Computational Identification of Tumor Anatomic Location Associated with Survival in 2 Large Cohorts of Human Primary Glioblastomas

BACKGROUND AND PURPOSE

Tumor location has been shown to be a significant prognostic factor in patients with glioblastoma. The purpose of this study was to characterize glioblastoma lesions by identifying MR imaging voxel-based tumor location features that are associated with tumor molecular profiles, patient characteristics, and clinical outcomes.

MATERIALS AND METHODS

Preoperative T1 anatomic MR images of 384 patients with glioblastomas were obtained from 2 independent cohorts (n = 253 from the Stanford University Medical Center for training and n = 131 from The Cancer Genome Atlas for validation). An automated computational image-analysis pipeline was developed to determine the anatomic locations of tumor in each patient. Voxel-based differences in tumor location between good (overall survival of >17 months) and poor (overall survival of <11 months) survival groups identified in the training cohort were used to classify patients in The Cancer Genome Atlas cohort into 2 brain-location groups, for which clinical features, messenger RNA expression, and copy number changes were compared to elucidate the biologic basis of tumors located in different brain regions.

RESULTS

Tumors in the right occipitotemporal periventricular white matter were significantly associated with poor survival in both training and test cohorts (both, log-rank P < .05) and had larger tumor volume compared with tumors in other locations. Tumors in the right periatrial location were associated with hypoxia pathway enrichment and PDGFRA amplification, making them potential targets for subgroup-specific therapies.

CONCLUSIONS

Voxel-based location in glioblastoma is associated with patient outcome and may have a potential role for guiding personalized treatment.

Timeliness of epidemiological outbreak investigations in peer-reviewed European publications, January 2003 to August 2013

Binary file ES_Abstracts_Final_ECDC.txt matches

Effect of a serogroup A meningococcal conjugate vaccine (PsA-TT) on serogroup A meningococcal meningitis and carriage in Chad: a community study [corrected]

BACKGROUND

A serogroup A meningococcal polysaccharide-tetanus toxoid conjugate vaccine (PsA-TT, MenAfriVac) was licensed in India in 2009, and pre-qualified by WHO in 2010, on the basis of its safety and immunogenicity. This vaccine is now being deployed across the African meningitis belt. We studied the effect of PsA-TT on meningococcal meningitis and carriage in Chad during a serogroup A meningococcal meningitis epidemic.

METHODS

We obtained data for the incidence of meningitis before and after vaccination from national records between January, 2009, and June, 2012. In 2012, surveillance was enhanced in regions where vaccination with PsA-TT had been undertaken in 2011, and in one district where a reactive vaccination campaign in response to an outbreak of meningitis was undertaken. Meningococcal carriage was studied in an age-stratified sample of residents aged 1-29 years of a rural area roughly 13-15 and 2-4 months before and 4-6 months after vaccination. Meningococci obtained from cerebrospinal fluid or oropharyngeal swabs were characterised by conventional microbiological and molecular methods.

FINDINGS

Roughly 1·8 million individuals aged 1-29 years received one dose of PsA-TT during a vaccination campaign in three regions of Chad in and around the capital N'Djamena during 10 days in December, 2011. The incidence of meningitis during the 2012 meningitis season in these three regions was 2·48 per 100,000 (57 cases in the 2·3 million population), whereas in regions without mass vaccination, incidence was 43·8 per 100,000 (3809 cases per 8·7 million population), a 94% difference in crude incidence (p<0·0001), and an incidence rate ratio of 0·096 (95% CI 0·046-0·198). Despite enhanced surveillance, no case of serogroup A meningococcal meningitis was reported in the three vaccinated regions. 32 serogroup A carriers were identified in 4278 age-stratified individuals (0·75%) living in a rural area near the capital 2-4 months before vaccination, whereas only one serogroup A meningococcus was isolated in 5001 people living in the same community 4-6 months after vaccination (adjusted odds ratio 0·019, 95% CI 0·002-0·138; p<0·0001).

INTERPRETATION

PSA-TT was highly effective at prevention of serogroup A invasive meningococcal disease and carriage in Chad. How long this protection will persist needs to be established.

FUNDING

The Bill & Melinda Gates Foundation, the Wellcome Trust, and Médecins Sans Frontères.

Inferring disease-related pathways using a probabilistic epistasis model

We present a probabilistic model called a Joint Intervention Network (JIN) for inferring interactions among a chosen set of regulator genes. The input to the method are expression changes of downstream indicator genes observed under the knock-out of the regulators. JIN can use any number of perturbation combinations for model inference (e.g. single, double, and triple knock-outs). RESUITS/CONCLUSIONS: We applied JIN to a Vibrio cholerae regulatory network to uncover mechanisms critical to its environmental persistence. V. cholerae is a facultative human pathogen that causes cholera in humans and responsible for seven pandemics. We analyzed the expression response of 17 V. cholerae biofilm indicator genes under various single and multiple knock-outs of three known biofilm regulators. Using the inferred network, we were able to identify new genes involved in biofilm formation more accurately than clustering expression profiles.

Quality of in-hospital care for adults with acute bacterial meningitis: a national retrospective survey

BACKGROUND

Most adults with bacterial meningitis and meningococcal septicaemia present to junior doctors who have limited experience of these conditions. In contrast to paediatric practice, data from industrialized countries with regard to current hospital management practice are lacking.

AIM

To examine whether current practice meets recommended standards in hospital management of community-acquired bacterial meningitis and meningococcal septicaemia among adults.

DESIGN

National audit of medical records.

METHODS

We conducted a survey of all patients with acute bacterial meningitis and meningococcal septicaemia admitted to 18 randomly selected acute hospitals in England and Wales between 1 January 2000 and 31 December 2001. All stages of care, including pre-hospital management, initial hospital assessment, record keeping, and ongoing hospital and public health management, were assessed.

RESULTS

We identified 212 cases of bacterial meningitis and meningococcal septicaemia; 190 cases remained in the final analysis. Clinical record keeping did not meet acceptable standards in 33% of cases. Parenteral antibiotics were given within 1 h of hospital arrival in 56% of cases, increasing to 79% among those with an initial differential diagnosis that included bacterial meningitis or meningococcal septicaemia. A full severity of illness assessment was made in 27%. The quality of clinical practice varied widely between hospitals. This was most pronounced in the timeliness of consultant review (p < 0.0005).

