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Biomedical subjects

D W Lee

Publications and source records attributed to D W Lee.

At least 55 records · Page 3Linked to original sources
PubMed2001

Patterns of temperament and character in subjects with obsessive-compulsive disorder.

BACKGROUND: The purpose of this study was to assess the temperament and character patterns of obsessive-compulsive disorder (OCD) patients and to investigate the relationship between patterns of temperament and character and the severity of obsessive-compulsive symptoms. METHOD: The subjects were 40 patients who met DSM-IV criteria for OCD and 40 age-, sex-, and IQ-matched healthy controls. All subjects completed Cloninger's Temperament and Character Inventory. Other instruments included the Yale-Brown Obsessive Compulsive Scale, the Beck Depression Inventory, and the Beck Anxiety Inventory. RESULTS: OCD patients showed significantly higher scores of harm avoidance and lower scores of novelty seeking and self-directedness compared with healthy comparison subjects. In addition, the high harm avoidance and low self-directedness scores are correlated with a greater severity of obsessive-compulsive symptoms in OCD subjects (multiple regression analysis, beta = 0.39, t = 2.54, df = 34, p = .016; beta = -0.41, t = 2.46, df = 34, p = .019, respectively). CONCLUSION: OCD patients had distinct patterns of temperament and character compared with healthy comparison subjects. In addition, these patterns are specifically related to the severity of obsessive-compulsive symptoms.

Adult↗
PubMed2001

Why leaves turn red in autumn. The role of anthocyanins in senescing leaves of red-osier dogwood.

Why the leaves of many woody species accumulate anthocyanins prior to being shed has long puzzled biologists because it is unclear what effects anthocyanins may have on leaf function. Here, we provide evidence for red-osier dogwood (Cornus stolonifera) that anthocyanins form a pigment layer in the palisade mesophyll layer that decreases light capture by chloroplasts. Measurements of leaf absorbance demonstrated that red-senescing leaves absorbed more light of blue-green to orange wavelengths (495-644 nm) compared with yellow-senescing leaves. Using chlorophyll a fluorescence measurements, we observed that maximum photosystem II (PSII) photon yield of red-senescing leaves recovered from a high-light stress treatment, whereas yellow-senescing leaves failed to recover after 6 h of dark adaptation, which suggests photo-oxidative damage. Because no differences were observed in light response curves of effective PSII photon yield for red- and yellow-senescing leaves, differences between red- and yellow-senescing cannot be explained by differences in the capacities for photochemical and non-photochemical light energy dissipation. A role of anthocyanins as screening pigments was explored further by measuring the responses PSII photon yield to blue light, which is preferentially absorbed by anthocyanins, versus red light, which is poorly absorbed. We found that dark-adapted PSII photon yield of red-senescing leaves recovered rapidly following illumination with blue light. However, red light induced a similar, prolonged decrease in PSII photon yield in both red- and yellow-senescing leaves. We suggest that optical masking of chlorophyll by anthocyanins reduces risk of photo-oxidative damage to leaf cells as they senesce, which otherwise may lower the efficiency of nutrient retrieval from senescing autumn leaves.

Adaptation, Physiological↗
PubMed2000

Proliferation-associated SNF2-like gene (PASG): a SNF2 family member altered in leukemia.

To identify genes involved in cell growth and/or apoptosis in leukemia, differential display was used to identify mRNAs that showed altered expression levels after cytokine withdrawal from the cytokine-dependent MO7e cell line. Sequence analysis of one transcript that showed a profound decrease in expression after cytokine withdrawal revealed it to be a member of the SNF2 family of chromatin remodeling ATPases. This cDNA had a 2514-nucleotide (838-amino acid) open reading frame and encoded an additional 230 amino acids at the NH2 terminus compared with the murine homologue, lsh, and the human counterpart, Hells. This gene locus has been designated SMARCA6 (SWI/SNF2-related, matrix-associated, actin-dependent regulator of chromatin, subfamily A, member 6). The highest levels of mRNA expression in humans are observed in proliferative tissues such as the thymus, testis, and bone marrow. Whereas cytokine withdrawal in MO7e cells leads to apoptosis and decreased mRNA expression, growth arrest without the induction of apoptosis of MO7e cells also leads to down-regulation of mRNA expression, suggesting an association with cell proliferation and not suppression of apoptosis. Nuclear localization of this SNF2-like putative helicase is dependent on a nuclear localization sequence located in the NH2-terminal region. Based on sequence homology to other SNF2-like helicases, the pattern of tissue expression, and the association of expression with cell proliferation, we refer to the protein product as proliferation-associated SNF2-like gene product [PASG (D. W. Lee et al., Blood, 94: 594a, 1999)]. Examination of acute myelogenous leukemia and acute lymphoblastic leukemia samples revealed a high frequency of a PASG transcript containing an in-frame 75-nucleotide deletion, which codes for a conserved motif known to be critical for the transactivation activity of a related yeast SWI/SNF polypeptide. These results extend our knowledge of this SNF2-like family member and suggest a role for PASG in leukemogenesis.

