Widespread Pain Phenotypes Impact Treatment Efficacy Results in Randomized Clinical Trials for Interstitial Cystitis/Bladder Pain Syndrome: A MAPP Network Study

Clinical trials of pain are notoriously difficult and inefficient in demonstrating efficacy even for known efficacious treatments. Determining the appropriate pain phenotype to study can be problematic. Recent work has identified the extend of widespread pain as an important factor in the likelihood of response to therapy, but has not been tested in clinical trials. Using data from three previously published negative studies of the treatment of interstitial cystitis/ bladder pain with data on the extent of widespread pain, we examined the response of patients to different therapies base on the amount of pain beyond the pelvis. Participants with predominately local but not widespread pain responded to therapy targeting local symptoms. Participants with widespread and local pain responded to therapy targeting widespread pain. Differentiating patients with and without widespread pain phenotypes may be a key feature of designing future pain clinical trials to demonstrate treatments that are effective versus not.

Optimizing and Accelerating the Development of Precision Pain Treatments for Chronic Pain: IMMPACT Review and Recommendations

Large variability in the individual response to even the most-efficacious pain treatments is observed clinically, which has led to calls for a more personalized, tailored approach to treating patients with pain (ie, "precision pain medicine"). Precision pain medicine, currently an aspirational goal, would consist of empirically based algorithms that determine the optimal treatments, or treatment combinations, for specific patients (ie, targeting the right treatment, in the right dose, to the right patient, at the right time). Answering this question of "what works for whom" will certainly improve the clinical care of patients with pain. It may also support the success of novel drug development in pain, making it easier to identify novel treatments that work for certain patients and more accurately identify the magnitude of the treatment effect for those subgroups. Significant preliminary work has been done in this area, and analgesic trials are beginning to utilize precision pain medicine approaches such as stratified allocation on the basis of prespecified patient phenotypes using assessment methodologies such as quantitative sensory testing. Current major challenges within the field include: 1) identifying optimal measurement approaches to assessing patient characteristics that are most robustly and consistently predictive of inter-patient variation in specific analgesic treatment outcomes, 2) designing clinical trials that can identify treatment-by-phenotype interactions, and 3) selecting the most promising therapeutics to be tested in this way. This review surveys the current state of precision pain medicine, with a focus on drug treatments (which have been most-studied in a precision pain medicine context). It further presents a set of evidence-based recommendations for accelerating the application of precision pain methods in chronic pain research. PERSPECTIVE: Given the considerable variability in treatment outcomes for chronic pain, progress in precision pain treatment is critical for the field. An array of phenotypes and mechanisms contribute to chronic pain; this review summarizes current knowledge regarding which treatments are most effective for patients with specific biopsychosocial characteristics.

Acupuncture versus massage for pain in patients living with advanced cancer: a protocol for the IMPACT randomised clinical trial

INTRODUCTION

Pain, comorbid fatigue and sleep disturbances are common and distressing symptoms for patients with advanced cancer, negatively impacting their quality of life. Clinical guidelines recommend non-pharmacological interventions, including acupuncture and massage, for pain management in adult patients with cancer in adjunct to conventional care. However, high-quality evidence about the comparative effectiveness and long-term durability of these therapies for symptom management is limited.

METHODS AND ANALYSIS

We describe the design of a two-arm, parallel group, multicentre randomised controlled trial that investigates the use of acupuncture versus massage for musculoskeletal pain among 300 patients with diverse types of advanced cancer. The primary aim is to evaluate the long-term effectiveness (26 weeks from randomisation) of acupuncture vs massage for pain (primary outcome) and comorbid symptoms (fatigue, sleep disturbance and quality of life). The secondary aim is to identify patient-level demographic characteristics (eg, sex, race, age), clinical factors (eg, insomnia, pain severity) and psychological attributes that are associated with a greater reduction in pain for either acupuncture or massage. Patients will receive weekly acupuncture or massage treatments for 10 weeks, followed by monthly booster sessions up to 26 weeks. The primary endpoint will be the change in worst pain intensity score from baseline to 26 weeks. We will collect validated patient-reported outcomes at multiple time points over 26 weeks.

ETHICS AND DISSEMINATION

The Institutional Review Board at Memorial Sloan Kettering Cancer Center in New York approved this protocol. Results will be disseminated via peer-reviewed scientific journals and conference presentations. Our findings will help patients and healthcare providers make informed decisions about incorporating non-pharmacological treatments to manage pain for patients with advanced cancer.

