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Biomedical subjects

J L Huang

Publications and source records attributed to J L Huang.

At least 19 recordsLinked to original sources
PubMed2003

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.

Acyclovir↗
PubMed2003

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.

Adolescent↗
PubMed2002

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.

Adolescent↗
PubMed2001

Energy gaps in "metallic" single-walled carbon nanotubes.

Metallic single-walled carbon nanotubes have been proposed to be good one-dimensional conductors. However, the finite curvature of the graphene sheet that forms the nanotubes and the broken symmetry due to the local environment may modify their electronic properties. We used low-temperature atomically resolved scanning tunneling microscopy to investigate zigzag and armchair nanotubes, both thought to be metallic. "Metallic" zigzag nanotubes were found to have energy gaps with magnitudes that depend inversely on the square of the tube radius, whereas isolated armchair tubes do not have energy gaps. Additionally, armchair nanotubes packed in bundles have pseudogaps, which exhibit an inverse dependence on tube radius. These observed energy gaps suggest that most "metallic" single-walled nanotubes are not true metals, and they have implications for our understanding of the electronic properties and potential applications of carbon nanotubes.

Journal Article↗
PubMed2001

Atomically resolved single-walled carbon nanotube intramolecular junctions.

Intramolecular junctions in single-walled carbon nanotubes are potentially ideal structures for building robust, molecular-scale electronics but have only been studied theoretically at the atomic level. Scanning tunneling microscopy was used to determine the atomic structure and electronic properties of such junctions in single-walled nanotube samples. Metal-semiconductor junctions are found to exhibit an electronically sharp interface without localized junction states, whereas a more diffuse interface and low-energy states are found in metal-metal junctions. Tight-binding calculations for models based on observed atomic structures show good agreement with spectroscopy and provide insight into the topological defects forming intramolecular junctions. These studies have important implications for applications of present materials and provide a means for assessing efforts designed to tailor intramolecular junctions for nanoelectronics.

Journal Article↗
PubMed2001

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.

Adolescent↗
PubMed2001

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.

Adolescent↗
PubMed2001

Evaluation of Th1/Th2 ratio and cytokine production profile during acute exacerbation and convalescence in asthmatic children.

BACKGROUND: Th2-type cytokines, such as IL-4 and IL-5, are generally believed to play an important role in the pathogenesis of allergic asthma. In contrast, Th1-type cytokine, especially interferon (IFN)-gamma, is thought to have a downregulatory effect on Th2 immune response cells. Thus, the imbalance of Th1 and Th2 cells may be a key factor in relation to disease severity. OBJECTIVE: The aim of this study is to examine the changes in the Th1/Th2 ratios and cytokine production profiles of asthmatic children at acute attacks and convalescent stages. METHODS: Twelve asthmatic patients were included in this study. The percentages of IFN-gamma- or IL-4-producing cells were determined with a flow-cytometric method of intracellular protein detection. Fresh whole blood obtained from normal controls and patients at two stages was stimulated with brefeldin A, phorbol myristate acetate, and ionomycin for 4 hours. Cells were fixed and stained intracellularly with fluorescein isothiocyanate- or phycoerythrin-conjugated antibody specific to each cytokine in combination with anti-CD4. ELISA assays were applied to measure cytokine concentrations of supernatant from peripheral blood mononuclear cells (PBMC) activated with phorbol myristate acetate and ionomycin for 24 hours. RESULTS: Among CD4+ cells, the percentage of IL-4+ cells decreased significantly from 8.18 +/- 4.77% at acute attacks to 4.18 +/- 1.26% (P < .020) at convalescence. The percentage of IFN-gamma+ cells also decreased from 13.49 +/- 4.21% to 9.03 +/- 5.42% (P < .052). The Th1/Th2 ratios of patients at the two stages were similar, and both were lower than the normal controls. Significantly higher IL-5 and lower IFN-gamma production were detected from activated PBMC of asthmatic patients than normal controls. CONCLUSIONS: The decrease of IFN-gamma+ and IL-4+ cells detected at the single-cell level may explain the potential mechanism of convalescence from acute asthma attacks. High Th1/Th2 ratio and low IL-5 production from the PBMC of normal controls support the idea of a biased Th2 immune response in asthmatic patients.

Acute Disease↗
PubMed2001

The higher likelihood of developing cardiomegaly during follow-up in patients with syndrome X and abnormal thallium-201 myocardial perfusion SPECT.

