Functional MRI reveals an interhemispheric dissociation of frontal and temporal language regions in a patient with focal epilepsy

We report the case of a patient with frontal lobe epilepsy in whom the Wada test failed to lateralize representation of language (fluent speech was observed after amobarbital injection on both the right and left side). Functional magnetic resonance imaging (fMRI) during a lexical processing task revealed an atypical organization of language represented by an interhemispheric dissociation of language regions with a right frontal dominance and a left temporal dominance. Consistent with the fMRI results, the patient's ability to name pictures was not reliably impaired by electrocortical stimulation (ECS) of left frontal cortex. The findings from Wada, fMRI, and ECS were confirmed by a lack of language impairment after left frontal lobectomy for seizures. This case illustrates that fMRI can precisely map cortical language networks in epileptic patients and that fMRI may be used to help interpret laterality results provided by the Wada procedure.

Heterogeneous case definitions used for the surveillance of influenza in Europe

We reviewed the case definitions used by 21 influenza sentinel-based surveillance networks in Western Europe. Two clinical syndromes were used with a wide range of case definitions that nevertheless shared common criteria. Although there is currently no international consensus, efforts are being undertaken to standardise influenza case definitions in Europe.

SARS: UK public health response--past, present and future

The emergence of severe acute respiratory syndrome (SARS) in China, the occurrence of epidemics of SARS in China and a number of Southeast Asian countries, and its spread to countries elsewhere, have presented major challenges to public health systems throughout the world. Although very few true cases of SARS were detected in the United Kingdom, the public health response to the threat of SARS was considerable. The main components of this response were the early detection, isolation and reporting of cases, and the provision of comprehensive information to health professionals, cases, their contacts and the public. The development of the response to SARS raised a number of more general issues relevant to future infectious epidemic threats. Although the World Health Organisation has now declared SARS 'contained', the possibility of re-emergence is ever present. All countries will need to be vigilant and plan their response to the possibility of a renewed SARS epidemic.

A decade of change: tuberculosis in England and Wales 1988-98

Tuberculosis cases in children (aged under 15 years) in the National Surveys rose from 308 (rate: 3.3 per 100,000) in 1988 to 408 (4.2 per 100,000) in 1993 and then fell to 364 (3.6 per 100,000) in 1998. The rates in white children were 1.6, 2.0, and 1.1 per 100,000 respectively; in Indian subcontinent children, the rates were unchanged between 1988 and 1993 at around 33 per 100,000 but fell to 23 per 100,000 in 1998. In black African children, the rates were 15, 34, and 71 per 100,000 respectively. From 1988 to 1998, the proportion of cases resident in London more than doubled to 49% (rate: 11.9 per 100,000) and the proportion of cases in children born abroad increased from 13% to 27% in the country as a whole. Although the overall rate of tuberculosis in children in England and Wales has changed little between 1988 and 1998, the distribution of disease has changed in line with the change in adults. Services for the diagnosis and treatment of tuberculosis in children should be adapted to the changing pattern of disease in this group. Continuous enhanced tuberculosis surveillance will enable more detailed and timely scrutiny of trends in tuberculosis in the future.

Appropriateness of thresholds currently used to describe influenza activity in England

The timing and magnitude of influenza virus activity in England each winter remain unpredictable. Nevertheless, it is important to describe levels of activity in a timely manner, using defined 'threshold values'. This informs public health practitioners and the general public of the level of influenza virus circulation, and provides an indication of when sufficient activity is occurring in the community to warrant the use of antiviral drugs. Data presented here suggest that the current numerical thresholds, and their corresponding descriptions, are no longer appropriate for the levels of activity recently observed in England. Based on integrated clinical and virological data, we suggest alternative threshold values of 'baseline' activity (0-30/100,000 population), 'normal seasonal' activity (30-200/100,000) and 'epidemic' activity (> 200/100,000).

Epidemiology and control of tuberculosis in Western European cities

SETTING

Major cities of Western Europe.

OBJECTIVE

To describe major variations in the epidemiology and control of tuberculosis in large Western European Cities.

DESIGN

Postal survey using contacts identified through the EURO-TB surveillance network.

