavirus (MERS-CoV) is an emerging coronavirus involved in severe acute respiratory distress syndrome (ARDS) and rapid renal failure. Hospital outbreak and nosocomial transmission were reported, however, several issues remain on the viral excretion course.

Objectives

Describe the kinetics and pattern of viral excretion in two infected patients.

Study design

After the initial diagnosis, blood, urine, rectal and respiratory samples were collected regularly, aliquoted and stored at −80 °C. Real-time reverse transcriptase polymerase chain reaction assay targeted the UpE and Orf1a regions of the MERS-CoV genome.

Results

In patient 1, who died of refractory ARDS and renal failure, MERS-CoV RNA was detected in pharyngeal and tracheal swabs, as well blood samples and urine samples until the 30th day. Rectal swabs were negative. Patient 2 also developed multiple-organ failure, but survived, with persisting renal insufficiency (creatinine clearance at 30 mL/min) and persistent interstitial syndrome albeit weaned off mechanical ventilation and no longer requiring oxygen. Tracheal aspirations were positive until the 33rd day, while nasopharyngeal swabs were negative. All other biological samples were negative.

Discussion

Lower respiratory tract excretion of MERS-CoV could be observed for more than one month. The most severely ill patient presented an expression of the virus in blood and urine, consistent with a type-1 interferon mediated immunological response impaired in patient 1, but developed by patient 2. These results suggest that infection control precautions must be adequately evaluated in clinical wards and laboratories exposed to MERS-CoV.

Influenza at the animal–human interface: a review of the literature for virological evidence of human infection with swine or avian influenza viruses other than A(H5N1)

Factors that trigger human infection with animal influenza virus progressing into a pandemic are poorly understood. Within a project developing an evidence-based risk assessment framework for influenza viruses in animals, we conducted a review of the literature for evidence of human infection with animal influenza viruses by diagnostic methods used. The review covering Medline, Embase, SciSearch and CabAbstracts yielded 6,955 articles, of which we retained 89; for influenza A(H5N1) and A(H7N9), the official case counts of the World Health Organization were used. An additional 30 studies were included by scanning the reference lists. Here, we present the findings for confirmed infections with virological evidence. We found reports of 1,419 naturally infected human cases, of which 648 were associated with avian influenza virus (AIV) A(H5N1), 375 with other AIV subtypes, and 396 with swine influenza virus (SIV). Human cases naturally infected with AIV spanned haemagglutinin subtypes H5, H6, H7, H9 and H10. SIV cases were associated with endemic SIV of H1 and H3 subtype descending from North American and Eurasian SIV lineages and various reassortants thereof. Direct exposure to birds or swine was the most likely source of infection for the cases with available information on exposure.

First cases of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infections in France, investigations and implications for the prevention of human-to-human transmission, France, May 2013

In May 2013, Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infection was diagnosed in an adult male in France with severe respiratory illness, who had travelled to the United Arab Emirates before symptom onset. Contact tracing identified a secondary case in a patient hospitalised in the same hospital room. No other cases of MERS-CoV infection were identified among the index case’s 123 contacts, nor among 39 contacts of the secondary case, during the 10-day follow-up period.

S-OtrH3N2 viruses: use of sequence data for description of the molecular characteristics of the viruses and their relatedness to previously circulating H3N2 human viruses

Emergence of influenza viruses from the animal reservoir is a permanent challenge. The rapid description and immediate sharing of information on these viruses is invaluable for influenza surveillance networks and for pandemic preparedness. With the help of data generated from the World Health Organization Collaborating Centre for Reference and Research on Influenza at the United States Centers for Disease Control and Prevention, we provide here information on the swine–origin triple reassortant influenza A(H3N2) viruses detected in human cases in the north-east of the United States.

S-OtrH3N2 viruses: use of sequence data for description of the molecular characteristics of the viruses and their relatedness to previously circulating H3N2 human viruses

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Highly heterogeneous temperature sensitivity of 2009 pandemic influenza A(H1N1) viral isolates, northern France

We assayed the temperature sensitivity of 2009 pandemic influenza A(H1N1) viral isolates (n=23) and seasonal influenza A(H1N1) viruses (n=18) isolated in northern France in 2007/08 and 2008/09. All isolates replicated with a similar efficiency at 34 °C and 37 °C, and with a lower efficiency at 40 °C. The pandemic viral isolates showed a stronger heterogeneity in their ability to grow at the highest temperature, as compared with the seasonal isolates. No statistically significant difference in temperature sensitivity was observed between the pandemic viral isolates from severe and mild cases of influenza. Our data point to the impact of temperature sensitivity on the genetic evolution and diversification of the pandemic influenza A(H1N1) virus since its introduction into the human population in April 2009, and call for close surveillance of this phenotypic marker related to host and tissue tropism.

