Ren-Bin Tang

Identification of allergens and antigens of Bermuda grass (Cynodon dactylon) pollen by immunoblot analysis

Allergens and antigens of Bermuda grass pollen fractionated by SDS‐polyacrylamide gel electrophoresis and transferred to nitrocellulose membranes were identified using twenty‐one sera of Bermuda grass pollen‐allergic patients. The IgE‐ and IgG‐binding pollen components transferred to nitrocellulose were detected by reaction with enzyme‐labelled anti‐human IgE and anti‐human IgG, respectively. There was heterogeneity in both IgE‐ and IgG‐binding patterns of the allergic sera tested. Fourteen pollen components, ranging in molecular weight from 16000 to 88000 daltons, bound to IgE antibodies. Only two of the fourteen allergens identified reacted with IgE antibodies of more than 50% of the twenty‐one allergic sera. The pollen component with a molecular weight of 32000 daltons showed by far the highest frequency of IgE binding, being recognized by sixteen (76%) of the twenty‐one sera examined. Fifteen (71 %) of the twenty‐one sera tested had IgE antibodies that reacted with more than one of the fourteen allergenic components identified. Pollen components recognized by IgE antibodies also reacted with IgG antibodies, and there were components only recognized by IgG antibodies. Results obtained from this study should be useful both clinically and in research.

Isolation and characterization of a novel 98-kd Dermatophagoides farinae mite allergen

BACKGROUND Exposure to allergens from house dust mites is a significant cause of immediate hypersensitivity. Thus far, the active mite allergens defined are low molecular weight (MW) proteins or glycoproteins. However, other important mite allergens remain to be investigated. In this study a high MW mite antigen with a high IgE-binding activity was characterized. METHODS An anti-Dermatophagoides farinae (Df) monoclonal antibody, mAb642, which recognized a 98-kd allergenic mite protein, was used for affinity chromatography. The purified Df642 was characterized biochemically and immunologically. RESULTS Competitive ELISA demonstrated that mAb642 was inhibited by the interaction between serum IgE from allergic patients and Df642 antigen in a dose-dependent fashion. The IgE reactivity to both 98-kd and 92-kd components was removed or diminished by preincubation of asthmatic sera with Df642-coated CNBr-activated cellulose-4B gel. Two-dimensional immunoblot analysis revealed that there are at least 4 isoforms of Df642 that represent a minor component in the crude mite extract. The allergenicity of Df642 was assayed by IgE immunoassay with a large panel of 67 sera from asthmatic patients with positive skin reactions, and Df 642 showed positive IgE reactivity with more than 80% of the sera tested. Thus it should be classified as an important allergen. In addition, amino acid sequence analysis revealed that Df642 shares more than 50% homology with paramyosin from invertebrates. CONCLUSION We have identified and characterized a 98-kd house dust mite allergen that showed greater than 80% IgE reactivity with sera from patients allergic to mites. This is the first high MW allergen characterized to date, and it shares high sequence homology with paramyosins in invertebrates.

The prevalence of allergic disease and IgE antibodies to house dust mite In schoolchildren in Taiwan

The prevalance of positive specific IgE antibodies to house dust mites (Dermatophagoides pteronyssinus: D. farinae) was determined by enzyme‐linked immunosorbent assay (ELISA) in 5097 (61%) volunteers of 8345 schoolchildren aged between 7 and 14 yr from two government schools, All of them filled out a questionnaire concerning allergic symptoms. Among them, 412 (8·1%) children showed a positive reaction to at least one of the two mite allergens, the range varying between 5·6 and 11·2% according to the childs age. Boys had higher prevalence of positive mite specific IgE than girls (9·8% vs. 6·4%, P < 0·01), with the overall male to female ratio 1·5:1. The prevalence of bronchial asthma in boys and girls was 5·3% and 3·3% respectively. The positive mite specific IgE antibody in children with asthma and allergic rhinitis was 52% (103 of 198) and 28·7% (193 of 673) respectively. The mean levels of mite specific IgE were not significantly related to the age of onset and severity of asthmatic symptoms (P > 0·1), but were significantly different among subjects with current and past asthma (P < 0·001). It is suggested that the mire‐specific IgE may play a role in the pathogenesis of bronchial asthma in children.

