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D H Lee

Publications and source records attributed to D H Lee.

At least 91 records · Page 5Linked to original sources
PubMed2001

Antibacterial effect of antibiotic solution on cellular viability in canine veins.

Pretreatment of tissue by using antibiotics is a critical step to prevent microbial contamination before venous transplantation. In this study, the optimal time and temperature of antibiotic solution treatment for maintaining cellular viability with antibacterial effect were investigated. The antibiotic-nutrient solutions were composed of cefoxitin, lincomycin, vancomycin, and polymyxin B in RPMI-1640 medium. After various antibiotic solution treatment times (4, 8, and 12 h) and temperatures (4, 25, and 37 degrees C), the viabilities of cells dissociated from veins (jugular vein, femoral vein, superior vena cava, and inferior vena cava) were determined. Double staining by Griffonia simplicifolia agglutins-fluorescein isothiocyanate (GS1-FITC) and propidium iodide was used. To measure the antibacterial effect of the antibiotic solution, canine veins were artificially infected by 3 kinds of bacteria (Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae) and were treated by antibiotic solutions as viability test conditions. After the treatment with the antibiotic solution, the tissue was minced, and the homogenized tissue fraction was cultured on standard method agar. The colony that seemed to be resistant to the antibiotic solution was counted. At 37 and 25 degrees C, the viability of whole cells decreased significantly Asymptotic Significance 2-tailed (Asymp.Sig 2-tailed) < 0.05 after 4 h of antibiotic solution treatment, whereas at 4 degrees C it began to reduce significantly after 8 h of treatment. By antibiotic solution treatment at all 3 temperatures for 4 h, no significant difference in viability of the endothelial cells and whole cells was observed. To maintain the donor vein's cellular viability until transplantation, antibiotic solution treatment for 4 h at 4 degrees C is assumed to be appropriate.

Animals↗
PubMed2001

Infectivity of blood from PCR-positive, HBsAg-negative, anti-HBs-positive cases of resolved hepatitis B infection.

BACKGROUND: Numerous reports have noted the existence of sera, particularly from resolving cases of HBV infection, that are positive for HBV DNA by PCR, despite being negative for HBsAg and IgM anti-HBc. If such blood is infective and detectable by HBV NAT screening, it seems desirable to introduce such screening for transfused blood. STUDY DESIGN AND METHODS: Three chimpanzees were inoculated with serum and lymphocytes from three patients who were HBV DNA PCR positive, but HBsAg negative. The animals were tested over a period of 15 months for HBsAg, anti-HBs, anti-HBc, and HBV DNA by PCR. RESULTS: All animals remained uninfected. CONCLUSION: Small amounts of plasma and MNCs from HBV DNA-positive HBsAg-negative blood do not appear to be infectious; however, further studies with larger volumes of inoculum should be conducted.

Animals↗
PubMed2001

Automation of nucleic acid extraction for NAT screening of individual blood units.

BACKGROUND: Automation of NAT for single units of blood is currently hampered by the labor-intensive steps involved in the extraction of nucleic acids from samples before the amplification procedures. A new method has been developed for the automation of these steps using hydrophilic polyvinylidene fluoride (PVDF) filter plates. STUDY DESIGN AND METHODS: Quantitative nucleic acid recoveries from sera containing HCV, HIV, HBV, HAV, and human parvovirus B19 and from 3H-labeled HCV RNA were determined in parallel by the semi-automated PVDF method and a single-column method (Qiagen). Quantitative PCR was performed. RESULTS: Similar recoveries of HCV, HIV, and HBV (with silica beads) were observed with the PVDF method and with the Qiagen single-column method. The sensitivity of the PVDF-based PCR assay for HCV, HIV, and HBV in serially diluted serum samples was always within two serial dilutions of that obtained when the Qiagen single-column method was used in the same assays. With the use of 3H-labeled HCV RNA, recoveries of approximately 70 percent were found by both methods. CONCLUSION: The PVDF method will permit full automation of the simultaneous extraction of nucleic acid from sera containing HCV, HIV, and HBV. This procedure will permit NAT screening of individual units of blood, will replace the current screening of pools, and will achieve improved blood safety with reduced labor and costs.

Blood Transfusion↗
PubMed2001

DNA prime/canarypox boost-based immunotherapy of chronic hepatitis B virus infection in a chimpanzee.

