High-dose pulse methylprednisolone vs. dexamethasone standard therapy for severe and critical COVID-19 pneumonia: Efficacy assessment in a retrospective single-centre experience from Malaysia

INTRODUCTION

The use of dexamethasone (DXM) has been associated with decreased mortality in the patients with hypoxemia during the coronavirus disease-2019 (COVID-19) pandemic, while the outcomes with methylprednisolone (MTP) have been mixed. This real-life study aimed to evaluate the outcomes of patients with severe respiratory failure due to COVID-19 who were treated with high doses of MTP.

MATERIALS AND METHODS

This retrospective cohort study enrolled hospitalised patients between May 2021 and August 2021, aged 18 years and above, with severe respiratory failure defined by a ratio of oxygen saturation to fraction of inspired oxygen (SF ratio) of less than 235. The treatment protocol involved administering high-dose MTP for 3 days, followed by DXM, and the outcomes were compared with those of patients who received DXM alone (total treatment duration of 10 days for both groups).

RESULTS

A total of 99 patients were enrolled, with 79 (79.8%) receiving pulse MTP therapy and 20 (20.2%) being treated with DXM only. The SF ratio significantly improved from a mean of 144.49 (±45.16) at baseline to 208 (±85.19) at 72 hours (p < 0.05), with a mean difference of 63.51 (p < 0.001) in patients who received ≤750 mg of MTP. Additionally, in patients who received >750 mg of MTP, the SF ratio improved from a baseline mean of 130.39 (±34.53) to 208.44 (±86.61) at 72 hours (p < 0.05), with a mean difference of 78.05 (p = 0.001). In contrast, patients who received DXM only demonstrated an SF ratio of 132.85 (±44.1) at baseline, which changed minimally to 133.35 (±44.4) at 72 hours (p = 0.33), with a mean difference of 0.50 (p = 0.972). The incidence of nosocomial infection was higher in the MTP group compared with the DXM group (40.5% vs. 35%, p = 0.653), with a relative risk of 1.16 (95% CI: 0.60-2.23).

CONCLUSION

MTP did not demonstrate a significant reduction in intubation or intensive care unit admissions. Although a high dose of MTP improved gas exchange in patients with severe and critical COVID-19, it did not provide an overall mortality benefit compared to standard treatment.

Host inflammatory response is the major marker of severe respiratory syncytial virus infection in older adults

OBJECTIVES

We aim to study the viral kinetics and host inflammatory response of RSV infection in older adults, and their correlation with disease severity.

METHODS

We performed a prospective observational study in adults with RSV infection. We serially collected nasal-throat swabs for quantification of RSV-A and RSV-B viral load, and peripheral blood samples for measurement of cytokine/chemokine concentrations. The study endpoints were (i) requiring supplemental oxygen therapy, and (ii) non-invasive ventilation, intensive care, or died within 30 days of admission. We performed multivariable logistic regression models to identify independent variables for severe disease.

RESULTS

We enrolled 71 hospitalized patients and 10 outpatients treated for RSV infection (median age 75 years, 51% male, and 74% with comorbidities). Among hospitalized patients, 61% required supplemental oxygen therapy, and 18% had severe disease requiring non-invasive ventilation or intensive care, or died within 30 days. Inflammatory cytokine/chemokines IL-6, CXCL8/IL-8, CXCL9/MIG and CXCL10/IP-10 increased significantly during the acute phase of illness. IL-6 concentration was independently associated with severe disease after adjusting for confounding factors. RSV viral load was not associated with disease severity throughout the course of illness.

CONCLUSION

Host inflammatory response is a major marker of severe disease in older adults with RSV infection.

A case of co-infection: First reported case of severe plasmodium knowlesi malaria and dengue co-infection in Sabah, Malaysia

We report a rare case of severe Plasmodium knowlesi malaria and dengue co-infection in a 36-year-old lady with hyperparasitaemia, metabolic acidosis, haemolysis and acute kidney injury. She was in shock requiring inotropic support and elective intubation. She had pericardial tamponade which necessitate pericardiocentesis to allow for haemodynamic stability during haemodialysis. She underwent haemodialysis, was ventilated for six days and stayed in hospital for 29 days. She was discharged home well with almost complete renal recovery. Physicians must have a high degree of suspicion for dengue co-infection in malaria patients with plasma leakage such as pericardial effusion to allow for prompt management.

Genetic ablation of Cyp8b1 preserves host metabolic function by repressing steatohepatitis and altering gut microbiota composition

Both type 2 diabetes (T2D) and nonalcoholic steatohepatitis (NASH) are associated with reduced hepatic mitochondrial respiratory capacity. Cholic acid (CA) is the predominant 12α-hydroxylated bile acid that regulates hepatic lipid metabolism, and its circulating levels are negatively correlated with insulin resistance. Abolishing CA synthesis via the genetic disruption of the enzyme sterol 12α-hydroxylase ( Cyp8b1^-/-) leads in resistance to diabetes and hepatic steatosis. Here, we show that long-term stimulation of hepatic lipogenesis leads to a severe impairment in overall metabolic and respiratory function in control mice ( Cyp8b1^+/+) but strikingly not in Cyp8b1^-/- mice. Cyp8b1^-/- mice are protected from such metabolic impairments associated with T2D and NASH by inhibiting hepatic de novo lipogenic gene and protein expression and altering gut microbiota composition. The protective phenotype is compromised when NASH induction is independent of impairment in de novo lipogenesis (DNL). Consequently, Cyp8b1^-/- mice also show a reduction in hepatic inflammation and fibrosis along with a shift in antimicrobial dynamics in the small intestine. Our data show that the altered bile acid composition of Cyp8b1^-/- mice preserves metabolic and respiratory function by repressing hepatic DNL and driving favorable changes in gut antimicrobial responses.

Evaluation of three rapid oral fluid test devices on the screening of multiple drugs of abuse including ketamine

Rapid oral fluid testing (ROFT) devices have been extensively evaluated for their ability to detect common drugs of abuse; however, the performance of such devices on simultaneous screening for ketamine has been scarcely investigated. The present study evaluated three ROFT devices (DrugWipe^® 6S, Ora-Check^® and SalivaScreen^®) on the detection of ketamine, opiates, methamphetamine, cannabis, cocaine and MDMA. A liquid chromatography tandem mass spectrometry (LCMS) assay was firstly established and validated for confirmation analysis of the six types of drugs and/or their metabolites. In the field test, the three ROFT devices were tested on subjects recruited from substance abuse clinics/rehabilitation centre. Oral fluid was also collected using Quantisal^® for confirmation analysis. A total of 549 samples were collected in the study. LCMS analysis on 491 samples revealed the following drugs: codeine (55%), morphine (49%), heroin (40%), methamphetamine (35%), THC (8%), ketamine (4%) and cocaine (2%). No MDMA-positive cases were observed. Results showed that the overall specificity and accuracy were satisfactory and met the DRUID standard of >80% for all 3 devices. Ora-Check^® had poor sensitivities (ketamine 36%, methamphetamine 63%, opiates 53%, cocaine 60%, THC 0%). DrugWipe^® 6S showed good sensitivities in the methamphetamine (83%) and opiates (93%) tests but performed relatively poorly for ketamine (41%), cocaine (43%) and THC (22%). SalivaScreen^® also demonstrated good sensitivities in the methamphetamine (83%) and opiates (100%) tests, and had the highest sensitivity for ketamine (76%) and cocaine (71%); however, it failed to detect any of the 28 THC-positive cases. The test completion rate (proportion of tests completed with quality control passed) were: 52% (Ora-Check^®), 78% (SalivaScreen^®) and 99% (DrugWipe^® 6S).