Highly heterogeneous temperature sensitivity of 2009 pandemic influenza A(H1N1) viral isolates, northern France

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Kinetics of nasopharyngeal shedding of novel H1N1 (swine-like) influenza A virus in an immunocompetent adult under oseltamivir therapy

We describe a patient with confirmed novel H1N1 (swine-like) influenza A virus who had daily nasal swabs tested during oseltamivir therapy. Nasal shedding remained positive for 2 days and became negative on day 3. This report presents the first available data on the kinetics of shedding of this novel virus under antiviral therapy.

Early prediction of favourable recovery 6 months after mild traumatic brain injury

BACKGROUND

Predicting outcome after mild traumatic brain injury (MTBI) is notoriously difficult. Although it is recognised that milder head injuries do not necessarily mean better outcomes, less is known about the factors that do enable early identification of patients who are likely to recover well.

OBJECTIVE

To develop and internally validate two prediction rules for identifying patients who have the highest chance for good 6 month recovery.

METHODS

A prospective cohort study was conducted among patients with MTBI admitted to the emergency department. Apart from MTBI severity indices, a range of pre-, peri- and early post-injury variables were considered as potential predictors, including emotional and physical functioning. Logistic regression modelling was used to predict the absence of postconcussional symptoms (PCS) and full return to work (RTW).

RESULTS

At follow-up, 64% of the 201 participating patients reported full recovery. Based on our prediction rules, patients without premorbid physical problems, low levels of PCS and post-traumatic stress early after injury had a 90% chance of remaining free of PCS. Patients with over 11 years of education, without nausea or vomiting on admission, with no additional extracranial injuries and only low levels of pain early after injury had a 90% chance of full RTW. The discriminative ability of the prediction models was satisfactory, with an area under the curve >0.70 after correction for optimism.

CONCLUSIONS

Early identification of patients with MTBI who are likely to have good 6 month recovery was feasible on the basis of relatively simple prognostic models. A score chart was derived from the models to facilitate clinical application.

Humoral and cellular responses to influenza vaccination in human recipients naturally tolerant to a kidney allograft

Rare kidney allograft recipients enjoy unaltered graft function years after interruption of their immunosuppressive treatment. To assess the extent to which this state of 'operational tolerance' (TOL) is specific to the graft and not the result of a global immunodeficiency, we analyzed the response of such patients following influenza vaccination. Hemagglutination inhibition titers and frequency of IFNgamma-secreting T cells were measured before 1 and 3 months after vaccination. The proportion of healthy volunteers (HV) responding to vaccine was significantly higher than that of immunosuppressed (IS) patients. Three 'TOL' patients presented a humoral response similar to that of HV, whereas the two others had a poor response, like the IS recipients. Although the small number of patients does not allow for definitive conclusions to be made, these data suggest that the status of tolerance may be heterogeneous, with some patients with a global immunodeficiency and others with an adapted response to vaccination.

Natural variation can significantly alter the sensitivity of influenza A (H5N1) viruses to oseltamivir

Geographic spread of highly pathogenic avian H5N1 influenza viruses may give rise to an influenza pandemic. During the first months of a pandemic, control measures would rely mainly on antiviral drugs, such as the neuraminidase (NA) inhibitors oseltamivir and zanamivir. In this study, we compare the sensitivities to oseltamivir of the NAs of several highly pathogenic H5N1 viruses isolated in Asia from 1997 to 2005. The corresponding 50% inhibitory concentrations were determined using a standard in vitro NA inhibition assay. The K(m) for the substrate and the affinity for the inhibitor (K(i)) of NA were determined for a 1997 and a 2005 virus, using an NA inhibition assay on cells transiently expressing the viral enzyme. Our data show that the sensitivities of the NAs of H5N1 viruses isolated in 2004 and 2005 to oseltamivir are about 10-fold higher than those of earlier H5N1 viruses or currently circulating H1N1 viruses. Three-dimensional modeling of the N1 protein predicted that Glu248Gly and Tyr252His changes could account for increased sensitivity. Our data indicate that genetic variation in the absence of any drug-selective pressure may result in significant variations in sensitivity to anti-NA drugs. Although the clinical relevance of a 10-fold increase in the sensitivity of NA to oseltamivir needs to be investigated further, the possibility that sensitivity to anti-NA drugs could increase (or possibly decrease) significantly, even in the absence of treatment, underscores the need for continuous evaluation of the impact of genetic drift on this parameter, especially for influenza viruses with pandemic potential.