There are about 200 million chronic hepatitis B virus (HBV) carriers at high risk of development of cirrhosis and hepatocellular carcinoma. Termination of the carrier state may avert these risks. We have investigated immunotherapy for chronic HBV infection in a chimpanzee HBV carrier using recombinant DNA-based immunization followed by a recombinant canarypox booster. One week after the booster, HBV DNA declined greater than 400-fold and remained undetectable by the quantitative polymerase chain reaction (PCR) assay for 186 weeks. Plasma levels of hepatitis B surface antigen (HBsAg) declined for only a short time. The decline in HBV DNA correlated with a boost in gamma interferon production without a corresponding boost in cytotoxic T lymphocyte levels, and decline in the transcriptional template or covalently closed circular DNA level. Confirmation of these findings requires further studies in chimpanzees and/or in humans.

Alanine Transaminase↗
PubMed2001

Increased vascular endothelin-1 gene expression with unaltered nitric oxide synthase levels in fructose-induced hypertensive rats.

The present study aimed to investigate whether altered expression levels of endothelin-1 (ET-1) and nitric oxide synthase (NOS) are related to the development of insulin-resistant hypertension. Male Sprague-Dawley rats were fed a fructose-rich diet for 5 weeks. Systolic blood pressure significantly increased in fructose-fed rats. While serum free fatty acid (FFA) and plasma nitrite/nitrate (NOx) levels did not significantly differ between the fructose-fed and control groups, plasma insulin and serum triglyceride (TG) concentrations significantly increased in the former. ET-1 mRNA expression in the aorta increased to 195% in fructose-fed rats. Neither the protein expression of constitutive NOS (cNOS) nor that of inducible NOS (iNOS) were significantly affected by fructose feeding. However, NOx levels in the aorta were significantly increased. These results indicate that an increased expression of vascular ET-1 may be causally related to the development of hypertension in fructose-fed rats. However, an altered role of the vascular nitric oxide (NO) pathway may not be primarily involved in the development of fructose-induced hypertension.

Animals↗
PubMed2001

Anti-thrombotic effects of higenamine.

The anti-platelet and anti-thrombotic effects of higenamine, a benzyltetrahydroisoquinoline alkaloid of the roots of Aconitum japonicum (Ranunculaceae), were investigated. The degree of platelet aggregation was measured with platelet rich plasma (PRP). An acute thrombotic condition was induced in mice by the injection of the mixture of collagen and epinephrine. The thrombus formation was induced inside the arterio-venous shunt tube installed between an abdominal aorta and the renal vein of rats. Higenamine showed inhibitory activities to both human and rat platelet aggregation induced by ADP, collagen and epinephrine. It was more inhibitory to epinephrine induced aggregation (IC(50); 19 and 7.2 microM to human and rat platelets respectively) than ADP- or collagen-induced aggregation. The anti-thrombotic effects of higenamine were also observed in both mouse acute thrombosis model and rat arterio-venous shunt (AV-shunt) models. The oral administration of higenamine (50 or 100 mg/kg) increased the recovery rates from the acute thrombotic challenge in mice and lowered the weight of thrombus formed inside the AV-shunt tube in rats.

Alkaloids↗
PubMed2001

Development and performance of an alternative biofilter system.

Step tracer tests were carried out on lab-scale biofilters to determine the residence time distributions (RTDs) of gases passing through two types of biofilters: a standard biofilter with vertical gas flow and a modified biofilter with horizontal gas flow. Results were used to define the flow patterns in the reactors. "Non-ideal flow" indicates that the flow reactors did not behave like either type of ideal reactor: the perfectly stirred reactor [often called a "continuously stirred tank reactor" (CSTR)] or the plug-flow reactor. The horizontal biofilter with back-mixing was able to accommodate a shorter residence time without the usual requirement of greater biofilter surface area for increased biofiltration efficiency. Experimental results indicated that the first bed of the modified biofilter behaved like two CSTRs in series, while the second bed may be represented by two or three CSTRs in series. Because of the flow baffles used in the horizontal biofilter system, its performance was more similar to completely mixed systems, and hence, it could not be modeled as a plug-flow reactor. For the standard biofilter, the number of CSTRs was found to be between 2 and 9 depending on the airflow rate. In terms of NH3 removal efficiency and elimination capacity, the standard biofilter was not as good as the modified system; moreover, the second bed of the modified biofilter exhibited greater removal efficiency than the first bed. The elimination rate increased as biofilter load increased. An opposite trend was exhibited with respect to removal efficiency.

Air Pollutants, Occupational↗
PubMed2001

Body weight, alcohol consumption and liver enzyme activity--a 4-year follow-up study.

