Biomedical subjects

D H Lee

Publications and source records attributed to D H Lee.

At least 145 records · Page 8Linked to original sources

PubMed2000

Postoperative analgesic requirements in patients undergoing arthroscopic anterior cruciate ligament reconstruction.

Anterior cruciate ligament (ACL) procedures are associated with significant postoperative pain and have traditionally been done on a short-stay hospitalization basis because of concerns for adequate postoperative analgesia. A retrospective chart review was performed to determine postoperative intravenous patient-controlled analgesia (PCA) morphine requirements for 80 patients who had undergone arthroscopically assisted ACL reconstruction under general anesthesia by means of a patellar tendon autograft by 1 of 2 surgeons. The mean +/- SD PCA morphine used after surgery was 20.4+/-20.0 mg. There was a wide interpatient difference in postoperative opioid consumption: the amount of PCA morphine used ranged from 0 mg to 124 mg. A comparison between the surgeons revealed that 1 surgeon had significantly longer intraoperative surgical, tourniquet, and anesthesia times; however, there was no difference in the length of recovery room stay, amount of postoperative PCA morphine used, or time to hospital discharge. Predicting which patients may benefit from short-stay hospitalization after arthroscopic ACL reconstruction may be difficult because of considerable interpatient differences in postoperative analgesic requirements.

Adult↗

PubMed1999

Usefulness of cilostazol versus ticlopidine in coronary artery stenting.

A combination of ticlopidine and aspirin has been accepted as the standard antithrombotic regimen after coronary stenting. However, ticlopidine poses serious side effects such as neutropenia or thrombocytopenia. Cilostazol, a cyclic adenosine monophosphate phosphodiesterase inhibitor, is a novel antiplatelet agent with vasodilatory properties. We compared the efficacy and safety of cilostazol plus aspirin (C+A) with ticlopidine plus aspirin (T+A) in elective coronary stenting. Three hundred patients were randomly assigned to receive C+A or T+A 2 days before stenting. The primary end point was a composite of angiographic stent thrombosis, or major cardiac events (death, myocardial infarction, bypass surgery, repeat intervention) at 30 days. The secondary end points were bleeding vascular complications, neutropenia, thrombocytopenia, or side effects requiring discontinuation of the drugs at 30 days. The primary end point was reached in 1.4% in the C+A group and 2.0% in the T+A group (p = 1.0). The rate of bleeding vascular complications was 1.4% in the C+A group and 2.0% in the T+A group (p = 1.0). The rate of drug-related side effects was not statistically different between the 2 groups but slightly higher in the T+A group than in the C+A group (2.7% vs 0.7%, p = 0.37). However, neutropenia was seen in 2 patients only in the T+A group. As a poststenting antithrombotic, C+A is as effective as T+A in preventing major cardiac events including stent thrombosis, and safer in that it does not cause neutropenia despite the fact that there is no statistical difference in the incidence of adverse effects and complications.

Adult↗

PubMed1999

Activation of the thymidine kinase promoter by herpes simplex virus type 1 immediate early proteins.

The herpes simplex virus type 1 (HSV-1) thymidine kinase (TK) gene promoter contains binding sites for the cellular transcription factors such as Spl, CTF, and TFIID, each of which affects basal level expression of the TK gene. The transcription of the TK gene was induced by viral immediate early proteins, ICP0 and ICP4 in an additive manner, but was repressed by ICP22 and ICP27. To gain further insights into the role of ICP0 and ICP4 for expression of the TK gene during virus infection, several mutants with deletions or point mutations in each of the transcriptional regulatory elements were generated starting at -109 and progressing toward +1. According to the CAT assay involving these mutants, the cellular transcription factor (CTF) binding site was necessary for efficient expression in the presence of transfected ICP0 and ICP4 or during virus infection, whereas the Sp1 binding site had a minor effect on ICP0-mediated TK expression. These results indicate that the immediate early proteins of HSV-1 regulate expression of the TK gene during virus infection by modulating activities of cellular transcription factors such as CTF.

Animals↗

PubMed1999

CD28 costimulation augments IL-2 secretion of activated lamina propria T cells by increasing mRNA stability without enhancing IL-2 gene transactivation.