Binding of the hemagglutinin from human or equine influenza H3 viruses to the receptor is altered by substitutions at residue 193

Interactions of the hemagglutinin (HA) of influenza viruses with sialic acids (SA) are important for host range restriction. Most human H3s have a Ser193, while avian and equine H3s usually have an Asn or a Lys, respectively. To investigate the role of residue 193 in the recognition of SA, substitutions were introduced by mutagenesis within a human H3 and an equine H3. Hemadsorption assays performed on COS-1 cells expressing wt or mutated HAs, showed that a K193S substitution in the context of an equine H3 decreased its ability to bind several animal erythrocytes. Using de- and then alpha2,3 or alpha2,6 re-sialylated chicken erythrocytes we showed that for both human and equine H3s, substitution of a Serine by positively-charged Arginine or Lysine at position 193 increased binding to its preferred receptor, SAalpha2,6Gal and SAalpha2,3Gal, respectively. Moreover, when combined with the L194I substitution, the S193R substitution induced binding of the human H3 to NeuAcalpha2,3Gal.

Decreased fractal correlation in diurnal physical activity in chronic fatigue syndrome

OBJECTIVES

Our objectives were to study the temporal correlation of physical activity time series in patients with chronic fatigue syndrome (CFS) during normal daily life and to examine if it could identify the altered physical activity in these patients.

METHODS

Fractal scaling exponents of diurnal and nocturnal physical activity time series in 10 CFS patients and 6 healthy control subjects (CON) were calculated by the detrended fluctuation analysis (DFA) and the wavelet transform modulus maxima (WTMM) method. We hypothesized that, due to their illness- and/or fatigue-induced resting episodes, altered physical activity patterns in CFS patients might be observed at the interruption of activity bursts. Thus, we further developed a new method, the wavelet transform negative modulus maxima (WTNMM) method, which could evaluate the temporal correlation at the interruption of activities. We compared the fractal scaling exponents for CFS and CON by each method.

RESULTS

Both for CFS and CON, we found the fractal time structures in their diurnal physical activity records for at least up to 35 minutes. No group difference was found in nocturnal activities. The WTNMM method revealed that, in diurnal activities, CFS patients had significantly (p < 0.01) smaller fractal scaling exponent (0.87 +/- 0.03) compared to controls (1.01 +/- 0.03). Such a difference was identified neither by the DFA nor WTMM method.

CONCLUSIONS

CFS patients had more abrupt interruptions of voluntary physical activity during diurnal periods in normal daily life, probed by the decreased correlation in the negative modulus maxima of the wavelet-transformed activity data, possibly due to their exaggerated fatigue.

Brain engraftment of autologous macrophages transduced with a lentiviral flap vector: an approach to complement brain dysfunctions

Transplantation of ex vivo gene-corrected autologous cells represents an attractive therapeutic approach for brain diseases. Among the cells of the central nervous system, brain macrophages are promising candidates due to their role in tissue homeostasis and their implication in several neurological diseases. Up to now, gene transfer into macrophages has proven difficult by most currently available gene delivery methods. We describe herein, an efficient transduction of rat bone marrow-derived and brain macrophages with an HIV-1-derived vector containing a central DNA flap and encoding the GFP reporter gene (TRIP-DeltaU3-GFP). In primary cultures of macrophages our results show that more than 90% of the cells were transduced by the TRIP vector and that GFP expression remained stable for 1 month without cytopathic effect. In vivo, transplants of transduced macrophages into the striatum of adult rats exhibited long-term expression of GFP up to 3 months. Transduced macrophages were observed around the brain injection site and exhibited the brain macrophage/microglia phenotype. There was no significant sign of astrogliosis around the graft. These results confirm the potential of lentiviral vectors for efficient and stable ex vivo transduction of macrophages. Moreover, transduced autologous macrophages appear as a valuable vehicle for long-term and localized gene expression into the brain.