DISCUSSION

The quality of adult clinical practice for bacterial meningitis and meningococcal septicaemia needs improvement. This study provides a tool for developing targeted interventions to improve quality of care and outcome among adults with life-threatening infections, both in the UK and in other countries.

Case-control study for risk factors for Q Fever in southwest England and Northern Ireland

Q fever (Coxiella burnetti) is thought to account for 1% (700 cases) of community acquired pneumonia in the United Kingdom each year, and can result in serious complications such as endocarditis. Although outbreaks have frequently been reported worldwide, the causes are often not clearly identified and there have been few studies of risk factors in sporadic cases. We conducted a matched case-control study. Cases of acute Q fever in people aged over 15 years in southwest England and Northern Ireland were identified from January 2002 to December 2004. Controls were matched for age, sex and the general practice at which they were registered. Questionnaires asking about contact with animals, and leisure and work activities, were posted to cases and controls. Questionnaires were completed by 39/50 (78%) of the cases and 90/180 (50%) of the controls. In the single variable analysis, occupational exposure to animals or animal products was the only risk factor associated with cases at the 5% level (P=0.05, odds ratio (OR) 3.4). Long term illness appeared to be significantly protective (P=0.03, OR 0.3). In multivariable analysis the strength of association between occupational exposure and illness remained high (OR 3.6, 95% confidence interval (CI) 0.9 to 14.8) and smoking emerged as a possible risk factor. This is the first case-control study to identify occupational exposure to animals or animal products as the most likely route of infection in sporadic cases as opposed to outbreaks.

Changing epidemiology of bacterial meningitis among adults in England and Wales 1991-2002

We examined the epidemiology of community-acquired bacterial meningitis among adults in England and Wales between 1991 and 2002. Among 3169 cases, meningococcal infection was predominant among young adults and pneumococcal meningitis among older adults. Whilst infection due to most causes decreased, the incidence of tuberculous (TB) meningitis doubled over the 12 years. The mortality rate among meningococcal and pneumococcal infections fell from 0.45/10(5) to 0.31/10(5) (P=0.0001). This study demonstrates important changes in the epidemiology of bacterial meningitis among UK adults. Improvements in clinical management, childhood vaccination programmes and the re-emergence of tuberculosis are likely to be drivers of these changes.

Cryptosporidium outbreak linked to interactive water feature, UK: importance of guidelines

A need for national guidelines relating to interactive water features was highlighted following three outbreaks of cryptosporidiosis in the United Kingdom, all of which were related to public water features. In August 2003 the Health Protection Agency South West of England was notified of an outbreak of cryptosporidiosis associated with an interactive water feature designed for water play within an adventure park. The water feature was implicated following samples with a high coliform count and the presence of faecal coliforms. A case was defined as any child (younger than 16 years of age) who had visited the park during August and who subsequently had gastrointestinal symptoms and a faecal sample positive for cryptosporidium. Seventy one children were identified in the cohort. This outbreak of cryptosporidiosis was characterised by a very high attack rate (89%), relatively severe in duration (median 8 days) and had a relatively high hospital admission (16% of cases). The epidemic curve was consistent with a point source of infection, which corresponded to the date 80% of the cohort visited the park. This outbreak has similarities to two other cryptosporidiosis outbreaks reported in England in 2003 that involved public water features. These outbreaks raise issues about the operation and maintenance of water-based recreational attractions that very often involve children. The paper reflects on the basic control measures that can be taken and highlights the need for guidelines, especially since such attractions are becoming increasingly common. The Pool Water Treatment Advisory Group in United Kingdom has now produced guidelines.

HTLV-1 induced molecular mimicry in neurological disease

As a model for molecular mimicry, we study patients infected with human T-lymphotropic virus type 1 (HTLV-1) who develop a neurological disease called HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), a disease with important biological similarities to multiple sclerosis (MS) (Khan et al. 2001; Levin et al. 1998, 2002a; Levin and Jacobson 1997). The study of HAM/TSP, a disease associated with a known environmental agent (HTLV-1), allows for the direct comparison of the infecting agent with host antigens. Neurological disease in HAM/TSP patients is associated with immune responses to HTLV-1-tax (a regulatory and immunodominant protein) and human histocompatibility leukocyte antigen (HLA) DRB1*0101 (Bangham 2000; Jacobson et al. 1990; Jeffery et al. 1999; Lal 1996). Recently, we showed that HAM/TSP patients make antibodies to heterogeneous nuclear ribonuclear protein A1 (hnRNP A1), a neuron-specific autoantigen (Levin et al. 2002a). Monoclonal antibodies to tax cross-reacted with hnRNP A1, indicating molecular mimicry between the two proteins. Infusion of cross-reactive antibodies with an ex vivo system completely inhibited neuronal firing indicative of their pathogenic nature (Kalume et al. 2004; Levin et al. 2002a). These data demonstrate a clear link between chronic viral infection and autoimmune disease of the central nervous system (CNS) in humans and, we believe, in turn will give insight into the pathogenesis of MS.

Cryptosporidium outbreak linked to interactive water feature, UK: importance of guidelines

A need for national guidelines relating to interactive water features was highlighted following three outbreaks of cryptosporidiosis in the United Kingdom, all of which were related to public water features. In August 2003 the Health Protection Agency South West of England was notified of an outbreak of cryptosporidiosis associated with an interactive water feature designed for water play within an adventure park. The water feature was implicated following samples with a high coliform count and the presence of faecal coliforms. A case was defined as any child (younger than 16 years of age) who had visited the park during August and who subsequently had gastrointestinal symptoms and a faecal sample positive for cryptosporidium. Seventy one children were identified in the cohort. This outbreak of cryptosporidiosis was characterised by a very high attack rate (89%), relatively severe in duration (median 8 days) and had a relatively high hospital admission (16% of cases). The epidemic curve was consistent with a point source of infection, which corresponded to the date 80% of the cohort visited the park. This outbreak has similarities to two other cryptosporidiosis outbreaks reported in England in 2003 that involved public water features. These outbreaks raise issues about the operation and maintenance of water-based recreational attractions that very often involve children. The paper reflects on the basic control measures that can be taken and highlights the need for guidelines, especially since such attractions are becoming increasingly common. The Pool Water Treatment Advisory Group in United Kingdom has now produced guidelines.

