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Biomedical subjects

K W Chung

Publications and source records attributed to K W Chung.

At least 37 records · Page 2Linked to original sources
PubMed2000

Liver disease during the first post-transplant year in bone marrow transplantation recipients: retrospective study.

Liver dysfunction is a common problem in BMT recipients and it is important to determine the etiology in order to institute appropriate therapy. The purpose of this study was to evaluate the possible causes of liver dysfunction during the first post-transplant year in BMT recipients and to identify a possible relationship between pre-existing liver dysfunction and viral hepatitis with prognosis after BMT. We reviewed liver status before and after BMT in 130 consecutive patients at the Catholic Hematopoietic Stem Cell Transplantation Center. Liver dysfunction during the first post-transplant year occurred in 85 out of 101 (84. 2%) allogeneic BMT recipients and 13 out of 29 (44.8%) autologous BMT recipients. In allogeneic BMT, GVHD and drug hepatotoxicity were major causes. In autologous BMT, drug hepatotoxicity was the most common cause. Eighteen out of 130 patients (13.8%) had abnormal liver function tests before BMT. These patients did not have an increased risk of post-transplant liver dysfunction, GVHD, and death compared to patients who had normal liver function tests prior to BMT. Nine patients were hepatitis B antigen positive and three patients were anti-HCV positive prior to BMT. There was no significant increase in the incidence of post-transplant liver dysfunction, GVHD, and death in these patients.

Adult↗
PubMed1999

Testicular volume of boys after inguinal herniotomy: combined clinical and radiological follow-up.

A total of 173 boys aged 10 to 179 months with previous unilateral inguinal herniotomy were called back for follow-up. Clinical and ultrasound examinations of the scrotum were performed. The interval between operation and follow-up was 6 to 123 months (mean 31.68 months). One boy (0.58%) had a more than 50% and 10 (5.8%) had a more than 25% decrease in testicular volume on the operated side when compared with the non-operated side.

Adolescent↗
PubMed1999

A 45-kDa cAMP-dependent phosphoprotein which is related to the product of Mst57Dc in Drosophila melanogaster.

In Drosophila, the catalytic subunit of cAMP-dependent protein kinase (PKA) is preferentially expressed in the brain and the male reproductive organs. Although the cAMP response element binding protein (CREB) is a major target of PKA in the brain, the target of PKA in the male reproductive organs has been unknown. In the present study, three cAMP-dependent phosphoproteins (referred to as pp45, pp20, and pp10) were detected in the lumen fluid of male accessory glands. They were tissue-specific secretory proteins that accumulated only after eclosion, and were transferred to females during mating as other secretory proteins of the accessory glands. Among them, the 45-kDa phosphoprotein was partially purified and characterized. The purified protein was phosphorylated in vitro by the catalytic subunit of PKA. The partial amino acid sequence of this 45-kDa phosphoprotein was identical to the predicted amino acid sequence of the Mst57Dc cDNA, which is a male accessory gland transcript.

Amino Acid Sequence↗
PubMed1999

In vitro sensitivity of artemeter in Plasmodium falciparum-infected beta-thalassaemic trait erythrocytes.

Using an age-fractionated RBC model, we investigated the in vitro sensitivity of artemether in beta-thalassaemic RBC infected with the K1 and FC27 strains of Plasmodium falciparum and, to study the role of oxidant stress in modulating the sensitivity pattern, pro-oxidant (riboflavin) and antioxidant (vitamin E) agents were added to cultures in the presence of artemether. With the FC27 strain, the artemether IC50 doses in thalassaemic samples (whole blood and fractions) were significantly higher compared to equivalent normal RBC samples (P < 0.05). However, with the K1 strain, such a significant difference was not demonstrable. The addition of vitamin E reduced the antimalarial effect of artemether in both the FC27 and K1 strains (P < 0.0001). In contrast, the addition of riboflavin resulted in a significant increase in antimalarial activity (P < 0.0001). This effect of the drug combinations was not influenced by the red cell type (P < 0.0001) and there was no interaction between red cell type and drug type (P < 0.0001). These findings show that reduced sensitivity to artemether occurs in whole blood and age-fractionated beta-thalassaemic trait RBC. It appears that the RBC redox status does not influence the sensitivity to artemether.

Animals↗
PubMed1999

Management of foreign bodies in the gastrointestinal tract: an analysis of 104 cases in children.

