Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

INTRODUCTION

The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures.

METHODS

In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025.

FINDINGS

Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2-6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p<0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5-5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p<0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4-10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p<0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32-4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP >5mg/L, OR 3·55 [1·23-11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation.

INTERPRETATION

After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

E-Cigarette-Only and Dual Use among Adolescents: Emerging Behaviours with Different Risk Profiles

Background

E-cigarette-only use and dual-use are emerging behaviours among adolescent nicotine product users which have not yet been sufficiently explored. This study examines the epidemiology of, and the factors associated with, nicotine product use in adolescence, specifically defined as e-cigarette only, conventional cigarette only and dual-use.

Methods

This is a cross-sectional analysis of the 2018 Planet Youth survey completed by 15-16 year olds in the West of Ireland. Current nicotine product use, defined by use at least once in the past 30 days, was categorised as e-cigarette only, conventional cigarette only, and dual-use. The characteristics and risk factor profiles of the population are described, according to nicotine product use, using chi-square tests for categorical data and t-tests for continuous data. A main effects multinomial logistic regression model was used to compare the association between potential risk and protective factors across categories of use.

Results

Among 4422 adolescents 22.1% were current nicotine product users, consisting of 5.1% e-cigarette only users, 7.7% conventional cigarette only users, and 9.3% dual-users. Risk factor profiles differed across categories of use. Frequent participation in team sport significantly reduced the odds of conventional cigarette and dual use but had no association with e-cigarette only use (Cig only: adjusted odds ratio (AOR) 0.63, 95% confidence interval (CI) 0.44-0.90; Dual-use: AOR 0.63, 95% CI 0.43-0.93, E-Cig only: AOR 1.31, 95% CI 0.87-1.97, p = 0.199). Similarly, having higher value for conventional social norms reduced the odds of conventional cigarette and dual use but not e-cigarette only use.

Conclusions

This is the first study to show, among a generalisable sample, that dual-use is the most prevalent behaviour among adolescent nicotine product users in Ireland. Risk factor profiles differed significantly across categories of use with important implications for youth tobacco control policy.

Key messages

This is the first study to show that dual use of conventional and electronic cigarettes, an under-researched behaviour, is the most prevalent form of nicotine product use among adolescents in Ireland. Risk factor profiles of e-cigarette only, conventional cigarette only, and dual users differ significantly, and this has important implications for prevention initiatives and tobacco control policy.

Extended interval dosing of natalizumab in multiple sclerosis

BACKGROUND

Natalizumab (NTZ), a monoclonal antibody to human α4β1/β7 integrin, is an effective therapy for multiple sclerosis (MS), albeit associated with progressive multifocal leukoencephalopathy (PML). Clinicians have been extending the dose of infusions with a hypothesis of reducing PML risk. The aim of the study is to evaluate the clinical consequences of reducing NTZ frequency of infusion up to 8 weeks 5 days.

METHODS

A retrospective chart review in 9 MS centres was performed in order to identify patients treated with extended interval dosing (EID) regimens of NTZ. Patients were stratified into 3 groups based on EID NTZ treatment schedule in individual centres: early extended dosing (EED; n=249) every 4 weeks 3 days to 6 weeks 6 days; late extended dosing (LED; n=274) every 7 weeks to 8 weeks 5 days; variable extended dosing (n=382) alternating between EED and LED. These groups were compared with patients on standard interval dosing (SID; n=1093) every 4 weeks.

RESULTS

17% of patients on SID had new T2 lesions compared with 14% in EID (p=0.02); 7% of patients had enhancing T1 lesions in SID compared with 9% in EID (p=0.08); annualised relapse rate was 0.14 in the SID group, and 0.09 in the EID group. No evidence of clinical or radiographic disease activity was observed in 62% of SID and 61% of EID patients (p=0.83). No cases of PML were observed in EID group compared with 4 cases in SID cohort.

CONCLUSIONS

Dosing intervals up to 8 weeks 5 days did not diminish effectiveness of NTZ therapy. Further monitoring is ongoing to evaluate if the risk of PML is reduced in patients on EID.

Co-occurrence of two cases of progressive multifocal leukoencephalopathy in a natalizumab "infusion group"

We observed two cases of progressive multifocal leukoencephalopathy (PML) that occurred in the same "infusion group". The group consisted of four patients with relapsing-remitting multiple sclerosis (RRMS) who had been treated with natalizumab (NAT) in the same medical practice for more than four years at the same times and in the same room, raising concerns about viral transmission between members of the infusion group. DNA amplification and sequence comparison of the non-coding control region (NCCR) of JC virus (JCV) present in cerebrospinal fluid (CSF) samples from PML patients #1 and #2 revealed that the amplified JCV sequences differed from the JCV archetype. The NCRR of the viral DNA was unique to each patient, arguing against the possibility of viral transmission between patients. Statistical considerations predict that similar co-occurrences of PML are likely to happen in the future.