Hemagglutinin residues of recent human A(H3N2) influenza viruses that contribute to the inability to agglutinate chicken erythrocytes

To identify the molecular determinants contributing to the inability of recent human influenza A(H3N2) viruses to agglutinate chicken erythrocytes, phenotypic revertants were selected upon passage in eggs or MDCK cells. The Leu194Ile or Val226Ile substitutions were detected in their hemagglutinin (HA) sequence concomitantly with the phenotypic reversion. Remarkably, as little as 3.5% of variants bearing a Val226Ile substitution was found to confer the ability to agglutinate chicken erythrocytes to the virus population. Hemadsorption assays following transient expression of mutated HA proteins showed that the successive Gln226 --> Leu --> Ile --> Val changes observed on natural isolates resulted in a progressive loss of the ability of the HA to bind chicken erythrocytes. The Val226Ile change maintained the preference of the HA for SAalpha2,6Gal over SAalpha2,3Gal and enhanced binding of the HA to alpha2,6Gal receptors present on chicken erythrocytes. In contrast, simultaneous Ser193Arg and Leu194Ile substitutions that were found to confer the ability to agglutinate sheep erythrocytes increased the affinity of the HA for SAalpha2,3Gal.

The transcription/replication activity of the polymerase of influenza A viruses is not correlated with the level of proteolysis induced by the PA subunit

The PA subunit of the influenza virus polymerase has been shown to induce degradation of coexpressed proteins, but its role in the replication activity of the polymerase is not fully understood. Here, PA proteins derived from several influenza A viruses were examined at 37 and 33 degrees C for both the level of proteolysis they induced and the efficiency with which they ensured transcription/replication of a viral-like RNA within a polymerase complex reconstituted in vivo from cloned cDNAs. Two mutants of A/Victoria/3/75 PA showed a decreased ability to induce proteolysis as compared to the wild-type PA, but still appeared to be as active as the wild-type protein with respect to the polymerase activity. Furthermore, we observed that the ability of PR8-PA to induce proteolysis was severely impaired at 33 degrees C as compared to 37 degrees C, while the efficiency with which the PR8-derived polymerase complex ensured transcription/replication of the viral-like RNA was similar at both temperatures. Taken together, our observations suggest that the transcription/replication activity of the polymerase of influenza A viruses is not correlated with the level of proteolysis induced by the PA subunit.

Residue 627 of PB2 is a determinant of cold sensitivity in RNA replication of avian influenza viruses

Human influenza A viruses replicate in the upper respiratory tract at a temperature of about 33 degrees C, whereas avian viruses replicate in the intestinal tract at a temperature close to 41 degrees C. In the present study, we analyzed the influence of low temperature (33 degrees C) on RNA replication of avian and human viruses in cultured cells. The kinetics of replication of the NP segment were similar at 33 and 37 degrees C for the human A/Puerto-Rico/8/34 and A/Sydney/5/97 viruses, whereas replication was delayed at 33 degrees C compared to 37 degrees C for the avian A/FPV/Rostock/34 and A/Mallard/NY/6750/78 viruses. Making use of a genetic system for the in vivo reconstitution of functional ribonucleoproteins, we observed that the polymerase complexes derived from avian viruses but not human viruses exhibited cold sensitivity in mammalian cells, which was determined mostly by residue 627 of PB2. Our results suggest that a reduced ability of the polymerase complex of avian viruses to ensure replication of the viral genome at 33 degrees C could contribute to their inability to grow efficiently in humans.

Fatigue in disease-free cancer patients compared with fatigue in patients with chronic fatigue syndrome

The goal of our work was to assess fatigue in disease-free cancer patients with help of a validated fatigue questionnaire. Furthermore, we wished to analyse the relationship between severe fatigue and former treatment modalities, problems of concentration and motivation, physical activity, functional impairment, depression and anxiety and finally, to compare severely fatigued disease-free cancer patients and patients with Chronic Fatigue Syndrome (CFS). The participants were 85 adult cancer patients and 16 patients with CFS. The cancer patients were all disease-free and had been off treatment for a minimum of 6 months. They were asked to participate in this study by their physician when they came to the hospital for control visits. Patients who were willing to participate completed four questionnaires. The Checklist Individual Strength was used to measure fatigue. In addition, the Beck Depression Inventory, the Spielberger Trait Anxiety Inventory and the Nottingham Health Profile were used. Results indicate that 19% of the disease-free cancer patients were severely fatigued. Their fatigue experience is comparable to that of patients with CFS. Severe fatigue is associated with problems of concentration and motivation, reduced physical activity, emotional health problems and pain. Furthermore, a relation was found between fatigue and depression and anxiety. No relation was found between fatigue and type of cancer, former treatment modalities, duration of treatment and time since treatment ended. In conclusion, for one fifth of a group of disease-free cancer patients fatigue is a severe problem long after treatment. In addition to fatigue, these patients experience several psychological and physical problems.