BACKGROUND AND STUDY AIMS: Ingested foreign bodies may be managed by endoscopy, observation, or surgery. The aim of the study was to investigate the methods of removal of foreign bodies according to type and location, success rates, and complications. PATIENTS AND METHODS: The charts of 104 children who had ingested foreign bodies were retrospectively reviewed. RESULTS: Of the patients, 80 (76.9%) were managed endoscopically. The overall success rate for endoscopic management was 98.8%. There were no complications during endoscopic interventions. In 23 cases the foreign bodies spontaneously passed through the gastrointestinal tract (22.1%). Surgical removal of a foreign body was done in only one case (0.96%). The majority of the foreign bodies which were located in the upper gastrointestinal tract could be removed endoscopically regardless of the nature of the material. Foreign bodies in the small and large intestine tended to pass through spontaneously without complications. CONCLUSIONS: It appears that the endoscopic approach is the preferable method for the extraction of upper gastrointestinal foreign bodies in child patients because of its high success rate, and that foreign bodies in the small and large intestine tend to be passed spontaneously without complications.

Adolescent↗
PubMed1999

The metabolic effects of estriol in female rat liver.

The effects of estriol on oxygen uptake, glucose release, lactate and pyruvate production, beta-hydroxybutyrate and acetoacetate production in perfused rat liver as well as, carbon uptake in rat liver and intracellular calcium in isolated Kupffer cells were investigated. Basal oxygen consumption of perfused liver increased significantly in estriol or ethanol-treated rats. But these increased effects were blocked by gadolinium chloride pretreatment. In a metabolic study, pretreatment with estriol resulted in a decrease in glucose production and in glycolysis while an increase in ketogenesis. A more oxidized redox state of the mitochondria was indicated by increased ratios of perfusate [lactate]/[pyruvate] and decreased ratios of perfusate [beta-hydroxybutyrate]/[acetoacetate]. Carbon uptake of Kupffer-cell increased significantly in estriol-treated rats. But these increased uptake were not shown in rats pre-treated by gadolinium chloride blocking phagocytosis. In isolated Kupffer cells from estriol-treated rats, intracellular calcium was more significantly increased after addition of lipopolysaccharide (LPS) than in controls. These findings suggest that the metabolic effects of estriol (two mg per 100 mg body wt) can be summarized to be highly toxic in rat liver, and these findings suggest that oral administration of estrogens may induce hepatic dysfunctions and play a role in the development of liver disease.

3-Hydroxybutyric Acid↗
PubMed1998

Experience of orthotopic liver transplantation in 11 patients with liver cirrhosis from Korea: medical factors affecting outcome.

Orthotopic liver transplantation (OLT) has evolved to become a standard treatment of choice for end-stage liver diseases. The present study was performed to evaluate the peri-operative medical factors affecting transplantation outcome and to determine if patients with type B viral cirrhosis were acceptable for OLT. A total of 11 patients with end-stage cirrhosis, who have received OLT in Kangnam St. Mary's Hospital since May 1993, included 8 HBV-related cases, 1 Hepatitis C Virus (HCV)-related case, and 2 non-B, non-C cases. One-year cumulative survival rate by Kaplan-Meier method was 43.7%. Factors significantly associated with 1-year survival of the recipients during pre-OLT period were performance status and modified Pugh-Child score (p=0.015 and p=0.015, respectively). Among those 4 patients who lived longer than 1 year, 3 of 4 patients with HBsAg-positive had no HBV re-infection with our protocol. These results suggest that, to improve the outcome of OLT in cirrhosis patients, transplantation should be performed in the stage when patients maintain better performance and hepatic functional reserve during the end-stage of liver cirrhosis. In addition, patients with cirrhosis caused by HBV infection may be indicated for OLT, because HBV re-infection is preventable effectively with a high-dose hepatitis B immunoglobulin protocol.

Adolescent↗
PubMed1997

The extensor retinacular system at the metacarpophalangeal joint. Anatomical and histological study.

