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Biomedical subjects

J H Hwang

Publications and source records attributed to J H Hwang.

At least 55 records · Page 3Linked to original sources
PubMed2000

Effects of crude drugs on glucose uptake in 3T3-L1 adipocytes.

In this study, various water-extracted crude drugs from Radix Asparagi, Radix Ginseng, Radix Scutellariae, Cortex Lycii Radicis, Cortex Phellodendri and Radix Ophiopogonis were investigated in their effects on [3H]-2-deoxyglucose uptake in 3T3-L1 adipocytes. Following treatment of cells with various crude drugs for 60 mim, the basal [3H]-2-deoxyglucose uptake in cultured 3T3-L1 cells was changed by Radix Asparagi from 140 pmole/min/mg protein of control to 513 (0.1 mg/ml), 201 (1 mg/ml) and 97 (10 mg/ml). Glucose uptake was changed to 324 (0.1 mg/ml), 146 (1 mg/ml) and 46 (10 mg/ml) with Radix Ginseng. In the presence of Radix Scutellariae, glucose uptake was changed to 215 (0.1 mg/ml), 213 (1 mg/ml) and 34 (10 mg/ml). In the presence of Cortex Lycii Radicis, glucose uptake was 230 (0.1 mg/ml), 188 (1 mg/ml) and 38 (10 mg/ml). In the case of Cortex Phellodendri and Radix Ophiopogonis, uptake was changed to 142 (0.1 mg/ml), 132 (1 mg/ml), 24 (10 mg/ml) and 489 (0.1 mg/ml), 374 (1 mg/ml), 344 (10 mg/ml), respectively. In insulin-stimulated cells, the [3H]-2-deoxyglucose uptake was changed by Radix Asparagi from 570 pmole/min/mg protein of the control to 816 (0.1 mg/ml), 674 (1 mg/ml) and 532 (10 mg/ml). After incubation with Radix Ginseng, the glucose uptake was changed to 254 (0.1 mg/mi), 123 (1 mg/mi) to 76 (10 mg/mi). In the presence of Radix Scutellariae, the glucose uptake was changed to 315 (0.1 mg/ml), 265 (1 mg/ml) and 33 (10 mg/ml). After incubation of Cortex Lycii Radicis, the uptake activity was changed to 281 (0.1 mg/ml), 248 (1 mg/ml) and 37 (10 mg/ml). In the case of Cortex Phellodendri and Radix Ophiopogonis, the activity of glucose uptake was measured as 747 (0.1 mg/ml), 523 (1 mg/ml), 33 (10 mg/ml) and 753 (0.1 mg/ml), 740 (1 mg/ml), and 421 (10 mg/ml), respectively. These results indicate that the water-extracted materials of Radix Asparagi and Radix Ophiopogonis increase the glucose uptake in basal and insulin-stimulated 3T3-L1 adipocytes.

3T3 Cells↗
PubMed1999

Heterologous gene expression in avian cells: potential as a producer of recombinant proteins.

We have explored the possibility of using avian cells for the expression of human proteins. We found that various avian cells including quail fibrosarcoma cells (QF), duck embryo cells (DE) and primary chicken embryo fibroblasts (CE) could efficiently be transfected with DNA by calcium phosphate coprecipitation, and that promoters which are transcriptionally active in mammalian cells also functioned well in these avian cells. Among the promoters we tested, the major immediate early promoter of human cytomegalovirus drove the highest level of chloramphenicol acetyl transferase (CAT) expression, outperforming the SV40 early promoter and the RSV LTR. Using the bacterial CAT gene as a reporter, we found that levels of CAT activity were higher in QF and DE cells than in mammalian cells such as CHO, HeLa, Vero and 293T cells. We further cloned a sequence encoding human erythropoietin (EPO) and compared its expression in QF and mammalian cells. Consistent with the CAT data, in transient transfection assays, QF cells produced higher levels of EPO than the mammalian cell lines tested. QF cells which can be passaged permanently were stably transfected with an EPO expression vector. The subcloned QF line was able to produce up to 1,700 U/ml EPO from 3 x 10(6) cells in 72 h. Purified QF-produced EPO showed a broad but discrete protein band, ranging from 33 to 41 kD and was as biologically active as CHO-produced EPO. Although a number of factors still remain to be optimized, our results demonstrate the potential of avian cells such as QF as producers of heterologous proteins.