Remission of systemic lupus erythematosus disease activity with regulatory cytokine interleukin (IL)-35 in Murphy Roths Large (MRL)/lpr mice

The immunological mechanisms mediated by regulatory cytokine interleukin (IL)-35 are unclear in systemic lupus erythematosus (SLE). We investigated the frequency of CD4(+) CD25(+) forkhead box protein 3 (FoxP3)(+) regulatory T (Treg ) and IL-10(+) regulatory B (Breg ) cells and related immunoregulatory mechanisms in a female Murphy Roths Large (MRL)/lpr mouse model of spontaneous lupus-like disease, with or without IL-35 treatment. A remission of histopathology characteristics of lupus flare and nephritis was observed in the MRL/lpr mice upon IL-35 treatment. Accordingly, IL-35 and IL-35 receptor subunits (gp130 and IL-12Rβ2) and cytokines of MRL/lpr and BALB/c mice (normal controls) were measured. The increased anti-inflammatory cytokines and decreased proinflammatory cytokines were possibly associated with the restoration of Treg and Breg frequency in MRL/lpr mice with IL-35 treatment, compared to phosphate-buffered saline (PBS) treatment. mRNA expressions of Treg -related FoxP3, IL-35 subunit (p35 and EBI3) and soluble IL-35 receptor subunit (gp130 and IL12Rβ2) in splenic cells were up-regulated significantly in IL-35-treated mice. Compared with the PBS treatment group, IL-35-treated MRL/lpr mice showed an up-regulation of Treg -related genes and the activation of IL-35-related intracellular Janus kinase/signal transducer and activator of transcription signal pathways, thereby indicating the immunoregulatory role of IL-35 in SLE. These in vivo findings may provide a biochemical basis for further investigation of the regulatory mechanisms of IL-35 for the treatment of autoimmune-mediated inflammation.

Aberrant expression of regulatory cytokine IL-35 in patients with systemic lupus erythematosus

Objective

This study characterizes an IL-35-mediated regulatory role in patients with systemic lupus erythematosus (SLE).

Methods

Plasma of SLE patients and healthy controls (HCs) was analyzed for the concentrations of IL-35 and soluble gp130 by using ELISA. mRNA expression of IL-35 subunit (p35 and EBI3) and its receptor (gp130 and IL-12Rβ2) in peripheral blood mononuclear cells (PBMCs) was assessed by RT-qPCR. Flow cytometry was performed to evaluate the number of CD4+CD25highCD127−Treg cells and the expression of IL-35 receptor on the CD4+ helper (Th) cells and CD19+ B cells. Plasma collected from SLE patients and HCs was assayed for cytokine and chemokine expression by Luminex multiplex assay.

Results

Plasma IL-35 and soluble gp130 levels positively correlated with each other and were significantly higher in patients with severe SLE compared with HCs. Significantly higher levels of inflammatory cytokines/chemokines CCL2, CXCL8, IL-6, interferon (IFN)-γ, IL-10 and IL-17A were observed in plasma of SLE patients than HCs. mRNA levels of IL-35 and its receptor were significantly positively correlated in PBMCs from SLE patients and their levels were higher in SLE than HCs. The increase significantly correlated with changes in SLE Disease Activity Index (SLEDAI) (all p < 0.05). In addition, the number of Treg cells in severe and moderate SLE patients were both significantly lower than HCs, where the ratio of CD4+CD25−effector T cell %/CD4+CD25highCD127−Treg % was found to be significantly higher in severe SLE patients. Furthermore, the expression of gp130 on CD4+ Th cells and percentage of Tregs were positively correlated with each other, and both were negatively correlated with SLEDAI.

Conclusion

Our findings indicate that high level of plasma IL-35 in active SLE patients expressed with low level of IL-35 receptor (gp130) on CD4+ Th cells. These data raise the possibility that the level of IL-35 expression in SLE patients is not sufficient to induce the production of CD4+CD25highCD127−Tregs, and subsequently suppress the release of inflammatory cytokines and chemokines upon inflammation.

Members of the receptor for advanced glycation end products axis as potential therapeutic targets in patients with lupus nephritis

The relationship of inflammation and the expression of full-length receptor for advanced glycation end products (flRAGE) on monocytes, plasma levels of RAGE ligand high mobility group box protein 1 (HMGB1), soluble RAGE (sRAGE) and endogenous secretory RAGE (esRAGE) was assessed to elucidate the effect of HMGB1/DNA/RAGE-mediated innate inflammatory responses in patients with lupus nephritis. Cell surface expression of flRAGE was elevated on the monocytes of lupus patients, correlated with plasma HMGB1 levels. Plasma sRAGE level negatively correlated with systemic lupus erythematosus (SLE) disease activity index. Plasma esRAGE level was significantly lower in SLE patients with flare while esRAGE/sRAGE ratio negatively correlated with complement C3 level. HMGB1 alone could moderately induce ex vivo IL-6 production from monocytes, resulting in activation of intracellular p38 mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase and nuclear factor (NF)-κB. Moreover, toll-like receptor-9 ligand together with HMGB1 exhibited a synergistic effect on IL-6 and IL-12p70 secretions and the phosphorylation of p38 MAPK and NF-κB. Therefore, over-expression of flRAGE in lupus may lead to the amplification of RAGE ligands-mediated inflammatory responses through the activation of p38 MAPK and NF-κB. Plasma sRAGE may serve as a potential biomarker for disease activity and a future therapeutic target in SLE.

Polymer-induced change in scaling behavior in two-dimensional homogeneous turbulent thermal convection

We study the effects of polymers in two-dimensional turbulent thermal convection using a shell model. In the absence of polymers, the inverse energy cascade in two dimensions leads to the observed Bolgiano-Obukhov scaling. When polymers are added, energy is extracted from the flow by the polymers, and as a result, the thermal balance between buoyancy and inertia in Bolgiano-Obukhov scaling is destroyed around the scales at which polymers interact strongly with the flow. This results in an increase in the Bolgiano scale and leads to a change in the scaling behavior of the velocity and temperature fluctuations for scales below the modified Bolgiano scale. We make theoretical estimates of the dependence of the mean rate of energy extracted by the polymers and the mean energy dissipation rate on the polymer relaxation time. Our theoretical analysis further leads to the prediction that the heat transport is not altered much by the polymers in two dimensions. We show that our theoretical estimates and prediction are in good agreement with the numerical results.

Transnasal penetrating intracranial injury with a chopstick

We report the first case of a transnasal penetrating intracranial injury in Hong Kong by a chopstick. A 49-year-old man attempted suicide by inserting a wooden chopstick into his left nose and then pulled it out. The chopstick caused a transnasal penetrating brain injury, confirmed by contrast magnetic resonance imaging of the brain. He was managed conservatively. Later he developed meningitis without a brain abscess and was prescribed antibiotics for 6 weeks. He enjoyed a good neurological recovery. This case illustrates that clinician should have a high index of suspicion for penetrating intracranial injury due to a nasally inserted foreign body, even though it had already been removed. In such cases moreover, brain magnetic resonance imaging is the imaging modality of choice, as it can delineate the path of penetration far better than plain computed tomography.