Case-control study for risk factors for Q fever in southwest England and Northern Ireland

Q fever (Coxiella burnetti) is thought to account for 1% (700 cases) of community acquired pneumonia in the United Kingdom each year, and can result in serious complications such as endocarditis. Although outbreaks have frequently been reported worldwide, the causes are often not clearly identified and there have been few studies of risk factors in sporadic cases. We conducted a matched case-control study. Cases of acute Q fever in people aged over 15 years in southwest England and Northern Ireland were identified from January 2002 to December 2004. Controls were matched for age, sex and the general practice at which they were registered. Questionnaires asking about contact with animals, and leisure and work activities, were posted to cases and controls. Questionnaires were completed by 39/50 (78%) of the cases and 90/180 (50%) of the controls. In the single variable analysis, occupational exposure to animals or animal products was the only risk factor associated with cases at the 5% level (P=0.05, odds ratio (OR) 3.4). Long term illness appeared to be significantly protective (P=0.03, OR 0.3). In multivariable analysis the strength of association between occupational exposure and illness remained high (OR 3.6, 95% confidence interval (CI) 0.9 to 14.8) and smoking emerged as a possible risk factor. This is the first case-control study to identify occupational exposure to animals or animal products as the most likely route of infection in sporadic cases as opposed to outbreaks.

Invasive group A streptococcal disease: should close contacts routinely receive antibiotic prophylaxis?

Group A streptococci (Streptococcus pyogenes) causes a wide range of illnesses from non-invasive disease--eg, pharyngitis--to more severe invasive infections--eg, necrotising fasciitis and toxic shock-like syndrome. There remains uncertainty about the risk of secondary cases of invasive disease occurring among close contacts of an index case and how best to manage that risk. We do not consider that currently available evidence justifies the routine administration of chemoprophylaxis to close contacts. We suggest that the appropriate response should be to routinely inform all household contacts of a patient with invasive group A streptococcal disease about the clinical manifestations of invasive disease and to seek immediate medical attention if they develop such symptoms.

Clusters of meningococcal disease in school and preschool settings in England and Wales: what is the risk?

AIMS

To assess the risk of further cases in educational settings in order to inform policy on managing cases and clusters of meningococcal disease.

METHODS

Between 1 April 1995 and 31 March 2001, surveillance in preschool and school settings in England and Wales identified 114 clusters of meningococcal disease. Twenty clusters were reported in preschool settings, 43 in primary, 46 in secondary, and five in independent schools. Seventy three clusters (64%) consisted of two or more confirmed cases, of which 30 had two or more serogroup C cases. Following the introduction of the national meningococcal serogroup C vaccination programme in 1999, no serogroup C clusters were observed between April 2000 and March 2001.

RESULTS

The relative risk of further cases in the four weeks after a single case compared with the background rate was raised in all settings, ranging from RR 27.6 (95% CI 15.2 to 39.9) in preschool settings to RR 3.6 (95% CI 2.5 to 4.6) in secondary schools. Absolute risk estimates ranged from 70/100 000 in preschool settings to 3.0/100 000 in secondary schools. The relative risk of clustering was similar for serogroup B and C strains. Most (68%) second cases occurred within seven days of the first case.

CONCLUSIONS

Although there was a higher risk of further cases of meningococcal disease in schools and especially in preschool settings, it is not known whether widespread antibiotic use after single cases reduces risk of further cases and if there is a real risk of harm. Evidence of risk reduction is needed to inform public health policy.

Efficacy of modified recombinant type II collagen in modulating autoimmune arthritis

OBJECTIVE

Previous studies have shown that an analog peptide of the immunodominant T cell determinant of type II collagen (CII), i.e., CII(256-276)(N(263), D(266)), was able to suppress the immune response to CII and the development of arthritis in DR1-transgenic mice. The present study tested the hypothesis that introduction of the same amino acid substitutions into full-length CII might improve the efficacy of the mutant collagen in achieving suppression of autoimmune arthritis.

METHODS

Using recombinant technology, full-length CII was modified, while the native conformation was retained. Two point mutations were introduced within the immunodominant T cell determinant to convert the F(263) to N and E(266) to D, using a baculovirus expression system that has previously been utilized in the production of recombinant CII (rCII).

RESULTS

The mutant rCII(N(263), D(266)) was capable of reducing the incidence and severity of arthritis as well as the antibody response to CII when administered to DR1-transgenic mice that display susceptibility to collagen-induced arthritis. More importantly, it was significantly more effective than the synthetic analog peptide, CII(256-276)(N(263), D(266)). Its mechanism of suppression may be explained by the secretion of predominantly Th2 cytokines by the T cells immunized with rCII(N(263), D(266)). Administration of rCII(N(263), D(266)) was ineffective in suppressing arthritis in IL4(-/-) mice, suggesting that the profound suppressive effects of rCII(N(263), D(266)) were mediated through the production of interleukin-4.

CONCLUSION

These findings describe a promising specific immunotherapy for patients with DR1-mediated autoimmunity to CII.

Investigation of an outbreak of E. coli O157 infections associated with a trip to France of schoolchildren from Somerset, England

A retrospective cohort study was conducted after 2 confirmed and 8 probable cases of VTEC 0157 occurred in a schoolgroup from Somerset following a trip to France. The strain of the 2 confirmed cases was vero-cytotoxin type 2, phage type 34. Despite its low statistical power due to small numbers, this study suggested the most likely vehicle of infection was cucumber salad (crude RR=4.3, 95%CI [0.6-29], adjusted OR=107, 95%CI indeterminate, p=0.08). The cucumbers were purchased from Belgium but it was not possible to trace them back to source. The international nature of this outbreak emphasises the importance of close collaboration between organisations in the management of outbreaks, of ensuring international standards in food safety, and of agreeing a common standard in VTEC typing across Europe.

Socioeconomic inequality and meningococcal disease

Incidence of meningococcal disease was associated with socioeconomic deprivation across a rural English region. In young children the incidence was twice as high in the most deprived compared with the least deprived electoral wards. By addressing social inequalities the incidence of this serious infection could be reduced.