Animals↗
PubMed1999

The changes of serum soluble intercellular adhesion molecule-1 after systemic steroid treatment in vitiligo.

Cell surface adhesion molecules are thought to play an important role in establishing intercellular contacts that are necessary for immunological reactions. Intercellular adhesion molecule-1 (ICAM-1, CD54) is a crucial adhesion molecule in mediating cell to cell adhesion during inflammatory responses, including non-MHC-restricted cytotoxicity. In this study, the sICAM-1 levels of ten healthy control subjects and seven generalized active vitiligo patients were measured by ELISA. The sICAM-1 levels were also correlated with the clinical courses in 33 patients with active vitiligo, who received systemic steroid treatment for 3 months. The average serum level of sICAM-1 was significantly higher in patients with active vitiligo than in the healthy control subjects. The sICAM-1 levels significantly decreased after systemic steroid treatment in the clinically improved group. These results suggest that immune activation is involved in active vitiligo and that changes of sICAM-1 levels can be a marker in the course of vitiliginous lesions.

Adult↗
PubMed1999

The antiallodynic effects of intrathecal cholinesterase inhibitors in a rat model of neuropathic pain.

BACKGROUND: This study determined the effect of intrathecally administered cholinesterase inhibitors, edrophonium and neostigmine, on nerve injury-induced, touch-evoked allodynia and identified the pharmacologic characteristics of this action. METHODS: Rats were prepared with tight ligation of the left L5 and L6 spinal nerves and with lumbar intrathecal catheters fitted for long-term monitoring. Edrophonium (3, 10, 30, or 100 microg) or neostigmine (0.3, 1, 3, or 10 microg) was administered intrathecally. Tactile allodynia and motor weakness were assessed. To evaluate the pharmacologic characteristics of the activity, a muscarinic receptor antagonist or a nicotinic receptor antagonist was administered intrathecally before edrophonium or neostigmine was injected. To compare the action of subtype antagonists, the M1 muscarinic receptor antagonist pirenzepine, the M2 antagonist methoctramine, the M3 antagonist 4-DAMP (diphenylacetoxy-N-methypiperidine), and the M4 antagonist tropicamide were administered intrathecally before cholinesterase inhibitors were injected. RESULTS: Intrathecal edrophonium or neostigmine produced a dose-dependent antagonism of the touch-evoked allodynia. Neostigmine resulted in a moderate effect on motor weakness at doses of 3 and 10 microg. Pretreatment with intrathecal atropine but not mecamylamine yielded a complete antagonism of the effects of the cholinesterase inhibitors. In addition, antiallodynia produced by edrophonium (100 microg) was reversed by pretreatment with methoctramine, 4-DAMP, tropicamide, and pirenzepine. In the neostigmine (10 microg) group, only the M1 antagonist pirenzepine had a moderate effect on reversal of increased allodynic threshold. CONCLUSIONS: These experiments suggest that intrathecal edrophonium or neostigmine produces an antagonism on touch-evoked allodynia at the spinal level in a rat model of neuropathic pain and that the antiallodynic action of cholinesterase inhibitors is probably mediated by a spinal muscarinic system, especially at the M1 receptor subtype.

Animals↗
PubMed1999

Nonspecific interstitial pneumonia with fibrosis: serial high-resolution CT findings with functional correlation.