TRIAL REGISTRATION NUMBER

NCT04095234.

Symptom Variability and Early Symptom Regression in the MAPP Study: A Prospective Study of Urological Chronic Pelvic Pain Syndrome

PURPOSE

We examined symptom variability in men and women with urological chronic pelvic pain syndrome. We describe symptom fluctuations as related to early symptom regression and its effect on estimated 1-year symptom change. We also describe a method to quantify patient specific symptom variability.

MATERIALS AND METHODS

Symptoms were assessed biweekly in 424 subjects with urological chronic pelvic pain syndrome during 1 year. To evaluate the impact of early symptom regression subjects were classified as improved, no change or worse according to the rate of change using 1) all data, 2) excluding week 0 and 3) excluding weeks 0 and 2. Patient specific, time varying variability was calculated at each interval using a sliding window approach. Patients were classified as high, medium or low variability at each time and ultimately as high or low variability overall based on the variability for the majority of contacts.

RESULTS

Prior to excluding early weeks to adjust for early symptom regression 25% to 38% and 5% to 6% of patients were classified as improved and worse, respectively. After adjustment the percent of patients who were improved or worse ranged from 15% to 25% and 6% to 9%, respectively. High and low variability phenotypes were each identified in 25% to 30% of participants.

CONCLUSIONS

Patients with urological chronic pelvic pain syndrome show symptom variability. At study enrollment patients had worse symptoms on average, resulting in a regression effect that influenced the estimated proportion of those who were improved or worse. Prospective studies should include a run-in period to account for regression to the mean and other causes of early symptom regression. Further, symptom variability may be quantified and used to characterize longitudinal symptom profiles of urological chronic pelvic pain syndrome.

Living roots magnify the response of soil organic carbon decomposition to temperature in temperate grassland

Increasing atmospheric carbon dioxide (CO2 ) concentration is both a strong driver of primary productivity and widely believed to be the principal cause of recent increases in global temperature. Soils are the largest store of the world's terrestrial C. Consequently, many investigations have attempted to mechanistically understand how microbial mineralisation of soil organic carbon (SOC) to CO2 will be affected by projected increases in temperature. Most have attempted this in the absence of plants as the flux of CO2 from root and rhizomicrobial respiration in intact plant-soil systems confounds interpretation of measurements. We compared the effect of a small increase in temperature on respiration from soils without recent plant C with the effect on intact grass swards. We found that for 48 weeks, before acclimation occurred, an experimental 3 °C increase in sward temperature gave rise to a 50% increase in below ground respiration (ca. 0.4 kg C m(-2) ; Q10  = 3.5), whereas mineralisation of older SOC without plants increased with a Q10 of only 1.7 when subject to increases in ambient soil temperature. Subsequent (14) C dating of respired CO2 indicated that the presence of plants in swards more than doubled the effect of warming on the rate of mineralisation of SOC with an estimated mean C age of ca. 8 years or older relative to incubated soils without recent plant inputs. These results not only illustrate the formidable complexity of mechanisms controlling C fluxes in soils but also suggest that the dual biological and physical effects of CO2 on primary productivity and global temperature have the potential to synergistically increase the mineralisation of existing soil C.

Reporting of missing data and methods used to accommodate them in recent analgesic clinical trials: ACTTION systematic review and recommendations

Missing data in clinical trials can bias estimates of treatment effects. Statisticians and government agencies recommend making every effort to minimize missing data. Although statistical methods are available to accommodate missing data, their validity depends on often untestable assumptions about why the data are missing. The objective of this study was to assess the frequency with which randomized clinical trials published in 3 major pain journals (ie, European Journal of Pain, Journal of Pain, and Pain) reported strategies to prevent missing data, the number of participants who completed the study (ie, completers), and statistical methods to accommodate missing data. A total of 161 randomized clinical trials investigating treatments for pain, published between 2006 and 2012, were included. Approximately two-thirds of the trials reported at least 1 method that could potentially minimize missing data, the most common being allowance of concomitant medications. Only 61% of the articles explicitly reported the number of patients who were randomized and completed the trial. Although only 14 articles reported that all randomized participants completed the study, fewer than 50% of the articles reported a statistical method to accommodate missing data. Last observation carried forward imputation was used most commonly (42%). Thirteen articles reported more than 1 method to accommodate missing data; however, the majority of methods, including last observation carried forward, were not methods currently recommended by statisticians. Authors, reviewers, and editors should prioritize proper reporting of missing data and appropriate use of methods to accommodate them so as to improve the deficiencies identified in this systematic review.

