Biomedical subjects

Dah-Chin Yan

Publications and source records attributed to Dah-Chin Yan.

15 recordsLinked to original sources

PubMed2006

Effect of interleukin-15 on alloreactivity in umbilical cord blood.

Interleukin(IL)-15 is a promising immunotherapeutic agent for immune reconstitution following stem cell transplantation. To investigate whether IL-15 would aggravate graft-versus-host disease (GVHD) in the setting of unrelated umbilical cord blood (CB) transplantation, we examined the effect of IL-15 on activation marker expression, proliferation and cytokine production of CB in a one-way mixed lymphocyte culture (MLC) assay. We found that IL-15 differentially enhanced CD69 and CD25 expression on CB T cells following allo-stimulation. The maximum degree of allo-specific CB proliferation was achieved on Day 6. IL-15 down-regulated the CB alloreactive proliferative response on Days 4, 6, and 8, with preferentially enhanced autologous proliferation. Exogenous IL-15 further enhanced CB TNF-alpha and IL-10 production in both autologous and allogeneic MLC 6 days after allopriming. Thus, IL-15 was effective in enhancing activation marker expression and cytokine production during CB alloreactivity, but failed to enhance allospecific proliferation. Further studies would be needed to study the role of IL-15 on GVHD in the setting of CB transplantation.

Antigens, CD↗

PubMed2006

Myocarditis presenting as gastritis in children.

Vomiting and abdominal pain are common pediatric complaints encountered by emergency physicians. The differential diagnosis of abdominal pain is extensive. Herein, we report 2 cases with fatal myocarditis who initially presented with abdominal pain and vomiting. Both cases were presented with abdominal pain, vomiting, and loose stools. On arrival at our emergency department, hypotension, tachycardia, and cyanotic extremities were found. Their serum troponin-I levels were elevated. The echocardiogram demonstrated poor left ventricular performance and a decreased ejection fraction. In both cases, an arrhythmia and a coma developed within hours and were shortly followed by death. The clinical presentations of acute myocarditis are variable, ranging from an initial mild discomfort to acute progressive heart failure, and at times, even death. Abdominal pain may be a manifestation of systemic disease, an extra-abdominal lesion, or myocarditis. Although myocarditis associated with abdominal pain or vomiting remains a diagnostic challenge to physicians, it should be considered in the differential diagnosis of children with gastritis and hypotension or who are refractory to rehydration therapy.

Abdominal Pain↗

PubMed2006

Clinical observation of meningitis caused by penicillin-susceptible and -non-susceptible Streptococcus pneumoniae in Taiwanese children.

AIM: To compare differences between clinical features and outcome in bacterial meningitis caused by penicillin-susceptible Streptococcus pneumoniae (PSSP) with that caused by penicillin-non-susceptible Streptococcus pneumoniae (PNSP). METHODS: All patients <18 yrs hospitalised with pneumococcal meningitis between January 1984 and December 2002 at Chang Gung Children's Hospital, Taipei were reviewed retrospectively. RESULTS: There were 28 PNSP (63.6%) and 16 PSSP cases of meningitis eligible for the study. The incidence of PNSP meningitis increased significantly over the 8-yr period (p = 0.007). Age <4 yrs (78.6% vs 50%), a lower initial white blood count (mean 11.7 vs 19.9 x10(9)/L), admission to the intensive care unit (70.4% vs 50%) and mortality (28.6% vs 6.3%) were more common in the PNSP group. However, the only significant finding was a lower proportion of polymorphic neutrophils in the CSF of the PNSP meningitis group (p = 0.04). CONCLUSIONS: There was an increase in PNSP isolates from patients with meningitis over the 8-yr study period. No major differences were observed in clinical or laboratory features or outcome between the PSSP and PNSP groups.

Adolescent↗

PubMed2005

Prevalence and severity of symptoms of asthma, rhinitis, and eczema in 13- to 14-year-old children in Taipei, Taiwan.

