Safety and immunogenicity of an oral DNA vaccine encoding Sip of Streptococcus agalactiae from Nile tilapia Oreochromis niloticus delivered by live attenuated Salmonella typhimurium

Attenuated Salmonella typhimurium SL7207 was used as a carrier for a reconstructed DNA vaccine against Streptococcus agalactiae. A 1.02 kb DNA fragment, encoding for a portion of the surface immunogenic protein (Sip) of S. agalactiae was inserted into pVAX1. The recombinant plasmid pVAX1-sip was transfected in EPC cells to detect the transient expression by an indirect immunofluorescence assay, together with Western blot analysis. The pVAX1-sip was transformed by electroporation into SL7207. The stability of pVAX1-sip into Salmonella was over 90% after 50 generations with antibiotic selection in vitro while remained stable over 80% during 35 generations under antibiotic-free conditions. The LD50 of SL/pVAX1-sip was 1.7 × 10(11) CFU/fish by intragastric administration which indicated a quite low virulence. Tilapias were inoculated orally at 10(8) CFU/fish, the recombinant bacteria were found present in intestinal tract, spleens and livers and eventually eliminated from the tissues 4 weeks after immunization. Fish immunized at 10(7), 10(8) and 10(9) CFU/fish with different immunization times caused various levels of serum antibody and an effective protection against lethal challenge with the wild-type strain S. agalactiae. Integration studies showed that the pVAX1-sip did not integrate with tilapia chromosomes. The DNA vaccine SL/pVAX1-sip was proved to be safe and effective in protecting tilapias against S. agalactiae infection.

The pathology of selenium deficiency in Cyprinus carpio L

Selenium is essential for the normal life processes, and all animals, including fish, need this inorganic element. In order to research the pathology of selenium deficiency in common carp, Cyprinus carpio L., 360 juvenile carp were allocated to three treatments. Each treatment containing 120 fish was randomly divided into four groups, fed with purified diets containing selenium at 0, 0.15, 0.30 and 0.45 mg kg(-1). The results indicated that the morbidity and mortality rates of the test groups were negatively correlated with the level of selenium in the diets. The morbidity and mortality rates were, respectively, 46.7%, 33.3%, 13.3%, 0 and 26.7% 16.7%, 6.7%, 0. The affected fish exhibited pathological changes, such as 'thin back disease' and lordosis. Histologically, there was no abnormality observed in muscles, liver and pancreas. Ultrastructurally, there was swelling of the mitochondria of the cardiac muscle cells, the liver cells and renal tubular epithelial cells, with disintegration and lysis of the cristae of the mitochondria which vesiculated. Serum glutamic oxaloacetic transaminase and glutamic pyruvic transaminase levels were increased and the activity of the serum glutathione peroxidase and the serum superoxide dismutase was decreased; in contrast, the serum malonaldehyde concentration was increased.

Neonatal lupus complicated by hemorrhagic stroke

Neonatal lupus is a passively acquired autoimmune syndrome resulting from the transplacental passage of maternal anti-Ro/SSA and/or anti-La/SSB antibodies to the fetus. Few past studies have reported central nervous system involvement in neonatal lupus, and most cases had a good neurological outcome. We report here a preterm case of neonatal lupus with thrombocytopenia and comorbid hemorrhagic stroke. In the follow-up, the infant developed spastic quadriplegia and showed delayed milestones. We believe that this is the first reported case of neonatal lupus accompanied by perinatal hemorrhagic stroke. We present this case to remind clinicians to conduct regular central nervous system surveys in cases of neonatal lupus.

Detection of Rickettsia spp. and host and habitat associations of fleas (Siphonaptera) in eastern Taiwan