Reviewing the development, evidence base, and application of the revised dengue case classification

With the example of dengue, an evidence-based approach to prospectively develop a case classification is described, gathering evidence for identifying strength and weaknesses of the existing model, collecting new data describing the disease as it occurs globally, further developing a new model that can be applied in practice and field testing the newly developed model in comparison to the previous model. For each step in this process, the highest available level of evidence has been applied. This process has been initiated by the World Health Organization’s (WHO) Special Programme for Research and Training in Tropical Diseases (TDR) and WHO’s Department for Control of Neglected Tropical Diseases (NTD), developing the following for dengue. Since the early 1970s, dengue has been classified into dengue fever, dengue haemorrhagic fever grades I and II and dengue shock syndrome grades III and IV (DF/DHF/DSS). However, in recent years, a growing number of dengue clinicians have questioned the shortcomings of this scheme. The issues have revolved around the complexity of confirming DHF in clinical practice, misclassifying severe cases as DF, and the emphasis on haemorrhage rather than plasma leakage as the underlying problem in most severe dengue cases. Step 1: A systematic literature review highlighted the shortcomings of the DF/DHF/DSS scheme: (1) difficulties in applying the criteria for DHF/DSS; (2) the tourniquet test has a low sensitivity for distinguishing between DHF and DF; and (3) most DHF criteria had a large variability in frequency of occurrence. Step 2: An analysis of regional and national dengue guidelines and their application in the clinical practice showed a need to re-evaluate and standardize guidelines as the actual ones showed a large variation of definitions, an inconsistent application by medical staff, and a lack of diagnostic facilities necessary for the DHF diagnosis in frontline services. Step 3: A prospective cohort study in seven countries, confirmed the difficulties in applying the DF/DHF/DSS criteria even in tertiary care hospitals, that DF/DHF/DSS do not represent levels of disease severity and that a clear distinction between severe dengue (defined by plasma leakage and/or severe haemorrhage, and/or organ failure) and (non-severe) dengue can be made using highly sensitive and specific criteria. In contrast, the sub-grouping of (non-severe) dengue into two further severity levels was only possible with criteria that gave approximately 70% sensitivity and specificity. Step 4: Three regional expert consensus groups in the Americas and Asia concluded that ‘dengue is one disease entity with different clinical presentations and often with unpredictable clinical evolution and outcome’ and that, revising the results of Step 3, DF/DHF/DSS is not related to disease severity. Step 5: In a global expert consensus meeting at WHO in Geneva/Switzerland the evidence collected in Steps 1–4 was reviewed and a revised scheme was developed and accepted, distinguishing: dengue with or without warning signs and severe dengue; the further field testing and acquisition of further prospective evidence of the revised scheme was recommended. Step 6: In 18 countries, the usefulness and applicability of the revised classification compared to the DF/DHF/DSS scheme were tested showing clear results in favour of the revised classification. Step 7: Studies are under way on the predictive value of warning signs for severe dengue and on criteria for the clinical diagnosis of dengue which will complete the evidence foundation of the revised classification. The analysis has shown that the revised dengue case classification is better able to standardize clinical management, raise awareness about unnecessary interventions, match patient categories with specific treatment instructions, and make the key messages of patient management understandable for all health care staff dealing with dengue patients. Furthermore, the evidence-based approach to develop prospectively the dengue case classification could be a model approach for other disease classifications.

Psychometric properties of the Kansas City Cardiomyopathy Questionnaire (KCCQ)

BACKGROUND

The Kansas City Cardiomyopathy Questionnaire (KCCQ) is a well-established instrument used to evaluate the health status of heart failure (HF) patients. There has been a lack of clarity about the best way to conceptualize the KCCQ. The purpose of this investigation of the KCCQ was to: (1) explore the factor structure with an exploratory factor analyses; (2) perform reliability and validity testing to determine the best factor solution for item groupings; and (3) determine the most meaningful components of health status captured by the KCCQ.