BACKGROUND: This prospective study was performed in order to investigate the effect of baseline body mass index (BMI), BMI changes, baseline alcohol consumption, and changes in alcohol consumption on liver enzyme activity. METHODS: This study population consisted of 6846 male workers in a steel manufacturing company who had undergone health examinations in 1994 and 1998. RESULTS: The risk for elevated both aspartate aminotransferase (AST) and alanine aminotransferase (ALT) values over the four years increased with the baseline BMI and BMI changes, but not with alcohol consumption. Compared with the subject BMI < 20, the adjusted odds ratios (OR) for those with baseline BMI 20-21.9, 22-24.9, 25- were 1.2, 1.6, 1.7 in AST and 1.4, 2.4, 2.8 in ALT, respectively. Compared with subjects who either lost or maintained their weight, the adjusted OR for men with slight, moderate, and heavy weight gain were 1.7, 2.6, 6.8 in AST and 2.4, 3.9, 11.3 in ALT, respectively. However gamma-glutamyl transferase (GGT) was associated with BMI changes and baseline alcohol consumption, not with baseline BMI and changes in alcohol consumption. Compared with subjects who lost or maintained weight, the adjusted OR for men with slight, moderate, and heavy weight gain were 2.4, 4.4 and 8.5, respectively. In comparison with non-drinkers, the adjusted OR for light, moderate and heavy drinkers were 1.8, 2.1 and 5.8, respectively. CONCLUSION: These data suggest that body weight, rather than alcohol consumption, may be the major factor in determining the serum level of liver enzymes. Even when body weight was not generally considered to be overweight, slight to moderate gains in weight were associated with increases in serum liver enzymes.

Adult↗
PubMed2001

Bilateral conjunctival mucosa-associated lymphoid tissue lymphoma misdiagnosed as allergic conjunctivitis.

PURPOSE: This report aimed to discuss two nearly identical cases of primary conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma mimicking allergic conjunctivitis. METHODS: Two patients were referred for intractability to conventional treatment of initial diagnoses of allergic conjunctivitis. On ocular examination, normally pigmented, giant papilla-like lesions were found bilaterally in the upper conjunctiva. Excisional biopsies were performed. RESULTS: Histopathologic and immunohistochemical examination of the conjunctival biopsies indicated MALT lymphoma in both patients. The patients subsequently received radiation therapy and achieved complete remission with no evidence of recurrence during follow-up periods of 13 and 11 months. CONCLUSION: Conjunctival low-grade lymphoma may share similar clinical features with allergic conjunctivitis. Ophthalmologists should be concerned that primary conjunctival low-grade malignant lymphoma can be misdiagnosed as allergic conjunctivitis

Adult↗
PubMed2001

Expression of vascular endothelial growth factor and inducible nitric oxide synthase in pterygia.

PURPOSE: To evaluate the expression of vascular endothelial growth factor (VEGF) in pterygium and investigate the interrelationships between VEGF and nitric oxide (NO) in the development of pterygia. METHODS: Specimens of normal conjunctiva acquired incidentally to conjunctival transplantation during pterygium and strabismus surgery and the excised pterygium were used in this study. Cryopreserved tissue specimens consisting of normal conjunctiva and pterygium were used to study the expression of VEGF and inducible NO synthetase (iNOS), using immunohistochemistry. For confirmation of NOS activity, reduced nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase staining was done. Enzyme-linked immunosorbent assay (ELISA) for detection and quantification of VEGF was performed. RESULTS: Expression of VEGF and iNOS was strongly revealed mainly in the epithelium of the head portions of pterygial specimens, although not in the epithelium of conjunctival ones. Pterygial epithelium was stained with NADPH diaphorase, confirming NOS activity. ELISA showed a greater amount of VEGF in pterygium (11.7 +/- 2.1 pg/mg) compared with normal conjunctiva (4 +/- 0.47 pg/mg) ( p < 0.05). CONCLUSION: These data are the first to demonstrate that VEGF and NO may play an important role in the development of pterygium and to identify VEGF and NO in the epithelium of pterygium. We hypothesize that environmental stress, such as ultraviolet irradiation and local inflammation stimulate the elaboration of NO and VEGF, resulting in the conjunctival fibrovascular ingrowth characteristic of pterygium.

Adult↗
PubMed2001

Radiologic anatomy of the rabbit liver on hepatic venography, arteriography, portography, and cholangiography.