OBJECTIVE: We assessed serial changes in high-resolution CT findings and pulmonary function in patients with nonspecific interstitial pneumonia with fibrosis. MATERIALS AND METHODS: Serial high-resolution CT findings in 13 patients with biopsy-proven nonspecific interstitial pneumonia with fibrosis (mean follow-up period, 11 months) and pulmonary function tests (mean follow-up period, 11 months) were retrospectively analyzed. On CT, the presence and extent of ground-glass opacity, irregular linear opacity, honeycombing, and consolidation were assessed. RESULTS: On initial CT, all patients had areas of ground-glass opacity (mean +/- SD, 21.6% +/-14.4) and irregular linear opacity (5.0% +/- 5.2). The areas of ground-glass opacity decreased significantly on follow-up CT (13.5% +/- 10.5, p = .003). The areas of irregular linear opacity decreased slightly (4.2% +/- 5.2, p > .05). Initial forced vital capacity (69.4% +/- 16.0) improved significantly on follow-up examination (83.9% +/- 16.5) (p = .003). The decrease in the extent of ground-glass opacity on CT correlated significantly with changes in forced vital capacity (r = -.702, p = .007) and diffusing capacity for carbon monoxide (r = - .597, p = .031). CONCLUSION: In patients with nonspecific interstitial pneumonia with fibrosis, areas of ground-glass opacity decrease on follow-up high-resolution CT, and the extent of decrease correlates significantly with that of functional improvement.

Adult↗
PubMed1999

Venous dynamics in leg lymphedema.

To determine whether there is anatomical and/or functional impairment to venous return in patients with lymphedema, we examined venous dynamics in 41 patients with unilateral leg lymphedema. A Volometer was used for computer analysis of leg volume, a color Duplex Doppler scanner was used to determine deep vein patency and skin thickness, and Air-plethysmography was used to assess ambulatory venous pressure, venous volume, venous filling index and the ejection fraction. In the lymphedematous leg, volume and skin thickness were uniformly increased (126.4 +/- 21.3% and 156.9 +/- 44.5%) (mean +/- S.D.), respectively. The ambulatory venous pressure was also increased (134 +/- 60.7%) as was the venous volume (124.5 +/- 37.5%), and the venous filling index (134.5 +/- 50.5%). The ejection fraction was decreased (94.9 +/- 26.1%). Greater leg volume correlated with increased venous volume and venous filling index (values = 0.327, 0.241, respectively) and decreased ejection fraction (r = -0.133). Increased subcutaneous thickness correlated with increased venous filling index and venous volume (r = 0.307, 0.126, respectively) and decreased ejection fraction (r = -0.202). These findings suggest that soft tissue edema from lymphatic stasis gradually impedes venous return which in turn aggravates the underlying lymphedema.

Female↗
PubMed1999

Changes in lymphatic function after complex physical therapy for lymphedema.

Twenty-two extremities of 19 lymphedema patients (6 arms, 16 legs) were treated by 2 weeks of complex physical therapy (CPT) and self home maintenance therapy (bandage/wearing of elastic garment and exercise). In addition to the clinical response of volume reduction before and 3 months after CPT, we analyzed the functional changes of the peripheral lymphatic system by use of lymphoscintigraphy (LS). Before CPT, the main LS findings of lymphedema included dermal backflow (100%), absent or faintly visualized regional lymph nodes (95.5%), presence of collateral lymphatic vessels (68.2%), and no or barely visualized lymphatic vessels (27.3%). LS findings suggesting improved lymphatic function after CPT were a decrease in dermal backflow (72.7%), an increase in radioisotope uptake by lymphatic vessels (27.3%), and an increase in radioisotope uptake by lymph nodes (9.1%). 81.8% of limbs showed improved lymphoscintigraphic findings and no change in 9.1%. In the others (9.1%), LS findings appeared worse. There was, however, no correlation between LS "improvement" and the amount of limb volume reduction.

Antimony↗
PubMed1999

Current status of peritoneal dialysis in Korea: efforts to achieve optimal outcome.