Rickettsia typhi and Rickettsia felis (Rickettsiales: Rickettsiaceae) are two rickettsiae principally transmitted by fleas, but the detection of either pathogen has rarely been attempted in Taiwan. Of 2048 small mammals trapped in eastern Taiwan, Apodemus agrarius Pallas (24.5%) and Mus caroli Bonhote (24.4%) (both: Rodentia: Muridae) were the most abundant, and M. caroli hosted the highest proportion of fleas (63.9% of 330 fleas). Two flea species were identified: Stivalius aporus Jordan and Rothschild (Siphonaptera: Stivaliidae), and Acropsylla episema Rothschild (Siphonaptera: Leptopsyllidae). Nested polymerase chain reaction targeting parts of the ompB and gltA genes showed six fleas to be positive for Rickettsia spp. (3.8% of 160 samples), which showed the greatest similarity to R. felis, Rickettsia japonica, Rickettsia conorii or Rickettsia sp. TwKM01. Rickettsia typhi was not detected in the fleas and Rickettsia co-infection did not occur. Both flea species were more abundant during months with lower temperatures and less rainfall, and flea abundance on M. caroli was not related to soil hardness, vegetative height, ground cover by litter or by understory layer, or the abundance of M. caroli. Our study reveals the potential circulation of R. felis and other rickettsiae in eastern Taiwan, necessitating further surveillance of rickettsial diseases in this region. This is especially important because many novel rickettsioses are emerging worldwide.

International consensus on (ICON) pediatric asthma

Asthma is the most common chronic lower respiratory disease in childhood throughout the world. Several guidelines and/or consensus documents are available to support medical decisions on pediatric asthma. Although there is no doubt that the use of common systematic approaches for management can considerably improve outcomes, dissemination and implementation of these are still major challenges. Consequently, the International Collaboration in Asthma, Allergy and Immunology (iCAALL), recently formed by the EAACI, AAAAI, ACAAI, and WAO, has decided to propose an International Consensus on (ICON) Pediatric Asthma. The purpose of this document is to highlight the key messages that are common to many of the existing guidelines, while critically reviewing and commenting on any differences, thus providing a concise reference. The principles of pediatric asthma management are generally accepted. Overall, the treatment goal is disease control. To achieve this, patients and their parents should be educated to optimally manage the disease, in collaboration with healthcare professionals. Identification and avoidance of triggers is also of significant importance. Assessment and monitoring should be performed regularly to re-evaluate and fine-tune treatment. Pharmacotherapy is the cornerstone of treatment. The optimal use of medication can, in most cases, help patients control symptoms and reduce the risk for future morbidity. The management of exacerbations is a major consideration, independent of chronic treatment. There is a trend toward considering phenotype-specific treatment choices; however, this goal has not yet been achieved.

Coronary artery dilation among patients with paediatric-onset systemic lupus erythematosus

OBJECTIVES

This study aimed to evaluate increased coronary artery dimensions in patients with paediatric-onset systemic lupus erythematosus (SLE) in comparison with healthy controls, and to identify risk factors associated with increased coronary artery dimensions in the SLE patients.

METHODS

As part of a longitudinal cohort study of coronary artery disease (CAD) in paediatric-onset SLE, 83 children with SLE and 36 healthy controls were enrolled for a cross-sectional analysis. Their coronary artery diameters were measured by echocardiography while their body mass index (BMI), blood pressure, and other cardiovascular factors were recorded. The age at diagnosis, serum uric acid (UA) and creatinine levels, and other lupus-related factors were further evaluated in SLE patients. Data were analysed using linear regression.

RESULTS

Mean body surface area (BSA)-adjusted dimensions of the left coronary artery (LCA) and right coronary artery (RCA) were significantly larger in SLE patients than in controls (both p < 0.001). The age at diagnosis, BMI, and serum UA and creatinine levels were associated with LCA and RCA diameters. There were no correlations between the coronary artery diameters and blood pressure, SLE duration, SLE Disease Activity Index (SLEDAI), C-reactive protein (CRP), C3, C4, anti-double-stranded-DNA (anti-dsDNA), or lipid profile. In multivariate analysis, serum UA level, age at diagnosis, and BMI were consistently associated with coronary artery dimensions (p < 0.001, p = 0.008, and p = 0.006 for LCA; p = 0.020, 0.013, and 0.008 for RCA).

CONCLUSIONS

Increased coronary artery diameters were found in children with SLE and were associated with higher serum UA levels. The pathogenic mechanisms warrant further investigation.

Toll-like receptor 4 signaling promotes the immunosuppressive cytokine production of human cervical cancer

OBJECTIVES

To investigate the expression of TLR-4 (toll-like receptor) on human cervical cancer and find the biological function of the TLR-4 signal system.