BACKGROUND: The prevalence of asthma and allergic diseases in children has increased worldwide. OBJECTIVE: To perform the phase 3 survey of the International Study of Asthma and Allergies in Children (ISAAC) to report the time trend of the prevalence and severity of asthma and allergic diseases in children in Taipei. METHODS: Two junior high schools in each of the 12 school districts in Taipei were randomly chosen to enter the study. All students aged 13 to 14 years in the chosen schools were invited to participate in written and video questionnaires in Chinese (identical to those of the ISAAC phase 1 survey). The study was performed between December 1, 2001, and January 31, 2002. All data analysis followed the protocol of the ISAAC and then was submitted to the ISAAC International Data Center. RESULTS: Of 6653 eligible children from 23 high schools (1 school refused participation), 6381 (95.9%) participated. The prevalence of symptoms of asthma, allergic rhinitis, and atopic eczema in the past 12 months in 13- to 14-year-old children increased by 37%, 51%, and 193%, respectively, on written questionnaires during a 7-year period. The severity of asthma symptoms, including more than 4 wheezing attacks in the past 12 months, wheezing that disturbs sleep more than once per week, and wheezing that limited speech in the past 12 months, did not show any significant changes on written questionnaires during the 7 years. CONCLUSION: The increasing prevalence of symptoms of asthma, allergic rhinitis, and atopic eczema in 13- to 14-year-old children in Taipei in a 7-year period is a significant burden on public health systems in Taiwan.

Adolescent↗

PubMed2005

Effect of FK506 on the interleukin 15-driven proliferation and apoptosis of anti-CD3-activated umbilical cord blood T cells.

BACKGROUND: Increased susceptibility of umbilical cord blood (CB) T cells to FK506 immunosuppression may contribute to the lessened severity of graft-vs-host disease in CB transplantation. OBJECTIVE: To investigate the FK506 sensitivity of interleukin 15 (IL-15)- and IL-2-driven proliferation and apoptosis of anti-CD3-stimulated CB T cells compared with adult peripheral blood (APB) T cells. METHODS: Surface flow cytometric analysis (CD25 and CD95), carboxyfluorescein diacetae succinimidyl ester staining to track CD3+ T-cell division, and flow cytometric analysis of apoptotic cell death using Annexin V were performed to determine the effect of FK506 on CD3+ T-cell activation and apoptosis after anti-CD3 stimulation in the presence of IL-15 or IL-2. RESULTS: IL-15 is superior to IL-2 in promoting CD25 expression and proliferation of anti-CD3-stimulated CB and APB T cells. Although IL-15-driven proliferation evaluated by carboxyfluorescein diacetae succinimidyl ester staining revealed comparable sensitivity to FK506 in anti-CD3-stimulated CB and APB T cells, IL-15-driven CD25 up-regulation in CB T cells was more sensitive to FK506 inhibition than APB T cells. FK506 down-regulated anti-CD3-induced apoptosis in CB and APB T cells (P < .01). However, the FK506 sensitivity of anti-CD3-induced T-cell apoptosis was lost in IL-15-supplemented CB cultures (P = .51) but not in corresponding APB cultures (P = .002). The IL-15-enhanced Fas expression on CB T cells (CD95) was decreased by FK506, similar to that observed with adults. CONCLUSIONS: We observed differential FK506 sensitivity of IL-15-driven CD25 up-regulation and apoptotic response comparing CB and APB T cells. This finding suggests the potential therapeutic benefit of FK506 in ameliorating graft-vs-host disease by decreasing IL-15-driven donor T-cell proliferation without inhibiting associated activation-induced apoptosis during CB transplantation.

Adult↗

PubMed2005

Clinical and laboratory manifestations of Kikuchi's disease in children and differences between patients with and without prolonged fever.