Effect of raloxifene on disease activity and vascular biomarkers in patients with systemic lupus erythematosus: subgroup analysis of a double-blind randomized controlled trial

OBJECTIVES

The purpose of this study was to identify the effect of raloxifene on disease activity and vascular biomarkers in patients with systemic lupus erythematosus (SLE).

METHODS

Subgroup data were analyzed for postmenopausal female SLE patients who participated in a randomized controlled trial of raloxifene on glucocorticoid-induced osteoporosis. Patients who were receiving a stable daily dose of prednisolone (≤10 mg) for ≥6 months were assigned to receive raloxifene (60 mg/day) or placebo on top of calcium and vitamin D. Disease activity was assessed by the Safety of Estrogens in Lupus Erythematosus National Assessment (SELENA), SLE disease activity index (SLEDAI) and physicians' global assessment (PGA) every three months. Lupus flares were assessed by the SELENA flare instrument. Serial serum levels of homocysteine, high-sensitivity C-reactive protein (hsCRP) and soluble thrombomodulin (sTM) were measured.

RESULTS

A total of 62 patients (30 raloxifene, 32 placebo) were studied (age 52.5 ± 6.7 years; SLE duration 9.3 ± 7.6 years; menopause duration 7.2 ± 6.6 years). The SLEDAI at entry was 1.8 ± 2.3 (SLEDAI ≥ 6 in 8%). After 12 months, a significant gain in bone mineral density (BMD) of the lumbar spine (1.6%, p = 0.02), and reduction in bone resorption and formation markers was observed in the raloxifene but not in the placebo treated patients. The SELENA-SLEDAI and PGA scores area under the curve over 12 months were not significantly different between the two groups. There were three episodes of mild/moderate lupus flares (33% musculoskeletal, 33% dermatological) in the raloxifene group, compared to nine episodes of mild/moderate flares (27% musculoskeletal, 45% dermatological) in the placebo group (p = 0.11). The low density lipoprotein (LDL) cholesterol level increased significantly in the placebo but not raloxifene treated patients. No significant changes in homocysteine, hsCRP and sTM levels were observed in either group of patients.

CONCLUSIONS

Raloxifene significantly improves lumbar spine BMD in SLE patients but does not cause an increase in lupus activity or flares.

Muramyl dipeptide mediated activation of human bronchial epithelial cells interacting with basophils: a novel mechanism of airway inflammation

Respiratory tract bacterial infection can amplify and sustain airway inflammation. Intracytosolic nucleotide-binding oligomerization domain-containing protein 2 (NOD2) is one member of the nucleotide binding and oligomerization domain (NOD)-like receptor (NLR) family, which senses the conserved structural peptidoglycan component muramyl dipeptide (MDP) in almost all bacteria. In the present study, activation of the NOD2 ligand MDP on primary human bronchial epithelial cells (HBE) co-cultured with human basophils was investigated. Cytokines, NOD2, adhesion molecules and intracellular signalling molecules were assayed by enzyme-linked immunosorbent assay or flow cytometry. The protein expression of NOD2 was confirmed in basophils/KU812 cells and HBE/human bronchial epithelial cell line (BEAS-2B) cells. MDP was found to up-regulate significantly the cell surface expression of intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 on basophils and HBE in the co-culture system with or without basophil priming by interleukin (IL)-33 (all P < 0·05). MDP could further enhance the release of inflammatory cytokine IL-6 and chemokine CXCL8, and epithelium-derived anti-microbial peptide β-defensin 2 in the co-culture. HBE cells were the major source for the release of IL-6, CXCL8 and β-defensin2 upon stimulation by MDP in the co-culture system. The expression of ICAM-1 and VCAM-1 and release of IL-6 and CXCL8 were suppressed by various signalling molecule inhibitors, implying that the interaction between basophils and primary human bronchial epithelial cells could be regulated differentially by the mitogen-activated protein kinase pathways and nuclear transcription factors. The results therefore provide a new insight into the functional role of basophils in innate immunity, and the link between respiratory bacteria-mediated innate immunity and subsequent amplification of allergic inflammation in the airway.

Angioplasty and stenting for intracranial atherosclerotic stenosis: position statement of the Hong Kong Society of Interventional and Therapeutic Neuroradiology

As a means of preventing secondary ischaemic stroke, angioplasty and stenting are considered potentially beneficial for patients with severe intracranial atherosclerotic stenosis. However, the role of stenting has been challenged since the publication of the first randomised controlled trial on Stenting versus Aggressive Medical Management for Preventing Recurrent stroke in Intracranial arterial Stenosis (SAMMPRIS). This indicated that aggressive medical management was superior to stenting using Wingspan to prevent recurrent stroke, because stenting has a high peri-procedural stroke and death rate. In this paper, we review the management of intracranial atherosclerosis, revisit the skepticism on stenting, and state our position on the topic in the form of recommendations. These are based on the prevalence of the disease in Hong Kong, the high risk of recurrent stroke despite medical therapy in the presence of haemodynamic intracranial stenosis without sufficient collaterals, an analysis of the weak points of SAMMPRIS, and results of clinical studies in Hong Kong.

An integrated lab-on-a-disc for automated cell-based allergen screening bioassays

We have utilized various valving scheme to leverage purely rotation-regulated flow control to enable comprehensive cell-based bioassays (CBBs) on centrifuge-based lab-on-a-disc (LOAD). A LOAD has been developed to examine allergic degranulation from live basophils for allergens screening for the first time, which can also be adjusted to suit a wide range of CBBs. In this system, controlled allergic reaction together with mediator separation from basophils using siphon valving and centrifugal sedimentation are realized inside microstructured network. The entire degranulation analysis process including on-demand release of samples, reaction and degranulation, allergic mediator separation and detection is executed in an automatic sequence within a single run. To validate our cell-based approach, detection of degranulation mediated by known secretagagues, ionomycin or chemotatic peptide formyl-methionine-leucine-pheylalanine (fMLP), is first demonstrated. Further experiments using real allergens house dust mite protein (Der p1) and its corresponding human serum IgE also show positive results. The overall efficiency of the assay is 80.6%, which is comparable to other conventional methods. With 4 identical units on a disc running in a parallel format, the device offers the possibility of single-step, multiplexed allergens screening. The device is capable of reporting a result within 30 min. It has many desirable merits including fast and multiplexed analysis, low cost, single-step operation, minimal sample volume, less discomfort and most importantly increased safety as patients are no longer susceptible to possible anaphylactic shock reactions induced by the common skin-prick-test. The flexibility of the flow control within the device makes it suitable to a wide range of CBBs.

A narrative review of evidence-based recommendations for the physical examination of the lumbar spine, sacroiliac and hip joint complex

Non-specific low back pain is a frequent complaint in primary care, but the differential diagnosis for low back pain can be complex. Despite advances in diagnostic imaging, a specific pathoanatomical source of low back pain can remain elusive in up to 85% of individuals. Best practice guidelines recommend that clinicians conduct a focused physical examination to help to identify patients with non-specific low back pain and an evidence-based course of clinical management. The use of sensitive and specific clinical methods to assess the lumbar spine, sacroiliac and hip joints is critical for effective physical examination. Psychosocial factors also play an important role in the evaluation of individuals with low back pain, but are not included in this narrative review of physical examination methods. Physical examination of the lumbar spine, sacroiliac and hip joints is presented, organized around patient position for efficient and effective clinical assessment.

