Lumbar spine bone mineral density predicts endothelial reactivity in patients with systemic lupus erythematosus.

OBJECTIVES: To explore whether endothelial function is related to bone mineral density (BMD) in patients with systemic lupus erythematosus (SLE). METHODS: Consecutive adult SLE patients and age-, sex-, BMI- and smoking-status-matched healthy controls were studied. Subjects with hypertension, hyperlipidemia, diabetes mellitus, renal impairment, dysthyroidism, history of or treatment for cardiovascular and cerebrovascular disorders, antiphospholipid syndrome, positive antiphospholipid antibodies or bone loss were excluded. Endothelial function was assessed by measuring flow-mediated dilatation (FMD) at the brachial artery and carotid intima-media thickness (IMT) by ultrasound. Lumbar and hip BMD were measured by dual-energy x-ray absorptiometry. Fasting blood samples were assayed for atherogenic index and high sensitivity C-reactive protein (hsCRP). Regression models were constructed to study the relationship between FMD and BMD. RESULTS: One hundred and ten subjects (55 SLE and 55 matched healthy controls) were studied. While there were no differences between SLE patients and controls in menopausal status, blood pressure, atherogenic index, carotid IMT and BMD, SLE patients had significantly poorer FMD even after adjustment for age, gender, smoking and baseline brachial artery diameter. Also, SLE patients with lumbar osteopenia had significantly lower FMD than those with normal BMD. Multivariate regression revealed that lower FMD was associated with lower lumbar BMD and higher serum hsCRP in SLE patients, but these relationships were absent amongst healthy controls. CONCLUSIONS: Lumbar vertebral BMD predicted endothelial reactivity in SLE patients without clinically-overt bone loss and atherosclerosis. Thus, early atherosclerotic disease should be considered in lupus patients especially if vertebral bone loss is evident.

The induction of experimental autoimmune myocarditis in mice lacking CD4 or CD8 molecules [corrected].

Experimental induction of most autoimmune diseases appears to depend on the activation of CD4+ T helper cells, while CD8+ lymphocytes may have a role in disease progression. To study the role of CD4+ and CD8+ T cell subsets in T cell-dependent autoimmunity, mice lacking CD4 or CD8 molecules after gene targeting were injected with cardiac myosin to induce organ specific autoimmune myocarditis. Mice homozygous for the CD8 mutation (CD8-/-) developed significantly more severe disease as compared to CD4+/-CD8+/- controls. Surprisingly, CD4-/- mice developed autoimmune myocarditis with infiltration of TCR alpha beta +CD4-CD8- T cells in the heart tissue and appearance of autoantibodies. These data demonstrate that the lack of CD4+ or CD8+ T cells has no significant influence on the initiation of autoimmune myocarditis. CD4+ and CD8+ cells regulate disease severity and these results may explain the occurrence of autoimmunity in CD4 immunodeficiencies.

Characterization of cytotoxic T-lymphocyte epitopes and immune responses to SARS coronavirus spike DNA vaccine expressing the RGD-integrin-binding motif.

Integrins are critical for initiating T-cell activation events. The integrin-binding motif Arg-Gly-Asp (RGD) was incorporated into the pcDNA 3.1 mammalian expression vector expressing the codon-optimized extracellular domain of SARS coronavirus (SARS-CoV) spike protein, and tested by immunizing C57BL/6 mice. Significant cell-mediated immune responses were characterized by cytotoxic T-lymphocyte (51)Cr release assay and interferon-gamma secretion ELISPOT assay against RMA-S target cells presenting predicted MHC class I H2-Kb epitopes, including those spanning residues 884-891 and 1116-1123 within the S2 subunit of SARS-CoV spike protein. DNA vaccines incorporating the Spike-RGD/His motif or the Spike-His construct generated robust cell-mediated immune responses. Moreover, the Spike-His DNA vaccine construct generated a significant antibody response. Immunization with these DNA vaccine constructs elicited significant cellular and humoral immune responses. Additional T-cell epitopes within the SARS-CoV spike protein that may contribute to cell-mediated immunity in vivo were also identified.

Atherogenic serum lipid profile is an independent predictor for gouty flares in patients with gouty arthropathy.

