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Biomedical subjects

H K Chang

Publications and source records attributed to H K Chang.

160 records · Page 9Linked to original sources
PubMedDate not supplied

Expression of the MAGE 3 gene product in squamous cell carcinomas of the head and neck.

BACKGROUND: The melanoma antigen (MAGE) 3 gene may be a useful tumor specific marker since it is expressed in a variety of cancers. MATERIALS & METHOD: The expression and intracellular location of MAGE 3 gene product were investigated in 40 squamous cell carcinomas, 2 tumor lines, 20 benign diseases, and 20 normal tissues of the head and neck. Immunohistochemical staining with anti-MAGE 3 mAb 57B was conducted from fresh frozen specimens. Correlations between MAGE 3 expression and clinicopathological parameters were also evaluated. RESULTS: The MAGE 3 gene product was detected in squamous cell carcinomas (18/40, 45%) and in tumor cell lines (2/2, 100%), but not in benign diseases and normal tissues. No significant correlation was drawn between MAGE 3 expression and clinical parameters including clinical stages and metastasis. CONCLUSION: These results show MAGE 3 antigen could represent a potential target for immunotherapy in head and neck squamous cell carcinomas.

Antigens, Neoplasm↗
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HLA-B51 and its allelic types in association with Behçet's disease and recurrent aphthous stomatitis in Korea.

OBJECTIVE: This case-control study was undertaken to evaluate the association of HLA-B51 antigen and its allelic types with Behçet's disease (BD) and with recurrent aphthous stomatitis (RAS), to investigate the degree of this association with diagnostic types and clinical variables of BD. METHODS: The DNA typing of HLA-B51 by nested PCR-SSP was performed in 61 patients with BD, 56 patients with RAS, and in 70 healthy controls. Also, blind quality control study was done to assess the accuracy of nested PCR-SSP in HLA-B51-positive and negative BD patients on the microlymphocytotoxicity. In addition, direct DNA sequencing analysis was carried out in HLA-B51-positive individuals. RESULTS: The outcome of nested PCR-SSP showed 100% concordance with those of the microlymphocytotoxicity. The prevalence of HLA-B51 in patients with BD was 55.7%, 16.1% in patients with RAS, and 15.7% in healthy controls. According to the diagnostic types of BD, all ten patients with complete BD had HLA-B51 antigen, and 47.1% in patients with incomplete BD (p = 0.002). In addition, the prevalence of HLA-B51 was statistically significant in patients with BD who had uveitis (p = 0.003) or erythema nodosum (p = 0.042). Direct DNA sequencing analysis revealed that the major allelic types in BD, RAS, and in healthy control were mostly HLA-B*51011. CONCLUSIONS: Compared to patients with RAS or healthy controls, prevalence of HLA-B51 in the Korean patients with BD was much higher. The BD patients with B51 seemed to be susceptible for manifesting uveitis, erythema nodosum, and the full-blown syndrome as complete BD. Therefore the presence of HLA-B51 antigen in BD patients would be a genetic marker for the severe disease. In addition, there was no difference on the major allelic types of HLA-B51 in BD, RAS, and in healthy control.

Adult↗
PubMedDate not supplied

Osteonecrosis and bone infarction in association with Behcet's disease: report of two cases.

We describe two cases with Behcet's disease (BD) developing osteonecrosis or bone infarction. One patient developed the extensive bone infarction of the left knee without the use of corticosteroids. The other patient had osteonecrosis at the right femoral head. He had had a past history of significant corticosteroid administration to treat several complications of BD such as central nervous system involvement, uveitis, gastrointestinal involvement, and pulmonary involvement. Anticardiolipin (aCL) antibodies were positive in these two patients. One was IgG type, and the other was IgM type. However, it remains unclear that there is relationship between the presence of aCL antibodies and occurrence of osteonecrosis.

Adult↗
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[The coexistence of vesicoureteral reflux and ureteropelvic junction obstruction in children].

From January 1982 to December 1990, there were 229 cases with 337 ureters having vesicoureteral reflux (VUR). Thirteen of them (3.86%) were also found to have ureteropelvic junction (UPJ) obstruction in the same ureter. They were categorized into three groups based on the therapeutic implications. Group 1 (two ureters) underwent pyeloplasty. Group 2 (two ureters) received both pyeloplasty and reimplantation. The remaining nine ureters having VUR and pseudo-obstruction fell into group 3, and two of them became true UPJ obstruction eventually. We stressed the importance of evaluating upper urinary tract in all refluxed ureters with inappropriately dilated renal pelvis. By doing that we can avoid unnecessary surgery and prevent complications from wrong sequence of operation to a least extent.