Since its introduction in 1981, peritoneal dialysis (PD) has become firmly established as an effective mode of renal replacement therapy and serves an increasing patient population in Korea. The latest registry data indicate that about 3700 end-stage renal disease patients are maintained on chronic PD, representing 24.1% of the country's dialysis population. The majority (93.3%) of these patients are on continuous ambulatory peritoneal dialysis (CAPD) using the two-bag disconnect system, while only 3.3% are on automated PD. Under current renal reimbursement policies, most dialysis patients have to pay 20% of dialysis fees. Thus CAPD patients on 4 x 2-L daily exchanges pay about US$200 per month, not including medication and travel costs. Traditionally, most PD centers in Korea have used the "standard" prescription of 4 exchanges of 2 L of solution for most of their patients. A recent survey of 1467 patients who commenced CAPD in 1997 revealed that 84% of these patients were initially prescribed 4 x 2-L exchanges, while 12% were given a daily volume of 6 L. With this standard prescription, the percentages of Korean CAPD patients initially achieving the adequacy target of Kt/V urea > or = 2.0 and standardized creatinine clearance (SCCr) > or = 60 L/week/1.73 m2, were 74.4% and 82.1%, respectively. It is likely that, among current Korean CAPD patients, a much lower percentage will achieve the clearance targets compared to this initial outcome, but the precise data are not available. However, it is not clear whether the levels of small-solute clearance recommended for optimal PD outcomes, and proposed by the NKF-DOQI guidelines, will bring the expected benefits to Korean patients. Overall survival of Korean PD patients appears to be as good as, or even better than, that in most other countries. Recently, a single large PD center reported patient survival of 92.1%, 85.6%, 81.4%, and 67.6% at 1, 2, 3, and 5 years respectively. Other centers also reported similar outcomes. As in other countries, cardiovascular deaths predominate among Korean patients: death was due to cardiac causes in 29%, to vascular causes in 21%, and to infectious causes in 24%. Peritonitis is the most important barrier to prolonged use of CAPD in Korea, and more PD patients transfer to hemodialysis because of peritonitis than in other countries. To further reduce the morbidity and mortality of Korean PD patients, various control measures need to be implemented that can reduce or prevent peritonitis and other infectious complications. Also, to further improve long-term patient outcome, Korean nephrologists need to establish and practice optimal clearance targets in the chronic care of these patients.

Cause of Death↗
PubMed1998

Race and clinical outcome in patients with carcinoma of the uterine cervix treated with radiation therapy.

OBJECTIVES: The aim of this study was to examine factors underlying differences in outcome between African-American (AA) and Caucasian (C) patients undergoing radiation therapy (RT). METHODS: Patient, tumor, treatment characteristics, and the outcome of 316 AA and 94 C cervical cancer patients who underwent RT were compared. Median follow-up was 72.4 months. RESULTS: AA patients had a trend to a poorer 8-year cause-specific survival (47.9 vs 60.6%) (P = 0.10) compared to C patients with a significant difference seen in stage IIB-IVA disease (34.3 vs 59.5%) (P = 0.04). Several factors correlated with poor outcome were present in the AA group including lower mean hemoglobin levels during RT (P = 0.001), lower median income (P = 0.001), and less frequent intracavitary RT (P = 0.09). In addition, while uncommon in C patients, health problems were major reasons for treatment protraction and inability to undergo intracavitary RT in the AA patients. Multivariate analysis demonstrated that race was not an independent prognostic factor after controlling for difference in patient, tumor, and treatment factors. CONCLUSIONS: AA cervical cancer patients possess multiple factors that adversely impact upon the efficacy of RT. These findings may add further insight into the observed differences in outcome of cervical cancer patients based on race.

Adult↗
PubMed1998

Chaotic and periodic heart rate dynamics in uncomplicated intrauterine growth restricted fetuses.

We studied how chaotic and periodic heart rate dynamics differ between normal fetuses (n = 192) and uncomplicated intrauterine growth restricted fetuses (n = 86), aged 31-42 weeks of gestation. We analyzed each fetal heart rate time series for 25 min. We quantified the chaotic dynamics of each fetal heart rate time series by correlation dimension. The periodic dynamics were analyzed by power spectral analysis. The correlation dimension and, therefore, the complexity, of the heart rate dynamics of the uncomplicated intrauterine growth restricted fetuses was significantly lower than that of the normal fetuses, which was marked at 38-42 weeks of gestation. The low-frequency (0.04-0.15 Hz) component and, therefore, the periodicity of the low-frequency range was significantly higher than that of the normal fetuses during all the gestational weeks. These results mean that, although the intrauterine growth restricted fetuses are not severely compromised, the overall integrity of their cardiovascular control is impaired, especially at term; and sympathetic modulation is increased, both of which may contribute to increased perinatal mortality.