RESULTS

Twenty cities responded. In most cities, notification rates were substantially higher than national rates. Rates ranged from less than 10 per 100,000 in Reykjavik and Belfast to over 70 per 100,000 in Lisbon. MDR-TB ranged from less than 1% of cases in many cities to over 5% in Rome and Milan. The proportion of patients estimated to be HIV-positive ranged from less than 5% in many countries to over 20% in Milan. These variations in epidemiology were accompanied by major variations in control policy, particularly in approaches to new entrant screening and BCG vaccination.

CONCLUSION

In Western Europe, tuberculosis is primarily a problem of large cities. Some of these cities have very high rates of tuberculosis. There is little consensus about the best approaches to control. The evidence base for the effectiveness of different aspects of TB control needs to be strengthened.

Three years of low influenza activity--no reason for complacency

Influenza activity in England and Wales has been unusually low over the last three years. Despite this, substantial morbidity and mortality has occurred in subgroups of the population. Furthermore, the influenza season 2001/02 was characterised by the emergence of a new subtype of the influenza A virus (H1N2), a timely reminder that it is not possible to assess the impact of a change in the virus strains circulating without having a comprehensive surveillance infrastructure in place.

Dissociation of augmented physiological, hormonal and cognitive responses to hypoglycaemia with sustained caffeine use

In patients with Type I diabetes and healthy volunteers, ingestion of modest amounts of caffeine augments the usual symptomatic and counter-regulatory responses to hypoglycaemia. The aim of the present study was to determine whether these are lost with sustained caffeine use, i.e. does tolerance develop? Eleven healthy caffeine consumers underwent two identical hyperinsulinaemic glucose clamp procedures. For 7 days prior to each clamp, subjects consumed a caffeine-free diet supplemented with 200 mg of caffeine capsules twice daily (caffeine-replete) or placebo (caffeine-withdrawn). During each clamp, blood glucose was held for 80 min at 4.5 mmol/l and then 2.5 mmol/l. At 85 min, subjects were given a 200 mg caffeine capsule. Measurements were taken of symptoms, plasma catecholamine, middle cerebral artery blood velocity (V(MCA)) and cognition. Following the acute caffeine challenge and during hypoglycaemia, V(MCA) fell only in the caffeine-withdrawn condition [-5.1 (-7.3, -3.0) cm/s compared with -1.9 (-4.0, +0.2) cm/s in caffeine-replete condition; P <0.04; values are differences (95% confidence intervals)]. Plasma catecholamine levels and global cognitive performance were unaffected by caffeine status, whereas tests of executive intellectual function were better preserved during hypoglycaemia in the caffeine-replete condition ( P <0.05). The influence of caffeine on hypoglycaemic symptomatic awareness depended upon the duration of the hypoglycaemic stimulus. At onset, symptoms were more intense in caffeine-withdrawn state ( P <0.01); however, with increasing duration of hypoglycaemia, symptom intensity was greater in caffeine-replete condition ( P <0.05). Thus previous caffeine consumption influences the physiological and symptomatic responses to acute hypoglycaemia, but complete tolerance does not develop with sustained use.

An evaluation of the genetic stability and pathogenicity of the Russian cold-adapted influenza A donor strains A/Leningrad/134/17/57 and A/Leningrad/134/47/57 in ferrets

The influenza A components of live attenuated vaccines used in Russia have been prepared as reassortants of the cold-adapted (ca) H2N2 viruses, A/Leningrad/134/17/57-ca (Len/17) and A/Leningrad/134/47/57-ca (Len/47), and virulent epidemic strains. The lesions responsible for attenuation within the six internal genes of each donor strain have been sequenced and described, but relatively little is known as to their stability before and after passage in susceptible hosts. In the work reported in this paper, RT-PCR restriction analysis and limited sequencing of individual genes were used to evaluate the stability of lesions in stocks of the both donor strains after passage in ferrets, which have been used widely as susceptible hosts for assessment of the virulence of influenza strains. Len/47 was shown to possess expected lesions by RT-PCR and restriction analysis. Substitution at position 1066 of the NP gene, which has been previously reported to be unique to Len/47 [Klimov et al., Virology 186 (1992) 795], was also shown to be present in all clones of Len/17. This change was confirmed by limited sequence analysis and was shown to be retained in progeny viruses isolated from the lungs and turbinates of inoculated ferrets. Two other changes in the PB2 and PB1 genes that were present in Len/47 were detected by limited sequence analysis alone. Further previously unreported minor changes were shown to be present for Len/17 and Len/47, but not both, and their significance is unknown. Limited replication of each donor strain occurred in ferrets and minimal clinical signs and histopathology were present. By contrast, the parental strain Len/57 and the recent epidemic strain A/Sydney/6/97 induced clinical signs and histopathology that were typical of influenza disease.