Child↗
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The prevalence of atopy and atopic diseases in Behçet's disease.

OBJECTIVE: The prevalence of Th-2 cell-mediated diseases, such as atopic diseases, has been noted to be low in Th-1 cell-mediated diseases. This study was undertaken to assess the prevalence of atopy and atopic diseases in Behçet's disease (BD), a Th-1 cell-mediated disease, and to investigate the clinical association between the atopy and the development of severe manifestations in BD. METHODS: We examined 70 consecutive BD patients and 113 controls without BD or other inflammatory rheumatic diseases. The cumulative history of severe manifestations in BD patients was investigated during the disease course. A skin prick test was performed in all the subjects, and atopy was defined as present when the size of one or more allergen-induced wheals was equal to or larger than that caused by histamine. Atopic diseases were defined as present when there were relevant responses for atopic diseases on the questionnaires in the subjects with atopy. In addition, serum IgE levels and peripheral blood eosinophil counts were measured. RESULTS: The prevalence of atopy and atopic diseases was significantly lower in BD patients than in controls. Other atopy parameters, such as serum IgE levels and peripheral blood eosinophil counts, were also significantly lower in BD patients when compared with controls. However, atopy, serum IgE levels, and peripheral blood eosinophil counts did not differ significantly between BD patients with and without severe manifestations. CONCLUSION: The prevalence of Th-2 cell-mediated conditions, such as atopy and atopic diseases, appeared to be lower in BD, a Th-1 cell-mediated disease. In addition, a Th-1 and Th-2 balance may not influence the development of severe manifestations in BD.

Adult↗
PubMedDate not supplied

Validation of the classification criteria commonly used in Korea and a modified set of preliminary criteria for Behçet's disease: a multi-center study.

OBJECTIVE: Recently we have proposed a modified set of criteria to settle the questions raised regarding the International Study Group (ISG) criteria for Behçet's disease (BD). The aim of the present study was to validate the two pre-existing criteria sets commonly used in Korea, the ISG criteria and the criteria of the Behçet's Disease Research Committee of Japan (Japanese criteria), as well as the proposed modified criteria. METHODS: The study population included 155 consecutive patients with BD and 170 controls with non-Behçet's rheumatic diseases. Detailed data for all of the subjects were recorded prospectively by the participating physicians on a standard form that listed the clinical features of BD. The sensitivity, specificity, and accuracy of each set of the criteria were measured. RESULTS: Of the three criteria sets employed, the modified criteria were the most accurate, with an accuracy of 96.3%. The ISG criteria often failed to classify the following patients with BD: patients with only oral and genital ulcerations, certain patients with intestinal ulcerations, patients who did not manifest oral ulcerations, and patients with acute disease but fewer than three recurrent oral ulceration relapses in a 1-year period. The Japanese criteria also failed to categorize the following patients with BD: patients with oral and genital ulcerations, and patients with oral ulcerations, skin lesions, and a positive pathergy reaction. In addition, the Japanese criteria misclassified some of the control subjects with non-Behçet's uveitis as having BD. CONCLUSIONS: The results of this study suggest that there are some points that need to be reconsidered in the clinical application of the two pre-existing sets of criteria. Although the modified criteria were the most accurate, further validation studies will be required in other ethnic populations.

Adult↗
PubMedDate not supplied

Cervical spine involvement in longstanding ankylosing spondylitis.