UNLABELLED: Seo TS, Oh JH, Lee DH, et al. Radiologic anatomy of the rabbit liver on hepatic venography, arteriography, portography, and cholangiography. Invest Radiol 2001;36:186-192. RATIONALE AND OBJECTIVES: The radiologic anatomy of rabbit liver has received little study but is important in many experimental investigations. METHODS: Twenty-four rabbits were studied by using hepatic venograms, aortograms, hepatic arteriograms, cholangiograms, and portograms. RESULTS: In all cases, the right, middle, and left hepatic veins drained into the inferior vena cava just below the diaphragm, and the caudate lobe hepatic vein drained more inferiorly. The proper hepatic artery was a branch of the common hepatic artery in 96%. The first branch of the proper hepatic artery was the caudate lobe artery. The remaining main hepatic artery was divided into the right and left hepatic arteries. The left hepatic artery was further divided into the medial and lateral segmental branches in 95%. The anatomy of the portal vein or bile duct was the same as the hepatic artery in 100% of cases. CONCLUSIONS: Knowledge of the normal patterns and variations of the vessels and bile duct will be helpful for experiments of the rabbit liver in future studies.

Animals↗
PubMed2001

Effect of tumor necrosis factor-alpha on experimental otitis media with effusion.

OBJECTIVES/HYPOTHESIS: Up to the present, many reports have demonstrated that local immune response is associated with maintenance and persistence of effusion in the middle ear cavity. Resulting retention of inflammatory cells and mediators in the middle ear results in ongoing effusion. The purpose of this study was to clarify the role of tumor necrosis factor in experimental otitis media with effusion, which was induced by transtympanic injection of tumor necrosis factor in the rats. STUDY DESIGN: Four groups were designed in two experiments. The purpose of experiment 1 was to confirm that transtympanic injection of TNF-alpha produces the middle ear effusion. In experiment 2, TNFsolRI was used to evaluate the possibility as an inhibitor in otitis media with effusion. METHODS: The histopathological changes were observed under light microscope, and the changes in microvascular permeability were examined using Evans blue vital dye technique. RESULTS: Middle ear effusion was developed in 70% of specimens, and histopathological changes, such as subepithelial edema and marked infiltration of neutrophils, were present in 100% at 24 hours after administration of tumor necrosis factor-alpha through transtympanic approach. Extravasation of Evans blue dye was found in all specimens injected by tumor necrosis factor-alpha, which was qualified using a fluorescence microscope and quantified using a spectrophotometer. These histopathological findings and changes in microvascular permeability were significantly reduced by tumor necrosis factor soluble receptor type I. CONCLUSIONS: Neutrophil infiltration, subepithelial edema, increased microvascular permeability, and resultant effusion were indirectly proved to be induced by tumor necrosis factor-alpha. We hope that this study may contribute to understanding the role of tumor necrosis factor-alpha in otitis media with effusion and clarifying the future role of tumor necrosis factor soluble receptor type I in preventing otitis media with effusion.

Animals↗
PubMed2001

June 2001: 61 year old woman with confusion and obtundation.

The June COM. A 61 year old female presents with a three week history of increasing confusion, lethargy and headache. A neurological exam revealed disorientation, mild expressive aphasia, bilateral papilledema, and a right pronator drift. She had a craniotomy and resection of tumor. The tumor histologically was consistent with a solitary fibrous tumor displaying malignant features of hypercellularity, marked nuclear atypia, high mitotic activity, and a high proliferation index. This case is unique as the first malignant variant of solitary fibrous tumor to be reported intracranially.

Antigens, CD34↗
PubMed2001

Effects of smoking cessation on changes in blood pressure and incidence of hypertension: a 4-year follow-up study.

We performed the present study to investigate the effects of smoking cessation on changes in blood pressure and incidence of hypertension. We evaluated 8170 healthy male employees at a steel manufacturing company who had received occupational health examinations at the company's health care center in 1994 and were reexamined in 1998. Adjustment covariates were the baseline age, body mass index, cigarette smoking, alcohol consumption, exercise, family history of hypertension, systolic or diastolic blood pressure, and changes in body mass index and alcohol consumption during the follow-up period. The adjusted relative risks of hypertension in those who had quit smoking for <1, 1 to 3, and >/=3 years were 0.6 (95% CI 0.2 to 1.9), 1.5 (95% CI 0.8 to 2.8), and 3.5 (95% CI 1.7 to 7.4), respectively, compared with current smokers. The trends for increased risk of hypertension for longer periods of smoking cessation were observed in subgroups of those who maintained weight as well as those who gained weight after smoking cessation. The adjusted increments in both systolic and diastolic blood pressure were higher in those who had quit for >/=1 year than in current smokers. These trends among weight losers, as well as gainers and maintainers, were similar. We observed progressive increases in blood pressure with the prolongation of cessation in men, although at this time the mechanism remains unknown and must be clarified. This study implies that the cessation of smoking may result in increases in blood pressure, hypertension, or both.