OBJECTIVE: Atherogenic serum lipid profile possesses pro-inflammatory properties and is associated with more active RA. While prevalent in patients with gout, whether atherogenic lipid profile is associated with gouty flares is unknown. This study aims to investigate whether atherogenic serum lipid predicts gouty flares in patients with gout. METHODS: Adult patients (age > or =21 yrs) who suffered from gout were prospectively followed between September 2006 and November 2007 and their demographic, clinical and laboratory data were collected. Episodes of gouty flares over this observation period were recorded and factors predictive of gouty flares were studied by regression models. RESULTS: Of the 100 patients, 80 were men, 65 were ethnic Chinese, 31 were Malay and the rest were Indian and Caucasian. The mean age and duration of gout (+/-S.D.) were 61.9 +/- 14.0 and 6.6 +/- 7.8 yrs, respectively. The mean serum uric acid and creatinine levels were 537.6 +/- 142.8 and 173.6 +/- 119.9 micromol/l, respectively. In univariate analysis, longer duration of gout, higher adjusted mean serum creatinine, lower adjusted mean fasting serum, total cholesterol and high-density lipoprotein cholesterol (HDL-C) levels were associated with gouty flares. After adjustment for potential confounders in multivariate regression models, longer duration of gout and lower adjusted mean fasting serum HDL-C level remained independently predictive of gouty flares. CONCLUSIONS: Low serum high-density lipoprotein cholesterol level was an independent predictor for gouty flares. Whether optimizing serum HDL-C level can benefit patients with gout in terms of reducing gouty flares needs to be addressed by controlled trials.

Less mortality but more relapses in experimental allergic encephalomyelitis in CD8-/- mice.

Mice lacking in CD8 were generated from homologous recombination in embryonal stem cells at the CD8 locus and bred with the experimental allergic encephalomyelitis (EAE)-susceptible PL/JH-2u through four backcross generations to investigate the role of CD8+ T cells in this model of multiple sclerosis. The disease onset and susceptibility were similar to those of wild-type mice. However, the mutant mice had a milder acute EAE, reflected by fewer deaths, but more chronic EAE, reflected by a higher frequency of relapse. This suggests that CD8+ T lymphocytes may participate as both effectors and regulators in this animal model.

Neuropsychiatric lupus and reversible posterior leucoencephalopathy syndrome: a challenging clinical dilemma.

Reversible posterior leucoencephalopathy syndrome (RPLS) has been increasingly recognized and reported in the literature. While the condition has been well described in patients with acute hypertension, pre-eclampsia, eclampsia, post-transplantation and chemotherapy, RPLS has been increasingly identified in patients with autoimmune diseases such as systemic lupus erythematosus (SLE). Though experience in the diagnosis and management of RPLS in patients with SLE is likely accumulating, few have systematically worked out the strategy to distinguish RPLS from neuropsychiatric SLE (NPSLE) and lupus-related complications of the central nervous system (CNS). Prompt recognition of, and differentiation between, these conditions is essential since their clinical presentations substantially overlap and yet their management strategy and subsequent outcomes can be entirely different. Indeed, inappropriate treatment such as augmentation of immunosuppression may be detrimental to patients with RPLS. A high index of suspicion of RPLS, prompt magnetic resonance imaging of the brain, including diffusion imaging, exclusion of CNS infection and metabolic derangement, a comprehensive medication review accompanied by timely and aggressive control of blood pressure and seizure are keys to successful management of RPLS. Such treatment strategy ensures a very high chance of total neurological recovery in lupus patients with RPLS.

Microarray and real-time RT-PCR analyses of differential human gene expression patterns induced by severe acute respiratory syndrome (SARS) coronavirus infection of Vero cells.

Vero E6 African green monkey kidney cells are highly susceptible to infection with the newly emerging severe acute respiratory syndrome coronavirus (SARS-CoV), and they are permissive for rapid viral replication, with resultant cytopathic effects. We employed cDNA microarray analysis to characterize the cellular transcriptional responses of homologous human genes at 12 h post-infection. Seventy mRNA transcripts belonging to various functional classes exhibited significant alterations in gene expression. There was considerable induction of heat shock proteins that are crucial to the immune response mechanism. Modified levels of several transcripts involved in pro-inflammatory and anti-inflammatory processes exemplified the balance between opposing forces during SARS pathogenesis. Other genes displaying altered transcription included those associated with host translation, cellular metabolism, cell cycle, signal transduction, transcriptional regulation, protein trafficking, protein modulators, and cytoskeletal proteins. Alterations in the levels of several novel transcripts encoding hypothetical proteins and expressed sequence tags were also identified. In addition, transcription of apoptosis-related genes DENN and hIAP1 was upregulated in contrast to FAIM. Elevated Mx1 expression signified a strong host response to mediate antiviral resistance. Also expressed in infected cells was the C-terminal alternative splice variant of the p53 tumor suppressor gene encoding a modified truncated protein that can influence the activity of wild-type p53. We observed the interplay between various mechanisms to favor virus multiplication before full-blown apoptosis and the triggering of several pathways in host cells in an attempt to eliminate the pathogen. Microarray analysis identifies the critical host-pathogen interactions during SARS-CoV infection and provides new insights into the pathophysiology of SARS.