Enhanced surveillance scheme for suspected meningococcal disease in five regional health authorities in England: 1998

Enhanced surveillance of meningococcal disease (ESMD) began in five English regions on 1st January 1998. The aims of the scheme were to obtain accurate incidence data and develop a robust surveillance system with which to monitor the impact of a new meningococcal serogroup C conjugate vaccine. During 1998, 2,314 suspected cases of meningococcal disease were identified. The majority (84%) was classified as invasive meningococcal disease, with infection of N. meningitidis confirmed in 66%. Sixteen per cent of suspected cases were subsequently given an alternative diagnosis. Age differences between those classified as meningococcal disease and those not, implied a higher index of suspicion of meningococcal disease in younger children. Regions with high rates of meningococcal disease were due to a higher rate of serogroup C. ESMD increased ascertainment of meningococcal disease and deaths. Cases were 34% greater than identified through statutory notifications, an additional 6.8% confirmed infections were identified than were reported to the PHLS Meningococcal Reference Unit (MRU) and deaths were 24% greater than death registrations. These data were used to inform the national meningococcal serogroup C conjugate vaccination programme in England and Wales. In 1999 ESMD was extended to all regions of England, Wales and Northern Ireland.

The role of IL-4 in regulation of murine collagen-induced arthritis

Collagen-induced arthritis (CIA) is a murine model of autoimmune-mediated polyarthritis. CIA can be prevented by the administration (intravenously) of CII, inducing regulatory CD4+ T cells which produce Th2 cytokines. However, the relative importance of IL-4 in suppressing arthritis remains unclear. To address this question, a neutralizing monoclonal antibody to IL-4 was given to mice treated with tolerized, CII-specific cells. The antibody significantly reversed the expected suppression of arthritis. Moreover, CII administered intravenously to DBA/1 IL4-/- mice (developed by backcrossing C57B1/6 IL4-/- to wild-type DBA/1 mice) was completely ineffective in suppressing disease. These data support the importance of IL-4 in the regulation of autoimmune arthritis. Compensatory increases in mRNA message for other Th2 cytokines were observed, but they did not restore suppression of arthritis. Antibodies to CII, mostly IgG2a, were increased in IL4-/- mice. These studies represent a unique opportunity to analyze the role of IL-4 and its absence on an autoimmune murine model of arthritis.

Risk of laboratory-acquired meningococcal disease

Five probable secondary cases of meningococcal disease were identified in microbiology laboratory workers in England and Wales during a 15-year period. All cases had prepared suspensions of Neisseria meningitidis outside a safety cabinet upto seven days before onset of illness. Relative risk in laboratory workers compared with the background adult population was 184 (95% CI 60-431). In view of the potentially serious outcome from this infection, a safety cabinet should always be used when preparing or working with suspensions of meningococci. Vaccination policy for microbiology laboratory workers should be reviewed.

Improved rate of isolation of Neisseria meningitidis by direct plating of pharyngeal swabs

Culturing of pharyngeal swabs for Neisseria meningitidis is an important clinical and epidemiological tool. Routine methods include direct plating onto solid medium or later plating in the laboratory. A comparison of these methods used with 490 high school students found a significantly higher carriage rate with direct plating (11.8 versus 6.1%; P < 0.001).

Anti-Human type II collagen CD19+ B cells are present in patients with rheumatoid arthritis and healthy individuals

OBJECTIVE

To determine the frequency and repertoire of CD19+ B cells capable of producing antibodies reactive to type II collagen (CII) in synovial fluid (SF) and peripheral blood (PB) of patients with rheumatoid arthritis (RA) and PB of healthy control individuals.

METHODS

CD19+ B cells were isolated and activated to secrete immunoglobulins (Ig) by CD4+ T cells. Frequencies of anti-CII B cells were determined by limiting dilution analysis. The isotype and cross-reactivity of the antibodies produced were determined by ELISA.

RESULTS

SF and PB from 5 patients and PB from 4 healthy controls were analyzed. Anti-CII CD19+ B cells were identified in all samples tested. In the RA SF, the percentage of activated B cells reactive to human CII was significantly higher than in the PB of patients with RA (p < 0.05) or controls (p < 0.01). A majority of anti-human CII B cells from patients' SF secreted IgG isotype, whereas most anti-human CII B cells in PB of patients and controls secreted IgM. The anti-CII B cells, regardless of source, are usually reactive to both native and denatured human CII, to different types of human collagens, and to type II collagens from different species.

CONCLUSION

Anti-CII CD19+ B cells responsive to activated helper T cells are present in both patients with RA and healthy individuals. However, these B cells, especially those secreting the IgG isotype, accumulate in the inflamed joints of RA patients.

A gene expression map for Caenorhabditis elegans

We have assembled data from Caenorhabditis elegans DNA microarray experiments involving many growth conditions, developmental stages, and varieties of mutants. Co-regulated genes were grouped together and visualized in a three-dimensional expression map that displays correlations of gene expression profiles as distances in two dimensions and gene density in the third dimension. The gene expression map can be used as a gene discovery tool to identify genes that are co-regulated with known sets of genes (such as heat shock, growth control genes, germ line genes, and so forth) or to uncover previously unknown genetic functions (such as genomic instability in males and sperm caused by specific transposons).

Preventing secondary meningococcal disease in health care workers: recommendations of a working group of the PHLS meningococcus forum

Based on new data on the risk of secondary meningococcal disease in health care workers, a review of published cases and an assessment of the available evidence, a change to the recommendations for giving chemoprophylaxis to health care workers in England and Wales is proposed. Previous guidance recommended prophylaxis only for those who had given mouth to mouth resuscitation. Chemoprophylaxis is now recommended for health care workers whose mouth or nose has been directly and heavily exposed to respiratory droplets/secretions from a case of meningococcal disease around the time of hospital admission. Wearing surgical face masks is encouraged to reduce risk of exposure.

Prevention of meningococcal infection in laboratory workers--an audit of practice in England and Wales

A survey of clinical microbiology laboratories in England and Wales found that in 12% of laboratories a class 1 microbiological safety cabinet was not always used for manipulating suspensions of live meningococci. The recommendation that a safety cabinet should always be used for such purposes needs reiteration and implementation.

Risk factors for meningococcal disease in university halls of residence

A retrospective ecological study was undertaken to identify social and environmental factors associated with increased incidence of meningococcal disease in university halls of residence. A standardized questionnaire was sent to UK universities and colleges of higher education outside London, for distribution to halls containing at least 50 students. Incidence rate ratios of invasive meningococcal disease were obtained for a range of social and environmental variables. Multi-variable Poisson regression analysis identified 3 factors as having a strong association: a high proportion of first year undergraduate residents (P = 0.0008), decreasing smokiness of the hall bar (P < 0.0001), and opening of hall bar before 1990 (P = 0.0001). The inverse relationship between disease incidence and smokiness of bars was an unexpected finding, and may be due to confounding factors. Universities should continue to promote awareness of meningococcal disease, encourage vaccination of first year students against serogroup C disease, and where appropriate, take measures to reduce overcrowding.