Female↗
PubMed1998

Heterogeneity of human papillomavirus DNA in a patient with Bowenoid papulosis that progressed to squamous cell carcinoma.

Bowenoid papulosis (BP) of the genitalia, characterized by the histological findings of a squamous cell carcinoma, follows a largely benign clinical course. The detection of oncogenic human papilloma viruses (HPV) from BP points to an aetiological role of these viral infections. A 47-year-old man with multiple genital skin lesions was seen over a 10-year period with the diagnosis of BP. Recently, he attended again with a recurrent genital tumour that was diagnosed as squamous cell carcinoma. His genital lesions progressed and became polymorphic in appearance, from a wart-like tumour to a reddish invasive plaque. To screen for the presence of different HPV sequences from different skin lesions and to correlate each HPV type with distinct clinical manifestations, polymerase chain reaction and single-strand conformational polymorphism (PCR-SSCP) were performed. PCR-SSCP revealed the presence of several types of HPV from different genital lesions. Sequencing results disclosed that he had a mixed infection of HPV6b, HPV16, HPV18 and HPV33, respectively. Interestingly, the clinical findings were fairly well correlated with the oncogenic potential of HPV found from each lesion.

Bowen's Disease↗
PubMed1998

Recent advances in radiology of the interstitial lung disease.

Idiopathic interstitial pneumonias are currently classified into four categories of disease: usual, desquamative, and acute interstitial pneumonia, and nonspecific interstitial pneumonia and fibrosis. Usual interstitial pneumonia appears on high-resolution CT (HRCT) as patchy subpleural areas of ground-glass opacity, irregular lines, and honeycombing. Desquamative interstitial pneumonia presents as patchy subpleural areas of ground-glass opacity in middle and lower lung zones. Acute interstitial pneumonia presents as extensive bilateral airspace consolidation and patchy or diffuse bilateral areas of ground-glass opacity. Nonspecific interstitial pneumonia and fibrosis appears as patchy or diffuse areas of ground-glass opacity with associated areas of consolidation and irregular lines. In a subset of patients with diffuse lung disease (especially in those with chronic interstitial lung disease), accurate diagnosis can be made with HRCT findings only, without surgical biopsy. However, HRCT provides a lower level of confidence in the diagnosis of acute or subacute interstitial lung disease such as infection, diffuse alveolar damage, drug reaction, or hemorrhage. Additional expiratory HRCT scans and scans with patients prone help to narrow the differential diagnosis among various diseases and help diagnose or exclude subtle disease in the posterior part of the lung, respectively. HRCT provides a reproducible method for evaluating the global extent of disease. It also discriminates between fibrotic and reversible inflammatory diseases.

Acute Disease↗
PubMed1998

Invasive pulmonary aspergillosis: prediction at thin-section CT in patients with neutropenia--a prospective study.

PURPOSE: To evaluate prospectively the usefulness of thin-section computed tomography (CT) in the prediction of biopsy-proved invasive pulmonary aspergillosis in patients with neutropenia. MATERIALS AND METHODS: In 11 consecutively seen neutropenic patients, 12 open-lung biopsies were performed prospectively for suspected angioinvasive (n = 10) or airway-invasive (n = 2) pulmonary aspergillosis. Thin-section CT findings in the patients with angioinvasive pulmonary aspergillosis were reviewed, and the findings were compared with those of other diseases. RESULTS: Five of 12 biopsy specimens were positive for angioinvasive pulmonary aspergillosis; none was positive for airway-invasive pulmonary aspergillosis. In five (50%) of 10 cases, suspicion of angioinvasive pulmonary aspergillosis proved to be correct. The most common CT findings were segmental areas of consolidation plus ground-glass attenuation (four of five cases [80%]) and at least one nodule surrounded by a halo (two of five cases [40%]). Segmental areas of consolidation plus ground-glass attenuation were seen as isolated findings in three and mixed findings with nodules that have a surrounding halo in one case. In two patients, at least one nodule with a halo was an isolated finding in one patient and a mixed finding in one patient. Mucormycosis, organizing pneumonia, and pulmonary hemorrhage produced similar findings. CONCLUSION: At thin-section CT, segmental areas of consolidation plus ground-glass attenuation or at least one nodule with the halo sign were seen in patients with invasive pulmonary aspergillosis. The findings were nonspecific, however, and can be seen in neutropenic patients with mucormycosis, organizing pneumonia, or pulmonary hemorrhage.