The pathways leading to activation in lamina propria (LP) T cells are different from peripheral T cells. LP T cells exhibit enhanced IL-2 secretion when activated through the CD2 pathway. Coligation of CD28 leads to synergistic enhancement of IL-2 secretion. Previous studies have characterized the CD28 augmentation of TCR-mediated signaling in peripheral blood T cells through transcriptional activation of an IL-2 promoter CD28 response element (CD28RE), along with enhanced mRNA stability. This study characterized molecular events involved in CD28 costimulation of IL-2 production in LP mononuclear cells (LPMC). LPMC exhibited increased IL-2 production in response to CD28 costimulation, compared with cells activated through CD2 alone. IL-2 secretion was paralleled by increased expression of IL-2 mRNA, resulting from enhanced IL-2 mRNA stability. In contrast to transcriptional activation in PBMC, EMSA revealed that CD28 coligation of CD2-activated LPMC does not result in increased binding of trans-factors to the CD28RE, nor did Western blots detect changes in I-kappaBalpha or I-kappaBbeta levels following CD28 coligation. Furthermore, CD28 coligation fails to enhance IL-2 promoter-reporter or RE/AP construct expression in CD2-activated LPMC. The results reported herein indicate that the molecular mechanisms involved in CD28 cosignaling and regulation of IL-2 secretion in LP T cells are unique to that compartment and differ from those seen in peripheral blood T cells. These observations suggest a biological significance for different mechanisms of IL-2 activation in initiation and maintenance of the cytokine repertoire found in the mucosa.

Adjuvants, Immunologic↗

PubMed1999

OEIS complex (omphalocele-exstrophy-imperforate anus-spinal defects) in monozygotic twins.

The omphalocele-exstrophy-imperforate anus-spinal defects (OEIS) complex is a consistent and recognizable pattern of midline abdominal and pelvic defects. It is rare, affecting 1 in 200,000 to 400,000 pregnancies and is even rarer in twin gestations. This is an autopsy study of OEIS complex in monozygotic twins after pregnancy termination at 20 weeks of gestation. Unremarkable family history but concordance of monozygotic twins for the defects may support the theory that early malformation complexes, e.g., OEIS, and monozygotic twinning are manifestations of the same disturbance of early blastogenesis.

Abnormalities, Multiple↗

PubMed1999

A novel parvovirus isolated from Manchurian chipmunks.

A novel parvovirus was identified in Manchurian chipmunks inhabiting Korea. Hepatitis B surface antigen (HBsAg) was detected in sera from 4 animals among 62 apparently healthy chipmunks. Electron microscopic examination of the HBsAg-positive sera revealed virus-like spherical particles 20-22 nm in diameter. Extraction of nucleic acid under annealing conditions from the serum samples containing virus-like particles yielded a single species of DNA molecule with the electrophoretic mobility of 5.6-kb double-stranded DNA. Four overlapping clones that encompassed almost the full-length viral genome, except both ends, were obtained. By sequencing these clones, we determined the sequence of 5097 nucleotides of the viral DNA. Two open reading frames were identified, with the left side open reading frame encoding a putative nonstructural protein and the right side open reading frame encoding a putative capsid protein. The nucleotide and amino acid sequences showed significant homology to parvovirus B19 and simian parvovirus, but showed little homology to other mammalian autonomous parvoviruses or adeno-associated viruses. These observations indicate that the virus isolated from Manchurian chipmunks is a novel parvovirus and may be a potentially useful animal model of human B19 infection as a new member of the Erythrovirus genus of the Parvoviridae.

Amino Acid Sequence↗

PubMed1999

Somatic mutations of the first 14 exons of APC in hamartomatous polyps of the colon.

Although hamartomatous or hyperplastic polyps are rarely accompanied by adenomatous or carcinomatous foci, the role of APC (MIM# 175100) mutations in these polyps is not clear. The neoplastic potential of these polyps was assessed with regard to somatic mutation of the first 14 exons of APC. DNA from 14 hamartomatous polyps (12 patients with juvenile polyp, JP; two patients with Peutz-Jeghers syndrome, PJS) and 27 hyperplastic polyps was used. Exons 1-14 of APC were amplified using verified oligonucleotide primers, and PCR-SSCP analysis was performed. Translation-terminating mutation in exon 15 was also screened using the protein truncation test. All mutations found were transitions or transversions with heterozygous alleles of both wild-type and mutant APC in exons 2, 9, 10, and 11. Four hamartomatous polyps (three from JP and one from PJS) showed seven, new mutations and one common APC variant (codon 486), whereas no hyperplastic polyps demonstrated mutation. APC mutation was not correlated with previous history of colorectal carcinoma or number of polyps. Since all mutations were missense or silent mutations occurred in exons not previously known to have functionally relevant area, their phenotypic implication appeared to be limited.