Regulation of cartilage collagenase by doxycycline

OBJECTIVE

To investigate the ability of doxycycline to modulate collagenases, cytokines, and cytokine receptors in chondrocytes from osteoarthritic (OA) cartilage.

METHODS

Chondrocytes were isolated from human OA cartilage and treated with doxycycline. Synthesis of collagenases, cytokines, and cytokine receptors was quantified by Northern and Western blot analysis and RNase protection assay.

RESULTS

We observed significant inhibition of matrix metalloproteinases (MMP-1) and MMP-13 mRNA and protein production by chondrocytes, isolated from OA cartilage, after treatment with doxycycline. The decrease in collagenase protein level paralleled a decrease in mRNA for these enzymes, suggesting a transcriptional/posttranscriptional level of control. In addition, treatment with 10 microg/ml doxycycline resulted in 2.2-fold upregulation of transforming growth factor (TGF-beta3) and a significant decrease of interleukin 1alpha (IL-1alpha), IL-1beta, and IL-6 mRNA. Upregulation of TGF-beta RI and TGF-beta RII was also detected. These cytokines are known to affect collagenase expression and could contribute to inhibition of MMP-1 and MMP-13 production by OA chondrocytes. A decrease in IL-1alpha, IL-1beta, and IL-6 would reduce stimulation of MMP production, while an increase in TGF-83 would lead to downregulation of local proinflammatory cytokine production as well as of the collagenases themselves.

CONCLUSION

Our findings show that a decrease in MMP-1 and MMP-13 collagenase production by articular chondrocytes in response to treatment with doxycycline can be explained by a regulatory effect of doxycycline on the production of cytokine and cytokine receptors.

Accumulation of T cells reactive to type II collagen in synovial fluid of patients with rheumatoid arthritis

OBJECTIVE

To determine if type II collagen (CII) reactive T lymphocytes selectively accumulate in the inflamed joint of patients with rheumatoid arthritis (RA) and to study the specificity of the CII reactive cells.

METHODS

Synovial fluid (SF) cells or peripheral blood lymphocytes were cultured with interleukin 2 (IL-2) for 24 h and then cultured at limiting dilution concentrations in the presence of filler cells and IL-2. The outgrowing cell lines were screened for their responses to CII. The percentages of the CII reactive T cells from SF were compared with those from peripheral blood of patients with RA. The CII reactive T cell lines were tested for their responses to different types of collagen.

RESULTS

CII reactive T cell lines were identified in the SF of 3 RA patients; the frequencies were 5.0% (11/219), 3.7% (5/134), and 3.5% (3/86), respectively. In contrast, none of CII-specific T cell lines were identified in peripheral blood of the patients. The T cell lines recognized both human and bovine CII and, to a lesser extent, type I collagen.

CONCLUSION

CII reactive T cells are present in high frequency in the inflamed joint of patients with RA, where they may play an important role in the pathogenesis of RA.

Immunogenicity and arthritogenicity of recombinant CB10 in B10.RIII mice

Two major T cell determinants are recognized by I-Ar-specific T cells in CII, the immunodominant CII610-618 (GPAGT AGA R) within CB10 and the subdominant CII445-453 (GPAGP AGE R) within CB8. Although the determinants differ by only two residues, CB8 is capable of inducing collagen-induced arthritis (CIA), while CB10 is not. We, therefore, investigated the structural differences between the two determinants that are critical to inducing arthritis. When the CB10 determinant was mutated to that of CB8 using recombinant techniques, the resulting mutant rCB10T614P,A617E product became arthritogenic. Conversely, when the CB8 determinant was mutated to that of CB10, the resulting mutant CB8P449T,E452A was no longer arthritogenic. Comparison of the epitope specificity of the autoantibodies induced by wild-type CB10 and mutant rCB10T614P, A617E revealed no qualitative differences. T cells from mice immunized with either CB10 or mutant rCB10 produced predominantly Th1 cytokines when cultured with the immunizing Ag. In contrast, when cultured with mouse CII, T cells from mice immunized with the nonarthritogenic CB10 produced predominantly Th2 (IL-4 and IL-10) cytokines whereas the arthritogenic mutant rCB10 induced predominantly Th1 (IFN-gamma) cytokines. We conclude that the T cell cytokine response most critical for the induction of CIA is that induced against the corresponding homologous murine T cell determinant and, further, that the structural differences between the T cell determinants in CB8 and -10 are important in breaking self tolerance and inducing autoimmune response.

Principal components analysis to summarize microarray experiments: application to sporulation time series

A series of microarray experiments produces observations of differential expression for thousands of genes across multiple conditions. It is often not clear whether a set of experiments are measuring fundamentally different gene expression states or are measuring similar states created through different mechanisms. It is useful, therefore, to define a core set of independent features for the expression states that allow them to be compared directly. Principal components analysis (PCA) is a statistical technique for determining the key variables in a multidimensional data set that explain the differences in the observations, and can be used to simplify the analysis and visualization of multidimensional data sets. We show that application of PCA to expression data (where the experimental conditions are the variables, and the gene expression measurements are the observations) allows us to summarize the ways in which gene responses vary under different conditions. Examination of the components also provides insight into the underlying factors that are measured in the experiments. We applied PCA to the publicly released yeast sporulation data set (Chu et al. 1998). In that work, 7 different measurements of gene expression were made over time. PCA on the time-points suggests that much of the observed variability in the experiment can be summarized in just 2 components--i.e. 2 variables capture most of the information. These components appear to represent (1) overall induction level and (2) change in induction level over time. We also examined the clusters proposed in the original paper, and show how they are manifested in principal component space. Our results are available on the internet at http:¿www.smi.stanford.edu/project/helix/PCArray .