SEMI-CONSTRAINED TOTAL ELBOW ARTHROPLASTY IN CHINESE RHEUMATOID PATIENTS

Seventeen Coonrad-Morrey semi-constrained total elbow replacements were performed on 14 Chinese rheumatoid patients. The elbows were reviewed retrospectively after a mean follow-up of 36 months (range 12–89 months.) After the operation, all patients were satisfied and there was no pain in 15 elbows. There was no radiological sign of loosening in the implanted prostheses and bone graft was incorporated in 93% of primary elbow replacements. The Mayo Elbow Performance Score was improved from an average of 40 (range 20–75) to an average of 93 (range 65–100). The arc of flexion was improved from an average of 89° (range 0°–125°) to 104° (range 35°–125°). The sizes of implants can be predicted accurately by the planning template in only four elbows (24%) and there were early complications in seven elbows (41%), with one prosthesis removed because of deep infection.

A randomized-controlled trial to investigate the effects of rivoglitazone, a novel PPAR gamma agonist on glucose-lipid control in type 2 diabetes

AIM

To examine the efficacy, safety and tolerability of rivoglitazone, a novel thiazolidinedione (TZD), and explore its effects on glucose and lipid control compared to placebo and pioglitazone in Chinese type 2 diabetic patients who are treatment naÏve or treated with a single oral blood glucose-lowering drug.

METHODS

This was a double-blind, randomized, placebo- and active-controlled study. A total of 287 Chinese type 2 diabetic patients with suboptimal glycaemic control (defined as HbA1c ≥6.5 to <10% and fasting plasma glucose ≥7 to ≤15 mmol/l) were enrolled. One hundred and seventy-four eligible patients were randomized into one of the five treatment arms for 12 weeks: placebo, pioglitazone 30 mg daily, rivoglitazone of dose 0.5, 1.0 or 1.5 mg daily. In a full set analysis, we used analysis of covariance to compare the primary endpoint defined as change in HbA1c from baseline to week 12/last observation carried forward in the rivoglitazone group at each dose level with the placebo group.

RESULTS

Changes in HbA1c were -0.11% in the 0.5-mg group; -0.22% in the 1-mg group and -0.17% in the 1.5-mg rivoglitazone group; -0.06% in the 30-mg pioglitazone group and 0.61% in the placebo group. Compared to placebo, changes were significant in all active treatment groups (all p < 0.05). Increase in high-density lipoprotein cholesterol and decrease in triglyceride were observed in the rivoglitazone 1 and 1.5 mg groups, respectively, compared to placebo from baseline to week 12 (p < 0.05). Drug-related oedema was reported in eight patients (7.7%) in all rivoglitazone groups compared to six patients (16.2%) in the pioglitazone group and one patient (3.0%) in the placebo group.

CONCLUSIONS

Rivoglitazone is an efficacious, safe and well-tolerated TZD which improved glycaemic control in Chinese type 2 diabetic patients up to 3 months.

Deep brain stimulation in a Chinese Tourette's syndrome patient

A 31-year-old Chinese man with intractable severe, lifelong Tourette's syndrome characterised by forceful self-injurious motor tics and socially embarrassing vocal tics was treated with bilateral deep brain stimulation. Electrodes were implanted into the thalamic targets at the centromedian-parafascicular complex according to Hassler's nomenclature. A dramatic reduction of tics resulted. At 18 months postoperatively, there was an 81% improvement in his total tics count and a 58% improvement in his Yale Global Tic Severity Scale. His modified Rush video scale decreased from 13 to 8 and visual analogue scale from 10 to 3. These data show that bilateral deep brain stimulation of the thalamus can have a favourable immediate effect on severe tics in a selected group of adult patients suffering from intractable Tourette's syndrome and postoperatively the beneficial effects persisted for at least 18 months.

Photodynamic therapy (PDT) - Initiation of apoptosis via activation of stress-activated p38 MAPK and JNK signal pathway in H460 cell lines

AIMS

The purpose of this study was to investigate the photoefficacies of protoporphyrin IX (PpIX) generated by drug precursor 5-aminolevulinic acid (ALA) and its hexyl ester (H-ALA) on two human non-small lung carcinoma cell lines (H460/Bcl-2 and H460/neo).

MAIN METHODS

Drug uptake and the photoefficacies of PpIX were measured by flow cytometry and MTT assay; while the mode of cell death and alternation of signal transduction pathways were studied with 4',6-diamidino-2-phenylindole (DAPI) staining and Western blot analysis, respectively.

KEY FINDINGS

The flow cytometric analysis of H-ALA (5μM) uptake revealed optimal fluorescent intensity at 8h incubation, while ALA (0.5mM) was still far from saturation. The LD(30) of H-ALA-PDT was 30μM, 2J/cm(2), while the LD(30) of ALA-PDT was 3mM, 2J/cm(2). The dark toxicities mediated by both pro-drug H-ALA and ALA were negligible. By DAPI staining, apoptotic cell death was observed. In addition, by Western blot analysis, H-ALA- and ALA-mediated PDT initiated apoptotic cell death via the up-regulation and activation of p38 mitogen activated protein kinase (MAPK), the stress-activated c-jun N-terminal kinases (JNK) and ERK.

SIGNIFICANCE

These results suggested that H-ALA and ALA mediated PDT displayed similar photocytotoxicities towards the two non-small lung cancer cells. Our present study also demonstrates H-ALA or ALA mediated PDT in H460 cells are closely related to the activation of p38 MAPK and JNK signalling pathway.

Growth of dielectric-embedded silicon nanocrystallites for light-emitting device application

Dielectric films with embedded silicon Si nanocrystallites (Si-Nc) have been recognized as promising light-emitting materials for future integrated photonics based on silicon technology. This work reports a novel method of making this kind of material by high-temperature annealing of Si-rich oxide or nitride films which gives rise to the phase separation reaction and the formation of crystalline silicon nanoclusters in the films. Various characteristics of these materials were studied in detail by using transmission electron microscope, X-ray photoelectron spectroscopy (XPS), Raman, and photoluminescence (PL). Strong transverse optical (TO) mode of Si-Nc at around 516 cm(-1) was found in the Raman spectra of the annealed dielectric films. XPS studies indicate that the Si 2p spectra could be transformed from a random bonding structure (as-deposited) to a random mixing of Si-Nc with stoichiometric oxide or nitride phase after the high-temperature annealing. The energy locations of PL were found to depend on the amount of rich Si and the annealing conditions. Longer and higher temperature annealing can result in the growth of the Si-Nc size and leads to a red-shift of PL. Direct correlation among the crystallite sizes with the PL peaks was found.

DNA damage as a biomarker for assessing the effects of suspended solids on the orange-spotted grouper, Epinephelus coioides

In Hong Kong, suspended solids (SS) introduced by dredging and mud disposal activities are a major cause of mass mortality in cage-cultured marine fish. We have used DNA damage in liver cells, as determined by the comet assay, to assess the impact of SS on the orange-spotted grouper Epinephelus coioides. Seabed sediments were collected from a heavily polluted site in Victoria Harbor and two less polluted sites in Port Shelter and Mirs Bay. Sediments from Victoria Harbor contained higher levels of copper (Cu) and polycyclic aromatic hydrocarbons (PAHs) than those from the other sites. In a 10-day experiment, SS from all three sites induced significant increase in comet tail length, but not in percentage (%) tail DNA. In a 20-day experiment, fish exposed to polluted SS from Victoria Harbor exhibited a significant increase in comet tail length after 5 days and % tail DNA after 10 days. After a 10-day recovery period, however, DNA damage was reduced as tail length and % tail DNA returned to control levels. These results suggest that DNA damage measured by the comet assay is a highly sensitive biomarker for assessing the genotoxic effects of SS to marine fish.