Molecular evaluation of BK polyomavirus nephropathy

Understanding at a molecular level, the immunologic response of polyomavirus nephropathy (PVN), a critical cause of kidney graft loss, could lead to new targets for treatment and diagnosis. We undertook a transcriptional evaluation of kidney allograft biopsies from recipients with PVN or acute rejection (AR), as well as from recipients with stable allograft function (SF). In both the PVN and AR groups, Banff histologic scores and immunohistochemical analysis of inflammatory infiltrates were similar. Despite their different etiologies, the transcriptional profiles of PVN and AR were remarkably similar. However, transcription of genes previously linked to AR including CD8 (65.9 +/- 18.8) and related molecules IFN-gamma(55.1 +/- 17.0), CXCR3 (49.9 +/- 12.8) and perforin (153.8 +/- 50.4) were significantly higher in PVN compared to AR (30.9 +/- 2.0, 14.0 +/- 7.3, 12.1 +/- 7.3 and 15.6 +/- 3.8-fold, respectively; p < 0.01). Importantly, transcription of molecules associated with graft fibrosis including matrix collagens, TGFbeta, MMP2 and 9, as well as markers of epithelial-mesenchymal transformation (EMT) were significantly higher in PVN than AR. Thus, renal allografts with PVN transcribe proinflammatory genes equal in character and larger in magnitude to that seen during acute cellular rejection. BK infection creates a transcriptional microenvironment that promotes graft fibrosis. These findings provide new insights into the intrarenal inflammation of BK infection that promotes graft loss.

Convection-enhanced intraparenchymal delivery (CEID) of cytosine arabinoside (AraC) for the treatment of HIV-related progressive multifocal leukoencephalopathy (PML)

AIDS-related PML continues to be a relatively common and rapidly fatal infection in patients with AIDS, and no effective therapy has been established to alleviate the effects of this disease. Through the years, isolated reports and small case studies have shown somewhat encouraging results using cytosine arabinoside (AraC) in the treatment of PML. The optimism behind the use AraC for this disease began to fade with ACTG trial 243, which suggested that AraC had no benefit in patients with HIV-related PML. In this article, we provide evidence that suggests that the failure of AraC in the ACTG trial may have been due to insufficient delivery of the drug through traditional intravenous and intrathecal routes. Furthermore, we provide evidence that convection-enhanced intraparenchymal delivery of AraC may prove to be a safe and effective means of treating this infection, and we outline a clinical trial that we have recently undertaken to test this hypothesis.

Evaluating the neck for percutaneous dilatational tracheostomy

PURPOSE

The aims of this article are to study how variations in the anatomy of the neck may influence the success of percutaneous dilatational tracheostomy (PDT).

PATIENTS AND METHODS

Four hundred and ninety-seven patients were included in this study. Patients with a short neck and altered tracheal anatomy were evaluated on the basis of difficulty with PDT, use of long shank tracheostomy tubes, and need for open surgical tracheostomy.

RESULTS

33 (6.6%) patients had an apparently reduced cricoid ring to sternum distance and a deeply lying trachea. Nine of these patients were referred for open surgical tracheostomy. A further five patients had altered tracheal anatomy secondary to disease or surgery. Two of these patients were also referred for open surgical tracheostomy. Thus, unfavourable neck anatomy was responsible for 2.2% (11/497) of patients being referred for open surgical tracheostomy.

CONCLUSION

Variations in the anatomy of the neck can make PDT both difficult and hazardous. Patients with a deeply lying trachea may need a long shank tube. Open surgical tracheostomy is indicated in some patients with a deeply lying trachea and conditions producing secondary deformity of the trachea. All patients should have a detailed history and thorough clinical examination of the neck and thorax prior to PDT. The selective use of chest radiography, MRI, and ultrasound assessment prior to PDT can assist in the identification of patients unsuitable for this technique.

Percutaneous dilatational tracheostomy: haemorrhagic complications and the vascular anatomy of the anterior neck. A review based on 497 cases

In a series of 497 PDT procedures done in the intensive therapy unit at Morriston Hospital between 1992 and 1999, PDT was abandoned because of bleeding in 6 patients and was noted to be a problem in a further 18 cases (overall incidence 4.8%). In all cases, haemorrhage was successfully arrested. Surgical tracheostomy was necessary in 6 of these 24 cases. The source of bleeding in 4 of these patients was attributed to the inferior thyroid vein (2 cases), high brachiocephalic vein, and possibly an aberrant anterior jugular communicating vein, respectively. In one patient, the vessel presumed injured could not be identified and in another patient, bleeding was related to multi-system disease. We conclude that the risk of bleeding, although low, can be minimised if the operator maintains a high index of suspicion for aberrant vascular anatomy and investigates possible abnormalities with diagnostic ultrasound. Injury to vessels low in the neck can be reduced by not fully extending the neck and siting the stoma at the upper tracheal rings. The possibility of developing a tracheoarterial fistula is reduced if the stoma is situated above the 4th tracheal ring and fibreoptic endoscopy is used to confirm correct tracheostomy tube placement.