Evidence for evolutionary stasis and genetic drift by genetic analysis of two equine influenza H3 viruses isolated in France

The amino acid sequences of the HA(1) portion of the haemagglutinin of two equine A(H3N8) influenza viruses isolated in France in 1993 and 1998 were analysed to determine their evolutionary relationship with 51 other HA(1) amino acid sequences available in databanks. Our data show that the French strain isolated in 1993 belongs to a group of phylogenetically related viruses branched on the main trunk, illustrating the main lineage of evolution of the equine-2 H3 sequences before its split into two distinct lineages in the late 1980s. By contrast, the 1998 French isolate appears to belong to the more recent 'Eurasian' lineage. These data suggest that equine-2 strains antigenically related to old prototype viruses may cocirculate with the more recent 'Eurasian' and 'American' lineages. In conclusion, it may be necessary to include both strains representative of recent equine influenza variants and an older prototype strain in the current equine influenza vaccines.

Genetic analysis of the compatibility between polymerase proteins from human and avian strains of influenza A viruses

In order to determine how efficiently the polymerase proteins derived from human and avian influenza A viruses can interact with each other in the context of a mammalian cell, a genetic system that allows the in vivo reconstitution of active ribonucleoproteins was used. The ability to achieve replication of a viral-like reporter RNA in COS-1 cells was examined with heterospecific mixtures of the core proteins (PB1, PB2, PA and NP) from two strains of human viruses (A/Puerto Rico/8/34 and A/Victoria/3/75), two strains of avian viruses (A/Mallard/NY/6750/78 and A/FPV/-Rostock/34), and a strain of avian origin (A/Hong Kong/156/97) that was isolated from the first human case of H5N1 influenza in Hong Kong in 1997. In accordance with published observations on reassortant viruses, PB2 amino acid 627 was identified as a major determinant of the replication efficiency of heterospecific complexes in COS-1 cells. Moreover, the results showed that replication of the viral-like reporter RNA was more efficient when PB2 and NP were both derived from the same avian or human virus or when PB1 was derived from an avian virus, whatever the origin of the other proteins. Furthermore, the PB1 and PB2 proteins from the A/Hong- Kong/156/97 virus exhibited intermediate properties with respect to the corresponding proteins from avian or human influenza viruses, suggesting that some molecular characteristics of PB1 and PB2 proteins might at least partially account for the ability of the A/Hong Kong/156/97 virus to replicate in humans.

Comparative analysis of the ability of the polymerase complexes of influenza viruses type A, B and C to assemble into functional RNPs that allow expression and replication of heterotypic model RNA templates in vivo

Influenza viruses type A, B, and C are human pathogens that share common structural and functional features, yet they do not form natural reassortants. To determine to what extent type-specific interactions of the polymerase complex with template RNA contribute to this lack of genotypic mixing, we investigated whether homotypic or heterotypic polymerase complexes support the expression and replication of model type A, B, or C RNA templates in vivo. A plasmid-based expression system, as initially described by Pleschka et al. [(1996) J. Virol. 70, 4188-4192] for influenza A virus, was developed for influenza viruses B/Harbin/7/94 and C/Johannesburg/1/66. The type A core proteins expressed heterotypic model RNAs with similar efficiencies as the homotypic RNA. The influenza B virus model RNA was efficiently expressed by all three types of polymerase complexes. Although no functional polymerase complex could be reconstituted with heterotypic P protein subunits, when the influenza A virus P proteins were expressed together with heterotypic nucleoproteins, significant, albeit limited, expression of RNA templates of all influenza virus types was detected. Taken together, our results suggest that less strict type-specific interactions are involved for the polymerase complex of influenza A compared with influenza B or C viruses.

Production of influenza virus in serum-free mammalian cell cultures

Human influenza viruses are routinely isolated and grown in a variety of mammalian cell substrates. However, influenza viruses for use as inactivated vaccine are still produced in embryonated eggs. Using a perfusion culture-based bioreactor process using serum-free medium, both human and equine influenza viruses of different types and subtypes could be produced to high titres. Classical DEAE-dextran microcarriers were found to be more suitable than polyester sponge carriers for virus production. In addition, MDCK cells grown in serum-free medium were further validated as the most suitable cell substrate compared to Vero and BHK-21 C13 cells for large scale virus production of influenza virus. Finally, to minimize potential contamination by adventitious agents, it was demonstrated that a new serum-free medium in which all animal-derived products are replaced by a plant extract, efficiently supports the growth of MDCK cells as well as the production of influenza virus in the presence of trypsin when using the perfusion bioreactor process.