METHODS AND RESULTS

A secondary analysis of data from 280 adults with stage-C HF enrolled from three US northeastern sites was conducted to test the KCCQ subscale structure. Criterion-related validity for the Self-efficacy subscale was tested with the Dutch Heart Failure Knowledge Scale and the Self-care of Heart Failure Index Self-care Confidence Scale. Overall, internal consistency reliability (Cronbach's alpha) for the KCCQ and subscales was 0.92, social interference (seven items, 0.90), physical limitation (four items, 0.84), symptoms (eight items, 0.86), independent care (two items, 0.80), and self-efficacy (two items, 0.63). Two items failed to correspond to a previously identified factor so the independent care subscale was added. Items intending to measure quality of life were loaded in the social interference subscale.

CONCLUSIONS

We recommend eliminating the quality of life subscale and including those items in the social interference subscale, and eliminating the self-efficacy items and re-evaluating the items related to independent care.

Multiplex allele-specific polymerase chain reaction for detection of isoniazid resistance in Mycobacterium tuberculosis

SETTING

Pham Ngoc Thach Tuberculosis Reference Hospital, Ho Chi Minh City, Viet Nam.

DESIGN

A multiplex allele-specific polymerase chain reaction (MAS-PCR) was developed to detect mutations at the two most common sites responsible for isoniazid (INH) resistance in Mycobacterium tuberculosis: katG315 and inhA-15. The MAS-PCR is able to detect rare mutations at katG315, in addition to katG S315T. Conventional phenotypic proportion drug susceptibility testing on Löwenstein-Jensen media was used as a gold standard to compare the sensitivity and specificity of the commercial MTBDRplus line-probe assay and the MAS-PCR in 100 INH-resistant and 50 INH-susceptible isolates collected consecutively at Pham Ngoc Thach Hospital reference laboratory.

RESULTS

The sensitivity and specificity on culture isolates were 90% (n = 90/100, 95%CI 0.83-0.94) and 100% (n = 50/50, 95%CI 0.93-1.0), respectively, for the MAS-PCR and the MTBDRplus assay.

CONCLUSION

The MAS-PCR described here represents an alternative method for rapid screening for INH resistance in M. tuberculosis isolates.

Type I interferon inhibits expression of the alternative GATA3 transcript in human Th2 cells (57.22)

The GATA3 transcription factor contributes to multiple immune processes, including the differentiation of T helper type 2 (Th2) cells. Th2 cells regulate many aspects of allergic disorders and express GATA3 in response to IL-4 signaling. Subsequently, GATA3 promotes transcription of the Th2 cytokines while also creating a feed-forward loop that stabilizes Th2 commitment. A previous study in mice has shown that Th2 commitment is accompanied by increased utilization of an alternate first exon (exon 1A) in the GATA3 transcript via an upstream promoter. The resulting transcript contains the same protein coding sequence but permits cell-specific control of expression levels. We previously demonstrated that the antiviral cytokine type I interferon (IFN-α/β) suppresses GATA3 mRNA and protein levels both in developing Th2 cells and in fully committed Th2 cells, leading to a decrease in Th2 cytokine expression. Here, we show that IL-4 significantly enhances utilization of exon 1A in the GATA3 transcripts in human Th2 cells. IFN-α/β preferentially inhibits expression of the exon 1A transcript, suggesting that IFN-α/β can regulate Th2 cells without affecting the basal levels of GATA3 required for other immune processes. Thus, IFN-α/β suppresses GATA3 in human Th2 cells and may be useful as a novel therapeutic for asthma and allergy.

Killer Proteins: Development of a bacteriocidal assay to study the role of complement in killing bacteria. (41.8)

Complement is an important component in the innate immune system’s defense against bacterial infections. In this unit, we teach basic principles of innate immunity by focusing on the biochemical nature of the complement cascade and its role in directly killing bacteria. We have developed a classroom curriculum that combines didactic course material with a novel laboratory exercise to help students understand the concept of complement in immunology. We have developed a bacteriocidal assay that students will perform to demonstrate the ability of complement to kill bacteria. This laboratory exercise, and subsequent background discussions, will introduce two key aspects of innate immunity. First, complement is a natural group of proteins secreted predominately by the liver which is an effective bacteriocidal agent. Second, complement and antibodies work harmoniously together to recognize and eliminate bacteria as a bridge to adaptive immunity. Students will be able to study the effects of both complement alone and complement plus antibody complexes in this bacteriocidal experiment. An interactive, hands-on laboratory activity enables students to quantify bacterial cell death with a colony forming unit assay of E.coli . Through this exercise, students will be able to focus on basic principles of innate immunity, experimental design and execution, and data analysis.