Colonic Polyps↗

PubMed1999

The synergistic transactivation of the hepatitis B viral (HBV) pregenomic promoter by the E6 protein of human papillomavirus type 16 (HPV-16 E6) with HBV X protein was mediated through the AP1 site of E element in the enhancer I (EnI) in human liver cell.

Infection by HBV of a cell already infected with other viral species or vice versa has been suggested as being involved in hepatocellular carcinoma. Using the CAT assay method, we investigated the interactive roles of HBx and potentially oncogenic and transactivating viral early proteins such as Ad5 E1A, HPV-16 E6, and SV40 T ag. In the presence of HBx, only HPV-16 E6 showed significant synergistic transactivation of EnI. We further investigated the function of the HPV-16 E6 using deletion, heterologous promoter, and mutation analyses on the EnI promoter. The results showed that the synergistic effect was mediated through the AP1 site of the E element in EnI by the direct activation of AP1 and support the idea that the infection by HBV of the cell with other viral species such as HPV-16 could increase the transcription activity of the HBV and other oncogenes containing an AP1 site in the promoter.

Carcinoma, Hepatocellular↗

PubMed1999

Different strains and substrains of rats show different levels of neuropathic pain behaviors.

This study compared and contrasted the manifestation of neuropathic pain behaviors in several strains of rats. These included ACI, Brown-Norway, Fischer 344, Lewis, Long-Evans, Sprague-Dawley, and Wistar-Furth, all obtained from Harlan Sprague-Dawley Inc. Comparison was also made between two substrains of Sprague-Dawley rats: one from Harlan and the other from Sasco. Neuropathic injury was produced by tightly ligating the left L5 and L6 spinal nerves with the animals under halothane anesthesia. Tests were conducted for 2 weeks to examine behavioral signs representing mechanical allodynia, cold allodynia, and spontaneous pain. There was no difference between strains in any of the tested behaviors before surgery. After neuropathic injury, rats in most groups developed high levels of behavioral signs of various components of neuropathic pain; however, some strains of rats showed weak behavioral signs of neuropathic pain. When a comparison was made between two substrains of Sprague-Dawley rats from two different sources, the ones from Sasco showed weaker behavioral signs than those from Harlan. When comparisons were made between different strains of rats from the same source (Harlan), Brown-Norway and Long-Evans rats showed the smallest magnitude of neuropathic pain behaviors. The data indicate that different strains and substrains of rats display different degrees of pain behaviors, suggesting that strains and substrains are important variables in the development of neuropathic pain after peripheral nerve injury.

Animals↗

PubMed1999

Fibrinogen gene polymorphism in a non-Caucasian population.

OBJECTIVE: The purpose of this study was to investigate the two polymorphisms of fibrinogen gene (RsaI and MnlI RFLPs in the coding region of the fibrinogen gene) in Koreans, and their relation to plasma fibrinogen. METHODS: Using PCR-amplified DNAs, RsaI and MnlI RFLPs were analyzed in 112 patients with coronary artery disease (CAD) and 137 healthy subjects. To compare the mean of plasma fibrinogen and lipid levels among different genotypes, one-way analysis of variance (ANOVA) test was performed. RESULTS: Allele frequencies of fibrinogen gene polymorphism in Koreans were not significantly different between CAD and control groups; fibrinogen polymorphism in this population showed a lack of association with plasma fibrinogen levels, but significant association with BMI (p < 0.05). CONCLUSION: This evidence suggests that in Korean populations, fibrinogen gene polymorphism is not a factor in the expression of atherosclerosis. There might, however, be an association between fibrinogen gene and obesity in such population.

Aged↗

PubMed1999

Posttraumatic elbow arthritis and arthroplasty.

Elbow contractures without significant articular injury can be treated with soft-tissue procedures, such as joint capsular releases, resection of heterotropic ossification, and joint debridement. Elbows with significant intra-articular injuries or posttraumatic arthritis require some form of joint reconstruction, such as a distraction arthroplasty, interposition arthroplasty, or implant replacement arthroplasty. With a better understanding of the surgical indications for elbow arthroplasty, improvements in surgical technique, improvements in elbow implants, and increased surgical experience, the results of implant arthroplasty for the posttraumatic elbow continue to improve.