Antibiotic resistant tuberculosis in the United Kingdom: 1993-1999

BACKGROUND

The re-emergence of tuberculosis as a global health problem over the past two decades, accompanied by an increase in tuberculosis drug resistance, prompted the development of a comprehensive national surveillance system for tuberculosis drug resistance in 1993.

METHODS

The UK Mycobacterial Resistance Network (Mycobnet), which includes all mycobacterial reference and regional laboratories in the UK, collects a minimum dataset on all individuals from whom an initial isolate of Mycobacterium tuberculosis complex has been isolated and submitted by source hospital laboratories. Data sought include susceptibility to first line antibiotics, demographic, geographical, and risk factor information.

RESULTS

There were 25 217 reports of initial isolates of M tuberculosis complex in the UK between 1993 and 1999. All were tested for sensitivity to isoniazid, rifampicin, and ethambutol and 12 692 of the isolates were also tested for sensitivity to pyrazinamide and streptomycin. A total of 1523 (6.1%) isolates were resistant to one or more drugs, 1397 isolates (5.6%) were resistant to isoniazid with or without resistance to other drugs, and 299 (1.2%) were multidrug resistant. Although the numbers of drug resistant isolates increased over the period, the proportions remained little changed. Certain groups of people were at a higher risk of acquiring drug resistant tuberculosis including younger men, residents of London, foreign born subjects, patients with a previous history of tuberculosis and those infected with HIV.

CONCLUSION

Although the proportion of drug resistant tuberculosis cases appears to be stable in the UK at present, more than one in 20 patients has drug resistant disease at diagnosis and more than one in 100 has multidrug resistant disease. Tuberculosis control measures should be strengthened to minimise the emergence of drug resistance through rapid diagnosis, rapid identification of drug resistance, supervised treatment, and maintenance of comprehensive surveillance.

An estimate of the contribution of HIV infection to the recent rise in tuberculosis in England and Wales

BACKGROUND

The number of patients with tuberculosis has been increasing slowly in England and Wales since the late 1980s. HIV infection has been a contributory factor to increases in tuberculosis in a number of comparable industrialised countries. This study investigated the extent of tuberculosis and HIV co-infection in England and Wales in 1993 and 1998, and estimated its contribution to the increase in tuberculosis observed during this period.

METHODS

Patients aged 16-54 years old at diagnosis on the 1993 and 1998 National Tuberculosis Survey databases were matched with those on the HIV/AIDS patient database. A coded process maintained patient confidentiality. Primary outcome measures were the increase between 1993 and 1998 in the numbers with both infections reported and an estimate of the proportion of the increase in tuberculosis during this period attributable to HIV co-infection.

RESULTS

In 1993 61 (2.2%) tuberculosis patients aged 16-54 years matched with patients reported to the HIV database, increasing to 112 (3.3%) in 1998 (p=0.08; OR 1.35; 95% CI 0.97 to 1.87). Patients co-infected with HIV contributed an estimated 8.5% of the increase in number of tuberculosis patients between 1993 and 1998 nationwide (11% in London). In both years prevalence of co-infection was greatest in London and in patients of white and black African ethnic groups.

CONCLUSIONS

In 1998 the number of tuberculosis patients co-infected with HIV in England and Wales, though still small, had nearly doubled since 1993, with most of the increase occurring in London. As HIV infection may be undiagnosed in patients with tuberculosis, and tuberculosis may be unreported in patients with diagnosed HIV infection, the true extent of co-infection will have been underestimated by this study. In addition, constraints in coded matching make it inevitable that some reported co-infections are missed. Routine HIV testing of all patients with tuberculosis should now be considered, particularly in patients of white or black African ethnic origin under 55 years of age.