An overview of the recent outbreaks of the avian-origin influenza A (H7N9) virus in the human

&NA; Since the first human infection with influenza A (H7N9) viruses have been identified in Shanghai on March 31, 2013, the latest variant of the avian flu virus has spread across four Chinese provinces recently. Human infections with avian influenza are rare and this is the first time that human infection with a low pathogenic avian influenza A virus has been associated with fatal outcome. To date (May 5th, 2013), China had reported 128 confirmed H7N9 infections in human, among 27 died. Most reported cases have severe respiratory illness resulting in severe pneumonia and in some cases have died. No evidence of sustained human‐to ‐humans at this time, however, there is one family cluster with two confirmed cases for which human‐to‐human transmission cannot be ruled out. Recent evidence showed that the gene sequences of this novel H7N9 virus is primarily zoonotic and may be better adapted than other avian influenza viruses to infect human. Effective global infection control is urgently needed, and further surveillance and analyses should be undertaken to identify the source and mode of transmission of these viruses.

Constipation in Taiwan elementary school students: A nationwide survey

Background: To evaluate the prevalence and associated factors of childhood constipation in Taiwan. Methods: Healthy children between 7 and 12 years of age were interviewed to determine the prevalence of constipation and associated demographic and dietary factors. A nationwide sample of 2,375 children was selected with complex multistaged sampling throughout Taiwan. Results: In total, 2,375 individuals (1,282 boys and 1,093 girls, mean age = 9.3 ± 2.2 years) were interviewed, with a response rate of 95.1%. The prevalence of constipation was 32.2%, and girls were more likely to have constipation than boys (36.1% vs. 29.2%, p = 0.0012) in this study. The prevalence of constipation was inversely related to age (24.4% for children aged 11 and 12, 34.0% for children aged 9 and 10, and 39.6% for children aged 7 and 8, p < 0.001). Constipated children were more likely to report irregular bowl movements (37.2% vs. 29.3%, p = 0.003), and constipated children had a significantly lower body mass index (17.5 kg/m2 vs. 18.3 kg/m2, p < 0.001). The dietary intake for children with constipation was associated with lower intake of vegetables (4.2 servings/week vs. 5.8 servings/week, p < 0.05), fruits (5.6 servings/week vs. 7.0 servings/week, p < 0.05), soybean products (2.2 servings/week vs. 2.9 serving/week, p < 0.05), and eggs (3.9 servings/week vs. 4.6 servings/week, p < 0.05). Conclusion: Constipation is common in Taiwanese school‐aged children, especially in girls. Less frequent consumption of vegetables, fruits, soybean products, and eggs is associated with childhood constipation. Establishing a regular bowel habit is encouraged to decrease the risk of constipation, and allowing the children a relaxed and sufficient time to defecate after school is essential.

A rare complication in a child undergoing chemotherapy for acute lymphoblastic leukemia: Superior sagittal sinus thrombosis

We report the case of a 4-year-old boy with acute lymphoblastic leukemia in high-risk group who suffered from generalized tonic-colonic seizure evolving into status epilepticus, and subsequent left hemiparesis during his first reinduction chemotherapy, consisting of dexamethasone, vincristine, l-asparaginase, and epirubicin. Superior sagittal sinus and cerebral venous thrombosis, predominantly in right side, were proved by brain magnetic resonance imaging. After aggressive treatment with low-molecular weight heparin (LMWH), left hemiparesis improved in 1 week. And he was fully ambulatory 3 weeks later. The second cycle of reinduction chemotherapy was conducted smoothly with the concomitant use of LMWH. This case illustrates the strong correlation of the rare thrombotic complication, superior sagittal sinus thrombosis, and hypercoagulable status secondary to combination use of l-asparaginase and corticosteroid. Early and vigilant recognition of superior sagittal sinus thrombosis and prompt anticoagulation with LMWH may prevent further neurological damage.

Hyperbilirubinemia with urinary tract infection in infants younger than eight weeks old

Background: Hyperbilirubinemia is one of the most common causes for hospital admission in neonatal infants. Previous studies have found that jaundice may be one of the initial symptoms related to urinary tract infection (UTI) in infants. This study is to evaluate the incidence and related factors of neonatal infants with the initial presentation of hyperbilirubinemia and final diagnosis of UTI in a tertiary teaching hospital. Methods: We retrospectively investigated the medical records of admitted infants younger than 8 weeks old with hyperbilirubinemia between January and December 2008. The jaundiced infants having tests of urinalysis were enrolled into our study and grouped into UTI or no UTI group according to the findings of urinary culture. Results: A total of 217 neonatal jaundiced infants were enrolled. Among them, 12 cases (5.5%) were grouped into the UTI group, and the most common cultured bacterium from their urine was Escherichia coli. There was no significant difference in the babies’ birth weight, maternal conditions, or total bilirubin levels between the two groups. There was also no significant difference between the two groups in their admission age (9.7 ± 13.5 days vs. 6.1 ± 6.7 days in UTI and no UTI groups, respectively) or the ratio of outpatients (50% vs. 25% in UTI and no UTI groups, respectively) (p > 0.05). The cases of UTI group had significantly lower hemoglobin (15.2 ± 2.7 g/dL vs. 17.2 ± 2.3 g/dL, respectively) and higher formula feeding rate (8.3% vs. 2.9%, respectively) than the no UTI group (p < 0.05). Conclusion: The incidence of UTI in the admitted infants with hyperbilirubinemia was as high as approximately 5.5%. The most common cultured bacterium in urine was E coli. Therefore, performing urinary tests to exclude the possibility of coincidental UTI may be necessary for admitted jaundiced infants younger than 8 weeks old.