Pattern recognition of genomic features with microarrays: site typing of Mycobacterium tuberculosis strains

Mycobacterium tuberculosis (M. tb.) strains differ in the number and locations of a transposon-like insertion sequence known as IS6110. Accurate detection of this sequence can be used as a fingerprint for individual strains, but can be difficult because of noisy data. In this paper, we propose a non-parametric discriminant analysis method for predicting the locations of the IS6110 sequence from microarray data. Polymerase chain reaction extension products generated from primers specific for the insertion sequence are hybridized to a microarray containing targets corresponding to each open reading frame in M. tb. To test for insertion sites, we use microarray intensity values extracted from small windows of contiguous open reading frames. Rank-transformation of spot intensities and first-order differences in local windows provide enough information to reliably determine the presence of an insertion sequence. The nonparametric approach outperforms all other methods tested in this study.

Prostaglandin E2 selectively inhibits human CD4+ T cells secreting low amounts of both IL-2 and IL-4

PGE2 is a potent inflammatory mediator with profound immune regulatory actions. The present study examined the effects of PGE2 on the activation/proliferation of CD4+ T cells using 37 cloned CD4+ T cell lines. Ten T cell clones sensitive to PGE2 and 10 T cell clones resistant to PGE2, as measured by proliferation in response to anti-CD3 Ab, were selected for comparison. It was found that the PGE2-sensitive T cells were characterized by low production (<200 pg/ml) of both IL-2 and IL-4, while PGE2-resistant T cells secreted high levels (>1000 pg/ml) of IL-2, IL-4, or both. The roles of IL-2 and IL-4 were confirmed by the finding that addition of exogenous lymphokines could restore PGE2-inhibited proliferation, and PGE2-resistant Th1-, Th2-, and Th0-like clones became PGE2 sensitive when IL-2, IL-4, or both were removed using Abs specific for the respective lymphokines. In addition, we showed that the CD45RA expression in PGE2-sensitive T cells was significantly lower than that in PGE2-resistant cells (mean intensity, 1.2 +/- 0.6 vs 7.8 +/- 5.7; p = 0.001). In contrast, CD45RO expression in PGE2-sensitive T cells was significantly higher that that in PGE2-resistant cells (mean intensity, 55.7 +/- 15.1 vs 33.4 +/- 12.9; p = 0.02). In summary, PGE2 predominantly suppressed CD45RA-RO+ CD4+ T cells with low secretion of both IL-2 and IL-4.

Meningococcal disease at the University of Southampton: outbreak investigation

In October 1997, an outbreak of meningococcal disease occurred at the University of Southampton. All six cases were first year students living in halls of residence. Microbiological characterization of case and carrier strains, case interviews, and a meningococcal carriage prevalence survey were used to investigate the outbreak. Five cases were due to serogroup C strains, one case was unconfirmed. Serotyping did not distinguish between the strains but gene sequencing permitted identification of two distinct strains in the outbreak. Although none of the cases was known to each other, three had attended the same nightclub one evening 3-4 days before illness. Meningococcal carriage rates in undergraduates were within the range expected (147/587, 25%), but no carriers of outbreak strains were identified in this sample. The findings suggest that in communities with a high degree of social interaction, the introduction of highly virulent meningococcal strains may result in enhanced transmission with clustering of cases.

Practical guidelines for responding to an outbreak of meningococcal disease among university students based on experience in Southampton

Six students at the University of Southampton developed meningococcal disease in October 1997, five of them with confirmed serogroup C infections, and three died. The outbreak had major organisational and financial implications for the agencies involved. Detailed planning and good working relationships with the management of higher educational institutions can prove invaluable in such situations. This paper summarises the management of the outbreak in Southampton and presents recommendations based on our experience.

Molecular definition and characterization of recombinant bovine CB8 and CB10: immunogenicity and arthritogenicity

Theoretically, the ability to produce recombinant type II collagen (CII) peptide fragments in a prokaryotic expression system would be extremely useful for preparing adequate amounts of CII peptides suitable for therapeutic uses. Bacteria do not contain the enzymes involved in the extensive posttranslational modifications that occur during the biosynthesis of CII, such as the hydroxylation of prolyl and lysyl residues and glycosylation of hydroxylysyl residues. As these posttranslational modifications may play a role in the immune and arthritogenic response to CII, it was unclear whether collagen expressed in Escherichia coli would be immunologically comparable to tissue-derived CII. Therefore, we prepared recombinant proteins for CB8 and CB10 by cloning CB8 (CII 403-551) and CB10 (CII 552-897) genes from bovine chondrocytes by RT-PCR technique and expressing them in an E. coli expression system. Characterization of these recombinant proteins revealed that both rCB8 and rCB10 stimulated T cell proliferation in a T cell determinant-specific manner. The T cells from mice immunized with rCB8 respond specifically to a synthetic peptide, CII 445-453, the CB8 T cell determinant. Conversely, rCB10-primed T cells respond strongly to CII 610-618, the CB10 T cell determinant. Recombinant CB8-induced autoantibodies that bound to mouse CB8 as effectively and in the same topographic distribution as tissue-derived CB8. Finally, when rCB8 and rCB10 proteins were used to immunize B10.RIII (H-2(r)) mice, rCB8 induced arthritis in 33% of the mice, very similar to the incidence induced by tissue-derived CB8 peptide. As was found to be the case with tissue-derived CB10, rCB10 was completely ineffective in inducing arthritis. Pathological changes of arthritic joints in the mice immunized with rCB8 were similar to those observed in mice immunized with tissue-derived CB8. Thus, these recombinant CII peptides expressed in E. coli can induce an effective immunologic response and suggest that functionally useful CII peptides can be generated by the prokaryotic expression system.

Automation of yeast two-hybrid screening

We have developed an automated format for screening yeast two-hybrid libraries for protein-protein interactions. The format consists of a liquid array in which pooled library subsets of yeast, expressing up to 1000 different cDNAs, are mated to a yeast strain of the opposite mating type, expressing a protein of interest. Interactors are detected by a liquid assay for beta-galacsidase following prototrophic selection. The method is demonstrated by the detection of interactions between two encoded yeast RNA polymerase subunits in simulated libraries of varied complexity. To demonstrate its utility for large scale screening of complex cDNA libraries, two nuclear receptor ligand-binding domains were screened through two cDNA libraries arrayed in pooled subsets. Screening these libraries yielded clones which had previously been identified in traditional yeast two hybrid screens, as well as several new putative interacting proteins. The formatting of the cDNA library into pooled subsets lends itself to functional subtraction of the promiscuous positive class of interactor from the library. Also, the liquid arrayed format enables electronic handling of the data derived from interaction screening, which, together with the automated handling of samples, should promote large-scale proteome analysis.