The anatomy of the sagittal bands was studied in 56 cadaver digits. The sagittal band is part of an extensor retinacular system which is integrated with the extrinsic and intrinsic musculotendinous structures. The extensor retinacular system is a single unit with radial and ulnar components and has transverse, sagittal and oblique fibres. The transverse-sagittal fibres, along with the palmar plate, form a closed cylindrical tube which surrounds the metacarpal head. The oblique fibres form the triangular lamina distal to the sagittal band. The radial component of the sagittal band is often thinner and longer than the ulnar component. The sagittal band envelops the extensor digitorum tendon and the superficial fibres are thinner than deep fibres, especially in the central digits. The central digits have palmar soft tissue confluence on each side consisting of the sagittal band, palmar plate, annular pulley and deep transverse metacarpal ligament. The sagittal band also appears to envelop the superficial interosseous tendons on both sides. Our findings explain the propensity for radial sagittal band injuries and suggest that the sagittal band is the primary stabilizer of the extensor digitorum at the metacarpophalangeal joint.

Adult↗
PubMed1996

Identification of ovarian enhancer-binding factors which bind to ovarian enhancer 1 of the Drosophila genes yp1 and yp2.

It has been reported that three different DNA regions-the fat body enhancer and ovarian enhancers 1 and 2-direct the tissue-specific expression of yp1 and yp2 in Drosophila melanogaster. In the present study, we identified ovarian enhancer 1-specific binding proteins. Electrophoretic mobility shift assay revealed that these proteins are present in the adult ovary, but not in adult testis or fat body. Southwestern blot analysis showed that about 130 kDa and 40 kDa proteins, designated OEF1 and OEF2, respectively, from ovarian nuclear or crude extracts bind specifically to the ovarian enhancer 1. The two proteins were partially purified by streptavidin/agarose-DNA affinity chromatography, and their binding activity was confirmed by electrophoretic mobility shift assay. These ovarian enhancer factors may play an important role in the regulation of transcription of yp1 and yp2 in the ovary.

Animals↗
PubMed1996

Dietary zinc deficiency alters 5 alpha-reduction and aromatization of testosterone and androgen and estrogen receptors in rat liver.

We studied the effects of zinc deficiency on hepatic androgen metabolism and aromatization, androgen and estrogen receptor binding, and circulating levels of reproductive hormones in freely fed, pair-fed and zinc deficient rats. Hepatic conversion of testosterone to dihydrotestosterone was significantly less, but formation of estradiol from testosterone was significantly greater in rats fed the zinc-deficient diet compared with freely fed and pair-fed control rats. There were significantly lower serum concentrations of luteinizing hormone, estradiol and testosterone in rats fed the zinc-deficient diet. No difference in the concentration of serum follicle-stimulating hormone was observed between the zinc-deficient group and either control group. Scatchard analyses of the receptor binding data showed a significantly higher level of estrogen receptor in zinc-deficient rats (36.6 +/- 3.4 fmol/mg protein) than in pair-fed controls (23.3 +/- 2.2 fmol/mg protein) and a significantly lower level of androgen binding sites in rats fed the zinc-deficient diet (6.7 +/- 0.7 fmol/mg protein) than in pair-fed control rats (11.3 +/- 1.2 fmol/mg protein). There were no differences in hepatic androgen and estrogen receptor levels between freely fed and pair-fed controls. These findings indicate that zinc deficiency reduces circulating luteinizing hormone and testosterone concentrations, alters hepatic steroid metabolism, and modifies sex steroid hormone receptor levels, thereby contributing to the pathogenesis of male reproductive dysfunction.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1996

Bone mineral density of the spine using dual energy X-ray absorptiometry in patients with non-insulin-dependent diabetes mellitus.

To evaluate the influence of non-insulin-dependent diabetes mellitus (NIDDM) on bone mineral density (BMD), we measured BMD in 185 female patients with NIDDM using dual energy X-ray absorptiometry (DEXA). BMD was measured in lumbar vertebrae (L2-4). BMD is slightly higher in the diabetic patients compared with control subjects and bone loss related to menopause starts before the onset of menopause. The BMD of postmenopausal women showed a definite decrease with aging and there was abrupt bone loss after 55 years of age (p < 0.05). In relation to the duration of diabetes, the decrease of BMD for 15 years was 10.0%. BMD was negatively correlated with age, years since menopause (YSM), and disease duration (r = -0.584, r = -0.470, r = -0.186). These results suggest that age, YSM, and the duration of disease appear to be the risk factors for decreased BMD in the diabetic patients.

Absorptiometry, Photon↗
PubMed1994

Inactivation of phospholipase A2 by naturally occurring biflavonoid, ochnaflavone.