METHODS

The immunohistochemistry method was performed to study the protein expression and distribution of TLR-4. The viability of HeLa cells was determined by cell viability assay. Cell proliferation was detected by FCM, ELISA and Western blot were used to observe the gene and protein expression of IL-6 and TGF-beta1 in Hela cell lines.

RESULTS

TLR-4 was over-expressed in cervix cancer, and its activation by LPS promotes proliferation and anti-apoptosis in Hela cells in vitro. Moreover the cell line proliferation increased in a dose- and time-dependent manner. The production of IL-6 and TGF-beta1 were promoted through the activation of the NF-kappaB signaling pathway.

Minimally invasive esophagectomy versus open esophagectomy, a symptom assessment study

Minimally invasive esophagectomy (MIE) is used with hope to decrease the morbidity associated with an open esophagectomy. Reflux and dumping syndromes are the most important functional complaints in patients after esophagectomy. This study compares the functional benefits of MIE with open esophagectomy. The study enrolled patients who underwent either minimally invasive or open esophagectomy for cancer between 2004 and 2009. No patients in the MIE group had a pyloroplasty or myotomy. Each patient in the MIE group was paired to a patient in the open esophagectomy group via propensity matching. Matching variables included age, race, gender, preoperative treatment, history of prior cancer, American Society of Anesthesiologists Risk Scale, performance status, clinical stage, body mass index, histology, level of anastomosis, and time elapsed since surgery. The patients were asked to answer 26 questions about their reflux and dumping using validated questionnaires. A total of 181 patients were included in the study. From this group, 44 pairs of patients were created and used for the analysis. The median follow-up was 12.1 months for the MIE group and 18.3 months for the open group. The reflux score was slightly worse in the MIE group (5.5 versus 3.5, P= 0.021). There was no difference in the dumping symptoms between the two groups. The most common complaints seen in the dumping questionnaire in almost one-third of all patients were early satiety, abdominal discomfort, nausea, and diarrhea. Of the patients, 77% were satisfied or very satisfied with their condition in the MIE group compared with 93% in the open group (P= 0.287). Reflux, dumping, and overall satisfaction after MIE without pyloroplasty are comparable with those obtained after open esophagectomy with a pyloric drainage procedure.

Acute pancreatitis in pediatric and adult-onset systemic lupus erythematosus: A comparison and review of the literature

This study aimed to compare differences of acute pancreatitis between adult- and pediatric-onset systemic lupus erythematosus (SLE) patients and to clarify the risk factors for mortality. Medical records that carried the dual diagnosis of SLE and acute pancreatitis between 1991 and 2005 were reviewed. Forty-eight episodes of acute pancreatitis were identified in 13 pediatric-onset SLE (pSLE) and 27 adult-onset SLE (aSLE) patients. The prevalence was 1.34% overall, with higher prevalence in pSLE (5.22%) compared with aSLE (0.99%) ( p < 0.001). The SLEDAI score on presentation of acute pancreatitis was higher in pSLE (mean ± SD: 21.77 ± 13.09) than in aSLE patients (13.37 ± 8.32) ( p = 0.05). Eleven patients died during episodes of acute pancreatitis and mortality rate was significantly higher in pSLE than in the aSLE group (53.8% and 14.8%, respectively, p = 0.015). Mortality was associated with concurrent SLE symptoms ( p = 0.049), higher SLEDAI score at presentation of acute pancreatitis ( p = 0.011), severe acute pancreatitis ( p < 0.001), and the presence of complications ( p < 0.001). The multivariate logistic regression analysis showed that severity of acute pancreatitis was the most powerful risk factor for mortality in SLE patients with this disease. In summary, our results indicate that acute pancreatitis occurs more frequently, tends to be more severe, and is associated with higher mortality in pSLE patients when compared with aSLE patient.