Prevalence, morbidity and service need among South Asian and white adults with intellectual disability in Leicestershire, UK

BACKGROUND

Previous reports have suggested that South Asian and white UK populations have different prevalences of intellectual disability (ID), related psychological morbidity and service use. The aim of the present study was to compare these rates among South Asian and white adults in Leicestershire, UK.

METHOD

This cross-sectional study is comprised of two parts. The analysis of prevalence is based on data from all South Asian and white adults known to the Leicestershire Learning Disabilities Register in 1991, with population denominators being drawn from the 1991 census. The other analyses use data collected from the most recent semi-structured home interviews, carried out between 1987 and 1998, with 206 South Asian and 2334 white adults.

RESULTS

The prevalence of ID in adults in Leicestershire is 3.20 per 1000 in South Asians and 3.62 per 1000 in whites. Among adults with ID, South Asians have similar prevalences of disabilities to whites and significantly lower skill levels. South Asians show similar levels of psychological morbidity, but make significantly lower use than whites of psychiatric services, residential care and respite care. South Asians use community services as extensively as whites, but feel that they have a substantially greater unmet need, especially with regard to social services.

CONCLUSION

South Asian and white populations have similar prevalences of ID and related psychological morbidity. Culturally appropriate services for South Asian adults may need to focus on skill development and community care.

The molecular epidemiology of tuberculosis in inner London

The study used DNA fingerprint typing (spoligotyping and Heminested-lnverse-PCR) of Mycobacterium tuberculosis from all culture-confirmed inner London patients over a 12-month period to describe transmission. The methodology was evaluated by comparison with standard IS6110 typing and by examining its ability to identify known household clusters of cases. Isolates sharing indistinguishable typing patterns using both techniques were defined as clustered. Clusters were investigated to identify epidemiological links. The methodology showed good discriminatory power and identified known household clusters of cases. Of 694 culture-confirmed cases, 563 (81%) were typed. Eleven (2%) were due to laboratory cross-contamination and were excluded. Of the remaining 552 isolates 148 (27%) were clustered. Multivariate analysis indicated that clustering was more common in those with pulmonary smear positive disease (P < 0.02); those born in the United Kingdom (P < 0.0003) and in patients living in south London (P = 0.02). There was also a trend towards clustering being more common in those not known to have HIV infection (P = 0.051). The results suggest that in inner London, recent local transmission makes an important contribution to notification rates.

Structural consequences of divalent metal binding by the adenylyl cyclase toxin of Bordetella pertussis

Adenylyl cyclase toxin of Bordetella pertussis has been shown by several investigators to require Ca(2+) for its actions on target cells, but little is known about the nature and specificity of divalent metal binding to this novel toxin. Calcium is the preferred divalent metal since toxic actions are markedly reduced in the presence of divalent species other than calcium. Mn(2+) EPR was used to quantitate and characterize divalent metal binding and revealed that the toxin contains approximately 40 divalent metal sites, consisting of at least one class of high-affinity sites that bind Mn(2+) with a K(D) of 0.05 to 0.35 microM and one or more classes of lower affinity sites. Water proton relaxation data indicate that approximately 30 of these sites are completely inaccessible to bulk solvent. Our observations, together with the sequence homology between adenylyl cyclase toxin and the alkaline protease of Pseudomonas aeruginosa, indicate that the formation of five beta-sheet helices within the repeat domain of the toxin upon binding Ca(2+) is required for cell intoxication.