Infectious Endocarditis in Pediatric Patients: Analysis of 19 Cases Presenting at a Medical Center

BACKGROUND/PURPOSE Infectious endocarditis (IE) is a rare, but potentially fatal disease in pediatric patients. In this study, we reviewed the symptoms and signs, etiology, laboratory findings and outcomes of IE patients over the past 10 years. METHODS Patients (< 18 years old) with definite IE according to the modified Duke criteria, or patients with positive pathological findings, between September 1998 and September 2008 were included in the study. The etiology, symptoms and signs, laboratory findings and outcomes were collected via chart review. RESULTS Nineteen cases (13 boys and 6 girls) ranging in age from 2.5 months to 18 years (mean = 7.98 years; median = 5 years) were included. Nine out of 17 cases (52.9%) had microscopic hematuria and two out of three (66.7%) cases showed elevated rheumatoid factor levels. Seventeen (89.5%) had fever and seven (36.8%) had major vessel embolic events. Blood cultures yielded Staphylococcus aureus in seven cases, and viridans Streptococci in two cases. The other three cases had Pneumococcus, Pseudomonas aeruginosa and Candida albicans. Two patients died and one was discharged in a critical condition. Two of the seven (28.6%) patients with a positive blood culture for S. aureus died, three (42.9%) had an embolic event and one (14.3%) had central nervous system complications (intracranial hemorrhage). The initial C-reactive protein levels in the blood culture-positive group were significantly higher than those in the blood culture-negative group (p = 0.035). CONCLUSION S. aureus is one of the most common etiologies in IE patients, while viridans Streptococcus accounts for fewer cases than suggested by previous studies. IE caused by S. aureus seems to carry a higher risk of mortality, and embolic events are associated with increased mortality.

The diagnostic value of serum interleukins 6 and 8 in children with acute gastroenteritis.

Objectives: Early identification of the pathogen causing acute gastroenteritis in children helps the physicians managing the disease and prevents unnecessary antibiotic treatment. C-reactive protein (CRP), interleukin (IL) 6 and IL-8 play a major role in immune responses and have been studied in a large number of infectious and noninfectious inflammatory diseases. The purpose of this study was to determine the serum IL-6 and IL-8 concentrations early in the course of acute gastroenteritis to see if these cytokines were useful diagnostic markers in differentiating viral from bacterial gastroenteritis. Methods: Interleukin 6, IL-8 and CRP were measured in 18 patients with bacterial gastroenteritis, 21 patients with viral gastroenteritis and 17 healthy children. Results: Interleukin 6 and CRP concentrations in patients with bacterial gastroenteritis were significantly higher than those in patients with viral gastroenteritis and healthy controls (P < 0.001). IL-8 concentrations in patients with viral and bacterial gastroenteritis were both increased and were not statistically different. IL-6 and IL-8 levels had diagnostic sensitivities of 79% and 50% and specificities of 86% and 67%, respectively. The combination of IL-6 and CRP had a sensitivity of 94%, specificity of 71%, a positive predictive value of 74% and a negative predictive value of 93.75%. Conclusions: Serum IL-6 may be a useful marker for early differentiation of viral and bacterial gastroenteritis in children, especially in combination with CRP.

EXPRESSION OF SERUM IL-2, IL-2R, AND CD8 LEVELS DURING HYPOSENSITIZATION IN HOUSE-DUST-SENSITIVE ASTHMATICS

In this study, we used the enzyme-linked immunosorbent assay (ELISA) to evaluate the changes of serum interleukin-2 (IL-2), interleukin-2 receptor (IL-2R), and suppressor/cytotoxicity factor (CD8) in house dust-sensitive asthmatic children during hyposensitization. Patients before immunotherapy presented significantly higher serum levels of IL-2 and IL-2R than normal subjects (p less than 0.001), but these levels became normal after three years of hyposensitization. No significant difference of serum CD8 level was noted between pretreated patients and normal controls. Although the serum CD8 level in treated patients also decreased after three years of immunotherapy, this decrease was not significant compared with the pretreated patients (p greater than 0.05). This study suggests that serum IL-2 and IL-2R markers might be helpful in analyzing allergic states associated with immune activation and in evaluating the therapeutic effects of hyposensitization.