Pediatric lupus in Asia

Of all patients with systemic lupus erythematosus (SLE), 15-20% are diagnosed during childhood, with disease onset prior to the age of 16 years. Because disease expression in SLE is influenced by environment factors and differs between racial and ethnic groups. The aims of this review were to describe prevalence, clinical manifestations, common infectious complications, and outcome of pediatric-onset SLE in Asia. The prevalence of pediatric-onset SLE was 6.3-19.3 per 100,000 in Asia. The ratio of female to male was 4.7-6.2. The mean age at diagnosis of pediatric-onset SLE was 8.6-13.5 years. The most common clinical features of pediatric-onset SLE in Asia were cutaneous rashes, arthritis, hematological involvement and nephritis. The occurrence of nephritis varies from 29% to 81%. The most common histopathology of lupus nephritis was diffuse proliferative glomerulonephritis (WHO Class-IV) which occurred in 39.4-54% of case of lupus nephritis. Pediatric-onset SLE patients with infections have poor outcomes than uninfected patients. Gram-negative bacilli are the most common microorganisms responsible for bacteremia in Asian patients with SLE. Recurrent major infections predict poorer disease outcome and associated organ damage in pediatric-onset SLE. Improving the survival of SLE patients was reported in Asia in recent decades. The survival was 92% at the age of 5 years, 86% at 10 years and 79% at 15 years in children with SLE in Taiwan in 2008.

19p13.2 microduplication causes a Sotos syndrome-like phenotype and alters gene expression

Up to 90% of individuals affected by Sotos syndrome have a pathogenic alteration of NSD1 (encodes nuclear receptor-binding Su-var, enhancer of zeste, and trithorax domain protein 1), a histone methyltransferase that functions as both a transcriptional activator and a repressor. Genomic copy number variations may also cause a Sotos-like phenotype. We evaluated a three-generation family segregating a Sotos-like disorder characterized by typical facial features, overgrowth, learning disabilities, and advanced bone age. Affected individuals did not have a detectable NSD1 mutation, but rather were found to have a 1.9 Mb microduplication of 19p13.2 with breakpoints in two highly homologous Alu elements. Because the duplication included the DNA methyltransferase gene (DNMT1), we assessed DNA methylation of peripheral blood and buccal cell DNA and detected no alterations. We also examined peripheral blood gene expression and found evidence for increased expression of genes within the duplicated region. We conclude that microduplication of 19p13.2 is a novel genomic disorder characterized by variable neurocognitive disability, overgrowth, and facial dysmorphism similar to Sotos syndrome. Failed compensation of gene duplication at the transcriptional level, as seen in peripheral blood, supports gene dosage as the cause of this disorder.

Flow density of a reversible ratchet

By defining "flow density" in a reversible ratchet, a kind of Brownian motor that runs four processes in a two-dimensional parameter space to complete a cycle, we analytically investigate the behavior of the motor's integrated flow in terms of the magnitude and location of the density maximum. It turns out that flow density gives information that can serve as a guide for obtaining the most suitable integrated flow important in the design of reversible ratchets.

An epidemiological survey of low back pain and axial spondyloarthritis in a Chinese Han population

OBJECTIVE

To investigate the prevalence of low back pain (LBP) and axial spondyloarthritis (SpA) in a Chinese Han population.

METHODS

A face-to-face investigation was performed in the Han population of Dalang Town, Yangshan County, Guangdong Province, China, using a questionnaire established in France in 1999. First the clinical features associated with SpA were investigated, then the human leucocyte antigen (HLA)-B27 and sacroiliac joint radiographic examinations were carried out. Finally, the diagnosis of SpA was determined by rheumatologists.

RESULTS

A total of 13 315 subjects participated in the study and 10 921 were aged >16 years; of these, 787 (7.21%) had LBP. There were 92 axial SpA patients (0.782% in subjects >16 years old and 11.96% in subjects with LBP). There were 29 (0.253%) cases of ankylosing spondylitis (AS), 60 (0.507%) undifferentiated axial SpA (USpA), and three (0.022%) psoriatic arthritis (PsA). Patients in the SpA groups had higher percentages in onset <40 years, insidious onset, morning stiffness, and affected for >3 months compared with those in other LBP groups. Simultaneous symptoms associated with spondylitis, such as buttock pain, heel pain, psoriasis, and SpA family history, were more commonly present. Of the axial SpA patients, 82.67% were HLA-B27 positive, clearly a greater percentage than those (11.65%) in other LBP groups.

CONCLUSIONS

The survey questionnaire for SpA in this study is useful for axial SpA screening in China. In southern China, the prevalence of LBP is 7.21%. The prevalence of axial SpA is 0.782%. USpA is the most common subtype of SpA, followed by AS.