Theiler's virus and Mengo virus induce cross-reactive cytotoxic T lymphocytes restricted to the same immunodominant VP2 epitope in C57BL/6 mice

C57BL/6 mice develop a virus-specific cytotoxic T-lymphocyte (CTL) response after intraperitoneal inoculation with either the DA strain of Theiler's virus or Mengo virus, two members of the Cardiovirus genus. These CTLs contribute to viral clearance in the case of Theiler's virus but do not protect the mice from the fatal encephalomyelitis caused by Mengo virus. In this study we show that DA and Mengo virus-induced CTLs are cross-reactive. The cross-reactivity is due to a conserved, H-2Db-restricted epitope located between amino acid residues 122 and 130 of the VP2 capsid protein (VP2(122-130)). This epitope is immunodominant in C57BL/6 mice infected with Theiler's virus. The VP2(122-130) epitope, initially identified for Mengo virus, is the first CTL epitope described for Theiler's virus.

Control by Ig genes of the responsiveness to a neutralization viral B cell epitope

In the present study, we analyzed the capacity of seven strains of mice to produce Abs against the neutralization poliovirus C3 B cell epitope, chemically or genetically linked to two different carrier proteins (MalE and keyhole limpet hemocyanin) or to recombinant hepatitis B surface Ag particles. Following immunization with these different immunogens, all strains of mice developed high Ab titers against the carrier proteins. However, only four strains of mice developed a significant Ab response against the poliovirus C3 B cell epitope. Indeed, in contrast to BALB/c, DBA/1, DBA/2, and 129 sv mice, C57BL/6, C3H, and CBA/J mice failed to produce anti-C3 Abs after immunization with the various C3 immunogens. Using various H-2 congenic strains on BALB/c or C57BL/10 background, this study clearly showed that the response to the C3 B cell epitope is not controlled by MHC genes. In contrast, analysis of anti-C3 Ab responses in IgH congenic mouse lines on BALB/c or C57BL/6 background demonstrated that the capacity to respond to this B cell epitope is controlled by genes closely linked to V(H) genes. This study therefore represents the first demonstration that the V(H) polymorphism can limit the Ab response to a viral neutralization epitope, and therefore has important implications for vaccine development.

Control by Ig genes of the responsiveness to a neutralization viral B cell epitope

In the present study, we analyzed the capacity of seven strains of mice to produce Abs against the neutralization poliovirus C3 B cell epitope, chemically or genetically linked to two different carrier proteins (MalE and keyhole limpet hemocyanin) or to recombinant hepatitis B surface Ag particles. Following immunization with these different immunogens, all strains of mice developed high Ab titers against the carrier proteins. However, only four strains of mice developed a significant Ab response against the poliovirus C3 B cell epitope. Indeed, in contrast to BALB/c, DBA/1, DBA/2, and 129 sv mice, C57BL/6, C3H, and CBA/J mice failed to produce anti-C3 Abs after immunization with the various C3 immunogens. Using various H-2 congenic strains on BALB/c or C57BL/10 background, this study clearly showed that the response to the C3 B cell epitope is not controlled by MHC genes. In contrast, analysis of anti-C3 Ab responses in IgH congenic mouse lines on BALB/c or C57BL/6 background demonstrated that the capacity to respond to this B cell epitope is controlled by genes closely linked to V(H) genes. This study therefore represents the first demonstration that the V(H) polymorphism can limit the Ab response to a viral neutralization epitope, and therefore has important implications for vaccine development.

Protection of non-murine mammals against encephalomyocarditis virus using a genetically engineered Mengo virus

Genetically engineered Mengo viruses with artificial deletions in the 5' noncoding poly(C) tracts are highly attenuated for pathogenicity when introduced as live vaccines into the natural murine host. Inoculation produces lifelong protective immunity without disease or viral persistence. This report extends the vaccination studies to non-murine hosts, including baboons, macaques and domestic pigs, all of which are susceptible to severe cardiovirus epizootics. All animals of these species that were inoculated with vMC24, an engineered strain of Mengo, seroconverted. When the immunized animals were challenged, they were protected against lethal doses of encephalomyocarditis virus (EMCV) derived from currently circulating epizootic strains. In baboons, the neutralizing antibody titers induced by vMC24 were significantly higher than from an inactivated EMCV vaccine. Moreover, terminal histopathology on baboons (inoculated intramuscularly), macaques (inoculated intracerebrally), and pigs (inoculated intramuscularly) showed few, if any, gross lesions characteristic of EMCV-like disease, in the vMC24 vaccinates. We suggest that genetically engineered, short poly(C) Mengo viruses may be universally potent attenuated vaccines for many types of animals and can possibly provide safe, efficacious protection against all cardioviruses of the EMCV serotype.