Alternative Splicing↗
PubMed2000

Noninsecticidal parasporal proteins of a Bacillus thuringiensis serovar shandongiensis isolate exhibit a preferential cytotoxicity against human leukemic T cells.

A Bacillus thuringiensis isolate, 89-T-34-22, belonging to the serovar shandongiensis (H22) produced noninsecticidal and nonhemolytic proteins crystallizing into irregular-shaped parasporal inclusions. The proteins showed in vitro cytotoxicity to human cells, including cancer cells, only when activated by protease treatment. The human leukemic T (MOLT-4) cells were > 100 times more susceptible than HeLa and normal T cells to the proteins of 89-T-34-22. The cytotoxicity was dose dependent and the median effective concentration for the MOLT-4 was 3.5 microg/ml. The cytopathy induced by the 89-T-34-22 proteins was characterized by remarkable condensation of the nucleus and cell-ballooning. Five major parasporal proteins of 89-T-34-22, with molecular masses in the range of 16-160 kDa, shared no similarity with the previously reported proteins in terms of the N-terminal sequence.

Amino Acid Sequence↗
PubMed2000

No association between butyrylcholinesterase K-variant and Alzheimer disease in Chinese.

Increased butyrylcholinesterase (BChE) activity has been reported to be associated with the formation of amyloid plaques and neurofibrillary tangles and may consequently be involved in the pathogenesis of Alzheimer disease (AD). Because the catalytic activity of BChE-K variant is reduced by one-third compared with non-variant, we speculated that BChE-K variant has a protective effect on AD. However, Lehmann et al. [1997] reported a synergistic effect between the genes for BChE-K variant and apolipoprotein E (ApoE) epsilon 4, which increases the risk for late onset AD. In the present study, we tested 89 Chinese AD patients and 101 Chinese controls and found no evidence of association between BCHE-K and AD of either early or late onset (age > 65 years). No evidence of a synergistic effect was found between the BCHE-K variant and APOE epsilon 4 in this study. Our data suggest that BChE-K variant has no modifying effect on the pathogenesis of AD. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:167-169, 2000.

Aged↗
PubMed2000

Prolonged exposure to cigarette smoke blocks the neurotoxicity induced by kainic acid in rats.

We examined the effects of cigarette smoke (CS) on three parameters associated with kainic acid (KA)-induced neurotoxicity: seizure activity, cell loss in the hippocampus, and increased Fos-related antigen (FRA) expression. Animals were exposed to the main stream of CS from 15 Kentucky 2R1F research cigarettes containing 28.6 mg tar and 1.74 mg nicotine per cigarette, for 10 min a day, 6 days per week, for 4 weeks, using an automatic smoking machine. KA administration (10 mg/kg, i.p.) produced robust behavioral convulsions lasting 4-5 h. Pre-exposure to CS significantly reduced the seizures, mortality, and severe loss of cells in regions CA1 and CA3 of the hippocampus after KA administration. Consistently, pre-exposure to CS significantly attenuated the KA-induced increased FRA immunoreactivity in the hippocampus. In contrast, pretreatment with central nicotinic antagonist, mecamylamine (2 or 10 mg/kg, i.p.) blocked the neuroprotective effects mediated by CS in a dose-dependent manner. These results indicate that CS exposure provides neuroprotection against the KA insult via nicotinic receptor activation.

Animals↗
PubMed2000

The conformation and activity relationship of benzofuran type of angiotensin II receptor antagonists.