Lack of association of mannose-binding lectin gene polymorphisms with development and clinical manifestations of systemic lupus erythematosus in Chinese children

Mannose-binding lectin (MBL) gene polymorphisms may be associated with adult-onset systemic lupus erythematosus (SLE), but studies in children with SLE are rare. This study tested the genetic association between MBL polymorphisms and paediatric-onset SLE in a cohort of Chinese children in Taiwan. In all 150 children with SLE and 100 healthy controls of comparable age were genotyped for codon 52, 54 and 57 mutations of the MBL gene using a polymerase chain reaction–based assay. Clinical manifestations, organ involvement, disease activity, laboratory characteristics and outcome were recorded and compared between patients with different MBL genotypes. Codon 54 mutation was fairly common in both SLE patients and controls, whereas codon 52 and codon 57 mutations were not detected in our study subjects. No statistically significant differences were found in allele frequencies of the codon 54 mutation between SLE and control groups. Moreover, no association was found between this MBL polymorphism and clinical manifestations, organ involvement, disease activity, laboratory characteristics or outcome of SLE. These results suggest that MBL polymorphisms do not influence susceptibility to paediatric-onset SLE and do not influence clinical manifestations of SLE in Chinese children.

Prevalence of pediatric systemic lupus erythematosus and juvenile chronic arthritis in a Chinese population: a nation-wide prospective population-based study in Taiwan

OBJECTIVE

To estimate the national prevalence of systemic lupus erythematosus (SLE) and juvenile chronic arthritis (JCA) in Chinese children in Taiwan.

METHODS

A nationwide prospective population based epidemiologic study for the prevalence of pediatric SLE and JCA was undertaken in Taiwan (23 million inhabitants). The population at risk was identified as children under the age of 16 living in Taiwan (5.78 million). All citizens have been obligated to participate in Taiwan's National Health Insurance program since 1995. This gave us access to nationwide case data from the Major Illness/Injury registry and enabled us to calculate population prevalence. The population data were derived from the 1999 Taiwan census.

RESULTS

Three hundred sixty-five and 218 prevalent cases of pediatric SLE and JCA were identified, respectively. The prevalence of pediatric SLE was 6.3 per 100,000 (95% CI: 5.7-7.0). The prevalence in girls (11.2 per 100,000, 95% CI: 10.0-12.5) was 6.2 times higher than that in boys (1.8 per 100,000, 95% CI: 1.4-2.4). The prevalence of SLE substantially increased in children over the age of seven, especially in girls. The prevalence of JCA was 3.8 per 100,000 (95% CI: 3.3-4.3). The figures were similar for boys (3.5 per 100,000, 95% CI: 2.9-4.2) and girls (4.1 per 100,000, 95% CI: 3.3-4.9).

CONCLUSION

In this first population based epidemiologic survey of pediatric SLE and JCA in Taiwan, we provided a good starting point in our understanding of the epidemiology of these serious conditions in the Chinese population. The discrepancies between our prevalence figures and those reported from Western countries are possibly the results from true differences pertaining to ethnicity, geography or both. Future studies are necessary to elucidate the implications suggested by these data.

Sequential changes to clinical parameters and adhesion molecules following intravenous pulse cyclophosphamide and methylprednisolone treatment of refractory juvenile idiopathic arthritis

It is believed that the systemic subtype and the positive rheumatoid factor, polyarticular subtype of juvenile idiopathic arthritis (JIA) show the least favorable outcomes for therapy; patients with systemic JIA are often resistant to recommended therapeutic modalities. We report the sequential changes to clinical and laboratory findings from pulse therapy with monthly intravenous cyclophosphamide (0.5 g/m2 body surface area) administration combined with methylprednisolone (30 mg/kg; 1 gm maximum) for 6 months, following which the medication interval was elongated to 3 months for a total of from 7 to 12 courses. Among 4 children suffering from refractory systemic JIA, 3 demonstrated clinical improvement, 2 of whom achieved clinical remission. Furthermore, we also adminstered this therapy to a girl suffering from refractory polyarticular JIA, following which she revealed clinical remission subsequent to 9 courses of such therapy. From our experience, we suggest that patients afflicted with JIA that is unresponsive to traditional medication may experience benefit from this type of pulse therapy.