Type I interferon reverses human Th2 commitment and stability by repressing GATA3 (91.11)

CD4+ T helper-type 2 (Th2) cells regulate inflammatory responses to helminth infections while also mediating pathological processes of asthma and allergy. IL-4 drives Th2 development by inducing the expression of the GATA3 transcription factor. GATA3 positively reinforces its own expression thereby promoting IL-4-independent stability in Th2 cells. In this study, we found that type I interferon (IFN-α/β) potently blocked human Th2 development and inhibited cytokine secretion from pre-committed Th2 cells. Further, IFN-α/β inhibited Th2 cytokine secretion from CRTH2+ cells isolated from peripheral blood. This negative regulatory pathway was operative in human, but not mouse CD4+ T cells and was specific to type I interferon as neither IL-12 nor IFN-γ mediated such inhibition. IFN-α/β blocked Th2 cytokine secretion through the inhibition of GATA3 expression during both Th2 development and in fully committed Th2 cells. Thus, we demonstrate a novel role for IFN-α/β in blocking Th2 commitment, highlighting its potential as a therapy for atopy and asthma.

Reduced helminth burden increases allergen skin sensitization but not clinical allergy: a randomized, double-blind, placebo-controlled trial in Vietnam

BACKGROUND

Observational evidence suggests that infection with helminths protects against allergic disease and allergen skin sensitization. It is postulated that such effects are mediated by helminth-induced cytokine responses, in particular IL-10.

OBJECTIVE

We tested this hypothesis in a rural area of central Vietnam where hookworm infection is endemic.

METHODS

One thousand five hundred and sixty-six schoolchildren aged 6-17 were randomly allocated to receive either anti-helminthic therapy or a placebo at 0, 3, 6, and 9 months. We compared changes in the prevalence of exercise-induced bronchoconstriction, allergen skin sensitization, flexural eczema on skin examination, questionnaire-reported allergic disease (wheeze and rhinitis symptoms), and immunological parameters (hookworm-induced IFN-gamma, IL-5, IL-10) between 0 and 12 months.

RESULTS

One thousand four hundred and eighty-seven children (95% of these randomized) completed the study. The most common helminth infections were hookworm (65%) and Ascaris lumbricoides (7%). There was no effect of the therapy on the primary outcome, exercise-induced bronchoconstriction (within-participant mean percent fall in peak flow from baseline after anti-helminthic treatment 2.25 (SD 7.3) vs. placebo 2.19 (SD 7.8, P=0.9), or on the prevalence of questionnaire-reported wheeze [adjusted odds ratio (OR)=1.16, 95% confidence interval (CI) 0.35-3.82, P=0.8] and rhinitis (adjusted OR=1.39, 0.89-2.15, P=0.1), or flexural dermatitis on skin examination (adjusted OR=1.15, 0.39-3.45, P=0.8). However, anti-helminthic therapy was associated with a significantly higher allergen skin sensitization risk (adjusted OR=1.31, 1.02-1.67, P=0.03). This effect was particularly strong for children infected with A. lumbricoides at baseline (adjusted OR=4.90, 1.48-16.19, P=0.009). Allergen skin sensitization was inversely related to hookworm-specific IL-10 at baseline (adjusted OR=0.76, 0.59-0.99, P=0.04). No cytokine tested, including IL-10, changed significantly after the anti-helminthic therapy compared with the placebo.

CONCLUSION

A significant reduction in worm burden over a 12-month period in helminth-infected children increases the risk of allergen skin sensitization but not of clinical allergic disease. The effect on skin sensitization could not be fully explained by any of the immunological parameters tested.

Quantification of artemisinin in human plasma using liquid chromatography coupled to tandem mass spectrometry

A liquid chromatographic tandem mass spectroscopy method for the quantification of artemisinin in human heparinised plasma has been developed and validated. The method uses Oasis HLB mu-elution solid phase extraction 96-well plates to facilitate a high throughput of 192 samples a day. Artesunate (internal standard) in a plasma-water solution was added to plasma (50 microL) before solid phase extraction. Artemisinin and its internal standard artesunate were analysed by liquid chromatography and MS/MS detection on a Hypersil Gold C18 (100 mm x 2.1 mm, 5 microm) column using a mobile phase containing acetonitrile-ammonium acetate 10mM pH 3.5 (50:50, v/v) at a flow rate of 0.5 mL/min. The method has been validated according to published FDA guidelines and showed excellent performance. The within-day, between-day and total precisions expressed as R.S.D., were lower than 8% at all tested quality control levels including the upper and lower limit of quantification. The limit of detection was 0.257 ng/mL for artemisinin and the calibration range was 1.03-762 ng/mL using 50 microL plasma. The method was free from matrix effects as demonstrated both graphically and quantitatively.