Expression and localization of IL-1beta mRNA is interrelated with cytoskeletal rearrangement in monocytes stimulated by adherence: a light microscopy in situ hybridization study

Differences in IL-1beta mRNA expression, stability and translation between non-adherent monocytes and those stimulated by adherence suggest that cytokine regulation is coupled to the function and assembly of cytoskeletal structures. In situ hybridization studies were performed to visualize expression and positioning of IL-1beta mRNA in adherently cultivated monocytes. IL-1beta mRNA expression was heterogeneous with high transcript levels found in spread or polarized cells. Transcripts were compartmentalized to the perinuclear region in spread cells, and partially redistributed with polarization. In contrast to mRNA distribution in other motile cell populations, IL-1beta mRNA did not localize to the distal or proximal actin cytoskeleton. Perinuclear confinement of transcripts required intact actin microfilaments. Treatment with cytoskeleton disruption and detergent extraction suggested that most non-translated IL-1beta mRNA was associated with intermediate filaments. In monocytes stimulated by LPS, IL-1beta, but not IL-1Ra transcripts were redistributed and partially associated, yet not bound to actin microfilaments. The present study demonstrates that IL-1beta mRNA expression and localization in adherent monocytes is interrelated with the cytoskeletal rearrangement upon adherence, spreading and polarization.

Regulation of Staphylococcus aureus-mediated activation of interleukin-18 in peripheral blood mononuclear cells

Bacteria and bacterial antigens strongly induce cytokine secretion by peripheral blood leukocytes and thereby initiate an inflammatory cascade with potentially deleterious consequences for the host. The present study focussed on receptors and signal transduction pathways involved in activation of interleukin (IL)-18 by heat-inactivated Gram-positive Staphylococcus aureus Cowan strain I (SAC). Similarly to IL-12/IL-12p40, IL-10 and IFN-gamma, SAC dose-dependently activated IL-18. Secretion of IL-18 was independent of functional activity of IL-10, IL-12 or IFN-gamma. Lipoteichoic acid (LTA), a structural component of SAC, was not sufficient for activation of IL-18, while it dose-dependently induced IL-10. In contrast to IL-12, blockade of CD14 only partially diminished secretion of IL-18 and did not affect secretion of IL-10, suggesting involvement of other receptors (e.g., Toll-like receptors) in SAC responses. Further down-stream however, secretion of IL-10, IL-12 and IL-18 was uniformly inhibited by blockade of G-protein-mediated kinase activation by mastoparan. Secretion of IL-18 required phosphatidylinositol-3'-kinase, and secretion of IL-12 phosphotyrosine kinase activity. The data demonstrate that SAC potently activates secretion of IL-18 by peripheral blood mononuclear cells with differential involvement of cell-surface receptors and signal transduction pathways as compared to other natural killer- and T cell-promoting cytokines.

Factors that determine false recall: a multiple regression analysis

In the Deese-Roediger-McDermott (DRM) paradigm, subjects study lists of words that are designed to elicit the recall of an associatively related critical item. The 55 lists we have developed provide levels of false recall ranging from .01 to .65, and understanding this variability should provide a key to understanding this memory illusion. Using a simultaneous multiple regression analysis, we assessed the contribution of seven factors in creating false recall of critical items in the DRM paradigm. This analysis accounted for approximately 68% of the variance in false recall, with two main predictors: associative connections from the study words to the critical item (r = +.73; semipartial r = +.60) and recallability of the lists (r = -.43; semipartial r = -.34). Taken together, the variance in false recall captured by these predictors accounted for 84% of the variance that can be explained, given the reliability of the false recall measures (r = .90). Therefore, the results of this analysis strongly constrain theories of false memory in this paradigm, suggesting that at least two factors determine the propensity of DRM lists to elicit false recall. The results fit well within the theoretical framework postulating that both semantic activation of the critical item and strategic monitoring processes influence the probability of false recall and false recognition in this paradigm.

Can calls to NHS Direct be used for syndromic surveillance?

This study assessed whether NHS Direct could be a useful source of surveillance data for communicable diseases, using influenza as a pilot condition. Data on the weekly total number of calls and the number from people reporting influenza-like symptoms to three pilot NHS Direct sites were collected between November 1999 and March 2000. NHS Direct data were compared with routinely available influenza surveillance data. The NHS Direct call rate peaked at 331 per 100,000 population in week 52 of 1999. The percentage of calls for 'influenza-like illness' (one site) peaked at 15% during week 51. Information about weekly call numbers to NHS Direct could be produced in a timely way. It was not clear whether the observed peak in calls reflected a true increase in influenza or whether it was the result of an increase in calls over the Christmas/Millennium holiday period due to more difficulty in accessing other services. The ability to assess the proportion of calls made directly by, or on behalf of, each age group will be of vital importance in interpreting seasonal respiratory disease.