Population requirement for adult critical-care beds: a prospective quantitative and qualitative study

BACKGROUND

The provision of adult critical-care facilities is not based on a rational or scientific assessment of need. We aimed to define the numbers of adult critical-care beds required for a population of 500000.

METHODS

In five hospitals in Wales, UK, we classified patients who might be suitable for critical care in intensive-care or high-dependency units. On every 12th day for 1 calendar year, we counted the numbers of such patients admitted in a defined geographical population. A panel of ten intensivists made consensus decisions about whether individual patients were in the appropriate unit. The data were used to predict the numbers of beds and units required for the population.

FINDINGS

4058 patients were suitable for critical care, of whom 3028 lived in the study area. 56.4% were in general wards, 22.3% in high-dependency units, and 21.3% in intensive-care units. The mean risk of death was 22.0% and the in-hospital death rate 17.3%. According to the masked consensus, 41.3% of patients required high-dependency beds and 21.5% intensive-care beds. Mean risk of death increased from general wards (14.7%) to high-dependency units (19.2%) to intensive care (37.0%). Based on the consensus decisions, the average daily requirement of intensive-care beds was 21 and of high-dependency beds 43; to meet needs 95% of times required 30 and 55 beds, respectively, in a single critical-care unit.

INTERPRETATION

We estimated, scientifically, numbers of adult critical-care beds required to meet population needs. Studies are necessary periodically to track changes in admissions requiring critical care.

Nonproductive human immunodeficiency virus type 1 infection of human fetal astrocytes: independence from CD4 and major chemokine receptors

Human immunodeficiency virus type 1 (HIV-1) infection of the brain is associated with neurological manifestations both in adults and in children. The primary target for HIV-1 infection in the brain is the microglia, but astrocytes can also be infected. We tested 26 primary HIV-1 isolates for their capacity to infect human fetal astrocytes in culture. Eight of these isolates, independent of their biological phenotype and chemokine receptor usage, were able to infect astrocytes. Although no sustained viral replication could be demonstrated, the virus was recovered by coculture with receptive cells such as macrophages or on stimulation with interleukin-1beta. To gain knowledge into the molecular events that regulate attachment and penetration of HIV-1 in astrocytes, we investigated the expression of several chemokine receptors. Fluorocytometry and calcium-mobilization assay did not provide evidence of expression of any of the major HIV-1 coreceptors, including CXCR4, CCR5, CCR3, and CCR2b, as well as the CD4 molecule on the cell surface of human fetal astrocytes. However, mRNA transcripts for CXCR4, CCR5, Bonzo/STRL33/TYMSTR, and APJ were detected by RT-PCR. Furthermore, infection of astrocytes by HIV-1 isolates with different chemokine receptor usage was not inhibited by the chemokines SDF-1beta, RANTES, MIP-1beta, or MCP-1 or by antibodies directed against the third variable region or the CD4 binding site of gp120. These data show that astrocytes can be infected by primary HIV-1 isolates via a mechanism independent of CD4 or major chemokine receptors. Furthermore, astrocytes are potential carriers of latent HIV-1 and on activation may be implicated in spreading the infection to other neighbouring cells, such as microglia or macrophages.

Percutaneous dilatational tracheostomy under ultrasound guidance

Diagnostic ultrasound may be used to assess the suitability of patients for percutaneous dilatational tracheostomy (PDT) in the intensive care unit (ICU). It may identify patients unsuitable for PDT, prevent puncture of aberrant vessels, estimate the distance from the surface of the skin to the trachea, and ensure accurate placement of the needle in the trachea. We conclude that diagnostic ultrasound permits careful evaluation of patients for whom PDT is being considered, and adds to the safety of the procedure.

Protection from Lyme neuroborreliosis in nonhuman primates with a multiantigenic vaccine

In an effort to develop an effective and safe vaccine for lyme disease, rhesus macaques were injected with a multiantigenic preparation of Borrelia burgdorferi, strain N40. One month later animals were boosted before intradermal challenge with infectious B. burgdorferi. Challenges were performed at 1 and again at 5 months after the booster vaccination. Vaccinated and control nonvaccinated animals were monitored for development of systemic infection by measurement of serum anti-spirochetal antibodies by ELISA and Western blotting, and neurological involvement was monitored by testing of cerebrospinal fluid (CSF) and PCR analysis of central nervous system (CNS) tissue obtained at necropsy. Two control nonhuman primates (NHPs), given saline injections instead of vaccine and then challenged with B. burgdorferi, developed CSF pleocytosis, PCR positivity of the brain, and high levels of specific anti-B. burgdorferi antibody in the serum and CSF. Necropsy studies revealed widespread invasion of the CNS of one of these animals by the spirochete. In contrast, none of the four vaccinated animals developed evidence of invasion of the CNS after either of two challenge inoculations with infectious B. burgdorferi. In addition to resisting infection, no vaccinated animal demonstrated any untoward consequence of vaccination. These data demonstrate that a multiantigenic vaccine is effective in preventing systemic infection and lyme neuroboreliosis in NHPs and suggest that a successful vaccine could be developed in humans which would prevent lyme disease.