Arm Injuries↗

PubMed1999

Size assessment of adenoid and nasopharyngeal airway by acoustic rhinometry in children.

Adenoid hypertrophy is known as the most common cause of nasal obstruction in children; thus, adenoidectomy with, or without, tonsillectomy is one of the most commonly performed surgical procedures in the paediatric population. Although many methods have been suggested, few studies have reported on how to assess adenoid size, pre-operatively. Acoustic rhinometry is an objective technique as well as a non-invasive method, which can be easily used in young children. This study confirmed that acoustic rhinometry is a non-invasive and objective technique for assessing the geometry of the nasal cavity and nasopharynx. Forty children were evaluated using symptomology, two different radiological measurements and acoustic rhinometry; the results were compared with endoscopic findings. Clinical symptoms and A/N ratio measured with Fujioka's method significantly correlated with the endoscopic assessment findings (r = 0.769 and 0.604 respectively). Significant increases in the cross-sectional area and volume of the nasopharynx were observed at the adenoid notch after adenoidectomy (p < 0.005 and p < 0.005, respectively). Acoustic rhinometry showed a high degree of correlation of which adenoid occupied the nasopharyngeal airway under endoscopic examination (r = 0.771). Thus, the study concluded that acoustic rhinometry can be as good an objective method for measuring adenoid sizes as endoscopy and can be used as one of the pre-operative examination tools for adenoidectomy.

Adenoids↗

PubMed1999

Randomized placebo-controlled trial of Helicobacter pylori eradication for iron-deficiency anemia in preadolescent children and adolescents.

BACKGROUND: A few cases relating H. pylori infection to iron-deficiency anemia have been described recently. We investigated the role of H. pylori infection in iron-deficiency anemia in preadolescent children and adolescents. PATIENTS AND METHODS: We conducted a double-blind, placebo-controlled therapeutic trial in 43 subjects (mean age, 15.4 years) with iron-deficiency anemia. Endoscopy was performed, and biopsy specimens were examined by urease test and histological analysis. Twenty-two of 25 H. pylori-positive patients were assigned randomly to three groups. Group A patients were given oral ferrous sulfate and a 2-week course of bismuth subcitrate, amoxicillin, and metronidazole. Group B patients were given placebo for iron and a 2-week course of triple therapy. Group C patients were given oral ferrous sulfate and a 2-week course of placebo. Iron status was reassessed 4 weeks and 8 weeks after the 2-week regimen ended. RESULTS: Of the 43 subjects with iron-deficiency anemia, 25 (58.1%) had H. pylori in the antrum. Group A and B subjects, who received eradication therapy, showed a significant increase in hemoglobin level as compared with group C subjects at 8 weeks after therapy (p = .0086). CONCLUSIONS: Treatment of H. pylori infection was associated with more rapid response to oral iron therapy as compared with the use of iron therapy alone. Such treatment also led to enhanced iron absorption even in those subjects who did not receive oral iron therapy.

Adolescent↗

PubMed1999

Tendon transfers for restoring hand intrinsic muscle function: a biomechanical study.

Four fresh-frozen arms were biomechanically tested to determine the effect of the route of tendon transfer (dorsal vs volar) and the site of digital tendon insertion (A1 pulley, A2 pulley, proximal phalanx, or lateral band/extensor mechanism) on restoring metacarpophalangeal joint flexion and interphalangeal joint extension. A volar carpal canal route of tendon transfer appears to be more mechanically efficient than a dorsal intermetacarpal route. A lateral band insertion provides a small but significant increase in proximal interphalangeal and distal interphalangeal joint extension.

Biomechanical Phenomena↗

PubMed1999

Galanin inhibits acetylcholine release from rat cerebral cortex via a pertussis toxin-sensitive G(i)protein.