As a continuing effort to establish the structure and activity relationship in a benzofuran type of angiotensin II antagonist, we synthesized various regioisomers and performed a series of QSAR analyses. The conformational analyses of target isomers were carried out using molecular mechanics and fine-tuned using the information from the NMR NOE experiment. The conformations of compounds with a good binding activity are quite similar to that of DuP753, a prototype of AII antagonist, suggesting that these compounds also bind to the same site of AII receptor. We then studied the compounds with a varied length of the hydroxyl group bearing side chain to find out the optimum distance between the hydroxyl group and the imidazole ring. The CoMFA with these compounds gave acceptable statistical measures (cross-validated r2 and conventional r2 to be 0.881 and 0.974, respectively) and the map was well consistent with the previously proposed pharmacophore.

Algorithms↗
PubMed2000

Diagnostic and therapeutic fistuloscopy: an adjuvant management in postoperative fistulas and abscesses after upper gastrointestinal surgery.

BACKGROUND AND STUDY AIMS: Postoperative fistulas and abscesses pose difficult management problems. We report our experience in the use of fistuloscopy in postoperative fistulas and abscesses after upper gastrointestinal surgery. PATIENTS AND METHODS: From June 1993 to January 1997, nine patients (seven men, two women; mean age 65) with postoperative fistulas and abscesses were treated with therapeutic fistuloscopy. Diagnostic fistuloscopy was carried out using a 5-mm choledochoscope under fluoroscopic guidance. Therapeutic procedures included mechanical debridement, irrigation, and sealing of fistula with fibrin sealant and gelatin sponge. RESULTS: The patients were suffering from duodenal stump fistula (three cases), gastrojejunostomy dehiscence after gastrectomy (three cases), gastropleurocutaneous fistula (two cases), and subphrenic abscesses (two cases). Fistuloscopy was performed 4-19 days (mean 12 days) after the diagnosis of the fistula. The median number of sessions required was 2 (range 1-4). The average daily fistula output prior to fistuloscopy was 154 ml (range 30-560 ml), and all fistulas healed in an average of 18.7 days (range 2-46 days) after index fistuloscopy. No procedure-related complications occurred. The mean hospital stay was 61 days. During a mean follow-up period of 12 months, no recurrent abscesses or fistulas developed. CONCLUSIONS: Fistuloscopy provides a new means of managing patients with postoperative fistula and abscess formation.

Abscess↗
PubMed2000

Eradication of Helicobacter pylori prevents recurrence of ulcer after simple closure of duodenal ulcer perforation: randomized controlled trial.

OBJECTIVE: In this randomized trial, the authors sought to determine whether eradication of Helicobacter pylori could reduce the risk of ulcer recurrence after simple closure of perforated duodenal ulcer. BACKGROUND DATA: Immediate acid-reduction surgery has been strongly advocated for perforated duodenal ulcers because of the high incidence of ulcer relapse after simple patch repair. Although H. pylori eradication is now the standard treatment of uncomplicated and bleeding peptic ulcers, its role in perforation remains controversial. Recently a high prevalence of H. pylori infection has been reported in patients with perforations of duodenal ulcer. It is unclear whether eradication of the bacterium confers prolonged ulcer remission after simple repair and hence obviates the need for an immediate definitive operation. METHODS: Of 129 patients with perforated duodenal ulcers, 104 (81%) were shown to be infected by H. pylori. Ninety-nine H. pylori-positive patients were randomized to receive either a course of quadruple anti-helicobacter therapy or a 4-week course of omeprazole alone. Follow-up endoscopy was performed 8 weeks, 16 weeks (if the ulcer did not heal at 8 weeks), and 1 year after hospital discharge for surveillance of ulcer healing and determination of H. pylori status. The endpoints were initial ulcer healing and ulcer relapse rate after 1 year. RESULTS: Fifty-one patients were assigned to the anti-Helicobacter therapy and 48 to omeprazole alone. Nine patients did not undergo the first follow-up endoscopy. Of the 90 patients who did undergo follow-up endoscopy, 43 of the 44 patients in the anti-Helicobacter group and 8 of the 46 in the omeprazole alone group had H. pylori eradicated; initial ulcer healing rates were similar in the two groups (82% vs. 87%). After 1 year, ulcer relapse was significantly less common in patients treated with anti-Helicobacter therapy than in those who received omeprazole alone (4.8% vs. 38.1%). CONCLUSIONS: Eradication of H. pylori prevents ulcer recurrence in patients with H. pylori-associated perforated duodenal ulcers. Immediate acid-reduction surgery in the presence of generalized peritonitis is unnecessary.