BACKGROUND: Kikuchi's disease (KD) is characterized by cervical lymphadenopathy with or without fever. It has been recognized worldwide but seldom reported in pediatric patients. METHODS: From January 1985 through December 2001, 64 patients younger than 18 years of age with pathologic proof of KD were enrolled in this study. The clinical manifestations, laboratory data and outcomes were reviewed. RESULTS: There were 35 male patients and 29 female patients with age ranging from 2 to 18 years and a median age of 16. All patients had cervical lymphadenopathy except 1 who had generalized lymphadenopathy. Lymph nodes of 32 patients (50%) were painful or tender or both. Lymphadenopathy was unilateral in 52 patients (82.5%). Lymphadenopathy associated with fever was observed in 21 patients (32.8%). Other signs such as skin rash, hepatomegaly or body weight loss were less common. Twenty-six patients (40.6%) had leukopenia and 2 patients had leukocytosis. Nearly one-fourth of the patients had mild liver dysfunction. Virologic or immunologic studies were normal in most patients. Patients with prolonged fever were more likely to have leukopenia (P < 0.05). All patients recovered, but 1 developed systemic lupus erythematosus 5 years later, and the other had vasculitis syndrome 2 years later. CONCLUSIONS: The clinical presentation of KD in pediatric patients is similar to that of adults. KD is a benign, self-limiting disease; prolonged fever occurred only in 32.8% of pediatric patients in our cohort. Leukopenia was the only feature significantly associated with prolonged fever.

Adolescent↗

PubMed2005

Epstein-Barr virus-associated infectious mononucleosis and risk factor analysis for complications in hospitalized children.

The characteristics of Epstein-Barr virus (EBV)-associated infectious mononucleosis (IM) in Chinese children are rarely reported. To evaluate the clinical presentations and risk factors for complications of EBV-associated IM in previously healthy children in Taiwan, hospitalized children with the diagnosis of IM due to EBV infection from January 1998 to December 2002 were enrolled. Patients had to fulfill the serologic criteria for the diagnosis of primary EBV infection [viral capsid antigen immunoglobulin M (IgM)-(+), viral capsid antigen IgG-(+), and anti-Epstein-Barr nuclear antigen (EBNA) antibody-(-) with exclusion of other concurrent infections or underlying diseases]. Ninety eight children were eligible, with 79% younger than 5 years old (mean, 4.0 +/- 2.3 years). The male-to-female ratio was 2:1. Nearly all patients suffered from fever (mean duration 10.3 +/- 6.0 days). Cough/rhinorrhea, tonsillopharyngitis, cervical lymphadenopathy and hepatosplenomegaly were found over half of the patients. Atypical lymphocytosis (mean, 12 +/- 13%) and elevated serum aspartate aminotransferase (AST; mean, 167 +/- 183 IU/L) and alanine aminotransferase (mean, 221 +/- 222 IU/L) were the most striking laboratory findings. Various complications, including hematologic, hepatobiliary, central nervous system, and obstructive airway problems occurred in about 20% of patients with significantly prolonged course of hospitalization. All patients recovered uneventfully under supportive and immunomodulating management. Female gender, no signs of tonsillopharyngitis, white blood cell count < or =10,000/mm3 and AST > or =150 IU/L were significant risk factors for the occurrence of complications. Clinicians should monitor such patients closely and give proper treatment to decrease possible morbidity or even mortality should complications occur.

Adolescent↗

PubMed2004

The use of bispectral index to monitor unconscious children.

The use of the Glasgow Coma Scale may be limited by the experience of physicians, errors resulting from subjectivity, the inability of patients to respond, and discontinuity. This study demonstrates that the Bispectral Index scores correlate well with scores from the Glasgow Coma Scale and that Bispectral Index scores can provide real-time, objective, and continuous monitoring of the consciousness level of critically ill children. Sixteen patients with consciousness disturbance, who were admitted to a pediatric intensive care unit of a tertiary university-affiliated children's hospital, were enrolled in this study. The patients received 34 Glasgow Coma Scale assessments and Bispectral Index scores. The age of patients ranged from 10 to 192 months (mean +/- S.E. = 68.4 +/- 12.3 months). Glasgow Coma Scale ranged from 3 to 11 (mean +/- S.E. = 6.3 +/- 0.4), and Bispectral Index score ranged from 0 to 100 (mean +/- S.E. = 55.4 +/- 5.6). A positive correlation was found to exist between Glasgow Coma Scale and Bispectral Index score (r = 0.76, P < 0.001). In conclusion, the Bispectral Index score correlates well with the Glasgow Coma Scale in critically ill children who score between 3 and 11 on the Glasgow Coma Scale.