Monthly Recurrent Herpes Simplex Virus Blepharitis in a Boy for More Than 10 Years

Ocular herpes simplex virus (HSV) infection is generally accepted to be a unilateral disease and simultaneous bilateral recurrent ocular HSV disease is uncommon. Recurrent ocular herpes was generally thought to be characterized by corneal involvement. We here report an 11-year-old boy with monthly bilateral recurrent HSV type 1 blepharitis for more than 10 years. He had a general normal immunological examination. Only supportive or topical acyclovir ointment treatment proved adequate for controlling the monthly recurrent disease without corneal involvement or other sequelae to date. The case highlights the unusual presentation, general normal immune function, clinical course and treatment opinion for recurrent HSV blepharitis.

Use of a new fluorescence immunoassay to detect anti-dsDNA antibodies is more correlated with disease activity and complement than the ELISA method in SLE patients

To determine whether the serum levels of anti-double strand DNA (anti-dsDNA) autoantibodies detected using a newly developed fluorescence immunoassay (FIA) in patients with systemic lupus erythematosus (SLE) correlated more with clinical parameters, such as SLE disease activity index (SLEDAI), complement and the occurrence of nephritis when compared with traditional enzyme-linked immunosorbent assay (ELISA), we prospectively collected 124 serum samples from 31 patients who had juvenile-onset SLE and were regularly monitored every 2 months at our outpatient clinic. At every visit, clinical manifestations and laboratory parameters were assessed and the SLEDAI was determined. Correlation analyses between the two different measurements of anti-dsDNA antibodies and SLEDAI, serum complement levels and the occurrence of nephritis were performed. The results showed that anti-dsDNA autoantibodies detected using both ELISA and FIA significantly correlated with SLEDAI, and significantly and inversely correlated with the serum levels of C3 and C4. FIA had significantly higher correlation with SLEDAI and C4 than did ELISA. The mean values of anti-dsDNA antibodies detected using FIA in patients with nephritis were significantly higher than in those without nephritis. In contrast, the values of anti-dsDNA antibodies detected using ELISA did not show significant differences between these two groups. We conclude that FIA had better correlation with SLEDAI, C4 and the occurrence of nephritis, and comparable correlations with C3 that were similar to the results found using ELISA. Thus, it is worthwhile developing the FIA method for clinical evaluation of disease activity in SLE patients.

Association between serum inflammatory cytokines and disease activity in juvenile idiopathic arthritis

Circulating interleukin-1beta (IL-1beta), IL-6, tumour necrosis factor-alpha (TNF-alpha), osteocalcin, and conventional parameters of inflammation were examined serially in 14 children with juvenile idiopathic arthritis (JIA) to determine any correlation with the disease activity. Serum IL-1beta was undetectable in all JIA patients. Serum IL-6, white blood cell counts, platelet counts, erythrocyte sedimentation rate and C-reactive protein levels were significantly elevated in the active phase of JIA, whereas hemoglobin levels were significantly lower. Osteocalcin levels were decreased and TNF-alpha increased in active JIA status, but these differences showed no statistical significance. We concluded that inflammatory cytokines play an important role in JIA. Monitoring IL-6 in children with JIA is useful in determining disease activity and response to therapy. These findings confirm earlier reports.

Anaphylaxis to riboflavin (vitamin B2)

BACKGROUND

Vitamin supplements are used more commonly in normal healthy subjects than in patients with vitamin deficiency. Thiamine (vitamin B,) is the vitamin that most frequently induces allergic reactions. To the best of our knowledge, no case of anaphylaxis to riboflavin (vitamin B2) has thus far been reported in the literature.

OBJECTIVE

We describe a previously healthy 15-year-old boy in whom anaphylaxis developed several times after he drank one soft drink or took a single multivitamin tablet. This study was done to determine which of the many components found in the soft drink and vitamin tablet caused the anaphylactic reaction.

METHODS

In an outpatient clinic with the availability of complete resuscitative procedures, we performed single-blind prick skin tests and intradermal skin tests on the patient with various pure vitamin components of the soft drink and the multivitamin tablet. Physiologic saline and histamine were used for negative and positive controls, respectively.

