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Biomedical subjects

K W Chung

Publications and source records attributed to K W Chung.

At least 19 recordsLinked to original sources
PubMed2003

Endoscopic hemoclipping using a transparent cap in technically difficult cases.

BACKGROUND AND STUDY AIMS: Technical difficulties have been experienced in endoscopic hemoclipping on the posterior wall of the body of the stomach because the angle of approach is tangential. It has been suggested that the use of a transparent cap on the tip of the endoscope could help to solve this problem. The purpose of this study was to examine the efficacy of endoscopic hemoclipping using a transparent cap over the tip of the endoscope. PATIENTS AND METHODS: A total of 74 patients with a bleeding peptic ulcer or stigmata of recent hemorrhage underwent endoscopic hemoclipping. Technical difficulty in hemoclipping was experienced in 18 patients and the transparent cap was used in these cases. We therefore conducted a nonrandomized prospective study to compare bleeding control with the hemoclip with and without the aid of a transparent cap. RESULTS: There were no statistically significant differences between the patients treated with the cap and those treated without the cap with regard to the initial hemostasis rate (94.4 % vs. 91.1 %), the rebleeding rate (11.7 % vs. 11.8 %), or the permanent hemostasis rate (94.4 % vs. 96.4 %). CONCLUSIONS: Although there was no statistically significant difference between patients treated with or without a transparent cap, hemoclipping with the aid of the cap made it possible to clip a lesion too tangential to be clipped without it. However, this study did not compare conventional hemoclipping with hemoclipping using a cap because the cap was only used in cases in which conventional clipping had failed.

Duodenal Ulcer↗
PubMed2002

Ruptured adrenocortical carcinoma as a cause of paediatric acute abdomen.

Adrenocortical carcinoma (ACC) is rare in children. Its presentation is usually related to hormonal activity of the tumour. We report a case of childhood ACC that presented as an acute abdomen due to tumour rupture. This is the first reported case of a ruptured ACC as a cause of paediatric acute abdomen.

Abdomen, Acute↗
PubMed2002

Toxicological studies in tropical ecosystems: an ecotoxicological risk assessment of pesticide runoff in South Florida estuarine ecosystems.

A multiyear study in the C-111 canal system and associated sites in Florida Bay was undertaken to determine the potential pesticide risk that exists in South Florida. After the examination of extensive pesticide concentration data in surface water, tissues, and semipermeable membrane devices (SPMDs), canal contamination seems to be derived from the extensive agricultural production that drains into the C-111 canal. The results of this study indicate that runoff from agricultural processes led to quantifiable pesticide residues in both canal and bay surface water, which occasionally exceeded current water quality criteria. The major pesticide of concern was endosulfan, which was detected at 100% of the sites sampled. Endosulfan exposure did not cause any acute effects in fish and crustaceans deployed in field bioassays. Chronic effects were observed in copepods, clams, and oysters but could not be attributed to endosulfan exposure. The decision to alter the C-111 canal flow and allow increased freshwater flow into the adjacent Everglades National Park may result in discharges of pesticides into the Everglades. Continued monitoring in this area is needed during this change in flow regime.

Agriculture↗
PubMed2001

The relationship of histologic activity to serum ALT, HCV genotype and HCV RNA titers in chronic hepatitis C.

It is unclear whether serum ALT levels or virological characteristics of hepatitis C virus(HCV) including HCV genotypes and HCV RNA titers, can reflect the degree of histological injury in chronic hepatitis C. The aim of this study was to investigate the relationships between the levels of histological damage and serum ALT levels, HCV genotypes or circulating HCV RNA titers in chronic hepatitis C. A total of 56 patients underwent liver biopsy and the histological activity index (HAI) was evaluated by Knodell's scoring system. HCV genotype by RT-nested PCR and HCV RNA quantitation by competitive RT-PCR were performed. Thirty-four patients were infected with HCV genotype 1b, 20 patients with genotype 2a, and 2 patients with undetermined type. Serum ALT levels were not positively correlated with total HAI score or HCV RNA titers, but showed a linear correlation with scores of piecemeal necrosis (r=0.32, p<0.05) and portal inflammation (r=0.27, p<0.05). HCV genotype had no significant correlation with RNA titers, HAI score or with serum ALT levels. Also, no statistical relationship was seen between HCV RNA titer and HAI score. These results suggest that liver histology is essential to evaluate the severity of chronic hepatitis C precisely.