Pneumopericardium: an unusual cause for cardiac arrest

A 1-year-old boy breathing via a T-piece system and recovering from meningococcal septicaemia in the intensive care unit suffered a severe bout of coughing and developed bilateral pneumothoraces and tension pneumopericardium resulting in electromechanical dissociation and asystole. Conventional cardiopulmonary resuscitation and adrenaline boluses were unsuccessful. Administration of 20 ml.kg-1 of colloid and 3 mmol.kg-1 of sodium bicarbonate solutions produced instantaneous return of cardiac, output. The deleterious effects of cardiac tamponade appeared to decrease with increasing cardiac filling pressures. The patient was managed conservatively and he made a full recovery with no signs of residual neurological deficit.

Failure of cytarabine in progressive multifocal leukoencephalopathy associated with human immunodeficiency virus infection. AIDS Clinical Trials Group 243 Team

BACKGROUND

Progressive multifocal leukoencephalopathy affects about 4 percent of patients with the acquired immunodeficiency syndrome (AIDS), and survival after the diagnosis of leukoencephalopathy averages only about three months. There have been anecdotal reports of improvement but no controlled trials of therapy with antiretroviral treatment plus intravenous or intrathecal cytarabine.

METHODS

In this multicenter trial, 57 patients with human immunodeficiency virus (HIV) infection and biopsy-confirmed progressive multifocal leukoencephalopathy were randomly assigned to receive one of three treatments: antiretroviral therapy alone, antiretroviral therapy plus intravenous cytarabine, or antiretroviral therapy plus intrathecal cytarabine. After a lead-in period of 1 to 2 weeks, active treatment was given for 24 weeks. For most patients, antiretroviral therapy consisted of zidovudine plus either didanosine or stavudine.

RESULTS

At the time of the last analysis, 14 patients in each treatment group had died, and there were no significant differences in survival among the three groups (P=0.85 by the log-rank test). The median survival times (11, 8, and 15 weeks, respectively) were similar to those in previous studies. Only seven patients completed the 24 weeks of treatment. Anemia and thrombocytopenia were more frequent in patients who received antiretroviral therapy in combination with intravenous cytarabine than in the other groups.

CONCLUSIONS

Cytarabine administered either intravenously or intrathecally does not improve the prognosis of HIV-infected patients with progressive multifocal leukoencephalopathy who are treated with the antiretroviral agents we used, nor does high-dose antiretroviral therapy alone appear to improve survival over that reported in untreated patients.

Organ donation in the UK: a survey by a British Transplantation Society working party

BACKGROUND

During the past few years the number of organ donors in the UK has declined after a slow but steady increase during the 1980s. Concern about the decline led to a survey by the British Transplantation Society. The report of this survey highlighted a number of reasons for the decline and this manuscript presents and discuss the main items in the report.

METHODS

Comprehensive information relating to organ donation was obtained by a combination of structured interviews during visits to intensive care units (ICUs) and neurosurgical units, the use of detailed questionnaires sent to all UK ICUs, and from the register held by the United Kingdom Transplant Support Service Authority.

RESULTS

The information obtained highlighted a number of reasons for the decline in organ donor numbers and these are presented and discussed. The pool of potential donors is shrinking as death rates from road traffic accidents and intracranial haemorrhage decrease. Also the increasing use of modern imaging techniques has improved predictive ability in patients with severe brain damage with the result that more patients whose prognosis is assessed as hopeless are not treated by ventilation. Inadequacies both in intensive care unit bed provision and the resourcing of the transplant co-ordinator service were also thought to be important.

CONCLUSIONS

Eight recommendations have been made, covering ICU bed provision, neurosurgical provision, transplant surgical staffing, the transplant co-ordinator network, reimbursement to donor units, asystolic donation, live donor transplantation, and interventional ventilation.

Expression of tyrosine hydroxylase in an immortalized human fetal astrocyte cell line; in vitro characterization and engraftment into the rodent striatum