Cytotoxic T cell response to Mengo virus in mice: effector cell phenotype and target proteins

The Mengo virus specific cytotoxic T lymphocyte (CTL) response was investigated after intraperitoneal infection of mice with the attenuated Mengo virus strain vMC24. A high level of CTL activity was detected in spleen cell cultures obtained from infected C3H/HeJ (H-2k) or C57BL/6 (H-2b) mice after a secondary in vitro stimulation with Mengo virus-infected cells. The CTL activity, which was MHC class I-restricted, was shown to be mediated by CD8+ T cells. Recombinant vaccinia viruses that expressed capsid proteins VP0, VP1 or VP3 were produced and used to identify the protein(s) recognized by the Mengo virus-specific CTLs. In both C3H/HeJ and C57BL/6 mice, analysis of CTL activity against target cells expressing each capsid protein showed that VP0 was the only capsid protein recognized by the CD8+ CTLs. The CTL epitope(s) could be further located in the C-terminal half of VP0, i.e. in capsid protein VP2. Moreover, using unlabelled target cells expressing VP0 as cold competitors, we were able to almost completely inhibit recognition and lysis of Mengo virus-infected cells by specific CD8+ CTLs. Thus, the CTL response directed against VP2 was immunodominant in both C3H/HeJ- and C57BL/6-infected mice.

Attenuated Mengo virus: a new vector for live recombinant vaccines

Several features make Mengo virus an excellent candidate for use as a vaccine vector. The virus has a wide host range, including rodents, pigs, monkeys, and most likely humans, and expresses its genome exclusively in the cytoplasm of the infected cell. Stable attenuated strains exist which are deleted for part of the 5' noncoding region of the genome. Here we report an attenuated Mengo virus recombinant, vLCMG4, that encodes an immunodominant cytotoxic T-lymphocyte epitope of the lymphocytic choriomeningitis virus (LCMV) nucleo-protein. vLCMG4 induced protective immunity against lethal LCMV infection after a single, low-dose immunization in BALB/c mice and elicited an LCMV-specific CD8+ cytotoxic T lymphocyte response. This demonstrates the potential of recombinant Mengo virus vaccines to confer protection against infectious diseases by the induction of cellular immune responses.

Ability of linear and cyclic peptides of neutralization antigenic site 1 of poliovirus type 1 to induce virus cross-reactive and neutralizing antibodies

Eight peptides encompassing neutralization antigenic site 1 of poliovirus type 1 (residues 93-103 of VP1) were synthesized in linear or cyclized form and used to immunize rabbits. The resulting anti-peptide antibodies were tested for their ability to react with linear peptide 95-104, with infectious virus D-particles and heated C-particles and for their capacity to neutralize poliovirus infectivity. A good correlation was observed between the ability of different peptide antisera to immunoprecipitate D-particles and neutralize virus infectivity. The peptides that induced a neutralizing antibody response in the highest number of immunized animals contained flanking residues 104-115 in addition to the 93-103 residues of the epitope. However, a high neutralizing antibody titre was also obtained in two of ten animals immunized with peptide 93-104 cyclized via an amide bond between Asp93 and Lys103. It seems, therefore, that, at least in rabbits, the T-cell epitope recently identified in residues 103-115 of VP1 need not be present in the peptide immunogen in order to obtain poliovirus-specific neutralizing antibodies.

Attenuated Mengo virus as a vector for immunogenic human immunodeficiency virus type 1 glycoprotein 120

Introduction of a sequence encoding 147 amino acids from human immunodeficiency virus type I (HIV-1) strain MN glycoprotein gp120 into the RNA genome of the stably attenuated Mengo virus strain vM16 yielded an infectious recombinant virus, vMLN450, which expressed the heterologous HIV-1 sequence along with the normal Mengo virus proteins. The HIV-1 gp120 sequence, fused to the amino terminus of the short, nonstructural Mengo virus leader polypeptide was recognized by a gp120 V3 loop-specific monoclonal antibody. When inoculated into mice, recombinant virus vMLN450 elicited a high-titer anti-HIV-1 antibody response as well as an HIV-1MN-specific cytotoxic cellular immune response. An anti-HIV-1 antibody response could also be detected in cynomolgus monkeys after a single immunization. We propose that attenuated Mengo virus can serve as an effective expression vector in cell systems and various animal species and offers another approach to the development of new, live recombinant vaccines.