OBJECTIVE: To investigate the degree of ossification and the frequency of ankylosis between the atlas and the dens of the axis in patients with longstanding ankylosing spondylitis (AS), to assess radiological involvement of the cervical spine, and to determine their correlations with structural severity and clinical variables, including neurological abnormalities. METHODS: In 61 AS patients with disease duration over 7 years, the findings of conventional radiographs were graded by the Bath Ankylosing Spondylitis Radiology Index (BASRI), and the ossification levels between the atlas and the dens and the severity of zygapophyseal (ZA) joint lesions were scored using multislice CT. Neurological examinations and somatosensory evoked potentials (SSEP) were performed by neurologists. RESULTS: According to the BASRI, 50 patients (82.0%) had radiological changes of the cervical spine > or = score 1. Thirty-seven patients (60.6%) revealed a certain extent of the atlantodental ossification, and the presence of partial or complete atlantodental ankylosis was seen over 30% of the patients. The BASRI-cervical spine score and the atlantodental ossification levels correlated with disease duration. ZA involvement was observed in 49 patients (80.3%), including 23 with ZA fusion (37.7%). Although 4 of 11 patients with atlantoaxial subluxation showed abnormal SSEP none had significant neurological complications. This might be attributed in part to atlantodental ankylosis and ZA fusion. Finally, ossifications of the anterior and posterior longitudinal ligaments were found 26.2 and 29.5%, respectively. CONCLUSION: Cervical spine involvement and atlantodental ossification or ankylosis appear to be common in patients with longstanding AS, and to be particularly more severe in patients with a longer disease duration.

Adult↗
PubMedDate not supplied

Fibromyalgia in Behçet's disease is associated with anxiety and depression, and not with disease activity.

OBJECTIVE: To determine the prevalence of fibromyalgia (FM) in Korean patients with Behçet's disease (BD) and to evaluate the association between FM and clinical and psychological variables. METHODS: Seventy patients with BD were examined for FM tender points and asked to complete a Korean version of the Fibromyalgia Impact Questionnaire (FIQ). Disease activity was measured using the erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and a clinical activity score, which was calculated by summing the clinical manifestations. The State-Trait Anxiety Inventory (STAI) and Beck Depression Inventory (BDI) were used for psychometric scoring. RESULTS: Twenty-six BD patients (37.1%) met the American College of Rheumatology criteria for FM. The patients who met the criteria for FM were more frequently female, less frequently employed, and less well educated. Age, disease duration, clinical manifestations, medication, and measures of disease activity did not differ between BD patients with and without FM. Nevertheless, BD patients with FM had higher STAI and BDI scores than did patients without FM (all p < 0.05). FM tender points were significantly correlated with the STAI and BDI, and not with disease activity variables. The FIQ scores were also strongly correlated with the STAI and BDI scores, and not with disease activity. CONCLUSION: FM was very common among BD patients and was associated with the presence of anxiety and depression, and not with disease activity.

Adult↗
PubMedDate not supplied

Interleukin-18 gene polymorphisms in Korean patients with Behçet's disease.

OBJECTIVE: There is strong evidence that Th1-type cytokines play an important role in the pathogenesis of Behçet's disease (BD). Interleukin (IL)-18 is a proinflammatory cytokine that mediates Th1-polarized immune responses, and elevated levels of IL-18 have been observed in the sera and bronchoalveolar lavage fluid of patients with active BD. Therefore, the aim of this study was to investigate the potential associations of two single nucleotide polymorphisms (SNPs) at positions -137 (G/C) and -607 (C/A) in the promoter region of the IL-18 gene with a susceptibility to BD in the Korean population. METHODS: Ninety-eight patients with BD and 105 healthy controls were studied. All of the subjects were genotyped using sequence specific PCR. The genotypes and alleles between patients with BD and controls were compared using the chi2 test, together with Yate's correction where appropriate. Haplotype analysis was assessed using the EH program. RESULTS: The genotype and allele distributions of the two SNPs did not differ significantly between patients with BD and controls. The haplotype frequencies of the IL-18 promoter polymorphisms were also similar between patients with BD and controls. However, the frequency of the GG genotype at position -137 was significantly higher in BD patients with ocular lesions than in those without ocular lesions (p = 0.026, pc = 0.048, OR = 4.1). CONCLUSION: Although the IL-18 gene polymorphisms were not associated with a susceptibility to BD in the Korean population, the patients carrying the GG genotype at position -137 had a higher risk of developing the ocular lesions. Further studies in other populations are required to confirm these results.

Adult↗
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Gas exchange and haemodynamics during high frequency body surface oscillation in rabbits.