Adult↗
PubMed2001

The behavior of a poly(aniline) solid contact pH selective electrode based on N,N,N',N'-tetrabenzylethanediamine ionophore.

A hydrogen ion-selective solid-contact electrode based on N,N,N',N'-tetrabenzylethanediamine has shown the best Nernstian slope and selectivity and the widest response range in a Tris buffered pH sample solution. Its linear dynamic range was pH 3.50-11.94, and the Nernstian slope showed 52.1 mV/pH (at 20 +/- 0.2 degrees C). When it was directly applied to human whole blood (in pH range 6.0-8.5) we could obtain the same satisfying results. This electrode continuously contacted a Tris 7.47 buffered solution, human whole blood and a hydrofluoric acid solution for one month without any loss of performance. Also, hydrofluoric acid did not influence the surface of this electrode, and thus it was maintained without showing any changes in potentials after being used in a hydrofluoric acid solution. The standard deviation in the determined e.m.f. differences was 1.5 mV (N = 5) for Tris buffer solutions of pH 6.5 and 1.1 mV at a Tris buffer solutions of pH 8.5. The 90% response time of the electrodes obtained by injecting of hydrochloric acid into the Tris buffer sample solution was less than 10 s. Especially, in the this paper, with these potential response characteristics of hydrogen ion selective poly(aniline) solid contact electrode, we have also presented the pH response mechanism of this electrode and the role of poly(aniline) and a doped anion in a poly(aniline) layer.

Journal Article↗
PubMed2001

Effect of centrifugal force on cellular activity of osteoblastic MC3T3-E1 cells in vitro.

The effects of centrifugal force on growth and differentiation of osteoblastic cells cultured in alpha-MEM containing 1% Fetal bovine serum were investigated by assays of DNA synthesis, alkaline phosphatase activity and osteocalcin-production in osteoblastic MC3T3-E1 cells. Centrifugation of the cells in low concentrations (1%) of fetal bovine serum caused a 1.9-fold increase of [3H]thymidine incorporation on day 3 from the start of centrifugation, and gradually decreased with culture up to day 9. Alkaline phosphatase activity was not affected by centrifugal force until day 5, and increased rapidly after day 7. Stimulation of DNA synthesis by centrifugation was abolished in the presence of H-7, an inhibitor of protein kinase C. These results suggest that centrifugal force stimulates the proliferation of osteoblastic cells through an autocrine secretion of some diffusable growth- promoting activity. Additional centrifugation of the cells also slightly stimulated alkaline phosphatase activity, although this did not directly influence the cell's osteocalcin-production activity.

Alkaline Phosphatase↗
PubMed2001

Hepatopulmonary syndrome in poorly compensated postnecrotic liver cirrhosis by hepatitis B virus in Korea.

BACKGROUND: Hepatopulmonary syndrome (HPS) refers to the association of hypoxemia, intrapulmonary shunting and chronic liver disease. But there is no clear data about the prevalence of HPS in postnecrotic liver cirrhosis by hepatitis B virus (HBV), the most common cause of liver disease in Korea. The aim of this study was to investigate the prevalence of HPS in poorly compensated postnecrotic liver cirrhosis by HBV, and the correlation of the hepatopulmonary syndrome with clinical aspects of postnecrotic liver cirrhosis by HBV. METHODS: Thirty-five patients underwent pulmonary function test, arterial blood gas analysis and contrast-enhanced echocardiography. All patients were diagnosed as HBV-induced Child class C liver cirrhosis and had no evidence of intrinsic cardiopulmonary disease. RESULTS: Intrapulmonary shunt was detected in 6/35 (17.1%) by contrast-enhanced echocardiography. Two of six patients with intrahepatic shunts had significant hypoxemia (PaO2 < 70 mmHg) and four showed increased alveolar-arterial oxygen gradient over 20 mmHg. Only cyanosis could reliably distinguish between shunt positive and negative patients. CONCLUSIONS: The prevalence of intrapulmonary shunt in poorly compensated postnecrotic liver cirrhosis by HBV was 17.1% and the frequency of hepatopulmonary syndrome was relatively low (5.7%). 'Subclinical' hepatopulmonary syndrome (echocardiographically positive intrapulmonary shunt but without profound hypoxemia) exists in 11.4% of cases with poorly compensated postnecrotic liver cirrhosis by HBV. Cyanosis is the only reliable clinical indicator of HPS of HBV-induced poorly compensated liver cirrhosis. Further studies are required to determine if the prevalence and clinical manifestations of HPS varies with etiology or with geographical and racial differences.

Adult↗