Adolescent↗
PubMed2001

Ultrastructural changes of hepatic stellate cells in the space of Disse in alcoholic fatty liver.

BACKGROUND: Hepatic stellate cell (HSC) has been suggested to play a role in fibrogenesis in alcoholic liver disease. We evaluate the correlation with fibrogenesis and ultrastructure of hepatic stellate cells in alcoholic fatty liver. METHODS: We studied 6 patients with alcoholic fatty liver and 5 non-alcoholic fatty liver. The numbers of fat droplets in hepatic stellate cell was determined by electron microscopy. We also studied the grading of deposition of collagen fibers in the space of Disse. We were to evaluate the structure of hepatic stellate cells in the space of Disse by light and electron microscopy. RESULTS: Wider distribution of fat droplets in hepatic stellate cells in alcoholic fatty liver than in normal liver. The hypertrophied endoplasmic reticulum in hepatic stellate cells is a prominent findings in alcoholic fatty liver. We observed basement membrane-like materials in patients with alcoholic fatty liver with hepatic fibrosis. CONCLUSION: The results demonstrate that, in patients with alcoholic fatty liver by alcoholic liver injury, the hepatic stellate cells may play an important role in the fibrogenesis of perisinusoidal spaces in the liver.

Adult↗
PubMed2000

Hormone replacement therapy in women with pre-existing hyperpigmented lesions.

OBJECTIVES: This study was performed to determine whether skin pigmentation is darkened after hormone replacement therapy (HRT). METHODS: The color of hyperpigmentary lesions and control sites before and after 1, 2, and 3 months of HRT was measured. RESULTS: All of the three tested sites showed no significant pigment alteration in 3 months of follow up after starting HRT (P>0.05). Age, duration of menopause, and sex hormone levels did not correlate with pigmentation level. CONCLUSIONS: Pigmentation changes after HRT are not significantly associated with the treatment. This finding suggests that low-dose estrogen replacement therapy does not induce pigmentation changes alone and that differences in individual susceptibility and end organ responsiveness or other multiple factors in addition to the sex hormone may be responsible for the development and darkening of hyperpigmentary lesions.

Adult↗
PubMed2000

Can bone turnover markers correlate bone mass at the hip and spine according to menopausal period?

Changes in bone turnover with years since menopause (YSM) are responsible for bone loss and play a major role in osteoporosis. Although single measurements of the bone turnover marker appear unlikely to be clinically useful in predicting bone mineral density, the usefulness of these measurements in relation to the YSM has not been well established. The establishment of this relationship was the aim of this study. To address this issue, we have measured a battery of sensitive and specific markers of bone turnover in 272 women postmenopausal from -5 to 15 a, and the data was correlated with bone mineral density (BMD) at different skeletal sites measured utilizing dual-energy X-ray absorptiometry (DXA). Bone formation was assessed by serum osteocalcin (OC), and bone resorption by Pyr and D-pyr. The three markers and BMD were compared between the groups (YSM). Among the three markers, only Pyr exhibited a significant difference between pre and postmenopausal groups. In the aspect of correlation between bone turnover marker and BMD according to the groups (YSM), we found negative strong correlations between the BMD of lumbar spine (L2-4) vs. Pyr (P=0.01, r=-0.75) in the premenopausal group (-5 approximately 0 YSM), and we found negative correlation between the BMD of L2-4 vs. osteocalcin (P=0.05, r=-0.2 and P=0.01, r=-4).44) in the postmenopause groups (0 approximately 5 and 5 approximately 10 YSM). We concluded that Pyr in women -5 approximately 0 YSM and osteocalcin in women 0 approximately 10 YSM displayed negative correlation with BMD of L2-4.

Absorptiometry, Photon↗
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↗