Adolescent↗

PubMed2004

Vesicoureteral reflux in hospitalized children with urinary tract infection: the clinical value of pelvic ectasia on renal ultrasound, inflammatory responses and demographic data.

BACKGROUND: The aims of this study were to determine whether renal pelvis dilation on ultrasound was reliable in predicting vesicoureteral reflux (VUR) and to assess the relationship of other clinical information of VUR in children with urinary tract infection (UTI). METHODS: We retrospectively reviewed clinical data, renal echo, and voiding cystourethrogram (VCUG) results in hospitalized children with their first episode of UTI, aged from 1 month to 5 years, during a 1-year period. RESULTS: There were 114 children with 228 kidneys eligible for the study. Unilateral pelvis size greater than 8 mm had 2.4 (p = 0.049, 95% CI: 1.0-5.9) and 3.7 (p = 0.025, 95% CI: 1.2-11.3) times greater risk for VUR and severe reflux, respectively. The sensitivity in detecting severe reflux was 27.8%, and the specificity was 90.5%. The positive and negative predictive values in suggesting severe VUR were 20.0% and 93.6%, respectively. The sum of bilateral pelvis sizes greater than 16 mm had higher risk for VUR and severe reflux (4.1 and 4.6 times) and similar specificity and negative predictive value for severe reflux. Age, gender, C-reactive protein, leukocytosis, pyuria and acute pyelonephritis did not show significant relationships to the reflux. CONCLUSIONS: Unilateral pelvis size greater than 8 mm or the sum of the bilateral pelvis sizes greater than 16 mm was associated with VUR, especially severe VUR. The possibility of severe reflux was lower than 10% when the reverse criteria were applied. However, the dilation of the renal pelvis did not predict all VUR precisely. We concluded that VCUG should still be performed in hospitalized children with UTI.

Acute Disease↗

PubMed2003

Effect of interleukin 15 and interleukin 2 on anti-CD3-induced T-cell activation and apoptosis in children with common variable immunodeficiency.

BACKGROUND: Defective T-cell function and susceptibility to apoptosis following activation may contribute to the immunodeficiency observed in common variable immunodeficiency (CVID) patients. Interleukin (IL) 2 benefits CVID children by boosting T-cell function. OBJECTIVE: To investigate the effect of another IL-2 common gamma-chain signaling cytokine, IL-15, on T-cell activation and apoptosis of peripheral blood mononuclear cells (PBMCs) from children with CVID compared with IL-2. METHODS: Five children treated at the Chang Gung Children's Hospital, Taoyuan, Taiwan, during 1998 to 2002 who fulfilled World Health Organization criteria for CVID and 8 age-matched, healthy controls were enrolled. The PBMCs were stimulated with anti-CD3 in the presence or absence of IL-2 and IL-15 for 4 days, followed by 24-hour incubation with anti-Fas to induce apoptosis. Surface expression of CD69, CD25, and CD95 (Fas) on CD3+ T cells was evaluated by flow cytometry. The degree of apoptosis was evaluated by propidium iodide-phycoerythrin/annexin V-fluorescein isothiocyanate flow cytometric staining. RESULTS: Following anti-CD3 activation, CD69 and CD25 expression of CVID CD3+ PBMCs was enhanced to levels comparable to controls. Exogenous IL-15 resulted in further enhancement of anti-CD3-induced CD69 expression to a greater extent than that achieved with IL-2. A greater degree of apoptosis was found in CVID patients than controls following anti-CD3 stimulation (P = 0.001). IL-15 but not IL-2 further increased anti-CD3-induced apoptosis in control PBMCs (P = 0.001). In contrast, the degree of anti-CD3-induced apoptosis in CVID PBMCs was unaffected by IL-15 or IL-2. Addition of anti-Fas to cultures prestimulated with anti-CD3 further increased the apoptosis in control PBMCs but had no effect on apoptosis of CVID PBMCs. CONCLUSION: Comparable anti-CD3-induced activation and enhanced apoptosis were observed in PBMCs from children with CVID compared with controls. The degree of apoptosis in CVID PBMCs was not affected by exogenous IL-15 or anti-Fas, suggesting a preactivated status in vivo.