'Syndrome X' describes patients with exertional chest pain and a normal coronary arteriogram. In some patients, acute myocardial ischemia can be demonstrated by regional myocardial perfusion defects on thallium-201 exercise test. However, some patients with typical angina have normal perfusion on thallium-201 heart scintigraphy. It is not clear whether there are different prognoses for patients with normal and abnormal thallium studies. In this study, the clinical features, long term follow-up and clinical results of syndrome X patients with normal and abnormal thallium studies were evaluated to determine the differences between these two groups. Fifty-nine patients (52 males, seven females, mean age 62+/-6 years) with syndrome X were enrolled and divided into two groups on the basis of results of thallium-201 heart scintigraphy. Group I was comprised of 22 patients with normal thallium-201 perfusion scan and group II was comprised of 37 patients with abnormal thallium-201 heart scan. All subjects received coronary arteriography, exercise test, thallium-201 myocardial SPECT, ejection fraction of left ventricle, echocardiography, blood analysis and long term follow-up with questionnaire for 10 years. Lower maximal rate-pressure product and higher angina scores were found in group II. More patients developed cardiomegaly (nine of 33 patients) in group II than in group I (one of 21 patients). Both groups, however, were at low risk for cardiac events (cardiac death or myocardial infarction).

Aged↗
PubMed2001

Exposure to a high concentration of mite allergen in early infancy is a risk factor for developing atopic dermatitis: a 3-year follow-up study.

The cause of allergy is multi-factorial, and the development of an allergic disease seems to be the result of an interaction between genetic and environmental factors. The goal for preventing the development of allergic diseases is to avoid sensitization to allergens. The aim of this work was to study whether or not exposure to environmental allergens early in infancy would influence the occurence of various allergic diseases in later life. On an annual basis, a total of 931 healthy newborns were followed-up until they reached 3 years of age. The occurence of allergic diseases was recorded by trained medical students during visits. Measurement of Dermatophagoides pteronyssinus (Der p 1) concentration in house dust was performed when each baby was 18 and 36 months old. Total and specific immunoglobulin E (IgE) antibodies against Der p 1, cow's milk, and egg white were evaluated at birth and at 18 months of age. The following results were obtained: at 3 years of age, 10.4% had bronchial asthma (BA), 21.4% atopic dermatitis (AD), 7.0% urticaria, and 46.8% had experienced wheezing; higher family allergy scores led to a higher incidence of AD (p=0.0012); exposure to a mite allergen concentration of 1 microg/g of dust may be associated with a higher incidence of AD (p=0.0156); the presence of Der p 1 IgE antibody at 18 months of age was associated with a higher incidence of BA (p=0.0001); and children sensitized to egg whites at 18 months of age had an increased risk of developing AD at 3 years of age (p=0.0187). Hence, early exposure to mite allergen is a risk factor for the development of atopic dermatitis, but seems not to be related to the development of bronchial asthma. Early sensitization to egg whites increases the risk of developing AD. The early detection of serum Der p 1 IgE antibody is associated with a higher incidence of bronchial asthma.

Age Factors↗
PubMed2001

Mechanism of spontaneous transition from typical atrial flutter to atrial fibrillation: role of ectopic atrial fibrillation foci.

Paroxysmal AF has been known to be initiated by ectopic beats, especially in the pulmonary veins (PVs), and radiofrequency catheter ablation could cure it. We considered that the spontaneous transition from typical atrial flutter to AF also could be initiated by ectopic beats. Twenty patients (18 men, mean age 66 +/- 14 years) with episodes of spontaneous transition from typical atrial flutter to AF were included in this study. They underwent detailed mapping of both atria. All the patients had spontaneous AF initiated by ectopic beats, and all of them had typical atrial flutter and spontaneous transition from typical atrial flutter (12 patients with counterclockwise atrial flutter and 8 patients with clockwise atrial flutter) to AF. The transition was initiated by ectopic beats from the PVs (17 foci, 85%), crista terminalis (2 foci, 10%), and superior vena cava (1 focus, 5%). After successful ablation of AF foci, typical atrial flutter was induced again, but no spontaneous transition was found after at least 10 minutes of observation. We concluded that paroxysmal AF and spontaneous transition from typical atrial flutter to AF were initiated by ectopic beats, and successful catheter ablation of the ectopic foci can eliminate paroxysmal AF and spontaneous transition from typical atrial flutter to AF.

Aged↗
PubMed2001

Identification of B-cell epitope of dengue virus type 1 and its application in diagnosis of patients.

Using a serotype-specific monoclonal antibody (MAb) of dengue virus type 1 (DEN-1), 15F3-1, we identified the B-cell epitope of DEN-1 from a random peptide library displayed on phage. Fourteen immunopositive phage clones that bound specifically to MAb 15F3-1 were selected. These phage-borne peptides had a consensus motif of HxYaWb (a = S/T, b = K/H/R) that mimicked the sequence HKYSWK, which corresponded to amino acid residues 111 to 116 of the nonstructural protein 1 (NS1) of DEN-1. Among the four synthetic peptides corresponding to amino acid residues 110 to 117 of the NS1 of DEN-1, -2, -3, and -4, only one peptide, EHKYSWKS (P14M) of DEN-1, was found to bind to 15F3-1 specifically. Furthermore, P14M was shown to inhibit the binding of phage particles to 15F3-1 in a competitive inhibition assay. Histidine(111) (His(111)) was crucial to the binding of P14M to 15F3-1, since its binding activity dramatically reduced when it changed to leucine(111) (Leu(111)). This epitope-based peptide demonstrated its clinical diagnostic potential when it reacted with a high degree of specificity with serum samples obtained from both DEN-1-infected rabbits and patients. Based on these observations, our DEN-1 epitope-based serologic test could be useful in laboratory viral diagnosis and in understanding the pathogenesis of DEN-1.