Comparison of MAS-PCR and GenoType MTBDR assay for the detection of rifampicin-resistant Mycobacterium tuberculosis

SETTING

Pham Ngoc Thach Hospital for Tuberculosis and Lung Diseases, the tertiary referral hospital for tuberculosis (TB) in Southern Vietnam.

OBJECTIVE

To develop and evaluate a simple, rapid and accurate multiplex allele specific polymerase chain reaction (MAS-PCR) test to detect rifampicin (RMP) resistance point mutations at codons 516, 526 or 531 in the rpoB gene of Mycobacterium tuberculosis.

DESIGN

The novel MAS-PCR was compared with the commercial M. tuberculosis Drug Resistance (MTBDR) test in 104 RMP-resistant and 50 RMP-susceptible routine isolates, defined by conventional 1% phenotypic susceptibility testing.

RESULTS

The sensitivity of the MAS-PCR and MTBDR tests was respectively 83.7% (95%CI 75.1-90.2) and 93.3% (95%CI 86.6-97.3). Both tests were 100% specific. The negative predictive value was 74.6% (95%CI 65.3-83.1) for the MAS-PCR and 87.7% (95%CI 80.0-93.6) for the MTBDR test.

CONCLUSION

The MTBDR test, although more sensitive, is currently prohibitively expensive in resource-poor, high-burden settings. The MAS-PCR described here presents a less laborious economic alternative. A susceptible result returned by either test cannot be used to exclude multidrug-resistant TB.

Strobilurin fungicides induce changes in photosynthetic gas exchange that do not improve water use efficiency of plants grown under conditions of water stress

The effects of five strobilurin (beta-methoxyacrylate) fungicides and one triazole fungicide on the physiological parameters of well-watered or water-stressed wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and soya (Glycine max Merr.) plants were compared. Water use efficiency (WUE) (the ratio of rate of transpiration, E, to net rate of photosynthesis, A(n)) of well-watered wheat plants was improved slightly by strobilurin fungicides, but was reduced in water-stressed plants, so there is limited scope for using strobilurins to improve the water status of crops grown under conditions of drought. The different strobilurin fungicides had similar effects on plant physiology but differed in persistence and potency. When applied to whole plants using a spray gun, they reduced the conductance of water through the epidermis (stomatal and cuticular transpiration), g(sw), of leaves. Concomitantly, leaves of treated plants had a lower rate of transpiration, E, a lower intercellular carbon dioxide concentration, c(i), and a lower net rate of photosynthesis, A(n), compared with leaves of control plants or plants treated with the triazole. The mechanism for the photosynthetic effects is not known, but it is hypothesised that they are caused either by strobilurin fungicides acting directly on ATP production in guard cell mitochondria or by stomata responding to strobilurin-induced changes in mesophyll photosynthesis. The latter may be important since, for leaves of soya plants, the chlorophyll fluorescence parameter F(v)/F(m) (an indication of the potential quantum efficiency of PSII photochemistry) was reduced by strobilurin fungicides. It is likely that the response of stomata to strobilurin fungicides is complex, and further research is required to elucidate the different biochemical pathways involved.

Cerebral calpain in fatal falciparum malaria

Disruption of axonal transport may represent a final common pathway leading to neurological dysfunction in cerebral malaria (CM). Calpains are calcium (Ca2+)-activated cysteine proteases which have been implicated in axonal injury in neurological diseases of various aetiologies. In this study we examined the association between mu- and m-calpain, the specific inhibitor calpastatin, and axonal injury in post mortem brain tissue from patients who died from severe malaria. Calpains were associated with axons labelled for the beta-amyloid precursor protein that detects impaired axonal transport. Elevated levels of calpastatin were rarely observed in injured axons. There were increased numbers of neurones with mu-calpain in the nuclear compartment in severe malaria cases compared with non-neurological controls, and increased numbers of glia with nuclear mu-calpain in CM patients compared with non-CM malaria cases and non-neurological controls. There was marked redistribution of calpastatin in the sequestered Plasmodium falciparum-infected erythrocytes. Responses specific to malaria infection were ascertained following analysis of brain samples from fatal cases with acute axonal injury, HIV encephalitis, and progressive multifocal leucoencephalopathy. Our findings implicate a role for calpains in the modulation of disease progression in CM.