Metabolic syndrome, endothelial injury, and subclinical atherosclerosis in patients with systemic lupus erythematosus

OBJECTIVES

To study the link between metabolic syndrome (MetS), endothelial injury, and atherosclerosis in patients with systemic lupus erythematosus (SLE).

METHODS

Consecutive SLE patients without a history of arterial thrombosis were screened for atherosclerosis at the carotid and coronary arteries by B-mode ultrasound [intima-media thickness (IMT)] and multidetector computed tomography (MDCT) scan (Agatston calcium scores), respectively. Plasma levels of homocysteine, high-sensitivity C-reactive protein (hsCRP), soluble vascular cell adhesion molecule (sVCAM)-1, P-selectin, and soluble thrombomodulin (sTM) were assayed. Patients were stratified according to the National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP III) criteria for MetS, using the Asian criteria for abdominal obesity. Risk factors for atherosclerosis were studied.

RESULTS

Of the 123 SLE patients (93% women; age 47.9+/-11 years; SLE duration 10.9+/-7.0 years) studied, 20 (16.3%) had MetS. The prevalence of MetS in the SLE patients was significantly higher than in 492 age- and sex-matched healthy controls (9.6%; p=0.03). Coronary calcification and abnormal carotid IMT were detected in 38 (31%) and 72 (59%) of SLE patients, respectively. Patients with MetS had a significantly higher Agatston score (69.5+/-95 vs. 16.4+/-57; p=0.03) and a numerically higher carotid IMT (p=0.43) than those without. In a logistic regression model, the MetS [odds ratio (OR) 3.11, 95% confidence interval (CI) 1.01-9.59, p=0.049] was associated with coronary atherosclerosis after adjustment for age and other risk factors. In addition, patients with MetS had significantly higher levels of hsCRP (p=0.002), homocysteine (p=0.03), and sTM (p=0.01).

CONCLUSIONS

The MetS is more prevalent in SLE patients than the general population and is associated with endothelial injury and coronary atherosclerosis. More aggressive control of risk factors is justified in these patients.

Decreased expression of T lymphocyte co-stimulatory molecule CD26 on invariant natural killer T cells in systemic lupus erythematosus

CD26, a T cell co-stimulatory molecule and dipeptidyl peptidase IV for the degradation of interferon-gamma-induced chemokine, participates in multiple immunopathological roles in leukocyte homing and inflammation. Decreased circulating concentration of soluble (s)CD26 in patients with systemic lupus erythematosus (SLE), rheumatoid arthritis and murine model of arthritis and encephalomyelitis have been reported. In the present study, the plasma concentration of sCD26 and chemokines, and cell surface expression of CD26 on monocytes, CD4+T lymphocytes, CD8+T lymphocytes, CD19+B lymphocytes and invariant natural killer T (iNKT) lymphocytes were analyzed using ELISA and flow cytometry, respectively, in 23 SLE patients and 14 sex- and age-matched control subjects. Although there was no significant difference between plasma concentrations of soluble CD26 in SLE patients with controls (p > 0.05), there was significant elevated Th1 chemokines CXCL10 and CXCL9 but not Th2 chemokine CCL2, and down-regulation in iNKT lymphocytes number and cell surface expression of CD26 on CD4+T and iNKT lymphocytes of SLE patients compared with controls (all p < 0.05). Decreased circulating number of iNKT cells and CD26 on iNKT cells can be important for the immunopathogenesis by exacerbating Th1-related inflammation in SLE.

Activation profile of Toll-like receptors of peripheral blood lymphocytes in patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease associated with aberrant activation of T and B lymphocytes for the production of inflammatory cytokines and autoreactive antibodies. Animal studies of SLE have indicated that Toll-like receptors (TLR) are important in the pathogenesis of murine lupus. In the present clinical study, differential protein expressions of TLR-1-9 of monocytes and different lymphocyte subsets from patients with SLE and normal control subjects were determined by flow cytometry. Results showed that the expression of intracellular TLRs (TLR-3, -8, -9) and extracellular TLRs (TLR-1, -2, -4, -5, -6) were elevated in monocytes, CD4(+) T lymphocytes, CD8(+) T lymphocytes and B lymphocytes of SLE patients compared to control subjects (all P < 0.001). Moreover, cell surface expression of TLR-4 on CD4(+) T lymphocytes and CD8(+) T lymphocytes, and TLR-6 on B lymphocytes, were correlated positively with SLE disease activity index (SLEDAI) (TLR-4 on CD4(+) T lymphocytes and CD8(+) T lymphocytes: r = 0.536, P = 0.04; r = 0.713, P = 0.003; TLR-6 in B lymphocytes: r = 0.572, P = 0.026). In concordance with the above results, there is an observable increased relative induction (%) of inflammatory cytokine interleukin (IL)-1beta, IL-6, IL-10 and IL-12, chemokines CCL2, CXCL8, CCL5 and CXCL10 from peripheral blood mononuclear cells (PBMC) upon differential stimulation by PolyIC (TLR-3 ligand), lipopolysaccharide (TLR-4 ligand), peptidoglycan (TLR-2 ligand), flagellin (TLR-5 ligand), R837 (TLR-7 ligand) and CpG DNA (TLR-9 ligand) in SLE patients compared to controls. These results suggest that the innate immune response for extracellular pathogens and self-originated DNA plays immunopathological roles via TLR activation in SLE.

Interleukin-17A activation on bronchial epithelium and basophils: a novel inflammatory mechanism

Basophils are the accessory cell type for T-helper (Th)2 induction and initiators in immunoglobulin E-mediated chronic allergic inflammation. Basophils and Th17 cells accumulate at the inflammatory sites, such as the airways of allergic asthmatic patients. We investigated the activation of interleukin (IL)-17A on the primary human basophils/KU812 basophilic cells and primary human bronchial epithelial cells/BEAS-2B bronchial epithelial cells. Cytokines, chemokines, adhesion molecules and intracellular signalling molecules were assayed by ELISA or flow cytometry. Co-culture of bronchial epithelial cells and basophils could significantly induce the release of IL-6, an epithelial inflammatory cytokine, and CCL2, a chemokine for basophils, esosinophils and monocytes. Such induction was synergistically enhanced by IL-17A, and direct interaction between these two cells was necessary for IL-17A-induced IL-6 and CCL2 release. Surface expression of intercellular adhesion molecule-1 on bronchial epithelial cells was also upregulated upon their interaction. The interaction of basophils and bronchial epithelial cells under IL-17A stimulation was differentially regulated by extracellular signal-regulated kinase, c-Jun N-terminal protein kinase, p38 mitogen-activated protein kinase and nuclear factor-kappaB pathways. These findings suggest a novel immunopathological role of Th17 cells and basophils in allergic asthma through the activation of granulocyte-mediated inflammation initiated by the direct interaction between basophils and bronchial epithelial cells.