Intravenous tolerization with type II collagen induces interleukin-4-and interleukin-10-producing CD4+ T cells

Intravenous (i.v.) administration of type II collagen (CII) is an effective way to induce tolerance and suppress disease in the collagen-induced arthritis (CIA) model. In this study, we demonstrated that a single i.v. dose of CII (as low as 0.1 mg/mouse) completely prevented the development of CIA. This suppression was accompanied by decreases in levels of antibody specific for the immunogen, bovine CII and autoantigen, mouse CII. Splenocytes obtained from CII-tolerized mice and stimulated with CII in vitro produced predominantly the T helper 2 (Th2)-type cytokines interleukin-4 (IL-4) and interleukin-10 (IL-10). In contrast, cells obtained from mice immunized with CII produced predominantly interferon-gamma (IFN-gamma). Two-colour flow cytometric analysis of cytokine expression and T-cell phenotype demonstrated that CD4+ cells and not CD8+ or gammadelta+ cells were the predominant regulatory cells producing IL-4 and IL-10. Transgenic mice bearing a T-cell receptor (TCR) specific for CII had a greater increase in the number of IL-4-secreting CD4+ cells, as well as a marked increase of IL-4 in culture supernatants. This cytokine was produced by transgene-bearing T cells. Elucidation of mechanisms for the induction of tolerance in mature T cells is an important line of study in autoimmune models because of the potential application for treating organ-specific autoimmune disease.

Routine reporting or sentinel surveys for HIV/AIDS surveillance in resource-poor settings: experience in South Africa, 1991-97

Information from routine and sentinel surveillance was used to monitor the HIV/AIDS epidemic in KwaZulu-Natal, South Africa between 1991 and 1997. Comparisons were made between data obtained from (1) sentinel surveillance for antenatal HIV infection, pulmonary tuberculosis (PTB), and AIDS in a single health district and (2) province-wide sentinel surveillance for antenatal HIV infection, legally required notification of cases of PTB, and voluntary notification of AIDS cases. HIV prevalence among antenatal clinic attenders in the sentinel district rose rapidly and at similar rates to provincial figures: 4.2% vs 4.8% in 1992 to 25.9% vs 26.9% in 1997. PTB incidence increased four-fold in the sentinel district over the study period, whereas provincial PTB figures from passive surveillance fluctuated widely and showed no clear increase (Chi-square for trend 425.5, P<0.00001). AIDS incidence in the sentinel district increased dramatically while provincial data from the voluntary reporting system showed a less consistent and much slower rise (Chi-square for trend 9.07, P=0.003). Incidence of AIDS in 1997 was estimated as 437/10(5) in the sentinel district compared to 32/10(5) in the provincial figures. Routine disease notification and voluntary reporting systems are likely to underestimate the impact of the HIV/AIDS epidemic in resource-poor settings. Sentinel surveillance at representative sites should be developed to validate or replace passive surveillance systems.

Characterization of recombinant type II collagen: arthritogenicity and tolerogenicity in DBA/1 mice

Recombinant human type II collagen (rhCII) was produced using both the HT1080 mammalian cell expression system (rhCIIht) and a baculovirus expression system (rhCIIbac). The biosynthesis of CII requires extensive post-translational modifications, such as the hydroxylation of prolyl and lysyl residues and glycosylation of hydroxylysyl residues. Amino acid analyses indicated that the rhCIIbac was adequately hydroxylated at prolyl residues but underhydroxylated at lysyl residues and underglycosylated compared with tissue-derived hCII, while rhCIIht was hyperhydroxylated and hyperglycosylated at lysyl residues. When the murine collagen-induced arthritis (CIA) model was used to investigate the immunological properties of the two forms of recombinant CII, each induced a high incidence of arthritis following immunization of susceptible mice when emulsified with complete Freund's adjuvant (CFA). However, the severity of the arthritis, as assessed by the number of affected limbs, was significantly higher in mice immunized with rhCIIht than in mice immunized with rhCIIbac. These data indicate that the degree of hydroxylysine glycosylation may play a role in the induction of the arthritogenic response to CII. Each of the recombinant collagens was comparable to tissue-derived hCII in their ability to induce tolerance and suppress arthritis when given as intravenous or oral tolerogens. Taken together, our data suggest that recombinant CII can be prepared in adequate amounts for therapeutic uses and that the material is immunologically comparable to tissue-derived hCII when used to induce tolerance.

Characterization of a peptide analog of a determinant of type II collagen that suppresses collagen-induced arthritis

Immunization of susceptible strains of mice with type II collagen (CII) elicits an autoimmune arthritis known as collagen-induced arthritis (CIA). One analogue peptide of the immunodominant T cell determinant, A9 (CII245-270 (I260-->A, A261-->B, F263-->N)), was previously shown to induce a profound suppression of CIA when coadministered at the time of immunization with CII. In the present study, A9 peptide was administered i.p., orally, intranasally, or i.v. 2 to 4 wk following CII immunization. We found that arthritis was significantly suppressed even when A9 was administered after disease was induced. To determine the mechanism of action of A9, cytokine responses to A9 and wild-type peptide A2 by CII-sensitized spleen cells were compared. An increase in IL-4 and IL-10, but not in IFN-gamma, was found in A9 culture supernatants. Additionally, cells obtained from A9-immunized mice produced higher amounts of IL-4 and IL-10 when cultured with CII compared with cells obtained from mice immunized with A2, which produced predominantly IFN-gamma. Suppression of arthritis could be transferred to naive mice using A9-immune splenocytes. Lastly, phosphorylation of TCRzeta was not altered in the immunoprecipitates from the lysates of cells exposed to analogue peptides (A9 and A10) together with wild-type A2 in a T cell line and two I-Aq-restricted, CII-specific T hybridomas. We conclude that analogue peptide A9 is effective in suppressing established CIA by inducing T cells to produce a Th2 cytokine pattern in response to CII.