To establish the clinical feasibility of high frequency body surface oscillation (HFBSO) as a mode of controlled ventilation for infants and to examine its effects on basic haemodynamic parameters, we studied twelve intact rabbits in two groups. The animals were placed in a body chamber with their heads remaining outside through a neck-hole. The mean chamber pressure was maintained at -3 to -4 cmH2O and a piston pump, operating at 3, 6, 9, 12 and 15 Hz, created pressure swings in the chamber, thus generating oscillatory tidal volumes. A fresh-airflow of 2 1.min-1 was used over the mouth. In the first group of six rabbits, we obtained the relationship between tidal volume (VT) and frequency (f) which maintained a normocapnic state (PaCO2 = 40 +/- 2 mmHg) when the animals were paralysed. The average tidal volumes required were between 1.36 and 1.78 ml.kg-1 for the 3-15 Hz frequency range, or about 1/4 of the spontaneous tidal volume. The corresponding mean PaO2 was 66.7 mmHg at 3 Hz and 73.4 mmHg at 9 Hz. These results indicate that adequate ventilation and acceptable gas exchange took place in these experimental animals during HFBSO. In the second group, six rabbits were catheterized with catheter-tip pressure transducers in order to obtain the aortic (ABP), central venous (CVP) and intrathoracic pressures. The arterial pressure profile was severely deranged by HFBSO, but, electronic subtraction of the intrathoracic pressure swings from the ABP signal resulted in the return of the normal pressure profile.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
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High frequency chest wall compression and carbon dioxide elimination in obstructed dogs.

High frequency chest wall compression (HFCWC) was studied as a method of assisting ventilation in six spontaneously breathing anesthetized dogs. Under a constant level of anesthesia, the dogs became hypercapneic after airflow obstruction was created by metal beads inserted in the airways. HFCWC was achieved by a piston pump rapidly oscillating the pressure in a modified double blood pressure cuff wrapped around the lower thorax. Thirty minute periods of spontaneous ventilation were alternated with thirty minute periods of spontaneous breathing plus HFCWC at 3, 5 or 8 Hz. The superimposition of HFCWC to spontaneous ventilation resulted in little change in the PaO2. The PaCO2, however, was reduced in every case from a mean of 6.55 +/- 0.59 to 4.72 +/- 0.32 kPa at 3 Hz (p less than 0.05), 6.92 +/- 0.57 to 3.9 +/- 0.45 kPa at 5 Hz (p less than 0.01) and 7.10 +/- 0.65 to 4.56 +/- 0.59 kPa at 8 Hz (p less than 0.05). This occurred despite a decrease in spontaneous minute ventilation. We conclude that HFCWC can assist in elimination of CO2 in obstructed spontaneous breathing dogs with hypercapnea.

Animals↗
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Regional hypoventilation and bronchoconstriction during pulmonary air embolism.

The hypothesis that experimental pulmonary air embolism would lead to bronchoconstriction in the upper lungs and a shift in ventilation toward the lower lung regions was tested in anaesthetized and paralyzed dogs. During constant rate air infusion (0.15 ml X kg-1 X min-1), regional distribution indices were obtained using radioactive xenon boli injected at the mouth at residual volume. The results show that there was a shift of inspired xenon toward the dependent lungs after 30 min of air infusion and that this shift was accompanied by a rise in pulmonary artery pressure, a slight decrease in vital capacity, a significant increase in closing volume and an increase in airway resistance. Inspiring 5% CO2 after the shift did not reverse the distribution of xenon boli. Intravenous injection of isoproterenol after the changes had occurred, on the other hand, invariably returned the distribution toward control values. These findings indicate that hypoventilation and bronchoconstriction occurred in the non-dependent lungs during pulmonary air embolism.

Airway Resistance↗
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[Pressure-flow relationship in the airways (author's transl)].

The perplexing features of the pressure-flow relationship in the pulmonary airways have been explained on the basis of a combined experimental-theoretical study. By systematically plotting the in vivo data on the pressure-flow relationship existing in the literature in a dimensionless manner (Moody diagram), we confirmed the results reported by Lisboa et al. [8] : contrary to the well-known theory of Jaffrin and Kesic [6], it appeared that under certain spontaneous breathing conditions Reynolds number is not the only parameter which governs the flow in the airways. We further confirmed this result using a cast of the central airways and a piston pump. The data showed that the pressure-flow relationship depended greatly on frequency, tidal volume and the physical properties of the gas used. After a systematic variation of these parameters, a dimensionless parameter epsilon, which depends importantly on local acceleration, was identified. This new parameter, together with those already identified (Re : Reynolds number; alpha : Womersley number), define the pressure-flow relationship in a given geometry during the course of a respiratory cycle. Implications of this theoretical knowledge on the measurement and interpretation of airway resistance are discussed.

Gases↗