Anti-Bacterial Agents↗
PubMed2000

Increased levels of interleukin-6 are associated with lymphocytosis in bronchoalveolar lavage fluids of idiopathic nonspecific interstitial pneumonia.

Local overexpression of interleukin-6 (IL-6) experimentally induces lymphocytic infiltration in the bronchial tree of rat. Among idiopathic interstitial pneumonia (IIP), nonspecific interstitial pneumonia/fibrosis (NSIP) has an increased number of lymphocytes in bronchoalveolar lavage (BAL) fluid when compared with usual interstitial pneumonia (UIP). To reveal a relation of IL-6 with the lymphocyte infiltration of NSIP, IL-6 was measured in BAL fluids of idiopathic NSIP (n = 7), idiopathic UIP (n = 16), and normal control subjects (n = 45). IL-6-producing sites were assessed by IL-6 protein stain on biopsy specimens of NSIP, UIP, and normal lung of mediastinal tumors. Lymphocyte numbers and IL-6 levels in BAL fluids were higher in NSIP than those in UIP (p < 0.01, respectively), which were also higher when compared with those of normal control subjects (p < 0.01, respectively). In NSIP, the levels of IL-6 correlated with the number of lymphocytes (r = 0.93, p < 0.01). UIP cases were divided into two groups: high-UIP (n = 7) or low-UIP (n = 9) according to IL-6 levels greater than or within the 95 percentile of normal control subjects, respectively. The high-UIP group had BAL lymphocytosis when compared with the low-UIP group (p < 0.05). IL-6 stained on epithelial cells of the bronchial tree and on alveolar macrophages of NSIP and UIP. In conclusion, the lymphocytosis in BAL fluid of patients with NSIP and a subgroup of UIP is associated with the high levels of IL-6 and its sources are the epithelial cells of the small airway and the alveolar macrophages.

Adult↗
PubMed2000

Design of a synthetic leptin agonist: effects on energy balance, glucose homeostasis, and thermoregulation.

We have previously reported that a synthetic peptide amide corresponding to amino acid residues 116-130 of mouse leptin, LEP-(116-130), reduces body weight gain, food intake, and blood glucose levels in ob/ob and db/db mice. In the present study we show that the activity of LEP-(116-130) resides in a restricted sequence between amino acid residues 116-122. A synthetic peptide corresponding to this sequence (Ser-Cys-Ser-Leu-Pro-Gln-Thr) has been named OB3. Single point D-amino acid substitution was used to study the structure-function relationship of each residue in OB3. D-Amino acid analogs of OB3 were synthesized by the solid phase method, purified to 98+%, and administered (1 mg/day, ip) for 7 days to female C57BL/6J ob/ob mice. The effects of the peptides on body weight gain, food and water intake, glucose homeostasis, and thermoregulation were assessed. In most cases, the efficacy of OB3 on all parameters tested was reduced by substitution of an L-amino acid with its corresponding D-isoform. A statistically significant increase (2.6-fold) in the weight-reducing effect of OB3, however, was observed by inversion of the configuration of the leucine residue at position 4 (Leu-4) of OB3 by substitution with its D-amino acid isoform [D-Leu-4]. Compared with OB3, mice treated with [D-Leu-4]-OB3 consumed 7.9% less food and 16.5% less water. Blood glucose was normalized to levels comparable to those in wild-type control mice within 2 days after initiation of [D-Leu-4]-OB3 treatment. Unlike native leptin, however, neither OB3 nor any of its D-amino acid-substituted analogs had any apparent effect on thermogenesis. Our results indicate that synthetic peptide strategies may be useful in the development of potent and stabile pharmacophores with potential therapeutic significance in the treatment of human obesity and its related metabolic dysfunctions.

Amino Acid Substitution↗
PubMed2000

Inhibition of fungal cell wall synthesizing enzymes by trans-cinnamaldehyde.