Characterization of a Peptide Analog of a Determinant of Type II Collagen That Suppresses Collagen-Induced Arthritis

Immunization of susceptible strains of mice with type II collagen (CII) elicits an autoimmune arthritis known as collagen-induced arthritis (CIA). One analogue peptide of the immunodominant T cell determinant, A9 (CII245–270 (I260→A, A261→B, F263→N)), was previously shown to induce a profound suppression of CIA when coadministered at the time of immunization with CII. In the present study, A9 peptide was administered i.p., orally, intranasally, or i.v. 2 to 4 wk following CII immunization. We found that arthritis was significantly suppressed even when A9 was administered after disease was induced. To determine the mechanism of action of A9, cytokine responses to A9 and wild-type peptide A2 by CII-sensitized spleen cells were compared. An increase in IL-4 and IL-10, but not in IFN-γ, was found in A9 culture supernatants. Additionally, cells obtained from A9-immunized mice produced higher amounts of IL-4 and IL-10 when cultured with CII compared with cells obtained from mice immunized with A2, which produced predominantly IFN-γ. Suppression of arthritis could be transferred to naive mice using A9-immune splenocytes. Lastly, phosphorylation of TCRζ was not altered in the immunoprecipitates from the lysates of cells exposed to analogue peptides (A9 and A10) together with wild-type A2 in a T cell line and two I-Aq-restricted, CII-specific T hybridomas. We conclude that analogue peptide A9 is effective in suppressing established CIA by inducing T cells to produce a Th2 cytokine pattern in response to CII.

Outbreaks of waterborne infectious intestinal disease in England and Wales, 1992-5

Following the introduction of an improved surveillance system for infectious intestinal disease outbreaks in England and Wales, the Public Health Laboratory Service Communicable Disease Surveillance Centre received reports of 26 outbreaks between 1 January 1992 and 31 December 1995 in which there was evidence for waterborne transmission of infection. In these 26 outbreaks, 1756 laboratory confirmed cases were identified of whom 69 (4%) were admitted to hospital. In 19 outbreaks, illness was associated with the consumption of drinking water from public supplies (10 outbreaks) or private supplies (9 outbreaks). The largest outbreak consisted of 575 cases. In 4 of the remaining 7 outbreaks, illness was associated with exposure to swimming pool water. Cryptosporidium was identified as the probable causative organism in all 14 outbreaks associated with public water supplies and swimming pools. Campylobacter was responsible for most outbreaks associated with private water supplies. This review confirms a continuing risk of cryptosporidiosis from chlorinated water supplies in England and Wales, and reinforces governmental advice to water utilities that water treatment processes should be rigorously applied to ensure effective particle removal. High standards of surveillance are important for prompt recognition of outbreaks and institution of control measures. As microbiological evidence of water contamination may be absent or insufficient to implicate a particular water supply, a high standard of epidemiological investigation is recommended in all outbreaks of suspected waterborne disease.

Characterization of signal transduction through the TCR-zeta chain following T cell stimulation with analogue peptides of type II collagen 260-267

The immunodominant T cell determinant of type II collagen (CII) recognized by DBA/1 mice (I-Aq) is CII 260-267. The aims of this study were to determine the role of the amino acid residues within CII 245-270 in T cell signal transduction. To that end, we utilized I-Aq-restricted, CII-specific T cell hybridomas and examined tyrosine phosphorylation of TCR-zeta following stimulation with either wild-type CII 245-270 or a panel of analogue peptides. A variety of patterns occurred, ranging from increased phosphorylation of TCR-zeta to either partial or a complete abrogation of phosphorylation. Critical substitutions also completely abrogated the phosphorylation of ZAP70, a downstream molecule in TCR-zeta signaling. Evaluation of the supernatants of the T cell hybridomas for cytokine production in response to the peptides revealed a close correlation between the induction of phosphorylation of TCR-zeta and the amount of cytokine induced. Selected analogue peptides were tested as tolerogens in neonatal mice. Analogues that did not induce the phosphorylation of zeta chain, such as B3 (CII 251-270s263F-->N), were completely unable to induce tolerance, while analogues that caused a partial phosphorylation, such as B6 (CII 251-270s267Q-->T) and A3 (CII 245-270s269P-->A), induced partial tolerance judged by intermediate degrees of suppression of arthritis. We conclude that discrete alterations in specific amino acid residues of antigenic peptides had profound effects on T cell signaling and that the signaling correlated with T cell cytokine secretion and T cell function in the induction of tolerance and suppression of arthritis.

Induction of autoimmune arthritis in HLA-DR4 (DRB1*0401) transgenic mice by immunization with human and bovine type II collagen

Although associations between the expression of particular HLA genes and the susceptibility to specific autoimmune diseases has been known for some time, the role that these HLA molecules play in the autoimmune response is unclear. Through the establishment of a chimeric HLA-DR/I-E transgene, we have examined the function of the rheumatoid arthritis (RA) susceptibility allele HLA-DR4 (DRB1*0401) in presenting antigenic peptides derived from the model Ag, type II collagen (CII), and in mediating an autoimmune response. As a transgene, the chimeric DR4 molecule conferred susceptibility to an autoimmune arthritis induced by immunization with human CII or bovine CII. These mice developed an inflammatory, autoimmune arthritis that was similar both histologically and in severity to that previously described for the collagen-induced arthritis model. The DR4-mediated autoimmune arthritis was accompanied by T cell and B cell responses to both the immunogen and the autoantigen, murine CII. The DR4-restricted T cell response to human CII was focused on an immunodominant determinant within CII263-270 and a minor determinant within CII286-300, the same CII determinants recently identified for yet another RA susceptibility allele, HLA-DR1 (DRB1*0101). Thus these data demonstrate that, like HLA-DR1, HLA-DR4 is capable of binding peptides derived from human CII and therefore probably plays a role in the autoimmune response to human CII observed in RA patients.

National outbreak of Salmonella senftenberg associated with infant food

Eight cases of Salmonella senftenberg infection in infants were identified in the first half of 1995 in England, five were indistinguishable S. senftenberg strains. A case-control study showed an association between illness and consumption of one brand of baby cereal (P = 0.03). The cereal manufacturer reported isolating S. senftenberg in June 1994 from an undistributed cereal batch. Outbreak strains and the cereal strain were all plasmid-free in contrast to other human isolates of S. senftenberg in the same period. Changes in the production process were implemented to prevent further contamination. Surveillance centres should strengthen the detection and investigation of outbreaks of gastrointestinal infection in susceptible groups, especially young children. In this outbreak, the study of only five cases led to identification of the vehicle of infection. Even when few cases are reported, epidemiological investigation in conjunction with molecular typing may lead to public health action which prevents continuing or future outbreaks.