Elevation of Pro-Inflammatory Cytokines, C-Reactive Protein and Cardiac Troponin T in Chronic Renal Failure Patients on Dialysis

Chronic renal failure (CRF) patients suffer from a chronic inflammation. They are at increased risk of cardiovascular disease. In order to investigate this inflammatory process and cardiovascular risk factors associated with haemodialysis (HD) and peritoneal dialysis (PD), we compared serum/plasma pro-inflammatory cytokines, C-reactive protein (CRP), and cardiac troponin T (cTnT) of 146 CRF patients treated or not treated with PD or HD. Serum cytokines and CRP as well as plasma cTnT were measured by enzyme-linked immunosorbent assay, chemiluminescence immunoassay, and electrochemiluminescence immunoassay, respectively. Results indicated that serum interleukin (IL)-18 concentrations were significantly higher in PD and low creatinine clearance pre-dialysis CRF (LCC) patients than HD patients (both p < 0.05). IL-6 and tumour necrosis factor (TNF)-alpha concentrations were significantly higher in PD patients than LCC patients (both p < 0.01). Serum hsCRP and plasma cTnT in HD were significantly higher than LCC (both p < 0.01). The elevation of pro-inflammatory cytokines should play an important role in the chronic inflammation and increased cardiovascular risk of CRF patients on dialysis. We are evaluating further the diagnostic and prognostic applications of pro-inflammatory cytokines and biochemical inflammatory markers for these patients.

Caseinolytic protease: a protein vaccine which could elicit serotype-independent protection against invasive pneumococcal infection

Invasive pneumococcal diseases incur significant mortality, morbidity and economic costs. The most effective strategy currently available to reduce the burden of these diseases is vaccination. In this study, we evaluated the protective efficacy of immunizing mice with caseinolytic protease (ClpP) protein antigen whose gene sequences were shown to be highly conserved in different strains of Streptococcus pneumoniae in an invasive-disease model (intraperitoneal infection model), and protection against invasive challenge with 12 different serotypes of S. pneumoniae was assessed in two murine strains. Our findings demonstrated that active immunization with ClpP and passive immunization with antibodies specific for ClpP could elicit serotype-independent protection effectively against invasive pneumococcal infection. Therefore, to our knowledge, this study is the first report that immunization with single pneumococcal ClpP protein antigen could protect against such broad-range pneumococal strains, which thus supports the development of ClpP as a human penumococcal vaccine.

Usefulness of laboratory mental stress test in patients with stable coronary artery disease

BACKGROUND AND HYPOTHESIS

Many episodes of ischemia in daily life are silent occurring during sedentary activities and may be related to mental stress. In 35 patients with stable angina and positive exercise test awaiting bypass surgery, we investigated whether laboratory mental stress tests would trigger ischemia of a comparable severity to that occurring in daily life and attempted to elucidate some of the underlying mechanisms.

METHODS

All patients underwent exercise testing, personality assessment, 2-day Holter monitoring, and laboratory mental stress tests while on their usual medications.

RESULTS

Only four patients (12%) had positive mental stress test (ST depression > or = 0.1 mV). All episodes were silent and usually associated with fast heart rate (> 90 beats/min). In contrast, ambulatory ischemia was common (average duration of 51 min per 24 h), and at least one episode was recorded in 27 patients (77%) including the 4 with positive test. Patients with positive mental stress test had a higher heart rate during testing (124 +/- 24 vs. 86 +/- 16 beats/min, p < 0.01), and a shorter exercise time and time to 1 mm ST depression on cycle ergometry than those with negative mental stress test. None of the four patients were on beta blockers. There was no difference in personality inventory between the two groups. Comparisons between patients with and without positive mental stress test revealed no difference in the duration and frequency of ambulatory ischemia, or in the occurrence of silent ischemia. However, the heart rate at onset of ambulatory ischemia tended to be higher in the patients with positive mental stress test (96 +/- 9 vs. 62 +/- 43, p = 0.07). Further subgroup analysis in patients without beta blockers (4 mental stress test positive and 18 negative) showed similar results.

CONCLUSIONS

Laboratory mental stress test is a weak inducer of ischemia detected by electrocardiographic monitoring in patients with frequent ambulatory ischemia. Wall motion evaluation during mental stress test may improve sensitivity. While larger scale studies may determine its clinical role, the present study illustrated that patients with heightened heart rate response to mental stress were identified in whom beta blockers could be the drug of choice.

Photoluminescence of silicon nanocrystals embedded in silicon oxide

The bonding structure and the optical properties of silicon-rich silicon oxide films which were prepared using plasma-enhanced chemical vapor deposition (PECVD) with thermal oxidation were studied in detail. The composition and bonding structures were explored using X-ray photoelectron spectroscopy (XPS). The luminescent properties were studied using Raman spectroscopy and photoluminescence (PL) measurements. Results show that high-temperature (approximately 1000 degrees C) annealing of as-deposited Si-rich silicon oxide gives rise to phase separation and formation of crystalline Si phases in the oxide films. Upon high temperature annealing, the PL (550-900 nm) intensity was significantly reduced in stoichiometric oxide or in low Si-content (prepared with [N2O]/[SiH4] gas flow ratio > 2.5) films whereas an opposite trend was found in higher Si-rich samples. Particularly, for the red band (650 nm) and the infrared band (750 nm), the PL intensity was significantly enhanced by annealing slightly Si-rich samples ([N2O] / [SiH4] = 2.5) at 1100 degrees C. This observation was explained by the formation of Si nanocrystallites via phase separation reaction and the removal of defect-related absorption centers during annealing.

Activation of peripheral Th17 lymphocytes in patients with asthma

A recently identified interleukin (IL)-17-producing T-helper (Th) lymphocyte subset, which comprises Th17 cells producing hallmark cytokines IL-17A, IL-17F and IL-22, is involved in chronic inflammatory diseases. Elevated gene and protein expressions of IL-17 are manifested in allergic asthma. We further characterized the activation of Th17 cells in asthmatic patients. Peripheral blood mononuclear cells (PBMC) were purified from 31 asthmatic patients and 20 sex- and age-matched control subjects. The number of IL-17A secreting cells in peripheral blood was enumerated by enzyme-linked immunosorbent spot assay. Cell surface expression of Th17-related chemokine receptor CCR6, and plasma level of IL-17A, IL-17F and IL-22, and ex vivo production of IL-17A and IL-22 were measured by flow cytometry and enzyme-linked immunosorbent assay, respectively. The number of peripheral Th17 lymphocytes, expression of CCR6 on Th cells, and ex vivo IL-23, anti-CD3 and anti-CD28 induced production of IL-22 by PBMC were significantly elevated in asthmatic patients compared with control subjects (all p < 0.01). This clinical study further confirmed increased number of peripheral Th17 lymphocytes and cell surface expression of CCR6 receptors on Th cells in asthmatic patients. Pro-inflammatory cytokine IL-23 can exacerbate disease severity by activating pathogenic Th17 lymphocytes to release downstream inflammatory cytokine IL-22 in asthma.

Expression and functional analysis of toll-like receptors of peripheral blood cells in asthmatic patients: implication for immunopathological mechanism in asthma

BACKGROUND

We investigated the expression profile of toll-like receptors (TLRs) and TLR ligand-activated production profile of asthma-related inflammatory cytokines in asthmatic patients. The expression of TLR1-8 on monocytes, CD4+ T helper lymphocytes, CD8+ T cytotoxic lymphocytes, CD19+ B lymphocytes, and dendritic cells, and ex vivo production of cytokines from peripheral blood mononuclear cells activated by TLR ligands were measured by flow cytometry.