The use of primary human fetal tissue in the treatment of neurodegenerative disorders, while promising, faces several difficult technical and ethical issues. An alternative approach that would obviate these problems would be to use immortalized cell lines of human fetal central nervous system origin. An immortalized human fetal astrocyte cell line (SVG) has been established (45) and herein we describe the in vitro and in vivo characteristics of this cell line which suggest that it may be a useful vehicle for neural transplantation. The SVG cell line is vimentin, GFAP, Thy 1.1 and MHC class I positive, and negative for neurofilament and neuron specific enolase, consistent with its glial origin. To determine whether the cell line could be used as a drug delivery system, a cDNA expression vector for tyrosine hydroxylase was constructed (phTH/Neo) and stably expressed in the SVG cells for over 18 months as demonstrated by immunohistochemistry and Western blotting of the stable transfectants. HPLC analysis of the supernatant from these cells, termed SVG-TH, consistently found 4-6 pmol/ml/min of l-dopa produced with the addition of BH4 to the media. Furthermore, in cocultivation experiments with hNT neurons, PC-12 cells and primary rat fetal mesencephalic tissue, both the SVG and SVG-TH cells demonstrated neurotrophic potential, suggesting that they constituitively express factors with neuroregenerative potential. To determine the viability of these cells in vivo, SVG-TH cells were grafted into the striatum of Sprague-Dawley rats and followed over time. A panel of antibodies was used to unequivocally differentiate the engrafted cells from the host parenchyma, including antibodies to: SV40 large T antigen (expressed in the SVG-TH cells), human and rat MHC class 1, vimentin, GFAP, and tyrosine hydroxylase. While the graft was easily identified with the first week, over the course of a four week period of time the engrafted cells decreased in number. Concomittantly, rat CD4 and CD8 expression in the vicinity of the graft increased, consistent with xenograft rejection. When the SVG-TH cells were grafted to the lesioned striatum of a 6-hydroxydopamine lesioned rats, rotational behavior of the rat decreased as much as 80% initially, then slowly returned to baseline over the next four weeks, parallelling graft rejection. Thus, the SVG-TH cells can induce a functional recovery in an animal model of Parkinson's disease, however as a xenograft, the SVG cells are recognized by the immune system.

Expression of Tyrosine Hydroxylase in an Immortalized Human Fetal Astrocyte Cell Line; in Vitro Characterization and Engraftment into the Rodent Striatum

The use of primary human fetal tissue in the treatment of neurodegenerative disorders, while promising, faces several difficult technical and ethical issues. An alternative approach that would obviate these problems would be to use immortalized cell lines of human fetal central nervous system origin. An immortalized human fetal astrocyte cell line (SVG) has been established (45) and herein we describe the in vitro and in vivo characteristics of this cell line which suggest that it may be a useful vehicle for neural transplantation. The SVG cell line is vimentin, GFAP, Thy 1.1 and MHC class I positive, and negative for neurofilament and neuron specific enolase, consistent with its glial origin. To determine whether the cell line could be used as a drug delivery system, a cDNA expression vector for tyrosine hydroxylase was constructed (phTH/Neo) and stably expressed in the SVG cells for over 18 months as demonstrated by immunohistochemistry and Western blotting of the stable transfectants. HPLC analysis of the supernatant from these cells, termed SVG-TH, consistently found 4-6 pmol/ml/min of 1-dopa produced with the addition of BH4to the media. Furthermore, in cocultivation experiments with hNT neurons, PC-12 cells and primary rat fetal mesencephalic tissue, both the SVG and SVG-TH cells demonstrated neurotrophic potential, suggesting that they constituitively express factors with neuroregenerative potential. To determine the viability of these cells in vivo, SVG-TH cells were grafted into the striatum of Sprague-Dawley rats and followed over time. A panel of antibodies was used to unequivocally differentiate the engrafted cells from the host parenchyma, including antibodies to: SV40 large T antigen (expressed in the SVG-TH cells), human and rat MHC class 1, vimentin, GFAP, and tyrosine hydroxylase. While the graft was easily identified with the first week, over the course of a four week period of time the engrafted cells decreased in number. Concomittantly, rat CD4 and CD8 expression in the vicinity of the graft increased, consistent with xenograft rejection. When the SVG-TH cells were grafted to the lesioned striatum of a 6-hydroxydopamine lesioned rats, rotational behavior of the rat decreased as much as 80% initially, then slowly returned to baseline over the next four weeks, parallelling graft rejection. Thus, the SVG-TH cells can induce a functional recovery in an animal model of Parkinson's disease, however as a xenograft, the SVG cells are recognized by the immune system.

p53 dependent growth suppression by the c-Abl nuclear tyrosine kinase

Growth suppression by the Rb and p53 tumor suppressor proteins is mediated through effects on cell cycle regulatory proteins at the G1/S transition. Because overexpression of c-Abl induces G1 arrest in fibroblasts, we reasoned that c-Abl may also affect cell cycle proteins which regulate G1. We used fibroblasts containing disruptions of the Rb or p53 genes to genetically test the role of these proteins in c-Abl growth suppression. We find that c-Abl requires p53 but not Rb to suppress growth. c-Abl binds p53 in vitro and enhances p53 dependent transcription from a promoter containing p53 DNA binding sites. An Abl mutant which no longer binds p53 does not enhance p53 transcriptional activity and fails to suppress growth. These findings provide a novel link between a growth inhibitory tyrosine kinase and the p53 tumor suppressor protein.