PCR-RFLP genotyping for exon 1 and promoter region mutations of the human mannose binding lectin (MBL-2) gene.

The Mannose Binding Lectin (MBL) plays an important role in innate immunity and its genetic deficiencies are associated with frequent and prolonged infections. Serum MBL determination may not accurately detect acute phase protein levels and it is also difficult to detect dysfunctional protein. Genotyping of the exon 1 and promoter regions in the MBL gene will provide useful information on the presence of deficiencies in patients. A reproducible PCR-RFLP method is described to accurately detect genotypes of exon 1 and polymorphic haplotypes of the promoter region in the MBL gene.

One hundred years of physiology education in Singapore.

Physiology is the study of normal function in the body and how genes, proteins, organ systems interact to maintain health. It provides a foundation for the health sciences profession and life science research. Physiology education in Singapore began soon after the establishment of the Federated States Government Medical School in 1905. The importance of Physiology to medical education was recognised by the appointment of a separate lecturer in Physiology in 1906, followed by the appointment of Professor James Argyll Campbell as the first King Edward VII professor and endowed Chair in Physiology in 1912. The teaching of Physiology in the early days was focused on the basics of normal function with little correlation to clinical problems and application. However, by the 1970s, first-year medical students were given the opportunity to visit hospitals where they were tutored by clinicians to help them apply Basic Physiology to clinical problems. Curriculum changes in the subsequent years emphasised a reduction in content, integration among preclinical subjects, independent learning and clinical relevance. Physiology is taught not only to medical but also dental, pharmacy and life science students. The teaching of Physiology to science students is a collaborative effort between the Department of Physiology, Faculty of Medicine and the Department of Biological Sciences, Faculty of Science. A lot of the teaching of Physiology to life science students occurs not in classrooms but in the laboratories, where students work closely with research supervisors and mentors on research projects. There has been a very significant increase in the number of students doing research projects in Physiology in recent years, especially in the areas of Cell Physiology, Immunology and Neurobiology. The completion of the human genome sequence poses new challenges to understand function, especially how genes, proteins and organ systems interact to sustain function. Physiology education will be increasingly important in the undergraduate and graduate life science and medical curriculum. Further, the country's vision of being the biomedical R&D and healthcare hub for the region means that Physiology education must remain at the forefront to prepare the next generation of doctors, clinician-scientists, researchers and entrepreneurs.

The NUS MBBS-PhD programme: nurturing clinician-scientists for tomorrow.

The MBBS-PhD programme is a significant milestone in medical education in Singapore. In July 2000, the Faculty of Medicine, National University of Singapore launched this programme in collaboration with the Institute of Molecular and Cell Biology, with support from the Economic Development Board, and the Agency for Science, Technology and Research, Singapore. The objectives of the programme are to nurture and develop the talents of the brightest medical students by integrating clinical and basic biomedical research training, as well as to stimulate advanced basic and applied research in areas of growing importance to clinical medicine. The programme also aims to train clinician-scientists who will interface basic biology and clinical practice to solve biomedical problems and spearhead biomedical research initiatives in Singapore. Successful MBBS-PhD graduates can pursue career tracks in clinical research, basic biomedical research or in the biotechnology industry.

Effects of peritoneal macrophages from women with endometriosis on endometrial cellular proliferation in an in vitro coculture model.