RESULTS

Riboflavin, a component of both the soft drink and the vitamin tablet, produced positive reactions on intradermal skin tests in the patient. Positive reactions were not present in the normal control subjects.

CONCLUSIONS

Riboflavin is a previously unreported cause of anaphylaxis. Free-form riboflavin may potentially be associated with an anaphylactic reaction. It is a vitamin widely used in many patients with chronic disease and in healthy subjects. Vitamin B2 must be considered as a cause of anaphylaxis.

High-level expression of recombinant dengue viral NS-1 protein and its potential use as a diagnostic antigen

The prevalence of NS1 Ab response in patients with dengue viral infection and the potential of using recombinant NS1 protein as a diagnostic antigen for dengue viral infection were investigated. In this study, the full-length and C-terminal half of NS1 proteins (rNS1, rNS1-C) were highly expressed (10-30 mg/l) and further purified and refolded. The good antigenicity of the full-length rNS1 protein was confirmed by interaction with 19 dengue NS1-specific monoclonal antibodies (MAbs) in ELISA; however, the antigenicity of rNS1-C was relatively lower. The full-length rNS1 antigen also differentiated reliably between sera from dengue virus-infected patients and sera from normal controls. When rNS1 was used as an antigen to detect human anti-NS1 IgM and IgG Ab, the anti-NS1 Ab response was found in 15 of 17 patients (88%) with primary dengue infection and all 16 patients (100%) with secondary dengue infection. These results indicated that using the full-length rNS1 whose antigenicity is restored as ELISA antigen, a high anti-NS1 antibody prevalence could be detected in patients with either primary or secondary dengue infection. This finding suggested that the anti-NS1 antibody appeared not only in secondary and severe dengue virus infection and might not correlate the pathogenesis of dengue hemorrhagic fever. The study also verified that our purified rNS1 protein showed similar immunological properties as native dengue viral proteins. Genetic engineering production of recombinant NS1 antigen could provide a safe and valuable resource for dengue virus serodiagnosis.

HLA-DRB1 antigens in Taiwanese patients with juvenile-onset systemic lupus erythematosus

OBJECTIVE

This study was done to investigate the frequency of HLA-DRB1 antigens in juvenile-onset systemic lupus erythematosus (SLE) in the Taiwanese population.

PATIENTS AND METHODS

Thirty-four Taiwanese patients with juvenile onset SLE and 200 unrelated healthy controls were studied. HLA-DRB1 typing was performed with polymerase chain reaction (PCR) and the sequence-specific oligonucleotide probe (SSO) typing method.

RESULT

Among the 14 investigated DRB1 alleles, the frequency of HLA-DRB1*1602 was higher in juvenile onset SLE patients than the controls (15.15% vs 4.50%, odds ratio 3.66, 95% confidence interval 1.15-11.68, Pc = 0.04). Although there were differences in the frequencies of DRB1*0301, DRB1*0803, and DRB1*1501 between patients and controls, the associations were statistically insignificant.

CONCLUSION

The frequency of HLA-DRB1*1602 was significantly higher in patients with juvenile onset SLE than in healthy controls. This finding differs from those in the previous studies in Caucasian and Japanese adult onset SLE patients.

Clinical characteristics of juvenile rheumatoid arthritis in Taiwan

This study aimed to investigate the clinical features of juvenile rheumatoid arthritis among Taiwan children. The medical records of 228 children who had juvenile rheumatoid arthritis treated in the Chang Gung Medical Center in Taiwan from 1978 through 1998 were retrospectively reviewed. A total of 146 boys and 82 girls (M:F ratio, 1.8:1) were included in this study. Clinical and laboratory data of these patients were collected from medical charts. Pauciarticular onset (56%) was the most common type of juvenile rheumatoid arthritis, followed by polyarticular (36%) and systemic (8%) type. The positive rate for rheumatoid factor, human leukocyte antigen B27, and antinuclear antibody were 9.2%, 55.2%, and 16.2%, respectively. Uveitis was observed in 5.7% of patients. Compared with previous reports in other regions and populations, remarkably different features of juvenile rheumatoid arthritis were found in this study, which included a higher prevalence among boys than girls, a high positive rate of human leukocyte antigen B27, and a low rate of uveitis.