Galanin has been implicated in various physiological functions including memory, feeding and pain perception. Using rat cerebral cortical slices and synaptosome preparations incubated with [(3)H]choline in Kreb's-Ringer solution, galanin was shown to inhibit both spontaneous and K(+)-stimulated [(3)H]ACh release in a concentration-related manner [EC(50)= 35 nM]. The galanin-mediated inhibition on spontaneous and K(+)-stimulated [(3)H]ACh release was respectively regulated by pertussis toxin-sensitive G(alphai3)and G(alphai1). These suggest that galanin is a negative modulator of cortical cholinergic function and most probably acting on presynaptic cholinergic terminals. Although galantide blocked the galanin-mediated inhibitory effect on [(3)H]ACh release, it mimicked galanin in blocking K(+)-stimulated [(3)H]ACh release, indicating that galantide may have a more complicated pharmacology than being a galanin receptor antagonist. In addition, we demonstrate that galanin and beta-amyloid peptide(1-42)synergistically attenuated K(+)-evoked [(3)H]ACh release from synaptosomes prepared from rat cerebral cortex. Since galanin is increased in Alzheimer's disease brain, our results suggest that galanin may be involved in cholinergic dysfunctions that occur in Alzheimer's disease.

Acetylcholine↗

PubMed1999

S-methylation of 2-mercaptopyrazine in rat liver microsomes and cytosol.

1. 2-(Allylthio)pyrazine (2-AP) has been demonstrated to protect the liver against toxicants by inhibiting CYP2E1 activity. Since 2-mercaptopyrazine (2-MP) is presumed to be a metabolite of 2-AP, the experiments were performed to determine whether rat liver microsomal and/or cytosolic preparations could catalyse the S-methylation of 2-MP. 2. It was found that both rat liver microsomes and cytosol could catalyse the S-methylation of 2-MP. The microsomal activity displayed biphasic substrate kinetics, with apparent Km = 8.44+/-2.68 and 417+/-74 microM for the high- and low-affinity activities respectively. The high-affinity activity had an apparent Km for S-adenosyl-L-methionine (Ado-Met) of 3.52 microM. The cytosolic activity also displayed biphasic substrate kinetics, with apparent Km of 3.26+/-0.62 and 91.6+/-23.1 microM for the high- and low-affinity activities respectively. 3. The microsomal S-methylation of 2-MP was inhibited by 2,3-dichloro-alpha-methylbenzylamine (DCMB), SKF-525A and benzylamine, known microsomal thiol methyltransferase (TMT) inhibitors, whereas cytosolic activity was inhibited by anisic acid and 3-chlorobenzoate, which also inhibit cytosolic thiopurine methyltransferase (TPMT). Both activities were inhibited by S-adenosyl-L-homocysteine (Met-Hcy). 4. These results suggest that both TMT and TPMT may be involved in the in vivo methylation of 2-MP.

Aniline Compounds↗

PubMed1999

Significance of the anti-E2 response in self-limited and chronic hepatitis C virus infections in chimpanzees and in humans.

To determine whether there was a correlation between the kinetics or frequency of antibody to mammalian-derived hepatitis C virus (HCV) second envelope protein (E2) and development of chronicity or self-limitation of HCV infections, serial sera were examined for anti-E2, anti-HCV with confirmation with Matrix 2.0 (Abbott Laboratories, Abbott Park, IL), and reverse transcriptase-polymerase chain reaction (RT-PCR) from 6 cases of self-limited infection and 6 cases of chronic infection in chimpanzees, and from 5 cases of self-limited infection and 3 cases of chronic infection in patients. Anti-E2 developed earlier, more frequently, and to higher titer in chimpanzees and patients who were developing chronic infection than in those with self-limited infections. Thus anti-E2 is unlikely to play a role in self-limitation of the infection. However, long-term persistence of anti-E2 correlates with chronic infection. There was little or no correlation between the timing of development of anti-E2 and anti-HCV.

Animals↗

PubMed1999

Paroxysmal tachycardia and hypertension with or without ventricular fibrillation during laparoscopic adrenalectomy: two case reports in patients with noncatecholamine-secreting adrenocortical adenomas.

We present two cases of sudden unanticipated cardiovascular complications in patients with noncatecholamine-secreting adrenocortical adenomas during laparoscopic adrenalectomy. In the first case, the patient developed paroxysmal tachycardia and hypertension followed by ventricular fibrillation shortly after clipping of the adrenal vein. In the second case, the patient suffered hypertension and bigeminy during manipulation of the adrenal gland just around the adrenal vein. Awareness of such complications during either conventional or laparoscopic adrenalectomy is important even if the operation is performed in a patient with an apparently noncatecholamine-secreting adrenocortical adenoma.

Adenoma↗