OBJECTIVE: To study the effects of peritoneal macrophages on endometrial cellular proliferation in an in vitro coculture model and to compare the magnitude of these effects between macrophages from women with endometriosis and normal women. DESIGN: Controlled study of peritoneal macrophage function. SETTING: University hospital. PATIENT(S): Patients with a normal peritoneal cavity (n = 15) and with pelvic endometriosis (n = 20) undergoing laparoscopy. INTERVENTION(S): Peritoneal macrophages were cocultured with endometrial epithelial and stromal cells; endometrial cell cultures without macrophage coculture acted as controls. MAIN OUTCOME MEASURE(S): Endometrial cellular proliferation measured by 3H-thymidine incorporation. RESULT(S): Endometrial epithelial cells cocultured with peritoneal macrophages from women with endometriosis showed significantly increased proliferation compared with cocultures using macrophages from normal women when assessed at 24 hours (1.56 versus 1.03 times, respectively, over control) and at 72 hours (1.55 versus 1.10 times over control). Endometrial stromal cells cocultured with peritoneal macrophages from women with endometriosis similarly exhibited increased proliferation compared with cocultures using macrophages from normal women when assessed at 24 hours (1.65 versus 1.17 times over control) and at 72 hours (1.65 versus 1.21 times over control). CONCLUSION(S): Peritoneal macrophages of patients with endometriosis stimulate cellular proliferation of endometrial epithelial and stromal cells in vitro.

Generation of mutant mice lacking surface expression of CD4 or CD8 gene targeting.

With the use of homologous recombination in embryonic stem cells, two new strains of mice lacking surface CD4 or CD8 expression have been generated. It is hoped that they will be useful mouse strains for the study of autoimmune diseases, tissue transplantation rejections and tumour rejections.

Oral tolerance: mechanisms and therapy of autoimmune diseases.

Oral tolerance is a state of immune hyporesponsiveness induced by the oral or mucosal exposure to antigens. This state is dependent on the dose of the oral antigen administered, with a low dose stimulating regulatory T cell development leading to an active immune suppression that is transferable via T cells. The active mechanism appears to be a cytokine mediated immune deviation with a predominant Th2 and Th3 response (TGF-beta). In contrast, high dose oral antigens lead to clonal deletion and anergy. The active suppression of low dose oral tolerance can also suppress an unrelated immune response (bystander suppression) paving the way for therapy of autoimmune diseases like rheumatoid arthritis. Oral tolerance has been effective in the treatment of autoimmune diseases like experimental autoimmune encephalomyelitis (EAE), collagen-induced arthritis (CIA) and insulin-dependent diabetes in animals. However, recent studies in human autoimmune diseases have not been as effective but the results are encouraging and more work is required to understand the mechanisms involved and other factors that may modulate the response.

Rheumatoid arthritis in Singapore: carpal predominance and lower incidence of erosive changes.

Radiographs of the hand and wrists in 33 patients with a diagnosis of classic or definite rheumatoid arthritis were reviewed. The mean duration of disease was about five years. A scoring system for quantitative analysis was used to assess the presence and severity of erosions, joint space narrowing and deviation of joint alignment. No radiological abnormality was seen in 30% of patients while in another 30%, only minor radiological changes were seen. Moderate to severe radiological abnormality was seen in only 40% and in this group of patients all showed more severe disease in the wrists than in the finger joints. Erosions in the fingers were only seen in 21% of patients and erosions in the wrists were present in 57%. Previous reports have indicated that disease in the wrists can be more severe than the hands in up to 60% while the incidence of erosions can be expected to range from 40% at 3 months to 95% at 10 years. Although the sample size in this study is small, the findings suggest that the radiological pattern of rheumatoid in the hands in Singapore is quite different from that classically described in temperate countries as the incidence of erosions appears lower while disease in the wrists can be expected to be more severe than in the fingers in almost all cases. The usual radiological criteria used to aid diagnosis of the disease may not be applicable.

Acquired factor VIIIC deficiency due to circulating factor VIIIC inhibitors.

The management of patients with Factor VIIIC inhibitor is frequently a therapeutic challenge. Treatment is often individualized. We describe 3 patients, nonhaemophilic adults, with bleeding diatheses caused by a circulating inhibitor to Factor VIIIC. One patient had long standing rheumatoid arthritis. The other two did not have any apparent underlying disease, although one of them had an antecedent antecedent phenylbutazone injection for arthralgias. Prednisolone was prescribed for two patients which resulted in rapid clinical improvement and the eventual normalization of Factor VIIIC activity. The role and rationale of immunosuppressive therapy in Factor VIIIC inhibitor is reviewed.