Inoculation of nonhuman primates with the N40 strain of Borrelia burgdorferi leads to a model of Lyme neuroborreliosis faithful to the human disease

We injected rhesus macaques with a highly infective strain of Borrelia burgdorferi to assess whether experimentally inoculated nonhuman primates (NHPs) could serve as models of human Lyme neuroborreliosis (LNB). The animals developed biopsy-confirmed erythema migrans in the area of the inoculations. ELISA testing of sera revealed strong antibody reactivity to B burgdorferi antigens, and Western blotting showed that 16-, 22-, 31-, 34-, and 41-kd proteins of the spirochete were major antigens recognized by antibody. Culture and polymerase chain reaction (PCR) testing of serial CSF specimens revealed that chronic infection of the CNS occurred in all NHPs injected. CSF pleocytosis occurred concurrently with CNS infection. Brain MRI revealed intense meningeal inflammation in one NHP as manifested by gadolinium uptake by the dura at the base of the temporal lobes. All animals had measurable antibody in the CSF after invasion. These studies are the first to demonstrate that experimental LNB in NHPs is a reliable model faithful to the human disease, with spirochetal invasion of the subarachnoid space. This also is the first report of CSF samples positive by culture in experimental LNB. Inflammation in the CNS as manifested by CSF pleocytosis and MRI findings was also correlated with the presence of spirochetal DNA detected by PCR. These data support the hypothesis that the pathogenesis of LNB is associated with direct spirochetal invasion, and provide evidence that CNS involvement is more common than heretofore thought.

Munchausen's syndrome. A case presenting as asthma requiring ventilation

We present a variant of Munchausen's syndrome not previously described in which acute severe asthma is the presenting complaint. The clinical presentation is so extreme that the patient has received artificial ventilation on several occasions despite having had normal arterial blood gas values. The patient appears to be able to mimic the signs of severe respiratory distress by means of a protracted Valsalva manoeuvre, and all signs of acute asthma instantaneously disappear with sedation. Because of the chronic 'asthma', and the frequent dramatic acute episodes, the patient successfully claims invalidity benefit, and has done so for many years.

A rabbit model of Lyme neuroborreliosis: characterization by PCR, serology, and sequencing of the OspA gene from the brain

To test whether rabbits can serve as a model for Lyme neuroborreliosis (LNB), we injected New Zealand white rabbits with Borrelia burgdorferi. We obtained samples of blood and CSF for culture, polymerase chain reaction/hybridization (PCR/H), serology, and Western blot. We then sacrificed the rabbits 2 to 3 months after infection and removed organs for culture and PCR/H analysis. The rabbits developed an antibody response, characterized by ELISA and Western blot analysis, consistent with a systemic infection. PCR/H and blood cultures were negative, but PCR/H analysis of CSF in one rabbit was positive. Positive PCR/H analysis of organs from the rabbits was consistent with widespread dissemination of the organism. The most consistently infected organ was the CNS. To determine whether antigenic variation occurred at the genetic level, we compared the sequences of the OspA gene of both the infecting strain and the brain PCR product. The differences between the two were minimal, indicating that variation in the OspA gene did not occur during in vivo infection in the rabbit. Thus, rabbits, after intradermal inoculation with B burgdorferi, develop a chronic systemic infection in which the CNS is a consistent target. These data indicate that rabbits may be an excellent model of LNB.

Intensive Care Society's Acute Physiology and Chronic Health Evaluation (APACHE II) study in Britain and Ireland: a prospective, multicenter, cohort study comparing two methods for predicting outcome for adult intensive care patients

OBJECTIVE

To compare the ability of two methods--Acute Physiology and Chronic Health Evaluation (APACHE II) and Mortality Prediction Model (MPM)--to predict hospital outcome for a large group of intensive care patients from Britain and Ireland.

DESIGN

Prospective, multicenter, cohort study.

SETTING

Twenty-six general intensive care units in Britain and Ireland.

PATIENTS

A total of 8,724 patients admitted to the study.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Probabilities of hospital death for patients were estimated by applying APACHE II and MPM. Predicted risks of hospital death were compared with observed outcomes using four methods of assessing the overall goodness of fit. APACHE II performed better than MPM; the calibration curve for APACHE II lay closer to the line of perfect predictive ability. Lemeshow-Hosmer chi-square statistics were 81 and 57 for APACHE II, and 2515 and 1737 for MPM. The overall correct classification rate for APACHE II was 79%, and this classification rate was 74% for MPM, applying a decision criterion of 50%. The area under the receiver operating characteristic curve was 0.83 with APACHE II and 0.74 with MPM. Even after modifications to the MPM for the assessment of coma, the performance of APACHE II was superior.

CONCLUSIONS

APACHE II demonstrated a higher degree of overall goodness of fit, which was superior to MPM for groups of intensive care patients from Britain and Ireland.

[The role of modern imaging methods in the determination of childhood obesity]

Authors compare on the basis of their examinations carried out with modern imaging methods the ultrasound and computer tomography techniques in order to determine the fatty layer of the body surface and the visceral fatty quantities. Ultrasound is well usable and documentable to determine the fatty layer of the body surface, because it is not invasive. Computer tomography is more precise but it is a methodology involving x-ray burden. With this method, first of all the visceral fat quantity can be examined. Its application is indicated only in cardiovascular endangered obese children.