Molecular analysis of Mycobacterium tuberculosis causing multidrug-resistant tuberculosis meningitis

SETTING

Tertiary referral hospitals in southern Vietnam.

OBJECTIVE

Molecular characterisation of multidrug-resistant (MDR) tuberculous meningitis (TBM).

DESIGN

Mycobacterium tuberculosis isolates from the cerebrospinal fluid (CSF) of 198 Vietnamese adults were compared with 237 isolates from patients with pulmonary tuberculosis (PTB) matched for age, sex and residential district. Isolates resistant to isoniazid or rifampicin (RMP) were sequenced in the rpoB and katG genes, inhA promoter and oxyR-ahpC intergenic regions.

RESULTS

While drug resistance rates were lower in the CSF (2.5% MDR) than pulmonary isolates (5.9% MDR), the difference was not significant. The most commonly mutated codons were 531, 526 and 516 in rpoB and 315 in katG. Four novel triple mutants in rpoB were identified.

CONCLUSION

RMP resistance is a good surrogate marker for MDR-TBM in this setting. However, probes directed against these three codons would have a maximum sensitivity of only 65%. A rapid phenotypic detection test may be more applicable for the diagnosis of MDR-TBM.

A simple and rapid liquid chromatographic assay for evaluation of potentially counterfeit Tamiflu

A simple and rapid liquid chromatographic assay for the evaluation of potentially counterfeit oseltamivir (Tamiflu has been developed and assessed. The assay uses approximately 1mg Tamiflu powder when used for authentication and content estimate. The procedure was validated using 50 replicates analysed during five independent series with a total R.S.D. of 11.2%. The assay can also be used to monitor the exact content of oseltamivir in Tamiflu capsules. One Tamiflu capsule was transferred to a 250mL volumetric flask and 150mL water was added. The flask was placed in an ultrasonic bath at 40 degrees C for 20min to dissolve the capsule. The solution was allowed to cool to room temperature before the flask was filled up to the mark (250mL). A small aliquot was centrifuged and then directly injected into the LC-system for quantification. Oseltamivir was analysed by liquid chromatography with UV detection on a Hypersil Gold column (150mmx4.6mm) using a mobile phase containing methanol-phosphate buffer (pH 2.5; 0.1M) (50:50, v/v) at a flow rate of 1.0mL/min. The assay was implemented for the analysis of Tamiflu purchased over the Internet and at local pharmacies in Thailand and Vietnam.

Evolution and adaptation of H5N1 influenza virus in avian and human hosts in Indonesia and Vietnam

Highly pathogenic avian influenza virus H5N1 is endemic in poultry in East and Southeast Asia with disease outbreaks recently spreading to parts of central Asia, Europe and Africa. Continued interspecies transmission to humans has been reported in Vietnam, Thailand, Cambodia, Indonesia and China, causing pandemic concern. Here, we genetically characterize 82 H5N1 viruses isolated from poultry throughout Indonesia and Vietnam and 11 human isolates from southern Vietnam together with sequence data available in public databases to address questions relevant to virus introduction, endemicity and evolution. Phylogenetic analysis shows that all viruses from Indonesia form a distinct sublineage of H5N1 genotype Z viruses suggesting this outbreak likely originated from a single introduction that spread throughout the country during the past two years. Continued virus activities in Indonesia were attributed to transmission via poultry movement within the country rather than through repeated introductions by bird migration. Within Indonesia and Vietnam, H5N1 viruses have evolved over time into geographically distinct groups within each country. Molecular analysis of the H5N1 genotype Z genome shows that only the M2 and PB1-F2 genes were under positive selection, suggesting that these genes might be involved in adaptation of this virus to new hosts following interspecies transmission. At the amino acid level 12 residues were under positive selection in those genotype Z viruses, in the HA and PB1-F2 proteins. Some of these residues were more frequently observed in human isolates than in avian isolates and are related to viral antigenicity and receptor binding. Our study provides insight into the ongoing evolution of H5N1 influenza viruses that are transmitting in diverse avian species and at the interface between avian and human hosts.