Adolescent↗

PubMed2003

The RANTES promoter polymorphism: a genetic risk factor for near-fatal asthma in Chinese children.

BACKGROUND: RANTES promoter polymorphisms were found associated with asthma/atopy in some studies but not others, possibly reflecting the genetic heterogeneity among different ethnicities and different asthma severity. OBJECTIVE: The purpose of this investigation was to test the genetic association between the RANTES -28C/G and -403G/A polymorphisms and asthma/atopy in a cohort of Chinese children, with particular emphasis on those patients who had experienced life-threatening asthma attacks. METHODS: Forty-eight children with near-fatal asthma, 134 children with mild-to-moderate asthma, 69 children with allergic disorders but no asthma, and 107 nonasthmatic nonatopic control children were genotyped through use of a PCR-based assay. RESULTS: No significant difference was demonstrated for frequency of the RANTES -28C/G polymorphism when the mild-to-moderate asthma, atopic/nonasthmatic, and normal control groups were compared. The RANTES -28G allele was present in a significantly higher proportion of the children with near-fatal asthma compared with the nonasthmatic nonatopic controls (odds ratio, 2.93 [1.41-6.06]; P =.006) and the children with mild-to-moderate asthma (odds ratio, 3.52 [1.73-7.16]; P =.001). The frequency of -28G allele carriage correlated with asthma severity. The RANTES -28G allele was also associated with an increased blood eosinophil count and a higher degree of bronchial hyperresponsiveness. The RANTES -403G/A polymorphism did not influence asthma/atopy susceptibility, blood eosinophil count, or bronchial hyperresponsiveness. Interestingly, a higher frequency of -403A allele carriage was observed in the moderate asthma subgroup compared with the mild asthma analog. CONCLUSIONS: We conclude that the RANTES -28C/G polymorphism exacerbates asthma severity, representing a genetic risk factor for life-threatening asthma attacks in Chinese children. In addition, the linkage disequilibrium between these 2 polymorphisms is a potential confounder that must be considered in the design and interpretation of RANTES gene association studies.

Asthma↗

PubMed2003

Primary school nurses' knowledge/competence pertaining to childhood asthma and its management prior to and following a National Asthma Education Program in Taiwan.

The main purpose of the National Asthma Education Program was to provide asthma education to school nurses in Taiwan. It was also designed to enhance the knowledge and competence of school nurses in managing the asthmatic problems that children experience while in school. In addition to providing instruction about current asthma management skills, tools, and other relevant information, the program demonstrated the use of the peak flow meter for asthmatic children. A single, 4-hr session conducted in each county and city in Taiwan, the National Asthma Education Program began on August 1, 1999, and ended December 31, 2000. A total of 829 school nurses joined the program, with an overall attendance rate of 74%. Significant effects of this program on nurses' asthma care knowledge and competence and case management efficacy were noted. The participating school nurses' demographics, however, were found to be irrelevant to these effects. Expecting the training activities to help relieve the anxieties of managing asthmatic cases in the school environment, participants reported that the training was of much benefit to them. Development of a teaching program to elevate school nurses' capabilities in asthmatic student care in the school environment and the implications of such a program within Taiwanese schools were also discussed.

Adult↗

PubMed2003

Hyper-IgM syndrome: a case report.