Immunogenic and isotype-specific responses to Russian and US cold-adapted influenza a vaccine donor strains A/Leningrad/134/17/57, A/Leningrad/134/47/57, and A/Ann Arbor/6/60 (H2N2) in mice

The immunogenicity of the Russian cold-adapted (ca) donor stains, A/Leningrad (Len)/134/17/57 and A/Leningrad/134/47/57, and the US strain A/Ann Arbor (AA)/6/60-ca, were compared in BALB/c mice with their respective wild-type parental viruses. Each ca donor strain was less immunogenic than its wild-type parent. The vaccinating dose, when administered twice, which prevented multiplication of a standard challenge of parental wild-type virus in 50% of mice (the 50% protective dose or PD(50)), was shown for A/Len/134/17/57-ca, A/Len/134/47/57-ca, and A/AA/6/60-ca to be 10(3.77), 10(4.32), and 10(4.70), respectively. These findings were extended by measuring the number of antibody secreting cells induced in the lungs and mediastinal lymph nodes of mice infected with the same ca donors using an ELISPOT assay. When each donor strain was administered twice at a dose of 100 PD(50) over a 3-week interval, the overall immunoglobulin isotype antibody secreting cell profiles were shown to be similar. However, A/Len/134/17/57-ca and A/Len/134/47/57-ca induced significantly higher total immunoglobulin responses in the lungs than A/AA/6/60-ca (P < 0.05). A/Len/134/17/57-ca also induced a significantly greater IgA response in the lungs than A/AA/6/60-ca (P < 0.05). These results suggest that A/Len/134/17/57-ca is a superior immunogen to A/Len/134/47/57-ca which in turn is more immunogenic than A/AA/6/60-ca.

Socioeconomic status, ethnicity, and health care access among young and healthy women

This study examined: (a) the relationship between socioeconomic status (SES) and health care access among healthy women; (b) which SES variable(s) were most strongly associated with HCA; and (c) whether the SES/HCA relationship was the same for Black and White women. A total of 383 women (57.4% Whites and 42.6% Blacks) participated in the study. Independent variables included family income, education levels, occupation, median income within zip code of participants' residence, and ethnicity. Dependent variables were the total and subscale scores (accessibility, accommodation, and affordability) on a measure of health care access. Family income was the SES variable that showed the strongest positive association with total health care access, and there was a significant interaction between occupation and ethnicity for total health care access. Unique relationships were observed between each SES variable and each subscale on the health care access measure. The overall patterns between SES and health care access were similar for Blacks and Whites. Results suggest that the relationship between health care access and SES should be investigated through a multi-dimensional approach, and that an array of SES variables must be considered when designing interventions to improve health care access among healthy women.

RhoA is required for monocyte tail retraction during transendothelial migration

Transendothelial migration of monocytes is the process by which monocytes leave the circulatory system and extravasate through the endothelial lining of the blood vessel wall and enter the underlying tissue. Transmigration requires coordination of alterations in cell shape and adhesive properties that are mediated by cytoskeletal dynamics. We have analyzed the function of RhoA in the cytoskeletal reorganizations that occur during transmigration. By loading monocytes with C3, an inhibitor of RhoA, we found that RhoA was required for transendothelial migration. We then examined individual steps of transmigration to explore the requirement for RhoA in extravasation. Our studies showed that RhoA was not required for monocyte attachment to the endothelium nor subsequent spreading of the monocyte on the endothelial surface. Time-lapse video microscopy analysis revealed that C3-loaded monocytes also had significant forward crawling movement on the endothelial monolayer and were able to invade between neighboring endothelial cells. However, RhoA was required to retract the tail of the migrating monocyte and complete diapedesis. We also demonstrate that p160ROCK, a serine/threonine kinase effector of RhoA, is both necessary and sufficient for RhoA-mediated tail retraction. Finally, we find that p160ROCK signaling negatively regulates integrin adhesions and that inhibition of RhoA results in an accumulation of beta2 integrin in the unretracted tails.