Temporal patterns of human immunodeficiency virus type 1 transcripts in human fetal astrocytes

Human immunodeficiency virus type 1 (HIV-1) infection of the developing central nervous system results in a dementing process in children, termed HIV-1-associated encephalopathy. Infection of astroglial elements of the pediatric nervous system has been demonstrated and suggests that direct infection of some astrocytes may contribute to the neurologic deficit. In this model, HIV-1 establishes a persistent state of infection in astrocytes, which can be reactivated by the cytokines tumor necrosis factor alpha (TNF-alpha) and interleukin 1 beta (IL-1 beta). To better understand the natural history of viral persistence in astroglial cells, we characterized infection at the transcriptional level. The most abundant viral transcript during the establishment of persistence was the subgenomic multiply spliced 2-kb message, similar to mononuclear cell models of HIV-1 latency. Following reactivation with TNF-alpha or IL-1 beta the multiply spliced 2-kb message remained the most abundant viral transcript, in contrast to infected mononuclear cells in which reactivation leads to the reemergence of the 9- and 4-kb transcripts. Further characterization of the persistent 2-kb transcript by PCR amplification of in vitro-synthesized viral cDNA showed that, in the absence of cytokine stimulation, the most abundant multiply spliced transcripts were the Nef- and Rev-specific messages. However, following cytokine stimulation, double- and triple-spliced Tat-, Rev-, and Nef-specific messages could be identified. Immunohistochemical staining demonstrated that, during viral persistence, astrocytes expressed Nef protein but few or no viral structural proteins. These results demonstrate that viral persistence in astrocytes at the transcriptional level is fundamentally different from that seen in mononuclear cells and could account for the virtual absence of astroglial expression of viral structural antigens in vivo.

Intensive Care Society's APACHE II study in Britain and Ireland--II: Outcome comparisons of intensive care units after adjustment for case mix by the American APACHE II method

OBJECTIVES

To compare outcome between intensive care units in Britain and Ireland both before and after adjustment for case mix with the American APACHE II method and to validate the American APACHE II method in Britain and Ireland.

DESIGN

Prospective, cohort study of consecutive admissions to intensive care units.

SETTING

26 general intensive care units in Britain and Ireland.

SUBJECTS

8796 admissions to the study intensive care units.

MAIN OUTCOME MEASURE

Death or survival at discharge from intensive care unit and hospital.

RESULTS

At discharge from both intensive care unit and hospital there was a greater than twofold variation in crude mortality between the 26 units. After adjustment for case mix, variations in mortality were still apparent. For four intensive care units the observed numbers of deaths were significantly different from the number predicted by the American APACHE II equation. The overall goodness of fit, or predictive ability, of the APACHE II equation for the British and Irish data was good, being only slightly inferior to that obtained when the equation was tested on the data from which it had been derived. When patients were grouped by various factors such as age and diagnosis, the equation did not adjust across the subgroups in a uniform manner.

CONCLUSIONS

The American APACHE II equation did not fit the British and Irish data. Use of the American equation could be of advantage or disadvantage to individual intensive care units, depending on the mix of patients treated.

Intensive Care Society's APACHE II study in Britain and Ireland--I: Variations in case mix of adult admissions to general intensive care units and impact on outcome

OBJECTIVES

To describe the extent of variation in the case mix of adult admissions to general intensive care units in Britain and Ireland and investigate the impact of such variation on outcome.

DESIGN

Prospective, cohort study of consecutive admissions to intensive care units.

SETTING

26 general intensive care units in Britain and Ireland.

SUBJECTS

9099 admissions to the intensive care units studied.

MAIN OUTCOME MEASURE

Death or survival at discharge before and after adjustment of case mix (age, history of chronic conditions, surgical status, diagnosis, and severity of illness) according to the APACHE II method.

RESULTS

Important differences in case mix were found, with large variations between the units. Hospital mortality was significantly associated with most of the case mix factors investigated.

CONCLUSIONS

Comparing crude death rates in hospital between intensive care units may be misleading indicators of performance. The collection of data on case mix needs to be standardised and differences in case mix adjusted for when comparing outcome between different intensive care units.

Regulation of the host range of human papovavirus JCV

Human papovavirus JCV is associated with the human demyelinating disorder progressive multifocal leukoencephalopathy. In tissue culture, the virus is largely restricted to growth in primary human fetal glial cell. In this study, we demonstrate two levels of regulation of the viral host range. Expression of the early JCV mRNA, which encodes the essential viral protein, large tumor antigen (T antigen), depends on recognition of the early enhancer/promoter elements by tissue-specific factors found in both human and rodent glial cells. In the presence of JCV T antigen, viral DNA replication requires a species-specific factor, presumably a component of DNA polymerase, which is found in a wide range of primate cells. We further demonstrate that simian virus 40 T antigen has sufficient homology to efficiently substitute for the analogous JCV protein in initiating viral DNA replication.