Hyperimmunoglobulin M syndrome is a rare primary immunodeficiency disorder. We report a case of a 6-month-old boy who suffered from developmental delays, frequent respiratory tract infection, and unusual fungal and bacterial infection. X-linked hyperimmunoglobulin M syndrome was ultimately diagnosed with decreasing immunoglobulin-G, A, and E (immunoglobulin G = 51.3 mg/dL, immunoglobulin A = 8.32 mg/dL, immunoglobulin E <17.5 mg/dL), elevating immunoglobulin M (immunoglobulin M = 140 mg/dL), and decreasing T-cell expression of the CD40 ligand over flow cytometry. Seizure episodes and hypotonia developed with greater signal intensity at the putamen in a brain magnetic resonance imaging, which is compatible with hypoxic ischemic encephalopathy. This is the youngest proven case of hyper-IgM syndrome in Taiwan ever reported.

CD4-Positive T-Lymphocytes↗

PubMed2003

Rotavirus gastroenteritis associated with afebrile convulsion in children: clinical analysis of 40 cases.

BACKGROUND: The purpose of this study was to evaluate the clinical manifestations and outcomes of hospitalized children with afebrile seizures following rotavirus gastroenteritis. METHODS: We conducted a retrospective study enrolling patients under 18 years old who were admitted to our hospital during a 10-year period with the diagnosis of rotavirus gastroenteritis. We identified and further analyzed patients who presented with afebrile seizures, without previous seizure disorders, electrolyte imbalances or hypoglycemia. The statistical methods used were the Chi-square test, the Kruskal-Wallis test and the Mann-Whitney test. RESULTS: Of 1937 patients, 40 patients (24 female and 16 male patients) met the inclusion criteria. The incidence of afebrile seizures following rotavirus gastroenteritis was 2.06%. The age of the patients ranged from 6 months old to 6 years old (mean, 1.9 years). The highest incidence of afebrile seizures was 4.67% in children 1 to 2 years of age (p < 0.001). Twenty-seven patients (67.5%) had two or more seizures, which usually were in clusters within a 24-hour period. No status epilepticus was observed. More than half of the patients (52.5%) suffered from seizures on the third day of diarrhea. Only five of 35 patients showed abnormal electroencephalogram (EEG) findings, which reverted to normal in four of the patients during the follow-up period. Most patients did not require long-term anticonvulsant treatment. During the follow-up period, all patients displayed normal psychomotor development without the recurrence of seizures, except in one patient who had a febrile convulsion. CONCLUSION: We found that the course of afebrile seizures following rotavirus gastroenteritis was benign with satisfactory outcomes.

Adolescent↗

PubMed2002

Improving the diagnosis of acute appendicitis in children with atypical clinical findings using the technetium-99m hexamethylpropylene amine oxime-labelled white-blood-cell abdomen scan.

BACKGROUND: Diagnosing acute appendicitis in children with equivocal signs and symptoms may be difficult. The usual approach is hospital observation and frequent re-examination. However, many surgeons are reluctant to delay surgery because of the risk of perforation and a negative laparotomy. OBJECTIVE: To assess and compare the value of the technetium-99m hexamethylpropylene amine oxime ((99m)Tc-HMPAO)-labelled white-blood-cell (WBC) abdomen scan in the diagnosis of acute appendicitis in children with atypical clinical presentation. PATIENTS AND METHODS: Fifty children with acute right lower quadrant abdominal pain and possible acute appendicitis, but atypical findings were included. After IV injection of (99m)Tc-HMPAO-labelled WBCs, serial anterior abdomen scans were obtained using a gamma camera. RESULTS: Thirty-three children underwent surgery, while 17 children were managed conservatively and were followed up for at least 1 month. Four children had false-positive results and one child had a false-negative scan result. The overall sensitivity, specificity, accuracy, positive predictive value and negative predictive value of the scan to diagnose acute appendicitis in children with atypical findings was 96.7, 80.0, 90.0, 87.8 and 94.1%, respectively. CONCLUSIONS: The (99m)Tc-HMPAO WBC abdomen scan is a potential tool for diagnosing acute appendicitis in children with atypical clinical findings. The high sensitivity and negative predictive value allows early discharge from the emergency department to avoid costly observation in hospital and potentially unnecessary surgery in those patients with negative scans.

Acute Disease↗