Potential use of poliovirus as a vector

The live attenuated Sabin strains of poliovirus have proven their efficacy at inducing a good humoral and secretory antibody response in humans. The extensive characterization of poliovirus neutralization antigenic sites and the atomic resolution of the three-dimensional structure of the viral capsid have enabled the use of the most stably attenuated poliovirus strain (the Sabin type 1 strain) as a vector for the presentation of short foreign antigenic domains in place of one of its own neutralization antigenic sites. The creation of such chimeras has been achieved by manipulating poliovirus infectious cDNA and transfecting the resulting chimeric cDNAs onto susceptible cell cultures. However, this epitope-presentation system has a limitation in terms of the sequence and size of the foreign domain that can be incorporated into the poliovirus capsid without disrupting virus viability. This has led to the construction of poliovirus hybrid genomes bearing insertions of longer heterologous sequences in place of part of the poliovirus structural genes. Upon transfection onto susceptible cells providing the poliovirus structural proteins in trans (e.g. cells previously infected with the Sabin 1 strain), stocks of encapsidated RNA replicons which expressed the foreign protein could be obtained. In addition, viable recombinant viruses bearing insertions of heterologous sequences at various places into the poliovirus genome without deleting poliovirus sequences have been reported. Potential applications of these chimeric and recombinant polioviruses in the engineering of new recombinant vaccines are discussed.

Poliovirus chimeras expressing sequences from the principal neutralization domain of human immunodeficiency virus type 1

Sequences from the principal neutralization domain of human immunodeficiency virus type 1 (HIV-1) strain LAI or RF have been expressed in antigenic site 1 of the capsid of the Sabin strain of poliovirus type 1. A number of the resulting chimeras were viable. Viable variants bearing mutations within the insertion site spontaneously arose from several nonviable chimeras. In general, these mutations result in a decrease in positive charge in the substituted antigenic site 1. Two of the chimeras were genetically stable and have been further characterized. Both chimeras were neutralized by various HIV-1 neutralizing antibodies. In rabbits, both chimeras produced high levels of antibodies which react with HIV-1 gp120/160 in immunoprecipitation and enzyme-linked immunosorbent assays. One of the chimeras (HIV-1LAI) produced a significant but weak HIV-1 neutralizing response.

Development of intelligence and memory in children with hemiplegic cerebral palsy. The deleterious consequences of early seizures

Although substantial data exist regarding the consequences of early lateralized cerebral lesions on intelligence and language ability, little is known about the development of other cognitive functions after such lesions. We examined the development of both verbal and nonverbal memory in 82 hemiplegic children, grouped according to hemispheric side of injury and presence or absence of seizure disorder. The control group consisted of 41 age-matched normal children, most of them siblings of the patients. Measures were obtained of intelligence and of immediate and delayed recall for prose passages, word paired associates and geometric designs. Electrophysiological and neuroradiological measures were available for a majority of the patients. The scores of the hemiplegic children on the IQ and memory tests did not exhibit the pattern seen in brain-damaged adults, in that the children's deficits showed no relation to hemispheric side of damage. Indeed, early cerebral damage to either hemisphere, even if extensive, resulted in relatively few and mild deficits if the damage was unaccompanied by seizure activity. By contrast, early lateralized lesions that were accompanied by a seizure disorder resulted in both a high incidence and degree of deficit that was unrelated to lesion side.

A Gly1 to Ala substitution in poliovirus capsid protein VP0 blocks its myristoylation and prevents viral assembly

Capsid protein VP4 of poliovirus is acylated with myristic acid via an amide linkage to its N-terminal glycine residue. Our previous studies suggested that myristic acid plays a role in poliovirus assembly and in the early events of infection. In order to understand better its role in the assembly process, we introduced a Gly1 to Ala amino acid substitution in the myristoylation signal sequence of VP4. This substitution prevented VP0 myristoylation in vivo and abolished the infectivity of genomic transcripts harbouring the mutation. These mutated RNAs were still able to replicate in the transfected cells but the assembly processes were inefficient and no mature virions could be detected.