Intravenous anaesthesia with propofol and alfentanil. The influence of age and weight

Sixty healthy patients undergoing body surface surgery were anaesthetised with continuous infusions of propofol (200 micrograms/kg/minute) and alfentanil (0.25 microgram/kg/minute). Additional bolus doses of propofol (20 mg) were given if movement occurred. The incidence of patient movement in response to skin incision was significantly less in patients over 45 years of age than in those below 45 years (p less than 0.05). Maintenance dosage of propofol sufficient to abolish movement decreased with increasing age (p less than 0.001). Systolic blood pressure decreased in most patients over the first 10 minutes of anaesthesia and the magnitude of this decrease increased with age (p less than 0.0001). These parameters did not correlate strongly with body weight. Dose requirements of propofol are not the same for patients of all ages and strongly suggest that young and old patients should not be treated as a homogeneous group, either for investigative or clinical purposes.

Anaesthesia with ICI 35,868 monitored by the cerebral function analysing monitor (CFAM)

Ten patients who received bolus doses of the cremophor formulation of ICI 35,868 were monitored using the Cerebral Function Analysing Monitor (CFAM). Visual inspection of the traces obtained showed an easily recognizable pattern which was associated with an increasing depth of anaesthesia. Statistical analysis showed a high correlation between venous blood levels of the drug and changes recorded by the CFAM, although there was marked inter-patient variation. It is suggested that this variation is due to the effect of a time-lag between changes in drug concentration in the brain and venous blood.

Dose requirements of ICI 35,868 (propofol, 'Diprivan') in a new formulation for induction of anaesthesia

In order to avoid Cremophor-related reactions and reduce the incidence of pain on injection, diisopropylphenol (ICI 35,868; propofol) has been reformulated as an emulsion. One hundred and fifteen patients received an induction dose of propofol in the new formulation. The dose required to induce anaesthesia in 95% of healthy, unpremedicated patients was 2.5 mg/kg. Induction was associated with a degree of cardiovascular and respiratory depression. There were no adverse reactions although there were a number of minor side-effects. The incidence of pain on injection was low (3%) and the overall quality of induction was assessed as good or adequate in 92% of patients.

The cardiorespiratory effects of ICI 35 868 in patients with valvular heart disease

The haemodynamic effects at induction of anaesthesia with ICI 35 868 (1.5 mg/kg) are reported in ten patients with severe aortic or mitral valve disease. The average decrease of mean arterial pressure was 19.1% (p less than 0.01), heart rate decreased by 10% (p less than 0.01). Cardiac index and stroke volume index were both little changed but there were significant reductions in rate pressure product and left ventricular stroke work index (p less than 0.01).

Changes in cerebral electrical activity measured by the Cerebral Function Analysing Monitor following bolus injections of thiopentone

Seven premedicated patients were anaesthetized with thiopentone administered incrementally every 180 s while cerebral electrical activity was recorded with the Cerebral Function Analysing Monitor (CFAM). Arterial blood samples were collected at 40, 90 and 165 s after each bolus of thiopentone for the measurement of plasma total and bound thiopentone concentrations. The correlation between free thiopentone concentration and the CFAM representation of mean electroencephalogram (EEG) amplitude was -0.78 (P less than 0.001), excluding values following the first two boluses. Beta band percentage activity was inversely related (r = 0.70-0.90; P less than 0.05- less than 0.001) and delta directly related (r = 0.76-0.86; P less than 0.05- less than 0.001) to log of free thiopentone concentration, including all values. The closest correlations (beta, r = 0.88, P less than 0.001; delta r = 0.80, P less than 0.001) were found at 90 s after each bolus.

A comparison of midazolam and diazepam for intravenous sedation in dentistry

In a randomised cross-over trial, midazolam, a new water soluble benzodiazepine was compared with the conventional diazepam preparation (Valium) in 34 patients aged 16-45 years who were undergoing outpatient conservation dentistry. Midazolam hydrochloride (0.17 mg/kg) was virtually free of venous complications and showed advantages over diazepam (0.32 mg/kg) in providing a faster onset of action, higher incidence of amnesia and more rapid recovery. Midazolam produced a higher incidence of respiratory side effects hiccough (17.6% compared with 2.9%), brief apnoea following induction (11.8% compared with 5.8%), and airway obstruction during maintenance (8.8% compared with 0%). These may be related to the greater potency of midazolam as suggested by the smaller total dose required. Cardiovascular changes and operating conditions were similar.

The cerebral function analysing monitor (CFAM). A new microprocessor-based device for the on-line analysis of the EEG and evoked potentials

A description is given of a new microprocessor-based device for EEG analysis. The Cerebral Function Analysing Monitor (CFAM) analyses the EEG amplitude and frequency distribution. It produces a detailed plot of amplitude trends and separate traces of the percentage activity in each of the classical EEG frequency bands. Its clinical application was studied in five patients anaesthetized with thiopentone, and nitrous oxide and halothane in oxygen. During maintenance of anaesthesia, there was a gradual decrease in EEG amplitude and shift towards lower frequency EEG activity. Discontinuation of nitrous oxide resulted in a marked increase in EEG amplitude and an increase in alpha and beta band activity. Discontinuation of halothane resulted in smaller alterations in the CFAM trace. This device provides easily interpreted processed EEG data and merits further investigation.