This study examined the inhibitory effects of trans-cinnamaldehyde (CA), an aromatic aldehyde derived from Cinnamomi Cortex, on Saccharomyces cerevisiae cell wall synthesizing enzymes in vitro. This compound was found to be a noncompetitive inhibitor of beta-(1,3)-glucan synthase and a mixed inhibitor of chitin synthase 1 with 50% inhibitory concentrations (IC50) of 0.84 and 1.44 mM, respectively. Chitin synthases 2 and 3 were less sensitive than chitin synthase 1 to CA. CA can be useful as a model compound of cell wall inhibitors for the development of effective antifungal agents.

Acrolein↗
PubMed2000

Myelomatous effusion with poor response to chemotherapy.

While pleural effusion in multiple myeloma is relatively infrequent, myelomatous pleural effusion is extremely rare. We experienced a 61-year-old woman with IgD-lambda multiple myeloma and pleural effusion. The diagnosis was made originally by pleural biopsy, pleural fluid cytology and immunoelectropheresis of pleural fluid. Transient improvement of the pleural effusion was observed after administration of combination chemotherapy of vincristine, melphalan, cyclophosphamide, prednisone (VMCP)/vincristine, cyclophosphamide, adriamycin, prednisone (VCAP). Two months later, myelomatous pleural effusion recurred and no response to salvage therapy was observed. We reviewed the clinical feature of this case and literature concerning myelomatous pleural effusion.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Effects of irradiance and spectral quality on leaf structure and function in seedlings of two Southeast Asian Hopea (Dipterocarpaceae) species.

We studied the development of leaf characters in two Southeast Asian dipterocarp forest trees under different photosynthetic photon flux densities (PFD) and spectral qualities (red to far-red, R:FR). The two species, Hopea helferi and H. odorata, are taxonomically closely related but differ in their ecological requirements; H. helferi is more drought tolerant and H. odorata more shade tolerant. Seedlings were grown in replicated shadehouse treatments of differing PFD and R:FR. We measured or calculated (1) leaf and tissue thicknesses; (2) mesophyll parenchyma, air space, and lignified tissue volumes; (3) mesophyll air volumes (V(mes)/A(surf)) and surfaces (A(mes)/A(surf)); (4) palisade cell length and width; (5) chlorophyll/cm and a/b; (6) leaf absorption; and (7) attenuance/absorbance at 652 and 550 nm. These characters varied in response to light conditions in both taxa. Characters were predominantly affected by PFD, and R:FR slightly influenced many characters. Leaf characters of H. odorata were more plastic in response to treatment conditions. Characters were correlated with each other in a complex fashion. Variation in leaf anatomy is most likely a consequence of increasing leaf thickness in both taxa, which may increase mechanical strength and defense against herbivory in more exposed environments. Variation in leaf optical properties was most likely affected by pigment photo-bleaching in treatments of more intense PFD and was not correlated with A(max). The greater plasticity of leaf responses in H. odorata helps explain the acclimation over the range of light conditions encountered by this shade-tolerant taxon. The dense layer of scales on the leaf undersurface and other anatomical characters in H. helferi reduced gas exchange and growth in this drought-tolerant tree.

Journal Article↗
PubMed1999

Epitope mapping of secreted mouse leptin utilizing peripherally administered synthetic peptides.

We have recently reported that intraperitoneal (i.p.) administration of synthetic peptide amides corresponding to amino acids 106-140 of mouse leptin significantly reduced food intake and body weight gain in female C57BL/6J ob/ob mice. These results suggested that leptin activity was localized in domains toward its C-terminus between residues 106-140. In the present study, 14 overlapping peptides encompassing the complete sequence of secreted mouse leptin were synthesized, and their effects on body weight and food intake in female C57BL/6 J ob/ob mice were assessed. When given as seven daily 1-mg i.p. injections, only peptides corresponding to amino acids 106-120, 116-130 and 126-140 caused significant reductions in body weight and food intake. These results confirmed our earlier study and suggest that in contrast to the domain encompassed by amino acids 106-140, the N-terminal of mouse leptin between amino acids 21-105 may not contain functional epitopes that can be utilized as lead compounds in the development of peripherally administered bioactive peptide analogs or nonpeptide mimetics of leptin, which may have potential usefulness in treatment of the energy imbalance associated with obesity.

Amino Acid Sequence↗