Amino Acid Sequence↗
PubMed2001

Lowered IL-4-producing T cells and decreased IL-4 secretion in peripheral blood from subjects with juvenile rheumatoid arthritis.

BACKGROUND: To evaluate T helper 1 (Th1)/Th2 cells and cytokines in patients with three different subtypes of juvenile rheumatoid arthritis (JRA). METHODS: Peripheral blood was obtained from 25 children with JRA suffering from active arthritis (8 systemic, 9 pauciarticular and 8 polyarticular). Eight healthy children were recruited as controls. T helper cells from peripheral blood mononuclear cells (PBMC) were evaluated by using intracellular staining analysis of cytokine production with 3-colored flow cytometry. A Th1 cell was defined as an interferon-gamma (IFN-gamma) producing CD4+ cell, and a Th2 cell as an interleukin-4 (IL-4) producing CD4+ cell. The production of IL-2, IL-4, IL-5 and IFN-gamma from PBMC was measured by ELISA. RESULTS: In comparison with normal controls, the patients with JRA had significantly fewer Th2 cells among their PBMC (0.78 +/- 0.56% vs. 5.44 +/- 2.33%, p < 0.001). The percentage of Th1 cells among PBMC was not different between patients and normal controls (4.32 +/- 3.24% vs. 4.52 +/- 2.56%, p > 0.5). The ratio of Th1/Th2 cells in the patient group was significantly higher than the control group (8.38 +/- 8.63 vs. 0.95 +/- 0.66, p < 0.001). After 24-hour culture, the PBMC from JRA patients produced less IL-4 than that of controls (3.61 +/- 0.56 pg/mL vs. 4.29 +/- 0.68 pg/mL, p = 0.002). The production of IL-2, IL-5, and IFN-gamma did not show significant differences between JRA patients and normal controls. CONCLUSION: Decreased IL-4 producing T-helper cells were identified in all three subtypes of JRA. This implicates that an imbalance of Th sub-populations might be a predominant factor in JRA pathogenesis.

Adolescent↗
PubMed2001

Correlation of total and specific serum immunoglobulin E levels with the severity of chronic sinusitis in children.

Chronic sinusitis is frequently associated with allergy and asthma. Previous studies have shown that serum immunoglobulin E (IgE) levels correlate with allergy and asthma in adults. Because the role of allergic inflammation in the severity of chronic sinusitis remains controversial in children, we set out to determine whether a correlation exists between serum levels of total and specific IgE and the severity of chronic sinusitis in children. Forty-four children with chronic sinusitis were enrolled in the study. Computed tomographic scans were reviewed and scored for the severity of sinusitis. All children were mite-sensitive. Serum samples were assayed for total IgE and specific IgE antibodies to mite allergen using a fluoroimmunoassay. Fourteen subjects had extensive sinus disease. There was no significant difference in the average of total and specific IgE between the subjects with extensive and limited disease (p = 0.562 and 0.755, respectively). Thirty-four subjects were diagnosed with asthma. The subjects with extensive sinus disease had a higher prevalence of moderate to severe asthma than the subjects with limited disease (p = 0.006), but there was no significant difference in the average of total and specific IgE between the subjects with different severities of asthma. (p = 0.833 and 0.425, respectively). The data suggests that levels of total or specific IgE do not correlate with severity of chronic sinusitis in children. Nonetheless, the severity of chronic sinusitis and asthma correlate well with each other irrespective of total and specific IgE.

Adolescent↗
PubMed2001

Paradoxical vocal cord adduction mimicking as acute asthma in a pediatric patient.

We report an adolescent girl with paradoxical vocal cord adduction who presented with acute onset of hyperventilation, wheezing and stridor that did not respond to bronchodilator and anti-inflammation therapy. The paradoxical vocal cord motion was confirmed by flexible fiberoptic bronchoscopic examination. We found the stridor was induced by hyperventilation, and was caused by paradoxical vocal cord movement. The abnormal cord motion may be psychogenic and could be misdiagnosed as asthma. It is important to investigate the underlying background and social history and to avoid unnecessary use of beta-agonists, steroids, and even endotracheal intubation or tracheostomy.

Acute Disease↗