Adolescent↗
PubMed1998

Computed radiography of the chest in patients with paraesophageal varices: diagnostic accuracy and characteristic findings.

OBJECTIVE: The purpose of our study was to determine the diagnostic accuracy of computed radiography of the chest in the detection of paraesophageal varices and to describe the characteristic radiographic findings. SUBJECTS AND METHODS: From June 1995 through May 1997, in 100 consecutive patients, portal hypertension was diagnosed through both clinical and radiologic evidence. Computed radiographs of the chest and hepatic helical CT scans of these 100 patients with portal hypertension and 20 control subjects were analyzed by two chest radiologists and one abdominal radiologist, who were not aware of the results of the other study. RESULTS: On CT, paraesophageal varices were seen in 38 (38%) of 100 patients with portal hypertension. Overall, the sensitivity, specificity, and accuracy of chest computed radiography in the detection of paraesophageal varices were 53% (20/38), 90% (74/82), and 78% (94/120), respectively. In the patients with paraesophageal varices, splenomegaly (29/38, 76%), lateral displacement or obliteration of the inferior portion of the azygoesophageal interface (18/38, 47%), obliteration or nodularity of the inferior portion of the descending thoracic aorta interface (9/38, 24%), lateral displacement of the right inferior paraspinal interface (6/38, 16%), lateral displacement of the left inferior paraspinal interface (4/38, 11%), and varices in the left inferior pulmonary ligament (1/38, 3%) were seen on chest computed radiographs. Paraesophageal varices smaller than the diameter of the descending thoracic aorta (usually <2.5 cm) were not detected. CONCLUSION: Although chest computed radiography is only moderately sensitive for paraesophageal varices, the findings are characteristic when well developed, with a limited differential diagnosis. Splenomegaly, whether detected clinically or radiographically, eliminates most other diagnostic possibilities.

Adult↗
PubMed1998

Nonspecific interstitial pneumonia with fibrosis: high-resolution CT and pathologic findings.

OBJECTIVE: The purpose of our study was to describe high-resolution CT findings of nonspecific interstitial pneumonia with fibrosis and to compare findings seen on CT with pathologic findings. MATERIALS AND METHODS: High-resolution CT findings of biopsy-proven non-specific interstitial pneumonia with fibrosis from 23 consecutive patients (one man and 22 women) were analyzed retrospectively by two chest radiologists. CT findings were compared with pathologic findings. RESULTS: The predominant high-resolution CT finding, seen in all patients, was bilateral patchy areas of ground-glass opacity with (35%) or without (65%) areas of consolidation. Irregular linear opacities (87%), thickening of bronchovascular bundles (65%), and bronchial dilatation (52%) were also frequently seen. Honeycombing was not seen in any patient. All parenchymal abnormalities showed subpleural predominance. Areas of ground-glass opacity with or without irregular linear opacity or bronchial dilatation on CT corresponded pathologically to areas of interstitial thickening caused by varying degrees of interstitial inflammation and fibrosis showing temporal uniformity. Areas of consolidation, seen at five biopsy sites, represented the areas of bronchiolitis obliterans organizing pneumonia, foamy cell collections in alveolar spaces, or microscopic honeycombing with mucin stasis. CONCLUSION: On high-resolution CT, nonspecific interstitial pneumonia with fibrosis is most commonly revealed as patchy subpleural areas of ground-glass opacity mixed with irregular linear opacity or bronchial dilatation. These areas represent interstitial thickening caused by varying degrees of interstitial inflammation, fibrosis, or both.

Adult↗