DISCUSSION

Ex vivo productions of TNF-alpha, IL-10, and IL-1beta by TLR4 and TLR5 ligand LPS and flagellin were significantly lower in asthmatic patients (all P < 0.05). Expression of TLR4 and TLR5 was also found to be significantly lower in asthmatic patients when compared to that of control subjects (all P < 0.05). Therefore, the decreased activation of TLR4 and TLR5 in asthmatic patients might contribute to the immunopathological mechanisms of asthma by reducing the release of Th1 and anti-inflammatory cytokines.

Effects of glycemic index meal and CHO-electrolyte drink on cytokine response and run performance in endurance athletes

OBJECTIVE

To examine the effect of the glycemic index (GI) of a pre-exercise (PRE-ex) meal on plasma cytokine responses and endurance performance when carbohydrate-electrolyte (CHO-E) drink was consumed during exercise.

METHODS

Eight endurance-trained male runners (age: 28.6+/-2.7 years; body mass: 61.9+/-1.71 kg; V O(2max): 58.5+/-1.6 ml kg(-1)min(-1)) completed three trials in a randomized order. The pre-exercise meal consisted of either high-GI (HGI) (GI=83), low-GI (LGI) foods (GI=36) or control (CON) (low energy sugar-free jelly) was given to the participant 2h before a 21-km performance run on a level treadmill. During each trial, 2 ml kg(-1) BM of 6.6% CHO-E solution was consumed immediately before exercise and every 2.5-km afterward. Blood samples were collected before (pre-meal), and 120 min after ingestion the meal (120 min), immediately (POST), and 60 min (POST-60 min) after exercise.

RESULTS

No difference was found in time to complete the 21-km run between LGI and HGI. The interleukin-6 (IL-6) level increased by more than 100 times immediately after exercise in the three trials and returned to the basal level only on LGI at POST-60 min. In contrast, interleukin-2 (IL-2) level showed a transitory decrease at POST on CON (p<0.001). Glucose concentrations did not recover to the pre-meal level by POST-60 min on HGI only. Cortisol concentrations increased throughout the exercise and were lower on LGI when compared with CON (p<0.05) at POST-60 min.

CONCLUSIONS

HGI and LGI demonstrated similar performance when CHO-E solution was consumed during a 21-km run. However, pre-exercise LGI meal attenuated the increases in cortisol and quickened the recovery of the increased IL-6 value.

Study of gene-gene interactions for endophenotypic quantitative traits in Chinese asthmatic children

BACKGROUND

Asthma is a complex disease resulting from interactions between multiple genes and environmental factors. Study of gene-gene interactions could provide insight into the pathophysiology of asthma.

METHODS

We investigated the interactions among 18 single-nucleotide polymorphisms in eight candidate genes for plasma total immunoglobulin E (IgE) concentration and peripheral blood (PB) eosinophil count in 298 Chinese asthmatic children and 175 controls. Generalized multifactor dimensionality reduction and generalized linear model were used to analyze gene-gene interactions for the quantitative traits.

RESULTS

A significant interaction was found between R130Q in IL13 and I50V in IL4RA for plasma total IgE concentration, with a cross-validation (CV) consistency of nine of 10 and a prediction error of 41.1% (P = 0.013). Plasma total IgE concentration was significantly higher in the high-risk than the low-risk groups (P < 0.0001). For PB eosinophil count, significant interaction was found between C-431T in TARC and RsaI_in2 in FCERIB, with a CV consistency of nine of 10 and a prediction error of 40.2% (P = 0.009). PB eosinophil count was significantly higher in the high-risk group than the low-risk groups (P < 0.0001). Generalized linear model also revealed significant gene-gene interaction for the above two endophenotypes with P = 0.013 for plasma total IgE concentration and P = 0.029 for PB eosinophil count respectively.

CONCLUSIONS

Our data suggest significant interactions between IL13 and IL4RA for plasma total IgE concentration, and this is the first report to show significant interaction between TARC and FCERIB for PB eosinophil count in Chinese asthmatic children.

Genomewide selection in oil palm: increasing selection gain per unit time and cost with small populations

Oil palm (Elaeis guineensis Jacq.) requires 19 years per cycle of phenotypic selection. The use of molecular markers may reduce the generation interval and the cost of oil-palm breeding. Our objectives were to compare, by simulation, the response to phenotypic selection, marker-assisted recurrent selection (MARS), and genomewide selection with small population sizes in oil palm, and assess the efficiency of each method in terms of years and cost per unit gain. Markers significantly associated with the trait were used to calculate the marker scores in MARS, whereas all markers were used (without significance tests) to calculate the marker scores in genomewide selection. Responses to phenotypic selection and genomewide selection were consistently greater than the response to MARS. With population sizes of N = 50 or 70, responses to genomewide selection were 4-25% larger than the corresponding responses to phenotypic selection, depending on the heritability and number of quantitative trait loci. Cost per unit gain was 26-57% lower with genomewide selection than with phenotypic selection when markers cost US $1.50 per data point, and 35-65% lower when markers cost $0.15 per data point. With population sizes of N = 50 or 70, time per unit gain was 11-23 years with genomewide selection and 14-25 years with phenotypic selection. We conclude that for a realistic yet relatively small population size of N = 50 in oil palm, genomewide selection is superior to MARS and phenotypic selection in terms of gain per unit cost and time. Our results should be generally applicable to other tree species that are characterized by long generation intervals, high costs of maintaining breeding plantations, and small population sizes in selection programs.

In vitro and clinical immunomodulatory effects of a novel Pentaherbs concoction for atopic dermatitis

BACKGROUND

Our group recently reported a randomized and placebo-controlled clinical trial on the efficacy of a twice-daily concoction of five herbal ingredients (Pentaherbs formulation, PHF) in treating children with atopic dermatitis (AD).

OBJECTIVES

To investigate the immunomodulatory effects that may be induced by PHF treatment.

METHODS

We investigated the effects of PHF on cytotoxicity and proliferation of phytohaemagglutinin (PHA)- and staphylococcal enterotoxin B (SEB)-stimulated peripheral blood mononuclear cells (PBMC) isolated from buffy coat of blood donors. PHF-induced immunomodulation for five inflammatory mediators in cultured PBMC was measured by reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. The effects of a 3-month, open-label study of PHF on circulating inflammatory mediators in children with AD were also assessed.

RESULTS

PHF at up to 1 mg mL(-1) dose-dependently suppressed PBMC proliferation. The addition of PHF to cultured PBMC reduced supernatant concentrations of brain-derived neurotrophic factor (BDNF), interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha in response to PHA, and BDNF and thymus and activation-regulated chemokine (TARC) following SEB stimulation. PHF increased epithelial cell-derived neutrophil activating peptide-78 levels in culture supernatants. At the RNA level, PHF suppressed the transcription of BDNF, TARC, IFN-gamma and TNF-alpha. Twenty-eight children with AD were treated with PHF for 3 months, and their mean plasma concentrations of BDNF and TARC decreased significantly from 1798 pg mL(-1) and 824 pg mL(-1) at baseline to 1378 pg mL(-1) and 492 pg mL(-1) (P = 0.002 and 0.013, respectively) upon study completion.

CONCLUSIONS

PHF possesses in vitro and in vivo immunomodulatory properties that may mediate the clinical efficacy observed in AD treatment.