Ochnaflavone, a medicinal herb product isolated from Lonicera japonica, strongly inhibited rat platelet phospholipase A2 (IC50, about 3 microM). Inactivation was concentration and pH dependent (maximum inactivation occurred between pH 9.0 and 10.0). Ochnaflavone inhibited the enzyme by a noncompetitive manner, with the apparent Ki value of 3 x 10(-5) M. Reversibility was studied directly by dialysis method; the inhibition was irreversible. In addition, the inhibitory activity of ochnaflavone is rather specific against group II phospholipase A2 than group I phospholipase A2 (IC50, about 20 microM). Addition of excess Ca2+ concentration up to 8 mM did not antagonize the inhibitory activity of ochnaflavone. These results indicate that the inhibition of phospholipase A2 by ochnaflavone may result from direct interaction with the enzyme.

Animals↗
PubMed1994

Acute herpetic esophagitis--a case report.

We report a case of acute herpetic esophagitis in a 33 year old man who was presumed to be immuno-compromised following prolonged steroid and cyclosporin treatment for acute rejection of a transplanted kidney. In Korea, all reported cases of herpetic esophagitis have been diagnosed in immuno-compromised and debilitated patients with a typical endoscopic appearance of ulcerating lesions. However, our patient showed multiple vesicular lesions without ulcer along the entire esophagus. The diagnosis was confirmed by colorimetric detection of herpes virus DNA using in situ hybridization. The endoscopic findings reported herein probably represent the typical early stage of acute herpetic esophagitis.

Acute Disease↗
PubMed1994

Oestrogen but not testosterone increases bone density in orchiectomized rats more when fed moderately magnesium-deficient fructose than moderately magnesium-deficient cornstarch.

To investigate interactions between circulating sex hormones, dietary fructose and magnesium on bone mineral density and numbers of trabeculae, 10 weeks old orchiectomized and sham-orchiectomized rats were studied. One-third of the orchiectomized animals were injected with beta-oestradiol-3-benzoate twice per week in sesame oil; another one-third, testosterone cypionate; the remaining one-third as well as the sham-orchiectomized animals, sesame oil only. All animals were fed either fructose or cornstarch without added magnesium. After 14 weeks, a 24 h urine sample was collected for measurements of calcium, magnesium, phosphorus, and cAMP. Blood was collected for determinations of calcium, magnesium, phosphorus, 25-monohydroxy and 1,25-dihydroxycholecalciferols, oestrogen, testosterone, and parathyroid hormone. Femurs were used for measurements of bone mineral density, and tibiae, for numbers of trabeculae. Exogenous testosterone interacted with starch and magnesium deficiency to decrease serum calcium concentration significantly, which increased circulating parathyroid hormone. High circulating parathyroid hormone raised urinary cAMP and serum 1,25-dihydroxycholecalciferol. Increased parathyroid hormone, cAMP and 1,25-dihydroxycholecalciferol may be responsible for bone resorption which was noted in reductions of bone mineral density and the numbers of trabeculae in the group. In contrast, exogenous oestrogen interacted with fructose and magnesium deficiency to increase serum calcium concentration which caused a reduction of circulating parathyroid. Low parathyroid hormone, reduced 1,25-dihydroxycholecalciferol and cAMP may explain the increased bone mineral density and the numbers of trabeculae in this group.

Animals↗
PubMed1993

Detection of HCV RNA using reverse transcription and nested polymerase chain reaction in chronic non-A, non-B liver diseases in Korea.

To investigate the interrelationship between the anti-HCV prevalence and the HCV RNA positivity in chronic non-A, non-B (NANB) liver diseases in Korea (n = 137), we performed RT-nested PCR using 4 primers in the 5'-noncoding region of HCV genome. The overall HCV RNA positive rates were 62.8%; 87.7% (57/65) of anti-HCV positive cases and 40.3% (29/72) of anti-HCV negative cases. Four patterns according to the combination of anti-HCV and HCV RNA assays could be observed; 41.6% in [anti-HCV+/HCV RNA+], 5.8% in [anti-HCV+/HCV RNA], 21.2% in [anti-HCV+/HCV RNA], and 31.4% in [anti-HCV+/HCV RNA]. Our results suggested that HCV may be still related to chronic NANB liver diseases negative for anti-HCV, and other unknown agents, so-called non-B non-C, might be accounted for patients negative for both, although a low concentration of HCV RNA, or the presence of HCV RNA or HBV DNA in liver tissue should be excluded.

Hepacivirus↗