A case of pneumonia presenting with the acute respiratory distress syndrome.

Adult respiratory distress syndrome (ARDS) or high permeability pulmonary oedema (HPPE) is an uncommon presentation of a viral pneumonia and usually occurs in the setting of a fulminant or severe viral pneumonia. High permeability pulmonary oedema (HPPE) can be loosely defined as those forms of pulmonary oedema with normal cardiac function associated with the accumulation of protein-rich fluid in the interstitial or intraalveolar spaces. Through the years, a number of phrases have been used to describe this entity: white lung, shock lung, wet lung, adult hyaline membrane disease, ARDS and others. The aetiology is varied but the clinical, radiologic and pathologic pictures are similar. In fact the pathologic picture is so consistent from patient to patient regardless of aetiology that it has been suggested that the term HPPE be used in place of the other commonly used ones. A case of HPPE of possible viral aetiology who responded to prompt intervention with a successful outcome, is described here.

Validity and reliability of the EQ-5D self-report questionnaire in Chinese-speaking patients with rheumatic diseases in Singapore.

OBJECTIVE: We assessed the psychometric properties of a Singaporean Chinese version of the EQ-5D, a health-related quality of life (HRQoL) instrument. MATERIALS AND METHODS: Consecutive outpatients with rheumatic diseases seen for routine follow-up consultations at the National University Hospital, Singapore were interviewed twice within 2 weeks using a standardised questionnaire containing the EQ-5D, the Short-Form 36 Health Survey (SF-36), the Learned Helplessness Subscale, a pain Visual Analogue Scale (VAS) and assessing demographic and psychosocial characteristics. To assess the validity of the EQ-5D, 13 hypotheses relating the EQ-5D self-classifier (5 dimensions) or visual analogue scale (EQ-VAS) to SF-36 scores or other variables were examined using the Mann-Whitney U test, Kruskal-Wallis or Spearman's correlation coefficient. Test-retest reliability was assessed using Cohen's kappa. RESULTS: Forty-eight subjects were studied (osteoarthritis: 16; rheumatoid arthritis: 22; systemic lupus erythematosus: 8; spondyloarthropathy: 2; female: 93.8%; mean age: 56.4 years). Seven of 13 a-priori hypotheses relating EQ-5D to external variables were fulfilled, supporting the validity of the EQ-5D. For example, subjects reporting moderate or extreme problems for EQ-5D dimensions generally had lower median SF-36 scores than those without such problems. Cohen's kappa for test-retest reliability of the self-classifier ranged from 0.41 to 1.00 (n = 42; median interval: 7 days, interquartile range: 7 to 11 days). CONCLUSIONS: The Singaporean Chinese EQ-5D self-classifier appears to be a valid measure of HRQoL in Singaporeans with rheumatic diseases; however, the reliability of the EQ-VAS requires further investigation. These data provide a basis for further studies of the Singaporean Chinese EQ-5D.

Systemic lupus erythematosus: initial manifestations and clinical features after 10 years of disease.

We studied the initial manifestations and late features in our lupus patients. The clinical data of patients fulfilling the American College of Rheumatology criteria for systemic lupus erythematosus (SLE) were entered prospectively for newly diagnosed patients and cumulatively for those with at least 10 years of disease duration. Ninety-seven Group A (newly diagnosed; 86 females and 11 males; mean age 31 years; 83 Chinese, 11 Malays, and 3 Indians) and 58 Group B (more than 10 years disease duration; 56 females and 2 males; mean age 41 years; 50 Chinese, 5 Malays, and 3 Indians) lupus patients were studied. The commonest clinical features in Group A were: haematological (73%), arthritis (57%), malar rash (43%), renal disorder (31%) and photosensitivity (30%). Group B patients had haematological (78%), malar rash (73%), arthritis (69%), renal disorder (59%) and photosensitivity (33%). Renal disorder was significantly increased over the years (P < 0.001). Hypertension was present in 18% (Group A) and 59% (Group B) (P < 0.00001), diabetes mellitus in 5% (Group A) and 10% (Group B) (P = ns), atherosclerosis in 2% (Group A) and 7% (Group B) (P = ns). Cataract formation was not present in Group A patients but was present in 10% of Group B patients. Renal disorders and morbidity factors like hypertension and cataracts increased significantly over the years. Optimum treatment of lupus patients should therefore include close attention to these factors.