Compressed indexing and local alignment of DNA

MOTIVATION

Recent experimental studies on compressed indexes (BWT, CSA, FM-index) have confirmed their practicality for indexing very long strings such as the human genome in the main memory. For example, a BWT index for the human genome (with about 3 billion characters) occupies just around 1 G bytes. However, these indexes are designed for exact pattern matching, which is too stringent for biological applications. The demand is often on finding local alignments (pairs of similar substrings with gaps allowed). Without indexing, one can use dynamic programming to find all the local alignments between a text T and a pattern P in O(|T||P|) time, but this would be too slow when the text is of genome scale (e.g. aligning a gene with the human genome would take tens to hundreds of hours). In practice, biologists use heuristic-based software such as BLAST, which is very efficient but does not guarantee to find all local alignments.

RESULTS

In this article, we show how to build a software called BWT-SW that exploits a BWT index of a text T to speed up the dynamic programming for finding all local alignments. Experiments reveal that BWT-SW is very efficient (e.g. aligning a pattern of length 3 000 with the human genome takes less than a minute). We have also analyzed BWT-SW mathematically for a simpler similarity model (with gaps disallowed), and we show that the expected running time is O(/T/(0.628)/P/) for random strings. As far as we know, BWT-SW is the first practical tool that can find all local alignments. Yet BWT-SW is not meant to be a replacement of BLAST, as BLAST is still several times faster than BWT-SW for long patterns and BLAST is indeed accurate enough in most cases (we have used BWT-SW to check against the accuracy of BLAST and found that only rarely BLAST would miss some significant alignments).

AVAILABILITY

www.cs.hku.hk/~ckwong3/bwtsw

CONTACT

twlam@cs.hku.hk.

Hypercytokinemia and hyperactivation of phospho-p38 mitogen-activated protein kinase in severe human influenza A virus infection

BACKGROUND

We postulate that hypercytokinemia plays a role in immunopathogenesis of severe human influenza.

METHODS

We prospectively studied 39 consecutive patients who were hospitalized with severe influenza A virus infection. On laboratory confirmation of the diagnosis, paired acute-phase (obtained at hospital admission) and convalescent-phase (obtained >10 days after hospital admission) plasma samples were collected for assay of 11 cytokines and chemokines (interleukin [IL] 1 beta; IL-6; IL-10; IL-12p70; tumor necrosis factor alpha; IL-8; monokine induced by interferon [IFN]-gamma; IFN-inducible protein 10; monocyte chemoattractant protein 1; regulated upon activation, normal T cell-expressed and secreted; and IFN-gamma) using cytometric bead-array analysis and enzyme-linked immunosorbent assay. Simultaneously, virus concentration in the acute-phase nasopharyngeal aspirate was determined using real-time quantitative reverse-transcriptase polymerase chain reaction. Intracellular signaling molecules regulating lymphocyte activation, phospho-p38 mitogen-activated protein kinase and phospho-extracellular signal-regulated protein kinase in CD4+ and CD8+ T lymphocytes were studied in the acute-phase samples using flow cytometric analysis and were compared with results for samples from healthy control subjects.

RESULTS

Statistically significant increases in plasma IL-6 (3.7-fold increase), IL-8 (2.6-fold increase), IFN-induced protein 10 (4.9-fold increase), and monokine induced by IFN-gamma (2.3-fold increase) concentrations were detected during acute illness (P < .01 for all, by Wilcoxon signed-rank test); the highest concentrations were observed on symptom days 3 and 4. Corresponding plasma cytokine and chemokine concentrations and nasopharyngeal viral loads showed statistically significant correlations (rho = 0.41, 0.49, 0.54, and 0.46, respectively; P < or = .01). Phospho-p38 mitogen-activated protein kinase expression in CD4+ lymphocytes was increased, correlating with cytokine concentrations (e.g., for IFN-induced protein 10, rho = 0.78; P < .01); phospho-extracellular signal-regulated protein kinase was suppressed. Advanced age and comorbidity were associated with aberrant IL-6, IL-8, and monokine induced by IFN-gamma responses (P < .05, by Mann-Whitney U test). An elevated IL-6 concentration was independently associated with prolonged hospitalization (hospitalization for >5 days; P = .02), adjusted for age, comorbidity, and virus load.

CONCLUSIONS

Hypercytokinemia (of proinflammatory and T helper 1 cytokines) is detected in severe influenza, correlating with clinical illness and virus concentration. Hyperactivation of phospho-p38 mitogen-activated protein kinase (in T helper cells) is possibly involved. Early viral suppression may attenuate these potentially deleterious cytokine responses.

Association of prostaglandin-endoperoxide synthase 2 gene polymorphisms with asthma and atopy in Chinese children

BACKGROUND

Cyclooxygenase-2 (COX-2) plays essential roles in inflammation. Previous studies have suggested associations between prostaglandin-endoperoxide synthase 2 (PTGS2) polymorphisms and prostaglandins production in asthma.

OBJECTIVE

We have investigated the effects of Chinese tagging single nucleotide polymorphisms (SNPs) of PTGS2 on asthma traits in 299 Chinese asthmatic children and 175 controls.

METHODS

Plasma total and allergen-specific IgE were measured by enzyme immunoassay. PTGS2.8473T-->C in the 3'-untranslated region of exon 10 and three tag SNPs covering most of the variations in PTGS2 haplotypes in Chinese were genotyped by restriction fragment length polymorphism.

RESULTS

Among the four SNPs, only PTGS2.8473 showed significant association with asthma (P = 0.034) and atopy (P = 0.005 when compared with non-atopic controls; P = 0.023 with all controls). Carriers of the C allele had a 1.5-fold (95% confidence interval: 1.01-2.30) risk of developing asthma than those homozygous for the T allele. Multivariate regression revealed significant correlations between PTGS2.8473 and forced expiratory volume in 1 s (FEV(1); P = 0.002) and peak expiratory flow rate (PEFR; P = 0.001) with age and gender adjusted. Patients with the C allele of PTGS2.8473 had significantly lower FEV(1) (median: 90.0%vs 98.0%; P = 0.0047) and PEFR (70.0%vs 73.5%; P = 0.0065) than those homozygous for the T allele. No significant association between plasma total and allergen-specific IgE and these SNPs or with their haplotypes was found.

CONCLUSIONS

PTGS2.8473 polymorphism is associated with asthma, atopy and lung function but not plasma IgE in Chinese children. This may help to explore the pharmacogenetics of COX-2 inhibitors.

Increased expression of plasma and CD4+ T lymphocyte costimulatory molecule CD26 in adult patients with allergic asthma

CD26, which is a costimulatory molecule and peptidase, is responsible for the degradation of interferon (IFN)-gamma-induced chemokines. To elucidate the immunopathological role of CD26 in allergic asthma, we investigated plasma soluble CD26 (sCD26) concentration and its cell surface expression on lymphocytes, monocytes, CD4+ T helper, CD8+ T suppressor plus cytotoxic T, invariant natural killer T (iNKT), and CD19+ B lymphocytes in allergic asthmatic patients. Plasma sCD26 was significantly elevated in asthmatic patients regardless of inhaled corticosteroid treatment (all P < 0.05). Cell surface expression of CD26 was significantly up-regulated on lymphocytes, especially on CD4+ and iNKT lymphocytes (all P < 0.05), but not on other cell types. Significant positive correlations were found between sCD26 and the percentage of eosinophils, Th2-related chemokines CCL5 and CCL22, and costimulatory molecule sCTLA-4 (all P < 0.05). In conclusion, the aberrant expression of CD26 may contribute to the inflammatory process and Th2 predominance in the immunopathogenesis of allergic asthma.